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Biomedical subjects

D J Goldstein

Publications and source records attributed to D J Goldstein.

At least 109 records · Page 6Linked to original sources
PubMed1993

Fluoxetine: a randomized clinical trial in the maintenance of weight loss.

Because current weight-reduction treatments have considerable recidivism, a therapy that could help patients maintain weight loss would be of benefit. A six-center, randomized, double-blind trial compared the effects of the specific serotonin uptake inhibitor, fluoxetine hydrochloride, and placebo on maintenance of weight loss. Obese outpatients who had lost > or = 3.6 kg after 8 weeks of single-blind fluoxetine 60 mg/day in the qualification phase (N=317 [70.4% of patients entered]; mean +/- standard deviation [SD] weight loss, 6.8 +/- 2.8 kg) were randomly assigned to fluoxetine 20 mg/day (N=104), fluoxetine 60 mg/day (N=106), or placebo (N=107) for 40 weeks (maintenance phase). Patients received minimal nutrition/dietary counseling. Qualification phase clinic visits were biweekly; maintenance phase visits were monthly for 4 months, then bimonthly for 6 months. Patients treated with fluoxetine 60 mg/day continued to lose weight for 8 additional weeks (16 weeks total; maximum mean +/- SD weight loss, 7.2 +/- 4.6 kg); those treated with fluoxetine 20 mg/day or placebo began to regain weight. Mean weights remained below baseline values at week 48 (all groups); treatment differences were not statistically significant. Study completion rates were comparable (fluoxetine 20 mg/day, 67.3%; fluoxetine 60 mg/day, 56.6%; placebo, 67.3%; p = 0.175). Among commonly reported adverse events (> 10% incidence), only asthenia was reported statistically significantly (p < 0.050) more frequently with fluoxetine than with placebo. Few patients discontinued for any single adverse event. Fluoxetine 60 mg/day was effective for a longer period than fluoxetine 20 mg/day or placebo in maintaining weight loss. Overall, fluoxetine was safe and well tolerated.

Adolescent↗
PubMed1993

Fish oil has protective and therapeutic effects on proteinuria in passive Heymann nephritis.

Passive Heymann nephritis (PHN) is a rat model of membranous nephropathy induced by injecting anti-Fx1A. The onset of proteinuria in PHN is caused by complement-mediated injury to glomerular epithelial cells (GEC) accompanied by enhanced glomerular eicosanoid production. In addition, sublethal injury by complement of rat GECs in culture leads to phospholipase activation, phospholipid hydrolysis and release of arachidonic acid and dienoic prostanoids. Based on these findings, we undertook to determine if substituting arachidonic acid (omega-6) in GEC membrane phospholipids with omega-3 fatty acids derived from fish oil would alter the development and course of proteinuria in PHN. We found that rats fed a diet containing 10% fish oil for four weeks prior to antibody injection developed 50 to 60% less proteinuria between two and six weeks after anti-Fx1A than rats fed an equivalent diet containing 10% safflower oil, and had substantial enrichment of glomerular phospholipids with omega-3 fatty acids and displacement of arachidonic acid. This outcome was associated with a 50% reduction in release of glomerular thromboxane B2 (stable metabolite of thromboxane A2) in the fish oil group. More importantly, when PHN rats with well established proteinuria while on regular chow were randomized to three dietary groups, those fed fish oil had a 25 to 50% decline in proteinuria as compared to those fed lard or safflower oil. This difference was evident within two weeks of randomization and persisted until the end of the study after eight weeks. In neither study could the differences in urine protein excretion be accounted for by protein or calorie deprivation, or by differences in blood pressure, renal function, immune response to sheep IgG, or glomerular deposition of IgG or complement. Thus, our results indicate that dietary fish oil has protective and therapeutic effects with regard to proteinuria in PHN. These benefits may relate to alterations in membrane phospholipid composition in favor of omega-3 fatty acids and release of less reactive trienoic eicosanoids.

Animals↗
PubMed1993

Intramuscular picenadol in patients with postoperative pain.

