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Biomedical subjects

G Fink

Publications and source records attributed to G Fink.

At least 19 recordsLinked to original sources
PubMed2005

Polymerization of w/o microemulsions for the preparation of transparent SiO2/PMMA nanocomposites.

Reverse w/o microemulsions composed of methyl methacrylate (MMA) forming the oil phase, nonionic surfactants, and water are used for the synthesis of transparent SiO2/PMMA nanocomposites. An inorganic precursor, tetraethoxysilane (Si(OEt)(4), TEOS), is hydrolyzed in the reverse micelles containing aqueous ammonia. During the hydrolysis of TEOS, polymerization of the continuous MMA phase is initiated using AIBN (azobisisobutyronitrile), and after thermal polymerization at 333 K for 12 h, solid blocks of PMMA are obtained in which nanometer-sized silica particles are trapped in the solid polymer matrix. According to small-angle X-ray and dynamic light scattering experiments, the water droplets in MMA microemulsions are 12 nm (R(W) = 13) in diameter, whereas after polymerization of the microemulsion, the SiO2 particles in the transparent SiO2/PMMA composites are 26 nm in diameter. Transmission electron micrographs demonstrate a low degree of agglomeration in the composites. In comparison with materials generated from micelle-free solutions, the particle size distribution is narrow. The reverse micelle-mediated approach produces composites of high transparency comparable with that of pure PMMA.

Journal Article↗
PubMed2005

[Apraxias].

Apraxias are deficits in higher motor behaviour that are not primarily caused by elementary deficits of the sensorimotor system, communication problems, or dementia. These patients present with deficits such as imitating meaningful or meaningless gestures and in dexterity or purposeful use of objects. The different forms of apraxia originate from lesions of different levels/structures of the motor system, reflecting its complexity. Apraxias are caused by deficits in motor programmes generated in the frontal motor areas, in modality-specific higher sensorimotor control, or at the highest level of motor planning and motor conception. The types of apraxia differentially affect activities of daily living and hence show marked differences in the prognosis of recovery and the physiotherapeutic treatment required. Therefore, appropriate diagnosis and treatment of the different forms are of foremost clinical importance.

Apraxias↗
PubMed2005

Implementing SPAM into STMAS: a net sensitivity improvement in high-resolution NMR of quadrupolar nuclei.

Gan and Kwak recently introduced two new tools for high-resolution 2D NMR methods applied to quadrupolar nuclei: double-quantum filtering in STMAS (DQF-STMAS) and the soft-pulse added mixing (SPAM) idea. Double-quantum filtering suppresses all undesired signals in the STMAS method with limited loss in sensitivity. With SPAM, all pathways are added constructively after the second hard-pulse instead of using a single pathway as previously. Here, the sensitivity, advantages and drawbacks of DQF-STMAS are compared to 3QMAS. Additionally, SPAM can be included into DQF-STMAS method, resulting in a net sensitivity gain with respect to 3QMAS of ca. 10-15.

Journal Article↗
PubMed2003

Hyperuricemia as a prognostic factor in pulmonary arterial hypertension.

Pulmonary arterial hypertension is a malignant disease with a median survival of 3 years. Uric acid levels are elevated in severe heart failure and in states of hypoxemia. Early data suggest a correlation between hyperuricemia and severe pulmonary arterial hypertension. We studied 29 patients with pulmonary arterial hypertension diagnosed and treated between 1998 and 2001. Clinical characteristics (6 min walk test and New York Heart Association class) and hemodynamic parameters (pulmonary artery pressure, pulmonary vascular resistance and cardiac output) were evaluated and correlated to uric acid level in a retrospective study. Uric acid levels correlated positively with New York Heart Association class (r=0.66, P<0.001) and negatively with 6 min walk test (r=-0.35, P=0.03). Uric acid levels were higher in patients who died than in patients who survived at the end ofthe follow-up period (8.8 vs. 5.7 mg/dl, P=0.001). This study shows that uric acid levels are elevated in severe pulmonary arterial hypertension and can be used as a prognostic marker of disease severity.

Adolescent↗
PubMed2003

Successful lung transplantation following lung volume reduction surgery.

