Investigation of the dynamics of the spread of human immunodeficiency virus to brain and other tissues by evolutionary analysis of sequences from the p17gag and env genes.

The time of spread of human immunodeficiency virus type 1 (HIV-1) from lymphoid to nonlymphoid tissues in the course of infection was investigated by sequence comparisons of variants infecting a range of lymphoid and nonlymphoid tissues from three individuals with AIDS in the pl7gag gene and regions flanking the V1/V2 hypervariable regions. Phylogenetic analysis in both regions revealed several lineages in each individual that contained sequences from both lymphoid and nonlymphoid tissues such as the brain. This observation contrasts strongly with the previously described organ-specific sequences in the V3 region in this study population and other investigations. Although individual pairwise comparisons of relatively short sequences such as p17gag are subject to considerable stochastic error, we found that the diversity of gag sequences in variants from lymphoid tissue was consistently lower than that found among variants amplified from the brain. By estimating mean synonymous pairwise distances in the p17gag region, we were able to make an approximate calculation of the ages of populations in different tissues. Those from lymphoid tissue ranged from 2.65 to 5.6 years in the three study subjects, compared with 4.1 to 6.2 years for variants in the brain. Indeed, variants infecting the brain were no more closely related to each other than they were to variants infecting other tissues in the body. In two of the three individuals, these times of divergence indicate that infection of the brain may have occurred as an early event in the progression to disease, preceding the onset of AIDS by several years. This study is the first in which it was possible to estimate times of diversification in different tissues in vivo and is of importance in understanding the dynamics of the spread of HIV-1 into nonlymphoid tissues and its possible adaptation for replication in different cell types.     

Endogenous prostaglandin secretion during cloprostenol-induced abortion in mares

Repeated administration of prostaglandin is the treatment of choice for the termination of pregnancy in mares more than 40 days pregnant. Even though it is well documented that PGF-2 or analogue needs to be administered every 12–24 h for successful induction of abortion, little is known about the underlying endocrine changes and the mechanism by which abortion occurs. The aim of this study was to characterize the changes in PGF-2, progesterone and estrogen secretion during prostaglandin-induced abortion. Six mares, 82–102 days pregnant, were treated daily with 250 μg cloprostenol, blood was collected at 1-h intervals until fetal expulsion and pregnancy examination was performed daily. Four mares, 92–97 days pregnant, received no treatment but were subjected to the same hourly blood collections and daily genital examinations described for cloprostenol-treated mares for 3 days. Mean time from first cloprostenol administration until fetal expulsion was 48.6 ± 5.6 h and required 2.8 ± 0.2 cloprostenol administrations. In all mares, progesterone concentrations decreased in a near linear manner after the first cloprostenol administration and were invariably low (1.3 ± 0.2 ng ml⁻¹, mean ± SEM) at the time of fetal expulsion. Mean estrogen secretion remained unchanged until 5 h before fetal expulsion and then decreased rapidly to non-pregnant levels. Endogenous PGF-2 secretion rate increased with each cloprostenol administration and culminated in sustained PGF-2 secretion which persisted until fetal expulsion was completed. From these results we conclude that cloprostenol-induced abortion is associated with endogenous PGF-2 secretion, fetal expulsion coincides with sustained PGF-2 secretion and low progesterone concentrations and plasma estrogen concentrations remain unchanged until hours before fetal expulsion.     

Activation of a muscle-specific enhancer by the Ski proto-oncogene.

In transgenic mice, muscle-specific expression of the c-ski oncogene induces hypertrophy exclusively in a subset of fast muscle fibers. Here we report that regulatory elements from two genes expressed in fast fibers, myosin light chain 1/3 (MLC) and muscle creatine kinase (MCK), were activated when co-transfected with c-ski expression vectors in myoblasts. The expression from the MLC enhancer was reduced when the c-ski oncogene was cotransfected with MyoD into NIH3T3 fibroblasts. Activation of the MLC enhancer by Ski also occurred in vivo, since bigenic progeny generated by mating MLC-CAT and MSV-skitransgenic mice displayed higher CAT activity in their muscles than did the MLC-CAT parental line. Identification of gene targets for the fiber-specific action of the c-ski gene product provides a molecular model that could be used for the further dissection of Ski-induced hypertrophy, both in tissue culture and in vivo.     

In vitro acclimatization of date palm (Phoenix dactylifera L.) plantlets: A quantitative comparison of epicuticular leaf wax as a function of polyethylene glycol treatment

Wax deposits on leaf surfaces ofin vitro-grown plantlets,in vitro plantlets treated with polyethylene glycol and greenhouse-grown seedlings from five cultivars of date palm (Phoenix dactylifera L.) were extracted and quantified. Significant variations among treatments and cultivars were obtained. Greenhouse-grown plants had the greatest wax deposits followed by the acclimatized plantlets.In vitro plantlets had an average of 15% of the wax of greenhouse plants. Cultivar and plant age differences had a significant effect on the quantity of wax deposits. Greenhouse seedlings of Majhool, Deglet Noor and Khadraoui (cultivars grown under irrigation) had less wax accumulation than Zahidi and Sayer, dryland cultivars.The increase in wax deposition as a result of polyethylene glycol treatment, explains in part, the decreased water loss observed in acclimatized plantlets when transferredex vitro. Abbreviations EW epicuticular wax - NAA naphthalene acetic acid - PEG polyethylene glycol     

Galactosyl transferases of baby hamster kidney (BHK) cells. Characterization of two oligosaccharide products synthesised using bovine asialo submaxillary-gland mucin as acceptor

