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Biomedical subjects

A Falk

Publications and source records attributed to A Falk.

At least 19 recordsLinked to original sources
PubMed1992

The glucosinolate-degrading enzyme myrosinase in Brassicaceae is encoded by a gene family.

A full-length cDNA clone (MB3) and three partial clones (MA1, MB1 and MB2) which encode myrosinase (thioglucoside glucohydrolase, EC 3.2.3.1) were isolated from a Sinapis alba (white mustard) cDNA library. Nucleotide sequence analysis of these clones revealed that they are encoded by a gene family. Southern blot analysis with gene-specific probes showed that the gene family consists of a least two subfamilies (MA and MB) each with several members both in S. alba and in Brassica napus (oilseed rape). In Arabidopsis thaliana (wall cress) only three myrosinase genes seem to be present. Northern blot analysis indicated that all the myrosinase mRNA species have the same size, approximately 1.95 kb.

Amino Acid Sequence↗
PubMed1992

Renal elimination of verbenols in man following experimental alpha-pinene inhalation exposure.

The renal elimination of verbenols after experimental exposure to (+) and (-)alpha-pinene was studied in humans following exposure to 10, 225, and 450 mg.m-3 terpene in an exposure chamber. The pulmonary uptake was about 60%. About 8% was eliminated unchanged in exhaled air. Depending on the exposure level, about 1%-4% of the total uptake was eliminated as cis- and trans-verbenol. Most of the verbenols were eliminated within 20 h after a 2-h exposure. The renal excretion of unchanged alpha-pinene was less than 0.001%.

Adult↗
PubMed1992

Job strain and mortality in elderly men: social network, support, and influence as buffers.

The aim was to investigate whether job strain affects mortality in a representative population of elderly men, and whether social network and social support outside the workplace can buffer the negative health effects of job strain. A higher relative mortality risk (RR) was found among men exposed to job strain (RR = 1.7). The combination of exposure to job strain and seven different measures of weak social network and social support was associated with a further increased RR ranging from 2.1 to 4.6.

Aged↗
PubMed1992

Knee effusion: normal distribution of fluid.

Although visualization of articular fluid on MR images of the knee is common, no specific MR criteria that enable assessment of the quantity of the effusion have been established. We performed MR of three cadaveric knee specimens after the instillation of increasingly large volumes of fluid and studied the distribution of the fluid. When 4 ml of fluid was injected, the anteroposterior diameter of the suprapatellar recess was 4 mm on midline sagittal MR images and 10.0-12.5 mm on lateral sagittal MR images, corresponding to the usual routine radiographic criteria for a knee effusion.

Humans↗
PubMed1992

The prevalence of diabetes mellitus and other risk factors of atherosclerosis in bradycardia requiring pacemaker treatment.

258 patients with pacemakers (PM) were examined retrospectively; 126 (48.8%) had second- or third-degree av-block (AVB), 43 (16.7%) atrial fibrillation with bradycardia (AFB), 63 (24.4%) sick sinus syndrome (SSS) and 26 (10.1%) other indications (OI). Control persons (CP) of same age and sex with regular sinus rhythm were recruited from in-patients of our hospital. Diabetes was found in 127 (49.2%) of PM (of adult onset only) and in 99 (38.4%) of CP (3 of juvenile onset; p < 0.025), in 68 (53.9%) of the patients with AVP (p < 0.05), 24 (55.8%) with AFB, 21 (33.3%) with SSS (n.s.) and 14 (53.8%) with OI (n.s.). Obesity was positively correlated concerning the entire PM group, blood pressure and smoking habits showed no correlation, cholesterol and triglycerides were inversely correlated (p < 0.05 up to p < 0.001). Myocardial infarction showed no difference between PM and CP, digitalis and diuretics were taken significantly more often (p < 0.001) by PM. We conclude that diabetes mellitus is a major risk factor for av-block of higher degree and atrial fibrillation with bradycardia, which is not influenced by other, diabetes-related risk factors of atherosclerosis.

Aged↗
PubMed1991

Human exposure to 3-carene by inhalation: toxicokinetics, effects on pulmonary function and occurrence of irritative and CNS symptoms.

