“Costs” of reproduction in reptiles

Summary Many theoretical models of life-history evolution rely on the existence of trade-offs between current fecundity and probable future fecundity and survival. Such costs of reproduction have been demonstrated only rarely. Field and laboratory studies on six species of Australian scincid lizards show that gravid females are more vulnerable to predation than are non-gravid females, primarily because (i) they are physically burdened (running speeds are reduced by 20 to 30%), and (ii) they bask more often (in some species). However, food intake is not reduced in gravid animals. A review of published literature suggests that reproductive trade-offs are widespread among reptiles, but the nature of the reproductive costs may vary widely among related species. Within the range of annual survivorship rates of most lizard species, trade-offs between fecundity and survival are likely to be the main evolutionary determinants of optimal levels of reproductive effort. Trade-offs between fecundity and bodily growth are less likely to be significant.     

Frequency of mutations in “thrombophilic state” genes in Uzbekistan

The frequency of mutations in a number of genetic markers, specifically factor V gene (G1691A), blood coagulation factor II gene (G20210A), and the methylenetetrahydrofolate reductase (MTHFR) gene (C677T), is studied in ethnic Uzbek patients with deep vein thrombosis of the lower extremities and in healthy donors. It is established that the incidence of mutant alleles among patients in Uzbekistan for FV Leiden is 12.9%; for prothrombin, 4%; and for MTHFR, 47.8%. The mutant allele C677T of the MTHFR gene has the highest expressivity in the appearance of MTHFR (47.8%). It is noted that this mutation in the MTHFR gene is encountered significantly more frequently in females with deep vein thrombosis than in males with deep vein thrombosis. The G20210A mutation in the prothrombin gene is encountered more rarely in the Uzbek population. The penetrance is studied and the role of these mutations in the appearance of deep vein thrombosis is estimated.     

“Facilitation” and “Reversal of Response” of Neurones in the Cerebral Cortex

IN the course of experiments in which movements were elicited by direct electrical stimulation of the cerebral cortex, Graham-Brown^1–4 and Sherrington⁵ found that, after each train of stimuli, there were prolonged changes in the excitability of the cortex. They showed that the motor responses of forelimb muscles in primates, even though elicited by identical cortical stimuli, could be extremely variable. Two of the phenomena they described in detail (see also Lilly⁶) were “facilitation” (the increased motor response resulting from a second train of stimuli when it was applied within 20 s after the first train) and “reversal of response” (when repeated, identical stimulation of the same cortical point elicited flexion instead of extension, or vice versa).     

Induction of isoenzymes of alcohol dehydrogenase in “flor” yeast

Summary Two isoenzymes of alcohol dehydrogenase (adh I and adh II) from Saccharomyces cheresiensis have been differentiated by thermal treatment of the crude extracts. The effect of pH on the stability and the K _m for ethanol are different for the two isoenzymes.The proportions in which they are present depend on the carbon source used by the yeast: adh I is the major component in cells grown on glucose, and adh II in those grown on ethanol. Cells grown on glucose plus ethanol show high levels of both isoenzymes, indicating that the synthesis of adh I is subjected to nutritional induction by glucose, and that of adh II by ethanol.The physiological roles of the two isoenzymes are discussed in relation with the nutritional characteristics of S. cheresiensis.     

The occurrence of “wasting disease” of Zostera in Ireland in the 1930's

There is only one publication quoted in connection with “wasting disease” of Zostera marina L. in Ireland. This was examined and it was concluded that in fact, it did not describe “wasting disease”, but merely the normal seasonal changes of Zostera. However, another report which has not been quoted before did give an account of the disease in County Down. Evidence that the disease occurred in County Mayo is presented for the first time.     

