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Biomedical subjects

J Lang

Publications and source records attributed to J Lang.

At least 235 records · Page 13Linked to original sources

[Preparation and characterization of liposomal adriamycin].

We established a more suitable methodology for preparing liposomal adriamycin (Lipo-ADM) by a remote loading technique. This procedure is convenient, simple with an entrapment efficiency of 95%. The mean diameter of liposome is about 100nm showing unilamellar spherical shape. The leakage ratio is about 10% within 24hr. Those characteristics fit for clinical demand.

Doxorubicin↗

[Overexpression of C-erbB3 in transitional cell carcinoma of the ovary].

OBJECTIVE: To determine the prevalence of C-erbB3 abnormal protein expression in transitional cell carcinoma of the ovary in our hospital and to analyse the correlation between the overexpression of C-erbB3 protein and prognostic parameters of transitional cell carcinoma of the ovary. METHODS: Thirty-two transitional cell carcinoma of the ovary and 20 normal ovaries were studied for overexpression of C-erbB3 protein by immunohistochemical staining (IHS), using the monoclonal antibody RJT2 on paraffin sections. RESULTS: Forty seven percent of 32 samples of transitional cell carcinoma of the ovary showed positive IHS with RJT2, and 39% of 20 normal ovaries showed positive cytoplasmic and membrane staining (P > 0.05). C-erbB3 overexpression did not correlate with age, CA125 levels, histological grade and lymph node metastases, but patients with overexpression of C-erbB3 had a poorer prognosis. CONCLUSION: Overexpression of C-erbB3 is a common event in transitional cell carcinoma of ovary. Further studies are warranted to clarify the role of C-erbB3 in transitional cell carcinoma of the ovary.

Carcinoma, Transitional Cell↗

Activity-dependent mobilization of the adhesion molecule polysialic NCAM to the cell surface of neurons and endocrine cells.

The alpha-2,8-linked sialic acid polymer (PSA) on the neural cell adhesion molecule (NCAM) is an important regulator of cell surface interactions. We have examined the translocation of PSA-NCAM to the surface of cultured cortical neurons and insulin secreting beta cells under different conditions of cell activity. Endoneuraminidase N, an enzyme that specifically cleaves PSA chains, was used to remove pre-existing PSA from the plasma membrane and the re-expression of the molecule was monitored by immunocytochemistry. Punctate PSA immunostaining was restored on the surface of 68% of neurons within 1 h. This recovery was almost completely prevented by tetrodotoxin, suggesting that spontaneous electrical activity is required. K+ depolarization (50 mM) allowed recovery of PSA surface staining in the presence of tetrodotoxin and this effect required the presence of extracellular Ca2+. Rapid redistribution of PSA-NCAM to the surface of beta cells was observed under conditions that stimulate insulin secretion. Ca2+ channel inhibition decreased both PSA-NCAM expression and insulin secretion to control, non-stimulated levels. Finally, subcellular fractionation of an insulin-secreting cell line showed that the secretory vesicle fraction is highly enriched in PSA-NCAM. These results suggest that PSA-NCAM can be translocated to the cell surface via regulated exocytosis. Taken together, our results provide unprecedented evidence linking cell activity and PSA-NCAM expression, and suggest a mechanism for rapid modulation of cell surface interactions.

Animals↗

Regulation of cytosolic calcium and insulin secretion by galanin and ATP receptors: interactions of pertussis-toxin-sensitive and -insensitive signalling pathways.

