Nitric oxide and gallbladder motility in prairie dogs

In this study we evaluated the role of nitric oxide (NO) on gallbladder motility in the normal prairie dog by 1) immunohistochemistry, 2) an enzymatic assay for NO synthase (NOS), and 3) an in vivo model to measure whole gallbladder tone and contractility. NOS was localized to gallbladder mucosal cells by NADPH-diaphorase and polyclonal antibodies to a constitutive brain NOS. Gallbladder mucosal homogenates demonstrated total NOS activity in the range of 578 +/- 115 pmol x mg protein(-1) x 30 min(-1). Blockade of NOS activity in vivo using N(omega)-nitro-L-arginine methyl ester resulted in an up to 80% increase in gallbladder tone from basal. A 40% increase in tone was seen with methylene blue, suggesting that tone was maintained by both NO activation of guanylate cyclase and possibly direct effects on Ca2+ channels. An exogenous nitrosothiol, S-nitroso-N-acetyl-cysteine, abolished cholecystokinin (CCK) octapeptide and bethanechol-stimulated gallbladder contraction. We conclude that the prairie dog gallbladder contains constitutive NOS and synthesizes NO, which is important for the maintenance of basal gallbladder tone and is an inhibitor of the contractile response of the gallbladder to agonists such as CCK and bethanechol.

Potentiation of GSK-3-catalyzed Alzheimer-like phosphorylation of human tau by cdk5

Tau protein from Alzheimer disease (AD) brain is hyperphosphorylated by both proline-dependent protein kinases (PDPKs) and non-PDPKs. It is presently unclear how PDPKs and non-PDPKs interact in tau hyperphosphorylation. Previously we have shown that non-PDPKs can positively modulate the activity of a PDPK (GSK-3) in tau phosphorylation (Singh et al. (1995) FEBS Lett. 358, 267-272). In this study we have investigated whether (A) non-PDPKs can also modulate the activity of the PDPK, cdk5, (B) a PDPK can modulate the activities of another PDPK, as well as non-PDPKs. We found that, like GSK-3, the activity of cdk5 is stimulated if tau were first prephosphorylated by any of several non-PDPKs (A-kinase, C-kinase, CK-1, CaM-kinase II). Prephosphorylation of tau by cdk5 stimulated both the rate and extent of a subsequent phosphorylation catalyzed by GSK-3. Under these conditions thr 231 phosphorylation was especially enhanced (9-fold). No significant stimulation of phosphorylation was observed when the order of these kinases was reversed (i.e. GSK-3 followed by cdk5). By contrast, prephosphorylation of tau by cdk5 served to inhibit subsequent phosphorylation catalyzed by C-kinase and CK-1, but not by A-kinase or CaM-kinase II. Our results suggest that in tau hyperphosphorylation in AD brain, cdk5-catalyzed phosphorylation may serve to upregulate the activity of GSK-3 and down-regulate the activities of C-kinase and CK-1.

Cigarette smoking as a predictor of death from prostate cancer in 348,874 men screened for the Multiple Risk Factor Intervention Trial

The association of cigarette smoking and mortality from prostate cancer was evaluated in 348,874 black and white men who were screened as part of the Multiple Risk Factor Intervention Trial (MRFIT). Current smoking status was assessed, serum cholesterol was measured, and demographics were recorded at screening; however, no information was collected on history of smoking, prostate screening, or diet. The vital status of each member of this cohort was ascertained through 1990. Death certificates were obtained from state health departments and coded by a trained nosologist. A total of 826 deaths due to prostate cancer occurred over an average of 16 years follow-up. The proportional hazards model was used to study the joint association of age, race, income, cigarette smoking, serum cholesterol level, and use of medication for diabetes mellitus on risk of death from prostate cancer. Statistically significant associations were observed with age (p < 0.01), cigarette smoking status (relative risk (RR) = 1.31, p < 0.01), black race (RR = 2.70, p < 0.01), and serum cholesterol (RR = 1.02 for 10 mg/dl higher cholesterol level, p < 0.05). Similar results were obtained when deaths that occurred during the first 5 years were excluded. Among cigarette smokers, there was some evidence of a dose-response relation (p = 0.20). The relative risk for those who reported that they smoked 1-25 cigarettes per day compared with nonsmokers was 1.21 (p = 0.04); the relative risk for those who reported smoking > or = 26 cigarettes per day compared with nonsmokers was 1.45 (p = 0.0003). These findings add to the limited evidence that cigarette smoking may be a risk factor for prostate cancer.

