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Biomedical subjects

A Lang

Publications and source records attributed to A Lang.

At least 163 records · Page 9Linked to original sources
PubMed1988

[Radiologic diagnosis of injuries of the wrist].

To visualise the rupture of the scaphoid bone it will be sufficient--as has been proven--to perform two additional projections from the navicular series besides the standard x-rays of the wrist joint, namely, with the hand in writing-pen position and in hyperpronation. With this procedure, almost all (99%) of fractures detected during first examination can be diagnosed. To prove the occurrence of fractures of the wrist besides those of the os naviculare, specific x-rays are employed in accordance with the results of an on-target clinical examination. Such x-rays are, in particular: lateral radioulnar x-ray rotated by 10 degrees in volar direction to assess the os triquetrum; lateral radioulnar x-ray in 10-30 degrees supination to visualise the os pisiforme; carpal tunnel x-ray to assess the entire hollow of the hand, in particular the volar parts of os pisiforme, os hamatum (hamulus) and os trapezium. Although such fractures can partly also be diagnosed by means of a navicular series, as already stated, it is not permissible to exclude the presence of a fracture if there are no abnormal findings in the navicular quartet whereas clinical findings are positive.

Carpal Bones↗
PubMed1987

Expression of melanoma-associated antigens in rapidly dividing human melanocytes in culture.

Conditions were established to induce rapid clonal growth of melanocytes from newborn foreskin. Surface antigen expression was analyzed using monoclonal antibodies derived by immunization of mice with melanoma cell, melanocyte, and placental membrane preparations. Unlike resting melanocytes in normal skin, cultured melanocytes expressed most major melanoma-associated antigens tested, e.g., nerve growth factor receptor, proteoglycan, transferrin-related Mr 97,000 protein antigen, Mr 120,000 protein, and gangliosides 9-O-acetyl GD3 and GD3. HLA-DR antigen and ganglioside GD2 were expressed at very low levels or not expressed. After several subpassages, most melanocyte cultures, including clones and melanocytes, initially sorted by rosetting with monoclonal antibody to nerve growth factor receptor, lost their characteristic bipolar morphology and expression of nerve growth factor receptor and Mr 97,000 antigen but continued to express high molecular weight proteins such as proteoglycan, Mr 130,000/105,000 and 120,000 antigen. The few melanocyte cultures that did maintain their characteristic bipolar to spindle morphology continued to express all melanoma-associated antigens and even began to express HLA-DR antigens. Melanocytes cultured in the presence of the phorbol ester 12-O-tetradecanoylphorbol-13-acetate also maintained their bipolar morphology, were often pigmented, and continued to express melanoma-associated antigens for several passages; they did not express HLA-DR antigen. Our studies indicate that rapidly proliferating melanocytes in culture undergo antigenic changes associated with malignancy.

Antibodies, Monoclonal↗
PubMed1987

Evidence suggesting under-treatment in adults with idiopathic focal segmental glomerulosclerosis. Regional Glomerulonephritis Registry Study.

During the past 11 years, the Metro Toronto Glomerulonephritis Registry has prospectively followed all cases of glomerulonephritis starting from the time of biopsy. Focal segmental glomerulosclerosis was diagnosed by strict histologic criteria in 103 patients. Exclusion of patients with follow-up of less than 12 months reduced the number to 93 (55 adults and 38 children). Mean length of follow-up from the time of biopsy was 61 months. Ninety percent of children, but only 33 percent of adults received treatment with steroids, with or without cytotoxic drugs (p less than 0.001). Complete remission, defined as daily proteinuria of less than 250 mg, was not different in adults (39 percent) from that in children (44 percent), with a mean remission duration for all patients of 38 months. Chronic renal insufficiency, defined as a creatinine clearance of less than 0.8 ml/second/1.73 m2 for more than 12 months, was similar in adults (40 percent) and children (34 percent). Five-year renal actuarial survival, defined as the absence of chronic renal insufficiency, was 96 percent for patients with a history of complete remission, and 55 percent for those without (p less than 0.0002). Logistic regression analysis showed treatment to be the only significant factor for complete remission (p less than 0.001). Complete remission, in turn, was important for renal preservation, defined as the absence of chronic renal insufficiency (p less than 0.001). Age did not affect the treatment response or long-term renal outcome in focal segmental glomerulosclerosis. yet, the percent of adults treated was much lower than that of children, despite the fact that the majority of the untreated adults had the same clinical parameters as the treated adults and children. Thus, a judicious course of treatment is as much indicated in adults as in children with this disorder.

Adolescent↗
PubMed1987

Modification of the polar head group of platelet-activating factor: influence on the biological activity.

