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Biomedical subjects

D E Jones

Publications and source records attributed to D E Jones.

At least 109 records · Page 6Linked to original sources
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↗
PubMed1986

Lipocyte hyperplasia and sexual maturation of Japanese quail (Coturnix coturnix japonica).

1. Hyperplastic growth of adipose tissue in Japanese quail (Coturnix coturnix japonica) was examined in relation to sexual maturity to determine whether fat cell number is fixed in mature individuals of this species. 2. Total DNA concentrations in the lipid (lipocyte) and non-lipid (stroma) fractions of collagenase (EC 3.4.24.3)-digested abdominal (retroperitoneal) fat depots were determined on a chronological-age basis from 28 to 240 d of age. The in vivo incorporation of [methyl-3H]thymidine into DNA of both the lipocyte and stroma fractions of abdominal fat from both ad lib. and restricted-fed (75% of ad lib.) females was also examined at ages before and subsequent to sexual maturity. 3. In both males and females, significant increases in abdominal fat weights at ages beyond sexual maturity were associated with increased lipocyte DNA. Regardless of the feeding regimen and stage of maturity, substantial radioactivity was recovered from both the stromal and lipocyte fractions of abdominal fat when female quail were examined 24 h after the administration of tritiated thymidine. When examined 5 d post-injection, the majority of the radioactivity was contained in the lipid fraction of collagenase-digested adipose tissue. 4. Both the total DNA content of adipose tissue and the incorporation of tritiated thymidine into adipose tissue indicated that lipocyte hyperplasia contributes to postmaturational increases in fat deposition.

Abdomen↗
PubMed1985

Application of response surface methods for evaluating the interactions of soman, atropine, and pralidioxime chloride.

Response surface methods were employed to model survival data obtained in guinea pigs following subcutaneous exposure to soman (GD; 30-84.6 micrograms/kg) with various treatment regimens (i.e., atropine/pralidioxime chloride [ATR/2-PAM] combinations, given im, 1 min post-GD). The analysis of the proportions of surviving animals in the various groups revealed that the use of individual treatment agents (i.e., ATR or 2-PAM) was effective in increasing survival. The level of GD exposure altered the nature of the ATR/2-PAM interaction. Exploration of the response surface indicates that the optimal treatment combinations (greater than 94% survival) of ATR/2-PAM change as a function of GD exposure in the following manner: GD 30 micrograms/kg-ATR/2-PAM, 217 mg/kg/0 mg/kg; GD 42.4 micrograms/kg-179/29 mg/kg; mg/kg; GD 60 micrograms/kg-148/83 mg/kg; GD 84.6 micrograms/kg-168/150 mg/kg. At higher exposures of GD (greater than 42.4 micrograms/kg), therapeutic synergy was observed with the use of the treatment combinations, as compared to optimal single agent treatments. Evaluation of the apparent toxicities of treatment combinations can also be determined in this procedure. RSM is not geometrically restricted by the number of variables under consideration. A variety of experimental designs, when used in conjunction with RSM, permit the modeling of multiple responses and provide estimates of optimal therapeutic modalities subject to constraints (e.g., behavioral toxicity).

Animals↗
PubMed1985

Assessing pyridostigmine efficacy by response surface modeling.

The therapeutic efficacy of atropine sulfate/pralidoxime chloride (ATR/2-PAM) treatment (im) therapy, and pyridostigmine bromide (PYR) pretreatment (oral) therapy were evaluated in soman-challenged guinea pigs. ATR/2-PAM efficacy was assessed as protective ratio (PR = treated soman LD50/control soman LD50); PYR efficacy was assessed both as PR and by response surface modeling (RSM) techniques. The optimal ATR/2-PAM treatment gave a PR of 3.78. PYR pretreatment (1 hr) produced a dose(log)-dependent (r = 0.96) inhibition of whole blood AChE and afforded significant (p less than 0.05) increases in PR (with doses greater than 0.12 mg/kg PYR) against soman when followed by 64 mg/kg ATR/100 mg/kg 2-PAM treatment. These PRs, however, were poorly correlated (r = 0.45) with the corresponding level of PYR-induced AChE inhibition. In contrast, RSM analysis of efficacy indicated that the optimal ATR/2-PAM dose combination varied as a function of both the soman-challenge level and the PYR pretreatment dose. Efficacy was therefore evaluated for varying PYR pretreatment doses in combination with the appropriate optimal ATR/2-PAM treatment (as determined by RSM for each soman challenge dose and PYR dose evaluated). When assessed in this manner, PYR efficacy (PYR) was found to be highly correlated (r = 0.97) with PYR-induced AChE inhibition. Since percentage of AChE inhibition was directly correlated with PYR dose (log), these results indicate that PYR pretreatment efficacy is a highly correlated, dose-dependent phenomenon, providing ATR/2-PAM treatment is optimized.