1. The analgesic efficacy and safety of a single 50 mg intramuscular dose of rac-picenadol, a centrally acting agonist-antagonist opioid analgesic, were compared with pethidine (meperidine) 100 mg and placebo in 60 patients with moderate to severe postoperative pain using hourly pain intensity and relief measurements for up to 6 h following injection of the study medications. 2. Both picenadol and pethidine were statistically significantly (P < 0.05) more effective than placebo in reducing pain intensity and in increasing total relief. Patients receiving picenadol and pethidine had higher frequency of somnolence than patients receiving placebo. In addition, patients receiving picenadol 50 mg experienced a higher incidence of confusion (30%), speech disorders (30%), and tremors (25%) than the patients receiving either pethidine or placebo. 3. These results were compared with those of a similar study which investigated the effects of a 25 mg intramuscular dose of picenadol vs pethidine and placebo. This comparison suggests that 25 mg of picenadol is a more acceptable dosage since both 25 and 50 mg were effective dosages.

Adult↗
PubMed1993

The human T-cell leukemia/lymphotropic virus type I p12I protein cooperates with the E5 oncoprotein of bovine papillomavirus in cell transformation and binds the 16-kilodalton subunit of the vacuolar H+ ATPase.

The human T-cell leukemia/lymphotropic virus type I (HTLV-I) induces T-cell leukemia and transforms human T cells in vitro. A recently identified protein with a molecular weight of 12,000 (12K) (p12I), encoded by single- and double-spliced mRNAs transcribed from the 3' end of the HTLV-I genome, has been shown to localize in the perinuclear compartment and in the cellular endomembranes. The p12I protein exhibits significant amino acid sequence similarity to the E5 oncoprotein of bovine papillomavirus type 1 (BPV-1). Both proteins are very hydrophobic, contain a glutamine residue in the middle of a potential transmembrane region(s), and are localized in similar cellular compartments. Because of these observations, we investigated whether the p12I resemblance to E5 correlated with a similarity in their biological behavior. We expressed the p12I protein to evaluate its ability to functionally cooperate with the BPV-1 E5 oncoprotein and to bind to a cellular target of the E5 protein, the 16K component of the vacuolar H+ ATPase. Cotransfection of the mouse C127 cell line with the p12I and E5 cDNAs showed that although p12I alone could not induce focus formation, it strongly potentiated the transforming activity of E5. In addition, the p12I protein bound to the 16K protein as efficiently as the E5 protein. These findings might provide new insight for potential mechanisms of HTLV-I transformation and suggest that p12I and E5 represent an example of convergent evolution between RNA and DNA viruses.

Amino Acid Sequence↗
PubMed1993

Transformation-specific interaction of the bovine papillomavirus E5 oncoprotein with the platelet-derived growth factor receptor transmembrane domain and the epidermal growth factor receptor cytoplasmic domain.

The bovine papillomavirus E5 transforming protein appears to activate both the epidermal growth factor receptor (EGF-R) and the platelet-derived growth factor receptor (PDGF-R) by a ligand-independent mechanism. To further investigate the ability of E5 to activate receptors of different classes and to determine whether this stimulation occurs through the extracellular domain required for ligand activation, we constructed chimeric genes encoding PDGF-R and EGF-R by interchanging the extracellular, membrane, and cytoplasmic coding domains. Chimeras were transfected into NIH 3T3 and CHO(LR73) cells. All chimeras expressed stable protein which, upon addition of the appropriate ligand, could be activated as assayed by tyrosine autophosphorylation and biological transformation. Cotransfection of E5 with the wild-type and chimeric receptors resulted in the ligand-independent activation of receptors, provided that a receptor contained either the transmembrane domain of the PDGF-R or the cytoplasmic domain of the EGF-R. Chimeric receptors that contained both of these domains exhibited the highest level of E5-induced biochemical and biological stimulation. These results imply that E5 activates the PDGF-R and EGR-R by two distinct mechanisms, neither of which specifically involves the extracellular domain of the receptor. Consistent with the biochemical and biological activation data, coimmunoprecipitation studies demonstrated that E5 formed a complex with any chimera that contained a PDGF-R transmembrane domain or an EGF-R cytoplasmic domain, with those chimeras containing both domains demonstrating the greatest efficiency of complex formation. These results suggest that although different domains of the PDGF-R and EGF-R are required for E5 activation, both receptors are activated directly by formation of an E5-containing complex.

3T3 Cells↗
PubMed1993

Increase in RNA and glycogen but not in DNA in developing human macrophages proven by integrating microdensitometry.

