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Biomedical subjects

P Hudson

Publications and source records attributed to P Hudson.

At least 91 records · Page 5Linked to original sources
PubMed1984

Production of monoclonal antibodies for affinity purification of bovine mullerian inhibiting substance activity.

Two monoclonal antibodies (IG8 and IG10) specific for Mullerian inhibiting substance (MIS) were obtained from the fusion between myeloma cell line SP2/0 and spleen cells from an A/J mouse immunized with partially purified MIS. The resulting hybridomas were screened by a solid-phase RIA and two lines were selected and cloned. Both MAbs IG8 and IG10 subsequently demonstrated specificity for MIS by their ability to inhibit biologically active MIS by precipitation with a second antibody, directly block MIS activity in the organ culture assay, and adsorb and elute active MIS when coupled to a solid support. SDS-polyacrylamide gel electrophoresis of affinity purified MIS demonstrated a major band at 140 kD in unreduced gels and two bands with approximate molecular weights of 70 and 74 KD following reduction. Protein bands were localized either directly by silver staining or on immunoblots developed with radiolabeled anti-MIS MA.

Animals↗
PubMed1983

Correlation of neurochemical and behavioral effects of triethyl lead chloride in rats.

Adult male Fischer-344 rats were dosed sc with 1 or 2.5 mg/kg of triethyl lead chloride (TEL) for 5 consecutive days. One week after the last dose, TEL-exposed rats had decreased Met-enkephalin in the hypothalamus, septum, and frontal cortex, while substance P was decreased in the hippocampus and frontal cortex. Dopamine (DA) and dihydroxyphenylacetic acid (DOPAC) in the caudate nucleus were not altered by TEL nor were serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in the caudate nucleus, hypothalamus, hippocampus, or frontal cortex. In a second experiment, rats were dosed with 1.75 mg/kg sc for 5 days. Subsequent assay of brain tissue indicated that TEL decreased met-enkephalin levels in the septum of rats one and seven days after cessation of dosing; effects on substance P were not observed. TEL-induced decreases in Met-enkephalin in the septum were temporally associated with increased hot plate latencies. One day after cessation of dosing with TEL, concentration of 5-HIAA in the caudate nucleus, hippocampus, frontal cortex, and brain stem, and 5-HT in the hippocampus and brain stem were increased. Biogenic amine concentrations were not affected in any other region or at any other time postdosing. A third experiment indicated that TEL-induced analgesia could be attenuated by 10 mg/kg chlordiazepoxide or 10 mg/kg of naloxone. The present results suggest that TEL-induced analgesia may be due to alterations in emotionality or reactivity to noxious stimuli, which may be associated with the alteration in delta opiate mechanism in the limbic system, such as the change of septal enkephalin neuronal activities.

Analgesia↗
PubMed1983

Demonstration of IgE and IgG antibodies against venoms in the blood of victims of fatal sting anaphylaxis.

Nine people died from insect sting anaphylaxis in North Carolina from 1979 to 1981. Postmortem blood specimens from eight of these subjects were analyzed for IgE and IgG antibodies against venoms. All eight were RAST positive to at least one of the venoms. IgE and IgG anti-venom levels were comparable to those of a group of untreated sting-allergic individuals. RAST to venoms was also performed on several control groups of sera and from 3% to 50% positive RAST results were found. The highest incidence was in rural North Carolina outdoor workers. The incidence of positive RAST results in the sting-death group was significantly different from that in the control groups. This is the first demonstration of IgE antibodies against venoms in the sera of victims of fatal anaphylaxis from stings and adds further evidence for the role of IgE in sting anaphylaxis.

Adult↗
PubMed1983

Vitreous humor magnesium in alcoholics.

