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Biomedical subjects

D Williamson

Publications and source records attributed to D Williamson.

117 records · Page 7Linked to original sources
PubMedDate not supplied

Calcified cutaneous nodules on the heels of children: a complication of heel sticks as a neonate.

We report the presence of calcified nodules on the heels secondary to heel sticks in healthy monozygotic twins in childhood. The subjects were born preterm at 34 weeks. The heels were normal at birth. While in the hospital, they underwent multiple heel sticks as a means of venesection. The wounds failed to heal normally and warty lesions developed. Calcified cutaneous nodules secondary to heel sticks have been reported primarily in high-risk, preterm infants. There have also been two reports of their development in normal healthy infants. To date, all reported lesions have been asymptomatic, with spontaneous resolution by 18-30 months. These cases indicate that such lesions can in fact be chronic, extending into childhood, when they may become symptomatic. Dermatologists should therefore consider this diagnosis as a cause of warty, calcified nodules on the heel in childhood as well as in infants and in neonates.

Calcinosis↗
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Guanine-plus-cytosine content, hybridization percentages, and EcoRI restriction enzyme profiles of spiroplasmal DNA.

The guanine-plus-cytosine (G + C) content of spiroplasmal DNA was calculated from the melting temperature determined spectrophotometrically and the buoyant density determined by equilibrium density gradient centrifugation in CsCl. Only two ranges of G + C values were found: 25-27 mol% and 29-32 mol%. The DNA of the following spiroplasmas has 25-27 mol% G + C: Spiroplasma citri (serogroup I-1); the spiroplasmas pathogenic to the honeybee (KC3, BC3, and B63; serogroup I-2); the corn stunt strain (E275; serogroup I-3); the tick strain 277F (serogroup I-4); the drosophila strain (serogroup II); and one group of flower spiroplasmas (serogroup III). The DNA of a second group of flower spiroplasmas (serogroup IV) and the SMCA strain (serogroup V) has a G + C content of 29-31 mol/. The classification of flower spiroplasmas into two groups on the basis of G + C content agrees well with the groupings based on serologic and protein analysis. Spiroplasmas isolated from honeybees in Morocco (B13) or froghoppers in Corsica (L89) have 29-31 mol% G + C, a value that corroborates the relatedness of these strains and the flower spiroplasmas of serogroup IV found by serologic analysis. Reannealing experiments between the vivo-labeled DNA of S. citri and unlabeled DNA of other spiroplasmas gave the following percentages of hybridization: 64% with honeybee spiroplasma DNA, 49% with corn stunt spiroplasma DNA, and 19% with tick spiroplasma 277F DNA; no significant hybridization was observed with DNA of any other spiroplasma. The taxonomic position of the tick spiroplasma 277F within serogroup I was confirmed by hybridization experiments involving [3H]DNA of this strain. The value of polyacrylamide gel analysis of DNA fragments produced by the action of EcoRI restriction enzyme on DNAs from various spiroplasmas is also discussed.

Animals↗
PubMedDate not supplied

Advances in wound care and healing technology.

Wounds are unique in so far as no disease process other than wounds would have existed from the beginning of mankind. Over the years, the management of wounds, especially that of chronic wounds, has had enormous social and economic implications worldwide. With an aging population, this impact is likely to increase. In recent years, this has been reflected by the birth and rapid growth of the new speciality of 'wound healing'. Continuous advances made in the study of the wound microenvironment, an ever-broadening understanding of the pathophysiology of wounds, and improved techniques in monitoring the response of healing have led to continuing developments in the treatment of chronic wounds. Current research focuses on growth factors and human skin substitutes that provide promising results. This article reviews advances made in wound care management over the years. Despite all these advances, it must be borne in mind that basic principles of wound care in a multidisciplinary team setting still remain the backbone of wound management.

Bandages↗
PubMedDate not supplied

Oral health knowledge, attitudes and preventive practices of third grade school children.

PURPOSE: The aim of study was to investigate the oral health knowledge, attitudes and preventive practices of third grade school children in Harris County. METHODS: In this cross-sectional study, oral health knowledge, attitudes, and preventive practices of the children were investigated by means of a self-administered, bilingual questionnaire. Three calibrated examiners collected data on dental caries, periodontitis, and fluorosis of 1,031 school children. RESULTS: Most children reported "fairly adequate" oral hygiene habits (58%) and oral health knowledge (48%), and "adequate" dietary patterns (59%). Children with inadequate oral health knowledge were twice as likely to have caries than children with adequate knowledge (OR = 2.05, 95% CI = 1.29, 3.28). The mean combined DMFT/dft scores of children with inadequate knowledge were significantly higher than the mean for children with adequate knowledge (t = 2.6, P = 0.009). CONCLUSIONS: Results indicate a need to improve oral health knowledge and preventive practices among the study population. Because of the cross-sectional nature of the study, it is not possible to illustrate a cause-effect relationship between oral health education and prevalence of caries.

Attitude to Health↗
PubMedDate not supplied

Mortality, cardiovascular risk factors, and diet in China, Finland, and the United States.

Mortality, cardiovascular risk factors, and diet were compared in Tianjin province, People's Republic of China; in North Karelia Province, Finland; and in the United States as a whole. People in Tianjin received 7 percent of their energy intake from saturated fats, whereas people in the United States received 13 percent and those in North Karelia received 20. The mean blood cholesterol levels for men were 158 milligrams per deciliter (mg per dl) for Tianjin, 216 mg per dl for the United States, and 241 mg per dl for North Karelia. The smoking prevalence among men was highest in Tianjin (66 percent), followed by the United States (42 percent) and Finland (36 percent). The differences among mortality rates for the three locales were less pronounced among women than among men. Age-standardized total mortality for women was highest for Tianjin and lowest in North Karelia. The reverse was true for men. Age-standardized total mortality for men was lowest in Tianjin and highest in North Karelia. Age-standardized ischemic heart disease mortality for men was lowest in Tianjin (99 per 100,000) and highest in North Karelia (730 per 100,000). For women, the corresponding figures were 83 per 100,000 in Tianjin and 164 per 100,000 in North Karelia. Although salt intake was higher in Tianjin than in North Karelia, the blood pressure was on average lower in persons from Tianjin than in those from North Karelia. The stroke mortality rate in Tianjin, however, was much higher than in either Finland or the United States. The strong discrepancy in stroke mortality relative to prevalence of hypertension and salt intake raises the issue of the etiology of stroke in Tianjin. Recently it has been reported that hemorrhagic stroke may be more common among people whose blood cholesterol level is very low and blood pressure level high. This joint condition may be relatively common in Tianjin and calls for longitudinal and case-control studies to clarify the relationships among these factors in Tianjin.

Adult↗