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R Berman

Publications and source records attributed to R Berman.

At least 19 recordsLinked to original sources
PubMed2001

Elevated motor threshold in drug-free, cocaine-dependent patients assessed with transcranial magnetic stimulation.

BACKGROUND: Transcranial magnetic stimulation (TMS) provides a noninvasive method of examining cortical inhibitory and excitatory processes and cortical excitability in awake subjects. There is evidence from clinical and electroencephalographic (EEG) data that cortical excitability may be abnormal in some psychiatric populations. Chronic cocaine abuse influences a number of neurotransmitters that are involved in the excitatory/inhibitory balance of the cerebral cortex. This pilot study was conducted to ascertain the possible utility of TMS in examining cortical excitability in a population of chronic cocaine abusers. METHODS: The right and left motor thresholds of ten cocaine-dependent subjects, according to DSM-IV, and ten normal control subjects were examined using single pulse TMS. RESULTS: The resting motor thresholds resulting from stimulation of the right or the left motor cortical regions were significantly elevated in cocaine-dependent subjects compared with matched control subjects. CONCLUSIONS: These pilot data suggest that chronic cocaine use significantly alters cortical excitability in the direction of increased inhibition or decreased excitability. We hypothesize that this observation reflects adaptation to those effects of cocaine intoxication that promote cortical excitability and seizures.

Adult↗
PubMed1999

Regulation of Akt/PKB activity, cellular growth, and apoptosis in prostate carcinoma cells by MMAC/PTEN.

Understanding the functional roles of the molecular alterations that are involved in the oncogenesis of prostate cancer, the second most frequent cause of cancer-related deaths among men in the United States is the focus of numerous investigations. To examine the possible significance of alterations associated with the tumor suppressor gene, MMAC/PTEN, in prostate carcinoma, the biological and biochemical effects of MMAC/PTEN expression were examined in LNCaP cells, which are devoid of a functional gene product. Acute expression of MMAC/PTEN via an adenoviral construct resulted in a dose-dependent and specific inhibition of Akt/PKB activation, consistent with the phosphatidylinositol phosphatase activity of MMAC/PTEN. MMAC/PTEN expression induced apoptosis in LNCaP cells, although to a lesser extent than that observed with p53 via an adenoviral construct. However, MMAC/PTEN expression produced a growth inhibition that was significantly greater than that achieved with p53. Overexpression of Bcl-2 in LNCaP cells blocked MMAC/PTEN- and p53-induced apoptosis but not the growth-suppressive effects of MMAC/ PTEN, suggesting that the growth regulatory effects of MMAC/PTEN involve multiple pathways. These studies further implicate the loss of MMAC/PTEN as a significant event in prostate cancer and suggest that reintroduction of MMAC/PTEN into deficient prostate cancer cells may have therapeutic implications.

Apoptosis↗
PubMed1999

Lineshifts in the Fundamental Band of CO: Confirmation of Experimental Results for N(2) and Comparison with Theory.

We have used a three-channel version of a tunable difference frequency laser spectrometer to measure the collisionally induced lineshifts at room temperature for 26 lines of the fundamental band of CO perturbed by nitrogen. Each lineshift was obtained directly by comparing the line center positions of two simultaneous recordings, one for a pressure-shifted line, and the other for the same line in pure CO line at very low pressure. The experimental results are found to be in complete agreement with earlier measurements and confirm that shifts as small as 3 MHz may be measured in such a system. Our results are compared with theoretical calculations. The part of the shifting coefficient antisymmetric with respect to a change in sign of the line number m, is in disagreement with the calculations. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

Spectral Profiles for Atmospheric Absorption by Isolated Lines: A Comparison of Model Spectra with P- and R-Branch Lines of CO in N(2) and Ar.

There is a need in atmospheric research to accurately model absorption profiles over a wide range of pressures and temperatures. Here we explore the suitability of four profiles to describe absorption by an isolated line. Three of the profiles, a Lorentzian, a Voigt profile, and a hard-collision model, are speed independent. The fourth profile is an empirical speed-dependent hard-collision model. We test the quality of the profile and the pressure dependence of the broadening by fitting to precise experimental absorption curves for CO broadened by N(2) and Ar. Of the four profiles, we find that only the empirical model is satisfactory. This profile also meets the need of atmospheric modeling in that it is easily evaluated. Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

An Algorithm for Calculating a Speed-Dependent Lorentzian Profile.

