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Biomedical subjects

M D Williams

Publications and source records attributed to M D Williams.

At least 91 records · Page 5Linked to original sources
PubMed1995

Richter hernia: a rare complication of laparoscopy.

A case of Richter hernia in the umbilical trocar site following laparoscopic cholecystectomy is presented. The fascia was not specifically closed after the laparoscopic cholecystectomy. The Richter hernia presented 2 days later, suffered a delay in diagnosis because of persistence of bowel function and required bowel resection 9 days later. A total of four known postoperative umbilical trocar site hernias, two of which were Richter hernias, have been reported following 1,979 laparoscopic cholecystectomies in two large community hospitals in Colorado: Saint Joseph Hospital in Denver and North Colorado Medical Center in Greeley. Thus, periumbilical trocar site incisional hernias following laparoscopic cholecystectomy are rare but potentially dangerous because of the susceptibility to Richter hernia.

Cholecystectomy, Laparoscopic↗
PubMed1994

Glutathione S-transferase-sspA fusion binds to E. coli RNA polymerase and complements delta sspA mutation allowing phage P1 replication.

Bacteriophage P1 is unable to form plaques on E. coli hosts lacking a functional sspA gene. However, sspA mutants can be infected by P1, resulting in the synthesis of P1 early gene products and accumulation of P1 DNA, but without P1 late gene product formation or host lysis. Overexpression of the stringent starvation protein (SspA) as a glutathione-S-transferase fusion results in complementation of the sspA mutation and production of viable viral particles as in sspA+ strains. This suggests that the GST-SspA protein functions in vivo in a similar manner as native SspA with respect to P1 replication. Here, evidence is presented that shows that SspA binds to RNA-polymerase. This supports the notion that SspA is involved in P1 replication since it is known that P1 requires host RNA-polymerase activity to replicate and this suggests a mechanism by which P1 redirects E. coli RNA-polymerase specificity from P1 early to P1 late genes.

Bacterial Proteins↗
PubMed1994

Isolation and structure of cephalostatins 10 and 11.

Further investigation of antineoplastic constituents from the marine worm Cephalodiscus gilchristi, employing a 450 kg re-collection from the Indian Ocean (Southeast Africa), has led to isolation and structural determination of two previously undetected members of the cephalostatin series, designated cephalostatins 10 [4] and 11 [5]. Structural analyses were conducted primarily employing high field 2D nmr and high resolution mass spectral techniques. All the stereochemical assignments were deduced using the original X-ray crystal structure of cephalostatin 1 and ROESY 2D nmr methods. Both cephalostatins 10 and 11 strongly inhibited growth of a series of important human cancer cell lines.

Animals↗
PubMed1994

Laparoscopic appendectomy, is it worth it?

The recent experience with open appendectomy was compared to our initial experience with laparoscopic appendectomy. Thirty-eight patients had open appendectomy for acute appendicitis. Two major and four minor complications occurred. Concurrently, 39 patients had laparoscopic appendectomy. There was one major and one minor complication. Of the laparoscopic patients, 69% received less than 24 hours of parenteral postoperative analgesia, compared to 44% of the patients in the open group. Fifteen of 39 laparoscopic patients (38%) were discharged within 24 hours of operation versus 3 of 38 (8%) in the open group. Total mean hospital cost for the laparoscopic group, $7,500, was significantly greater than for the open group, $5,700, because of increased laparoscopic equipment charges. Both open and laparoscopic appendectomy procedures were performed with minimal morbidity. The benefits of laparoscopy were earlier hospital discharge and less parenteral analgesic use, but it was significantly more expensive.

Acute Disease↗
PubMed1994

Starvation-induced expression of SspA and SspB: the effects of a null mutation in sspA on Escherichia coli protein synthesis and survival during growth and prolonged starvation.

Maxicell labelling and two-dimensional gel electrophoresis (2-D PAGE) have identified the proteins encoded by sspA and sspB (SspA, SspB) as proteins D27.1 and A25.8, respectively, in the Escherichia coli gene-protein database. SspA expression increases with decreasing growth rate and is induced by glucose, nitrogen, phosphate or amino acid starvation. The promoter, Pssp, is similar to gearbox promoters. Inactivation of SspA (sspA::neo) blocks sspB expression. [35S]-methionine-labelled proteins synthesized during growth and during stationary phase are different in delta sspA strains compared to sspA+ strains. This difference is enhanced during extended stationary phase (24-72 h). Long-term (10 d) viability of arginine-starved isogenic strains shows that sspA+ cultures remain viable significantly longer than delta sspA mutants. 2-D PAGE of proteins expressed during exponential growth shows that expression of at least 11 proteins is altered in delta sspA strains. A functional relA gene is required for sspA to affect protein synthesis.

Adaptation, Biological↗
PubMed1994

Polycythaemia rubra vera transforming to acute lymphoblastic leukaemia with a common immunophenotype.

