A case-control study of tattoos in young suicide victims as a possible marker of risk.

BACKGROUND: The goal was to examine tattooing in suicides, as tattoos have been associated with several risk factors for suicide. METHOD: A chart review of a three-year sample of 134 consecutive suicides in Mobile County, Alabama, was conducted. The prevalence of tattoos was compared between young (<30) white suicides and accidental deaths matched for age, gender and race, in a case-control study. RESULTS: Tattoos were found in 21% of suicides. Fifty-seven percent of young white suicides were tattooed compared to 29% of matched accidental deaths. LIMITATIONS: Findings are preliminary due to the small sample size. The study methodology precluded obtaining information of psychiatric diagnoses prior to death. CONCLUSIONS: Tattoos may be possible markers for lethality from both suicide and accidental death in young people, presumably because of shared risk factors such as substance abuse and personality disorder. Affective disorders should receive further, more specific studies. The clinical value of inquiring about tattoos in young people at risk of suicide needs further study.

Remodeling of lung interstitium but not resistance vessels in canine pacing-induced heart failure.

We previously showed that pacing-induced heart failure in dogs results in an enhancement of pulmonary vascular reactivity. In the present study we hypothesized that enhanced matrix deposition and structural remodeling of lung resistance microvessels would underlie these functional changes. Using biochemical measures, we found no difference in the normalized lung content of hyaluronan, uronic acid, and collagen between control dogs and dogs paced for 1 mo, although lung dry weight and noncollagen protein content increased significantly in the paced group (P < 0.05). From separate Formalin-fixed lung lobes, 5-microm frozen sections were prepared and stained with Masson's trichrome, and vascular structure was evaluated using standard morphometric techniques. When perivascular fluid cuffs were excluded from the measure of wall thickness, collagen and media volume fractions in any size range did not differ between paced and control groups. Similarly, in the paced group, medial thickness in <400-microm arterial or venular microvessels did not vary significantly from that in the controls. In contrast, the relationship of interstitial fluid pressure to lung water was significantly shifted to the right in the paced group, such that normal tissue pressures were observed, despite the increased water content. We conclude that although 1 mo of pacing-induced heart failure results in altered interstitial function, the attendant pulmonary hypertension and/or hormonal responses are insufficient to induce medial hypertrophy or other remodeling of the extra-alveolar microvasculature.

Effects of anesthesia and K+ ATP channel blockade on interstitial adenosine accumulation in ischemic rabbit myocardium.

Glibenclamide, a K+ ATP channel antagonist, blocks the anti-infarct effect of ischemic preconditioning in rabbits, but only when the latter are anesthetized with ketamine-xylazine. Furthermore, the protection triggered by pinacidil, a K+ ATP channel opener, can be aborted by treatment with the adenosine antagonist 8-(P-sulfophenyl)theophylline. This study tests whether either the anesthetic regimen or glibenclamide affects infarct size by modulating interstitial adenosine levels. Interstitial adenosine and total purine concentrations were assessed in open-chest rabbits by the microdialysis technique. Dialysis fibers were inserted into myocardium served by a coronary artery branch surrounded by a snare. All animals sustained a 30-min coronary occlusion and then 120-min reperfusion. Rabbits were anesthetized with either sodium pentobarbital or a ketamine-xylazine mixture. Half of the latter animals also received glibenclamide. The control levels of adenosine in the dialysate were comparable in the three groups, as were those of total purines, and the infusion of glibenclamide caused no change. Ischemia led to 10- to 20-fold increases in interstitial adenosine and 10- to 40-fold rises in total purine concentrations. These increases were equivalent in all groups. Further-more, infarct size as a percentage of the myocardium at risk was also comparable in the three groups. Neither the anesthetic agent nor glibenclamide appears to modulate interstitial adenosine release from ischemic tissue.

A new animal model of controlled coronary artery occlusion in conscious rabbits.

OBJECTIVE: The aim was to develop a method for installing a pneumatic occluder on the coronary artery of a rabbit, and to see whether repetitive coronary occlusions could induce collateral development as in dogs. METHODS: A superficial branch of the left coronary artery was encircled with a balloon occluder, and a catheter was inserted into the left atrial appendage of New Zealand White rabbits, with a survival rate of 89.5%. Baseline collateral flow was measured 5-7 d after surgery with radioactive microspheres while the artery was occluded. According to a predetermined schedule animals were assigned to control and experimental groups. In the latter the balloon was inflated for 2 min once every 15 min for 8 h per d, 5 d per week. Collateral flow measurements were repeated after 100 and 300 occlusions. In control animals repeat flow measurements were made approximately 4 and 14 d after the first determination. RESULTS: Inflation of the balloon occluder reliably resulted in marked S-T segment elevation which quickly resolved after balloon deflation. These changes were nearly identical after two weeks of observation. Average baseline collateral flows in both groups were less than 5% of normal myocardial flow. There was no appreciable change during the two week period of observation in either control rabbits or those receiving at least 300 2 min coronary occlusions. CONCLUSIONS: The rabbit tolerates implantation of a pneumatic coronary occluder without noticeable problem and can successfully serve as a small animal model of repetitive or chronic myocardial ischaemia. The surgical preparation is not difficult, and ischaemia can be reproducibly created and relieved for at least three weeks following surgery. Coronary collaterals are sparse in the rabbit, and repetitive occlusions can be instituted without the complication of collateral development.