A Retrospective Review of Secondary Hemophagocytic Lymphohistiocytosis (HLH) and Dengue-associated HLH from a Teaching Hospital in Singapore.

Real-world data on the outcome of Asian patients with secondary hemophagocytic lymphohistiocytosis (HLH), especially on dengue-associated HLH, are limited to small case series. This is a retrospective records review of adult patients with secondary HLH between 2015 and 2020. Thirty-two adult patients were followed up for a median of 6.6 months (range 0.1 - 75 months). 15 had underlying lymphomas, and 12 had viral infections. Hemophagocytosis was seen in 28 of 29 patients with a bone marrow biopsy. 100% and 76.5% of patients with and without an underlying malignancy required HLH-directed therapy and blood product transfusion. 12 of 15 patients with lymphomas were treated with additional chemotherapy. Patients with malignancy-associated HLH had poorer survival than non-malignancy-associated HLH (median overall survival (OS) 1.5 months versus not reached, p-value 0.003). The 1-year survival rates of patients with malignancy-associated HLH, HLH with unknown etiologies, and infection-associated HLH were 0.133 (95% CI: 0.036 - 0.484), 0.400 (95% CI: 0.137 - 1.000) and 0.833 (95% CI: 0.647 - 1.000), respectively. Malignancy significantly increased the risk of death compared to infection-associated HLH (HR 9.37, p-value 0.003). Eight patients were diagnosed with dengue-associated HLH with a median HSCORE of 240 (98-99% probability of HLH). Their mean ferritin was 34,740 ng/mL. Three patients required blood product transfusion, 5 required corticosteroids and/or etoposide, with a median duration of treatment of 31 days. Their overall survival rate was 87.5%. Our study highlights the stark contrast in the survival of secondary HLH patients with and without an underlying malignancy. We also present one of the world's most extensive case series of dengue-associated HLH.

Cultivating capacities in community-based researchers in low-resource settings: Lessons from a participatory study on violence and mental health in Sri Lanka.

Participatory methods, which rely heavily on community-based data collectors, are growing in popularity to deliver much-needed evidence on violence and mental health in low- and middle-income countries. These settings, along with local researchers, encounter the highest burden of violence and mental ill-health, with the fewest resources to respond. Despite increased focus on wellbeing for research participants and, to a lesser degree, professional researchers in such studies, the role-specific needs of community-based researchers receive scant attention. This co-produced paper draws insights from one group's experience to identify rewards, challenges, and recommendations for supporting wellbeing and development of community-based researchers in sensitive participatory projects in low-resource settings. Twenty-one community-based researchers supporting a mixed-methods study on youth, violence and mental health in Sri Lanka submitted 63 reflexive structured journal entries across three rounds of data collection. We applied Attride-Stirling's method for thematic analysis to explore peer researchers' learning about research, violence and mental health; personal-professional boundaries; challenges in sensitive research; and experiences of support from the core team. Sri Lanka's first study capturing experiences of diverse community-based researchers aims to inform the growing number of global health and development actors relying on such talent to deliver sensitive and emotionally difficult work in resource-limited and potentially volatile settings. Viewing participatory research as an opportunity for mutual learning among both community-based and professional researchers, we identify practice gaps and opportunities to foster respectful team dynamics and create generative and safe co-production projects for all parties. Intentional choices around communication, training, human and consumable resources, project design, and navigating instable research conditions can strengthen numerous personal and professional capacities across teams. Such individual and collective growth holds potential to benefit short- and long-term quality of evidence and inform action on critical issues, including violence and mental health, facing high-burden, low-resource contexts.

Fabrication of carbon and silver nanomaterials incorporated hydroxyapatite nanocomposites: Enhanced biological and mechanical performances for biomedical applications.

Hydroxyapatite is widely utilized for different biomedical applications because of its outstanding biocompatibility and bioactivity. Cuttlefish bones, which are available aplenty, are both inexpensive and eco-friendly sources for calcium carbonate. In the present study, cuttlefish bones-derived HAp nanorods have been utilized to fabricate HAp nanocomposites incorporating 1, 3 and 5 wt% each of GO, MWCNTs, GONRs and Ag NPs. Characterization using such techniques as XRD, FTIR, HRSEM and EDS was performed to analyze the physicochemical properties of nanocomposites, and MTT assay, hemolysis, bioactivity and drug release to evaluate the biological properties. The XRD and HRSEM results reveal that crystallite and particle size increase with increasing wt% of carbon nanomaterials and Ag NPs. However, the addition of nanomaterials did not modify the shape of HAp. The MTT assay and hemolysis results suggest GONRs possess better biocompatibility than GO and CNTs due to their smooth edge structure. While adding carbon materials up to 3 wt% caused an increase in the hardness, adding up to 5 wt% of them caused a decrease in the hardness due to the agglomeration of the particles. Biocompatibility and Vicker's hardness studies show that adding carbon nanomaterials up to 3 wt% caused significant improvement in biocompatibility and mechanical properties. Antibacterial activity test was performed to analyze the ability to preclude the formation of biofilms. The results showed better activity for silver-incorporated nanocomposites in the presence of E. coli and S. aureus bacteria. Drug release studies were performed using lidocaine drug and the results showed nearly similar drug release profile for all the samples except HAg3. Finally, nanocomposite HRA3 could be a suitable candidate for biomedical applications since it shows better biological and mechanical properties than GO and MWCNTs nanocomposites.

