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Biomedical subjects

D M Preston

Publications and source records attributed to D M Preston.

18 recordsLinked to original sources
PubMed1999

Prostate-specific antigen to predict outcome of external beam radiation for prostate cancer: Walter Reed Army Medical Center experience, 1988-1995.

OBJECTIVES: To assess the ability of pretreatment and post-treatment prostate-specific antigen (PSA) measurements, clinical tumor stage, tumor grade, Gleason sum, race, age, and radiation dose to predict the recurrence of prostate cancer following external beam radiation therapy (XRT) since the introduction of PSA as a tumor marker at one tertiary care center. METHODS: The recurrence of prostate cancer among 371 evaluable patients of 389 patients treated with XRT at Walter Reed Army Medical Center was analyzed using Kaplan-Meier survival methodology and Cox multivariable regression models. Serologic (PSA) recurrence was determined using three consecutive rises in PSA after a nadir value. Clinical recurrence was defined as local recurrence (palpable or positive biopsy) and/or distant (radiographically evident) recurrence. Mean and median follow-up is 40.2 and 39.4 months, respectively (range 3.0 to 89.5), and minimum follow-up is 18 months for patients who were alive at the time of analysis. No patient received adjuvant hormonal therapy. Potential prognostic factors evaluated are pretreatment PSA, PSA nadir, age, race, clinical tumor stage, tumor grade, Gleason sum, and radiation dose. RESULTS: Of the 371 evaluable patients, 125 had disease recurrence. The Kaplan-Meier 5-year disease-free survival (DFS) rates for significant pretreatment variables in univariate analyses are as follows: pretreatment PSA less than 4 (79%), 4.1 to 10 (67%), 10.1 to 20 (57%), 20.1 to 50 (27%), and more than 50 (0%); for clinical tumor Stage T1a-T1c (84%), T2a-T2c (51 %), and T3-T4 (29%); for tumor grade well (58%), moderate (58%), and poor (30%). Four-year DFS rates for Gleason sum are 2 to 4 (82%), 5 (72%), 6 (56%), and 7 to 10 (48%). In multivariable Cox regression analysis with backward elimination of nonsignificant variables, age, race, tumor grade, and radiation dose were eliminated, leaving pretreatment PSA, clinical tumor stage, and Gleason sum as significant prognostic factors. Analysis of a Cox model that included nadir PSA as a time-dependent variable showed it to be the strongest prognostic factor variable in the analysis. CONCLUSIONS: XRT remains a suitable treatment modality for patients with pretreatment PSA less than 20.0, clinical tumor Stages T1-T2, and Gleason sum 2 to 6 prostate cancer. Patients achieving a nadir value less than 0.5 have more durable treatment outcomes.

Aged↗
PubMed1998

Significance of familial history of prostate cancer to traditional prognostic variables, genetic biomarkers, and recurrence after radical prostatectomy.

OBJECTIVES: Prostate cancer (PCa) has a familial predisposition imparting an increased risk of developing the disease in those with a family history. The pathologic characteristics are similar to sporadic cases; however, the disease-free survival rates of hereditary PCa have recently been disputed, with one major study suggesting that familial cases have higher recurrence rates. Our study seeks to support or refute this association and to evaluate the genetic biomarkers p53, bcl-2, Ki-67, and neovascularity between familial and sporadic disease. METHODS: We retrospectively reviewed data of 573 patients who underwent radical prostatectomy over an 11-year period. Of these, 474 patients had known family history data. Univariable statistical analysis using the Pearson chi-square test and Kaplan-Meier disease-free survival analysis was performed to identify any correlation between the tested variables and family history. Smaller subsets of this cohort that had available archival material for immunohistochemical staining and family history data were analyzed in a similar manner. RESULTS: The preoperative variables (prostate-specific antigen, prostatic acid phosphatase, clinical stage, highest biopsy Gleason sum, and glandular differentiation) and postoperative variables (stage, highest Gleason sum, and glandular differentiation) did not correlate with family history. Kaplan-Meier disease-free survival analysis revealed no differences between sporadic and familial cases. The analysis of p53, bcl-2, Ki-67, and angiogenesis revealed that only increasing p53 expression and positive family history of PCa approached significance (P = 0.057). CONCLUSIONS: Prognostic variables routinely used in PCa and selected genetic biomarker immunostaining abnormalities are not significantly different in men with and without a family history of PCa. Disease-free survival after radical prostatectomy is also unaffected by family history.

Aged↗
PubMed1997

Incidence of stool guaiac conversion following extracorporeal shock wave lithotripsy.

