Search PubMed⌕ Search

Biomedical subjects

H Bryan

Publications and source records attributed to H Bryan.

At least 19 recordsLinked to original sources
PubMed2001

Long-pulsed Nd:YAG laser-assisted hair removal in pigmented skin: a clinical and histological evaluation.

OBJECTIVE: To determine the safety and effectiveness of a long-pulsed Nd:YAG laser at 1064 nm in effecting long-term hair reduction in patients with darkly pigmented skin. DESIGN: Nonrandomized before-after clinical and histological trial. SETTING: Private practice, ambulatory care facility. PATIENTS: Twenty women with skin phototypes IV through VI and dark brown to black terminal hair on the face, axillae, or legs. INTERVENTION: A series of 3 long-pulsed (50-millisecond) 1064-nm Nd:YAG laser treatments at fluences ranging from 40 to 50 J/cm(2) were delivered to the identified treatment areas on a monthly basis by a single operator. MAIN OUTCOME MEASURES: Global clinical grading scores of comparable before-after treatment photographs were determined by 2 independent medical assessors during each laser session and 1, 3, 6, and 12 months postoperatively. A dermatopathologist reviewed unmarked histological specimens obtained at baseline, immediately after the initial laser treatment, and at 1 and 6 months after the final laser session. RESULTS: Substantial hair reduction was seen after each of the 3 treatment sessions. Prolonged hair loss was observed 12 months after the final laser treatment (70%-90% hair reduction). Axillary hair was substantially more responsive to laser irradiation than was hair located on the legs and face. Adverse effects included mild to moderate treatment pain and rare occurrences of vesiculation and transient pigmentary alteration without fibrosis or scarring. Histological tissue changes mirrored clinical response rates, with evidence of selective follicular injury without epidermal disruption. CONCLUSION: The long-pulsed 1064-nm Nd:YAG laser is a safe and effective method of long-term hair reduction in patients with darkly pigmented skin.

Adult↗
PubMed1993

Compliance of the respiratory system in newborn infants pre- and postsurfactant replacement therapy.

Surfactant administration causes a rapid and dramatic improvement in gas exchange, but paradoxically, studies have failed to show an improvement in the mechanical properties of the lung. We have measured dynamic and static (passive flow-volume technique) compliance before and after a single dose of bovine lipid extract surfactant in 22 premature infants with RDS. This had no effect on the measured dynamic compliance. In contrast, surfactant significantly increased static compliance from 0.41 +/- 0.02 to 0.55 +/- 0.04 mL/cm H2O/kg. This improvement was the result of a substantial recruitment of lung volume after surfactant administration. This led us to reduce ventilator pressures, which produced an increase in both dynamic and static compliance, but did not recruit additional volume. We conclude that surfactant causes a substantial increase in static compliance due to volume recruitment, which is consistent with reports of increase in the measured FRC. However, despite this improvement, the compliance is still below our normal range.

Female↗
PubMed1992

The selective endothelin ETA receptor antagonist BQ123 antagonizes endothelin-1-mediated mitogenesis.

The mitogenic effects of endothelin isopeptides and the selective ETA receptor antagonist BQ123 were evaluated in rat aortic vascular smooth muscle cells. Endothelin-1 (ET-1) and endothelin-3 (ET-3) produced concentration-dependent increases in [3H]thymidine incorporation (EC50 = 0.1 and 25 nM, respectively). The ETB-selective agonist sarafotoxin 6c did not produce significant effects on [3H]thymidine incorporation. BQ123 produced selective and concentration-dependent inhibition of ET-1-mediated [3H]thymidine incorporation. These data demonstrate that ET-1-mediated mitogenesis in vascular smooth muscle is mediated by ETA receptors.

Animals↗
PubMed1992

Identification of endothelin receptor subtypes in rat kidney cortex using subtype-selective ligands.

125I-Endothelin (ET)-1 and 125I-ET-3 displayed specific, saturable, and high affinity binding to membranes prepared from rat kidney cortex. Saturation binding experiments using 125I-ET-1 and 125I-ET-3 revealed that 125I-ET-3 binding sites were 40-50% less abundant than 125I-ET-1 binding sites. The dissociation constants (Kd) and maximum binding (Bmax) for 125I-ET-1 and 125I-ET-3 with these membranes were 218 +/- 23 pM and 275 +/- 20 fmol/mg of protein and 207 +/- 19 pM and 113 +/- 17 fmol/mg of protein, respectively. In the presence of 10 nM sarafotoxin 6c, a selective agonist for ETb receptors, 125I-ET-1 binding was decreased by 45-50% and 125I-ET-3 binding was totally abolished, suggesting that approximately 40-50% of kidney cortex ET receptors are of the ETB subtype and that 125I-ET-1 binds to both ETA and ETB receptors with the same high affinity, whereas 125I-ET-3 binds to only ETB receptors with high affinity. In addition, in the presence of BQ123 [cyclo(D-Trp,D-Asp,L-Pro,D-Val,L-Leu)], a selective antagonist for ETA receptors, 125I-ET-1 binding was decreased by 50%, whereas 125I-ET-3 binding was unaffected. Our results strongly suggest that rat kidney cortex contains ETA and ETB receptors in a 50:50 ratio and that sarafotoxin 6c and BQ123 are valuable tools in identifying the subtypes of ET receptors in various tissues.

