Neu-Laxova syndrome is a heterogeneous metabolic disorder caused by defects in enzymes of the L-serine biosynthesis pathway.

Neu-Laxova syndrome (NLS) is a rare autosomal-recessive disorder characterized by a recognizable pattern of severe malformations leading to prenatal or early postnatal lethality. Homozygous mutations in PHGDH, a gene involved in the first and limiting step in L-serine biosynthesis, were recently identified as the cause of the disease in three families. By studying a cohort of 12 unrelated families affected by NLS, we provide evidence that NLS is genetically heterogeneous and can be caused by mutations in all three genes encoding enzymes of the L-serine biosynthesis pathway. Consistent with recently reported findings, we could identify PHGDH missense mutations in three unrelated families of our cohort. Furthermore, we mapped an overlapping homozygous chromosome 9 region containing PSAT1 in four consanguineous families. This gene encodes phosphoserine aminotransferase, the enzyme for the second step in L-serine biosynthesis. We identified six families with three different missense and frameshift PSAT1 mutations fully segregating with the disease. In another family, we discovered a homozygous frameshift mutation in PSPH, the gene encoding phosphoserine phosphatase, which catalyzes the last step of L-serine biosynthesis. Interestingly, all three identified genes have been previously implicated in serine-deficiency disorders, characterized by variable neurological manifestations. Our findings expand our understanding of NLS as a disorder of the L-serine biosynthesis pathway and suggest that NLS represents the severe end of serine-deficiency disorders, demonstrating that certain complex syndromes characterized by early lethality could indeed be the extreme end of the phenotypic spectrum of already known disorders.

Mutations in the enzyme glutathione peroxidase 4 cause Sedaghatian-type spondylometaphyseal dysplasia.

BACKGROUND: Sedaghatian-type spondylometaphyseal dysplasia (SSMD) is a neonatal lethal form of spondylometaphyseal dysplasia characterised by severe metaphyseal chondrodysplasia with mild limb shortening, platyspondyly, cardiac conduction defects, and central nervous system abnormalities. As part of the FORGE Canada Consortium we studied two unrelated families to identify the genetic aetiology of this rare disease. METHODS AND RESULTS: Whole exome sequencing of a child affected with SSMD and her unaffected parents identified two rare variants in GPX4. The first (c.587+5G>A) was inherited from the mother, and the second (c.588-8_588-4del) was de novo (NM_001039848.1); both were predicted to impact splicing of GPX4. In vitro studies confirmed the mutations spliced out part of exon 4 and skipped exon 5, respectively, with both resulting in a frameshift and premature truncation of GPX4. Subsequently, a second child with SSMD was identified; although DNA from the child was not available, the two unaffected parents were found by Sanger sequencing to each carry the same heterozygous stop mutation in exon 3 of GPX4, c.381C>A, p.Tyr127* (NM_001039848.1). CONCLUSIONS: Our identification of truncating mutations in GPX4 in two families affected with SSMD supports the pathogenic role of mutated GPX4 in this very rare disease. GPX4 is a member of the glutathione peroxidase family of antioxidant defence enzymes and protects cells against membrane lipid peroxidation. GPX4 is essential for early embryo development, regulating anti-oxidative and anti-apoptotic activities. Our findings highlight the importance of this enzyme in development of the cardiac, nervous, and skeletal systems.

You Can Change a Girl's Life Today: The Truth About Periods and Endometriosis.

While endometriosis, a condition where tissue growing outside the uterus causes pain and infertility, is generally widespread among teenage girls and women, it is often misdiagnosed leading to a delay in treatment while the symptoms and damage from the disease increase. This article uses a case study to illustrate the signs and symptoms of endometriosis in a teenage girl, while also discussing many factors surrounding the issue such as the incidence, disease burden, medical research and women, reasons for diagnostic delay, and the current recommended treatments. School nurses are in the unique position to identify young girls and adolescents who are presenting with painful periods or other symptoms possibly associated with endometriosis and can become advocates for the next generation of patients.

Laparoscopic intracorporeal cinch knots: changing the square knot paradigm.

