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J M Cox

Publications and source records attributed to J M Cox.

At least 37 records · Page 2Linked to original sources
PubMed1997

Bidirectional binding of the TATA box binding protein to the TATA box.

By selective attachment of a DNA cleavage agent to specific residues in the yeast TATA box binding protein (yTBP), we demonstrate that, in solution, yTBP binds to the TATA boxes of both the adenovirus major late promoter and the yeast CYC1 promoter with only a modest preference in orientation and binds well to several overlapping binding sites. The general factors TFIIA and TFIIB each increase the rotational and translational selectivity of yTBP but are not sufficient, at least individually, to confer a unique polarity to the preinitiation complex. We conclude that TBP alone cannot define the productive orientation of general factor assembly on a promoter.

Adenoviridae↗
PubMed1997

Prooxidant effects of maternal smoking and formula in newborn infants.

BACKGROUND: The purpose of this study was to use the breath ethane test to determine if either maternal cigarette smoking, formula, and/or deficiency of the antioxidant nutrients vitamins A and E was associated with oxidant stress in newborn infants. The rationale for this study was: (1) our observation that cigarette smoking was a source of oxidant stress in pregnant women, suggesting that it could be a source of oxidant stress for infants exposed in utero; (2) formula was predicted to be prooxidant compared to colostrum, which contains several compounds with antioxidant activity in vitro; and (3) deficiencies of vitamins A and E have been shown to promote oxidant stress in experimental animals. METHODS: Breath ethane, a volatile alkane produced by peroxide of n-3 fatty acids, was utilized as an index of oxidant stress status. Forty-five healthy full-term infants of the women mentioned above were studied at 18-24 h of age, after four to six feedings of breast milk (colostrum) or caseinbased infant formula. Relationships between infant breath ethane, maternal smoking, mode of infant nutrition, and serum concentrations of the antioxidant vitamins A and E of infants were examined. RESULTS: The breath ethane of the entire group of infants whose mothers smoked (n = 19) was increased compared to values of infants whose mothers did not smoke (n = 26): 97 +/- 16 versus 43 +/- 9 pmol/kg/min, p < 0.03. When infants of mothers who smoked were eliminated from the analysis in order to study effects of nutrition alone, formula appeared to be prooxidant compared to breast milk. Breath ethane of formula-fed infants (n = 16) was 62 +/- 13 versus 13 +/- 4 pmol/kg/min for breast-fed infants (n = 10), p < 0.04. For the group as a whole, there was no correlation between infant breath ethane and serum concentrations of vitamins A and E. CONCLUSIONS: Exposure to maternal smoking in utero is prooxidant in newborn infants. Formula also has a prooxidant effect compared to colostrum in newborn infants not exposed to maternal smoking in utero. Further investigations will be necessary to explore the clinical consequences of these observations.

Antioxidants↗
PubMed1997

Possible antioxidant effect of vitamin A supplementation in premature infants.

BACKGROUND: Increased lipid peroxidation caused by oxygen free radicals is thought to be one of the common pathogenetic mechanisms for the so-called oxygen radical diseases of prematurity. Since in vitro studies have shown that various forms of vitamin A can exert antioxidant effects that are more potent than those of vitamin E (treatment with which has been ineffective in these diseases), the purpose of this prospective, controlled study was to determine whether administration of supplemental vitamin A to premature infants deficient in this vitamin would have an antioxidant effect in vivo. METHODS: Fourteen infants (1181 +/- 35 g; gestational age 29 +/- 0.04 weeks) with a serum retinol concentration at 7 +/- 2 days of age in the deficient range, lower than 0.7 mumol/l (< 20 micrograms/dl), were enrolled in the study. Infants were randomized to receive the standard amount of vitamin A or standard plus supplemental (2.6 mumol/l [2500 IU] orally each day) vitamin A, beginning at 1 week of age. Antioxidant effects of supplementation were assessed by a decrease in lipid peroxidation, quantified by the ethane content of expired air. RESULTS: Three weeks after study enrollment, total daily vitamin A intake in the infants receiving supplements was 4.565 +/- 0.236 mumol (4354 +/- 225 IU) versus 1.879 +/- 0.317 mumol/l (1792 +/- 302 IU) in infants receiving standard amounts of the vitamin. In spite of the difference in intake of vitamin A, 3 weeks after study enrollment, serum retinol concentrations did not differ between the infants given supplements and those receiving standard amounts of vitamin A, 0.70 +/- 0.21 versus 0.66 +/- 0.07 mumol/l (20 +/- 6 micrograms/dl versus 19 +/- 2 micrograms/dl, respectively). In the infants receiving supplemental vitamin A, breath ethane values declined from baseline values. There was an inverse correlation between the number of weeks of supplementation and breath ethane values, whereas there was no significant correlation between the duration of the study and breath ethane values in the infants not given supplements. CONCLUSIONS: Our data suggest that supplementation with vitamin A in a small group of vitamin A-deficient preterm infants was associated with an antioxidant effect. Although no immediate clinical benefits were associated with supplementation, the data provide the rationale for future investigations of possible antioxidant effects of (larger amounts?) of vitamin A in higher risk premature infants born with subnormal serum retinol concentrations.

