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Biomedical subjects

S Reis

Publications and source records attributed to S Reis.

At least 37 records · Page 2Linked to original sources
PubMed1999

Acid-base properties and solubility of pindolol, diazepam and chlordiazepoxide in SDS micelles.

The effect of sodium dodecyl sulphate (SDS) on the acid-base properties and on the solubility of a beta-blocker (pindolol) and of two benzodiazepines (diazepam and chlordiazepoxide) has been assessed. The study was performed by potentiometric and spectrophotometric determinations of the acidity constants and by spectrophotometric evaluation of the solubilities of the pharmaceutical drugs in aqueous solution and in solutions to which was added SDS with concentrations below and above the critical micelle concentration (cmc), at 25 degrees C and at an ionic strength 0.1 M (NaCl). The effect of the organized assemblies on the pKa values was quantified by the application of two theoretical models that differ in the inclusion of ionic exchange between positively charged species in solution. These models have allowed the determination of the binding constants for drug/micelle and yielded values in good agreement with those obtained by the solubility method, and in addition provide a more detailed picture of the effect of drug charge on its partition. The results can be taken to evidence different interaction modes of the drugs with the SDS micelles.

Adrenergic beta-Antagonists↗
PubMed1999

A new look at low back complaints in primary care: a RAMBAM Israeli Family Practice Research Network study.

BACKGROUND: Low back pain (LBP) is one of the most frequent reasons patients seek consultations in primary care, and it is a major cause of disability. Our research examines the natural history of LBP and the prediction of chronicity in the context of patients presenting to family medicine clinics. METHODS: We performed a prospective cohort study of new episodes of LBP within the framework of a national family practice research network. The setting was 28 primary care family practice clinics located throughout Israel. Of 238 eligible subjects, 219 (92%) completed the study. RESULTS: During the 2-month study period, 2 subjects were referred to the emergency department and discharged, and 2 others were hospitalized. Forty-five percent did not require bed rest, and 38% of the employed were not absent from work. Seventy-one percent showed improvement in functional status; however, only 37% noted complete pain relief. Clinical and demographic data usually did not predict LBP-episode outcomes. The strongest predictors of chronicity were depression, history of job change due to LBP in the past, history of back contusion, lack of social support, family delegitimization of patient's pain, dissatisfaction with first office visit, family history of LBP or other chronic pain, coping style, and unemployment. CONCLUSIONS: The cohort patients displayed a relatively benign natural history of LBP, matched by benign clinical behavior from their physicians. In Israeli primary health care, acute LBP is infrequently associated with hospitalization or prolonged work absenteeism. Although most patients have functional improvement, pain often lingers. Almost all predictors of chronicity are psychosocial.

Adult↗
PubMed1998

A report from the Second International Forum for Primary Care Research on Low Back Pain. Reexamining priorities.

STUDY DESIGN: Consensus process. OBJECTIVES: Reexamining and redirecting the research agenda for low back pain in primary care. SUMMARY OF BACKGROUND DATA: Most research, publications, and funding have traditionally been directed toward specialty and biologically oriented investigations of "spinal disorders" from biomedical and biomechanical perspectives. Beginning in the mid-1980s, primary care researchers began to investigate this field in earnest, focusing on lower back pain as a pain syndrome within an individual, family, and community context. Unfortunately, more progress has been made on what should not be done in diagnosing and treating lower back pain than on what should be done. METHODS: This was a modified group process designed to reach consensus among an international group of primary care lower back pain researchers. RESULTS: Nearly all of the research priorities from the initial 1995 forum are still thought to be important, although only modest progress has been made on most of them. The priorities perceived to be the most feasible to investigate and the ones in which the greatest strides have been achieved are in methodologic rather than substantive areas. Identifying subgroups of people with lower back pain is still given top ranking in 1997, but the priorities have changed dramatically. Greater emphasis is given to finding predictors and risk factors for lower back pain chronicity, improving self-care strategies, and stimulating self-reliance. New items now make up 50% of the top 10 priorities. In general, the additions reflect a greater emphasis on expanding methodologic avenues of inquiry. CONCLUSIONS: Methodologic advances, the enlistment of new techniques and disciplines, and redirected research efforts may facilitate progress in the diagnosis and treatment of lower back pain.

Group Processes↗
PubMed1998

General practice care and patients' priorities in Europe: an international comparison.

Insight into patients' priorities with respect to health care should complement the views of professionals and policy makers on what is thought to be appropriate health care. To determine the strengths and weaknesses of general practice care from patients' perspectives written surveys were performed among patients in Denmark, Germany, Israel, Netherlands, Norway, Portugal, Sweden and United Kingdom (n = 3540). The potential quality problems identified were spread over the different countries: the low involvement of general practitioners in out-of-hours services in Portugal; the low provision of routine screening in Sweden, Norway and The Netherlands; the lack of a defined patient population in Germany; the lack of a formal gatekeeper role to secondary care in general practice in Germany and Sweden; and the low number of home visits in Sweden.

Europe↗
PubMed1998

Copper(II) increases bile acid binding to asparagine.

