Race-centrism: a critique and a research agenda

This article reviews some of the most prominent books in the field of race studies in the USA and identifies their shared assumptions: that racial inequality is the primary principle of stratification in the USA; that is has transformed but not lessened since the civil rights era; that it can be explained by the racist inclinations of the white majority, which operates as a collective, strategic actor to preserve its dominance; and finally, that racial domination plays a similarly crucial role around the world. I explore what kind of questions would need to be answered in order to put these assumptions on firmer empirical and theoretical ground and outline a corresponding research agenda. Some empirical evidence is provided to question the assumption that race plays a dominant role around the world and is associated with more political inequality than ethnic divisions.     

Intrachromosomal insertions: a case report and a review

Summary We describe the phenotype of a child having a recombinant chromosome 3 with a duplication 3q13.2 q25 derived from a paternal inv ins(3)(p25.3q25q13.2). A review of 27 reported cases of intrachromosomal insertions has revealed that for a carrier of intrachromosomal insertion the risk of a child with an unbalanced karyotype is 15%. This risk may be higher for particular insertions. The recombinant chromosome can have a duplication or a deletion of different segments depending on whether the insertion is direct or inverted, paracentric or pericentric, and whether there is meiotic crossing over in the inserted or the interstitial non-inserted segment. Several of the insertions have been difficult to interpret and some of them have been mistaken for paracentric inversions. Caution is therefore indicated in interpreting parental karyotypes of a child with a deletion or a duplication, particularly if it is interstitial. This is because, whereas a risk of recurrence of a child with an unbalanced karyotype is low in de novo cases and for carriers of paracentric inversions, it is high for carriers of insertions.     

Widowhood and mortality: a meta-analysis

Background

While the "widowhood effect" is well known, there is substantial heterogeneity in the magnitude of effects reported in different studies. We conducted a meta-analysis of widowhood and mortality, focusing on longitudinal studies with follow-up from the time of bereavement.

Methods and Findings

A random-effects meta-analysis was conducted to calculate the overall relative risk (RR) for subsequent mortality among 2,263,888 subjects from 15 prospective cohort studies. We found a statistically significant positive association between widowhood and mortality, but the widowhood effect was stronger in the period earlier than six months since bereavement (overall RR = 1.41, 95% CI: 1.26, 1.57) compared to the effect after six months (overall RR = 1.14, 95% CI: 1.10, 1.18). Meta-regression showed that the widowhood effect was not different for those aged younger than 65 years compared to those older than 65 (P = 0.25). There was, however, a difference in the magnitude of the widowhood effect by gender; for women the RR was not statistically significantly different from the null (overall RR = 1.04, 95% CI: 1.00, 1.08), while it was for men (overall RR = 1.23, 95% CI: 1.18, 1.28).

Conclusions

The results suggest that further studies should focus more on the mechanisms that generate this association especially among men.     

Wetlands and mosquitoes: a review

This review brings together information on mosquitoes, the diseases they transmit and the wetlands that provide habitats for the immature stages (eggs and larvae). Wetland values are mentioned, though the main literature on this does not generally overlap the mosquito issue. Mosquito management is overviewed to include: the use of larvicides, source reduction in intertidal wetlands and management in freshwater systems. There is not a great deal of information on mosquitoes and freshwater systems, except for constructed wetlands and they are considered separately. We then consider restoration mainly in the context of wetlands that have been the subject of habitat modification for mosquito control. Land use and climate change, as they affect mosquitoes and the diseases they transmit, are also reviewed, as this will affect wetlands via management activities. Finally the review addresses the critical issue of balancing health, both human and environmental, in an adaptive framework. It concludes that there is a need to ensure that both mosquito and wetland management communicate and integrate to sustain wetland and human health.     

Fixatives and fixation: a review

Conclusions During the period under review, various new fixatives have been introduced. The most important of these is glutaraldehyde which has become very widely used. The processes involved in fixation are becoming better understood in chemical and physical terms, largely due to developments in biochemistry and tanning. This understanding will become increasingly important as the resolution of macromolecules by the electron microscope increases. The images seen will then be able to be interpreted in the light of biochemical knowledge of the macromolecules and thus the gap between morphology and biochemistry will be bridged.Some of the fixatives have secondary uses in that they may demonstrate chemical substances. Others apparently destroy certain biological activities selectively.Increasing attention is being paid to the loss of substances from biological material during preparation. The importance of such studies cannot be overemphasized.No one fixative is ideal for all situations. By comparing the results obtained by a number of fixatives, and assessing the loss of substances during processing, it is far less likely that artefacts will be described as constant features.     