Administration, Oral↗
PubMed1996

Multilocus enzyme electrophoretic (MEE) analysis of Australian isolates of Salmonella enteritidis.

Seventy-three Australian isolates of Salmonella Enteritidis (SE) were analysed by multilocus enzyme electrophoresis (MEE) using a polyacrylamide gel system. Analysis of 11 enzyme loci identified eight electrophoretic types (ETs), with 61 of the isolates assigned to ET1, and 72 isolates considered to represent a clonal lineage. Representative isolates of each of the Australian ETs were then compared with isolates from England, Germany and the United States, using a starch gel system and 13 enzyme loci. The overseas isolates formed a single ET with representatives of the major Australian ET. It is concluded that Australian isolates of SE are closely related genetically to those from countries in which egg-borne transmission is common.

Alleles↗
PubMed1996

Sensitivity of Australian isolates of Salmonella enteritidis to nitrofurantoin and furazolidone.

Susceptibility of 66 and 62 Australian isolates of Salmonella enteritidis to nitrofurantoin and furazolidone, respectively, was determined. Most isolates were susceptible to both antibiotics. Cross-resistance was low among all isolates, but higher among the subset of phage type 4 isolates. These results contrast directly with those of a previous study (Rampling, A., Upson, R. and Brown, D.F.J. (1990) J. Antimicrob. Chemother., 25: 285-290). Sensitivity among Australian isolates of S. enteritidis does to some extent, support the contention that furans may have played a role in the selection and enhanced colonisation of poultry by Salmonella enteritidis in Britain. Furthermore, nitrofurantoin should not be used as a selective agent in the isolation of Salmonella enteritidis.

Animals↗
PubMed1996

Isolates of Salmonella enterica Enteritidis PT4 with enhanced heat and acid tolerance are more virulent in mice and more invasive in chickens.

Two Enteritidis PT4 isolates which differed in inherent tolerance to heat, acid, H2O2 and the ability to survive on surfaces were used to infect mice, day-old chicks or laying hens. The acid-, heat-, H2O2- and surface-tolerant isolate was more virulent in mice and more invasive in laying hens, particularly in reproductive tissue. However, no significant differences were observed in behaviour in chicks. Both PT4 isolates were able to infect chicks housed in the same room as infected birds, although the heat-tolerant isolate survived significantly better than the heat-sensitive one in aerosols.

Acids↗
PubMed1995

Conformation of Tax-response elements in the human T-cell leukemia virus type I promoter.

BACKGROUND: HTLV-I Tax is believed to activate viral gene expression by binding bZIP proteins (such as CREB) and increasing their affinities for proviral TRE target sites. Each 21 bp TRE target site contains an imperfect copy of the intrinsically bent CRE target site (the TRE core) surrounded by highly conserved flanking sequences. These flanking sequences are essential for maximal increases in DNA affinity and transactivation, but they are not, apparently, contacted by protein. Here we employ non-denaturing gel electrophoresis to evaluate TRE conformation in the presence and absence of bZIP proteins, and to explore the role of DNA conformation in viral transactivation. RESULTS: Our results show that the TRE-1 flanking sequences modulate the structure and modestly increase the affinity of a CREB bZIP peptide for the TRE-1 core recognition sequence. These flanking sequences are also essential for a maximal increase in stability of the CREB-DNA complex in the presence of Tax. CONCLUSIONS: The CRE-like TRE core and the TRE flanking sequences are both essential for formation of stable CREB-TRE-1 and Tax-CREB-TRE-1 complexes. These two DNA segments may have co-evolved into a unique structure capable of recognizing Tax and a bZIP protein.