Lymphoblastic transformation of polycythaemia rubra vera is an extremely rare phenomenon. A case of a 76 year old man with polycythaemia rubra vera who developed acute lymphoblastic leukaemia (ALL) 16 years after his initial diagnosis is reported. Membrane markers showed a CD10 positive (common ALL) immunophenotype. To our knowledge this association has not been previously recorded. The rare occurrence of ALL in polycythaemia rubra vera may indicate that in a minority of patients clonal expansion of an abnormal pluripotent haemopoietic stem cell is responsible for the polycythaemia rubra vera disease phenotype.

Aged↗
PubMed1993

"Poswillo'.

Explore the source record for details and available documents.

Anesthesia, Dental↗
PubMed1993

Hirschsprung's disease complicating colon atresia.

An infant with the rare association of colon atresia, total colonic Hirschsprung's disease, and tetralogy of Fallot is presented. While Hirschsprung's disease associated with atresia of the colon has been reported five times previously, this is the first case with associated congenital cardiac disease. As in previous reports, initial operations to relieve obstruction due to the colon atresia failed because of the unrecognized aganglionosis. This infant initially had an ileostomy performed as a newborn and then two failed attempts at closure of the ileostomy. In this case, as in four previously reported cases, histological examinations of resected colon from the initial operations were first reported as normal and only under the pressure of increasing clinical evidence was the pathology reviewed and the absence of ganglion cells appreciated. We stress the importance of suspecting the coexistence of Hirschsprung's disease and colon atresia when a functional obstruction is present after repair of the atresia.

Colon↗
PubMed1993

Isolation and structure of the marine sponge cell growth inhibitory cyclic peptide phakellistatin 1.

A new cell growth inhibitory (P-388 murine leukemia ED50 7.5 micrograms/ml) cycloheptapeptide designated phakellistatin 1 was isolated from two Indo-Pacific sponges, Phakellia costata and Stylotella aurantium. Structural elucidation was accomplished utilizing high field nmr, amino acid analyses, and mass spectral techniques (fab, tandem ms/ms), followed by chiral gas chromatographic procedures for absolute configuration assignments (all S-amino acid units). By these methods phakellistatin 1 [1] was found to be cyclo (Pro-Ile-Pro-Ile-Phe-Pro-Tyr), and this assignment was finally confirmed by an X-ray crystal structure determination.

Amino Acid Sequence↗
PubMed1993

Tumor necrosis factor-induced mortality is reversed with cyclooxygenase inhibition.

OBJECTIVE: The authors hypothesized that TNF would induce eicosanoid synthesis, and a cyclooxygenase inhibitor would attenuate both eicosanoid synthesis and improve survival in an LD90 TNF-induced (150 ng/kg/i.v./5 min) mortality model. SUMMARY BACKGROUND DATA: Tumor necrosis factor is a cardinal mediator in sepsis; however, little is known about its effects on arachidonate metabolism. METHODS: Conscious male rats with carotid arterial and jugular venous catheters were randomized for mortality: group I, TNF alone (150 kg/i.v./15 min, n = 30); group II, ibuprofen (30 mg/kg/i.v. at t = -20 and +240 min), plus TNF, (n = 28); and for hemodynamics, eicosanoid synthesis, blood gases: group III, TNF alone, (n = 8); group IV, ibuprofen + TNF (n = 8); group V, monoclonal antibody to TNF plus TNF (n = 8). Mortality was determined at 4-72 hr. Other parameters determined over 4 hours (0, 5, 60, 120, 240 min). RESULTS: TNF stimulated synthesis of (a) TXB2 (71 +/- 30 pg/ml, mean +/- SE at base vs. 117 +/- 18 at 4 hr, p < 0.02); (b) PGE2 (70 +/- 6 pg/ml at base vs. 231 +/- 68 at 4 hr, p < 0.02); (c) 6PGF (52 +/- 6 pg/ml at base vs. 250 +/- 80 at 4 hr, p < 0.02). Ibuprofen significantly (p < 0.05) inhibited eicosanoid synthesis from TNF. TNF-induced mortality (87%, 26/30) was dramatically decreased with ibuprofen (11%, 3/28), at 4, 24, and 72 hr (p < 0.01). Monoclonal antibody to TNF prevented all abnormalities and had 100% survival. Hemodynamic events were similar in both groups, but metabolic acidosis was attenuated with ibuprofen. CONCLUSIONS: TNF stimulates arachidonic acid metabolism in vivo. A cyclooxygenase inhibitor attenuates eicosanoid synthesis and dramatically improves survival. TNF appears to have different effect on tissues that synthesize certain eicosanoids. Hypotension from TNF is not mediated via the eicosanoids. TNF-induced mortality, like endotoxemia/sepsis may be mediated, in part, via arachidonic acid metabolites. These new findings support the notion that cyclooxygenase inhibitors may be used as adjunctive therapy in clinical sepsis.

6-Ketoprostaglandin F1 alpha↗
PubMed1992

Carotid body tumor.

