A 6-year experience with immediate reconstruction after mastectomy for cancer

A 6-year retrospective review is presented of 185 patients who underwent immediate reconstruction of the breast at the same operation as mastectomy for carcinoma. The patients were treated at two institutions under similar protocols of patient selection, surgical technique, and postoperative care. A detailed evaluation is presented from both the oncologic and surgical points of view. The data support the conclusion that immediate reconstruction of the breast does not alter survival or cancer recurrence rates and does not interfere with the treatment of primary or secondary disease. A low incidence of significant surgical complications is also detailed. Combined with previous reports answering psychological concerns about this mode and timing of reconstruction, this review offers significant reassurance about the overall safety of immediate reconstruction. The authors therefore recommend immediate reconstruction of the breast as a safe treatment option for the woman facing mastectomy.     

The separation of enantiomeric sugars by chromatographic methods

This paper has reviewed the number of chromatographic methods by which one may determine the absolute configuration of sugars. Both indirect methods (converting the enantiomeric pair into diastereomers) and direct methods (using chiral stationary phases) have been discussed. Resolving reagents for the indirect methods include chiral hydroxy compounds, chiral amines, and chiral thiols; with subsequent separation of the diastereomers either by gas-liquid chromatography or by high pressure liquid chromatography. Direct methods discussed have exclusively utilized chiral substitution of organopolysiloxane phases for the separation of enantiomeric sugars as volatile derivatives by gas-liquid chromatography.     

Larval development and metamorphosis in the marine pulmonate Amphibola crenata (Mollusca: Pulmonata)

The development of the free-swimming veliger of Amphibola is followed from hatching to settlement, and the larval structures compared with those of post-metamorphic juveniles and adult snails. Observations of living specimens and light-microscope sections were combined with scanning electron microscopy to build up a composite picture of veliger structure.
Four stages in the development of veligers are recognized, each being characterized by the appearance of organ systems such as the mantle cavity, larval heart, adult heart and kidney, and larval pallial gland. At or after metamorphosis, the larval systems (heart, kidney and pallial gland) disappear, and the developing adult organs move to the positions characteristic of adult snails.
Organogenesis in Amphibola veligers is compared with that of prosobranch and opisthobranch larvae, and with that of pulmonate larvae with direct development. The closest similarity is seen to be with opisthobranch veligers.     

Has treatment for childhood gastroenteritis changed?

Because so many children with gastroenteritis in our area were being treated with drugs, which are potentially harmful, we assessed the extent of treatment before admission to hospital of 288 children. Sixty four had been treated: 45 with antibiotic, antidiarrhoeal, or antiemetic drugs and 34 had been given glucose-electrolyte solution, 15 of those had also been given drugs; 119 had had no treatment. Since 1979 there has been a decrease in the use of drugs for gastroenteritis, but glucose-electrolyte mixtures are still underused.     

P. mirabilis RecA protein catalyses cleavage of E. coli LexA protein and the lambda repressor in vitro

Summary The cloned recA ⁺ gene of Proteus mirabilis substitutes for a defective RecA protein in Escherichia coli recA ^– mutants, and restores recombination, repair and phage induction functions to near normal levels. In a previous report, we described the purification and charactrisation of the recombination activities of the P. mirabilis RecA protein (West et al. 1983b). In this paper, we show that the purified protein catalyses the cleavage of both the Escherichia coli LexA protein and the bacteriophage lambda repressor in vitro. These results provide a direct biochemical basis for the interspecies complementation observed in vivo and suggest that P. mirabilis has an SOS regulatory network similar to that of E. coli.     

Membrane turnover in crab photoreceptors studied by high-resolution scanning electron microscopy and by a new technique of thick-section transmission electron microscopy

Summary Crab photoreceptors were examined after treatment by the osmium-DMSO-osmium method for high-resolution scanning electron microscopy. This technique of specimen preparation was also adapted for transmission electron microscopy, enabling sections up to 1 urn thick to be viewed in a conventional microscope at 75 kV. With appropriate pretreatment, some cytoskeletal elements can be visualised by both techniques. The methods were then used to investigate some of the daily changes known to occur in photoreceptor cell structure. Striking differences were found in the structure of Golgi bodies present in retinula cells during the synthesis and breakdown phases of the daily cycle of photoreceptor membrane turnover. Cyclic changes were also noticed in the mitochondria of retinula cells, and additional evidence was found for a previously proposed model of rhabdomeral microvillus formation.     