Reliable knot tying is a cornerstone of surgical technique, and the square knot and surgeon's knot constitute the greatest part of most surgeons' knot-tying skills. Traditionally, laparoscopic intracorporeal knot tying of a square knot or surgeon's knot is a direct translation from an open instrument tying technique. Given the technical and mechanical challenges imposed by standard laparoscopic instrumentation, performance of such a basic task is sometimes difficult and elusive, even for accomplished surgeons. Consequently, myriad technologies and techniques are used as work-arounds for this basic surgical task. However, the sometimes necessary tying of a snug and reliable intracorporeal knot is unavoidable. That laparoscopic intracorporeal knot tying must be translated from a 2-handed open surgical technique using flat knots deserves reassessment. Cinch knots, with unusual sliding and tightening properties, are currently used in surgery. With apparent complexity and exacting construction requirements, however, primary intracorporeal knot tying has not been described. Described herein is a technique for doing so. Also included is a review of cinch knot mechanics, an understanding of a fundamental scheme for their construction, and basic instrument maneuvers that enable easier intracorporeal tying of a most reliable knot, useful for multiport and, in particular, single-port laparoscopic knot tying.

Catching a resurgence: Increase in SARS-CoV-2 viral RNA identified in wastewater 48 h before COVID-19 clinical tests and 96 h before hospitalizations.

Curtailing the Spring 2020 COVID-19 surge required sweeping and stringent interventions by governments across the world. Wastewater-based COVID-19 epidemiology programs have been initiated in many countries to provide public health agencies with a complementary disease tracking metric and non-discriminating surveillance tool. However, their efficacy in prospectively capturing resurgences following a period of low prevalence is unclear. In this study, the SARS-CoV-2 viral signal was measured in primary clarified sludge harvested every two days at the City of Ottawa's water resource recovery facility during the summer of 2020, when clinical testing recorded daily percent positivity below 1%. In late July, increases of >400% in normalized SARS-CoV-2 RNA signal in wastewater were identified 48 h prior to reported >300% increases in positive cases that were retrospectively attributed to community-acquired infections. During this resurgence period, SARS-CoV-2 RNA signal in wastewater preceded the reported >160% increase in community hospitalizations by approximately 96 h. This study supports wastewater-based COVID-19 surveillance of populations in augmenting the efficacy of diagnostic testing, which can suffer from sampling biases or timely reporting as in the case of hospitalization census.

Quantitative analysis of SARS-CoV-2 RNA from wastewater solids in communities with low COVID-19 incidence and prevalence.

In the absence of an effective vaccine to prevent COVID-19 it is important to be able to track community infections to inform public health interventions aimed at reducing the spread and therefore reduce pressures on health-care, improve health outcomes and reduce economic uncertainty. Wastewater surveillance has rapidly emerged as a potential tool to effectively monitor community infections through measuring trends of RNA signal in wastewater systems. In this study SARS-CoV-2 viral RNA N1 and N2 gene regions are quantified in solids collected from influent post grit solids (PGS) and primary clarified sludge (PCS) in two water resource recovery facilities (WRRF) serving Canada's national capital region, i.e., the City of Ottawa, ON (pop. ≈ 1.1M) and the City of Gatineau, QC (pop. ≈ 280K). PCS samples show signal inhibition using RT-ddPCR compared to RT-qPCR, with PGS samples showing similar quantifiable concentrations of RNA using both assays. RT-qPCR shows higher frequency of detection of N1 and N2 gene regions in PCS (92.7, 90.6%, n = 6) as compared to PGS samples (79.2, 82.3%, n = 5). Sampling of PCS may therefore be an effective approach for SARS-CoV-2 viral quantification, especially during periods of declining and low COVID-19 incidence in the community. The pepper mild mottle virus (PMMoV) is determined to have a less variable RNA signal in PCS over a three month period for two WRRFs, regardless of environmental conditions, compared to Bacteroides 16S rRNA or human 18S rRNA, making PMMoV a potentially useful biomarker for normalization of SARS-CoV-2 signal. PMMoV-normalized PCS RNA signal from WRRFs of two cities correlated with the regional public health epidemiological metrics, identifying PCS normalized to a fecal indicator (PMMoV) as a potentially effective tool for monitoring trends during decreasing and low-incidence of infection of SARS-Cov-2 in communities.

