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Biomedical subjects

J R Bernstein

Publications and source records attributed to J R Bernstein.

At least 19 recordsLinked to original sources
PubMed1998

Characterization of olanzapine (LY170053) in human liver slices by liquid chromatography/tandem mass spectrometry.

Olanzapine metabolism was investigated using incubation of olanzapine with human liver slices. The intent of the investigation was to identify olanzapine metabolites and determine if the human liver slice incubations could potentially produce quantities of the olanzapine glucuronides for future studies. Along with known Phase 1 olanzapine metabolites, N-desmethyl-, 2-hydroxymethyl-, and 4'-N-oxide-, a new hydroxylated species was detected. Detection of Phase 2 metabolites included known N-10-glucuronides, a quaternary glucuronide and a novel glucuronide conjugate. This investigation showed the feasibility of using human liver slices to produce sufficient quantities of olanzapine glucuronides for further studies.

Antipsychotic Agents↗
PubMed1995

Transcalvarial primary lymphoma of bone. A report of two cases.

Primary lymphoma of bone is uncommon, and initial involvement of the calvarium is rare. We describe two cases originating as enlarging skull masses subsequently shown to involve the bony calvarium, extracranial soft tissues, and intracranial structures. Open biopsy revealed non-Hodgkin's lymphoma, large cell type, in both cases. A review of the pertinent literature follows.

Aged↗
PubMed1994

Disposition of 14C-dapoxetine in rats: complementary experiments with whole-body autoradiographic and tissue dissection techniques.

Tissue distribution studies, utilizing whole-body autoradiography and organ dissection techniques, were conducted in male Fischer 344 rats following the oral administration of 14C-dapoxetine HCl, a potent serotonin reuptake inhibitor. The preliminary study using whole-body autoradiography proved invaluable in locating radioactivity in an organ not usually harvested in a tissue distribution study, namely the preputial gland. Selected organs, based on whole-body autoradiography findings, were dissected from rats and analyzed for radiocarbon content by liquid scintillation counting and for parent drug and N-dealkylated metabolites by extraction and HPLC analysis. Highest concentrations of radiocarbon were observed in the organs of absorption and elimination (ileum, cecum, stomach, duodenum, liver, colon, and kidney) but notable quantities were observed in the lung and preputial and Harderian glands. Most tissues had returned to background radioactive levels 72 h after dosing but persistent concentrations of radiocarbon were present in the preputial gland and liver one week after the single dose of 14C-dapoxetine. Analysis by HPLC demonstrated the presence of parent drug and N-desmethyl metabolite (nor-dapoxetine) in those organs examined; however, the majority of the radioactivity remained unidentified.

Animals↗
PubMed1992

Disappearing breast calcifications: mammographic-pathologic discrepancy due to calcium oxalate.

We have reported a case in which breast biopsy was done to study suggestive microcalcifications that were confirmed by specimen radiography but were not evident with standard light microscopy. Examination of the specimen under polarized light revealed calcium oxalate crystals. Awareness of this potential pitfall should minimize the number of radiologic-pathologic discrepancies.

Adult↗
PubMed1991

Iatrogenic biliary tract complications: radiologic features and clinical significance.

Thirteen intrahepatic and 22 extrahepatic biliary tract complications were detected radiologically in 35 adult patients who had undergone cholecystectomy and bile duct exploration. Intraoperative usage of Fogarty balloon catheters to extract biliary calculi without fluoroscopic guidance resulted in focal ectasia or rupture of intrahepatic radicles in two and seven cases, respectively. Metallic surgical instruments such as Bakes dilators and biliary forceps or clamps accounted for most of the common duct injuries; these were manifested as submucosal dissection (two cases), transmural laceration (four cases), or localized trauma with subsequent stricture (three cases). Technical mishaps during T-tube placement led to common duct perforation (four cases) and extraluminal malposition of T tubes (three cases). The remaining complications included choledochoduodenal fistula (three cases), biliovenous fistula (two cases), biloma (three cases), and retained intraductal fragments of biliary drainage catheters (two cases). Knowledge about radiologic features and causal factors of such iatrogenic processes can play a crucial role in their prevention, correct diagnosis, and management.

Adolescent↗
PubMed1990

An alternative approach to nonpalpable breast biopsies.

Traditionally, when a negative specimen radiograph is obtained during biopsy of a nonpalpable breast lesion, immediate re-excision is performed in an attempt to successfully remove the lesion. Based on a retrospective study of the biopsy results of 792 nonpalpable breast lesions, the authors suggest delaying the re-excision, despite a negative specimen x-ray, until postoperative mammography confirms the persistence of the lesion. Utilization of this approach was associated with a comparably low incidence of missed lesions (3%) and had the added advantages of preserving breast tissue and decreasing operative time.

