Selective G protein signaling driven by substance P-neurokinin receptor dynamics.

The neuropeptide substance P (SP) is important in pain and inflammation. SP activates the neurokinin-1 receptor (NK1R) to signal via Gq and Gs proteins. Neurokinin A also activates NK1R, but leads to selective Gq signaling. How two stimuli yield distinct G protein signaling at the same G protein-coupled receptor remains unclear. We determined cryogenic-electron microscopy structures of active NK1R bound to SP or the Gq-biased peptide SP6-11. Peptide interactions deep within NK1R are critical for receptor activation. Conversely, interactions between SP and NK1R extracellular loops are required for potent Gs signaling but not Gq signaling. Molecular dynamics simulations showed that these superficial contacts restrict SP flexibility. SP6-11, which lacks these interactions, is dynamic while bound to NK1R. Structural dynamics of NK1R agonists therefore depend on interactions with the receptor extracellular loops and regulate G protein signaling selectivity. Similar interactions between other neuropeptides and their cognate receptors may tune intracellular signaling.

Clinical Manifestations and Genomic Evaluation of Melioidosis Outbreak among Children after Sporting Event, Australia.

Melioidosis, caused by the environmental gram-negative bacterium Burkholderia pseudomallei, usually develops in adults with predisposing conditions and in Australia more commonly occurs during the monsoonal wet season. We report an outbreak of 7 cases of melioidosis in immunocompetent children in Australia. All the children had participated in a single-day sporting event during the dry season in a tropical region of Australia, and all had limited cutaneous disease. All case-patients had an adverse reaction to oral trimethoprim/sulfamethoxazole treatment, necessitating its discontinuation. We describe the clinical features, environmental sampling, genomic epidemiologic investigation, and public health response to the outbreak. Management of this outbreak shows the potential benefits of making melioidosis a notifiable disease. The approach used could also be used as a framework for similar outbreaks in the future.

The role of payment and financing in achieving health equity.

OBJECTIVE: The aim was to identify healthcare payment and financing reforms to promote health equity and ways that the Agency for Healthcare Research and Quality (AHRQ) may promote those reforms. DATA SOURCES AND STUDY SETTING: AHRQ convened a payment and financing workgroup-the authors of this paper-as part of its Health Equity Summit held in July 2022. This workgroup drew from its collective experience with healthcare payment and financing reform, as well as feedback from participants in a session at the Health Equity Summit, to identify the evidence base and promising paths for reforms to promote health equity. STUDY DESIGN: The payment and financing workgroup developed an outline of reforms to promote health equity, presented the outline to participants in the payment and financing session of the July 2022 AHRQ Health Equity Summit, and integrated feedback from the participants. DATA COLLECTION/EXTRACTION METHODS: This paper did not require novel data collection; the authors collected the data from the existing evidence base. PRINCIPAL FINDINGS: The paper outlines root causes of health inequity and corresponding potential reforms in five domains: (1) the differential distribution of resources between healthcare providers serving different communities, (2) scarcity of financing for populations most in need, (3) lack of integration/accountability, (4) patient cost barriers to care, and (5) bias in provider behavior and diagnostic tools. CONCLUSIONS: Additional research is necessary to determine whether the proposed reforms are effective in promoting health equity.

Adenovirus vector vaccination induces expansion of memory CD4 T cells with a mucosal homing phenotype that are readily susceptible to HIV-1.

In the recently halted HIV type 1 (HIV-1) vaccine STEP trial, individuals that were seropositive for adenovirus serotype 5 (Ad5) showed increased rates of HIV-1 infection on vaccination with an Ad5 vaccine. We propose that this was due to activation and expansion of Ad5-specific mucosal-homing memory CD4 T cells. To test this hypothesis, Ad5 and Ad11 antibody titers were measured in 20 healthy volunteers. Dendritic cells (DCs) from these individuals were pulsed with replication defective Ad5 or Ad11 and co-cultured with autologous lymphocytes. Cytokine profiles, proliferative capacity, mucosal migration potential, and susceptibility to HIV infection of the adenovirus-stimulated memory CD4 T cells were measured. Stimulation of T cells from healthy Ad5-seropositive but Ad11-seronegative individuals with Ad5, or serologically distinct Ad11 vectors induced preferential expansion of adenovirus memory CD4 T cells expressing alpha(4)beta(7) integrins and CCR9, indicating a mucosal-homing phenotype. CD4 T-cell proliferation and IFN-gamma production in response to Ad stimulation correlated with Ad5 antibody titers. However, Ad5 serostatus did not correlate with total cytokine production upon challenge with Ad5 or Ad11. Expanded Ad5 and Ad11 memory CD4 T cells showed an increase in CCR5 expression and higher susceptibility to infection by R5 tropic HIV-1. This suggests that adenoviral-based vaccination against HIV-1 in individuals with preexisting immunity against Ad5 results in preferential expansion of HIV-susceptible activated CD4 T cells that home to mucosal tissues, increases the number of virus targets, and leads to a higher susceptibility to HIV acquisition.

