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Total lipid concentration of hairs increases after successful attenuation of extrahepatic portosystemic shunts in dogs
犬肝外门静脉分流术成功后毛发总脂质浓度增加
作者：Nausikaa Devriendt | Tania C. Nunes Rodrigues1 | Sophie Vandenabeele1 | Dominique Paepe1 | Emmelie Stock | Hilde de Rooster1
翻译：王帆
Abstract
Background: Skin and coat quality can reflect nutritional deficiencies in humans and dogs with liver diseases.
Hypothesis/Objectives: Determine skin and coat quality based on a scoring protocol and skin biopsies in dogs with an extrahepatic portosystemic shunt (EHPSS), and determine total lipid concentrations in hairs of dogs at time of surgery and 3months after successful shunt closure.
Animals: Ten client-owned dogs that underwent successful gradual attenuation of EHPSS, as defined by transsplenic portal scintigraphy, were included.
Materials and methods: A prospective cohort study was performed. All dogs underwent gradual attenuation of the EHPSS. Skin and coat scoring was performed at diagnosis, surgery, and 1 and 3months postoperatively. Hair was plucked from the lumbar region for total lipid analysis and an 8mm punch skin biopsy was taken at time of surgery and 3months postoperatively, when the dogs underwent transsplenic portal scintigraphy to determine EHPSS closure.
Results: No significant differences were observed in skin and coat scoring over time. Total lipid concentrations of hairs increased significantly from surgery to 3months postoperatively [30μg/mg hair (13–56μg/mg hair) to 47μg/ mg hair (25–63μg/mg hair); p =0.005]. Skin biopsies showed the presence of significantly more scales 3months postoperatively (p =0.018).
Conclusions and clinical relevance: A significant increase in total lipid concentrations in hairs suggests that successful surgical attenuation of EHPSS improves either intestinal absorption of lipids, fat metabolism in the liver, or a combination of both.
摘要
背景-皮肤和毛发质量可以反映肝病病人和患犬的营养不足。
假设/目的-根据评分方案和肝外门体静脉分流术(EHPSS)犬的皮肤活检确定皮肤和被毛质量, 并在手术时和成功放置分流器3个月后测定犬被毛中的总脂质浓度。
动物–纳入了10只经脾门静脉显影确定成功逐渐衰减EHPSS的家养犬。
材料和方法-进行了一项前瞻性队列研究。所有犬的EHPSS均逐渐衰减。在诊断、手术以及术后1个月和3个月时进行皮肤和被毛评分。从腰部拔去毛发进行总脂质分析, 并在手术时和术后3个月进行8 mm打孔皮肤活检, 此时犬接受经脾门静脉显像以确定EHPSS闭合。
结果-皮肤和被毛评分未观察到经时显著差异。从手术到术后3个月, 毛发的总脂质浓度显著增加[30µg/mg毛发 (13-56µg/ mg毛发) 至47µg/mg毛发 (25-63µg/mg毛发) ; P = 0.005]。皮肤活检显示术后3个月皮屑明显更多(P = 0.018)。
结论和临床相关性-毛发中总脂质浓度的显著增加表明, EHPSS的成功手术衰减改善了肠道脂质吸收、肝脏脂肪代谢或两者的组合。
KEYWORDS
关键词
canine, dermatology, hair, hepatopathy, internal medicine, lipids
犬、皮肤病、毛发、肝病、内科、脂质
INTRODUCTION
介绍
The skin is a large, metabolically active organ, and fatty acids – an essential part of the cell membrane – are vital for maintaining normal skin structure and function. Fatty acids are absorbed from the intestinal tract after forming micelles with bile acids. Bile acids are synthesised in the liver and secreted into the intestinal lumen via bile and undergo an enterohepatic cycle. Fatty acid deficiencies can be a consequence of fat malabsorption secondary to hepatic disease.
皮肤是一个大的代谢活跃的器官，脂肪酸是细胞膜的重要组成部分，对维持正常的皮肤结构和功能至关重要。脂肪酸与胆汁酸形成微粒之后从肠道被吸收。胆汁酸在肝脏中合成，通过胆汁分泌到肠腔，经历肠肝循环。脂肪酸缺乏可能是肝脏疾病继发的脂肪吸收不良的结果。
People with liver disease commonly have cutaneous abnormalities that reflect nutritional deficiencies or that might be indirectly caused by liver dysfunction. In dogs and cats, poor skin and coat conditions, such as excessive scales, greasy skin and poor hair growth,also can reflect nutritional deficiencies. In dogs, superficial necrolytic dermatitis (also called hepatocutaneous syndrome) is a rare ulcerative skin disease associated with liver diseases such as vacuolar hepatopathy and cirrhosis.
