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Biomedical subjects

Z Cohen

Publications and source records attributed to Z Cohen.

At least 199 records · Page 11Linked to original sources
PubMed1988

Clinical correlates of bacteremia in a Veterans Administration extended care facility.

Little is known about bacteremia in long-term care facilities. We have conducted a retrospective study during a 12-month period analyzing the clinical correlates of bacteremia in 533 chronically institutionalized, predominantly male patients, with an average age of 69 years. Thirty-four men had forty-two bacteremic illnesses during this period. The incidence rate was 0.30 episodes per 1000 patient care days, and the mortality rate was 21%. The urinary tract was the most frequently identified tissue source (56%), followed by respiratory tract (7%) and skin (7%). Providencia stuartii was the most common gram-negative organism, while Staphylococcus aureus, Streptococcus pneumoniae and enterococcus were the frequent gram-positive microbes. Gram-negative bacteremia accounted for 63% of the episodes (15% mortality rate), and gram-positive bacteremia accounted for 27% (18% mortality rate); 10% of the bacteremias were polymicrobial (25% mortality rate). Most of the isolated organisms were sensitive to available antimicrobial agents. The leading risk factor for bacteremia was an indwelling urinary catheter (odds ratio 39, 95% confidence limits 16 to 97). Patients with urinary catheters at the beginning of the study constituted only 5% of the population, but accounted for 40% of the gram-negative bacteremias during the year of observation.

Aged↗
PubMed1988

Cyclosporin A metabolites suppress T-cell proliferation by concanavalin A and in a mixed lymphocyte reaction.

To ascertain if cyclosporine metabolites (CMs) have immunosuppressive activity, bile, whole blood and urine taken from patients after cholecystectomy and from a liver transplant recipient on cyclosporin A (CsA) were assayed to determine their effect on T-cell proliferation induced by concanavalin A (Con A) and in a two-way mixed-lymphocyte response. Bile and whole blood from the liver transplant patient completely suppressed Con A proliferation and the mixed lymphocyte response (MLR) at dilutions at which normal bile and whole blood have no suppressive activity, but no such activity was noted from the urine. The CMs were separated into six peaks (fractions) by high-pressure liquid chromatography (HPLC). Metabolites were identified by internal standards and HPLC/mass spectrophotometric analysis. Cyclosporine metabolite fractions 2 and 3 from bile and blood had immunosuppressive activity similar to parent CsA whereas fractions 5 and 6 demonstrated less but substantial immunosuppressive activity. Fractions 2, 3 and 5 demonstrated an ability to inhibit two-way MLR similar to parent CsA; the other metabolite fractions were able to inhibit the MLR but to a lesser extent. These results demonstrate that a number of CMs have immunosuppressive effects similar to those of the parent compound, and this may account for the lack of correlation between whole blood CsA levels and immunosuppressive activity.

Chromatography, High Pressure Liquid↗
PubMed1987

Surveillance in relatives of patients with adenomatous polyposis.

Registry ascertainment of kindreds with adenomatous polyposis (AP) reduces the incidence of colorectal carcinoma by medical monitoring for offspring and siblings of affected patients. Due to its pleiomorphic genotype and a 50% risk for AP in each patient's progeny, early screening is mandatory. Flexible sigmoidoscopy, averaging from puberty to age 48, annually or every two years, is one diagnostic technique that does not result in excess patient discomfort or cost. Timely examination is facilitated when eye anomalies, osteomas, or epidermoid cysts are present in childhood as potential clinical markers for AP. Denial, misperceptions, and fear may impede surveillance in the absence of education by the registry health care team.

Adenoma↗
PubMed1987

A stapled S-shaped ileoanal reservoir.

An S-shaped ileoanal reservoir has the advantage of greater ease in obtaining adequate length for safe anastomosis vs. the J-pouch. The hand-sewn S-shaped pouch, however, takes considerably longer (70 vs. 20 minutes) to construct than either a hand-sewn or stapled J-pouch. Because of potential necrosis of the central bridge of tissue created between two longitudinal stapled lines in an S-pouch, the same techniques of stapling a J-pouch cannot be used in an S-pouch. The authors have developed a safe, rapid, stapling technique for construction of an S-pouch in the dog and have used it with success in four patients.

Anal Canal↗
PubMed1987

Surgery based on misdiagnosis of adenomatous polyposis. The Canadian Polyposis Registry experience.

