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Biomedical subjects

V Harrison

Publications and source records attributed to V Harrison.

At least 19 recordsLinked to original sources
PubMed2006

CASP and CONSORT.

Explore the source record for details and available documents.

Anti-Infective Agents, Local↗
PubMed2003

Effect of two breathing exercises (Buteyko and pranayama) in asthma: a randomised controlled trial.

BACKGROUND: Patients with asthma are interested in the use of breathing exercises but their role is uncertain. The effects of the Buteyko breathing technique, a device which mimics pranayama (a yoga breathing technique), and a dummy pranayama device on bronchial responsiveness and symptoms were compared over 6 months in a parallel group study. METHODS: Ninety patients with asthma taking an inhaled corticosteroid were randomised after a 2 week run in period to Eucapnic Buteyko breathing, use of a Pink City Lung Exerciser (PCLE) to mimic pranayama, or a PCLE placebo device. Subjects practised the techniques at home twice daily for 6 months followed by an optional steroid reduction phase. Primary outcome measures were symptom scores and change in the dose of methacholine provoking a 20% fall in FEV(1) (PD(20)) during the first 6 months. RESULTS: Sixty nine patients (78%) completed the study. There was no significant difference in PD(20) between the three groups at 3 or 6 months. Symptoms remained relatively stable in the PCLE and placebo groups but were reduced in the Buteyko group. Median change in symptom scores at 6 months was 0 (interquartile range -1 to 1) in the placebo group, -1 (-2 to 0.75) in the PCLE group, and -3 (-4 to 0) in the Buteyko group (p=0.003 for difference between groups). Bronchodilator use was reduced in the Buteyko group by two puffs/day at 6 months; there was no change in the other two groups (p=0.005). No difference was seen between the groups in FEV(1), exacerbations, or ability to reduce inhaled corticosteroids. CONCLUSION: The Buteyko breathing technique can improve symptoms and reduce bronchodilator use but does not appear to change bronchial responsiveness or lung function in patients with asthma. No benefit was shown for the Pink City Lung Exerciser.

Adrenergic beta-Agonists↗
PubMed2000

Responses of seventh grade students to "do you have a partner with whom you would like to have a baby?".

This study investigated differences in demographic data, self-esteem, and coping skills for 225 students in Grade 7 who reported having a partner with whom they wanted to have a baby and 946 students who did not. Data were collected on the Rosenberg Self-esteem Scale, the Family Crisis-oriented Personal Evaluation Scale, and questions related to attitudes towards teen pregnancy and demographic data. The sample included 548 (46.8%) boys and 624 (53.2%) girls whose mean age was 13.2 yr. Students with a partner had significantly lower scores on the curriculum questions, self-esteem, and family coping skills, combined with higher scores in passivity. They indicated a desire to have a greater number of children, beginning by having their first child at a younger age and believed that having a baby improves a couple's relationship. Possible approaches may include effective teaching methods to overcome passivity through boosting self-confidence, goal-setting, and acquiring a purpose in life besides parenting a child.

Adolescent↗
PubMed1999

Induced brain hypothermia in asphyxiated human newborn infants: a retrospective chart analysis of physiological and adverse effects.

