Biomedical subjects
B Tucker
Publications and source records attributed to B Tucker.
Oral ofloxacin therapy for lower respiratory tract infection.
We made an open, noncomparative evaluation of ofloxacin, 400 mg orally bid for 10 days, in 98 subjects with community-acquired pneumonia or pathogen-confirmed bronchitis. Thirty-nine (40%) of the subjects were treated in the hospital and 59 (60%) were treated as outpatients. The mean age of those treated was 56.2 years; 73 (74%) of the subjects either were more than 60 years old or had a history of chronic obstructive pulmonary disease, or both. There were 95 organisms initially isolated in sputum, aspirate, or lavage fluid; all were susceptible to ofloxacin, and none acquired resistance during therapy. Haemophilus influenzae was the most common pathogen (19 isolates), followed by Streptococcus pneumoniae (18) and Staphylococcus aureus (10). Clinical responses included cure in 70 patients (71%), improvement in 26 (27%), and failure in two (2%). After 10 days of therapy, pathogens persisted in two cases; in one case, Streptococcus salivarius was isolated, though it remained susceptible to ofloxacin, and in the other, Klebsiella pneumoniae was accompanied by superinfection due to a resistant strain of Serratia marcescens. We included in this study three confirmed cases of atypical pneumonia successfully treated with ofloxacin, two of them due to Mycoplasma pneumonia and one to Legionella pneumophila. Ofloxacin was well tolerated. Our data indicate that ofloxacin is effective and safe as specific and empiric treatment for many lower respiratory tract infections.
Comparison of haemostatic activity in haemodialysis and peritoneal dialysis patients with a novel technique, haemostatometry.
Bleeding due to impaired primary haemostasis is common in uraemia. However, thrombo-embolic episodes are also a clinical problem in dialysis patients. Platelet reactivity to shear stress (haemostasis, H1 and H2), exposure to collagen fibre (thrombus growth) and coagulation of flowing blood (clotting time, CT1 and CT2) were measured in non-anticoagulated blood samples taken immediately before and 18-24 h after haemodialysis (n = 26) and from patients maintained on continuous ambulatory peritoneal dialysis (CAPD, n = 30). H1 (p < 0.001), H2 (p < 0.01), percent thrombus growth rate (p < 0.03), CT1 (p < 0.01 and CT2 (p < 0.05) were restored towards normal after haemodialysis. Results obtained in the CAPD patients demonstrated that the mean values for formation of the haemostatic plug lay between the pre- and posthaemodialysis values; however, CT1 (p < 0.01) and CT2 (p < 0.05) were prolonged in CAPD compared with values after haemodialysis. These data, which indicate platelet function from non-anticoagulated blood and coagulation under flow conditions, (1) confirm that there is impaired haemostasis in uraemia; (2) demonstrate an improvement in haemostasis after haemodialysis; (3) show that peritoneal dialysis results in a haemostatic profile which falls between the pre- and posthaemodialysis pattern, and (4) show that neither dialysis modality returns haemostasis to normal.
Transcapillary fluid shifts in tissues of the head and neck during and after simulated microgravity.
To understand the mechanism, magnitude, and time course of facial puffiness that occurs in microgravity, seven male subjects were tilted 6 degrees head-down for 8 h, and all four Starling transcapillary pressures were directly measured before, during, and after tilt. Head-down tilt (HDT) caused facial edema and a significant elevation of microvascular pressures measured in the lower lip: capillary pressures increased from 27.7 +/- 1.5 mmHg (mean +/- SE) pre-HDT to 33.9 +/- 1.7 mmHg by the end of tilt. Subcutaneous and intramuscular interstitial fluid pressures in the neck also increased as a result of HDT, whereas interstitial fluid colloid osmotic pressures remained unchanged. Plasma colloid osmotic pressure dropped significantly by 4 h of HDT (21.5 +/- 1.5 mmHg pre-HDT to 18.2 +/- 1.9 mmHg), suggesting a transition from fluid filtration to absorption in capillary beds between the heart and feet during HDT. After 4 h of seated recovery from HDT, microvascular pressures in the lip (capillary and venule pressures) remained significantly elevated by 5-8 mmHg above baseline values. During HDT, urine output was 126.5 ml/h compared with 46.7 ml/h during the control baseline period. These results suggest that facial edema resulting from HDT is caused primarily by elevated capillary pressures and decreased plasma colloid osmotic pressures. The negativity of interstitial fluid pressures above heart level also has implications for maintenance of tissue fluid balance in upright posture.
Hearing loss in chronic renal failure-hearing threshold changes following haemodialysis.