肝病患病动物通常有皮肤异常，这反映了营养不足或可能是由肝功能障碍间接引起的。犬和猫的皮肤和被毛状况不佳，如皮屑过多、皮肤油腻、毛发生长不良，也可能反映出营养不足。在犬上，浅表坏死性皮炎(也称为肝皮综合征)是一种罕见的溃疡性皮肤病，与肝脏疾病如肝病空泡变性和肝硬化有关。
Dogs with congenital portosystemic shunts (PSS) typically have an underdeveloped liver as the shunting vessel directly connects the portal vein to the systemic circulation, bypassing the liver parenchyma. One of the consequences is a decreased production of bile, which can induce maldigestion and malabsorption. Surgical attenuation of the PSS aims at restoring the normal portal circulation and is the preferred method of treatment. In our experience, dogs with PSS have a poor skin and coat quality; however, little to no specific information about skin and coat changes in dogs with PSS is available in literature and, so far, no research has been performed on this subject.
具有先天性门静脉系统分流(PSS)的犬通常肝脏发育不全，因为分流血管直接连接门静脉到体循环，绕过肝实质。其后果之一是胆汁分泌减少，这可能导致消化不良和吸收不良。手术衰减PSS的目的是恢复正常的门静脉循环，是首选的治疗方法。根据我们的经验，患有PSS的犬的皮肤和被毛质量很差;然而，文献中几乎没有关于PSS犬的皮肤和被毛变化的具体信息，到目前为止，还没有对这一主题进行过研究。
The aim of this study was to assess skin and coat quality in dogs with PSS and to evaluate the effect of successful surgical attenuation. Besides skin and coat scoring, hair growth phases were assessed and total hair lipid analysis was performed. A former study in experimental dogs revealed that hair lipid analysis can be useful to assess dietary effects on canine skin and hair scores. Our hypothesis was that skin and coat quality would improve after successful surgical attenuation of extrahepatic PSS (EHPSS), leading to increased glossiness and softness and decreased greasiness and scaliness. Furthermore, we hypothesised that, preoperatively, only a small number of hairs would be in the anagen or growth phase and that the total lipid concentrations would be typically low, whereas the situation would normalise after successful surgery.
本研究的目的是评估患有PSS的犬的皮肤和被毛质量，并评估成功的手术衰减的效果。除皮肤和被毛评分外，还对毛发生长阶段进行评估并进行总毛发脂质分析。以前的一项实验犬的研究表明，毛发脂质分析可以用于评估饮食对犬类皮肤和毛发评分的影响。我们的假设是，肝外PSS (EHPSS)手术成功衰减后，皮肤和被毛质量将得到改善，从而增加光泽度和柔软度，减少油脂和皮屑。此外，我们假设，在术前，只有少量毛发处于生长期或生长期，总脂质浓度通常较低，而在手术成功后，情况将恢复正常。
MATERIALS AND METHODS
材料和方法
A prospective study was designed and approved by the local ethical and deontological committee (EC 2017/49 and DC 2017N06).
一项前瞻性研究由当地伦理和义务委员会设计并批准(EC 2017/49和DC 2017N06)。
Animals
动物
Dogs diagnosed with a congenital EHPSS undergoing surgical attenuation were enrolled. Dogs were treated with a liver-support diet combined with lactulose (0.5ml/ kg three times daily) and/or metronidazole (7.5–10mg/kg twice daily) for at least 4weeks before surgery. Gradual attenuation of the EHPSS was performed using either an ameroid constrictor or a thin film band. Postoperative medical therapy was the same as that given preoperatively until the 1month control visit after which everything except the liver-support diet was discontinued. Three months postoperatively, a transsplenic portal scintigraphy (TSPS) was performed to determine shunt closure. Dogs with persistent shunting, defined as having a shunt fraction >4.3%, were excluded from the study.
被诊断为先天性EHPSS的犬接受了手术衰减。术前至少4周给予肝脏支持粮联合乳果糖(0.5ml/ kg，每日3次)和/或甲硝唑(7.5-10mg /kg，每日2次)。EHPSS的逐渐衰减使用缩窄器或薄膜带进行。术后的药物治疗与术前相同，直到1个月的对照来访后，除肝支持饮食外，停止一切治疗。术后3个月，行经脾门静脉显像(TSPS)检查分流是否关闭。有持续分流的犬，定义为分流分数＞4.3%，被排除在研究之外。
Skin and coat scoring
皮肤和被毛评分
Skin and coat scoring was performed in all dogs at diagnosis, at time of surgery, and 1 and 3months postoperatively. The entire dorsal part from cranial to the scapulae until the sacrum was evaluated to attribute the scores. All dogs were scored by the same person (ND) in a room with ample light, and digital pictures were taken from frontal view of the head and from dorsal view of the body to objectively assess coat and eye colour over time. Six categories were evaluated: alopecia, glossiness, greasiness, softness, scaliness, and overall skin and coat quality score according to a scoring system published previously. Briefly, all of the above categories were scored from 1 to 5. Alopecia and glossiness were scored only on visual assessment, with alopecia ranging from no alopecia (1) to bald (5) and glossiness ranging from highly reflective (1) to dull (5). Greasiness and softness were assessed tactilely with greasiness ranging from dry (1) to greasy (5) and softness ranging from very soft (1) to coarse (5). Scaliness was assessed in three areas by parting the hair: between the scapulae, and in the thoracolumbar and the lumbar regions. Scoring ranged from a minimal amount of scales (1) to a very large amount of scales (5). Finally, the overall skin and coat quality was scored from normal (1) to abnormal (5) for that type of breed. The coat and eye colour were noted, and nasal planum and footpads were assessed for the presence of wounds, hyperkeratosis or any other abnormalities. The frequency of brushing and washing was surveyed.
