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Biomedical subjects

R A Feldman

Publications and source records attributed to R A Feldman.

At least 73 records · Page 4Linked to original sources
PubMed1989

The automatic internal cardioverter defibrillator (AICD): description and guidelines for interaction during cardiac arrest.

The development and increasing use of the automatic implantable cardioverter defibrillator (AICD) represents a major therapeutic advance for management of recurrent ventricular tachycardia and ventricular fibrillation. However, the AICD sensing functions that determine appropriate energy discharge may complicate resuscitation from cardiac arrest. This care report illustrates a properly functioning AICD interfering with the resuscitation of a 67-year-old man. In the presence of persistent ventricular tachycardia and ventricular fibrillation or successful conversion to a supraventricular tachycardia with pulses that exceed the rate cutoff, it may be helpful to inactivate the AICD with a magnet to prevent unneeded discharges during resuscitation and stabilization.

Aged↗
PubMed1989

A highly efficient retroviral vector allows detection of the transforming activity of the human c-fps/fes proto-oncogene.

We have constructed an efficient new retroviral vector containing strong promoting elements derived from the Friend murine leukemia virus (F-MuLV) long terminal repeat (LTR) and have used the vector to demonstrate that overexpression of human c-fps/fes can transform established mouse cells. When a c-fps/fes cDNA was cloned into the vector, this viral DNA and the recovered virus induced very high levels of the c-fps/fes product NCP92 and tumorigenic transformation of NIH 3T3 cells. Compared with an isogenic vector under control of a Moloney MuLV-derived LTR, the vector driven by the F-MuLV LTR induced 3- to 10-times-higher levels of expression of c-fps/fes, a higher level of phosphotyrosine in cellular proteins, and a virus whose transforming activity was 2 orders of magnitude greater. We conclude (i) that normal c-fps/fes can induce morphologic transformation and that its transforming activity is a function of the level of expression of NCP92 and (ii) that the vector based on the F-MuLV LTR is more efficient than the vector driven by a Moloney MuLV LTR in inducing high levels of expression and measurable biological activity.

Animals↗
PubMed1986

Occurrence and distribution of serotypes of the Arizona subgroup of Salmonella strains in the United States from 1967 to 1976.

The Salmonella Arizona subgroup contains gram-negative enteric bacteria that are closely related to other salmonellae biochemically, serologically, and genetically. Although the Arizona subgroup may be isolated from a wide variety of nonhuman and human sources, the arizonae are uncommonly recognized as human pathogens, and surprisingly little is known about their epidemiology. From 1967 through 1976, the Centers for Disease Control received 858 Arizona subgroup cultures from human and nonhuman sources representing 143 different serotypes in 33 somatic groups; several serotypes had not been previously reported. The 374 cultures from humans represent 71 different serotypes; extraintestinal isolates were present in 31 (44%) serotypes. Compared with data from a previous 20 years of surveillance, the proportion of Arizona subgroup strains isolated from stools, blood, and other sites was remarkably stable, but several serotypes showed marked changes in their frequency of isolation. In total, the ratio of extraintestinal to intestinal isolates was 0.37, but marked serotype-specific variation was noted, suggesting differences in virulence associated with serotype.

Amphibians↗
PubMed1986

Antipeptide antiserum identifies a widely distributed cellular tyrosine kinase related to but distinct from the c-fps/fes-encoded protein.

We raised antibodies directed against a synthetic peptide representing an amino acid sequence of the conserved kinase domain of the transforming protein of Fujinami sarcoma virus (FSV) (P140). The antiserum obtained specifically recognized FSV-P140 and its cellular homolog and in addition, it recognized a new cellular protein of 94,000 daltons (NCP94) in avian and mammalian cells. NCP94 was found to be associated with a cyclic nucleotide-independent protein kinase activity that was specific for tyrosine residues. Although NCP94 and FSV-P140 share antigenic determinants, NCP94 is not a cellular homolog of FSV-P140: NCP94 and the previously identified c-fps/fes product were different in their tryptic fingerprints and in their tissue specificities. Thus, the function of NCP94 in normal cells is probably different than that of the c-fps/fes product. NCP94 was expressed in every tissue and cell line that was examined. In chickens, NCP94 levels were highest during embryonic development and NCP94 expression was high in gizzard, brain, and spleen throughout embryonic and adult life. The universal expression of NCP94 suggests that this protein may be involved in an essential function of normal cells. NCP94 may be a new cellular tyrosine kinase of the src gene family.

Amino Acid Sequence↗
PubMed1985

Specific expression of the human cellular fps/fes-encoded protein NCP92 in normal and leukemic myeloid cells.

