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Biomedical subjects

R Robinson

Publications and source records attributed to R Robinson.

At least 343 records · Page 19Linked to original sources
PubMedDate not supplied

Rex mutant in the Norway rat.

A new rex or curly coat mutant in the Norway rat is reported. The vibrissae are bent, the coat is shorter than normal and has a harsh texture. The condition is due to a dominant gene designated rex (symbol Re). The coat of the homozygote (ReRe) is more severely affected than the heterozygote (Re+) and displays a transient baldness at about five weeks of age. Careful comparison suggests that Re is probably distinct from the four rexoid mutants previously described in the Norway rat.

Animals↗
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Chinese crested dog.

The Chinese crested dog is devoid of hair except for the crown of the head, lower part of the limbs and tail. The breed is produced by a dominant gene for hypotrichosis (Hr) in combination with the gene for long hair (l). The homozygote HrHr is a prenatal lethal, hence the Chinese crested dog is an obligate heterozygote. The long haired segregants, ++ ll, are known as powderpuffs.

Alopecia↗
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Gray mutant in the Mongolian gerbil.

A new autosomal recessive mutant, gray (symbol g), is reported for the Mongolian gerbil. The pelage of mutant animals is devoid of phaeomelanin pigment while the eumelanin is scarcely affected. The normal sandy-gray agouti wild type becomes a light gray. The phenotypes that result from combining the gray gene with previously reported color genes, nonagouti, (a,) and pink-eyed dilution (p), are described.

Albinism↗
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Brown and rust mutants of the Syrian hamster are p and b genes of mammalian coat colors.

The mutant genes of the Syrian hamster, which were originally designated as brown (b) and rust (r), are shown by morphological and phenotypic criteria, as well as by linkage studies in the case of brown, to be homologous with pink-eyed dilution (p) and brown (b), respectively, two well established loci in the genetics of mammalian pigmentation. It is proposed that the two mutants be appropriately redesignated.

Animals↗
PubMedDate not supplied

Dominant white spotting in the Chinese hamster.

An autosomal dominant white spotting mutant is described for the Chinese hamster. The mutant gene is designated as dominant spot (symbol Ds). The homozygote DsDs is a prenatal lethal while the heterozygote Ds + displays white spotting. The expression of white is variable, ranging from a white forehead spot to extensive white on the body. The venter is invariably white. Growth appears to be normal and the fertility of both sizes shows no impairment.

Animals↗
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Tabby pattern alleles of the domestic cat.

The status of genetic variation of tabby pattern in the domestic cat is reviewed. Three alleles of the tabby locus (T) have been identified, namely, Abyssinian (Ta), striped (T), and blotched (tb). Additional data are presented for the assortment of these alleles. The Abyssinian is incompletely dominant to the striped and blotched alleles, whereas striped is completely dominant to the blotched.

Alleles↗
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Two recessive rex coat mutants in the guinea pig.

Two rex type coat mutants of the guinea pig were found to display monogenic recessive inheritance at independent loci. The mutant alleles were designated rex (rx) and waved (wv). Both genes modify the normal smooth coat to a more upright, somewhat unkempt pelage. Macroscopically, the two rexes are scarcely distinguishable. Microscopically, however, small differences are apparent in the degree of coat modification. The hairs of rex show a greater curvature than normal and have irregular secondary bends and twists and variable diameter; so do those of waved, but to a lesser degree. The vibrissae of rex are curved or bent and may break off; those of waved are a mixture of straight, curved, and bent hairs.

Animals↗
PubMedDate not supplied

The American curl cat.

The American curl cat has ears that are curled backward at the apex of the pinnae in a characteristic manner. Breeding data indicate that the novel pinnate shape is inherited as a monogenic autosomal dominant trait. The mutant gene is designated as curl and symbolized by Cu.

Animals↗
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Expressivity of the Manx gene in cats.

New genetic data are presented which indicate that the assortment data for the mutant Manx gene, M, does not depart from normal expectation and does not enjoy a selective advantage at some stage of gametogenesis, as has been hypothesized. The variable expression of Manx taillessness is a remarkable and consistent feature of the Manx syndrome, encompassing the posterior skeleton, neural organization, and growth of soft tissues. The expression is partly genetic in origin, and the heritability is estimated to be in the region of h2 = 0.40 +/- 0.11.

