Mosaicism in autosomal dominant polycystic kidney disease revealed by genetic testing to enable living related renal transplantation

Patients with end-stage renal disease (ESRD) secondary to autosomal dominant polycystic kidney disease (ADPKD) receive fewer living-related kidney (LRK) transplants than other groups with ESRD. This relates to the difficulties in excluding the disease in potential donors. We report a case which highlights these difficulties and, by discovery of mosaicism for a new mutation, illustrates the role of clinical and molecular genetic resources in assessing young related kidney donors for patients with ADPKD.

Social semantics: altruism, cooperation, mutualism, strong reciprocity and group selection

From an evolutionary perspective, social behaviours are those which have fitness consequences for both the individual that performs the behaviour, and another individual. Over the last 43 years, a huge theoretical and empirical literature has developed on this topic. However, progress is often hindered by poor communication between scientists, with different people using the same term to mean different things, or different terms to mean the same thing. This can obscure what is biologically important, and what is not. The potential for such semantic confusion is greatest with interdisciplinary research. Our aim here is to address issues of semantic confusion that have arisen with research on the problem of cooperation. In particular, we: (i) discuss confusion over the terms kin selection, mutualism, mutual benefit, cooperation, altruism, reciprocal altruism, weak altruism, altruistic punishment, strong reciprocity, group selection and direct fitness; (ii) emphasize the need to distinguish between proximate (mechanism) and ultimate (survival value) explanations of behaviours. We draw examples from all areas, but especially recent work on humans and microbes.

The causes and consequences of variation in offspring size: a case study using Daphnia

Offspring size can have large and direct fitness implications, but we still do not have a complete understanding of what causes offspring size to vary. Daphnia (water fleas) generally produce fewer and larger offspring when food is limited. Here, we use a mathematical model to show that this could be explained by either: (1) an advantage of producing larger eggs when food is limited; or (2) a lower boundary on egg volume (below which eggs do not have sufficient resources to be viable), that is similar in volume to the evolutionarily stable egg volume predicted by standard clutch size models. We tested the first possibilities experimentally by placing offspring from mothers kept at two food treatments (high and low - leading to relatively small and large eggs respectively) into two food treatments (same as maternal treatments, in a fully factorial design) and measuring their fitness (reproduction, age at maturity, and size at maturity). We also tested survival under starvation conditions of offspring produced from mothers at low and high food treatments. We found that (larger) offspring produced by low-food mothers actually had lower fitness as they took longer to reproduce, regardless of their current food treatment. Additionally, we found no survival advantage to being born of a food-stressed mother. Consequently, our results do not support the hypothesis that there is an advantage to producing larger eggs when food is limited. In contrast, data from the literature support the importance of a lower boundary on egg size.

Direct fitness or inclusive fitness: how shall we model kin selection?

Two standard mathematical formulations of kin-selection models can be found. Inclusive fitness is an actor-centred approach, which calculates the fitness effect on a number of recipients of the behaviour of a single actor. Direct fitness is a recipient-centred approach, which calculates the fitness effect on the recipient of the behaviour of a number of actors. Inclusive fitness offers us a powerful heuristic, of choosing behaviour to maximize fitness, but direct fitness can be mathematically easier to work with and has recently emerged as the preferred approach of theoreticians. In this paper, we explore the fundamental connection between these two approaches in both homogeneous and class-structured populations, and we show that under simple assumptions (mainly fair meiosis and weak selection) they provide equivalent formulations, which correspond to the predictions of Price's equation for allele frequency change. We use a couple of examples to highlight differences in their conception and formulation, and we briefly discuss a two-species example in which we have a class of 'actor' that is never a 'recipient', which the standard direct fitness method can handle but the usual inclusive fitness cannot.

Demography, altruism, and the benefits of budding

It is now widely appreciated that competition between kin inhibits the evolution of altruism. In standard population genetics models, it is difficult for indiscriminate altruism towards social partners to be favoured at all. The reason is that while limited dispersal increases the kinship of social partners it also intensifies local competition. One solution that has received very little attention is if individuals disperse as groups (budding dispersal), as this relaxes local competition without reducing kinship. Budding behaviour is widespread through all levels of biological organization, from early protocellular life to cooperatively breeding vertebrates. We model the effects of individual dispersal, budding dispersal, soft selection and hard selection to examine the conditions under which altruism is favoured. More generally, we examine how these various demographic details feed into relatedness and scale of competition parameters that can be included into Hamilton's rule.