Blood pressure in minorities screened for the Multiple Risk Factor Intervention Trial (MRFIT)

THE AUTHORS PRESENT DATA FROM 361, 662 MEN ages 35 to 57, screened from 1973 to 1976 for possible participation in the Multiple Risk Factor Intervention Trial (MRFIT). Volunteers identified themselves as "white," "black," "Oriental," "Spanish American," "American Indian," or "other." They also noted if they were taking medication for diabetes. A trained technician measured blood pressure after participants had rested for 5 minutes, using the fifth Korotkoff sound to define diastolic pressure and averaging the second and third of three readings. Differences among the groups included the following: blacks had consistently higher systolic and diastolic blood pressure (SBP and DBP) than other groups; Orientals had slightly lower pressure than other nonblack groups; American Indians had somewhat higher pressure than other nonblack groups at ages 35 to 44 but lower at ages 45 to 54; Hispanics in Miami and Davis, California, had significantly higher SBP and DBP than whites in the same area; Orientals in California had significantly higher DBP (but not SBP) than whites in California.

Relationship between severity, necrosis, and apoptosis in five models of experimental acute pancreatitis

In an effort to elucidate factors that determine the severity of an attack of acute pancreatitis, we have quantitated the extent of necrosis and of apoptosis in five different models of experimental acute pancreatitis. Severe pancreatitis was induced by obstructing the opossum common bile-pancreatic duct, by administering to mice 12 hourly injections of a supramaximally stimulating dose of caerulein, and by feeding young female mice a choline-deficient, ethionine-supplemented diet. In each of these models of severe pancreatitis, marked necrosis but very little apoptosis was found. Mild pancreatitis was induced by obstructing the rat common bile-pancreatic duct and by infusing rats with a supramaximally stimulating dose of caerulein. In contrast to our findings in severe pancreatitis, mild pancreatitis was characterized by very little necrosis but a high degree of apoptosis. Our finding that the severity of acute pancreatitis is inversely related to the degree of apoptosis suggests that apoptosis may be a teleologically beneficial response to acinar cell injury in general and especially in acute pancreatitis.

Dopaminergic defect of enteric nervous system in Parkinson's disease patients with chronic constipation

Clinical studies suggest that gut disorders are common in Parkinson's disease, but the morphological basis is unknown. Depletion of dopamine-containing neurons in the central nervous system is a basic defect in Parkinson's disease. We compared colonic tissue from 11 patients with advanced Parkinson's disease, 17 with adenocarcinoma (normal tissue was studied), and five who underwent colectomy for severe constipation. Immunohistochemistry was used to stain myenteric and submucosal neurons for dopamine, tyrosine hydroxylase, and vasoactive intestinal polypeptide (VIP). Each class of neurons was quantified as a percentage of the total neuronal population stained for the marker protein gene product 9.5. Nine of the 11 Parkinson's disease patients had substantially fewer dopaminergic myenteric neurons than the other subjects (mean 0.4 [SE 0.2] vs 6.9 [2.3] in controls and 5.7 [2.0] in constipated subjects). There was very little difference between the groups in numbers of tyrosine-hydroxylase and VIP neurons. Two Parkinson's disease patients had similar distributions of all types of neurons, including dopaminergic myenteric neurons, to the controls. High-performance liquid chromatography showed lower levels of dopamine in the muscularis externa (but not mucosa) in four Parkinson's disease patients than in four controls (7.3 [5.1] vs 24.2 [4.6] nmol per g protein), but levels of dopamine metabolites were similar in the two groups. The identification of this defect of dopaminergic neurons in the enteric nervous system in Parkinson's disease may lead to better treatment of colorectal dysfunction in this disease.

