Biomedical subjects
Publications and source records attributed to H Beck.
We have presented six instances of Dieulafoy's lesion, two of which were diagnosed endoscopically preoperatively. Endoscopic electrocoagulation was used in two instances, one with success, and this may have a place in the treatment of these lesions. Oversewing alone of the lesion seems to be sufficient surgical treatment, if nonoperative measures, such as selective arterial embolization or endoscopic electrocoagulation fail or are unavailable.
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The measurement of color development with time in cells following the start of a staining reaction is of interest in a number of biological systems. These include the subsets of peripheral white blood cells after acridine orange staining, the uptake by cells and nuclei of fluorescent agents, especially antitumor drugs, and measurement of intracellular enzyme kinetics using fluorogenic or absorbing substrates. The present work describes a simple computer program for analyzing flow cytometric (FCM) data versus time, including both the population kinetics of color development and the variability of staining speed within one population of cells. A single-channel absorption measurement in flow (Technicon Hemalog D) was used to record peroxidase kinetics in peripheral blood cells. Every 5 s, a 64-channel absorption histogram was recorded, up to a maximum of 64 histograms. The data were then analyzed by a computer program which searched for the peak channel of each histogram. A least-squares fit was computed for these maxima. The asymmetries of the 64 absorption histograms were compared to see if there was more than one population present with different time constants. Although developed for enzyme kinetic measurements, this program may have wider usefulness in any measurements of time-dependent phenomena by FCM.
Three different dosage studies were carried out with midazolam in 47 institutionalized geriatric patients (17 males: mean age 82.9 years; 30 females: mean age 81.3 years) who were suffering from insomnia of long standing. Study I investigated the hypnotic efficacy of midazolam versus placebo in a double-blind, cross-over trial comparing the 7.5 and 15 mg doses of midazolam in 18 subjects. Both midazolam doses shortened sleep onset latency by 40 min (15 mg) and 31 min (7.5 mg). Both doses increased total sleep time compared with placebo. In study II, a comparative, cross-over trial in 10 subjects, an initial dose of 7.5 mg midazolam was sufficient to reduce the subjective appreciation of sleep onset time to less than 60 min on 66 of 70 study nights. Oxazepam (25 mg) had a comparable favourable effect but less frequently (53 of 70 nights). In study III, individual dose limits were investigated in 19 insomniac patients. The minimum effective dose was 7.5 mg. The maximum tolerated dose was in the range 15 to 52.5 mg according to the subjects' assessment. The most common optimum dose was 15 mg (10 of 19 patients). The higher doses prolonged sleep but midazolam appears to have a wide margin of safety as residual sedative effects appeared only after very high doses (four of 19 for 30 mg; eight of 19 for 37.5 mg). In some patients, 7.5 mg was the minimum dose that was effective in shortening sleep latency.(ABSTRACT TRUNCATED AT 250 WORDS)
Circannual changes of immunoreactive LH and FSH were documented on a circadian basis in January, March, June and October in four groups of subjects: seven young men, six elderly men, six elderly women and six men and women suffering from senile dementia. The sampling was serially dependent only for the young men and the core subgroups of elderly men and elderly women. A circadian rhythm for FSH was not detected in any group of subjects during any of the sampling sessions, whereas a circadian rhythm for LH was detected twice (June and October) in young men, once (October) in elderly demented patients, and not at all in the groups of elderly men and women. Both 24-h and yearly mean levels of gonadotrophins were higher in elderly subjects (two-to 25-fold according to the hormone, sex and season) than in young men. Circannual rhythms of plasma LH with large amplitudes were validated by the cosinor method, with an acrophase located in April or May. A circannual rhythm of plasma FSH was validated only in young men, with an acrophase in October. The persistence of a circannual rhythm of plasma LH with large amplitude in elderly subjects, associated with high mean levels of the hormone, especially in elderly women, suggests that this bioperiodicity of the pituitary gland is independent of gonadal function.