OBJECTIVE: To assess the physiological effects and adverse side-effects of induced hypothermia in asphyxiated newborn infants as a base for future controlled, randomized trials. DESIGN: Retrospective chart analysis with historical controls. SETTING: Tertiary neonatal intensive care unit of the University of Cape Town, South Africa. PATIENTS: Twenty-one asphyxiated newborns treated with induced hypothermia between September 1997 and February 1998 were compared to 15 asphyxiated newborn infants admitted during March to August 1997. The two groups of infants did not differ in patient characteristics or severity of asphyxia (comparison group vs hypothermia group: Apgar at 5 min 5.3 +/- 3.1 vs 5.2 +/- 2.3; base deficit 15.6 +/- 6.3 vs 11.5 +/- 7.2 and Thompson neurological score 10.1 +/- 4.0 vs 9.1 +/- 3.6). INTERVENTIONS: Hypothermia was induced by placing a cap formed from coolpacks, at a temperature of about 10 degrees C, around the head of asphyxiated newborn infants to maintain the nasopharyngeal temperature between 34 and 35 degrees C. Hypothermia was maintained for 3 days. MEASUREMENTS AND RESULTS: In the comparison group 4/15 infants died and in the hypothermia group 4/21 died. Hypothermia was induced at a median of 6.0 h (range 45 min to 53 h) post-partum, maintained for an average of 80 h (median 77.5 h, range 22 to 185 h) and resulted in an average nasopharyngeal temperature of 34.6 +/- 0.5 degrees C. Hypothermia reduced abdominal skin temperature from 36.3 +/- 0.5 degrees C to 35.1 +/- 0.35 degrees C (p = 0.0001), heart rate from 139 +/- 21 to 121 +/- 13 beats/min (p < 0.0001) and respiratory rate from 67 +/- 11 to 56 +/- 9 breaths/min (p = 0.005). Neither episodes of bradycardia nor dysrhythmias, apnea, clinical signs of bleeding diathesis in the hypothermia group nor differences in the frequency of hypoglycaemia and urinary output, blood in urine or tracheal secretion between the two groups were observed. In the survivors the neurological score, assessed at day 2 and day 5, fell from 10.9 +/- 3.5 to 8.1 +/- 4.5 in the hypothermia group and rose from 8.1 +/- 2. 5 to 9.0 +/- 3.1 in the comparison group (p = 0.003). CONCLUSIONS: Adverse effects of mild hypothermia induced for 3 days in asphyxiated newborns were significantly less than expected from previous reports on neonates with accidental hypothermia.

Apgar Score↗
PubMed1998

Relation of endometriosis and neuromuscular disease of the gastrointestinal tract: new insights.

OBJECTIVE: To investigate the neuromuscular activity of the gastrointestinal tract by antroduodenal manometry in women with endometriosis documented by laparoscopy, to assess the effects of diet and drug therapy on symptoms, and to assess the bacterial overgrowth that is commonly associated with these nerve diseases. DESIGN: Prospective, open-label study. SETTING: A clinical center for the care of women's health. PATIENT(S): Fifty women with endometriosis documented by laparoscopy and gastrointestinal tract symptoms characterized by chronic abdominal pain, nausea, vomiting, early satiety, bloating and distention, and altered bowel habits. INTERVENTION(S): Motility of the gastrointestinal tract was recorded and bacterial overgrowth was assessed. Treatment consisted of dietary changes, including reduction of glycemic carbohydrates, balancing with omega 9 oils, elimination of foods with caffeine and tyramine, and addition of omega 3 fatty acids, as well as drug therapy with clonazepam (0.25 mg 3 times per day). RESULT(S): All 50 women showed a characteristic motility change (ampulla of Vater-duodenal wall spasm, a seizure equivalent of the enteric nervous system). Forty of the women showed bacterial overgrowth. There was a significant reduction in the total symptom score after 8 weeks of treatment. CONCLUSION(S): This study suggests that endometriosis and gastrointestinal tract symptoms are a result of the dysfunction of hollow organs. Correction of the biochemical imbalance of the eicosanoid system and the hypersecretion of insulin that results from excessive intake of glycemic carbohydrates and lack of essential fatty acids significantly decreases symptoms in patients with endometriosis and associated neuromuscular disease of the gastrointestinal tract.

Adult↗
PubMed1997

Red blood cell magnesium and hypoxic-ischaemic encephalopathy.

In developing countries, birth asphyxia is frequently associated with hypoxic ischaemic encephalopathy. This has been attributed to inadequate obstetric care but poor nutrition may also be important. This study determines the association between magnesium stores and hypoxic ischaemic encephalopathy. The level of red blood cell magnesium was measured on 572 women in labour and on selected offspring in a teaching hospital in South Africa. Fifty five of the 572 women delivered infants with hypoxic ischaemic encephalopathy and had significantly lower red blood cell magnesium levels (1.40 mmol/l) than controls. In the latter the levels varied somewhat with the mode of delivery, vertex births 1.76 mmol/l, Caesarean sections 1.67 mmol/l and vacuum extractions 1.61 mmol/l. Infants with hypoxic ischaemic encephalopathy had a significantly lower red blood cell magnesium level (1.39 mmol/l) than normal infants (1.61 mmol/l). Fifty four of 55 babies were black and from poor social circumstances and nutritional deficiency may be relevant. Maternal height, age and the duration of labour did not influence the chance of hypoxic ischaemic encephalopathy and affected infants were more likely than normal ones to be meconium stained (50%), to have a low Apgar score (58%) and to need endotracheal intubation at birth (54%). An intervention study in early pregnancy may determine magnesium's role in hypoxic ischaemic encephalopathy associated with asphyxia.