Postmortem vitreous humor magnesium concentrations were determined in 27 alcoholics and in 27 nonalcoholics who died of various causes. No significant differences in magnesium values were present between these two groups. The concentrations in those dying with alcohol withdrawal syndrome or in those with postmortem findings limited to hepatic fatty change did not differ significantly from those in the nonalcoholic group or from those of the alcoholics dying of other causes. There was no correlation between vitreous humor magnesium concentrations and postmortem interval in any group. We conclude that vitreous humor magnesium determination is not helpful in the postmortem evaluation of suspected alcohol-related deaths or in determining postmortem interval.

Adolescent↗
PubMed1983

Characterization and localization of calcitonin messenger ribonucleic acid in rat thyroid.

DNA/RNA hybridization assays have been used to examine calcitonin (CT) RNA production in normal rat thyroids. A cloned CT cDNA which codes for the entire rat CT precursor was radiolabeled to a high specific activity and used in hybridization assays to explore 1) the sizes and relative quantities of CT RNA extractable from thyroids obtained from rats of differing ages; 2) the effect of calcium on the in vitro production of CT RNA in rat thyroid tissue slices; and 3) the localization, by hybridization histochemistry, of C cells in rat thyroid that contain CT RNA. The relative concentrations of CT RNA, per microgram of total thyroid RNA, increased remarkably with age, with 14-month-old rats having approximately 14-fold elevated concentrations of thyroidal CT RNA compared to 19-day-old rat fetuses. Of interest was the finding that a second larger species of CT RNA is only evident in thyroids obtained from 14-month-old animals. The effect of calcium on the in vitro production of CT RNA in rat thyroid tissues was studied over 3- and 6-h periods. Although previous investigations have shown that calcium causes an immediate and linear increase in CT secretion from the thyroid gland, no net increase vs. controls in the amount of CT RNA extractable from calcium-stimulated thyroid slices was observed. Finally, hybridization histochemistry, a technique that identifies in fixed tissue sections those areas that contain a specific mRNA population, was used to localize C cells in the thyroid containing CT RNA. Specific areas of rat thyroid hybridized with the CT cDNA probe and autoradiography revealed these areas to be parafollicular cells located only in the central portion of the thyroid lobes, mRNA quantities detected by hybridization histochemistry showed little variation over the central area of the thyroid, indicating the C cells in this region of the thyroid are accumulating CT RNA at approximately the same rate.

Animals↗
PubMed1983

Fulminant Rocky Mountain spotted fever. Its pathologic characteristics associated with glucose-6-phosphate dehydrogenase deficiency.

Three patients with documented fulminant Rocky Mountain spotted fever (RMSF) (death on or before day 5 of illness) had severe multisystemic injury as shown by clinical signs and laboratory data, but on microscopic examination showed minimal evidence of the typical mononuclear leukocytic response to rickettsial vascular infection and injury. Thrombosis was more extensive than in classic RMSF, with fibrin thrombi located in foci of rickettsial infection. These patients had a rash either preterminally or not at all, particularly severe Rickettsia-associated pulmonary lesions, and other shock-related lesions, eg, centrilobular hepatic necrosis. All three patients were male blacks with glucose-6-phosphate dehydrogenase deficiency, a condition recently associated with severity of RMSF. Diagnosis of fulminant RMSF requires awareness of its pathologic and epidemiologic aspects, and use of rickettsial isolation or specific immunofluorescence.

Adolescent↗
PubMed1982

Cloning of metallothionein cDNA from neonatal rat liver.

A metallothionein cDNA clone was isolated from a cDNA bank prepared from neonatal rat liver poly(A)-containing RNA by a colony screening procedure using [32P]cDNA probes prepared from mRNA of either metal-induced or uninduced rat livers. Nucleotide sequence analysis of this clone showed that it contained the entire 3' untranslated region and 30% of the coding sequence for a rat metallothionein. The sequence is remarkably homologous with the mouse metallothionein-I gene.

Animals↗
PubMed1982

Porcine relaxin: molecular cloning and cDNA structure.