Biopsy↗
PubMed1990

Percutaneous-endoscopic biliary stenting in patients with occluded surgical bypass.

PURPOSE: The purpose of this investigation was to test the feasibility of using a recently developed technique of placing internalized biliary stents into patients who have had reobstruction after initial surgical bypass. PATIENTS AND METHODS: Seven men and three women, 46 to 85 years of age (eight with pancreatic carcinoma, one with metastatic colon, and one with metastatic ovarian carcinoma), all had reobstruction after initial surgical bypass palliation. Subsequent attempts to place stents via endoscope failed in five patients; a pair of 7-Fr stents placed in one patient failed to drain well. Endoscopic stenting in four patients was not even attempted because of severely distorted anatomy. Nine of the 10 patients then had successful internal stent placement by a combined percutaneous-transhepatic and peroral-endoscopically guided technique. RESULTS: One of these nine placeable stents failed to drain well and the patient died 8 days later with massive tumor. Seven showed a significant decrease in bilirubin levels and improved quality of life. Two of these had sepsis that responded to antibiotics. Life span ranged between 11 days and 10 months, with one patient still alive; no deaths were directly due to stents. CONCLUSION: A combined transhepatic-peroral technique of placing internalized biliary stents can be expected to result in repalliation in a majority of patients with reobstruction after earlier surgical bypass and in whom subsequent attempts at endoscopic placement of stents have failed or in whom tumor growth prevents undertaking the endoscopic approach.

Aged↗
PubMed1990

An improved method of purifying inhibin radioligand for radioimmunoassay.

Polyacrylamide gel electrophoresis (PAGE) separation of bovine inhibin from free iodine after iodination is described. Previous methods of separation typically relied upon a G25 gel filtration and Matrix gel Red A affinity column chromatography protocol. When compared to column chromatography, PAGE-purified radiolabelled inhibin resulted in significantly increased binding (13.1% vs. 7.5%) and enhanced sensitivity (ED50 = 92 microliters inhibin standard vs. ED50 = 198 microliters inhibin standard) to the inhibin antibody #1989. Our results demonstrate an advantageous approach to purifying 31,000 Mr bovine inhibin radioligand after iodination for RIA.

Chromatography, Ion Exchange↗
PubMed1989

Needle localization of nonpalpable breast lesions with a portable dual-grid compression system. Work in progress.

A new device and a geometric algorithm facilitate consistent insertion of a needle tip into nonpalpable breast lesions on a single attempt. With the breast compressed by dual grid plates, two oblique exposures are taken. Three intersecting planes through the lesion referenced to the grid markings permit easy determination of the lesion coordinates. In initial trials for preoperative breast lesion localization in 11 patients, the needle tip was within the lesion in nine patients and was within 0.5 cm of the lesion in two patients. The results indicate that this system is very useful for accurate localization and needle aspiration of breast lesions.

Adult↗
PubMed1988

The metabolism and disposition of 14C-indolidan, a potent and orally active cardiotonic agent, in four species of laboratory animals.

1. The metabolism and disposition of 14C-indolidan, a potent, orally-active positive inotrope with vasodilator properties, has been studied after single dose oral administration to rats, mice, dogs and monkeys. 2. Excretion of 14C in all 4 species was mostly via the urine, largely as parent drug together with two other major metabolites. 3. The two metabolites have been isolated and identified, by mass spectroscopy and 1H-n.m.r., as a dehydro-compound, with a double bond in the pyridazanone ring, and a hydroxylated derivative of the parent drug. 4. Plasma t 1/2 values, based on 14C, were 14 h in dog, 5 h in mouse and 8 h in monkey. Plasma t 1/2 of parent drug, by h.p.l.c. was 10 h in dog, approx. 5 h in rodents, and 8 h in monkeys. 5. Tissue distribution in rats showed no accumulation in any tissue; 14C concn. in all tissues were indistinguishable from background 48 h after dosage. 14C peaked at 6-8 h for most tissues but in blood and plasma, 14C was maximal 1 h after dosing.

Administration, Oral↗
PubMed1988

Limitations of mammography in the identification of noninfiltrating carcinoma of the breast.