In order to quantitate DNA, RNA and glycogen contents of developing macrophages, blood monocytes were obtained from 19 healthy human subjects and examined after 0, 2, 4 and 6 days of suspension culture. Cytochemical staining was carried out by standard methods using Feulgen, cuprolinic blue and PAS. All specimens from all subjects were stained at the same time. Examination was carried out in an integrating microdensitometer, the staining intensities of individual cells being measured at appropriate wavelengths. Over the 6 days of culture, highly significant increases took place in RNA and glycogen, but no significant change was found in DNA content. These findings are taken to indicate that increased protein synthesis and the building up of fuel reserves are features of macrophage development but that S phase DNA replication does not occur.

Adult↗
PubMed1993

Analyses of suicidality in double-blind, placebo-controlled trials of pharmacotherapy for weight reduction.

BACKGROUND: The obese who seek therapy may also have depression and thus a risk for suicidality (suicidal acts and ideation). For this reason and because of interest in the potential impact of a medication with antidepressant properties on suicidality in a population without a primary diagnosis of depression, we performed a comprehensive analysis of suicidality data from clinical trials in patients seeking weight-reduction therapy. METHOD: Suicidality data from 11 double-blind controlled trials in the United States Investigational New Drug fluoxetine obesity clinical trial data base (3819 randomized outpatients) were reviewed. Trials lasted 6 to 60 weeks (continuous and intermittent therapy designs). They included obese men and women (median body mass index, 35.0 kg/m2). Trials excluded patients treated with antidepressants. Incidence of suicidality was analyzed by the incidence difference method. RESULTS: No fatal suicidal acts occurred. One suicide attempt was reported in a patient receiving placebo after prior fluoxetine therapy (intermittent therapy trial). The overall incidence of suicidal ideation among fluoxetine-treated and placebo-treated patients in the obesity clinical trials was 0.24%. The difference in incidence of emergent suicidal ideation in fluoxetine-treated (0.23%) and placebo-treated patients (0.27%) was not statistically significant. CONCLUSION: Based on these analyses of controlled clinical trials, suicidality occurs but has a low incidence rate in the obese who seek pharmacologic weight-reduction therapy. Fluoxetine-treated and placebo-treated patients did not differ statistically significantly in the incidence of suicidality either during or after discontinuation of therapy.

Adolescent↗
PubMed1993

Quantitative enzyme cytochemistry during human macrophage development.

Integrating microdensitometry was used to study changes in the intracellular activity of 4 enzymes during macrophage development. Suspension cultures of blood monocytes from 19 healthy human subjects were examined at 0, 2, 4 and 6 d. Mononuclear phagocytes were harvested by glass adherence and standard methods were used for cytochemical staining for NADH dehydrogenase, succinate dehydrogenase, acid phosphatase and alpha-naphthyl butyrate esterase. All specimens from all subjects were stained at the same time and staining intensities in individual cells were measured at appropriate wavelengths. A highly significant increase in enzyme activity with culture time was found for all 4 enzymes. These increases in mitochondrial, lysosomal and ectoenzyme activities during development indicate the increasing functional capabilities of the macrophages.

Acid Phosphatase↗
PubMed1993

Disordered macrophage development in Hodgkin's disease shown by quantitative cytochemistry.

In order to investigate the disordered maturation of mononuclear phagocytes previously found in Hodgkin's disease, integrating microdensitometry was used to quantitate changes in seven cytochemical constituents (NADH dehydrogenase, succinate dehydrogenase, acid phosphatase, alpha-naphthyl butyrate esterase, DNA, RNA and glycogen) of developing macrophages from 19 patients and 19 normal subjects. Individual cells were studied at intervals over six days of suspension culture; the results were subjected to analysis of variance. In both groups, all the constituents studied except DNA showed highly significant increases over the period of culture. Consistently lower levels of alpha-naphthyl butyrate esterase (approximately 65%) and increased levels of glycogen were present in the Hodgkin's group. The results show that (1) maturational changes occur in the cytochemical constituents of developing macrophages of Hodgkin's disease, and (2) there are disturbances affecting the specific enzyme alpha-naphthyl butyrate esterase and glycogen that are likely to have profound implications for host defense mechanisms.

