Current benzodiazepine issues

This article deals with some of the recent evidence bearing on the issues of the liability of benzodiazepines to lead to abuse, dependence, and adverse behavioral effects. Reviews of epidemiological, clinical and experimental literature indicated that the previous conclusion about abuse of these drugs still holds: the vast majority of the use of benzodiazepines is appropriate. Problems of nonmedical use arise nearly exclusively among people who abuse other drugs. Nevertheless, there are reasons for concern about patients who take benzodiazepines regularly for long periods of time. These drugs can produce physiological dependence when taken chronicaly, and although this does not appear to result in dose escalation or other evidence of psychological dependence, physiological dependence can result in patient discomfort if drug use is abruptly discontiniued. Also, physicians are currently prescribing shorter-acting benzodiazepines in preference to longer-acting benzodiazepines. The shorter-acting drugs can produce a more intense withdrawal syndrome following chronic administration. Furthermore, rates of use of benzodiazepines increase with age, and elderly patients are more likely than younger ones to take the drug chronically. The clearest adverse effect of benzodiazepines is impairment of memory. This, too, may be particular concern in older patients whose recall in the absence of drug is typically impaired relative to younger individuals, and who are more compromised following drug administration.This article was supported by USPHS Grant DA-00254 and by funding from Hoffmann-La Roche, Inc.     

Laparoscopy and major retroperitoneal vascular injuries (MRVI)

Injury to major retroperitoneal vessels is a potential serious complication of laparoscopy occurring when the Veress needle or trocar is inserted. This report is a review of major retropertioneal vascular injuries (MRVI) occurring during laparoscopy, as these injuries have not been well documented in the literature. A retrospective, observational review of general surgical laparoscopy cases was conducted over a 3.5-year period in three community, university-affiliated hospitals. We identified 4 MRVI in 3591 laparoscopic procedures. These cases were critically analyzed and compared. The incidence of MRVI was 0.1%. All cases occurred with the closed (blind) insertion technique of Veress needle and primary trocar insertion technique with disposable safety shield trocars. All patients sustaining MRVI had acute hypotension introperatively and significant blood loss necessitating postoperative transfusions. Recognition and rapid conversion to laparotomy are keys to enhancing outcome. There is significant potential for morbidity and mortality with laparoscopic MRVI, although each patient in this series was discharged without obvious short-term problems. The advantages of an open approach for primary trocar insertion are numerous and should alleviate the risk of MRVI associated with general laparoscopic surgery.Presented at the annual meeting of the Society of American Gastrointestinal Endoscopic Surgeons (SAGES), Orlando, FL, USA, 11–14 March 1995; and the Third European Congress of the European Association for Endoscopic Surgery, Luxembourg, 13–17 June 1995     

Wound cleansing by irrigation for implant surgery

Wound irrigation is an adjunct to all implant surgeries involving surgical incisions or arthroplasties. An understanding of the physics of wound irrigation provides a scientific basis for recommending wound irrigation systems for implant surgery. When inserting implants through surgical incisions, a low-pressure irrigation system is recommended for removing blood from the wound surface. In contrast, high-pressure irrigation systems are indicated to cleanse the intramedullary canal before cemented arthroplasty. With the advent of static and dynamic pressure transducers, irrigation systems can now be specifically designed to achieve these goals.     

Evaluation of a targeted HIV testing program for at-risk youth

With the advent of new therapies for HIV, case identification through HIV counseling and testing (CTS) has become critically important. Young women, youth of color, and disenfranchised youth are at significant risk of acquiring HIV. This study describes clients who access CTS at a program of comprehensive care for high-risk youth (aged 12 to 24 years), and assessed, using logistic regression analyses, whether youth at highest risk utilized CTS. Most of the 531 youth were female (72 percent) and nonwhite (60 percent). Sixty-eight percent received CTS. Logistic regression modeling revealed that white race and receiving care at the teaching hospital were the only independent predictors of testing. Data indicate that, despite targeted, youth-specific, developmentally appropriate and culturally sensitive outreach and intervention efforts, youth of color and high-risk youth are poorly accessing CTS. A greater understanding of the barriers to and cultural norms regarding CTS is needed.     

