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Biomedical subjects

R Altman

Publications and source records attributed to R Altman.

At least 19 recordsLinked to original sources
PubMed2000

Fast platelet suppression by lysine acetylsalicylate in chronic stable coronary patients. Potential clinical impact over regular aspirin for coronary syndromes.

BACKGROUND: The rapid utilization of fibrinolytics following Q-wave myocardial infarction has clearly modified the evolution of this disease. However, it is still not known whether the immediate inhibition of platelet aggregation (PA) during the coronary event improves outcomes. HYPOTHESIS: The present study was designed to test, in patients with known coronary artery disease (chronic stable angina), whether the particular kinetic pattern of lysine acetylsalicylate (LA) compared with aspirin may affect the time to onset of inhibition of platelet aggregation. METHODS: Ten patients suffering from chronic stable angina participated in this study to compare the efficacy and speed of the inhibition of PA with 320 mg of LA versus 320 mg of aspirin. All patients discontinued the use of aspirin and any other anti-inflammatory agents for 15 days prior to the beginning of the study. They were randomly assigned to LA or aspirin. Blood specimens were obtained to measure the PA at admission, and 5, 10, 20, 30, and 60 min after ingestion. Patients continued to take the assigned drug once a day for the following 4 days. On Day 5, a new blood sample was taken. After this, patients underwent a 15-day wash-out period, and then crossed over to the opposite drug. The samples were analyzed immediately using platelet-rich plasma stimulated with adenosine diphosphate (ADP) 2 mumol/l, collagen 1 microgram/ml, epinephrine 20 mumol/l, and sodium arachidonate acid 0.75 mm/l. RESULTS: The same level of PA inhibition after 30 and 60 min of aspirin administration can be obtained with LA 5 min following ingestion (sodium arachidonate acid: LA: 16.3 +/- 25.9 vs. aspirin 57.6 +/- 8.2; p = 0.00014; collagen: LA 18.9 +/- 20.1 vs. aspirin 47.2 +/- 10.5; p = 0.00092; ADP: LA 27.3 +/- 18.4 vs. aspirin 39.7 +/- 21.8, p = 0.18; epinephrine: LA 22.0 +/- 9.9 vs. aspirin 55.4 +/- 10.9, p = 0.00002. CONCLUSIONS: Platelet aggregation inhibition immediately following LA may have significant clinical implications for the treatment of coronary syndromes.

Analysis of Variance↗
PubMed1999

Lack of association between prior infection with Chlamydia pneumoniae and acute or chronic coronary artery disease.

BACKGROUND: Higher than normal serologic titers and the detection of bacteria within atheroma have suggested an association between Chlamydia pneumoniae (C. pneumoniae) infection and coronary heart disease (CHD), but the relationship has not been well established. HYPOTHESIS: The study was designed to establish a lack of relationship between chronic C. pneumoniae infection and CHD. METHODS: Chlamydia-specific IgG-antibody was assayed using an indirect immunofluorescence test in the serum of 159 patients with severe arterial disease and 203 patients with a heart valve prostheses and no demonstrable CHD. Fatal and nonfatal vascular events and systemic thromboembolism were recorded over a 2-year period. RESULTS: In the arterial group 107 patients (67.3%) and in the valvular group 120/203 (59.1%) were positive for C. pneumoniae antibody. The number of patients with fatal or nonfatal vascular events (double end point) in the arterial and valvular groups was 23 and 2, respectively (p < .0001). Triple end points (fatal plus nonfatal vascular events plus thromboembolism) were also more frequent in the arterial group (p < 0.002). The prevalence of chlamydia antibody positivity was the same in the arterial and valvular groups, and the occurrence of clinical events was also the same for chlamydia-positive (227 patients) as for chlamydia-negative (135 patients). After adjustment for confounding variables, only arterial disease was a predictive factor for double (OR 17.0; 95% CI 3.94-73.3) or triple (OR 3.12; 95% CI 1.56-6.25) end points. CONCLUSION: We find C. pneumoniae chronic infection not to be an independent risk factor for acute or chronic arterial disease.

Acute Disease↗
PubMed1999

Effects of ticlopidine or ticlopidine plus aspirin on platelet aggregation and ATP release in normal volunteers: why aspirin improves ticlopidine antiplatelet activity.

