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Biomedical subjects

J Wild

Publications and source records attributed to J Wild.

At least 55 records · Page 3Linked to original sources
PubMed1996

Folate intake in young women and their knowledge of preconceptional folate supplementation to prevent neural tube defects.

OBJECTIVES: To ascertain knowledge of periconceptional folate for prevention of neural tube defect (NTD) and to estimate folate intake in young women. STUDY DESIGN: Three hundred young women were questioned about their knowledge of folate for prevention of NTD. Their folate intake was assessed by food frequency questionnaire. RESULTS: Fourteen per cent of 16-19 year olds and 41% of undergraduates were aware of the need to increase folate intake before conception. Median folate intake was estimated to be 235 micrograms/d in 16-19 year olds and 248.5 micrograms/d in undergraduates. More than a quarter of women in both groups had folate intakes less than the reference nutrient intake (RNI) (200 micrograms/d) below which prevalence of NTD rises dramatically and these women would therefore be at increased risk of having a child with NTD should they have an unplanned pregnancy. CONCLUSIONS: Strategies are required to increase folate intake among young women and inform them of the benefit of peri-conceptional folate supplementation.

Adolescent↗
PubMed1996

A broad-host-range in vivo pop-out and amplification system for generating large quantities of 50- to 100-kb genomic fragments for direct DNA sequencing.

A prerequisite for sequencing large genomes is to obtain 30- to 150-kb genomic DNA fragments in adequate quantity. Previously, we developed a system which enables one to excise and amplify in vivo such segments directly from the Escherichia coli genome. This system, which employed the yeast Flp/FRT elements for excision and the plasmid R6K-based replication machinery for DNA amplification, permits one to bypass conventional cloning [Pósfai et al. (1994) Nucleic Acids Res. 22, 2392-2398]. To extend the applicability of such a system to many species, we describe here a broad-host-range (bhr) system in which the amplification of the excised DNA fragment depends on the oriV element and the Rep (TrfA) protein from the promiscuous RK2/RP4 plasmid. We have constructed insertion plasmids which carry the FRT and oriV sites. To introduce such plasmids into the appropriate position in the host genome, a short genomic sequence homologous to this position was cloned into the multiple cloning site (MCS) of the FRT/oriV insertion plasmid and then recombined into this position in the genome by RecA-mediated recombination. In such a manner, many strains with single FRT/oriV insertions at various positions could be generated. Subsequent genetic crosses or phage transduction allow two neighboring FRT/oriV sites (less than 150 kb apart) to be brought into a single genome. In the present report, the lacZ and phoB sites, which are 51 kb apart in the E. coli genome, were used for the introduction of the FRT/oriV sites. To deliver the Flp (excision) and Rep (amplification) functions in trans, the yeast FLP and RK2 plasmid trfA genes were placed under the control of the Ptet promoter/operator which is tightly regulated by the TetR repressor. The addition of heated chlortetracycline (cTc) inactivates TetR, turning on the synthesis of Flp and TrfA, which respectively, execute (i) excision of the 51-kb genomic segment between the two FRT sites (in lacZ and in phoB), and (ii) its amplification.

Chromosome Walking↗
PubMed1996

The influence of dietary folate and methionine on the metabolic disposition of endotoxic homocysteine.

