Biomedical subjects

J Ware

Publications and source records attributed to J Ware.

At least 91 records · Page 5Linked to original sources

PubMed1989

Effect of indomethacin in autotransplanted colonic tumors.

Seventy-five male Sprague-Dawley rats received weekly injections of dimethylhydrazine (DMH) for six months. Indomethacin was given orally to 40 of the rats. At the end of the allotted period, colonic tumors were autotransplanted into the subcapsular space of the left kidney. The autopsy demonstrated colonic tumors in 32 of 34 rats treated with DMH (94.1 percent), but only in 15 of 40 rats (37.5 percent) treated with DMH-indomethacin. Successful kidney autotransplantation was accomplished in 20 of 32 DMH-treated rats (63 percent) and in 5 of 15 DMH-indomethacin-treated rats (33.3 percent). Thus, the induction of colonic tumors by DMH and successful kidney autotransplants can be substantially abrogated by synchronous treatment with indomethacin.

1,2-Dimethylhydrazine↗

PubMed1989

Evidence of increased gluconeogenesis during hemorrhage in fed and 24-hour food-deprived rats.

Food withdrawal 24 hr before hemorrhage has been shown to increase experimental post-hemorrhage mortality, and survival is associated with the degree of hyperglycemia. Lack of hyperglycemic response has been attributed to depleted glycogen reserves after 24-hr food withdrawal. To investigate the effect of short-term food deprivation on glucose metabolism during hemorrhagic stress, glucose production (rate of appearance, Ra), glucose uptake (rate of disappearance, Rd), glucose clearance, and glucose recycling were investigated in fed and 24-hr food-deprived rats under basal conditions, and during hemorrhagic hypotension using 3-H3-U-C14-glucose. During hemorrhage, blood glucose levels were higher in fed rats. Hemorrhage induced a decrease in glucose clearance irrespective of nutritional state in both 24-hr starved animals and rats in the postprandial state. Calculated glucose recycling increased in both groups after hemorrhage. The results indicate that hemorrhagic stress induces a rapid increase in gluconeogenesis, as reflected by increased glucose recycling.

Animals↗

PubMed1989

Postnatal stimulation of rat surfactant protein A synthesis by dexamethasone.

The effects of postnatal dexamethasone treatment in vivo on the synthesis of surfactant protein A (SP-A) were examined at the protein and RNA levels. Rats ranging from 1 day old to adult were injected with 200 micrograms of dexamethasone/kg body wt or with vehicle alone and were killed 24 h after injection. One portion of the lung was metabolically labeled with [35S]methionine, the proteins immunoprecipitated using an antiserum to SP-A, and analyzed electrophoretically. Both newly synthesized intracellular and secreted SP-A levels were increased by dexamethasone, reaching averages of 2.3 and 4.5 times control values, respectively. Another portion of the lung tissue was used for RNA analysis. SP-A mRNA levels were also elevated an average of 1.4 times control values by hormone treatment. Dose-response experiments using 16-day-old pups showed that both total SP-A, as measured by enzyme-linked immunosorbent assay, and total SP-A mRNA levels were elevated with dexamethasone treatment, reaching maximal stimulation at 2 mg. We conclude that postnatal dexamethasone treatment in vivo results in increased levels of both newly synthesized SP-A and SP-A mRNA, suggesting that pretranslational events may in part contribute to this process.

Animals↗

PubMed1989

Identification of a F.VIII epitope recognized by a human hemophilic inhibitor.

Hemophilia A, one of the most common of the inherited bleeding disorders, results from a deficiency or abnormality of factor VIII (F.VIII). In approximately 15% of persons with hemophilia, treatment with exogenous F.VIII is complicated by the development of anti-F.VIII antibodies which block F.VIII coagulant activity. These antibodies have been termed inhibitors. To localize epitopes recognized by inhibitors, we used a lambda gt11 library which expresses small random fragments of F.VIII as fusion proteins. One epitope has been mapped to the 25-amino acid sequence lys-338 through asp-362 of F.VIII (E338-362). Immunoaffinity-purified antibodies that react with this epitope neutralize F.VIII:C activity. E338-362 is adjacent to an enzymatic cleavage site at arg-372 which is important in F.VIII activation. Hence, an antibody binding to E338-362 would probably block this cleavage and thereby block activation of F.VIII.

