An Endosomal Acid-Regulatory Feedback System Rewires Cytosolic cAMP Metabolism and Drives Tumor Progression

Although suppressed cAMP levels have been linked to cancer for nearly five decades, the molecular basis remains uncertain. Here, we identify endosomal pH as a novel regulator of cytosolic cAMP homeostasis and a promoter of transformed phenotypic traits in colorectal cancer. Combining experiments and computational analysis, we show that the Na+/H+ exchanger NHE9 contributes to proton leak and causes luminal alkalinization, which induces resting [Ca2+], and in consequence, represses cAMP levels, creating a feedback loop that echoes nutrient deprivation or hypoxia. Higher NHE9 expression in cancer epithelia is associated with a hybrid epithelial-mesenchymal (E/M) state, poor prognosis, tumor budding, and invasive growth in vitro and in vivo. These findings point to NHE9-mediated cAMP suppression as a pseudostarvation-induced invasion state and potential therapeutic vulnerability in colorectal cancer. Our observations lay the groundwork for future research into the complexities of endosome-driven metabolic reprogramming and phenotype switching and the biology of cancer progression.

IMPLICATIONS

Endosomal pH regulator NHE9 actively controls cytosolic Ca2+ levels to downregulate the adenylate cyclase-cAMP system, enabling colorectal cancer cells to acquire hybrid E/M characteristics and promoting metastatic progression.

Sequential Human Histology Results of the Subperiosteal Minimally Invasive Aesthetic Ridge Augmentation Technique (SMART): A Chronologic Wound Healing Proof-of-Principle Study

Traditional GBR procedures have been associated with frequent complications and compromised peri-implant esthetics. Tunneling techniques have been proposed as a promising alternative in this regard. More recently, a subperiosteal minimally invasive aesthetic ridge augmentation technique (SMART) was reported to have been clinically successful in a prospective case series. This technique includes the use of a bone graft/recombinant human platelet-derived growth factor-BB combination delivered to the site by a tunneling method. However, published histologic information regarding the nature of the regenerated tissue has been limited. The current study evaluated the histologic and histomorphometric findings of four human specimens harvested at 2, 5, 9, and 14 months after ridge augmentation using the SMART method. Evaluations of the wound healing and bone regeneration sequence over time found that the ridge augmentation was the result of extensive new bone formation that progressed through the woven bone to lamellar bone stages, with remodeling of the xenogeneic graft material and replacement by patient bone. This is the first study utilizing sequential human specimens to histologically examine the chronology of wound healing following alveolar ridge augmentation.

[Conventional paraffin embedding technique and double-embedding technique for minute oral biopsies and delicate pulp tissue - a comparative study]

BACKGROUND

Among oral biopsies, small incisional tissues, have to be preserved all through the processing and embedding to ensure optimal visualization of all the mucosal layers without compromise. Optimal tissue orientation is the most critical step in tissue processing for demonstration of definitive morphology in the sections, which is often more challenging in cases of minute/small or thinner sections using routine paraffin techniques to evaluate accurate diagnosis. Some modification is needed to handle these samples to get a better result. Double embedding technique with some modification has been widely used for small/ thin/ multiple biopsies and gives excellent results in many other fields like general pathology and biotechnology. The double embedding technique though produced excellent and significant results in mucosal biopsies yet, it is of minimal interest among oral pathologists. To best of our knowledge, this is the first study to use double embedding technique for pulp tissues.

OBJECTIVE

The present study was aimed to evaluate and compare the ease of embedding and sectioning sections using Agar-Paraffin double embedding technique for small oral mucosal biopsies and thin pulp tissues.

MATERIAL AND METHODS

A total of 40 oral tissue samples categorized into two groups were taken for the present study. Group I included 20 small oral mucosal biopsy samples of size ranging from 0.2 to 0.5 cm and Group II included 20 pulp tissues obtained from freshly extracted non carious tooth. 10 blocks were prepared by routine paraffin method and 10 blocks were prepared by modified double embedding method for each group. Scores were given by comparing all the criteria with that of the routine paraffin technique. Chi-square test was used for statistical analysis.

