Nagoya Journal of Medical Science

A pathogenic yeast Candida albicans is one of the most frequently isolated microorganisms in patients suffering from opportunistic infection. The typing of the isolates is important not only to elucidate the route of infection but to explore the evolution of the pathogenic yeast. This article presents an overview of recent research on the strain typing in different populations of C. albicans using the following DNA-based methods: electrophoretic karyotyping by pulsed field gel electrophoresis (PFGE), restriction fragment length polymorphism (RFLP) of digests of genomic DNA by restriction enzymes (with or without Southern hybridization with a DNA probe) and amplification of random or specific sequences by using polymerase chain reaction (PCR). The results of these methods were compared for strain discrimination. Studies on the genetic diversity of the strains among different individuals in a single population cohort, and among different populations of healthy carriers and immunocompetent and immunocompromised patients, were reviewed. Typing of the strains recurrently isolated through the episodes of diseases such as vaginitis and AIDS revealed the occurrence of strain variation or microevolution. Typing of isolates from nosocomial infections indicated the possible occurrence of horizontal transmission of the disease within a single hospital. In addition, recent studies suggested a possible mechanism that might involve the C. albicans-specific repetitive sequences, RPSs, for chromosome rearrangements leading to strain variation.

Our experience in the field of surgery for renal hyperparathyroidism, gained from 640 cases, the largest number in the world, was reviewed. Additional comments were made on the relation between renal transplantation and renal hyperparathyroidism.

The ret proto-oncogene encodes a receptor tyrosine kinase with a cadherin-like motif in the extracellular domain. Recently, it turned out that ret is the causative gene for the development of multiple endocrine neoplasia (MEN) type 2A and type 2B and Hirschsprung's disease. MEN 2A and MEN 2B mutations represent activating changes of ret whereas Hirschsprung mutations inactivate ret. In addition, another activating change of ret was found in papillary thyroid carcinoma, particularly in those cancers which developed in children from areas contaminated by the Chernobyl accident. This review summarizes the role of ret in the development of human disease.

Testicular sperm was retrieved from a man with complete epididymal obstruction, and intracytoplasmic sperm injection was performed on his wife's oocytes. In four mature treated, two fertilized eggs were obtained, and a clinical pregnancy was established with embryo transfers. One healthy girl (2715 g) was delivered by cesarean section at 38 weeks' gestation. Our case shows that the use of testicular sperm can result in a normal live birth.

The results of 30 consecutive microscopic vasovasostomy procedures performed at a single institution over a five-year period between 1991 and 1995 were reviewed. When the surgical outcomes of patients who were operated on less than five years after their vasectomy were compared with the outcomes of those patients who received a vasovasostomy more than five years after their vasectomy, decreases in technical success rates were observed as measured by appearance of sperm in ejaculate (56% vs. 36%), biologic recovery as measured by mean sperm counts (56 million vs. 35 million) and mean progressive sperm motility (44% vs. 21%), along with a decrease in clinical success, as measured by overall pregnancy rates (50% vs. 7%, p < 0.05). Therefore, a microscopic vasovasostomy within 5 years of a vasectomy is a favorable procedure for vasectomy reversal.

Hematomas and specimens were studied from 13 surgically-operated chronic subdural hematoma cases. Evacuated hematomas contained elevated potassium ions and slightly increased levels of Acetylcholinesterase (AChE), and the dural specimens including hematoma capsules stained positive for AChE using histochemical methods, especially in the inner membrane of the dura where the Masson Trichrome staining revealed damaged and irregular collagen fibers. This article suggests that the initial dural damage caused by trauma results in minor bleeding, which in turn causes a raised potassium ion concentration in the hemolytic fluid, which may also cause depolarization and elevated AChE in the dura.

A 27-year-old woman evacuated a hydatidiform mole at 11 weeks of gestation. Her serum human chorionic gonadotropin (hCG) levels declined progressively but reached a plateau of 2-3 mIU/ml thereafter. The patient was treated with two courses of methotrexate, which did not affect her hCG levels. She refused further chemotherapy and, for more than one year, she was managed expectantly until a significant rise in her hCG titer. Fortunately, an unexpected pregnancy and subsequent missed abortion led to a spontaneous regression of her hCG levels.