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Biomedical subjects

S Bank

Publications and source records attributed to S Bank.

At least 19 recordsLinked to original sources
PubMed1996

Solid-state 13C-NMR spectroscopy of adduction products of 2,5-hexanedione with ribonuclease, albumin, and rat neurofilament protein.

The Paal-Knorr condensation reaction between the gamma-diketone 2,5-hexanedione (2,5-HD) and epsilon-amine moieties of proteins of various molecular weight, including ribonuclease (RNase), bovine serum albumin (BSA) and rat neurofilament (NF), has been investigated by solid-state 13C-NMR spectroscopy. These proteins all reacted with 2,5-HD with the formation of 2,5-dimethylpyrrole (2,5-DMP) derivatives. The size and complexity of the protein affected the rate of formation of 2,5-DMP derivatives. Using the selective reducing reagent NaCNBH3, the Paal-Knorr reaction intermediates were trapped by conversion into amines, which were identified by solid-state NMR spectroscopy. The secondary autoxidation reaction following the formation of 2,5-DMP derivatives was also studied by solid-state NMR spectroscopy.

Animals↗
PubMed1996

Fulminant hepatic failure associated with oral administration of diazepam in 11 cats.

Acute fulminant hepatic necrosis was associated with repeated oral administration of diazepam (1.25 to 2 mg, PO, q 24 or 12 h), prescribed for behavioral modification or to facilitate urination. Five of 11 cats became lethargic, atactic, and anorectic within 96 hours of initial treatment. All cats became jaundiced during the first 11 days of illness. Serum biochemical analysis revealed profoundly high alanine transaminase and aspartate transaminase activities. Results of coagulation tests in 3 cats revealed marked abnormalities. Ten cats died or were euthanatized within 15 days of initial drug administration, and only 1 cat survived. Histologic evaluation of hepatic tissue specimens from each cat revealed florid centrilobular hepatic necrosis, profound biliary ductule proliferation and hyperplasia, and suppurative intraductal inflammation. Idiosyncratic hepatotoxicosis was suspected because of the rarity of this condition. Prior sensitization to diazepam was possible in only 1 cat, and consistent risk factors that could explain susceptibility to drug toxicosis were not identified. On the basis of the presumption that diazepam was hepatotoxic in these cats, an increase in serum transaminase activity within 5 days of treatment initiation indicates a need to suspend drug administration and to provide supportive care.

Animals↗
PubMed1996

Solid 13C CPMAS NMR spectroscopy studies of biosynthesis in whole cells of Methanosphaera stadtmanae.

Whole cells of Methanosphaera stadtmanae were grown in media containing [13C]CO2, [2-13C]acetate, [1-13C]acetate, [3-13C]serine and [1-13C]formate. The label incorporation was determined using solid state 13C CPMAS NMR spectroscopy. The incorporation of serine hydroxymethyl carbon into the purine rings of nucleic acids and most probably the methyl group of thymine is demonstrated. The one carbon atom pathway shown in our previous work is operative in the biosynthesis of purines and pyrimidines. In addition, these studies clearly identified signals not observed in solution NMR spectroscopy and revealed an important pathway not previously known. The reversibility of formyl-containing one carbon atom carriers is demonstrated. The pattern of labeled carbon atoms in sugars confirms the biosynthetic route from pyruvate, which is formed from acetic acid and carbon dioxide. Finally, a preliminary lipid assignment is indicated. The solid state 13C CPMAS NMR of these intact cells proved to be a facile method to follow specific pathways.

Acetic Acid↗
PubMed1996

Infected pancreatic necrosis and peripancreatic fluid collections: serendipitous response to antibiotics and medical therapy in three patients.

Three patients with clinical and radiologic evidence of pancreatic necrosis or peripancreatic fluid collections/inflammatory masses who were advised to have surgery on the basis of bacterial infection on skinny-needle aspiration of the pancreas but were deemed medically unstable or refused operative intervention were treated with intensive antibiotic therapy. All three patients survived the attack of acute pancreatitis with infection on medical therapy alone. This suggests that occasional patients with infected necrosis and/or peripancreatic collections/inflammatory masses may respond to antibiotics, especially those antibiotics that have recently been shown to have a high penetration into pancreatic tissue.

Acute Disease↗
PubMed1995

Can the radiologist recognize Helicobacter pylori gastritis?

