Sperm storage and antioxidative enzyme expression in the honey bee, Apis mellifera

Honey bee (Apis mellifera) sperm remains viable in the spermatheca of mated female honey bees for several years. During this time, the sperm retains respiratory activity, placing it at risk of the damaging effects of reactive oxygen species common to many biological processes. Antioxidative enzymes might help reduce this damage. Here we use quantitative real-time RT-PCR to establish gene-expression profiles in male and female honey bee reproductive tissues for three antioxidative enzymes: catalase, glutathione-S-transferase (GST) and superoxide dismutase (SOD1, cytosolic). Catalase and GST showed ten- to twenty-fold transcript increases in the sperm storage organs of mated queens vs. unmated queens, whereas SOD1 levels are high in both mated and unmated queens. Male reproductive and somatic tissues showed relatively high levels of all three antioxidant-encoding transcripts. All three enzymes screened were higher in mature males vs. young males, although this effect did not appear to be confined to reproductive tissues and, hence, need not reflect a role in sperm longevity. Furthermore, antioxidative enzyme transcripts remained present, and apparently increased, in male tissues long after sperm had matured and seminal fluid was produced. We also found measurable levels of catalase transcripts in honey bee semen. The presence of catalase transcripts in both reproductive tissues and semen in bees suggests that this enzyme might play a key role in antioxidative protection.

Prospective, intensive study of metabolic changes associated with 48 weeks of amprenavir-based antiretroviral therapy

To determine whether a 48-week course of amprenavir-based antiretroviral therapy is associated with metabolic alterations, 14 clinically stable human immunodeficiency virus (HIV)-infected, protease inhibitor-naive adults initiated amprenavir-based triple therapy. Twelve subjects (86%) achieved HIV RNA levels of <400 copies/mL at week 24. Fasting glucose and insulin levels did not change. Insulin sensitivity did not decrease in the first 24 weeks, but a trend toward a decrease appeared at week 48. Six subjects experienced onset or worsening of glucose tolerance by week 24. Levels of fasting triglycerides and low-density lipoprotein, high-density lipoprotein, and total cholesterol increased. Bone mineral content, lean tissue, total fat, trunk fat, limb fat, and the ratio of trunk to limb fat increased at week 48. Amprenavir-based therapy was associated with increases in serum lipid levels but no short-term decrease in insulin sensitivity. A trend toward insulin resistance appeared late in the study following weight gain, particularly of trunk fat, but without loss of limb fat.

Preliminary characteristics of the prothrombin converting enzyme from venom of Stephen's banded snake (Hoplocephalus stephensii)

Stephen's banded snake (Hoplocephalus stephensii) is an infrequently encountered Australian elapid species. The crude venom contains coagulant activity and the component responsible is a prothrombin activator requiring factor V for activity. SDS-PAGE of the isolated native protein revealed two bands at 23 and 36 kDa. These findings indicate that the procoagulant is similar to that found in the Australian tiger snake (Notechis scutatus) and thus resembles factor Xa.

Reliability and validity of a modified Colorado Symptom Index in a national homeless sample

This study examined the reliability and construct validity of a modified version of the Colorado Symptom Index (MCSI), a brief, self-report measure of psychological symptomatology, in a study of interventions to prevent homelessness. Eight projects in a national, cooperative study collected new data at baseline, 6, and 12 months using a set of common measures as well as site-specific instruments. The pooled sample consisted of 1,381 persons in treatment for mental illness or substance abuse (or both), of which 84% had a history of homelessness. The analyses employed classical and Rasch methods to examine the MCSI's content validity, internal consistency and item quality, test/retest reliability, dimensionality, appropriateness for the sample, construct validity, and responsiveness to change. This 14-item scale was found to be a reliable and valid measure of psychological symptoms in this sample. Its content was consistent with other symptom measures, its high internal consistency and test-retest coefficients supported its reliability, its relationships to other measures indicated that it had good construct validity, and it was responsive to change. We conclude that the MC

Central venous catheter placement in patients with disorders of hemostasis

BACKGROUND

Patients requiring central venous access frequently have disorders of hemostasis. The aim of this study was to identify factors predictive of bleeding complications after central venous catheterization in this group of patients.

METHODS

A retrospective analysis of all central venous catheters placed over a 2-year period (1997 to 1999) at our institution were performed. The age, sex, clinical diagnosis, most recent platelet count, prothrombin international normalized ratio (INR), activated partial thromboplastin time (aPTT), catheter type, the number of passes to complete the procedure, and bleeding complications were retrieved from the medical records.