A second generation transgenic mouse model expressing both hemoglobin S (HbS) and HbS-Antilles results in increased phenotypic severity

We report on a second generation of transgenic mice produced by crossing a transgenic mouse line expressing high levels of human alpha and beta S chains (alpha H beta S [beta MDD]) with a line expressing human alpha and beta S-Antilles (beta SAnt). We hypothesized that mice expressing both hemoglobins (Hbs) would have a more severe phenotype because the reduced oxygen affinity and solubility of the beta S-Antilles might enhance the rate and extent of polymer formation. We obtained mice that expressed both beta S and beta S-Antilles. The doubly transgenic mice that are heterozygous for deletion of mouse beta Major (beta MD) occurred with reduced frequency and those that are homozygous for deletion of mouse beta Major (beta MDD) occurred at a much reduced frequency and suffered early mortality. Human alpha was 58% of all alpha globin for all animals, whereas beta S and beta S-Antilles were 34% and 28% of all beta globins for beta MD mice and 42% and 36% for beta MDD mice. Hematocrit, Hb, and mean corpuscular Hb were normal for all transgenic mice, but reticulocyte levels were higher for the doubly transgenic mice versus alpha H beta S [beta MDD] mice older than 30 days (10.0% +/- 1.0% v 4.3% +/- 0.4%; P < .001, mean +/- SE, n = 20 and n = 10, respectively) and control mice (3.9% +/- 0.4%). Reticulocytosis was more severe in mice less than 30 days old ( > 20% for alpha H beta S beta S-Ant[beta MDD] mice). The median mean corpuscular hemoglobin concentration of doubly transgenic mice was higher than that of alpha H beta S[beta MDD] mice with a variable number of very dense cells. Delay times for polymerization of Hb in red blood cells from alpha H beta S beta S-Ant[beta MDD] mice were shorter than those of alpha H beta S[beta MDD] mice, and there were fewer cells with delay times greater than 100 seconds. Urine-concentrating ability in control mice under ambient conditions is 2,846 +/- 294 mOsm and was reduced 30% to 1,958 +/- 240 mOsm, P < 4 x 10(-8) in all mice expressing both transgenes. We conclude that doubly transgenic mice have a more severe phenotype than either of the two parental lines. These mice may be suitable for validating therapeutic intervention in sickle cell disease.

Biochemical and morphological changes that characterise recovery from necrotising biliary pancreatitis in the opossum

The events that characterise recovery from severe biliary pancreatitis have not been defined. This study used a reversible model of necrotising pancreatitis, induced by obstructing the opossum common bile pancreatic duct (CBPD), to evaluate this phenomenon. The CBPD of opossums was obstructed with a balloon tipped catheter for five days and then decompressed by removal of the catheter. Recovery was evaluated 0-90 days after relief of obstruction. Serum bilirubin and amylase values rapidly declined, reaching control values 7-14 days after removal of the obstructing catheter. Pancreatic protein and amylase values were transiently increased shortly after relief of obstruction but returned to control values 21 days after decompression. Pancreatic ornithine decarboxylase activity and incorporation of [3H]-thymidine into DNA were transiently increased 14 days after duct decompression suggesting that regeneration occurs at approximately that time. Foci of pancreatic necrosis involved roughly 40% of the gland at time of decompression but these foci gradually disappeared and the gland resembled that of control animals 60 days after decompression. Evidence of fibrosis or collagen deposition in the pancreas was not noted at any time. These studies show that recovery after necrotising biliary pancreatitis occurs comparatively rapidly and the restitution ad integrum occurs. Recovery from necrotising acute pancreatitis in this model is not associated with the development of chronic pancreatitis.