Amino Acid Sequence↗
PubMed1990

Perinatal factors associated with the respiratory distress syndrome.

Perinatal factors related to the incidence of respiratory distress syndrome were analyzed by the multiple logistic regression statistical method in 263 mothers and their 298 offspring delivered between 24 and 35 weeks' gestation in a 1-year period in a regional referral perinatal center. The risk of respiratory distress syndrome in white infants rose with decreasing gestational age (p less than 0.0001) while prolonged rupture of membranes of greater than 24 hours in the absence of maternal infection (28% of cases) was highly protective (p less than 0.0001). Compared with vaginal delivery, cesarean delivery without labor increased the risk of respiratory distress syndrome (p = 0.03). The administration of tocolytic drugs was unrelated to the incidence of respiratory distress syndrome, but corticosteroid therapy given at least 72 hours before delivery was protective (p = 0.03). Male and female infants were equally at risk for respiratory distress syndrome as were black and white infants, but other races had a lower incidence (p = 0.004). Infants with respiratory distress syndrome were on mechanical ventilators longer than those with other respiratory illnesses.

Adrenal Cortex Hormones↗
PubMed1987

Lecithin/sphingomyelin ratios in tracheal aspirates from newborn infants.

A sensitive and rapid high-performance liquid chromatography method for determining lecithin/sphingomyelin (L/S) ratios in small volume tracheal aspirates has been evaluated in 115 infants sampled within 3 h of delivery. Respiratory distress syndrome was present in 41 infants and all had L/S ratios of less than or equal to 15 (sensitivity 100%). Respiratory distress syndrome was absent in 74 infants, 67 of whom had L/S ratios of greater than 15 (specificity 91%). Serial tracheal aspirates (n = 68) in 27 infants showed little change in nine respiratory distress syndrome infants with L/S ratio less than or equal to 15 over 3 h while 18 nonrespiratory distress syndrome infants with L/S greater than 15 were more variable. In two infants initial immature ratios rose to maturity rapidly after birth. Comparison of amniotic fluid L/S ratios obtained within 2 h of delivery correlated with the corresponding tracheal aspirate L/S in 24 infants (r = 0.81, p less than 0.001) although the latter were three times higher. This method may have potential routine application in the assessment of surfactant replacement and mechanical ventilator therapies.

Amniotic Fluid↗
PubMed1985

Validation of a simple rapid high performance liquid chromatographic method for amniotic fluid lecithin/sphingomyelin ratios.

A simple, rapid and sensitive HPLC method for the determination of L/S ratios in amniotic fluids is described. The method is based on isocratic separation in the normal phase with UV detection. The procedure has good precision and was validated clinically and by comparison with a routine TLC method. Although L/S ratios differed from those obtained by TLC, the clinical correlation between these methods was good. In single and serial samples from 39 mothers (42 babies) the HPLC method predicted respiratory distress syndrome (RDS) in all 9 babies with L/S ratios less than 7. No babies with ratios above 7 developed RDS. This method has potential clinical usefulness for the assessment of fetal lung maturity.

Amniotic Fluid↗
PubMed1984

Coronary risk factors and exercise test performance in asymptomatic hypercholesterolemic men: application of proportional hazards analysis.

The association of established coronary risk factors with submaximal graded treadmill exercise test performance was examined in 6,850 asymptomatic, white 34--59-year-old hypercholesterolemic men screened between 1973 and 1976 at 12 North American Lipid Research Clinics for participation in their Coronary Primary Prevention Trial. The prevalence of ischemic electrocardiographic responses (greater than or equal to 1 mm S-T segment depression) was 8.6%. The Cox proportional hazards method was adapted so as to take into account the level of exercise at which ischemic responses occurred and to which subjects without ischemic responses were exposed. The results were compared with those obtained by standard logistic regression. In both models, age, blood pressure, plasma cholesterol, and (inversely) plasma high-density lipoprotein cholesterol and alcohol consumption were significant independent predictors of an ischemic response to exercise. Surprisingly, ischemic responses were less frequent in smokers than in nonsmokers. However, when the proportional hazards method was used, cigarette smoking was weakly but significantly (p less than 0.01) predictive of an ischemic response on the treadmill. Results from this model differed from those of the logistic model because the former takes into account the reduced exercise capacity of smokers, which renders them less likely to reach workloads sufficient to induce myocardial ischemia. The proportional hazards model similarly demonstrated a possible beneficial effect of habitual physical activity which was not apparent in the logistic model. Quetelet index and plasma triglyceride were only weakly associated with the probability of an ischemic response, and did not contribute significantly to either model.

