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Biomedical subjects

N Barnes

Publications and source records attributed to N Barnes.

At least 55 records · Page 3Linked to original sources

Liver transplantation for hepatic cirrhosis in cystic fibrosis.

About 10% of children with CF develop hepatic cirrhosis and progressive portal hypertension. As the portal hypertension worsens these children are likely to develop serious variceal bleeding and other complications including malnutrition and a decline in respiratory function. Indices of lung function may fall as much as 50% in a year and chest infections may require frequent admissions to hospital. The respiratory symptoms are often attributed to CF related lung disease and affected children may therefore be considered unsuitable for liver transplantation. We propose a simple scoring system which can help to select patients who should be referred for assessment of liver transplantation. After careful assessment and preparation children with lung function indices as low as 30% predicted can have a successful outcome after liver transplantation. With good graft function portal hypertension is relieved and absorption, nutrition and respiratory function all improve. The improved quality of life of these children is remarkable.

Adolescent↗

Candida glabrata epididymo-orchitis: an unusual infection rapidly cured with surgical and antifungal treatment.

We report a case of epididymo-orchitis and secondary fungaemia caused by Candida (previously Torulopsis) glabrata in an 83-year-old male patient who had diabetes mellitus, urinary outflow obstruction and previous bladder malignancy. We believe this to be a previously unreported site of infection with C. glabrata and we describe its rapid and successful treatment with combination anti-fungal therapy.

Aged↗

Effects of a thromboxane receptor antagonist on prostaglandin D2 and histamine induced bronchoconstriction in man.

Many prostanoids including are prostaglandin (PG) F2 alpha and PGD2 are potent bronchoconstrictor agents. There is evidence to suggest that airway thromboxane (TP) receptor may act as a common receptor for their bronchoconstrictor actions. We tested the hypothesis that inhaled prostaglandin (PG) D2-induced bronchoconstriction is mediated by interacting with the TP receptor antagonist, ICI 192605, on the bronchoconstrictor response to inhaled PGD2 in a double-blind, placebo-controlled and crossed-over trial in normal subjects. The effect of ICI 192605 on histamine induced bronchoconstriction served as control for non-specific bronchodilatory actions. The study had two phases; the first consisted of two inhaled PGD2 challenge study days, and the second phase was that of inhaled histamine. Each study day was separated by at least a week. On each study day, the challenge tests were carried out 30 min after ingestion of 100 mg ICI 192605 or placebo. Doubling concentrations of agonist were given till more than 35% fall in post-diluent specific airway conductance (sGaw) occurred. The concentration needed to cause a fall in a sGaw of 35% post-diluent value (PC35sGaw) was then determined from linear interpolation of the log dose-response. Eight male subjects (median age 26, range 20-35 years) completed the study. ICI 192605 did not change baseline airway calibre 30 min after ingestion on either PGD2 or histamine study days. ICI 192605 significantly shifted the dose-response curve to inhaled PGD2 to the right by a median of 3.4 fold (Wilcoxon rank sign test, P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Urological dysfunction in patients with diastematomyelia.

Little information exists concerning voiding dysfunction associated with diastematomyelia (splitting of the spinal cord). We present 27 patients 4 days to 62 years old (mean 13 years) who underwent neurosurgical intervention for treatment of this disorder. Of these patients 14 had urological evaluation, with 11 having undergone video urodynamics. Nine patients had minimal urological manifestations. No patient had a urodynamically proved hostile bladder nor evidence of upper urinary tract deterioration. In our experience, patients with a spinal cord fixation syndrome resulting from diastematomyelia not associated with a meningomyelocele appear to have a relatively benign course in terms of the urological manifestations. However, due to the lack of reports concerning the urological findings in this occult dysraphic state, we still suggest upper and lower urinary tract evaluation and followup.

Adolescent↗

A survey of the health of homeless children in Philadelphia shelters.