We have investigated the disposition of potentially endotoxic homocysteine (Hcy) and its transsulfuration metabolite cysteine (Cys) in 98 individuals (age range 20-66 years). Our study reports on the relationship between Hcy and two important dietary factors likely to influence plasma levels of this thiol: dietary folate and dietary methionine. chi2 analysis shows a low frequency of elevated plasma Hcy at high folate intake. This frequency for Hcy >10 micromol/liter with a folate intake >350 microg/day is significant (P < 0.02). The data reflect a tendency for elevated Hcy values to be associated with low dietary folate, although many subjects with a low dietary folate also had a low plasma Hcy. Intake of dietary methionine was found to be significantly higher in males than in females (P < .0001). This may account for the looser relationship between Hcy and its transsulfuration product, Cys, in females (R2 = 0.30) compared to males (R2 = 0.73), since conversion of methionine to SAM in males would activate cystathionine beta synthase and commit excess Hcy to transsulfuration. The generally lower methionine intake of females means that more Hcy is utilized in the remethylation cycle in which methionine is produced from the de novo methyl group of 5-methyltetrahydrofolate or from the preformed methyl group of betaine. Clearly a Hcy moiety locked up in remethylation would be further removed from Cys, the end product of transsulfuration. An increasing number of studies are clarifying the relationship between Hcy, folate, and other B vitamins. However, less attention seems to be given to the influence of dietary methionine on the disposition of Hcy. The present study supports biochemical theory and indicates that more focus should be given to the effect of dietary methionine on Hcy. These findings have particular significance since even moderate increases in plasma Hcy are associated with a toxic vascular effect. Consequently the relationship between dietary folate and Hcy levels should be a factor in evaluating recommended dietary allowances for this vitamin. The simplicity of our dietary folate questionnaire also raises the possibility of a screening test in which individuals can ascertain whether their folate intake is adequate to reduce Hcy levels to a benign value.

Adolescent↗
PubMed1996

Seven-year follow-up of speech/language impaired and control children: psychiatric outcome.

This study examined the 7-year psychiatric outcome of 202 speech/language (S/L) impaired and control children selected from a community sample at age 5 years. Children with S/L at age 5 years were more likely to be psychiatric cases at age 12.5 years than were normal controls, even if their S/L improved. Controlling for concurrent psychiatric disorder, S/L impairment at age 5 years was still associated with an increased rate of psychiatric disorder at 12.5 years. Psychiatric disorder at age 12.5 years was more likely to co-occur with language disorder than with speech disorder.

Articulation Disorders↗
PubMed1996

Involvement of the DnaK-DnaJ-GrpE chaperone team in protein secretion in Escherichia coli.

We used depletion studies designed to further investigate the role of the DnaK, DnaJ, and GrpE heat shock proteins in the SecB-dependent and SecB-independent secretion pathways. Our previous finding that SecB-deficient strains containing the grpE280 mutation were still secretion proficient raised the possibility that GrpE was not involved in this secretory pathway. Using depletion studies, we now demonstrate a requirement for GrpE in this pathway. In addition, depletion studies demonstrate that while DnaK, DnaJ, and GrpE are involved in the secretion of the SecB-independent proteins (alkaline phosphatase, ribose-binding protein, and beta-lactamase), they are not the primary chaperones in this process.

Alkaline Phosphatase↗
PubMed1996

Nitric oxide modulates regional blood flow differences in the fetal gastrointestinal tract.

We studied the role of endogenous nitric oxide (NO) in the regulation of gastrointestinal (GI) circulation in 11 chronically instrumented and unanesthetized late-gestation fetal sheep. Systemic and GI blood flows were measured by the radiolabeled microsphere technique. Mean arterial pressure (MAP), heart rate, blood flows, oxygen delivery, and vascular resistance were determined before and after infusion of the specific NO synthase inhibitor, N omega-nitro-L-arginine (L-NNA), to cumulative doses of 10 and 25 mg/kg. At both L-NNA doses, MAP increased, and combined ventricular output and heart rate decreased. GI blood flow and oxygen delivery decreased and vascular resistance increased for the stomach, all segments of the small intestine, and proximal colon and cecum but were unchanged in the middle and distal colon and rectum. Because blood flow reduction in the small intestine was pronounced (from 176 to 107 ml.min-1.100 g-1, P < 0.001) and blood flow in the large intestine was unchanged, distribution of intestinal blood flow became more uniform. Overall, blood flow reduction was proportionally greater in GI circulation than in the remainder of fetal circulation. In three additional animals we established that L-NNA reduced blood flow to the mucosal-submucosal layer (P < 0.02) but not to the muscularis serosa of the small intestine. In the same animals, L-arginine (250 mg/kg) restored systemic hemodynamics and partially restored small intestinal blood flow. Our results suggest that NO is an important differential regulator of vascular tone in the developing GI circulation.