To evaluate radiologic findings of Helicobacter pylori (H. pylori) in the upper gastrointestinal (UGI) tract, we retrospectively reviewed consecutive records of 676 symptomatic adults with gastric biopsies (224 positive) and 150 symptomatic adults with rapid urease tests (57 positive). All the UGI series of patients with positive biopsies or urease tests for H. pylori were compared with the UGI series of patients with negative urease tests. UGI examinations were evaluated blindly by two gastrointestinal radiologists without knowledge of clinical findings, original radiologic interpretations, or test results. They agreed that 8 of 18 (44%) UGIs of patients with H. pylori had abnormally increased gastric folds in the fundus, body, or antrum as compared with none of 14 (0%) UGIs of patients without H. pylori (p < 0.01) (P.P.V. = 1.0). Interobserver agreement was good (kappa = 0.63). Endoscopy in the eight patients with radiographic evidence of enlarged gastric folds all demonstrated marked abnormalities such as prominent gastric folds, gastric erythema, erosions, or peptic ulcers. Our findings indicate that enlarged gastric folds on the UGI series of a symptomatic adult are very suggestive of H. pylori gastritis.

Adult↗
PubMed1995

Fluctuations in serum amylase in patients with macroamylasemia.

OBJECTIVE: To report wide fluctuation of serum amylase in patients with macroamylasemia. It has generally been considered to remain constant. METHODS: Over the past 16 y, 18 patients have been diagnosed with macroamylasemia in our GI department. Of these, four patients were followed up with serial serum amylase determinations for a period of less than 1-4 y. Serum amylase was measured by the "Phadebas amylase test." Serum macroamylase was measured by "PEG precipitation technique." RESULTS: There was a wide fluctuation of serum amylase in three out of four patients. In the fourth patient, more persistent hyperamylasemia was noted during the shorter observation period. CONCLUSION: Marked fluctuation in serum amylase, ranging from 115 to 1160% in this study, may occur in patients with macroamylasemia. The reasons for these fluctuations are not clear but may be due to association-dissociation of amylase with serum proteins at variable time intervals. This fluctuation, especially when the amylase becomes normal (as in cases 1 and 3), may lead to confusion in differentiating macroamylasemia from other causes of hyperamylasemia.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Helicobacter pylori infection does not increase gastric antrum mucosal cell proliferation.

OBJECTIVES: Gastric carcinoma is the world's second most common cancer. Recent studies suggest an association between Helicobacter pylori and gastric carcinoma. The aim of this study was to address the effects of H. pylori infection on gastric antrum mucosal cell proliferation. METHODS: Forty patients undergoing upper endoscopy for standard indications were included in the study. A rapid urease test was used to determine the presence of H. pylori. Epithelial cell proliferation was determined by immunohistochemical techniques utilizing monoclonal antibody to bromodeoxyuridine. RESULTS: There were no significant differences in the number of labeled cells and in the proliferation fraction (p > 0.1) when patients with H. pylori were compared with those without, and when those over the age of 50 were compared to those under 50. The presence of ulcers similarly had no effect (p > 0.1). CONCLUSION: Helicobacter pylori infection does not increase gastric antrum mucosal cell proliferation.

Age Factors↗
PubMed1994

Diagnostic tests in chronic pancreatitis.

We review the values of various tests in the diagnosis of suspected chronic pancreatitis, and we give a practical approach to diagnosis. Most cases can be diagnosed by a consideration of history, simple radiology, and serum enzymes. Problems arise in patients with noncalcific early chronic pancreatitis, in whom pain alone is the main feature. In these patients, a sequence of tests may be required to arrive at a diagnosis of probable or possible pancreatitis to one that is proven. In some cases, only time will tell.

Cholangiopancreatography, Endoscopic Retrograde↗
PubMed1993

Analysis of alkylpyrrole autoxidation products by high-performance liquid chromatography with thermospray mass spectrometry and UV photodiode-array detection.

A method employing high-performance liquid chromatography with thermospray mass spectrometry (TSP-MS) and photodiode-array detection was developed and applied to the analysis of autoxidation products of 2,5-dimethyl-N-alkylpyrroles in aqueous solution under air or 18O2. Numerous oxidation products were separated, characterized and categorized, primarily as (1) non-polar oligomers without incorporated oxygen, and (2) polar, oxygen-containing monomers. Kinetic studies showed that oligomerization was the dominant autoxidation pathway, with production of unstable dimers and trimers and, ultimately, a high-molecular-mass sediment. TSP-MS together with UV and proton nuclear magnetic resonance spectral data revealed that both the dimer and trimer contained a novel methylene bridge. These results suggest that this method is suitable for the analysis of alkylpyrrole autoxidation products that may be relevant to hexane neuropathy and products that are responsible for the instability of fuels in storage.

