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Biomedical subjects

A Bergman

Publications and source records attributed to A Bergman.

At least 253 records · Page 14Linked to original sources
PubMed1982

Metabolism of 2,4',5-trichlorobiphenyl: role of the intestinal microflora in the formation of bronchial-seeking methyl sulphone metabolites in mice.

Groups of germ-free and conventional mice were treated with 2,4',5-trichlorobiphenyl (triCB) and [35S]cysteine or [35S]methionine, respectively. Control animals received the labelled amino acids only. Conventional mice accumulated significantly more extractable radioactivity both in lung and kidney tissues when compared to germ-free mice. The extracted radioactivity in lung and kidney tissues was shown to be due to the accumulation of methyl-[35S]sulphonyl-triCB. The low radioactivity in lungs of the germ-free mice was also shown to be due to the accumulation of small amounts of the sulphones. The results indicate an involvement of the intestinal flora in the formation of methyl sulphone metabolites of triCB.

Animals↗
PubMed1982

Metabolism of 2,4',5-trichlorobiphenyl: tissue concentrations of methylsulphonyl-2,4',5-trichlorobiphenyl in germfree and conventional mice.

Whole-body autoradiography of 2,4',5-[14C]trichlorobiphenyl ([14C]triCB) indicated that, whereas there was accumulation of radioactivity in the tracheobronchial mucosa of conventional (C) mice 1-7 days after injection, no such effect was observed in germfree (GF) mice 1 day after injection. At days 4 and 7 there was a low, but significant, uptake by the tracheobronchial mucosa of the GF mice. Chemical analysis showed that the concentrations of 4-methylsulphonyl-triCB (4-MeSO2-triCB) in lung, kidney and liver 7 days after administration of triCB were 6.5, 14.7 and 3.7 times higher, respectively, in C than in GF mice. The results are interpreted as indicating the existence of a major metabolic route to triCB methyl sulphones involving the intestinal microflora, and a minor route, not requiring the flora.

Animals↗
PubMed1982

Fetal distress due to intravenous administration of pethidine (meperidine) with promethazine during labour.

Fetal bradycardia due to uterine hypertonia was observed after the intravenous administration of pethidine (meperidine) 75 mg with promethazine 25 mg during active labour. These analgesic drugs are known to affect uterine contractions by enhancing both amplitude and frequency, but are thought to affect uterine tone minimally. Twenty cases of uterine hypertonia resulting in fetal bradycardia were monitored in a period of 6 months in women receiving these drugs during labour. In all cases, the uterine hypertonia appeared shortly after the drug administration. The uterine hypertonus as well as the fetal bradycardia were self limited and no intervention was undertaken. Recognition of this phenomenon is important in order to prevent unnecessary anxiety on the part of medical attendants.

Bradycardia↗
PubMed1982

Neuronal losses in mice following both prenatal and neonatal exposure to phenobarbital.

Mice were given phenobarbital (PhB) during neonatal development (NeoB group) and during pre- and neonatal development (Pre- and NeoB group). Prenatal exposure was accomplished transplacentally by feeding the pregnant mothers 3 g PhB/kg milled food on gestation days 9-18. Neonatal exposure was conducted directly by injecting the neonates daily with 50 mg PhB/kg on postnatal days 2-21. The brains of these animals were studied at age 50 days using H & E staining. Consistent with previous studies, NeoB animals had a 14-20% smaller cerebellar layer area than controls, 32% fewer cerebellar Purkinje cells and 34% fewer granule cells than controls. NeoB mice had a 14-18% smaller hippocampal layer and 17% fewer hippocampal pyramidal cells than controls. The number of the hippocampal granule cells was not reduced by early PhB administration. NeoB mice had an 18% smaller cerebral cortex area and 22% fewer cortical cells than controls. The pre- and NeoB animals did not differ from controls in the area of their cerebellar layers, but they did have fewer cerebellar Purkinje and granule cells. Similarly, the Pre- and NeoB animals did not differ from controls in the area of their hippocampal layers, but they had fewer pyramidal cells. The Pre- and NeoB animals had a smaller cerebral layer area than controls but did not differ significantly from controls in the number of cortical neurons. It was suggested that exposure to PhB during prenatal and neonatal periods is not additive. On the contrary, tolerance or compensatory mechanisms may develop after prenatal exposure and lessened the effect of subsequent neonatal PhB exposure.

Animals↗
PubMed1982

Human sperm penetration into cervical mucus in vitro: correlation between its quality, penetration capacity and velocity.

In vitro penetration tests of human sperm into cervical mucus were introduced in order to study the interaction between sperm and cervical mucus. In the present study the correlation between sperm velocity and penetration value has been assessed. 197 semen samples were run in the in vitro penetration test using semen of different qualities and cervical mucus of good quality. No differences were found either between sperm velocity in cervical mucus (17.3 +/- 0.9 micrometers/s) and in semen (19.9 +/- 0.8 micrometers/s) or at different distances measured along the flat capillary tube (1, 2 and 3 cm). A highly significant correlation was found between sperm velocity and penetration value rates (p less than 0.0001, r = 0.9). Thus, sperm velocity in semen is a variable of great importance in the assessment of the quality of the ejaculate.