BACKGROUND: Lung volume reduction surgery (LVRS) is an accepted treatment modality for patients with advanced emphysema. Recently, successful lung transplantation (LTX) has been reported following LVRS. We assess the pulmonary functions in lung transplant recipients after LVRS. METHODS: 8 patients - 5 males and 3 women--aged 53-66 years with advanced emphysema underwent LVRS. Following clinical deterioration and decline of pulmonary function, patients underwent single LTX. Post transplantation follow-up included pulmonary function, 6 minute walk distance (6 MWD) and recording perioperative complications. RESULTS: Median forced expiratory in one second (FEV 1) before and after LVRS were 24 % with 31 % predicted, respectively. All but one showed improvement in lung function and 6 MWD following LVRS. Median maximal 6 MWD before and after LVRS was 222 and 316 meters, respectively. Median time from LVRS to LTX was 46 months (range 10-83). All patients survived and were discharged after LTX. Median FEV1 before and after LTX was 23 % with 57 % predicted, respectively. Median 6MWD before and after LTX was 240 and 462 meters, respectively. NYHA classes improved from 3-4 to 1-2 in 7 surviving patients. At transplantation, bleeding due to pleural adhesions was observed in 4 patients; two required blood transfusions. One patient developed acute respiratory distress syndrome and one had unilateral vocal cord paralysis. At nine-month follow-up, 7 patients are doing remarkably well, while one patient died 6 months after LTX due to bronchiolitis obliterans syndrome (BOS). CONCLUSIONS: LVRS is a therapeutic option in patients with end-stage emphysema. When emphysema deteriorates, LTX can be successfully performed with significant improvement of quality of life without significant additional risk.

Aged↗
PubMed2002

Elevation of ELISA d-dimer levels in patients with primary pulmonary hypertension.

BACKGROUND: Vasoconstriction, vascular wall remodeling and thrombosis are considered as possible etiologies of primary pulmonary hypertension (PPH). D-dimer, a degradation product of fibrin, has been increasingly used as a marker and prognostic factor in various diseases. OBJECTIVE: To assess elevated ELISA D-dimer levels as a marker of endogenous fibrinolysis in patients with PPH. PATIENTS AND METHODS: Comparison of ELISA D-dimer levels of 12 PPH patients (11 female, 1 male) aged 27-73 years (median 51 years) with those of sex- and age-matched healthy controls. RESULTS: Eleven patients had New York Heart Association (NYHA) class III or IV symptoms, and one patient had NYHA class II symptoms. All patients with PPH were treated with anticoagulants and vasodilators: 5 patients were treated with continuous intravenous prostacyclin, 4 patients with continuous UT-15 and 2 patients with intermittent intravenous iloprost. Mean ELISA D-dimer levels +/- SD were significantly higher in the PPH group than in the matched control group (473 +/- 109 vs. 182 +/- 103 ng/ml; mean difference: 291 +/- 79, 95% CI: 240-341, p < 0.0001). CONCLUSION: These results suggest the possible involvement of endogenous fibrinolysis in the pathophysiology of PPH.

Adult↗
PubMed2001

Pulmonary function in patients with diabetes mellitus.

BACKGROUND: Pulmonary complications of diabetes mellitus have been poorly characterized. Although some authors have reported normal pulmonary function, others found abnormalities in lung volumes, pulmonary mechanics, and diffusing capacity. SUBJECTS AND METHODS: We studied pulmonary function in a group of patients with diabetes using a combined cardiopulmonary exercise test. Twenty-seven patients with diabetes aged 48 +/- 13 years participated in the study. RESULTS: Overall, forced vital capacity, forced expiratory volume in 1 second, and forced expiratory flow, midexpiratory phase, were within the predicted values, but the residual volume/total lung capacity ratio was slightly elevated. Comparison by diabetes type showed nonsignificant differences in forced expiratory volume in 1 second and forced expiratory flow, midexpiratory phase. Residual volume/total lung capacity ratio was significantly elevated in type 1 patients compared with type 2. Carbon monoxide diffusion capacity (DLCO) was normal in both groups. There was no correlation between the results on pulmonary function test and duration of disease, presence of microangiopathy, or glycemic control. The DLCO was significantly lower in patients with microangiopathic changes, but not when DLCO was corrected for alveolar volume. On the cardiopulmonary exercise test, maximal workload, maximum oxygen uptake, and maximal heart rate were less than predicted, whereas anaerobic threshold and ventilatory reserve were normal. No significant differences were noted in diabetes type, and there was no correlation between parameters of cardiopulmonary exercise test and the other variables. CONCLUSION: Spirometric values are preserved in patients with diabetes mellitus, and there are no defects in diffusing capacity. Cardiovascular factors may account for impaired physical performance. There is no need for routine screening of pulmonary function among diabetic patients.

Adult↗
PubMed2001

Pulmonary carcinoid: presentation, diagnosis, and outcome in 142 cases in Israel and review of 640 cases from the literature.

