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Biomedical subjects

S Goldman

Publications and source records attributed to S Goldman.

At least 253 records · Page 14Linked to original sources
PubMed1992

Perianal Paget's disease: report of five cases.

Paget's disease of the anus is a rare perianal disorder. The condition is often associated with underlying invasive carcinoma. The prognosis is poor when rectal adenocarcinoma is present. Five own cases of perianal Paget's disease are presented. In two of our cases an underlying adenocarcinoma was found in the anorectum. Adenocarcinoma is sweat gland ducts was found in one case. One patient developed an adenocarcinoma in the anorectal junction four years after the Paget diagnose. In only one of our cases no underlying adenocarcinoma was found.

Adenocarcinoma↗
PubMed1992

Interval cancer and survival in a randomized breast cancer screening trial in Stockholm.

The aim of the present study was to analyse the survival rate in a group of breast cancers detected in the intervals between screening examinations in relation to clinically detected cancers in a non-screened population. All interval and control cancers were recruited from a randomized controlled mammography screening trial in Stockholm. The overall survival up to eight years of observation was higher in 191 patients with interval cancers than in 142 control cancers (p = 0.01). There were no significant differences between the two groups with regard to tumor size, stage distribution, or mean age, though the interval group did have a larger proportion of younger women. The similarity was confirmed by multiple regression analysis. The overall survival stage by stage was consistently higher in interval cancers. The survival rate in the true interval cancers was similar to that for those found in retrospect to have been detectable or traceable at the time of screening. No correlation was found between the length of the interval and the survival of patients with interval cancers. These results contradict the hypothesis that a high growth rate is associated with a poorer prognosis and that interval cancers are a more aggressive form of breast neoplasia.

Adult↗
PubMed1992

Immunocytochemical analysis of receptors for estrogen and progesterone in fine needle aspirates from anal epidermoid carcinoma.

Fifteen patients with anal epidermoid carcinoma were examined with percutaneous or transanorectal fine needle aspiration (FNA) cytology. Aspirates from all patients allowed cytologic verification of the diagnosis. Estrogen receptor (ER) and progesterone receptor (PgR) were analyzed using an immunohistochemical technique well adapted for steroid receptor analysis in hormone-dependent carcinomas. Neither ER nor PgR could be detected in any of the aspirates. This finding is somewhat unexpected since there is a strong female predominance in this tumor type. However, our findings do not negate that sex steroid hormones may indirectly play a role in the tumorigenesis of anal epidermoid carcinoma.

Adult↗
PubMed1992

Effects of beta-adrenergic blockade on papillary muscle function and the beta-adrenergic receptor system in noninfarcted myocardium in compensated ischemic left ventricular dysfunction.

BACKGROUND: beta-Adrenergic receptor blockade has been reported to improve hemodynamics and beta-adrenergic receptor-adenylate cyclase function in idiopathic dilated cardiomyopathy. The purpose of this study was to determine the effects of beta-adrenergic receptor blockade on the beta-adrenergic receptor system and myocardial function in a model of compensated ischemic heart failure. METHODS AND RESULTS: We examined the effects of propranolol treatment on the beta-adrenergic receptor-adenylate cyclase system and isolated papillary muscle isometric function in noninfarcted left ventricular myocardium in rats after coronary artery ligation. In untreated rats with large myocardial infarction (MI), developed tension (DT) (3.0 +/- 0.7 versus 5.1 +/- 1.1 g/mm2), peak rate of tension rise (+dT/dt) (40.3 +/- 9.5 versus 71.2 +/- 12.0 g/mm2/sec), and peak rate of tension fall (-dT/dt) (24.4 +/- 5.0 versus 38.2 +/- 6.0 g/mm2/sec) were decreased (p < 0.05). In addition, DT, +dT/dt, and -dT/dt of untreated MI rats demonstrated an impaired response to isoproterenol stimulation compared with controls. beta-Adrenergic receptor density (Bmax) measured by [125I]iodocyanopindolol (ICYP) binding was decreased 23% after infarction (9.3 +/- 0.6 versus 12.0 +/- 1.8 fmol/mg protein [prot]) (p < 0.05); however, the dissociation constant (Kd) for ICYP was not changed (24.1 +/- 5.7 versus 33.2 +/- 12.1 pM). Adenylate cyclase activity in the presence of 10(-2) M MgCl2 was reduced (p < 0.05) in MI rats (30.3 +/- 10.8 versus 45.9 +/- 12.5 pmol cAMP/min/mg prot). Maximal isoproterenol (52.5 +/- 7.3 versus 79.9 +/- 10.0 pmol cAMP/min/mg prot), guanyl-5'-imidodiphosphate (GppNHp) (95 +/- 8 versus 141 +/- 25 pmol cAMP/min/mg prot) and forskolin (503 +/- 76 versus 753 +/- 157 pmol cAMP/min/mg prot) stimulation of adenylate cyclase was also decreased (p < 0.05). In addition, manganese-stimulated adenylate cyclase activity was depressed (p < 0.05) in MI rats compared with controls (23.5 +/- 2.8 versus 52.1 +/- 9.0 pmol cAMP/min/mg prot). Chronic propranolol treatment in MI rats improved DT (4.1 +/- 0.9 versus 3.0 +/- 0.7 g/mm2) and +dT/dt (54.4 +/- 11.3 versus 40.5 +/- 9.5 g/mm2/sec) (p < 0.05); however, isoproterenol-stimulated isometric function remained impaired. Propranolol treatment normalized Bmax (11.9 +/- 1.7 versus 9.3 +/- 0.6 fmol/mg prot) (p < 0.05), whereas adenylate cyclase activity remained depressed. CONCLUSIONS: After large MI in rats, there is impaired papillary muscle function with decreased beta-adrenergic receptors and adenylate cyclase activity in the noninfarcted myocardium. Propranolol treatment improved basal isometric muscle function and beta-adrenergic receptor density in rats after myocardial infarction but did not improve adenylate cyclase activity or isoproterenol-stimulated muscle function. These data suggest that there is a primary defect in adenylate cyclase function that persists despite upregulation of receptors with propranolol treatment.