The “Normalization” of Intersex Bodies and “Othering” of Intersex Identities in Australia

Once described as hermaphrodites and later as intersex people, individuals born with intersex variations are routinely subject to so-called “normalizing” medical interventions, often in childhood. Opposition to such practices has been met by attempts to discredit critics and reasserted clinical authority over the bodies of women and men with “disorders of sex development.” However, claims of clinical consensus have been selectively constructed and applied and lack evidence. Limited transparency and lack of access to justice have helped to perpetuate forced interventions. At the same time, associated with the diffusion of distinct concepts of sex and gender, intersex has been constructed as a third legal sex classification, accompanied by pious hopes and unwarranted expectations of consequences. The existence of intersex has also been instrumentalized for the benefit of other, intersecting, populations. The creation of gender categories associated with intersex bodies has created profound risks: a paradoxically narrowed and normative gender binary, maintenance of medical authority over the bodies of “disordered” females and males, and claims that transgressions of social roles ascribed to a third gender are deceptive. Claims that medicalization saves intersex people from “othering,” or that legal othering saves intersex people from medicalization, are contradictory and empty rhetoric. In practice, intersex bodies remain “normalized” or eliminated by medicine, while society and the law “others” intersex identities. That is, medicine constructs intersex bodies as either female or male, while law and society construct intersex identities as neither female nor male. Australian attempts at reforms to recognize the rights of intersex people have either failed to adequately comprehend the population affected or lacked implementation. An emerging human rights consensus demands an end to social prejudice, stigma, and forced medical interventions, focusing on the right to bodily integrity and principles of self-determination.     

“Diffusion” of microorganisms in calcium alginate beads

Summary The leakage of Serratia marcescens cells immobilised in Ca-alginate beads was quantified and the experimental values fitted to the pore diffusion model in order to obtain the biomass diffusion coefficient (D _x). This coefficient was then determined, resulting a value of 0.45 10^–7 cm² s^–1 at the beginning of the fermentation process. The variation of this coefficient, together with the porosity of the particles (_i), were also determined all along the process.     

Variation in the fixation image of “Structured granules” in Anabaena

Summary The varied appearance of so-called structured granules in vegetative cells and akinetes of Anabaena sp. is dependent upon the length of primary glutaraldehyde fixation, the type and duration of secondary fixation, and the temperature during both fixations as well as possible changes under electron bombardment. The image produced may be one of an open hole, an area of low to medium electron opacity or that of a dense structured body and may include all intergradations. These structured granules represent the cyanophycin granules of light microscopy. Various cytochemical tests did not establish their chemical composition.     

Continuation of Dabigatran Therapy in “Real-World” Practice in Hong Kong

Background

Dabigatran, an oral direct thrombin inhibitor, possesses several advantages over warfarin that can in principle simplify the management of stroke prevention in atrial fibrillation (AF). Nonetheless it remains unclear whether these advantages can translate to clinical practice and encourage long-term therapy. The objective was to describe long-term dabigatran therapy for stroke prevention in AF and to identify risk factors for discontinuation of therapy.

Methods and Results

We studied 467 consecutive Chinese patients (72±11 years, male: 53.8%) with a mean CHA₂DS₂-VASc score of 3.6 prescribed dabigatran for stroke prevention in AF from March 2010 to September 2013. Over a mean follow-up of 16 months, 101 patients (21.6%) permanently discontinued dabigatran. The mean time-to-discontinuation was 8 months. The most common reason for discontinuation was dyspepsia (30.7%), followed by other adverse events (17.8%) such as minor bleeding (8.9%), major gastrointestinal bleeding (7.9%), and intracranial hemorrhage (1%). Other reasons included dosing frequency (5.9%), fear of side effects (4.0%), lack of laboratory monitoring (1.0%), and cost (1.0%). Multivariable analysis revealed that low baseline estimated glomerular filtration rate (p = 0.02), absence of hypertension (p = 0.01), and prior use of a proton-pump inhibitor (p = 0.02) and H₂-receptor blocker (p = 0.01) were independent predictors of drug discontinuation. In addition, there were altogether 9 ischemic strokes (1.5%/years), 3 intracranial hemorrhages (0.5%/year), and 24 major gastrointestinal bleedings (4.1%/year).

