Selection bias: neighbourhood controls and controls selected from those presenting to a Health Unit in a case control study of efficacy of BCG revaccination

Background  

In most case control studies the hardest decision is the choice of the control group, as in the ideal control group the proportion exposed is the same as in the population that produced the cases.     

Laparoscopic hysterectomy in a case of male pseudohermaphroditism with persistent Mullerian duct derivatives

We describe laparoscopic diagnosis and treatment for a case of dysgenetic male pseudohermaphroditism with persistent Mullerian ducts. The patient, a 32 year old man, with a history of surgery for hypospadias and cryptorchidism during childhood, was referred because of anejaculation. He was of short stature, with male external genitalia composed of a small penis and hypoplastic testis (1 ml right, 6 ml left side). Plasma follicle stimulating hormone (FSH) was high (17 mUI/ml), testosterone low (1.9 ng/ml), and his karyotype was 46,XY. Pelvic ultrasound, nuclear magnetic resonance (NMR) and genitography disclosed a uterine-like structure with cavity communicating with the urethra. Laparoscopy and urethrocystoscopy confirmed the presence of a 4 cm uterus, which was removed endoscopically at the same time. A biopsy of the left gonad was also performed. The uterus contained endometrial tissue and was fibrotic. Histology of the left gonad showed spermatocytic arrest. We diagnosed dysgenetic male pseudohermaphroditism. Laparoscopy, in our opinion, is an optimal tool to diagnose and treat abnormal sexual conditions.      

Detection of ventricular thrombosis in acute myocardial infarction: Value of indium-111 platelet scintigraphy in relation to two-dimensional echocardiography and clinical course

In order to detect left ventricular (LV) thrombosis, ¹¹¹In-platelet scintigraphy and two-dimensional echocardiography were performed in 40 patients 15 days±6 days after acute myocardial infarction. A dual isotope subtraction method, using ¹¹¹In-platelet scintigraphy and ^99mTc-blood pool scintigraphy, was used to assess LV platelet deposition expressed as LV counts per pixed. Seven patients (group A) had a positive ¹¹¹In-platelet scintigram and 33 patients (group B) had a negative ¹¹¹In-platelet scintigram (LV counts per pixel: 0.56±0.23 and 0.28±0.19, respectively, P<0.05). Three group A patients but no group B patients had a positive echocardiogram. Arterial embolism was noted in four patients, of whom two showed both positive echocardiogram and platelet scintigram. LV counts per pixel were 0.57±0.13 and 0.31±0.21, respectively (P<0.02) in patients with and without arterial embolism. Thus, both ¹¹¹In-platelet scintigraphy and two-dimensional echocardiography can detect LV thrombosis. ¹¹¹In-platelet scintigraphy may help to define patients at risk for embolization and may be used in conjunction with echocardiography to study the effect of antithrombotic therapy.     

Topical aqueous extract of Ephedra alata can improve wound healing in an animalmodel

Purpose: Ephedra alata (E. alata) is perennial tough shrub plant that grows in Palestine and other regions. It is used often in folk''s medicine for the treatment of various diseases. In this project, E. alata extract was tested for its ability to improve wound and burn healing. Methods: An aqueous extract of E. alata was prepared and underwent several phytochemical analyses for the presence of the major classes of phytochemical compounds. After that, a polyethylene glycol-based ointment containing the extract of E. alata was prepared and its wound and burn healing activities were tested in-vivo using an animal model for deep wound and full thickness skin burn. The effect was compared against a placebo ointment. Skin biopsies were evaluated by a blinded clinical histopathologist, in addition to digital analysis. Results: Phytochemical analysis demonstrated the presence of the major classes of phytochemical compounds in the prepared extract including flavonoids, alkaloids, phytosteroids, phenolic compounds, volatile oils and tannins. As compared to placebo ointment, E. alata ointment significantly improved the healing of the wound ulcers, whereas it showed no advantage on the quality of the healing of burn ulcers. Conclusion: E. alata extract is rich in phytochemical compounds and can improve wound healing when applied topically.