Search PubMed⌕ Search

Biomedical subjects

H M Goodman

Publications and source records attributed to H M Goodman.

At least 127 records · Page 7Linked to original sources
PubMed1988

Continuous infusion fluoropyrimidines as salvage therapy for patients with advanced ovarian carcinoma.

A major challenge facing those caring for patients with ovarian carcinoma is inducing remission following the failure of first-line treatment. Toward this end, we have examined the efficacy of continuous infusion fluoropyrimidines. During a 2-year period, nine patients with recurrent ovarian carcinoma received treatment with continuous infusion 5-fluorouracil (5-FU) or 5-fluorouracil-deoxyribose as single agents or in combination with other drugs. Eight patients were evaluable, with responses obtained with each treatment regimen. Myelotoxicity was mild, with only 3 episodes of grade 4 toxicity out of 70 total cycles of chemotherapy. Mucositis was moderate to severe, tending to be the dose-limiting adverse effect. Continuous infusion 5-FU in these combinations appears to be active with very acceptable toxicity in heavily pretreated patients.

Adult↗
PubMed1988

Expression of the human growth hormone variant gene in cultured fibroblasts and transgenic mice.

The nucleotide sequence of the human growth hormone variant gene, one of the five members of the growth hormone gene family, predicts that it encodes a growth hormone-like protein. As a first step in determining whether this gene is functional in humans, we have expressed a mouse metallothionein I/human growth hormone variant fusion gene in mouse L cells and in transgenic mice. The growth hormone variant protein expressed in transiently transfected L cells is distinct from growth hormone itself with respect to reactivity with anti-growth hormone monoclonal antibodies, behavior during column chromatography, and isoelectric point. Transgenic mice expressing the growth hormone variant protein are 1.4- to 1.9-fold larger than nontransgenic controls, suggesting that the protein has growth-promoting properties.

Animals↗
PubMed1988

Developmental regulation of nodule-specific genes in alfalfa root nodules.

We have cloned alfalfa nodule-specific cDNAs that code for leghemoglobin (Lb), glutamine synthetase (GS), and three unidentified nodulins. Hybrid-select translation of nodule RNA followed by 2-D gel electrophoresis showed that the Lb-specific cDNA corresponded to at least four Lb species of 12 kDa. One of the unidentified cDNA clones (N-32/34) corresponded to at least five polypeptides of 32-34 kDa; a second unidentified cDNA clone (N-14) corresponded to an individual polypeptide of 14 kDa. The in vitro translation product(s) of the RNA hybrid selected by the third unidentified cDNA clone (N-22) formed a single band at 22 kDa on a one-dimensional gel. Northern and dot blot analyses of RNA isolated from wild-type nodules and from defective nodules elicited by a variety of Rhizobium meliloti mutants showed that 1) RNAs corresponding to the Lb, nodule-specific GS, and three unidentified nodulins were coordinately expressed during the course of nodule development, and 2) all five nodulins were expressed in Fix- nodules that contained infection threads and bacteroids but were not expressed in nodules that lacked infection threads and intracellular rhizobia.

Base Sequence↗
PubMed1988

A common trans-acting factor is involved in transcriptional regulation of neurotransmitter genes by cyclic AMP.

Activation of neurotransmitter receptors can regulate transcription in postsynaptic cells through the actions of second messengers. Trans-synaptic regulation of transcription appears to be an important mechanism controlling the synthesis of molecules involved in neuronal signaling, especially neuropeptides. Proenkephalin, vasoactive intestinal polypeptide, and somatostatin have been shown to be transcriptionally regulated by the second messenger, cyclic AMP (cAMP), as has the catecholamine synthesizing enzyme tryosine hydroxylase. cAMP-inducible elements have been mapped within these genes, and trans-acting factors which bind to several such elements have been identified. With the discovery that individual neurons generally contain multiple transmitters within their synaptic terminals, it has become important to understand in detail the mechanisms by which the synthesis of transmitters can be coregulated. Here we compare the structure and function of the proenkephalin cAMP-inducible enhancer with the mapped cAMP-inducible elements of the vasoactive intestinal polypeptide, somatostatin, and tyrosine hydroxylase genes and a putative cAMP-inducible element in the proto-oncogene c-fos. We have previously shown that the proenkephalin enhancer is composed of two different elements, ENKCRE-1 and ENKCRE-2. We show here that one of these, ENKCRE-2, is structurally similar to elements found within the vasoactive intestinal polypeptide, somatostatin, and tyrosine hydroxylase genes and binds a trans-acting factor that is competed for both in cotransfection experiments (in vivo) and in DNase I footprint assays (in vitro) by these other elements. The c-fos element has similar structural requirements to confer transcriptional induction by cAMP but competes less strongly. Protein purified by affinity chromatography with the ENKCRE-2 sequence binds to each of these elements. A second element within the proenkephalin cAMP-inducible enhancer, ENKCRE-1, binds a factor that is not competed for by these other genes and is therefore distinct. This analysis suggests a potential mechanism of transcriptional coregulation of the neuronally expressed genes investigated in this study and also demonstrates that multiple factors are involved in transcriptional activation by cAMP.