We have found that both an antibody directed against a synthetic peptide representing an amino acid sequence of the conserved kinase domain of transforming protein P140 of Fujinami sarcoma virus and a regressing tumor antiserum recognized the products of the c-fps/fes genes of both avian and mammalian cells. The anti-peptide antibody also recognized a 94-kilodalton protein that was related to but distinct from the c-fps/fes product in structure and in tissue distribution. A 92-kilodalton protein, NCP92, was found to be the mammalian counterpart of the previously identified avian c-fps/fes protein NCP98 by its structural similarity to NCP98, its associated tyrosine kinase activity, and its similar tissue distribution. The highest levels of NCP92 were found in tissue macrophages and in bone marrow. In bone marrow NCP92 expression was restricted to cells of the monocyte/macrophage and granulocyte lineages. That the expression of NCP92 is limited to these cell types was confirmed by the analysis of murine and human hematopoietic tumors representing different cell lineages: NCP92 was positive in leukemic cells of granulocytic and monocytic origin but not in B-lymphocytic, T-lymphocytic, or erythroid tumor cells. The expression of NCP92 seems to be related to the capacity of myeloid cells to differentiate and to respond to certain colony-stimulating factors.

Animals↗
PubMed1985

Electrical stimulation of the brain in treatment of chronic pain. Experience over 5 years.

Forty-eight patients underwent electrical stimulation of the brain for treatment of chronic pain between 1978 and 1983. Average pain duration prior to treatment was 4.5 years. Before selection for this procedure patients underwent pain treatment in a multidisciplinary pain center, intensive psychological and psychiatric evaluation, and assessment of pain responsiveness to intravenous administration of placebo, morphine, and naloxone. A total of 71 electrodes were placed in the 48 patients at a variety of stimulating targets, including the periaqueductal gray matter, periventricular gray matter, thalamus, and internal capsule. Seventy-two percent of patients experienced complete or partial pain relief. In addition, 59% of patients were able to discontinue narcotic usage. Twenty-five percent of patients returned to normal physical activities and another 33% showed marked improvement in functional capacity. Follow-up periods ranged from 2 to 60 months; with a mean follow-up period of 20 months. A variety of relatively minor complications occurred, but no mortality or permanent sequelae were experienced. No patient's pain was made worse as a result of electrical stimulation. Electrical stimulation of the brain offers a safe and relatively effective method for the treatment of chronic pain in appropriately selected patients, who are unresponsive to other forms of therapy.

Adult↗
PubMed1984

Unpasteurized milk. The hazards of a health fetish.

Meaningful differences in nutritional value between pasteurized and unpasteurized milk have not been demonstrated, and other purported benefits of raw milk consumption have not been substantiated. Conversely, the role of unpasteurized dairy products in the transmission of infectious diseases has been established repeatedly. To effectively counsel patients attracted by the health claims made for raw milk, practicing physicians must understand both the rationale used by proponents of raw milk and the magnitude of the risk involved in drinking raw milk.

Animals↗
PubMed1984

Importance of host factors in human salmonellosis caused by multiresistant strains of Salmonella.

Antimicrobial resistance patterns of Salmonella isolates from persons in randomly selected urban and rural counties in the United States were examined along with clinical and epidemiological characteristics of the host. Multiresistant strains, isolated from 66 (12.2%) of 542 persons evaluated, were associated with five of 20 variables in univariate analyses: serotype heidelberg, host of Hispanic origin, host exposure to penicillins within four weeks before stool culture, age greater than or equal to 60 years, and regular antacid use. By multiple linear regression, the first three variables were each significantly associated with infections due to multiresistant Salmonella. One or more of the last three variables, thought to be host factors that may promote disease, were present for persons yielding 38% of multiresistant strains but only 12% of sensitive strains (P less than .001). The relatively large proportion of multiresistant Salmonella among isolates from persons with these risk factors suggests that to cause disease, resistant organisms are more dependent than are sensitive organisms on host characteristics.

Adolescent↗
PubMed1983

Shigella infections in the United States, 1974-1980.

During the seven-year period 1974-1980, 93,516 Shigella isolates from humans were reported to the Centers for Disease Control, Atlanta, through a nationwide surveillance system. Over the past 30 years, the reported incidence of shigellosis has been declining in contrast to that reported for salmonellosis. Shigella sonnei (group D) now accounts for approximately 70% of the Shigella isolates reported, since most of the decline has been due to the increasingly less frequent infections caused by Shigella flexneri (group B); Shigella dysenteriae infections are now uncommon. The highest reported rates of shigellosis are from the western states and among children from one to five years of age. Among the total population of the United States, the ratio of S. flexneri to S. sonnei isolates was 0.28 among persons from one to 19 years of age and 0.45 among persons greater than or equal to 20 years of age; among American Indians the proportion of S. flexneri was much greater, the corresponding ratios being 2.1 and 2.9, respectively; in both groups the ratios for children younger than one year of age resembled those obtaining for adults. Age-related acquisition of immunity to S. sonnei may explain these observations.