Interactions of two bile acids (cholic and glycocholic acids) with asparagine have been studied by potentiometry in aqueous solutions under conditions similar to those observed in biological fluids (37 degrees C and I = 0.15 M NaCl), and in the absence and presence of copper(II). To characterize the equilibria for the systems copper(II)/bile acid/asparagine, specifically to assess cooperative binding between bile acids and asparagine, the acidity constant of asparagine and formation constants for copper(II)/bile acid and copper(II)/asparagine were also obtained under the same conditions. The results obtained suggest cooperativity in the binding of bile acid to asparagine in the presence of copper(II).

Asparagine↗
PubMed1998

Tetracycline, oxytetracycline and chlortetracycline determination by flow injection potentiometry.

This paper describes tetracycline (TCH), oxytetracycline (OTCH) and chlortetracycline (CTCH) determination by flow injection potentiometry. In the flow system proposed TC samples are inserted in a carrier solution and converged with a Cu(II) solution of known concentration; the Cu(II) decrease due to its complexation with tetracyclines (TC) was monitored. The detector used was a homogeneous crystalline CuS/Ag2S double membrane tubular electrode with increased sensitivity. The present system allows tetracyclines determinations within a 48.1-4.8 x 10(3) ppm for TCH, 49.1-4.9 x 10(3) ppm for OTCH and 51.5-5.1 x 10(3) ppm for CTCH and a precision better than 0.4% for the three TC species. This procedure accomplishes 150-200 samples h(-1) with a Cu(II) consumption of about 13 microg determination(-1).

Chlortetracycline↗
PubMed1998

Fluorimetric and solubility studies of nadolol and atenolol in SDS micelles.

The effect of sodium dodecyl sulfate (SDS) micelles on the spectrofluorimetric intensities and on the solubility of two beta-blockers (atenolol and nadolol) were studied at 25.0 +/- 0.1 degrees C and I = 0.1 M NaCl. From the dependence of these physical properties on SDS concentration it was possible to calculate the binding constants drug-micelle, and it was found that both techniques yield similar results for the binding constants, and that are in agreement with those calculated from the effect of micelles on the apparent acidity constants of the beta-blockers.

Adrenergic beta-Antagonists↗
PubMed1998

Acid/base properties of beta-blockers and benzodiazepines in sodium dodecyl sulfate micelles. A spectrophotometric and potentiometric study.

The effect of sodium dodecyl sulfate (SDS) micelles on the acid-base properties of two family of pharmaceutical drugs (beta-blockers and benzodiazepines) at 25 degrees C and I = 0.1 M NaCl have been studied. The characterization of the several solution equilibria for the system drug/SDS micelle solution was performed by potentiometry and spectrophotometry, below and above the critical micelle concentration (cmc). Two widely used models have been applied to quantify the effect of micelles on the pKa of the drugs, and the results obtained point to different interactions of each family of drugs with the micelles.

Adrenergic beta-Antagonists↗
PubMed1998

Telemedicine in primary care in Israel.

A primary-care teleconsulting system was established between an academic family medicine centre and a clinic about 50 km away. The videoconferencing units were connected at 384 kbit/s. Seven patients were examined by a physician in the clinic and then examined by a consulting physician using the telemedicine system. Four other patients were examined through the telemedicine system first and by a local physician later. The telemedicine consultation solved five of the patients' medical problems. The waiting period before receiving expert medical consultation was reduced. There was full patient satisfaction regarding this method of consultation, patient 'run around' was avoided and patients felt at ease. The telemedicine consultation process improved the patient-physician bond and the attending physician's level of confidence.

Adult↗
PubMed1996

[Guidelines for treating low back pain in primary care. The Israeli Low Back Pain Guideline Group].

Low back pain (LBP) is a common problem in primary care, the successful management of which poses special challenges for patients and practitioners alike. It has been estimated that all adults will suffer LBP sometime during their lifetimes. It is one of the most frequent reasons for visiting a primary care physician, yet practitioners often find it difficult and frustrating to treat. This medical protocol is concerned with the diagnosis, treatment, and follow-up of low back pain in adults. It was developed for community-based, primary care physicians (general practitioners, family physicians, and internists) to serve as a general outline, to be adjusted in accord with the individual's circumstances. The protocol provides a "Ten Commandments" for the care of LBP, outlines the background of the problem, presents an overall algorithm and deals with issues of diagnosis, imaging, and treatment. In general, LBP in primary care is conceived of as a benign ailment, and emphasis is placed on reducing pain, resuming functioning and returning to work. The main task of the physician is to distinguish the less than 10% of cases with serious, specific causes of LBP from the more than 90% with nonspecific etiologies. In the great majority of patients, imaging studies such as X-ray, CT, MRI, and bone scan, and also EEG are unnecessary.

Family Practice↗
PubMed1996

[Integration of the community emergency center into medical services].

