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Biomedical subjects

D Klein

Publications and source records attributed to D Klein.

At least 235 records · Page 13Linked to original sources

[Analysis of volatile nitrosamines in foods and beverages: validity of results].

Analytical methods for volatile nitrosamines in foods and beverages are described. The possibilities of loss and formation of these compounds are discussed for each analytical step. The validity of the gas chromatographic and high performance liquid chromatographic determinations is evaluated for each detector type.

Beverages↗

[Presence of volatile nitrosamines in food].

122 foods and 46 beers from the north-east of France and other areas are analysed. The solid frozen samples are finely ground, homogenized and suspended in mineral oil. The volatile nitrosamines are vacuum distilled and extracted with dichloromethane from the acidified distillate. The sample is concentrated and analysed with a gas chromatograph coupled to a TEA detector. The liquid samples are directly extracted with dichloromethane. The non grilled cured meat products are lightly polluted. The nitrosodimethylamine and nitrosopiperidine concentrations usually do not exceed 1 ppb. Only two samples out of about thirty are very polluted by the nitrosopiperidine (28,6 and 26 ppb), and also by the nitrosopyrrolidine (3 and 11 ppb). In the other samples this last nitrosamine is seldom and occurs only in trace amounts. The precooked canned meals and the cheese products are rarely and only lightly polluted. However beers are polluted most of the time. The nitrosodimethylamine is found in all the pale beers, with a concentration ranging from 0.1 to 21.3 ppb (m: 3.1). In dark beers the nitrosodimethylamine concentration ranges from 7.2 to 16.8 ppb (m: 10.1) and the nitrosopyrrolidine concentration has a mean value of 0.2 ppb.

Cheese↗

[Hemoglobin D Punjab. Apropos of 2 families].

Two families who are carriers of hemoglobin DPunjab in the heterozygous state are described. This is the first time hemoglobin DPunjab has been reported in Switzerland. The propositus of the first family had two periods of acute hemolysis, probably drug-induced, which were followed by reversible renal complications and which led to the discovery of the hemoglobin. Study of the second family was undertaken because of anemia in one of its members.

Aged↗

Vertical transmission of group B Streptococcus. Relation to intrauterine fetal monitoring.

A prospective study of 70 mother-infant pairs was designed to evaluate vertical transmission of group B Streptococcus (GBS) in relation to the use of intrauterine fetal monitors (IUFMs). Multiple-site cultures obtained from mothers during the intrapartum interval and those obtained from infants on day 1 and at discharge or day 4 were plated on a selective medium. Thirteen (27.1%) of 48 IUFM-exposed women vs seven (31.8%) of 22 non-IUFM-exposed women had GBS at one or more sites. The GBS colonization with maternally concordant serotypes occurred in eight (61.5%) of 13 infants born to GBS-colonized, IUFM-exposed women vs two (28.6%) of seven infants born to GBS-colonized, non-IUFM-exposed women. While this suggests that vertical transmission of GBS is enhanced by IUFM placement, the differences in these infant rates were not statistically significant.

Cervix Uteri↗

Evidence for thyroid hormone-dependent and independent glucocorticoid actions in cultured cells. Studies on the induction of growth hormone and glutamine synthetase in GH1 cells and tyrosine aminotransferase in Reuber H-35 cells.

The induction of growth hormone synthesis and mRNA by thyroid hormone in cultured GH1 cells is mediated by the thyroid hormone nuclear receptor. In addition, the regulation of the growth hormone response by glucocorticoid is highly dependent on the action of thyroid hormone. To clarify whether thyroid hormone has a general influence on glucocorticoid action in GH1 cells, the glucocorticoid induction of growth hormone and glutamine synthetase was simultaneously examined. In contrast to the growth hormone response, the induction of glutamine synthetase by glucocorticoid was not influenced by thyroid hormone. Both responses appear to be modulated by the glucocorticoid receptor, and thyroid hormone had no influence on nuclear-associated glucocorticoid receptor levels. These results suggest that the thyroid hormone control of glucocorticoid induction of growth hormone may be a selective process, and the nuclear associated receptors for both thyroid and glucocorticoid hormones interrelate to control the growth hormone response.

Cell Line↗

Problems in the control of hypertension in the community.

A hypertension survey was conducted in Montreal to determine the extent, nature and distribution of the control of hypertension. Of the 12 055 persons screened in shopping centres, workplaces and a random sample of homes in four census tracts the hypertension was not controlled in 69.0% to 80.3% of those with the condition in each setting. Nearly two thirds of those with hypertension were aware of their condition, 13% were aware but had never been treated, 13% were receiving treatment inadequate to control their hypertension, and 11% had discontinued treatment, most reporting that they had done so on the advice of their physician. Among those screened in their home, discontinuance of therapy was most often reported by those with a low income, but lack of awareness of their condition was no more prevalent in this group than in the other income groups. Efforts to control hypertension should be directed to the variety of causes of lack of control, which may occur with various frequencies in different communities, and for which screening alone may be inadequate.