To better define the management and behavior of carotid body tumors, a 34-year surgical experience with 33 tumors in 30 patients was reviewed. There were 20 women and 10 men with an age range of 20 to 78 years. All but one presented with a neck mass. Arteriography was performed on 21 patients and was diagnostic in every case. There was no surgical mortality. Complications occurred in eight patients (27%), and one long-term neurologic deficit occurred. Three of 33 tumors were malignant, and aggressive resection of all approachable disease with radiotherapy for unresectable metastases led to prolonged survival in each case. Carotid body tumors present with neck mass. Arteriography is diagnostic and surgery is indicated. Even for malignant tumors and metastases, aggressive resection and radiotherapy are indicated.

Adult↗
PubMed1992

Anemia in pregnancy.

In evaluating pregnant women with anemia, it is essential to do a complete history and physical examination, as well as a complete blood count with indices and a blood smear examination. Based on these findings, other tests such as ferritin and serum or red cell folate may be ordered. Because of the normal physiologic changes in pregnancy that affect the hematocrit, indices, and some other parameters, diagnosing true anemia, as well as the etiology of anemia, is challenging. Because of the increased nutritional requirements of the mother and fetus, the most common anemias are iron deficiency anemia and folate deficiency megaloblastic anemia. These anemias are more common in women who have inadequate diets and who are not receiving prenatal iron and folate supplements. Other less common causes of acquired anemia in pregnancy are aplastic anemia and hemolytic anemia associated with preeclampsia. In addition, congenital anemias such as sickle cell disease can impact on the health of the mother and fetus. Obviously, severe anemia has adverse effects on the mother and the fetus. There is also evidence that less severe anemia is associated with poor pregnancy outcome. The cause of this association has yet to be elucidated. It is important, however, to diagnose and treat anemia in pregnancy to provide for optimal health of the mother and infant.

Anemia↗
PubMed1992

Steroid use is associated with pneumonia in pediatric chest trauma.

A review of pediatric trauma focused on pediatric chest injuries was performed at a trauma center specializing in neurologic trauma. Eighty of 342 (23%) pediatric trauma patients admitted to the center had chest injuries. Age, gender, mechanism of injury, magnitude of injury, incidence of pulmonary infection, chest tube usage, endotracheal intubation, steroid or antibiotic usage, morbidity, and mortality data were reviewed. Sixteen of 78 children (20%) with chest injuries developed pulmonary infections and were compared with the noninfected group. Patients with pneumonia had a higher morbidity with significantly longer mean hospital stay (43.0 vs. 12.7 days; p = 0.001), duration of intubation (8.4 vs. 1.5 days; p = 0.001), and total days with chest tubes, (2.2 vs. 1.4 days; p = 0.02). Pneumonia was significantly associated with longer mean duration of steroid usage (6.4 vs. 0.8 days; p = 0.0001). Duration of steroid administration for the treatment of concomitant brain injury was a significant independent risk factor for the occurrence of pneumonia.

Adolescent↗
PubMed1992

The significance of neopterin and biopterin concentrations at presentation in haematological malignancies.

Urinary neopterin and biopterin concentrations were measured in 32 healthy controls and 53 patients with newly diagnosed haematological malignancies classified and staged by accepted criteria. The neopterin concentrations were only significantly raised in chronic lymphocytic leukaemia at stages III-IV. Total biopterin concentrations after oxidation with iodine at acid pH were decreased in chronic lymphocytic leukaemia stages O-II, multiple myeloma, and acute myeloid leukaemia but not in chronic lymphocytic leukaemia stages III-IV. Although of research interest, neopterin concentrations proved of little prognostic value at presentation, but taken with the biopterin concentration they may be useful for the assessment of tumour activity.

Biomarkers, Tumor↗
PubMed1991

Null mutation in the stringent starvation protein of Escherichia coli disrupts lytic development of bacteriophage P1.

As initial steps toward understanding the regulation and function of the stringent starvation protein (SSP) of Escherichia coli, we have isolated the ssp gene (encoding SSP), defined the operon in which ssp is found, and created insertion-deletion mutations of the ssp gene in recBC, sbc and recD strains by linear DNA transformation. During attempts to move the insertion-deletion structure to other strains by P1 transduction, we found that P1 was unable to form plaques on hosts lacking an intact ssp gene. The delta ssp mutation, however, did not affect transduction of the delta ssp strains and mutant strains were able to support lysogenic P1. When P1 lytic growth was induced, an increase in P1 DNA was detected without lysis or plaque formation. Examination of proteins synthesized in the delta ssp host during induction revealed the absence of P1 late gene products. Also, the apparent continued synthesis of early gene products during late time points was observed in the delta ssp host. The results reported here suggest that the defect in P1 lytic growth brought about by the absence of SSP occurs at the point at which bacteriophage P1 shifts from early to late gene expression. We also report the results of experiments on stable RNA synthesis following amino acid (aa) starvation induced by serine hydroxamate, and experiments on stable RNA synthesis following resupplementation of a limiting aa. These experiments show that SSP is not involved in stable RNA synthesis. Additionally, complementation studies have shown that ssp is identical to the previously described pog gene of E. coli.

Bacterial Proteins↗