OBJECTIVE: To determine the characteristic features and outcome of pulmonary carcinoid tumors in Israel. METHODS: Retrospective analysis of the clinicopathologic data and outcome of patients from four major hospitals in Israel in the last 20 years. RESULTS: There were 142 cases of pulmonary carcinoid tumors: typical (n = 128) and atypical (n = 14). We calculated an annual incidence of about 2.3 to 2.8 cases per 1 million population. The ratio of female to male patients was 1.6:1. The prevalence of smoking was similar to the general population in patients with typical carcinoids and twice as high in the atypical group. Bronchial obstruction was the cause of most of the presenting symptoms and signs and included obstructive pneumonitis, pleuritic pain, atelectasis, and dyspnea (41%). Carcinoid syndrome was extremely rare and occurred in only one patient with metastatic disease. Most of the tumors (68%) arose in the major bronchi. Diagnosis was made using fiberoptic bronchoscopy in 52% of patients without evidence of endobronchial hemorrhage. Nodal involvement and distant metastases occurred in 57% and 21%, respectively, in the atypical group, and 10% and 3%, respectively, in the typical group. The treatment of choice was surgical: lobectomy (56%) or pneumonectomy (16%). The respective 5-year survival rates for patients with typical and atypical tumors were 89% and 75% (not significant), and the 10-year survival rates were 82% and 56% (p < 0.05). A review of large series from the literature is presented. CONCLUSION: Pulmonary carcinoid is an uncommon tumor in the Israeli population. With early diagnosis and aggressive surgical therapy, long-term prognosis is excellent.

Adolescent↗
PubMed2001

Primary pulmonary hypertension in Israel: a national survey.

OBJECTIVES: To characterize the incidence of patients with primary pulmonary hypertension (PPH) in Israel and their outcomes. METHODS: We have evaluated retrospectively all the patients in Israel in whom PPH was diagnosed between the years 1988 and 1997. We looked at medical history, hemodynamic data, pulmonary function and gas exchange, and demographic variables. Patients were followed up for survival until November 1997. Life table analysis and Kaplan-Meier statistics were used to estimate the overall survival distribution. Regression analysis was used to examine the relations between survival and selected variables. RESULTS: Overall, we found 44 patients with PPH. The estimated incidence of PPH in Israel is 1.4 new cases per year per million population. The mean (+/- SD) age at diagnosis was 43 +/- 13 years. In the Jewish population, PPH was more frequent among immigrants from Europe and the United States. The mean interval from the onset of symptoms to diagnosis was 3 years (median, 2 years). The median survival time was 4 years. The 1-year, 3-year, and 5-year survival rates were 82%, 57%, and 43%, respectively. The major variables influencing the survival rate were the following: interval from symptom onset to diagnosis; and hemodynamic measurements (ie, mean pulmonary artery pressure, mean right atrial pressure, and cardiac index). In comparison to rates discerned from the National Institutes of Health registry data, the survival rate in Israel is somewhat better and prognosis is influenced by similar hemodynamic variables. CONCLUSION: PPH is a rare and fatal disease in Israel. New therapeutic modalities such as prostacyclin therapy and lung transplantation may improve survival among patients with this malignant disease.

Adolescent↗
PubMed2001

Relationship between pulmonary function and unsupported arm exercise in patients with COPD.

UNLABELLED: In patients with chronic obstructive pulmonary disease (COPD) the limitation on unsupported arm exercise (UAE) is predominantly respiratory muscle function-dependent. It is characterized by neuromechanical dysfunction (thoracoabdominal dyssynchrony) of the inspiratory muscles (diaphragm, accessory), superimposed by lung mechanics dysfunction. The undergoing mechanism is probably multifactorial. To study the relationship of resting pulmonary function and UAE performance in patients with COPD. Twenty-one patients, mean age 63 +/- 7 years, with COPD [forced expiratory volume in the first second (FEV1) 42 +/- 12% of predicted] underwent assessment of resting lung function (inspiratory capacity 57 +/- 17%; functional residual capacity 204 +/- 38% of predicted), maximal inspiratory pressure (67 +/- 14 cmH2O), upper arm circumference (30 +/- 2 cm), and symptom-limited cardiopulmonary UAE assessments. UAE consisted of bilateral anterior arm elevation to shoulder level at a rate of 40 arm strokes.minute-1. A series of stepwise multiple regression models were fitted to the data to predict exercise time from resting pulmonary function indices. RESULTS: Statistically significant correlations (r) were found between exercise time and inspiratory capacity (% of predicted) (r = 0.67, p = 0.0008), maximal inspiratory pressure (cmH2O) (r = 0.47, p = 0.03), upper arm circumference (r = 0.74, p = 0.0001), FEV1 (% of predicted) (r = 0.62, p = 0.0026), oxygen uptake (r = 0.56, p = 0.0085) and functional residual capacity (% of predicted) (r = -0.41, p = 0.06, borderline). Inspiratory capacity (% of predicted), functional residual capacity (% of predicted), upper arm circumference (cm) and FEV1 (% of predicted) explained 77% of the variance in exercise time. Therapeutic strategies that aim to increase inspiratory capacity or decrease functional residual capacity, or increase inspiratory muscle strength and upper arm/torso muscle endurance are likely to alleviate symptoms and improve UAE performance in patients with COPD.

