RFX6 regulates human intestinal patterning and function upstream of PDX1.

The gastrointestinal tract is complex and consists of multiple organs with unique functions. Rare gene mutations can cause congenital malformations of the human GI tract, although the molecular basis of these has been poorly studied. We identified a patient with compound-heterozygous mutations in RFX6 presenting with duodenal mal-rotation and atresia, implicating RFX6 in development of the proximal intestine. To identify how mutations in RFX6 impact intestinal patterning and function, we derived iPSCs from this patient to generate human intestinal organoids (HIOs). We identified that the duodenal HIOs and patient tissues had mixed regional identity, with gastric and ileal features. CRISPR-mediated correction of RFX6 restored duodenal identity. We then used gain- and loss-of-function and transcriptomic approaches in HIOs and Xenopus embryos to identify that PDX1 is a downstream transcriptional target of RFX6 required for duodenal development. However, RFX6 had additional PDX1-independent transcriptional targets involving multiple components of signaling pathways that are critical for establishing early regional identity in the GI tract. In summary, we have identified RFX6 as a key regulator in intestinal patterning that acts by regulating transcriptional and signaling pathways.

Generation and characterization of a zebrafish gain-of-function ACOX1 Mitchell disease model.

Background: Mitchell syndrome is a rare, neurodegenerative disease caused by an ACOX1 gain-of-function mutation (c.710A>G; p.N237S), with fewer than 20 reported cases. Affected patients present with leukodystrophy, seizures, and hearing loss. ACOX1 serves as the rate-limiting enzyme in peroxisomal beta-oxidation of very long-chain fatty acids. The N237S substitution has been shown to stabilize the active ACOX1 dimer, resulting in dysregulated enzymatic activity, increased oxidative stress, and glial damage. Mitchell syndrome lacks a vertebrate model, limiting insights into the pathophysiology of ACOX1-driven white matter damage and neuroinflammatory insults. Methods: We report a patient presenting with rapidly progressive white matter damage and neurological decline, who was eventually diagnosed with an ACOX1 N237S mutation through whole genome sequencing. We developed a zebrafish model of Mitchell syndrome using transient ubiquitous overexpression of the human ACOX1 N237S variant tagged with GFP. We assayed zebrafish behavior, oligodendrocyte numbers, expression of white matter and inflammatory transcripts, and analysis of peroxisome counts. Results: The patient experienced progressive leukodystrophy and died 2 years after presentation. The transgenic zebrafish showed a decreased swimming ability, which was restored with the reactive microglia-targeted antioxidant dendrimer-N-acetyl-cysteine conjugate. The mutants showed no effect on oligodendrocyte counts but did display activation of the integrated stress response (ISR). Using a novel SKL-targeted mCherry reporter, we found that mutants had reduced density of peroxisomes. Conclusions: We developed a vertebrate (zebrafish) model of Mitchell syndrome using transient ubiquitous overexpression of the human ACOX1 N237S variant. The transgenic mutants exhibited motor impairment and showed signs of activated ISR, but interestingly, there were no changes in oligodendrocyte counts. However, the mutants exhibited a deficiency in the number of peroxisomes, suggesting a possible shared mechanism with the Zellweger spectrum disorders.

The electrified artist: Edvard Munch's demons, treatments, and sketch of an electrotherapy session (1908-1909).

In 1908-1909, Norwegian artist Edvard Munch (1863-1944), best remembered for The Scream (1893), spent eight months under Daniel Jacobson's care in a private nerve clinic in Copenhagen. Munch was suffering from alcohol abuse, and his signs and symptoms included auditory hallucinations, persecutory delusions, paresthesias, paralyses, violent mood swings, depression, loss of control, fatigue, and the loss of his basic ability to take care of himself. He was treated with rest, a fortifying diet, massages, baths, fresh air, limited exercise, and nonconvulsive electrotherapy. After he had settled in, Jacobson allowed Munch to draw, paint, and engage in photography. Munch responded with a portrait of Jacobson and a small but intriguing sketch of himself at one of his electrotherapy sessions. In this article, we examine the circumstances that brought Munch to Jacobson's clinic and his therapies, with particular attention to electrotherapies. In so doing, we hope to provide a more complete picture of Munch's crisis in 1908, his nerve doctor, the rationales for medical electricity and other treatments he endured, and Scandinavian psychiatry at this moment in time.