Chromatography, High Pressure Liquid↗
PubMed1993

[Physical and mental development of children with congenital hypothyroidism].

69 children with congenital hypothyroidism, who were detected by neonatal screening in Lower Saxony, were reevaluated 1-12 years after diagnosis. They had been treated either by regional children's hospitals, local pediatricians or general practitioners. Substitution of thyroid hormone had started for the majority between day 7 and 14, for 17%, however, only later. Symptoms suggestive of hypothyroidism at birth were observed in 35 children, but only 3 cases were correctly diagnosed before the result of the screening was known. Further diagnostic tests to elucidate the cause of congenital hypothyroidism had been performed in 33 children. In 36 cases the etiology remained undiagnosed at the evaluation. Hormone therapy had been administered continuously in all cases. The somatic development of all children was normal. Bone age at the time of diagnosis was retarded in more than 50%, later it became normal in most cases. The psychomotor and intellectual development was satisfactory as assessed by psychometric tests. The mean value of the Intelligence Quotients in the children older than six years was 96.3. 5 children of this age group had an IQ below 85 and only one child had an IQ of more than 115. In the younger group the results were similar, but children younger than 4 years showed deficiencies in speech development. In summary, the somatic development of the re-examined children with congenital hypothyroidism was normal, but the psychomotor and intellectual development was only subnormal in some cases. It is therefore suggested that children with congenital hypothyroidism should be closely followed by experienced pediatricians, especially in the early years of life.

Age Determination by Skeleton↗
PubMed1992

C3a receptor on dibutyryl-cAMP-differentiated U937 cells and human neutrophils: the human C3a receptor characterized by functional responses and 125I-C3a binding.

The anaphylatoxic peptide C3a is part of a basic immunological defense mechanism, the complement system. Research on the human C3a receptor and signal transduction is hampered by the lack of a suitable human cell or cell line. We screened tumor cell lines and human blood cells for a C3a-dependent increase in cytosolic Ca2+ ([Ca2+]i) and analyzed this reaction in a fura-2/AM fluorescence assay for cells in suspension. U937 cells, when differentiated with dibutyryl-cAMP (Bt2cAMP), and purified human neutrophils reacted in a dose-dependent fashion to C3a and a C3a analogue synthetic peptide. We found complete homologous desensitization of this response and no heterologous desensitization to human C5a. Pertussis toxin totally blocked the increase in [Ca2+]i, indicating the possible involvement of a G-protein. Single-cell analysis by digital imaging fluorescence microscopy indicated that neutrophilic granulocytes responded to C3a. In binding studies with Bt2cAMP-differentiated U937 cells and human granulocytes, the 125I-C3a binding was displaced by C3a, yielding one class of C3a binding sites with dissociation constants (Kd) in the low nanomolar range. We identified myo-inositol 1,4,5-trisphosphate (IP3) as the second messenger possibly causing the [Ca2+]i increase and the release of N-acetyl-beta-D-glucosaminidase as one secretory cell response. By functional and binding studies we demonstrated the expression of the C3a receptor on Bt2-cAMP-differentiated U937 cells and human neutrophils and characterized parts of the C3a signal pathway. Our data support a physiological concept in which C3a might be more important than presently thought.

Acetylglucosaminidase↗
PubMed1992

P amylase is always greater than S in spot urine of normal subjects. Diagnostic implications.

Single random samples of urine were collected from 50 control subjects; 27 patients with chronic pancreatitis; 19 with acute pancreatitis; 6 with acute on chronic pancreatitis; five in the recovery phase of acute attack; four patients with pseudocysts. Salivary (S) and pancreatic (P) amylase values were measured by cellulose acetate electrophoresis. The P amylase values always exceeded those of S amylase in the control specimens. In acute pancreatitis, both the lower and upper levels of total and P amylase were considerably higher than in the controls, and these high values tended to return to normal during the recovery phase of acute pancreatitis. The S amylase values were often very low or undetectable during the acute phase. Values for P amylase exceeded control values in patients with pseudocysts even in the presence of chronic pancreatitis. In chronic calcific pancreatitis, S amylase was higher than P amylase. We conclude that P amylase is always greater than S amylase in normal urine specimens, and a change in this pattern may be helpful in diagnosing various forms of pancreatitis.

Amylases↗