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R Karp

Publications and source records attributed to R Karp.

At least 37 records · Page 2Linked to original sources
PubMed1988

The molecular analyses of an antimorphic mutation of Drosophila melanogaster, Scutoid.

A dominant mutation of Drosophila melanogaster, Scutoid (Sco), acts as an antimorphic allele of the no-ocelli (noc) gene. In Sco the noc region has been transposed from 35B to 35D on chromosome arm 2L and the noc gene is now adjacent to snail (sna). Induced revertants of Sco are frequently mutant for sna or are aberrations broken very close to sna. A molecular analysis of the Sco chromosome has confirmed that noc is transposed and fused to the sna region. However, only part of the noc region is included within the transposition. The breakpoints of 19 chromosomally aberrant Sco revertants have been mapped at the molecular level. Fourteen of these breakpoints map to the noc region, spread over about 80 kb of DNA. The breakpoints of the remaining five are not within the DNA of the noc region and appear to map within sequences from the sna region. This has been shown directly for three of these, those associated with T(2;3)ScoR+13, In(2L)ScoR+24 and In(2L)ScoR+26. Thus mutation of either noc or sna, genes which are apparently unrelated in their wild-type functions, can revert the antimorphic phenotype of Sco.

Animals↗
PubMed1985

Mutation of the Adh gene of Drosophila melanogaster containing an internal tandem duplication.

AdhnLA248 is an X-ray-induced mutation of the alcohol dehydrogenase gene of Drosophila melanogaster that lacks detectable ADH protein but is transcribed. The transcript of this mutant allele is longer than that of the wild type. This is because the mutation is a duplication of parts of the second and third exons of Adh and of the intron that normally separates them. The primary transcript of the mutant allele is processed by the removal of both of the identical copies of intron 3. This mutation presumably originated, in the haploid sperm, as two staggered single-stranded breaks that gave rise to the duplication as a consequence of replication after fertilization.

Alcohol Oxidoreductases↗
PubMed1985

Molecular analysis of the Adh region of the genome of Drosophila melanogaster.

A small region of the genome of Drosophila melanogaster has been cloned in a series of overlapping phage. A length of 165 X 10(3) base-pairs of contiguous DNA that spans polytene chromosome region 35A4 to 35B1 and includes the structural gene for alcohol dehydrogenase (Adh) as well as at least two other genes, outspread (osp) and no-ocelli (noc), has been characterized by mapping chromosome aberrations to the DNA. The relationship between osp and Adh is surprising: of nine osp alleles associated with chromosome breakpoints, five map distal (i.e. 5') to Adh and four map proximal (i.e. 3') to this gene. None affects the expression of Adh. As defined by these and other breakpoints, the osp gene spans at least 52 X 10(3) base-pairs and overlaps the Adh gene. The noc gene, as defined by the mapping of nearly 30 breakpoints, is at least 50 X 10(3) base-pairs in size. Alleles of noc and noc- deletions show either of two kinds of interaction with the recessive lethality of l(2)br29ScoR+1, a lethal that maps immediately distal to noc. One class of noc allele is viable when heterozygous with ScoR+1, while the other class is lethal or semi-lethal. Both classes, however, are homozygous or hemizygous viable. The locations of these two classes of noc allele on the DNA fall into two clusters, with those that are viable with ScoR+1 located proximal to those that are not. The physical boundary between these classes lies at a site just distal to that of the breakpoint of the inversion associated with ScoR+1 itself.

Alcohol Oxidoreductases↗
PubMed1984

The relationship between cardiac output and effective renal plasma flow in patients with cardiac disease.

The relationship between effective renal plasma flow (ERPF) and cardiac output was examined in 46 patients (22 with congestive heart failure and 24 following cardiac surgical procedures) by simultaneously measuring the global ERPF by the single-injection method and cardiac output by the thermodilution method. Of the patients in the heart-failure group, 21 also had pulmonary artery end diastolic pressure (PAEDP) recorded at the same time. ERPF and cardiac output were found to be related by the regression equation: cardiac output = 2.08 +/- 0.0065 ERPF (r, 0.80), with a SE of estimate of 0.81 l/min. ERPF and PAEDP were related by the regression equation: PAEDP = 45.02-0.0675 ERPF (r, 0.86), with a SE of estimate of 5.5 mm Hg. ERPF may be a useful noninvasive method of estimating cardiac output if it is known that no intrinsic kidney disease is present, and if the error of 0.81 l/min (1 SE of estimate) is within the range of clinical usefulness. The error is principally attributable to the determination of cardiac output by the thermodilution method.

Adult↗
PubMed1983

Increase in nociceptive input to spinocervical tract neurons following chronic partial deafferentation.

