Subcellular localization of marker enzymes, lipase and triglyceride in rat heart.

Subcellular fractions containing lipase and triglyceride, prepared from rat hearts homogenized in 0.25 m sucrose, were characterized by the use of marker enzymes. In addition to the usual mitochondrial and microsomal pellets, an additional fraction was sedimented between 8000 g × 10 min and 13 000 g × 10 min. Assays for N-acetyl-β-glucosaminidase, β-glucuronidase and cathepsin D indicated that the relative specific activity (R.S.A.) of these enzymes in this fraction was two to three times higher than any of the other subcellular fractions. Since these hydrolytic enzymes are “marker” enzymes for lysosomes in other tissues, the results indicate that it is possible to separate rat heart homogenate into several fractions, one of which has the characteristics of the light mitochondria or lysosomes. Several other hydrolytic enzymes (acid phosphatase, α-glucosidase and β-galactosidase) yielded R.S.A. values which indicated that there was no enrichment of their activity in the lysosomal fraction. The R.S.A. patterns of 5′-nucleotidase and alkaline phosphatase indicated that the plasma membranes (sarcolemma) were sedimenting with the microsomal fraction. This latter fraction exhibited a high R.S.A. of rotenone-insensitive NADH cytochrome-c reductase. Measurement of lipase activity and triglyceride content of the subcellular fractions indicated a relative enrichment of both of these in the lysosomal fraction. Although the R.S.A. of lipase was high in both the lysosomal and microsomal fractions, addition of serum in the assay reduced the R.S.A. of the lipase in the microsomal fraction without altering the high R.S.A. of the lysosomal pellet. Thus, a fraction has been separated from rat heart homogenates with lysosomal characteristics. Associated with this fraction was also an enrichment of triglyceride content and lipase activity, which may be important for turnover of the former in the heart cell.     

Role of angiogenesis in the pathogenesis of cholesteatoma in adults

The aim of the study was to compare the vessels among cholesteatoma perimatrix, cholesterol granuloma and skin sections and to investigate the localization and expression of CD34 antigen. 14 cholesteatoma specimens were used in this study. Comparative material consisted of skin specimens taken from the retroauricular area during the ear surgical procedure and 4 specimens of cholesterol granuloma collected from children. Monoclonal mouse antibodies against human CD34 were used for immunohistochemistry which was performed using a standard labelled avidin-biotin technique. Automatic imaging analyzing system was used for counting. The skin specimens showed presence of small blood vessels in the subepithelial area and around the glands. The mean number of the vessels in these specimens was 5.44/mm2 and the mean relative proportion of total vessel area/total area of connective tissue: 4.9+/-2.0%. In the specimens of cholesterol granuloma the mean number of vessels was 34.06+/-21.2/mm2 and the mean relative proportion of total vessel area/total area of connective tissue: 22.1+/-3.1%. In cholesteatoma perimatrix, the mean number of microvessels calculated within 1 mm2 of the subepithelial connective tissue was significantly higher (22.79+/-11.2/mm2) and the mean relative proportion of total vessel area/total area of the perimatrix was 12.1+/-2.8%. Angiogenesis appear in the subepithelial connective tissue of cholesteatoma (perimatrix). The process of angiogenesis makes possible and sustains the migration of keratinocytes into the cavity of the middle ear, their increased proliferation and the expansion of cholesteatoma. Therefore, angiogenesis is considered to be one of the destructive features of this disease.     

The epidemiology of asbestos-related diseases

Asbestos has been recognised as a potential health hazard since the 1940s. Of the two major species of asbestos; white asbestos (chrysotile) and blue asbestos (crocidolite), both of which are hazardous. The workers at extraction facilities are at the greatest risk of exposure to asbestos and, therefore, the development of asbestos-related diseases, commonly mesothelioma. However, other individuals at a high risk of exposure include asbestos-cement workers, insulation workers and ship-yard workers. Environmental exposure to asbestos can occur as a result of living in areas either characterised by natural outcrops of asbestos or asbestos-related materials, or those close to asbestos-producing or -using plants. Unfortunately, man-made fibre alternatives to asbestos, such as rock and slag-wool and glass wool, have also been shown to have a detrimental effect on human health. A characteristic of mesothelioma is that there is a long latency period (20-30 years) before the signs and symptoms of the disease become apparent. In addition, diagnosis of the disease can be difficult. The use of biological markers, such as tissue polypeptide antigen, may play a useful role in the early detection of the disease in individuals at risk.     

High activity of K+-dependent plasmalemmal Na+/Ca2+ exchangers in hippocampal CA1 neurons

Ca(2+) influx via reversed K(+)-dependent (NCKX) and/or K(+)-independent (NCX) plasmalemmal Na(+)/Ca(2+) exchangers may play a role in neuronal death following global brain ischemia to which CA1 neurons are particularly vulnerable. Therefore, this work tested whether the rates of Ca(2+) influx via reversed NCKX or NCX in cultured rat CA1 neurons differ from those in forebrain neurons (FNs) or cerebellar granule cells (CGCs). The NCKX-mediated Ca(2+) influx was several times more rapid in CA1 neurons than in FNs or CGCs and was not affected by Na(+)/Ca(2+) exchange inhibitors, KB-R7943 or bepridil. NCKX reversal inhibitors are not yet available. Their development would greatly facilitate further testing the role of NCKX in ischemic death of CA1 neurons.     