Impact of opioid maintenance treatment during pregnancy on neonatal birth weight and head circumference.

BACKGROUND: Pregnant mothers with opioid dependency commonly receive maintenance treatment of opioid (OMT), either as buprenorphine (BMT) or methadone maintenance treatment (MMT). We investigated, whether OMT adversely affects standardized neonatal anthropometric outcomes and whether BMT is potentially safer than MMT in this regard. METHODS: Retrospective chart review of mother infant dyad, with and without OMT. Infant's absolute and standardized (z-score) anthropometric outcomes at birth were first compared, between OMT and control group (negative meconium drug screen), and then between BMT and MMT group. These outcomes were also compared between infants who did or did not require treatment after birth for neonatal abstinence syndrome (NAS). RESULT: A total of 1479 participants with MDS were included [Control = 1251; OMT = 228 (MMT = 181; BMT = 47)]. Both the z-scores of birth weight (BW) and head circumference (HC) was lower in OMT group (p < 0.001). Among the OMT group, GA at delivery was slightly higher in the BMT group (p = 0.05). There was an inverse correlation between maternal dose at the time of delivery and anthropometric z-scores in the BMT group, mainly in female infants (BW: p = 0.006; HC: p = 0.003). Furthermore, In BMT group, infants with lower HC were more likely to require treatment for NAS (p = 0.01). CONCLUSION: HC and BW when comparing Z-scores were not different between MMT and BMT. High maternal dosing of buprenorphine is associated with lower BW and HC Z-scores but dose effect is not seen with methadone. In addition, there seems to be an association between NAS severity and HC, especially in the BMT group.

Granulomatous slack skin syndrome: Report of a unique case.

Granulomatous slack skin syndrome is a rare variant of cutaneous T-cell lymphoma (mycosis fungoides). It is characterized clinically by redundant skin folds, which show a predilection towards flexural areas such as the axilla and the groin. Histologically, it shows a granulomatous T-cell infiltrate and loss of elastic tissue. It has an indolent but progressive course; and is usually refractory to treatment. We report a unique case of slack skin syndrome, sparing the classical sites with rapid and unusual involvement of non-intertriginous areas.

Macrodystrophia Lipomatosa: An Unusual Cause of Localized Gigantism.

Macrodystrophia lipomatosa (MDL) is a rare congenital form of localized gigantism characterized by progressive overgrowth of all mesenchymal elements with a disproportionate increase in fibro adipose tissue. Here we report a case of 20 years old male who presented with history of painless gradual enlargement of entire left upper limb since childhood. Magnetic resonance imaging and histopathology confirmed the diagnosis of macrodystrophia lipomatosa. This condition has to be differentiated from other causes of localized gigantism, since these conditions differ in their course, prognosis, complications and treatment.

Persistent hiccups (singultus) as the presenting symptom of lateral medullary syndrome.

Lateral medullary syndrome (LMS) is a constellation of varied neurologic manifestations seen in cerebrovascular accidents. The posterolateral part of the medulla oblongata of the brain stem and cerebellum receiving arterial blood supply from the posterior inferior cerebellar artery are the areas commonly affected. We present a case of a middle aged gentleman referred to our hospital for persistent intractable hiccups as presenting symptom of LMS. He presented to our emergency room with persistent hiccups and left sided cerebellar signs. The patient had significant past history of alcohol and tobacco (smoking) dependence since 30 years apart from being a hypertensive.

Toll-like receptor genetic variants are associated with Gram-negative infections in VLBW infants.

