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Biomedical subjects

S Blum

Publications and source records attributed to S Blum.

At least 91 records · Page 5Linked to original sources
PubMed1991

Pneumothorax in AIDS.

OBJECTIVE: To determine risk factors for the development of pneumothorax in patients with the acquired immunodeficiency syndrome (AIDS). DESIGN: Prospective cohort study. SETTING: Tertiary care center. PATIENTS: Of 1030 patients with AIDS who were followed at Memorial Sloan-Kettering Cancer Center between 1 January 1980 and 30 September 1989, 20 (2%) developed pneumothorax that was unrelated to trauma or a pulmonary procedure. RESULTS: Of 20 patients with AIDS who presented with pneumothorax, 19 had compelling evidence of concurrent Pneumocystis carinii pneumonia. Using bivariate analysis, patients receiving aerosol pentamidine prophylaxis (relative risk, 17.6) and those with a history of P. carinii pneumonia (relative risk, 14.5) were more likely to develop pneumothorax. By Mantel-Haenszel stratified analysis, aerosol pentamidine use was a statistically significant risk factor independent of a history of P. carinii pneumonia. The pneumothorax-related mortality rate was 10% and there was considerable morbidity. CONCLUSIONS: Patients with AIDS at the highest risk for developing pneumothorax are those with a history of P. carinii pneumonia who are receiving aerosol pentamidine prophylaxis but who nevertheless develop P. carinii pneumonia. The benefits of aerosol pentamidine prophylaxis in these patients far outweigh this risk. Pneumocystis carinii pneumonia should be considered as the most likely diagnosis in any patient with AIDS who develops a pneumothorax.

Acquired Immunodeficiency Syndrome↗
PubMed1991

[Cognitive evoked potentials in the diagnosis of senile dementia and dementia of Parkinson's disease: significance of multivariate analysis].

P300 latency is often delayed in dementia but some authors have questioned its value in clinical practice, because of the relatively low specificity and sensibility of the method. Numerous parameters (latency, duration, amplitude and surface) of N100, N200 and P300 waves were therefore studied in patients with senile dementia, subjects suffering from Parkinson's disease with dementia, and non-demented elderly patients. Using discriminant analysis, more than 90% of the patients were correctly classified. This method could thus be contributory in diagnosing dementia in clinical practice.

Cognition↗
PubMed1991

Diabetes mellitus--a newly described risk factor for infection from Salmonella enteritidis.

Infections due to Salmonella serotype enteritidis have increased markedly in the northeastern United States. Due to the potential severity of these infections, host risk factors for infection were determined in the largest nosocomial S. enteritidis outbreak to have occurred in the United States. In a case-control study, patients in a New York City hospital who developed infection after exposure to an S. enteritidis-contaminated meal were more likely to be medication-dependent diabetics than were those who did not develop infection (17/75 vs. 7/80, Mantel-Haenszel adjusted odds ratio = 3.1, 95% confidence interval = 1.1, 8.6). Proposed mechanisms for diabetes as a risk factor for infection include decreased gastric acidity in diabetic patients and an autonomic neuropathy of the small bowel that reduces intestinal motility and prolongs gastrointestinal transit time.

Aged↗
PubMed1991

The Puerto Rico and New York State tumor registries: problems associated with the use of cancer incidence data in migrant studies.

This paper discusses specific problems pertaining to compatibility of data between the Puerto Rico and New York State tumor registries, which is applicable to other studies comparing cancer incidence rates from two distinct tumor registries. Discrepancies in the data between the two tumor registries were due to differences in quality control, under and overreporting of cancer cases, reliability indicators, and case criteria. A study comparing stomach cancer incidence rates between Puerto Rico and Puerto Rican migrants to New York City provided the foundation for this investigation.

Emigration and Immigration↗
PubMed1990

Translation initiation factors that function as RNA helicases from mammals, plants and yeast.

Ribosome binding to eukaryotic mRNAs requires the concerted action of three eukaryotic initiation factors: eIF-4A, eIF-4B and eIF-4F as well as the hydrolysis of ATP. These initiation factors are implicated in the unwinding of mRNA 5' secondary structure and have been isolated from mammals, yeast and wheat germ. We used an RNA unwinding assay to compare the activities of these factors from the different species. We also measured the inter-species interchangeability of these factors in the unwinding reaction. In mammals, it has been previously shown that a combination of rabbit reticulocyte eIF-4F and -4B or eIF-4A and -4B were active in the RNA unwinding assay. In wheat germ, the combination of eIF-4A and eIF-4F resulted in RNA unwinding in a reaction that was stimulated by eIF-4B. Mammalian eIF-4A was able to substitute in this system. We also show that yeast eIF-4A is able to effectively substitute for mammalian eIF-4A in duplex RNA unwinding in combination with mammalian eIF-4B, while wheat-germ eIF-4A was only partially able to substitute. Taken together, these results suggest that initiation factor requirements for RNA unwinding are largely similar in mammals, yeast and plants.