Animals↗
PubMed1985

Sarin intoxication elevates plasma pralidoxime.

Groups of guinea pigs were injected with a range of dosages for sarin (0, 140, 279, 557 micrograms/kg) followed by pralidoxime (2-PAM) and atropine sulfate (16 mg/kg). Poisoning by sarin in these animals elevated plasma pralidoxime content in a dose-dependent manner within 10 min of intoxication. Plasma levels after administration of 3.12 mg/kg of 2-PAM were elevated from a control mean of 6.18 micrograms/ml to a maximum of 13.78 micrograms/ml in animals given 557 micrograms/kg of sarin at 2 min after the injection of the therapeutic compounds. This suggests that pathophysiological changes following intoxication by potent inhibitors of cholinesterase result in a decrease in the rate and extent of distribution of therapeutic compounds. This effect is most likely a consequence of changes in cardiovascular functions influencing blood flow to various organs.

Animals↗
PubMed1985

Lipogenesis and lipolysis in fed and fasted chicks from high and low body weight lines.

Lipogenic and lipolytic capacities were examined in fasted and nonfasted 28-day-old chicks from high-weight (HW) and low-weight (LW) selected lines. Lipogenesis was assessed in liver and bone (sternum) tissues through the activities of malic enzyme (EC 1.1.1.40), citrate cleavage enzyme (EC 4.1.3.8), and acetyl coenzyme A carboxylase (EC 6.4.1.2), as well as through the in vitro incorporation of acetate-1-14C into liver and bone lipid fractions. Lipolysis was estimated through the in vitro release of free fatty acids (FFA) from abdominal adipose tissue and through plasma FFA. Fasting depressed lipogenesis and increased lipolysis. Regardless of the feeding state, LW chicks exhibited higher lipogenic and lipolytic capacities than their HW counterparts, suggesting that lipid degradation may be relatively more important than synthesis in determining net fat deposition. In addition, the incorporation of radioactive acetate into bone lipid was associated with detectable activity of lipogenic enzymes, providing further evidence that the skeleton is an important site of lipogenesis in the chicken.

Acetyl-CoA Carboxylase↗
PubMed1985

Breaking strength and composition of the skin of broiler chicks: response to dietary calorie-protein ratios.

Skin breaking strength and protein, fat moisture, and total collagen concentrations of skin from the breast, thigh, and back of male and female commercial broilers were measured in response to diets containing relatively wide or narrow ratios of calories to protein (C:P). Comparisons were made at 28, 42, and 56 days of age. Chicks fed diets containing relatively wide C:P ratios had weaker skin than those fed diets with narrower C:P ratios, with differences being greater at 56 days than at younger ages. Regardless of diet, males had stronger skin than females. Although the magnitude of the differences varied with age, breast skin was stronger than thigh skin, with skin from the back being intermediate in strength. The observed differences in breaking strength were not consistently associated with fat, protein, moisture, or collagen concentrations of the skin.

Animals↗
PubMed1984

Cervical intraepithelial neoplasia in adolescents.

Three hundred and eleven adolescent patients with abnormal Pap smears were referred for evaluation. Two hundred and ninety-three were evaluated with colposcopy and directed biopsies. Fourteen percent had normal findings, 42% CIN I, 22% CIN II, and 22% CIN III. The distribution of pathologic findings was similar to that in an adult population in the same clinic except that no invasive carcinomas were found in our adolescents. Since there was a predominance of exocervical lesions, only 3% of the patients required diagnostic conization. Ninety-four percent of the adolescents were treated by cryotherapy as compared to 68% of the adults. Since adolescents have significant cervical intraepithelial neoplasia, an abnormal Pap smear should be evaluated and a tissue diagnosis obtained. Outpatient therapy is well suited for the majority of teenagers because the lesions are commonly confined to the exocervix.

