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Biomedical subjects

D E Jones

Publications and source records attributed to D E Jones.

At least 19 recordsLinked to original sources
PubMed1992

Paneth cells of the human small intestine express an antimicrobial peptide gene.

Mucosal surfaces of several organ systems are important interfaces for host defense against microbes. Recent evidence suggests that antimicrobial peptides contribute to the defense of these surfaces. Defensins are one family of antimicrobial peptide, but their known distribution in humans has been limited to four members found in cells of myeloid origin. We sought to determine if the human defensin family was more complex. We found that the family of human defensins is diverse and is not restricted to expression in leukocytes. Southern blot and genomic clone analyses reveal that numerous defensin-related sequences are present in the human genome. A gene for a new human defensin family member was characterized. This gene, designated human defensin-5, is highly expressed in Paneth cells of the small intestine. This is the first example of an antimicrobial peptide gene expressed in an epithelial cell in humans. The data support the hypotheses that epithelial defensins equip the human small bowel with a previously unrecognized defensive capability which would augment other antimicrobial defenses.

Amino Acid Sequence↗
PubMed1990

Sjögren's syndrome in systemic sclerosis. A clinical study of 26 patients.

Features of Sjögren's syndrome were sought in 26 patients with systemic sclerosis and in age- and sex-matched control subjects. The assessments included a structured history to establish symptoms of dry eyes and dry mouth. Schirmer's I and II tear tests. Rose Bengal staining with slit lamp microscopy of the eyes, measurement of basal and stimulatory salivary secretion. We measured sweat secretion rates from the skin. Salivary scintigraphy and skin biopsies were performed on the patients. Only one patient showed the complete picture of Sjögren's syndrome with both clinical and investigational evidence of lacrimal and salivary gland involvement. A further patient had an abnormal Schirmer's II test and xerostomia with reduced salivary secretion and an abnormal scan, but no ocular symptoms and no keratoconjunctivitis sicca on ophthalmological examination. Two patients had reduced salivary flow and a dry mouth. A number of patients and control subjects showed various individual symptoms and signs of lacrimal and salivary disorders. These features alone are not sufficient for the diagnosis of Sjögren's syndrome. There is a clear need to adopt strict criteria for diagnosing the condition. The association of Sjögren's syndrome with systemic sclerosis seems doubtful and if it does occur it is very much less common than previously suggested.

Adult↗
PubMed1988

Characterization of a functional recombinant rat liver aldehyde dehydrogenase: expression as a non-fusion protein in E. coli.

A cDNA encoding a rat liver inducible aldehyde dehydrogenase carried in a pUC8 plasmid is expressed in E. coli as a dimeric enzyme molecule functionally and physically identical to the authentic rat enzyme. The cDNA appears to be transcribed using the lac promoter, but is translated from an initiator codon 174 base pairs from the 5' end of the cDNA. The aldehyde dehydrogenase polypeptide is not produced as a fusion protein. This is the first example of the production by E. coli of a catalytically active, multimeric eukaryotic protein which is not a fusion protein.

Aldehyde Dehydrogenase↗
PubMed1988

Extravasations of radiographic contrast material in the upper extremity.

Five significant extravasations of radiographic contrast material in the upper extremity were treated with early surgical drainage in an attempt to prevent extensive skin necrosis. Four of the five patients underwent operation within 6 hours of the extravasations, and all of these patients had excellent functional and cosmetic results without any evidence of skin necrosis. One patient who had a poor result did not undergo operation until 20 hours after a severe extravasation to the dorsum of the right hand. Most small-volume, less-extensive extravasations can be satisfactorily managed conservatively. Our clinical experience indicates that large subcutaneous extravasations of radiographic contrast material (volume more than 20 ml) should be surgically drained within 6 hours to prevent extensive damage to tissue.

Adult↗
PubMed1988

Cloning and complete nucleotide sequence of a full-length cDNA encoding a catalytically functional tumor-associated aldehyde dehydrogenase.