Reported COVID-19 vaccines side effects among Algerian athletes: a comparison between inactivated virus, adenoviral vector, and mRNA COVID-19 vaccines.

OBJECTIVES: Many types of COVID19 vaccines are administered globally, yet there is not much evidence regarding their side effects among athletes. This study evaluated the selfreported postvaccination side effects of inactivated virus, adenoviral vector, and mRNA COVID19 vaccines among Algerian athletes. METHODS: A cross-sectional survey-based study was carried out in Algeria between March 01 and 4 April 2022. The study used a validated questionnaire with twenty-five multiple-choice items covering the participants' anamnestic characteristics, post-vaccination side effects (their onset and duration), post-vaccination medical care, and risk factors. RESULTS: A total of 273 athletes completed the survey. Overall, (54.6%) of the athletes reported at least one local side effect, while (46.9%) reported at least one systemic side effect. These side effects were more prevalent among the adenoviral vector group compared to the inactivated virus and mRNA groups. The most common local side effect was injection site pain (29.9%), while Fever (30.8%) was the most prevalent systemic side effect. The age group of 31-40 years, allergy, previous infection with COVID-19, and the first dose of vaccines were associated with an increased risk of side effects for all groups of COVID-19 vaccines. Logistic regression analysis further revealed that compared to males, the incidence of reported side effects was significantly higher in females (odd ratio (OR) = 1.16; P = 0.015*) only for the adenoviral vector vaccine group. In addition, a significantly higher percentage of athletes group of high dynamic/moderate static or high dynamic /high static components suffered from post-vaccination side effects compared to the group of athletes with high dynamic/low static components (OR = 14.68 and 14.71; P < 0.001, respectively). CONCLUSIONS: The adenoviral vector vaccines have the highest rate of side effects, followed by the inactivated virus and mRNA COVID-19 vaccines. COVID­19 vaccines were well-tolerated among Algerian athletes and there were no reports of serious side effects. Nevertheless, further long-term follow-up study with a larger sample size of athletes (from different types and sports categories) is warranted to establish the long-term safety of the COVID-19 vaccine.

Lel A. Drachev and the Direct Electrometric Method.

In the bioenergetics studies, the direct electrometric method played an important role. This method is based on measuring the electrical potential difference (Δψ) between two compartments of the experimental cell generated by some membrane proteins. These proteins are incorporated into closed lipid-protein membrane vesicles associated with an artificial lipid membrane that separates the compartments. The very existence of such proteins able to generate Δψ was one of the consequences of Peter Mitchell's chemiosmotic concept. The discovery and investigation of their functioning contributed to the recognition of this concept and, eventually the well-deserved awarding of the Nobel Prize to P. Mitchell. Lel A. Drachev (1926-2022) was one of the main authors of the direct electrometrical method. With his participation, key studies were carried out on the electrogenesis of photosynthetic and respiratory membrane proteins, including bacteriorhodopsin, visual rhodopsin, photosynthetic bacterial reaction centers, cytochrome oxidase and others.

Indigenous Australian grass seeds as grains: macrostructure, microstructure and histochemistry.

Utilization of grains of local grasses by Australia's First Nations people for food and connection to Country has largely been lost due to colonization. Native Australian grain production has the potential to deliver environmental, economic, nutritional and cultural benefits to First Nations people and the wider community. Revitalization of the native grain food system can only be achieved if relevant properties of the grains are elucidated. This study aimed to characterize the grain structure and histochemistry of four Australian native grasses: Dactyloctenium radulans (Button Grass), Astrebla lappacea (Curly Mitchell Grass), Panicum decompositum (Native Millet) and Microlaena stipoides (Weeping Grass). For these species, as well as wheat and sorghum, whole-grain images were obtained via stereo microscopy, starch and the embryo were visualized, and sections of fixed grains were imaged via bright-field and fluorescence microscopy. The shape, size and colour of the whole native grains varied between the species. The aleurone layer was one-cell thick in the native species, as in the domesticated grains, except for Weeping Grass, which had a two-cell-thick aleurone. In the native grains, endosperm cell walls appeared thinner than in wheat and sorghum. Starch granules in Button Grass, Curly Mitchell Grass and Native Millet were found mainly in the central region of the starchy endosperm, with very few granules in the sub-aleurone layer, whereas Weeping Grass had abundant starch in the sub-aleurone. Protein appeared most abundant in the aleurone and sub-aleurone layers of the native grains, although in Button Grass, the starchy endosperm was observed to be rich in protein, as in wheat and sorghum. As a proportion of the whole grain, the embryo was larger in the native species than in wheat. The differences found in the grain properties among the four native Australian species have important implications for the agri-food industry in a changing climate.