The histopathology of 304 patients registered in the Canadian Familial Polyposis Registry (CFPR) with a diagnosis of supposed adenomatous polyposis (AP) was reviewed. The diagnosis was changed in 17 (5.6 percent) of these patients. Group 1 consisted of nine patients who had adenocarcinomas plus multiple tubular adenomas (seven) or metaplastic polyps (two). Eight patients who had no colon cancer comprised Group 2. In these patients, the diagnosis was changed to lymphoid polyposis (2), metaplastic polyps (3), isolated adenomas (2), or juvenile polyposis (1). All 17 patients had had previous colonic resections. Following the change in diagnosis, this treatment was considered inappropriate in 11 patients. Treatment, prognosis, and follow-up of patients and affected family members depend on the type of polyposis syndrome diagnosed. Correct histologic assessment of polyps prior to initial surgery is essential.

Adolescent↗
PubMed1987

S-pouches vs. J-pouches. A comparison of functional outcomes.

Subjects undergoing proctocolectomy with ileoanal anastomosis of either a J-shaped or an S-shaped ileal reservoir were studied with respect to functional status. Both subjective and objective measures were used. The S-pouch subjects appeared to have better early functional results, but no differences were found between groups evaluated at least one year from ileostomy closure. While virtually all subjects preferred restorative proctocolectomy to their previous loop ileostomy, there was a relatively high frequency of bowel-related symptoms, worries about bowel activity, and associated behavioral changes. The actual significance of these symptoms is difficult to determine at present. Further assessment of the quality of life in individuals with restorative proctocolectomy in comparison with subjects undergoing alternative surgical treatments is recommended.

Adolescent↗
PubMed1987

Complications of loop ileostomy.

We consider a proximal loop ileostomy to be an integral part of a pelvic pouch procedure with ileoanal anastomosis. In the absence of controlled studies and considering the reported poor results with high rates of pelvic sepsis when this operation is performed without a proximal defunctionalizing ileostomy, we will continue to routinely use proximal ileostomy in all patients undergoing this procedure. There is a high rate of complications related to loop ileostomy; however, they are not life threatening and do not preclude an excellent long-term result. Dehydration requiring readmission to the hospital occurred in 20 percent of the patients in this series. More sensitive clinical data, such as measurement of urinary electrolyte levels, should be used to identify patients at high risk for this complication. Septic complications were rare after closure of the loop ileostomy, but bowel obstruction was common. Bowel obstruction rarely required operative intervention, but it is possible that changing the method of closure may decrease the rate of obstruction. The use of loop ileostomy to bypass temporarily part of the terminal ileum may have significant metabolic effects that require further study.

Adolescent↗
PubMed1987

Digestibility of carbohydrate foods in an ileostomate: relationship to dietary fiber, in vitro digestibility, and glycemic response.

The aim of this study was to assess differences between starchy foods in the amount of carbohydrate which escapes small intestinal absorption. One ileostomate volunteer tested in metabolic feeding trials a total of 20 starchy foods (nine of which were repeated on two to seven occasions, mean 3.5 +/- 1.7). This ileostomate volunteer exhibited macronutrient and fiber losses that were within 97.3 +/- 6.6% of the mean, for a range of foods eaten by three other ileostomates and was therefore believed to be representative. Measurement of available carbohydrate in ileal effluent demonstrated a wide range of recoveries from 2.7 to 18% from different starchy foods. The available carbohydrate losses related to the fiber content (r = 0.885, p less than 0.001), in vitro digestibility of the food (r = -0.867, p less than 0.01), and their glycemic responses (r = -0.611, p less than 0.05). Our data support the concept that available carbohydrate losses to the colon may be greater in many foods than the carbohydrate entering the colon as dietary fiber. The food factors responsible are diverse and the possible metabolic consequences of carbohydrate malabsorption may be broad.

Blood Glucose↗
PubMed1987

Perianal Crohn's disease.

Various approaches to the management of perianal Crohn's Disease are discussed. In general, surgically, a conservative approach is taken because of the concern that wounds associated with the disease tend to heal poorly.

Crohn Disease↗
PubMed1987

Immune responses in small intestinal transplantation in the rat: correlation of histopathology and monocyte procoagulant activity.

No predictive serologic marker exists for rejection or graft versus host disease (GVHD) reactions in small intestinal transplantation (SIT). SIT was performed in Lewis (Lew) and Lew X Brown Norway Fl hybrid (LBN) rats in the following combinations: group 1, Lew X Lew; group 2 (isolated rejection), LBN X Lew, and group 3 (isolated GVHD), Lew X LBN. Procoagulant activity (PCA), an index of monocyte immune activation, was measured in the peripheral blood mononuclear cells of graft recipients to assess its value as an immunologic monitor. Histologic findings and PCA were evaluated on days 1, 2, and 3 and every 2 to 3 days after SIT. No pathologic findings of graft or host tissue developed in group 1 (n = 14). Histologic rejection (blunted villi and mononuclear cell infiltration) was seen beginning on day 5 in group 2 (n = 19); early GVHD (loss of nodal and splenic architecture) was first noted on days 5 and 6 in group 3 (n = 17). PCA elevation in SIT was seen to precede histologic evidence of rejection or graft versus host disease in this model and may constitute an important marker for these immunologic events.

