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Biomedical subjects

L Reynolds

Publications and source records attributed to L Reynolds.

At least 55 records · Page 3Linked to original sources
PubMed1997

Nutritional and economic benefits of Leucaena and Gliricidia as feed supplements for small ruminants in humid West Africa.

Considering leguminous trees Leucaena and Gliricidia as good sources of quality food, on-station and on-farm studies were conducted in the humid zone of West Africa to establish animal responses to levels, times and forms of browse supplementation, to develop alternative feeding strategies for utilising limited feed supply and to assess the economic benefits of feed supplements as against the use of tree foliage as mulch for crop production. Results indicate that at any level of supplement, sheep grew twice as fast as goats. The main benefits of supplementation came through increased growth and survival. Form and level of supplementation had significant effect on intake. Economic analyses showed that crop response to mulching was the principal competing determinant of whether the use of tree foliage as feed supplement was economic.

Africa, Western↗
PubMed1997

Umbilical cord blood interleukin-6 levels and neonatal morbidity.

OBJECTIVE: To study umbilical cord interleukin-6 levels and the occurrence of neonatal sepsis, congenital pneumonia, necrotizing enterocolitis, and grade II-IV intraventricular hemorrhage. METHODS: Umbilical cord blood was collected from 133 preterm newborns. The study population was divided according to the presence or absence of neonatal complications. Interleukin-6 levels and clinical characteristics were compared by univariate and multivariate analyses. RESULTS: Sixteen neonates had adverse outcomes, and 117 were unaffected. The median interleukin-6 level was significantly higher in affected than in unaffected infants (145 pg/mL versus 0 pg/mL, P = .002). Elevated interleukin-6 levels were associated independently with neonatal morbidity in multiple logistic regression modeling that included gestational age, birth weight, and antenatal steroid exposure. CONCLUSION: Umbilical cord blood interleukin-6 levels are elevated in neonates who subsequently develop sepsis, congenital pneumonia, necrotizing enterocolitis, or grade II-IV intraventricular hemorrhage.

Adult↗
PubMed1996

Comparison of the effects of sertraline and its metabolite desmethylsertraline on blockade of central 5-HT reuptake in vivo.

N-demethylation of the selective serotonin reuptake inhibitor sertraline to desmethylsertraline yields a compound with 10- to 20-fold less potency at blocking serotonin (5-HT) reuptake as measured in vitro. In the present study desmethylsertraline (DMS) was examined in two in vivo models of reuptake inhibition--elevation of extracellular 5-HT in the corpus striatum as measured by microdialysis and inhibition of firing of serotonin-containing dorsal raphe neurons. Whereas sertraline (1, 3.2, and 10 mg/kg s.c.) produced a dose-dependent increase in extracellular 5-HT and a decrease in 5-HIAA in rat striatum, desmethylsertraline was without effect on either parameter. In similar fashion, desmethylsertraline had no effect on dorsal raphe cell firing at a dose (1,000 micrograms/kg i.v.) nearly 20-fold the ED50 for sertraline (52 micrograms/kg). Taken together, these data suggest that DMS does not contribute to the blockade of central 5-HT reuptake produced by sertraline in vivo and therefore would be expected to play a negligible role in its clinical activity.

1-Naphthylamine↗
PubMed1996

A qualitative evaluation of the post accident notification system to health visitors.

Childhood accidental injuries are a major public health problem, whether measured in terms of morbidity or mortality, and accident prevention is subsequently a priority issue. The Accident and Emergency Notification System to health visitors provides them with vital information and statistics with which to plan accident prevention work, both on an individual basis or in group work. This small study aimed to look at this system from the health visitor's perspective and explore the action taken. The grounded theory approach was used to uncover the processes used by the health visitors. Data were collected using unstructured interviews and by writing notes. These were transcribed on the same day as recorded. Nine categories were identified and an analysis of the processes involved when receiving the notification slip is presented. The categories included 'knowing the family', 'age and development', 'pressure of work' and 'gut feeling/extra sensory perception'. This study is a small contribution to our understanding of the processes involved in everyday health visiting practice.

Accidents↗
PubMed1996

Effects of gender on listeners' judgments of speech intelligibility.

