Biomedical subjects

C E Jones

Publications and source records attributed to C E Jones.

At least 55 records · Page 3Linked to original sources

PubMed1997

A comparison of the dual lumen and coaxial catheters for temporary hemodialysis access.

Percutaneous central venous catheterization can provide reliable temporary hemodialysis access. The current study compared the hemodynamic performance of 28 coaxial catheters to 27 side by side catheters. A total of 675 dialysis sessions were evaluated to assess the flow characteristics of these two designs. The results demonstrated that the side by side catheter provided greater cumulative blood flow with more favorable venous and arterial pressures. Nevertheless, the coaxial catheter performed satisfactorily and met the minimum standards for these devices.

Adult↗

PubMed1996

Teaching pediatric and adolescent gynecology: a pilot study at one institution.

PURPOSE: To assess resident physicians' clinical recognition skills in Pediatric and Adolescent Gynecology. MATERIALS: 1) A questionnaire to identify demographic data and self-assessment as to the ability to perform a gynecologic evaluation of children. 2) Twenty color photographs of normal genitalia and common gynecologic problems in children. PARTICIPANTS: Sixty-one University of Tennessee resident physicians; 51 from the Memphis campus--20 obstetrics-gynecology (Ob-Gyn) residents, 20 pediatrics residents, and 11 family practice residents--and 10 Ob-Gyn residents from the Chattanooga campus. MAIN OUTCOME MEASURES: Ability to identify normal features of the prepubertal genitalia and to diagnose common gynecologic disorders. RESULTS: Ob-Gyn residents from the University of Tennessee, Memphis scored significantly better (58.1% correct) than did the other three groups; 38.8, 36.9, and 39.1%, respectively (p = .009). Mean performance score increased with higher pediatric gynecology PGY levels. PGY-4s performed best, whereas PGY-1s scored the lowest, with mean scores of 57.5% and 35.3%, respectively (p = .021). Residents who reported having a well-defined program in pediatric gynecology scored significantly better than those who did not have such a program, 55.3% and 39.5%, respectively (p < .001). CONCLUSIONS: A well-defined program in pediatric gynecology enhances resident education and provides them with better tools to perform gynecologic evaluations of children and adolescents.

Adolescent↗

PubMed1996

Outcome following colon surgery in the octagenarian.

The results of colon surgery in all individuals aged 80 years or greater at one teaching institution during the 1987-1993 time period were reviewed. Sixty patients, ranging in age from 80 to 92 years, underwent 41 elective operations and 21 emergency procedures. Emergency procedures resulted in death or a major complication in over one-half of patients, and only six were ultimately able to return home. Conversely, elective procedures were relatively well tolerated, and 31 of 37 survivors returned immediately to independent living (P = 0.006). Mortality was 33.3 per cent in emergency cases versus 9.8 per cent in elective operations (P < 0.03). The occurrence of a postoperative complication increased the length of stay by an average of 12 days. These data suggest that elective colon surgery in the elderly produces results little different from the population at large. Conversely, emergency operations are associated with a high morbidity and mortality rate. Age alone should not be a determining factor in who undergoes an elective colon operation. Greater efforts should be made to screen elderly individuals to limit emergency surgery.

Age Factors↗

PubMed1996

Technical results from the eversion technique of carotid endarterectomy.

A total of 167 carotid endarterectomies by the eversion technique were completed in 158 patients at a teaching hospital during the 6-year period ending July 1995. The average patient age was 66 years with a range of 39 to 89 years, and 99 (63%) were male. General anesthesia was employed routinely, and temporary indwelling shunts, were not used. Indications for endarterectomy included hemispheric transient ischemic attack (43), amaurosis fugax (20), stroke (41), and asymptomatic stenosis (63). Associated patient risk factors were not significantly different for men and women, and included diabetes mellitus (22%), tobacco abuse (72%), hypertension (69%), hypercholesterolemia (76%), cardiac disease (54%), and renal disease (21%). One (0.6%) permanent operative stroke and two (1%) 30-day hospital deaths occurred. Vascular laboratory follow-up was accomplished by duplex scanning with a documented sensitivity of 98 per cent in detecting a > or = 40 per cent stenosis. Eighty-nine per cent (148) of the 167 endarterectomies were tested at least once postoperatively. Overall laboratory follow-up averaged 17 months and ranged from one to 69 months. Residual stenosis, included perioperative thrombosis, occurred in 8 (5%) arteries. Recurrent stenosis was detected in four (2%) cases at 9, 24, 54, and 66 months after endarterectomy. Statistical analyses failed to implicate any specific patient risk factor, age, sex, or operative indication relevant to recurrent stenosis. Residual stenosis was correlated with younger patient age (P = 0.002), female gender (P = 0.12), and endarterectomy on the right side (P = 0.008). Carotid eversion endarterectomy appears to be a universally applicable, safe, and durable operative technique.