A comparative study on the effects of Mitchell and Benson relaxation techniques on quality of life of the old people in nursing homes: a quasi- experimental study.

BACKGROUND: There is slight evidence on the effectiveness of relaxation techniques to improve quality of life of the old people, and no comparative studies have particularly investigated this population. Hence, the present study was conducted to examine the effect of Mitchell relaxation versus Benson relaxation technique to improve quality of life of the old people. METHODS: In the present quasi-experimental study, 96 eligible old people in a nursing home were selected by available sampling method. Afterwards, they were assigned to three groups: Mitchell's Relaxation Technique, Benson Relaxation Technique, and control (each of 32 participants) using the random block sampling method. The intervention groups received relaxation for 8 weeks and 3 sessions of 20 min each week. However, the control group did not receive any relaxation. Data was gathered by questionnaires (SF-36) and (CASP-19) before (week 0) and after the intervention (week 8) and were analyzed using the SPSS software version 26. RESULTS: The results indicated that both Benson and Mitchell relaxation had improved the quality of life (SF-36) and (CASP-19) and their sub-scales in the participants compare to the control group (P < 0.001). Accordingly, the median (quartile 25, 75) of the specific quality of life of the participants before the intervention was 21 (18.25, 25.75) in the Benson group, 20.5 (16, 24) in the Michel group, and 21 (16.25, 24) in the control group. However, after the intervention they reached 35(26.25, 38.75), 34.5(26.75, 42.25), and 17 (14, 21) respectively. There was no statistically significant difference between the Benson and Michel relaxation groups. CONCLUSIONS: Based on the results, Benson and Mitchell relaxation techniques improve the quality of life of the old people. If the results be confirmed in other studies, the education of each of them, especially for the old people living in nursing homes and their caregivers, is suggested as routine care.

The Role of Benson's and Mitchell's Relaxation Techniques in the Management of Premenstrual Syndrome: An In-Depth Review.

Premenstrual syndrome (PMS) is a menstrual disorder characterized by physical, behavioral, and emotional symptoms typically occurring during the luteal phase. These symptoms are usually mild and somatic and often subside during or just before the start of menstruation. Medical professionals employ pharmacological and non-pharmacological treatments as the primary approach to managing PMS. One effective non-pharmacological method is Laura Mitchell's physiological relaxation treatment, which has been shown to enhance immunological function, reduce depression, and improve the overall quality of life. Another beneficial technique is Benson's relaxation technique, established by Herbert Benson in 1970, providing a simple yet powerful stress-release strategy. For this study, research papers were searched using various reputable databases such as PubMed, Scopus, Web of Science, and Google Scholar websites, with data collected up to the end of 2021. The publication dates of the review articles were not restricted, allowing for a comprehensive overview. However, it is important to note that only a limited number of accessible studies have been found, underscoring the need for further research. Future investigations should focus on high-quality evidence with reliable outcome measures to draw more conclusive results about which relaxation technique offers better relief for PMS.

Lipschitz Carnot-Carathéodory Structures and their Limits.

