New onset postural tachycardia syndrome following lightning injury

Lightning injuries are one of the top three causes of death from environmental causes. Survivors of lightning injuries may be left with injuries, which may affect either the somatic or autonomic nervous systems. We report on two previously healthy patients who developed severe forms of postural tachycardia syndrome following a lightning injury, and review the literature on the subject.     

Micropapillary bladder cancer: Current treatment patterns and review of the literature

ObjectivesNo guidelines exist for the management of micropapillary bladder cancer (MPBC) and most reports of this variant of urothelial carcinoma are case series comprising small numbers of patients. We sought to determine current practice patterns for MPBC using a survey sent to the Society of Urologic Oncology (SUO) and to present those results in the setting of a comprehensive review of the existing literature.Materials and methodsA survey developed by the Translational Science Working Group of the Bladder Cancer Advocacy Network–sponsored Think Tank meeting was distributed to members of the SUO. The results from 118 respondents were analyzed and presented with a literature review.ResultsMost survey respondents were urologists, with 80% considering bladder cancer their primary area of interest. Although 78% of the respondents reported a dedicated genitourinary pathologist at their institution, there were discrepant opinions on how a pathologic diagnosis of MPBC is determined as well as variability on the proportion of MPBC that is clinically significant. Among them, 78% treat MPBC differently than conventional urothelial carcinoma, with 81% reporting that they would treat cT1 MPBC with upfront radical cystectomy. However, the respondents had split opinions regarding the sensitivity of MPBC to cisplatin-based chemotherapy, which affected utilization of neoadjuvant chemotherapy in muscle-invasive disease.ConclusionsThe management of MPBC is diverse among members of the SUO. Although most favors early cystectomy for cT1 MPBC, there is no consensus on the use of neoadjuvant chemotherapy for muscle-invasive MPBC.     

A mouse model for the renal salt-wasting syndrome pseudohypoaldosteronism

Aldosterone-dependent epithelial sodium transport in the distal nephron is mediated by the absorption of sodium through the highly selective, amiloride-sensitive epithelial sodium channel (ENaC) made of three homologous subunits (α, β, and γ). In human, autosomal recessive mutations of α, β, or γENaC subunits cause pseudohypoaldosteronism type 1 (PHA-1), a renal salt-wasting syndrome characterized by severe hypovolemia, high plasma aldosterone, hyponatremia, life-threatening hyperkaliemia, and metabolic acidosis. In the mouse, inactivation of αENaC results in failure to clear fetal lung liquid at birth and in early neonatal death, preventing the observation of a PHA-1 renal phenotype. Transgenic expression of αENaC driven by a cytomegalovirus promoter in αENaC(−/−) knockout mice [αENaC(−/−)Tg] rescued the perinatal lethal pulmonary phenotype and partially restored Na⁺ transport in renal, colonic, and pulmonary epithelia. At days 5–9, however, αENaC(−/−)Tg mice showed clinical features of severe PHA-1 with metabolic acidosis, urinary salt-wasting, growth retardation, and 50% mortality. Adult αENaC(−/−)Tg survivors exhibited a compensated PHA-1 with normal acid/base and electrolyte values but 6-fold elevation of plasma aldosterone compared with wild-type littermate controls. We conclude that partial restoration of ENaC-mediated Na⁺ absorption in this transgenic mouse results in a mouse model for PHA-1.     

Depression severity is associated with increased risk behaviors and decreased CD4 cell counts

