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Biomedical subjects

P Stone

Publications and source records attributed to P Stone.

At least 19 recordsLinked to original sources
PubMed1996

Elastase release of basic fibroblast growth factor in pulmonary fibroblast cultures results in down-regulation of elastin gene transcription. A role for basic fibroblast growth factor in regulating lung repair.

We have reported previously that a factor released by elastase treatment of pulmonary fibroblast cultures is capable of down-regulating elastin gene expression. In the present study we have pursued the identification of the factor released by elastase treatment and the characterization of the level of elastin gene expression at which this factor exerts its effect. We have found by immunologic and biochemical procedures that elastase treatment results in the release of basic fibroblast growth factor (bFGF) that is bound within the matrix. Both purified bFGF and bFGF released by elastase from cell matrices decrease the transcriptional level of the elastin gene by 70-80% within 24 h. Transient transfections of pulmonary fibroblasts with a series of elastin promoter deletion constructs show that the region of the elastin gene responsive to bFGF is located within sequences spanning -900 to -200 base pairs. The biological implications of these findings coupled with our previous report are significant, since they demonstrate that elastase digestion of pulmonary fibroblast matrices not only results in the proteolysis of elastin but also results in the release of a potent regulator of elastin gene transcription whose activity can influence repair mechanisms.

Animals↗
PubMed1995

The incidence of hyperemesis gravidarum is increased among Pacific Islanders living in Wellington.

AIMS: To compare the incidence of hyperemesis gravidarum among Pacific Islanders living in Wellington with nonPacific Islanders and to investigate some properties of the disorder. METHODS: Data were collected on all first time admissions to Wellington Women's Hospital for hyperemesis gravidarum over a 5-year period. Women were classified as having severe hyperemesis gravidarum if abnormalities of serum electrolytes and liver function tests results were present and as less severe if these abnormalities were absent. Almost all women had ketonuria. Mantel-Haenszel odds ratios, chi 2 analysis and Fisher's 2-tailed exact test were used for statistical analysis. RESULTS: The proportion of hyperemesis gravidarum patients who were Pacific Islanders was significantly increased when compared to their proportion in a control group (p < 0.01). The difference remained significant when the hyperemesis patients were divided into less and more severe. Abnormal thyroid function test results were more common among Pacific Island patients than among nonPacific Island patients. This difference was significant (p < 0.01) only in the less severe group. CONCLUSION: The incidence of hyperemesis gravidarum is significantly increased among Pacific Island women (especially Samoans) living in Wellington and is often associated with abnormalities of thyroid function test results.

Female↗
PubMed1995

Measurements of blood pressure, oedema and proteinuria in a pregnant population of New Zealand.

This is the first report of the largest study of blood pressure measurement in pregnancy in a New Zealand population using standardized definitions and methodology. Over 3,800 women who delivered in an 8-month period in the Wellington region were included in the study. Blood pressure measurement and the presence of oedema and proteinuria were recorded from booking until delivery and in the puerperium. Only 2.7% of women were unable to be contacted after delivery for details on outcomes. The results established normal ranges for blood pressure throughout pregnancy. The data show that blood pressure greater than 140/90 until 35 weeks' gestation is outside 2 standard deviations at all gestations and justifies using these measurements as the definition of hypertension in pregnancy. The fall in blood pressure in the 2nd trimester was less than 1 mm Hg per week in both the systolic and diastolic pressures. This fall was smaller than previously recorded in other studies. Gestational hypertension was the commonest blood pressure abnormality occurring in 15.2% of the population. This represented 69% of the pregnant women with a hypertensive disorder. The overall incidence of both gestational hypertension and preeclampsia was 18.5% which is higher than reported in other parts of the world. In this study obesity was significantly associated with hypertensive disorders in pregnancy. An arm circumference of > 33 cm, one of the measurements of obesity, was found in 6.8% of the study population. Even after the effect of arm circumference was taken into account, hypertensive disorders were also more common in Pacific Island women.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1995

Breath-holding time in normal subjects, snorers, and sleep apnea patients.

BACKGROUND: The onset of irregular inspiratory muscle activity has been observed toward the breakpoint of the breath-holding maneuver. We wondered if this was similar to the increased respiratory effort with paradoxical breathing seen during the resolution of an apnea in obstructive sleep apnea syndrome (OSAS). STUDY OBJECTIVE: To compare the breakpoint of breath holding in normal subjects, OSAS patients, and snorers. METHODS: Thirty normal subjects, 30 patients with OSAS, and 16 snorers performed serial breath-holding maneuvers at functional residual capacity (FRC) under standardized pretest conditions using the rebreathing method of Read. RESULTS: Intergroup comparisons were carried out by analysis of variance with post hoc Tukey's Highest Significant Difference tests. Basal end-tidal carbon dioxide (EtCO2) was significantly higher in OSAS than in normal subjects and snorers. Basal breath-holding time (BHT) was shorter in OSAS as compared with that in normal subjects and snorers (p < 0.05). The maximal EtCO2 level attained was higher in OSAS as compared with normal subjects (p < 0.05) and snorers (p = 0.052). The maximal BHT in OSAS was shorter than in normal subjects (p < 0.05) but not in snorers. The slope of BHT/EtCO2 differed significantly in OSAS compared with normal subjects and snorers (p < 0.05). No significant correlation was found between slope BHT/EtCO2 and age or body mass index using multiple regression analysis. The FRC of OSAS patients and snorers were similar (p = 0.792). CONCLUSION: We conclude that BHT and slope of BHT/EtCO2 are different in OSAS subjects as opposed to those in normal subjects and snorers.