The number and histopathologic type of ovarian tumors operated during cesarean section at the Polish Mother's Health Institute between 1990-2000

OBJECTIVES: The differences exist in concerning the estimation of number and histopathological type of ovarian tumors in pregnancy. MATERIAL AND METHODS: From all 41,661 labours which took place in our Institute between 1990-2000 retrospective analysis of medical documentation of 11,050 caesarean sections (CS) as well as histopathological protocols were performed. RESULTS: The prevalence of ovarian tumors removed during CS performed between 28-41 weeks of gestation was 0.19%. The prevalence of malignancy was low (0.005% of all labours). Unilateral cystectomy was found to be the most frequent kind of surgery and adult teratoma, serous cyst and paraovarian cyst as most common histopathological tumor types. CONCLUSION: We conclude that ovarian tumors, especially of malignant type are rarely the complication of pregnancy. The most are benign, small, unilocular and smooth-wall cystic tumors.     

Notes on the state of ophthalmology in the ancient Egypt

The article presents the state of ophthalmological knowledge in the ancient Egypt. Medical and ophthalmological information included in Smith's and Ebers papyruses are discussed. The first ever known ophthalmologist by the name of Iry is mentioned. The article also presents the history of medical school in Alexandria.     

Father Waclaw Szuniewicz--Polish missionary, ophthalmologist, pioneer of refractive surgery of the cornea

The article presents the life and work of Polish missionary of Saint Vincent a Paulo order, an ophthalmologist, Father Wac?aw Szuniewicz. He was born in 1891 in the Vilnius region. He completed his medical studies in Moscow in 1916. He specialised in ophthalmology at Stefan Batory University in Vilnius. In 1927 he entered the missionary order and after being ordained n 1930, he was sent for mission to China. There he developed his involvement in ophthalmology and established the ophthalmic ward in Shuntehfu that became very renowned. After taking over by the communist in China, he went to US in 1948. He continued his experimental work on surgical method on changing corneal curvature at Yale University in New Haven. In 1952 he went to Brasil where he continued his work as a missionary and an ophthalmologist. He was a man of great kindness and knowledge. He had particular language skill. At high school and during his medical and theological studies, he mastered Russian, French, English, Latin and Hebrew. He also learnt Chinese and Portugese. He was able to communicate in Lithuanian and Byelorus. He died in Brazil on 16 october 1963. His scientific accomplishments make him one of the pioneers of refractive surgery of cornea.     

Organochlorines,lead, and mercury in Akwesasne Mohawk youth

Most humans have detectable body burdens of polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and p,p'-dichlorophenyldichloroethylene p,p'-DDE), a metabolite of p,p'-dichlorodiphenyltrichloroethane (DDT). Native American communities may be at increased risk of exposure through subsistence-based diets and greater physical contact with contaminated soil and water. In this article we describe the levels of toxicants (PCBs, p,p'-DDE, HCB, mirex, lead, and mercury) among youth 10-17 years old (n = 271) of the Akwesasne Mohawk Nation. Ultratrace, congener-specific PCB analysis of human serum quantitated 83 PCB congeners (plus 18 as pairs/triplets), in addition to p,p'-DDE, HCB, and mirex, and included all major Aroclor-derived congeners typically present in human samples. Twenty congeners (in 16 chromatographic peaks) were detected in 50% or more of the individuals sampled [geometric mean (GM) of the sum of these congeners = 0.66 ppb]. Thirteen congeners (in 10 peaks) were detected in 75% or more of the samples (GM = 0.51 ppb). Of the 20 congeners detected in 50% or more of the samples, 17 had five or more chlorine substitutions. International Union for Pure and Applied Chemistry congeners 118, 101(+90), and 153 were detected in nearly all participants (GM = 0.06 ppb, 0.05 ppb, 0.09 ppb, respectively). p,p'-DDE and HCB were detected in 100% and 98% of the samples (GM: p,p'-DDE = 0.37 ppb; HCB = 0.03 ppb). Mirex was detected in approximately 46% of the samples (GM = 0.02 ppb). No cases of elevated lead level were observed. One participant had a mercury level marginally higher than the U.S. Environmental Protection Agency's current level of concern (0.50 microg/dL). Although differences in analytic methods and participant ages limit comparability, toxicant levels from the Mohawk youth are lower than those associated with severe food contamination (Yusho and Yu-cheng) but similar to other chronically exposed groups.     

Extracranial stereotactic radiation delivery: expansion of technology beyond the brain

The development of improved immobilization systems, and a greater understanding of the radiobiologic considerations associated with stereotactic radiotherapy has recently led to the clinical implementation of this technology to extracranial sites. The shared principles of targeting and treatment delivery has led to a greater understanding of the potential role this therapy may have in the management of extracranial disease. This article will review, the radiobiologic considerations and the basic principles of physics and dosimetry that help govern the utilization of extracranial stereotactic radiotherapy. In addition, this article will summarize the data that exists in the literature to date, that has documented the rationale, and efficacy of this novel therapeutic approach.