Cervix Mucus↗
PubMed1982

Metabolism of 2,2',5,5'-tetrachlorobiphenyl: formation of mono- and bis-methyl sulphone metabolites with a selective affinity for the lung and kidney tissues in mice.

1. Distribution in mice of 2,2',5,5'-tetrachloro[14C]biphenyl has been studied by autoradiography. Radioactivity was specifically localized in the bronchial epithelium, the lung parenchyma, the kidney cortex and the adipose tissue. 2. Bis(methylsulphonyl)-2,2',5,5'-tetrachlorobiphenyl, a hitherto unknown metabolite of 2,2',5,5'-tetrachlorobiphenyl, has been identified in lung, kidney and liver of mice. 3- and 4-Methylsulphonyl-2,2'5,5'-tetrachlorobiphenyl were also present. 3. The ratio of the contents of 3- and 4-methylsulphonyl-2,2',5,5'-tetrachlorobiphenyl in the liver was 1.12 after 12 days. A lower ratio in lung and kidney indicates a high affinity of these tissues for the 4-methyl isomer.

Animals↗
PubMed1982

Penetration of human ejaculated spermatozoa into human and bovine cervical mucus. II. Pattern and velocity of penetration.

The pattern of penetration of human ejaculated spermatozoa into human cervical mucus (HCM) and bovine cervical mucus (BCM) was studied in an in vitro penetration system by means of plate capillary tubes. Sperm penetrate the HCM in a unique pattern making their way progressively forwards in a one-way direction in between the filaments. In contrast, sperm move preferably forward in BCM. The different patterns are probably due to different organizations of the glycoproteins. The penetration values (PV) were also different in the two systems when studied after short periods of incubation (15 and 30 min), but incubation for 1 h brought both systems to the same rate of PV. Thus, this period is enough to overcome the differences between the patterns of penetration. Sperm velocity in semen, in HCM, and in BCM were the same. Cervical mucus (CM) did not affect sperm velocity. A strong correlation (r = 0.8) was found between sperm velocity in the semen and its PV rate either in HCM or in BCM. The results of this study recommend the use of BCM as a reference CM in cross penetration tests and suggest its establishment as a routine method for assessment of sperm quality.

Animals↗
PubMed1981

Bronchial mucosal and kidney cortex affinity of 4- and 4,4'-substituted sulphur-containing derivatives of 2,2'-5,5'-tetrachlorobiphenyl in mice.

In order to evaluate further the structural requirements previously proposed for accumulation of polychlorinated biphenyls (PCB) and their sulphur-containing metabolites in the respiratory tract of mice, 4-methylthio-, 4-methylsulphonyl and 4,4'-bis(methylthio)-2,2',5,5'-[14C] tetrachlorobiphenyl were studied by whole body autoradiography. All the compounds gave rise to a strong accumulation of radioactivity in the mucosa of the bronchi, trachea and larynx. The first two substances were also concentrated in the mucosa of the nasal cavities. At the longer post-injection times all the compounds studied were localized in distinct sites of the kidney cortex. However, while the uptake of the monosubstituted sulphur-containing tetrachlorobiphenyl metabolites there was comparatively weak, the bis(methylthio) derivative showed a remarkable accumulation and retention in the kidney cortex. The study makes it possible to formulate the structural requirements for bronchial accumulation on the basis of the structure of the compounds that are accumulated rather than on the structure of the unmetabolized polychlorobiphenyls. Also with regard to the uptake in the kidney cortex a specific structure-dependency seems to exist.

Animals↗
PubMed1981

Penetration of human ejaculated spermatozoa into human and bovine cervical mucus. I. Correlation between penetration values.

Midcycle bovine cervical mucus (BCM), fresh (FBCM) or frozen at -20 degrees C (BCMF), and human cervical mucus (HCM) were collected and tested in in vitro penetration tests, using human ejaculated spermatozoa of good quality. Penetration tests were performed at 34 degrees C for 1 hour, and the penetration value (PV) was calculated. Duplicates of each run were in a narrow deviation. Correlations between PV rates of the same semen samples in the 3 sources were found to be significantly high (HCM versus FBCM, r = 0.958; HCM versus BCMF, r = 0.982, and FBCM versus BCMF, r = 0.985), suggesting that human ejaculated spermatozoa penetrate the cervical mucus of all three sources at the same rate.

Animals↗
PubMed1981

Filtering capacity of bovine cervical mucus towards abnormal forms of human-ejaculated spermatozoa.

