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Biomedical subjects

D E Johnson

Publications and source records attributed to D E Johnson.

At least 307 records · Page 17Linked to original sources
PubMed1991

Primary signet-ring cell carcinoma of the urinary bladder.

Primary signet-ring cell carcinoma is an uncommon malignancy arising in the urinary bladder. The authors report 12 cases collected at their institution. Median age for the ten men and two women was 58 years; the most frequent presentation was hematuria. In two of nine cases no mucosal lesion was cystoscopically visible. Eleven tumors were of nonurachal origin and one of urachal. At diagnosis, one tumor was stage B, two stage C, seven stage D, and two stages unknown. Nine of 12 patients were dead of disease (range, 1-16 months; median, 9 months), 1 alive with metastatic disease, 1 alive and well, and 1 dead of an unrelated cause. From a literature review, the authors accepted 35 cases that met their criteria and combined them with their 12 cases for statistical analysis. Prognosis was worse with a pure diffuse versus a mixed tumor (P = 0.004) and for nonurachal versus urachal origin (P = 0.005). The difference in five-year survival rates between stages B and D disease (P less than 0.05) was also statistically significant.

Adenocarcinoma, Mucinous↗
PubMed1991

The effect of glucocorticosteroids on serum, liver, and lung vitamin A and retinyl ester concentrations.

Vitamin A and its active metabolites are important factors in promoting normal respiratory epithelial differentiation and growth. Glucocorticoids, often used to treat chronic lung diseases in infancy and childhood, are known to increase serum retinol concentrations. To determine the effects of exogenous steroids on serum retinol and retinol-binding protein concentrations (as well as on liver and lung total vitamin A, retinol, and retinyl ester concentrations), 32 weanling Sprague-Dawley rats were divided into four equal experimental groups. Eight animals were vitamin A sufficient and received 7 days of intraperitoneal dexamethasone at 0.5 mg/kg/day (group SD), 8 were vitamin A sufficient and received placebo (group SP), 8 were made vitamin A deficient and subsequently received dexamethasone (group DD), and 8 were vitamin A deficient and received placebo (group DP). Dexamethasone increased serum retinol concentrations in the SD group (2.27 +/- 0.20 mumol/L) when compared with control (SP, 1.64 +/- 0.46 mumol/L, p less than 0.001) as well as with pretreatment baseline values (1.21 +/- 0.23 mumol/L, p less than 0.001). Lung total vitamin A, retinol, and individual retinyl esters were depleted by 56 +/- 19% in the SD group, whereas liver values were depleted by 36 +/- 23%. In the vitamin A-sufficient groups the relative percentages of four major retinyl esters (palmitate, stearate, oleate, and linoleate) did not change in either tissue after steroid exposure. The vitamin A-deficient groups had no detectable tissue vitamin A, and dexamethasone did not increase serum retinol concentrations in the DD group. Serum retinol-binding protein concentrations were significantly higher in both steroid-treated groups when compared with control.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Trauma in the arctic: an incident report.

On January 29, 1989, a military aircraft crashed on approach to an airfield in Alaska. The subsequent extraction, evacuation, and casualty resuscitation occurred at temperatures lower than -50 degrees F. Both the medical and military literature are replete with instructions and advice regarding the handling of trauma victims in the field in the Arctic environment; however, case reviews of such incidents are rare. In this case, the circumstances of the incident, and the organizations on which it fell, argued for almost ideal handling of the care of the victims. Problems that have an impact on the availability of casualty management, generally, in the Arctic such as a widely scattered population and sparse medical facilities, poorly defined evacuation routes, and marginal communication patterns, were not encountered in this review because of the unusual circumstances of this incident. The difficulties of field care in this environment, even under "ideal" conditions, however, are real and evident in this case history. Transportation assets are critical. Rehearsal, critique, refinement, and re-rehearsal of a mass casualty plan can significantly increase victim survival. Proper protocols and confidence in them take on an importance far beyond their benefit in a more temperate environment. Procedures must be worked out in advance, known by all concerned, and practiced, because the "rescuer" is at the same risk of hypothermia as the "victim" and, in addition, is responsible for thinking for the incapacitated patient. Rote-learned drills will be acknowledged far longer in the cold than unspecific guidelines. Survival for trauma victims may depend on those rote actions.

