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Biomedical subjects

M Green

Publications and source records attributed to M Green.

At least 847 records · Page 47Linked to original sources
PubMed1975

Sickle cell crisis treated by exchange transfusion. Treatment of two patients with heterozygous sickle cell syndrome.

In two patients with severe painful sickle cell crisis and a deteriorating clinical course, recovery coincided with large-scale exchange transfusions (6 liters). The one patient, with sickle cell beta thalassemia, achieved a 90% exchange, calculated on the sickle cell hemoglobin present before and after transfusion. The other patient, with sickle cell hemoglobin Hb A, S, and (Hb) C disease, also achieved an 80% exchange calculated on the level of HbA.S. AND C in samples before and after transfusion.

Adult↗
PubMed1975

DNA binding proteins in the cytoplasm and in a nuclear membrane complex isolated from uninfected and adenovirus 2 infected cells.

The DNA binding proteins in a nuclear membrane fraction that can synthesize DNA in vitro (referred to as "nuclear membrane complex") and in the cytoplasm of adenovirus infected and uninfected cells were isolated and characterized. Suspension cultures of human KB cells infected with human adenovirus 2 were treated with 25 mu-g/ml of arabinosylcytosine starting at 2 hr to block the synthesis of viral structural proteins, and then labeled with (3H)leucine from 6 to 24 hr after infection. Uninfected cells were treated similarly and labeled with (14C)leucine. The 3H-labeled proteins (infected cells) and 14C-labeled proteins (uninfected cells) isolated from the cytoplasm were mixed, as were the corresponding proteins isolated from the membrane complex, and each mixture was fractionated by stepwise elution from single-stranded DNA-cellulose columns. From 50 to 60% of the labeled protein in the membrane complex from infected cells and 40 to 50% of that from uninfected cells bound to DNA-cellulose in 0.05 M NaCl. Much less protein from the cytoplasm was bound to DNA cellulose, 20% from infected cells and 11% from uninfected cells. Gel electrophoresis of the mixture of 3H- and 14C-labeled proteins eluted from DNA-cellulose by different concentrations of NaCl revealed the following. (1) The 0.15 and 0.40 M NaCl eluates from the membrane complex of infected and uninfected cells contained a heterogenous mixture of similar polypeptides. (2) The 0.6 M NaCl eluate from the membrane complex derived from infected cells contained two major DNA binding proteins with molecular weights of 75,000 and 45,000 that were absent from uninfected cells. Large quantities of these two proteins were present in highly purified form in the 0.6 M NaCl eluate from the cytoplasm of infected cells. The DNA binding proteins of molecular weight 75,000 and 45,000 that are present in the cytoplasm are identical with those present in the membrane complex, as established by coelectrophoresis. (3) Two major cell-specific proteins of molecular weight 40,000 and 15,000-17,000 were present in the 2 M NaCl eluate of the membrane complex from uninfected and infected cells. A major cell-specific protein of molecular weight 33,000 was present in the 0.15 and 0.4 M NaCl eluates of the uninfected and infected cell cytoplasmic fractions. Aanalysis of cells labeled at 2-6 hr after infection in the absence of arabinosyl cytosine indicated that the synthesis of the DNA binding proteins of molecular weight 75,000 and 45,000 begins early after infection prior to the onset of viral DNA replication.

Adenoviridae↗
PubMed1975

Malignant fibrous xanthoma (xanthofibrosarcoma) of the larynx.

The xanthofibrosarcoma is a malignant variant of fibrous xanthoma. It is a rare tumor that derives from histiocytes. A case believed to be the first xanthofibrosarcoma reported in the larynx is presented. Differentiation between this tumor and benign lesion was difficult. The tumor proved malignant by metastasizing. Although few fibrous xanthomas become malignant they should raise a high index of suspicion when they are large, have infiltrative margins, and tend to recur locally. Treatment is by wide surgical excision. Close follow-up is mandatory. The prognosis once metastases appear is extremely poor.

Fibrosarcoma↗
PubMed1975

Bias against genetic hypotheses in adoption studies.

Genetic factors are implicated in the cause of psychopathological disorders whenever the incidence of disorder is greater among the adopted-away offspring of affected parents than among those of control (unaffected) parents. The lack of information about most parents who give their children up for adoption could result in the inclusion of a substantial number of high-risk parents in the control groups. This could bias an adoption study against a genetic hypothesis. The Minnesota Multiphasic Personality inventory scores of two groups of pregnant unwed mothers were compared to those of two other groups: married pregnant women and 18-year-old women. Comparisons disclosed that the unwed mothers had significant elevations on five to the nine clinical scales. Elevations on psychopathic deviancy and schizophrenia were particularly substantial. These results indicate a requirement to select control group parents who are representative of the general population.