Aspirin and ticlopidine are used to prevent arterial thrombosis. In some clinical settings ticlopidine is administered with aspirin for improving antithrombotic effect. We administered aspirin (100 mg/day), ticlopidine (500 mg/day), or ticlopidine and aspirin for 7 days to healthy volunteers. Platelet aggregation and ATP release induced by sodium arachidonate, ADP, or a combination of both were measured. Sodium arachidonate (0.25 mmol/L), which produces no platelet aggregation, combined with adenosine diphosphate (1 mumol/L), which produced a reversible platelet aggregation of 20% after ticlopidine, resulted in a synergistic platelet aggregation response in normal (74.6 +/- 9.2%) and in ticlopidine platelet-rich plasma (59.1% +/- 14.9%, p < 0.0001). Synergism after sodium arachidonate (0.75 mmol/L) plus adenosine diphosphate (4 mumol/L) fell from 75.8% +/- 11.0% and 59.1% +/- 15.6% after ticlopidine or aspirin, respectively, to 14.8% +/- 18.0% (p < 0.0001) after ticlopidine plus aspirin. Aspirin and ticlopidine alone did not inhibit adenosine triphosphate release as thoroughly as did aspirin plus ticlopidine. Aspirin or ticlopidine does not adequately prevent platelet activity as ticlopidine plus aspirin do. Addition of aspirin to treatment with ticlopidine improves their antiplatelet activity and better results could be obtained in arterial thrombotic prevention strategies.

Adenosine Triphosphate↗
PubMed1998

The septins are required for the mitosis-specific activation of the Gin4 kinase.

In budding yeast, a protein kinase called Gin4 is specifically activated during mitosis and functions in a pathway initiated by the Clb2 cyclin to control bud growth. We have used genetics and biochemistry to identify additional proteins that function with Gin4 in this pathway, and both of these approaches have identified members of the septin family. Loss of septin function produces a phenotype that is very similar to the phenotype caused by loss of Gin4 function, and the septins are required early in mitosis to activate Gin4 kinase activity. Furthermore, septin mutants display a prolonged mitotic delay at the short spindle stage, consistent with a role for the septins in the control of mitotic events. Members of the septin family bind directly to Gin4, demonstrating that the functions of Gin4 and the septins must be closely linked within the cell. These results demonstrate that the septins in budding yeast play an integral role in the mitosis-specific regulation of the Gin4 kinase and that they carry out functions early in mitosis.

Amino Acid Sequence↗
PubMed1998

Inter-observer reliability of the arthroscopic quantification of chondropathy of the knee.

BACKGROUND: Several scoring systems have been proposed in order to quantify the degree of cartilage damage observed by arthroscopy of the knee in patients with osteoarthritis. OBJECTIVE: To evaluate the inter-observer reliability of five different scoring systems of arthroscopic evaluation for chondropathy in osteoarthritis of the knee and to evaluate the utility of a training session between different observations on these scoring systems. METHODS: Videotapes of knee arthroscopies on five patients with osteoarthritis demonstrating different levels of severity of cartilage damage of the medial tibiofemoral compartment were analyzed by nine observers prior to (pre-training evaluation) and 2 months after a 6 h training session (post-training evaluation) by the following scoring systems: (1) cartilage deterioration by a 100 mm visual analogue scale (VAS), (2) overall assessment of degeneration in the entire medial compartment (cartilage, meniscus, osteophyte) using a 100 mm VAS, (3) French Society of Arthroscopy (SFA) Scoring System, (4) SFA Grading System, (5) American College of Rheumatology (ACR) Scoring System. RESULTS: At the pre-training evaluation, the SFA grading system produced the highest coefficient of reliability (r = 0.94), the other systems recording levels of < or = 0.80. At the post-training evaluation, the coefficient of reliability was r > 0.80 for four of the five scoring systems, with lack of improvement in the ACR Scoring System. CONCLUSION: There was an improved and acceptable inter-observer reliability for at least 2 months follow-up in four of five evaluated scoring systems of arthroscopically graded osteoarthritis of the knee following a training session. A scoring system using a 100 mm VAS may produce the best inter-observer reliability. These results show that scoring chondropathy is possible and demonstrate the importance of training in the analysis of articular cartilage breakdown.

Arthroscopy↗
PubMed1998

Anterior cervical osteophytes as a cause of pharyngeal stage dysphagia.

OBJECTIVE: To describe the association of anterior cervical osteophytes impairing epiglottic movement as an etiology of pharyngeal stage dysphagia. DESIGN: A retrospective chart review. SETTING: An academic affiliated Veterans Affairs Medical Center. PATIENTS: Veterans 60 years of age or older referred to speech pathology for dysphagia evaluation. RESULTS: Of 376 veterans evaluated consecutively since 1990, 40 patients had dysphagia determined to be secondary to cervical bony protuberances. The evaluation and management of three cases with functional consequences at level C3-5 with no dysphagia etiology present are described. CONCLUSION: Cervical osteophytes need to be considered in the differential diagnosis of dysphagia in older people.