在诊断时、手术时以及术后1和3个月对所有犬进行皮肤和被毛评分。从颅到肩胛骨直到骶骨的整个背侧部分被评估为评分。在光线充足的房间里，由同一个人(ND)对所有犬进行评分，并从头部正面和身体背面拍摄数字照片，以客观评估随着时间的推移被毛和眼睛的颜色。根据之前发布的评分系统，对6个类别进行了评估:脱毛、光泽度、油腻度、柔软度、皮屑以及整体皮肤和被毛质量评分。简单地说，以上所有类别的评分都从1到5分。脱毛和光泽度只根据视觉评估进行评分，脱毛从无脱毛(1)到秃顶(5)，光泽度从高度反光(1)到暗淡(5)。触觉上评估油腻度和柔软度，油腻度从干燥(1)到油腻(5)，柔软度从非常柔软(1)到粗糙(5)。通过将毛发分开，对三个区域的皮屑程度进行评估:肩胛骨之间、胸腰椎和腰部区域。评分范围从最少的皮屑(1)到非常多的皮屑(5)。最后，该品种的整体皮肤和被毛质量评分从正常(1)到异常(5)。记录被毛和眼睛的颜色，评估鼻平面和脚垫是否存在伤口、角化过度或任何其他异常。调查刷毛和洗澡的频率。
Lipid analysis of plucked hairs
拔毛进行脂质分析
After premedication and induction of the general anaesthesia at time of surgery and at time of TSPS, 10g hair was plucked from the lumbar area using a haemostat clamp. The hairs were stored at −80°C until analysis in batch at the end of the study. Total lipid extraction was performed in a dedicated laboratory (Upscience; Saint Nolff, France) by heating the hairs in the presence of hydrochloric acid. Subsequently, the samples were filtrated and lipids were extracted using petroleum ether. The solvent was removed by distillation and the residue dried. The total lipid content was quantified using a gravimetric method.
在给药前和手术时和TSPS时全麻诱导后，使用止血钳从腰部区域拔取10g毛发。毛发保存在- 80°C，直到研究结束时批量分析。总脂质提取在专门的实验室进行通过在盐酸的存在下加热毛发。随后，用石油醚对样品进行过滤和提取脂质。通过蒸馏除去溶剂，并使残渣干燥。用重量法测定总脂质含量。
Skin biopsies
皮肤活检
At the end of the EHPSS surgery, an 8mm punch biopsy was taken 2cm parasagittal of the umbilicus. A coin flip was performed to decide if the biopsy was taken from the left or right side. During the short general anaesthesia needed to perform TSPS, a similar biopsy was taken at the contralateral side. The skin was surgically prepared for the second biopsy in an identical way as for the first biopsy. Before performing the skin biopsy, a line was drawn on the skin with a skin marker to identify the direction of the hair growth. The skin defect was closed with one cruciate suture with poliglecaprone 25 4/0 (Monocryl, Ethicon Inc.). Skin biopsies were placed in formalin and stored until batch analysis at the end of the study.
EHPSS手术结束时，在脐矢状旁2cm处取8mm穿刺活检。通过抛硬币来决定活检是从左侧还是右侧取的。在进行TSPS所需的短暂全麻期间，在对侧进行了类似的活检。皮肤在第二次活组织检查时，以与第一次活组织检查相同的方式进行手术准备。在进行皮肤活检之前，用皮肤记号笔在皮肤上画一条线，以确定毛发生长的方向。皮肤缺损用聚卡普龙25 4/0十字缝线缝合。皮肤活组织切片置于福尔马林中保存，直到研究结束时进行批量分析。
Before embedding the biopsies in paraffin, samples were cut in two equal pieces parallel to the line indicating the direction of the hairs. Samples were embedded with the cut side down. Two 8μm slices were cut, mounted on a glass slide, and a haematoxylin & eosin stain was performed. Slides were analysed blindly by two persons (ND and SVDA) and, in case of different interpretations, a consensus was obtained by evaluating the samples together. Scales were assessed by comparing the thickness of hyperkeratosis with the thickness of the epidermis (0, hyperkeratosis<epidermis; 1, hyperkeratosis = epidermis; 2, hyperkeratosistwo times the epidermis) and categorised as compact (lamellar) or loose (Figure 1). Furthermore, the presence of inflammation was assessed (0, absent; 1, present). If pigmentation of the hair shafts was present (0, absent; 1, present), it was assessed whether or not this was distributed proportionally over the hair shaft. The number of anagen follicles and follicular units were counted and the number of anagen follicles was divided by the number of follicular units to obtain an overall idea about the proportion of hairs in the anagenic phase.