A retrospective study of 321 patients who underwent localizing mammography and excisional biopsy of the breast from 1984 to 1985 was performed. The study was undertaken to refine selection criteria for biopsy in women with nonpalpable mammographic abnormalities by comparing mammographic features and impression with histologic findings. Twenty-eight of 36 (78 per cent) noninfiltrating carcinomas presented with microcalcifications alone; in contrast, 27 of 39 (69 per cent) infiltrating carcinomas presented with a mass alone. As the number of microcalcifications increased, so did the incidence of carcinoma. The size of the mass was not a guide for predicting carcinoma. Although only 11 of 75 carcinomas presented as a mass with microcalcifications, 11 of 21 calcified masses were carcinoma. There were no significant differences in the mammographic presentation between ductal and lobular carcinoma. The sensitivity of the mammographic impression was 48/75 (0.64), and the specificity was 221/246 (0.898). The false-positive rate was 25/73 (0.34), and the false-negative rate was 10/141 (0.07). From this study, we concluded 1, the incidence of noninfiltrating carcinoma was significantly higher and the incidence of positive nodes was significantly lower in nonpalpable abnormalities than in palpable masses; 2, noninfiltrating carcinomas were generally associated with microcalcifications alone, but infiltrating carcinomas were generally associated with a mass alone, and 3, the diagnostic accuracy of mammography was limited by under-interpretation of the subtler signs of noninfiltrating carcinoma and by over-interpretation of mammographic findings generally accepted as criteria for carcinoma.

Biopsy↗
PubMed1987

Percutaneous-endoscopic biliary stent placement. A preliminary report.

The placement of large-bore endoprostheses for relief of biliary obstruction by the percutaneous-transhepatic route is painful, requires a large hepatic parenchymal tract, and has a fairly high complication rate. The alternative technique of endoscopically placing similar-sized stents requires special instruments and skills, and may fail in passing very tight stenoses. We report a simpler combined percutaneous-endoscopic biliary stent (PEBS) placement technique with a high placement rate used in 11 patients with advanced malignant obstruction. In all 11 patients, 10 and 11.5 French stents were easily placed. Three patients developed sepsis but responded to antibiotics. One clogged stent required replacement. Two stents needed later endoscopic adjustment. Results of liver function test improved in 10 patients, and 8 patients showed improved quality of life.

Aged↗
PubMed1986

The induction profile of three orally active imidazopyridine-containing cardiotonic agents in rat hepatic microsomes.

The induction of hepatic cytochrome P-450-linked monooxygenases has been studied after the twice daily, oral administration of two imidazo[4,5-c]pyridine-containing compounds and one imidazo[4,5-b]pyridine-containing drug. The compounds were administered by the oral route, at different doses, for 6 days after which time hepatic microsomes were prepared. In vitro biochemical assays revealed that all three compounds increased the O-deethylation of 7-ethoxyresorufin in a dose-dependent manner while not significantly affecting either the O-dealkylation of 7-ethoxycoumarin or the levels of NADPH-cytochrome c reductase. Ethylmorphine N-demethylation was decreased after dosing with the imidazo[4,5-b]pyridine-containing drug. Levels of cytochrome(s) P-450 and liver-to-body weight ratios were not significantly altered. The imidazo[4,5-b]pyridine-containing compound was more potent in terms of the induction of 7-ethoxyresorufin than either of the imidazo[4,5-c]pyridine-containing compounds but was approximately fourfold less active in this regard than 3-methylcholanthrene. No induction of cytochrome-P-450-linked monooxygenase activities was evident at a twice daily dose of 5 mg/kg for 6 days for all three compounds tested, constituting a no-effect level. The imidazo[4,5-c]pyridine-containing compounds exhibited modified Type II difference spectra when added to a suspension of rat hepatic microsomes. The imidazo[4,5-b]pyridine-containing compound has previously been reported to be a rapid and potent inducer of monooxygenase activity and have a Type II difference spectrum.

7-Alkoxycoumarin O-Dealkylase↗
PubMed1985

Mammography in women less than 40 years of age.

Carcinoma of the breast in women less than 40 years old is a significant problem, representing 7.4 per cent of the total number of carcinomas of the breast at our institution. It is apparent that mammography in this age group is of value in confirming the clinical suspicion of a malignant condition of the breast and in evaluating the remainder of the parenchyma of the breast for clinically occult lesions. However, one cannot over emphasize that a negative result from the mammogram should not delay biopsy in the presence of clinically suspicious lesions (1, 4). It is obvious that a larger series of patients is necessary to define the role of mammography in "young women."

Adult↗
PubMed1984

Necrotizing sarcoid-like granulomatosis: radiologic-pathologic correlation.

Necrotizing sarcoid-like granulomatosis is one of five forms of pulmonary disease characterized histologically by angiitis and granulomata formation. Although there have been several reports of the clinical and pathological characteristics of the disease, there has been little reported radiographic correlation. We present two patients with necrotizing sarcoid-like granulomatosis with radiographic and pathologic correlation. The radiographic finding of diffuse lesions, either bilateral nodules or nodular densities with or without cavitation, should prompt definitive diagnostic evaluation. Tissue diagnosis is imperative as necrotizing sarcoid-like granulomatosis has a relatively good prognosis when compared with other similar granulomatous diseases.

Adolescent↗