To study the mechanism(s) controlling expression of the tumor-associated aldehyde dehydrogenase (tumor ALDH), which appears during rat hepatocarcinogenesis, cDNAs encoding this isozyme were cloned and identified with an antibody probe. Poly(A)-containing RNA from HTC rat hepatoma cells, which have been shown to possess high levels of tumor ALDH, was used as template to synthesize double-stranded cDNA. The cDNA was methylated to protect internal sites. Two different synthetic DNA linkers were added sequentially to the cDNA to insure correct orientation for expression from the lac promoter of pUC8. A library of 100,000 independent members carrying inserts greater than 1 kilobase was obtained. From this library, two apparently identical tumor ALDH clones, differing only in size, were identified with an indirect immunological probe. The larger of the cDNA clones identified, pTALDH, was chosen for further study. Interestingly, since tumor ALDH is a dimeric enzyme, pTALDH directs synthesis of a functional tumor ALDH in the bacterial cell. The cDNA sequence has been confirmed by comparison to the amino acid sequence of tumor ALDH purified from HTC cells.

Aldehyde Dehydrogenase↗
PubMed1988

DNA, RNA and total protein content of leg and breast muscles of White Rock chickens selected for 56-day body weight.

Pectoralis and gastrocnemius muscles from White Rock chickens divergently selected for 29 generations for high or low 56-day body weight were analyzed for DNA, RNA and protein (mg/g) content at 12 ages between hatch and 273 days of age. Dimorphism between lines was maximum at day 18 for both muscle types and then declined with age. High-line chickens generally deposited relatively more muscle tissue than those from the low line. Although nonadditive genetic variation was evident for absolute muscle weights, it was more frequent for muscle weight relative to body weight. For both muscle types, DNA unit number, as measured by DNA content (mg/g), was larger for the high line than the low immediately after hatch and smaller in the high than in the low line from day 10 to 56 after which lines were similar. RNA and protein/g muscle were similar for both lines at most ages. Between days 4 and 56, a period of rapid muscle growth, DNA unit size (protein/DNA) of both muscle types was larger in the high than in the low line. Heterosis was positive for protein, DNA unit number and size, and negative for RNA content. While weight of pectoralis muscle was similar to that of one gastrocnemius muscle on day 1, by day 273 its weight was over 3-fold greater. DNA unit number was higher in pectoralis than gastrocnemius muscle from hatch to day 4, similar on days 7 and 10 and lower for pectoralis muscle beyond day 10. RNA content was similar at all ages except 4, 7 and 10 days. DNA unit size followed the same pattern as DNA unit number; however, greater nuclei number at hatch for the high line corresponded with low DNA unit size. This pattern suggests a higher rate of cellular filling for pectoralis than gastrocnemius muscle.

Aging↗
PubMed1988

Cricothyroid membrane puncture: oxygenation and ventilation in a dog model using an intravenous catheter.

A method for pediatric airway support was evaluated for the situation when mask ventilation or intubation is impossible. Mongrel dogs were sedated, intubated, and allowed to breathe room air for 30 min. Baseline variables were recorded, and the airway obstructed. After 2 to 3 min of hypoxia, arterial blood gas and hemodynamic data were again recorded. A percutaneous cricothyroid membrane puncture (PCMP) was then performed with a 12-ga iv catheter. Studies were carried out both in the presence and absence of spontaneous ventilatory efforts. With spontaneous ventilation, continuous low flow (1.0 L/min) oxygen insufflation provided oxygenation for 30 min and reversed increases in mean arterial pressure, pulmonary artery pressure (PAP), and systemic and pulmonary vascular resistance that had been produced by the obstruction. Respiratory acidosis occurred but was well tolerated. With paralyzed animals, whose ventilation was supported by a self-inflating bag with 10.0 L/min of oxygen, all hemodynamic variables except PAP returned to normal, oxygenation was excellent, and PaCO2 values were maintained at steady, but elevated levels. Complications included bilateral tension pneumothorax in one animal. This experimental study supports anecdotal experiences where PCMP has been used and has proven lifesaving when standard resuscitative measures to establish a clear airway have failed.

Airway Obstruction↗
PubMed1987

Dantrolene prevents the malignant hyperthermic syndrome by reducing free intracellular calcium concentration in skeletal muscle of susceptible swine.