Binding, Competitive↗
PubMed1988

Adenosine 3',5'-monophosphate-dependent loss of growth hormone binding in rat adipocytes.

GH exerts a number of metabolic effects on adipose tissue. Depending on the circumstances, it may increase or decrease glucose metabolism and lipolysis. These effects appear to be mediated by a single class of receptors, which bind GH with high affinity. Incubation of isolated rat adipocytes with a variety of lipolytic agents, including catecholamines, forskolin, or (Bu)2cAMP, decreased the specific binding of [125I]human (h) GH within 10 min. In the presence of 10 microM forskolin, GH binding declined to less than 20% of the control value within 50 min. Cholera and pertussis toxins, which increase cAMP secondary to ADP ribosylation of guanine nucleotide-binding proteins associated with hormone receptors, also decreased the binding of GH. None of these agents affected the rate of loss of cell-associated 125I when added to cells that had previously equilibrated with [125I]hGH. The inhibitory effects of forskolin and (Bu)2cAMP were at least as great when binding was measured in the presence of the protease inhibitor leupeptin, suggesting that increased rates of internalization and processing of bound hormone could not account for the decline in binding. Scatchard plots of data obtained in the presence of forskolin or (Bu)2cAMP were linear and parallel to control plots, indicating that the decline in binding could be accounted for by a decrease in the number of binding sites, with no change in affinity. To determine whether phosphorylation affected binding to receptors already present in the membrane or modified the turnover of receptors, we studied adipocyte ghosts, whose cellular apparatus for receptor turnover is disrupted. Incubation of adipocyte ghosts with cAMP-dependent protein kinase decreased the binding of [125I]hGH by 25%. The data suggest that cAMP-dependent phosphorylation of the GH receptor or a closely associated membrane protein renders the receptor incapable of binding GH.

Adipose Tissue↗
PubMed1987

Recombinant fragment of protein kinase inhibitor blocks cyclic AMP-dependent gene transcription.

Transcriptional regulation by cyclic adenosine monophosphate (cAMP) in mammalian cells could be mediated by a phosphoprotein substrate of the cAMP-dependent protein kinase or, as in prokaryotes, by a cAMP-binding protein. Two synthetic genes that code for an active fragment of the protein inhibitor of this kinase and a mutant inactive fragment were constructed and used to distinguish these alternatives. Transient expression of the active peptide product specifically inhibited the cAMP-stimulated expression of a cotransfected reporter gene by more than 90 percent, whereas the expression of the inactive peptide did not alter cAMP-stimulated gene expression. The results indicate that an active kinase catalytic subunit is a necessary intermediate in the cAMP stimulation of gene transcription.

Acetyltransferases↗
PubMed1987

Isolation and characterization of cDNA clones encoding pathogenesis-related proteins from tobacco mosaic virus infected tobacco plants.

Infection of the tobacco cultivar Samsun NN by tobacco mosaic virus (TMV) results in a hypersensitive response. During this defense reaction several host encoded proteins, known as pathogenesis-related proteins (PR-proteins), are induced. Poly(A)+ RNA from TMV infected tobacco plants was used to construct a cDNA library. Thirty two cDNA clones were isolated and after digestion with different restriction endonucleases, twenty clones were found to code for PR-1a, six clones for PR-1b, and four clones for PR-1c. Two independent cDNA clones of each class were further characterized by DNA sequence analysis. All clones analyzed contained the 138 amino acid coding regions of their respective mature proteins, but only partial sequences of the signal peptides. Minor differences between the nucleotide sequences for clones belonging to the same class were detected. Comparison of the amino acid sequence for PR-1a deduced from its nucleotide sequence with published data obtained by Edman degradation of the protein showed four differences. Analysis of the 3' ends of the cDNA clones indicates that various alternate poly(dA) addition sites are used. Southern blot analysis using these cDNAs as probes suggests the presence of multiple PR-protein genes in the genomes of tobacco and tomato plants.

Amino Acid Sequence↗
PubMed1987

Implantation of genetically engineered fibroblasts into mice: implications for gene therapy.