We present an algorithm for calculating speed-dependent Lorentzian profiles. Specifically, we show that the sum of two simple Lorentzians, subject to certain constraints, accurately reproduces a Lorentzian profile with a speed-dependent broadening. Further, the algorithm may be used in more complicated lineshapes in which the speed-dependent Lorentzian is embedded. The benefits resulting from this construction are simplicity of form, the ability to use the form in further symbolic manipulations, and the use of preexisting fast computer codes for the evaluation of the function. Such practical considerations make it possible to use speed-dependent lineshapes in applications such as atmospheric modeling, which demand accurate but computationally efficient absorption curves. In addition, several biases or problems, that occur when speed-dependent experimental profiles are fitted with a simple Lorentzian, are discussed. Copyright 1999 Academic Press.

Journal Article↗
PubMed1998

Reduced brain serotonin transporter availability in major depression as measured by [123I]-2 beta-carbomethoxy-3 beta-(4-iodophenyl)tropane and single photon emission computed tomography.

BACKGROUND: Prior research has suggested reductions in the density of serotonin transporter (SERT) binding sites in blood platelets and post-mortem brain tissue of depressed patients. We sought to determine whether patients with unipolar major depression have diminished SERT availability as assessed by both brainstem [123I] beta-CIT SPECT and platelet [3H]paroxetine binding. METHODS: Drug-free depressed and healthy subjects were injected with 211 +/- 22 MBq [123I] beta-CIT and imaged 24 +/- 2 h later under equilibrium conditions. A ratio of specific to nonspecific brain uptake (V3" = (brainstem-occipital)/occipital), a measure proportional to the binding potential (Bmax/Kd), was used for all comparisons. RESULTS: Results showed a statistically significant reduction in brainstem V3" values in depressed as compared to healthy subjects (3.1 +/- .9 vs. 3.8 +/- .8, p = .02). Platelet [3H]paroxetine binding was not altered (Bmax = 2389 +/- 484 vs. 2415 +/- 538 fmol/mg protein, p = .91) and was not significantly correlated with brainstem [123I] beta-CIT binding (r = -0.14, p = .48). CONCLUSIONS: These data are the first to suggest reductions in the density of brain SERT binding sites in living depressed patients. These findings provide further support for a preeminent role for alterations in serotonergic neurons in the pathophysiology of depression.

Adult↗
PubMed1998

Line Broadening in the Fundamental Band of CO in CO-He and CO-Ar Mixtures.

We present accurate broadening coefficients for many lines of the fundamental band of CO highly diluted in He and Ar at 301.5 K. It is shown that a soft collision model gives a reasonable fit to the data at pressures up to 1 atm. A distinction is drawn between the accuracy with which fitting parameters may be determined and the accuracy with which a spectral profile fits experimental data. Differences between a model profile and the experimental profile are quantified, and the underlying physics omitted from the spectral model is briefly discussed. Copyright 1998 Academic Press.

Journal Article↗
PubMed1998

Activity and passive-avoidance learning in cobalt-injected rats.

A wide range of cognitive-behavioral sequelae, including memory deficits, results from hard metal disease in humans. Cobalt is a common component in the manufacture of hard metals and is a biologically active, toxic substance. This study examined the effects of cobalt exposure in rats. Results showed decreased exploratory behavior and a trend for higher-dose subjects to show decreased passive avoidance learning. No significant differences in active maze learning were found. These results indicate the value of further explorations of the cognitive-behavioral effects of cobalt exposure and suggest a number of methodological cautions.

Animals↗
PubMed1997

Ciliary neurotrophic factor null allele frequencies in schizophrenia, affective disorders, and Alzheimer's disease.

Ciliary neurotrophic factor (CNTF) is a cytokine that has been reported to affect cellular differentiation. Mouse CNTF knockouts have progressive motor neuron atrophy, but this protein has uncertain physiological function in humans. A naturally occurring CNTF variant in man, observed in many populations, abolishes function of the protein product, providing the opportunity to study loss of CNTF function in humans. It has been reported previously that this variant does not predispose to several neurological and neuropsychiatric disorders, including Alzheimer's disease, but findings have been more ambiguous with respect to other conditions, such as schizophrenia. We report here allele frequencies for this null mutation in populations diagnosed with mood disorders (unipolar depression, single episode or recurrent; N = 59), schizophrenia (N = 66), or Alzheimer's disease (N = 93). We found no association of the CNTF null with any of these phenotypes. There is presently no known phenotype consistently associated with either heterozygosity or homozygosity for the CNTF null allele, suggesting either that this protein does not serve a necessary function in humans or is redundant with some other protein or that any human phenotype associated with absence of CNTF is considerably more subtle than that seen in mouse.