Evidence against the hypothesis that BCL-2 inhibits apoptosis through an anti-oxidant effect

We contrasted possible protection against apoptosis afforded by either BCL-2 expression or anti-oxidant inhibitors in the same tumor target challenged by two distinct triggers of apoptosis. Exposure of L929 fibroblasts to tumor necrosis factor (TNF) or etoposide (VP-16) induced apoptotic death with similar kinetics. Enforced expression of BCL-2 significantly protected against apoptosis induced by VP-16 but had no effect against TNF-induced apoptosis. In contrast, the anti-oxidants desferrioxamine, butylated hydroxyanisol and N-acetyl cysteine all inhibited TNF-induced apoptosis in a concentration-dependent fashion. Although exposure to VP-16 resulted in a significant generation of intracellular oxyradicals, the above three anti-oxidant inhibitors had no effect on VP-16-induced apoptotic death. Interestingly, enforced expression of BCL-2 also inhibited the ability of VP-16 to generate oxy-radicals and to depress intracellular glutathione levels. These results indicate that BCL-2 can exert anti-oxidant effects but argue against the hypothesis that these effects are critical to its protection against apoptosis.

Use of re-transfusion versus vacuum drains in primary total hip replacement

Whilst the use of re-transfusion drains in primary knee arthroplasty has gained acceptance in reducing the requirement for donor blood products postoperatively, their use in total hip arthroplasty remains uncertain. Using two groups of 32 patients, a comparison was made between re-transfusion drains and vacuum drains in primary total hip arthroplasty in one centre and the requirement for postoperative donor blood. No statistically significant difference was found between the groups in terms of blood loss (p=0.51) or requirements for postoperative blood transfusion (p=0.12). The use of re-transfusion drains in primary total hip arthroplasty did not alter the rate of postoperative blood transfusion. (Hip International 2005; 15: 223-5).

MRSA-free elective orthopaedic surgery.A dedicated elective orthopaedic ward free from MRSA Alexandra Hospital, Redditch, UK

Deep infection complicating arthroplasty surgery carries a heavy financial and emotional burden on any orthopaedic service. The cost of hospital acquired infection is estimated at 1 billion per year by the National Audit Office. Healthcare associated infection is an area currently under great scrutiny. The Alexandra Hospital, Redditch, has developed a dedicated elective orthopaedic ward free from methicillin-resistant Staphylococcus aureus (MRSA) that delivers high quality and high volume major joint replacement surgery through rigorous infection control. Between October 2001 and December 2002, the Alexandra Hospital had an infection rate of 0.21% for total knee replacements compared to the national rate of 2.1% p= 0.002 (CI 0.00005-0.01) The infection rate for total hip replacements was 1.31% compared to 3.8% nationwide. p= 0.01 (CI 0.004- 0.03). The total number of joint replacements performed per year, utilising the same number of elective beds, increased from 482 in 2001 to 629 in 2002. We believe that the MRSA screening policy and subsequent altered bed utilisation have contributed to lowering the rate of infection and improved efficiency. We have developed a safe, effective and efficient orthopaedic unit within the framework of an acute NHS trust. We believe the practical changes and modest investment that have been made within our department can be repeated in other units around the country with relative ease. (Hip International 2005; 15: 171-6).

Expression profiling reveals functionally important genes and coordinately regulated signaling pathway genes during in vitro angiogenesis

Angiogenesis is a complex multicellular process requiring the orchestration of many events including migration, alignment, proliferation, lumen formation, remodeling, and maturation. Such complexity indicates that not only individual genes but also entire signaling pathways will be crucial in angiogenesis. To define an angiogenic blueprint of regulated genes, we utilized our well-characterized three-dimensional collagen gel model of in vitro angiogenesis, in which the majority of cells synchronously progress through defined morphological stages culminating in the formation of capillary tubes. We developed a comprehensive three-tiered approach using microarray analysis, which allowed us to identify genes known to be involved in angiogenesis and genes hitherto unlinked to angiogenesis as well as novel genes and has proven especially useful for genes where the magnitude of change is small. Of interest is the ability to recognize complete signaling pathways that are regulated and genes clustering into ontological groups implicating the functional importance of particular processes. We have shown that consecutive members of the mitogen-activated protein kinase and leukemia inhibitory factor signaling pathways are altered at the mRNA level during in vitro angiogenesis. Thus, at least for the mitogen-activated protein kinase pathway, mRNA changes as well as the phosphorylation changes of these gene products may be important in the control of blood vessel morphogenesis. Furthermore, in this study, we demonstrated the power of virtual Northern blot analysis, as an alternative to quantitative RT-PCR, for measuring the magnitudes of differential gene expression.