在用石蜡包埋活组织切片之前，样本被切成两等分，平行于毛发的方向。样品被切割的一面朝下嵌入。切2片8μm切片，置于玻片上，进行苏木精-伊红染色。切片由两个人(ND和SVDA)盲法分析，在解释不同的情况下，通过共同评估样本获得共识。通过比较角化过度与表皮的厚度(0，角化过度＜表皮;1、角化过度=表皮;2，角化过度＜2倍表皮)，并分为致密(板层状)或疏松(图1)。此外，评估炎症的存在(0，无;1，有)。如果毛干有色素沉着(0，无;1，有)，它被评估是否这是分布在毛干的比例。统计发育期毛囊数和毛囊单位数，用发育期毛囊数除以毛囊单位数，得到发育期毛发比例的总体情况。
Statistical methods
统计学方法
Statistical analyses were performed using SPSS Statistics 26 (IBM). Wilcoxon signed rank tests were performed to assess changes in findings of skin biopsies and total lipid concentrations in hairs over time. Changes over time in skin and coat scoring, and changes in the frequency of brushing and washing were assessed using Friedman two-way analyses. Correlation between the thickness of scales based on histological evaluation and scaliness based on skin and coat scoring was assessed using Spearman rho correlation tests. Variables were considered significant if p ＜0.05.
使用SPSS Statistics 26 (IBM)进行统计分析。采用Wilcoxon符号等级检验来评估皮肤活检结果和毛发总脂质浓度随时间的变化。使用弗里德曼双向分析评估了皮肤和被毛评分随时间的变化，以及刷牙和清洗频率的变化。基于组织学评价的皮屑厚度与基于皮肤和被毛评分的皮屑厚度之间的相关性采用Spearman rho相关检验进行评估。如果p <0.05，则认为变量显著。
RESULTS
结果
Study population
研究群体
In total, 15 dogs were enrolled, of which five were excluded because of persistent shunting 3months postoperatively. Median age of included dogs at diagnosis was 12.5months (range 3–105months), median body weight was 3.0kg (1.4–7.8kg) and median body condition score 4 of 9 (2–6 of 9). At the time of diagnosis three dogs were neutered, the remaining dogs were all neutered at the time of EHPSS surgery (Table 1). Dog 6 had two single EHPSS that were gradually attenuated during two separate surgeries; samples of this dog were collected at the time of the first surgery and 3months after the second surgery.
共纳入15只犬，其中5只因术后3个月持续分流而被排除。入选犬在诊断时的中位年龄为12.5月龄(3 - 105月龄)，中位体重为3.0kg (1.4-7.8kg)，中位体况评分为4(9分)(2-6分)。在诊断时，3只犬被绝育，其余犬均在EHPSS手术时绝育(表1)。犬6有2只单独的EHPSS，在两次不同的手术中逐渐减弱;在第一次手术时和第二次手术后3个月收集该犬的样本。
No significant changes in the frequency the dogs were brushed and washed were present over time (p = 0.403 and p = 0.845, respectively).
随着时间的推移，犬被刷毛和洗澡的频率没有显著变化(p = 0.403和p = 0.845)。
Two dogs were presented with dermatological complaints 3months postoperatively. Dog 5 developed pruritic pyoderma for which cephalosporin was initiated at a dosage of 20mg/kg twice daily for 1month. Retrospectively, demodicosis was missed in this dog (see skin biopsies section). Dog 9 was found to have collarettes over the entire body and was treated locally with clorexyderm 4% shampoo three times a week for 3weeks.
2只犬术后3个月出现皮肤症状。犬5出现瘙痒性脓皮病，开始服用头孢菌素20mg/kg，每日两次，持续1个月。回顾性分析，这只犬未发现蠕形螨病(见皮肤活检部分)。犬9被发现全身都有表皮环，并在当地使用4%的氯己定香波，每周3次，持续3周。
Skin and coat scoring
皮肤和被毛评分
All dogs had brown eyes; only Dog 6 had light brown eyes. No changes in hair or eye colour were observed over time. The nasal planum and footpads were normal at all times in all dogs. No significant differences were present over time for any of the assessed features (Table 2).
