Reflection absorption infrared spectroscopy and temperature programmed desorption investigations of the interaction of methanol with a graphite surface

Reflection absorption infrared spectroscopy (RAIRS) and temperature programmed desorption (TPD) have been used to investigate the adsorption of methanol (CH(3)OH) on the highly oriented pyrolytic graphite (HOPG) surface. RAIRS shows that CH(3)OH is physisorbed at all exposures and that crystalline CH(3)OH can be formed, provided that the surface temperature and coverage are high enough. It is not possible to distinguish CH(3)OH that is closely associated with the HOPG surface from CH(3)OH adsorbed in multilayers using RAIRS. In contrast, TPD data show three peaks for the desorption of CH(3)OH. Initial adsorption leads to the observation of a peak assigned to the desorption of a monolayer. Subsequent adsorption leads to the formation of multilayers on the surface and two TPD peaks are observed which can be assigned to the desorption of multilayer CH(3)OH. The first of these shows a fractional order desorption, assigned to the presence of hydrogen bonding in the overlayer. The higher temperature multilayer desorption peak is only observed following very high exposures of CH(3)OH to the surface and can be assigned to the desorption of crystalline CH(3)OH.

Dental students' experiences with and attitudes toward people with mental retardation

BACKGROUND

People with mental retardation have limited access to oral health care. Dental school administrators reported minimal training in U.S. dental schools for these patients. As a result, students and practitioners may not be prepared to provide needed services.

METHODS

The authors surveyed 295 third- and fourth-year students at five dental schools about their didactic and clinical preparation for, attitudes toward and comfort levels with treating people with mental retardation, as well as whether their experiences affect their willingness to treat people with mental retardation. The authors analyzed data using previously developed statistical software.

RESULTS

A little more than 68 percent of respondents reported receiving five hours or less of instruction devoted to how to care for people with mental retardation, and 50.8 percent reported having no clinical training in this area. Nearly 60 percent reported that they had little to no confidence in providing care, while 74.6 percent reported they had little to no preparation in providing care. Students who had experience working with people with mental retardation attributed greater capabilities to such people than did students who had no such experience.

CONCLUSIONS

Many U.S. dental students are prepared inadequately to provide services for people with mental retardation. Spending time with these patients provides a more positive understanding of the capabilities of these people.

PRACTICE IMPLICATIONS

Increasing numbers of people with mental retardation no longer live in institutions, and they are dependent on dentists in private practice for care. Increased dental school training and continuing education programs are needed to meet this need.

Pulmonary manifestations of HIV infection in the era of highly active antiretroviral therapy

STUDY OBJECTIVES

To determine whether the spectrum of HIV-related pulmonary disease seen by a university medical center Pulmonary and Critical Care Medicine Service has changed since the introduction of highly active antiretroviral therapy (HAART).

DESIGN

Retrospective chart review.

SETTING

A tertiary care university hospital.

PATIENTS

All HIV-infected patients referred to the Pulmonary and Critical Care Medicine Service from January 1, 1993, through December 31, 1995 (era 1) and from July 1, 1997, through June 30, 2000 (era 2).

INTERVENTIONS

Inpatient and outpatient charts were reviewed for data regarding patient demographics, CD4 cell counts, viral load levels, duration of HIV seropositivity, history of opportunistic infections, and final diagnosis.

RESULTS

Pneumocystis carinii pneumonia (PCP) was less common in the HAART era than in the pre-HAART era, whereas bacterial pneumonia and non-Hodgkin's lymphoma (NHL) were more common in the HAART era than in the pre-HAART era. HAART was protective against PCP (odds ratio [OR], 0.37; confidence interval [CI], 0.16 to 0.89) in a manner dependent on the CD4 cell count. Patients receiving HAART were at increased risk for the development of bacterial pneumonia (OR, 2.41; CI, 1.12 to 5.17) and NHL (OR, 15.11; CI, 3.14 to 28.32). A history of PCP indicated a risk factor for bacterial pneumonia (OR, 2.14; CI, 1.13 to 4.04). A history of cytomegalovirus infection indicated a risk factor for NHL (OR, 6.0; CI, 1.27 to 28.32).

CONCLUSIONS

There have been significant changes in the spectrum of HIV-related pulmonary complications seen by our Pulmonary and Critical Care Medicine Service in the HAART era.

Risk factors for hypercarbia, subcutaneous emphysema, pneumothorax, and pneumomediastinum during laparoscopy

OBJECTIVE

To determine independent predictors for the development of hypercarbia, subcutaneous emphysema, pneumothorax, and pneumomediastinum during laparoscopy.