Apgar Score↗
PubMed1994

In vivo modulation of rat distal tubule net HCO3 flux by VIP, isoproterenol, angiotensin II, and ADH.

To examine the in vivo effects of agonists reported to influence bicarbonate flux (JtCO2), microperfusion experiments were carried out on distal tubules of normally fed or overnight-fasted rats. As we previously reported, distal tubules from fed rats reabsorbed no bicarbonate, whereas overnight-fasted rats consistently reabsorbed bicarbonate (JtCO2 10 +/- 3 pmol.min-1.mm-1; P < 0.01). Vasoactive intestinal peptide and isoproterenol infused intravenously (7.3 and 4.0 micrograms.kg-1.h-1, respectively) in fasted rats suppressed JtCO2 and, in the case of vasoactive intestinal peptide, elicited net bicarbonate secretion (JtCO2 -10 +/- 2 and -4 +/- 4 pmol.min-1.mm-1, respectively). In fed rats, angiotensin II infused at a rate of 1.2 micrograms.kg-1.h-1 stimulated bicarbonate reabsorption (JtCO2 16 +/- 3 pmol.min-1.mm-1), while antidiuretic hormone infused at 0.024 micrograms.kg-1.h-1 elicited a similar response (17 +/- 4 pmol.min-1.mm-1), both values being significantly different from control. These results, therefore, demonstrate for the first time that these agonists can modulate JtCO2 at the distal tubule site in vivo and therefore may be potential regulators of systemic acid-base balance.

Absorption↗
PubMed1994

Distal tubule unidirectional HCO3 reabsorption in vivo during acute and chronic metabolic alkalosis in the rat.

During metabolic alkalosis (MA) associated with 2 days of dietary chloride restriction, there is net bicarbonate secretion by rat distal tubules in vivo, whereas after 5 wk of chloride depletion alkalosis there is net bicarbonate reabsorption. To examine unidirectional components of net bicarbonate reabsorption during chronic MA, we measured distal tubule unidirectional bicarbonate secretion (Jsec) and reabsorption (Jreab), as well as the inhibitor sensitivity of Jreab. In control, 2-day, and 7-day alkalosis, Jsec was similar. Jreab, however, was only present in 7-day MA (17 +/- 3 pmol.min-1.mm-1, P < 0.05). This Jreab was completely suppressed by perfusion with 10(-7) M bafilomycin A1, partially suppressed with 10(-5) M Schering (Sch)-28080 (4 +/- 2 pmol.min-1.mm-1, P < 0.1), and converted into a secretory flux by 3 mM amiloride. We conclude that adaptation to chloride depletion MA from the acute secretory phase to the chronic state, where plasma bicarbonate is sustained at elevated levels, does not involve suppression of distal tubule Jsec but rather enhanced Jreab, which is sensitive to bafilomycin, Sch-28080, and amiloride.

Absorption↗
PubMed1994

In vivo adaptation of bicarbonate reabsorption by rat distal tubules during acid loading.

