Cow's milk-free diet does not prevent diabetes in NOD mice.

Early dietary exposure to cow's milk proteins has been proposed as an important environmental factor in the development of IDDM both in humans and in diabetes-prone rodents. To examine the significance of cow's milk protein in IDDM, 120 NOD mice were maintained, starting from conception until sacrifice, on one of four diets: standard PMI Picolab Rodent Diet 20, a milk-free modification of the standard Picolab diet, a milk-free diet incorporating 0.036% bovine serum albumin (BSA), and a milk-free diet including 0.036% bovine IgG (BGG). The cumulative IDDM incidence at 7 months for these mice in a specific pathogen-free environment on the respective diets was 78, 93, 93, and 67% for females, and 17, 54, 17, and 0% for males. The ages of diabetes onset and insulitis scores were similar for mice on each diet. The unexpectedly lower incidence of IDDM in mice on the milk-free diet that included BGG raises the possibility this cow's milk protein might possibly have some protective effect against the development of IDDM in NOD mice. Our main finding was that the standard, milk-free, and BSA-containing diets resulted in comparable incidences of IDDM in NOD mice, demonstrating that neither cow's milk whey proteins in general nor BSA in particular are significantly important as etiologic dietary agents in IDDM in NOD mice.

Prophylactic intravenous administration of caffeine and recovery after ambulatory surgical procedures.

OBJECTIVE: To determine whether prophylactic intravenous administration of caffeine, to daily caffeine users, decreases the frequency of postoperative headache and shortens recovery time. DESIGN: The study was a prospective, randomized, double-blind investigation with predetermined sample size and statistical power. MATERIAL AND METHODS: After Mayo Institutional Review Board approval and informed consent were obtained, 300 adult ambulatory surgical patients were enrolled in this study, which included randomization to receive either placebo or caffeine (200 mg intravenously) in the postanesthesia care unit. While recuperating, patients were allowed their choice of postoperative beverages. Before dismissal, patients completed a questionnaire providing details about intake of caffeine and tobacco, history of headache, and demographic data. Patients were considered "at risk" for symptoms of caffeine withdrawal if they did not drink a caffeinated beverage after the surgical procedure. RESULTS: Completed questionnaires were obtained from 234 patients. Patients at risk for symptoms of caffeine withdrawal were less likely to have a postoperative headache if they received caffeine intravenously rather than placebo-10% versus 23% (P < 0.05). Time until recovery was not significantly different between caffeine and placebo study groups. CONCLUSION: We conclude that prophylactic intravenous administration of caffeine was beneficial for those patients at risk for symptoms of caffeine withdrawal. For patients who consume caffeinated beverages on a daily basis, we recommend prophylactic administration of caffeine on the day of an ambulatory surgical procedure and anesthesia.

Celiac plexus block. Retrocrural computed tomographic anatomy in patients with and without pancreatic cancer.

BACKGROUND AND OBJECTIVES: Neurolytic celiac plexus block is often performed for analgesia from pancreatic cancer, but it is not known if the cancer alters the anatomy relevant to the successful performance of retrocrural celiac plexus block. METHODS: Abdominal computed tomographic scans were used to simulate retrocrural celiac plexus block in patients with and without pancreatic cancer. RESULTS: Simulated right-sided needle placement in the retrocrural space was more likely to fail in patients with pancreatic cancer than in patients without cancer. Such predicted failure often occurred when the cross-sectional area of the right retrocrural space was less than 1.0 cm2. CONCLUSIONS: The predicted success of stimulated retrocrural celiac plexus block differed between patients with and without pancreatic cancer. These findings have implications for the performance of celiac plexus block.

Psychogenic coma after use of general anesthesia for ethmoidectomy.

Failure of a patient to awaken promptly after use of general anesthesia may be due to various causes, including medication-related effects, neurologic insults, or metabolic disturbances. Herein we describe a 49-year-old woman with a history of depression, for which she was receiving treatment, who did not awaken promptly after use of general anesthesia for ethmoidectomy. Results of neurologic examinations were normal, as were laboratory tests and radiologic studies. Six hours after completion of the operation, the patient spontaneously awakened. We hypothesize that she underwent a transient, self-limited period of dissociation related to unresolved grief due to the recent death of a family member.

Ultraviolet action spectra for photobiological effects in cultured human lens epithelial cells.

The action spectrum for cell killing by UV radiation in human lens epithelial (HLE) cells is not known. Here we report the action spectrum in the 297-365 nm region in cultured HLE cells with an extended lifespan (HLE B-3 cells) and define their usefulness as a model system for photobiological studies. Cells were irradiated with monochromatic radiation at 297, 302, 313, 325, 334 and 365 nm. Cell survival was determined using a clonogenic assay. Analysis of survival curves showed that radiation at 297 nm was six times more effective in cell killing than 302 nm radiation; 297 nm radiation was more than 260, 590, 1400 and 3000 times as effective in cell killing as 313, 325, 334 and 365 nm radiation, respectively. The action spectrum was similar in shape to that for other human epithelial cell lines and rabbit lens epithelial cells. The effect of UV radiation on crystallin synthesis was also determined at different wavelengths. To determine whether exposure to UV radiation affects the synthesis of beta-crystallin, cells were exposed to sublethal fluences of UV radiation at 302 and 313 nm, labeled with [35S]methionine and the newly synthesized beta-crystallin was analyzed by immunoprecipitation and western blotting using an antibody to beta-crystallin. The results show a decrease in crystallin synthesis in HLE cells irradiated at 302 and 313 nm at fluences causing low cytotoxicity. The effect of radiation on membrane perturbation was determined by measuring enhancement of synthesis of prostaglandin E2 (PGE2). Synthesis of PGE2 occurs at all UV wavelengths tested in the 297-365 nm region.(ABSTRACT TRUNCATED AT 250 WORDS)

Self-evaluation effects of interpersonal versus intergroup social comparison.