Nitrinergic and peptidergic innervations and their inter-relationships in human colon

The distribution and colocalization of nitrinergic and peptidergic nerves were examined in six human colons. The tissues were fixed, cryosectioned, and standard immunohistochemistry was performed for several known neuropeptides. The same sections were stained for NADPH-diaphorase to denote nitric oxide synthase. NADPH-diaphorase-positive myenteric neurons were counted and colocalization noted for each peptide, as well as for peptide terminations. Galanin was the only neuropeptide that colocalized to a significant extent (23.0 +/- 7.21%) with NADPH-diaphorase-positive myenteric neurons. Many neuropeptide-containing nerve fibers had extensive terminations onto NADPH-diaphorase-positive neurons. Vasoactive intestinal peptide was the only neuropeptide that colocalized with NADPH-diaphorase to any extent in nerve fibers within circular muscle (59.5 +/- 9.3%). Fiber distribution in the longitudinal muscles showed a similar, but less dense pattern. These observations provide morphological evidence for the presence of nitric oxide, a candidate nonadrenergic noncholinergic neurotransmitter in the human colon.

Nitrinergic and peptidergic innervation of the human oesophagus

The distribution, colocalisation, and interconnections of nitrinergic and peptidergic neurons and nerves in the human oesophagus were examined. Cryosections of surgically resected tissues from eight subjects were studied with indirect immunofluorescence for the presence of 11 neuropeptides and neuron specific enolase. After immunohistochemistry, nitric oxide synthase was shown on the same sections with the beta nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase histochemical reaction. The histochemical findings were verified immunohistochemically on other sections with an antiserum against nitric oxide synthase. Most myenteric neurons (55%) were nitrinergic. Most (96%) received terminations positive for vasoactive intestinal polypeptide (VIP), calcitonin gene related peptide (CGRP) (80%), and galanin (59%). The neuronal somata of 14% also contained VIP, while 10% had galanin. Of the NADPH-diaphorase containing fibers seen in the muscle layers, many had closely associated VIP and galanin, but only rarely CGRP and substance P. Thus, despite abundant representation of both peptidergic and nitrinergic systems in oesophageal smooth muscle, only VIP and galanin colocalised to any significant extent with the nitrinergic elements. These findings provide morphological support for the role of nitric oxide as the non-adrenergic non-cholinergic inhibitory mediator in the human oesophagus and for its possible interactive role with the peptidergic system.

Multifactorial interactions in the aetiopathogenesis of EPH-Gestosis--a hypothesis

The aetiopathogenesis of EPH-Gestosis or pre-eclampsia-eclampsia is still not clear. Although many hypotheses implicating environmental, nutritional, immunological, and genetic factors have been put forward, no hypothesis provides the scientific basis for the early spiral arterial degenerative changes, and incomplete physiological trophoblastic invasion of the spiral arteries, leading to a high utero-placental resistance with reduced blood flow remains unexplained. To get an insight into the basic pathogenesis of EPH-Gestosis, the following hypothesis has been proposed. The hypothesis considers an abnormal proliferation of the spiral vessels as the key factor in the pathogenesis of the high uteroplacental resistance and the endothelial dysfunctions in EPH-Gestosis. Further it is proposed that this proliferation is on account of the enhanced polymerization of the deficient DNA triggered by the high steroidal level and relatively low micronutrient level in EPH-Gestosis during the early formative stages of the placental circulation. Steroidal hormone helps in polymerization of the DNA, micronutrients exert a controlling influence through DNA synthesis on cell proliferation. A critical balance of hormone-micronutrients such as vitamin A, B12, folic acid, etc., therefore, seems necessary for normal cellular proliferation. It appears therefore that there probably exists an imbalance with a high estrogen and a relatively low micro-nutrient level in EPH-Gestosis, triggering off a process of abnormal spiral vessel proliferation. These abnormal vessels with a deranged endothelial function may prevent the second wave of normal trophoblastic invasion assumed to be important for the establishment of the low resistance uteroplacental circulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Innervation of an esophageal ectatic submucosal blood vessel in achalasia and a comparison with normals

