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Biomedical subjects

C Ross

Publications and source records attributed to C Ross.

At least 91 records · Page 5Linked to original sources
PubMed1994

EEG power spectra in Huntington's disease: clinical and neuropsychological correlates.

Quantitative power spectral analysis (PSA) was applied to frontal (F3, F4, F7, F8), temporal (T5, T6), and occipital (O1, O2) EEGs of 16 Huntington's disease (HD) patients and eight healthy control subjects. PSA revealed HD patients' EEGs to be abnormal: (i) raw and percent Alpha power were reduced; (ii) raw and percent Theta power were reduced at F3 and F4; (iii) percent Delta and percent Beta power were increased; (iii) Theta frequency was reduced by approximately 1.0 Hz. Frontal and temporal EEG power measures and decreased EEG amplitude correlated with severity of neurological and cognitive impairment.

Adult↗
PubMed1994

Micromanipulation of human embryos to assist hatching.

OBJECTIVE: To determine the effects of zona slitting and subsequent embryo transfer performed on different days of in vitro human embryonic development to allow appropriate application of assisted hatching techniques to clinical IVF-ET. DESIGN: A microsurgical technique was used to make a standardized slit in the zona pellucida of bipronucleate human embryos on day 2, 3, or 5 after oocyte retrieval. A mock ET was performed after the procedure and the rate of blastocyst formation and the process of hatching in each embryo was monitored. SETTING: All embryos used were donated for research by patients attending the IVF Unit at the John Radcliffe Hospital, Oxford, United Kingdom. MAIN OUTCOME MEASURES: The effects of the mock ET on the integrity of zona-slit embryos was documented. The embryos were cultured further and parameters such as blastocyst formation, initiation, and completion of hatching were monitored in all three groups of embryos. RESULTS: The mock ET did not have a detrimental effect on embryos as assessed by their morphology and subsequent blastocyst formation rate. The technique used in this study to make an opening in the zona increased the rate and number of blastocysts hatching in all three groups compared with nonmanipulated controls. However, the day on which the slit was made did not significantly alter the outcome. CONCLUSION: A gap in the zona pellucida of human embryos significantly increases the rate of hatching. Micromanipulative techniques such as zona slitting can be suitably used for this purpose without loss of blastomeres through the gap in the zona or trapping of the embryo during the process of hatching.

Blastocyst↗
PubMed1994

Does isolated teratozoospermia affect performance in in-vitro fertilization and embryo transfer?

The effect of the strict classification of spermatozoal morphology on the outcome of in-vitro fertilization and embryo transfer treatment cycles has been assessed in a retrospective analysis of 2144 consecutive cycles. The patients all had a standardized long protocol gonadotrophin-releasing hormone analogue cycle, with luteal phase start, to achieve down-regulation. All treatment cycles where the sperm density was abnormal (< 20 x 10(6)/ml), or where progressive motility was abnormal (< 40%), were excluded. The study excluded treatment cycles where the oocytes inseminated did not include at least one grade 1 or grade 2 oocyte. The percentage of couples achieving the normalized results of the clinic, including median fertilization rate per patient, insemination rates, numbers of embryos transferred, rates of 'spare embryo' blastocyst formation, cumulative pregnancy rates and pregnancy outcome, were calculated. No statistically significant difference arose between the two groups of patients with regard to the percentage of patients achieving the normalized median fertilization rate or higher (group 1 with > 14% normal forms, and group 2 with > or = 4%, < or = 14% normal forms). There was a statistically significantly lower chance of achieving this rate in patients of group 3 (< 4% normal forms) (P < 0.005), but 68.6% did achieve that fertilization rate or higher. There was no statistically significant difference in any of the other end points. In conclusion, a morphological classification may be appropriate as an indicator for counselling patients with regard to treatment expectations, but its use would be seem inappropriate as an index of fertilizing potential in clinical management.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Role of hypothalamic histaminergic neurons in mediation of ACTH and beta-endorphin responses to LPS endotoxin in vivo.

