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Biomedical subjects

J Baumgartner

Publications and source records attributed to J Baumgartner.

At least 37 records · Page 2Linked to original sources
PubMed1991

Progressive multifocal leukoencephalopathy in persons infected with human immunodeficiency virus, San Francisco, 1981-1989.

Progressive multifocal leukoencephalopathy (PML), a rare neurological disease, has been sporadically reported in persons infected with human immunodeficiency virus (HIV), the causative agent of acquired immune deficiency syndrome (AIDS). From January 1981 through February 1989, in San Francisco, we identified 94 HIV-infected persons with PML, of whom 48 (51%) were pathologically confirmed (as required for AIDS case reporting). These 48 patients were significantly older when diagnosed with AIDS (20% older than 50 years) than patients with AIDS without PML. The remaining 46 (49%) patients, diagnosed clinically and by neuroimaging, did not differ significantly from definitive patients in demographic or survival characteristics after PML diagnosis. We detected antibodies to JC virus, the causative agent of PML, in 9 of 14 (64%) AIDS-related patients with PML, and in 9 of 14 (64%) matched control subjects, suggesting that determination of JC virus antibody status before AIDS diagnosis does not reliably indicate which patients will contract PML. Our study shows that the proportion of patients with AIDS who contracted PML remained stable between 1981 and 1988, but increased in the first 2 months of 1989. Our findings further indicate that PML in HIV-infected patients may be underestimated by as much as 50%.

Adolescent↗
PubMed1991

Evidence for molecular subtypes of HIV-associated lymphoma: division into peripheral monoclonal, polyclonal and central nervous system lymphoma.

The pathogenesis of the HIV-associated lymphomas is not well understood. In order to begin characterizing this class of lymphoma, we initiated a molecular genetic study of DNA extracted from 31 diagnostic biopsy specimens from patients diagnosed with AIDS-associated non-Hodgkin's lymphoma. Analysis of 25 peripheral lymphomas showed that 14 were monoclonal B-cell processes, while 11 appeared to be of polyclonal origin. Five of the 14 monoclonal lymphomas were found to have rearrangements of the c-myc gene. Epstein-Barr virus (EBV) genomes were found in seven out of 14 monoclonal samples, but only two out of nine polyclonal samples. The six primary central nervous system (CNS) lymphoma samples were more homogeneous than the peripheral samples and all were monoclonal, positive for EBV and lacked detectable c-myc gene rearrangements. This study allows us to subdivide the HIV-associated lymphomas into three major molecular subtypes: (1) monoclonal B-cell process frequently associated with c-myc rearrangement or detectable EBV genomes, (2) polyclonal B-cell process typically without evidence of EBV, and (3) monoclonal primary CNS process associated with EBV genomes and lacking detectable c-myc rearrangement.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Estimation of the quality of irradiated spermatozoa from cockerels using the classical method and zona-free hamster ova.

1. The quality of gamma irradiated spermatozoa from cockerels was investigated by measuring motility, oxygen consumption and ability to penetrate zona-free hamster ova. 2. Doses of 750 Gy slightly reduced motility and oxygen consumption; however, irradiated spermatozoa penetrated on average 56% (minimum 33%) of hamster ova. 3. The zona-free hamster ova test may be useful for estimating avian sperm quality.

Animals↗
PubMed1989

[Vascular complications in surgery of the hip joint].

The mechanisms of severe vascular injury during surgery of the hip joint are depicted with reference to the authors' own patient series and a review of the literature. Massive arterial hemorrhage is most commonly caused by the tip of a Hohmann retractor. Special care must be given to placement of the proximal retractor directly against the pelvis behind the anterior lip of the acetabulum, and this must be checked with the finger tip. Other mechanisms of injury are: massive venous bleeding can result if a coil of pelvic vein is rolled up with a Kirschner wire; arterial thrombosis can be caused by the polymerization heat of bone cement; or intimal dissection can be caused by pressure of a retractor or loosening of an intimal plaque, resulting in ischemia of the corresponding limb; arterio-arterial embolism can originate from appositional thrombus formation on a chronically weakened arterial wall; false aneurysms may be due to instrumental arterial injury; and arteriovenous fistulae can be caused by a piercing instrument. Laceration of the external iliac or common femoral artery is best treated by interposition of a saphenous vein graft. Angiological examination before and immediately after hip surgery is advocated.