We conducted a random-sample survey of homeless children and their mothers residing in Philadelphia (Pa) shelters. One hundred forty-six families were included in the final sample, resulting in an 80% response rate. The aims of the survey were to characterize the child's current and past health status, to determine access to and use of medical services, and to determine the serum erythrocyte protoporphyrin levels and tuberculin skin test status of the children. In addition, psychological tests were administered to both child and parent to assess developmental level and psychological problems. Finally, detailed questions were asked concerning the reasons for the homeless condition. The important reasons for homelessness cited in the survey included physical abuse, substance abuse, disagreements with landlords, and poor living conditions. The children's health problems included a high incidence of reported accidents and injuries, burns, and lead toxicity; the parents suffered from depression, physical abuse, and substance abuse. School-aged children tended to have low scores on tests of expressive vocabulary and word decoding, and preschoolers seemed to be below age expectations in receptive vocabulary and visual motor skills. The findings of this study suggest that homeless children tend to score poorly on developmental and psychological tests and tend to sustain serious burns and accidents. Policy implications of the survey include suggestions for health screening, rehabilitation, and education.

Accidents↗

Protein C deficiency and portal thrombosis in liver transplantation in children.

Changes in plasma protein C and antithrombin concentrations after liver transplantation were monitored in fourteen children and a control group of fourteen adults. In the children, there was a persistent deficiency in the plasma concentration of protein C and a less pronounced deficiency in antithrombin during the early postoperative period, causing a hypercoaguable state. A concomitant rise in plasminogen activator inhibitor further increased the risk of thrombosis by inhibiting fibrinolysis. These changes coincided with the peak incidence of portal vessel thrombosis (4-10 days). Replacement of plasma antithrombin, together with heparin, did not prevent portal thrombosis in two of the children. It is concluded that successful prevention will require protein C replacement together with antithrombin supplements up to, but not exceeding, normal plasma activity.

Adult↗

Recurrent tonsillitis and growth in children.

Anecdotal observations suggest an association between tonsil disease and growth retardation. This study compared height, weight and skinfold thickness measurements between a group of children (44) suffering from recurrent tonsillitis for a mean duration of 4 years, and a control group (34). No important differences were observed between the groups. Recurrent tonsil infection does not appear to retard the growth of children.

Body Height↗

Inhibition of protein cross-linking in Ca2+-enriched human erythrocytes and activated platelets.

Treatment of human erythrocytes with Ca2+, in the presence of ionophore A23187, causes the formation of high molecular weight (greater than 10(6)) membrane protein polymers. This phenomenon, known to involve cross-linking of essentially all of the band 4.1 and 2.1 (ankyrin) proteins, as well as some spectrin, band 3, and hemoglobin molecules, could be prevented by preincubating the cells with a noncompetitive inhibitor of intrinsic transglutaminase, 2-[3-(diallylamino)propionyl]benzothiophene, at concentrations of about (3-6) X 10(-4) M. The compound also eliminated the proteolytic breakdown of the two major transmembrane proteins band 3 and glycophorin, which would otherwise occur during the Ca2+ loading of fresh human red cells. In addition, the inhibitor effectively blocked the formation of a cross-linked protein polymer in thrombin-activated human platelets.

Blood Platelets↗

The effect of inhaled bronchoconstrictors on transcutaneous gas tensions in normal adult subjects.

The administration of histamine and leukotriene D4 (LTD4) by nebulised aerosol in logarithmically increasing doses to normal subjects resulted in significant bronchoconstriction. Transcutaneous oxygen tension (tcPO2) was monitored during and after the bronchial challenge tests. Following histamine challenge there was significant hypoxaemia in all subjects (mean fall in tcPO2, 20 mmHg). However, following LTD4 administration, there was a small and insignificant fall in tcPO2. Transcutaneous carbon dioxide tension (tcPCO2) was also monitored throughout bronchial challenge, but showed no significant change. We suggest that the hypoxaemia following histamine challenge was due to increased ventilation/perfusion (V/Q) mismatching in the lung induced by histamine deposition.

Administration, Inhalation↗

The effect of an oral leukotriene antagonist L-649,923 on histamine and leukotriene D4-induced bronchoconstriction in normal man.

We have studied the effect of prior treatment with an oral leukotriene (LT) antagonist L-649,923, on histamine and LTD4-induced bronchoconstriction in 12 normal male subjects in a double-blind, placebo-controlled, randomized, crossover trial. L-649,923 had no effect on histamine-induced bronchoconstriction but antagonized LTD4-induced bronchoconstriction, causing a mean shift to the right of the dose-response curves of 3.8-fold. This study demonstrates that LT antagonism is possible and safe in man and that LTD4-inhalation challenge testing can be used to detect LT antagonism.

Adult↗