Activating Transcription Factor 1↗
PubMed1995

Plasmid analysis of Australian strains of Salmonella enteritidis.

Using an in-well lysis technique, 73 Australian strains of Salmonella enteritidis were shown to possess a large plasmid, similar in size to that possessed by a reference phage type 4 strain. Restriction analysis of the large plasmid from nine strains using EcoRI, HindIII and PstI suggested that these plasmids are similar to or the same as the 38 MDa plasmid described in strains of this species from other parts of the world.

Australia↗
PubMed1995

Salmonella enteritidis: the egg and I.

The world-wide clinical incidence of Salmonella Enteritidis has increased markedly. The increase is associated with the enhanced ability of the bacterium to systemically colonise layer chickens. Subsequent contamination and consumption of intact shell eggs from colonised layer hens, either directly or in foods containing raw or lightly cooked eggs, causes human disease. Despite investigation, no change in the biology of the bacterium has been correlated with increased colonisation in chickens. To date, no method of control at the production level has proven effective; consumer education is the best means of minimising the public health risk.

Animals↗
PubMed1994

Patient benefits of attending a chiropractic low back wellness clinic.

OBJECTIVE: To demonstrate low back and/or leg pain patient reaction to attendance at a low back wellness school conducted to teach them how to control their back pain in daily living so as to reduce the incidence and severity of their problem. DESIGN: Sixty-one patients attending the clinic filled out a seven-question form that ranked their opinions of the class based on their feelings and reactions about it. SETTING: The private clinic of the author where a three-part back pain prevention clinic utilizing a slide lecture and patient participation was presented. PATIENTS: All suffered from low back and/or leg pain and were invited to attend at the time of their initial examination and report of findings. INTERVENTION: None. This is a patient questionnaire only. MAIN OUTCOME MEASURES: Immediately following the class, the patients were presented with a seven-question form to answer. RESULT: A very positive acceptance of low-back wellness training is evidenced by 95% of the patients feeling it was worth their time to attend and feeling they learned something to prevent reinjury in daily living; 100% felt it worth the doctor's time to present the class. CONCLUSION: Low back wellness school is a positive program from the patients' and doctor's viewpoints.

Adolescent↗
PubMed1993

Lysine-mannitol-glycerol agar, a medium for the isolation of Salmonella spp., including S. typhi and atypical strains.

An agar medium for the isolation of Salmonella spp. is described. The medium, lysine-mannitol-glycerol agar, has features of both xylose-lysine-deoxycholate agar and mannitol-lysine-crystal violet-brilliant green agar, but glycerol is added for the differentiation of Salmonella and Citrobacter spp. The medium facilitates the detection of strains having atypical fermentation patterns, such as the lactose- or sucrose-positive salmonellae. The medium also detects Salmonella typhi after enrichment.

Agar↗
PubMed1993

Distraction manipulation reduction of an L5-S1 disk herniation.

OBJECTIVE: A computed tomography (CT)-confirmed L5-S1 disk protrusion is reported to be reduced following chiropractic adjustment, as seen on repeat CT scanning. Correlation of the CT reports with the patient's symptoms before and after manipulation is reported. CLINICAL FEATURES: A 38-yr-old female was treated for low back pain and right lower extremity first sacral dermatome sciatica. CT confirmed disk herniations at both the L4-L5 and L5-S1 levels were found. Motor weakness of the right gluteus maximus muscle was found and extremely tight hamstring muscles accompanying positive straight leg signs were elicited. A clinical and imaging diagnosis of an L5-S1 disk herniation was made. INTERVENTION AND OUTCOME: Distraction type chiropractic manipulation, electrical stimulation, exercises, nutrition advice and low back wellness class were administered with complete relief of sciatic pain and nearly complete relief of low back pain. CONCLUSIONS: Chiropractic distraction manipulation is an effective treatment of lumbar disk herniation, if the chiropractor is observant during its administration for patient tolerance to manipulation under distraction and any signs of neurological deficit demanding other types of care.

Adult↗
PubMed1992

The interaction of methanol dehydrogenase and its electron acceptor, cytochrome cL in methylotrophic bacteria.

