Shriram Jakate

Is alpha‐synuclein in the colon a biomarker for premotor Parkinson's Disease? Evidence from 3 cases

Background: Despite clinicopathological evidence that Parkinsons disease (PD) may begin in peripheral tissues, identification of premotor Parkinsons disease is not yet possible. Alpha‐synuclein aggregation underlies Parkinsons disease pathology, and its presence in peripheral tissues may be a reliable disease biomarker. Objective: We sought evidence of alpha‐synuclein pathology in colonic tissues before the development of characteristic Parkinsons disease motor symptoms. Methods: Old colon biopsy samples were available for three subjects with PD. Biopsies were obtained 2‐5 years before PD onset. We performed immunohistochemistry studies for the presence of alpha‐synuclein and Substance P in these samples. Results: All subjects showed immunostaining for alpha‐synuclein (two, five and two years before first motor Parkinsons disease symptom). No similar alpha‐synuclein immunostaining was seen in 23 healthy controls. Staining of samples for substance P suggested colocalization of alpha‐synuclein and substance P in perikarya and neurites. Conclusions: This is the first demonstration of alpha‐synuclein in colon tissue prior to onset of PD. Additional study is required to determine whether colonic mucosal biopsy may be a biomarker of premotor PD.

Evidence that chronic alcohol exposure promotes intestinal oxidative stress, intestinal hyperpermeability and endotoxemia prior to development of alcoholic steatohepatitis in rats

BACKGROUND/AIMS Not all alcoholics develop liver disease (ALD). Thus, excessive ethanol consumption is necessary, but not sufficient, to induce alcoholic steatohepatitis (ASH) and ALD. Since endotoxemia is present in patients with ALD, it has been proposed that gut-derived, circulating endotoxin is the necessary co-factor for ASH. But, it is not known whether endotoxemia is the consequence or the trigger for ALD. Accordingly, the aim of the current study was to determine whether endotoxemia occurs prior to development of ASH and whether gut leakiness is the primary cause of the endotoxemia in an animal model of ASH. METHODS Time courses for development of gut hyperpermeability, nitric oxide production, oxidative injury to the gut, endotoxemia, and liver injury were assessed in rats during 10 weeks of daily alcohol gavage. RESULTS Liver fat and serum transaminase increased after 2 weeks, but evidence of liver cell injury and inflammation (ASH) occurred after 8 weeks. Gut leakiness, intestinal oxidative injury, and endotoxemia occurred in weeks 2-4 and progressed thereafter. CONCLUSIONS That alcohol-induced gut leakiness and endotoxemia preceded steatohepatitis indicates they are not the consequence of ALD. Our data support the hypothesis that gut leakiness resulting in endotoxemia is a key co-factor (trigger) for ASH.

Glycogenic hepatopathy: an underrecognized hepatic complication of diabetes mellitus.

Reported are the clinical and pathologic features of glycogenic hepatopathy, a pathologic overloading of hepatocytes with glycogen that is associated with poorly controlled diabetes mellitus. Fourteen cases were studied by stains, including hematoxylin and eosin, trichrome, periodic acid–Schiff, and periodic acid–Schiff with diastase. Ultrastructural analysis was performed in 2 cases. Medical records were reviewed for clinical presentations, laboratory findings, and clinical outcomes. The individuals ranged from 8 to 25 years of age. All had type I diabetes mellitus with poor glycemic control. The clinical presentations included hepatomegaly, abdominal pain, and elevated transaminases (range, 50–1600 IU/L). The transaminases were dramatically elevated in 3 cases to greater than 10 times the upper limit of normal. All biopsies showed diffusely pale staining hepatocytes on hematoxylin and eosin stains, with excessive glycogen accumulation demonstrated by periodic acid–Schiff stains. Ultrastructural examination revealed marked glycogen accumulation in the cytoplasm and nuclei. Most cases showed no evidence for fatty liver disease: steatosis was absent in 12 of 14 cases, simple steatosis was seen in 1 of 14 cases, and mild steatohepatitis was present in 1 of 14 cases. Mallory hyaline was absent in all cases, acidophil bodies were only rarely seen, and inflammation was absent or minimally present. Fibrosis was typically absent, with only 2 cases demonstrating focal mild fibrosis. Three patients had adequate follow-up and demonstrated improvement of liver enzyme levels with control of blood glucose. We conclude that glycogenic hepatopathy can cause hepatomegaly and significant transaminase elevations in individuals with type I diabetes mellitus. The pathology is distinct from steatohepatitis.