所有的犬都有棕色的眼睛;只有犬6有浅棕色的眼睛。随着时间的推移，没有观察到毛发或眼睛颜色的变化。所有犬的鼻平面和脚垫均正常。随着时间的推移，评估的任何特征都没有显著差异(表2)。
Skin biopsies
皮肤活检
Five of the 10 included dogs had skin biopsies taken at the left side and the remaining five at the right side at the time of surgery. Three months postoperatively, a significantly thicker layer of scales was present compared to that at the time of surgery (p = 0.018; Table 3, Figure 1). In the majority of dogs, the scales were loose. In dogs 7 and 10, the scales were compact at the time of surgery, and half of the scales were compact and half were loose in Dog 5 at the time of surgery and in dog 6 three months postoperatively. No correlation was present between the thickness of scales assessed on histological examination and scaliness based on skin and coat scoring (r = 0.234, p = 0.321).
在手术时，10只入选的犬中有5只在左侧进行了皮肤活检，其余5只在右侧进行了皮肤活检。术后3个月，皮屑层明显较手术时厚(p = 0.018;表3，图1)。在大多数犬，皮屑是松散的。犬7和犬10的皮屑在手术时是紧密的，犬5的皮屑在手术时一半是紧密的，一半是松散的，犬6的在术后3个月。组织学检查评估的皮屑厚度与基于皮肤和被毛评分的皮屑厚度之间不存在相关性(r = 0.234, p = 0.321)。
At the time of surgery, mild perivascular inflammation was present in two skin biopsies (dogs 1 and 6). Three months postoperatively, pronounced perivascular inflammation was present in one biopsy (Dog 6). Neither dog had any apparent dermatological abnormalities at any time point. One skin biopsy revealed granulocytic and lymphocytic mural folliculitis, perivascular inflammation with macrophages, plasma cells, lymphocytes and eosinophils, and demodicosis (3months postoperatively). When this skin biopsy was taken, the dog (Dog 9) presented clinically with collarettes. At the time of surgery and 3months postoperatively, follicular hyperkeratosis was present in biopsies of two dogs (dogs 1 and 3); and 3months postoperatively, mineralisation of one follicular border was seen in one biopsy (Dog 5).
手术时，两次皮肤活检显示轻度血管周围炎症(犬1和犬6)。术后3个月，一次皮肤活检显示明显血管周围炎症(犬6)。在任何时间点，犬均无明显皮肤异常。一次皮肤活检显示粒细胞和淋巴细胞毛囊壁炎，血管周炎，伴有巨噬细胞、浆细胞、淋巴细胞和嗜酸性粒细胞，以及蠕形螨病(术后3个月)。当进行皮肤活检时，犬(犬9)临床表现为表皮环。在手术时和术后3个月，两只犬(犬1和犬3)的活检中出现毛囊角化过度;术后3个月，在一次活检中发现一个毛囊边界矿化(犬5)。
Pigmentation of hairs did not change in any dog over time (p = 1.000). Moreover, the number of anagen follicles, follicular units and anagen follicles per follicle units did not change significantly over time (p = 0.123, p = 0.204 and p = 0.515, respectively; Table 3).
随着时间的推移，任何犬的毛发色素都没有变化(p = 1.000)。此外，毛囊生长期数、毛囊单位数和每毛囊单位的毛囊生长期数随时间变化不显著(p = 0.123、p = 0.204和p = 0.515;表3)。
Total lipid content of hairs
毛发脂质总量
Median lipid concentrations in hairs at the time of surgery and 3months postoperatively were 30μg/mg hair (13–56μg/mg hair) and 47μg/mg hair (25–63μg/mg hair), respectively (Figure 2). The lipid concentrations increased in all dogs over time and were significantly higher 3months postoperatively (p = 0.005).
手术时和术后3个月毛发中位脂质浓度分别为30μg/mg毛发(13-56μg /mg毛发)和47μg/mg毛发(25-63μg /mg毛发)(图2)。所有犬的脂质浓度均随时间增加而升高，术后3个月显著升高(p = 0.005)。
DISCUSSION
讨论
In this cohort of dogs, the concentration of total lipids in the hairs was significantly higher 3months after successful surgical attenuation of EHPSS than at the time of surgery in dogs with EHPSS. The skin and coat condition scores, however, failed to improve significantly 3months after EHPSS surgery that resulted in shunt closure. Likewise, the number of hairs in the anagen phase did not significantly increase after 3months.
