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Biomedical subjects

R E Perry

Publications and source records attributed to R E Perry.

16 recordsLinked to original sources
PubMed1992

Normal variation in anorectal manometry.

A study was performed to define the normal range of values for anorectal manometry. Normal volunteers were divided according to gender and parity. There were 20 males, 21 nulliparous females, and 18 multiparous females among the 59 subjects. Anorectal manometry using a radial eight-port catheter was performed during resting and squeezing maneuvers of the anal sphincter. Computerized data analysis and three-dimensional imaging were used to calculate sphincter length at rest and squeeze, mean maximum resting and squeeze pressures, and vector symmetry index. The sphincter length at rest and with squeezing in males was significantly greater compared with the two female groups (P < 0.007). Mean maximum squeeze pressures were also significantly elevated in the male group compared with the female groups (P = 0). Mean maximum resting pressures were significantly higher in nulliparous women than in multiparous women (P = 0.04). However, no difference in resting pressures was found between males and nulliparous females. A comparison of the symmetry of the anal canal revealed no differences among the three groups. Ranges for normal anorectal manometry are definable. Normal ranges are distinct for subgroups of patients, particularly with regard to gender and parity. Patients must be compared with their normal subgroups to correctly identify manometric abnormalities.

Adult↗
PubMed1992

Radiographically determined growth dynamics of primary lung tumors induced in dogs by inhalation of plutonium.

Beagles were exposed to aerosols of 239PuO2, 238PuO2, or 239Pu(NO3)4. Exponential growth constants for 50 primary lung tumors (23 bronchioloalveolar carcinomas, 22 papillary adenocarcinomas, 5 adenosquamous carcinomas) were calculated in 37 dogs, using sequential thoracic radiography. A wide range in doubling time (6 to 287 days) was observed. Mean +/- SEM doubling time was 93 +/- 10 days for bronchioloalveolar carcinoma, 107 +/- 13 days for papillary adenocarcinoma, and 101 +/- 36 days for adenosquamous carcinoma. Lung tumor growth rate in dogs was comparable to that in human patients with similar histologic tumor types. Linear regression analysis revealed significant (P < or = 0.0001) correlation between doubling time and survival of individual dogs. Doubling time was not significantly dependent on tumor type, sex, age at time of diagnosis, initial lung deposition, or isotope. Extrapolating time to tumor onset from tumor doubling time cannot be used to reliably predict the onset of malignancy.

Administration, Inhalation↗
PubMed1991

The reproducibility of measuring the anorectal angle in defecography.

Dynamic proctography is a radiographic procedure that has become widely used in the evaluation of pelvic floor function. The anorectal angle (ARA) is one parameter which is usually quantified during this examination. To determine the accuracy with which this measurement can be made, three physicians independently measured the resting and squeezing ARAs of 22 women. The coefficient of variation and the kappa statistic were used to describe the degree of agreement among the three examiners. These analyses revealed poor agreement among examiners for all 22 patients taken as individuals, (kappa less than or equal to 0.40; mean coefficient of variation at rest = 18 percent; mean coefficient during squeezing = 21 percent). These results suggest that measurements of ARAs will vary among examiners for any particular patient, even though individual examiners may demonstrate consistency in recording ARA data. There is wide interobserver variation in the measurement of the ARA from lateral radiographs, making quantification an exercise of only limited clinical value.

Adult↗
PubMed1991

Three-dimensional imaging of the lower esophageal sphincter in gastroesophageal reflux disease.

The resistance of the lower esophageal sphincter to reflux of gastric juice is determined by the integrated effects of radial pressures exerted over the entire length of the sphincter. This can be quantitated by three-dimensional computerized imaging of sphincter pressures obtained by a pullback of radially oriented pressure transducers and by calculating the volume of this image, in other words, the sphincter pressure vector volume. Validation studies showed that sphincter imaging based on a stepwise pullback of a catheter with four or eight radial side holes is superior to a rapid motorized pullback. Compared with 50 healthy volunteers, the total and abdominal sphincter pressure vector volume was lower in 150 patients with increased esophageal acid exposure (p less than 0.001) and decreased with increasing esophageal mucosal damage (p less than 0.01). Calculation of the sphincter pressure vector volume was superior to standard techniques in identifying a mechanically defective sphincter as the cause of increased esophageal acid exposure, particularly in patients without mucosal damage. The Nissen and Belsey fundoplication increased the total and intra-abdominal sphincter pressure vector volume (p less than 0.001) and normalized the three-dimensional sphincter image. Failure to do so was associated with recurrent or persistent reflux. These data indicate that three-dimensional imaging of the lower esophageal sphincter improves the identification of patients who would benefit from an antireflux procedure. Analysis of the three-dimensional sphincter pressure profile should become the standard for evaluation of the lower esophageal sphincter.