Aged↗
PubMed1998

The relationship between psychotherapist and prescribing psychiatrist. Some considerations.

We have reviewed the vagaries and vicissitudes of an increasingly common arrangement in contemporary mental health treatment, namely, the collaboration between psychotherapist and prescribing psychiatrist in the treatment of the patient who requires both psychotherapy and pharmacotherapy. Such a collaboration raises practical, legal, transference, counter-transference, economic, and training issues. It is our hope that this review of these issues will lead to further discussion as, in our experience, they have until now received scant attention in the mental health literature, in the day-to-day work of practitioners, and in supervision and training. We believe that successful collaboration can be achieved when sufficient awareness and planning are present at the outset.

Humans↗
PubMed1997

Control of mitotic events by Nap1 and the Gin4 kinase.

Little is known about the pathways used by cyclins and cyclin-dependent kinases to induce the events of the cell cycle. In budding yeast, a protein called Nap1 binds to the mitotic cyclin Clb2, and Nap1 is required for the ability of Clb2 to induce specific mitotic events, but the role played by Nap1 is unclear. We have used genetic and biochemical approaches to identify additional proteins that function with Nap1 in the control of mitotic events. These approaches have both identified a protein kinase called Gin4 that is required for the ability of Clb2 and Nap1 to promote the switch from polar to isotropic bud growth that normally occurs during mitosis. Gin4 is also required for the ability of Clb2 and Nap1 to promote normal progression through mitosis. The Gin4 protein becomes phosphorylated as cells enter mitosis, resulting in the activation of Gin4 kinase activity, and the phosphorylation of Gin4 is dependent upon Nap1 and Clb2 in vivo. Affinity chromatography experiments demonstrate that Gin4 binds tightly to Nap1, indicating that the functions of these two proteins are closely tied within the cell. These results demonstrate that the activation of Gin4 is under the control of Clb2 and Nap1, and they provide an important step towards elucidating the molecular pathways that link cyclin-dependent kinases to the events they control.

Base Sequence↗
PubMed1997

Prevalence of factor V Leiden mutation in various populations.

Resistance to activated protein C (APC) is the most common inherited risk factor for venous thrombosis. Most cases of APC resistance are caused by the point mutation nt 1691 G-A in factor V gene, referred to as factor V Leiden mutation. As initially shown in a Dutch population, this mutation has a carrier rate of 2.9%, the most frequent genetic disposition for thrombophilia and deep venous thrombosis. By large-scale epidemiological studies we have determined the prevalence of factor V Leiden mutation in populations from Poland (200), Argentina (215), Venezuela (126), Costa Rica (196), and India (150). The prevalences have been estimated for Poland (Warsaw) 5.0%, Argentina (Buenos Aires) 5.1%, Venezuela (Valencia) 1.6%, Costa Rica (San José) 2.0%, and India (Punjab) 1.3%. Based on worldwide distribution, it can be hypothesized that the factor V Leiden mutation has originated and accumulated in central European Caucasians and spread over the world by migration.

Argentina↗
PubMed1997

Recommendations for a core set of outcome measures for future phase III clinical trials in knee, hip, and hand osteoarthritis. Consensus development at OMERACT III.

Significant progress has been made in outcome measurement procedures for osteoarthritis (OA) clinical trials, and guidelines have been established by the US Food and Drug Administration, European League Against Rheumatism, the World Health Organization/International League of Associations for Rheumatology, and the Group for the Respect of Ethics and Excellence in Science. However, there remains a need for further international harmonization of measurement procedures used to establish beneficial effects in Phase III clinical trials. A key objective of the OMERACT III conference was to establish a core set of outcome measures for future phase III clinical trials. During the conference, using a combination of discussion and polling procedures, a consensus was reached by at least 90% of participants that the following 4 domains should be evaluated in future phase III trials of knee, hip, and hand OA: pain, physical function, patient global assessment, and, for studies of one year or longer, joint imaging (using standardized methods for taking and rating radiographs, or any demonstrably superior imaging technique). These evidence based preferences, achieved with a high degree of consensus, establish an international standard for future phase III trials and will also facilitate metaanalysis and Cochrane Collaborative Project goals.

Clinical Trials, Phase III as Topic↗