Case Report: Disseminated Burkholderia pseudomallei with Acute Suppurative Thyroiditis and Abscess Formation.

Melioidosis has a highly variable presentation. Almost any organ can be involved, although an antemortem diagnosis of acute suppurative thyroiditis (AST) has not, to our knowledge, been previously described. A 68-year-old Australian male with poorly controlled type 2 diabetes mellitus presented with fever, odynophagia, and thyroid function tests consistent with hyperthyroidism. Imaging demonstrated a lung abscess and an enlarged thyroid gland with three nodules. Blood cultures and fine-needle aspiration of the thyroid nodules grew Burkholderia pseudomallei. He received intravenous ceftazidime and concurrent oral trimethoprim/sulfamethoxazole (TMP/SMX) for 4 weeks followed by high-dose oral TMP/SMX for a further 3 months and made a complete recovery. Acute suppurative thyroiditis is an uncommon cause of hyperthyroidism and thyroid aspirates are not commonly sent for bacterial culture. The case highlights the need to consider AST in patients presenting with a hyperthyroid state and disseminated infection. It also demonstrates that in a case of disseminated melioidosis any symptom may be a clue to underlying metastatic infection.

Intractable cardiac arrest due to lidocaine toxicity successfully resuscitated with lipid emulsion.

OBJECTIVE: Demonstrate a case report involving successful use of lipid emulsion therapy for intractable cardiac arrest due to lidocaine toxicity. DATA SOURCE: Lipid emulsion therapy has been shown to be effective in treating the cardiotoxic effects of such drugs as bupivacaine, verapamil, propranolol, and clomipramine as mentioned in a 2009 editorial in Critical Care Medicine by Jeffrey Bent. The mechanism of action of lipid emulsion therapy is not well defined and has been postulated to work by both a "lipid sink," decreasing circulating amounts of drugs to the periphery, or through a direct "energy source" to the myocardium. We present a case report of a patient successfully resuscitated with lipid emulsion therapy after prolonged and intractable lidocaine toxicity. Lidocaine is generally considered much less cardiotoxic than other local anesthetics and is used commonly as infusions for intractable ventricular arrhythmias. CONCLUSION: This case demonstrates the need to consider lipid emulsion therapy in the advanced cardiac life support algorithm for lidocaine toxicity as well as other lipid soluble drug intoxications.

Risk factors for medication non-adherence in an HIV infected population in the Dominican Republic.

High levels of medication adherence are central to HIV treatment success. Barriers to medication adherence may differ by cultural setting. We aimed to determine risk factors for medication non-adherence in HIV infected individuals in the Dominican Republic. Adherence was measured in 300 individuals using a visual analog scale assessing the prior month and dichotomized at 95%. High levels of adherence were reported by 228 (76%). Risk factors for non-adherence included heavy alcohol use: 2.5 times odds (95% CI: 1.4-4.5), having children: 2.2 times higher odds (95% CI: 1.1-4.9) and perceptions of less social support related to adherence: 2 times higher odds (95% CI: 1.1-3.6). Culturally appropriate interventions are needed to address alcohol use, which is common in this setting. Parenting may represent a competing demand on time and resources and be an adherence barrier. Self-reported perceived lack of adherence support may be a useful marker for need for adherence interventions.

Efficient liver-directed gene transfer by in situ generation of retroviral vector from adenoviral templates.

UNLABELLED: To improve liver-directed retroviral-mediated gene transfer, we injected C57/BL10 mice intravenously with three adenoviral vectors encoding retroviral vector genome and structural components: AdGagPol expressing the respective structural genes of Moloney murine leukaemia virus, Ad10A1Env expressing the 10A1 envelope protein of 10A1-MuLV, and AdLEIN, encoding the LEIN retrovirus genome, expressing green fluorescence protein (eGFP) and the neomycin resistance gene. MATERIALS AND METHODS: The extent of eGFP expression was determined after 1 and 15 weeks by fluorescence microscopy and FACS analysis. Proviral integration was determined by a novel PCR-based technique. RESULTS: Hepatocytes infected with all three Ad vectors generated LEIN retrovirus after one week and in situ transduction of neighbouring cells resulted in stable proviral integration associated with eGFP expression ranging from 4.3% to 20.5% in different liver cell populations 15 weeks post-infection. CONCLUSION: Hybrid adeno-retroviral vectors can be efficiently used to improve the efficiency of retroviral-mediated gene transfer to the liver.

APOE epsilon3 gene transfer attenuates brain damage after experimental stroke.

