PubMed Health⌕ Search

Biomedical subjects

D H Wells

Publications and source records attributed to D H Wells.

At least 19 recordsLinked to original sources

Nucleotide sequence and predicted functions of the entire Sinorhizobium meliloti pSymA megaplasmid.

The symbiotic nitrogen-fixing soil bacterium Sinorhizobium meliloti contains three replicons: pSymA, pSymB, and the chromosome. We report here the complete 1,354,226-nt sequence of pSymA. In addition to a large fraction of the genes known to be specifically involved in symbiosis, pSymA contains genes likely to be involved in nitrogen and carbon metabolism, transport, stress, and resistance responses, and other functions that give S. meliloti an advantage in its specialized niche.

Agrobacterium tumefaciens↗

The composite genome of the legume symbiont Sinorhizobium meliloti.

The scarcity of usable nitrogen frequently limits plant growth. A tight metabolic association with rhizobial bacteria allows legumes to obtain nitrogen compounds by bacterial reduction of dinitrogen (N2) to ammonium (NH4+). We present here the annotated DNA sequence of the alpha-proteobacterium Sinorhizobium meliloti, the symbiont of alfalfa. The tripartite 6.7-megabase (Mb) genome comprises a 3.65-Mb chromosome, and 1.35-Mb pSymA and 1.68-Mb pSymB megaplasmids. Genome sequence analysis indicates that all three elements contribute, in varying degrees, to symbiosis and reveals how this genome may have emerged during evolution. The genome sequence will be useful in understanding the dynamics of interkingdom associations and of life in soil environments.

Bacterial Adhesion↗

Out-of-body experience and personality functioning.

Reporters of out-of-body experiences (n = 21) and nonreporters (n = 159) showed no significant differences on the Spheres of Control Scale, Self-efficacy Scale, and Purpose in Life Scale. However, reporters of out-of-body experiences showed significantly greater belief in Psi, Spiritualism, and Extraordinary Life Forms than nonreporters.

Adult↗

Flavobacterium meningosepticum in the neonatal period.

We have described a term newborn infant who developed Flavobacterium meningosepticum meningitis at 9 days of age. The case demonstrates the tenacity and changing antibiotic sensitivity of this organism. We used trimethoprim-sulfamethoxazole (Bactrim) intravenously to obtain CSF sterilization. On follow-up this child was neurologically intact.

Bacterial Infections↗

Suppuration of the submandibular salivary glands in the neonate.

Suppurative sialadenitis is rare in the neonate and usually involves the parotid glands. Two cases are reported of suppuration of the submandibular gland in the newborn. Diagnosis was made by clinical signs of infection, appearance of a unilateral, erythematous submandibular mass, and expression of pus from the orifice of Wharton duct under the tip of the tongue. Gram stain, culture, and antibiotic sensitivity studies were done on the purulent material. Staphylococcus aureus grew in both cases and was sensitive to treatment with methicillin sodium. This report discusses the management of these cases, with speculation about the possible cause. To my knowledge, these are the only two cases found in the literature of suppurative submandibular sialadenitis occuring as an isolated lesion in the neonatal period.

Humans↗

Nasojejunal feedings in low-birth-weight infants.

Continuous nasojejunal and intermittent nasogastric feedings were compared in a controlled prospective study in 21 low-birth-weight infants. The groups were comparable in regard to period of gestation, birth weight, head circumference, and clinical findings. Cumulative weight gain, caloric and fluid intake, percent weight lost, blood chemistry values, and complications were used in evaluating the two groups. Upon completion of the 21-day study, N/J infants were found to have had statistically better weight gain, caloric intake, and fluid intake (p = 0.05-0.001) during the early part of the study. Weight loss was less in the N/J group (p less than 0.01). Neither group had abnormalities of blood chemistry or significant complications. It is concluded that N/J feeding in the low-birth-weight neonate is a safe, effective means of early nutritional intake, with advantages most pronounced during the first two weeks of life.

Bacteria↗