Endoscopy in eosinophilic esophagitis: “feline” esophagus and perforation risk

BACKGROUND & AIMS Idiopathic eosinophilic esophagitis is an underdiagnosed disease with typical endoscopic findings, which have not been well described. METHODS Charts and pathology reports at two tertiary care centers from June 1993 to April 2002 were reviewed to describe the endoscopic findings of this disease and to correlate them with clinical characteristics. Eight patients were identified as having eosinophilic esophagitis based on clinical symptoms and pathology reports. RESULTS Soft and subtle ring(s) in the esophagus were found in 7 of 8 patients. In 3 of 8 patients, the esophagus appeared rigid. Mucosal rents occurred with simple passage of the endoscope in 5 of 8 patients. One patient developed a perforation after simple passage of the endoscope. Endoscopic findings can be normal or very subtle in these patients, and the findings can easily be missed during endoscopy. Tearing of the esophagus can occur with simple passage of the endoscope or biopsy even in the absence of overt rings. A minimum of 8 weeks of medical therapy (proton pump inhibitor, histamine antagonists, immunosuppressants) should be undertaken before considering dilation because of the high risk involved with the procedure and the good response to medical therapy. CONCLUSIONS We recommend considering dilation only in patients with eosinophilic esophagitis who do not respond to medical therapy and have rings that appear to be obstructing the lumen.

Nitric Oxide‐Mediated Intestinal Injury Is Required for Alcohol‐Induced Gut Leakiness and Liver Damage

BACKGROUND Alcoholic liver disease (ALD) requires endotoxemia and is commonly associated with intestinal barrier leakiness. Using monolayers of intestinal epithelial cells as an in vitro barrier model, we showed that ethanol-induced intestinal barrier disruption is mediated by inducible nitric oxide synthase (iNOS) upregulation, nitric oxide (NO) overproduction, and oxidation/nitration of cytoskeletal proteins. We hypothesized that iNOS inhibitors [NG-nitro-l-arginine methyl ester (l-NAME), l-N(6)-(1-iminoethyl)-lysine (l-NIL)] in vivo will inhibit the above cascade and liver injury in an animal model of alcoholic steatohepatitis (ASH). METHODS Male Sprague-Dawley rats were gavaged daily with alcohol (6 g/kg/d) or dextrose for 10 weeks +/- l-NAME, l-NIL, or vehicle. Systemic and intestinal NO levels were measured by nitrites and nitrates in urine and tissue samples, oxidative damage to the intestinal mucosa by protein carbonyl and nitrotyrosine, intestinal permeability by urinary sugar tests, and liver injury by histological inflammation scores, liver fat, and myeloperoxidase activity. RESULTS Alcohol caused tissue oxidation, gut leakiness, endotoxemia, and ASH. l-NIL and l-NAME, but not the d-enantiomers, attenuated all steps in the alcohol-induced cascade including NO overproduction, oxidative tissue damage, gut leakiness, endotoxemia, hepatic inflammation, and liver injury. CONCLUSIONS The mechanism we reported for alcohol-induced intestinal barrier disruption in vitro - NO overproduction, oxidative tissue damage, leaky gut, endotoxemia, and liver injury - appears to be relevant in vivo in an animal model of alcohol-induced liver injury. That iNOS inhibitors attenuated all steps of this cascade suggests that prevention of this cascade in alcoholics will protect the liver against the injurious effects of chronic alcohol and that iNOS may be a useful target for prevention of ALD.

Prevalence and significance of autoantibodies in patients with non-alcoholic steatohepatitis.

