Medical students' note-taking in a medical biochemistry course: an initial exploration

Beginning medical students spend numerous hours every week attending basic science lectures and taking notes. Medical faculty often wonder whether they should give students pre-printed instructors' notes before lectures. Proponents of this strategy argue that provided notes enhance learning by facilitating the accurate transmission of information, while opponents counter that provided notes inhibit students' cognitive processing or even discourage students from attending lectures. Little if any research has directly addressed medical students' note-taking or the value of providing instructors' notes. The educational literature does suggest that taking lecture notes enhances university students' learning. University students perform best on post-lecture testing if they review a combination of provided notes and their own personal notes, particularly if the provided notes follow a 'skeletal' format that encourages active note-taking.     

Telomerase is not an oncogene

In the decade since the telomere hypothesis of cellular aging was proposed, the two essential genes for human telomerase were cloned and characterized, allowing experimental proof of the causal relationships between telomere loss and replicative senescence, and telomerase activation and immortalization. These relationships were established using a variety of cultured human cell types from both normal and tumor tissues, and were largely confirmed in the telomerase knockout mouse. Taken together, the data provide strong support for the potential utility of telomerase detection and inhibition for cancer, and telomerase activation for degenerative diseases. The specificity of the promoter for the telomerase catalytic gene and the antigenicity of the protein product, hTERT, provide additional strategies for killing telomerase-positive tumor cells. Unfortunately, the strong link between telomerase and cancer has led some to confuse telomerase activation with cancer, and others to overstate the cancer risk of telomerase activation therapies for degenerative diseases. This review clarifies the difference between telomerase, which does not cause growth deregulation, and oncogenes, which do. It also addresses the concept of telomerase repression as a tumor suppressor mechanism early in life, with detrimental tissue degeneration and tumor-promoting consequences late in life. This extended view of the telomere hypothesis helps explain how telomerase inhibition can be therapeutic in cancer patients, while controlled telomerase activation for degenerative diseases may actually reduce, rather than increase, the frequency of age-related tumorigenesis.     

Impact of a medically supervised safer injecting facility on drug dealing and other drug-related crime

North America's first medically supervised safer injecting facility (SIF) recently opened in Vancouver, Canada. One of the concerns prior to the SIF's opening was that the facility might lead to a migration of drug activity and an increase in drug-related crime. Therefore, we examined crime rates in the neighborhood where the SIF is located in the year before versus the year after the SIF opened. No increases were seen with respect to drug trafficking (124 vs. 116) or assaults/robbery (174 vs. 180), although a decline in vehicle break-ins/vehicle theft was observed (302 vs. 227). The SIF was not associated with increased drug trafficking or crimes commonly linked to drug use.     

HIV seroprevalence among participants at a Supervised Injection Facility in Vancouver, Canada: implications for prevention, care and treatment

North America's first government sanctioned medically supervised injection facility (SIF) was opened during September 2003 in Vancouver, Canada. This was in response to a large open public drug scene, high rates of HIV and hepatitis C transmission, fatal drug overdoses, and poor health outcomes among the city's injection drug users. Between December 2003 and April 2005, a representative sample of 1,035 SIF participants were enrolled in a prospective cohort that required completing an interviewer-administered questionnaire and providing a blood sample for HIV testing. HIV infection was detected in 170/1007 (17%) participants and was associated with Aboriginal ethnicity (adjusted Odds Ratio [aOR], 2.70, 95% Confidence Interval [95% CI], 1.84–3.97), a history of borrowing used needles/syringes (aOR, 2.0, 95% CI, 1.37–2.93), previous incarceration (aOR, 1.87, 95% CI, 1.11–3.14), and daily injection cocaine use (aOR, 1.42, 95% CI, 1.00–2.03). The SIF has attracted a large number of marginalized injection drug users and presents an excellent opportunity to enhance HIV prevention through education, the provision of sterile injecting equipment, and a supervised environment to self-inject. In addition, the SIF is an important point of contact for HIV positive individuals who may not be participating in HIV care and treatment.     