Aged↗
PubMed1997

Direct Measurements of Line-Mixing Coefficients in the nu1 + nu2 Q Branch of CO2

High-resolution measurements of the (nu1 + nu2) Q branch of pure CO2 were made using a difference frequency spectrometer with resolution of 5 x 10(-5) cm-1 and a signal-to-noise ratio of 2000:1. Lines Q(2) through Q(32) were measured with up to 14 lines in a single spectrum. The analysis of the branch has been performed on data taken at 301 K and pressures less than 11 kPa. The spectra were analyzed on a line-by-line basis within the Rosenkranz approximation of weak overlap [P. W. Rosenkranz, IEEE Trans. Antennas Propagation AP-23, 498 (1975)]. The lineshape profile included Doppler broadening and Dicke narrowing [R. H. Dicke, Phys. Rev. 89, 472 (1953)] using a modified hard collision model [S. G. Rautian and I. I. Sobel'man, Sov. Phys. Uspekh. 9, 701 (1967)] with line mixing. For each line the broadening, Dicke narrowing, and line-mixing coefficients were determined. The broadening coefficients are in good agreement with measurements of lines belonging to different CO2 bands. Our measured line-mixing parameters are compared to those predicted by a relaxation matrix which was calculated from an exponential power gap (EPG) law [L. L. Strow, D. C. Tobin, and S. E. Hannon, J. Quant. Spectrosc. Radiat. Transfer 52, 281 (1994)]. The vibrational band intensity and the linear pressure shift of the branch were also measured. Copyright 1997Academic Press

Journal Article↗
PubMed1997

Testing Lineshape Models: Measurements for v = 1-0 CO Broadened by He and Ar

We present measurements of the spectral profiles of many P and R branch lines in CO-He and CO-Ar mixtures, all at 301.5 K. The lineshapes are compared with several semi-classical models and in particular with models that include the speed dependence of both the translational motion and the relaxation of the optical coherence. Using a correlated speed-dependent Galatry model proposed by Ciurylo and Szudy we find an apparent reduction of the Dicke narrowing, amounting to almost 100% in some cases with a strong dependence on the rotational quantum number. However, while the parameters of this and several other models may be adjusted to fit the experimental data within the noise, no single model is free of criticism. Several shortcomings of existing models are discussed. Plots of broadening coefficients versus line number are also given. Copyright 1997 Academic Press. Copyright 1997Academic Press

Journal Article↗
PubMed1997

Daily omeprazole surpasses intermittent dosing in preventing relapse of oesophagitis: a US multi-centre double-blind study.

INTRODUCTION: Relapse of erosive oesophagitis occurs in almost all patients if treatment is stopped after initial healing. AIM: To assess the potential of different therapeutic regimens of omeprazole to prevent relapse of erosive reflux oesophagitis after initial healing with omeprazole. PATIENTS AND METHODS: Patients whose active erosive reflux oesophagitis (grade > or = 2) had healed (grade 0 or 1) after 4-8 weeks of open-label omeprazole 40 mg daily (phase I) were eligible to join a multi-centre, 6-month double-blind, placebo-controlled maintenance study (phase II), which included endoscopy, symptom assessments, serum gastrin measurements, and gastric fundic biopsies. During phase I, endoscopy was performed at weeks 0, 4, and 8. At the end of phase I, 429 of 472 patients (91%) were healed, and there were significant reductions in heartburn, dysphagia and acid regurgitation. Of the 429 patients who healed, 406 joined phase II and were randomized to one of three groups: 20 mg omeprazole daily (n = 138), 20 mg omeprazole for 3 consecutive days each week (n = 137), or placebo (n = 131). During phase II, endoscopy was performed at months 1, 3, and 6 or at symptomatic relapse. RESULTS: The percentages of patients still in endoscopic remission at 6 months were 11% for placebo, 34% for omeprazole 3-days-a-week, and 70% for omeprazole daily. Both omeprazole regimens were superior to placebo in preventing recurrence of symptoms (P < 0.001); however, omeprazole 20 mg daily was superior to omeprazole 20 mg 3-days-a-week (P < 0.001). Compared to baseline, omeprazole therapy resulted in no significant differences among treatment groups in the distribution of gastric endocrine cells. CONCLUSIONS: These results show that after healing of erosive oesophagitis with 4-8 weeks of omeprazole, relapse of oesophagitis and recurrence of reflux symptoms can be prevented in 70% of patients with a maintenance regimen of 20 mg daily, but that intermittent dosing comprising 3 consecutive days each week significantly compromises efficacy.