The involvement of hypothalamic histaminergic neurons in the mediation of the ACTH and beta-endorphin (beta-END) response to lipopolysaccharide (LPS) endotoxin was investigated in conscious male rats. LPS stimulated the release of ACTH and beta-END dose-dependently and increased the hypothalamic concentration of the histamine (HA) metabolite tele-methylhistamine significantly and that of HA slightly, indicating an increased turnover of neuronal HA. Pretreatment with the HA synthesis inhibitor alpha-fluoromethyl-histidine administered intracerebroventricularly (i.c.v.) or intraperitoneally (i.p.) inhibited the ACTH and beta-END response to LPS about 60%, whereas i.p. administration of the H3 receptor agonist R(alpha)methylHA, which inhibits HA synthesis and release, decreased the response about 50%. Pretreatment with the H1 receptor antagonist mepyramine (67 micrograms x 2 i.c.v.) inhibited the hormone response to LPS about 50%, while pretreatment with equimolar doses of the H2 receptor antagonists cimetidine (67 micrograms x 2 i.c.v.) or ranitidine (83 micrograms x 2 i.c.v.) had no effect on the LPS-induced release of ACTH and beta-END. When the H1 receptor antagonists mepyramine and cetirizine were administered i.p. in doses (10 mg/kg) which penetrate the blood-brain barrier the hormone response to LPS was inhibited 50% and 30%, respectively. Administered i.p. the H2 receptor antagonists had no effect on the hormone response to LPS. We conclude that hypothalamic histaminergic neurons in rats are involved in the mediation of the ACTH and beta-END response to LPS stimulation via activation of central postsynaptic H1 receptors.

Adrenocorticotropic Hormone↗
PubMed1994

Q fever: an issue in occupational health & safety? An overview of the methods of control and the effects of Coxiella burnetii on the human host.

Q Fever has proved to be a virulent infectious disease for a great many years. A number of epidemics have occurred among laboratory workers engaged in research on C burnetii but few fatalities have been recorded and the course of the disease is generally uncomplicated and benign (Braunwald et al, 1987). By following the recommendations of a large number of scientists, implementing and maintaining basic control measures, the risk of contamination will be kept at a minimum.

Animals↗
PubMed1994

Effectiveness of adjunctive irrigation in early periodontitis: multi-center evaluation.

The purpose of this study was to determine the effect of daily water irrigation versus regular oral hygiene alone on gingival and periodontal health in periodontitis patients receiving supportive periodontal treatment. The study also sought to determine if there are enhanced benefits from using an antiplaque zinc sulfate rinse as an irrigant. One hundred fifty-five patients who have had periodontitis and had been treated either surgically or non-surgically completed the 6-month multi-center multi-national study. Patients with at least two 5 mm sites demonstrating bleeding on probing were assigned to 3 equal groups by balanced randomization. In all centers Group A (n = 57) performed regular oral hygiene only, and Group B (n = 58) irrigated with 500 ml water once daily after regular oral hygiene. Group C (n = 40) patients irrigated with a total of 500 ml once daily; following irrigation with 300 ml water, the patients then irrigated with an additional 200 ml with a zinc sulfate solution. The irrigants were diluted to provide the manufacturer's recommended daily dosage. The supragingival irrigation was performed with a commercially available oral irrigator. Bacterial measurements at baseline, 3 months, and 6 months were taken to determine the effect of irrigation on the target organisms and will be reported elsewhere. Gingival index: irrigation with water (Group B) was significantly better than normal oral hygiene (Group A) and irrigation with zinc sulfate (Group C) (P < 0.05) in reducing gingival inflammation. Bleeding on probing: significant reductions in bleeding on probing occurred for water (Group B) compared to normal oral hygiene (Group A) (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Diagnostic conundrums in substance abusers with psychiatric symptoms: variables suggestive of dual diagnosis.