OBJECTIVE: To test the hypothesis that single-nucleotide polymorphisms (SNPs) in Toll-like receptor (TLR) genes alter susceptibility to bacterial infections and modulate white blood cell (WBC) counts during infections in very low birth weight (VLBW) infants (birth weight <1500 g). STUDY DESIGN: VLBW infants recruited in a multicenter study were genotyped for nine functional TLR SNPs and associations between SNPs and infection rates examined. WBC counts obtained during infections were compared among infants with and without SNPs. RESULT: In our cohort (n=408), 90 infants developed bacterial infections. Presence of TLR4 (rs4986790 and rs4986791) variants were associated with Gram-negative (G-ve) infections. Female infants heterozygous for the X-linked IRAK1 (rs1059703) SNP had less G-ve infections. In regression models controlling for confounders, the TLR4 (rs4986790) SNP was associated with increased G-ve infections. The TLR5 (rs5744105) variant was associated with elevated WBC counts during infections. CONCLUSION: TLR genetic variants can contribute to increased risk of bacterial infections and altered immune responses in VLBW infants.

A TIR domain receptor-associated protein (TIRAP) variant SNP (rs8177374) confers protection against premature birth.

OBJECTIVE: To investigate whether single nucleotide polymorphisms (SNPs) in genes encoding the Toll-like receptor (TLR) signaling pathway modulate susceptibility to preterm birth (PTB). STUDY DESIGN: Prospective case-control study examining the contribution of nine TLR SNPs to PTB (<37 weeks) and PTB <32 weeks. Genotyping was done on neonatal blood using a multiplexed single-base extension assay. Chi-square test, Fischer's exact test and classification trees were used for data analysis. RESULT: Preterm infants (n=177) were more likely to be African American (P=0.02), and were more likely to be born to mothers who smoked (P=0.007), had pregnancy-induced hypertension (PIH; P=0.002) and placental abruption (P=0.0004) when compared with term infants (n=146). The TLR2, TLR4, TLR5, TLR9, nuclear factor-kappa B1 (NFκB1), NFκBIA and IRAK1 variants were not associated with PTB whereas the TIR domain receptor-associated protein (TIRAP) variant was more prevalent in term infants when compared with preterm infants born <32 weeks (P=0.004). PTB <32 weeks was more prevalent in infants without the TIRAP variant whose mothers had PIH and did not smoke (P=0.001). Presence of the TIRAP variant protected against PTB <32 weeks (P=0.015) in Caucasian infants. CONCLUSION: In our study, a TLR pathway adapter variant (TIRAP (rs8177374)) protected against PTB<32 weeks, supporting our hypothesis that genetic variation in the innate immune signaling pathway contributes to altered risk of PTB.

Ontogeny of growth-regulating genes in the placenta.

BACKGROUND: Placental nutrient flow is the primary determinant of fetal growth. This key function of the placenta depends on several growth-promoting or -suppressing imprinted genes including Insulin-like growth factor [IGF] axis genes, which regulate nutrient transfer across the placenta. However whether changes in the placental expression of these genes parallel increased fetal growth observed in the second and third trimester remains unknown. OBJECTIVE: The aim of our study was to determine the ontogeny of key IGF axis genes and other growth regulating imprinted genes in the placenta and to characterize patterns of placental gene expression associated with intrauterine growth restriction (IUGR). STUDY DESIGN: Real time RT-PCR analysis of 11 genes using specific probes were performed in the placental tissue collected at the time of delivery from 63 subjects with live birth pregnancies from 24 to 40 weeks gestation between 2009 -2010. RESULTS: We found that paternally expressed gene ZNF127 (p < 0.001) was upregulated whereas IGF1 (p = 0.001) and maternally expressed gene PHLDA2 (p = 0.001) were downregulated with advancing gestational age. ROC analysis revealed a significant change in the expression of the above genes early in the third trimester. When compared to age-matched appropriate for gestational age (AGA) infants, expression of PHLDA2 (p = 0.03) IGF2R (p < 0.05) was upregulated in IUGR infants. Maternal age was also a significant predictor for IUGR (p = 0.05). CONCLUSION: We found increased placental expression of growth-promoting imprinted genes and decreased expression of growth-suppressive imprinted genes with advancing gestational age. These changes in placental gene expression could potentially explain accelerated fetal growth seen in the third trimester. Upregulation of maternally expressed imprinted genes in IUGR population supports the "parental conflict hypothesis".

Rpb4, a non-essential subunit of core RNA polymerase II of Saccharomyces cerevisiae is important for activated transcription of a subset of genes.