Effects of age, sex and mental condition on the circadian and circannual rhythmicity of plasma prolactin in human subjects were investigated. Circannual changes were recorded on a circadian basis in January, March, June and October in four groups of subjects: seven young men, six elderly men, six elderly women and six senile demented patients (two men and four women). Blood samples were drawn every 4 h over a 24-h period at the four sampling sessions. Circadian rhythms of the hormone were validated in all groups and at all sampling sessions except twice in elderly demented subjects. The 24-h mean levels of prolactin in plasma were approximately the same in young and elderly subjects. The circadian acrophases were most often located in the vicinity of 02.00-04.00 h. The circannual rhythmicity of the hormone showed a sex difference; the rhythm was not validated in either young or elderly men but was detected in the groups of elderly women and elderly demented patients (mainly women). The acrophases were located in May. This paper strongly suggests a sex difference in the circannual rhythmicity of plasma prolactin levels in elderly subjects.
An angiogram of the lumbar venous plexus was obtained following accidental insertion of a peridural catheter into the plexus. The problem of vascular puncture is discussed and the possible methods of prevention of intravascular injection of local anaesthetic are outlined.
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A genetic map of the Y chromosome of Drosophila hydei has been constructed from deletion/complementation experiments, with the aid of male sterile mutants of the Y chromosome. A central conclusion of our experiments is that not more than a single complementation group can be detected in each of the lampbrush loop forming sites. Additional complementation groups, functionally independent of lampbrush loops, reside between these loci. Six complementation groups have been defined by several methods of mapping. An additional ten complementation groups are indicated, but their exact definition requires further investigation. The "synthetic sterility" of mutations in these ten loci contributes to the difficulty in unequivocally establishing their individual boundaries. Mapping problems also arise from the instability of certain mutants.
Circadian changes in plasma 18-hydroxy-11-deoxycorticosterone (18-OH-DOC), total and unbound cortisol were studied in four groups: seven healthy young men, six elderly men, six elderly women and six elderly demented patients of both sexes. The daily activities of the subjects were synchronous; blood samples were taken every 4 h and 4 hourly urine samples were collected only from the young men. A circadian rhythm was defined for plasma 18-OH-DOC, total and unbound cortisol in all groups; the secretory patterns of these steroids were parallel, as were the profiles of urinary 18-OH-DOC and unconjugated cortisol. When compared with respect to sex, the 24-h mean level of total cortisol was higher in women; that of unbound cortisol was higher in the three groups of elderly patients than in the young men. No major changes in plasma steroids were observed between elderly demented patients (mainly women) and healthy elderly women. The phasing of total and unbound cortisol showed no major modifications with age, sex or senile dementia. Acrophases of 18-OH-DOC were earlier in elderly patients than in young men. Amplitudes were not modified with sex in elderly patients but were always lower in the demented patients. A circadian rhythm was defined for 18-OH-DOC, unconjugated cortisol, 17-hydroxycorticosteroids (17-OH-CS) and 17-ketosteroids in the urine of the young men. The acrophases of 18-OH-DOC and unbound cortisol were close, as were those of 17-OH-CS and 17-ketosteroids. The lag was short between the acrophases of 18-OH-DOC in plasma and urine and between those of plasma unbound cortisol and urinary unconjugated cortisol; it was much larger between the acrophases of plasma total cortisol and 17-OH-CS. Thus, the process of ageing, and the possible alterations in the central nervous system which are often seen in normal ageing, induced no major modifications in the temporal organization of adrenocortical function, even in subjects who were very advanced in age.
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Hyperthermic perfusion was used in 15 adult patients with soft tissue sarcoma of the limbs. Only patients were selected with prognostically unfavorable or recurrent tumors, which were excised with a limited safety margin. Three patients died from pulmonary metastases 16, 24 and 34 months after perfusion. In 2 patients a local recurrence developed. Ten patients are alive and free of recurrence. The follow-up period ranges from 7 - 47 months with a median of 30 months. These results encourage the further use of hyperthermic perfusion.