Targeting PDK4 inhibits breast cancer metabolism.

Dysregulated metabolism in the form of aerobic glycolysis occurs in many cancers including breast carcinoma. Here, we report PDK4 (pyruvate dehydrogenase kinase 4) as key enzyme implicated in the control of glucose metabolism and mitochondrial respiration is relatively highly expressed in breast cancers, and its expression correlates with poor patient outcomes. Silencing of PDK4 and ectopic expression of miR-211 attenuates PDK4 expression in breast cancer cells. Interestingly, low miR-211 expression is significantly associated with shorter overall survival and reveals an inverse correlation between expression of miR-211 and PDK4. We have found that depletion of PDK4 by miR-211 shows an oxidative phosphorylation-dominant phenotype consisting of the reduction of glucose with increased expression of PDH and key enzymes of the TCA cycle. miR-211 expression causes alteration of mitochondrial membrane potential and induces mitochondrial apoptosis as observed via IPAD assay. Further, by inhibiting PDK4 expression, miR-211 promotes a phenotype shift towards a pro-glycolytic state evidenced by decreased extracellular acidification rate (ECAR); increased oxygen consumption rate (OCR); and increased spare respiratory capacity in breast cancer cell lines. Taken together this data establishes a molecular connection between PDK4 and miR-211 and suggests that targeting miR-211 to inhibit PDK4 could represent a novel therapeutic strategy in breast cancers.

A randomized, controlled Phase III trial of therapeutic plasma exchange with fresh-frozen plasma (FFP) prepared with amotosalen and ultraviolet A light compared to untreated FFP in thrombotic thrombocytopenic purpura.

BACKGROUND: Photochemical treatment of fresh-frozen plasma (FFP) with amotosalen and ultraviolet (UV) A light (PCT FFP) results in inactivation of a broad spectrum of pathogens while retaining coagulation factor activity, antithrombotic proteins, and von Willebrand factor-cleaving protease (VWF-CP) activity. STUDY DESIGN AND METHODS: A randomized, controlled, double-blind Phase III trial was conducted with PCT FFP or control FFP for therapeutic plasma exchange (TPE) in patients with thrombotic thrombocytopenic purpura (TTP). Owing to the rarity of this diagnosis, the trial was not powered to demonstrate small differences between treatment groups. Patients were treated with study FFP for a maximum of 35 days until remission was achieved (for a maximum of 30 daily study TPEs with no remission) plus an additional 5 days after remission. RESULTS: Among the 35 patients treated, the primary endpoint, remission within 30 days, was achieved by 14 of 17 (82%) PCT patients and 16 of 18 (89%) control patients (p = 0.658) The 90 percent confidence interval for treatment difference in remission rate for test - control was (-0.291 to 0.163). Time to remission, relapse rates, time to relapse, total volume and number of FFP units exchanged, and number of study TPEs were not significantly different between groups. Improvement in VWF-CP and inhibitors was similar for both groups. The overall safety profile of PCT FFP was similar to control FFP. No antibodies to amotosalen neoantigens were detected. CONCLUSION: The comparable results between treatment groups observed from this small trial suggest that TPE with PCT FFP was safe and effective for treatment of TTP.

TRALI: correlation of antigen-antibody and monocyte activation in donor-recipient pairs.

