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S Kaplan

Publications and source records attributed to S Kaplan.

At least 55 records · Page 3Linked to original sources
PubMed2001

Factor V Leiden and its relation to left ventricular thrombus in acute myocardial infarction.

OBJECTIVE: The genetic defect of coagulation factor V, known as factor V Leiden, produces a resistance to degradation by activated protein C (APC) and increases the risk of venous thrombosis. However, the role of factor V Leiden in the formation of left ventricular (LV) thrombus has not been studied. We investigated whether factor V Leiden is a risk factor for LV thrombus in patients with acute myocardial infarction (AMI). METHODS AND RESULTS: We have analyzed clinical, echocardiographic and biochemical data in 135 consecutive patients (aged 58 +/- 13 years; 31 women) with first anterior AMI. Two-dimensional echocardiographic examination was performed on days 1, 3, 7, 15 and 30; LV thrombus was detected in 33 (24.4%) of 135 patients with AMI. The study also included 95 control subjects. Healthy age and sex-matched subjects without a personal or family history of ischaemic heart disease, stroke or thromboembolic disease served as a control group. Blood samples from the patients and controls were analyzed for the factor V Leiden mutation by DNA analysis, using the polymerase chain reaction. In addition, concentrations of fibrinogen, von Willebrand factor (vWF), tissue plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1) and D-dimer were measured in 135 patients. There was no significant difference in the prevalence of factor V Leiden between patients and control subjects. The prevalence of the factor V mutation was 9% (3/33) in patients with thrombus, and 7.7% (8/103) in patients without thrombus. The prevalence of factor V Leiden was 7.3% (7/95) in control subjects. No significant differences in plasma fibrinogen (480 +/- 195 vs. 444 +/- 179 mg/dl, p = 0.6), D-dimer (471 +/- 256 vs. 497 +/- 293 ng/dl, p = 0.7), vWF (112 +/- 18 vs. 103 +/- 15%, p=0.5), PAI-1 (26.7+/- 9.8 vs. 28.1 +/- 10.2 ng/dl, p = 0.6), and t-PA (19.8 +/- 8.7 vs. 17.2 +/- 9.1 ng/dl, p = 0.7), levels are found in patients with LV thrombus when compared with those without LV thrombus. Multivariate analyses showed that peak creatine kinase level (p = 0.002) and LV wall motion score index (p = 0.003) were independent predictors of LV thrombus formation. CONCLUSION: Factor V Leiden mutation is not a risk factor for LV thrombus formation in patients with AMI.

Analysis of Variance↗
PubMed2001

[Effects of factor V Leiden mutations on prognosis in patients with acute myocardial infarction].

OBJECTIVE: Factor V Leiden mutation, the genetic defect underlying resistance to activated protein C, is the most common risk factor for venous thrombosis. Factor V Leiden mutation and its relation to post-myocardial infarction (MI) complications including angina pectoris, heart failure, reinfarction and cardiac mortality has not been investigated. We aimed to investigate this relation. METHODS: The prevalence of factor V Leiden mutation was investigated in 122 patients with first acute myocardial infarction (aged 56 +/- 11, 82 men/40 women). These patients were divided into two groups according to whether the patients had factor V Leiden mutation (Group I) or not (Group II). Post MI complications were evaluated during 18 months. Blood samples from the patients were analyzed for factor V Leiden mutation by DNA analysis, using the polymerase chain reaction (PCR). RESULTS: Factor V Leiden was detected in 11 (9%) patients (aged; 54 +/- 10, 5 women/men) and was not detected in 111(90%) patients (aged; 56 +/- 11; 35 women/76 men) of the 122 patients. There were no significant differences between Group I and Group II in terms of post MI complications, including reinfarction (27% vs. 29%; p > 0.05, respectively), angina pectoris (45% vs. 38%; p > 0.05, respectively), heart failure (27% vs. 23%; p > 0.05, respectively) and cardiac mortality (18% vs. 14%; p > 0.05, respectively). CONCLUSION: Post MI complications, including reinfarction, heart failure, angina pectoris and cardiac mortality were not increased in patients with factor V Leiden.