Thoracic and lumbar spine fractures

The management of thoracic and lumbar spine fractures is a controversial topic. This article seeks to examine the anatomy, mechanism of injury, classification, initial assessment and treatment and the definitive management, both conserva tive and operative of these injuries, and to try and explain the pros and cons of each.

Endothelin (ET)-1-induced inhibition of ATP release from PC-12 cells is mediated by the ETB receptor: differential response to ET-1 on ATP, neuropeptide Y, and dopamine levels

During sympathetic neurotransmitter release, there is evidence for differential modulation of cotransmitter release by endothelin (ET)-1. Using nerve growth factor (NGF)-differentiated PC12 cells, the effects of ET-1 on K(+)-stimulated release of ATP, dopamine (DA), and neuropeptide Y (NPY) were quantified using high-pressure liquid chromatography or radioimmunoassay. ET-1, in a concentration-dependent manner, inhibited the release of ATP, but not DA and NPY. Preincubation with the ET(A/B) antagonist, PD 142893 (N-acetyl-beta-phenyl-D-Phe-Leu-Asp-Ile-Ile-Trp), reversed the inhibitory effect of ET-1 on ATP release, which remained unaffected in the presence of the ET(A)-specific antagonist BQ123 [cyclo(D-Asp-Pro-D-Val-Leu-D-Trp)]. The ET(B) agonists, sarafotoxin 6c (Cys-Thr-Cys-Asn-Asp-Met-Thr-Asp-Glu-Glu-Cys-Leu-Asn-Phe-Cys-His-Gln-Asp-Val-Ile-Trp), BQ 3020 (N-acetyl-[Ala(11,15)]-endothelin 1 fragment 6-21Ac-Leu-Met-Asp-Lys-Glu-Ala-Val-Tyr-Phe-Ala-His-Leu-Asp-IIe-IIe-Trp), and IRL 1620 (N-succinyl-[Glu(9), Ala(11,15)]-endothelin 1 fragment 8-21Suc-Asp-Glu-Glu-Ala-Val-Tyr-Phe-Ala-His-Leu-Asp-Ile-Ile-Trp), decreased K(+)-stimulated release of ATP in a dose-dependent manner, and this effect was reversed by the ET(B) antagonists RES 701-1 [cyclic (Gly1-Asp9) (Gly-Asn-Trp-His-Gly-Thr-Ala-Pro-Asp-Trp-Phe-Phe-Asn-Tyr-Tyr-Trp)] and BQ 788 (N-[N-[N-[(2,6-dimethyl-1-piperidinyl)carbonyl]-4-methyl-l-leucyl]-1-(methoxycarbonyl)-D-tryptophyl]-D-norleucine sodium salt). Preincubation of PC12 cells with pertussis toxin reversed the ET-1-induced inhibition of the K(+)-evoked ATP release. Real-time intracellular calcium level recordings were performed on PC-12 cell suspensions, and ET-1 induced a dose-dependent decrease in the K(+)-evoked calcium levels. Nifedipine, the L-type voltage-dependent Ca(2+) channel antagonist, caused inhibition of the K(+)-stimulated ATP release, but the N-type Ca(2+) channel antagonist, omega-conotoxin GVIA, did not reverse the effect on ATP release. These data suggest that ET-1 modulates the release of ATP via the ET(B) receptor and its associated G(i/o) G-protein through attenuation of the influx of extracellular Ca(2+) through L-type channels.

Spite and the scale of competition

In recent years there has been a large body of theoretical work examining how local competition can reduce and even remove selection for altruism between relatives. However, it is less well appreciated that local competition favours selection for spite, the relatively neglected ugly sister of altruism. Here, we use extensions of social evolution theory that were formulated to deal with the consequences for altruism of competition between social partners, to illustrate several points on the evolution of spite. Specifically, we show that: (i) the conditions for the evolution of spite are less restrictive than previously assumed; (ii) previous models which have demonstrated selection for spite often implicitly assumed local competition; (iii) the scale of competition must be allowed for when distinguishing different forms of spite (Hamiltonian vs. Wilsonian); (iv) local competition can enhance the spread of spiteful greenbeards; and (v) the theory makes testable predictions for how the extent of spite should vary dependent upon population structure and average relatedness.