Adult↗
PubMed1991

Serum aminoglycoside clearance is predicted as poorly by renal aminoglycoside clearance as by creatinine clearance in critically ill patients.

OBJECTIVE: To determine the relationships among serum aminoglycoside clearance, renal aminoglycoside clearance, measured creatinine clearance, and estimated creatinine clearance derived from a standard formula in critically ill patients. SETTING: A ten-bed general ICU in a university hospital. PATIENTS: Eighteen critically ill patients who were being treated with gentamicin or tobramycin for severe infections, and were hemodynamically stable. INTERVENTIONS: The various clearances were measured simultaneously after the administration of a dose of aminoglycoside by assaying serial blood samples for aminoglycoside and creatinine concentration, and by measuring the content of these substances in urine collected over the same time period. OUTCOME MEASURES: The slopes, intercepts and coefficients of determination (r2) of the various regressions were determined, along with the 95% confidence intervals for the prediction of serum aminoglycoside clearance from each other variable. RESULTS: Renal aminoglycoside clearance, creatinine clearance, and estimated creatinine clearance accounted for only 58%, 59%, and 62%, respectively, of the variance in serum aminoglycoside clearance. Only 64% of the variance in renal aminoglycoside clearance was explained by creatinine clearance. Substantial and variable nonrenal aminoglycoside clearance was evident. CONCLUSIONS: The 95% confidence intervals for the prediction of serum aminoglycoside clearance from each index of renal function indicated that none of these indices provided acceptable accuracy for the prediction of serum aminoglycoside clearance and dosage requirements in critically ill patients. Renal aminoglycoside clearance was not better than creatinine clearance in this respect, and thus no other index of renal function is likely to be more accurate. This finding implies that the only accurate method of determining the dose requirements to achieve target serum concentrations in such patients will be individualized pharmacokinetic dosing.

Aminoglycosides↗
PubMed1990

Manometric diagnosis of anal sphincter injuries.

A manometric technique of anal pressure vectography has been developed for the detection of anal sphincter injuries. Manometric symmetry of the anal sphincter can be visualized on the pressure vectorgram and quantified as a vector symmetry index. The mean vector symmetry index in asymptomatic women was 0.76, compared with 0.33 in incontinent women with a known sphincter injury (p = 0.0001). Among women who were incontinent without having a recognized sphincter injury, nearly half of those who had a previous episiotomy had subnormal (less than 0.60) vector symmetry indices (p = 0.0003). The values were in the same range as those from known injuries, suggesting the presence of an occult sphincter injury. In contrast, normal symmetry indices were found in all those who had never had an episiotomy or who presented with outlet constipation. We conclude that the vector symmetry index can expose occult anal sphincter injuries and may have a role in the selection of patients for sphincter repair.

Adolescent↗
PubMed1989

Office colonoscopy--a safe procedure in selected patients.

Colonoscopy is a common procedure, usually performed in a hospital setting. Hospital backup is desirable for high-risk patients, but the cost to benefit ratio may be unnecessarily high for low-risk patients. The demand for colonoscopic examinations is escalating, and cost containment has become an important issue. One way to reduce the cost is to eliminate the hospital component by performing the examination in the office. Over the past two and a half years, colonoscopy was performed on selected patients in the authors' office. Five hundred fifty-four office colonoscopies were performed to date, including biopsy or polypectomy in 348. Basic principles of safe intravenous sedation and colonoscopy were followed strictly. The cecum was reached in 92 percent of cases, and no significant complications were encountered. Office colonoscopy is a safe alternative to hospital colonoscopy. It confers significant cost savings to the patient and allows more efficient use of the physician's time.

