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Biomedical subjects

J Yount

Publications and source records attributed to J Yount.

8 recordsLinked to original sources
PubMed1997

Idiopathic torsion dystonia linked to chromosome 8 in two Mennonite families.

The DYT1 locus on chromosome 9q34 is responsible for most childhood limb-onset idiopathic torsion dystonia (ITD). Linkage to DYT1 has been excluded in families with adult-onset, and predominantly cranial-cervical, ITD. We mapped a locus (DYT6) associated with prominent cranial-cervical ITD in two large Mennonite families to chromosome 8. An identical haplotype spanning 40-cM segregates with ITD in these families, suggesting a shared mutation from the recent past.

Adolescent↗
PubMed1997

Mapping a gene for adult-onset primary open-angle glaucoma to chromosome 3q.

Glaucoma is the third-leading cause of blindness in the world, affecting >13.5 million people. Adult-onset primary open-angle glaucoma (POAG) is the most common form of glaucoma in the United States. We present a family in which adult-onset POAG is inherited as an autosomal dominant trait. Twelve affected family members were identified from 44 at-risk individuals. The disease-causing gene was mapped to chromosome 3q21-24, with analysis of recombinant haplotypes suggesting a total inclusion region of 11.1 cM between markers D3S3637 and D3S1744. This is the first report of mapping of an adult-onset POAG gene to chromosome 3q, gene symbol GLC1C.

Adult↗
PubMed1996

Weill-Marchesani syndrome--possible linkage of the autosomal dominant form to 15q21.1.

Weill-Marchesani syndrome comprises short stature, brachydactyly, microspherophakia, glaucoma, and ectopia lentis is regarded as an autosomal recessive trait (McKusick 277600). We present two families each with affected individuals in 3 generations demonstrating autosomal dominant inheritance of Weill-Marchesani syndrome. Linkage analysis in these 2 families suggests a gene for Weill-Marchesani syndrome maps to 15q21.1. The dislocated lenses and connective tissue disorder in these families suggests that fibrillin-1 and microfibril-associated protein 1, which both map to 15q21.1, are candidate genes for Weill-Marchesani syndrome. Immunohistochemistry staining of skin sections from family 1 showed an apparent decrease in fibrillin staining compared to control individuals.

Abnormalities, Multiple↗
PubMed1996

A second gene for cerulean cataracts maps to the beta crystallin region on chromosome 22.

Congenital cataracts are one of the most common major eye abnormalities and often lead to blindness in infants. At least a third of all cases are familial. Within this group, highly penetrant, autosomal dominant forms of congenital cataracts (ADCC) are most common. ADCC is a genetically heterogeneous group of disorders, in which at least eight different loci have been identified for nine clinically distinct forms. Among these, Armitage et al. (Nature Genet. 9: 37-40, 1995) mapped a gene for cerulean blue cataracts to chromosome 17q24. Bodker et al. (Am. J. Med. Genet. 37: 54-59, 1990) described a large family with cerulean blue cataracts, in which the affected daughter of affected first cousins was presumed to be homozygous for the purported gene. We report linkage in this family to the region on chromosome 22q that includes two beta crystallin genes (CRYBB2, CRYBB3) and one pseudogene (CRYBB2P1). The affected female in question is homozygous at all markers.

Cataract↗
PubMed1987

Chemically induced bowel denervation improves survival in short bowel syndrome.

This study evaluates the effect of chemically induced bowel denervation on survival, weight gain or loss, transit time, and d-xylose absorption in rats following 80% small bowel resection. Forty-three male Sprague-Dawley rats (150 g) underwent 80% midsmall bowel resection and anastomosis. Twenty rats were short bowel controls (group I). In 23 rats (group II), a 2.0 cm segment of jejunum proximal to the anastomosis was denervated by application of 0.1% benzalkonium chloride (BK) for 30 minutes. Ten additional rats underwent sham laparotomy without bowel resection. Five remained untreated (group III) and in 5 (BK) denervation was added (group IV). Bowel denervation was confirmed by histologic study in all (BK) rats. Weight and daily food and water intake were measured for 30 days and the groups compared. Weight in group I was 43.8 +/- 52.9 g, group II 95.0 +/- 50.1, (P less than .005), group III 177 g, and group IV 175 g. Food intake was greater in group I than II (P less than .05) and was similar to groups III and IV. Water intake calculated as animal weight (g)/mL H2O ingested was lowest in group I (P less than .05). Mortality was 30% in group I (6/20) and only 8.6% in group II (2/23). No deaths were observed in unresected controls (III and IV). Twenty-four additional rats were evaluated for d-xylose absorption and transit time by bringing out a loop enterostomy 10.0 cm from the Ligament of Treitz. Twelve rats were ostomy controls (group V).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Reverse electrical pacing improves intestinal absorption and transit time.

This study evaluates the effect of reverse electrical pacing on intestinal absorption and transit time in an enterostomy model. Twenty-five male Sprague-Dawley rats (148 to 208 gm) underwent division and anastomosis of the proximal jejunum to eliminate the proximal gastroduodenal pacemaker. A 30.0 cm loop ileostomy was formed, and leads were placed at 1.0 and 3.0 cm proximal to the stoma. Reverse pacing was done with a 0.25 Hz, 50 msec pulse at 0.1 mA. Transit time was evaluated with 1.0 ml barium gavage and was 12 +/- 4 minutes in group I controls (n = 13) versus 27 +/- 21 minutes in group II (n = 12) reverse-paced rats (p less than 0.025). D-Xylose absorption was determined in 18 rats. Levels were 14.0 +/- 3.6 mg/dl in control rats (n = 6) and 15.5 +/- 3.4 mg/dl in reverse-paced rats (n = 6). Increasing the pulse milliamperage to 2.0 mA (n = 6) increased D-xylose serum levels to 38.8 +/- 27.7 mg/dl (p less than 0.05). Transit rate and net water flux were determined in eight additional rats with 15 cm Theiry-Vella loops. Transit rate was measured with 0.2 ml of methylene blue and was 3.00 +/- 2.32 ml/min in unpaced rats compared with 9.95 +/- 0.71 ml/min with reverse pacing (p less than 0.025). Water flux studies showed that control rats had a net secretory loss of 0.20 +/- 0.48 ml/cm while paced rats absorbed 0.08 +/- 0.12 ml/cm. These data indicate that reverse electrical pacing increases transit time and nutrient and fluid absorption. These observations suggest that reverse electrical pacing may be a useful adjunct in instances of short gut associated with an enterostomy.

Animals↗