Accidents, Aviation↗
PubMed1991

Proteus mirabilis flagella and MR/P fimbriae: isolation, purification, N-terminal analysis, and serum antibody response following experimental urinary tract infection.

Urinary tract infection with Proteus mirabilis may lead to serious complications, including cystitis, acute pyelonephritis, fever, bacteremia, and death. In addition to the production of hemolysin and the enzyme urease, fimbriae and flagellum-mediated motility have been postulated as virulence factors for this species. We purified mannose-resistant/proteuslike (MR/P) fimbriae and flagella from strains CFT322 and HU2450, respectively. Electron microscopy revealed highly concentrated preparations of fimbriae and flagella. Fimbrial and flagellar structural subunits were estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be 18.5 and 41 kDa, respectively. N-terminal sequencing revealed that 10 of the first 20 amino acids of the major MR/P subunit matched the sequence of the P. mirabilis uroepithelial cell adhesin N terminus and 11 of 20 amino acids matched the predicted amino acid sequence of the Escherichia coli P fimbriae structural subunit, PapA. In addition, 90 and 80% homologies were found between the first 20 amino acids of P. mirabilis flagellin and those of Salmonella typhimurium phase-1 flagellin and the E. coli hag gene product, respectively. An enzyme-linked immunosorbent assay using purified antigens showed a strong reaction between the MR/P fimbriae or flagella and sera of CBA mice challenged transurethrally with P. mirabilis. A possible role for MR/P fimbriae in the pathogenesis of urinary tract infection is supported by (i) a strong immune response to the antigen in experimentally infected animals, (ii) amino acid sequence similarity to other enteric surface structure, and (iii) our previously reported observation that MR/P fimbriae are expressed preferentially as the sole fimbrial type in human pyelonephritis isolates.

Amino Acid Sequence↗
PubMed1991

The human fibroblast growth factor receptor genes: a common structural arrangement underlies the mechanisms for generating receptor forms that differ in their third immunoglobulin domain.

To determine the mechanisms by which multiple forms of fibroblast growth factor (FGF) receptors are generated, we have mapped the arrangement of exons and introns in the human FGF receptor 1 (FGFR 1) gene (flg). We found three alternative exons encoding a portion of the third immunoglobulin (Ig)-like domain of the receptor. One of these alternatives encodes a sequence that is part of a secreted form of FGFR 1. The other two encode sequences that are likely part of transmembrane forms of FGFR 1. One of these forms has not been previously reported in published cDNAs. Also, we have determined the structural organization of a portion of the human FGFR 2 gene (bek) and found a similar arrangement of alternative exons for the third Ig-like domain. The arrangement of these genes suggests that there are conserved mechanisms governing the expression of secreted FGF receptors as well as the expression of at least two distinct membrane-spanning forms of the FGF receptors. The diverse forms appear to be generated by alternative splicing of mRNA and selective use of polyadenylation signals.

Amino Acid Sequence↗
PubMed1991

Microprobe analysis of maturation-related elemental changes in rat parotid secretory granules.

Electron probe X-ray microanalysis was use to quantitate the elemental and mass changes that take place during the secretory granule maturation process. A single injection of isoproterenol stimulated the depletion of secretory granules from rat parotid acinar cells. Granules at different stages of maturation were analyzed as they reaccumulated within the cells over time. Dry mass measurements revealed that secretory material becomes concentrated about twofold within maturing granules. Nearly all of the increase in mass concentration could be attributed to a reduction in water space. Data are presented that indicate that Na, K, Cl, and water all efflux from secretory granules during maturation. In contrast, granule S content is positively correlated with maturation. Hence, significant changes in granule elemental and water contents occur during the maturation process.

Animals↗
PubMed1991

Incidence and pathology of spontaneous renal pelvis transitional cell carcinomas in rats.