The first community emergency center (CEC) in Israel was established in 1988 in Jerusalem. It provided medical services after health fund clinic working hours, in a primary care facility, by primary care physicians. In the past 5 years Israel has witnessed growth in this method of health care delivery and more than 20 such centers have been established throughout the country. We describe a CEC in a small town, and its function and its integration within the regional medical services. 2 retrospective studies examined 3 aspects of the CEC: patient profiles including age, sex, and major diagnoses, use of specific services; and referrals to the emergency room.

Adolescent↗
PubMed1995

Talking about the pain: a patient-centered study of low back pain in primary care.

Despite considerable research, low back pain (LBP) often proves resistant to treatment. This study was designed to increase the understanding of low back pain through access to patients' perceptions, beliefs, illness behaviors and lived experiences. The findings are based on focus groups, individual interviews and participant observation conducted in primary care practices and community settings in three regions in Israel. Inclusion criteria for the interviews and groups include age greater than 18 years and a history of at least one episode of LBP. Seventy-six LBP subjects between the ages of 18 and 67 (mean 39.5) participated, 65% male and 35% female. The analytic method is content analysis, consisting of a formal, multi-step process designed to elucidate inherent patterns and meanings. This research finds that LBP subjects articulate a rich world of pain sensation, awareness and meanings. From subjects' own words and experiences we present a patient-centered classification system of backache symptoms based on typical pain intensity, dysfunction, duration and treatment. An elaborate system of explanatory models of LBP and a typology of dominant coping styles designed to either minimize pain or maximize function are also derived. Subjects choose multiple conventional and alternative treatments based on 'what works', and articulate ample criticisms of and suggestions for the medical system. In addition, we find that variations in the social construction of the back pain experience vary sharply, even between similar neighboring communities. Given the difficult state of diagnosis and treatment and the frustration of practitioners, attempts at greater understanding of patients' health beliefs, experiences, and behaviors are warranted.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Potentiometric determination of formation constants of copper(II)/bile acid/peptide in aqueous solution.

A potentiometric method was used to study the equilibria in aqueous solution for the systems copper(II)/bile acid salt/peptide [bile acid salt-sodium cholate or glycocholate; and peptide-glutamic acid (glutamate), glutamine or glutamylglutamic acid], specifically to assess cooperative binding between small peptides and bile acids in the presence of copper(II). The results obtained suggest large cooperativity in formation of ternary complexes with amino acids when they are coordinated to copper(II) as bidentate ligands.

Amino Acid Sequence↗
PubMed1994

T cell recognition of carbohydrates on type II collagen.

A critical event in an immune response is the T cell recognition of peptides bound to major histocompatibility complex (MHC) molecules on the surface of an antigen presenting cell (APC). Although the majority of eukaryotic proteins are glycosylated, it has not yet been shown that T cell recognition of such proteins involves recognition of the bound carbohydrates. Type II collagen (CII), the major protein constituent of joint cartilage, is posttranslationally modified by hydroxylation and glycosylation of lysines. In this report we show that posttranslational modifications of the immunodominant peptide CII(256-270) generate a structural determinant that is distinct from the determinant represented by the corresponding synthetic peptide. Elimination of carbohydrates, present on CII, by two different biochemical methods revealed that the carbohydrates, O-linked to the hydroxylysines within the CII(256-270) determinant, were crucial for the reactivity towards the posttranslationally modified peptide. Furthermore, a T cell hybridoma specific for the glycosylated determinant was stimulated by tryptic CII-peptides presented by fixed APCs, thus showing that the carbohydrates are involved in the trimolecular complex T cell receptor/peptide/MHC. Finally, the importance of the bound carbohydrates for the arthritogenicity of CII was investigated by comparing the development of arthritis after immunization with carbohydrate-depleted and glycosylated CII, respectively. Incidence, time of onset, and severity of the disease were significantly affected by the elimination of carbohydrates, whereas no significant difference in anti-CII antibody titers was seen.

Amino Acid Sequence↗
PubMed1994

Rumination in two developmentally normal children: case report and review of the literature.

This report describes the cases of two normal 6-year-old children, both of whom experienced rumination for a period of 6 to 8 months, followed by full remission. For each of these children, rumination was a reaction to situational stress (adoption and maladaption, respectively). These cases represent the addition of a new form of rumination to the literature: a benign, self-limited childhood disorder of mentally and developmentally normal children, distinctly different from "rumination disorder," as defined by the Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R).

Adjustment Disorders↗
PubMed1993

Mucolipidosis type IV: a mild form with late onset.

A 16-year-old girl is presented with mild clinical manifestations and late onset of mucolipidosis type IV (MLIV). The patient, an Ashkenazi Jew, has had minor motor difficulties and mild psychological disturbances since early childhood. Her vision began deteriorating at 12 years of age, due to bilateral corneal opacities and retinal degeneration. At present she attends a regular high school, although she is slow and scholastic achievements are lower than average. Electron microscopic examination and biochemical studies were typical for MLIV, namely, abnormal ganglioside retention and typical pattern of phospholipids accumulation. This very mild presentation of MLIV suggests a broader spectrum of heterogeneity of this disorder and raises the possibility that MLIV, at least among Ashkenazi Jews, might be more frequent than estimated hitherto, due to undiagnosed mild patients.

Adolescent↗