Activated Protein C Resistance↗
PubMed2000

Physician-patient communication in HIV disease: the importance of patient, physician, and visit characteristics.

BACKGROUND: Although previous work that considered a variety of chronic conditions has shown that higher quality physician-patient communication care is related to better health outcomes, the quality of physician-patient communication itself for patients with HIV disease has not been well studied. OBJECTIVE: To determine the relationship of patient, visit, physician, and physician practice characteristics to two measures of physician-patient communication for patients with HIV disease. DESIGN: Cross-sectional survey of physicians and patients. SETTING: Cohort study enrolling patients from throughout eastern Massachusetts. STUDY SUBJECTS: 264 patients with HIV disease and their their primary HIV physicians (n = 69). MEASUREMENTS: Two measures of physician-patient communication were used, a five-item general communication measure (Cronbach's alpha = 0.93), and a four-item HIV-specific communication measure that included items about alcohol, drug use, and sexual behaviors (Cronbach's alpha = 0.92). RESULTS: The mean age of patients was 39. 5 years, 24% patients were women, 31.1% were nonwhite, and 52% indicated same-sex contact as their principal HIV risk factor. The mean age of physicians was 39.1 years, 33.3% were female, 39.7% were specialists, and 25.0% self-identified as gay, lesbian, or bisexual. In multivariable models relating patient and visit characteristics to general communication, longer reported visit length (p<.0001), longer duration of the physician-patient relationship (p =.02), and female gender (p =.04) were significantly associated with better communication. The interaction of patient gender and visit length was also significant (p =.02); longer visit length was more strongly associated with better general communication for male than female patients. In similar models relating patient and visit characteristics to HIV-specific communication, longer visit length (p <.0001) and less advanced disease stage (p =.009) were associated with better communication. In multivariable models relating physician and practice characteristics to general communication no variables were significant. However, both female physician gender (p =.002) and gay/lesbian/bisexual sexual preference (p =.003) were significantly associated with better HIV-specific communication. CONCLUSIONS: In this study, female and homosexual physicians provided higher quality HIV-specific communication than male and heterosexual physicians. Better understanding the processes by which female and homosexual physicians achieve higher quality communication may help other physicians communicate more effectively. Health care providers and third-party payers should be aware that shorter visits may compromise physician-patient communication, and that this effect may be more consequential for male patients.

Adult↗
PubMed2000

Respiratory pathways of Rhodobacter sphaeroides 2.4.1(T): identification and characterization of genes encoding quinol oxidases.

Rhodobacter sphaeroides 2.4.1(T) respires aerobically via a branched respiratory chain consisting of both cytochrome c oxidases and quinol oxidases. Here, genes from chromosome II encoding two distinct quinol oxidases have been characterized. The qoxBA genes encode a putative heme-copper quinol oxidase, whereas the qxtAB genes encode a quinol oxidase homologous to the cyanide-insensitive oxidase of Pseudomonas aeruginosa. No phenotype was observed for mutations in either oxidase in the wild-type background. A strain containing a qxtA mutation in a cytochrome bc(1) complex mutant background was unable to grow aerobically. No role was found for the Qox oxidase, nor was a qoxB::lacZ transcriptional fusion expressed under a variety of conditions. These are the first molecular studies to characterize the quinol oxidases of R. sphaeroides 2.4.1(T).

Aerobiosis↗
PubMed2000

Impact of baseline symptom severity on future risk of benign prostatic hyperplasia-related outcomes and long-term response to finasteride. The Pless Study Group.