Spontaneous transitional cell carcinoma (TCC) originating from renal pelvis is very rare. Metastasis from this tumor having been reported only once previously. Data from control groups of 17 carcinogenicity studies in Sprague-Dawley and 10 carcinogenicity studies in Fischer 344 (F-344) rats were reviewed and evaluated to determine the incidence and pathology of TCC. Renal pelvis TCC were observed in 1 male and 1 female Sprague-Dawley rat and in 1 male F-344 rat. Metastasis from TCC to the lung was observed in 1 male Sprague-Dawley rat. Detailed histopathological features of this tumor are described and discussed.

Animals↗
PubMed1991

Small intestinal starch digestion in steers: effect of various levels of abomasal glucose, corn starch and corn dextrin infusion on small intestinal disappearance and net glucose absorption.

Eight Holstein steers (four at 300 kg, four at 406 kg) fitted with an elevated carotid artery, hepatic portal and mesenteric venous catheters, and abomasal and ileal cannulas were used in several 4 x 4 Latin square experiments to evaluate small intestinal starch digestion. They were fed alfalfa hay at 1.5% of BW and abomasally infused with water or glucose, corn starch or corn dextrin (one carbohydrate per Latin square) at 20, 40 or 60 g/h, with subsequent determination of small intestinal disappearance and net portal glucose absorption. Increasing the amount of all three carbohydrates infused abomasally increased the amount of carbohydrate disappearing in the small intestine. Increased infusion of glucose caused a continual increase (linear, P less than .01) in net glucose absorption, whereas net glucose absorption for starch and dextrin was maximal at the 20 g/h infusion (quadratic, P less than .05). With the 60 g/h infusion, 94% of the glucose but only 38% of starch and 29% of small intestinal dextrin disappearance could be accounted for as net glucose absorption, leaving a large portion of starch and dextrin disappearance unaccounted for. Of the infused starch and dextrin passing the ileum, 5.8 and 7.3%, respectively, was unpolymerized glucose, indicating that, at least in the distal small intestine, complete starch hydrolysis exceeded the capacity for glucose disappearance. It is concluded that only about 35% of the raw corn starch disappearing in the steer's small intestine resulted in net portal glucose absorption.

Animals↗
PubMed1991

Effects of cimaterol on energetics and carcass characteristics of Suffolk ewe lambs.

The effects of cimaterol, a beta agonist, on basal metabolic rate, heat increment, maintenance requirements and carcass characteristics were determined using six treated and six control Suffolk ewe lambs. The lambs were fed a pelleted diet (18.7% CP, 2.64 Mcal ME/kg) with or without .5 mg cimaterol/kg BW.75 daily for 70 d. Heat production was monitored for 2 d on each animal at three levels of intake by respiration calorimetry. A 7-d total collection digestion trial was conducted on each animal at both high and low levels of intake. Cimaterol-fed lambs gained more (P less than .05) weight (174 vs 107 g/d) and had a higher (P less than .01) gain/feed ratio (151 vs 90 g/kg) than controls. Cimaterol did not affect diet digestibility or methane production. It reduced (P less than .01) urinary N excretion by 12% and improved (P less than .001) N retention by 18%. Cimaterol also increased carcass weight (26.9 vs 22.1 kg), dressing percentage (57.2 vs 53.9), longissimus muscle area (22.5 vs 15.0 cm2) and leg score (14.3 vs 12.2). Heat production was, on the average, elevated 7 to 10% on d 1 to 4 of cimaterol feeding but reverted to control levels by d 10. Cimaterol did not have any long-term thermogenic effects, either expressed as partial efficiency of ME use for growth (.48 vs .49), as maintenance ME requirements (76 vs 75 kcal/kg BW.75) or as fasting heat production (84 vs 80 kcal/kg BW.75) for treated vs control lambs, respectively. Results indicate little long-term thermogenic effect of cimaterol, even though growth rate and protein deposition were increased.

Adrenergic beta-Agonists↗
PubMed1991

Maintenance requirements of beef cattle as affected by season on different planes of nutrition.

