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Biomedical subjects

M A Kraus

Publications and source records attributed to M A Kraus.

28 records · Page 2Linked to original sources

Laparoscopic identification of preperitoneal nerve anatomy in the inguinal area.

The laparoscopic approach has recently been utilized for inguinal hernia repair. Nerve injuries are now being reported. The femoral branch of the genitofemoral nerve and the lateral cutaneous nerve of the thigh appear most at risk. The purpose of this study was to determine the feasibility of identifying these nerves laparoscopically on either a routine or selective basis. Twenty patients scheduled for laparoscopic inguinal hernia repair were prospectively selected. An attempt was made to identify these nerves so that optimum placement of staples could occur. The femoral branch of the genitofemoral nerve was identified in 19 of 20 patients and the lateral cutaneous nerve of the thigh in 18 of 20 patients. A review of 125 laparoscopic inguinal hernia repairs revealed five nerve injuries (4%). Details are given and recommendations discussed. Knowledge of preperitoneal anatomy and awareness of the location of these nerves should lead to a safer dissection and more accurate application of staples, hopefully decreasing the incidence of nerve injury.

Adult↗

Nerve injury during laparoscopic inguinal hernia repair.

This report presents a case of injury to the lateral cutaneous nerve of the thigh during laparoscopic inguinal hernia repair. Both this nerve and the femoral branch of the genitofemoral nerve are at risk during laparoscopic inguinal hernia repair. Pertinent anatomy is reviewed and suggestions made to prevent this injury. This case does not appear to be an isolated event, and hopefully this report will bring attention to this potential complication.

Adult↗

An advanced affinity membrane for covalent binding of amino ligands.

We report here an advanced, chemically active and yet hydrolytically stable microporous membrane which allows permanent covalent binding of amino ligands such as proteins. Rapid, single-step immobilizations produce a high density of immobilized ligands. Surface chemistry of the membrane is specifically designed to have extremely low nonspecific binding. Binding characteristics of the UltraBind membrane, various immobilization techniques and optimum immobilization conditions for diagnostic immunoassays are described.

Amines↗

Choledochoduodenostomy: importance of common duct size and occurrence of cholangitis.

Choledochoduodenostomy was performed in 68 patients. In these cases, we attempted to determine any correlation between the size of the common duct and subsequent cholangitis. Follow-up information was available in 64 (94%) of the cases, with a mean follow-up of three years. The most common indication for choledochoduodenostomy was choledocholiothiasis. Prior biliary surgery was used in 33 (48%) patients. Benign disease was present in 51 patients, and 17 patients had malignant neoplasms. The mean size of the common duct was 2.1 cm and the range was 1.0 to 4.0 cm. Only two patients (2.8%) experienced episodes of cholangitis after choledochoduodenostomy and both of these patients had a common duct that measured less than 1.6 cm at the time of anastomosis. Other procedures than choledochoduodenostomy should be considered when common duct size is less than 1.6 cm.

Adult↗

Positive nitrogen balance using isotonic crystalline amino acid solution.

A study of 50 patients was undertaken to determine the effects of an isotonic 5 percent crystalline amino acid solution on nitrogen balance. Patients were divided randomly into two groups: 24 receiving amino acids and 25 receiving dextrose in water. (One patient in the treatment group dropped out after one day of intravenous therapy.) Administration of amino acids postoperatively maintained nitrogen balance, as compared with controls. No untoward metabolic changes or other complications occurred. Amino acid peripherally administered is an alternate source of calories and nitrogen. It is of value in treating short-term under-nutrition.

Abdomen↗

Persistent increases in basal cerebral metabolic activity induced by morphine sensitization.

To characterize the underlying neuroanatomic substrate of morphine (MS) sensitization, changes in the local cerebral metabolic rate for glucose (LCMRglu) were examined in 95 brain regions of male F-344 rats using the 2-deoxy-D-[1-14C]glucose method. The results of these experiments demonstrate that MS-induced sensitization is manifested by increases in basal metabolic activity that last for at least 6 days. Although changes in basal metabolic rate were found to be more extensive in the presence of conditioned cues, the increases in LCMRglu in nonconditioned sensitized rats indicate a basic underlying pharmacologic effect of MS sensitization on basal brain activity. Regions in which MS sensitization had a lasting pharmacologic effect include the shell of the nucleus accumbens, the prelimbic area of the prefrontal cortex, and the dorsolateral prefrontal cortex. Interestingly, the core of the nucleus accumbens and regions of the caudate were found to have an increased LCMRglu only in the presence of conditioned cues, indicating conditioned brain activity without observable changes in behavior. The previous administration of an MS-sensitizing treatment was also found to alter the cerebral metabolic response to a subsequent acute MS challenge (0.5 mg/kg, subcutaneously), most notably in forebrain systems. The more widespread activation of brain structures in the basal state in the presence of conditioned cues suggests that these MS-sensitized rats may model an altered brain state related to craving in the abstinent opiate addict.