Food acquisition by competing surfperch on a patchy environmental gradient

Synopsis Black surfperch, Embiotoca jacksoni, and striped surfperch, Embiotoca lateralis, coexisted along steep sloping rocky habitats at Santa Cruz Island, California. The range of depths occupied (to 15 m) was characterized by a strong gradient in abundance of prey and a changing mosaic of substrate types from which surfperch harvested food. Availability of prey and diversity of benthic substrates were greatest in shallowest areas and both declined with increasing depth. Individuals of both surfperch species were residential within a narrow range of depths, with the result that different segments of their populations were consistently exposed to different foraging environments. These two phenomena (residential behavior combined with a gradient in availability of resources) resulted in variation in foraging behaviors and diets among individuals that resided at different depths. The pattern of within-population variation differed between the surfperch species. Black surfperch individuals achieved similar taxonomic diets and expended similar foraging effort at all depths, but deep-water foragers captured much less prey biomass per unit effort. The taxonomic composition of striped surfperch diets differed among depths, and although similar amounts of prey biomass were captured everywhere, individuals in deep areas expended much greater effort to obtain that level of food return. For both species, habitat profitability (food return to foraging effort) declined with depth. The difference in habitat profitability appeared to influence fitness components of both surfperches. Individuals occupying deep habitats were about 5% shorter in standard length than conspecifics of the same chronological age living in shallow areas; the disparity in body size resulted in an estimated difference in clutch size of 10–18%.     

Toxicity and mutual interactions of cadmium and zinc ions in normal and carcinogen-transformed mouse cells

The toxicity of chloride salts of physiological (zinc, manganese, nickel) and non physiological (cadmium) bivalent metal ions was studied in normal or carcinogen-transformed mouse embryo fibroblast cells. The dose response curves for toxicity to both types of cells exhibited similar shapes. The transformed cells, however, were about twice as sensitive to zinc toxicity as normal cells. When normal and transformed cells were grown together and incubated for several hours with an appropriate concentration of zinc, the malignant cells were selectively killed. Cadmium was much more toxic than the three other metal ions in both types of cells. Its toxic effect was reversed by simultaneous addition of zinc at nontoxic concentrations.Abbrevications CFA colony forming ability - MCA 3-methylcholanthrene     

Inhibition of exogenous NADH oxidation in plant mitochondria by chlorotetracycline in the presence of calcium ions

Chlorotetracycline inhibits the uncoupled oxidation of exogenous NADH by Jerusalem artichoke (Helianthus tuberosus L.) mitochondria extensively (over 80%) and rapidly (inhibition complete in 10 s) in the presence of added Ca²⁺. Half-maximal inhibition is observed at 15 μM chlorotetracycline in the presence of 2 mM Ca²⁺. The oxidation of succinate is only affected marginally by chlorotetracycline plus Ca²⁺. The inhibition of NADH oxidation and the fluorescence of CTC are well correlated. Mn²⁺ is the only other cation which shows an (increased) inhibition in the presence of chlorotetracycline. The inhibition by Ca²⁺ and chlorotetracycline disappears at acid pH, and the pH optimum in their presence is 6.4. The inhibition caused by other lipid-soluble Ca²⁺-chelators is not reversible or is enhanced by the addition of excess Ca²⁺. In contrast, inhibition caused by relatively water-soluble chelators is completely reversed by added Ca²⁺. It is suggested that a neutral 1:2 complex is formed between Ca²⁺ and chlorotetracycline which can substitute for Ca²⁺ bound at sites in the lipophilic phase of the inner mitochondrial membrane, which are essential for the activity of the external NADH dehydrogenase.