RESULTS

In a 2-year period, 2,010 central venous catheters were placed in 1,825 patients. Three hundred and thirty placements were in patients with disorders of hemostasis. In 88 of the 330 patients, the underlying coagulopathy was not corrected before catheter placement. In these patients, there were 3 bleeding complications requiring placement of a purse string suture at the catheter entry site. In the remaining 242 patients, there was 1 bleeding complication. Of the variables analyzed, only a low platelet count (<50 x 10(9)/L) was significantly associated with bleeding complications.

CONCLUSION

Central venous access procedures can be safely performed in patients with underlying disorders of hemostasis. Even patients with low platelet counts have infrequent (3 of 88) bleeding complications, and these problems are easily managed.

Pregnancy and perinatal outcomes in migraineurs using sumatriptan: a prospective study

BACKGROUND

Sumatriptan is an acute treatment for migraine which is often used by women in their child-bearing years, and who become unexpectedly pregnant. Within the context of the post-marketing use of sumatriptan injection for the acute treatment of migraine, and in compliance with approved labeling, we wished to compare perinatal pregnancy outcomes in women who did and did not use the drug after conception.

METHODS

Open-label, prospective study conducted in 12,339 migraineurs (including 9,861 women) whose demography and consumption pattern of sumatriptan injections were typical, and were predicted to include 150 pregnancies. Outcome of pregnancy was the end-point.

RESULTS

There were 168 of 173 pregnancies that were well-documented. Sumatriptan was only used prior to conception in 92 cases. There were 76 first trimester exposures to sumatriptan. There were no differences in pregnancy outcome between the two groups.

CONCLUSIONS

Perinatal and pregnancy outcome did not differ between patients who had and had not used sumatriptan after conception, at the resolution of these sample sizes. This study design complements the ongoing pregnancy registry, which is now widened to patients exposed to all formulations of sumatriptan.

The impact of emotions on cardiovascular health

Recent research suggests that the maintenance of emotional well-being is critical to cardiovascular health. People who feel lonely, depressed, and isolated have been found to be significantly more likely to suffer illnesses and to die prematurely of cardiovascular diseases than those who have adequate social support. Consequently, the development of appropriate interventions to improve the emotional health of people with certain psychosocial risk factors has become an important research goal. It is anticipated that such interventions will increase the life expectancy of people at risk and that it may also save millions of dollars in medical care costs. First, however, researchers in this field must identify specific emotional risk factors and must agree upon a working definition of "good emotional health." Such explicit definitions, as well as additional data, are essential to educating physicians and insurers so that consideration of emotional health can be integrated into basic medical care.

AHCPR-funded rural managed care centers: report from the field

In 1994, the Agency for Health Care Policy and Research awarded cooperative agreements to five University-based groups to promote the establishment of managed care institutions and development of rural health networks. This paper summarizes the experiences of these rural managed care centers in the first three years of this initiative. Key ingredients for achieving the project's goals that are identified by the project directors are reported as "foundations" that must be in place from the outset, or "building blocks" that can be developed along the way. The development of information systems and efforts to foster leadership in the medical community are areas in which grant funding of this type can be most effective.

Investigation of female survival benefit in metastatic melanoma

Epidemiological studies show female survival benefit in advanced metastatic melanoma. In investigating a possible mechanism for this female survival benefit, we have previously reported that the female steroid 17beta-oestradiol significantly reduces invasion of a human melanoma cell line (A375-SM cells) and ocular melanoma cells through fibronectin. Neither cell type was found to possess oestrogen receptor-alpha. The aim of the current study was to obtain further information on the extent to which progression of cutaneous melanoma might be sex steroid sensitive by (a) examining the relationship between circulating sex steroids, sex hormone binding globulin and disease progression; (b) examining the relationship between sex steroid structure and the ability of steroids to reduce invasion of a melanoma cell line in vitro; and (c) examining the effects of sex steroids on proliferation of these cells in vitro. We report a significant reduction in circulating oestrone with disease progression in male but not female patients. Examining steroids for their ability to inhibit invasion of A375-SM cells through fibronectin in vitro, oestrogenic compounds (17beta-oestradiol and oestrone) were found to inhibit invasion; in this respect, oestrone was approximately 50 times more potent than 17beta-oestradiol; steroids lacking the benzene ring structure did not inhibit invasion, indeed dehydroepiandrosterone (DHEA) which acts as a precursor to androgenic steroids significantly enhanced invasion. Proliferation of A375-SM cells was unaffected by 17beta-oestradiol, oestrone or dihydrotestosterone when cells were cultured on plastic; in contrast, all three steroids induced modest proliferation of cells when grown on fibronectin with dihydrotestosterone the most mitogenic of the three steroids. These data are consistent with sex steroids playing a role in melanoma progression.

