Skin tension lines in the domestic pig.

The skin tension lines of the domestic pig have been mapped. With a 6mm punch biopsy, local relative skin forces can be determined. The influence of various factors (such as age, fat deposition, gascial attachments, and previous scarring) on the direction of the skin tension lines is discussed.     

Low back pain in the workman in Canada.

Groups of 25 Workmen''s Compensation Board patients (WCP group) and 25 non-Workmen''s Compensation Board patients (NWCP group) hospitalized because of low back pain were compared. The WCP group had a significantly higher male:female ratio, incidence of sudden onset and precipitating factors, and prevalence of weakness, decreased reflexes and sensory loss. Surgical treatment and multiple operations were significantly more frequent in the WCP group, as was complete long-term relief or worsening after operation. Adequate partial relief was significantly more frequent in the NWCP group. The differences suggest more severe conditions in the workmen. Prevalence of psychological factors was not significantly different, although a trend was observed for this to be greater in the WCP group.     

Skin response to X-irradiation in the guinea-pig.

Skin reaction to X-irradiation has been studied in the albino guinea-pig; early response in limited-field irradiations of the flank is comparable to that commonly seen in rodents, swine and man, and is dose-dependent with a dynamic range from mild erythema to moist desquamation. The peak early skin reaction is seen between 14 and 21 days after irradiation, and declines before 30 days except at the highest doses used. Fractionation of the X-ray dose at 24 hours results in a 'sparing' of about 340 rad. Permanent partial epilation is detectable at doses in excess of 1400 rad, and complete epilation at 1 year occurs in 50 per cent of irradiated fields at 1740 rad. Twenty-four hour two-dose fractionation results in a 'sparing' of about 500 rad for epilation. Palpable dermal 'fibrosis' is detectable at 3 months after irradiation in fields given more than 2070 rad, and at 1 year after irradiation in fields given more than 1800 rad; 50 per cent of fields showed palpable 'fibrosis' at 1 year at 1930 rad. Unlike domestic swine and man, skin fields in the guinea-pig showed no dimensional contraction after X-ray doses which produced gross early skin damage.     

Cardiac abnormalities in liver cirrhosis.

Cirrhosis is associated with several circulatory abnormalities. A hyperkinetic circulation characterized by increased cardiac output and decreased arterial pressure and peripheral resistance is typical. Despite this hyperkinetic circulation, some patients with alcoholic cirrhosis have subclinical cardiomyopathy with evidence of abnormal ventricular function unmasked by physiologic or pharmacologic stress. Florid congestive alcoholic cardiomyopathy develops in a small percentage, but the concurrent presence of cirrhosis seems to retard the occurrence of overt heart failure. Even nonalcoholic cirrhosis may be associated with latent cardiomyopathy, although overt heart failure is not observed. Tense ascites is associated with some cardiac compromise, and removing or mobilizing ascitic fluid by paracentesis or peritoneovenous shunting results in short-term increases in cardiac output. Cirrhosis also appears to be associated with a decreased risk of major coronary atherosclerosis and an increased risk of bacterial endocarditis. Small hemodynamically insignificant pericardial effusions may be seen in ascitic patients. The release of atrial natriuretic peptide appears to be unimpaired in cirrhosis, although the kidney may be hyporesponsive to its natriuretic effects.     

Mitochondrial abnormalities in progressive ophthalmoplegia.

A clinically diagnosed case of progressive external ophthalmoplegia was biopsied and ultrastructurally evaluated. The disease was found to be characterized by numerous giant mitochondria. The intramitochondrial changes consisted of either swirls of cristae or of paracrystalline structures which were in apposition with the membranes of the cristae. The internal structure of the paracrystalline units consisted of parallel bands of material which were aligned in the same plane as the membranes of the related cristae.     

Skin rejection in graft-versus-host disease.

Graft-versus-host disease is becoming a common clinical problem, one which can require the consultation of a plastic surgeon for restoration of skin coverage. An understanding of the immunological basis of the disease is essential to the clinical management of this condition. A case of GVHD is reported, and the principles of treatment are discussed.