In this paper we discuss the convergence of distances associated to converging structures of Lipschitz vector fields and continuously varying norms on a smooth manifold. We prove that, under a mild controllability assumption on the limit vector-fields structure, the distances associated to equi-Lipschitz vector-fields structures that converge uniformly on compact subsets, and to norms that converge uniformly on compact subsets, converge locally uniformly to the limit Carnot-Carathéodory distance. In the case in which the limit distance is boundedly compact, we show that the convergence of the distances is uniform on compact sets. We show an example in which the limit distance is not boundedly compact and the convergence is not uniform on compact sets. We discuss several examples in which our convergence result can be applied. Among them, we prove a subFinsler Mitchell's Theorem with continuously varying norms, and a general convergence result for Carnot-Carathéodory distances associated to subspaces and norms on the Lie algebra of a connected Lie group.

Comparative Efficacy of Mitchell's and Benson's Relaxation Techniques in Alleviating Pain and Improving Quality of Life Among Patients With Premenstrual Syndrome: A Randomized Controlled Trial.

Background Most women of reproductive age suffer physical discomfort or distress in the weeks before menstruation. Even though symptoms are typically not severe enough to impede daily activities seriously, they occasionally can. Physical problems like breast discomfort and bloating can also be a problem. The most irritating symptoms are those that affect mood and behaviour. Women of reproductive age experience premenstrual syndrome frequently, necessitating study into non-pharmacological methods for symptom reduction. Methodology The objective of the study was to evaluate and compare the clinical efficacy of Benson's relaxation technique to Laura Mitchell's physiological approach in patients with premenstrual syndrome. Study design was comparative parallel experimental study with patient-reported questionnaire data (online) collected before and post-intervention in tertiary hospital setting. Participants were 70 adult females aged 18 to 35 with premenstrual syndrome. Patients were administered Benson's relaxation technique once a day for a month versus Mitchell's relaxation technique once a day for a month. Both techniques were first taught for one session followed by home program to be performed by patients. The premenstrual syndrome questionnaire and a numerical pain rating scale were used to quantify premenstrual symptoms pre and post-intervention. Results The result revealed significant (p<0.01) improvement in premenstrual symptoms in both groups following the intervention. However, Bensons' relaxation technique was found to be more significant while alleviating the premenstrual symptoms. Conclusions When it comes to lowering the intensity of premenstrual syndrome in young people, Benson's relaxation method is superior to Mitchell's. Both approaches should be entrenched as a regular practice and can be employed on patients to improve their menstrual well-being.

A de novo heterozygous variant in ACOX1 gene cause Mitchell syndrome: the first case in China and literature review.

BACKGROUND: Mitchell syndrome (MITCH) is a rare autosomal dominant hereditary disorder, characterized by episodic demyelination, sensorimotor polyneuropathy and hearing loss. MITCH is caused by heterozygous mutation in the ACOX1 gene, which encodes straight-chain acyl-CoA oxidase, on chromosome 17q25.1.  Only 5 unrelated patients have been reported so far, and no reports from China. Here, we describe the first MITCH case in a Chinese individual. CASE PRESENTATION: A 7-year-old girl initially presented with diffuse desquamatory rash at age 3. Her clinical symptoms in order of presentation were diffuse desquamatory rash, gait instability, ptosis with photophobia, hearing loss, abdominal pain, diarrhea, nausea, and dysuria. Genetic analysis demonstrated that the patient carried a heterozygous variant c.710A>G(p.Asp237Ser) in the ACOX1 gene, which can cause MITCH symptoms. This is the first MITCH case with gastrointestinal and urinary tract symptoms. After administrating N acetylcysteine amide (NACA), some symptoms were relieved and the patient's condition improved. CONCLUSION: This is the first MITCH case in the Chinese population, and we expanded the genotype spectrum of it. The p.Asp237Ser may be a mutational hotspot in ACOX1 regardless of race. In terms of diagnosis, patients with recurrent rash, gait instability, and hearing loss with some autonomic symptoms should raise the suspicion of MITCH and proper and prompt treatment should be given.

Visceral Haemoproteus minutus Infection in a Major Mitchell's Cockatoo (Lophochroa leadbeateri).

