Search PubMed⌕ Search

Biomedical subjects

J Steinberg

Publications and source records attributed to J Steinberg.

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

Review of methods to predict and detect atrial fibrillation in post-cardiac surgery patients.

Atrial fibrillation (AF) is the most common sustained arrhythmia after cardiac surgery. Postoperative AF is known to substantially lengthen hospital stay and affect patient recovery. Identification of those at risk of developing AF after surgery and early detection of AF during recovery would be extremely helpful in effective management of these patients, including targeting prophylactic therapy to prevent AF in high-risk patients. In this communication, diagnostic methods to identify those at risk of developing AF after surgery and early identification of AF before, during, and after surgery have been reviewed. Signal-averaged P wave analysis, done before surgery, identifies patients who are likely to develop AF during recovery. When combined with low ejection fraction, signal-averaged P wave can discriminate those who develop AF from those who do not. During recovery, AF can be detected early either from a detailed analysis of atrial activity in a 10-second electrocardiogram or an analysis of R-to-R intervals from an extended rhythm strip (1 minute or longer). Analysis of the 10-second electrocardiogram includes median QRST subtraction from rhythm data and detection and analysis of atrial signals in the resulting residual. AF is detected from extended rhythm strips by using a statistical model to identify the presence of characteristic irregular patterns of R-to-R intervals.

Atrial Fibrillation↗
PubMed1998

Application of the international prognostic index in a study of Chinese patients with non-Hodgkin's lymphoma and a high incidence of primary extranodal lymphoma.

BACKGROUND: Chemotherapy containing anthracycline is the standard initial treatment for aggressive non-Hodgkin's lymphoma (NHL), and the International Prognostic Index (IPI) is widely accepted as the standard tool for determining the prognosis of patients with this disease. However, the data on which the IPI was based primarily came from studies conducted in Western countries. It may not be directly applicable to Asian populations, in which the incidence of primary extranodal lymphoma (PENL) is known to be high. METHODS: The authors conducted a retrospective study of 218 patients with aggressive NHL who were treated with chemotherapy. They analyzed the distribution of stage and pathology, prognostic factors, toxicity, and treatment outcome. The IPI was then applied and its ability to identify distinct prognostic groups tested. RESULTS: Eighty-six patients (39.4%) had lymph node lymphoma (LNL) and 132 (60.6%) had primary extranodal lymphoma (defined as non-Hodgkin's lymphoma with primary presentation, bulk of disease, and histologic confirmation at an extranodal site). The most common primary extranodal sites were the stomach (22%) and Waldeyer's tonsillar ring (18.9%). The complete response rate of PENL patients to chemotherapy containing anthracycline was 52%, as compared with 64% of the LNL group. The 5-year survival rates for patients with LNL and PENL were 57.4% and 52.1%, respectively. The toxicity in the two patient groups was similar. Four of the prognostic factors in the IPI-age, serum LDH, performance status, and disease stage-predicted significantly different survival for PENL and LNL patients. However, the number of extranodal sites involved was not a significant predictive variable in PENL. CONCLUSIONS: The IPI was applicable to this Chinese population in which the incidence of PENL was high, although the number of extranodal sites did not achieve statistical significance as a risk factor. A proposal for modification was made. Chemotherapy containing anthracycline was an effective treatment for both PENL and LNL patients.

Adolescent↗
PubMed1998

Improving preventive health care in a medical resident practice.

