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Biomedical subjects

T Stern

Publications and source records attributed to T Stern.

17 recordsLinked to original sources
PubMed2002

Design and characterization of protein-based microcapsules as a novel catamenial absorbent system.

Hollow and flexible crosslinked microcapsules of soybean protein, 150-300 microm in diameter, were produced using a modified solvent evaporation method. A maximum plasma absorption of approximately 2000% was obtained. At this swelling rate though, microcapsules bursting was initiated. Thus, the effective absorption capacity may not exceed 1700%. The observed presence of residual unreacted protein inside the microcapsules, was believed to be the main osmotic driving force, to which the extensive swelling and eventual bursting of the microcapsules may be attributed. Thermal analysis of the microcapsules revealed their amorphous nature, as opposed to the significantly crystalline nature of the original protein.

Absorption↗
PubMed2001

Effects of atorvastatin on early recurrent ischemic events in acute coronary syndromes: the MIRACL study: a randomized controlled trial.

CONTEXT: Patients experience the highest rate of death and recurrent ischemic events during the early period after an acute coronary syndrome, but it is not known whether early initiation of treatment with a statin can reduce the occurrence of these early events. OBJECTIVE: To determine whether treatment with atorvastatin, 80 mg/d, initiated 24 to 96 hours after an acute coronary syndrome, reduces death and nonfatal ischemic events. DESIGN AND SETTING: A randomized, double-blind trial conducted from May 1997 to September 1999, with follow-up through 16 weeks at 122 clinical centers in Europe, North America, South Africa, and Australasia. PATIENTS: A total of 3086 adults aged 18 years or older with unstable angina or non-Q-wave acute myocardial infarction. INTERVENTIONS: Patients were stratified by center and randomly assigned to receive treatment with atorvastatin (80 mg/d) or matching placebo between 24 and 96 hours after hospital admission. MAIN OUTCOME MEASURES: Primary end point event defined as death, nonfatal acute myocardial infarction, cardiac arrest with resuscitation, or recurrent symptomatic myocardial ischemia with objective evidence and requiring emergency rehospitalization. RESULTS: A primary end point event occurred in 228 patients (14.8%) in the atorvastatin group and 269 patients (17.4%) in the placebo group (relative risk [RR], 0.84; 95% confidence interval [CI], 0.70-1.00; P =.048). There were no significant differences in risk of death, nonfatal myocardial infarction, or cardiac arrest between the atorvastatin group and the placebo group, although the atorvastatin group had a lower risk of symptomatic ischemia with objective evidence and requiring emergency rehospitalization (6.2% vs 8.4%; RR, 0.74; 95% CI, 0.57-0.95; P =.02). Likewise, there were no significant differences between the atorvastatin group and the placebo group in the incidence of secondary outcomes of coronary revascularization procedures, worsening heart failure, or worsening angina, although there were fewer strokes in the atorvastatin group than in the placebo group (12 vs 24 events; P =.045). In the atorvastatin group, mean low-density lipoprotein cholesterol level declined from 124 mg/dL (3.2 mmol/L) to 72 mg/dL (1.9 mmol/L). Abnormal liver transaminases (>3 times upper limit of normal) were more common in the atorvastatin group than in the placebo group (2.5% vs 0.6%; P<.001). CONCLUSION: For patients with acute coronary syndrome, lipid-lowering therapy with atorvastatin, 80 mg/d, reduces recurrent ischemic events in the first 16 weeks, mostly recurrent symptomatic ischemia requiring rehospitalization.

Aged↗
PubMed2001

Novel synthetic selectively degradable vascular prostheses: a preliminary implantation study.