In a previous study it was found that the expression of the exogenous fMet-Leu-Phe-receptor (NFPR) in the insulin-secreting cell line RINm5F mediates inhibition of hormone release and additionally raises cytosolic calcium concentration ([Ca2+]i) by activating phospholipase C (PLC) in a pertussis-toxin (PTX)-sensitive manner. We investigated whether an endogenous receptor could elicit similar effects and examined the interaction with PTX-insensitive signalling pathways. The hormone galanin inhibited insulin release at subnanomolar concentrations and increased [Ca2+]i, mainly by a PTX-sensitive mechanism with an EC50 (50 nM) comparable with that for hyperpolarization of membrane potential. The effect of galanin or fMet-Leu-Phe on [Ca2+]i was inhibited by pre-activation of the P2-receptor by ATP, which mobilizes calcium in a PTX-insensitive fashion. Simultaneous activation of the P2- and peptide receptors caused additive increases in [Ca2+]i saturating at a calcium concentration corresponding to the optimal ATP response. This suggests a specific convergence of PTX-sensitive and -insensitive pathways. In contrast, galanin and FMLP inhibited the insulin secretion induced by ATP (1-100 microM), but only when added prior to the nucleotide. In permeabilized cells, FMLP added after the calcium stimulus still inhibited secretion, indicating that the inefficacy observed in intact cells was not due to the rapid ATP-evoked rise in [Ca2+]i. Thus, (i) insulin-secreting cells possess an endogenous PTX-sensitive pathway mobilizing [Ca2+]i, (ii) inhibitory hormones preferentially activate different effectors depending on the agonist concentration and (iii) activation of NFPR or galanin receptor reveals an unusual dissociation between [Ca2+]i rises and insulin secretion, pointing towards an overriding inhibitory control of exocytosis.

Animals↗

Hypophyseal ligaments.

Described are for the first time: a. Posterolateral hypophyseal ligament which is seen in most dissections b. Anterolateral ligament which is always developed c. A middle superior ligament d. Inferior anterior and e. inferior posterior hypophyseal ligament.

Humans↗

Evoked potential monitoring during repeatedly induced ventricular fibrillation for internal defibrillator implantation.

Repeated induction of ventricular fibrillation (VF) with circulatory compromise during implantable cardioverter defibrillator (ICD) testing may cause cerebral injury. To test this hypothesis, somatosensory evoked potentials (SEP), a more sensitive marker of injury, were recorded in patients (N = 10) undergoing ICD implantation. SEP were recorded before induction of anesthesia, after induction of anesthesia, before and at several times following induction of VF. Possible modifying factors of the SEP measurements such as anesthetic application, blood pressure, body temperature, and hematocrit remained constant throughout the operations. Central conduction time was unaffected by ICD defibrillation testing. Amplitude of SEP primary complexes was transiently reduced at 34.9% (P < 0.01) by defibrillation testing, but returned to control within 10 minutes after testing. It is concluded that while ICD defibrillation testing may produce transient changes in SEP, there is no evidence of residual cerebral injury.

Adult↗

[Sensory and current political weaknesses of prismatic correction with the Polatest].

BACKGROUND: The adherence of the Polatest try to enforce prismatic correction in cases of heterophoria, asthenopia, dyslexia and other kinds of disorders. They claim that some sensorial anomalies exist which can be diagnosed only by the Polatest and for which special terminology is used. The Polatest-Doctrine in microtropias, subnormal binocular vision and obligate fixation disparity leads to excessive amount of prisms and unnecessary eye muscle surgery. METHOD AND CONCLUSION: The reason for this is the erroneous interpretation of the Stereo-test with the two triangles, where it is not possible to distinguish between binocular vision or monocular suppression of the binocular visible dot. As some opticians prescribe prisms on their own, sometimes for patients who are treated by ophthalmologists, this method leads to arguments between ophthalmologists and those opticians.

Child↗

Synthesis and characterization of anti-idiotypic anti-T4 antibodies.