Adenylyl Cyclases↗
PubMed1992

Arterial mechanics in spontaneously hypertensive rats. Mechanical properties, hydraulic conductivity, and two-phase (solid/fluid) finite element models.

To characterize the interaction between mechanical and fluid transport properties in hypertension, we measured in vivo elastic material constants and hydraulic conductivity in intact segments of carotid arteries in normal and spontaneously hypertensive rats (SHR). With the use of a finite element model, the arterial wall was modeled as a large-deformation, two-phase (solid/fluid) medium, which accounts for the existence and motion of the tissue fluid. Measurements of internal diameter and transmural pressures were obtained during continuous increases in pressure from 0 to 200 mm Hg. Strain and stress components were calculated based on a pseudostrain exponential energy density function. To measure the hydraulic conductivity, segments of the carotid artery were isolated, filled with a 4% oxygenated albumin-Tyrode's solution, and connected to a capillary tube. The movement of the meniscus of the capillary tube represented the fluid filtration across the artery. To study the influence of transmural pressure on hydraulic conductivity, measurement of fluid filtration across the arterial wall was obtained at transmural pressures of 50 and 100 mm Hg. The material constants in the SHR (n = 9) were higher (p less than 0.05 for all variables) than in normal rats (n = 10): c = 1,343 +/- 96 versus 1,158 +/- 65 mm Hg, b1 = 1.84 +/- 0.24 versus 1.22 +/- 0.22, b2 = 0.769 +/- 0.114 versus 0.616 +/- 0.11, b3 = 0.017 +/- 0.005 versus 0.0065 +/- 0.002, b4 = 0.206 +/- 0.04 versus 0.083 +/- 0.03, b5 = 0.0594 +/- 0.007 versus 0.0217 +/- 0.006, and b6 = 0.22 +/- 0.09 versus 0.123 +/- 0.02, respectively. The hydraulic conductivity of the total wall, calculated from the filtration data, was lower (p less than 0.05) at both 50 and 100 mm Hg in the SHR (n = 6) compared with normal rats (n = 7): 1.12 +/- 0.31 x 10(-8) and 0.72 +/- 0.23 x 10(-8) versus 1.95 +/- 0.53 x 10(-8) and 1.35 +/- 0.47 x 10(-8) cm/(sec.mm Hg), respectively. The intergroup comparisons between 50 and 100 mm Hg in both SHR and normal rats were also different (p less than 0.05). The finite element model was used to predict tissue fluid pressure distribution, tissue fluid velocity distribution, and total Cauchy stress gradients developed in the arterial wall during fluid pressurization in both species.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1992

Positron emission tomography-guided stereotactic brain biopsy.

We describe a technique that allows target definition for stereotactic brain biopsy using coordinates calculated on stereotactic positron emission tomographic (PET) images. In this study, PET images were obtained using [18F]-labeled fluorodeoxyglucose, a marker for glucose metabolism. The difference between PET-calculated and actual stereotactic coordinates of simulated targets is within PET spatial resolution. Combined computed tomography- and PET-guided stereotactic biopsies were performed in 11 patients with brain tumors. In this report, we describe two representative patients who underwent stereotactic brain biopsy using the present technique. Because of the complementary role of PET and computed tomography, their integration in multimodality planning might optimize the target selection for stereotactic brain biopsies.