Effects of gender on listeners' judgments of intelligibility were investigated. Subjects (15 women; 15 men) provided magnitude-estimation scaling responses and over-all impression of the intelligibility of a male and female speaker's comparable versions of audiotaped speech samples varying systematically in terms of the number of phonemes produced correctly. There was no significant difference between male and female subjects' magnitude-estimation scaling responses; however, their over-all impressions of the intelligibility of the speakers tended to differ. Women indicated that the male speaker was more understandable, and men indicated that the female speaker was more understandable. Magnitude-estimation scaling may provide an objective means for evaluating a speaker's intelligibility. It appears to transcend gender-biases associated with judgments of speech intelligibility.

Adult↗
PubMed1996

Total lymphoid irradiation as rescue therapy after heart transplantation.

BACKGROUND: Allograft dysfunction develops in a proportion of heart transplant recipients without significant cellular infiltrate in endomyocardial biopsies and with normal coronary arteries at angiography. The mechanisms responsible for this presentation are unclear, and the prognosis is poor. We report encouraging experience with total lymphoid irradiation given in addition to cyclosporine A, cyclophosphamide, and prednisolone therapy in three heart transplant recipients with poor graft function with normal endomyocardial biopsies and coronary angiography. METHODS: Three patients who had severe allograft dysfunction after orthotopic heart transplantation, with normal endomyocardial biopsies and coronary angiography, were successfully treated with total lymphoid irradiation. Biventricular failure developed in each patient despite immunosuppression with cyclosporine A, azathiaprine, oral prednisolone, cyclophosphamide, and intravenous methylprednisolone therapy. Total lymphoid irradiation was given with standard mantle and inverted y fields over 10 treatments to achieve a cumulative dose of 8 Gy. RESULTS: Each patient had a significant improvement in clinical response and in ventricular performance after total lymphoid irradiation, which was well tolerated in each case. The patients remain well at 8, 9, and 12 months after completion of treatment. CONCLUSIONS: Total lymphoid irradiation should be considered as adjunct therapy to conventional immunosuppression for heart transplant recipients with poor graft function in the absence of cellular rejection or coronary artery disease.

Adult↗
PubMed1995

Sedentarisation of cattle farmers in the derived savannah region of south-west Nigeria: results of a survey.

The aim of this study was to assess the process and extent of sedentarisation among Fulani cattle owners in the derived savannah zone of south-west Nigeria. The results, based on a survey of 66 randomly-selected cattle owners, indicate an on-going process of settlement. Previously cattle owners visited the zone for dry season grazing but an increasing number were found to be settling and becoming mixed livestock/crop farmers. Generally herd sizes were larger among recent settlers but with longer duration of settlement and with cattle rearers' involvement in crop production, the herds became less mobile between seasons and herd size decreased and the proportion of farms with mixed zebu/trypanotolerant cattle herds increased. There was also evidence that some indigenous Yoruba crop farmers were becoming mixed farmers by purchasing cattle, hiring Fulani herdsmen for management, then taking up the management themselves.

Agriculture↗
PubMed1995

Do protective devices prevent needlestick injuries among health care workers?

OBJECTIVES: To determine the effectiveness and direct of two protective devices-a shielded 3 ml safety syringe (Safety-Lok; Becton Dickinson and Co., Becton Dickinson Division, Franklin Lakes, N.J.) and the components of a needleless IV system (InterLink; Baxter Healthcare Corp., Deerfield, Ill.)--in preventing needlestick injuries to health care workers. DESIGN: Twelve-month prospective, controlled, before-and-after trial with a standardized questionnaire to monitor needlestick injury rates. SETTING: Six hospital inpatient units, consisting of three medical units, two surgical units (all of which were similar in patient census, acuity, and frequency of needlesticks), and a surgical-trauma intensive care unit, at a 900-bed urban university medical center. PARTICIPANTS: All nursing personnel, including registered nurses, licensed practical nurses, nursing aides, and students, as well as medical teams consisting of an attending physician, resident physician, interns, and medical students on the study units. INTERVENTION: After a 6-month prospective surveillance period, the protective devices were randomly introduced to four of the chosen study units and to the surgical-trauma intensive care unit. RESULTS: Forty-seven needlesticks were reported throughout the entire study period, 33 in the 6 months before and 14 in the 6 months after the introduction of the protective devices. Nursing staff members who were using hollow-bore needles and manipulating intravenous lines accounted for the greatest number of needlestick injuries in the pre-intervention period. The overall rate of needlestick injury was reduced by 61%, from 0.785 to 0.303 needlestick injuries per 1000 health care worker-days after the introduction of the protective devices (relative risk = 1.958; 95% confidence interval, 1.012 to 3.790; p = 0.046). Needlestick injury rates associated with intravenous line manipulation, procedures with 3 ml syringes, and sharps disposal were reduced by 50%; however, reductions in these subcategories were not statistically significant. No seroconversions to HIV-1 or hepatitis B virus seropositivity occurred among those with needlestick injuries. The direct cost for each needlestick prevented was $789. CONCLUSIONS: Despite an overall reduction in needlestick injury rates, no statistically significant reductions could be directly attributed to the protective devices. These devices are associated with a significant increase in cost compared with conventional devices. Further studies must be concurrently controlled to establish the effectiveness of these devices.