Adult↗

[Degenerative ocular retinal albinism in a girl ten years old (author's transl)].

Ocular albinism with myopia and impaired vision (R.E. 0.2; L.E. 0.6), but without nystagmus, were observed in a 10-year-old girl. The electrophysiological tests indicate, in addition, the presence of a tapetoretinal degeneration. It is assumed that the patient is carrier of two genes, a sex-linked one responsible for albinismus solum fundi and a second one of autosomal-recessive type, responsible for the tapetoretinal degenerartion.

Albinism↗

[Haemoglobinosis C/beta-thalassemia double heterozygosity in an Algerian patient with total suppression of haemoglobin A synthesis (author's transl)].

The authors describe the case of a young Algerian, aged 32, suffering from mild icterus, accompanied by a marked splenomegaly. The blood count revealed a moderate degree of anaemia with reticulocytosis, pronounced anisocytosis, micro-spherocytes, bulls eye cells, folded cells, hypochrome cells, a marked polychromasia and a mild erythroblastosis. Present also were hyperbilirubinaemia, raised plasma haemoglobin, zero haptoglobin, a reduced osmotic fragility and half-life of erythrocytes. Haemoglobin electrophoresis showed 17.25% haemoglobin F, 62.8% haemoglobin C+A2 and no haemoglobin A. The genetic study indicated that the patient was a double heterozygote C/beta thalassaemia, his mother and his son both suffering from this disease. This thalassemic gene of type beta (0) totally inhibited the synthesis of haemoglobin A, the defect found in our patient.

Adult↗

[Do all cases of trisomy 18 with long survival (beyond 10 years) show mosaicism in fibroblasts? (author's transl)].

Description of a young girl aged 16 1/2 years who presents the typical features of trisomy 18 : small height, microdolichocephaly, anti-mongoloid palpebral fissures, micrognathia, microstomia, arched palate, malformed ears, atrophy of thenars and hypothenars, clinodactyly of fifth fingers and abortive cutaneous syndactyly between IV and V. At the lower limbs, there is a shortening of the right leg, an atrophy of the calves, as well as genua valga and bilateral pes excavatus with dorsiflexion of the toes. The gait is rigid with enlarged basis of sustentation. The results of the cardiac examination point to a minor ventricular septal defect. The development of secondary sexual characters (breasts and body hair) corresponds to the puberal age; the large pudendal lips are hypoplastic. The X-rays show a double left kidney. There is a very severe oligophrenia (I.Q. = 20). Cytogenetic examinations showed a typical trisomy 18 in 100% of observed lymphocytes, while the analysis of cutaneous fibroblasts revealed a mosaicism with 87% of trisomic cells. Out of 11 cases of trisomy 18 with long survival from the literature only 3 cases were of mosaic type. The authors assume that this small number of mosaic cases in trisomy is probably due to the fact that no examination of fibroblasts has been carried out in the seven other cases.

Abnormalities, Multiple↗

[Influence of microorganisms on the formation of nitrosamines].

The N-nitroso compounds synthesis from amine and nitrite contained in food is influenced by many factors: -the pH; -the temperature; -the amine basicity; -the presence of organic groups which catalyse or inhibit the reaction. The chemical nitrosation of the amino group takes place at pH between 2 and 4,5. At the near neutrality pH of most of food, this synthetis, cannot be realised. Under these conditions the nitrosamine occurence can be explained by the effect of microorganisms. We have studied the influence of moulds used in cheese making on the nitrosation reaction in a middle where nitrate and amino groups are found together. The middles are realised on caseine or curdled milk, and contained 150 mg/l of nitrate and 100 mg/l of piperidine. The nitrosopiperidine has been identified in all the middles studied. The results are discussed concerning the risk of nitrosamine formation of this type of food during the technological process.

Amines↗

[Relase of organochloride pesticides during acute weight losses (author's transl)].

The increase of blood organochloride pesticide levels and the urinary excretion have been determined in 4 human subjects undergoing a caloric restriction sequence (500 total K. calories per day) followed by a total starvation period of 36 hours. The severe lipolysis due to the caloric restriction causes an important liberation of fat-soluble pesticides especially DDT and DDE (30 ppb of total DDT equivalents) and an increase of urinary excretion (15 ppb of total DDT equivalents).

Adult↗