Anti-Ulcer Agents↗
PubMed1996

Clinical and biochemical effects of catecholamine depletion on antidepressant-induced remission of depression.

BACKGROUND: Most hypotheses of the therapeutic mechanism of action of antidepressant drugs have focused on the role of the monoamines. We examined the effect of catecholamine depletion on antidepressant-induced remission. METHOD: The tyrosine hydroxylase inhibitor alpha-methylparatyrosine and the antihistamine diphenhydramine hydrochloride were administered, during separate test sessions, to depressed patients in remission maintained with either norepinephrine reuptake inhibitors (desipramine [n = 7] or mazindol [n = 2]) or serotonin reuptake inhibitors (fluoxetine hydrochloride [n = 9] or sertraline hydrochloride [n = 1]). Because of considerable sedation associated with alpha-methylparatyrosine testing, diphenhydramine was used as an active control rather than an inactive placebo. The effects of alpha-methylparatyrosine and diphenhydramine on depression, anxiety, and plasma catecholamine metabolites were assessed. RESULTS: alpha-Methylparatyrosine produced similar significant decreases in plasma 3-methoxy-4-hydroxyphenylethyleneglycol and homovanillic acid levels in the treatment groups. alpha-Methylparatyrosine produced a robust increase in depressive symptoms on the Hamilton Depression Rating Scale, including depressed mood, decreased concentration, anhedonia, loss of interest, and feelings of worthlessness, helplessness, and hopelessness, in the desipramine-mazindol but not in the fluoxetine-sertraline group. Diphenhydramine had no effects on mood in either treatment group. CONCLUSIONS: The therapeutic effects of norepinephrine reuptake inhibitors, but not serotonin reuptake inhibitors, are reversed by catecholamine depletion. Considered with previous reports that serotonin depletion produces depressive relapses in patients in remission maintained with serotonin reuptake inhibitors, but not norepinephrine reuptake inhibitors, these findings suggest that antidepressants may not work via a single monoamine-related mechanism.

1-Naphthylamine↗
PubMed1996

Effect of human growth hormone on human pancreatic carcinoma growth, protein, and cell cycle kinetics.

The role of human growth hormone (hGH) as a nutritional adjunct for cancer patients is controversial because of its potential mitogenic effects on tumor growth. No studies to date have examined the effect of hGH on human tumor response in vivo. In Vitro: Athymic mice were injected (s.c.) daily with hGH (GH, n=14) or saline (CTL, n=14). On Day 10, serum was collected and added to human pancreatic carcinoma cells in culture. In Vivo: Athymic mice were inoculated (s.c.) with human pancreatic carcinoma cells. On Day 14, mice were randomized to receive daily either hGH (GH, n=14) or saline (CTL, n=12). On Day 29, animals received [3H]phenylalanine for tissue protein fractional synthetic rate (FSR) measurement. Tumors were excised and cell cycle kinetics analyzed. Data are expressed as mean +/- SEM. Statistical analysis was performed by unpaired t test and/or ANOVA where appropriate. In Vitro: Serum from GH-treated animals had elevated IGF-1 levels (287 +/- 34 ng/ml vs 157 +/- 53 ng/ml, P<0.001) and significantly stimulated cell growth (No. cells x 10(3)/well) compared with CTL serum (925 +/- 31 vs 747 +/- 38, P<0.001). In Vivo: Serum for GH-treated animals had elevated IGF-1 levels (287 +/- 34 ng/ml vs 157 +/- 53 ng/ml, P<0.001) and significantly stimulated cell growth (No. cells x 10(3)/well) compared with CTL serum (925 +/- 31 vs 747 +/- 38, P<0.001). In Vivo: Growth hormone had no significant effect on tumor growth rate (mm3/day) (1.45 +/- 0.47 CTL vs 1.57 +/- 0.66 GH), final tumor weight (mg) (0.19 +/- 0.15 CTL vs 0.17+/- 0.06 GH), DNA Index (1.5 +/- 0.1 CTL vs 1.5 +/- 0.1 GH), percent S phase (20.3 +/- 3.3 CTL vs 22.1 +/- 3.0 GH), or tumor FSR (%/day) (51.1 +/- 17.8 CTL vs 70.2 +/- 61.1 GH). Growth hormone significantly elevated serum IGF-1 levels (ng/ml) (176 +/- 48 CTL vs 222 +/- 53 GH, P<0.005) and liver FSR (%/day) (62.8 +/- 17.8 CTL vs 79.7 +/- 12.7 GH, P<0.005). Serum of GH-treated mice increased human pancreatic cell growth in vitro. In vivo, GH administration raised serum IGF-1 levels and increased liver protein FSR, without tumor growth, cell cycle kinetics, or protein FSR.