Two studies tested the prediction that the outcome of social comparison will differ depending on whether interpersonal or intergroup comparison processes have been engaged. Results of an experiment in which college student participants were assigned to membership in a minority or majority social category confirmed the predicted three-way interaction effect of in-group salience, target group membership, and upward-downward comparison on self-assessments of academic ability. Majority group members exhibited contrast effects in their self-ratings following exposure to a videotape of an in-group member displaying either very high or very low academic competence. Self-evaluations of minority group members revealed assimilation effects in response to in-group comparisons and contrast effects in response to out-group comparisons. In a second, follow-up experiment, this in-group assimilation effect was found to be dependent on intergroup contrast.

Perioperative ingestion of caffeine and postoperative headache.

The interruption of daily consumption of caffeine-containing beverages can cause headache and other symptoms within 8 hours. Resumption of caffeine alleviates these symptoms. Surgical patients routinely fast preoperatively and may have postoperative symptoms from caffeine withdrawal. In the current study, we determined whether perioperative caffeine consumption altered the incidence of postoperative headache. After institutional approval of the study design, 233 surgical outpatients were surveyed about history of headaches, caffeine consumption, and the presence and severity of headaches postoperatively. Of the 233 patients, 190 (82%) drank caffeinated beverages daily (mean daily consumption, 290 mg of caffeine). Postoperative headaches occurred in 22% of patients who routinely drank caffeinated beverages but in only 7% of those who did not (P < 0.03). Other factors associated with postoperative headaches included a history of frequent headaches (P < 0.0001), age of 50 years or younger (P < 0.002), and amount of daily caffeine ingested (P < 0.01). Among daily caffeine drinkers, those who drank caffeinated beverages on the day of the surgical procedure had a lower incidence of postoperative headaches than did those who abstained (17% versus 28%; P < 0.04). Postoperative headaches may be related to several factors. Perioperative intake of caffeine altered postoperative well-being. Caffeine given preoperatively may limit postoperative withdrawal headaches among the millions of daily drinkers of caffeinated beverages. A randomized, prospective, and blinded trial to test this hypothesis is warranted.

Clinical significance of pulmonary aspiration during the perioperative period.

BACKGROUND: Pulmonary aspiration of gastric contents during the perioperative period may be associated with postoperative mortality or pulmonary morbidity. Recent determination of the incidence of perioperative pulmonary aspiration and evaluation of factors related to clinical outcomes is lacking. METHODS: We retrospectively reviewed the perioperative courses of 172,334 consecutive patients 18 yr of age or older who underwent 215,488 general anesthetics for procedures performed in all surgical specialties from July 1985 to June 1991. Pulmonary aspiration was defined as either the presence of bilious secretions or particulate matter in the tracheobronchial tree or, in patients who did not have their tracheobronchial airways directly examined after regurgitation, the presence of an infiltrate on postoperative chest roentgenogram that was not identified by preoperative roentgenogram or physical examination. RESULTS: Pulmonary aspiration occurred in 67 patients (1:3,216 anesthetics). Fifteen aspirations occurred in 13,427 (1:895) anesthetics of patients undergoing emergency surgery, and 52 occurred in 202,061 (1:3,886) anesthetics of patients undergoing elective surgery (P < .001). Of the 66 patients who survived their surgery, 42 (64%) did not develop a cough or wheeze, a decrease in arterial hemoglobin oxygen saturation while breathing room air > 10% less than the preoperative value, or radiographic abnormalities within 2 h of aspiration. These 42 patients had no respiratory sequelae. Of the 24 patients who had one or more of these findings, 13 required mechanical ventilatory support for more than 6 h. Three of the six patients whose lungs required mechanical ventilation for more than 24 h died from pulmonary insufficiency (overall mortality = 1:71,829 anesthetics). CONCLUSIONS: This study suggests that patients with clinically apparent aspiration who do not develop symptoms within 2 h are unlikely to have respiratory sequelae.

Cemented versus noncemented total hip arthroplasty--embolism, hemodynamics, and intrapulmonary shunting.

Bone cement implantation syndrome is characterized by hypotension, hypoxemia, cardiac arrhythmias, cardiac arrest, or any combination of these complications. It may result from venous embolization that occurs in conjunction with intramedullary hypertension in the femur during insertion of the prosthesis in patients undergoing cemented total hip arthroplasty (THA). Intramedullary hypertension does not occur in patients undergoing noncemented THA. In this study, we sought to compare embolization between patients undergoing cemented and noncemented THA and to determine whether this state resulted in cardiorespiratory deterioration. In this prospective investigation of 35 patients undergoing elective THA, we used transesophageal echocardiography and invasive hemodynamic monitoring, and in 12 of them, we monitored distribution of pulmonary ventilation and perfusion intraoperatively. Embolization was significantly greater after insertion of the prosthesis in patients undergoing cemented than in those undergoing noncemented THA. Cemented THA was also associated with decreased cardiac output and increased pulmonary artery pressure and pulmonary vascular resistance. Increases in ventilation-perfusion mismatching, however, could not be demonstrated 30 minutes after insertion of the femoral prosthesis. Intraoperative monitoring for embolism may help physicians assess patients in whom cardiorespiratory function deteriorates during THA.