Religion and Spirituality in the Face of Illness: How Cancer, Cardiac, and HIV Patients Describe their Spirituality/Religiosity

This study reports the results of semi-structured interviews conducted with 60 medically ill (cancer, myocardial infarction, HIV/AIDS) people in an attempt to define what people facing a life-threatening illness mean when they say they are 'spiritual' or 'religious'. Questions were asked about beliefs and affective, behavioral, and somatic realms. Subjects initially self-identified as considering themselves to be spiritual, religious, or both. While some similarities existed between the groups (e.g. amount of time spent in prayer, beliefs set the tone for their life, give them a sense of well-being, guidance, a sense of right and wrong, a connection to God, and a sense they will live on in some form), significant differences were discovered in overall belief systems, as well as in interpretation of the mechanisms whereby subjects' beliefs impacted their health and their recovery. Those identifying as spiritual described recovery and healing as happening through them whereas those identifying as religious were more likely to say it happens to them. In addition, significant differences existed between the groups in their overall view of God, self, world, and others. Implications for future studies are discussed.     

Commercial applications of Tuned Aperture Computed Tomography

Tuned Aperture Computed Tomography will allow the creation of three-dimensional images of dental structures from layers of digital information that can be gathered in the dental office. These three-dimensional images will give a fuller view of the structures, thereby providing more information from which to make a better diagnosis. Unlike similar medical tomosynthetic imaging techniques, TACT should be easily accommodated into dental practice needs.     

The effects of microencapsulation on pancreatic islet osmotically induced volumetric response

Microencapsulation of pancreatic islets has been proposed as a means to prevent allograft rejection and to protect islets during cryopreservation. The aim of this study was to investigate: 1) the effects of the cryoprotectants (CPAs) dimethyl sulfoxide (DMSO) and ethylene glycol (EG) on the volume of Ca2+ alginate microcapsules, and 2) the effects of microencapsulation on the volumetric response of human and canine pancreatic islets during CPA equilibration. Stock sodium alginate with a high mannuronic acid content (HM) or a high guluronic acid content (HG) was used to generate empty capsules (mean diameter 200 microm) with an electrostatic generator. The capsules were held in place by a holding pipette system and videotaped during the addition of 2 or 3 M CPA at 22 degrees C. Islets (isolated from human cadaveric donors and mongrel dogs and then cultured overnight at 37 degrees C) were encapsulated in alginate (HM), loaded into a microperfusion chamber, and the change in islet volume was videotaped after exposure to the same CPAs and concentrations. These were compared to the volume responses of nonencapsulated islets. Images were analyzed using a computerized image analysis system and the data were analyzed using ANOVA. HG microcapsules showed a significant (p < 0.05) increase in volume following exposure to EG but not to DMSO. HM microcapsule volume did not change significantly following exposure to either EG or DMSO and was therefore chosen as the substrate for islet encapsulation. Free, nonencapsulated canine and human islets responded to the osmotic challenge of the 2 M DMSO by shrinking to 70.00 +/- 1.04% (mean +/- SEM) and 70.11 +/- 1.05%, and in 2 M EG to 72.89 +/- 1.93% and 69.33 +/- 1.38%, respectively, of the isotonic volume before returning to the original cell volume. Exposure to 3 M DMSO or EG resulted in a further dehydration to 65.89 +/- 0.91% and 67.67 +/- 1.91% for canine and 62.22 +/- 0.66.% or 65.89 +/- 1.30% for human islets. Minimum volumes were reached within 30-40 s after exposure to the cryoprotectant. Encapsulated human islets reached 86.88 +/- 1.47% of their original volume in 2 M and 80.33 +/- 0.89% in 3 M DMSO, and 87.33 +/- 1.86% in 2 M and 82.80 +/- 1.57% in 3 M EG. This volume change was significantly less (p < 0.01) than that observed in corresponding free islets. Encapsulated canine islets reached 83.67 +/- 2.13% of their original volume in 2 M and 78.22 +/- 0.95% in 3 M DMSO, and 85.44 +/- 1.92% in 2 M and 78.11 +/- 2.01% in 3 M EG. As with human islets, this was significantly different than free islets (p < 0.01). These minimal volumes were reached within 30-50 s. These results demonstrate that there are cryoprotectant and alginate-specific interactions and that microencapsulation modulates the degree of osmotically induced shrinkage of islets. The development or modification of existing cryopreservation protocols to improve postcryopreservation recovery or function must account for these factors.