Animals↗
PubMed1990

Expression of translation initiation factor 4A from yeast and mouse in Saccharomyces cerevisiae.

The eukaryotic translation initiation factor 4A (eIF-4A) plays an important role in regulating initiation. To analyze its function in yeast, we carried out a mutational analysis of the TIF1 and TIF2 genes, which encode eIF-4A. Expression of these two yeast genes has also been investigated at the transcriptional level and it has been found that both are expressed in wild-type yeast cells. Analysis of the expression of eIF-4A-beta-galactosidase fusion proteins reveals that the TIF2 gene is more highly expressed than the TIF1 gene. Interestingly, the yeast eIF-4A protein shows a high degree of amino acid sequence similarity to the mouse homologue. However, we find that the mammalian factor does not support protein synthesis in yeast either in vivo or in vitro.

Animals↗
PubMed1990

Translation initiation factor-dependent extracts from Saccharomyces cerevisiae.

Translation initiation factor 4A- and 4E-dependent extracts were developed from Saccharomyces cerevisiae and used to study factor requirements for translation of individual mRNAs in vitro. Whereas all mRNAs tested required eIF-4A, mRNAs devoid of secondary structure in their 5' untranslated region did not require exogenous eIF-4E for translation. The latter included alfalfa mosaic virus RNA4, mRNA containing the untranslated region of tobacco mosaic virus RNA and mRNA containing part of the untranslated region of poliovirus RNA. Furthermore, initiation of translation on mRNAs containing part of the untranslated region of poliovirus RNA is most likely internal.

Animals↗
PubMed1990

The 5'-leader sequence of tobacco mosaic virus RNA mediates initiation-factor-4E-independent, but still initiation-factor-4A-dependent translation in yeast extracts.

Messenger RNAs encoding chloramphenicol acetyltransferase (CAT) with or without the 5'-leader sequence of tobacco mosaic virus (TMV) RNA were synthesized in vitro and translated in Saccharomyces cerevisiae extracts dependent on eukaryotic initiation factors eIF-4E or eIF-4A. The 5'-leader sequence of TMV RNA renders translation of CAT mRNA eIF-4E-independent but still 4A-dependent.

Chloramphenicol O-Acetyltransferase↗
PubMed1990

A set of human putative lymphocyte G0/G1 switch genes includes genes homologous to rodent cytokine and zinc finger protein-encoding genes.

Lymphocyte G0/G1 switch genes (G0S genes) are potential oncogenes and may regulate, be regulated by, or be coordinately regulated with, latent lymphotropic viruses. To identify these genes, a cDNA library was prepared from blood mononuclear cells that had been cultured for 2 hr with a T-cell mitogen (lectin) and cycloheximide. Eight differentially hybridizing recombinants were characterized by RNA and DNA blotting and sequencing. One cDNA (G0S7) corresponded to the oncogene c-fos. Another cDNA (G0S19) was homologous (70%) to a cDNA encoding a murine inhibitor of stem cell proliferation (the cytokine MIP1 alpha) and, less closely, to other members of the "small inducible" secreted protein-encoding gene family. Whereas cDNA hybridization to genomic DNA blots indicated a small subfamily of G0S19 genes, simple patterns of bands indicated that most cDNAs, including G0S30 cDNA, corresponded to single-copy genes. The 3' noncoding sequence of G0S30 cDNA was homologous (87-89%) to the 3' noncoding sequences of certain rodent genes (NGFI-A, Krox24, EGR1) that encode zinc finger proteins (putative transcriptional regulators). This degree of evolutionary conservation suggests an important function for the 3' noncoding region. The 3' noncoding regions of some cDNAs contained the TTATTTAT (mRNA destabilization) element. The corresponding RNAs each formed doublets in agarose gels. Previous studies of c-fos RNA from HeLa cells indicate that this is due to cycloheximide-dependent stabilization of poly(A) tails. Our results reveal the power of cycloheximide enrichment in isolating what would appear to be significant low-abundance mRNAs.

Base Sequence↗
PubMed1990

Three human homologs of a murine gene encoding an inhibitor of stem cell proliferation.