Acid Phosphatase↗
PubMed1992

The BPV-1 E5 protein, the 16 kDa membrane pore-forming protein and the PDGF receptor exist in a complex that is dependent on hydrophobic transmembrane interactions.

The E5 oncoprotein of bovine papillomavirus type 1 is a 44 amino acid, highly hydrophobic protein that induces the stable transformation of immortalized murine fibroblasts, presumably through its activation of growth factor receptors. Previous studies have shown that the E5 protein complexes with the 16 kDa (16k) pore-forming protein of vacuolar H(+)-ATPases. This integral membrane protein is essential for the acidification and function of subcellular compartments that process growth factor receptors. Using an SV40 expression system in COS cells, we analyzed whether the E5-16k complexes bind additional cellular proteins, including growth factor receptors. These studies demonstrate that E5 binds to both the 16k protein and the PDGF receptor and that this tri-component complex can be isolated with antibodies specific for each protein. Importantly, the 16k protein bound to the PDGF receptor in the absence of E5, suggesting that E5 binds to the PDGF receptor via its interaction with the 16k protein. An E5 mutant lacking the hydrophilic carboxyl-terminal 14 amino acids retained binding to both 16k and the PDGF receptor, indicating that E5 binds to these proteins through its hydrophobic, membrane-associating domain. These studies reveal that hydrophobic, intramembrane interactions govern the association of E5, 16k and the PDGF receptor, suggesting a ligand-independent mechanism for receptor activation and a potential link between receptor signal transduction pathways and membrane pore activity.

Adenosine Triphosphatases↗
PubMed1992

The BPV-1 E5 oncoprotein expressed in Schizosaccharomyces pombe exhibits normal biochemical properties and binds to the endogenous 16-kDa component of the vacuolar proton-ATPase.

The 44-amino-acid E5 oncoprotein of bovine papillomavirus type 1 transforms immortalized murine fibroblast cell lines. This highly hydrophobic protein forms homodimers, localizes to intracellular membrane compartments (including the Golgi apparatus), and forms a complex with the 16-kDa membrane-embedded constituent (16k) of the vacuolar proton-ATPase. To develop a system for the genetic and biochemical analysis of the E5/16k interaction, the E5 gene was cloned into a new vector which was designed for expression in the fission yeast Schizosaccharomyces pombe. The E5 protein synthesized in this system dimerized normally and bound to endogenous and overexpressed S. pombe 16k protein. Comparison of the S. pombe and mammalian 16k proteins showed strong conservation in carboxyl-terminal amino acids but greater variation in the amino-terminal sequences, suggesting that E5 was interacting with the 16k carboxyl domains. Finally, a new protein epitope tag is described which permitted for the first time the coprecipitation of E5 with antibodies directed against the 16k protein.

Amino Acid Sequence↗
PubMed1992

Variation in the dry mass of mouse embryos throughout the preimplantation period.

Information on the net balance of embryonic metabolism during the preimplantation period is provided by measurements of embryo dry mass. The dry mass of mouse embryos at 10 defined stages of preimplantation development was measured using the Vickers M86 scanning microinterferometer. The results demonstrate that there is an overall loss of dry mass from the unfertilized ovum (39.10 +/- 0.6 ng) to the late blastocyst stage (32.80 +/- 0.53 ng) with these differences being highly significant. However, there is a significant increase in embryonic dry mass from the 1-cell (36.88 +/- 0.34 ng) to 2-cell stage (40.48 +/- 0.40 ng). These results suggest that protein synthesis exceeds degradation during the 2-cell stage but that from the 4-cell to morula stage the reverse is true. In addition, the variation in dry mass between embryos at the same developmental stage is extremely small, suggesting that this may be a useful indicator of embryonic viability.

Animals↗
PubMed1992

A glutamine residue in the membrane-associating domain of the bovine papillomavirus type 1 E5 oncoprotein mediates its binding to a transmembrane component of the vacuolar H(+)-ATPase.

