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Biomedical subjects

V Pavlik

Publications and source records attributed to V Pavlik.

14 recordsLinked to original sources
PubMed2005

Changing patient characteristics and survival experience in an Alzheimer's center patient cohort.

BACKGROUND: Large and diverse dementia patient cohorts can further a variety of research programs aimed at improving diagnosis, treatment, and meaningful survival in AD. METHOD: We recruited 1,502 dementia patients between 1989 and 2002, subclassified using standardized criteria and laboratory procedures, and treated according to established guidelines. Baseline clinical and psychometric measures were repeated annually, in person or by use of a multi-modal telephone follow-up program that included many of the measures obtained at in-person visits. We tracked vital status of all subjects at 6-month intervals and offered autopsies to all participants. We assessed for cohort effects in baseline characteristics by 2-year intervals, examined the characteristics and outcomes for those who remained active compared to those who were eventually lost to follow-up, examined survival times for demographic or diagnostic subgroups, and assessed the accuracy of clinical diagnoses versus neuropathology. RESULTS: The average age at entry, average educational level, and baseline MMSE scores for subjects are increasing over time, and probable AD diagnoses are also increasing. Most (80.6%) subjects have remained active in our Center; those who did not were more likely to have a non-AD diagnosis. Survival averages 5.2 years (CI 4.98--5.37) and is influenced by age and gender, but not by diagnosis of probable versus possible AD. Our diagnostic accuracy is 89.6%, with high sensitivity to the presence of AD (96%). CONCLUSIONS: In a large and representative clinical cohort, the demographics of AD are changing over time. Careful analyses of those who continue and those who drop out from follow-up suggest that atypical diagnosis, rather than severity or demographic issues accounts for most of the attrition. Clinicians are likely to encounter increasingly older patients with milder disease, and these trends have implications for the design of clinical trials. Survival from the onset of first symptoms, similar for probable and possible AD cases, may be increasing over time.

Aged↗
PubMed1999

New profiles of diabetic ketoacidosis: type 1 vs type 2 diabetes and the effect of ethnicity.

BACKGROUND: Diabetic ketoacidosis (DKA) has been reported to occur in type 2 diabetes, but the frequency and distinguishing features of this syndrome remain to be defined. We determined the "diabetic types," ethnic distributions, and phenotypes of patients with DKA in an urban hospital. METHODS: We reviewed the hospital admissions and followed the clinical course of adults who developed DKA. We classified patients as "type 1," "type 2," or "new onset" based on their treatment history. New-onset patients were reassessed 2 1/2 years or more after the episode of DKA and classified as "type 1" or "type 2" based on insulin requirements. We compared the groups for ethnic distributions and clinical features. RESULTS: Of 141 patients, 55 (39%) who presented with DKA had type 2 diabetes, while 75 (53%) had type 1 diabetes and 11 (8%) could not be "typed." Hispanics mainly had type 2 and whites predominantly had type 1, while African Americans had a slight preponderance of type 1 diabetes (P=.001). Type 1 patients were mainly lean, while the body mass indexes (BMIs) (calculated as the weight in kilograms divided by the square of height in meters) of type 2 patients were bimodally distributed (33% with BMI<25 and 51% with BMI>30; P<.001). Age of onset of diabetes was predominantly younger than 40 years in the type 1 group but was more broadly distributed in the type 2 group (P<.001). Ninety-three percent of the new-onset patients who were reassessed had type 2 diabetes. Half of the type 2 patients had no identifiable stress factor associated with the episode of DKA. CONCLUSIONS: A high proportion of DKA in nonwhite adults occurs in persons with type 2 diabetes, especially in those with previously undiagnosed diabetes. The frequency and clinical heterogeneity of this syndrome in a multiethnic population have significant implications for the diagnosis, classification, and management of adults with diabetes.

Adult↗
PubMed1999

Ethnicity affects the postprandial regulation of glycogenolysis.