Adolescent↗
PubMed1983

Cytoplasmic localization of the transforming protein of Fujinami sarcoma virus: salt-sensitive association with subcellular components.

Fujinami sarcoma virus (FSV) encodes a transforming protein of 130,000 daltons (P130) which is associated with a tyrosine-specific protein kinase activity. To elucidate mechanisms involved in cell transformation by FSV, we have studied the intracellular location of P130 in rat cells nonproductively infected with FSV. Immunofluorescent staining of several FSV-transformed rat cell lines with a tumor regressor antiserum specific against the fps sequences of P130 showed that the major staining was localized in the cytoplasm. Staining was also seen in cell ruffles and in some cases at areas of cell contact. The cytoplasmic location of P130 staining in cells infected with temperature-sensitive mutants of FSV was unchanged when they were grown at permissive or nonpermissive temperature. Cell fractionation of FSV-transformed cells under various conditions showed that the ionic strength used during cell fractionation had a striking effect on the distribution of P130. At 10 mM NaCl, 70% of P130 sedimented in the large granule fraction, whereas at 500 mM NaCl 70 to 90% of P130 was recovered in the cytosol fraction. Furthermore, a combination of ionic and nonionic detergents that effectively solubilized subcellular membranes was insufficient to solubilize P130 unless the salt concentration was raised. We conclude that the majority of P130 and its associated protein kinase activity are localized in the cytoplasm and that P130 is not an integral membrane protein.

Animals↗
PubMed1983

Infant botulism in the United States: an epidemiologic study of cases occurring outside of California.

Data were obtained for the 96 hospitalized cases of infant botulism reported to the Centers for Disease Control between 1976-1980 from all states other than California. Forty-one cases were associated with Clostridium botulinum type A, 53 with type B, one with type F, and one with a strain of C. botulinum capable of producing both type B and F toxin. Cases occurred in 25 states; the disease was more common in the western part of the United States, with the highest attack rates reported for Utah and New Mexico. Birth-weights of hospitalized infants with infant botulism tended to be high compared with birth-weights in the United States population. Mothers of infants with infant botulism tended to be older and better educated than mothers in the general population. Seventy per cent of infants had been predominantly breast-fed; breast-feeding in type B cases was associated with a significantly older age at onset of illness.

Birth Weight↗
PubMed1983

Campylobacter enteritis in the United States. A multicenter study.

During a 15-month study, 8097 fecal specimens submitted to clinical microbiology laboratories at eight hospitals in different parts of the United States were examined. Campylobacter jejuni was isolated from 4.6%, Salmonella from 2.3%, and Shigella from 1.0%. Isolation rates for each pathogen were highest from stool specimens that were watery, bloody, or contained leukocytes. The peak isolation rate for C. jejuni was in persons ages 10 to 29 years; for Salmonella, in children younger than age 10 years; and for Shigella, in children ages 5 to 9 years. The clinical features of the three infections were nearly identical. In contrast, abdominal pain, bloody diarrhea, fever, tenesmus, and abnormal sigmoidoscopy findings were present significantly more often in patients infected with C. jejuni than in a control group of patients with diarrhea. Of patients with leukocytes in their stools and a history of fever, 45.9% were infected with one of the three pathogens. Use of laboratory and clinical findings defined groups with high or low risk of these three infections but could not accurately predict isolation. Fecal cultures had the highest yields when obtained from patients within 7 days from the onset of symptoms.

Adolescent↗
PubMed1983

Risk factors for necrotizing enterocolitis in infants weighing more than 2,000 grams at birth: a case-control study.

A retrospective case-control study of necrotizing enterocolitis (NEC) was conducted among infants weighing greater than 2,000 g at birth. Twenty-three infants met the NEC criteria for inclusion in the study; 12 weighed 2,001 to 2,500 g at birth and 11 weighed greater than 2,500 g at birth. Hypoglycemia occurred in 7/12 (55%) infants weighing 2,001 to 2,500 g and in 4/35 (11%) control subjects (P less than .02). In infants weighing greater than 2,500 g at birth, polycythemia (occurring in 7/12 study infants (58%) and 5/32 (16%) control infants) and respiratory distress (3/11 study infants (27%) and 0 control subjects) were significantly associated with NEC (P less than .02). Larger infants with a history of perinatal stress and/or physiologic immaturity are likely to be at greater risk for NEC than their normal counterparts.

Birth Weight↗