The 44-amino-acid E5 oncoprotein is the major transforming protein of bovine papillomavirus type 1. It is a highly hydrophobic polypeptide which dimerizes and localizes to the Golgi apparatus and endoplasmic reticulum membranes. Recent evidence suggests that E5 modulates the phosphorylation and internalization of the epidermal growth factor and colony-stimulating factor 1 receptors and constitutively activates platelet-derived growth factor receptors in C127 and FR3T3 cells. Although no direct interaction with these growth factor receptors has yet been identified, the E5 oncoprotein has been shown recently to interact with the hydrophobic 16-kDa component of the vacuolar H(+)-ATPase (16K protein) [D. J. Goldstein, M. E. Finbow, T. Andresson, P. McLean, K. Smith, V. Bubb, and R. Schlegel, Nature (London) 352:347-349, 1991]. In the current study, we have further analyzed the E5-16K protein complex by fast protein liquid chromatography and shown that each E5 dimer appears to bind two 16K proteins. In order to define the specific amino acid residues of E5 which participate in this binding, mutated E5 epitope fusion proteins were analyzed for their ability to coprecipitate 16K protein. Transformation-defective mutants containing amino acid substitutions within the short hydrophilic carboxyl-terminal domain retained the ability to associate with the 16K protein. However, E5 mutants lacking the glutamine residue in the hydrophobic domain were markedly inhibited in 16K protein binding. Most interestingly, the placement of a glutamine in several random hydrophobic sequences facilitated 16K protein binding, defining this residue as a potential binding site for the 16K protein component of the proton pump and exemplifying the critical role of hydrophilic amino acids for mediating specific interactions between transmembrane proteins.

Amino Acid Sequence↗
PubMed1992

Nephrotoxic antiserum identifies a beta 1-integrin on rat glomerular epithelial cells.

A postulated mechanism of immune glomerular injury is a direct interaction between antibody and glomerular epithelial cell (GEC) surface antigens. To explore this hypothesis, we examined the interaction of the noncomplement-fixing gamma 2-subclass of sheep anti-rat nephrotoxic serum (NTS), which causes immediate complement- and neutrophil-independent proteinuria in vivo, with rat GECs in culture. Reactivity of NTS with GEC surface antigens was determined by positive immunofluorescence of GEC plasma membranes and by the ability of NTS-coated tissue culture wells to provide an adhesive substrate for GECs. NTS immunoprecipitated two proteins (135 and 118 kDa) from surface-labeled GECs. Proteins of similar molecular mass were precipitated by a polyclonal rabbit antibody that identifies the beta 1-integrin chain of the mouse fibronectin receptor (anti-FnR). In addition, NTS identified similarly sized bands on Western blot analysis of cell membranes from isolated rat glomeruli. Similar reactivity was eluted from the glomeruli of proteinuric rats injected with NTS. NTS significantly inhibited GEC adhesion to laminin, types I and IV collagen, and fibronectin and prevented GEC spreading on types I and IV collagen. Anti-FnR similarly inhibited GEC adhesion. Cell viability was not affected. These results show that NTS recognizes a pair of GEC surface proteins that have the characteristics of an alpha- and beta 1-integrin and, at low concentrations, disrupt cell-matrix interactions.

Animals↗
PubMed1992

Serum bilirubin levels, intracranial hemorrhage, and the risk of developmental problems in very low birth weight neonates.

To study whether elevated levels of bilirubin in the neonatal period increase the risk of developmental problems for very low birth weight neonates, the investigators used data from a geographically based sample of 495 very low birth weight neonates, born January 1, 1985, to December 31, 1989, who survived to 1 year of adjusted age. Maximum neonatal bilirubin levels were found in medical records. A developmental problem was defined as either cerebral palsy or a Bayley Mental Developmental Index of less than 68 at 1 year adjusted age. Potentially confounding factors were controlled using logistic regression. To control for the effects of intracranial abnormalities (eg, intraventricular hemorrhage), separate logistic regression analyses were carried out for three strata, defined according to the results of cranial ultrasonography. In these analyses, the following odds ratios (with 95% confidence limits) were found for the association of maximum neonatal bilirubin concentration and developmental problems: for subjects without intracranial abnormalities, 0.9 (0.7, 1.9); for subjects with uncomplicated intracranial hemorrhage, 1.5 (0.8, 2.5); for subjects with complicated intracranial hemorrhage or intraparenchymal echo-densities, 1.2 (0.4, 3.6). In summary, in analyses controlled for confounding factors, maximum neonatal bilirubin level was not consistently associated with the risk of developmental problems identifiable at 1 year.

Bilirubin↗