Acquisition of surgical skills: a randomized trial of didactic, videotape, and computer-based training

BACKGROUND

Although computer-based training (CBT) can enhance didactic instruction, few studies have assessed the efficacy of CBT for basic surgical skills training. This study compares CBT with traditional methods of basic surgical skills training.

METHODS

Sixty-nine naive medical students were randomized into 3 treatment groups for basic surgical skills instruction: didactic, videotape, or CBT. All instructional material contained the same pictures, text, and audio. With use of a multiple-choice question examination and a series of performance stations, students were objectively assessed before, immediately after, and 1 month after skills instruction. Raters were blinded to treatment modality during the follow-up evaluation.

RESULTS

There were no significant differences among the groups before treatment. After treatment, the didactic group scored higher on the multiple-choice question examination. In contrast, the videotape and CBT groups demonstrated statistically significant (P < .01) enhancement of technical skills compared with the didactic group. After 1 month, a calculated performance quotient revealed statistically significant (P < .01) improvement only in the CBT group. The amount of time students spent practicing their skills was not significantly different among the groups.

CONCLUSIONS

CBT is as effective as, and possibly more efficient, than traditional methods of basic surgical skills training for medical students.

How pediatric educators know what to teach: the use of teaching scripts

OBJECTIVE

Expert clinical teachers in medicine use teaching scripts. The aim of this study was to determine whether pediatricians also use common components of teaching scripts.

METHODS

Seventy-three pediatric clerkship directors identified anticipated errors and teaching points in response to two short vignettes. The content analysis of responses, which we completed, was analyzed by rank and receipt of teaching awards.

RESULTS

Greater than 87% of respondents identified at least one of three anticipated learner errors and greater than 80% of respondents identified at least one of three to four teaching points. Teaching points related directly to anticipated errors in 60% of responses. Level of experience and receipt of teaching awards had no impact on response content.

CONCLUSIONS

Consistent with findings on the use of teaching scripts, pediatrics' educators achieved high congruence on anticipated errors and teaching points on two teaching vignettes. These findings support the hypothesis that developing teaching expertise is associated with other script components.

3-nitropropionic acid oxidase from horseshoe vetch (Hippocrepis comosa): a novel plant enzyme

A novel enzyme that catalyses the oxygen-dependent oxidation of 3-nitropropionic acid (3NPA) to malonate semialdehyde, nitrate, nitrite and H2O2 has been purified from leaf extracts of the horseshoe vetch, Hippocrepis comosa, and named 3NPA oxidase. The enzyme is a flavoprotein with a subunit molecular mass of 36 kDa containing 1 molecule of FMN and exhibits little specificity for all nitroalkanes tested other than 3NPA (apparent Km 620 microM). The maximum enzyme activity in vitro was expressed at pH4.8 and was inhibited strongly by the products nitrate and nitrite. 3NPA oxidase activity was detected in green shoots, which also contain high concentrations of 3NPA, from plants grown with nitrate, ammonium or N2 as sources of nitrogen. Enzyme activity was absent from roots and cell cultures, neither of which accumulate high levels of 3NPA.

Neuromuscular blockers

The use of corrosive, injectable neuromuscular blockers has been a treatment option for many years; however, the more recent advent of botulinum toxin (BTX) treatment has revived interest in localized treatments. This article reviews the use of local anesthetics, alcohol, phenol, and BTX treatment for localized muscular overactivity syndromes.

Releasing resources for reinvestment in health gain

The National Health Services in Wales has adopted a strategic approach based on health gain. Five approaches to meeting this problem are considered (i) eliminating basic inefficiencies; (ii) eliminating unnecessary clinical activity; (iii) doing what is done now but differently; (iv) investing now to save later and (v) withdrawing from a particular area of activity, because it is less important than other competing claims. Each of these is briefly considered with particular reference to the Welsh situation. Three particular lines of advance are identified to achieve the above: creating new sources of information; working more effectively across organisational boundaries; and making the cultural changes to make it all possible.

Ebola (subtype Reston) virus among quarantined nonhuman primates recently imported from the Philippines to the United States

In April 1996, laboratory testing of imported nonhuman primates (as mandated by quarantine regulations) identified 2 cynomolgus macaques (Macaca fascicularis) infected with Ebola (subtype Reston) virus in a US-registered quarantine facility. The animals were part of a shipment of 100 nonhuman primates recently imported from the Philippines. Two additional infected animals, who were thought to be in the incubation phase, were identified among the remaining 48 animals in the affected quarantine room. The other 50 macaques, who had been held in a separate isolation room, remained asymptomatic, and none of these animals seroconverted during an extended quarantine period. Due to the rigorous routine safety precautions, the facility personnel had no unprotected exposures and remained asymptomatic, and no one seroconverted. The mandatory quarantine and laboratory testing requirements, put in place after the original Reston outbreak in 1989-1990, were effective for detecting and containing Ebola virus infection in newly imported nonhuman primates and minimizing potential human transmission.