In a variety of human genetic diseases, replacement of the absent or defective protein provides significant therapeutic benefits. As a model for a somatic cell gene therapy system, cultured murine fibroblasts were transfected with a human growth hormone (hGH) fusion gene and cells from one of the resulting clonal lines were subsequently implanted into various locations in mice. Such implants synthesized and secreted hGH, which was detectable in the serum. The function of the implants depended on their location and size, and on the histocompatibility of the donor cells with their recipients. The expression of hGH could be modified by addition of regulatory effectors, and, with appropriate immunosuppression, the implants survived for more than 3 months. This approach to gene therapy, here termed "transkaryotic implantation," is potentially applicable to many genetic diseases in that the transfected cell line can be extensively characterized prior to implantation, several anatomical sites are suitable for implantation, and regulated expression of the gene of therapeutic interest can be obtained.

Animals↗
PubMed1987

Purification and immunochemical characterization of a dihydrofolate reductase-thymidylate synthase enzyme complex from wild-carrot cells.

An enzyme complex with dihydrofolate reductase (DHFR, E.C.1.5.1.3.) activity was purified to apparent homogenity from wild-carrot cells. The complex has a mol. wt of 286 kd and contains five polypeptide chains of 95, 70, 50, 45 and 26 kd. The DHFR enzyme activity and methotrexate-binding site are on the 45-kd subunit. Folate analogs (methotrexate, aminopterin and formylaminopterin) as well as SH-group inhibitors [p-hydroxymercuribenzoate, 5,5' -dithiobis(2-nitrobenzoic acid), or N-ethylmaleimide] inhibit DHFR. Thymidylate synthase (TS, E.C.2.1.1.45) activity co-purified with the enzyme complex through each of seven steps and co-eluted from gel filtration columns with the DHFR activity at the mol. wt of the enzyme complex. Further identification of TS within the complex was achieved using a Leishmania DHFR-TS antisera which specifically inhibited the carrot TS, although it immunoprecipitated both TS and DHFR. Polyclonal antisera, raised against and specific for the complex as judged by Ouchterlony double diffusion tests and Western blot analysis, inhibited and immunoprecipitated both DHFR and TS. The Leishmania antisera also identified the 70-kd polypeptide within the purified complex as TS in a Western blot experiment. The functions of the other three polypeptides have not yet been established.

Journal Article↗
PubMed1987

Cloning and sequencing of the mumps virus fusion protein gene.

The fusion protein (F) gene of mumps virus was cloned from a cDNA library constructed from infected cell mRNA. The F-specific plasmids were identified by hybridization to a degenerate oligonucleotide probe whose sequence was deduced from the N-terminal amino acid sequence of the F2 protein. The complete nucleotide sequence of the F gene was determined. The gene is 1786 nucleotides long and encodes one long open reading frame of 538 amino acids. The F protein has a 19-amino acid signal peptide cleaved between Cys and Val residues. The cleavage site for activation of the F0 protein into the mature F1,2 is Arg-Arg-His-Lys-Arg. A stretch of 30 hydrophobic amino acids near the C-terminus of the protein is followed by several charged amino acids and appears to serve as the anchoring domain for the protein in the lipid bilayer. The F gene of mumps virus is highly related to the F gene of the paramyxovirus SV-5.

Amino Acid Sequence↗
PubMed1987

Clinical trial of etoposide and cisplatin as salvage therapy in advanced ovarian carcinoma.

The combination of etoposide and cis-platinum was evaluated in the treatment of advanced ovarian cancer. Of 13 treated patients, 4 demonstrated complete clinical responses and 3 demonstrated partial clinical responses. The mean progression free interval was 14 months+ for the complete responders and 8.3+ months for the partial responders. The 100 mg/m2 dose of etoposide appears to be critical in attaining response. This etoposide and cisplatinum combination appears to be effective as a salvage regimen in ovarian carcinoma.

Adult↗
PubMed1987

Combined chemotherapy and radiation therapy for advanced carcinoma of the cervix.

Ten patients with advanced squamous cell carcinoma of the uterine cervix received induction chemotherapy with cis-platinum, mitomycin-C, vincristine, and bleomycin (BOMP) over a 5 week period, followed by radiotherapy with concomitant weekly cisplatinum. Two patients were FIGO stage I-B barrel-shaped, five were stage II-B, and three were III-B. All patients responded to induction chemotherapy with five complete and five partial responses. At the completion of radiation therapy, nine patients had negative biopsies. One patient never reached a complete response and died of distant metastasis. Another underwent total exenteration for a central recurrence and was found to have microscopic paraaortic lymph node involvement. A third recurred in the parametrium. Two patients with barrel-shaped tumors underwent extrafascial hysterectomies; both had negative specimens and tolerated surgery well. Although follow-up is short, this new approach for advanced carcinoma of the cervix yielded excellent results and was well tolerated.

