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Biomedical subjects

W D Ashworth

Publications and source records attributed to W D Ashworth.

5 recordsLinked to original sources
PubMed1990

Day and night esophageal motor function.

Circadian rhythmic variation has been documented in gastric, small bowel and colonic motility. Morning and evening studies of esophageal motility were performed to assess whether similar rhythmicity exists in esophageal function. Fifteen healthy male subjects were studied twice on separate study days. Esophageal manometry was performed either at 10 AM or 10 PM after a standardized meal given 10 h prior to each study. Lower esophageal sphincter pressures, distal esophageal contractile amplitudes, distal esophageal contractile durations, and the velocity of propagation of peristaltic waves in the proximal and distal esophagus were measured. No significant differences were detected in esophageal function between day and night studies. These findings suggest either 1) nocturnal slowing of gastrointestinal motility is not a generalized characteristic of the entire GI tract, or 2) a two time-point study is not adequate to detect a true circadian rhythm in esophageal motor function.

Adult↗
PubMed1981

Nucleotide sequence variants of Rattus norvegicus mitochondrial DNA.

The mitochondrial DNA (mtDNA) molecules of different albino, domesticated rats (Rattus norvegicus) of the SASCO colony are of two kinds (SASCO-1 and SASCO-2) in regard to their sensitivity at certain sites to a number of restriction enzymes. MtDNA molecules from Utah wild R. norvegicus (Wild-UT) have sensitivities to restriction enzymes which differ at some sites from either SASCO-1 or SASCO-2 mtDNA molecules. Four single nucleotide differences were found among the HindIII F fragments (169 nucleotides) of SASCO-1, SASCO-2, and Wild-UT mtDNAs. Arguments are presented in favor of the interpretation that each variant nucleotide is the third nucleotide of the codon containing it, and that none of the four differences would result in a difference in the respective amino acid translated.

Animals↗
PubMed1976

Duodenal contraction wave patterns in patients with and without ulcer.

To determine whether differences in frequency of specific wave sequences and types existed in the four parts of the duodenum in ulcer subjects and controls an analysis of contraction waves in 14 controls and 10 duodenal ulcer patients of similar age was done by a statistical analysis of differences between the two groups. A water-perfused tube system was used. Differences in motor activity, namely, decreased frequency of waves in the proximal duodenum and increased frequency of waves in the distal duodenum in ulcer subjects as compared to controls was demonstrated. This involved a statistically significant decrease in numbers of mixing (or basic rhythm) waves in the proximal duodenum. Increased numbers of isolated waves were found in ulcer patients in the distal duodenum. The predominant types of contraction waves in both ulcer and control subjects were isolated and simultaneous waves, with peristaltic waves were less common in the fasting state. These findings suggest that differences exist in the types of contraction waves in duodenal ulcer subjects compared to controls.

Duodenal Ulcer↗