RESULTS

The average ease score for the Agar-Paraffin double embedded small/minute biopsies showed better scores than the pulp tissue with that of the routine technique. However, no statistically significant difference was seen among embedding and sectioning sections between the two groups.

CONCLUSION

Modified double embedding method is simple and reliable alternative technique that helps in better orientation, processing and sectioning especially for oral small or thin biopsies and delicate pulp tissues.

Trans-aortic DORV repair

Double-outlet right ventricle (DORV) is a group of complex ventriculoarterial connections. In the literature, there are reports of trans-aortic correction of tetralogy of Fallot, as well as ventricular septal defects and complex DORV without right ventricular outflow tract obstruction. However, a pure trans-aortic approach for DORV ventricular septal defect (VSD) right ventricular outflow tract obstruction repair is not reported in the literature. We present a case of pure trans-aortic repair of DORV VSD pulmonary stenosis (PS) in an adult. A 20-year-old male with a known case of DORV, VSD, and PS presented with cyanosis. A pure trans-aortic repair of DORV was done. Complete trans-aortic DORV VSD PS repair is yet to be reported in the literature. The trans-aortic approach avoids a right atriotomy, right ventriculotomy, and injury to coronary arteries in cases of complicated tetralogy of Fallot and avoids injury to the tricuspid valve. This approach can be used in selected patients for intracardiac repair. The advantages are excellent visualization of the defects and avoidance of injury to the aortic cusps and bundle of His. In addition, placement of the VSD patch on the left ventricular outflow side may prevent residual shunts after repair.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12055-023-01564-x.

Prospective observational study on clinical and epidemiological profile of adult patients presenting to the emergency department with suspected upper gastrointestinal bleed

BACKGROUND AND OBJECTIVE

Bleeding from the upper gastrointestinal (GI) tract is one of the common medical emergencies. In this study, we assessed patients' socio-demographic and clinical characteristics and the association of clinical characteristics with treatment outcomes among patients with suspected upper gastrointestinal bleed (UGIB) presenting to the emergency department (ED). At present, there is a scarcity of data on UGIB in Northern part of India.

MATERIAL AND METHOD

The study was a single-center, prospective observational study conducted at an urban tertiary care center. Consecutive patients with suspected UGIB were enrolled in the study from August 2020 to February 2022. A detailed history was obtained, including demographic data such as age and sex, presenting complaints, history of presenting illness, history related to co-morbidities, addiction, and drug history. Pre-endoscopic Rockall and Glasgow-Blatchford Score were calculated for each patient. The patients were subsequently followed up till discharge from the hospital. The final outcomes with regard to mortality, need for blood transfusion, length of emergency department stay, and discharge were noted.

RESULT

141 patients were included in the study. The mean age of the patients with suspected UGIB was 48 ± 14 years. 115 (81.6%) patients were male. The most common co-morbidity was chronic liver disease (40;28.4%). The most frequent presenting complaint in this study was hematemesis (96; 68.1%), followed by melena (76;53.9%). The mean (Standard Deviation, SD) of the Rockall Score was 2.46 ± 1.75. The mean (SD) of the Glasgow Blatchford Score was 12.46 ± 3.15 in patients with UGIB.

CONCLUSION

In our study, hematemesis was the most prevalent symptom of suspected UGIB, followed by melena. Portal hypertension was the most common cause of UGIB. Most frequent comorbidities in patients suspected of UGIB were alcohol intake, Nonsteriodal Antiinflammatory Drugs (NSAIDs) abuse, and co-morbidities such as underlying chronic liver disease, hypertension, and diabetes. Early endoscopy can be of great utility to reduce morbidity and mortality.

Maternal Tuberculosis Leading to Congenital Tuberculosis: A Case Report

In India, tuberculosis (TB) is a severe public health concern. We report a case of a 45-day male baby who had respiratory distress and fever, whose mother was diagnosed with pulmonary TB infection prior to delivery which was confirmed by a positive Cartridge-Based Nucleic Amplification Test (CBNAAT) from the sputum and was on antitubercular therapy (ATT). Due to the symptoms, signs, and maternal TB history, congenital TB was strongly suspected. A positive CBNAAT result from the gastric lavage further supported this suspicion. This case emphasizes the value of obtaining details on the mother's TB history to aid in the early diagnosis of congenital TB and expedite the treatment and prognosis.