Adult↗
PubMed1983

Effects of a face mask and pneumotachograph on breathing in sleeping infants.

The effect of facial attachments on breathing was measured by respiratory induction plethysmography (RIP) during quiet sleep in 32 studies in 18 infants. The addition of a face mask plus pneumotachograph led to an increase in tidal volume (VT) (22.0 +/- 13.5%, p less than 0.01) during 5-min sleep studies when compared to measurements using RIP alone. Applying only the mask rim also led to an increase in VT (14.6 +/- 3.1%, p less than 0.05). A significant increase in VT was noted in 3 of 6 infants studied when a lightweight cardboard ring was in place perinasally. Respiratory frequency fell significantly in the mask/pneumotachograph group (-5.9 +/- 10.0%, p less than 0.05) and with the mask rim (-7.4 +/- 8.8%, p less than 0.01), but there was individual infant variation. Minute ventilation rose significantly (19.1 +/- 16.9%, p less than 0.01) only with the addition of the mask and pneumotachograph. Instrument deadspace can account for some of the increase in VT noted, but in its absence, sensory stimulation of the trigeminal area can augment tidal breathing.

Humans↗
PubMed1979

Postnatal lung growth after repair of diaphragmatic hernia.

The lungs of two patients who died eight months and 64 months after repair of a left-sided diaphragmatic hernia on the first day of life were examined. Lung volumes were appropriate for the size of the children, and the ratio of right lung volume to left lung volume was also normal in both patients. The lungs, however, were grossly abnormal with evidence of enlargement and destruction of respiratory tissue. The left lung was affected more than the right in both subjects. In one patient the total number of alveoli in the lungs was similar to that of normal children of the same age, but this was because the right lung had more than twice as many alveoli as the left lung. It appears that alveolar multiplication is impaired after repair of diaphragmatic hernia. The number of bronchioles was reduced in the infant with very few alveoli, and there may have been too few bronchioles in the other patient.

Child, Preschool↗
PubMed1978

Cis-diamminedichloroplatinum (NSC-119875) in childhood malignancies: a Southwest Oncology Group study.

Children with malignancies resistant to conventional therapy were treated with cis-diamminedichloroplatinum (PDD), 15 to 20 mg/m2, given daily by rapid intravenous infusion for 5 days at 3-wk intervals. Eleven of 24 children with acute lymphocytic leukemia (ALL) received two or more courses; among these no remissions occurred. Fifty-four children with solid tumors were treated: 25 neuroblastoma, 9 rhabdomyosarcoma, 4 Ewing sarcoma, 2 testicular embryonal carcinoma, 2 retinoblastoma, and 12 miscellaneous tumors. One complete remission, 3 partial remissions, and 2 improvements were observed in children with neuroblastoma. One girl with metastatic osteogenic sarcoma achieved a partial remission. One child with metastatic testicular embryonal carcinoma showed improvement. The side effects were vomiting controlled by antiemetics in 26 children and transient elevations of serum creatinine and BUN in 14 children. Nineteen of 39 children with solid tumors, who received more than one course of PDD, had moderately severe myelosuppression caused by PDD. In summary, PDD is a promising agent in neuroblastoma, osteogenic sarcoma, and testicular embryonal carcinoma, and an ineffective agent in ALL. The effect of PDD on other types of solid tumors should be evaluated in the future.

Adolescent↗
PubMed1977

Dose-response relationships between amino acid intake and blood levels in newborn infants.

The objective of the present investigation was to investigate the nature of the blood amino acid response with amino acid intake in newborn infants. Forty-nine newborn infants of 640 to 4020 g birth weight and 26 to 40 weeks gestational age were placed on one of the following regimes within 48 hr of birth: intravenous dextrose with intravenous feeding of three levels of crystalline amino acid mixture, or of one level of casein hydrolysate, or with oral feeding of two levels of milk formula. Blood amino acid levels at 132 hr after feeding of graded levels of the intravenous amino acid solution were evaluated by regression analyses and compared to blood levels when casein hydrolysate was fed intravenously or milk formula was fed orally. At low levels of amino acid intake, such as were achieved with formula feeding, blood levels were relatively unchanged. However, with higher intakes, as were obtained with intravenous feedings, blood levels increased at rates which could be defined for each amino acid. This observation suggests that if the composition and rate of delivery of an amino acid solution is known, blood levels may be predicted.

Age Factors↗
PubMed1976

Mutilating lawn mower injuries in children.

Serious injuries from riding power mowers were sustained by 18 children. Eleven children were passangers on the mower and fell into its path. The injuries required an extensive number of hospitalizations and reconstructive procedures. Fifteen patients suffered considerable residual deformities. Operating riding power mowers in the vicinity of children must be actively discouraged.

Accidents, Home↗