Adult↗
PubMed1987

Tight clustering of human hepatitis B virus integration sites in hepatomas near a triple-stranded region.

The open circular genome of human hepatitis B virus (HBV) is known to contain a partially double-stranded DNA with a single-stranded gap region of variable length. This circular structure of the genome is maintained by base-pairing of the 5' ends of the two DNA stands, the long or L(-) strand and the short or S(+) strand. By cloning, mapping, and sequencing studies, we have localized three recombinational junctions of the integrated HBV in two hepatoma samples, HT14 and FOCUS. Breakpoints of recombination derived from these results and those of others appear to be clustered and coincidental with the identified 5' or the deduced 3' end of the long-strand DNA, respectively. Statistical analysis of these results supports the hypothesis that integration preferentially occurs in an extremely narrow region on the HBV genome. This site-specific recombinational mechanism appears to be conserved among different HBV subtypes. No extensive sequence homology was found between each pair of the recombining parental molecules; however, at the site of crossover, 2- to 3-base-pair junctional homology was consistently observed. Examination of the patterns of the integrated HBV DNAs allowed us to categorize these various patterns into four different groups according to their end specificity and strand polarity. The molecular form of relaxed circle is proposed to be one major substrate for HBV integration. The effect of free strand in the integration of HBV is emphasized in this model. Unlike any other known DNA animal viruses, the site specificity of HBV integration appears to be similar to that of the retroviruses.

Adult↗
PubMed1987

Pituitary secretions related to adrenocorticotropic hormone induce sensitivity of adipose tissue to the insulin-like actions of growth hormone.

In its initial encounter with growth hormone (GH) in vitro, epididymal fat excised from GH-deficient rats responds with an insulin-like increase in glucose metabolism. Tissues freshly excised from normal rats are refractory to the insulin-like effects of GH, but become sensitive immediately after surgical stress. Reversal of refractoriness is prevented by administration of the opioid antagonist, naloxone, just prior to stress, suggesting a possible role of beta-endorphin or related peptides. These experiments were undertaken to determine the source of these peptides which might equally well be released from the pituitary, adrenal medullae, or nerve endings in response to stress. Since adrenalectomy, like stress, also results in increased secretion of adrenocorticotropic hormone (ACTH) and related peptides, we studied the effects of GH on glucose oxidation in adipose tissue obtained from adrenalectomized rats and found a significant insulin-like response to GH in tissues studied 4 days after adrenalectomy. This effect was not due to GH deficiency, since plasma concentrations were only slightly reduced by adrenalectomy. Administration of naloxone (250 micrograms/rat), 30 or 60 min before sacrifice, or dexamethasone (100 micrograms/injection), 60 and 120 min before sacrifice, prevented a response to GH without affecting circulating levels of GH. The effects of adrenalectomy could not be reproduced by preincubation of adipose tissue from normal nonstressed rats with ACTH and beta-endorphin, but were duplicated by preincubation of adipose tissue for 15 min in medium in which pituitary glands had previously incubated in the presence of corticotropin-releasing hormone (0.1 microM) and arginine vasopressin (0.2 microM). Addition of naloxone (250 micrograms/ml) blocked this effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1986

Evidence in favor of the symbiotic origin of chloroplasts: primary structure and evolution of tobacco glyceraldehyde-3-phosphate dehydrogenases.

We report nucleotide sequences of cDNAs for the nuclear genes encoding chloroplast (GapA and GapB) and cytosolic (GapC) glyceraldehyde-3-phosphate dehydrogenases (GAPDH) from N. tabacum. Comparison of nucleotide sequences indicates that the GapA and GapB genes evolved following duplication of an ancestral gene about 450 million years ago. However, the divergence of GapA/B and GapC occurred much earlier in evolution than the divergence of GapC and GAPDH genes of animals and fungi, suggesting that chloroplast and cytosolic GAPDHs evolved from different lineages. Comparison of amino acid sequences shows that the chloroplast GAPDHs are related to GAPDHs found in thermophilic bacteria, while the cytosolic GAPDH is related to the GAPDH found in mesophilic prokaryotes. These results strongly support the symbiotic origin of chloroplasts.

Amino Acid Sequence↗
PubMed1986

Plant glutamine synthetase complements a glnA mutation in Escherichia coli.

A glutamine synthetase gene from alfalfa (Medicago sativa) has been expressed in Escherichia coli after fusion of bacterial transcription and translation signals to a complete alfalfa glutamine synthetase coding sequence. Synthesis of the alfalfa glutamine synthetase enzyme in Escherichia coli was demonstrated by functional genetic complementation of a glutamine synthetase-deficient mutant and by immunoblotting analysis. These results should facilitate protein engineering and structure-function analysis of the plant enzyme.

Base Sequence↗