BACKGROUND: TRALI may be a severe reaction associated with transfusion of plasma-containing blood components. TRALI has usually been associated with antibodies against granulocytes and HLA class I antigens, but more recently with antibodies against HLA class II and monocytes. TRALI cases were investigated to determine correlation between antigen and antibody. Additionally, activation of monocytes by TRALI serums was studied. STUDY DESIGN AND METHODS: Sixteen cases of TRALI were investigated. All patients were typed for HLA antigens. Implicated donors were screened for HLA antigens and antibodies against granulocytes and monocytes. In 6 cases, recipient monocyte activation was measured in vitro after incubation with TRALI and control serums. In four cases, monocyte activation was measured after incubation of TRALI serums against a panel of monocytes of known HLA antigen type. RESULTS: In 14 of the 16 cases (87.5%), antigen-antibody correlation was identified. TRALI monocytes, incubated with implicated TRALI serum (n = 6), expressed significantly greater cytokine and tissue factor (p < 0.05, repeated-measures ANOVA) than controls. Panel monocytes incubated with TRALI serum showed increased expression of cytokine and/or tissue factor when corresponding antigen was present. CONCLUSION: In most cases of TRALI, a correlation between antigen and antibody can be identified. Activation of monocytes and their subsequent release of cytokines may play a role in the pathogenesis of TRALI.

Transfusion-related acute lung injury: report of a clinical look-back investigation.

CONTEXT: Transfusion-related acute lung injury (TRALI) is a syndrome that includes dyspnea, hypotension, bilateral pulmonary edema, and fever. TRALI is the third leading cause of transfusion-related mortality, but it is probably underdiagnosed and underreported. OBJECTIVE: To determine if blood products from a frequent plasma donor, whose blood product was implicated in a fatal case of TRALI, caused symptoms of TRALI in other recipients of her plasma. DESIGN, SETTING, AND PARTICIPANTS: Retrospective chart review (conducted from November 2000 through April 2001) of 50 patients who received blood components within 2 years (October 1998 through October 2000) from a donor linked to a transfusion-related fatality. MAIN OUTCOME MEASURE: Occurrence of mild/moderate (dyspnea with fever, chills, hypotension, and/or hypoxemia) or severe (acute pulmonary edema or need for mechanical ventilation) reaction associated with transfusion. RESULTS: Superimposed illness prevented assessment of TRALI in 14 patients. Of the 36 patient charts that could be reviewed, 7 mild/moderate reactions were reported in 6 patients (16.7%) and 8 severe reactions were reported in 8 patients (22.2%). Of 5 patients who received multiple transfusions from the same donor, 2 experienced 2 reactions: one had 2 mild/moderate reactions and the other had both a mild/moderate and a severe reaction. While 5 of the 7 mild/moderate reactions were reported to the hospital transfusion service, only 2 of the 8 severe reactions were reported. Only 2 reactions (1 mild/moderate and 1 severe) were reported to the regional blood collection facility. CONCLUSIONS: TRALI was frequently underdiagnosed and underreported in recipients of blood products from a donor whose blood products may have caused TRALI in several transfusion recipients. Clinical education and awareness of this often-overlooked diagnosis are imperative for appropriate prevention and treatment.

Pharmacokinetic study of FFP photochemically treated with amotosalen (S-59) and UV light compared to FFP in healthy volunteers anticoagulated with warfarin.

BACKGROUND: To date, no clinical trials have characterized FFP infusion efficacy, and infusion still carries infectious risk. This single-blinded crossover study compared postinfusion kinetics of FVII in photochemically treated FFP to standard FFP. STUDY DESIGN AND METHODS: Subjects donated plasma by apheresis. Half of the collected plasma was treated with the psoralen amotosalen hydrochloride (S-59) and UVA light, and half were prepared as standard plasma. Subjects received warfarin over 4 days to lower FVII levels. On Day 4, subjects received 1 L of either treated or standard FFP. After 2 weeks, subjects underwent a regimen identical to that with the other type of FFP. RESULTS: After warfarin ingestion, the mean FVII concentration was 0.33 IU per mL. Both types of FFP exhibited comparable FVII kinetics, with a mean peak increment of 0.10 to 0.12 IU per mL occurring at the end of infusion. The effect disappeared after 8 hours. DISCUSSION: Study data of warfarin-treated healthy volunteers demonstrate that psoralen plus UV-treated FFP provides an equivalent in vivo coagulation response to control plasma. A 1-L dose of FFP in adults may provide an initial increment of 0.10 IU per mL of FVII. In the absence of bleeding, FVII levels return to baseline after 8 hours.