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Biomedical subjects

S Holm

Publications and source records attributed to S Holm.

At least 271 records · Page 15Linked to original sources
PubMed1975

Distribution and metabolism of 2,4,5,2', 5'-pentachlorobiphenyl.

Single doses of 2,4,5,2',5-pentachlorobiphenyl uniformly labeled with 14-C have been administered intravenously and orally to mice. Whole-body autoradiograms and scintillation counting of tissue samples have shown that most radioactivity leaves the circulation for the tissues within one hour. Peak concentrations varied, being highest in brown fat, which after 24 hours comprised the major reservoir of the unchanged compound in the body. Radioactivity disappeared rather rapidly drom most other tissues, although the longest retention occurred in bronchial epithelium and some parts of the renal tubules. The excretion of radioactivity was mainly through the bile, into feces, with a half-time of six days. There was little unchanged compound in the feces, the major metabolite was a hydroxylated derivative, both free and conjugated.

Adipose Tissue, Brown↗
PubMed1975

Experimental male genital tuberculosis-appraisal of protective value of BCG vaccination.

As part of an experimental study of the spread of urogenital tuberculosis, the development of tuberculous infection was compared in vaccinated and non-vaccinated guinea pigs after challenge with Mycobacterium tuberculosis strain H37Rv into the seminal vesicle. The animals were saccrified 35 days after challenge. Morphological observations indicate that tuberculous infection in an immunized animal is retarded, but spreads by the same routes as in an nonimmunized animal. On microbial enumeration significantly lower numbers of organisms were recovered from the inoculated seminal vesicle and regional iliac lymph nodes of the BCG-vaccinated guinea pigs.

Animals↗
PubMedDate not supplied

Separation of systematic and random differences in ordinal rating scales.

We introduce a new statistical method, which separates and measures different types of variability between paired ordered categorical measurements. The key to the separation is a two-way augmented ranking approach of observations in a contingency table. It means that cases classified in a specific category by one rater will be internally ranked according to the classifications from the other. This enables us to extract the component of interobserver variation which is not systematic. The variance of the rank differences between judgements is a suitable measure of this interrater variability, which we characterize as random. The empirical measure of random interjudge disagreement, which lies between 0 and 1, is called the relative rank variance and is an estimate of a parameter defined on the multinomial probability distribution in the contingency table. The systematic differences are determined by the marginals and described by two empirical measures, relative position and relative concentration; both measures lie between -1 and 1. Our method is applied to data sets from a reliability study of two clinical rating scales for assessing hydrocephalus and subarachnoid haemorrhage.

Data Interpretation, Statistical↗
PubMedDate not supplied

Streptococcal toxic shock syndrome in a postpartum woman. Case report and review of the literature.

A case of streptococcal toxic shock syndrome in a 29-year-old postpartum woman is described. The patient presented with hypotension, coagulation defects, adult respiratory distress syndrome and scarlet exanthema as a complication of hemolytic group A streptococcal endometritis. One hundred and twenty-two other cases of streptococcal toxic shock syndrome in the literature are reviewed and the criteria of the syndrome discussed. Streptococcal toxic shock syndrome seems to be increasing along with more frequent invasive streptococcal infections in several countries. It is therefore important to recognize and treat the infection as early as possible to minimize the risk of mortality.

Adult↗
PubMedDate not supplied

Saliva-resistant coating of tablets prevents oral release of penicillin: plasma but not saliva equivalence.

OBJECTIVE: To investigate saliva and plasma concentrations of penicillin after the intake of a conventional phenoxymethylpenicillin (PcV) tablet and a tablet with saliva-resistant coating (PcVsr), both containing 1 g penicillin. METHODS: The study had an open randomized crossover design and involved 24 healthy subjects. Saliva and blood were sampled intermittently for 6 h after tablet intake. RESULTS: Within the first 10 min after tablet intake penicillin was detected in saliva in ten subjects taking PcV and in none taking PcVsr (P < 0.001). These initial saliva concentrations were short-lasting, but in some subjects 50 to 100 times higher than those following the peak concentration in plasma, i.e. at 40 min or more after swallowing. From 40 min and onwards the saliva concentrations of penicillin were very similar for the two formulations. The elimination of high initial saliva concentrations may diminish ecological disturbances of the mouth flora as well as removing the unpleasant taste of penicillin. The plasma concentrations of penicillin were similar for the two formulations throughout the 6-h sampling period and the mean ratio of the area under the plasma concentration-time curve was 99% for PcVsr in relation to PcV, the 90% confidence interval being 86-115%. The corresponding values for the maximum plasma concentration were 108% and 93 127%. The time to maximum concentration was 45 min for PcVsr and 41 min for PcV. Thus, with regard to standard criteria which are based on systemic (plasma) concentrations, the formulations were bioequivalent despite the substantial difference in initial local (saliva) concentrations. CONCLUSION: Saliva-resistant coating of tablets can prevent oral release of penicillin without affecting the plasma concentrations. From a clinical point of view both local and systemic equivalence should be established before bioequivalence is assumed.

Adult↗
PubMedDate not supplied

Regional myocardial oxygen consumption estimated by carbon-11 acetate and positron emission tomography before and after repetitive ischemia.

