Intraepithelial Carcinoma of the Cervix Uteri in Women Aged under 35 Years

The number of cases of intraepithelial carcinoma of the cervix among women of different age groups has been related to the number of cervical smears from women of the same age groups. Among women aged 25 to 34 years the incidence of intraepithelial carcinoma was 0·67% and among those aged 35 to 44 years it was 0·75%. The overall rate of intraepithelial carcinoma in women under 35 years was 0·55% compared with an overall rate of 0·59% in women over 35 years.If screening of women for cervical cancer is to play any part in preventive medicine it is suggested that the national campaign for the early detection of cervical cancer should be expanded to encourage practitioners to take cervical smears from younger women, particularly from those under 35 years.     

The occurrence and localisation of heavy metals and glycogen in the earthwormsLumbricus rubellus andDendrobaena rubida from a heavy metal site

Summary The lead content of whole earthworms, highest in contaminated site specimens, was significantly higher inDendrobaena rubida thanLubricus rubellus and a species difference in zinc was also recorded. Selective feeding and differential absorption are discounted and a species difference in maximum tolerance to body lead is suggested. Copper was low in all specimens. Chloragocytes and intestinal tissue showed significantly higher lead levels in contaminated earthworms than in control material. Ultrastructurally, chlorgocytes from contaminated earthworms showed electron dense flecks associated with the chroragosome peripheries and within the debis vesicles. Very fine flecks occurred in the nuclei, but mitochondria and Golgi were indistinguishable from control material. Preliminary X-ray microanalysis of contaminated chloragocytes revealed lead and phosphorus. The deposits within the chloragocytes might represent unbound lead precipitated by phosphate buffer; flecks being absent from contaminated, citrate buffered material and from control material. The chloragosomes are proposed as possible sites for sequestered lead.Chloragocyte and intestinal glycogen levels were significantly higher in control material where the chloragocyte cytoplasm was rich in -glycogen rosettes, these being absent from lead contaminated cells. The glycogen-lead correlation suggests that the metabolism of contaminated chloragocytes is directed towards lead sequestration, though differing nutritional states cannot be ignored.The assistance of Mr. P.M. Webster, University of Keele, is gratefully acknowledged.     

The structure of the salt gland of Aegiceras corniculatum

Summary The salt glands of Aegiceras corniculatum have been examined by light- and electron-microscope techniques. A gland consists of a large number of abutting secretory cells and a single, large basal cell. The secretory cells and basal cell are joined by well defined plasmodesmata. The glandular cuticle shows differences between the top and sides of the gland, which may indicate a variation in the nature or quality of wax deposited. These variations may be significant in the secretion process, in view of the lack of evidence for the presence of pores. In ultrastructure, the secretory cells are generally similar to others that have been described, though there is no evidence of any particular association of vacuoles within these cells.     

Aggregation of hydroxyapatite crystals

A system to study the aggregation of hydroxyapatite crystals was developed. The effect of several factors (Ca²⁺ × P_i product, Ca²⁺ /P_i ratio, pH, and various substances) were tested. Pb²⁺, Zn²⁺, Mg²⁺ and methyleneblue had only small effects; citrate inhibited aggregation. Pyrophosphate was a strong inhibitor and the diphosphonates disodium ethane-1-hydroxy-1,1-diphosphonate and disodium duchloromethylene diphosphonate were even more potent. The monophosphonate pentanemonophosphonate had no effect. Potent inhibition also occurred with glycosaminoglycans: heparin > hyaluronic acid > dermatan sulfate > chondroitin 4-sulfate > chondroitin 6-sulfate. Urine also showed high inhibitory activity. The inhibition of heparin but not that of hyaluronic acid, PP_i or urine was abolished by egg white lysozyme. The effects described might be relevant in the normal mineralization process as well as in the mechanisms leading to pathological calcification, such as urinary stone formation.     

Lipids in plant tissue cultures. VI. Effect of temperature on the lipids of Brassica napus and Tropaeolum majus cultures

The lipid contents of callus cultures of rape (Brassica napus) and nasturtium (Tropaeolum majus) increase in response to decreasing the temperature, though to different degree. Irrespective of the incubation temperature the lipids in cultures of both plants contain as predominant classes steryl glycosides, esterified steryl glycosides, sterols, steryl esters and fatty acids and, as minor constituents, various proportions of triacylglycerols, phospholipids and several unidentified fractions.The ratio of phospholipids to triacylglycerols as well as the ratio of diacylglycerophosphorylethanolamines to dicylglycerophosphorylcholines increase with time both in rape cultures incubated at 30°C and in those kept at 5°C.The lipids in rape and nasturtium cultures grown at 30°C contain smaller proportions of polyunsaturated fatty acids than the lipids in cultures incubated at 5°C. Erucic acid, the major constituent fatty acid of the seed lipids, in both plants, occurs only in trace amounts in the lipids of callus cultures. In contrast, linoleic and linolenic acids, which occur only in traces in the seed lipids of nasturtium, are major constituent fatty acids in the lipids of callus cultures derived from seedlings of this plant.The levels of constituent polyunsaturated fatty acids in the diacylglycerophosphorylethanolamines and the diacylglycerophosphorylcholines increase with time whereas in the triacylglycerols only linolenic acid is slightly increased.     