Astrocytoma↗
PubMed1992

Captopril and ANP: changes in renal hemodynamics, glomerular-ANP receptors and guanylate cyclase activity in rats with heart failure.

To define the renal effects of atrial natriuretic peptide (ANP) in heart failure, we studied rats with heart failure after coronary artery ligation. The rats received either captopril (2 milligrams drinking water) or placebo for 4 weeks. Glomerular filtration rate, renal plasma flow, filtration fraction, urine volume, urinary sodium excretion and the percent fractional excretion of sodium were measured before and after an infusion of ANP (0.3 microgram/kg/min). To determine whether changes in ANP receptor binding and responsiveness occur in heart failure and after captopril treatment, we performed radioreceptor binding studies and measured guanylate cyclase activity. Atrial natriuretic peptide in sham-operated rats decreased mean arterial pressure from 118 +/- 5 to 95 +/- 5 mm Hg (P less than .001), increased urine volume from 0.06 +/- 0.02 to 0.16 +/- 0.05 ml/min/kg (P less than .05), urinary sodium excretion, 14.2 +/- 3.1 to 41.4 +/- 8.9 mu eq/min/kg (P less than .02), filtration fraction from 0.30 +/- 0.03 to 0.40 +/- 0.4 (P less than .05), and the percent fractional excretion of sodium from 0.84 +/- 0.19 to 2.85 +/- 0.61 (P less than .02). Atrial natriuretic peptide in untreated rats with heart failure produced no significant systemic or renal hemodynamic effects. In rats with heart failure treated with captopril, ANP decreased mean arterial pressure from 93 +/- 4 to 86 +/- 4 mm Hg (P less than .05) and increased hematocrit from 50 +/- 2 to 52 +/- 1 (P less than .001).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Observations, legends, and conjectures concerning restricted T-cell receptor usage and autoimmune disease.

It has become clear over the past few years that a variety of experimental autoimmune conditions are mediated by T cells bearing a highly restricted subset of antigen receptors. This restricted TcR usage raises important questions concerning not only the recognition of autoantigens, but also the pathogenic mechanisms underlying many models of autoimmunity. Furthermore, the extension of these findings in certain cases to human disease has raised the possibility of specific therapeutic immune intervention. In this review, we examine the available data on restricted T-cell receptor usage in autoimmune disorders and explore the interpretations and the theoretical and practical implications of these findings.

Autoimmune Diseases↗
PubMed1992

Cardiac effects of 3,5-diiodothyropropionic acid, a thyroid hormone analog with inotropic selectivity.

Thyroid hormone exerts a strong positive inotropic action on the heart and induces alpha-myosin heavy chain (MHC) gene expression. 3,5-Diiodothyropropionic acid (DITPA), a carboxylic acid analog with low metabolic activity, was observed to induce alpha-MHC mRNA in heart cell culture with EC50 approximately 5 x 10(-7) M. To determine if the compound has positive inotropic actions, the effects of DITPA and L-thyroxine on heart rate, left ventricular pressures, left ventricular dP/dt, myosin isoenzymes and hepatic alpha-glycerolphosphate dehydrogenase activity were compared in hypothyroid rats. Binding affinities of DITPA and triiodothyronine for bacterially expressed alpha-1 and beta-1 thyroid hormone receptors (TRs) also were determined. Over the dosage range of 150 to 1500 micrograms/100 g, DITPA produced increases in left ventricular dP/dt comparable to those obtained with L-thyroxine at dosages of 1.5 to 15 micrograms/100 g, but with significantly less tachycardia. The increase in alpha-MHC mRNA was about the same with both compounds whereas alpha-MHC protein content and GPDH activity increased less with DITPA. These differences could not be explained by preferential binding of DITPA to TR subtypes. Because heart rate is a major determinant of myocardial oxygen consumption, DITPA is able to achieve increased cardiac performance at lower myocardial oxygen costs.

Animals↗
PubMed1992

Baroreflex control of heart rate in rats with heart failure after myocardial infarction: effects of captopril.