Adult↗

PubMed1996

Complementation of a pgk deletion mutation in Saccharomyces cerevisiae with expression of the phosphoglycerate-kinase gene from the hyperthermophilic Archaeon Sulfolobus solfataricus.

The gene encoding phosphoglycerate kinase (PGK) from the Archaeon Sulfolobus solfataricus, an organism growing optimally at 87 degrees C, was inserted into a yeast expression vector under the control of the galactose-inducible GAL1 yeast promoter. This vector was then transformed into a pgk::TRP1 yeast mutant, a strain inhibited for growth on galactose or glucose due to its lack of PGK enzyme. Slow-growing transformants were obtained on galactose plates at 37 degrees C, but not 28 degrees C. These transformants contained low levels of transcripts of the heterologous gene and low amounts of thermostable PGK activity. Weak expression of the hyperthermophile gene in yeast, a mesophile, therefore enabled complementation of the yeast pgk defect at 37 degrees C but not at 28 degrees C.

Base Sequence↗

PubMed1996

The effects of acne treatment with a combination of benzoyl peroxide and erythromycin on skin carriage of erythromycin-resistant propionibacteria.

Concomitant application of 5% w/w benzoyl peroxide and 3% w/w erythromycin has previously been shown to prevent the overgrowth, on the skin of acne patients, of erythromycin-resistant coagulase-negative staphylococci, which occurs when the antibiotic is used alone. Two in vivo studies were carried out to assess the ability of the same therapeutic combination to inhibit the growth of pre-existing erythromycin-resistant propionibacteria and to prevent the selection of resistant strains during treatment. A double-blind clinical trial in 37 patients with mild to moderate acne vulgaris showed that the combination brought about a > 3 log10 c.f.u. reduction in total propionibacterial numbers/cm2 after 6 weeks therapy (P < 0.001, Wilcoxon's matched pairs) and also significantly reduced the number of erythromycin-resistant propionibacteria (P < 0.05). In contrast, erythromycin alone reduced the total propionibacterial count by < 1.5 log10 c.f.u./cm2 after 6 weeks (P < 0.05) and did not affect the number of erythromycin-resistant strains. The combined formulation was significantly more effective at reducing total propionibacterial numbers at 6 (P < 0.01, Mann-Whitney) and 12 weeks (P < 0.05) than erythromycin alone, although, after 12 weeks, the anti-propionibacterial efficacy of both preparations was less marked. Five patients on combination therapy, and five treated with erythromycin alone, acquired erythromycin-resistant strains de novo at week 6 or week 12. In an open study in 21 acne patients, who each carried > 10(3) c.f.u. erythromycin-resistant propionibacteria/cm2 skin pretreatment, the combination of erythromycin and benzoyl peroxide reduced the total propionibacterial count by > 2.5 log10 and the number of erythromycin-resistant strains by a similar amount (P < 0.001, Wilcoxon). This was accompanied by highly significant reductions in acne grade and lesion counts (P < 0.001). These data suggest that the combination of 5% w/w benzoyl peroxide and 3% w/w erythromycin has greater in vivo anti-propionibacterial activity than 3% w/w erythromycin alone, and brings about significant clinical improvement in acne patients with high numbers of erythromycin-resistant propionibacterial strains pretreatment.

