Effect of Mutans streptococcal colonization on plaque formation and regrowth in young children--a brief commnunication.

OBJECTIVES: Visible plaque on the maxillary anterior teeth of young children has been identified as a risk indicator for early childhood caries. The present study examined whether this plaque is related to the colonization of children's teeth with Mutans streptococci (MS) or toothbrushing frequency. METHODS: Thirty-nine children, aged 12 to 36 months, had plaque scores, and plaque samples were taken from the labial surfaces of the maxillary incisors at baseline and repeated 3 days after suspended oral hygiene (plaque regrowth). RESULTS: A positive correlation was found between the baseline percent MS and regrowth plaque score and between baseline and regrowth plaque scores. Plaque scores of those that brushed zero to one time a day were not different from those who brushed two or more times a day. CONCLUSIONS: This study suggests that the presence of plaque on the anterior teeth of young children is consistent and related to MS colonization.     

Fibre-supplemented tube feeding in the hospitalised elderly

OBJECTIVES: To evaluate the effect of fibre supplementation in enteral feeding on bowel function in hospitalised geriatric patients, and to assess its metabolic and nutritional efficiency. DESIGN: Prospective randomised controlled trial with stratification for diabetes. SETTING: Department of Geriatrics at the University of Antwerp. SUBJECTS: During 30 months (January 2000-June 2002) every hospitalised patient requiring tube feeding was assessed for eligibility (n = 183). Finally 172 patients (19% diabetics) were randomised. METHODS: An enteral nutritional regimen consisting of 30 kcal/kg in 2000 ml with a calorie/nitrogen ratio of 156 with or without fibre was instituted. At weekly intervals, stool output was qualitatively evaluated by recording frequency, volume (small <1/2 cup, large >1/2 cup) and consistency (solid-formed, soft-pasty or liquid-watery). Nutritional and metabolic effects were evaluated through laboratory analysis. RESULTS: Overall mortality was 24% with a trend for excess mortality in diabetic patients (33.3% versus 21.6% in non-diabetics; P = 0.176). There was no difference in duration of feeding between the fibre group (27.5 days; 95% CI = 19.1-35.9) and the no fibre group (27.9 days; 95% CI = 20.2-35.5). In the fibre-supplemented group, stool frequency was lower (4.1 per week; 95% CI = 3.7-4.6) than in controls (6.3 per week; 95% CI = 5.6-6.9). Qualitatively, stool consistency was higher (P < 0.001) but no difference in volume was noted. There were no differences in final laboratory parameters between groups. CONCLUSIONS: Fibre supplementation improved bowel function with reduced stool frequency and more solid stool consistency. It did not affect the nutritional efficiency of enteral feeding in hospitalised geriatric patients. Diabetes may be a risk factor for mortality in malnourished patients requiring tube feeding.     

Nijmegen breakage syndrome gene (NBS1) is not the tumor suppressor gene at 8q21.3 involved in colorectal carcinoma

Genetic instability is characteristic of cancer cells, both at the chromosomal level (e.g., aneuploidy, aneusomy, translocations), and at the sequence level (e.g., microsatellite instability). Colorectal cancers (CRCs) can be divided into two groups: tumors of the proximal colon, where microsatellite instability is frequent and chromosomal aberrations are rare, and tumors of the distal colon, where microsatellite instability is less frequent and chromosomal aberrations are common. Constitutional chromosomal instability is a hallmark of the Nijmegen breakage syndrome (NBS), a disorder in which the NBS1 gene is mutated. In a previous study, we found an elevated frequency of allelic imbalance (AI) at the 8q21.3 NBS1 locus in proximal, though not distal CRCs. This result suggested that the loss of NBS1 might contribute to the genetic instability, and thus the malignant progression, of proximal CRC. We therefore sequenced the 16 exons of the NBS1 gene in all cases where we had observed AI. Of the 29 cases, none showed any sequence anomaly, although several polymorphisms were found. We also studied markers flanking the recently described Rad54B gene, which is a member of the Rad52 epistasis group to which NBS1 itself belongs. Mutations of this gene, located a few cM distal to NBS1, have been found in colorectal cancer and in primary lymphomas, and it may thus be the target of AI at 8q21. We found that AI at Rad54B was not frequent, and none was observed in cases showing AI at NBS1.     

Simultaneous measurement and integrated analysis of analgesia and respiration after an intravenous morphine infusion

BACKGROUND: To study the influence of morphine on chemical control of breathing relative to the analgesic properties of morphine, the authors quantified morphine-induced analgesia and respiratory depression in a single group of healthy volunteers. Both respiratory and pain measurements were performed over single 24-h time spans. METHODS: Eight subjects (four men, four women) received a 90-s intravenous morphine infusion; eight others (four men, four women) received a 90-s placebo infusion. At regular time intervals, respiratory variables (breathing at a fixed end-tidal partial pressure of carbon dioxide of 50 mmHg and the isocapnic acute hypoxic response), pain tolerance (derived from a transcutaneous electrical acute pain model), and arterial blood samples were obtained. Data acquisition continued for 24 h. Population pharmacokinetic (sigmoid Emax)-pharmacodynamic models were applied to the respiratory and pain data. The models are characterized by potency parameters, shape parameters (gamma), and blood-effect site equilibration half-lives. All collected data were analyzed simultaneously using the statistical program NONMEM. RESULTS: Placebo had no systematic effect on analgesic or respiratory variables. Morphine potency parameter and blood-effect site equilibration half-life did not differ significantly among the three measured effect parameters (P > 0.01). The integrated NONMEM analysis yielded a potency parameter of 32 +/- 1.4 nm (typical value +/- SE) and a blood-effect site equilibration half-life of 4.4 +/- 0.3 h. Parameter gamma was 1 for hypercapnic and hypoxic breathing but 2.4 +/- 0.7 for analgesia (P < 0.01). CONCLUSIONS: Our data indicate that systems involved in morphine-induced analgesia and respiratory depression share important pharmacodynamic characteristics. This suggests similarities in central mu-opioid analgesic and respiratory pathways (e.g., similarities in mu-opioid receptors and G proteins). The clinical implication of this study is that after morphine administration, despite lack of good pain relief, moderate to severe respiratory depression remains possible.