Animals↗
PubMed1987

Ambulatory procedures in anorectal surgery.

In view of the broad spectrum of conventional and unconventional STDs in the homosexual man, the following diagnostic workup is recommended: History. Physical examination, including proctosigmoidoscopy with biopsy. Urethral, pharyngeal, and rectal cultures. Darkfield examination of any genital ulceration. Stool cultures for bacteria and parasites. Serologic analysis, including VDRL and, where indicated, for Chlamydia trachomatis and amebiasis. It is an essential part of proctologic practice for the surgeon to be able to recognize, diagnose, and treat sexually transmitted diseases.

Ambulatory Surgical Procedures↗
PubMed1987

Ticarcillin/clavulanic acid (Timentin) compared to metronidazole/netilmicin in preventing postoperative infection after elective colorectal surgery.

A randomized controlled trial was performed to compare the effectiveness of ticarcillin/clavulanic acid to metronidazole/netilmicin in preventing postoperative infections after elective colorectal surgery. Ninety-two patients were randomly allocated to receive three doses of ticarcillin, 3 g, with clavulanic acid, 100 mg every 8 hours, or three doses of metronidazole, 500 mg, and netilmicin, 80 mg intravenously every 8 hours. All patients received a mechanical bowel preparation with 3 L of Go-lytely solution. There were no operative deaths. Eight patients had wound infections--three in the ticarcillin/clavulanic acid group and five in the metronidazole/netilmicin group. One patient in the ticarcillin/clavulanic acid group had an intra-abdominal abscess. There were two anastomotic leaks, one in each group. Ticarcillin/clavulanic acid and metronidazole/netilmicin appear to be equally effective in preventing postoperative infections after elective colorectal surgery.

Adolescent↗
PubMed1987

Pharmacokinetic changes of several antibiotics in chickens during induced fatty liver.

The concentrations of five antibiotics (erythromycin, lincomycin, penicillin G, streptomycin and oxytetracycline) were determined in chicken serum before and after induced fatty liver. The pharmacokinetic variables were calculated according to the obtained data. The crossover trial design involved 10 chickens for each antibiotic. The fatty liver was produced by oestradiol-dipropionate injections and monitored by serum malic enzyme activity determinations. Protein binding of the respective antibiotics was determined in vitro in the serum obtained from normal and oestrogen-treated birds. Induction of fatty liver caused several changes in the determined variables. The measured peak concentrations were higher for lincomycin and erythromycin and lower for penicillin and oxytetracycline while streptomycin remained unchanged. The peak concentration of streptomycin appeared earlier and the peak of oxytetracycline later than in the normal chickens. The elimination half-lives were shorter for erythromycin, lincomycin and streptomycin and increased for penicillin and oxytetracycline. The area under the concentration curve (AUC) decreased for erythromycin, penicillin and streptomycin, increased for oxytetracycline and remained unchanged for lincomycin. The body clearance (ClB/f) and the apparent specific volume of distribution (Vd(area'/f) were considerably changed in association with fatty liver induction. Since the fraction of the drug absorbed (f) is not known, it can only be speculated that changes in distribution rather than reduced liver function altered the kinetics. The protein binding was decreased for all the antibiotics, but this did not seem to be the reason for changes in kinetics, except perhaps in the case of penicillin.

Animals↗
PubMed1987

Current status of the continent ileostomy.

The continent ileostomy has substantial advantages over the standard ileostomy in that it provides a socially acceptable, odourless, appliance-free stoma. The author presents the experience at the Toronto General Hospital from 1977 to 1984 with this procedure which was performed on 123 patients, in conjunction with proctocolectomy (36) and as a conversion from an ileostomy or colostomy (87). There were no postoperative deaths. Modifications to prevent nipple valve sliding have included the addition of staples across the valve and synthetic mesh slings around the outlet. Reservoir ileitis remains a difficult problem, most likely due to stagnant bacterial overgrowth. The operation should not be performed on patients with Crohn's disease, and in the obese, technical difficulties present considerable risk. The procedure should be confined to large centres where the surgeons are experienced in the procedure.

Adult↗