Recordings from antidromically identified spinocervical tract (SCT) cells in the partially deafferented spinal cord of chloralose-anesthetized cats have revealed reorganization of their input from peripheral receptors in the skin. Immediately after dorsal rhizotomy of segments L5, L6, S1, and S2, (sparing L7), units in L6 had a lower than normal probability of responding to moderate pressure, mechanical nociceptive, noxious heat, and cooling inputs. This persisted for about 6 weeks, after which normal or even larger than normal proportions of SCT units could be driven by these inputs. The proportion of units driven by hair deflection remained large throughout this period. Responses in the L7 segment with intact L7 dorsal root were unchanged. We suggest that afferent fibers from different receptor types differ in the extent of their normal functional projection, accounting for the selective changes after acute deafferentation. The chronic changes may reflect a differential ability of surviving afferent fibers to undergo compensatory changes in their projection (e.g., sprouting) after chronic rhizotomy.

Afferent Pathways↗
PubMed1982

Dermoid cyst of the tongue with sinus tract.

This article reports a rare case of a dermoid cyst of the body of the tongue in a 5-year-old child. A small nodule in the midline of the dorsum of the tongue had been present since birth. Surgically removed, the lesion was of a sinus tract that was apparently also present since birth. It was connected to the cyst within the musculature of the tongue. There has been no recurrence.

Child, Preschool↗
PubMed1981

Posttransplant serum analysis in human kidney allografts.

Monitoring of 25 first cadaver transplant recipients was carried out weekly after transplantation. A total of 441 sera were tested from these patients against B and T lymphocytes at 4 degrees C and 37 degrees C for development of cytotoxic antibodies. Thirteen of the 25 patients (52%) developed B-cold antibodies as their first antibodies and all had functioning kidneys. Five of the patients developed B-warm antibodies initially, and all 5 rejected their transplants within 24 days. Of the seven patients who did not develop antibodies, 3 rejected their kidneys within 72 days. We conclude that it is important to distinguish between two types of antibodies to B lymphocytes--those reactive in the cold and those reactive in the warm--since they have opposite effects. Of the 17 successful grafts, 13 first developed B-cold cytotoxins.

B-Lymphocytes↗
PubMed1980

Electron probe analysis of cultured vascular smooth muscle.

Mitochondrial and cytoplasmic composition were determined with electron probe analysis in freeze-dried guinea pig aortic smooth muscle cells cultured on stainless steel grids. The mitochondrial calcium content in normal cells was low: not significantly different from that detected in the cytoplasm. Mitochondrial calcium granules were found in less than 3% of the cells, and in these the cytoplasmic K/Na ratio was reduced, indicating that they were damaged. There were no major differences between the cytoplasmic concentrations of K, Cl, Ca, Mg, and S of cultured cells and those previously found in adult vascular smooth muscle (Somlyo et al '79). There was no evidence of nuclear Na or Ca sequestration in cultured cells, and the transmitochondrial Na, Cl, and K gradients were small. Attempts to selectively remove adhering, extracellular ions with a 2-second wash with isotonic ammonium acetate were unsuccessful because they were accompanied by loss of cell K.

Animals↗
PubMed1976

Antigen dose response and specificity of production of the lymphokine eosinophil stimulation promoter.

The present investigations of the recently discovered lymphokine eosinophil stimulation promoter have (1) shown that the assay system is highly sensitive and reproducible via the establishment of dose-response curves and their statistical analysis, (2) demonstrated that the direct assay is specific with use of eosinophilrich peritoneal exudate cells obtained from mice with either schistosomiasis or trichinosis, (3) demonstrated that the indirect test with splenic lymphocytes is specific with use of both the above method and radioisotope-labeled antigens, and (4) provided information on the roles of eosinophils and mononuclear cells via purification, reconstitution, and the use of antiserum to eosinophils.

Animals↗
PubMed1976

The eosinophil stimulation promoter test in murine and human Trichinella spiralis infection.

A test for the lymphokine eosinophil stimulation promoter (ESP) has been adapted to the study of Trichinella spiralis infections in mice and has been used as an aid in the diagnosis of trichinosis in a patient. With use of soluble antigen extracted from T. spiralis larvae and peritoneal exudate cells rich in eosinophils obtained from mice with trichinosis of four weeks' duration, a dose-response curve was constructed and analyzed. The soluble larval antigens greatly enhanced the migration of eosinophils from the mice with trichinosis but had no effect on the eosinophils from mice with schistosomiasis, nor did soluble schistosome egg antigens have any effect on the cells from mice with trichinosis. On two occasions peripheral white blood cells from a patient with presumed T. spiralis infection gave strongly positive results in ESP tests on stimulation with soluble larval antigen, but the cells did not respond significantly to soluble schistosome egg antigen; the result in the ESP test was positive before the patient's serum produced a weakly positive agglutination response.

Animals↗