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Biomedical subjects

J T Burns

Publications and source records attributed to J T Burns.

14 recordsLinked to original sources
PubMed1995

Streptococcal preseptal cellulitis complicated by the toxic Streptococcus syndrome.

BACKGROUND: After decades of decline in the incidence of severe infections secondary to group A streptococci, a dramatic increase in the frequency and severity of infections with these organisms has been reported since 1984, including a "toxic Streptococcus syndrome," resembling staphylococcal toxic shock syndrome. To the authors' knowledge, this entity has never been described after ocular infection. METHODS: In a previously healthy 3-year-old boy, preseptal cellulitis developed secondary to minor trauma to the eyelid, progressing rapidly to hypotension, respiratory distress, and an erythrodermic desquamating rash. Ocular and blood cultures grew group A beta-hemolytic streptococci. Appropriate antibiotic coverage and management of systemic manifestations led to rapid improvement, although necrosis developed in the right upper anterior eyelid, requiring skin grafts. RESULTS: More than 3 years since the incident, the patient is free of infection and has a good cosmetic result after skin grafting and revisions for scarring and adhesions. CONCLUSIONS: Streptococcal preseptal cellulitis is not unusual, particularly after trauma. Ophthalmologists must be aware of the re-emergence of more virulent organisms with increased potential for morbidity and mortality.

Anti-Bacterial Agents↗
PubMed1994

Temporal synergism of corticosterone and prolactin in the Syrian hamster, Mesocricetus auratus.

To augment the limited work reported in the literature regarding testing of the hormonal temporal synergism hypothesis in Syrian hamsters (Joseph MM, Meier AH. Proc Soc Exp Biol Med. 1974;146:1150-5), a large experiment with female hamsters was conducted. Forty-eight received corticosterone at 18:00 h on January 21, 23, 25, 27, and 29 and ovine prolactin at one of six times of day beginning January 22 for 8 days; 36 received saline (at 18:00) and prolactin at one of the six times of day for 8 days; 35 received only prolactin at one of the six times of day for 8 days; and 16 received no injections. Twelve hamsters receiving corticosterone and prolactin and eight uninjected hamsters were on running wheels. The corticosterone and prolactin group not on wheels had a body weight gain and no circadian rhythm of weight gain, but did have circadian rhythms of response in organ weight, per 100 g of body weight, and in weights of fat pads and uteri. The corticosterone and prolactin group with access to running wheels gained in body weight and had larger ovaries and smaller fat pads. Hamsters receiving saline and prolactin had a body weight gain, but had no circadian rhythms of response in organ weights. The hamsters receiving only prolactin gained in body weight but had no rhythms of response, except for unexpected circadian rhythms in body weight gain and weights of fat pads. The uninjected hamsters had a modest weight gain. Most or all hamsters with access to running wheels free-ran, and the corticosterone injections did not appear to synchronize the locomotor activity rhythms.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1986

Use of the parascapular flap in hand reconstruction.

A parascapular free flap was used in the treatment of the injured hand of an octogenarian. The flap was done following a pollicization of the index finger. This reconstructive procedure was done 8 days after the original injury.

Aged↗
PubMed1983

Intercostal nerve transfer in brachial plexus injuries: an experimental study.

Eighteen adult mongrel dogs underwent unilateral surgical disruption of the brachial plexus. Twelve animals (Group I) had as a second-stage procedure transfer of T4 and T5 intercostal nerves and their accompanying vascular bundles to the distal musculocutaneous nerve stump. Six animals (Group II) had restoration of musculocutaneous nerve continuity with conventional interpositional sural nerve cable grafts. Group I animals demonstrated significantly better electromyographic evidence of reinnervation and, comparing appearance and weight of operated and unoperated biceps muscles at the time of animal sacrifice, maintained greater gross weight and more normal overall appearance of muscle. Histologic study of muscle tissue showed no significant difference between the two groups whereas musculocutaneous nerve histology distal to all anastomoses revealed less fibrous tissue and a greater number of healthy-appearing axons in Group I. It is concluded that vascularized intercostal nerve transfer as performed in this study has theoretical advantages over conventional nonvascularized intercostal nerve transfer but additional investigation is required to make this determination. The superiority of vascularized intercostal nerve transfers over conventional interpositional sural nerve cable grafts has been demonstrated.

Animals↗
PubMed1982

Scanning electron microscopic study of disturbances in arterial walls following microsurgical needle perforations.

In the canine femoral artery we studied the extent of endothelial and subendothelial damage caused by the passage of seven different commonly used microsurgical needles. Precautions were taken to prevent collapse and risk of early vascular trauma prior to needle perforations and fixation for SEM. Since surgical anastomosing procedures are done with grafted vascular segments maintained at normal length and Omm Hg pressure, prior to clamp removal and redilation, SEM specimens were prepared under similar conditions. Under normal vessel tension, needles were passed through the vessel thus producing an entry and exit wound. Vascular templates were constructed with sagittally sectioned arteries pinned to cardboard mounts to display the needle puncture sites and prevent vascular shrinkage. Mounted vessels were maintained in oxygenated lactate-ringers at body temperature prior to glutaraldehyde fixation. Intimal folds consisting of normal undislodged endothelial cells were seen in all areas except at needle puncture sites. Needles produced varying degrees of gross damage at entry and exit wounds. Most taper point needles tend to spread apart intimal folds while some cutting edge needles slice through endothelial cells. Cutting edge needles tend to tear off endothelial cells surrounding the wound exposing the internal elastic lamina. We have observed intact cytoplasmic extensions between endothelial cells of adjacent intimal folds remote from the wound. These extensions appear broken in the vicinity of the wound. At certain lesion sites smooth muscle cells are regularly spaced between intact and cut elastic fibers. SEM provides ultrastructural information of mechanical disturbances to the walls of arteries caused by common microsurgical needles.

Animals↗
PubMed1967

Effects of magnesium pemoline and dextroamphetamine on human learning.

Two central nervous system stimulants, magnesium pemoline and dextroamphetamine, were tested to see if they facilitate learning in human subjects. Subjects under placebo learned faster than the subjects under any of the several doses of magnesium pemoline; however, none of these differences reached statistical significance. Subjects who received dextroamphetamine learned significantly more slowly than those who received placebo.

Adult↗
PubMedDate not supplied

[Internal coordination of circadian rhythms and temporal synergism in animal adaptive reactions].

The multioscillatory principle of circadian organization of organism functions is based on the ability of some organs and cells to generate independent set of oscillations with 24 hours period. Coexistence of two or more independent rhythm producers provides a flexible structure of numerous cycles that take place in organism. The stable changes of circadian rhythms can be caused either by external factors (e.g., seasonal changes of photoperiod, socially determined changes of labour regime, cycles of sleep, feeding time) or by some inner factors, e.g. stress syndrome or illness. In its turn the changes in phase relations between circadian rhythms of some hormones and neuromediators play an important role in formation of some adaptive reactions, i.e. seasonal changes in reproductive system, peculiarities of lipid metabolism, migration behaviour, preparation to hibernation, or the rate of metamorphism in amphibians. These data allow to formulate the hypothesis of temporal synergism. According to this hypothesis morphophysiological effect caused by joint action of two or more hormones or neuromediators is dependent on the phase relationships of their circadian rhythms.

Adaptation, Physiological↗