Aged↗
PubMed2001

Evidence of increased matrix metalloproteinase-9 concentration in patients following cardiopulmonary bypass.

Cardiopulmonary bypass (CPB) is associated with a systemic inflammatory response, which can result in acute lung injury known as "postperfusion syndrome." Neutrophil activation with concomitant serine protease release has been implicated in the pathogenesis of "postperfusion syndrome." Increased plasma levels of neutrophil elastase (NE) have been demonstrated in patients undergoing CPB, and it is well documented that both NE and matrix metalloproteinase-9 (MMP-9) have a synergistic role in pulmonary injury. We, therefore, hypothesized that plasma levels of MMP-9 would be elevated in patients after CPB. Human plasma was obtained after informed consent from eight patients undergoing CPB. Plasma was collected at the start of CPB, 5 minutes after the initiation of CPB, and at the termination of CPB (156 +/- 17 min). All samples were analyzed by both standard enzyme-linked immunosorbent assay (ELISA) and gelatin zymography for MMP-9 (free and total enzyme) concentration. Data were expressed as means +/-SE and assessed by analysis of variance (ANOVA). Plasma MMP-9 concentration was significantly increased at the end of CPB (191 +/- 30.4 ng/mL; p <.05) as compared to both the start of CPB (28.3 +/- 13.2 ng/mL) and 5 minutes after the initiation of CPB (44.3 +/- 15.4 ng/mL). Patients undergoing CPB show an increase in serum MMP-9 levels. Prior studies utilizing an animal model of "postperfusion syndrome" have shown that inhibition of MMP-9 and NE prevented pulmonary injury following CPB. The results of the current study suggest that such an approach may also have merit in the clinical setting of cardiopulmonary bypass.

Adult↗
PubMed2000

[Preflight assessment by hypoxic inhalation test in cardiopulmonary patients].

Flying may expose passengers to hypoxic conditions, which may induce hypoxemia, particularly in those with chronic heart and/or lung disease. Onset of dyspnea, wheezing, chest pain, cyanosis and right heart failure can lead to urgent need for oxygen during flight. The hypoxia inhalation test (HIT) provides a safe and simple means of identifying those who may develop hypoxemia during flight. We report our experience with 48 self-reporting patients who underwent HIT prior to pre-planned air travel. They inhaled for 15-minute periods a reduced oxygen concentration (F1O2 15%) under normobaric conditions, during which O2 saturation was monitored by pulse oximeter; electrocardiogram, blood pressure and symptoms were also monitored. O2 saturation of < 85% (PaO2 50 mm Hg) was considered a positive test. In the 8 cases (17%) with a positive test, 5 had chronic obstructive pulmonary disease and 3 had cardiovascular and/or combined heart-lung disease. We calculated predicted O2 partial pressure in altitude (PaO2ALT) and compared it to actual results in the 8 patients with a positive HIT. In 5, use of the predicted formula would have under-diagnosed the hypoxemia that developed during the HIT. Thus, the results of the HIT changed treatment strategy in these patients. We recommend that patients with positive tests use O2 (2LPM or 4LPM) during flight. HIT is practical and of potential benefit in the objective assessment of patients with various degrees of heart, lung or combined heart-lung disease. Clinicians should be aware of the relative risk of hypoxia during flight in such patients, and of the value of HIT in identifying them, leading to increase in its use.

Aerospace Medicine↗
PubMed2000

[High dose endobronchial brachytherapy for malignant airway obstruction: first study of 30 patients].

Brachytherapy is especially suitable for palliative treatment of endobronchial tumors adjacent to internal organs that might be damaged by intensive external beam radiation, but are easily accessed with a flexible bronchoscope. This treatment is mostly palliative. 30 patients underwent such palliative high-dose endobronchial brachytherapy to alleviate malignant airway obstruction. With the aid of a flexible fiberoptic bronchoscope an endobronchial catheter was inserted adjacent to the tumor and treatment delivered using a 192Ir remote afterloader for 5-10 min, in 2 or 3 sessions. There was symptomatic improvement in 26 (86%) and objective improvement in 27 (90%). 1 patient died of hemoptysis.

Aged↗