Direct Service Costs↗
PubMed1995

Acoustic reflex measures at high probe frequency: a phasor diagram approach.

Acoustic reflex measures at high probe frequencies (above 660 Hz) have not been extensively reported in the published literature. Studies of the acoustic reflex at low probe frequencies conflict as to the effect of the reflex on resistance, although all researchers agree that the reflex increases the amount of negative reactance (stiffness). These differences may reflect methodological differences across studies. Lutman and his associates (Lutman and Martin 1979; Lutman et al., 1984) have used phasor diagrams to provide evidence for the effect of the reflex being on reactance, with constant resistance for low probe frequencies (220 and 660 Hz). The present study incorporated the use of this method in order to investigate the effect of the reflex at a 1000 Hz probe frequency in 30 normal ears. Phasor diagrams of probe tip susceptance and conductance values obtained for three stimuli at a 1000 Hz probe frequency were analysed qualitatively. Eighty-two out of a total of 90 phasor diagrams obtained were matched to the constant-resistance stiffness-change model, suggesting that similar effects of the reflex are seen at low and high probe frequencies in most cases. This was noted to be the case for ears that were either stiffness-dominated or at their natural frequency at the 1000 Hz probe. However, the effect of the reflex on mass-dominated systems was less clear and needs further clarification.

Acoustic Stimulation↗
PubMed1995

The acoustic reflex at a 1000 Hz probe frequency: phasor and vector analysis.

Phasor plots of reflex growth functions have been inconclusive concerning the effect of the reflex for mass dominated ears. The present study aimed to establish whether vector plots clarified the effects of the reflex for phasors not showing a clear circular shape. Measured admittance data (ipsilateral reflexes across a wide intensity range) was represented as both phasor diagrams and converted to impedance quantities, represented as vectors. The results analysed for 34 ears showed few unclassifiable phasor diagrams. In addition, all growth functions showed increased stiffness on vector analysis. Resistance changes appeared to be variable. The results suggest that vector diagrams may be a useful way of representing data that is not clearly represented via phasor diagrams. The current study, however, does not clarify the pattern for mass dominated ears.

Adolescent↗
PubMed1994

Direction of susceptance and conductance acoustic reflexes at high probe frequencies.

Previous investigations have shown that for low probe frequencies (220 and 660 Hz) the direction of susceptance and conductance reflexes is related to baseline transmission properties. Previously documented reflex patterns, caused by the stiffening of the ossicular chain, are characterised by decreases in both components at 220 Hz (-B-G) and increases in susceptance and decreases in conductance (+B-G) at 660 Hz. In the present study, the direction of susceptance and conductance acoustic reflexes was investigated at a probe frequency of 1000 Hz, where ears are expected to be less stiffness dominated than at the low frequencies, and for which there is little description of reflex patterns in the published literature. The pattern of ipsilateral susceptance and conductance reflexes from 30 normal ears was recorded across a wide intensity range at this probe frequency for three stimulus frequencies (0.5, 1 and 2 kHz). Reflexes were classified as either increases (+) or decreases (-) for each component, at threshold and at suprathreshold intensity levels. Ears were grouped according to transmission properties at 1000 Hz, and reflex patterns observed within each group of subjects were examined. Patterns observed in these subjects at the 1000 Hz probe frequency included: +B-G; +B+G; -B+G and -B-G. There appeared to be a relationship between baseline transmission and reflex patterns. Further, patterns appear to be consistent with theoretical models of the effect of the acoustic reflex, particularly for ears where stiffness is significant in the baseline condition. The effect of the reflex for mass dominated systems requires further investigation.

Acoustic Impedance Tests↗
PubMed1993

Temporary focal cerebral ischemia in spontaneously hypertensive rats: the effect of ibuprofen on infarct volume.