在这组犬中，EHPSS手术成功衰减3个月后，毛发中总脂浓度明显高于有EHPSS的犬手术时。然而，在导致分流关闭的EHPSS手术后3个月，皮肤和被毛状况评分没有明显改善。同样，3个月后，生长期毛发数也没有显著增加。
In contrast to the skin itself, hair is metabolically in - active tissue with a composition that corresponds to an exposure of elements via blood and skin. The liver is an important organ for fat metabolism; within the liver, fatty acids can be either oxidised or incorporated into complex lipids. Locally synthesised triglycerides can be stored in the liver or packed into very-low density lipoproteins which are secreted into the blood. In an experimental study in dogs, it was shown that plasma cholesterol and triglyceride concentrations decreased by 42% and 53%, respectively, weeks after the creation of a portocaval shunt. Creation of portocaval shunts are performed in humans with familial hypercho - lesterolaemia. After the creation of a portocaval shunt in these people, hepatic biopsies revealed that the total hepatic cholesterol concentration decreased by 27%, and the free fraction of hepatic cholesterol decreased by 75%. Furthermore, it was shown that the activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase, the rate-limiting enzyme of cholesterol synthesis, decreased by 56%. In contrast to these observations, a previous study revealed that dogs with congenital PSS had a 12-fold increased staining intensity of lipids within the liver parenchyma using oil-red-O stain compared to healthy dogs. Moreover, the lipid content in dogs with PSS differed from that in healthy dogs, with a shift to - wards short-chain and omega-3 fatty acids. The accumulation of fat in the liver in the form of lipogranulomas in dogs with PSS has also been described in other studies. Lipogranulomas in dogs with PSS consist of Kupffer cells containing lipid vacuoles, similar to observations made in people with steatohepatitis. One of the studies in dogs showed a significant decrease in steatosis based on histological examination of the liver 2–13months after surgical attenuation of PSS. Interestingly, in humans with congenital PSS, capillarisation of the sinusoidal endothelial cells has been described; however, no documentation about this is available in dogs with PSS. Capillarisation or the loss of fenestrations between the sinusoidal endothelial cells in the liver promotes steatosis in humans, and capillarisation in turn promotes hepatic fibrosis. TABLE 3 Capillarisation can cause, besides alteration in lipid metabolism, alterations in the amino acid, glucose, iron and bile acid metabolism. The significant increase in total lipid concentrations in hairs found in the current study might reflect restoration of the lipid metabolism 3months after successful attenuation of EHPSS, and hence potentially indicate reversion of capillarisation of sinusoidal endothelial cells. Alternatively, these findings might reflect an improved absorption of lipids from the intestines. Unfortunately, as no liver biopsies were obtained, the concentrations of lipids in the liver parenchyma could not be evaluated in parallel.
与皮肤本身相反，毛发是代谢活跃的组织，其组成与通过血液和皮肤暴露的元素相对应。肝脏是脂肪代谢的重要器官;在肝脏内，脂肪酸可以被氧化或并入复杂的脂类。局部合成的甘油三酯可以储存在肝脏中，或形成极低密度的脂蛋白中，分泌到血液中。在一项对犬的实验研究中，发现在门腔静脉分流形成几周后，血浆胆固醇和甘油三酯浓度分别下降了42%和53%。在家族性高胆固醇血症患病动物中进行门腔静脉分流。在这些患病动物中建立门静脉分流后，肝活检显示肝总胆固醇浓度下降了27%，肝游离胆固醇含量下降了75%。结果表明，3-羟基-3-甲基戊二酰辅酶A还原酶是胆固醇合成的限速酶，其活性降低了56%。与这些观察结果相反，先前的一项研究显示，与健康的犬相比，患有先天性PSS的犬使用油红- o染色法对肝实质内脂质的染色强度增加了12倍。此外，PSS犬的脂质含量与健康犬不同，向短链脂肪酸和Ω-3脂肪酸转移。其他研究也描述了PSS犬肝脏中脂肪以脂肪肉芽肿的形式积累的情况。患有PSS的犬体内的脂肪肉芽肿由含有脂质液泡的Kupffer细胞组成，与脂肪性肝炎患病动物的观察结果相似。其中一项对犬的研究显示，PSS手术衰减2 - 13个月后，肝脏组织学检查显示脂肪变性明显减少。有趣的是，在患有先天性PSS的人类中，已经描述了窦内皮细胞的毛细血管化;然而，没有关于PSS犬的相关文献。毛细血管化或肝内窦内皮细胞间开窗的缺失促进人体脂肪变性，而毛细血管化反过来又促进肝纤维化。除了脂质代谢的改变外，毛细血管化还会引起氨基酸、葡萄糖、铁和胆汁酸代谢的改变。在目前的研究中发现，毛发中总脂质浓度的显著升高可能反映了EHPSS成功衰减3个月后脂质代谢的恢复，因此可能表明窦内皮细胞毛细血管化的逆转。或者，这些发现可能反映了从肠道吸收脂质的改善。不幸的是，由于没有获得肝脏活检，无法同时评估肝实质中的脂质浓度。
The hairs of dogs in the current study were judged to be mildly softer, and the median overall skin and coat quality was mildly lower at the 3months follow-up visit, indicating improved skin and coat quality. However, statistical significance was not reached. This might be attributed to the small number of dogs included or it might be that more time is needed for the skin and coat to improve significantly after the PSS is closed. It is, however, important to note that a subjective scoring system was used to assess the skin and coat quality. Nevertheless, a preliminary study, validating this skin and coat scoring system, showed that intraobserver variability was moderate to substantial. Although the latter study aimed at assessing the skin and coat quality in dogs with different hair coats (i.e. long-haired, short-haired and wire-haired dogs), only two wire-haired dogs were included, making it impossible to assess the skin and coat scoring system in dogs with this hair type. As two dogs in the current study were wire-haired dogs (Dachshund and West Highland white terrier), this might have influenced the results.