Depression is a common comorbidity among HIV-infected individuals. We studied the relationship between depressive symptoms, risk behaviors (risky-sexual behavior, tobacco, alcohol, and illicit drug use) and HIV outcomes. This cross-sectional study conducted in 2009 at the Washington University HIV Clinic included screening for depression with patient health questionnaire, survey of sexual behavior, illicit drug, alcohol, and tobacco use within 30 days. Sociodemographics, plasma HIV RNA levels, CD4 cell counts, and sexually transmitted disease test results were obtained from medical records. Multivariate logistic and linear regression models were used to assess the association between depressive symptoms severity and risk behaviors, HIV outcomes and combination antiretroviral therapy (cART) adherence. A total of 624 persons completed the assessment of whom 432 (69%) were male and 426 (68%) African-American. The median CD4 cell count was 410 cells/mm³ and 479 persons (77%) were on cART of whom 112 (23%) had HIV RNA level > 400 copies/mL. Overall, 96 (15%) had symptoms of major depressive disorder. Depressive symptom severity was associated with increased likelihood of high-risk drinking (odds ratio [OR], 2.4; 95% confidence interval [CI], 1.1–5.1), current tobacco use (OR, 1.8; 95% CI, 1.1–2.9), illicit drug use (OR, 1.7; 95% CI, 1.0–2.8), and risky-sexual behavior (OR, 1.5; 95% CI, 0.8–2.7). Suboptimal cART adherence (visual analog scale < 95%) was also associated with depressive symptoms severity (p < 0.05). After adjustment for age, sex, race, receipt of cART, and cART adherence, depressive symptoms severity was independently associated with lower CD4 cell count (p < 0.05) but not with higher HIV RNA level (p = 0.39). Depression adversely affects HIV-infected individuals, requiring greater effort at utilizing multidisciplinary interventions.     

Maximizing the benefits of antiretroviral therapy for key affected populations

Introduction

Scientific research has demonstrated the clinical benefits of earlier initiation of antiretroviral treatment (ART), and that ART can markedly reduce HIV transmission to sexual partners. Ensuring universal access to ART for those who need it has long been a core principle of the HIV response, and extending the benefits of ART to key populations is critical to increasing the impact of ART and the overall effectiveness of the HIV response. However, this can only be achieved through coordinated efforts to address political, social, legal and economic barriers that key populations face in accessing HIV services.

Discussion

Recent analyses show that HIV prevalence levels among key populations are far higher than among the general population, and they experience a range of biological and behavioural factors, and social, legal and economic barriers that increase their vulnerability to HIV and have resulted in alarmingly low ART coverage. World Health Organization 2014 consolidated guidance on HIV among key populations offers the potential for increased access to ART by key populations, following the same principles as for the general adult population. However, it should not be assumed that key populations will achieve greater access to ART unless stigma, discrimination and punitive laws, policies and practices that limit access to ART and other HIV interventions in many countries are addressed.

Conclusions

Rights-based approaches and investments in critical enablers, such as supportive legal and policy environments, are essential to enable wider access to ART and other HIV interventions for key populations. The primary objective of ART should always be to treat the person living with HIV; prevention is an important, additional benefit. ART should be provided only with informed consent. The preventive benefits of treatment must not be used as a pretext for failure to provide other necessary HIV programming for key populations, including comprehensive harm reduction and other prevention interventions tailored to meet the needs of key populations. An end to AIDS is only possible if we overcome the barriers of criminalization, stigma and discrimination that remain key drivers of the HIV epidemics among key populations.     

Degenerative adult onset scoliosis

There are people who have no history of scoliosis who develop spinal deformity of a progressive nature as adults, associated with severe degenerative disc disease. The clinical syndrome associated with this deformity is not well documented. In an attempt to describe this clinical syndrome more precisely, 21 patients with the diagnosis of degenerative scoliosis were identified and reviewed. Review included history with pain drawings when available, physical examination, bone densities, and standing spinal roentgenograms. Patients with spinal compression fractures, spondylolyses, prior history of scoliosis or radiographic findings consistent with an idiopathic scoliosis were excluded. Our review shows that these patients can develop, along with progressive scoliosis, loss of lumbar lordosis with a resulting flat back deformity. These patients commonly present in the sixth decade with a predominantly stenotic symptom complex, but often lack the classic feature of relief in a sitting posture. The number of male and female patients was approximately equal. Roentgenogram findings show a high angle deformity over a short number of spinal segments and an absence of bony features associated with idiopathic scoliosis such as lateral vertebral wedging and alterations of the lamina. The incidence of this condition remains to be established.     