Amputation, Surgical↗
PubMed1988

DNA content of spermatozoa in different genetic lines of turkeys.

The variability of DNA content in turkey spermatozoa of four different lines and its correlation with body weight and sperm concentration were studied. In lines selected for lower body weight the DNA content was 2.034 and 2.036 pg per spermatozoon. In lines selected for higher body weight the DNA content was 2.267 and 2.370 pg per spermatozoon. Sperm concentration in 1 mm3 of semen, however, was higher in lines with a lower body weight (6.08-6.21 million) in comparison with lines selected for higher body weight (5.46-5.67 million). The correlations between the DNA content and sperm concentration were negative (r ranged from -.457 to -.860).

Animals↗
PubMed1987

[Is it necessary to operate on asymptomatic aneurysms? Apropos of 114 surgically treated asymptomatic aneurysms].

A six years retrospective analysis of asymptomatic aneurysms (A.A.) was done in 4 neurosurgical departments: 114 AA were clipped in 99 patients. In 44 patients (48 asymptomatic aneurysms) the surgical procedure was achieved in one step for both symptomatic and asymptomatic aneurysms. In 59 patients (66 asymptomatic aneurysms) the surgical procedure was delayed as it necessitated a second and elective craniotomy. As regard the treatment of asymptomatic aneurysms, there was no morbidity, and one death due to a massive pulmonary embolism. These surgical results are undoubtebly better than the risk of hemorrhage from unruptured aneurysm as emphasized in the literature.

Adult↗
PubMed1986

Isolation and partial characterization of Japanese quail oviduct mRNAs.

The total mRNA was prepared from laying quail oviduct and, after denaturation with dimethyl sulphoxide and glyoxal, characterized by agarose gel electrophoresis. The electrophoresis showed that the preparation contains physically homogeneous molecules of mRNAs, which migrate as discrete bands. The molecular weights of four major oviduct mRNAs coding for conalbumin, ovalbumin, ovomucoid, and lysozyme were determined. The biological activity of mRNAs was assayed in a cell-free translation system derived from rabbit reticulocytes. One of the translation products, ovalbumin, was proved by immunoprecipitation.

Animals↗
PubMed1985

Methylation of plasmacytoma c-myc genes.

The chromosomal translocation associated with many tumors of immunoglobulin-producing cells frequently results in the joining of the immunoglobulin heavy-chain locus and the c-myc oncogene. This translocation of c-myc has profound structural and functional consequences for the oncogene, including loss of the 5' end of the gene and transcriptional deregulation. We report in this communication that translocation results in a new methylation pattern of c-myc. In normal kidney and liver tissue, the c-myc gene is methylated at its 3' end. The translocated gene in plasmacytoma DNA is extensively demethylated. On the other hand, the nonrearranged c-myc gene in plasmacytoma DNA (which is transcriptionally silent) is extensively methylated. In addition, we confirm the nucleotide sequence (with 19 discrepancies out of 1400 bp) 5' to the murine c-myc gene, as reported by Corcoran et al. [Cell 40 (1985) 71-79].

Animals↗
PubMed1985

The effect of total body gamma-irradiation on mortality, egg production and egg weight of Japanese quails.

Male and female Japanese quail 21 weeks old, that were given total body doses of 60Co gamma-rays ranging from 0 to 30 Gy, showed a peak in mortality at 6-8 days post-irradiation. The LD 50/30 was 22.5 Gy, and the LD 90/30 was 26.7 Gy. No differences were evident in mortality between males and females. The reduction in egg production by 30 days post-irradiation was related linearly to the dose, for doses above 6 Gy. The reduction in egg weight (30 days post-irradiation laying period) was also related linearly to the dose.