Acne Vulgaris↗

PubMed1995

Extracellular epitopes of platelet glycoprotein Ib alpha reactive with serum antibodies from patients with chronic idiopathic thrombocytopenic purpura.

Glycoproteins (GPs) IIb/IIIa and Ib/IX are principal targets of autoantibodies (autoAbs) in idiopathic thrombocytopenic purpura (ITP). Platelet-associated Abs against GPIIb/IIIa primarily recognize discontinuous or nonlinear epitopes (Fujisawa et al, Blood 81:1284, 1993). This study focused on whether Abs against the extracellular domain of GPIb/IX might react with short linear amino acid (aa) sequences of GPIb alpha. Complementary DNAs (cDNAs) coding for two overlapping fragments of GPIb alpha were amplified, cloned into pFLAG.2 plasmids, and expressed in Escherichia coli DH5 alpha competent cells as FLAG fusion proteins, which were purified by anti-FLAG immunoaffinity chromatography. Of 16 selected ITP sera containing anti-GPIb/IX, 6 reacted in microtiter radioimmunoassays (RIAs) with recombinant protein fragment 2 (aas 240 to 485); 1 also with fragment 1 (aas 1 to 247). When synthetic peptides corresponding to 4 segments of fragment 2 with high antigenic indices (P1 to P4) were used as targets in RIAs, all 6 sera reacted with P2 (aas 326 to 346); 1 also reacted with P4 (aas 389 to 412). P2 was shown to be present on the surface of intact platelets by adsorption studies, and anti-P2 was detected in direct eluates of platelets from ITP patients. Glycocalicin in solution effectively competed with immobilized P2 for anti-P2; P2 in solution was a less effective competitor. Epitope scanning with a panel of synthetic 15-mer peptides localized the P2 epitope to the sequence, TKEQTTFPP. Epitope definition may offer insight into the pathophysiology of and more specific treatments for ITP.

Amino Acid Sequence↗

PubMed1995

Pericardial repair depresses canine cardiac catecholamines and met-enkephalin.

Decreased cardiac catecholamines were observed following incision and repair of the pericardium in sham-operated vs. unoperated control dogs. Animals were assigned to five groups: unoperated, sham-operated intact pericardia, open pericardia, sutured pericardia and complete ventricular sympathectomy. Hearts were collected four weeks after surgery. Sympathectomy decreased catecholamine content when compared to all other groups. Hearts with open/sutured pericardia contained significantly less catecholamines than controls. When the pericardium was intact or left open following incision, cardiac catecholamines were unchanged compared to unoperated controls. Since opioid peptides are colocalized with catecholamines, we measured met-enkephalin and met-enkephalin-arg-phe, proenkephalin A peptide products, in parallel samples. Similar to norepinephrine, met-enkephalin was decreased following both sympathectomy and pericardial repair. However, met-enkephalin-arg-phe, which may be more associated with the myocardium than its innervation, was not changed by any treatment. The sutured pericardium more than the stress of surgery apparently alters the tissue catecholamines and enkephalin. This may have resulted from the mechanical friction at the site of repair. Epinephrine and met-enkephalin contents in sympathectomized hearts were significantly lower than unoperated controls but were not significantly different from the intermediate values observed in the sutured group. The functional consequences of these changes on neuroendocrine status are unclear and will require further evaluation. The results also emphasize the need for careful attention to proper controls for surgical studies.

Animals↗

PubMed1995

The phosphoglycerate kinase and glyceraldehyde-3-phosphate dehydrogenase genes from the thermophilic archaeon Sulfolobus solfataricus overlap by 8-bp. Isolation, sequencing of the genes and expression in Escherichia coli.