BACKGROUND: The ambulatory care resident practice is an opportunity to enhance the skills, knowledge, and attitudes for effective provision of preventive health services (PHS). OBJECTIVE: To determine whether a required intervention at a university medical resident practice would lead to improved performance of 6 secondary PHS. METHODS: A sequentially randomized chart analysis was performed at 2 clinics, a collaborative nurse practitioner practice (NP) and a resident practice (RP) to determine performance rate of secondary PHS (pelvic, prostate, and breast examinations, stool guaiac testing, mammography, and prostate-specific antigen determination). A significantly lower (36.9%) PHS performance rate was noted in the RP compared with 84.5% in NP for all 6 secondary PHS studied. An intervention was implemented in the RP: following every resident-patient clinic encounter a discussion and documentation of the patient's PHS status was required as part of the assessment and plans of management. At the end of 1 year the effect of this intervention on performance rates of the 6 PHS in the RP was analyzed. RESULTS: There was a statistically significant difference (P < .001) between the PHS performance rates of NP and RP at the beginning. The intervention resulted in improved PHS performance rates in the RP; compared with the NP at the end of the study no statistical difference was noted between the groups. CONCLUSIONS: Despite various task force recommendations, PHS performance rates are generally suboptimal in varied clinic settings, including those of resident practices in teaching hospitals. Physicians and residents believe in the importance of health maintenance but fall short of their ideal in practice. Interventions to improve performance rates have been described; we are detailing a simple, inexpensive, and practical method that achieved positive results.

Aged↗
PubMed1998

Intraventricular perineurioma: case report.

OBJECTIVE AND IMPORTANCE: Perineurioma, a rare benign nerve sheath neoplasm occurring in either an intraneural or soft tissue form, has never been reported to arise in the central nervous system. CLINICAL PRESENTATION: We describe the clinical, radiological, and pathological features of a perineurioma arising in the choroid plexus of the third ventricle in a 65-year-old woman and causing obstructive hydrocephalus. INTERVENTION: The lesion, apparently unassociated with a nerve, was gross totally resected by frontal craniotomy using a left-sided transcallosal approach. Short-term follow-up showed no evidence of recurrence. CONCLUSION: Perineurioma of the variety found in soft tissue may occur in the central nervous system, wherein it shows the typical light microscopic, immunohistochemical (epithelial membrane antigen- and Collagen IV-positive, S-100 protein-negative), and ultrastructural (pinocytotic vesicles, discontinuous basement membrane) features.

Aged↗
PubMed1998

Implementing a clinical pathway for congestive heart failure: experiences at a teaching hospital.

Clinical pathways are processes of care that use a multidisciplinary team effort to move patients toward a designed outcome. This article details the challenges of a Quality Enhancement and Clinical Resource Management Team in designing and implementing a successful congestive heart failure pathway at a teaching hospital. Academic institutions have the resources as part of their research mission, to enhance the development of clinical pathways and assess their outcomes.

Aged↗
PubMed1998

Delivery of preventive healthcare to older African-American patients: a performance comparison from two practice models.

While there is an increasing recognition by primary care providers of the importance of preventive health services (PHS), the delivery of such services has in general been substandard in many ambulatory care settings. Patient sociodemographic status and the structural and operational procedures of different clinic models are all believed to affect delivery of PHS. We conducted a 2-year, retrospective, sequentially randomized chart analysis of African-American patients above age 50, comparing primary, secondary, and tertiary PHS performance rates in two practice models: a medicine resident/faculty physician clinic (MR) and a nurse practitioner/faculty physician clinic (NP). Sociodemographics, disease profile, and PHS completion rates from 132 NP and 111 MR patient charts were abstracted. Apart from age, sociodemographic features were similar in both patient groups. While there were differences between clinics with regards to disease profiles (P < 0.05), and the higher number of diseases per patient (P < 0.0001) in the MR population, the NP collaborative practice had significantly better PHS performance. Rates of immunization (influenza/pneumococcal), pelvic/pap and prostate examinations, stool-guaiac testing, mammography, and functional assessment (activities of daily living, instrumental activities of daily living, and mental status testing) were > 90% in the NP and < 60% in MR patients. Although lower completion rates were found for dietary counseling (60%), auditory screening (36%), dental examination (41%), and obtaining advanced directives (24%) in the NP clinic, the rates were higher than those for the MR clinic. In this NP collaborative model, a high level of preventive health services was delivered while providing primary care to an older, inner city, African-American population of low socioeconomic means.

Black or African American↗
PubMed1998

Human immunodeficiency virus in semen arises from a genetically distinct virus reservoir.

