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Biomedical subjects

A R Perez

Publications and source records attributed to A R Perez.

5 recordsLinked to original sources
PubMed2001

Obesity adversely affects the outcome of antireflux operations.

BACKGROUND: We hypothesized that obesity was associated with long-term failure of antireflux procedures, and that in obese patients antireflux operations were easier to perform via thoracotomy, and therefore likely to have a higher success rate than transabdominal (laparoscopic or open) antireflux procedures. The aims of this study was to determine the impact of obesity on the success of antireflux operations, and to compare the success rates of transthoracic and laparoscopic approaches in obese patients with gastroesophageal reflux. METHODS: The records of 224 consecutive patients undergoing antireflux surgery by two surgeons in a university-based tertiary care center were reviewed and patients contacted for follow-up assessment. The patients were classified into groups based on the type of operation performed and the calculated body mass index (BMI): normal (BMI 30). Recurrences were documented by symptoms responsive to acid-suppressive medication and radiologic or pH probe studies. RESULTS: Among the 224 patients included in this study, 187 underwent laparoscopic Nissen fundoplications (LNF) and 37 underwent Belsey Mark IV(BM4) procedures. The mean follow-up period was 37 months. The three groups included 89 (39.7%) patients classified as having normal weight, 87 (38.8%) as overweight and 48 (21.4%) as obese. Normal, overweight, and obese patients were similar in terms of age, gender, hiatal hernia size, degree of esophagitis, and comorbid conditions. A total of 26 recurrences occurred, giving an overall recurrence rate of 11.6%. There were 4 recurrences in the normal group (4.5%), 7 in the overweight group (8.0%; p not significant vs normal), and 15 in the obese group (31%; p < 0.001 vs normal; p <.001 vs overweight). The recurrence rate was similar between LNF and BM4 in each BMI subgroup, although in aggregate, the recurrence rate after BMW was greater than after LNF (10/37 vs 16/187; p < 0.02). CONCLUSIONS: Obesity adversely affects the long-term success of antireflux operations. Although athoracotomy provides optimal exposure of the hiatal structures in obese patients, a transthoracic approach was associated with a higher recurrence rate than LNF. Given the high failure rate of antireflux operations in obese patients, intensive efforts at sustained weight loss should be made before consideration of surgery.

Body Mass Index↗
PubMed2000

SpoIIB localizes to active sites of septal biogenesis and spatially regulates septal thinning during engulfment in bacillus subtilis.

A key step in the Bacillus subtilis spore formation pathway is the engulfment of the forespore by the mother cell, a phagocytosis-like process normally accompanied by the loss of peptidoglycan within the sporulation septum. We have reinvestigated the role of SpoIIB in engulfment by using the fluorescent membrane stain FM 4-64 and deconvolution microscopy. We have found that spoIIB mutant sporangia display a transient engulfment defect in which the forespore pushes through the septum and bulges into the mother cell, similar to the situation in spoIID, spoIIM, and spoIIP mutants. However, unlike the sporangia of those three mutants, spoIIB mutant sporangia are able to complete engulfment; indeed, by time-lapse microscopy, sporangia with prominent bulges were found to complete engulfment. Electron micrographs showed that in spoIIB mutant sporangia the dissolution of septal peptidoglycan is delayed and spatially unregulated and that the engulfing membranes migrate around the remaining septal peptidoglycan. These results demonstrate that mother cell membranes will move around septal peptidoglycan that has not been completely degraded and suggest that SpoIIB facilitates the rapid and spatially regulated dissolution of septal peptidoglycan. In keeping with this proposal, a SpoIIB-myc fusion protein localized to the sporulation septum during its biogenesis, discriminating between the site of active septal biogenesis and the unused potential division site within the same cell.

Bacillus subtilis↗
PubMed1998

The large window ductus: a surgical trap.

A rare window type of patent ductus arteriosus is reported that was large (15 mm in maximal transverse dimension) but had virtually no length and hence was externally invisible. The smaller aortic isthmus (4 mm in diameter), which was intrapericardial, was mistaken for the ductus and was inadvertently clip-occluded, leading to death. After a specific diagnosis is made, the large window ductus should be patched on cardiopulmonary bypass with a transpulmonary approach.

Aorta, Thoracic↗