Modelling photochemical oxidant formation, transport, deposition and exposure of terrestrial ecosystems

The chemical processes responsible for production of photochemical oxidants within the troposphere have been the subject of laboratory and field study throughout the last three decades. During the same period, models to simulate the atmospheric chemistry, transport and deposition of ozone (O(3)) from individual urban sources and from regions have been developed. The models differ greatly in the complexity of chemical schemes, in the underlying meteorology and in spatial and temporal resolution. Input information from land use, spatial and temporally disaggregated emission inventories and meteorology have all improved considerably in recent years and are not fully implemented in current models. The development of control strategies in both North America and Europe to close the gaps between current exceedances of environmental limits, guide values, critical levels or loads and full compliance with these limits provides the focus for policy makers and the support agencies for the research. The models represent the only method of testing a range of control options in advance of implementation. This paper describes currently applied models of photochemical oxidant production and transport at global and regional scales and their ability to simulate individual episodes as well as photochemical oxidant climatology. The success of current models in quantifying the exposure of terrestrial surfaces and the population to potentially damaging O(3) concentrations (and dose) is examined. The analysis shows the degree to which the underlying processes and their application within the models limit the quality of the model products.

A randomized trial of amitriptyline and mexiletine for painful neuropathy in HIV infection. AIDS Clinical Trial Group 242 Protocol Team

BACKGROUND

Painful sensory neuropathy is a common complication of HIV infection. Based on prior uncontrolled observations, we hypothesized that amitriptyline or mexiletine would improve the pain symptoms.

METHOD

A randomized, double-blind, 10-week trial of 145 patients assigned equally to amitriptyline, mexiletine, or matching placebo. The primary outcome measure was the change in pain intensity between baseline and the final visit.

RESULTS

The improvement in amitriptyline group (0.31+/-0.31 units [mean+/-SD]) and mexiletine group (0.23+/-0.41) was not significantly different from placebo (0.20+/-0.30). Both interventions were generally well tolerated.

CONCLUSIONS

Neither amitriptyline nor mexiletine provide significant pain relief in patients with HIV-associated painful sensory neuropathy.

Buchu--South Africa's amazing herbal remedy

Buchu leaves and oil of buchu were used by the indigenous people of South Africa for hundreds of years. The medicinal use of buchu was taken up by the early Dutch settlers and later introduced into the pharmaceutical industry in the UK. Buchu preparations are now used as a diuretic and for a wide range of conditions including stomach aches, rheumatism, bladder and kidney infections and coughs and colds.

A cysteine endopeptidase with a C-terminal KDEL motif isolated from castor bean endosperm is a marker enzyme for the ricinosome, a putative lytic compartment

A papain-type cysteine endopeptidase with a molecular mass of 35 kDa for the mature enzyme, was purified from germinating castor bean (Ricinus communis L.) endosperm by virtue of its capacity to process the glyoxysomal malate dehydrogenase precursor protein to the mature subunit in vitro (C. Gietl et al., 1997, Plant Physiol 113: 863-871). The cDNA clones from endosperm of germinating seedlings and from developing seeds were isolated and sequence analysis revealed that a very similar or identical peptidase is synthesised in both tissues. Sequencing established a presequence for co-translational targeting into the endoplasmic reticulum, an N-terminal propeptide and a C-terminal KDEL motif for the castor bean cysteine endopeptidase precursor. The 45-kDa pro-enzyme stably present in isolated organelles was enzymatically active. Immunocytochemistry with antibodies raised against the purified cysteine endopeptidase revealed highly specific labelling of ricinosomes, organelles which co-purify with glyoxysomes from germinating Ricinus endosperm. The cysteine endopeptidase from castor bean endosperm, which represents a senescing tissue, is homologous to cysteine endopeptidases from other senescing tissues such as the cotyledons of germinating mung bean (Vigna mungo) and vetch (Vicia sativa), the seed pods of maturing French bean (Phaseolus vulgaris) and the flowers of daylily (Hemerocallis sp.).

A phase I/II trial of nimodipine for HIV-related neurologic complications

BACKGROUND

Few effective treatments are available for AIDS dementia complex (ADC) and HIV-associated neuropathy. However, recent in vitro studies indicate that nimodipine, a voltage-dependent calcium channel antagonist, can prevent HIV-related neuronal injury and may provide a novel form of treatment for these disorders.