Carnosine and cancer: a perspective

The application of carnosine in medicine has been discussed since several years, but many claims of therapeutic effects have not been substantiated by rigorous experimental examination. In the present perspective, a possible use of carnosine as an anti-neoplastic therapeutic, especially for the treatment of malignant brain tumours such as glioblastoma is discussed. Possible mechanisms by which carnosine may perform its anti-tumourigenic effects are outlined and its expected bioavailability and possible negative and positive side effects are considered. Finally, alternative strategies are examined such as treatment with other dipeptides or β-alanine.     

Sialidase and malignancy: a minireview

Aberrant sialylation in cancer cells is thought to be a characteristic feature associated with malignant properties including invasiveness and metastatic potential. Sialidase which catalyzes the removal of sialic acid residues from glycoproteins and glycolipids, has been suggested to play important roles in many biological processes through regulation of cellular sialic acid contents. The altered expression of sialidase observed in cancer would, therefore, suggest its involvement in the malignant process. In mammalian cells, three types of sialidase cloned and characterized to date were found to behave in different manners during carcinogenesis. Recent progress in molecular cloning of these sialidases has facilitated elucidation of the molecular mechanisms and significance of these alterations. Herein we briefly describe our own studies on sialidase changes associated with malignant transformation and summarize the topic from both a retrospective and a prospective viewpoint. Sialidases are indeed closely related to malignancy and are thus potential targets for cancer diagnosis and therapy.     

Elderly and humor: a review

Ageing can be associated with physical, cognitive and/or social loss. Most older people, however, cope well with this loss, perhaps by using humour. In this review the research findings concerning humour were collected. Twenty six relevant publications were found. The sense of humour does not seem to be greater in older than in younger adults. There are no indications that humour appreciation or production is associated with longevity. In older people there is a correlation between humour on the one hand and well-being and morale on the other. It has not been proven, however, that the use of humour by the elderly people has a favourable influence on their health. In health care for older people humour is sometimes used as a therapy. Scientific evidence of any positive effects of humour on mental health was not found. It is perhaps better for caretakers to show appreciation for the humour of older people than to make jokes about older people oneself.     

Thiopurine methyltransferase: a review and a clinical pilot study

Thiopurine methyltransferase (TPMT) is an important enzyme in the metabolism of 6-mercaptopurine (6MP), which is used in the treatment of acute lymphoblastic leukemia (ALL). TPMT catalyzes the formation of methylthioinosine monophosphate (MetIMP), which is cytotoxic for cultured cell lines, and it plays a role in detoxification of 6MP. Population studies show a genetic polymorphism for TMPT with both high and low activity alleles. About 1 of 300 subjects is homozygous for the low activity. The function TPMT plays in detoxification or therapeutic efficacy of 6MP in vivo is not clear. In this article the genetic polymorphism of TPMT is reviewed and the contribution of TPMT to the cytotoxic action, or detoxification, of 6MP in children with ALL is discussed. Induction of TPMT activity has been described during the treatment for ALL. We performed a pilot study on the influence of high-dose 6MP infusions (1300 mg/m² in 24 h) on TPMT activity of peripheral blood mononuclear cells (pMNC) of eleven patients with ALL. The TPMT activities were in, or, above the normal range. There was no statistically significant difference between the TPMT activities before and after the 6MP infusions. MetIMP levels in pMNC increased during successive courses. This might be explained by TPMT induction, but other explanations are plausible as well. Twenty five percent of the TPMT assays failed, because less than the necessary 5·10⁶ pMNC could be isolated from the blood of leukopenic patients. Red blood cells can not be used for TPMT measurements, since transfusions are frequently required during the treatment with 6MP infusions. Therefore, the influence of high-dose 6MP infusions on TPMT activity can only be investigated further when a TMPT assay which requires less pMNC has been developed.     

BglII and MunI: what a difference a base makes

Restriction endonucleases are resilient to alterations in their DNA-binding specificities. Structures of the BglII and MunI endonucleases bound to their palindromic DNA sites, which differ by only their outer base pairs from the recognition sequences of BamHI and EcoRI, respectively, have recently been determined. A comparison of these complexes reveals surprising differences and similarities in structure, and provides a basis for understanding the immutability of restriction endonucleases.