Amino Acid Sequence↗

PubMed1989

An arginine to cysteine amino acid substitution at a critical thrombin cleavage site in a dysfunctional factor VIII molecule.

We have analyzed the factor VIII (FVIII) protein and the nucleotide sequence around two thrombin cleavage sites, at arginine 372 in the FVIII heavy chain and arginine 1689 in the FVIII light chain in a naturally occurring dysfunctional FVIII variant, FVIII Okayama. The patient was a 42-year-old hemophiliac with a FVIII coagulant activity of 0.03 U/mL and a FVIII antigen level of 0.8 U/mL. The patient's FVIII was not thrombin activatable to levels seen in normal plasma. Immunoblotting of partially purified FVIII Okayama and normal FVIII showed that thrombin cleavage of the 92 kilodalton (Kd) heavy chain was impaired in the mutant protein. The patient's genomic DNA was amplified using the polymerase chain reaction with two sets of synthetic oligonucleotide primers spanning amino acid residues 319 to 400 and 1630 to 1720. Sequence analysis of the amplified DNA fragments revealed a cytosine to thymine transition, converting an arginine to a cysteine codon at residue 372. No abnormality was found in the FVIII light chain region analyzed. The patient's hemophilic brother and carrier mother revealed the same mutation. We conclude that the pathogenesis of hemophilia A in this patient is probably due to an arginine to cysteine substitution at a thrombin cleavage site in the FVIII heavy chain.

Adult↗

PubMed1989

The effect of hyperosmolar infusions on survival after hemorrhage.

Hyperglycemia has previously been reported beneficial for survival after hemorrhage. In the present investigation, rats depleted of liver glycogen after 24 h food deprivation were infused either A: isotonic NaCl (300 mosm/kg H2O), B: glucose (1,800 mosm/kg), C: Xylose (2,000 mosm/kg) or D: NaCl (1,800 mosm/kg), during 60 min hemorrhage, and observed for recovery or death for seven days. During hemorrhage, all animals given hyperosmolar infusions had higher serum osmolality and greater plasma refill compared to group A. Increments in serum osmolality correlated inversely to hematocrit developments, p less than 0.05. Only 2/18 animals given isotonic NaCl survived, while survival in the other groups were 14/18 (glucose infused), 20/22 (xylose infused) and 20/20 (hypertonic NaCl). Best survival was noted in the groups with the highest final osmolality, and largest reduction in hematocrits; groups C and D, while significantly more animals given glucose died compared to group D. It is concluded that induction of hyperosmolality during the early phase of hemorrhage is associated with increased survival in hemorrhage, irrespective of hyperosmolar agent infused. The benefits of hyperglycemic hyperosmolality is primarily related to the osmolar properties of this solute, and not the immediate need for glucose as substrate.

Animals↗

PubMed1989

Glucose kinetics in haemorrhagic hyperglycemia.

Haemorrhagic hyperglycemia has been demonstrated to have beneficial effects on fluid homeostasis, and insulin resistance has been reported in vitro after haemorrhage. In the present study the interrelation of peripheral levels of insulin, glucagon, and adrenalin and the rate of glucose disappearance (Rd) in haemorrhagic hyperglycemia were determined in vivo. Rd was determined by single injection of 3-3H-glucose in three groups of postprandial rats: controls, rats submitted to rapid blood loss, and rats receiving a constant 30% glucose infusion. The level of hyperglycemia after bleeding was 22.9 +/- 1.9 mmol x 1(-1) (mean +/- 1 S.E.), and during infusion it was 20.4 +/- 1.4 mmol x 1(-1). The Rd value of controls was 8.2 +/- 0.5 mmol x 100 g-1 x min-1, during glucose infusion it was 34.1 +/- 0.6, and after haemorrhage it was 9.7 +/- 0.4. Both treatments increased insulin levels by greater than 200%. These results show an important role of insulin resistance in causing hyperglycemia after experimental haemorrhage in the rat.