Patients with substance dependence and psychiatric symptoms often present a diagnostic conundrum because each of these problems may mutually and reciprocally complicate the other. This may challenge the ability to identify dual-diagnosis patients who have both a substance abuse disorder and a definitive symptom-based psychiatric disorder. The main purpose of this explorative study was to identify variables suggestive of dual diagnosis in the population of substance-dependent patients with psychiatric symptoms. A secondary purpose was to examine the subgroups in this population for their distinctiveness from one another. Based upon clinical experience and the literature, seven independent variables were hypothesized as suggestive of dual diagnosis. Seventy-nine patients with substance dependence and psychiatric symptoms of depression, anxiety, and/or psychosis were assessed for symptom and disorder status generating three subgroups: I) 20 patients with psychiatric symptoms not meeting thresholds for clinical significance; II) 36 patients exhibiting a psychiatric disorder (dual diagnosis); and III) 23 patients with psychiatric symptoms meeting thresholds for clinical significance but not for a disorder. Odds ratios were calculated to examine the risk for dual diagnosis using the seven independent variables. A persistent increased risk for dual diagnosis was observed in patients who were positive for the seven variables. The seven variables were combined into an overall measure of patients' risk for dual diagnosis. Mean scores were significantly different for the three groups F(2, 76) = 8.4, p < .001. This study indicates variables that may be suggestive of dual diagnosis and finds subgroup distinctiveness in this sample. Both of these findings have treatment implications.

Adult↗
PubMed1994

What cost ritual?

Following the 1991 Nuffield Theatre Nurses Award, I was encouraged to pursue further research into the scrub procedure. My interest had originally started when looking at the possibility of installing electronic eye taps into the theatres. I reasoned that by reducing the amounts of heated water flowing unused during the scrub procedure I would be able to justify the cost of these taps. A pilot survey I undertook showed that on costs alone this was not proven. A more logical and research based approach to the subject was required. My main objectives were to ascertain costs and timings of the traditional scrub; compare the costs with other acceptable alternatives; explore 'costs' relating to wider environmental concerns; examine the effectiveness of current practice. I looked at the Government statistics for England during 1990/91. It showed an annual total of 741,393 operating sessions with a total of 3,353,797 operations performed. The total of cases in orthopaedic, opthalmic, general and gynaecological operations totalled 2,301,272 cases. These four categories were the ones I chose to research.

Clinical Nursing Research↗
PubMed1994

L-arginine stimulates host defenses in patients with breast cancer.

BACKGROUND: The amino acid L-arginine is known to have immunostimulatory effects in animals and healthy human volunteers. We have studied the effect of dietary supplementation with L-arginine (30 gm/day for 3 days) on host defenses in patients with breast cancer. METHODS: Mitogenic responses of peripheral blood lymphocytes to concanavalin A, phytohemagglutinin, and pokeweed mitogen and phenotype analysis of lymphocyte subsets and activation markers were assessed before and after 3 days of L-arginine supplementation. The effect of L-arginine supplementation on natural killer and lymphokine-activated killer cell cytotoxicity and serum levels of the cytokines interleukin-1 beta and 2, interferon-gamma, and tumor necrosis factor-alpha were also measured. RESULTS: L-arginine significantly increased lymphocyte mitogenic reactivity to concanavalin A, phytohemagglutinin, and pokeweed mitogen (mean percentage increases: 64% [p < 0.001], 65% [p < 0.001], and 48% [p < 0.05], respectively). Natural killer and lymphokine-activated killer cell cytotoxicity was also significantly enhanced after L-arginine intake (mean percentage increase, 81% and 107% [p < 0.001]). However, no corresponding increase in circulating CD16+ and CD56+ cells was obtained: Arginine supplementation did not increase the level of serum cytokines. CONCLUSIONS: Dietary supplementation with L-arginine in patients with breast cancer significantly enhances host defenses and therefore may have a role in adjuvant treatment.

Aged↗