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Biomedical subjects

M Kennedy

Publications and source records attributed to M Kennedy.

At least 307 records · Page 17Linked to original sources
PubMedDate not supplied

Human sperm morphology and in vitro fertilization: sperm tail defects are prognostic for fertilization failure.

The aim of this study was to determine the relationship between sperm morphology and fertilization rates in vitro. Semen samples were obtained from 50 couples undergoing IVF treatment. Sperm morphology was classified by strict criteria (Tygerberg) according to head, midpiece and tail defects in neat semen and after sperm selection by Percoll gradient centrifugation. Percoll preparation significantly increased the percentage of sperm with normal morphology from 13 to 20%. However, the greatest single regression coefficient was observed with the percentage of sperm with tail defects and correlated negatively with fertilization rates in vitro both before and after Percoll preparation. Therefore, tail morphology may be of value as a prognostic factor in assisted conception both before and after Percoll preparation.

Female↗
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Hepatic veno-occlusive disease associated with comfrey ingestion.

A 23 year old man presented with hepatic veno-occlusive disease and severe portal hypertension and subsequently died from liver failure. Light microscopy and hepatic angiography showed occlusion of sublobular veins and small venous radicles of the liver, associated with widespread haemorrhagic necrosis of hepatocytes. The patient had been on a predominantly vegetarian diet and, prior to his illness, took comfrey leaves which are known to contain hepatotoxic pyrrolizidine alkaloids. Comfrey is widely used as a herbal remedy, but so far has only been implicated in two other documented cases of human hepatic veno-occlusive disease. A possible causal association of comfrey and this patient's veno-occlusive disease is suggested by the temporal relationship of the ingestion of comfrey to his presentation, the histological changes in the liver and the exclusion of other known causes of the disease.

Adult↗
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Total parenteral nutrition decreases luminal mucous gel and increases permeability of small intestine.

The distribution of fluorescein isothiocyanate dextran 70,000 (FITC-dextran) and mucous gel across the lumen of small intestine was observed as an investigation into the role of mucous gel on permeability in total parenteral nutrition (TPN). Thirty-two rats were randomly divided into two groups fed with either TPN or oral rat food. On day 4 or 7, FITC-dextran (750 mg/kg body weight) was given through the gastroduodenal tube. After 1 hour, blood samples were taken by aortic puncture to analyze plasma FITC-dextran by fluorescence spectrometry. Samples of small intestine with luminal contents were frozen and sectioned in a cryostat for fluorescence microscopy; the same sections were placed in a 0.2% celloidin solution for 3 minutes to preserve mucous gel and stained by periodic acid-Schiff reaction for light microscopy. The plasma level of FITC-dextran after 1 hour of this marker injection showed a significant increase (p < .01) in the TPN group compared with the rat food group on days 4 and 7. Morphologic findings on days 4 and 7 were similar in both the jejunum and ileum: The mucous gel filled the spaces between villi and FITC-dextran centered in the lumen in the rat food group, whereas the mucous gel decreased and FITC-dextran filled the spaces between villi in the TPN group. FITC-dextran and mucous gel showed complementary distributions in both groups. These data suggest that TPN decreases luminal mucous gel and increases permeability of small intestine in rats.

Animals↗
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Increasing prevalence of resistance mutations in antiretroviral-naïve individuals with established HIV-1 infection from 1996-2001 in St. Louis.

BACKGROUND: Transmission of drug-resistant virus in HIV-1 infected individuals is well documented, particularly in patients with primary infection. Prevalence in chronically infected antiretroviral-naïve patients is reportedly low. Routine genotyping in this population is not recommended. PURPOSE: The purpose of this study was to evaluate resistance profiles in patients with established HIV infection in St. Louis. METHOD: We selected specimens from drug-naïve individuals (CD4 >300 cells/mL and VL >1000 copies/mL) with established HIV infection between 1996-2001. 62 of 75 specimens were available for genotyping. We excluded patients with evidence of acute HIV infection and long-term nonprogressors. RESULTS: The overall prevalence of resistance was 11% (7/62). From 1996 to 1998, a prevalence of 4% was observed (1/27 individuals). During the subsequent period from 1999 to 2001, the frequency increased to 17% (6/35 participants; p =.08; 95% CI 5-29%). CONCLUSION: The results suggest that the prevalence of primary resistance is increasing in our region to the point that it justifies genotypic testing in all individuals before the initiation of antiretroviral therapy. This has to be considered when designing antiretroviral clinical trials.

Adolescent↗
PubMedDate not supplied

Recent developments in the toxicology of anabolic steroids.

Anabolic steroids are extensively abused as ergogenic aids by athletes (and others). A number of features of anabolic steroid use and toxicology have been recently reviewed in the Journal, and a large body of data has accumulated concerning their toxic nature. The lipoprotein profile induced by anabolic steroids carries a markedly adverse cardiovascular risk. Glucose metabolism is significantly altered and includes peripheral insulin resistance, hyperinsulinaemia and attenuated responses to glucagon. Hypertension has been noted. Psychiatric and psychological alterations are major toxicities of anabolic steroids, and probably constitute the major mechanism of their action. Hepatic neoplasia occurs in the setting of abuse of this class of drugs, and may be related to their use, although there is no convincing evidence that other malignancies are induced in athletes who abuse them. Gross disturbance of reproductive function occurs in both sexes: hypogonadal states are common and prolonged. The anabolic steroids are toxic drugs with both long and short term effects. Their abuse by athletes is to be decried, particularly in view of the frequent and prolonged use by the young.

