Photochemical transformation of the DDT and methoxychlor degradation products, DDE and DMDE, by sunlight

DDE and DMDE, degradation products of the pesticides DDT and methoxychlor, rapidly undergo an unusual photoisomerization in solution when exposed to sunlight. The isomerization involves the exchange of a vinyl chlorine and an ortho aromatic hydrogen. Other photoproducts identified were corresponding benzophenones and 1,1-diaryl-2-chloroethylenes. Quantum yields for the reactions were measured and then used to compute sunlight photolysis half-lives for DMDE and DDE. Although both compounds absorb only the short-wavelength ultraviolet component of sunlight, their photolysis was found to be surprisingly rapid. During summer at latitude 40 degrees N, the photolysis half-lives near the surface of a water body are one hour and one day for dissolved DMDE and DDE, respectively. Photolysis of the DDE photoisomers is about an order of magnitude slower than that of DDE, suggesting that they may accumulate under environmental conditions. The DDE photoisomers photocyclize to form chlorinated dibenzofulvene and dichlorofluorenone. Neither DDE nor its photoisomers photoreact in solution to form PCB's. The environmental significance of these results is discussed, and its is suggested that the persistence of DDE in inland surface waters may be related to its tendency to sorb onto sediments and biota where not light is present.     

Cerebrospinal fluid inositol monophosphatase: elevated activity in depression and neuroleptic-treated schizophrenia

In this study we assessed whether widely accepted risk factors for atherosclerotic vascular diseases such as lipoprotein(a) [Lp(a)], a cholesterol-rich lipoprotein under strict genetical control, and other lipid parameters change with age. The variations of blood levels and the pathophysiological role of Lp(a) in old people, and particularly in the oldest old, are unknown. Accordingly, we measured Lp(a) levels as well as total, LDL, and HDL cholesterol (CT), and triglycerides (TG) in sera from 75 healthy centenarians, 114 randomly selected subjects under 65 years, 73 randomly selected elderly people, and 30 healthy selected elderly people. The results showed that Lp(a) serum levels did not vary by age group, including centenarians. Remarkably, one-quarter of the centenarians had high Lp(a) serum levels even though they never suffered from atherosclerosis-related diseases. At variance with young and aged people, centenarians with high Lp(a) serum levels also had high plasma concentrations of the proinflammatory cytokine IL-6, suggesting that genetic control of the Lp(a) serum level may attenuate with age and that environmental factors such as chronic subclinical inflammatory processes may play a role. We also showed that most centenarians are paradoxically characterized by low HDL-CT and relatively high TG levels, which together are considered to be strong risk factors for coronary heart disease. On the whole, these data support the hypothesis that a continuous and complex reshaping of lipid metabolism occurs in physiological aging, likely contributing to successful aging.     

Pulmonary sequestration: six unusual presentations

In a review of 26 cases of sequestration, six patients with unusual radiographic features are described in detail. Three children had congestive heart failure, and congenital heart disease was suspected. One patient with a cystic upper lobe sequestration was thought to have a pneumatocele or infected cyst. In two other cases the sequestrations had features of a solid mass lesion. One of these was erroneously diagnosed as a mesothelioma or bronchogenic cyst, and the other as a carcinoma.     

Internet integrated in the daily medical practice within an electronic patient record

Healthcare enters the information age and professionals are finding an ever-growing role for computers in the daily practice of medicine. However, a number of problematic issues are associated with electronic publications, especially through Internet. Whilst access to any information has been improved, access to specific information has become more and more difficult [1], due to the lack of a general meta-knowledge allowing to structure Internet resources. Physicians have to learn and adapt themselves to computers and Internet, but Internet has to meet the specific requirements of Healthcare. Important issues must therefore be addressed to allow a real and daily use of Internet in the medical practice. The paper discusses most of these issues and proposes a solution developed at the University Hospital of Geneva that integrates an Electronic Patient Record with Internet, without compromises on security or on performances and that runs on standard PCs'.     