The reservoir of human immunodeficiency virus (HIV) in semen is unknown. Several lines of evidence suggest that semen HIV may not arise from the same reservoir of infection as peripheral blood. If true, the viral burden in the two compartments could be qualitatively and quantitatively different, a scenario of potentially profound significance for the design of effective strategies of treatment, disease monitoring, and infection containment. We report here that the ratio of infected to uninfected leukocytes in ejaculated semen specimens is highly discordant with paired blood samples, demonstrating that they derive from distinct populations of infected cells. In addition, infectious HIV was isolated from semen cells, but not from blood cells, of an individual on triple antiretroviral therapy; the absence of major resistance-conferring mutations in the semen virus indicates that it was replicating in isolation from the antiviral agents. The compartmentalization of blood and semen infection was further supported by genetic analysis of several infectious HIV clones isolated from semen cells and peripheral blood cells of another donor not on antiretroviral therapy. Protease gene sequence analyses revealed significant divergence of the two viral populations. These findings confirm the distinct compartmentalization of HIV in the semen of this study cohort, and support the concept that semen HIV arises from an isolated reservoir of infection that may function independently in the pathobiology of HIV disease.

Amino Acid Sequence↗
PubMed1997

Effect of excitatory amino acids on rat hypothalamic somatostatin secretion in vitro.

We studied the effect of various agonists of excitatory amino acid (EAA) receptor subtypes on somatostatin (SRIF) release from incubated rat hypothalamic slices. N-Methyl-D-aspartic acid (NMDA) and L-glutamate (1 x 10(-7) to 1 x 10(-3) M) stimulated, in a dose-dependent fashion, SRIF release. The maximal effect was obtained at a concentration of 1 x 10(-4) M for both drugs. The IC50 was 3.2 x 10(-5) M and 2.1 x 10(-5) M for NMDA and L-glutamate, respectively. Incubation with 2.5 x 10(-4) M D-2-amino-5-phosphonovalerate (a NMDA receptor antagonist) or 2-amino-4-phosphonobutyrate (a metabotropic receptor antagonist) was without significant effect on basal SRIF secretion and completely blocked the increase in SRIF release induced by 5 x 10(-5) M NMDA or L-glutamate, respectively. Incubation with 1 x 10(-4) M kainate or 0.5 x 10(-4) M alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) did not change basal SRIF secretion. Incubation with 2 x 10(-4) M gamma-D-glutamylglycine (a specific antagonist of kainate and AMPA receptors) had no effect under basal conditions or during exposure to kainate or AMPA. Our data demonstrate that EAAs stimulate SRIF secretion in vitro, by an action through NMDA and metabotropic receptors but not kainate or AMPA receptors.

Animals↗
PubMed1997

Glutamate and N-methyl-D-aspartate stimulate rat hypothalamic corticotropin-releasing factor secretion in vitro.

It is known that in vivo excitatory amino acids (EAA) stimulate the hypothalamo-pituitary-adrenal axis. However their site of action is not fully understood. We investigated the possibility of a direct action of EAA on the secretion of the major adrenocorticotropin hormone (ACTH) secretagogue: corticotropin-releasing factor (CRF) from incubated rat hypothalamic slices. N-methyl-D-aspartic acid (NMDA) or L-glutamate (1 x 10(-7) to 1 x 10(-3) M) stimulated in a dose-dependent fashion CRF release. The maximal effect was obtained at a concentration of 1 x 10(-4) M for both drugs. The IC50 was 1.3 x 10(-5) M and 3.3 x 10(-5) M for NMDA and L-glutamate, respectively. Incubation with 2.5 x 10(-4) M D-2-amino-5-phosphonovalerate (a NMDA receptor antagonist) or 2-amino-4-phosphonobutyrate (a metabotropic receptor antagonist) was without significant effect on basal CRF secretion and completely blocked the increase in CRF release induced by 5 x 10(-5) M NMDA or L-glutamate, respectively. Incubation with 1 x 10(-4) M kainate or 0.5 x 10(-4) M AMPA did not change basal CRF secretion. Incubation with 2 x 10(-4) M gamma-D-glutamylglycine (a specific antagonist of kainate and AMPA receptor) had no effect under basal conditions or during exposure to kainate or AMPA. Our data demonstrate that EAA could stimulate directly CRF secretion, by an action through NMDA and metabotropic receptors, but not kainate or AMPA receptors. These findings may be relevant to the regulation of the hypothalamo-pituitary adrenal axis, both under basal conditions and during exposure to stress.