Malignant hyperthermia (MH) is a pharmacogenetic disorder of skeletal muscle triggered when susceptible subjects are exposed to volatile anesthetic agents and/or depolarizing muscle relaxants. We have used Ca2+ selective microelectrodes to measure in vivo the intracellular free [Ca2+] in skeletal muscle of MH susceptible swine before and after the administration of dantrolene. We have investigated the effectiveness of this muscle relaxant in preventing clinical MH and the relationship between the resting intracellular free [Ca2+] and the probability of inducing the MH syndrome. The resting intracellular free [Ca2+] was 0.41 +/- 0.01 microM (M +/- SEM), which agrees with our previous measurements in susceptible swine. The administration of 0.5, 1, 2, 2.5 and 3 mg/Kg Dantrolene, reduced the intracellular free [Ca2+] to 0.31, 0.21, 0.09, 0.08, 0.08 microM respectively. The 0.5 mg/Kg dose induced a moderate decrease of [Ca2+]i and failed to prevent the MH syndrome after exposure to halothane (2%). The 1 mg/Kg dose produced a further reduction in [Ca2+]i and was sufficient to prevent the clinical syndrome in 2 out of 3 animals. The 2.5 mg/Kg dose was uniformly protective in all animals. These results suggest that the mechanism by which dantrolene protects susceptible animals exposed to triggering agents is by reducing the intracellular free [Ca2+] in skeletal muscle.

Anesthetics↗
PubMed1987

Evaluation of the atypical Pap smear.

Two hundred thirty-six consecutively referred patients with "atypical" but not dysplastic Pap smears were evaluated by colposcopy and directed biopsies to assess the significance of this ambiguous result. Additionally the histologic diagnosis was compared with the results obtained by repetition of the Pap smear, interpretation of cervigrams, and the visual impression of the coloposcopist to evaluate the accuracy of these three modalities as intermediate screening procedures. Fifty-eight patients (25%) had biopsy-proved cervical intraepithelial neoplasia. Repeat Pap smears identified only 17% of these patients. Colposcopists noted atypical transformation zones in 97% of the patients with cervical intraepithelial neoplasia. Cervigrams identified 81% of the cervical intraepithelial neoplastic lesions but had a 15% method failure (uninterpretable). The time-honored tradition of repeating atypical smears before definitive diagnostic procedures are performed is to be condemned. Neither colposcopy nor cervicography was judged to be an ideal intermediate screening procedure, but both were superior to Pap smear repetition.

Adult↗
PubMed1987

Growth-associated traits in parental and F1 populations of chickens under different feeding programs. 1. Ad libitum feeding.

Two experiments were conducted to compare body composition, plasma concentrations of glucose, lipid and protein, gastrointestinal tract (GIT) morphology, and digestive enzyme activities among populations of chickens exhibiting wide differences in growth. In the first experiment, males from a high weight (HW) line, a low weight (LW) line, and crosses between the lines (HL) were examined. In the second experiment, the same high weight (HW') line, a White Leghorn (LEG) line and their crosses (HLEG) were compared. In both experiments, comparisons were made at both 25 and 61 days of age. The HW chicks were heavier and had larger breasts and longer shanks than the LW or LEG chicks. Although the crosses (HL, HLEG) exhibited values for these traits intermediate to those of the parental lines, HLEG chicks tended to resemble one of the parental lines more closely than did the HL chicks. Differences among all mating combinations were significant for body fat, but the crosses (HLEG, HL) tended to more closely resemble their HW parental line. The HW chicks had significantly higher concentrations of glucose, lipid, and protein in plasma at 25 but not 61 days of age. No differences in glucose, lipid, or protein concentrations in plasma were observed in the second experiment. When expressed as a percentage of body weight, LW and LEG chicks tended to have larger GIT than HW chicks, whereas crosses more closely resembled the HW line. Although significant differences in digestive enzyme activities were obtained, these differences were generally associated with differences in body weight. It was concluded that genetic variation in the traits examined was dependent on both population and age.

Animals↗
PubMed1987

Growth-associated traits in parental and F1 populations of chickens under different feeding programs. 2. Ad libitum and intermittent feeding.