Apolipoprotein E (apoE, protein; APOE, gene) is the major lipid-transport protein in the brain and plays an important role in modulating the outcome and regenerative processes after acute brain injury. The aim of the present study was to determine if gene transfer of the epsilon3 form of APOE improves outcome in a murine model of transient focal cerebral ischaemia. Mice received an intrastriatal injection of vehicle, a second-generation adenoviral vector containing the green fluorescent protein gene (Ad-GFP) or a vector containing the APOE epsilon3 gene (Ad-APOE) 3 days before 60 mins focal ischaemia. Green fluorescent protein expression was observed in cells throughout the striatum and subcortical white matter indicating successful gene transfer and expression. ApoE levels in the brain were significantly increased after Ad-APOE compared with Ad-GFP or vehicle treatment. Ad-APOE treatment reduced the volume of ischaemic damage by 50% compared with Ad-GFP or vehicle treatment (13+/-3 versus 29+/-4 versus 27+/-5 mm(3)). The extent of postischaemic apoE immunoreactivity was enhanced in Ad-APOE compared with Ad-GFP or vehicle treated mice. These results show the ability of APOE gene transfer to markedly improve outcome after cerebral ischaemia and suggest that modulating apoE levels may be a potential strategy in human stroke therapy.

Apolipoprotein E delivery by peritoneal implantation of encapsulated recombinant cells improves the hyperlipidaemic profile in apoE-deficient mice.

Plasma apolipoprotein E (apoE) is a 34-kDa polymorphic protein which has atheroprotective actions by clearing remnant lipoproteins and sequestering excess cellular cholesterol. Low or dysfunctional apoE is a risk factor for hyperlipidaemia and atherosclerosis, and for restenosis after angioplasty. Here, in short-term studies designed to establish proof-of-principle, we investigate whether encapsulated recombinant Chinese hamster ovary (CHO) cells can secrete wild-type apoE3 protein in vitro and then determine whether peritoneal implantation of the microcapsules into apoE-deficient (apoE(-/-)) mice reduces their hypercholesterolaemia. Recombinant CHO-E3 cells were encapsulated into either alginate poly-l-lysine or alginate polyethyleneimine/polybrene microspheres. After verifying stability and apoE3 secretion, the beads were then implanted into the peritoneal cavity of apoE(-/-) mice; levels of plasma apoE3, cholesterol and lipoproteins were monitored for up to 14 days post-implantation. Encapsulated CHO-E3 cells continued to secrete apoE3 protein throughout a 60-day study period in vitro, though levels declined after 14 days. This cell-derived apoE3 was biologically active. When conditioned medium from encapsulated CHO-E3 cells was incubated with cultured cells pre-labelled with [(3)H]-cholesterol, efflux of cholesterol was two to four times greater than with normal medium (at 8 h, for example, 7.4+/-0.3% vs. 2.4+/-0.2% of cellular cholesterol; P<0.001). Moreover, when secreted apoE3 was injected intraperitoneally into apoE(-/-) mice, apoE3 was detected in plasma and the hyperlipidaemia improved. Similarly, when alginate polyethyleneimine/polybrene capsules were implanted into the peritoneum of apoE(-/-) mice, apoE3 was secreted into plasma and at 7 days total cholesterol was reduced, while atheroprotective high-density lipoprotein (HDL) increased. In a second study, apoE was detectable in plasma of five mice treated with alginate poly-l-lysine beads, 4 and 7 days post-implantation, though not at day 14. Furthermore, their hypercholesterolaemia was reduced, while HDL was clearly elevated in all mice at days 4 and 7 (from 18.4+/-6.2% of total lipoproteins to 31.1+/-6.8% at 7 days; P<0.001); however, these had rebounded by day 14, possibly due to the emergence of anti-apoE antibodies. We conclude that microencapsulated apoE-secreting cells have the potential to ameliorate the hyperlipidaemia of apoE deficiency, but that the technology must be improved to become a feasible therapeutic to treat atherosclerosis.

ApoE gene therapy to treat hyperlipidemia and atherosclerosis.

Atherosclerosis is the leading cause of death in industrialized countries and is becoming an increasingly worldwide risk to health. Apolipoprotein E (ApoE) is a blood circulating protein with pleiotropic atheroprotective properties that has emerged as a strong candidate for treating hypercholesterolemia and cardiovascular disease. In this review, we discuss the major developments in both viral and non-viral vectors aimed at achieving efficient delivery and sustained expression of an ApoE transgene. The technological advances in engineering viruses include cross-packaging to generate different serotypes of recombinant adeno-associated virus, and the use of multiple-deleted and helper-dependent recombinant adenovirus vectors to minimize immune responses and to package genomic loci. Non-viral ApoE delivery systems, including plasmids and cell-based therapy are also described in this review. Finally, a radical alternative to gene addition that has the potential for permanent cure in many genetic diseases--'targeted gene editing'--is reviewed. This technology uses synthetic oligonucleotides to correct underlying point mutations in situ and has been evaluated for repairing dysfunctional APOE genes.