Animals↗
PubMed1997

Intracellular levels of SGP-2 (Clusterin) correlate with tumor grade in prostate cancer.

Our previous observations in LNCaP cells in vitro demonstrated an association between apoptotic cell death resistance and SGP-2 (Clusterin) overexpression. Accordingly, we hypothesized that high levels of cellular SGP-2 would aid in identifying biologically aggressive prostate cancer cells with unique survival advantages. To test this hypothesis, 40 archival radical prostatectomy and/or biopsy specimens of varying grades of prostate cancer were subjected to immunohistochemical SGP-2 staining. The resulting epithelial stains were quantified subjectively on a scale of 1-3 by four independent observers. Benign prostatic epithelial cells from young donors served as controls and showed a consistently weak staining intensity. In contrast, prostate cancer specimens showed varying degrees of staining intensity that correlated with a Gleason pattern (P = 0.006). This correlation supports the hypothesis that protection from apoptotic death may account, in part, for biologically aggressive tumor behavior.

Adenocarcinoma↗
PubMed1996

The advantages of the disease model.

Health care professionals are interested in practical definitions that provide solutions to problems. There are many advantages to defining chemical dependence as a disease. This paper gives a health care professional clear directions regarding identifying the problem of chemical dependence and specifying a specific treatment plan for patients. We review the issues of personal responsibility, the moral model of addictions, and the neuropharmacology of the disease process, and advocate for the disease model as an effective, practical method for treating alcoholism and drug dependence.

Attitude of Health Personnel↗
PubMed1995

Amino acids and ammonia in the cerebral cortex, the corpus striatum and the brain stem of the mouse prior to the onset and after a seizure induced by hyperbaric oxygen.

The contents of amino acids (AA) and ammonia (NH3) were measured in corpus striatum, brain stem and cerebral cortex of two strains of mice exposed to hyperbaric oxygen (HBO). Mice of the HBO-sensitive strain (CD1) were exposed to 600 kPa O2 for 24 min versus 90 min for mice of the normal C57 strain, so that 50% of the mice in both strains developed a generalized convulsion. In the cortex of exposed but unconvulsed (EXUN) C57 mice, the contents of taurine, glutamine and NH3 increased while that of GABA decreased when compared to control mice. In the CD1 mice, NH3 content was increased while that of Asp decreased. After a convulsion, NH3 was increased in both strains, the AA contents returned to normal in C57 but Asp remained low in CD1 mice. Somewhat similar changes occurred in the striatum except that NH3 levels were less affected while GABA ones were significantly decreased in the CD1 mice exposed to HBO, whether convulsed or not. In the EXUN brain stem, Asp and Glu contents decreased. These decreases were greater in C57 on a percentage basis than in CD1 mice. GABA content was decreased in the C57 strain. After a convulsion, Asp and Glu levels remained low and NH3 accumulated in CD1 whereas in C57 only the Glu level was decreased. The cortical and striatal changes may indicate a lesser GABA supply in C57 strain and some Asp release in CD1 strain. In the brain stem of both strains, Asp and Glu release is possible in addition to GABA in C57 strain.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMed1995

Management of recurrent priapism with epinephrine self-injection and gonadotropin-releasing hormone analogue.

A case of recurrent priapism in a young black man without sickle cell anemia is reported. Due to almost daily episodes of prolonged painful erections, the patient was instructed in intracorporeal injection using an epinephrine self-injection kit, which provided complete detumescence on 31 occasions. The patient refused surgical intervention and was treated with monthly intra-muscular gonadotropin-releasing hormone analogue. Priapism episodes completely abated by the second and final monthly gonadotropin-releasing hormone analogue injection without recurrence during 4 months of followup. Normal erectile function was maintained during and after gonadotropin-releasing hormone analogue therapy. Epinephrine self-injection and gonadotropin-releasing priapism.