Damage control in orthopaedic trauma

The last century has seen great strides in the care of the polytrauma patient. Prior to the 1950s, routine operative stabilization of long bone fractures was not performed. With the advent of modern methods of fracture fixation the philosophy of early total care arrived and all fractures were operatively fixed at an early stage. Further understanding of the inflammatory response in trauma has now led to the concept of damage control orthopaedics. The aim of this review is to highlight this philosophy and its use in the polytrauma patient.

Prostanoid-induced modulation of neuropeptide Y and noradrenaline release from the rat mesenteric bed

1. A variety of prostanoids were examined for their ability to alter the periarterial nerve stimulation-induced release of noradrenaline (NA) and neuropeptide Y immunoreactive compounds (NPY-ir) from the perfused mesenteric arterial bed of the rat. 2. Periarterial nerve stimulation (16 Hz) increased the overflow of NA, NPY-ir and perfusion pressure. 3. The prostacyclin (PGI2) analogues, carbaPGI2 and cicaprost both produced a concentration-dependent attenuation of the nerve stimulation-induced increase in NA, NPY-ir overflow and perfusion pressure. 4. The prostaglandin (PG) analogue PGE2 attenuated the evoked increase in NPY-ir overflow as well as a modest decrease in NA. 5. PGE1, sulprostone and iloprost attenuated the nerve stimulation-induced increase in NA overflow but not NPY-ir. 6. Neither PGF2alpha nor the thromboxane A2 analogue U46619 altered the evoked increase in NA or NPY-ir overflow. 7. The results support the view that sympathetic co-transmitter release can be differentially modulated by paracrine/autocrine mediators at sympathetic neuroeffector junctions.

Even more extreme fertility insurance and the sex ratios of protozoan blood parasites

Theory developed for malaria and other protozoan parasites predicts that the evolutionarily stable gametocyte sex ratio (z*; proportion of gametocytes that are male) should be related to the inbreeding rate (f) by the equation z*=(1-f)/2. Although this equation has been applied with some success, it has been suggested that in some cases a less female biased sex ratio can be favoured to ensure female gametes are fertilized. Such fertility insurance can arise in response to two factors: (i) low numbers of gametes produced per gametocyte and (ii) the gametes of only a limited number of gametocytes being able to interact. However, previous theoretical studies have considered the influence of these two forms of fertility insurance separately. We use a stochastic analytical model to address this problem, and examine the consequences of when these two types of fertility insurance are allowed to occur simultaneously. Our results show that interactions between the two types of fertility insurance reduce the extent of female bias predicted in the sex ratio, suggesting that fertility insurance may be more important than has previously been assumed.

Alterations of rCBF and mitochondrial dysfunction in major depressive disorder: a case report

OBJECTIVE

A mitochondrial disease might be considered when depressive disorder is associated with diabetes mellitus or other symptoms commonly found in mitochondrial disease. Scattered regional cerebral blood flow (rCBF) decreases and increases have been reported in depressive and mitochondrial disorders. A 61-year-old male patient with early adult onset of depressive disorder and a slowly developing multiorgan syndrome including diabetes mellitus was investigated.

METHOD

99mTc-HMPAO rCBF SPECT and muscle biopsy to assess mitochondrial functions were performed in the patient.

RESULTS

Alterations of rCBF were found in the patient, with the most pronounced decreases in the left dorsolateral frontal and inferior parietal lobes, and the most pronounced increases in the bilateral superior parietal lobes. Muscle biopsy revealed myopathy and decrease of mitochondrial adenosine triphosphate production rates (MAPRs).

CONCLUSION

The MAPRs decreases support the suspicion of mitochondrial dysfunction in the patient. A subgroup of depressed patients may have mitochondrial dysfunctions.