Arachidonic acid metabolism results in the generation of oxygen radicals and production of prostanoids which are proposed to adversely influence cerebral ischemia. Inhibition of cyclooxygenase, an enzymatic step in arachidonic acid metabolism, has effected an improvement in histologic outcome after cerebral ischemia. However, there has been no attempt to determine whether this effect occurs during vascular occlusion or during reperfusion. We assessed the effect of cyclooxygenase inhibition on infarct volume in the setting of either temporary or permanent middle cerebral artery occlusion (MCAo). Rats were allotted to one of the following groups: Groups I and II, 180 min of MCAo and 120 min of reperfusion; and Groups III and IV, 180 min of permanent MCAo. In Groups I and III, vehicle only was given, whereas in Groups II and IV, ibuprofen was given throughout the study period (MCAo with or without reperfusion). After the ischemic period the brains were analyzed for infarct volume (mm3, mean +/- S.D.) by 2,3,5-triphenyltetrazolium chloride stain. For animals in which reperfusion was allowed, ibuprofen reduced infarct volume (Group I, 122 +/- 15 mm3 vs. Group II, 63 +/- 7 mm3). However, in animals with permanent MCAo, ibuprofen worsened infarct volume (Group III, 79 +/- 8 mm3 vs. Group IV, 110 +/- 13 mm3). These data suggest that the beneficial effect of cyclooxygenase inhibition occurs during reperfusion.

Animals↗
PubMed1993

Focal cerebral ischemia in rats. Effect of hypervolemic hemodilution with diaspirin cross-linked hemoglobin versus albumin on brain injury and edema.

BACKGROUND: Hemodilution has had limited success as a treatment of cerebral ischemia. When using a non-oxygen-binding fluid, the therapeutic efficacy of hemodilution-induced increases in blood flow are offset by concomitant decreases in oxygen content. METHODS: The effect of hemodilution, with diaspirin cross-linked hemoglobin (DCLHb), on brain injury and edema was assessed during middle cerebral artery occlusion (180 min) and reperfusion (120 min) in rats (blood volume increased by approximately 30% and n = 10 for each group): (1) 44/B: 8.0 ml of donor blood was given; (2) 30/albumin: hematocrit was decreased to 30% with 10% albumin; (3) 30/DCLHb: hematocrit was decreased to 30% with 10% DCLHb; or (4) 9/DCLHb: hematocrit was decreased to 9% with DCLHb. Infarct size was analyzed with 2,3,5-triphenyltetrazolium chloride, and edema by microgravimetry. RESULTS: Brain injury (percent of the hemispheric area ipsilateral to ischemia, mean +/- SD) was greater in the 44/B group (44 +/- 4) versus the 30/albumin group (37 +/- 3). In addition, brain injury was greater in the 44/B and 30/albumin groups versus the 30/DCLHb group (27 +/- 4); which was in turn greater than the 9/DLCHb group (18 +/- 3). Specific gravity was greater (less brain water) in all hemodiluted groups versus the 44/B group. CONCLUSIONS: These results support a hypothesis that hemodilution decreases focal cerebral ischemic injury, and when an oxygen-binding fluid is used, there is a dose-dependent effect of hemodilution on ischemia. In addition, these results suggest that hemodilution, as achieved with DCLHb, was more effective in reducing ischemic brain damage than was the same degree of hemodilution as achieved with albumin.

Albumins↗
PubMed1992

A polymerase chain reaction-based method for isolation of gene-specific sequences from the interferon-alpha gene cluster.

The interferon-alpha gene is a gene family of over 20 distinct genes having 80-95% homology with one another at a nucleotide level. Because of the high homology in the gene cluster, the available interferon-alpha gene probes can hybridize to multiple bands of different size on Southern blot analysis of restricted human genomic DNA. We used the polymerase chain reaction with the primers synthesized from Alu repetitive sequence and the conserved sequences of the interferon-alpha gene cluster to generate specific probes for individual interferon-alpha genes. The amplification products were subcloned into a plasmid vector and analyzed by DNA sequencing and Southern blotting of the restricted human placental DNA. One clone, which derived from interferon-alpha 14 gene, produced a single 5.2-kb band in Southern blots of the HindIII-restricted human placental DNA. This stands in contrast to the 10 bands of different size that were detected with a cDNA for the interferon-alpha I' gene. Our results indicate that a polymerase chain reaction-based method can be used to isolate gene-specific sequences from the interferon-alpha gene cluster. Since a variety of human cancers has been found to have the complete or partial deletion of the interferon-alpha gene cluster, the gene-specific probe generated by this method may aid in determining the breakpoints in the vicinity of the gene cluster.

Animals↗