Animals↗
PubMed1985

[Early surgery of ruptured aneurysms. A factor in preventing ischemia].

110 patients with ruptured aneurysms were operated on within 4 to 96 hours after subarachnoid hemorrhage. Clinical grades (Hunt) were: 1-2-3 in 93 cases and 4-5 in 17 cases. Among the patients grades 1-2-3, 81% had a good out come without any neurological abnormality, among the patients graded 4-5, only 27% had a fair out come. Cerebral ischemia has been noted (CTS can + neurological deficits) in 7 cases only among patients graded 1-2-3 (93 cases). The results, concerning ischemia, are better than the natural course of ruptured aneurysms and better than the course in series with delayed operation. Probably vasospasm is not alone to create ischemia.

Adult↗
PubMed1981

[Surgical and pathological study of the approach to the superior choroid plexus of the 3 rd ventricle. One case of posterior choroid arteriovenous aneurysm (author's transl)].

The authors describe a case of an arterio venous malformation of the tela choroidea of the third ventricle which was feeding by the postero medial choroidal artery and draining by the internal cerebral vein. This A-V malformation was microsurgically excluded in sitting position by an occipital interhemispheric, transtentorial and transversal transcallosal approach without any postsurgical clinical signs. An anatomical study of this region shows an easy recognition of the choroidal postero medial artery by the regular presence of an arterial loop which concavity is crossed by the terminal segment of the basilar vein of Rosenthal. The knowledge of the occipital internal veins drained in the callosal posterior vein to form a common trunk, the cuneo limbic vein drained itself into the vein of Galen is important to know. This venous system is to preserve at the time of retraction of the occipital lobe to not give rise to infarction and therefore hemianopsia. At least the transverse section of the posterior part of corpus callosum permits a good approach of the roof of the third ventricle and is clinically very harmless if the protection of the cuneo limbic vein is assumed.

Adult↗
PubMed1978

Number of response alternatives and spatial arrangement on a visual discrimination task.

Normal children, 30 each from ages 5 and 7 yr., were administered a visual discrimination test through a programmed learning machine. Visual discrimination was defined as a match-to-sample task in which subjects pointed to the geometric form, number, or printed letter of the alphabet that matched the stimulus form. Procedures were designed to eliminate learning variables. Although both age groups performed well, there was a statistically significant difference in the total performance at the two ages. A 3-way analysis of variance showed age, number of response alternatives, and type of stimulus form were significant variables; all interactions were significant. It appeared that the significant variable for the 5-yr.-olds was the type of geometric configuration, while the variable most important for the 7-yr.-olds was the number of response alternatives. Patterns of errors on the most difficult item showed the 5-yr.-olds made errors involving a reversal or rotation of the stimulus figure, while the 7-yr.-olds made errors involving some detail of the stimulus figure.

Child↗
PubMed1977

[HLA-B27 antigen and alkaptonuria].

Study of urinary homogentisic acid and a determinantion of group HLA were carried out for 36 members of a family spread over three generations with three cases of ochronotic rheumatism in the second generation. Alkaptonuria was discovered in seven other subjects, six of them members of the third generation: urinary elimination was poor, less than 0.60 g/24 hours. There is a certain degree of consanguinity in the family studied here and these findings do not therefore rule out a recessive autosomal transmission of the alkaptonuria. They do however lead to the consideration that alkaptonuria may sometimes be found in heterozygotic subjects. A genetic relationship between HLA complex and alkaptonuria can only be claimed with difficulty from this familial study, but the high frequency of B 27 antigen (29 out of 36 members carring it) leaves room for the hypothesis that the B 27 gene, or more precisely a gene associated with the B 27 gene, plays a part in the development of ochronotic rheumatism.

Adult↗