Animals↗

PubMed1988

Neurophysins as tumor markers for small cell carcinoma of the lung. A cancer and Leukemia Group B evaluation.

Plasma human neurophysins (HNPs) were evaluated as tumor markers for patients with small cell carcinoma of the lung (SCCL) who were entered on limited disease and extensive disease treatment trials conducted by Cancer and Acute Leukemia Group B (CALGB). HNP values obtained before treatment showed 44% of tumors secreting vasopressin-associated HNP (VP-HNP), 14% secreting oxytocin-associated HNP (OT-HNP), and 11% producing both HNPs. There was a significantly higher incidence of HNP-secreting tumors for patients with extensive disease and two or more metastatic lesions than for patients with limited disease. There were no clear differences in response to treatment or in survival between patients with HNP-secreting tumors and those with nonsecreting tumors. Response to treatment evaluated by the change in plasma HNP, gave a 91% agreement with independently derived clinical impressions. Our data indicates that HNP evaluations provide sufficient sensitivity to forecast clinical response when it cannot be clearly assessed by conventional methods.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1988

Localization of a factor VIII-inhibiting antibody epitope to a region between residues 338 and 362 of factor VIII heavy chain.

We have used a recombinant DNA epitope library to localize the binding region of a factor VIII (FVIII) monoclonal antibody that neutralizes coagulant activity. The antibody, C5, has previously been described and has been shown to have a FVIII neutralizing potency of 1488 Bethesda units per mg of purified immunoglobulin. A recombinant DNA epitope library was constructed from short, random FVIII cDNA fragments and immunologically screened with C5 to identify bacteriophage expressing the antigenic determinant. The isolation and characterization of immunoreactive bacteriophage restricted the C5 epitope to the overlapping or shared DNA sequence of nine different clones and corresponded to amino acid residues 338-362 of the mature FVIII peptide. The defined epitope is between the proposed activated protein C cleavage site (Arg-336) and thrombin cleavage site (Arg-372) on the amino-terminal 90-kDa FVIII heavy-chain subunit. The identification of the epitope of an inhibiting anti-FVIII antibody between two critical cleavage sites suggests that this amino acid sequence plays a role in regulating FVIII coagulant activity.

Amino Acid Sequence↗

PubMed1988

Posthemorrhage glycogen and lactate metabolism in the liver: an experimental study with postprandial rats.

Glycogen and lactate metabolism was studied in livers from three groups of postprandial rats sustaining 70 mm Hg hemorrhagic hypotension for variable periods, 60 min (60H group), 120 min (120H group), and nonbled controls. The donor livers were investigated after completed hemorrhage using an in vitro perfusion system with L-lactate as substrate, together with U-C14-lactate. The residual glycogen stores were determined after perfusions. The incorporation of labelled lactate to glucose was increased in the 120H group by 66.7% and 116.8% compared to the 60H group and controls (p less than 0.01), but glycogenolysis was still the main source of glucose released in the 120H group. Glycogen formation from labelled lactate was 46.6% higher in the 120H group compared to controls (p less than 0.05) and lactate oxidation was decreased by 67.5% (p less than 0.05). The data suggest that hepatocytes are capable of rapid change from glycolysis to gluconeogenesis during hemorrhagic hypovolemia. However, energy-sparing glycogen breakdown is given priority over gluconeogenesis as long as glycogen remains available.

Animals↗

PubMed1988

Genetic defect responsible for the dysfunctional protein: factor IXLong Beach.

DNA sequence analysis of the gene coding for the variant protein, factor IXLong Beach (FIXLB), has identified a transition mutation in an otherwise normal factor IX (FIX) gene. Genomic DNA clones spanning 35 kilobase (kb) pairs of the FIXLB gene were isolated. A gene analysis strategy that specifically characterized exons and their flanking intron sequences predicted the entire amino acid sequence of FIXLB. A thymine to cytosine transition causes the substitution of a threonine codon (ACA) for an isoleucine codon (ATA) in exon VIII of the FIXLB gene. This mutation results in an amino acid substitution at residue 397 of the FIX zymogen and the phenotypic display of hemophilia-B. Previous studies revealed that activated purified FIXLB (FIXaLB) had normal Ca2+, phospholipid, and factor VIIIa binding characteristics. However, FIXaLB activated factor X or factor VII (with their cofactors Ca2+ and phospholipid) at significantly reduced rates, suggesting that the defect in FIXaLB lies near or within the catalytic triad of the FIX heavy chain. Identification of an amino acid substitution near the carboxy-terminus of the FIXaLB heavy chain supports the earlier characterization of this variant protein. Moreover, our data identify a residue in the catalytic domain of FIXa essential for normal function.