Adolescent↗
PubMed1984

Abnormal cervical cytology in sexually active adolescents.

A routine Pap smear was performed on 1,207 sexually active adolescents seen in a public health department family planning clinic. One hundred and thirty-two (11%) had abnormal findings and were referred for evaluation to the gynecologist of their choice. Thirty-five patients (27%) failed to keep their initial referral appointment, and twenty-eight patients (21%) were inadequately evaluated. Therefore, only 69 patients (52%) were evaluated by colposcopy with directed biopsies. Fifty of the 69 patients (72%) had cervical intraepithelial neoplasia. Sexually active adolescents should be routinely screened with Pap smears and those with abnormal findings should be evaluated and a tissue diagnosis obtained. The primary care provider must reinforce the need for complete evaluation and therapy. Referral must be made to a gynecologist who is expert in the evaluation of abnormal Pap smears.

Adolescent↗
PubMed1984

Expression of tumor-associated aldehyde dehydrogenase during rat hepatocarcinogenesis using the resistant hepatocyte model.

The resistant hepatocyte model was used to study expression of tumor-associated aldehyde dehydrogenase (ALDH) activity during the course of rat hepatocarcinogenesis. The hepatic ALDH phenotype was determined at intervals over 280 days by histochemical analysis, total ALDH activity assays and gel electrophoresis, using propionaldehyde and NAD (P/NAD) to characterize normal liver ALDH activity or benzaldehyde and NADP (B/NADP) to determine tumor-associated ALDH activity. By total activity assays and gel electrophoresis, no significant changes in ALDH activity occurred until day 70. However, histochemical analysis clearly demonstrated changes in ALDH activity early in neoplastic development. Intense focal hepatocyte staining with P/NAD and/or B/NADP was first detectable at day 28. The number of P/NAD-positive foci increased until day 35 then declined until day 70. The number of B/NADP-positive foci also increased until day 35, but then remained relatively constant for the remainder of the experiment. GGT activity of serial sections indicated that early ALDH-positive lesions represent a small subpopulation (9%) of all GGT-positive foci. However, by day 168 a significant portion (80%) of persistent GGT-positive neoplastic nodules were also B/NADP-positive histochemically. In addition, virtually all hepatocellular carcinomas (96%) generated by this protocol possessed significantly elevated levels of tumor-associated ALDH by histochemical analysis, total ALDH activity and gel electrophoresis. These results indicate that early appearing ALDH-positive lesions may define one early subpopulation of all initiated cells that have a high probability of progressing to the ultimate neoplasm.

Aldehyde Dehydrogenase↗
PubMed1984

Group B streptococcal colonization patterns in mothers and their infants.

Maternity patients and their newborn infants were cultured for group B streptococci (GBS) at Tampa General Hospital, Tampa, Fla., from September 1982 to May 1983. Culture swabs were placed into Lim Group B Strep Broth (GIBCO Laboratories, Madison, Wis.) and quantitated for GBS. A strong correlation was found between the numbers of GBS in the maternal vagina and the infant rectum. Infants symptomatic for early-onset GBS disease were delivered by mothers heavily colonized (greater than or equal to 3 X 10(4) GBS per swab) at the vagina. Such mothers were identified as GBS carriers by slide coagglutination and latex agglutination after their broth cultures had been incubated for 5 h. These data indicate that maternity patients at high risk of delivering infants heavily colonized with GBS and potentially symptomatic for early-onset GBS disease can be rapidly and selectively identified.

Agglutination Tests↗
PubMed1984

Surgical decision in glaucoma simplex.

The indications for 220 trabeculectomies performed by six surgeons at three different centres were studied. 82% of the decisions to operate were based on a non-progressive but high risk situation. The 18% of cases showing preoperative deterioration were characterised by early presentation and low preoperative residual pressures. There was a distinct similarity in the incidence of individual indications at the different centres.

Glaucoma, Open-Angle↗