The inhibition of acid and pepsin secretion by metiamide and atropine was studied in the anaesthetized Heidenhain-pouch cat. Metiamide strongly inhibited acid secretion induced by histamine, pentagastrin or carbachol. Metiamide had not effect on pepsin secretion stimulated by pentagastrin and carbachol but was effective on histamine-stimulated pepsin secretion. Atropine strongly inhibited pepsin secretion but was not as effective as metiamide in the inhibition of acid secretion. Reperfusion of the pouch with acid + salicylic acid also increased pepsin secretion. This increased pepsin output was abolished by atropine, but not by metiamide. It is postulated that (1) the peptic cell probably has only cholinergic receptors which can be additionally triggered by HCl passing the peptic cell, and (2) H2-antagonists only inhibit pepsin secretion indirectly via reduction of acid output.
Circadian changes in plasma levels of melatonin, prolactin, LH and FSH were studied in four groups: seven healthy young men, six elderly men, six elderly women and six elderly demented patients (two men and four women). The daily activities of the subjects were synchronous and blood samples were taken every 4 h. The 24-h mean concentrations of prolactin in plasma were the same in all groups, whereas those of LH and FSh were twice as high in the elderly as in the young men and eight and 23 times higher respectively in the elderly women. The 24-h mean plasma levels of melatonin in the elderly were half those in the young, but were not influenced by the sex or mental condition of the subjects. A statistically significant circadian rhythm for melatonin was defined in the four groups, for prolactin in all groups except the elderly men and for LH only in the demented patients and in the young men. No circadian rhythm could be detected for FSH in any of the four groups. The acrophases of melatonin and prolactin ranged between 02.30 and 04.00 h, those of LH (when a rhythm was validated) clustered around 01.00 h. The circadian rhythms of plasma levels of melatonin, prolactin and LH are not modified in old age nor in dementia. A positive correlation has been demonstrated in young men between melatonin and LH and between melatonin and prolactin, but no such correlation could be found in the elderly.
The aminoglycosides butirosin and bekanamycin (Kanendomycin) were tested for their nephrotoxicity in female albino Wistar rats (n = 110). The antibiotics were administered i.m. over a course of 5 days; dosage interval 12 h, dosage 2,5, 5, 10, 20, 100 and 500 mg/kg per day, respectively. For comparative evaluation of nephrotoxicity the urinary excretion of tubular cells and enzymes (MDH, GOT, LDH) were taken. Additionally, serum urea and urine protein (qualitatively) were determined, and the kidneys were investigated histologically. The experiments revealed that both aminoglycosides had tubulotoxic and glomerulotoxic effects. The lowest doses that induced pathologic cell excretion (tubulotoxic threshold doses) were 5 mg/kg per day for either drug. It may be concluded that nephrotoxicity of butirosin and bekanamycin does not differ within the range of dosages which are used in human therapy. Compared with other established aminoglycosides advantages with respect to nephrotoxicity could not be found.
The cephalosporins cefamandole, EMD 29 645, and EMD 29 946 were tested for their nephrotoxicity in female albino Wistar rats (n = 120). The antibiotics were administered i.m. over a course of 5 days; dosage interval 12 h, dosages 1000, 2000, 3000, and 5000 mg/kg per day, respectively. For comparative evaluation of nephrotoxicity, the urinary excretion of tubular cells and enzymes (MDH, GOT, LDH) were taken. Additionally serum urea and urine protein (qualitatively) were determined. Furthermore the kidneys were investigated histologically. These experiments revealed the following tubulotoxic threshold doses: cefamandole: 3000 mg/kg per day, EMD 29 645: 2000 mg/kg per day, and EMD 29 946: 5000 mg/kg per day. EMD 29 645 was also found to be glomerulotoxic at higher doses.