Terpenes, especially 3-carene, may irritate the skin and mucous membranes and prolonged exposure may result in allergic contact dermatitis or chronic lung function impairment. The toxicokinetics of 3-carene were studied in human volunteers exposed by inhalation (2 hr 50 W) in an exposure chamber on three occasions. The exposure concentrations were approximately 10, 225, and 450 mg/m3 3-carene. The relative pulmonary uptake was high, approximately 70% for the higher exposure levels. Total uptake increased linearly with increasing exposure. The blood clearance of 3-carene observed in this study, 0.9 liter.kg-1.hr-1, indicates that 3-carene is fairly readily metabolized. About 3% of the total uptake was eliminated unchanged via the lungs while less than 0.001% was eliminated in the urine after the end of exposure. A long half time in blood was observed in the terminal phase which indicates a high affinity to adipose tissues. A statistically significant divergence between ratings of irritation during the high exposure level and during the medium and control levels was observed. The difference in airway resistance after exposure to a high concentration of 3-carene compared to control level was not significant (P = 0.02).

Administration, Inhalation↗
PubMed1991

Potency assay and characterization of lymphocytosis promoting factor in whole cell and acellular pertussis vaccines.

Potency assay in mice to evaluate the immunogenic properties of a number of candidate Lymphocytosis Promoting Factor (LPF) antigen in whole cell and acellular pertussis vaccines is described. Potency was estimated both by the conventional WHO intracerebral challenge test and an LPF-toxin challenge method. The latter method involved intraperitoneal injection of dilutions of test and reference preparations followed by challenging the animals 28 days later by LPF combined with AlPO4 adjuvant and estimating the total white blood cells three days after challenge. The method has been in routine use for the past four years and has given consistent results with reproducible specific activity and ED50 values. LPF antigen prepared by different chemical treatment or by genetic alteration of the molecule showed differences in specific activity, although different batches made by the same procedure appeared to give consistent values. Only two preparations, did not give specific activity close to what was given by LPF in whole cell vaccine by the LPF challenge method. Some preparations did not give any activity. In the intracerebral challenge method, many preparations failed to protect, while some gave a low degree of protection. The content of residual ADP ribosylating activity also varied. These three tests can be used for characterizing the LPF antigen of acellular pertussis vaccines.

Animals↗
PubMed1990

Gender differences in TRH-stimulated TSH and prolactin in primary degenerative dementia and elderly controls.

We performed thyrotropin-releasing hormone (TRH) stimulation testing in 18 nondepressed patients with primary degenerative dementia (10 M, 8F; average age +/- SD = 68 +/- 7) and 12 elderly controls (7M, 5F; average age +/- SD = 61 +/- 6). Six patients were retested approximately 2 years later. Initial Mini-Mental State Examination scores for patients ranged from 2 to 28 (average +/- SD = 18 +/- 6) and the scores for the control subjects were all equal to 30. Protirelin (500 micrograms) was injected iv and blood was sampled at 0, 15, 30, 45, 60, and 90 min for thyrotropin-stimulating hormone (TSH) and prolactin (PRL). There were no significant differences between patients and controls in baseline T4, T3 uptake, TSH, or PRL. No significant differences were found between patients and controls for either TRH-stimulated TSH or PRL at all time points. Duration of illness, severity of dementia, and severity of depressive symptoms did not correlate significantly with stimulation test results. There were, however, significantly greater responses in stimulated TSH and PRL for women compared with men in both patients and controls. Upon repeat testing (n = 6), TRH-stimulated TSH and PRL were not significantly different from the initial results.

Aged↗
PubMed1990

Liquid/air partition coefficients of four terpenes.

The liquid/air partition coefficients of four common terpenes, alpha-pinene, beta-pinene, 3-carene, and limonene, have been determined in vitro using head space technique. The liquids used were water, human blood, and olive oil. alpha-Pinene, beta-pinene, and 3-carene were practically insoluble in water and limonene was slightly soluble; all were readily dissolved in olive oil. The oil/air partition coefficients ranged from 2900 to 5700 in the order alpha-pinene, beta-pinene, 3-carene, and limonene. The blood/air partition coefficients ranged from 15 to 42 in the same order as for oil/air.

Bicyclic Monoterpenes↗
PubMed1989

Cardiopulmonary dysfunction in a feline septic shock model: possible role of leukotrienes.