We investigated the effect of nutrient intake on glucose metabolism in normal Mexican-Americans (n = 6) and European-Americans (n = 6). Subjects were studied after an 18-h fast and after 5-6 h of ingestion of hourly meals that supplied 6.35 or 12.75 micromol glucose. kg(-1). min(-1). Endogenous glucose production (EGP), gluconeogenesis (GNG), and glycogenolysis (GLY) were estimated by mass isotopomer analysis with [U-(13)C]glucose infusions. Fasting EGP, GNG, and GLY did not differ between the groups. Food ingestion lowered the molar rate of GNG by only 31%. However, while consuming the lower quantity of nutrients, Mexican-Americans had higher plasma glucose (P < 0.05), a 39% higher rate of EGP (P < 0.05), and a 68% (P < 0.025) higher rate of GLY than the European-Americans. At the higher intake, EGP and GLY were suppressed completely in both groups. There was a linear relationship between insulin concentrations, EGP, and GLY in both groups, but the slope of the line was significantly (P < 0.05) greater in the European-Americans. We conclude that the sensitivity of GLY to nutrient intake differs between ethnic groups and that this may play a role in the increased predisposition of Mexican-Americans to type II diabetes.

Adult↗
PubMed1994

Noradrenaline mediates paradoxical effects on rat neocortical neurons after GABA withdrawal.

1. The aim of the present study was to determine the role of noradrenergic neurotransmission in neuronal activities intracellularly recorded in neocortical slices obtained from rats presenting the gamma-aminobutyric acid (GABA) withdrawal syndrome (GWS), a focal epilepsy consecutive to the interruption of a chronic intracortical GABA infusion into the somatomotor cortex. Neurons recorded in the epileptic focus area (n = 52) were bursting or nonbursting cells. Intrinsic bursting (IB, n = 20) cells presented bursts of action potentials (APs) to an intracellular depolarizing current injection and paroxysmal depolarization shifts (PDSs) to white matter stimulation. Synaptic bursting (SB, n = 22) cells presented only PDSs. Nonbursting (NB, n = 10) cells presented no burst after either synaptic stimulation or depolarizing current injection. Results were compared with those obtained from NB neurons (n = 4) recorded in slices from saline-infused rats. 2. In all of the recorded neurons, bath application of norepinephrine (NE, 10 and 100 microM) provoked a depolarization (1-5 mV) associated with a decrease in input K+ conductance having a mean reversal potential at -90 to -102 mV, not significantly different for bursting and nonbursting cells. This reversal potential differed from that of Cl(-)-mediated inhibitory postsynaptic potentials (-70 mV) elicited in NB cells by electrical stimulation of the white matter. 3. In IB cells, the NE-induced depolarization replaced the intrinsic bursts by a sustained repetitive discharge of single APs and caused intrinsic bursts to appear during previously subthreshold depolarizing current pulses. These NE-increased activities were abolished by dihydropyridine nitrendipine (1 microM) and by Cd2+ (0.5 mM) or Co2+ (2 mM), thus confirming that Ca2+ currents contribute to burst generation in IB cells. 4. In both NB and SB cells recorded in slices from GWS rats, NE provoked the appearance of intrinsic bursts of APs during steps of depolarizing current injections. In addition, in NB cells, NE caused synaptic bursts to appear after white matter stimulation. These NE-induced bursts were dihydropyridine (nitrendipine, 1 microM)- and Cd2+ (0.5 mM)- or Co2+ (2 mM)-sensitive and were related to an increased AP-afterdepolarization. The fast AP-afterhyperpolarization was not affected by NE. In NB cells recorded in slices from saline-infused rats (n = 4) NE did not provoke the appearance of bursts even when stimulation intensity was increased up to three times.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1992

Advances in the community control of hypertension: from epidemiology to primary care practice.