The prevalence of sensorineural hearing loss, measured by pure tone audiometry, was determined in 66 patients with chronic renal failure and threshold changes following haemodialysis were measured in 31 patients. The incidence of hearing loss was 41% in the low, 15% in the middle and 53% in the high frequency ranges respectively. No correlations with weight changes, haematocrit, metabolic bone disease or ototoxic drug history were found. Of 62 ears studied, 38% had a decrease in low frequency threshold after dialysis and 9% had an increase. Threshold in 22/31 ears with pre-existing low frequency loss altered after dialysis with little change in other frequencies and no correlation with weight changes. In conclusion, we find a high incidence of low and high frequency hearing losses in chronic renal failure patients. Fluctuation in low frequencies with dialysis is common. Possible mechanisms include treatment induced changes in fluid and electrolyte composition of endolymph.
Adjacent-2 disjunction of a maternal t(9;22) leading to duplication 9pter----q22 and deficiency of 22pter----q11.2.
The proposita presented at birth with multiple congenital anomalies including craniofacial anomalies, bilateral cleft lip and palate, abnormalities of the urogenital system, talipes equinovarus, and the DiGeorge sequence. Cytogenetic investigation showed a 46,XX,-22,+der(9)t(9;22)(q22;q11.2) karyotype. The mother, maternal uncle, and maternal grandmother of the infant are carriers of a reciprocal balanced translocation involving chromosomes 9 and 22 at regions q22 and q11.2, respectively. The unbalanced karyotype seen in the proposita arose due to an adjacent-2 disjunction of the quadrivalent in the mother. Prenatal diagnosis of the second pregnancy of this woman showed a similar karyotype. Review of the literature shows that adjacent-2 disjunction may occur preferentially when certain chromosomes are involved in translocations.
Enhanced in vitro hemostasis and reduced thrombolysis in cyclosporine-treated renal transplant recipients.
In vitro hemostatometry and assessment of thrombolysis was carried out in three groups of 72 renal transplant recipients. In one (triple, n = 21) immunosuppression was with cyclosporine, azathioprine, and prednisolone, while a second group (CsA, n = 29) received cyclosporine and prednisolone alone, and the third group (Aza, n = 22) azathioprine and prednisolone. Results were compared with those in 30 normal controls. A statistically significant increase in hemostasis compared with controls was seen in the triple group and in patients in the CsA group studied within 2 years of transplantation. Hemostasis in the Aza group did not differ from normal. All patients in this group had been transplanted more than 2 years before study. Thrombolysis times were significantly prolonged compared with controls in all three groups. Cyclosporine treatment is associated with enhanced hemostasis and reduced thrombolysis, especially during the first 2 years after renal transplantation. If these in vitro findings reflect events in vivo, this may throw light upon the pathogenesis of the obliterative arteriolopathy that is a feature of cyclosporine nephrotoxicity.
Successful pregnancy in a renal transplant recipient with type I primary hyperoxaluria.
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Seizures related to blood transfusion and erythropoietin treatment in patients undergoing dialysis.
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Three different, non-mosaic sex chromosome abnormalities (direct cytotrophoblasts, mesenchymal core cultures, and abortus skin fibroblasts): implications for elucidating chorionic villi mosaicism.
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Seizures in haemodialysis patients treated with recombinant human erythropoietin.
Administration of recombinant erythropoietin (r-HuEPO) is an effective treatment for the anaemia of chronic renal failure, but in some patients it has been accompanied by elevated blood pressure. This study focuses on seven patients with end-stage renal failure, managed on haemodialysis, who developed probable hypertensive encephalopathy with seizures during treatment with r-HuEPO. All made a full recovery. The events were not clearly related to the haemoglobin concentrations achieved, and four patients have subsequently been restarted on r-HuEPO therapy at a reduced dose, resulting in a slower increase in haemoglobin with no recurrence of episodes of severe hypertension. Close attention needs to be paid to blood pressure in patients commencing erythropoietin therapy, and it seems prudent to aim for a gradual increase in haemoglobin concentration to allow the circulation to adapt to changes in oxygen delivery and haematocrit.
Erythraemia in renal transplant recipients treated with cyclosporin.
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Postoperative infection with the automatic implantable cardioverter defibrillator: clinical presentation and use of the gallium scan in diagnosis.
This report describes three patients with infection involving an automatic implantable cardioverter defibrillator. All three patients presented with fever, fluid in the pulse generator pocket, leukocytosis and an elevated erythrocyte sedimentation rate. A gallium scan, together with aspiration and culture of the fluid from the pocket, confirmed the diagnosis in each case.
A comparison of HIV antibody and HIV viral findings in blood and saliva of HIV antibody-positive juvenile hemophiliacs.
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An unusual case of two- and three-rooted premolars.
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Guides to success in oral surgery.
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