Achalasia is a disease of the esophagus characterized by incomplete relaxation of the lower esophageal sphincter, resulting in obstruction. Aperistalsis and dilation of the esophageal body occurs later, contributing to the esophageal dysfunction. Gastrointestinal bleeding in achalasia is an infrequent complication usually caused by stasis ulcer, esophageal varices, carcinoma, or pneumatic dilation of the sphincter. We describe here a patient with longstanding achalasia who bled vigorously from a proximal esophageal site that can be identified as arterial bleeding by endoscopy. Subsequent esophageal resection allowed detailed histological and immunohistochemical examination, which revealed a vascular ectasia. This lesion was associated with an unusually rich network of nerve fibers containing calcitonin gene-related peptide. Neuropeptide Y- and substance P-containing fibers were found to be decreased in this lesion as compared with controls. On the other hand vasoactive intestinal peptide- and nitric oxide synthase-containing fibers appeared quantitatively similar to those of controls. Calcitonin gene-related peptide is known to be involved in angiogenesis and may have played a causative role in the development of this lesion. Vascular ectasia may represent a hitherto unreported complication of achalasia.

Emerging facets of diastolic heart failure

One hundred patients with congestive cardiac failure (52 males and 48 females) with age ranging from 16 to 56 yrs (mean age 42 +/- 6) were studied to determine the relative prevalence of systolic and diastolic failures, their clinical profiles and common aetiologies. Age matched 25 control subjects were also studied to established a normal range of echocardiographic values for LV diastolic function. Thirty eight patients (38%) were found to have pure diastolic heart failure and another 5 (5%) and 57 (57%) were detected to have mixed and systolic failures respectively. An attempt to correlate the clinical assessment of diastolic failure with echo doppler study showed the sensitivity and specificity of the clinical criteria for diagnosis of diastolic heart failure to be 100% and 91.94% respectively. Of the 38 cases of diastolic failure detected 39.5% had hypertension, 31.6% ischaemic heart disease and 13.16% hypertrophic cardiomyopathy.

Effect of homeopathic drugs plumbum and opium on experimentally induced lead toxicity in rats

Homeopathic drugs plumbum 1M and Opium 30 were partially effective in the recovery of delta ALAD activity of the lead (150 mg% lead acetate) intoxicated rats. Plumbum 1M did not exhibit protective effect when dietary lead at high concentrations (> 25 mg% lead acetate) were given concurrently as assessed by blood delta ALAD activity and hemoglobin concentration. However it was partially effective in the recovery of delta ALAD activity and relieving anemia caused by chronic exposure of low doses of lead (below 15 mg% lead acetate).

Predictors of mortality from idiopathic dilated cardiomyopathy in 356,222 men screened for the Multiple Risk Factor Intervention Trial

Possible predictors of mortality from idiopathic dilated cardiomyopathy were studied in 356,222 men who were screened as part of the Multiple Risk Factor Intervention Trial. The vital status of each member of this cohort was ascertained through 1986. Death certificates were obtained from state health departments and coded by a trained nosologist. Individuals with a history of myocardial infarction were excluded. A total of 206 deaths due to idiopathic dilated cardiomyopathy occurred in the cohort of 356,222 men after an average of 12 years of follow-up. The age-specific rates of mortality from idiopathic dilated cardiomyopathy increased from 0.10 per 10,000 person-years among men aged 35-39 years to 1.16 per 10,000 person-years among men aged 55-57 years. The proportional hazards model was used to obtain adjusted estimates of relative risks. Statistically significant, independent associations were observed with cigarettes smoked per day (p < 0.001), diastolic blood pressure (p < 0.001), and diabetes mellitus (relative risk (RR) = 2.97, p < 0.001). Black race was also associated with an increased risk of death from idiopathic dilated cardiomyopathy (RR = 1.59 and p = 0.045 without adjustment for income; RR = 1.58 and p = 0.058 with adjustment for income). No association was found with serum cholesterol or income. The information about possible risk factors obtained in this study may contribute to future preventive programs for idiopathic dilated cardiomyopathy.