METHODS

To determine the safety and possible efficacy of this agent, 41 patients with mild to severe ADC, including 19 patients with neuropathy, were entered into the AIDS Clinical Trial Group multicenter, phase-I and phase-II study. Nimodipine at 60 mg p.o., five times daily; 30 mg p.o., three times daily; or placebo was administered for 16 weeks as adjuvant treatment to antiretroviral therapy.

RESULTS

Neuropsychological performance at baseline, measured by the composite neuropsychological Z score (NPZ-8), correlated significantly with the ADC stage and with CSF levels of neopterin, a marker of immune activation. No significant differences in toxicity were observed among the three arms. Intent-to-treat analysis showed no significant change in the NPZ-8, although improvement was suggested in the high-dose arm. In addition, a trend toward stabilization in peripheral neuropathy was observed in both nimodipine arms compared with placebo.

CONCLUSIONS

Nimodipine and other similar nonantiretroviral agents may provide a safe and promising avenue of treatment for neurologic disorders associated with HIV infection. The results of this study indicate that further clinical trials are warranted.

Small bowel obstruction caused by a dislodged biliary stent

Biliary stents are commonly used in the management of obstructive jaundice. Complications at the time of insertion are not uncommon, but late complications due to dislodged stents have not been previously reported.

Failure of cytarabine in progressive multifocal leukoencephalopathy associated with human immunodeficiency virus infection. AIDS Clinical Trials Group 243 Team

BACKGROUND

Progressive multifocal leukoencephalopathy affects about 4 percent of patients with the acquired immunodeficiency syndrome (AIDS), and survival after the diagnosis of leukoencephalopathy averages only about three months. There have been anecdotal reports of improvement but no controlled trials of therapy with antiretroviral treatment plus intravenous or intrathecal cytarabine.

METHODS

In this multicenter trial, 57 patients with human immunodeficiency virus (HIV) infection and biopsy-confirmed progressive multifocal leukoencephalopathy were randomly assigned to receive one of three treatments: antiretroviral therapy alone, antiretroviral therapy plus intravenous cytarabine, or antiretroviral therapy plus intrathecal cytarabine. After a lead-in period of 1 to 2 weeks, active treatment was given for 24 weeks. For most patients, antiretroviral therapy consisted of zidovudine plus either didanosine or stavudine.

RESULTS

At the time of the last analysis, 14 patients in each treatment group had died, and there were no significant differences in survival among the three groups (P=0.85 by the log-rank test). The median survival times (11, 8, and 15 weeks, respectively) were similar to those in previous studies. Only seven patients completed the 24 weeks of treatment. Anemia and thrombocytopenia were more frequent in patients who received antiretroviral therapy in combination with intravenous cytarabine than in the other groups.

CONCLUSIONS

Cytarabine administered either intravenously or intrathecally does not improve the prognosis of HIV-infected patients with progressive multifocal leukoencephalopathy who are treated with the antiretroviral agents we used, nor does high-dose antiretroviral therapy alone appear to improve survival over that reported in untreated patients.

Ontogenesis of lateralized rotational behavior in hamsters: a time series study

This is a longitudinal study of the postnatal development of lateralized rotational behavior. Hamsters (n = 75) were tested for spontaneous rotational behavior in cylindrical arenas, from P2 (P1 = day of birth) to P60. A daily laterality index was calculated for each animal, of which the averages and standard deviations were used to follow the animals' lateralized behavior. A strong variability between and within animals appeared throughout development, with a tendency to the right side in most animals, which declined after the first postnatal week. No oscillatory cycles were identified. To study patterns of development, the series were divided into four periods and the animals were separated into five groups. The laterality indexes of all four periods were significantly different between the groups. A total of 79% of the animals showed consistent behavior along development: either a preference to one side (20% left, 26% right), or no preference at all (33%). The remaining animals changed preference during development. Only a few animals remained strongly lateralized throughout the 60 days, most of them showing a slight, non-significant preference after P10. Results suggest an ontogenetic decrease in lateralization of this behavior that could in part be explained by the maturation of an interhemispheric regulatory system.

HIV rounds at Cornell: selected neurologic complications of HIV disease

Neurological disorders are among the most frequent and devastating complications of HIV infection and AIDS. As patients survive longer with the availability of highly active anti-retrovital therapy, it is likely that the frequency of some of these disorders will increase, since patients will survive long enough to develop them. The central and peripheral nervous system may be affected by numerous primary and secondary complications. These neurological disorders include HIV dementia, primary CNS lymphoma, toxoplasmosis, progressive multifocal leukoencephalopathy, vacuolar myelopathy, peripheral neuropathies, and myopathy. In this review we discuss current thoughts on clinical features, pathogenesis, diagnostic evaluation, treatment and clinical trials in several of these HIV-associated neurologic disorders.