Animals↗
PubMed1996

Market changes create need for practice budgets.

The increasing prevalence of managed care, capitation, and physician practice acquisition is forcing physician practices to operate in a more businesslike way. As a first step toward more businesslike operations, practices of all sizes should prepare formal annual budgets to help predict and manage revenue and expenses.

Budgets↗
PubMed1996

Increasing revenue through fee review and adjustment.

Medical group practices are under increasing pressure to deliver care more cost-efficiently. To remain competitive, practices must find ways to increase their fee-for-service revenue. One way for medical group practices to increase revenue is to review fees in accordance with industry standards and to adjust them, as needed.

Fee Schedules↗
PubMed1996

Strategic plan can start physician network on path to success.

Forming physician networks can improve the ability of healthcare organizations to attract managed care contracts. However, forming physician networks can be risky for organizations new to such affiliations. One way healthcare organizations can reduce the risk and improve the odds of success in network participation is to develop a strategic plan.

Community Networks↗
PubMed1996

A comparative evaluation of the in vitro penetration performance of the improved Crest complete toothbrush versus the Current Crest complete toothbrush, the Colgate Precision toothbrush and the Oral-B P40 toothbrush.

Removal of plaque and debris from interproximal surfaces during toothbrushing has generally been difficult to achieve, in large part because traditional flat-bristled toothbrushes do not offer good interproximal penetration. As a result, a number of varying bristle designs have been developed, with the rippled-design brush shown to be particularly effective at removing interproximal plaque. Recently, an existing brush, the original Crest Complete, was modified to offer a more deeply rippled version. This study evaluated the interproximal penetration of four bristle designs: rippled pattern (original Crest Complete), deeper rippled pattern (improved Crest Complete), multi-level (Colgate Precision), and flat-tufted (Oral-B P40). The study used a previously reported in vitro model for determining interproximal penetration of manual toothbrushes (J Clin Dent 5:27-33, 1994). In order to effectively mimic the in-use characteristics of toothbrushing, this model is based on analysis of videotaped consumer brushing habits, tooth morphology, and in vivo plaque tenacity characteristics and uses the three most predominantly used brushing techniques (circular, up-and-down, and back-and-forth, with the brush held at both 45 and 90 degrees to the tooth surface). In addition, the model's brush stroke length, brush force, and brush speed are likewise based on analysis of consumer brushing patterns. The results of the study indicate that the new Crest Complete with deeper rippled bristles provided significantly superior (p < or = 0.05) interproximal penetration than the Colgate Precision and Oral-B brushes overall and for three of the four brush strokes tested. In addition, the new Crest Complete was found to provide significantly superior interproximal penetration to the original Crest Complete overall and in circular and up-and-down strokes, and the original Crest Complete provided superior overall interproximal penetration to the Colgate and Oral-B brushes.

Analysis of Variance↗
PubMed1995

Nonenzymatic degradation and salvage of dietary folate: physicochemical factors likely to influence bioavailability.