Eight Hereford steers with an initial weight of 344 kg and a final weight of 476 kg were allotted randomly to two groups that were alternated between low (120 x maintenance) and high (2.27 x maintenance) intakes during five consecutive seasons in order to measure effects of season (cold stress) and intake on thermoneutral energy requirements. The steers were housed outdoors with neither shelter nor bedding and adapted to the specified intake levels for 21 to 31 d before each season's measurement of maintenance. Maintenance energy requirements were estimated as fasting heat production (FHP) and maintenance metabolized energy (MEm) by respiration calorimetry at thermoneutral temperatures. The high plane of nutrition caused a consistent increase of about 7% in FHP and 14% in MEm averaged across seasons (P less than .05). Within plane of nutrition, season had no effect on FHP or MEm, with the exception that values recorded in fall were lower than those recorded during the first summer (P less than .05). Nevertheless, daily gain during the winter acclimatization period was lower (P less than .05). We conclude that season had no effect on thermoneutral maintenance energy requirements (FHP, MEm) even though cold increased requirements for weight maintenance or gain. No interactions were found between season and plane of nutrition for the parameters measured. Acute cold stress, rather than chronically elevated metabolic rate, likely was responsible for poorer feedlot performance during the cold months of the year.

Animal Nutritional Physiological Phenomena↗
PubMed1991

Variation among twin beef cattle in maintenance energy requirements.

The genetic variation in energy expenditures of cattle at fasting (FHP) and maintenance (MEm) was determined by using 12 pairs of monozygous twins at 20 mo of age. The pairs were of two breed types, eight Angus x Hereford (three steers, five heifers) and four Barzona x Hereford (three steers, one heifer). The heifers were 132 +/- 13 d pregnant at the time of measurement. The pairs were fed at 1.15 x maintenance energy requirements for a minimum of 30 d prior to heat production (HP) measurements in dual indirect respiration calorimetry chambers. The diet fed was cracked corn:alfalfa hay (45:55) with a determined ME of 2.47 +/- .02 Mcal/kg DM. This diet was fed individually for 7 d prior to and during two consecutive 22-h HP measurements. The animals then were fasted for 2 d and fasting heat production measurements (FHP) were made on d 3 and 4 of the fast. Metabolizable energy required for MEm was calculated iteratively by assuming a semi-log relationship between HP and metabolizable energy intake. There were no differences (P greater than .10) in measured energy expenditures due to different breed type. The FHP and efficiency of ME use for MEm (Km) were similar between sexes, although heifers had lower (P less than .025) MEm than steers. Twin pair effects were detected for FHP (P less than .005) and MEm (P less than .05) but not for Km. Broad sense heritability estimates were calculated as the intraclass correlation between members of monozygous twin pairs. Heritability estimates for MEm, FHP, and Km were .52 +/- .22, .75 +/- .13, and .34 +/- .27, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1991

Energy utilization and organ mass of Targhee sheep selected for rate and efficiency of gain and receiving high and low planes of nutrition.

Two experiments were conducted to examine changes in usage of energy and visceral organ mass in Targhee lambs selected on the basis of improved rate and efficiency of growth. In Exp. 1, Targhee ram lambs from a breeding line selected for improved growth rate and feed efficiency and a control line that was maintained without selection for 20 yr were provided with either a high (ad libitum) or low (maintenance) plane of nutrition. Rams were slaughtered and weights of the visceral organs were recorded. Analysis of variance, using a factorial model with BW as a covariant, was used to examine effects of lines of breeding, plane of nutrition, interaction between line of breeding and plane of nutrition, and days on feed. Weights of liver, kidneys, rumen, abomasum, and small and large intestines from lambs receiving a high plane of nutrition were, respectively, 39, 25, 12, 28, 40, and 31% greater than weights of those tissues in lambs receiving a low plane of nutrition. Ruminal weights were 13% greater for rams from the select line of breeding than for those from the control line. In Exp. 2, seven Targhee ewe lambs from the select line and eight from the control line were examined for differences in heat production and energy usage by indirect open circuit respiration calorimetry using a completely randomized design. Fasting heat production of lambs from the select line was 7.8% greater than that of lambs from the control line. Partial efficiencies of ME used for maintenance and tissue accretion were not different between lines of breeding.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Nutritional Physiological Phenomena↗
PubMed1991

Pregnancy and lactation in beef heifers grazing tallgrass prairie in the winter: influence on intake, forage utilization, and grazing behavior.