The overlapping genes encoding phosphoglycerate kinase (PGK) and glyceraldehyde-3-phosphate dehydrogenase (GraP-DH) from the hyperthermophilic archaeon Sulfolobus solfataricus have been cloned and sequenced. PCR primers based on highly conserved regions of different PGK sequences were used to isolate an internal region of the pgk gene. This was then used to screen a genomic library to isolate the full length pgk gene. A 2.5-kb BglII fragment of S. solfataricus DNA contained both the pgk gene and the gap gene immediately downstream. Unexpectedly, the pgk and gap genes were found to overlap by 8 bp, with the initiation codon of the gap gene preceding the termination codon of the pgk gene. Evidence that the two genes are co-transcribed was obtained by Northern-blot analysis. The S. solfataricus PGK amino acid sequence shows 43% and 45% identity to the PGK sequences of the Archaea Methanobacterium bryantii and Methanothermus fervidus, respectively. High level expression of the S. solfataricus PGK and GraP-DH in Escherichia coli was achieved, with heat treatment at 80 degrees C proving an effective first step in the purification of these recombinant enzymes from extracts of the E. coli host. Purified recombinant S. solfataricus PGK and GraP-DH showed half lives of 39 min and 17 h, respectively, at 80 degrees C. Unlike bacterial GraP-DH enzymes, S. solfataricus GraP-DH was able to use both NAD+ and NADP+ as cofactors, but exhibited a marked preference for NADP+.

Amino Acid Sequence↗

PubMed1995

Cloning and sequencing of a gene from the archaeon Pyrococcus furiosus with high homology to a gene encoding phosphoenolpyruvate synthetase from Escherichia coli.

A gene from the hyperthermophilic archaeon Pyrococcus furiosus, strain Vc1 (DSM 3638), contains an 817-amino-acid open reading frame which shows 42% identity to the phosphoenolpyruvate (PEP) synthetase of Escherichia coli. This putative P. furiosus PEP synthetase is slightly larger than the E. coli enzyme, the region between residues 58 and 89 being absent from the latter.

Amino Acid Sequence↗

PubMed1995

Adolescent victims of sexual assault.

PURPOSE: The purpose of this study was to evaluate a group of female adolescent victims (n = 176) of sexual assault and assess the similarities and differences between them and older female victims. METHODS: All the adolescents in this study were physically mature. The demographic data and the findings of the medical evaluation are compared with those of women, 25-44 years of age, who were assaulted during the same time period (n = 197). RESULTS: The mean age of the adolescent patients was 15.2 (+/- 1.6), while the control group had a mean age of 31.9 (+/- 5.1). Racial distribution was similar in both groups. One hundred thirty-nine (79%) adolescents reported prior consensual sexual activity and 32 (18%) had been pregnant at least once. Thirty-one adolescents (19%) reported a previous sexual assault. Many adolescent victims (64%) knew their assailant. Weapons or physical force was used less frequently to subdue an adolescent victim, and firearms were used very infrequently in adolescent assault. Use of alcohol or drugs just prior to the assault was prevalent among adolescent victims (47%). Finally, adolescent victims were less likely to sustain physical injuries during the assault. CONCLUSION: The preexisting relationship between the victim and the assailant may explain other elements that distinguish an adolescent rape victim from her adult counterpart. Compared to adolescent victims, the assault on adult women is more often perpetrated by a stranger, the victim is more likely to be abducted, and weapons, especially firearms, are more likely to be used to carry out the victim's capture.

Adolescent↗

PubMed1995

Human parvovirus B19 infection in healthcare workers.

This paper reports the occurrence of human parvovirus B19 infection in seven healthcare workers in an acute hospital. The clinical presentation mimicked that of rubella and the diagnosis was made by the detection of human parvovirus B19 IgM antibody in blood samples taken from the affected members of staff. The paper discusses the importance of accurate diagnosis of B19 infection because this virus has been implicated in causing or exacerbating a variety of medical conditions. B19 infection may be serious for people with chronic haemolytic anaemias, those who are immunocompromised or those who are pregnant. B19 infection in pregnancy may be a cause of hydrops fetalis, particularly if the infection occurs during the second trimester. This is in contrast to the risk of intra-uterine rubella infection which is maximal in the first few weeks of pregnancy and which affects fetal development. The paper highlights the need for guidelines for occupational health practitioners on the management of parvovirus B19 infection and the need to make healthcare workers aware of the importance of this infection.

Adult↗

PubMed1995

Comparative study of the growth of Listeria monocytogenes in defined media and demonstration of growth in continuous culture.