Engineered CaM2 modulates nuclear calcium oscillation and enhances legume root nodule symbiosis

The key physiological event essential to the establishment of nitrogen-fixing bacteria and phosphate-delivering arbuscular mycorrhizal symbioses is the induction of nuclear calcium oscillations that are required for endosymbioses. These regular fluctuations in nucleoplasmic calcium concentrations are generated by ion channels and a pump located at the nuclear envelope, including the CYCLIC NUCLEOTIDE GATED CHANNEL 15 (CNGC15). However, how the CNGC15s are regulated in planta to sustain a calcium oscillatory mechanism remains unknown. Here, we demonstrate that the CNGC15s are regulated by the calcium-bound form of the calmodulin 2 (holo-CaM2), which, upon release of calcium, provides negative feedback to close the CNGC15s. Combining structural and evolutionary analyses of CaM residues with bioinformatic analysis, we engineered a holo-CaM2 with an increased affinity for CNGC15s. In planta, the expression of the engineered holo-CaM2 accelerates the calcium oscillation frequency, early endosymbioses signaling and is sufficient to sustain over time an enhanced root nodule symbiosis but not an increased arbuscular mycorrhization. Together, these results reveal that holo-CaM2 is a component of endosymbiosis signaling required to modulate CNGC15s activity and the downstream root nodule symbiosis pathway.

Nutrient acquisition is fundamental to life. Plants have evolved strategies to overcome soil phosphate limitation and gain access to atmospheric dinitrogen by developing beneficial associations with arbuscular mycorrhizal (AM) fungi and nitrogen-fixing bacteria, respectively. Unlike other crops, the vast majority of legumes have mastered associations with both endosymbionts, positioning them as key crops to develop sustainable agricultural practices in both developed and developing countries (1).The entry of nitrogen-fixing bacteria, known as rhizobia, and AM fungi into legume roots is initiated by the recognition of the endosymbiont. Host plants have plasma-membrane receptor-like kinases (2–6) that recognize rhizobial elicitors, lipochitooligosaccharides (LCOs), also known as Nod factors (7), and mycorrhizal factors composed of derivatives of LCOs and shorter chain chitooligosaccharides (8, 9). Although rhizobial and AM elicitors are recognized by different complexes of receptor-like kinases (10, 11), both symbionts require the activation of calcium oscillations in root epidermal nuclei (9, 12, 13) to set off the endosymbiosis program. In the model legume Medicago truncatula, two types of nuclear envelope localized ion channels are required to generate the calcium oscillation; the DOESN’T MAKE INFECTIONS1 (DMI1) channel and paralogs of CYCLIC NUCLEOTIDE GATED CHANNEL 15 (CNGC15) (14), and the calcium pump, MCA8 (15). Similar to the animal CNGCs, plant CNGCs are tetrameric ion channels that can include different CNGC units (16, 17). In M. truncatula, CNGC15a, CNGC15b, and CNGC15c are all involved in nuclear calcium oscillation in the root epidermis, nodulation, and arbuscular mycorrhization, suggesting that the three units could assemble into a heterocomplex at the nuclear envelope (14). However, how CNGC15s are regulated in planta to sustain a calcium oscillatory mechanism remains unknown.In this study, we demonstrate that CNGC15s are regulated by the calcium-bound form of the calmodulin 2 (holo-CaM2) in planta, which shapes the oscillatory pattern of nucleoplasmic calcium concentration by providing negative feedback on CNGC15s to cause its closure. By engineering CaM2 to generate CaM2^R91A, which specifically increased holo-CaM2 binding affinity to each CNGC15 unit, we accelerated closure of CNGC15s and increased the calcium oscillation frequency. We further show that accelerating the calcium oscillation frequency was sufficient to accelerate the early endosymbiosis signaling and that the expression of CaM2^R91A resulted in an enhanced root nodule symbiosis but not enhanced AM colonization. Our data reveal differential regulation of rhizobia and AM endosymbioses by CaM2^R91A and suggest that modulating calcium signaling can be used as a strategy to positively impact symbiosis with nitrogen-fixing bacteria.     

Management of neurovascular complications in extended skull base surgery

Combined oncologic approaches to the skull base now permit resection of extensive basicranial neoplasms. Despite advances in microsurgical techniques, disabling or life-threatening complications are still encountered in such surgery. Successful management of these sequelae is dependent upon meticulous intraoperative care and compulsive postoperative clinical assessment. Perioperative neurovascular complications were recorded in 154 consecutive skull base procedures. The most frequent severe complication was cerebral edema, which occasionally required surgical intervention. Dysphagia was the most common complication noted in the late postoperative period. Based upon this review, the management and methods found to minimize the incidence of various perioperative neurovascular complications related to extended skull base surgery are described.