The filtration capacity of bovine cervical mucus (BCM), fresh bovine cervical mucus (FBCM) or frozen and thawed bovine mucus (BCMF) was studied, using human-ejaculated spermatozoa in comparison with the properties of human cervical mucus (HCM). Thirty semen specimens of good quality were used in cervical mucus (CM) penetrations, using capillary tubes containing CM of 30 HCM, 77 FBCM and 77 BCMF samples. Spermiocytograms were carried out on semen and cervical mucus at 1st and 3rd centimeter of the capillary tube after one hour of incubation. Smears were stained by Papanicolaou and the patterns of seven forms of sperm cells (normal, tapering, macrocephals, microcephals, pinhead, neck pathology and amorphous cells) were counted on a total of 100 cells in each slide. A clear, highly significant (P less than 0.0001) selection of cells penetrating the CM has been shown, preventing certain abnormal forms from penetrating the CM (macrocephals, neck pathology and amorphous cells) and enabling good penetration of normal sperm forms and moderate penetration of tapering, microcephals and pinhead cells. On the average, a specimen with normal sperm forms of 72% showed a spermiocytogram of 90% normal forms at the 3rd centimeter of migration. The same patterns of filtration were recorded in all the three sources of CM. It is suggested that BCM be used as a filter towards abnormal sperm forms in a highly teratozoospermic ejaculate in order to improve its quality for artificial inseminations.

Animals↗
PubMed1981

Audiogenic seizures and neuronal deficits following early exposure to barbiturate.

Sabra mice (n = 232) received phenobarbital (PhB) during the period of their prenatal development (PB group), or during the period of their neonatal development (NB group). PB mice received the barbiturate transplacentally by feeding their mothers PhB in their diet (3 g/kg food) on gestation days 9-18. NB mice received daily injections of PhB on postnatal days 2-21. On postnatal days 28-31 subjects were tested for their susceptibility to audiogenic seizures. Only 10% of the PB mice seized, a rate similar to the 13% of controls. However, the seizure rate of NB mice was three times higher than controls (37%, p less than 0.001). Sample groups were kept until day 50 and their brains removed and saved for quantitative histological analysis of the hippocampal neurons. In PB mice, there was only a small deficit in the number of the hippocampal pyramidal neurons compared to controls (15%, p less than 0.01), and no deficit in the granule cells. On the other hand, NB mice sustained a 35% deficit in the number of the pyramidal cells (p less than 0.001) and a 21% deficit in the granule cells (p less than 0.01). The sensitive period for the neuronal damage corresponded with the sensitive period for changes in seizures. Although other parts of the brain are also involved in seizure, the correlationi of the seizure with the hippocampus is important because the hippocampus is one of the major structures determining seizure.

Acoustic Stimulation↗
PubMed1981

Relationship between intellectual status and reading skills for developmentally disabled children.

The relationship between WISC-R Full Scale IQ and scores on the Woodcock Reading Mastery Tests were explored for 80 developmentally disabled children. While the children's reading skills correlated moderately and significantly with intellectual status, abstract reading skills, e.g., word comprehension, correlated more highly with Full Scale IQ than did concrete ones, e.g., word identification. The development of concrete learning patterns by such children was discussed, with an emphasis on the emotional importance of these learning styles to the children and their families.

Child↗
PubMed1981

Accuracy of some routine method used in clinical chemistry as judged by isotope dilution-mass spectrometry.

Serum from patients was pooled, filtered, dispensed, and frozen. This pooled specimen was used for accuracy control in 64 participating laboratories in Sweden. Mean values ("state-of-the-art" values) were obtained for creatinine, cholesterol, glucose, urea, uric acid, and cortisol. These values were compared with values obtained with highly accurate reference methods based on isotope dilution-mass spectrometry. Differences were marked in the case of determination of creatinine and cortisol. Concerning the other components, the differences between the state-of-the-art value and the values obtained with the reference methods were negligible. Moreover, the glucose oxidase and the oxime methods for determination of glucose and urea were found to give significantly lower values than the hexokinase and urease methods, respectively. We conclude that methods with a higher degree of accuracy are required for routine determination of creatinine and cortisol.

Blood Chemical Analysis↗
PubMed1980

Cysteine and methionine-precursors of methyl sulphone metabolites of 2,4',5-trichlorobiphenyl in mice.

In order to account for the origin of the sulphur atom in methyl sulphones derived from polychlorinated biphenyls (PCB), groups of mice were treated with 2,4'-5-trichlorobiphenyl and [35S]cysteine or [35S]methionine, respectively. Control animals received the labelled amino acids only. The radioactive substances extracted from lung tissue were characterized by partition between hexane and sulphuric acid, thin-layer radiochromatography (TLRC), gas chromatography (GC) and mass fragmentography (MF). In lung extracts of both experimental groups sulphuric acid soluble metabolites were present: Their Rf-values on TLRC were identifical with that of 4-methylsulphonyl-2,4'-5-trichlorobiphenyl and their identity was confirmed by GC and GC-MF, which also indicated the presence of a minor sulphone isomer. The study shows that both cysteine and methionine could function as donors of the sulphur atom in the methyl sulphone metabolites derived from PCB.

Animals↗