A 1-year-old major Mitchell's cockatoo (Lophochroa leadbeateri) was presented for evaluation of weakness, diarrhea with undigested seeds in the droppings, and weight loss. Leukocytosis with severe heterophilia, monocytosis, and lymphocytosis was noted on the complete blood count. Altered plasma biochemical parameters included a slight increase in creatine kinase and mild hypoproteinemia. Two blood smears before and after 2 days of treatment revealed mild polychromasia and anisocytosis but no blood parasites. Radiographic and computed tomographic imaging of the cockatoo were helpful in identifying airsacculitis, pneumonia, and gastrointestinal motility disorders. The patient died 5 days after treatment for the presenting clinical problems. On the gross postmortem examination, dark red foci in the ventricular muscle layers and 1-3-mm white foci in the myocardium, opaque air sacs, and dark lungs were identified. Histopathologic examination of submitted tissue samples found severe granulomatous ventriculitis and myocarditis with intralesional Haemoproteus species megalomeronts. Qualitative polymerase chain reaction testing for the cytochrome b (cyt b) gene performed on pooled heart, liver, kidney, and intestinal tissues identified 99.5% homology to Haemoproteus minutus. This case report demonstrates the expansion of the geographic range of H minutus to France and potentially to Belgium, which may compromise breeding and conservation of Australian parrots living outdoors. Challenging diagnosis, rapid disease progression, and the absence of validated treatment protocols for psittacine patients suggest that the use of preventive measures to reduce the presence of insect vectors such as hippoboscid flies and biting midges (Culicoides) should be considered. Haemoproteus minutus should be considered and potentially screened by polymerase chain reaction testing on blood samples, especially in the case of highly susceptible avian species (eg, Australian parrots in Europe) that present with sudden weakness, heterophilic leukocytosis, and monocytosis associated with mild anemia.

Comparison of modified Mitchell and Chevron osteotomies for hallux valgus.

BACKGROUND: Good clinical and radiological outcomes in mild-moderate hallux valgus (HV) can be achieved with Chevron osteotomy (CO) and modified-Mitchell osteotomy (MMO). The main goal of the present study was to compare the clinical and radiological outcomes after CO and MMO in HV. METHODS: The study included 45 patients, comprising 40 females with a mean follow-up of 87.5 ± 27.8 months. The outcome measurements of metatarsal length (MT1), HV angle (HVA), intermetatarsal angle (IMA), clinical outcomes, and metatarsalgia were evaluated pre- and postoperatively. RESULTS: No significant difference was determined between the MMO and CO groups in respect of metatarsalgia and AOFAS scores. The CO resulted in a significantly larger decrease in the MT1. The mean HVA and IMA correction was significantly greater after MMO than after CO. CONCLUSION: Since MMO may prevent MT1 shortening, which is a typical problem in the Mitchell osteotomy, MMO may be preferred over CO in patients with preoperative shortened first metatarsal.

Professor George Archibald Grant Mitchell (1906-1993): his work with penicillin during World War II.

George Archibald Grant Mitchell, OBE, TD, MB, ChB, ChM, MSc, DSc, FRCS (1906-1993) was a professor of anatomy at the University of Manchester from 1946 to 1973. He is mainly remembered for his research in neuroanatomy, especially of the autonomic nervous system. He studied medicine at the Aberdeen University, and after qualifying in 1929 he held posts in surgery and anatomy and worked as a surgeon in the Highlands. In 1939, he joined the Royal Army Medical Corps. He was based in Egypt and the Middle East, where he carried out trials of sulphonamides and penicillin on wounded soldiers; in 1943, he returned to England as Adviser in Penicillin Therapy for 21 Army Group, preparing for the invasion of Europe.

Bayesian inference for fitting cardiac models to experiments: estimating parameter distributions using Hamiltonian Monte Carlo and approximate Bayesian computation.

Customization of cardiac action potential models has become increasingly important with the recognition of patient-specific models and virtual patient cohorts as valuable predictive tools. Nevertheless, developing customized models by fitting parameters to data poses technical and methodological challenges: despite noise and variability associated with real-world datasets, traditional optimization methods produce a single "best-fit" set of parameter values. Bayesian estimation methods seek distributions of parameter values given the data by obtaining samples from the target distribution, but in practice widely known Bayesian algorithms like Markov chain Monte Carlo tend to be computationally inefficient and scale poorly with the dimensionality of parameter space. In this paper, we consider two computationally efficient Bayesian approaches: the Hamiltonian Monte Carlo (HMC) algorithm and the approximate Bayesian computation sequential Monte Carlo (ABC-SMC) algorithm. We find that both methods successfully identify distributions of model parameters for two cardiac action potential models using model-derived synthetic data and an experimental dataset from a zebrafish heart. Although both methods appear to converge to the same distribution family and are computationally efficient, HMC generally finds narrower marginal distributions, while ABC-SMC is less sensitive to the algorithmic settings including the prior distribution.

