A theoretical consideration of extensions of the Z-plasty principle

For the release of congenital or posttraumatic webs a variety of local skin flap techniques have been described. Confusion exists on how much lengthening may be obtained by each of these techniques, as well as on how much lateral slack is needed for the flaps to be shifted. These techniques and the results they provide are reviewed, calculated, and visualized by diagrams. It is concluded that the Z-plasty and its modifications lead to superior lengthening-to-narrowing ratios. Combined YV-plasties have their advantage in that resection of scarred skin will be obtained. Position, extent and orientation of the scar or web will generally indicate which technique is to be used in each individual case.     

Synthesis and antimalarial activity of new atovaquone derivatives

In this paper we describe the design and synthesis of 18 derivatives of the antimicrobial atovaquone which were substituted at the 3-hydroxy group by ester and ether functions. The compounds were evaluated in vitro for their activity against the growth of Plasmodium falciparum, the malaria causing parasite. All the compounds showed potent activity, with IC₅₀ values in the range of 1.25–50 nM, comparable to those of atovaquone and much higher than chloroquine or quinine.     

Recent trends in early outcome of adult patients after heart transplantation: a single-institution review of 251 transplants using standard donor organs.

Older age, prior transplantation, pulmonary hypertension, and mechanical support are commonly seen in current potential cardiac transplant recipients. Transplants in 436 consecutive adult patients from 1994 to 1999 were reviewed. There were 251 using standard donors in 243 patients (age range 18-69 years). To emphasize recipient risk, 185 patients who received a nonstandard donor were excluded from analysis. The indications for transplant were ischemic heart disease (n = 123, 47%), dilated cardiomyopathy (n = 82, 32%), and others (n=56, 21%). One hundred and forty-nine (57%) recipients were listed as status I; 5 and 6% were supported with an intra-aortic balloon and an assist device, respectively. The 30-d survival and survival to discharge were 94.7 and 92.7%, respectively; 1-year survival was 89.1%. Causes of early death were graft failure (n = 6), infection (n = 4), stroke (n = 4), multiorgan failure (n = 3) and rejection (n = 2). Predictors were balloon pump use alone (OR= 11.4, p =0.002), pulmonary vascular resistance > 4 Wood units (OR = 5.7, p = 0.007), pretransplant creatinine > 2.0 mg/dL (OR = 6.9, p = 0.004) and female donor (OR = 8.3, p = 0.002). Recipient age and previous surgery did not affect short-term survival. Heart transplantation in the current era consistently offers excellent early and 1-year survival for well-selected recipients receiving standard donors. Early mortality tends to reflect graft failure while hospital mortality may be more indicative of recipient selection.     

Electron microscopic studies of endocrine hyperplasia in duodenal adenomas in familial adenomatous polyposis

Summary Electron microscopical studies on endocrine cell hyperplasia of duodenal adenomas from five patients with familial adenomatous polyposis were performed. All the endocrine cell types normally found in the duodenal mucosa were identified. A constant feature was proliferation of duodenal-enterochromaffin cells but an increase in the number of all other endocrine cell types apart from pyloricgastrin cells and somatostatin cells, was also observed. Certain types of intestinal endocrine cells (the intestinal enterochromaffin cell and the glicentin cell) are rare cells in the normal duodenal mucosa. The finding of these cells may indicate increased biological aggressivity.     

Suggestions for the assessment of the allergenic potential of genetically modified organisms

The prevalence of allergic diseases has been increasing continuously and, accordingly, there is a great desire to evaluate the allergenic potential of components in our daily environment (e.g., food). Although there is almost no scientific evidence that genetically modified organisms (GMOs) exhibit increased allergenicity compared with the corresponding wild type significant concerns have been raised regarding this matter. In principle, it is possible that the allergenic potential of GMOs may be increased due to the introduction of potential foreign allergens, to potentially upregulated expression of allergenic components caused by the modification of the wild type organism or to different means of exposure. According to the current practice, the proteins to be introduced into a GMO are evaluated for their physiochemical properties, sequence homology with known allergens and occasionally regarding their allergenic activity. We discuss why these current rules and procedures cannot predict or exclude the allergenicity of a given GMO with certainty. As an alternative we suggest to improve the current evaluation by an experimental comparison of the wild-type organism with the whole GMO regarding their potential to elicit reactions in allergic individuals and to induce de novo sensitizations. We also recommend that the suggested assessment procedures be equally applied to GMOs as well as to natural cultivars in order to establish effective measures for allergy prevention.