Animals↗
PubMed1996

Comparative effects of combination drug therapy regimens commencing with either losartan potassium, an angiotensin II receptor antagonist, or enalapril maleate for the treatment of severe hypertension.

OBJECTIVE: To compare the efficacy and safety of a regimen of losartan potassium (losartan) and a regimen of enalapril maleate (enalapril) in a randomized trial of patients with severe hypertension in which the initial treatments were blinded. DESIGN AND METHODS: Seventy-five patients, 23-74 years of age, with sitting diastolic blood pressure of 115-130mmHg, were enrolled in a 12-site multicenter study. The primary efficacy parameters were the change in trough systolic and diastolic blood pressure, as well as response to treatment in terms of categories of hypertensive response. RESULTS: A gradual reduction in mean sitting diastolic blood pressure was observed in all patients treated from week 1 to 12 (10-29mmHg for the losartan regimen and 14-32 mmHg for the enalapril regimen). At week 4, a substantial number of patients remained on monotherapy at either the initial dose or double the dose of losartan (52%) or enalapril (72%). The blood pressure curves for each treatment were parallel over time. The enalapril-based regimen elicited a statistically significantly greater reduction in blood pressure than the losartan-based regimen, although the mean differences in the blood pressure response between the two treatment groups was small. Based on sitting diastolic blood pressure < 90 mmHg or a reduction in blood pressure of at least 10 mmHg, 98% of the patients assigned to the losartan regimen and 100% of the patients assigned to the enalapril regimen had a satisfactory response with a regimen of one to three antihypertensive drugs. Headache was the most common adverse experience in both treatment groups (occurring in 22% of patients assigned to the losartan regimen and 20% of patients assigned to the enalapril regimen). CONCLUSIONS: In this study, the losartan-based regimen effectively lowered blood pressure, was generally well tolerated, and was generally similar to the enalapril-based regimen in the treatment of patients with severe hypertension.

Adult↗
PubMed1995

Proteocephalus chamelensis n. sp. (Cestoda: Proteocephalidae) from the "guavina" Gobiomorus maculatus (Osteichthyes: Eleotrididae) in Chamela Bay, Jalisco, México.

A new species of Proteocephalus inhabiting the eleotridid estuarine fish Gobiomorus maculatus is described from Chamela Bay, Jalisco State, Mexico. The new species and P. pugetensis are nearly identical in strobila length, presence of a vestigial apical organ, having vaginae only anterior to the cirrus sac, an average of 4-7 uterine diverticula per proglottis, and a ratio of cirrus sac length to proglottis width averaging approximately 1:4. Proteocephalus pugetensis differs from the new species by having an average of 35 rather than 68 testes per proglottis, vitelline follicles terminating posteriorly at the level of the anterior margin of the ovary rather than at the level of the posterior margin, and equatorial genital pores rather than genital pores located in the anterior 1/4 of the proglottis. Finally, Proteocephalus pugetensis occurs from estuarine habitats along the Pacific coast of the United States; the new species was collected from an estuarine habitat on the Pacific coast of México.

Animals↗
PubMed1994

Escherbothrium molinae n. gen. et n. sp. (Eucestoda: Tetraphyllidea: Triloculariidae) in Urotrygon chilensis (Chondrichthyes: Myliobatiformes: Urolophidae) from the Gulf of Nicoya, Costa Rica.

Cestodes collected in spiral valves of the stingray Urotrygon chilensis from the Pacific coast of Costa Rica represent an undescribed species of Tetraphyllidea. By possessing more than 2 loculi as well as an apical sucker on each bothridium, the new species is diagnosably distinct from all other tetraphyllidean genera; therefore, a new genus is proposed for it. The new species also possesses globular structures irregularly arranged on the surface of the bothridia. We found similar structures on the bothridial faces of Trilocularia acanthiaevulgaris, possibly indicating phylogenetic relationships with the new species. This possibility is enhanced by the observation that the bothridia of T. acanthiaevulgaris comprise 2 loculi and an apical sucker, rather than 3 loculi.

Animals↗