OBJECTIVES: To evaluate the long-term effects of finasteride on symptoms, acute urinary retention (AUR), and the need for benign prostatic hyperplasia (BPH)-related surgery in relationship to baseline symptom severity. METHODS: A total of 3040 men with BPH were treated for 4 years with finasteride or placebo. The changes from baseline in symptoms and the incidence of BPH-related surgery and AUR were determined in men with mild (less than 8), low-moderate (8 to 12), high-moderate (13 to 19), and severe (greater than 19) baseline quasi-American Urological Association symptoms for all patients and for the subgroup with a baseline prostate-specific antigen (PSA) level of 1.4 ng/mL or greater. RESULTS: In patients who completed the 4-year study, the change in symptom score, stratified by baseline symptom severity, was +1.4 +/- 0.5 (mild), -0.8 +/- 0.3 (low-moderate), -3.6 +/- 0.3 (high-moderate), and -7.7 +/- 0.5 (severe) in finasteride-treated patients and, respectively, +3.4 +/- 0.5, +0.7 +/- 0.3, -1.4 +/- 0.3, and -5.3 +/- 0.6 in placebo-treated patients (between-group P <0.01). The between-group differences were greater in the subgroup of patients with a baseline PSA of 1.4 ng/mL or greater. The risk of BPH-related surgery increased among placebo patients with increasing baseline symptom severity to a greater extent than the risk of AUR. Finasteride reduced the risk of AUR or the need for BPH-related surgery in all subgroups (P <0.001), especially in men with a baseline PSA of 1.4 ng/mL or greater. CONCLUSIONS: Compared with placebo, finasteride had a beneficial effect on symptoms, AUR, and BPH-related surgery in all symptom categories. BPH-related surgery, but not AUR, occurred more commonly in placebo-treated men with more severe baseline symptoms. The greatest absolute benefit of finasteride on symptoms and the reduction in risk of AUR and surgery was in men with higher baseline symptom scores and a baseline PSA level of 1.4 ng/mL or greater.

Aged↗
PubMed2000

Cardiac dysfunction and mortality in HIV-infected children: The Prospective P2C2 HIV Multicenter Study. Pediatric Pulmonary and Cardiac Complications of Vertically Transmitted HIV Infection (P2C2 HIV) Study Group.

BACKGROUND: Left ventricular (LV) dysfunction is common in children infected with the human immunodeficiency virus (HIV), but its clinical importance is unclear. Our objective was to determine whether abnormalities of LV structure and function independently predict all-cause mortality in HIV-infected children. METHODS AND RESULTS: Baseline echocardiograms were obtained on 193 children with vertically transmitted HIV infection (median age, 2.1 years). Children were followed up for a median of 5 years. Cox regression was used to identify measures of LV structure and function predictive of mortality after adjustment for other important demographic and baseline clinical risk factors. The time course of cardiac variables before mortality was also examined. The 5-year cumulative survival was 64%. Mortality was higher in children who, at baseline, had depressed LV fractional shortening (FS) or contractility; increased LV dimension, thickness, mass, or wall stress; or increased heart rate or blood pressure (P0.02 for each). Decreased LV FS (P<0.001) and increased wall thickness (P=0.004) were also predictive of increased mortality after adjustment for CD4 count (P<0.001), clinical center (P<0.001), and encephalopathy (P<0.001). FS showed abnormalities for up to 3 years before death, whereas wall thickness identified a population at risk only 18 to 24 months before death. CONCLUSIONS: Depressed LV FS and increased wall thickness are risk factors for mortality in HIV-infected children independent of depressed CD4 cell count and neurological disease. FS may be useful as a long-term predictor and wall thickness as a short-term predictor of mortality.

Cardiovascular Diseases↗
PubMed2000

Absence of cardiac toxicity of zidovudine in infants. Pediatric Pulmonary and Cardiac Complications of Vertically Transmitted HIV Infection Study Group.