A basic requirement for physiological studies with Listeria monocytogenes is a chemically defined medium that supports growth of the bacterium in batch and continuous culture. A number of such media have been devised but comparative studies of their efficiency are few and none has been used in continuous culture. Six of the media were compared for their ability to sustain sequential growth of L. monocytogenes in static and aerated batch culture with glucose as sole carbon source. The most suitable, judged on the basis of ease of preparation, growth rate and yield, was that of Trivett and Meyer (1971). This medium was shown to support growth of L. monocytogenes NCTC 7973 in continuous culture in a chemostat. A lytic phenomenon, noted with the same strain under anaerobic conditions and in batch culture in the chemostat, is discussed.

Aerobiosis↗

PubMed1995

Loss of heterozygosity for DNA polymorphisms mapping to chromosomes 10 and 17 and prognosis in patients with gliomas.

Twenty nine patients with gliomas were investigated for loss of heterozygosity for 40 DNA polymorphisms in tumour DNA, particularly concentrating on those mapping to chromosomes 10 and 17. Eight of 18 grade IV gliomas showed loss of sequences from chromosomes 10, 17, or both. The data suggested total loss of one copy of chromosome 10, but there were interstitial deletions of the short arm of chromosome 17 in three of five tumours. Heterogeneous interstitial deletions of chromosome 17 were also found in two lower grade astrocytomas and one benign oligodendroglioma. The striking finding of this study was that patients with high grade gliomas whose tumours exhibited loss of heterozygosity for chromosomes 10, 17, or both survived significantly longer after surgery (median 17.4 months) than those whose tumours did not show loss of these chromosomes (median 6.7 months). These findings suggest that there is a subset of particularly aggressive high grade gliomas with no currently known molecular genetic abnormalities.

Adult↗

PubMed1994

Spectrum of Ig classes, specificities, and titers of serum antiglycoproteins in chronic idiopathic thrombocytopenic purpura.

The characteristic decreased recovery and survival of transfused platelets in nonalloimmunized patients with idiopathic thrombocytopenic purpura (ITP) suggest that plasma antiplatelet autoantibodies (autoAbs) are present in almost all cases. Studies emphasizing reactions of IgG autoAbs with platelet glycoprotein (GP) IIb/IIIa indicate that less than 50% of ITP patients have detectable serum Abs, and that many of these Abs may not be pathogenic because they are directed against epitopes in the cytoplasmic domain of GPIIIa (Fujisawa et al, Blood 77:2207, 1991 and 79:1441, 1992). We evaluated the contribution of Ig classes other than IgG to the overall incidence of serum Abs in 47 patients with chronic ITP and the frequency of reactions with GPs IIb/IIIa, Ib/IX, IV, and Ia/IIa. Abs were further characterized by their reactions with cytosolic or exosolic GP epitopes and their titers and apparent affinities. Using immunobead techniques we found (1) anti-GPs in 85% of sera; (2) IgA and IgG Abs each in 68%, together in 51%; (3) IgM agglutinins in 15%, always with another Ab class; (4) GP Ib/IX, IIb/IIIa, IV, and Ia/IIa targets in 83%, 81%, 38%, and 28% of cases, respectively; (5) 93% of positive sera reactive with more than one GP; but GP IV or Ia/IIa never the sole target; (6) Abs against cytosolic epitopes on one or more of GPs IIIa, Ib alpha, and IIb beta in 66% of sera, always accompanied by Abs against exosolic epitopes of the same or a different GP; (7) autoAbs against cytosolic GP epitopes in 38% of 16 patients recovered from posttransfusion purpura and drug purpura; and (8) evidence that serum ITP Abs, often high-titered, saturate platelets less than alloAbs against the same GPs. Whereas Abs against external GP epitopes are a distinctive marker for ITP in 80% of patients, Abs against internal GP epitopes are likely a secondary phenomenon of platelet destruction and not pathogenic. Anti-GPs against exosolic epitopes were also found in eluates of patient's platelets, suggesting that they have pathogenic significance.

Amino Acid Sequence↗

PubMed1994

External ear reconstruction. Use of a pivoting helix, porous polyethylene implant.