BACKGROUND: Vascular grafts perform less well than autologous arterial or vein grafts. The purpose of this study was to evaluate the short-term performance of selectively biodegradable filament-wound vascular prostheses, comprising elastomeric poly(ether urethane) (Lycra) scaffolds and flexible, hydrophilic biodegradable coatings. MATERIALS AND METHODS: Two types of selectively biodegradable vascular grafts were manufactured, comprising a filament-wound Lycra scaffold, subsequently coated with a biodegradable poly(ethylene glycol)/poly(lactic acid) (PELA) block copolymer. The two types of grafts differed in both the overall porosity of the scaffold and the hydrophilicity of the biodegradable constituent. A 60-mm-long and 6-mm-diameter filament-wound and polytetrafluoroethylene (ePTFE) grafts were implanted as interposition prostheses, randomly, at the right- and left-side carotid arteries. RESULTS: Implantation studies proved the grafts to be patent and pulsatile for periods of up to 3 months. Increasing the scaffold porosity and enhancing the hydrophilicity of the biodegradable component improved both the transmural tissue ingrowth process and the vascularization of the prosthesis wall. Also, a well-adhered peripheral tissue and a thin, uniform intima and endothelial lining were obtained. All ePTFE graft controls, although patent, were rather stiff and nonpulsatile. A thick pseudointima, poorly attached to the prosthesis inner surface, was observed. The compliance of the wet grafts was significantly higher than in the dry state, stemming mainly from the water-plasticizing effect on the biodegradable component. The grafts explanted after a period of 6 weeks exhibited compliance only slightly lower than that of the wet grafts. After 12 weeks, however, the hoop compliance was 20% lower than that prior to implantation. At 100 mm Hg, for example, the original compliance of the wet graft was 2.5%/100 mm Hg decreasing to 2.0%/100 mm Hg after a 3-month implantation. The compliance reduction with implantation is attributed to the ingrowth of the perigraft tissue as revealed by the histological study. A compliance of 2.0%/100 mm Hg is slightly better than that of a standard PTFE graft with an original compliance of 1.6%/100 mm Hg. Yet it is still an order of magnitude smaller than that of a canine carotid artery. CONCLUSIONS: The improved mechanical properties and enhanced healing of the highly porous filament-wound Lycra scaffold graft coated with hydrophilic biodegradable PELA has the potential of being a highly effective small caliber prosthetic graft.

Absorbable Implants↗
PubMed2000

Impact of race and gestational age on red blood cell indices in very low birth weight infants.

BACKGROUND: Normative data for hematologic values in the very low birth weight infants are limited and inconsistent, with the reported mean hematocrit (HCT) in these infants ranging from 43.5% to 60%. No data are available on the effect of race. OBJECTIVES: To establish normative data for hemoglobin (Hb) and HCT by arterial sampling obtained during the first 3 hours after birth in black and white premature infants </=31 weeks of gestation. METHODS: Retrospective chart review of all infants </= 31 weeks of gestation born between June 1994 and October 1998. INCLUSION CRITERIA: infant </=31 weeks of gestation who had an arterial blood sample obtained in the first 3 hours after birth. EXCLUSION CRITERIA: infants were excluded if they had any medical condition that may affect the red blood cell indices (eg, twin-to-twin transfusion or fetomaternal hemorrhage). RESULTS: Of 428 infants, 188 who met both inclusion and exclusion criteria were classified into 3 gestational age groups: group 1 = 23 to 25 weeks of gestation (n = 40); group 2 = 26 to 28 weeks (n = 60); and group 3 = 29 to 31 weeks (n = 88). There were statistically significant differences between groups 1 and 3 in HCT, Hb, mean corpuscular Hb (MCH), and mean corpuscular volume (MCV). No differences in HCT and Hb values were noted in relation to sex, mode of delivery, multiple gestation, antenatal steroids, or maternal smoking. In group 3, the mean Hb, HCT, and MCV values were higher in white infants than in black infants (16.7 +/- 1.6 g/dL vs 15.4 +/- 1. 7 g/dL; 50.0 +/- 5.0 vs 45.5 +/- 4.6; and 112 +/- 5 fL vs 107 +/- 8 fL, respectively). CONCLUSIONS: Hb, HCT, and MCH values are described for premature infants </=31 weeks of gestation born in North America. Hb and HCT increased, whereas MCV decreased with gestational age. Hb, HCT, and MCV values are statistically higher in white infants than in black infants.

Black People↗
PubMed1999

Continuous deformation versus faulting through the continental lithosphere of new zealand

Seismic anisotropy and P-wave delays in New Zealand imply widespread deformation in the underlying mantle, not slip on a narrow fault zone, which is characteristic of plate boundaries in oceanic regions. Large magnitudes of shear-wave splitting and orientations of fast polarization parallel to the Alpine fault show that pervasive simple shear of the mantle lithosphere has accommodated the cumulative strike-slip plate motion. Variations in P-wave residuals across the Southern Alps rule out underthrusting of one slab of mantle lithosphere beneath another but permit continuous deformation of lithosphere shortened by about 100 kilometers since 6 to 7 million years ago.

Journal Article↗
PubMed1999

Anxiety in patients with pulmonary disease: comorbidity and treatment.

