Family- and genus-level 16S rRNA-targeted oligonucleotide probes for ecological studies of methanotrophic bacteria.

Methanotrophic bacteria play a major role in the global carbon cycle, degrade xenobiotic pollutants, and have the potential for a variety of biotechnological applications. To facilitate ecological studies of these important organisms, we developed a suite of oligonucleotide probes for quantitative analysis of methanotroph-specific 16S rRNA from environmental samples. Two probes target methanotrophs in the family Methylocystaceae (type II methanotrophs) as a group. No oligonucleotide signatures that distinguish between the two genera in this family, Methylocystis and Methylosinus, were identified. Two other probes target, as a single group, a majority of the known methanotrophs belonging to the family Methylococcaceae (type I/X methanotrophs). The remaining probes target members of individual genera of the Methylococcaceae, including Methylobacter, Methylomonas, Methylomicrobium, Methylococcus, and Methylocaldum. One of the family-level probes also covers all methanotrophic endosymbionts of marine mollusks for which 16S rRNA sequences have been published. The two known species of the newly described genus Methylosarcina gen. nov. are covered by a probe that otherwise targets only members of the closely related genus Methylomicrobium. None of the probes covers strains of the newly proposed genera Methylocella and "Methylothermus," which are polyphyletic with respect to the recognized methanotrophic families. Empirically determined midpoint dissociation temperatures were 49 to 57 degrees C for all probes. In dot blot screening against RNA from positive- and negative-control strains, the probes were specific to their intended targets. The broad coverage and high degree of specificity of this new suite of probes will provide more detailed, quantitative information about the community structure of methanotrophs in environmental samples than was previously available.

Relationship between socioeconomic factors and severe childhood injuries.

The objective was to examine the relationship between injury rates and socioeconomic factors for children in Hamilton County, Ohio, using small-area analysis. The subjects were county residents less than 15 years old who were hospitalized or died of injuries between January 1, 1993, and December 31, 1995; they were identified through a population-based trauma registry. The census tract was the unit of analysis; the rate of injury per 100,000 population was the dependent variable. Risk factors included median income, level of education, percentage below the poverty level, percentage unemployment, percentage non-Caucasian, and percentage families headed by females. There were 2,437 children meeting the case definition; injuries per census tract ranged from 0 to 2,020.2 per 100,000 per year. Census tracts with higher injury rates had lower median incomes, more people with less than a high school education, more unemployment, more families headed by females, more people living below the poverty level, and more non-Caucasians than those with lower rates. In a regression model, percentage of people living below the poverty level, percentage of those who did not graduate from high school, and percentage unemployment were significant risk factors for injuries, P < .001. Since small-area analysis examines associations on an ecological level rather than an individual level, these studies should always be interpreted with caution because an association found at the level of the census tract may not apply at the individual level. Interventions to reduce injuries should target socioeconomically disadvantaged children living below the poverty level and those in areas with fewer high school graduates and more unemployment.

Can urine clarity exclude the diagnosis of urinary tract infection?

OBJECTIVES: To determine the association of clear urine by visual inspection with the absence of significant bacteruria, and to compare it with standard urinalysis. METHODS: The study was performed in the emergency department of Children's Hospital Medical Center, Cincinnati, Ohio. It was a prospective, convenience sample of children <21 years of age who had catheterized or midstream clean-catch urine specimen collected for culture. Clinical findings including the presence or absence of fever, abdominal pain, dysuria, frequency, and urgency were collected for each patient. Urine was visually assessed for clarity by 2 independent observers using a standardized technique. Standard laboratory urinalysis and microscopy were also performed on all specimens. A positive urine culture was defined as >/=10(4) colony-forming unit (CFU)/mL of a urinary pathogen if obtained by catheterization and >/=10(5) CFU/mL if obtained by midstream. RESULTS: Samples were obtained from 159 patients ranging in age from 4 weeks to 19 years. Females comprised 77% of the patients. One hundred ten of the samples (69%) were clear to visual inspection. There were a total of 29 positive cultures; however, 3 were in children with clear urine. The finding of clear urine on visual inspection had a negative predictive value of 97.3%. These results were similar to those obtained with standard urinalysis. CONCLUSION: Clear urine on visual inspection cannot completely eliminate the possibility that a child has a urinary tract infection. However, it is a reproducible test that offers the advantages of being simple, fast, and inexpensive. The finding of clear urine should be considered a reasonable and relatively effective bedside screen for the presence of a urinary tract infection.

Childhood injuries and deaths due to falls from windows.

BACKGROUND: Unintentional injuries are the leading cause of death in children, and falls are the most common type of unintentional injury in the US. The incidence of falls from windows, a common cause of death in urban areas, has not been described outside major cities such as New York and Chicago, and rates in urban and suburban areas have not been compared. OBJECTIVE: To estimate the incidence and identify the population at risk for falls from windows among children in Hamilton County, Ohio. DESIGN: Retrospective case series identified using Cincinnati Children's Hospital Medical Center (CHMC) Trauma Registry. SETTING: Hamilton County, Ohio, which has urban and nonurban areas. PARTICIPANTS: Children less than 15 years old residing in Hamilton County, Ohio, presenting to CHMC in Cincinnati, Ohio, after a fall from a window between January 1, 1991, and December 31, 1997. OUTCOME MEASURE: Annual incidence by age, race, gender, and residence of those who fell from windows. RESULTS: Over the 7-year study period, 86 (6.3%) of 1,363 falls were from windows. The mortality rate for falls from windows was 4.7%, compared to 0.07% for all other falls presenting to CHMC (P<.0001). Children 0-4 years old had a higher rate of falls than children aged 5-14 (14.6/100,000 vs. 2.0/100,000) (P<.0001). Males were twice as likely to fall as females (P<.016), and black children were three times more likely to fall than non-black children (P<.002). The incidence of falls in the city of Cincinnati was four times that of the non-urban area (P<.0002). CONCLUSIONS: Injuries from falls from windows are a public health problem in Hamilton County, Ohio, especially for young, urban children.

Relationship between serum glucose and injury severity score in childhood trauma.

PURPOSE: The aim of this study was to examine the relationship between initial serum glucose and injury severity score (ISS) in children with multiple trauma. METHODS: Charts from all patients 0 to 19 years of age admitted to a children's hospital in 1995 with acute multiple trauma were reviewed. Data collected included initial serum glucose level, heart rate (HR), systolic blood pressure (SBP), Injury Severity Score (ISS), age, gender, location of trauma, and need for intravenous fluids or epinephrine. Data were analyzed using multiple linear regression. RESULTS: A total of 185 charts were reviewed. The mean ISS was 11.3; the mean glucose was 162.8 mg/dL. After adjusting for age, gender, HR, SBP, and administration of epinephrine or fluid bolus, a significant direct relationship between serum glucose and ISS was found (r = 0.52, P < .01). A stronger relationship was found in children less than 2 years old (r = 0.60, P = .04). CONCLUSIONS: A significant direct relationship exists between glucose and ISS in children with multiple trauma. High glucose values may indicate more severe injury, especially in children less than 2 years old.