Conclusion

Dabigatran discontinuation is very common amongst Chinese AF patients. This reveals a management gap in the prevention of stroke in AF.     

The Morphometrics of “Masculinity” in Human Faces

In studies of social inference and human mate preference, a wide but inconsistent array of tools for computing facial masculinity has been devised. Several of these approaches implicitly assumed that the individual expression of sexually dimorphic shape features, which we refer to as maleness, resembles facial shape features perceived as masculine. We outline a morphometric strategy for estimating separately the face shape patterns that underlie perceived masculinity and maleness, and for computing individual scores for these shape patterns. We further show how faces with different degrees of masculinity or maleness can be constructed in a geometric morphometric framework. In an application of these methods to a set of human facial photographs, we found that shape features typically perceived as masculine are wide faces with a wide inter-orbital distance, a wide nose, thin lips, and a large and massive lower face. The individual expressions of this combination of shape features—the masculinity shape scores—were the best predictor of rated masculinity among the compared methods (r = 0.5). The shape features perceived as masculine only partly resembled the average face shape difference between males and females (sexual dimorphism). Discriminant functions and Procrustes distances to the female mean shape were poor predictors of perceived masculinity.     

“Intracisternal microtubules” in neurons of dog ganglia

Summary The changes which occur in the ultrastructure of the mesothoracic retractor unguis muscle of the cockroach Periplaneta americana as a result of disuse are described. Breakdown of myofibrils, sarcoplasmic reticulum, and mitochondria are all marked, this degeneration only being apparent 9 weeks after the operation.     

“Glial inhibition” of memory in Alzheimer's disease

<正>Two recent studies on Nature Medicine and Nature Communications reported the unusual roles of astrocytes in the brain,that is,release gamma-aminobutyric acid(GABA)and impair hippocampal memory in Alzheimer’s disease(AD).AD represents one common form of neurodegenerative diseases,and is characterized by progressive dementia.The pathological feature of an AD brain includes the appearance     

Management of “psychosomatic” problems in clinical practice

Skilled interviewing and investigation are essential in the diagnosis and treatment of “psychosomatic” illness, the term “psychosomatic” being used in its more colloquial sense to refer to illness characterized by somatic symptoms and related psychopathologic disorders but without organic disease.Treatment of these patients is difficult. They respond best to a psychologically oriented physician who is able and willing to take final responsibility for both physical and psychological care. The hazards of ignoring the psychosocial dimension in patient management are emphasized. Although the family physician generally is the most appropriate therapist, there may be a role for a “liaison physician”, a specially trained consultant who is thoroughly familiar with both physical and psychological processes and their interaction.     

“Neural” computation of decisions in optimization problems

Highly-interconnected networks of nonlinear analog neurons are shown to be extremely effective in computing. The networks can rapidly provide a collectively-computed solution (a digital output) to a problem on the basis of analog input information. The problems to be solved must be formulated in terms of desired optima, often subject to constraints. The general principles involved in constructing networks to solve specific problems are discussed. Results of computer simulations of a network designed to solve a difficult but well-defined optimization problem-the Traveling-Salesman Problem-are presented and used to illustrate the computational power of the networks. Good solutions to this problem are collectively computed within an elapsed time of only a few neural time constants. The effectiveness of the computation involves both the nonlinear analog response of the neurons and the large connectivity among them. Dedicated networks of biological or microelectronic neurons could provide the computational capabilities described for a wide class of problems having combinatorial complexity. The power and speed naturally displayed by such collective networks may contribute to the effectiveness of biological information processing.     