OBJECTIVES: To study, in a prospective fashion, acute traumatic effects on the gastrointestinal tract of patients treated by extracorporeal shock wave lithotripsy (ESWL). METHODS: Stool samples from each of 54 patients were tested before and after ESWL for conversion to hemoccult positive. A minimum of one negative pre-ESWL stool guaiac test was required for inclusion into the study. A minimum of two stool guaiac tests were done after ESWL to verify negativity. Patients who converted to a positive hemoccult test after ESWL were then evaluated by colonoscopy for the source of bleeding. RESULTS: Fifty patients completed the study. A single patient (2.0%) converted to a positive post-ESWL hemoccult test and was evaluated with colonoscopy. This patient was found to have two benign adenomatous polyps in the sigmoid and descending colon after treatment for a left renal pelvis calculus. An additional patient with a slightly positive post-ESWL conversion refused further evaluation. The overall post-ESWL conversion rate to guaiac positive, therefore, was less than 4% (2 of 51 patients). CONCLUSIONS: There is no evidence of significant trauma or detectable bleeding in the normal gastrointestinal tract caused by ESWL as measured by postprocedure stool guaiac testing. Guaiac testing of the stool after ESWL may unmask pre-existing gastrointestinal disease. Therefore a positive guaiac test after ESWL warrants further evaluation. This study reaffirms that ESWL is a safe, minimally invasive technique for the treatment of urolithiasis, without significant adverse side effects on the gastrointestinal tract.

Digestive System↗
PubMed1997

Intracranial metastatic adenocarcinoma of the prostate presenting as visual disturbance.

We report two cases of intracranial metastatic adenocarcinoma of the prostate that presented with visual disturbance. The two patients had no prior history of prostate cancer and both underwent invasive neurosurgical procedures. Progressive neurological decline mandated craniotomy in one patient and the other patient underwent transphenoidal surgery for biopsy. Androgen deprivation therapy was instituted postoperatively for both patients when prostate cancer was determined to be the source of the metastatic lesions.

Abducens Nerve↗
PubMed1986

Severe chronic constipation of young women: 'idiopathic slow transit constipation'.

A series of 64 women complaining of severe constipation is described, in each of whom delayed elimination of markers from the colon was demonstrated but a barium enema was normal. All completed a detailed questionnaire and the responses are compared with those obtained in an age-matched series of healthy women with no bowel complaint. In each group 40 women also recorded in a manner suitable for analysis all food eaten over a period of seven days. The patients passed about one stool weekly with the aid of laxatives, and were greatly troubled by abdominal pain, bloating, malaise and nausea, to the extent that the symptoms were a major social disability and many lost time from work. Decreased bowel frequency and other symptoms were often first noticed around the age of puberty and slowly became worse until they were severe by the third decade. In a few, the symptoms began suddenly after an abdominal operation c-accident. Comparison with the control group showed no evidence that the patients had been underweight at any time or that they took less fibre; treatment with a bran supplement did not usually help them. The patients experienced rectal sensation before defaecation less often than the control subjects and they used digital pressure to assist defaecation more frequently. The women with constipation tended to have more painful and irregular menstrual periods, and there was an increased incidence of ovarian cystectomy and hysterectomy. Hesitancy in starting to pass urine was more common, as were some somatic symptoms such as cold hands or blackouts. Attention is drawn to this distinctive combination in young women of slow total gut transit time and a colon of normal width on barium enema, associated with abdominal, anorectal, gynaecological and somatic symptoms, as a disorder which can be disabling and particularly difficult to treat.

Adolescent↗
PubMed1985

Experience of posterior division of the puborectalis muscle in the management of chronic constipation.

Nine women with severe chronic constipation who were unable to expel a water-filled rectal balloon underwent posterior division of the puborectalis muscle. Pre-operative concentric needle electromyography and measurement of the anorectal angle at rest and during straining suggested that the puborectalis muscle failed to relax during attempted defaecation in these patients. Two patients reported improvement after surgery and had normal balloon expulsion after operation. However seven patients reported no benefit from surgery and tests of defaecatory function and anorectal angle did not change. Incontinence for solid stool was not reported following puborectalis muscle division although five patients reported incontinence of flatus, liquid stool and mucus.

Adult↗
PubMed1985

Anismus in chronic constipation.

Among patients complaining of constipation, a group can be defined in which there is slow whole gut transit shown by retention of radiopaque markers but a rectum and colon of normal width judged by measurements of barium enema radiographs compared with control observations. It is not known whether their symptoms are due to an abnormality of colonic motility or to a failure of the defecatory mechanism. Defecation was simulated experimentally in a group of these patients by asking them to expel a water-filled rectal balloon. The constipated patients were not able to expel the balloon, whereas normal subjects could do so. Electromyography of the striated pelvic floor muscles during attempts at expulsion of the balloon in the constipated patients showed failure of the normal inhibition of resting activity. Failure of external and sphincter relaxation on attempted defecation may contribute to the symptoms of some patients who complain of constipation.

Adolescent↗
PubMed1985

Pelvic motility and response to intraluminal bisacodyl in slow-transit constipation.

The resting motility of the pelvic colon was studied in 28 patients with constipation and compared with control subjects and patients with diarrhea. Colonic activity in patients who had been shown to have slow colonic transit was not significantly different from controls. In contrast, activity in patients who complained of constipation but who were found to have normal colonic transit time was increased (P less than 0.02). The response of the pelvic colon to the introduction of a surface-acting laxative was studied in 18 patients with slow-transit constipation. Eleven patients developed progressive peristaltic waves, while in 7 there was no response. It is possible that the relative inactivity of the colon in the latter group is due to a disorder of the myenteric plexus. If so, the bisacodyl stimulation test may distinguish patients with an abnormal myenteric plexus from those in whom it is normal.