Adult↗
PubMed1989

Rectopexy without resection for rectal prolapse.

Forty-three patients underwent simple posterior suture rectopexy for repair of rectal prolapse. Follow-up was obtained in 42 patients (mean 28 months). The recurrence rate was 2 percent (one patient). Postoperative morbidity and mortality were 20 percent and 0, respectively. The proportion of continent patients increased from 36 percent preoperatively to 74 percent postoperatively. Constipation increased after suture rectopexy but was managed conservatively. We believe that simple suture rectopexy offers a safe and effective alternative to other, more complex procedures for the treatment of rectal prolapse.

Aged↗
PubMed1989

Rectal prolapse: rational therapy without foreign material.

A number of operations are available for the correction of rectal prolapse. Rational judgement is required for the selection of the most appropriate procedure for each patient. Perineal rectosigmoidectomy offers a reasonable alternative to an abdominal procedure in patients who are elderly and debilitated. Simple suture rectopexy is our procedure of choice for an abdominal prolapse repair. We believe that simple rectopexy offers comparable results with less risk than procedures utilizing resection or foreign material. Colon resection should be reserved for those patients who require surveillance for colon polyps or have a history of diverticulitis.

Adult↗
PubMed1989

Nonenzymatic glycosylation (glycation) of lens crystallins in diabetes and aging.

Lens crystallin glycation, thiol oxidation and aggregation showed parallel changes in streptozotocin-diabetic and aging rats. The levels of the disulfide-linked HMW aggregates were essentially the same in the diabetic and senile cataracts, but glycation was significantly lower in the latter. Inhibition of glycation by acetylating potential glycation sites by aspirin during in vitro glycation and in diabetic rats has led to inhibition of protein thiol oxidation and aggregation. A predominance of glycated crystallins, gamma crystallin in particular, was noticed in the HMW aggregates. Likewise, the glycate portion of the whole crystallin preparation showed an enrichment of the HMW aggregates. These observations strongly suggest a significant contribution by crystallin glycation in the formation of disulfide-linked aggregates.

Acetylation↗
PubMed1987

Progressive changes in lens crystallin glycation and high-molecular-weight aggregate formation leading to cataract development in streptozotocin-diabetic rats.

Because of their remarkable longevity, lens crystallins undergo a substantial amount of glycation (non-enzymatic glycosylation) during diabetic hyperglycemia. These post-translational modifications have the potential to disrupt the structural and functional properties of the lens crystallins and contribute to the formation of cataracts. Streptozotocin-induced diabetic rats were used to study the relationship between glycation of lens proteins and the formation of insoluble high-molecular-weight (HMW) aggregates believed to be responsible for cataract formation. After the onset of diabetes, cataracts developed in about 12- to 13 weeks. The animals were followed in this manner until cataracts developed and for an additional 63 days. Five control and five diabetic rats were killed every 3 weeks and lenses removed. Levels of glycated protein and glycated amino acids in lenses from each animal were examined by affinity chromatography. In addition, the changes in crystallin composition and development of HMW aggregates were monitored by molecular-sieve HPLC techniques. As diabetic hyperglycemia continued there was a linear increase in glycated protein in both the soluble and insoluble fractions. This increase was paralleled by an increase in the soluble HMW and insoluble HMW aggregates. Other changes included a decrease in reactive sulfhydryls which indicates an increase in disulfide bond formation. The gamma-crystallin levels also decreased in a linear fashion during the hyperglycemic pre-cataract and cataract stages. It appears that the glycation of lens crystallin, the disappearance of reactive sulfhydryls and the formation of HMW aggregates are interrelated.

Amino Acids↗
PubMed1986

High-performance liquid chromatographic separation and quantitation of glycosylated hemoglobin A2 as an alternate index of glycemic control.

By a combination of DEAE-cellulose chromatography and cation-exchange high-performance liquid chromatography glycosylated components of hemoglobin (Hb) A2 were separated and quantitated from persons with diabetes and some common hemoglobinopathies. Hb A2Ic values correlated well with total glycosylated Hb levels assayed by affinity chromatography, and Hb AIc, Hb SIc and Hb CIc levels, determined by high-performance liquid chromatography. The results indicate that Hb A2Ic may serve as an alternate index of glycemic control.

Blood Glucose↗