We carried out in vivo microperfusion experiments in acid-loaded rats to characterize the adaptive response of the unidirectional components secretory flux (Jsec) and reabsorptive flux (Jreab)] of distal tubule bicarbonate reabsorption and to test the hypothesis that Jreab is dependent on bafilomycin A1-sensitive H(+)-adenosinetriphosphatase activity. During 18 h of severe acidosis there was a significant decrease in Jsec (-15 +/- 3 vs. -38 +/- 5 pmol.min-1.mm-1, P < 0.05) and a significant increase in Jreab (37 +/- 6 vs. 0 +/- 5 pmol.min-1.mm-1, P < 0.05), which was insensitive to 10(-5) M bafilomycin A1, 10(-5) M Sch-28080, and 3 mM amiloride. After 3 days of acid loading, these same inhibitors reduced Jreab by approximately 60%. However, when water flux was completely inhibited by isosmotic perfusion, a significant Jreab (15 +/- 2 pmol.min-1.mm-1) resistant to 10(-5) M bafilomycin A1 persisted, as in severe acidosis. In reabsorbing distal tubules of overnight-fasted rats, Sch-28080 elicited no inhibition, whereas bafilomycin A1 and amiloride had significant effects (28 +/- 5, 24 +/- 4, respectively, vs. 50 +/- 4 pmol.min-1.mm-1 for fasted rats, P < 0.05). Thus, although Jsec is reduced in the transition from mild to severe metabolic acidosis of 18-h duration, the predominant effect is a stimulation of bafilomycin A1-resistant Jreab.

Acclimatization↗
PubMed1991

Bicarbonate secretion in vivo by rat distal tubules during alkalosis induced by dietary chloride restriction and alkali loading.

To examine in vivo the separate effects on distal tubule JtCO2, of dietary chloride restriction, bicarbonate loading, and changes in luminal chloride concentration, we microperfused distal tubules at a physiologic flow rate (8 nl/min) with solutions containing either 45 or 0 mM chloride (after gluconate substitution). Rats were fed a diet containing zero, minimal, or normal amounts of chloride, while drinking either water or a solution of 0.15 M sodium bicarbonate. Neither extracellular fluid volume contraction nor negative chloride balance ensued. Analysis of covariance with repeated measures demonstrated that dietary chloride, drinking sodium bicarbonate, and perfusion with either 45 mM or zero chloride, each have separate and significant modulating effects on distal tubule bicarbonate secretion. During mild alkalemia, there is modest bicarbonate secretion which is significantly different from zero (-9.9 +/- 3.2 pmol.min-1.mm-1, P less than 0.01), and which is suppressed after perfusion with zero chloride. In contrast, during more pronounced metabolic alkalosis after supplemental bicarbonate drinking, the bicarbonate secretory flux is brisk (-26 +/- 3 pmol.min-1.mm-1) and significantly different from zero and persists (-11 +/- 3 pmol.min-1.mm-1) even during perfusion with zero luminal chloride. Accordingly, in this two-day model of alkalosis induced by dietary chloride restriction, there is regulatory secretion of bicarbonate by distal tubules in vivo which is modulated by luminal chloride concentration.

Absorption↗
PubMed1991

Pneumocystis carinii pneumonia: detection of parasites by immunofluorescence based on a monoclonal antibody.

A monoclonal antibody-based immunofluorescence test for the detection of Pneumocystis carinii was evaluated in comparison with the conventional direct staining by Grocott's silver methenamine technique. A total of 254 respiratory samples from HIV positive and other immunocompromised patients were examined. Cysts were detected in 30 (12%) of samples using the monoclonal test, but only 15 (6%) positives were found using the Grocott method. There is need for a speedy and efficient test for detection of these organisms, and the monoclonal test was found to be more reliable, quicker and more sensitive than the Grocott technique.

Acquired Immunodeficiency Syndrome↗
PubMed1980

Histological demonstration and frequency of intrahepatocytic copper in patients suffering from alcoholic liver disease.

This study was carried out to determine whether stainable copper accumulates in the hepatocytes of patients with alcoholic liver disease. Liver sections from 44 cases of alcoholic cirrhosis and 32 cases of non-cirrhotic alcoholic liver disease were stained by the rubeanic acid, rhodanine and orcein methods. Intrahepatocytic copper granules were found in 13 cases of cirrhosis (30%), but in none of the non-cirrhotic livers. The abundance of granules did not appear to be related either to the activity of the cirrhotic process or to the presence of cholestasis. It may well be that alcoholic cirrhosis is the most common disease associated with excess of intrahepatocytic copper.

Adult↗