We injected rabbits with purified monoclonal murine immunoglobulin (IgG1) or polyclonal antithyroxine antibodies (anti-T4) and polyclonal anti-triiodothyroacetic acid (anti-Triac) antibodies to stimulate the production of anti-idiotypic antibodies. Purified immunoglobulins from all five rabbits immunized with monoclonal primary antibodies were able to inhibit the interaction between [125I]T4 and the primary antibody. The preimmune sera were inactive. This effect was not due to endogenous T4 contamination or contamination with the injected primary antibody. Half-maximal inhibition of binding of primary antibody with anti-idiotype was between 1.6 and 30 micrograms of total immunoglobulins. Addition of normal mouse IgG1 did not alter the inhibitory effect of the anti-idiotypic antibody, suggesting that this effect is specific. These anti-idiotypic antibodies reacted differently with different polyclonal antibodies, reflecting the heterogeneous nature of polyclonal antibody populations. Polyclonal antibodies were less effective in stimulating anti-idiotypic antibody production. One polyclonal anti-T4 and one anti-Triac antibody produced weak anti-idiotypic antibody that had to be used at a concentration of > 600 micrograms of total immunoglobulins to be inhibitory. Both inhibited the binding of T4 to the monoclonal anti-T4 antibody. However, they were ineffective in inhibiting the function of their own antigen, the polyclonal anti-T4 or anti-Triac antibody. We tested the most potent anti-idiotypic antibodies for their ability to compete with T4 for other T4-binding proteins. Specific inhibition of T4 binding to thyroid-binding globulin was observed with half-maximal effect at approximately 450 micrograms of total IgG.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

[The former place of execution of the Lucerne herd in Emmen (1562-1798)(1562-1798) and slaughter yard belonging to it (1562-1866): pathologico-anatomic findings in excavated animal bones].

During archaeological excavations of the former knackers yard in Emmen (Canton Lucerne) skeletons and individual bones of more than 700 animals were recovered. 110 bone samples had lesions and were examined macroscopically and radiologically, 100 were from horses, 9 from dogs and only one from cattle. According to morphological and etiopathogenetical criteria, lesions are presented in the following groups: tooth irregularities (10), degenerative changes in bones and joints due to overload and aging (80), trauma and infection (10), other lesions (10). Over 80% of pathological bone samples presented degenerative changes: spondylosis and spondylarthrosis, arthropathies (mainly spavin and ringbone in horses) and ossifying periostitis due to mechanical stress (Periostitis of phalanx I and periostitis of the dorsal cortex of the third metacarpal bone).

Abattoirs↗

Severe hypertriglyceridemia and pancreatitis when estrogen replacement therapy is given to hypertriglyceridemic women.

Our specific aim was to assess severe hypertriglyceridemia and pancreatitis that occurred when postmenopausal estrogen replacement therapy (ERT) or tamoxifen had been given by their physicians to women with preexisting, usually covert, primary familial hypertriglyceridemia. We retrospectively studied 31 women referred for diagnosis and therapy of hypertriglyceridemia over 2.75 years whose initial visit fasting plasma triglyceride levels were > 750 mg/dl. Of the 31 women with hypertriglyceridemia, 12 (39%) had been given exogenous estrogen by their physicians (11 ERT, one tamoxifen). Ten of the 12 women, while undergoing ERT, had triglyceride levels > 1200 mg/dl. In triglyceride referral categories 750 to 1000, 1000-1500, and > 1500 mg/dl, 17% (2 of 12), 33% (3 of 9), and 70% (7 of 10), respectively, of the 31 women with hypertriglyceridemia were receiving ERT. The higher the triglycerides were at referral, the greater was the likelihood that women were taking ERT (x2 = 6.6, p = 0.035). Four of the seven women with triglyceride levels > 1500 mg/dl while undergoing ERT were hospitalized with severe acute pancreatitis; another two had severe abdominal pain thought to be pancreatic in origin. To quickly lower dangerously high triglyceride levels, ERT was stopped in all 12 women. Lopid (1.2 to 1.5 gm/day) was given to the seven women not already taking it, and four were also given omega-3 fatty acids (4 to 15 gm/day). Median plasma triglyceride level at the initial visit in the 12 women undergoing ERT was 1665 mg/dl.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Pain↗

Conserved transducer coupling but different effector linkage upon expression of the myeloid fMet-Leu-Phe receptor in insulin secreting cells.