Alleles↗
PubMedDate not supplied

Post-traumatic stress disorder in hospitalized patients with burn injuries.

The degree to which patients hospitalized for a major burn displayed symptoms of post-traumatic stress disorder or met the full criteria for this disorder was assessed during the course of hospitalization. Fifty-four consecutive patients were screened weekly for symptoms of post-traumatic stress disorder. Sixty-three percent showed intrusive recollections of the initial trauma (partial diagnostic criteria) and 16 (29.6%) of the sample met full criteria for post-traumatic stress disorder at some point during the hospitalization. None of the patients met the full diagnostic criteria at discharge from the hospital, although one did at follow-up. Post-traumatic stress disorder was found to be related to patients' total body surface area burn, length of hospital stay, sex (female patients), and lack of responsibility for the injury. The results suggest that although post-traumatic stress disorder in patients with burn injuries generally resolves without interventions other than standard hospital care, it might be preventable if patients who are at risk for developing it receive appropriate psychologic treatment soon after the injury.

Adolescent↗
PubMedDate not supplied

Postnatal follow-up of hydronephrosis detected by prenatal ultrasound: the natural history.

Babies with hydronephrosis detected antenatally who were born at or referred to our hospital from 1990 to 1995 were followed up with ultrasound (U/S), micturating cystourethrogram (MCU) or nuclear medicine studies after birth. One hundred and three patients were diagnosed antenatally at 17-42 weeks gestation. Twelve cases were excluded from the analysis of the results because of incomplete data. Fifty-one (56%) patients had hydronephrosis without organic obstruction, and 80% of these became normal in 3 years. Fifteen patients (17%) had a normal scan 4 days after birth. This suggests the possibility of antenatal spontaneous regression. Seven (8%) had a ureterocele and 4 (5%) had pelviureteric junction (PUJ) obstruction. Four (5%) had vesicoureteric reflux, and 4 (5%) had primary megaureter. Two (2%) had posterior urethral valves (PUV), 3 (3%) had refluxing primary megaureter, and 1 (1%) had urethral atresia. Fifteen patients (17%) underwent surgical intervention. Six had a nephrectomy, 1 a vesicostomy, 3 an Anderson-Hynes pyeloplasty, 3 had the ureterocele unroofed, 1 had a ureteric reimplant, and 1 ablation of valves. In 42 infants with 60 abnormal kidneys, the renal anteroposterior diameter of the pelvis was measured. Retrospectively, 48 kidneys diagnosed as having hydronephrosis, antenatally had a renal pelvis diameter > or = 4 mm before 33 weeks gestation or > or = 7 mm after 33 weeks gestation. One patient with PUJ obstruction lost kidney function, but there is no good marker to detect these patients. Early unroofing of ureteroceles may rescue kidney function. Our follow-up protocol for antenatal hydronephrosis is U/S at 4 days, 1 month and 1 year of age. An MCU is not required unless the ureter is seen on antenatal U/S. If dilatation persists past 1 month, a radionucleotide (MAG3) scan and repeat U/S are performed at 3 months. The methods for assessing obstruction and the indications for surgical intervention in these patients require reexamination.

Female↗
PubMedDate not supplied

The influence of HIV-related support groups on survival in women who lived with HIV. A pilot study.

To determine the effect of support groups on survival, the authors retrospectively studied 21 HIV-seropositive women who died during the course of participation in a natural history study of HIV. Groups were composed of women who self-selected HIV support groups before death (n = 11) and a comparison group (n = 10). Survival analysis found group participation to be associated with increased longevity (73 months vs. 45 months; P = 0.011). Proportional-hazards regression demonstrated that HIV-related support groups and smaller family size significantly influenced survival (P = 0.0002). Factors related to group participation and ways in which support groups might promote longevity are discussed.

Adaptation, Psychological↗
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Study of the ventilation of middle ear using radioactive xenon.

The greatest contribution of nuclear medicine has been to make possible dynamic measurements of regional function. It is conceivable that if this technology could be successfully used to measure the ventilation and clearance of the middle ear, answers to some of the most crucial problems in otology may be found. The objectives of this paper are three-fold: 1) A descriptive account of radiotracers and radiodetectors with emphasis on Xenon133. 2) The development of scintillographic techniques for the dynamic study of the ventilation of the ear and sinuses. 3) The methods that are being explored for the quantification of these functions.

Ear, Middle↗