Growth traits and digestive enzyme activities were compared in parental lines and F1 crosses under ad libitum and alternate-day feeding. Responses to the feeding regimens were, in general, dependent on the background genome and age. Population by feeding regimen interactions were more prevalent for growth traits than for enzymatic activities. Although chickens adapted morphologically and physiologically to the particular feeding regimen to which they were exposed, the degree of adaptation was population dependent. Moreover, a line of White Leghorns differed considerably in response compared to a line of White Rocks selected for low body weight, demonstrating that weight is primarily a result of metabolic and behavioral processes rather than the determiner of those processes.

Animals↗
PubMed1987

Growth-associated traits in parental and F1 populations of chickens under different feeding programs. 3. Eating behavior and body temperatures.

In two experiments, parental populations of chickens and their F1 crosses were fed ad libitum or on alternate days. Eating and drinking behaviors, ability to compensate for fasting, and surface and cloacal temperatures were measured. Genetic and environmental (due to fasting) differences in feeding and drinking behaviors were found. Chicks from lines selected for larger body weight were better able to compensate for a 24-hr fast than those selected for smaller weight. Crosses were similar to the parental line that was the better compensator. Correlations between surface temperatures and body weights were consistently positive.

Animals↗
PubMed1987

Selection for body weight at eight weeks of age. 18. Comparisons between mature and immature pullets at the same live weight and age.

Body component and compositional traits were measured at the same age and live body weight in sexually mature and immature pullets from several genetic stocks. Populations included parental lines of White Plymouth Rocks selected for 25 generations for high and low juvenile body weight, their reciprocal F1 crosses, and an F2, as well as dwarfs from the parental lines. Although matched for age and body weight, percent liver weight and percent breast weight were greater for mature than immature pullets. Population by physiological stage interactions for percentages of abdominal fat and carcass lipid resulted from differences between mature and immature pullets, which were greater in the parental than in the cross and dwarf populations. Moreover, the pattern was reversed in the parental populations. The data supported the hypothesis that compositional requirements, independent of age and body weight, are necessary for the onset of egg production, and that these requirements vary among populations. They also demonstrated physiological buffering properties of heterozygosity and of the sex-linked dwarfing allele.

Animals↗
PubMed1987

Evaluation of two commercial broiler male lines differing in efficiency of feed utilization.

Factors potentially influencing feed conversion were studied in two lines of broilers known to differ in efficiency of feed utilization. When fed diets differing in energy, line by diet interactions were seldom significant and line effects were greater than those between diets. Chicks from the more efficient line had less plumage cover, less fat, and spent more time sitting than those from the less efficient line. These data imply that improved feed conversion is a function of several traits.

Animal Nutritional Physiological Phenomena↗
PubMed1986

Prophylaxis of Rift Valley fever with antiviral drugs, immune serum, an interferon inducer, and a macrophage activator.

Rift Valley fever virus (RVFV), a member of the family Bunyaviridae, extended its range from sub-Saharan Africa into Egypt in 1977. Its clinical spectrum is recognized to include severe manifestations such as hemorrhagic fever and encephalitis. For these reasons, as well as the limited knowledge of specific therapy for Bunyaviridae infections, we investigated several prophylactic regimens for RVF in a mouse model. Rimantadine, thiosemicarbazone, and inosiplex were ineffective. Pretreatment with glucan was of some use, but the most encouraging results were obtained with the antiviral drug ribavirin, passive antibody, or an interferon inducer polyriboinosinic-polyribocytidylic acid complexed with poly-L-lysine and carboxymethylcellulose (poly[ICLC]). Ribavirin and poly(ICLC) were also shown to be efficacious in preventing disease in hamsters. Ribavirin (loading dose of 50 mg/kg followed by 10 mg/kg at 8-h intervals for 9 days) suppressed viremia in RVF-infected rhesus monkeys. Ribavirin also reduced virus yield in infected cell cultures; sensitivity varied markedly with cell type but not with virus strain. Immune mouse ascitic fluid, with a plaque reduction neutralization titer of 1:1024, was effective in a dose of 4 ml/kg, a volume approximately equivalent to administration of a unit of convalescent plasma to a human. Poly(ICLC) may well have functioned through interferon induction, since RVFV was shown to be sensitive to interferon in cell culture, and since another macrophage activator (glucan) was only marginally effective. These studies suggest that ribavirin, poly(ICLC), and convalescent plasma may have a role in prevention or therapy of human RVF.

Animals↗