Extracts of BHK (baby hamster kidney) cells catalyse incorporation of galactose from UDP-galactose into asialo bovine submaxillary gland mucin. The galactosylated oligosaccharide products were released by alkaline-borohydride treatment and purified by Bio-Gel P2 chromatography and high-performance liquid chromatography. The structures of the oligosaccharide sequences synthesised have been identified unequivocally by high resolution 500 MHz 1H-NMR as galactosyl-(beta 1----3) N-acetylgalactosamine and galactosyl (beta 1----4) N-acetylglucosaminyl (beta 1----3)-N-acetylgalactosamine. Characterization of the latter sequence shows the presence in bovine mucin of the type III core sequence N-acetylglucosamine-(beta 1----3) N-acetylgalactosamine. Fractionation of BHK cell extracts on alpha-lactalbumin-Agarose has shown that the (beta 1----4)-galactosyl transferase responsible for synthesis of the trisaccharide binds to alpha-lactalbumin, a modulator of the (beta 1----4)-galactosyl transferase involved in N-glycan assembly. The evidence that the same transferase activity may be responsible for galactose transfer to both O-glycans and N-glycans is discussed.     

Mammary skin oedema: a new prognostic indicator for breast cancer.

Mammary skin thickening shown on the mammogram was measured in 220 patients with non-inflammatory breast cancer, and the mean skin oedema was derived by taking the mean of five measurements from separate sites on the breast (upper part, lower part, medial part, lateral part, and areola) after subtracting the corresponding figures from the opposite (normal) breast. The prevalence of appreciable oedema (greater than 0.25 mm) was 70% for tumours less than 1 cm and 100% for tumours more than 3 cm in diameter. This measure of oedema correlated positively and significantly with tumour size and lymph node status. In a minimum of 60 months'' follow up patients developing recurrence had significantly higher oedema values. The amount of oedema also predicted recurrence better than lymph node status, tumour size, or tumour stage. Oedema and tumour size, information available preoperatively, provide a simple means of assessing prognosis before definitive treatment.     

Hormone rhythms and breast cancer chronoepidemiology: salivary progesterone concentrations in pre- and post-menarchal girls and in normal premenopausal women

Orcadian and circatrigintan time series of salivary progesterone levels in premenarchal and adolescent girls and healthy mature premenopausal women have been investigated as a possible determinant for breast cancer risk. Circadian variations in progesterone appear to be more random than systematic and estimates of total daily progesterone output are better represented by samples pooled from several 2-hr specimens. Different patterns of circatrigintan progesterone secretion in girls are recognised and relate to those experienced in infertile and fertile women, though their relation to chronological or menarchal age is as yet uncertain. These data suggest that the measurement of salivary progesterone at premenarche, adolescence and maturity is a feasible, though statistically difficult, study for prospective identification of individuals at risk for breast cancer.     

A simple liquid medium for chlamydospore formation in Candida albicans

A new, relatively simple and inexpensive liquid medium was devised to produce all structural forms ofC. albicans. Optimum conditions to induce the yeast cells, germ tubes, pseudohyphae and chlamydospores along with the methods to obtain them are described.Supported in part by Grant CA 20917, National Cancer Institute, National Institutes of Health and ALSAC.     

Scanning electron microscopy of the respiratory surfaces of Saccobranchus (=Heteropneustes) fossilis (Bloch)

Summary The gill secondary lamellae are generally covered with epithelial cells whose outer surfaces form numerous microvilli. The surface of the primary lamellae is characterised by microridges. A particular type of surface sculpturing seems to be associated with given cell boundaries.Further evidence for the derivation of the air tube and fans which guard its entrance by modification of the basic gill structure has been obtained from both the gross surface architecture and microstructure of the individual cell surfaces. Secondary lamellae are represented by stubby projections which generally have a biserial arrangement. The outer surfaces of the epithelia overlying the capillaries of these respiratory islets are coated with microvilli as in the secondary lamellae. On the other hand, the relatively smooth-surfaced lanes between groups of respiratory islets have a microridged surface similar to that of the primary gill lamellae.It is suggested that previous estimates of surface area, and consequently diffusing capacities of the air-breathing organ, have been low in view of the increased surface, due to both their gross and microstructure. Estimates for gill surface area may need very little correction as the spaces between the microvilli and microridges are probably filled with mucus under normal conditions.We thank Mr. John Clements for his excellent technical assistance and the Department of Botany, Bristol University for the use of their scanning electron microscope     

Mastalgia: psychoneurosis or organic disease?

To test the traditional surgical view that pain in the breast is largely an expression of psychoneurosis, the Middelesex Hospital Questionnaire was given to 317 women with mastalgia and 170 controls with varicose veins. Their scores were compared with those of 173 women psychiatric outpatients tested by the designers of the questionnaire. The results were broadly similar in the mastalgia and varicose veins groups, and where there were significant differences women with varicose veins had a higher psychoneurotic score in each case. Within the mastalgia group no difference in scores was observed between patients with cyclical mastalgia and those with mastalgia due to periductal mastitis. Both groups of surgical outpatients had significantly lower scores in major traits than the psychiatric group, except for a small group of patients with breast pain who persistently failed to respond to treatment. Patients with mastalgia are therefore no more "neurotic" than those with varicose veins, and differ greatly from patients with recognized psychoneurosis. Most patients have a physiological or pathological basis for their breast pain, and they deserve an appropriate diagnostic and therapeutic approach.