PURPOSE: To review the progress in hypertension control in the United States since 1972, to examine the factors that contributed to that progress and to consider areas in which further improvement is required. METHODS: A review of epidemiological, clinical and health services research related to hypertension control was conducted. We report our experience in evaluating hypertension control in a multi-ethnic community clinic population as an illustration of the challenges of hypertension management in primary care practice. SUMMARY OF FINDINGS: Hypertension prevalence in the United States population has remained relatively stable, whereas actual blood pressure levels in the population have declined slightly. Most Americans (approximately 80%) have had a blood pressure check within the past year, but the rate of blood pressure control in treated hypertensives has been disappointing. The current diagnostic and therapeutic criterion of blood pressure < or = 140/90 mmHg, regardless of individual patient characteristics (e.g. age, race), should be re-evaluated.

Ambulatory Care↗
PubMed1980

[Changes in the extracellular potassium concentration and the slow negative potential in the cerebral cortex].

Changes of potassium concentration in the extracellular space ([K+]0) of the g. suprasylvius of cat cerebral cortex were recorded by means of K+ selective microelectrodes; the electrical field potential was recorded simultaneously. Under deep anesthesia a single electrical stimulus, applied to the cortical surface, at intensity enough to elicit the slow negativity, caused a local increase of [K+]0 reaching 0.1-1.5 mM. The time course of the K+ signal coincide with the course of the slow negativity. It is supposed that the slow negativity reflects glial depolarizaion arising under the action of K+ ions.

Animals↗
PubMed1979

Low impedance coaxial K+ selective microelectrodes.

A procedure for preparing coaxial K+ selective microelectrodes with a low longitudinal resistance (Re) of the liquid ion exchanger selective barrel is described. The low resistance was attained by inserting another microelectrode filled with 0.5 mol . 1-1 KCl into the ion-exchanger column (Corning 477317). The lower longitudinal resistance decreases the noise level and consequently increases the resolving power five times. This modification makes it possible to measure small and rapid K+ concentration changes.

Electrophysiology↗
PubMed1978

Acute massive pulmonary thromboembolism in experiment. Comparison of the effect of fibrinolytic and anticoagulant treatment.

The authors have created a suitable model of a massive pulmonary thromboembolism with autologous blood clots in 38 dogs. The pathophysiological changes were studied, and the effect of the fibrinolytic and anticoagulation treatments were comparatively evaluated. The evaluation was based on angiopulmography, scanning of the lungs, ECG and postmorten findings. The most efficacious was the fibrinolytic treatment, which led to the cure of 4 out of 6 dogs. The heparin therapy was less efficacious. The spontaneous lysis of massive thromboemboli did not manifest itself within 12 hr. These experimental notions helped the authors to attain success in clinical routine, primarily with the fibrinolytic treatment.

Acute Disease↗
PubMedDate not supplied

A diabetes control program in a public health care setting.

The Houston Diabetes Control Program is part of an effort by the State of Texas and approximately 30 other programs throughout the United States to ensure that persons with diabetes-related complications receive ongoing state-of-the-art preventive care and treatment. For the past 5 years, this program has served an urban, high-risk patient population with special cultural, ethnic, and economic challenges. The intervention has included the development and implementation of protocols for the prevention and care of diabetes-related complications of the eyes, lower extremities, and cardiovascular system, as well as general management of diabetes and patient and professional education. The program is ongoing in nine community health centers located in low-income neighborhoods of a large metropolitan area. The results thus far indicate an increase in sensitive eye examinations from 8 percent to 26 percent of the patient population, a reduction in incidence of legal blindness from 9.5 to 2.7 per 1,000 during a 4-year period, an increase in foot examinations from 18 percent to 44 percent of the patient population, and 77 percent of hypertensive patients in good control of blood pressure at less than 160 over 95 mmHg (millimeters of mercury). On the average, there have not been significant long-term improvements in weight reduction or blood glucose control. The major challenges for this program are (a) improvement in control of glycemia, hypertension, and cholesterol; (b) more effective diet and physical activity interventions; and (c) more effective education approaches that help patients to understand metabolic and cardiovascular functions. These challenges will require collaboration of health care professionals in constructive and imaginative ways through their unselfish commitment toward common goals.

Aged↗