Adoption↗
PubMed1975

Cell-free translation of immunoglobulin messenger RNA from MOPC-315 plasmacytoma and MOPC-315 NR, a variant synthesizing only light chain.

Total poly(A)-containing mRNA was isolated from the MOPC-315 and MOPC-315 NR plasmacytomas. The RNA was further fractionated on sodium dodecyl sulfate-sucrose gradients. The MOPC-315 mRNA fractions directed the synthesis of both the heavy chain and light chain precursor of the MOPC-315 IgA protein in a cell-free extract of Ehrlich ascites tumor cells. None of the MOPC-315 NR mRNA fractions tested programmed the synthesis of the heavy chain in this system. Analysis of cell-free products by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and by immunoprecipitation demonstrated that no translatable heavy chain mRNA could be extracted from the MOPC-315 NR variant plasmacytoma.

Animals↗
PubMed1975

Analysis of multiple viral genome fragments in adenovirus 7-transformed hamster cells.

The presence of multiple copies of a portion of the viral genome was demonstrated in Ad7-transformed cells by a new method based on the kinetic analysis of labeled viral DNA reassociation in the presence of unlabeled transformed cell DNA. DNA-DNA homology measurement utilizing defined DNA fragments (restriction endonuclease digests) as labeled probes supported the above conclusion.

Adenoviridae↗
PubMed1975

Properties of oncornavirus RNA-directed DNA polymerase, the RNA template, and the intracellular products formed early during infection and cell transformation.

We have investigated three aspects of RNA turmor virus replication and cell transformation: (1) the properties of the purified avian and mammalian viral RNA-directed DNA polumerase, (2) some characteristics of the viral 60-70S RNA genome, 30-40S RNA subunits and intracellular viral RNA species, and (3) the interaction of the viral DNA polymerase with its RNA template early during infection and cell transformation by the murine sarcoma-leukemia virus (MSV[MLV]). Avian myeloblastosis virus (AMV) contains two forms of RNA-directed DNA polymerase, alpha, consisting of a single polypeptide of molecular weight 65,000, and alphabeta, consisting of two polypeptides of molecular weights 65,000 and 105,000. The alpha and alphabeta forms of AMV DNA polymerase both possess RNase H activity that requires free end termini on the ribopolymer and can degrade the RNA of the RNA-DNA hybrid in the 3' to 5' and 5' to 3' directions. But, alpha and alphabeta possess a different mode of exoribonuclease activity. While alphabeta RNase H is a processive exoribonuclease that degrades the polynucleotide chain to a core residue before attacking a second chain, alpha RNase H is a random exoribonuclease that releases the polynucleotide after each scission. Highly purified Moloney-MSV(MLV) DNA polymerase has both RNase H activity and the ability to read viral 60-70S RNA. These activities comigrate through five different steps of purification and are present at levels comparable to those found in purified AMV DNA polymerase. The MSV(MLV) 60-70S RNA genome and 35S RNA subunits were shown by periodate oxidationtritiated borohydride reduction to contain adenosine as the major 3'-terminal nucleoside. Poly (A) segments were isolated from viral 60-70S and 35S RNA by treatment with RNase A or RNase T1 and purified by afinity chromatography and gel electrophoresis. Viral poly(A) was shown to be present at the 3' terminus as -G(C,U)A190AOH. The similar sequence reported for poly(A) present in mammalian mRNA suggests that similar mechanisma are involved in the transcription and processing of both cellular and viral DNA sequences. Within transformed cells replicating MSV(MLV), viral 35S and 20S RNA were found in membrane-bound polyribosomes, whereas only 35S RNA was detected in free polyribosomes. The origin and function of 20S RNA is unknown. The early events during rapid infection and cell transformation of mouse 3T6 cells by the Harvey strain of MSV(MLV) were studied. By both autoradiographic analysis and molecular hybridization, viral DNA synthesis was detected in the cytoplasm by 1 hour after infection, reached a maximum at 2 hours, and subsequently decreased. Cytological chase experiments produced evidence that cytoplasmic viral DNA was transported to the nucleus. In situ hybridization experiments using radioactive viral DNA product as a probe demonstrated the rapid association of viral DNA sequences with the chromocenters of interphase nuclei and with the centromeric heterochromatin regions of some chromosomes.

Avian Myeloblastosis Virus↗
PubMed1975

Isolation of DNA polymerase gamma from an adenovirus 2 DNA replication complex.