Rural attachments for students in the health professions: are they worthwhile?

In the period 1991-96, 156 undergraduates from 14 health disciplines at the University of Sydney completed rural attachments in rural and remote areas of Australia as part of the Rural Careers Project. On return from their attachment, students were encouraged to write a brief report of their experiences. Ninety-two available reports were analysed as one means of assessing the success of the attachments with respect to informing students about rural health issues and stimulating their interest in rural careers after graduation. A content analysis of the students' written comments about their perceptions and experiences was completed. Students were extremely positive about the value of the attachments and expressed more positive than negative comments regarding their perceptions of rural life and work. The results show that rural attachments are indeed worthwhile learning opportunities.

Abbreviated educational session improves cranial computed tomography scan interpretations by emergency physicians

STUDY OBJECTIVE

Previously published research (phase I) demonstrated a concerning misinterpretation rate of cranial computed tomography (CT) scans by emergency physicians. This study (phase II) determined whether an abbreviated educational session would improve emergency physician interpretation skills of cranial CT scans.

METHODS

Participants in this prospective, interventional study in a county hospital ED were patients undergoing cranial CT scanning during ED evaluations and attending level emergency physicians. An abbreviated educational session on cranial CT interpretation skills was given to the same attending emergency physicians who participated in phase I. The educational session included basic CT interpretation skills and misinterpreted CT scans from phase I. We determined the postsession accuracy rate of the emergency physicians on 324 ED patient CT scans. The CT interpretation accuracy rates were then compared between phase I and phase II to determine the effectiveness of the educational session.

RESULTS

The radiology/ED CT scan concordance rate improved from 61.3% (kappa = .22) to 88.6% (kappa = .70; P < .0001). Potentially clinically significant CT scan misinterpretations decreased from 24.1% to 4.0% (P < .0001). Most importantly, major missed findings on CT scans decreased from 11.4% to 2.8% (P < .0001). Continuous quality improvement monitoring found no instance of clinically significant patient mismanagement.

CONCLUSION

Within the limits of this study, we conclude that emergency physicians' interpretation skills of cranial CT scans may be improved using a 1-hour educational session.

Comparison of measures of exposure to asbestos in former crocidolite workers from Wittenoom Gorge, W. Australia

Determinations of exposure-response relationships between crocidolite and the major asbestos-related diseases in the Wittenoom cohort have previously depended on the validity of estimates of airborne exposure to asbestos. This work aims to validate the airborne exposure measurements by obtaining measurements of the concentrations of uncoated crocidolite fibers and asbestos bodies retained in the lungs of individual workers, and to estimate the half-life of crocidolite fibers in the lungs. Samples of lung tissue, excluding tumor, of all former Wittenoom workers known to have died in Western Australia (WA) were sought from teaching hospitals, pathology departments, and the Coroner's pathologist. The lung specimens were processed using Pooley's method with TEM for counts of fibers of all types and using Smith and Naylor's method with conventional light microscopy for asbestos bodies (AB). Multiple linear regression was utilized to examine the associations between crocidolite concentrations in the lung and duration of employment at Wittenoom, time since last employed at Wittenoom, nature of job, estimated average fiber concentration at the worksite, and estimated cumulative crocidolite exposure (CCE) in fiber-years/ml for each subject. Lung tissue from 90 cases was processed and there was good agreement between counts of crocidolite fibers, asbestos bodies, and CCE. Correlations were 0.77 for AB and fibers, 0.54 for AB and CCE, and 0.58 for CCE and fibers, after log transformation. The half-life of crocidolite fibers in the lung was estimated at 92 months (95% CI 55-277 months). Previous estimates of airborne exposure to Wittenoom crocidolite have been reasonably reliable. The relatively simple technique of light microscopy for counting ABs in lung tissue also provides a useful and reliable indication of the level of past occupational exposure to crocidolite in subjects whose exposure has been only to crocidolite. The half-life of crocidolite fibers in the lungs of former Wittenoom workers is about 7-8 years.

Cocaine-associated intracranial hemorrhage: absence of vasculitis in 14 cases

Complications associated with the use of cocaine are varied, and include cerebral hemorrhage and ischemia, with vasculitis and vasospasm as possible etiologies. We reviewed selected brain samples from 14 autopsy cases of cocaine-related cerebrovascular disease. Intracerebral or subarachnoid hemorrhage was present in 12 cases. Intracranial arterioles were either normal or showed nonspecific changes. From these observations, we suggest that intracranial hemorrhages occur in the absence of readily detectable vascular abnormalities.