Dopaminergic function and the cortisol response to dexamethasone in psychotic depression

1. It has been hypothesized that psychotic symptoms in depression may be due to increased dopamine activity secondary to hypothalamic-pituitary-adrenal (HPA) axis overactivity. 2. To test this hypothesis, the authors examined the cortisol response to dexamethasone suppression test (DST, 1 mg orally) and multihormonal responses to apomorphine (APO, 0.75 mg s.c.)--a dopamine agonist--in 150 drug-free hospitalized patients with DSM-IV major depressive episode with psychotic features (MDEP, n=35), major depressive episode without psychotic features (MDE, n=74), or schizophrenia paranoid type (SCZ, n=41), and 27 hospitalized healthy controls (HCs). 3. MDEPs showed increased activity of the HPA system (i.e. higher post-DST cortisol levels) than HCs, SCZs and MDEs. However, there were no differences in adrenocorticotropic hormone (ACTH), cortisol, prolactin and growth hormone (GH) responses to APO between MDEPs and MDEs and HCs. On the other hand, SCZs showed lower APO-induced ACTH stimulation and a higher rate of blunted GH than HCs, MDEs and MDEPs, suggesting a functional alteration of the hypothalamic dopamine receptors in SCZs. 4. In the total sample and in each diagnostic group, DST suppressors and non-suppressors showed no differences in hormonal responses to APO. 5. These results suggest a lack of causal link between HPA axis hyperactivity and dopamine dysregulation. In contrast to schizophrenia, psychotic symptoms in depression seem not to be related to dopamine function dysregulation.     

Diagnosis and Incidence of fetal Parvovirus Infection in an Autopsy Series: I. Histology

This study was undertaken to obtain additional information about the incidence and characteristics of fetal parvovirus B19 infection in an unselected autopsy series, and to assess the distribution and quantitation of inclusions in various organs. Autopsy records from 673 fetal and neonatal autopsies performed at Women and Infants' Hospital during 1985 through 1990 were reviewed. Thirty-two cases of hydrops fetalis were identified, and, of these, 5 had parvovirus infection. This gives an incidence of fetal parvovirus infection resulting in hydrops fetalis of 0. 7% among all autopsies, and a 16% incidence among cases of hydrops. Thirty-five percent of the cases of hydrops had malformations; a muscular ventricular septal defect was noted in one of the 5 cases of parvovirus infection. All 5 parvovirus cases had characteristic erylhroid nuclear inclusions, and these inclusions were resistant to tissue degenerative changes. The most reliable tissue for histologic diagnosis was the liver, followed by heart and lung. Only 2 of 5 placentas had diagnostic inclusions, making examination of the placenta alone insufficient for ruling out fetal parvovirus infection.     

Superior accuracy of anatomic positioning with echocardiographic- over fluoroscopic-guided endomyocardial biopsy

To assess the superior anatomic positioning of echocardiographic-guided endomyocardial biopsy compared to traditional fluoroscopic-guided technique, these two modalities were compared in a blinded fashion during femoral sheath endomyocardial biopsy in 21 patients, 19 being evaluated after orthotopic cardiac transplantation. The simultaneous fluoroscopic and echocardiographic imaging indicated that traditional fluoroscopic positioning of the bioptome against the septum is inaccurate in over half of patients undergoing biopsy. This finding should be considered in cardiomyopathy patients or those at high risk for biopsy-related complications. © 1993 Wiley-Liss, Inc.     

Acute dieldrin exposure in relation to brain monoamine oxidase activity and concentration of brain serotonin and 5-hydroxyindoleacetic acid

Rainbow trout, White Leghorn chickens and golden hamsters were administered dieldrin or the vehicle in various dosages and routes of injection. Whole brain serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) concentrations were measured. In separate experiments, monoamine oxidase (MAO) activity was determined in brain homogenates incubated with pargyline or dieldrin. Serotonin content increased maximally at 10 mg/kg dieldrin. Brain MAO activity was significantly decreased by dieldrin in chicken and hamster, but trout enzyme activity was unaffected. The 5-HIAA content reflected MAO inhibition and interference with 5-HIAA transport from brain.