Animals↗

Small and middle molecular weight solute clearance in nocturnal intermittent peritoneal dialysis.

OBJECTIVES: To determine the dialysate-to-plasma (D/P) concentration ratios and peritoneal dialytic clearance (CI(D)) of substances with a wide range of molecular weights in subjects receiving a simulated nocturnal intermittent peritoneal dialysis (NIPD) session. DESIGN: Open-label single-dose study. SUBJECTS: Six end-stage renal disease patients undergoing peritoneal dialysis (PD). SETTING: Clinical research center of a university-affiliated hospital. INTERVENTIONS: Subjects received intravenous gentamicin and vancomycin on the first day of the study. Subjects received no PD until their return on the following day, when subjects underwent a simulated NIPD session utilizing four 2- to 2.5-L peritoneal dialysate dwells of 2 hours. Blood and dialysate samples were collected immediately before the session and after each dialysate dwell for determination of urea, creatinine, gentamicin, vancomycin, and beta2-microglobulin (beta2M) concentrations. Each solute's D/P concentration ratio and peritoneal CI(D) were calculated. MEASUREMENTS AND MAIN RESULTS: The (mean +/- SD) 2-hour D/P concentration ratios were 0.78 +/- 0.05 (urea), 0.49 +/- 0.11 (creatinine), 0.38 +/- 0.08 (gentamicin), 0.11 +/- 0.06 (vancomycin), and 0.07 +/- 0.03 (beta2M). Peritoneal CI(D) values (mL/min of dialysis) were 19.0 +/- 2.8 (urea), 12.1 +/- 3.5 (creatinine), 8.4 +/- 2.8 (gentamicin), 2.7 +/- 1.5 (vancomycin), and 1.7 +/- 0.8 (beta2M). The D/P concentration ratios and peritoneal CI(D) values for urea, creatinine, and gentamicin were significantly different from vancomycin and beta2M (repeated measures ANOVA, p < 0.05). Beta2-microglobulin peritoneal CI(D) was strongly related to gentamicin peritoneal CI(D) (r = 0.96, p < 0.05). CONCLUSION: Small molecular weight solutes have significantly greater D/P and peritoneal CI(D) than middle molecular weight solutes in NIPD. In NIPD, daily peritoneal CI(D) of beta2M is lower than that reported in continuous ambulatory PD. NIPD also results in lower drug CI(D) than that reported in continuous ambulatory PD studies.

Adult↗

Effects of dialysis membrane on intradialytic vancomycin administration.

STUDY OBJECTIVE: To quantify the influence of hemodialyzers on vancomycin removal when the drug was infused during hemodialysis. DESIGN: Prospective, controlled, crossover study with three arms. SETTING: A university-affiliated medical center. PATIENTS: Eight subjects receiving outpatient hemodialysis. INTERVENTIONS: The three treatment arms were vancomycin 1000 mg infused after dialysis was completed (control), and the same dosages infused during the last hour of hemodialysis with a cellulose triacetate (CT) and a cellulose acetate (CA) hemodialyzer. MEASUREMENTS AND MAIN RESULTS: The areas under the curve from time zero to 44 hours (AUC0-44 hrs) for the three study arms were significantly different (p < 0.05), with the mean vancomycin AUC0-44 hrs being significantly lower when administered during CT and CA dialysis (73.7% and 87.2% of control; p < 0.05 vs control). The mean vancomycin peak concentration achieved during CT dialysis was significantly lower than for the CA and control arms (20.5, 23.9, 27.0 mg/L, respectively). Forty-four-hour postinfusion concentrations were similarly lower. CONCLUSION: Clinicians should recognize that the composition of the hemodialyzer significantly influences vancomycin serum concentrations when the drug is administered during hemodialysis.

Anti-Bacterial Agents↗