Anabolic Agents↗
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Mechanisms of surfactant dysfunction in early acute lung injury.

Surfactant dysfunction that occurs during acute lung injury is associated with alterations in phospholipid, total protein, and surfactant apoprotein content. The functional importance of these changes was examined by characterizing the biophysical properties and biochemical composition of lung surfactant from endotoxin-treated guinea pigs (LPS) with acute lung injury. Static and dynamic lung compliance significantly decreased following endotoxin exposure. Lavage fluid demonstrated a neutrophil predominance, and tissue histopathology revealed inflammation consistent with acute lung injury. LPS surfactant isolated by ultracentrifugation had minimum surface tensions of 21 dynes/cm compared to 2 dynes/cm among control samples. Biochemical abnormalities in LPS surfactant included increased total protein, decreased phosphatidylcholine, and increased sphingomyelin, phosphatidylethanolamine, and lysophosphatidylcholine. The addition to normal guinea pig surfactant of butanol extracts precipitated from lavage fluid of LPS animals and containing known amounts of protein caused elevations in minimum surface tensions to > or = 20 dynes/cm at protein to phospholipid ratios equivalent to those observed in LPS surfactant pellets. Addition of equal amounts of precipitate isolated from control animals had no effect on interfacial properties. Furthermore, addition of lysophosphatidylcholine and sphingomyelin to normal surfactant to simulate composition changes observed in LPS surfactant had minimal effect on surface film behavior. The results support the hypothesis that aqueous soluble inhibitors of surfactant are generated within the alveolar compartment during acute inflammation, and that surfactant dysfunction cannot be accounted for on the basis of phospholipid composition changes.

Animals↗
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Aphemia associated with bilateral striato-capsular lesions subsequent to cerebral anoxia.

A case is presented of a 13-year-old right-handed male who exhibited bilateral striato-capsular lesions following an episode of cerebral anoxia and a range of clinical features typical of aphemia. The findings of a neurological assessment, neuroradiological assessment and battery of speech/language tests are described and their implications for current theories regarding the role of the basal ganglia in speech/language function discussed. The patient initially demonstrated an isolated loss of the ability to articulate words without the loss of the ability to write or comprehend spoken language. His initial mutism later resolved into a dysarthria with features similar to those seen in hypokinetic dysarthria. It was concluded that striato-capsular lesions in childhood are capable of producing temporary language disturbances and in some cases a persistent dysarthria.

Adolescent↗
PubMedDate not supplied

Strategic performance measurement systems: next step after dashboards.

This article has summarized work being done at the leading edge of strategic performance measurement. Initiatives that today seem ivory-towerish tomorrow may represent the mainstream. Compared with the organizations profiled here, other health systems may be smaller, be less automated, or lack expertise in statistics and graphic presentation. Such differences should not prevent any hospital, medical group, HMO, or integrated delivery system from embracing in its own way the essential aspects of strategic performance measurement: Developing--as the cornerstone for measurement--a clear mission, vision, and strategy based on the organization's core values, core competencies, and customer expectations. Developing high-level performance measures of the organization's current performance and progress toward its strategic vision. Cascading measures throughout the entire organization, from the governing board and senior management down to operating clinical and administrative units. Expanding measures beyond internal operations to include measures of community or population health, systemwide measures along the continuum of care, and environmental scanning of key external trends. Using measurement actively throughout the organization to drive strategic planning and continuous improvement. Such efforts are not an "add-on" to busy board and executive agendas; they are an integral part of them. When measures on performance reports are reflective of organizational reality--like the speed and compass gauges on a jetliner's instrument panel--knowledgeable leaders will use them with ease. Even such complex constructs as spider diagrams, says Dr. Berman, are putty in a board's hands when the measures are pertinent and directors are educated about them. "They're useful decision-making tools because they're easy for our board members and managers to understand," he sums up. "They provide a snapshot of our organization."

Decision Making, Organizational↗
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The use of a quality-improvement approach to reduce needlestick injuries in a Saudi Arabian hospital.

OBJECTIVE/DESIGN: An increase was noted in the incidence of needlestick injuries in our institution. A retrospective study was carried out analyzing the accident reports and medical records of needle-stick injuries from January 1995 to July 1996. Study variables included monthly incidence; location; injury site; mechanism; staff vocational status; source virological status; staff immunity; and serological conversion to hepatitis B and C viruses and the human immunodeficiency virus (HIV). SETTING: 350-bed general hospital in Western Saudi Arabia employing 2,083 employees of many different nationalities. RESULTS: 126 injuries were identified. Thirty percent of injuries occurred in the operating room and 28% on general wards. Twenty-five injuries occurred during a surgical procedure in the operating room, 22 injuries were caused by undisposed sharps, 11 occurred during suturing, 11 occurred during injection, and 10 occurred while disposing of refuse. At least 38% of the injuries were avoidable. Sixty percent of those injured were nurses, 30% were medical staff, and 6% were housekeeping staff. Nine of the identifiable sources were hepatitis B surface antigen-positive, nine were hepatitis C antibody-positive, and none were anti-HIV positive. Eighty-nine percent of injuries involved the hands. None of our injured employees had seroconverted at 3, 6, or 9 months follow-up to HIV, hepatitis C, or hepatitis B. Eighty-four percent of injured staff were hepatitis B immune. CONCLUSION: Steps taken to reduce the future incidence of injuries included the provision of readily accessible sharps boxes, a hospitalwide education program focusing on safe handling and disposal of sharps, and the development of clear policies and procedures for dealing with sharps injuries. A further study will be conducted 12 months after the introduction of these measures.

Blood-Borne Pathogens↗