Relaxin is a peptide hormone produced by the corpora lutea of ovaries during pregnancy, softening and lengthening the ligaments of the pelvis and softening the cervix in order to make childbirth easier. In attempts to determine the nucleotide sequence coding for relaxin, recombinant DNA techniques were used to obtain a cDNA clone bank from total mRNA isolated from the ovaries of pigs in late pregnancy. Clones were screened using cDNA initiated by synthetic oligonucleotide primers coding for the Trp Val Glu Ile sequence of the porcine relaxin B chain. The synthetic undecamer [5'-ATCTCCACCCA-3'] was found to prime a specific 32P-labeled cDNA of approximately 300 nucleotides containing B chain and signal peptide coding sequences, as verified by nucleic acid sequence analysis. This cDNA was used to probe the ovarian clone bank. Several clones containing large inserts which hybridized to this probe were subjected to sequence analysis and some of these were found to contain the preprorelaxin coding region, comprising a signal peptide of 24 amino acids, a B chain of 32 amino acids, a large C peptide of 104 amino acids, and an A chain of 22 amino acids. From the amino acid sequence of prorelaxin derived in this way, it appears that the processing of prorelaxin involves two enzymes with chymotrypsin-like and trypsin-like specificity, respectively. In comparisons of porcine and rat preprorelaxins, the C region had as much amino acid sequence homology as the B and A chains. The C region is also rich in charged amino acids, suggesting a role for it beyond simply ensuring proper disulfide bond formation.

Animals↗
PubMed1981

Molecular cloning and characterization of cDNA sequences coding for rat relaxin.

Using a synthetic oligonucleotide primer, cloned DNA fragments, each containing the entire coding sequence of rat relaxin, have been isolated from a clone 'bank' of ovarian mRNA sequences. The nucleotide sequence of these clones demonstrates that relaxin is synthesized as a preprorelaxin molecule with an unexpectedly large connecting peptide of 105 amino acid residues.

Amino Acid Sequence↗
PubMed1981

Multishot firearm suicide. Examination of 58 cases.

Suicide by firearm is a frequent mode of death and the most common mode of suicide in the United States. So typically is there but one bullet entrance would in the suicide victim, and so often are there multiple wounds with homicide that some investigators and the public are unaware or forget that the person intending suicide may discharge his gun into himself more than once. The frequency, incidence, and other characteristics of the phenomenon deserve more recognition. The data presented are from medical examiner reports and related material from 7,895 gunshot deaths, including 3,522 suicides by firearm, that occurred in North Carolina in the 7-year period 1972-1978. The 58 multishot firearm suicides represent 0.7% of all firearm deaths (one in 136) and 1.6% of forearm suicides (one in 61). Characteristics of the individual entrance wounds such as body regions involved and muzzle distance were the same as those of single shot cases. Long gun use was not rare, but 0.22 caliber handguns predominated. Other characteristics of weapon, victim, wounds, and situations are presented. Each of the cases was assessed by forensic pathologists as it was reported and was reviewed again for the study. The type of data presented is one advantage of a structured, centrally guided, statewide medical examiner system.

Abdominal Injuries↗
PubMed1981

Hybridization histochemistry: use of recombinant DNA as a "homing probe" for tissue localization of specific mRNA populations.

A procedure, termed hybridization histochemistry, has been developed to locate in specially prepared whole sections of tissue those areas which contain specific mRNA populations. Three 32P-labelled recombinant DNA probes were used; one complementary to endorphin mRNA, one complementary to growth hormone mRNA and one a fragment of bacterial DNA. The specific cell populations or tissue regions binding the probe were identified by autoradiography. Hybridization histochemistry is thus similar in principle to immunohistochemical procedures. The endorphin probe consistently labelled the rat pituitary pars intermedia which is known to be particularly rich in the corresponding mRNA. Likewise the growth hormone probe specifically labelled the anterior pituitary. Control tissues were not labelled by either probe, nor did the bacterial DNA probe significantly label any tissue, providing further evidence of the specificity of the procedure. These results, which are highly reproducible, indicate that the mRNA species for endorphin and growth hormone are present in whole sections of pituitary in a physical state which leaves them accessible to cDNA probes. This initial success provides encouragement that hybridization histochemistry, with further refinement, should have wide applicability in the localization and semi-quantitative analysis of intracellular mRNA in whole frozen sections of tissue.