We investigated the oxidative degradation pathway of 5CH3-H4PteGlu, the main extracellular folate and the predominant form of the vitamin found in food and blood. 5CH3-H4PteGlu is oxidized to 5CH3-5,6-H2PteGlu which subsequently undergoes C9-N10 bond cleavage yielding a pteridine residue and P-ABG, the latter step resulting in irreversible loss of vitamin activity. Under moderately acid conditions typical of the postprandial gut (pH 3.5) 5CH3-H4PteGlu is fairly stable (t1/2 = 273.6 min), while 5CH3-5,6-H2PteGlu is rapidly degraded (t1/2 = 16.9 min). In a neutral environment (pH 6.4) stability is reversed; 5CH3-H4PteGlu t1/2 = 12.0 mins, 5CH3-5,6-H2PteGlu t1/2 = 1504.6 min. Ascorbic acid was efficacious in the facile salvage of 5CH3-H4PteGlu from 5CH3-5,6-H2PteGlu which occurred rapidly and with significant efficiency (100% conversion) under acid (pH 3.5) conditions, t1/2 = 1.3 min (1 mmol/liter ascorbate), but was less efficient under neutral (pH 6.4) conditions t1/2 = 273.6 min (36% conversion). The presence of zinc and iron broadly maintains the pattern of effect, but increases all reaction rates. PteGlu was stable under all conditions studied. These results obtained in an artificial environment were supported by findings in human gastric juice: at a gastric pH of 1.47 with low endogenous ascorbate (7.0 mumol/liter), 5CH3-5,6-H2PteGlu and 5CH3-H4PteGlu both degrade instantly via C9-N10 bond cleavage to yield an equimolar amount of P-ABG. If the same gastric juice is spiked at 58.0 mumol/liter ascorbate (moderate endogenous concentration), 5CH3-H4PteGlu is stable (t1/2 = 334.7 min), while 5CH3-5,6-H2PteGlu is instantly salvaged to 5CH3-H4PteGlu with 43.3% efficiency, and the remaining 5CH3-5,6-H2PteGlu is degraded to P-ABG. In gastric juice with an elevated pH of 7.0 and no endogenous ascorbate, 5CH3-5,6-H2PteGlu and 5CH3-H4PteGlu are both stable, with no C9-N10 bond cleavage. This, for 5CH3-H4PteGlu, is in apparent contrast to findings at pH 6.4 in an artificial environment. The same gastric juice spiked to 50 mumol/liter ascorbate did not result in 5CH3-H4PteGlu salvage from 5CH3-5,6-H2PteGlu.(ABSTRACT TRUNCATED AT 400 WORDS)

Ascorbic Acid↗
PubMed1995

The Malone antegrade continence enema for neurogenic and structural fecal incontinence and constipation.

Problems of fecal elimination are commonly encountered by the pediatric urologist and surgeon. The Malone antegrade continence enema has been described as a means to administer a large volume enema via a continent catheterizable appendicocecostomy, resulting in reliable fecal elimination. Of 22 patients undergoing this procedure 16 reported total continence 4 months or longer after surgery. Complications are relatively minor and tap water appears to be a safe solution for the antegrade continence enema. A nonrefluxing, imbricated appendicocecostomy is preferable to prevent cutaneous fecal or gas leaks.

Adolescent↗
PubMed1995

Continuous measurement of blood flow in the superior sagittal sinus of the lamb.

We assessed the validity of recording blood flow in the superior sagittal sinus (Qss) as a measure of cerebral blood flow (CBF). While anesthetized, 10 lambs were instrumented with a transit-time ultrasonic flow probe around the superior sagittal sinus to measure Qss, electrodes to assess sleep state, catheters to measure cerebral perfusion pressure (Pcp), and an occlusive cuff around the common brachiocephalic artery to vary blood pressure. After 72 h recovery, lambs were studied during spontaneous sleep-wake cycles to establish 1) the normal range of Qss and 2) the response rate of Qss to rapid alterations of Pcp. Subsequently, the lambs were reanesthetized, and the measurement of Qss was calibrated and validated. Qss was linearly related to the arterial inflow of 35% of the brain mass (y = 0.5 x + 1.6, r = 0.93, n = 4). Qss was greater in active sleep (154.1 +/- 45.7 ml.min-1 x 100 g-1, mean +/- SD, n = 5) than in quiet sleep (97.1 +/- 40.8 ml.min-1 x 100 g-1) and quiet wakefulness (107 +/- 44.3 ml.min-1 x 100 g-1, P < 0.05). Qss responded rapidly (within one beat) to spontaneous and to induced transient changes in Pcp. We conclude that recording blood flow in the superior sagittal sinus provides a simple, continuous, and quantitative measure of CBF from a defined area of the brain and is appropriate for studying transient changes in the cerebral circulation.

Animals↗