The aim of the present study was to explore the possible involvement of leukotrienes (LTs) in the development of cardiopulmonary dysfunction in experimental septic shock. Sepsis was induced in anesthetized cats by infusion of liver Escherichia coli bacteria. One series (N = 6) was pretreated with diethylcarbamazine (DEC), a 5-lipooxygenase inhibitor; another series (N = 7) was pretreated with FPL 55712, a LTC4-D4 antagonist; and a third series (N = 8) served as septic controls. After 2 hr of bacteremia, there were no differences in cardiac function in the three series. By subjecting the heart to volume load, two points on a Starling curve were obtained, indicating the limits of the functional cardiac reserve. This loading procedure disclosed a significantly better preserved left ventricular function in the DEC-pretreated group as compared with the other two groups. Pretreatment with DEC and FPL 55712 had no effects on early pulmonary vascular reactions. However, the tracheal pressure response was less pronounced after pretreatment compared with septic controls. Calculated airway resistance was less increased and pulmonary compliance less decreased in the two pretreated groups. Furthermore, arterial hypoxia was prevented by pretreatment. It is concluded that this study suggests that LTs are involved in the development of myocardial insufficiency in experimental bacteremic septic shock. Moreover, the results strongly indicate that LTs may be of importance in compromising pulmonary gas exchange, partly by effects on the smaller airways.

Airway Resistance↗
PubMed1985

Intestinal hemodynamic effects of dextran-induced hyperviscosity in the cat.

A hyperviscous state with red cell aggregation and increased plasma viscosity was induced in cats by intravenous infusion of high molecular weight dextran. A segment of the small intestine was isolated with intact vascular and nervous supply and placed in a plethysmograph for determination of the intestinal tissue volume and capillary filtration coefficient. The intestinal blood flow was measured by a drop recorder unit. Measurements of intestinal blood flow, flow resistance and capillary filtration coefficient were performed during normotension and regional hypotension before and after infusion of high molecular weight dextran. After infusion of high molecular weight dextran, there was a twofold increase of blood viscosity and a threefold increase of plasma viscosity. Erythrocyte sedimentation rate exceeded 100 mm/h. Intestinal blood flow decreased by 35% during normotension and by 45% during regional hypotension. Intestinal flow resistance increased by 45% during normotension and by 65% during hypotension. The capillary filtration coefficient was not affected by the dextran infusion. It is concluded that the intestinal hemodynamic effects of high molecular weight dextran are mainly dependent of the increased plasma viscosity and that the number of perfused capillaries is not reduced by obstructing red cell aggregates.

Animals↗
PubMed1978

Preferential charging of tRNA-Met-f in Escherichia coli K12.

The charging of tRNA-Met-f and tRNA-Met-m in vivo and in vitro and initiation of polysomes during methionine limitation were studied in two strains of Escherichia coli K12. In the wild-type strain the distribution of polysomes as well as the kinetic parameters of methionyl-tRNA synthetase indicate preferential acylation of tRNA-Met-f. This preferential charging of tRNAM-et-f does not take place in a mutant strain which is also defective in initiation of polysomes during methionine limitation.

Adenosine Triphosphate↗
PubMed1978

Prophylaxis with isoniazid in inactive tuberculosis. A Veterans Administration Cooperative Study XII.

Based on a study indicating a significant rate of reactivation of tuberculosis in Veterans Administration patients with inactive disease, a cooperative study was initiated to determine the prophylactic effect of isoniazid on the rate of reactivation. A randomized double-blind study was designed, utilizing three regimens, two with isoniazid and one with placebo only. Two consecutive years of taking pills in one of the three regimens was followed by five years of observation. A total of 7,036 patients with inactive disease, some of whom had received prior chemotherapy, were entered into the study. Only 63 reactivations of tuberculosis were found, for a total rate of reactivation of 9/1,000 (less than 1%) over the seven-year period. Although no significant differences in the rate of reactivation were found among any of the regimens, there was a significant reduction in the rate of reactivation among those who had not received any prior chemotherapy and received isoniazid (INH) in this study, compared with those who received placebo only.

Antitubercular Agents↗
PubMedDate not supplied

Identity and name changes.

The theoretical literature as well as case material presented point to the intimate relationship of name changes to identity struggles. Names have strong affective value and symbolize an important part of a person's identity. The cultural and social value of a name may be secondary to the personal meaning of that name to the individual who in changing it will reveal an inner change in his sense of identity or an inability to integrate a diffuse sense of identity. The answer to "what's in a name?" may be "Identity's in a name."

Culture↗