Difficulties in the management of superior vena caval obstruction in young adults

Case records of 50 patients of superior vena caval obstruction in young adults treated and followed-up at Radiotherapy Department, Medical College Hospitals, Calcutta have been looked into. Twenty-eight out of these 50 patients had disease confined to mediastinum only during presentation. In consideration of the fact that the optimum management of superior vena caval obstruction depends upon a balance between just adequate pretreatment investigation and early institution of treatment, the various difficulties in the management discussed. With the existing infrastructural facilities, the institutional policy for the management of superior vena caval obstruction in young adults whose disease is confined to mediastinum only, during presentation, is described.

Epiphyseal stapling for leg equalization in developing countries

Epiphyseal stapling to arrest growth in the longer limb in growing children has been used in 923 cases over 26 years in the management of leg length inequality. Five hundred and three were assessed at the end of growth. Seventy-one percent had 0.5 cm to 1 cm of shortening and 80% did not need an orthosis. Although other methods are available, this technique is particularly valuable in developing countries because it needs only basic surgical facilities and the financial cost is low.

Peptidergic innervation of the human esophageal smooth muscle

Studies were performed to define the peptidergic nature of intramural nerves in the human esophagus. Cryosections of uninvolved surgically resected tissues from 14 individuals were studied by immunofluorescence for the localization of 10 neuropeptides. Myenteric neurons showed bombesin-, calcitonin gene-related peptide-, galanin-, substance P-, vasoactive intestinal polypeptide-, leucine-enkephalin-, methionine-enkephalin-, neuropeptide Y-, and somatostatin-like immunoreactivity. Submucous neurons had all the above except neuropeptide Y, methionine-enkephalin, leucine-enkephalin, and bombesin. Both groups of neurons received nerve terminations positive for calcitonin gene-related peptide, galanin, neuropeptide Y, substance P, and vasoactive intestinal polypeptide. Myenteric neurons additionally received terminations positive for neuropeptide Y, methionine-enkephalin, and somatostatin. All muscle layers had varicose fibers that reacted for calcitonin gene-related peptide, galanin, neuropeptide Y, and substance P. Longitudinal and circular muscle received few nerves reactive for leucine-enkephalin, whereas methionine-enkephalin was localized in a few nerve endings in the circular muscle. Somatostatin- and bombesin-reactive nerves occurred in longitudinal muscle. No cholecystokinin-reactive nerves were found. This study extends the results of previous studies and shows the previously undescribed presence of calcitonin gene-related peptide- and galanin-reactive nerves in the human esophagus and identifies neuropeptides that may serve as motor, sensory, and modulatory neurotransmitters of esophageal nerves.

Localization of calcitonin gene-related peptide in human esophageal Langerhans cells

Previously undescribed calcitonin gene-related peptide-immunoreactive intraepithelial cells were seen in specimens of esophageal mucosa obtained by biopsy or surgical resection from 14 individuals. These calcitonin gene-related peptide-immunoreactive cells were sparsely seen in normal mucosa but increased markedly in esophagitis. They were inaccessible to routine histological stains, but osmication showed them as dendritic forms resembling Langerhans cells of the skin. Their cytological identity was determined with immunocytochemical tests for human antigenic markers such as Ia, HLA-DR, and OKT6 for Langerhans cells, Leu-M5 and Leu-M3 for intraepithelial macrophages, CD3 and TCR-1 for T-lymphocytes, Leu-14 for B-lymphocytes, S-100 for Merkel cells, and chromogranin for amine precursor uptake and decarboxylation cells. Double localization showed that calcitonin gene-related peptide immunoreactivity colocalized with Ia, HLA-DR, and OKT6 but not with the other markers. These studies show that intraepithelial Langerhans cells in the esophageal mucosa contain calcitonin gene-related peptide, which may serve as an immunomodulator.