BACKGROUND: Preserved myocardial oxygen consumption estimated by carbon 11-acetate and positron emission tomography (PET) in myocardial regions with chronic but reversibly depressed contractile function in patients with ischemic heart disease have been suggested to be caused by repeated short episodes of acute myocardial ischemia. To evaluate this hypothesis myocardial 11C-acetate PET imaging was performed before and after acute repetitive myocardial ischemia. METHODS AND RESULTS: In open chest dogs (n = 8), the left anterior descending coronary artery was occluded 4 times for 5 minutes alternating with 5 minutes of reperfusion. Before and after repetitive coronary occlusions, oxygen 15 water/oxygen 15 carbon monoxide (blood flow), and 11C-acetate (oxygen consumption) PET imaging were performed. Left ventricular regional systolic wall thickening was measured with sonomicrometry. Forty-five minutes after the ischemic episodes, systolic ventricular wall thickening was decreased by 90%, whereas myocardial blood flow was reduced by 21% compared with baseline values (P < .05). Ninety minutes after the ischemic episodes, estimated oxygen consumption was unaltered compared with the baseline level despite a sustained 70% decrease in the regional contractile function (P < .05). CONCLUSIONS: Oxygen consumption estimated by 11C-acetate PET imaging is preserved after repeated episodes of acute myocardial ischemia despite a severe impairment of contractile function.

Acetates↗
PubMedDate not supplied

Coregulation of glucose uptake and vascular endothelial growth factor (VEGF) in two small-cell lung cancer (SCLC) sublines in vivo and in vitro.

We examined the relationship between (18)F- labeled 2-fluro-2-deoxy-d-glucose (FDG) uptake, and expression of glucose transporters (GLUTs) in two human small-cell lung cancer (SCLC) lines CPH 54A and CPH 54B. Changes in the expression of GLUTs and vascular endothelial growth factor (VEGF) during 12-, 18-, and 24 hours of severe hypoxia in vivo (xenografts) and in vitro (cell cultures) were recorded for both tumor lines. The two SCLC lines are subpopulations of the same patient tumor. In spite of their common genomic origin they represent consistently different metabolic and microenvironmental phenotypes as well as treatment sensitivities. There were higher levels of Glut-1 protein in 54B and a correspondingly higher FDG uptake in this tumor line (P<.001). During hypoxia a significant upregulation of in VEGF mRNA, GLUT-1 mRNA, and Glut-1 and -3 protein occurred with a distinctly different time course in the two cell lines. A similar co-upregulation of GLUT and VEGF was seen in hypoxic tumors of both lines. There were no significant changes of HIF-1alpha mRNA during hypoxia in either of the cell lines. A more detailed understanding of such correlations between glucose metabolism, angiogenesis, and microenvironmental phenotype of tumors, by positron emission tomography (PET) and molecular techniques might further sophisticate our interpretation of glycolytic predominance in tumors as seen by 18FFDG PET.

Animals↗
PubMedDate not supplied

Regional cerebral blood flow assessed by 133Xe inhalation and emission tomography: normal values.

Regional cerebral blood flow (rCBF) in the cerebral hemispheres and the cerebellum was measured by single photon emission computed tomography with inhalation of 133Xe in 39 normal volunteers at test. The goal of this study was to assess the normal flow pattern and its variations. Five parallel tomographic slices through the brain were recorded with a resolution element of 1.7 X 1.7 X 2.0 cm (full width at half maximum). The blood flow distribution showed that the predominantly gray matter areas displayed flow approximately double that of the predominantly white matter regions. The CBF distribution was practically symmetrical with a side-to-side difference averaging 1.4 +/- 1.4 ml/100 g/min. This means that a difference exceeding 4.2 ml/100 g/min (approximately 9% of mean CBF) is abnormal with a confidence level of below 5%. The measured average CBF and cerebellar blood flow were 56 +/- 7 and 54 +/- 6 ml/100 g/min (mean +/- 1 SD), respectively. A significant correlation was found between CBF and PCO2, and between CBF and age. Repeat measurements in an additional 30 subjects showed a day-to-day variability of -0.2 +/- 6.4 ml/100 g/min of the difference between the first and the second measurement. This corresponds to random methodological and biological errors of 6.4/square root 2 = 4.6 ml/100 g/min and is a measure of the overall intraindividual variability. Xenon-133 tomography is atraumatic and affords rCBF images free of the superposition artifacts that practically invalidate the nontomographic approaches in the studies of cerebrovascular disease. The rCBF tomograms are blurred, particularly due to Compton scatter. Relative to this factor, the errors caused by local variations in the tissue:blood partition coefficient are less important.

Adult↗
PubMedDate not supplied

Variations in the nutrition of the canine intervertebral disc induced by motion.

In this experiment study, we have investigated some transport and metabolic parameters of the canine intervertebral disc induced by spinal motion. The movements of the spine were obtained during supervised exercise, where either moderate, violent, or specific movements were performed. The results show changes in the metabolic rates as well as in concentration profiles of metabolites of the exercised groups in comparison to the control group. An increasing aerobic metabolism was noted in the outer part of the annulus and in the central part of the nucleus pulposus, resulting in a reduction of the lactate concentration. These findings do indicate that spinal movements, over a longer period of time give rise to positive nutritional variations. Furthermore, the reported changes might be of significance also for the human lumbar disc problem, since previous studies have demonstrated nutritional similarities between the discs of dogs and men.

Animals↗