The major DNA polymerase in a nuclear membrane complex that is capable of synthesizing viral DNA sequences in vitro has been purified about 900-fold from adenovirus 2-infected KB cells. The enzyme was characterized as belonging to the class of mammalian DNA polymerases (DNA polymerase gamma) that can utilize poly(A) with oligo(dT) as template primer.

Adenoviridae↗
PubMed1975

Relationship of phase IV to closing volume in lateral body positions.

We studied the effect of body position in humans on the relationship between exhaled vital capacity (VC) and both helium (He) and nitrogen (N2) concentrations after delivery of an He bolus at residual volume (RV) followed by 100% oxygen to total lung capacity. Phase IV, defined as the % VC at the first sharp and permanent increase in N2 and He, occurred at a mean of 15.7% VC while seated, 60.0% VC in right lateral and 59.6% VC in left lateral positions. He bolus delivery above RV but well below 60% VC resulted in the disappearance of phase IV. Lung pressure-volume (PV) curves had inflections at the volume of phase IV in the seated position: but the inflections were well below phase IV in lateral positions. Phase IV increased to higher volumes at higher mouth pressures. The relationship between phase IV and mouth pressure fell near the respiratory system relaxation PV curves. The findings suggest the higher phase IV in lateral positions is due to sequence of emptying without airway closure and is influenced by active expiration.

Helium↗
PubMed1975

Aggressive behavior in English nurseries and play groups: sex differences and response of adults.

Aggressive behaviors were incident sampled in 5 nursery schools, 5 play groups, and 5 day nurseries in England. In 13 of 15 institutions, boys had a greater probability of being involved in aggressive incidents than girls. The initiator of an aggressive encounter was likely to be successful if there was no adult interaction, but to be unsuccessful if an adult intervened. There was no consistent evidence that adults intervened differentially in boy-boy, boy-girl, and girl-girl encounters.

Aggression↗
PubMed1975

The source of Na+ and Cl- activities on the skin surface. Experiences with electrode measurements in children.

We have used ion-specific electrodes in an attempt to map the sodium and chloride activities on the skin under differing surface conditions. The range of values and the standard deviations are so wide that a baseline for the untreated dry skin is precluded. In patients with cystic fibrosis, a wide range of values is also found. For this group, measurements on dry skin taken immediately after washing were in the same low range as for healthy subjects. The range of measurements on the dry skin of newborn infants was similar for full-term infants with reactive sweat glands and for premature infants who failed to show sweating responsiveness to natural reflex stimulation as well as local glandular stimulation with sudorific drugs. For only two conditions have measurements of sodium and chloride activities on the surface of the skin been of value: (1) on the sweat-covered skin for the detection of the high values encountered in cystic fibrosis, and (2) on the dry skin surface, deprived of autonomic innervation (spinal paraplegia), extremely low sodium and chloride activities reflect absent gland activity.

Adolescent↗
PubMed1975

Method for the production of severe ventricular dysrhythmias in small laboratory animals.

In earlier reports from this laboratory, it was shown that 3 weeks' pretreatment with desoxycorticosterone acetate (DCA) pellet implantation and saline as drinking fluid caused a nearly 20,000-fold potentiation of the acute cardiotoxicity of isoproterenol. In such animals, the beta-receptor stimulant consistently elicited severe ventricular dysrhythmias, usually leading to ventricular fibrillation (VF) and death. In the present study, a similar enhancement of isoproterenol arrhythmogenic activity after DCA-saline pretreatment was demonstrated also in the guinea pig and albino mouse. It was found, further, that isoproterenol consistently caused an alteration of the total myocardial electrolyte content in DCA-saline-treated rats, consisting of a decrease of magnesium (Mg) and potassium (K) levels and elevation of sodium (Na). In control rats, on the other hand, isoproterenol did not alter the myocardial Mg content and increased K. The emertence of cardiac irregularities and VF could be inhibited by pretreatment with antiarrhythmic drugs. On a molar basis, these agents decreased the incidence of VF in the following descending order: dl-propranolol (100), practolol (39), d-propranolol (34), sotalol (20), quinidine (8), and lidocaine (5). In the presence of any of the listed drugs, except for lidocaine, isoproterenol did not lower Mg levels and had variable effects on those of Na and K. Pretreatment with Mg gluconate was likewise effective in preventing isoproterenol-induced dysrhythmias and death. These findings demonstrate that: a) sensitization of the myocardium by DCA-saline treatment is not species-specific for the rat; b) this phenomenon can be a useful method for the screening of antiarrhythmic drugs; and c) isoproterenol-induced dysrhythmias may be associated with myocardial electrolyte alterations involving especially Mg depletion.

Animals↗