On the Mechanism of Sustained Mitochondrial Membrane Potential Without Functioning Complex IV.

In intact mitochondria, the transport of electrons, respiration and generation of proton gradients across the inner membrane (proton motive force) are mutually coupled, according to Peter Mitchell's hypothesis on oxidative phosphorylation. Thus, the inhibition of electron transport at either respiratory complex III or IV in the electron transport chain leads to failure in producing proton motive force along with the abolition of respiration. Here, we determined the mitochondrial membrane potential (MMP), as a measure of proton motive force, and cellular respiration in various cultured cells and demonstrated that inhibition of complex IV by KCN abolished mitochondrial respiration while MMP was sustained. These results are unexpected and appear incompatible with Mitchell's chemiosmotic hypothesis.

The Need for Consistency with Physical Laws and Logic in Choosing Between Competing Molecular Mechanisms in Biological Processes: A Case Study in Modeling ATP Synthesis.

Traditionally, proposed molecular mechanisms of fundamental biological processes have been tested against experiment. However, owing to a plethora of reasons-difficulty in designing, carrying out, and interpreting key experiments, use of different experimental models and systems, conduct of studies under widely varying experimental conditions, fineness in distinctions between competing mechanisms, complexity of the scientific issues, and the resistance of some scientists to discoveries that are contrary to popularly held beliefs-this has not solved the problem despite decades of work in the field/s. The author would like to prescribe an alternative way: that of testing competing models/mechanisms for their adherence to scientific laws and principles, and checking for errors in logic. Such tests are fairly commonly carried out in the mathematics, physics, and engineering literature. Further, reported experimental measurements should not be smaller than minimum detectable values for the measurement technique employed and should truly reflect function of the actual system without inapplicable extrapolation. Progress in the biological fields would be greatly accelerated, and considerable scientific acrimony avoided by adopting this approach. Some examples from the fundamental field of ATP synthesis in oxidative phosphorylation (OXPHOS) have been reviewed that also serve to illustrate the approach. The approach has never let the author down in his 35-yr-long experience on biological mechanisms. This change in thinking should lead to a considerable saving of both time and resources, help channel research efforts toward solution of the right problems, and hopefully provide new vistas to a younger generation of open-minded biological scientists.

A fresh "slant" on modified Mitchell bladder neck reconstruction: A contemporary single-institution experience.

Introduction: Patients with neurogenic urinary incontinence due to an incompetent outlet may be offered bladder neck reconstruction, but the quest for the perfect surgical-outlet procedure continues. Our aim was to characterize continence and complications after modified Mitchell urethral lengthening/bladder neck reconstruction (MMBNR) with sling and to introduce a modification of exposure that facilitates subsequent steps of MMBNR. Methods: A single-institution, retrospective cohort study of patients who underwent primary MMBNR between May 2011 and July 2019 was performed. Data on demographics, urodynamic testing, operative details, unanticipated events, continence, bladder changes, and additional procedures were collected. A 2013 modification that permits identification of the incompetent bladder neck prior to urethral unroofing was applied to the last 17 patients. The trigone and bladder neck are exposed via an oblique low anterolateral incision on the bladder. Ureteral reimplantation is not routinely performed. Focal incision of the endopelvic fascia after posterior plate creation limits breadth of blunt dissection for sling placement. Descriptive statistics were utilized. Results: A total of 25 patients (13 females) had MMBNR with sling at a median age of 10 years [interquartile range (IQR) 8-11]. Bladder augmentation was performed concurrently in 14/25 (56%) patients. At a median of 5.0 (IQR 3.9-7.5) years follow-up after MMBNR, 9/11 (82%) without bladder augmentation and 13/14 (93%) with bladder augmentation had no leakage per urethra during the day without further continence procedures. Of the three patients with persistent incontinence, two achieved continence with bladder wall Botox injection (overall continence 24/25, 96%). New and recurrent vesicoureteral reflux was noted in five patients and one patient, respectively. Two patients required subsequent bladder augmentation for pressures and one other will likely require it. None have required bladder neck closure or revision. Conclusion: MMBNR with sling provides promising continence per urethra in neurogenic bladder with low need for secondary continence procedures. Ongoing modifications may achieve elusive total continence.