Carbon Dioxide↗
PubMed1994

A cost-utility analysis of intensive therapy. II: Quality of life in survivors.

A questionnaire designed to assess changes in quality of life was sent to 56 survivors of critical illness one year after their admission to an intensive therapy unit. Forty-one patients completed the questionnaire, and for the majority, quality of life remained unchanged (n = 25). However significant decreases in quality of life were found in those patients who previously enjoyed a good quality of life or were admitted with respiratory problems. Survivors also recorded significant decreases in five aspects of their perceived quality of life (ability to think and remember, seeing family, their contribution to society, activities outside work and income). As part of a previous study, the costs incurred by each of these patients had been measured so that changes in quality of life detected in this study could be combined to the individual costs and expressed as cost per quality adjusted life year. The cost of intensive therapy for a patient surviving for one year after acute respiratory or cardiovascular disease was 2600 pounds. The total hospital cost per quality adjusted life year was estimated at 7500 pounds, which places intensive therapy at the higher end of health programme costs. If the costs of nonsurvivors are included in the cost per quality adjusted life year calculation, the cost of intensive care increases considerably.

Adult↗
PubMed1994

Nasal resistance in obstructive sleep apnea.

BACKGROUND: Acute increases in nasal resistance are known to induce upper airway occlusion in predisposed subjects. With the limited efficacy of nasal surgery alone in the treatment of obstructive sleep apnea (OSA), the relevance of chronically increased nasal resistance in the pathophysiologic features of OSA remains undetermined. METHODS: Seventy-one patients with OSA (apnea+hypopnea index > 15 [AHI]) and 70 antisocial snorers (ASS [AHI < 15]) referred for routine assessment of sleep-disordered breathing had concomitant measurement of combined (CNR) and highest unilateral (HUNR) nasal resistance by anterior rhinomanometry. RESULTS: Nine individuals (five of 71 in the OSA group and 4 of 70 in the ASS group, 0.5 < p < 0.75) had an abnormally elevated CNR. The HUNR was increased in 21 individuals (11 of 70 in the ASS group and 10 of 71 in the OSA group, 0.25 < p < 0.5). There was no significant difference between CNR in OSA (1.5[0.5]) (mean [SE]) and ASS (1.6 [0.2]) groups. No correlation was found between CNR and the AHI in OSA or in ASS. The Mean HUNR in the OSA group was 5.5 (0.9) (mean [SE]) and in ASS was 5.3(0.6), which were not significantly different (p = 0.89). The HUNR also did not correlate with the AHI in either OSA or ASS. CONCLUSION: Chronic changes in nasal resistance are not a significant risk factor for the development or severity of OSA.

Airway Resistance↗
PubMed1993

Factors associated with social and behavioral problems among children recently diagnosed with brain tumor.

Compared the psychological adjustment of 81 children with brain tumors to that of 31 control children with various malignancies not involving the central nervous system. Both groups exhibited significantly increased frequencies of elevations on one or more age- and gender-corrected Social Competence and Behavior Problems scales of the Child Behavior Checklist (CBCL) relative to normative expectations. Comparison of the Brain Tumor and Cancer Control groups revealed no significant differences on any CBCL scale. Among children diagnosed with brain tumors, stepwise multiple regression analyses revealed that low child IQ, residence in a single-parent family, moderate to severe disfigurement, low SES, tumor location, and severe functional impairment were associated with decreased Social Competence scores. Elevated Behavior Problems scores were associated with younger maternal age at the child's birth, tumor location, and residence in a single-parent family. Results reinforce the need to consider complex relationships between demographic characteristics of the child's family, type of brain damage, and the cosmetic and functional status of the child in determining acute psychological adjustment of brain-damaged children.

Adaptation, Psychological↗
PubMed1993

A cost-benefit analysis of intensive therapy.

The daily costs of 90 critically ill patients treated on an intensive therapy unit were calculated on an individual patient basis. Twenty-one patients (23%) died on the intensive therapy unit and another 13 (15%) died within one year of discharge. The results demonstrate that there is wide variation in costs among the patients and the diagnoses. The mean daily cost of nonsurvivors was almost 300 pounds greater than that of survivors (816 pounds (95% confidence interval = 649-982 pounds) versus 550 pounds (498-601 pounds). Renal failure, sepsis and pneumonia proved to be some of the most expensive conditions to treat, and postoperative respiratory failure the cheapest. The cost of the first day of management was significantly related to the APACHE II score and individual costs on the first day may be predicted from admission APACHE II score. Patients who die in the intensive therapy unit continue to incur the same level of expenditure throughout admission. The study could not provide conclusive answers concerning the trend in daily costs for survivors.

Adult↗