METHODS

We reviewed 968 laparoscopic cases between January 1, 1997, and December 31, 1998. Patients who had hypercarbia (end-tidal carbon dioxide of 50 mmHg or greater), pneumothorax/pneumomediastinum, and subcutaneous emphysema were compared with controls according to age, operative time, type of surgery, extraperitoneal or intraperitoneal approach, preexisting medical conditions, body mass index, sex, use of Hasson technique, and number of surgical ports. Maximum positive end-tidal CO(2) (PETCO(2)) was added as an independent variable for subcutaneous emphysema, pneumothorax, and pneumomediastinum. Data were analyzed using univariate analysis and then subjected to multivariate analysis using multiple logistic regression analysis.

RESULTS

Incidence rates were 5.5% for hypercarbia, 2.3% for subcutaneous emphysema, and 1.9% for pneumothorax/ pneumomediastinum. Independent risk factors for development of hypercarbia were operative time greater than 200 minutes (odds ratio [OR] 2.02), patient age greater than 65 years (OR 2.19), and Nissen fundoplication surgery (OR 3.18). Predictors of the development of subcutaneous emphysema were PETCO(2) greater than 50 mmHg (OR 3.49), operative time greater than 200 minutes (OR 5.27), and the use of six or more surgical ports (OR 3.06). Variables that predicted the development of pneumothorax and/or pneumomediastinum were PETCO(2) greater than 50 mmHg (OR 4. 15) and operative time greater than 200 minutes (OR 20.49).

CONCLUSION

Longer operative times, higher maximum measured end-tidal CO(2), greater number of surgical ports, older patient age, and Nissen fundoplication surgery predispose patients to hypercarbia-related complications during laparoscopy.

The ability of recombinant tissue plasminogen activator to inhibit post-radical pelvic surgery adhesions in the dog model

We investigated the ability of recombinant tissue plasminogen activator to inhibit post-radical pelvic surgery adhesions formation in 40 adult female canines undergoing radical hysterectomy, bilateral salpingo-oophorectomy, omentectomy, resection of pelvic and abdominal peritoneum, and placement of a peritoneal access catheter. Immediately after operation one half of animals received either recombinant tissue plasminogen activator, 1 mg/kg weight, diluted in 9 ml sterile normal saline solution per milligram of the plasminogen activator or 10 ml vehicle per kilogram intraperitoneally every 12 hours for a total of 10 doses. A single control animal died postoperatively of complications of intestinal obstruction. No bleeding abnormalities were noted in either group of animals. Four weeks after surgery, animals underwent reexploration and adhesions were quantified. Adhesion scores for the animals treated with recombinant tissue plasminogen activator (n = 20; mean score, 1.29 +/- 1.97; median, 0.6) were significantly less than for control animals (n = 19; mean score, 4.64 +/- 3.71; median, 3.86; p = 0.03). Whereas recombinant tissue plasminogen activator appears to effectively prevent post-radical pelvic surgery adhesions in this canine model, phase I and II trials in humans will be required to determine safety and clinical benefit.

Gonadal protection and fecundity rates in cyclophosphamide-treated rats

Premature ovarian failure and reduced fecundity are well-documented consequences of cytotoxic chemotherapy used to treat patients with malignant diseases. To investigate the ability of different hormonal agents to block the effects of cyclophosphamide (CTX) on reproductive function, sexually mature female Long-Evans rats were studied. Model development demonstrated that CTX, 6 mg/kg/day, 5 days/week for 3 weeks, was successful at inducing acyclicity and significantly reducing fertility and fecundity, with acceptable mortality, when compared to higher/lower dosages. Utilizing this model, animals were treated with CTX in combination with an inert vehicle, Lupron, 80 micrograms/kg every 24 h, Lupron, 40 micrograms/kg every 12 h, or s.c. progesterone capsules obtaining serum progesterone levels of 20-30 ng/ml. We concluded that progesterone was able to protect the gonad from the negative effects of CTX, maintaining fertility and fecundity rates not significantly different from those of untreated control animals. Lupron given every 12 h had a similar effect on fertility, but failed to protect fecundity (P less than 0.001).

Surgical antibiotic prophylaxis, patient morbidity, and cost reduction: a three-year study

Twenty-five to 50 percent of all antibiotics prescribed for hospitalized patients are for prevention, not treatment, of infection. Procedures to institute rational, cost-effective utilization of these agents should have a significant impact on drug cost and pharmacy inventory. Several authors have described antibiotic cost reduction programs using pharmacy intervention. Unfortunately, measures that are successful in one institution may not be effective or appropriate in another. A three-year study was undertaken to examine the impact on physician prescribing of an infection control bulletin and formalized recommendation for antibiotic utilization. Patient records also were examined to determine if any change in antibiotic utilization would influence patient morbidity. Over the three examination periods there was a significant reduction in cost of prophylaxis in 7 surgical groups, and a trend toward cost reduction in 21 additional groups. Cost of prophylaxis also increased in other surgical groups. Cost reduction was associated with limited duration of prophylaxis and a shift toward use of first generation cephalosporin products. Patient morbidity did not differ significantly.