Base Sequence↗

PubMed1987

Hypovolemic stress-induced glycogenolysis. Isolated liver perfusion study.

Intrinsic hepatic glycogenolysis was examined after hypovolemic stress. Hemorrhagic hypotension of 70 (P70) and 40 mm Hg (P40) for 60 min was inflicted for two postprandial groups and of 70 mm Hg (S70) in a 24-h starved group. The results were compared with three control groups; one postprandial (Pc), one 24-h starved (Sc), and one starved for 9 h (Sc:9) to mimic the glycogen depletion produced by 70 mm Hg hemorrhagic hypotension. Glucose output was studied in vitro using av recirculating isolated liver perfusion system with a perfusate free of glucose and endocrine stimulation. Liver glycogen determination was made before perfusion start. Although the glycogen stores were decreased after hemorrhage glucose yield was increased (P70) and unchanged (P40) as compared to controls (Pc and Sc: 9). Both starved groups delivered small amounts of glucose, but the released fraction of the S70 group was more than twice that from the Sc group. These data suggest a liver enzyme activation with increased velocity of the enzyme-substrate reactions responsible for glycogen degradation, induced during in vivo hemorrhage and persisting for at least 30 min in vitro perfusion.

Animals↗

PubMed1987

Nucleotide sequence of a cDNA for a member of the human 90-kDa heat-shock protein family.

This paper describes the isolation and sequence of a human cDNA homologous to a class of proteins commonly referred to as 90-kDa heat-shock proteins. The complete nucleotide sequence of 2563 bp and the deduced amino acid sequence are presented. A single long open reading frame encodes a protein of 83,303 Da, the amino acid composition of which correlates well with that determined for the human 90-kDa heat-shock or 'stress' protein [Welch, W.J. and Feramisco, J.R., J. Biol. Chem. 257 (1982) 14949-14959]. Moreover, sequence analysis of this gene reveals extensive homology with the Drosophila 83-kDa and yeast 90-kDa heat-shock proteins. A comparison of the translated product of the human cDNA to the published yeast 90-kDa heat-shock protein reveals more than 60% homology at both the nucleotide and amino acid levels. Several regions of 50 aa or more show greater than 90% identity. This cDNA also hybridizes with an RNA species which increases upon heat shock of HeLa cells.

Amino Acid Sequence↗

PubMed1987

Is SPECT of the spleen worthwhile in the evaluation of liver disease severity?

SPECT of the spleen has been performed with 99Tcm-sulphur colloid in 53 patients, and SPECT of the liver has been performed in 57 patients. All patients had histologically proven liver disease and were classified by the degree of severity, Group A-severe, Group B-moderate, Group C-mild. The patients were further classified as cirrhotic and non-cirrhotic. Eight controls were also studied. There is positive though poor correlation between splenic volume and uptake (r2 = 0.55). Splenic volume and uptake are significantly different in Group A patients compared with all other groups (p less than 0.001). They are also significantly different in cirrhotics versus non-cirrhotics and cirrhotics versus controls (p less than 0.001). Splenic SPECT was unhelpful in distinguishing between moderate and mild liver disease. SPECT of the spleen is a time consuming technique but a useful adjunct to liver SPECT in patients with portal hypertension.

Electronic Data Processing↗

PubMed1987

Effect of food deprivation on survival after hemorrhage in the rat.