Racemic analogues of platelet-activating factor and its lyso derivatives have been prepared in which one methyl of the trimethylammonium group has been replaced by ethyl, propyl, allyl, or carboxymethylene. The influence of chemical modification on the biological activity was assessed by measuring platelet aggregation and desensitization. The results point to a crucial role of a positively charged polar head group for the expression of biological activity of platelet-activating factor. There are also some indications of a more non-specific interaction of the polar head group of platelet-activating factor with its platelet binding sites.

Humans↗
PubMed1986

Pharmacokinetics of erythromycin in patients with different degrees of renal impairment.

The kinetics of erythromycin (E.) was studied in 16 patients with different degrees of impairment of renal function after a single intravenous dose. Renal clearance of E. was found to be significantly correlated to the creatinine clearance. Total recovery in urine did not exceed 7.5%. As expected from the small fraction excreted via the kidneys, the elimination half-life and the total clearance of E. did not depend on renal function. We conclude that impairment of renal function does not justify a dose adjustment of E. Hearing acuity should, however, be monitored during treatment since transient deafness predominantly in patients with renal failure has been reported by various authors.

Adult↗
PubMed1985

Striatal dopamine distribution in parkinsonian patients during life.

Eleven neuropsychologically normal Parkinsonian patients were studied with [18F]6-fluoro-L-dopa and positron tomography. In all of the patients dopaminergic activity was reduced in the putamen on the side opposite to the major motor signs. The reduction was similar in tremulous and rigid patients. In contrast dopaminergic activity was normal in the caudate nuclei. It is argued that the putamen is mainly involved in the regulation of movement while the caudate nuclei assume a role in cognitive processes.

Adult↗
PubMed1985

[Synthesis and biologic activity of some stable structure analogs of platelet activating factor].

Physiologically stable structure analogues of the platelet-activating factor (PAF-acether), the acetyl group of which had been substituted by short-chain alkyl rests, had been synthesized and been tested with regard to their biological activity against thrombocytes. Five differently substituted 2-alkylmalonic acid esters with methyl rest up to n-pentyl rest had been applied the basic products. The n-propyl compound exhibits the most intense biological activity, which is, however, essentially reduced against the PAF-acether. With conditions of the examination, all the other derivatives possess a more decreased activity.

Chemical Phenomena↗
PubMed1984

Immune response-associated production of neopterin. Release from macrophages primarily under control of interferon-gamma.

Neopterin, a compound derived from GTP, represents a precursor molecule of biopterin that is an essential cofactor in neurotransmitter synthesis. We have recently reported that in vivo as well as in vitro immune responses are accompanied by an increased release of neopterin and that this phenomenon can be used for the biochemical monitoring of diseases accompanied by hyperimmune stimulation. This article deals with the cellular origin and the control of this immune response-associated neopterin release in vitro. Using highly purified or monoclonal cellular reagents we demonstrate that macrophages (M phi) stimulated with supernatants from activated T cells release large amounts of neopterin into culture supernatants. Further experiments involving induction of neopterin release from M phi with various human recombinant interferons (IFNs) or neutralization of the effect of T cell supernatants with various monoclonal anti-IFN antibodies revealed immune IFN as the active principle. It thus appears that a metabolic pathway so far exclusively known in context with the generation of an essential cofactor of neurotransmitter-synthesis during immune responses is also activated in M phi under stringent control by immune IFN-like lymphokines.

Biopterins↗
PubMed1984

[Social behavior of 5 to 7-year-old children at risk as newborn infants with special reference to parental child-rearing behavior].

A questionnaire was used to investigate the social behaviour of 168 5-7 year olds, who as neonates had been at risk for developing psychomotor disturbances, and the educational behaviour of their parents. 52 six year olds with an uneventful perinatal period formed the control group. Sociodemographic data did not differ between the two groups. The basic tendency of the children's temperament ( liveliness vs. calmness ) during the first year was similar in both groups. Achievement of developmental milestones (gross motor activity, language, bladder and bowel control) was reached at similar age. The parents' educational behaviour did not differ. The social behaviour of the children at risk, as judged by the inhibited or aggressive behaviour, was also equal to the controls. The psychomotor development of the same population of children had been found to be normal in most cases at age 3-42 (mean 15) months ( Schweiz . med. Wschr . 109, 215 [1979]). According to the present study, this risk population of newborns also showed normal social behaviour.

Age Factors↗
PubMed1984

A double-blind trial of clonazepam in benign essential tremor.

Clonazepam has been reported to be of some value in the treatment of benign essential tremor in open trials. The efficacy of clonazepam was evaluated in a double-blind placebo-controlled study using up to 4 mg/day. By a variety of objective measures, clonazepam was not found to be an effective form of therapy.

Adult↗
PubMed1983

Localized amyloidosis of urethra.

A case of primary amyloidosis of the urethra is described. Although rare, this entity is important since its antecedent causes, clinical symptoms, and panendoscopic and radiographic appearance are similar to and must be differentiated from carcinoma of the urethra. The prognosis of this disorder is excellent, and aggressive therapy is not indicated.

Adult↗