The localisation of lead in the skin of light- and dark-adapted Xenopus laevis

Summary Toads pretreated for 2 months on either a dark or a light background were then exposed to lead nitrate at 50 ppm lead for 21 days, the illumination regimes being maintained. Metal analysis of dorsal skin showed significantly higher lead levels (p<0.01) in dark-adapted toads. No precipitated lead deposits were observed at the ultrastructural level, necessitating X-ray microanalysis of sections containing melanophores, gland cells and general (non-melanophore) cytoplasm. Analysis showed the lead to be concentrated within the melanosomes of the melanophores, and to be significantly higher (p<0.01) in individual melanosomes of dark-adapted toads than in light-adapted ones. Copper was also found to be concentrated in the melanosomes and was higher (p<0.01) in the melanosomes of the dark-adapted toads.The results are consistent with the known affinity of melanin for heavy metals and the documented increase in melanophore number under prolonged dark background regimes. Since all toads received the same lead exposure, the melanosome results give rise to speculation that higher melanin levels might occur in individual melanosomes of dark-adapted skin.     

REDOX PROPERTIES OF CYTOCHROME OXIDASE AND VASCULAR REACTIVITY OF ASTROCYTOMAS AND NEUROBLASTOMAS IN VIVO

Abstract— Dual wavelength reflection spectrophotometry was used to determine steady state changes in the reduction-oxidation ratio of cytochrome c oxidase ( a,a ₃) and vascular reactivity accompanying progressive growth of cortical and subcutaneous astrocytomas and neuroblastomas in vivo. Blood volume responses indicate that vessels invading the tumors retain regulatory reactivity typical of the body region of implantation and do not acquire those typical of the tissue of origin of the neoplastic cells. In comparison with non neoplastic tissue, early stage tumor growth was associated with highly oxidized ratios of cytochrome a,a ₃. A transition to highly reduced cytochrome a,a ₃ occurred during late stage tumor development. Such differences from normal cerebral tissues reflect alterations in micro-circulation and respiratory chain function accompanying the dynamics of tumor growth, and could provide a basis for selective therapeutic measures.     

The effects of proteases on proteins and glycoproteins of Dictyostelium discoideum plasma membranes

Dictyostelium discoideum cells were incubated with proteases, the plasma membranes subsequently isolated and changes in proteins and glycoproteins examined with dodecylsulfate gel electrophoresis. Low papain concentrations gave rise to a protein band which apparently derived from actin. Since actin was the only protein attacked, the results suggest some part of the actin is exposed on the outer surface of the cell. Higher papain concentrations released a substantial portion of actin from the plasma membrane and partially digested some of the glycoproteins. Since the new actin-derived band was not further digested, the glycoproteins may be required to stabilize the actin polymer rather than anchor those actin molecules which are directly associated with the plasma membrane. Pronase treatment released the two myosin heavy chains from the plasma membrane, in particular the higher molecular weight chain. Actin was not affected. Some glycoproteins were digested. Trypsin attacked many of the plasma membrane proteins, and the myosin heavy chains were completely removed. Actin was only moderately affected. However, the glycoproteins were entirely resistant to trypsin. Apparently the myosin heavy chains are attacked either due to their partial exposure on the cell surface or the exposure of proteins which anchor them in the membrane. These anchoring proteins cannot be glycoproteins or actin. Proteins and glycoproteins were largely digested when isolated plasma membranes were incubated with papain and pronase. The effects of trypsin on whole cells and isolated plasma membranes were similar.     

Digesta retention time in roe deer <Emphasis Type="Italic">Capreolus capreolus</Emphasis>, as measured with cerium-, lanthanum- and chromium-mordanted fibre

Studies on particle retention time in ruminants are commonly conducted utilizing chromium (Cr) and/or a lanthanide bound to feeds. Both types of markers have different chemical properties which potentially bias estimates of digesta retention—their combined use is therefore a topic of ongoing discussion. In order to evaluate the suitability of two lanthanides for studies assessing the passage kinetics of different-sized particles, we measured the mean retention time in roe deer with cerium (Ce) and lanthanum (La) labelled to the same particle length and compared it to Cr-mordanted fibre of the same size. We expected a simultaneous excretion of Ce- and La-labelled fibre, but a delayed excretion of Cr-mordanted fibre compared to the other markers. In this study, the mean retention times of Ce- and La-labelled fibre did not differ significantly, and Cr-mordanted fibre was retained on average 5 h longer than Ce and La. Despite the limitation of the small sample size, Ce and La showed the same excretion pattern and can therefore be recommended as mordants in studies assessing passage kinetics of different particle sizes.     

Combining proteomics and bioinformatics to explore novel tegumental antigens as vaccine candidates against Echinococcus granulosus infection

Echinococcus granulosus is the parasite responsible for cystic echinococcosis (CE), an important worldwide-distributed zoonosis. New effective vaccines against CE could potentially have great economic and health benefits. Here, we describe an innovative vaccine design scheme starting from an antigenic fraction enriched in tegumental antigens from the protoscolex stage (termed PSEx) already known to induce protection against CE. We first used mass spectrometry to characterize the protein composition of PSEx followed by Gene Ontology analysis to study the potential Biological Processes, Molecular Functions, and Cellular Localizations of the identified proteins. Following, antigenicity predictions and determination of conservancy degree against other organisms were determined. Thus, nine novel proteins were identified as potential vaccine candidates. Furthermore, linear B cell epitopes free of posttranslational modifications were predicted in the whole PSEx proteome through colocalization of in silico predicted epitopes within peptide fragments identified by matrix-assisted laser desorption/ionization-TOF/TOF. Resulting peptides were termed “clean linear B cell epitopes,” and through BLASTp scanning against all nonhelminth proteins, those with 100% identity against any other protein were discarded. Then, the secondary structure was predicted for peptides and their corresponding proteins. Peptides with highly similar secondary structure respect to their parental protein were selected, and those potentially toxic and/or allergenic were discarded. Finally, the selected clean linear B cell epitopes were mapped within their corresponding 3D-modeled protein to analyze their possible antibody accessibilities, resulting in 14 putative peptide vaccine candidates. We propose nine novel proteins and 14 peptides to be further tested as vaccine candidates against CE.