The changes in plasma glucose concentration and hematocrit during, and 7-day survival after, 60-min hemorrhagic hypotension (55 mmHg MAP) were investigated in postprandial and 6- or 24-h food-deprived rats. During hemorrhage, postprandial rats developed hyperglycemia, 30% greater than 6-h and 150% higher than 24-h food-deprived rats. Blood loss and plasma refill were greater in postprandial rats compared to 24-h food-deprived rats. Food deprivation for 24 h resulted in significantly increased mortality (6/13) posthemorrhage. All postprandial rats survived (13/13). A further three groups of animals deprived of food for 24 h were submitted to hemorrhage volume similar to that of postprandial rats. When no infusion was given during hemorrhage all rats died after hemorrhage (10/10). Saline infusion did not increase survival. Infusion of a similar volume of hypertonic glucose resulted in improved survival (not significant vs postprandial). Short-term food deprivation alters responses to stress and influences the outcome after standardized hemorrhage. Induction of hyperglycemia during hemorrhage was associated with survival.

Animals↗

PubMed1987

The effect of hemorrhagic stress on liver gluconeogenesis. An isolated rat liver perfusion study with three-carbon units as substrates.

This effect of hypovolemic stress on hepatic gluconeogenesis has been studied using isolated perfused organs obtained from starved rats subjected to 60 min hemorrhagic hypotension at 70 mmHg. Four different substrates were used: lactate, pyruvate, glycerol and alanine. The substrates were added without any stress endocrine stimulation in the perfusate. Using a recirculating system and supraoptimal substrate availability, a significant higher rate of gluconeogenesis was confirmed for the stressed donor livers: glycerol (+100%), alanine (+97%), lactate (+64%) and pyruvate (+62%). Glucose accumulation was linear for all control and experimental groups. In the absence of added stress hormones, known to stimulate gluconeogenesis, the findings are concordant with an in vivo hormone activation of key enzymes in the gluconeogenic pathway, persisting for the 60 min duration of the in vitro perfusion.

Alanine↗

PubMed1987

In-vitro production of nitrosamines by bacteria isolated from the operated stomach.

Evidence is presented of in-vitro catalysis of nitrosation by organisms isolated from the hypoacidic operated stomach. Subjects taking part in a prospective study of potential premalignancy after benign ulcer surgery underwent endoscopy, and samples of gastric juice were obtained aseptically. The organisms present were identified using the API system and tested for their ability to catalyse the nitrosation of the secondary amine, morpholine, at neutral pH and 37 degrees C. Four of the five species tested were found to be capable of the catalysis. Cellular disruption and denaturation of protein abolished the catalytic ability, suggesting that the catalysis is mediated by an enzymic system. Osmotic shock experiments indicate that the enzyme site may be on the inner membrane.

Female↗

PubMed1987

An investigation of possible risk factors associated with gastric cancer after benign ulcer operations.

The risk of developing gastric cancer has been investigated in a case-control study and in a prospective investigation. In the case-control study, 1495 cases of gastric cancer were identified in five city hospitals and matched with autopsy controls from the same hospitals. The frequency of operations for benign ulcer [partial gastrectomy (PG) and gastroenterostomy] was similar in the two groups. Thus, there was no increased risk for late gastric cancer after an ulcer operation. A total of 140 operated ulcer subjects [80 truncal vagotomy and drainage (TVD), 60 PG and 78 nonoperated cases attending with dyspepsia (C)] were examined by endoscopy, multiple gastric biopsy and analysis of gastric juice for nitrite. Biopsies were graded for gastritis and a gastritis index was derived (normal, 1; superficial gastritis, 2; chronic atrophic gastritis: mild, 3; moderate, 4; severe, 5). More atrophic gastritis was found in operated subjects than in controls: TVD, 2.3 +/- 0.08 (mean +/- SE); PG, 2.6 +/- 0.1 versus C, 1.8 +/- 0.08, p less than 0.01. The severity of atrophic gastritis increased after an operation interval of 20 years in PG subjects (p less than 0.05). Intestinal metaplasia was a common change, but unequivocal epithelial dysplasia was not observed. Two cases of operated stomach cancer were found. High levels of nitrite were positively correlated with pH and a high gastritis index. This evidence does not suggest that ulcer surgery leads to either an increased risk of cancer or a precancerous condition.

Gastrectomy↗