Six ruminally and eight bifistulated (ruminal and esophageal) Hereford x Angus heifers were used to determine effects of pregnancy and early lactation on forage intake and utilization under grazing conditions. Three ruminally and three bifistulated heifers were bred (pregnant/lactating; P/L; average calving date was February 11, 1989); remaining heifers served as controls (C). The experiment consisted of three periods (P1 = average of 55 d before parturition; P2 = average of 12 d before parturition; P3 = average of 26 d after parturition). All heifers grazed the same 24-ha Flint Hills range pasture. Dehydrated alfalfa pellets were supplemented at .5% BW/heifer daily prepartum and at .8% BW/heifer daily postpartum. Treatment x period interactions were noted (P less than .10) for forage OM intake, ruminal capacity, indigestible ADF (IADF) fill, and grazing time but not for OM digestibility or IADF passage rate (P greater than .10). In P1 and P3, P/L heifers had greater (P less than .10) forage OM intake than C heifers, whereas no differences were noted (P greater than .10) in P2. Pregnant/lactating heifers spent less time (P less than .10) grazing than did controls in P2 and more time (P less than .10) than controls in P3. Ruminal IADF fill and ruminal capacity, as measured by water fill, tended (P = .14 and .16, respectively) to differ between the two groups in P2. Digestibility of OM was unaffected (P greater than .10) by physiological status, whereas IADF passage rate was greater (P less than .10) in P/L heifers. Only minor differences were noted for the chemical composition of diets selected by the two groups. Ruminal fermentation patterns shifted only slightly; the largest effects were in P3, when P/L heifers had greater (P less than .10) propionate and less (P less than .10) acetate (mol/100 mol) than C heifers. In summary, during the period just before parturition, differences in forage OM intake between P/L and C heifers disappeared, and ruminal fill and capacity tended to be lower for P/L heifers. Intake was 16% greater for P/L than for C heifers during the early postpartum period. Organic matter digestibility was not influenced by physiological status, even though IADF passage rates were greater for P/L heifers.

Animals↗
PubMed1991

Physical and chemical components of the empty body during compensatory growth in beef steers.

The composition of carcass and noncarcass tissue growth was quantified by serial slaughter of 26 Angus x Hereford crossbred steers (initial age and weight 289 +/- 4 d and 245 +/- 4 kg) during continuous growth (CON) or compensatory growth (CG) after a period of growth restriction (.4 kg/d) from 245 to 325 kg BW. All steers were fed a 70% concentrate diet at ad libitum or restricted levels. Homogenized samples of 9-10-11th rib and noncarcass tissues were analyzed for nitrogen, fat, ash, and moisture. Growth rate from 325 to 500 kg BW was 1.54 and 1.16 kg/d for CG and CON steers. The weight of gut fill in CG steers was 10.8 kg less (P less than .05) before realimentation and 8.8 kg more (P less than .10) at 500 kg BW than in CON steers. The allometric accretive rates for carcass chemical components relative to the empty body were not affected by treatment. However, the accretive rates for CG steers were greater (P less than .01) for noncarcass protein (.821 vs .265), noncarcass water (.861 vs .507), and empty-body protein (.835 vs. .601) than for CON steers. Final empty-body fat was lower (P less than .001; 24.2 vs 32.4%) and empty-body protein higher (P less than .001; 16.6 vs 14.8%) in CG steers than in CON steers. Consequently, net energy requirements for growth (NEg) were approximately 18% lower for CG steers. We conclude that reduced NEg requirements and changes in gut fill accounted for most of the compensatory growth response exhibited in these steers.

Animal Nutritional Physiological Phenomena↗
PubMed1991

Hematological and blood chemistry profiles of American bison grazing on Konza Prairie of Kansas.

Normal hematological and blood chemistry parameters were measured in 45 American bison (Bison bison) that were divided into three age groups for comparison. There was a statistically significant (P less than 0.05) increase with advancing age in mean corpuscular volume, mean corpuscular hemoglobin, absolute neutrophil and eosinophil counts, total protein, globulin, creatinine, and blood urea nitrogen. There was a statistically significant (P less than 0.05) decrease with advancing age in levels of sorbital dehydrogenase, alkaline phosphatase, glucose, sodium, calcium and phosphorus.

Aging↗