In neutrophils fMet-Leu-Phe activates phospholipase C via a pertussis toxin sensitive G-protein and induces granule secretion. We have transfected a human cDNA sequence encoding the fMet-Leu-Phe receptor into the insulin secreting cell line RINm5F to study receptor-effector coupling with special regard to secretion. Stable overexpression resulted in membrane hyperpolarization, reduction of cAMP accumulation and inhibition of insulin secretion upon exposure of cells to fMet-Leu-Phe with EC50 values in the pmol range. As in the neutrophil, nanomolar concentrations of ligand induced membrane depolarization and activation of phospholipase C, with subsequent mobilization and influx of calcium. In permeabilized cells the inhibitory effect of fMet-Leu-Phe on secretion was partially retained indicating a direct action of the fMet-Leu-Phe receptor on exocytosis. Pertussis toxin abolished the effects of fMet-Leu-Phe. Our results suggest conserved coupling from fMet-Leu-Phe receptor to pertussis toxin sensitive transducers analogous to the mechanism in neutrophils. However, the net biological effect of receptor activation is determined by additional factors intrinsic to the host cell.

Alanine↗

Different inhibitory effect of etomidate and ketoconazole on the human adrenal steroid biosynthesis.

The narcotic agent etomidate and the antimycotic drug ketoconazole are known to block steroid biosynthesis in man. To study the different effects of these imidazole derivatives on human adrenal steroid biosynthesis we incubated slices of human adrenal glands with 3H-labeled precursors and increasing concentrations of etomidate or ketoconazole (0-2000 microM). After extraction the labeled metabolites were separated by thin-layer chromatography and quantified by scintillation counting. Etomidate inhibited most potently 11 beta-hydroxylase activity by suppressing the formation of corticosterone from 11-deoxycorticosterone to 1% of control [50% inhibitory concentration (IC50) 0.03 microM] while ketoconazole suppressed 11 beta-hydroxylase to only 39% of control activity (IC50 15 microM). Ketoconazole however, most potently blocked the conversion of 17 alpha-hydroxy-progesterone to androstenedione by C17,20-desmolase to about 15% of control activity (IC50 1 microM) while etomidate showed a much weaker effect on this enzyme with a suppression to 50% of C17,20-desmolase control activity at a concentration of 380 microM. Both imidazole drugs showed a similar strong inhibitory effect on the activity of 17 alpha-hydroxylase (IC50 6-18 microM) and 16 alpha-hydroxylase (IC50 4-8 microM) and did not affect 21-hydroxylase. These in vitro data indicate a predominant inhibitory effect of etomidate on corticosteroid biosynthesis by relative selective inhibition of 11 beta-hydroxylase and of ketoconazole on the adrenal androgen biosynthesis by a predominant inhibition of C17,20-desmolase. This differential inhibitory effect of etomidate and ketoconazole on human steroid biosynthesis may be of clinical importance for a possible therapeutic use of these imidazole derivatives in endocrine disorders.

Adrenal Glands↗

Departmental audit in histopathology.

Audit is now part of any laboratory service. Histopathology is no exception, and we have set up a system which allows us to review 4% of our specimens. These specimens are identified using a random number generator and reviewed by a consultant pathologist. Both slides and wet specimens are reviewed and graded according to a set scheme. The results from the first year of operation (1990) show a high rate of accuracy with no serious diagnostic disagreements between the auditor and the reporting pathologist. However, some errors which we would wish to prevent were detected and the audit has allowed us to take corrective measures. In our opinion, this form of audit is useful and necessary to maintain good clinical practice. The cost is considerable--histopathology is by its nature labour intensive. Recognition of this fact by health boards is essential if such systems are to continue.

Biopsy↗