Anxiety is a common and sometimes disabling symptom among patients with respiratory disease. Anxiety disorders appear to be the most prevalent psychiatric disorders in clinical samples of patients with pulmonary disease. Recognition that the differential diagnosis of dyspnea and anxiety includes both pulmonary and psychiatric conditions can be crucial to appropriate medical management and minimizing iatrogenic harm. This article reviews the epidemiology, comorbidity, diagnosis, and treatment of anxiety syndromes in patients with pulmonary disease. Successful treatment of anxiety disorders can substantially improve quality of life and a variety of treatment options are available. Safe and effective pharmacotherapy requires attention to potential adverse drug effects on pulmonary function and drug-to-drug interactions. Nonpharmacological treatments such as cognitive/behavioral therapies offer effective treatment without the risk of medication side effects.

Antidepressive Agents↗
PubMed1997

[Typical sports injuries, sports specific risks and comparison with other sources of accidents].

In the discussion of limiting the growth of medical spending there are intentions to exclude the costs of sport injuries from coverage by the public health insurance system. The aim of this study is to analyse typical sport injuries and to compare them with injuries from other fields of accidents and thus to deliver arguments in the discussion of costs in public health system.

Athletic Injuries↗
PubMed1995

Derivatization of a new poly(ether urethane amide) containing chemically active sites.

A novel poly(ether urethane amide) was synthesized by chain-extending the prepolymer with fumaric acid, resulting in a polymer exhibiting superior mechanical properties and containing chemically active derivatization sites, stemming from the fumaramide double bond. The derivatization of the active sites was performed via a Michael-like addition of amine-terminated poly(ethylene oxide) chains, which when performed in bulk, greatly affected the mechanical properties of the polymer, except in the case in which a relatively high molecular weight was grafted. Surface grafting of the polymer led to a significantly lower effect on its mechanical properties, which was minimal when a high molecular weight molecule was used.

Absorption↗
PubMed1982

The pubococcygens and female orgasm: a correlational study with normal subjects.

The relationship of pubococcygeal condition to orgasmic responsiveness in 102 women from a university community was examined in a controlled, prospective investigation. Pubococcygeal strength was measured with a perineometer while responsiveness was assessed by a standardized interview yielding reliable measures of self-reported orgasmic response. Subjects whose responsiveness might have been impaired by such factors as alcohol consumption, inadequate stimulation, and high sexual anxiety were excluded from analyses. Excellent within-session but poor across-session test-retest reliability of the perineometer measures was noted. Initial Strength Contracting proved to be the most reliable measure. Though the majority of the parous women had performed Kegel exercises after delivery, parity was negatively related to pubococcygeal strength on most measures. Contrary to experimental hypotheses, pubococcygeal strength was not found to be positively related to frequency or self-reported intensity of orgasm. Furthermore, women with higher pubococcygeal strength did not report that vaginal stimulation contributed more to attainment of orgasm, nor did they rate vaginal sensations during coitus as more pleasurable. Only in the case of pleasurability of orgasm through clitoral stimulation was a significant, though low, relationship obtained. Possible factors contributing to the discrepancy between these findings and previous uncontrolled investigations are discussed, as are the implications of these findings for the use of Kegel exercises in the treatment of orgasmic dysfunction.

Adult↗
PubMedDate not supplied

[Clinical pedographic radiological findings after basal valgus osteotomy of metatarsal 1--a prospective study].

AIM: This study investigated the influence of valgusizing base wedge osteotomy of metatarsal 1 (MT 1) subsequently on the entire forefoot. METHOD: Pre- and post-operatively 22 cases were investigated between 1998 and 2000 both clinically and radiologically with pedographic analysis in 20 of these cases. RESULTS: According to the Kitaoka Score we could establish preoperative 37 and postoperative 72 out of 100 possible points. Following the MT 1-base wedge osteotomy with a distal soft-tissue procedure, the central forefoot region (MT 2/3) showed reduced pressure-induced pain, unchanged callus development, and reduced maximum load pressure. When the Plus-Index (MT 1 longer than MT 2) could be preserved in the valugusizing MT 1-base wege osteotomy, the metatarsalgia in the central forefoot region not only improved generally, but also the maximum loading pressure was clearly reduced. In cases with a post-operative Minus-Index (MT 1 shorter than MT 2), as well as in those Plus-Index cases undergoing a Keller procedure in the valgusizing base wedge osteotomy, the elevated pressure values in the central forefoot region persisted. CONCLUSION: In valgusizing MT 1-base wege osteotomy with preservation of the Plus-Index (MT 1 longer MT 2), metatarsalgia can be improved and the maximum loading pressure in the central forefoot can be reduced.

Adult↗