Activation of the renin-angiotensin and sympathetic nervous systems in heart failure may result in altered baroreflex control of heart rate. To determine the specific effects of treatment with captopril on baroreceptor dysfunction in heart failure, baroreflex control of heart rate was measured in conscious rats with heart failure 6 weeks after ligation of the left coronary artery. Plasma norepinephrine was measured as a reflection of sympathetic nervous system activity. After bolus injections of phenylephrine (2-50 micrograms/kg) and nitroprusside (2-50 micrograms/kg), the arterial baroreflex was analyzed by fitting percentage of mean arterial pressure changes and heart rate changes to a logistic regression function. There were no differences in baroreflex function between normal and sham-operated rats. Plasma norepinephrine was increased (P < .05) in the heart-failure rats and did not change with captopril treatment. In untreated rats, heart failure increased (P < .05) the centering point by 900%, threshold by 243% and saturation by 89%, whereas decreasing (P < .05) the operational point by 73%. There was a decrease (P < .05) in the nitroprusside-related gain and an increase (P < .05) in phenylephrine-related gain, but the overall baroreflex gain was not changed. In heart-failure rats, captopril increased (P < .05) threshold, saturation and centering point and decreased (P < .05) operational point and nitroprusside- and phenylephrine-related gain abnormalities. The increase in operational point and decreases in threshold, saturation, centering point and phenylephrine-related gain were the results of a specific interactive effect of captopril in heart failure (P = .0033, .0176, .0509, .0217 and .0567, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Effects of captopril on contractility after myocardial infarction: experimental observations.

After large myocardial infarction, compromised left ventricular (LV) function and changes in the peripheral circulation result in the syndrome of chronic congestive heart failure. Although treatment with angiotensin-converting enzyme inhibitors improve cardiovascular function, it is difficult to determine whether this benefit is due to changes in organ versus muscle function. The rat model of heart failure, created by ligating the left coronary artery, results in pathophysiology that is similar to that seen in patients, i.e., increased LV end-diastolic pressure and volume, hypertrophy of the noninfarcted myocardium, prolongation of the time constant of LV relaxation, decreased venous compliance, and increased total blood volume. In noninfarcted papillary muscles, isolated from rats with heart failure, maximal developed tension and peak rate of tension rise (+dT/dt) are decreased, time to peak tension is prolonged, and myocardial stiffness is increased. Morphologic changes include an increase in papillary muscle myocyte cross-sectional area and an increase in myocardial hydroxyproline content. Captopril (2 g/liter drinking water) alters LV loading by decreasing arterial pressure, increasing venous compliance, and decreasing blood volume. This results in a decrease in LV end-diastolic pressure and volume. In the noninfarcted myocardium, time to peak tension is shortened, whereas developed tension, +dT/dt, and muscle stiffness remain abnormal. Captopril decreases myocyte cross-sectional area, but collagen content remains elevated. Thus, in the rat infarct model of heart failure, treatment with captopril alters LV remodeling and hypertrophy but produces only modest improvement in muscle function.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Effects of endogenous dopamine on kinetics of [3H]N-methylspiperone and [3H]raclopride binding in the rat brain.

Competition by endogenous dopamine with the binding of D2 dopamine receptor ligands may be important in the interpretation of positron emission tomography (PET) neuroreceptor studies. PET studies with N-methylspiperone (NMSP) have revealed increased D2 dopamine receptors in schizophrenia, whereas studies with raclopride (RAC) have not detected such differences. This may be due, at least in part, to differences in competition with endogenous dopamine for ligand binding. To determine effects of endogenous dopamine on in vivo receptor binding, adult male rats were preinjected with amphetamine and reserpine prior to [3H]NMSP or [3H]RAC. Striatal to cerebellar ratios of ligand binding were determined. To approximate the conditions of a PET study, a kinetic model was employed to examine effects of pharmacologically increasing brain dopamine levels (amphetamine pretreatment) on PET ligand binding. In these experiments, tail veins and arteries were cannulated and kinetic parameters determined from normalized integral plots in rats treated with amphetamine prior to radioligand injection. Both [3H]NMSP (43.5%) and [3H]RAC (41.5%) binding were significantly decreased after amphetamine pretreatment, whereas after reserpine pretreatment [3H]RAC binding was increased (52.7%). Kinetic studies revealed a marked resistance of [3H]NMSP to competition with endogenous dopamine released by amphetamine. In contrast, kinetic parameters of [3H]RAC were markedly reduced at all time intervals. This suggests significant differences in competition with endogenous dopamine by [3H]NMSP and [3H]RAC, determined kinetically. These findings may have important implications for the interpretation of PET neuroreceptor studies.

Amphetamine↗
PubMed1991

Transanorectal ultrasonography in the staging of anal epidermoid carcinoma.