Goals The aim of this study is to evaluate the prevalence and the clinical and histologic correlates of autoantibodies in patients with nonalcoholic steatohepatitis (NASH). Background Antinuclear antibodies (ANA) and anti-smooth muscle antibodies (ASMA) have been identified in patients with NASH. The significance of autoantibodies in NASH is uncertain. Study Clinical data from patients with a histologic diagnosis of NASH at a university hospital in Chicago, Illinois between January 1999 and April 2003 were reviewed retrospectively. Seventy-four patients who were tested for autoantibodies and had no history of alcohol abuse or a systemic autoimmune disease were included. Demographic information and laboratory data were collected. Autoantibody titers ≥1:40 were considered positive. A single pathologist reviewed all liver biopsies and scored features of NASH and identified characteristics of autoimmune hepatitis. Results Thirty-four percent of patients with NASH had positive ANA titers and 6% were ASMA positive. Demographic and laboratory parameters did not differ by ANA status, except that women were more frequently ANA positive then men (P = 0.01). The severity of steatosis, inflammation, and fibrosis on liver biopsy were similar in the ANA positive and negative groups. Only 15% of ANA positive patients with NASH had a plasma cell infiltrate on liver biopsy and there was no difference in the frequency of histologic features of autoimmune hepatitis between ANA positive and negative patients. Conclusions Antinuclear antibodies are common in patients with NASH and most frequently represent a nonspecific antibody response that is not associated with the pattern or severity of injury on liver biopsy.

Sleep deprivation worsens inflammation and delays recovery in a mouse model of colitis

BACKGROUND AND AIM We recently showed that patients with inflammatory bowel disease (IBD) report significantly more sleep disturbances. To determine whether disrupted sleep can affect the severity of inflammation and the course of IBD, we used an animal model of colonic inflammation to determine the effects of acute and chronic intermittent sleep deprivation on the severity of colonic inflammation and tissue damage in colitis and recovery from this damage. METHODS Acute sleep deprivation (ASD) consisted of 24h of forced locomotor activity in a mechanical wheel rotating at a constant speed. Chronic intermittent sleep deprivation (CISD) consisted of an acute sleep deprivation episode, followed by additional sleep deprivation periods in the wheel for 6h every other day throughout the 10day study period. To induce colitis, mice were given 2% dextran sodium sulfate (DSS) in their daily drinking water for 7days. The development and severity of colitis were monitored by measuring weight loss and tissue myeloperoxidase (MPO) activity daily and colon histology scores 10days after initiation of colitis. RESULTS ASD or CISD did not cause colonic inflammation in vehicle-treated mice. Changes in daily body weight, tissue MPO levels and colon histopathology score were similar between mice that were sleep deprived and controls. Daily DSS ingestion caused colitis in mice. ASD worsened colonic inflammation: tissue MPO levels in ASD/DSS-treated mice were significantly higher than in DSS-treated mice that were not sleep deprived. However, the worsening of colonic inflammation by ASD was not enough to exacerbate clinical manifestations of colitis such as weight loss. In contrast, the deleterious effects of CISD were severe enough to cause worsening of histological and clinical manifestations of colitis. The deleterious effects of sleep deprivation on severity of colitis appeared to be due to both increased colonic inflammation and a decrease in the ability of mice to recover from DSS-induced colonic injury. CONCLUSION Both acute and chronic intermittent sleep deprivation exacerbate colonic inflammation. Thus, sleep deprivation could be an environmental trigger that predisposes IBD patients to develop flare ups and a more severe disease course. These results provide a scientific rationale to conduct an interventional trial to determine whether improvement in sleep patterns will prevent IBD flare ups, modify the disease course, and improve quality of life.