Sertoli cells of adult rats “in vitro”

Summary A cell line obtained from isolated seminiferous tubules of adult rat testis has been studied in vitro over a period of 35 days.Light and electron microscopic studies performed from hour 2 to the end of culture have shown the presence of a monomorphic cell population. After 5–6 days of culture the cells formed a monolayer. The cytoplasm of the cells contained numerous lipid bodies and produced numerous projections. The nucleus showed several indentations and one or more nucleoli. From the 9th to the 15th day of culture the cells developed a large amount of endoplasmic reticulum, Golgi apparatus and aggregates of electron dense granules. From the 20th to 40th day the cell cultures progressively degenerated.Immunochemical analysis of the culture medium revealed the presence of estradiol-17, which reached its maximum production rate from the 8th day to the 18th day of culture. Corresponding to cell involution estradiol concentration underwent a rapid decrease.On the basis of morphological and biochemical data the cells could be considered Sertoli cells.This work was supported by Grants n. 74.00155.04 and n. 75.01224.04 from the Consiglio Nazionale delle Ricerche (C.N.R.), Rome, Italy, and by Istituto di Ricerca F. Angelini, Rome, ItalyPart of this work was presented at the 10th Italian Congress of Electron Microscopy. Ostuni 1–4 October 1975The excellent technical assistance of Miss Laura Vassallo, Daniela Venturini and Mr. Massimo Rosati and Mario Termine is deeply appreciated     

Recirculation of “B” Lymphocytes in Immunized Rats

THYMUS-derived, T lymphocytes and bursa-equivalent B lymphocytes cooperate in the initiation of the humoral antibody response of mammals to a variety of antigens^1–5. The B cells are antibody-forming-cell precursors (AFCP) and the T cells are helper cells which serve to augment the antibody response produced by the precursor cells⁶. Mitchison and his colleagues^4,5,7 have shown that the interaction between carrier and hapten-primed cells in the adoptive secondary antibody response to hapten-protein conjugates is an example of cooperation between T and B lymphocytes respectively.     

Delayed Appearance of Lactobacilli in the Intestines of Chicks Reared in a “New” Environment

Male chicks (1 day old; Vantress × Arbor Acre) were fed a basal folic acid-deficient diet, a 5% uric acid-containing diet with and without 5 mg/lb (453.5 g) of bacitracin and 20 mg/lb of sodium penicillin G, the basal diet supplemented with only the antibiotics, and the basal diet plus 500 μg/lb of folic acid. The chicks were reared in a room which had not been used previously for housing chickens (“new” environment). Bacteriological analyses of the contents of the small intestine revealed a decrease in numbers of streptococci and “anaerobic” bacteria in the chicks receiving dietary antibiotics. No persistent changes were seen in the numbers of coliform bacteria. Lactobacilli were not detected in any of the groups until 3 weeks after feeding.     

Detection of Concealed “Illegitimate” Nuclei in Tetrad Analysis of the Diploid Progeny of Heterokaryons in Saccharomyces cerevisiae

In this work, the studies on the previously detected phenomenon of concealed heterokaryosis in Saccharomyces cerevisiaewere continued. In genetic and Southern blotting experiments, one of the nuclei in the heterokaryon was shown to be active (capable of division and ensuring the corresponding cell phenotype), whereas the other was not expressed until the heterokaryotic clone was transferred to the medium selective for this concealed nucleus. Moreover, the concealed nucleus was able to assume the active state after fusion with the second parental nucleus. It was analyzed whether the nuclei with new marker combinations occurring in meiosis can behave as exceptional nuclei. Tetrad analysis of hybrids carrying the kar1mutation in their nuclei revealed the relatively high percentage of exceptional tetrads (more than 10%). One spore in these tetrads usually formed diploid cells capable of sporulation. The presented data of genetic and molecular biological studies testify in favor of the assumption that abnormal spores contain two nuclei, which form an illegitimate hybrid after fusion. An extraneous nucleus (termed x) has usually a genotype close to that of one of the spores in this tetrad. Thus, it was assumed that the additional DNA replication round occurs in the absence of cell division during one of meiotic divisions. Results of cytological analysis conducted by the method of specific DNA staining confirmed the existence of exceptional tetrads, one spore of which contains two nuclei.