Mitchell-Riley Syndrome: Improving Clinical Outcomes and Searching for Functional Impact of RFX-6 Mutations.

Aims/Hypothesis: Caused by biallelic mutations of the gene encoding the transcription factor RFX6, the rare Mitchell-Riley syndrome (MRS) comprises neonatal diabetes, pancreatic hypoplasia, gallbladder agenesis or hypoplasia, duodenal atresia, and severe chronic diarrhea. So far, sixteen cases have been reported, all with a poor prognosis. This study discusses the multidisciplinary intensive clinical management of 4 new cases of MRS that survived over the first 2 years of life. Moreover, it demonstrates how the mutations impair the RFX6 function. Methods: Clinical records were analyzed and described in detail. The functional impact of two RFX6R181W and RFX6V506G variants was assessed by measuring their ability to transactivate insulin transcription and genes that encode the L-type calcium channels required for normal pancreatic beta-cell function. Results: All four patients were small for gestational age (SGA) and prenatally diagnosed with duodenal atresia. They presented with neonatal diabetes early in life and were treated with intravenous insulin therapy before switching to subcutaneous insulin pump therapy. All patients faced recurrent hypoglycemic episodes, exacerbated when parenteral nutrition (PN) was disconnected. A sensor-augmented insulin pump therapy with a predictive low-glucose suspension system was installed with good results. One patient had a homozygous c.1517T>G (p.Val506Gly) mutation, two patients had a homozygous p.Arg181Trp mutation, and one patient presented with new compound heterozygosity. The RFX6V506G and RFX6R181W mutations failed to transactivate the expression of insulin and genes that encode L-type calcium channel subunits required for normal pancreatic beta-cell function. Conclusions/Interpretation: Multidisciplinary and intensive disease management improved the clinical outcomes in four patients with MRS, including adjustment of parenteral/oral nutrition progression and advanced diabetes technologies. A better understanding of RFX6 function, in both intestine and pancreas cells, may break ground in new therapies, particularly regarding the use of drugs that modulate the enteroendocrine system.

Network representation and analysis of energy coupling mechanisms in cellular metabolism by a graph-theoretical approach.

Mechanisms coupling the chemical reactions of oxidation and ATP synthesis in cellular metabolism by the fundamental biological process of oxidative phosphorylation (OX PHOS) in mitochondria provide > 90% of the energy requirements in living organisms. Mathematical graph theory methods have been extensively used to characterize various metabolic, regulatory, and disease networks in biology. However, networks of energy coupling mechanisms in OX PHOS have not been represented and analyzed previously by these approaches. Here, the problem of biological energy coupling is translated into a graph-theoretical framework, and all possible coupling schemes between oxidation and ATP synthesis are represented as graphs connecting these processes by various intermediates or states. The problem is shown to be transformed into the hard problem of finding a Hamiltonian tour in the networks of possible constituent mechanisms, given the constraints of a cyclical nature of operation of enzymes and biological molecular machines. Accessible mathematical proofs of three theorems that guarantee sufficient conditions for the existence of a Hamiltonian cycle in simple graphs are provided. The results of the general theorems are applied to the set of possible coupling mechanisms in OX PHOS and shown to (1) unequivocally differentiate between the major theories and mechanisms of energy coupling, (2) greatly reduce the possibilities for detailed consideration, and (3) deduce the biologically selected mechanism using additional constraints from the cumulative experimental record. Finally, an algorithm is constructed to implement the graph-theoretical procedure. In summary, the enormous power and generality of mathematical theorems and approaches in graph theory are shown to help solve a fundamental problem in biology.