DNA, Recombinant↗
PubMed1980

An experimental method for thermal control of heart rate: work in progress.

Evaluation of the postoperative course of coronary artery bypass patients shows that a number develop supraventricular arrhythmias that may be responsive to sino-atrial node (SAN) cooling. The sinus rate can be controlled within a clinically useful range with topical cooling probes (thermodes). The data on the variations of heart rate caused by modest nodal hypothermia indicate that a nonpharmacologic clinical system for control of supraventricular tachyarrhythmias is feasible. Prototype thermodes suitable for SAN implantation have been developed.

Animals↗
PubMed1979

Tissue differentiation and susceptibility to embryonal tumor induction by ethylnitrosourea in the opossum.

Opossums (Didelphis virginiana Kerr) exposed to 100 mg ENU/kg in single or incremental doses early in postnatal life developed a spectrum of epithelial and mesenchymal neoplasms including several types of embryonal neoplasms not previously induced in laboratory animals. A correlation was apparent to a varying degree between susceptibility to tumor induction and the state of morphologic maturation of the presumed target tissues at the light microscopic level for embryonal tumors of the eye, kidney, and brain. The susceptibility of the opossum eye to an ENU-induced intraocular teratoid medulloepithelioma extended over the period from 1 to between 3 and 4 weeks of age and was correlated with the differentiation of the apparent target cell, the nonpigmented ciliary epithelium of the pars ciliaris retinae. Induction of nephroblastomas was correlated with the presence in the kidney of stem cells (metanephric blastema) through the period from birth to between 6 and 8 weeks of age. Although susceptibility of the opossum brain to ENU induction of gangliogliomas was correlated with the state of differentiation of the germinal matrix from birth to 56 days of age, induction of these tumors was essentially limited to the 1st week postpartum. No definite correlation between vulnerability to tumor induction and tissue maturation was evident for a tumor of the jaw (ameloblastoma) with presumed origin from embryonic dental remnants. Our results indicated that the opossium early in postnatal life is a useful model for the induction and characterization of certain of the major dysontogenetic tumors, which have been difficult or impossible to reproduce in the traditional laboratory species.

Age Factors↗
PubMed1977

Malarial antibodies in tropical splenomegaly syndrome in Papua New Guinea.

Levels of species and class-specific malarial antibody were studied in 249 New Guineans with tropical splenomegaly syndrome (TSS) and in 87 control subjects living in the same area. Titres of IgG and IgM antibody to Plasmodium falciparum, P. vivax and P. malariae were estimated by indirect immunofluorescence. Both Ig and IgM antibody levels were higher in subjects with TSS than in controls; IgM titres were highest in those with the greatest splenic enlargement. Responses to all three species were comparable. It is concluded that there is no evidence from this study to incriminate any one species of malaria parasite in the production of tropical splenomegaly syndrome.

Adolescent↗
PubMed1977

Fatal poisoning with propoxyphene: report from 100 consecutive cases.

The first 100 deaths caused by propoxyphene and recorded by the Chief Medical Examiner of North Carolina were studied. Victims ranged evenly in age from the second to the seventh decade. Over 65% were suicides with a female to male ratio of 2:1. Blood propoxyphene concentrations of 0.2 mg/dl were fatal, representing rapid ingestion of approximately ten capsules. In North Carolina, deaths due to propoxyphene have increased from five in 1969 to 49 in 1975. Raising physician-awareness of propoxyphene's toxicity and placing the drug in Schedule II are two of the author's recommendations for reducing the number of propoxyphene deaths.

Adolescent↗