We have used the porous polyethylene, pivoting helix framework for ear reconstruction at RLAMC since 1989 with no major complications. Postoperatively, patients have an external ear that resembles a normal ear and is sturdy enough to support eye wear. The aesthetic results have been well received by the patients and their families (Fig 8). Most children are reluctant to undergo surgery; however, those patients with ear deformities often are eager for external ear reconstruction surgery, and the majority of our pediatric patients have been pleased with the postoperative results (Fig 9). The success of this procedure depends on a number of factors, including proper patient selection, suitable selection of materials for the reconstruction, the technical skills of the surgeon, and the surgical team's attention to detail in the intraoperative period. The perioperative nurse, functioning as the patient advocate, plays an integral role in the success or failure of this procedure.

Burns↗

PubMed1994

Chronic sympathectomy of canine cardiac ventricles affects Gs-adenylyl cyclase coupling and muscarinic receptor density.

The effect of chronic ventricular sympathectomy on sarcolemmal muscarinic receptor (MR) and beta-adrenoceptor densities and coupling of these receptors to adenylyl cyclase was examined. Microsomal membranes were isolated from right and left ventricles of control dogs (sham- and nonoperated) and dogs with ventricles sympathectomized 4 weeks earlier. Relative to control membranes, MR density was decreased in left but not right ventricular (LV, RV) membranes from sympathectomized hearts. Relative carbachol inhibition of adenylyl cyclase was similar in RV and LV membranes from both heart groups, however, Although beta-adrenoceptor densities and ratio of beta 1- and beta 2-adrenoceptor subtypes did not change, basal adenylyl cyclase activity was 40% less in sympathectomized membranes as compared with control membranes. Furthermore, relative stimulation of adenylyl cyclase by isoproterenol was twofold greater in sympathectomized heart membranes. Because maximally stimulated adenylyl cyclase activity by NaF or MnCl2 was identical in sympathectomized and control membranes, the reduction in basal activity may not be related to a decrease in Gs and adenylyl cyclase. In support of this hypothesis, Gs alpha content as estimated from optimal cholera toxin-catalyzed ADP-ribosylation was similar in control and sympathectomized membranes. Therefore, an alteration in Gs interaction with adenylyl cyclase may account for the reduction in basal adenylyl cyclase activity and the increased relative responsiveness of adenylyl cyclase to isoproterenol in chronically sympathectomized ventricular membranes.

Adenylyl Cyclases↗

PubMed1994

Inhibition of erythromycin-resistant propionibacteria on the skin of acne patients by topical erythromycin with and without zinc.

Propionibacteria resistant to high concentrations of erythromycin [minimal inhibitory concentration (MIC) > or = 0.5 mg/ml] are now commonly isolated from the skin of antibiotic-treated acne patients. This double-blind study was carried out to assess the ability of 4% w/v erythromycin with and without 1.2% w/v zinc acetate to reduce the numbers of erythromycin-resistant propionibacteria in vivo, and also to monitor the acquisition of resistant strains de novo during therapy. Under laboratory conditions, erythromycin-resistant propionibacteria were shown to be as sensitive to zinc acetate as fully sensitive strains. In vivo, the erythromycin/zinc complex and erythromycin alone produced highly significant reductions in total propionibacteria (P < 0.001) and in the number of erythromycin-resistant strains (P < 0.001 at 8 weeks). After 12 weeks, resistant propionibacteria were reacquired, or acquired de novo, by three patients treated with erythromycin alone and four patients treated with the erythromycin/zinc complex. In contrast, changes in numbers of Micrococcaceae were slight and, after 12 weeks, erythromycin-resistant strains were predominant in both treatment groups. In vitro MIC determinations suggested that this finding might be explained by the exceptionally high degree of erythromycin resistance displayed by some staphylococcal strains (MIC > 4 mg/ml) and by the relative insensitivity of all staphylococcal strains to zinc acetate. Erythromycin with and without zinc was clinically effective, and both preparations produced significant reductions in acne grade, and inflamed and non-inflamed lesion counts (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Acetates↗