Mastocytic Enterocolitis: Increased Mucosal Mast Cells in Chronic Intractable Diarrhea

CONTEXT In some adult patients with chronic intractable diarrhea, the diagnosis remains elusive even after detailed evaluations, and colonic or duodenal biopsy specimens may appear unremarkable on routine hematoxylin-eosin staining. OBJECTIVES To assess the concentration of mast cells in colonic or duodenal biopsy specimens by immunohistochemical analysis for mast cell tryptase from patients with chronic intractable diarrhea and to evaluate their response to drugs affecting mast cell function. DESIGN Mast cells per high-power field were assessed in biopsy specimens from 47 patients with chronic intractable diarrhea, from 50 control subjects, and from 63 patients with other specific diseases that cause chronic diarrhea (inflammatory bowel disease, celiac disease, collagenous colitis, and lymphocytic colitis). Patients with chronic intractable diarrhea who had more than 20 mast cells per high-power field were administered drugs affecting mast cell mediator function and release. RESULTS The mean +/- SD concentration of mast cells in the 50 control subjects was 13.3 +/- 3.5 cells per high-power field; hence, patients with more than 20 mast cells per high-power field were considered to have increased mast cells. Thirty-three (70%) of 47 patients with chronic intractable diarrhea had increased mast cells, and symptoms were controlled by drug therapy in 22 (67%) of the 33 patients. No patient had systemic or cutaneous mastocytosis. No increase in mast cells was seen in patients with other common causes of chronic diarrhea. CONCLUSIONS In chronic intractable diarrhea, colonic or duodenal biopsy specimens may appear unremarkable on routine hematoxylin-eosin staining, but increased mast cells may be demonstrated by immunohistochemistry for mast cell tryptase, with the novel term mastocytic enterocolitis describing this condition. Similar increases in mast cells are not apparent in control populations or in patients with other specific diseases that cause chronic diarrhea. The cause of the increased mast cells remains to be elucidated.

Tumor angiogenesis in primary and metastatic colorectal cancers.

PURPOSE: Angiogenesis is needed to sustain growth of both primary and metastatic lesions; however, comparisons in microvessel density between a primary tumor and its metastases have not been widely performed. We studied microvessel density in primary colorectal cancers and their liver metastases. METHODS: Sections from 32 primary lesions and 53 hepatic metastases were immunostained with a monoclonal antibody for von Willebrands factor, an endothelial cell marker. Blood vessels were quantified under X 100 magnification using both conventional light microscopy and computer-assisted image analysis. Primary and metastatic angiogenesis scores (AS),i.e.,vessel counts, were analyzed with respect to tumor size, hepatic multicentricity, synchronicity, resectability, and patient survival. Using computer-assisted calculations, the same analyses were performed using blood vessel to tumor surface area ratios, vessel wall thickness, and intensity of immunostaining. RESULTS: Angiogenesis scores were significantly lower in metastatic lesions compared with their primary tumors (P<0.0001). Primary AS did not correlate with metastatic tumor size, resectability, multicentricity, or patient survival. Metastatic AS strongly predicted patient survival (P<0.0009) but with a negative coefficient,i.e.,higher scores were associated with improved survival. Metastatic AS were higher in resectable than in nonresectable metastases and in solitary than in multiple metastases; however, these trends were not statistically significant. Metachronous liver lesions had significantly higher angiogenesis scores than synchronous metastases (P<0.04). Similar trends were seen using computer-assisted image analysis. CONCLUSIONS: These results indicate that in presence of an established metastasis, there is a weak angiogenic relationship between a primary tumor and its metastasis. Heterogeneity in metastatic lesions cannot be explained solely by studying angiogenesis in primary tumors. Microvessel density in a primary tumor may not be useful as an independent prognostic indicator in late stages of disease. In such cases, assessment of microvessel density in a metastatic tumor whenever possible may be an indicator of prognosis.

Resolution of cirrhosis in autoimmune hepatitis with corticosteroid therapy.

Successful therapy for liver diseases, including autoimmune hepatitis, primary biliary cirrhosis, and hepatitis C, has been associated with a reduction in hepatic fibrosis. Recently, a study of needle liver biopsy specimens documented resolution of cirrhosis in a small group of patients with autoimmune hepatitis who responded to corticosteroid therapy. We describe a woman with autoimmune hepatitis who had cirrhosis on a wedge biopsy of the liver in 1985 and who attained a biochemical response with immunosuppressive therapy. A repeat wedge liver biopsy performed 14 years later was normal, providing unequivocal evidence that cirrhosis can reverse completely in autoimmune hepatitis.