Residual impact of the biocontrol inoculant Pseudomonas fluorescens F113 on the resident population of rhizobia nodulating a red clover rotation crop

A field trial was previously conducted in which sugarbeet seeds were either untreated, inoculated with the biocontrol strain Pseudomonas fluorescens F113Rif, or treated with chemical fungicides. Following harvest of sugarbeet, the field site was sown with uninoculated red clover. The aim of this study was to assess the residual impact of the microbial inoculant (and the fungicide treatment) on the diversity of resident rhizobia nodulating the red clover rotation crop. The percentage of nodules yielding rhizobial isolates after surface disinfection was 67% in the control and 70% in the P. fluorescens F113Rif treatment, but only 23% in the chemical treatment. Isolates were characterized by RAPD analysis. The main RAPD cluster (arbitrarily defined at 70% similarity) was prevalent in all three treatments. In addition, the distribution of RAPD clusters followed a log series model, regardless of the treatment applied, indicating that neither the microbial inoculant nor the fungicide treatment had caused a strong perturbation of the rhizobial population. When the P. fluorescens F113Rif and control treatments were compared using diversity indices, however, it appeared that the genetic diversity of rhizobia was significantly less in the inoculated treatment. The percentage of rhizobia sensitive to 2,4-diacetylphloroglucinol (Phl; the antimicrobial metabolite produced by P. fluorescens F113Rif) fluctuated according to field site heterogeneity, and treatments had no effect on this percentage. Yet, the proportion of Phl-sensitive isolates in the main RAPD cluster was lower in the P. fluorescens F113Rif treatment compared with the control, raising the possibility that the residual impact of the inoculant could have been partly mediated by production of Phl. This impact on the rhizobial population took place without affecting the functioning of the Rhizobium-clover symbiosis.

Endometrial hyperplasia and mineralization in zoo felids treated with melengestrol acetate contraceptives

Melengestrol acetate (MGA) contraceptives are widely used in zoo felids to regulate fertility and may have deleterious effects on endometrial health. To determine whether MGA exposure was associated with endometrial disease, the genital tracts of 212 zoo felids (99 MGA treated and 113 control) representing 23 species were evaluated. Adenomatous and cystic hyperplasia were prevalent in both MGA-treated (85%) and control (61%) groups, and the risk of developing these lesions increased with age. Treatment with MGA further increased the risk of developing advanced hyperplasia regardless of dose, and treatment for >72 months significantly elevated that risk, whereas parous animals had a lower risk. Endometrial polyps, fibrosis, adenomyosis, and hydrometra occurred in both MGA-treated and control animals. MGA treatment was associated with an increased risk of hydrometra and mineralization but not of adenomyosis, polyps, or fibrosis after adjusting for advanced hyperplasia. Acute or chronic endometritis were associated with advanced hyperplasia but not with MGA treatment. These results indicate that proliferative and inflammatory endometrial lesions are common spontaneous diseases in zoo cats, and MGA contraceptives increase the risk of some diseases. The association of MGA with endometrial lesions that could impair fertility should be considered when using this contraceptive in genetically valuable felids.

Differences in resting state regional cerebral blood flow assessed with 99mTc-HMPAO SPECT and brain atlas matching between depressed patients with and without tinnitus

An increased occurrence of major depressive disorder has been reported in tinnitus patients, and of tinnitus in depressive patients. Involvement of several Brodmann areas (BAs) has been reported in tinnitus perception. The aim of this study was to assess the regional cerebral blood flow (rCBF) changes in depressed patients with and without tinnitus. The rCBF distribution at rest was compared among 45 patients with a lifetime prevalence of major depressive disorder, of whom 27 had severe tinnitus, and 26 normal healthy subjects. 99mTc-hexamethylenepropylene amine oxime (99mTc-HMPAO) single photon emission computed tomography (SPECT), using a three-headed gamma camera, was performed and the uptake in 34 functional sub-volumes of the brain bilaterally was assessed by a computerized brain atlas. Decreased rCBF in right frontal lobe BA 45 (P<0.05), the left parietal lobe BA 39 (P<0.00) and the left visual association cortex BA 18 (P<0.05) was found in tinnitus patients compared with non-tinnitus patients. The proportion of tinnitus patients with pronounced rCBF alterations in one or more of the temporal lobe BAs 41+21+22 was increased compared to gender matched controls (P<0.00) and patients without tinnitus (P<0.05). Positive correlations were found between trait anxiety scales from the Karolinska Scales of Personality and rCBF in tinnitus patients only in three limbic BAs (P<0.01), and inverse correlations in non-tinnitus patients only in five BAs subserving auditory perception and processing (P<0.05). rCBF differences between healthy controls and depressed patients with and without tinnitus were found in this study. The rCBF alterations were distributed in the cortex and were particularly specific in the auditory cortex. These findings suggest that taking audiological symptoms into account may yield more consistent results between rCBF studies of depression.