The interactions of methanol dehydrogenase (MDH, EC1.1.99.8) with its specific electron acceptor cytochrome cL has been investigated in Methylobacterium extorquens and Methylophilus methylotrophus. The MDHs of these two very different methylotrophs have the same alpha 2 beta 2 structure; the interaction of these MDHs with their specific electron acceptor, cytochrome cL, has been studied using a novel assay system. Electrostatic reactions are involved in 'docking' of the two proteins. EDTA inhibits the reaction by a process involving neither metal chelation nor the 'docking' process. Chemical modification studies showed that the two proteins interact by a 'docking' process involving interactions of lysyl residues on MDH and carboxyl residues on cytochrome cL. When 'zero length', two stage cross-linking was done (with proteins from both bacteria), the alpha-subunits of MDH cross-linked with cytochrome cL by way of lysyl groups on MDH and carboxyl groups on the cytochrome. Tuna mitochondrial cytochrome c provided a model for cytochrome cH which is the electron acceptor for cytochrome cL in the 'methanol oxidase' electron transport chain. Tuna cytochrome c was shown to form crosslinked products with carboxyl-modified cytochrome cL. MDH and tuna cytochrome c competed for the same domain on cytochrome cL. It was concluded that MDH reacts with cytochrome cL by an electrostatic reaction which involves carboxyl groups on cytochrome cL and amino groups on the alpha-subunit of MDH. The same domain on cytochrome cL is involved in subsequent 'docking' with its electron acceptor.

Alcohol Oxidoreductases↗
PubMed1992

Substance abuse and syphilis in urban adolescents: a new risk factor for an old disease.

The incidence of syphilis is increasing. To identify the epidemiologic characteristics of adolescents with syphilis in an urban adolescent clinic, we performed a retrospective review and case-control study of 59 patients with syphilis and 111 sex-matched controls seen at our institution between 1985 and 1988. Only 24% of cases occurred in males, in contrast with 61% in a 1977-1981 study. Almost one-half (46%) of cases occurred in asymptomatic individuals, and only 24% were diagnosed at the initial visit. Patients with syphilis were more likely to have a history of substance abuse (odds ratio, 4.94; 95% confidence interval, 1.83, 13.3). This study suggests that the epidemiology of syphilis in adolescents may be changing. The high percentage of asymptomatic syphilis cases underscores the need for a high index of suspicion, particularly in sexually active adolescents who abuse drugs.

Adolescent↗
PubMed1990

Pediatric nutritional assessment.

Nutritional assessment is an important facet of the medical care of infants and children. An accurate assessment allows for the early detection and treatment of nutrient deficiencies. The traditional nutritional assessment includes anthropometric measurements, biochemical evaluation, clinical examination, and dietary evaluation. Newer techniques include the assessment of body composition using total body electrical conductivity or bioelectrical impedance. The sophistication of nutritional support makes it necessary to identify more sensitive methods for accurate nutritional assessment.

Anthropometry↗
PubMed1989

A numerical taxonomic study of proteolytic and lipolytic psychrotrophs isolated from caprine milk.

Lipolytic and proteolytic psychrotrophs were isolated from raw and pasteurized goats' milk, which had been stored at 5 degrees C for 7 d. The 241 strains isolated and 20 reference strains were examined by 149 biochemical, physiological, and morphological tests. The results yielded 195 characters suitable for taxonomic analysis. Computer-assisted complete linkage analysis, using the Jaccard coefficient, produced 22 phenons at 75% S. The results showed that Pseudomonas fluorescens was the predominant psychrotrophic bacterium, but that Pseudomonas fragi was dominant in some milk samples. Strains of Serratia liquefaciens and Flavobacterium balustinum were also identified.

Animals↗
PubMed1989

Identification of psychrotrophic pseudomonads from goats' milk by computer-assisted analysis of carbon source assimilation data.

The results of carbon source assimilation tests on a group of psychrotrophic pseudomonas were compared with published data for established Pseudomonas taxa, using computer-assisted numerical taxonomic analysis and a modified diagnostic computer program. Several phenons were not grouped at the biovar level by numerical taxonomic analysis. Identification of strains by the diagnostic program revealed heterogeneity among those in the unassigned phenons, and supported a continuum concept among the fluorescent pseudomonads.

Animals↗