Adult↗
PubMed1985

Towards a radiologic definition of idiopathic megacolon.

Measurements of bowel width and rectal area were used to define normal limits of size in 50 double-contrast barium enema films. Two types of patient with constipation were defined by comparison with these results. In 18 women with prolonged whole-gut transit time, the measurements were within the normal range. Of 11 men and 9 women with a previous radiologic diagnosis of idiopathic megacolon, all had an enlarged rectum and the abnormal width extended proximally to involve the colon for a variable distance. A width of 6.5 cm at the pelvic brim provides a convenient and discriminating separation of normal from abnormal.

Chronic Disease↗
PubMed1985

Positive correlation between symptoms and circulating motilin, pancreatic polypeptide and gastrin concentrations in functional bowel disorders.

Motilin, pancreatic polypeptide and gastrin blood concentrations in response to drinking water have been studied in 40 patients with functional bowel disease and compared with results in two groups of healthy control subjects. Patients with slow transit constipation and idiopathic megacolon showed impaired motilin release. Pancreatic polypeptide release was reduced in patients with slow transit constipation, but increased in those with functional diarrhoea. Gastrin release was impaired in all groups complaining of chronic constipation. Circulating motilin, pancreatic polypeptide and gastrin concentrations appear to bear some relationship to intestinal transit time in patients with functional bowel disorders.

Adult↗
PubMed1985

Effect of different drinks on fluid and electrolyte losses from a jejunostomy.

The effectiveness of 5 different solutions on the absorption of fluid and electrolytes was tested in 7 patients with a proximal intestinal stoma and large fluid losses, all of whom previously needed intravenous infusions to maintain balance. In 4 patients it proved possible to replace the intravenous infusions with an enteral supplement. The WHO glucose/electrolyte solution without added potassium (NaCl 3.5 g, NaHCO3 2.5 g, glucose 20 g/l) gave satisfactory results, though was slightly less effective than a solution containing more sodium in which maltose was substituted for glucose. Neither sucrose nor an oligosaccharide (Caloreen) gave an advantage over glucose in the formulations used. In 3 patients losses were so great, and absorption of sodium from oral solutions so small, that intravenous supplements had to be continued. These 3 patients could be distinguished from the other 4 by the fact that more than 250 ml emerged from the stoma during the 3 hours after a drink of 500 ml of glucose/electrolyte solution. In all patients a drink of water or tea led to a loss of sodium from the stoma; water should be restricted in such patients and replaced by a glucose/electrolyte solution.

Administration, Oral↗
PubMed1984

The balloon proctogram.

A balloon filled with barium has been used to simulate a soft stool for the radiological study of disorders of defaecation. Lateral radiographs demonstrate the level of the pelvic floor in relation to the pubococcygeal line, the change in the anorectal angle and the behaviour of the anal sphincters. In 12 patients with faecal incontinence, successfully treated surgically by postanal sphincter repair, the anorectal angle was reduced from 135 degrees +/- 4.4 degrees (s.e.m.) to 103 degrees +/- 4.1 degrees and the anorectal junction rose by 1.5 +/- 0.4 cm. In 10 patients with slow-transit constipation there was no pelvic descent and no change in the anorectal angle on straining. These patients were unable to expel the balloon and the results suggest that the pelvic floor does not relax normally.

Constipation↗
PubMed1984

Results of colectomy for severe idiopathic constipation in women (Arbuthnot Lane's disease).

Twenty-one women with slow-transit constipation have been treated by bowel resection. All had a normal barium enema, but an increased colonic transit time. Pathological examination of the resected colons showed no evidence of aganglionosis. Some of the patients were treated by segmental colonic resection, anorectal myectomy, anal stretch or internal sphincterectomy but were not helped. Colectomy with ileorectal or caecorectal anastomosis gave the best results; on balance, ileorectal anastomosis seems preferable. Of sixteen patients who underwent colectomy, ten subsequently had normal bowel function and four were markedly improved. The spontaneous bowel frequency in this group rose from 0.3 +/- 0.1 (s.e.m.) to 21.7 +/- 8.3 weekly (P less than 0.001).

Adolescent↗
PubMed1983

Carcinoma of the anus in Crohn's disease.

The incidence of gastrointestinal cancer in patients with Crohn's disease may be slightly increased. We report 2 cases of squamous cell carcinoma of the anus occurring in patients with distal Crohn's disease.

Aged↗
PubMed1983

The "air enema" in acute colitis.

The plain abdominal radiograph is an important investigation in acute colitis, but may fail to demonstrate the state of the colon owing to a lack of intracolonic gas. The extent of the colitis can be demonstrated by introducing air directly into the large bowel; the air also provides sufficient contrast to distinguish a granular from an ulcerated mucosa. The "air enema" may be used as an alternative to an unprepared barium enema. Its accuracy has been established by comparison with an unprepared barium enema in 10 patients with acute colitis.

Acute Disease↗