Adult↗
PubMed1995

[Radiologic visibility of breast fibroadenomas].

From a clinical point of view, all mammary fibroadenomas are similar. However some of them are not visible in mammograms, phenomenon probably related to glandular density. Aiming to elucidate whether the lack of visibility is caused by the glandular density or by tumor itself, a three stage study was performed. In 201 cases the mammographic visibility of fibroadenomas was determined and correlated with patient's age, the presence of fibrocystic disease and tumor histological type; after surgical excision, 18 fibroadenomas were sliced into 5 mm thick samples and X rayed to determine their visibility; finally 2 visible and 2 non visible tumors were calcinated at 550 degrees C and their ashes subjected to X-ray diffraction analysis. Twenty two percent of fibroadenomas were not visible on mammography, this percentage was higher for intracanalicular tumors, in younger women and in the presence of fibrocystic disease. Sixteen percent of excised and sliced tumors were not visible on X rays. Also, differences were found in X-ray diffraction studies between visible and invisible tumors, probably related to NaCl and KCl tumor content.

Adolescent↗
PubMed1994

Effect of streptozotocin-induced diabetes on somatostatin receptors in the anterior pituitary, hypothalamus and cerebral cortex of the male rat.

In order to better understand the mechanisms underlying the reduction in GH secretion in diabetic rats, we have characterized and measured SRIH receptors in the hypothalamus and anterior pituitary gland 5 and 9 days after induction of diabetes in the rat. Experimental diabetes was induced by an intraperitoneal injection of streptozotocin (STZ) at a dose of 65 mg/kg. Basal plasma GH was significantly reduced in diabetic rats. Chronic insulin replacement therapy partly restored plasma GH and blood glucose levels in these animals. A significant reduction in SRIH receptor concentrations was demonstrated in the hypothalamus and anterior pituitary gland, 5- and 9- days after STZ injection. These changes were not significantly corrected by insulin replacement. Cerebral cortex SRIH receptor concentrations were unaffected by experimental diabetes. We conclude that hypothalamic and pituitary SRIH receptor levels are lowered in diabetic rats. These changes may contribute to aberrant GH secretion in diabetes and they indicate that pituitary sensitivity to exogenous somatostatin should be tested in diabetic patients.

Animals↗
PubMed1994

Intramuscular versus oral antibiotic therapy for the prevention of meningitis and other bacterial sequelae in young, febrile children at risk for occult bacteremia.

Because studies of the treatment of children with occult bacteremia have yielded conflicting results, we compared ceftriaxone with amoxicillin for therapy. Inclusion criteria were age 3 to 36 months, temperature > or = 39 degrees C, an acute febrile illness with no focal findings or with otitis media (6/10 centers), and culture of blood. Subjects were randomly assigned to receive either ceftriaxone, 50 mg/kg intramuscularly, or amoxicillin, 20 mg/kg/dose orally for six doses. Of 6733 patients enrolled, 195 had bacteremia and 192 were evaluable: 164 Streptococcus pneumoniae, 9 Haemophilus influenzae type b, 7 Salmonella, 2 Neisseria meningitidis, and 10 other. After treatment, three patients receiving amoxicillin had the same organism isolated from their blood (two H. influenzae type b, one Salmonella) and two from the spinal fluid (two H. influenzae type b), compared with none given ceftriaxone. Probable or definite infections occurred in three children treated with ceftriaxone and six given amoxicillin (adjusted odds ratio 0.43, 95% confidence interval 0.08 to 1.82, p = 0.31). The five children with definite bacterial infections (three meningitis, one pneumonia, one sepsis) received amoxicillin (adjusted odds ratio 0.00, 95% confidence interval 0.00 to 0.52, p = 0.02). Fever persisted less often with ceftriaxone (adjusted odds ratio 0.52, 95% confidence interval 0.28 to 0.94, p = 0.04). Although the difference in total infections was not significant, ceftriaxone eradicated bacteremia, prevented significantly more definite focal bacterial complications, and was associated with less persistent fever.

Administration, Oral↗