BACKGROUND: Perinatal exposure to zidovudine may cause cardiac abnormalities in infants. We prospectively studied left ventricular structure and function in infants born to mothers infected with the human immunodeficiency virus (HIV) in order to determine whether there was evidence of zidovudine cardiac toxicity after perinatal exposure. METHODS: We followed a group of infants born to HIV-infected women from birth to five years of age with echocardiographic studies every four to six months. Serial echocardiograms were obtained for 382 infants without HIV infection (36 with zidovudine exposure) and HIV-58 infected infants (12 with zidovudine exposure). Repeated-measures analysis was used to examine four measures of left ventricular structure and function during the first 14 months of life in relation to zidovudine exposure. RESULTS: Zidovudine exposure was not associated with significant abnormalities in mean left ventricular fractional shortening, end-diastolic dimension, contractility, or mass in either non-HIV-infected or HIV-infected infants. Among infants without HIV infection, the mean fractional shortening at 10 to 14 months was 38.1 percent for those never exposed to zidovudine and 39.0 percent for those exposed to zidovudine (mean difference, -0.9 percent; 95 percent confidence interval, -3.1 percent to 1.3 percent; P=0.43). Among HIV-infected infants, the mean fractional shortening at 10 to 14 months was similar in those never exposed to zidovudine (35.4 percent) and those exposed to the drug (35.3 percent) (mean difference, 0.1 percent; 95 percent confidence interval, -3.7 percent to 3.9 percent; P=0.95). Zidovudine exposure was not significantly related to depressed fractional shortening (shortening of 25 percent or loss) during the first 14 months of life. No child over the age of 10 months had depressed fractional shortening. CONCLUSIONS: Zidovudine was not associated with acute or chronic abnormalities in left ventricular structure or function in infants exposed to the drug in the perinatal period.

Anti-HIV Agents↗
PubMed2000

Redox signaling: globalization of gene expression.

Here we show that the extent of electron flow through the cbb(3) oxidase of Rhodobacter sphaeroides is inversely related to the expression levels of those photosynthesis genes that are under control of the PrrBA two-component activation system: the greater the electron flow, the stronger the inhibitory signal generated by the cbb(3) oxidase to repress photosynthesis gene expression. Using site-directed mutagenesis, we show that intramolecular electron transfer within the cbb(3) oxidase is involved in signal generation and transduction and this signal does not directly involve the intervention of molecular oxygen. In addition to the cbb(3) oxidase, the redox state of the quinone pool controls the transcription rate of the puc operon via the AppA-PpsR antirepressor-repressor system. Together, these interacting regulatory circuits are depicted in a model that permits us to understand the regulation by oxygen and light of photosynthesis gene expression in R.SPHAEROIDES:

Antifungal Agents↗
PubMed2000

Pulmonary artery catheterization and clinical outcomes: National Heart, Lung, and Blood Institute and Food and Drug Administration Workshop Report. Consensus Statement.

OBJECTIVE: The efficacy and safety of the pulmonary artery catheter are under scrutiny because of its association with increased morbidity and mortality in observational studies. In response, the National Heart, Lung, and Blood Institute (NHLBI) and the US Food and Drug Administration (FDA) conducted the Pulmonary Artery Catheterization and Clinical Outcomes workshop in Alexandria, Va, on August 25 and 26, 1997, to develop recommendations regarding actions to improve pulmonary artery catheter utility and safety. PARTICIPANTS: The NHLBI and FDA planning task force selected a workshop chairperson, subcommittee chairs, and participants. Approximately 85 participants were selected for their collective expertise in critical care, pulmonary medicine, cardiovascular medicine and surgery, pediatrics, nursing, biostatistics, and medical economics. The meeting was open to industry representatives and other government and lay observers. This workshop was funded by the NHLBI and the FDA's Division of Devices. EVIDENCE: Published reports relating to the efficacy and safety of the pulmonary artery catheter, especially consensus documents developed by professional societies. CONSENSUS PROCESS: The planning task force disseminated materials, held teleconferences, and developed draft position papers prior to the workshop. These were modified during the workshop and thereafter in the course of several teleconferences, and presented to the entire group for final modifications and approval. CONCLUSIONS: A need exists for collaborative education of physicians and nurses in performing, obtaining, and interpreting information from the use of pulmonary artery catheters. This effort should be led by professional societies, in collaboration with federal agencies, with the purpose of developing and disseminating standardized educational programs. Areas given high priority for clinical trials were pulmonary artery catheter use in persistent/refractory congestive heart failure, acute respiratory distress syndrome, severe sepsis and septic shock, and low-risk coronary artery bypass graft surgery. JAMA. 2000;283:2568-2572