Fifty consecutive patients with anal canal epidermoid carcinoma were evaluated by transanorectal ultrasonography (TRUS) at diagnosis. Forty-six patients were treated with primary radiotherapy plus bleomycin. Twenty-eight of the last 30 patients underwent, in addition, planimetric volume determination. The ultrasound findings were compared with clinical stage as assessed by digital palpation. Tumours in clinical stages T1-2 showed evidence of penetration through the anorectal muscular wall at ultrasound (UT3-4) in two-thirds of the cases. This was the case in all tumours in clinical stages T3-4. A clear correlation between tumour size, depth of invasion, and tumour volume, respectively, and residual tumour after a "pre-operative" dose of 40 Gy plus bleomycin was found. When combining clinical stage with TRUS, all tumours classified as T1-2/UT1-2 had a complete response (CR) after the first radiotherapy period, whereas the corresponding figures for those with deep invasion ultrasonographically (T1-2/UT3-4 and T3-4/UT3-4) were 64 percent and 0 percent, respectively. It thus appears that TRUS could complement digital palpation in staging anal canal carcinoma.

Adult↗
PubMed1991

A randomized prospective study on the effect of short and long buserelin treatment in women with repeated unsuccessful in vitro fertilization (IVF) cycles due to inadequate ovarian response.

Fifty four women with repeated unsuccessful in vitro fertilization (IVF) cycles due to inadequate ovarian response to stimulation with human menopausal gonadotropins (hMG) participated in this study. They were randomized to receive either gonadotropin releasing hormone agonist (GNRHa), Buserelin, prior to and during induction of ovulation by hMG (Group I--long protocol), or GnRHa starting on the first day of the cycle together with induction of ovulation by hMG (Group II--short protocol). Mean follicular phase serum luteinizing hormone (LH) and progesterone (P) levels were significantly lower in Group I than in Group II (P less than 0.01). Cancellation rate was significantly lower in Group I than in Group II (P less than 0.01). The long GNRHa protocol resulted in statistically significant lower cancellation rates, more oocytes per pickup (OPU), more embryos transferred per patient, and a higher pregnancy rate. Significantly more hMG ampoules and more treatments days were required in the long GNRHa protocol. Our data demonstrate that the use of GNRHa prior to and during ovarian stimulation with hMG offers a very good alternative for patients with repetitive unsuccessful IVF cycles due to inadequate response.

Adult↗
PubMed1991

The use of long-acting gonadotropin-releasing hormone agonist (GnRH-a; decapeptyl) and gonadotropins versus short-acting GnRH-a (buserelin) and gonadotropins before and during ovarian stimulation for in vitro fertilization (IVF).

The efficiency of two ovarian stimulation protocols using different gonadotropin-releasing hormone agonists (GnRH-a) for in vitro fertilization (IVF) was examined and compared with human menopausal gonadotropin (hMG)-only stimulation. Fifty-four patients who had 57 aspiration cycles were treated with protocol 1, which consisted of long-acting GnRH-a D-Trp6 (Decapeptyl Depot) and hMG. Protocol 2 entailed intranasal administration of short-acting GnRH-a (Buserelin) and human menopausal gonadotropin (hMG) in 66 women who underwent 70 aspiration cycles. Fifty-five patients who had 59 ovum pickups (OPU) treated with hMG only served as a control. No differences were observed in cycle parameters and hormonal concentrations among the three groups. The total clinical pregnancy rates per OPU for patients receiving protocols 1 and 2 were 12.3 and 27.1%, respectively (P less than 0.05). The pregnancy loss was significantly lower in protocol 2 than in protocol 1 (26.3 versus 71.4%; P less than 0.05). Our data show superiority of short-acting GnRH-a over the long-acting agents in achievement of pregnancy and its outcome, though neither was significantly different from the hMG-only protocol.

Adult↗
PubMed1991

Transrectal ultrasound and computed tomography in preoperative staging of lower rectal adenocarcinoma.

A comparison of transrectal ultrasound (TRUS) and computed tomography (CT) for staging of rectal carcinoma was performed. Thirty-two patients were examined by TRUS and 30 by CT. The results of these preoperative examinations were compared with postoperative histopathological findings. TRUS had an accuracy of 81% and it predicted perirectal tumor growth with a sensitivity of 90% and a specificity of 67%, whereas the corresponding figures for CT were 52%, 67%, and 27%. These findings indicate that TRUS is more efficient than CT in staging local tumor growth in rectal cancer. Neither technique, however, can reliably identify lymph node metastases, since no correlation was found between lymph node size as observed on CT and TRUS and tumor involvement as evaluated histopathologically.

Adenocarcinoma↗