本研究中犬的毛发被判定为轻度柔软，在3个月的随访中，整体皮肤和被毛质量的中位值轻度较低，表明皮肤和被毛质量有所改善。然而，没有达到统计显著性。这可能是因为纳入的犬只数量较少，也可能是因为PSS关闭后，皮肤和被毛需要更多的时间来显著改善。然而，重要的是要注意，主观评分系统是用来评估皮肤和被毛质量。然而，一项验证这种皮肤和被毛评分系统的初步研究表明，观察者内部的多样化是中等到相当大的。虽然后一项研究旨在评估不同毛(即长毛、短毛和钢丝毛)的犬的皮肤和被毛质量，但只包括了两只钢毛犬，因此无法评估该毛类型犬的皮肤和被毛评分系统。由于目前研究中的两只犬是钢毛的犬(腊肠犬和西高地白梗)，这可能会影响结果。
During skin and coat scoring, a relatively large variety in the amount of scales was detected at different time points in different dogs, and this variation was not statistically significant. By contrast, based on the skin biopsies, a significantly thicker layer of scales was detected 3months postoperatively than at the time of surgery. This was an unexpected finding, as we hypothesised that the amount of scales would decrease after successful surgical shunt attenuation. The increased amount of scales found on the skin biopsies 3months postoperatively most likely can be attributed to an increased turnover of the skin. The turnover of the epidermis, from stratumbasale to stratum granulosum, takes approximately 22days in healthy dogs. Most likely, more time is needed for the skin to completely normalise after establishment of normal portal circulation.
在皮肤和被毛评分过程中，不同犬在不同时间点的皮屑数量变化较大，但这种变化不具有统计学意义。相比之下，基于皮肤活检，术后3个月检测到的皮屑层明显较手术时厚。这是一个意想不到的发现，因为我们假设在成功的手术分流衰减后皮屑的数量会减少。术后3个月皮肤活检中发现的皮屑数量增加很可能是由于皮肤的周转增加。在健康的犬上，表皮从基底层到颗粒层的转变大约需要22天。最有可能的情况是，在建立正常的门静脉循环后，皮肤完全恢复正常需要更多的时间。
The hair cycle encompasses different stages, with the anagen phase being the growth phase and the telogen phase being the rest phase. The current study failed to demonstrate that the amount of anagen follicles per follicular unit changed after successful shunt attenuation. The duration and length of different hair cycles depend on different variables, such as genetic background, age, sex, breed, body region, hormonal influences, seasonal changes, nutrition, health status, environmental factors and drug therapy.28 Different dog breeds with different hair types, and hence different hair growth patterns, were included in the study, dogs were enrolled during different seasons, and the majority of dogs were neutered during the surgery. For these reasons, it is most likely that a larger number of dogs is needed to assess the influence of shunt attenuation on hair growth.