Catheterization, Swan-Ganz↗
PubMed2000

From redox flow to gene regulation: role of the PrrC protein of Rhodobacter sphaeroides 2.4.1.

Activation of photosynthesis (PS) gene expression by the PrrBA two-component activation system in Rhodobacter sphaeroides 2.4.1 results from the interruption of an inhibitory signal originating from the cbb(3) cytochrome c oxidase via its interaction with oxygen, in conjunction with the Rdx redox proteins. The CcoQ protein, encoded by the ccoNOQP operon, which encodes the cbb(3) cytochrome c oxidase, was shown to act as a "transponder" that conveys the signal derived from reductant flow through cbb(3) to oxygen, to the Prr system. To further define the elements comprising this signal transduction pathway we considered the prrC gene product, which to date possessed no definable role in this signal transduction pathway despite its being part of the prrBCA gene cluster. Similar to mutations in cbb(3) and rdx, suitably constructed prrC deletion mutations lead to PS gene expression in the presence of high oxygen. Unlike mutations that remove cbb(3) terminal oxidase activity or Rdx function, the PrrC deletion mutant shows no effect upon cbb(3) activity, nor does it affect the ratio of the carotenoid (Crt) spheroidene (SE) to spheroidenone (SO). Thus, the PrrC deletion mutant behaves identically to the CcoQ deletion mutant. Taking these and previous results together, we suggest that PrrC is located upstream of the two-component PrrBA activation system in the signal transduction pathway but downstream of the cbb(3) cytochrome c oxidase and its "transponder" CcoQ. The PrrC deletion mutant was also shown to lead to an increase in the DorA protein under aerobic conditions as was shown earlier for the cbb(3) mutant. Finally, PrrC is a member of a highly conserved family of proteins found in both prokaryotes and eukaryotes, and this appears to be the first instance in which a direct regulatory role has been ascribed to a member of this protein family.

Alkaline Phosphatase↗
PubMed2000

TspO of rhodobacter sphaeroides. A structural and functional model for the mammalian peripheral benzodiazepine receptor.

The function and specific structural aspects of the tryptophan-rich sensory protein (TspO) of Rhodobacter sphaeroides 2.4.1 were studied using site-directed mutagenesis involving some 17 different amino acids. The choice of these amino acids changes was dictated from an analysis of the TspO family of proteins derived from the data bases. These studies demonstrated the importance of several highly conserved tryptophan residues in the sensory transduction pathway involving TspO through the proposed binding of an intermediate(s) in the tetrapyrrole biosynthesis pathway. These studies also revealed that the substitution of one or several of the amino acid residues dramatically affected, either directly or indirectly, the levels of TspO in the membranes of R. sphaeroides. Mounting evidence is presented suggesting that TspO normally forms a dimer within the bacterial outer membrane, and the dimer form of TspO may be the active form for TspO function. Because our earlier studies provided us with a functional framework within which to view these amino acid substitutions, we are able to suggest a preliminary model for TspO structure-function. Not only do these studies tell us more about TspO, but they also shed light on the TspO homologue, the drug-binding component of the mitochondrial peripheral benzodiazepine receptor. Mounting evidence draws numerous parallelism between these proteins and supports the significance of using TspO as a model for the structure and function of the mitochondrial protein.

Amino Acid Sequence↗
PubMed2000

DNA sequence analysis of the photosynthesis region of Rhodobacter sphaeroides 2.4.1.