A major role in the regulation of eukaryotic protein-coding genes is played by the gene-specific transcriptional regulators, which recruit the RNA polymerase II holoenzyme to the specific promoter. Several components of the mediator complex within the holoenzyme also have been shown to affect activation of different subsets of genes. Only recently has it been suggested that besides the largest subunit of RNA polymerase II, smaller subunits like Rpb3 and Rpb5 may have regulatory roles in expression of specific sets of genes. We report here, the role of Rpb4, a non-essential subunit of core RNA polymerase II, in activation of a subset of genes in Saccharomyces cerevisiae. We have shown below that whereas constitutive transcription is largely unaffected, activation from various promoters tested is severely compromised in the absence of RPB4. This activation defect can be rescued by the overexpression of cognate activators. We have localized the region of Rpb4 involved in activation to the C-terminal 24 amino acids. We have also shown here that transcriptional activation by artificial recruitment of the TATA-binding protein (TBP) to the promoter is also defective in the absence of RPB4. Surprisingly, the overexpression of RPB7 (the interacting partner of Rpb4) does not rescue the activation defect of all the promoters tested, although it rescues the activation defect of the heat shock element-containing promoter and the temperature sensitivity associated with RPB4 deletion. Overall, our results indicate that Rpb4 and Rpb7 play independent roles in transcriptional regulation of genes.

Anesthetic-like interactions of nitric oxide with albumin and hemeproteins. A mechanism for control of protein function.

Noncovalent bonding interactions of nitric oxide (NO) with human serum albumin (HSA), human hemoglobin A, bovine myoglobin, and bovine cytochrome c oxidase (CcO) have been explored. The anesthetic nitrous oxide (NNO) occupies multiple sites within each protein, but does not bind to heme iron. Infrared (IR) spectra of NNO molecules sequestered within albumin, with NO present, support the binding of NO and NNO to the same sites with comparable affinities. Perturbations of IR spectra of the Cys(34) thiol of HSA indicate NO, NNO, halothane, and chloroform can induce similar changes in protein structure. Experiments evaluating the relative affinities of binding of NO and carbon monoxide (CO) to iron(II) sites of the hemeproteins led to evidence of NO binding to noniron, nonsulfur sites as well. With HbA, IR spectra of cysteine thiols and/or the iron(II) N-O stretching region denote changes in protein structure due to NO, NNO, or CO occupying noniron sites with an order of decreasing affinities of NO > NNO > CO. Loss of NO from some, not all, noniron sites in hemeproteins is very slow (t(1/2) approximately hours). These findings provide examples in which NO and anesthetics alter the structure and properties of protein similarly, and support the hypothesis that some physiological effects of NO (and possibly CO) result from anesthetic-like noncovalent bonding to sites within protein or other tissue components. Such bonding may be involved in mechanisms for control of oxygen transport, mitochondrial respiration, and activation of soluble guanylate cyclase by NO.

Potential roles of myoglobin autoxidation in myocardial ischemia-reperfusion injury.

The source(s) of reactive partially reduced oxygen species associated with myocardial ischemia/reperfusion injury remain unclear and controversial. Myoglobin has not been viewed as a participant but is present in relatively high concentrations in heart muscle and, even under normal conditions, undergoes reactions that generate met (Fe3+) species and also superoxide, hydrogen peroxide, and other oxidants, albeit slowly. The degree to which the decrease in pH and the freeing of copper ions, as well as the variations in pO2 associated with ischemia and reperfusion increase the rates of such myoglobin reactions has been investigated. Solutions of extensively purified myoglobin from bovine heart in 50 mM sodium phosphate buffer were examined at 37 degrees C. Sufficiently marked rate increases were observed to indicate that reactions of myoglobin can indeed contribute substantially to the oxidant stress associated with ischemia/reperfusion injury in myocardial tissues. These findings provide additional targets for therapeutic interventions.

Cytochrome c oxidase catalysis of the reduction of nitric oxide to nitrous oxide.

Reduction of nitric oxide (NO) to nitrous oxide (N2O) is catalyzed by bovine heart cytochrome c oxidase (CcO) in anaerobic solutions at pH 7.2 and 20 degrees C. Cyanide inhibits and forms Fea3(3+)CN. The mononitrosyl (Fea3(2+)NO), but not the dinitrosyl (Fea3(2+)NO; CuB+NO), is a likely intermediate in N2O formation. One-electron reduction of NO at Fea3(2+) could yield N2O via HNO. However, a two-electron reduction of the NO ligand to give an intermediate that reacts with a second NO to give N2O and H2O appears more likely. Conversion of NO to N2O is favored by low levels of both NO and O2, higher NO levels can inhibit both cytochrome c oxidase and NO reductase activities. Raising the O2 level will favor catalysis of NO oxidation to NO2 by CcO. The reactions of NO and the specific CcO activity that occur in tissue will be critically dependent on NO, O2, and CcO levels.