Measurement of macrophage-mediated cytotoxicity against adherent and non-adherent target cells by release of 11 indium-oxine

This report describes the utilization of 111 indium-oxine chelate ([111In]Ox) for studies of macrophage-mediated cytotoxicity. [111In]Ox efficiently labeled both non-adherent and adherent tumor targets with no decrease in cell viability. Spontaneous release of intracellularly incorporated [111In]Ox was very slow (0.25-0.50%/h) from most targets, making isotope-release assays of at least 48 h feasible. In addition, released [111In]Ox was not reutilized. In contrast to its low spontaneous release from intact cells, incorporated [111In]Ox was rapidly released from tumor targets after interaction with activated macrophages. Levels of [111In]Ox released in response to cytolytic macrophages correlated well with those observed for the 51Cr and [3H]TdR radiolabels. Therefore, [111In]Ox can be utilized for relatively short-term (less than 20h) assays with lymphoma targets, as well as for longer-term assays with adherent cells. This should facilitate the testing, with the same radioisotope-release assay, of a wide range of tumor targets for susceptibility to macrophage-mediated cytotoxicity.     

Morphology and position of growth cones in the developing Xenopus spinal cord

Axonal growth cones in longitudinal fiber tracts of the developing spinal cord of Xenopus were examined using electron microscopy. Fiber tracts of the spinal cord develop by the ingrowth of fibers, into pre-existing longitudinally oriented spaces between adjacent neuroepithelial cells of the neural tube. Growth cones seen among the neurites of the tracts were identified by their generally larger size (1.2 X 4.5 micrometer), bulbous and irregular outlines, and cytoplasmic components. Overall cytoplasmic density was usually less than that of surrounding neuroepithelial cells and axons. They contained few organelles, among them assorted clear and densecored vesicles, agranular reticulum, and occasional mitochondria and autographic vacuoles. Microtubules were rarely present. Growth cones appeared to conform in outline to the space which they occupied. Smaller extensions which resembled the filopodia described by others insinuated themselves among other elements of the fiber fascicles. The filopodia contained a fine granular or filamentous feltwork. Growth cones consistently appeared at the interface of other axons in the fascicle and the peripheral neuroepithelial endfeet. In longitudinal sections of fascicles containing more than one growth cone, the growth cones were layered in a pattern suggesting that new cones are added by pushing between the next youngest fibers and the peripheral neuroepithelial processes of the cord. The possible significance of this finding in the achievement of order in the spinal tracts is discussed.     

Evaluation of cefaclor in acute otitis media caused by ampicillin-resistant H. influenzae

Cefaclor was used to treat 13 children with acute otitis media caused by ampicillin-resistant strains of Hemophilus influenzae. The children were re-examined on days 4, 10, and 28. Pharmacologic compliance was assessed by means of a bioinhibition assay on a urine specimen obtained on days 4, 7, and 10. Nine of the 13 children had evidence by tympanogram of residual otitis media with effusion (secretory otitis media). Of these, three were noted to have a bulging, yellow or grey eardrum, which suggested an ongoing acute process. A second middle ear culture was obtained from two of the 3 children, but no pathogens were recovered. Two others had recurrence of otitis shortly after cessation of therapy. Cefaclor is an acceptable antibiotic for the treatment of ampicillin-resistant acute otitis media; but, after cefaclor therapy, some children continued to have a bulging eardrum and sterile pus in the middle ear or had recurrences of otitis soon after cessation of therapy.     

Carcinoma of the larynx in an 11-year-old boy with late cervical metastasis: report of a case with a ten-year follow-up

An 11-year-old boy with laryngeal carcinoma underwent a partial laryngectomy. Subsequently, a cervical metastatic node developed eight months following a tonsillectomy; a radical neck dissection was performed. The patient has remained free of disease over a ten-year follow-up period. In our review of the English literature, no similar case report was found. The potential relationship of tonsillectomy to alterations in local T cell-mediated immune response is discussed.