This paper describes the DNA sequence of the photosynthesis region of Rhodobacter sphaeroides 2.4.1 (T). The photosynthesis gene cluster is located within a approximately 73 kb Ase I genomic DNA fragment containing the puf, puhA, cycA and puc operons. A total of 65 open reading frames (ORFs) have been identified, of which 61 showed significant similarity to genes/proteins of other organisms while only four did not reveal any significant sequence similarity to any gene/protein sequences in the database. The data were compared with the corresponding genes/ORFs from a different strain of R.sphaeroides and Rhodobacter capsulatus, a close relative of R. sphaeroides. A detailed analysis of the gene organization in the photosynthesis region revealed a similar gene order in both species with some notable differences located to the pucBAC = cycA region. In addition, photosynthesis gene regulatory protein (PpsR, FNR, IHF) binding motifs in upstream sequences of a number of photosynthesis genes have been identified and shown to differ between these two species. The difference in gene organization relative to pucBAC and cycA suggests that this region originated independently of the photosynthesis gene cluster of R.sphaeroides.

Base Sequence↗
PubMed2000

Same-day surgery managed care: monitoring patient and system variances.

The Same-Day Surgery (SDS) nursing staff at a Midwestern medical center tracked the causative factors for prolonged stays (> 2 hours) in SDS. A review of retrospective data identified that postoperative patient stays averaged between 2 and 3 hours. The top three variances for prolonged stays in SDS were pain, nausea and transportation home. Based on this data, several practice changes that were incorporated to address these variances are reported in this article.

Ambulatory Surgical Procedures↗
PubMed2000

An examination of bias in volunteer subject selection: findings from an in-depth child abuse study.

Remarkably few reported studies tested the assumption that a research sample can be constructed which is representative of the population of interest. In order to investigate potential volunteer bias in abuse research, we utilized a database assembled for an NIMH funded study investigating the relationship among adolescent physical abuse, suicidal behavior, and psychopathology. Extensive information was available concerning the nonparticipant pool from which this sample was assembled, allowing for a comprehensive assessment of possible sample bias. The volunteer sample of 99 abused families who agreed to participate in our study was compared on a large number of variables with a random sample of 99 abused families who declined to participate. Comparisons of the two groups did not support the hypothesis that the non-participating families represented a more dysfunctional population. The two groups were far more similar to, than disparate from, each other.

Adolescent↗
PubMed2000

Cardiac structure and function in fetuses of mothers infected with HIV: the prospective PCHIV multicenter study.

BACKGROUND: This study was designed to determine if vertically transmitted HIV infection and maternal infection with HIV are associated with altered cardiovascular structure and function in utero. METHODS: Fetal echocardiography was performed in 173 fetuses of 169 HIV-infected mothers (mean gestational age, 33.0 weeks; SD = 3.7 weeks) at 5 centers. Biparietal diameter, femur length, cardiovascular dimensions, and Doppler velocities through atrioventricular and semilunar valves and the umbilical artery were measured. Measurements were converted to z scores based on published normal data. RESULTS: Fetuses determined after birth to be HIV-infected had similar echocardiographic findings as fetuses later determined to be HIV-uninfected except for slightly smaller left ventricular diastolic dimensions (P =.01). The femur length (P =.03) was also smaller in the fetuses postnatally identified as HIV-infected. Differences in cardiovascular dimensions and Doppler velocities were identified between fetuses of HIV-infected women and previously published normal fetal data. The reason for the differences may be a result of maternal HIV infection, maternal risk factors, or selection bias in the external control data. CONCLUSIONS: Vertically transmitted HIV infection may be associated with reduced left ventricular size but not with altered cardiac function in utero. Fetuses of HIV-infected mothers may have abnormal cardiovascular structure and function and increased placental vascular resistance, regardless of whether the fetuses are subsequently found to be infected with HIV.

Adult↗