The G0S19 genes are members of the "small inducible" family of genes, which have similar exon-intron organizations and encode secreted proteins with similar dispositions of cysteine and proline residues. G0S19-1 mRNA is increased shortly after the addition of lectin or cycloheximide to cultured human blood mononuclear cells. The cDNA sequence is homologous to that of a murine gene encoding an inhibitory cytokine (MIP1 alpha/SCI), which decreases hemopoietic stem cell proliferation. The homology extends to the 3' noncoding region, which contains two conserved elements: (i) GGGACTCTTC, a potential transcription factor NF chi B-binding site, and (ii) TTTTGTAATTTATTTT, which is found in some related genes (e.g., that encoding the immediate early protein ornithine decarboxylase). A similar but complementary sequence is present in human immunodeficiency virus. Two of the three human genes that hybridize to G0S19-1 cDNA were sequenced. G0S19-1 has 5' AP1-like recognition elements as found in some other phorbol ester-responsive genes (e.g., c-fos). G0S19-2 has a 5' Alu sequence, but is likely to be expressed because of the conservation of sections of the gene believed to be important for function. The 5' flanks of both genes contain the nucleotide motifs CK-2 and SRE, indicating cytokine-like genes with the potential to respond to growth factors. G0S19-1 is the main G0S19 gene expressed in adult T lymphocytes and may encode a homeostatic negative regulator of the size of cell populations (or subpopulations) which are derived ultimately from marrow stem cells. As such, it is a potential antioncogene.

Amino Acid Sequence↗
PubMed1990

Current trends in routine newborn male circumcision in New York State.

Despite the fact that circumcision of the new-born male has been practiced for at least 6,000 years, the procedure remains controversial. Circumcision rates in the United States remain among the highest of any nation in the industrialized world, yet there is little descriptive data on the demographic characteristics of newborns who are circumcised. New York State's hospital discharge data were used to examine demographic patterns for the procedure for the period 1980-1986. Circumcision was less common in New York City than in other areas of New York State, and was more common in private hospitals than in public hospitals. Whites had the highest rate of circumcision (70%), while Hispanics had the lowest (25%). Newborns under Medicaid coverage were more likely to be circumcised in voluntary hospitals than in public hospitals (45% vs 33%). We conclude that circumcision rates vary depending on a variety of factors, some of which may be attributable to the physician and others to family and society.

Circumcision, Male↗
PubMed1990

AIDS mortality among Puerto Ricans and other Hispanics in New York City, 1981-1987.

Analysis of AIDS mortality data for New York City for 1981-1987 reveals that Puerto Ricans represent the racial/ethnic group most severely affected by this city's AIDS epidemic. Cumulative age-adjusted AIDS mortality rates among Puerto Rico-born males are significantly higher (362 per 100,000) than among blacks (267), whites (182), or other Hispanic (217) males, and cumulative age-specific mortality rates for males are highest for the Puerto Rico-born in every adult age group. AIDS proportional mortality analysis indicates that in 1987 the proportion of all deaths due to AIDS was 10% among those Puerto Rican-born, 12% among other Hispanics (which includes at least 50% United States-born Puerto Ricans), 6% among blacks, and 2% among whites.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Translation in Saccharomyces cerevisiae: initiation factor 4A-dependent cell-free system.

Yeast Saccharomyces cerevisiae genes TIF1 and TIF2 (translation initiation factor) encode a protein tentatively called translation initiation factor (Tif) due to the similarity of its amino acid sequence and its molecular weight to mammalian eukaryotic initiation factor 4A. To clarify whether Tif is involved in translation, we produced an affinity-purified anti-Tif antibody by using Tif isolated from a Tif-overproducing yeast strain as immunogen and an Escherichia coli strain expressing Tif from an expression vector to provide the extract for affinity purification of the antibody. By using chromatographic procedures and the affinity-purified anti-Tif antibody as probe to identify Tif-containing fractions, we purified Tif from wild-type yeast cells. When yeast cells containing the only TIF1 gene on a plasmid under the control of the galactose-inducible CYC1-GAL10 promoter were grown in medium containing glucose as the carbon source, the production of Tif was shut off and growth was arrested. Lysates made from these cells were inactive in in vitro translation. Addition of Tif to these lysates restored in vitro protein synthesis. These results show that Tif is a translation factor, the yeast homologue of mammalian translation initiation factor 4A.

Blotting, Western↗
PubMed1989

Stop, thief!

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Hospital Administration↗
PubMed1989

Stomach cancer in a native and migrant population in Puerto Rico and New York City, 1975 to 1979.

This study compares age-adjusted stomach cancer incidence and mortality rates, by sex, among Puerto Rican-born residents of New York City (NYC/PR) and Puerto Rico (PR/PR) for the time period 1975 through 1979. One, three, and five year observed survival for cases diagnosed between 1975 and 1977 were compared. The results indicate that age-adjusted stomach cancer incidence rates per 100,000 among NYC/PR males (58.94) and females (27.58) were slightly higher compared to rates among PR/PR males (54.48) and females (25.73), while age-adjusted mortality rates were substantially higher among PR/PR males (46.38 vs. 37.29) and females (22.76 vs. 17.84), although these differences were not statistically significant. Differentials in observed survival consistently favored NYC/PR after one (43% vs. 35%), three (20% vs. 14%), and five years (11% vs. 9%) of follow-up.

Adult↗