Disclosure of cancer diagnosis and prognosis in Northern Tanzania.

Whether to tell patients with cancer about their diagnoses and prognoses is a matter of great debate. While many argue the importance of giving this information to facilitate informed decision-making, others argue that this same information can extinguish hope. Although there is some evidence that disclosure of this information is now commonplace in many Northern and Western settings, there are very few data about this issue from resource-poor nations describing physicians' decision-making regarding whether to disclose this information. Using a combination of ethnographic and other qualitative methods including participant observation, semi-structured interviews, informal interviews, and a review of key documents in Northern Tanzania, we map some of the salient issues in this setting. Like their colleagues in many other parts of the world, Tanzanian physicians often withhold diagnostic and prognostic information from patients. In addition, however, to the cultural arguments often used to justify this practice, issues of treatment availability and patient poverty also influenced the physicians' disclosure practices. Expatriate and Tanzanian physicians practicing in Northern Tanzania often had different approaches to informing patients of their diagnoses and prognoses. Some Tanzanian physicians advocated the use of a "roundabout" approach to disclosure, arguing that it was more reflective of the normal mode of discourse in Tanzania than the more direct approach advocated by many of their expatriate colleagues. Expatriate physicians and some of their Tanzanian colleagues felt that such an indirect approach often left patients confused, or indeed, uninformed.

Langerhans cells are more efficiently transduced than dermal dendritic cells by adenovirus vectors expressing either group C or group B fibre protein: implications for mucosal vaccines.

Vaccines against viruses need to target dendritic cells (DC) and stimulate mucosal immunity. Most vaccine studies have focussed on monocyte-derived or dermal DC (dDC) but recent evidence suggests that Langerhans cells (LC) may stimulate mucosal immunity more effectively. New chimeric adenovirus vectors expressing fibre protein from group B adenoviruses (rAd5/11), which utilise CD46 rather than the Coxsackie adenovirus receptor (CAR), have been developed as vaccines to improve transduction and overcome problems of pre-existing vector immunity. Transduction of LC and dDC by rAd5/11 and standard rAd5 expressing green fluorescent protein (GFP) showed that both DC types were more efficiently transduced by rAd5/11 than by rAd5. Although expression of CD46 and the integrins alphavbeta3 and alphavbeta5, which recognise the adenovirus penton base and mediate virus internalisation, was similar in LC and dDC, LC expressed higher levels of GFP. Transduction by electroporation of plasmid also resulted in higher GFP expression in LC, suggesting differences between the two DC populations at a post-entry stage. Transduction with either vector did not induce maturation of LC or dDC and did not affect their ability to stimulate T cells. These findings suggest that vaccine strategies that target LC with adenovirus vectors may be worthy of exploration.

Acute regression of advanced and retardation of early aortic atheroma in immunocompetent apolipoprotein-E (apoE) deficient mice by administration of a second generation [E1(-), E3(-), polymerase(-)] adenovirus vector expressing human apoE.

Apolipoprotein E (apoE) is a 34 kDa glycoprotein with multiple actions that help protect against the development of atherosclerosis. Here, we have assessed the atheroprotective potential of an [E1(-), E3(-), polymerase(-)] adenovirus vector expressing human apoE, comparing intramuscular and intravenous (liver-directed) injections in hypercholesterolaemic apoE-deficient mice (apoE(-/-)). Intramuscular injections resulted in low expression of apoE and afforded no protection against atherogenesis. In contrast, 3 and 7 days after intravenous injections into young (6-8-week-old) apoE(-/-) mice, plasma levels of apoE were elevated and were accompanied by reductions in plasma cholesterol and normalization of lipoprotein profiles. Thereafter, plasma apoE was still detectable up to day 70, but gradually declined, although no humoral immune response was evoked, and there was a return to dyslipoproteinaemia. High levels of the vector genome were still present in livers of treated animals at 70 days, implying that decrease in apoE expression was due to cellular shutdown of the cytomegalovirus promoter. Importantly, liver-directed apoE gene transfer to these young mice retarded progression of atherosclerosis by 38% (treated, 8.21 +/- 1.05%; untreated, 13.26 +/- 0.98%, P < 0.05), during the 70 day study period. Moreover, when 10-month-old apoE(-/-) mice with advanced atherosclerosis were treated with the adenovirus vector, there was clear regression of aortic lesion area by 1 month [24.3 +/- 1.7% compared to 40.7 +/- 2.6% in baseline controls (P < 0.002)]. We conclude that the stability of the adenovirus vector genome in the livers of intravenously treated animals provides an ideal platform to evaluate liver-specific promoters for sustained transgene expression and control of atherosclerotic lesion pathology.