毛发周期包括不同的阶段，生长期是生长阶段，终止期是休息阶段。目前的研究未能证明成功的分流衰减后，每个毛囊单位的生长期毛囊数量发生了变化。不同毛发周期的持续时间和长度取决于不同的变量，如遗传背景、年龄、性别、品种、身体部位、激素的影响、季节变化、营养、健康状况、环境因素和药物治疗研究中包括了不同品种、不同毛发类型、因此也就有不同的毛发生长模式的犬，犬在不同的季节被招募，大多数犬在手术过程中被节育。基于这些原因，很可能需要更多的犬来评估分流衰减对毛发生长的影响。
Several limitations are present in this study. The number of dogs included was relatively small and the study encompassed dogs with several types of coats. In addition, no control group of healthy breed- and agematched dogs was included. Furthermore, the skin and coat scoring system used was rather subjective. Nevertheless, it always was performed by the same person and photographs were taken to evaluate coat and eye colour at the end of the study. The person performing the scoring was, however, not blinded to the time elapsed since diagnosis/surgery. Although hair samples and skin and coat scoring were based on the dorsal region, skin biopsies were taken at the ventral side for practical reasons, which might be a possible explanation for the absence of a correlation between the amount of scales found on biopsies and the scaliness judged during skin and coat scoring. Although it is possible that differences in hair and skin samples might be different at both anatomical locations, samples at the time of surgery and 3months postoperatively were always taken from the same region in order to be able to compare results at both time points. Furthermore, the stratum corneum can have a thicker ‘basket-weave-like’ aspect secondary to formalin fixation, and processing of samples for histological examination might affect scales on the biopsies by dehydration of the samples. Nevertheless, as biopsies in all except one dog were taken only 3months apart, it is unlikely that differences found in scales on the biopsies between surgery and 3months postoperatively were a consequence of longer formalin exposure. Although skin preparation might affect the amount of scales, this is unlikely in this study as the skin was always scrubbed prior to taking skin biopsies by a standardised presurgical protocol. Despite the fact that 3months postoperatively significantly more hyperkeratosis was seen, the thickness of hyperkeratosis was never more than two times the thickness of the epidermis, and, hence, hyperkeratosis might not have been appreciated during skin and coat scoring. Finally, two dogs were presented with clinical signs of pyoderma 3months postoperatively which might have influenced the skin and coat quality.
本研究存在一些局限性。研究纳入的犬的数量相对较少，研究包括了具有几种类型皮毛的犬。此外，没有纳入健康犬种和年龄匹配的对照组。此外，使用的皮肤和被毛评分系统是相当主观的。然而，测试总是由同一个人进行，并在研究结束时拍摄照片来评估被毛和眼睛的颜色。然而，进行评分的人对诊断/手术后的时间并不是盲目的。虽然毛发样本和皮肤和被毛评分是基于背侧区域，但出于实际原因，皮肤活组织检查是在腹侧进行的，这可能解释了活组织检查中发现的皮屑数量与皮肤和被毛评分中判断的皮屑数量之间缺乏相关性。尽管两个解剖位置的毛发和皮肤样本的差异可能不同，但手术时和术后3个月的样本总是取自同一区域，以便能够比较两个时间点的结果。此外，角质层可能有较厚的“篮状”方面，仅次于福尔马林固定，并处理组织学检查的样本可能会影响组织切片上的皮屑脱水样本。然而，由于除一只犬外，其余所有犬的活组织检查仅相隔3个月进行，因此，手术和术后3个月之间的活组织检查中发现的鳞差异不太可能是长时间接触福尔马林的结果。尽管皮肤准备可能会影响皮屑的数量，但在本研究中这是不可能的，因为在采用标准化的手术前方案进行皮肤活检之前，皮肤总是经过擦洗。虽然术后3个月角化过度明显增多，但角化过度的厚度从未超过表皮厚度的两倍，因此，在皮肤和被毛评分时可能没有发现角化过度。最后，2只犬在术后3个月出现脓皮病的临床症状，这可能影响了皮肤和被毛质量。
In conclusion, there are indications that successful closure of EHPSS has a positive effect on skin and coat quality in dogs that underwent surgical shunt attenuation. The total lipid concentration in the hairs was significantly higher 3months after successful surgical attenuation of EHPSS compared to preoperatively. The skin and coat quality ameliorated, and significance was not reached, suggesting that more time is needed after gradual surgical attenuation.
总之，有迹象表明，成功关闭EHPSS对经过手术分流衰减的犬的皮肤和被毛质量有积极的影响。EHPSS手术成功后3个月，毛发中总脂质浓度明显高于术前。皮肤和被毛质量改善，但未达到显著性，提示手术逐渐衰减后需要更多时间。
FIGURE 1 Skin biopsy of Dog 7 stained with haematoxylin & eosin at the times of surgery (a) and transsplenic portal scintigraphy (TSPS) 3months after successful surgical attenuation (b) Scales were assessed by comparing the layer of hyperkeratosis with the thickness of the epidermis. At the time of surgery, hyperkeratosis (solid black line) was thinner than the epidermis (dashed black line), leading to scale score of 0, and scales were judged to be compact. At the time of TSPS, hyperkeratosis (solid black line) was more than twice as thick as the epidermis (dashed black line), leading to a scale score of 2 with scales being loose.
图1手术时用苏木精和伊红染色的犬7的皮肤活检(a)和手术成功衰减3个月后经脾门静脉显像(TSPS) (b)通过比较角化过度层和表皮厚度来评估皮屑。手术时角化过度(实黑线)比表皮(虚线黑线)更薄，皮屑评分为0，判断皮屑致密。TSPS发生时角化过度(实黑线)是表皮(虚线黑线)的2倍多，皮屑疏松。
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发表于 2022-11-7 20:10:20
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