Monkeypox epidemiology, clinical presentation, and transmission: a systematic review

BACKGROUND

The new zoonotic viral infection, monkeypox, is a global health issue. Our study aimed at studying the epidemiology, clinical presentation, complications, case fatality rate, and transmission among the present cases of monkeypox infection.

METHODS

Articles were searched in PubMed, Google Scholar, and Science Direct databases using the keywords "Monkeypox" [MeSH] or "Monkeypox virus" (MeSH). Narrative reviews, conference abstracts, commentaries, and articles in languages other than English were excluded.

RESULTS

From three databases, 1442 studies were identified. Seven hundred ten articles were excluded because they included data before 2022, leaving 732 items for screening. After filtering 320 data due to data duplication, 412 remained. Due to the inclusion of systematic reviews, meta-analyses, reviews, comments, and articles in languages other than English, 257 were excluded. Eligibility based on full-text review was applied to the remaining 155, excluding 129. So, the study covered a total of remaining 26 articles. We studied 2352 confirmed cases from published literature, accounting for approximately 4% of infected cases worldwide. Around 81.71% of patients have a bisexual or men having sex with men (MSM) preference. Approximately 30.18% of confirmed cases were HIV positive. Male sex was also identified as a risk factor in our review.

CONCLUSION

Monkeypox human-to-human and human-to-animal transmission are rising. Thus, it is essential to do research on the prevention, clinicodemographic trends, and treatment of monkeypox. Understanding this will enable us to treat monkeypox patients with a targeted and focused approach.

Correlation and agreement between arterial and venous blood gas analysis in patients with hypotension-an emergency department-based cross-sectional study

BACKGROUND

Blood gas analysis is integral to assessing emergency department (ED) patients with acute respiratory or metabolic disease. Arterial blood gas (ABG) is the gold standard for oxygenation, ventilation, and acid-base status but is painful to obtain. Peripheral venous blood gas (VBG) is a valuable alternative as it is less painful and easy to collect. The comparability of ABG and VBG was studied in various conditions. But in hypotension, previous findings were inconsistent. So, we studied the correlation and agreement between ABG and VBG in hypotensive patients.

METHODOLOGY

The study was conducted at the emergency department of a tertiary healthcare center in Northern India. Patients with hypotension above 18 years who satisfied the inclusion criteria were clinically evaluated. Patients who require ABG as a part of routine care were sampled. ABG was collected from the radial artery. VBG was obtained from the cubital or dorsal hand veins. Both samples were collected within 10 min and were analyzed. All ABG and VBG variables were entered in premade proforma. The patient was then treated and disposed of according to institutional protocol.

RESULTS

A total of 250 patients were enrolled. The mean age was 53.25 ± 15.71 years. 56.8% were male. The study included 45.6% septic, 34.4% hypovolemic, 18% cardiogenic, and 2% obstructive shock patients. The study found a strong correlation and agreement for ABG and VBG pH, pCO2, HCO3, lactate, sodium, potassium, chloride, ionized calcium, blood urea nitrogen, base excess, and arterial/alveolar oxygen ratio. Hence, regression equations were made for the aforementioned. There was no correlation observed between ABG and VBG pO2 and SpO2. Our study concluded that VBG could be a reasonable alternative for ABG in hypotensive patients. We can also mathematically predict values of ABG from VBG using regression equations derived.

CONCLUSIONS

ABG sampling causes most unpleasant experiences to patients and is associated with complications like arterial injury, thrombosis, air or clotted-blood embolism, arterial occlusion, hematoma, aneurysm formation, and reflex sympathetic dystrophy. The study has shown strong correlations and agreements for most ABG and VBG parameters and can predict ABG mathematically using regression formulas formulated from VBG. This will decrease needle stick injury, consume less time, and make blood gas evaluation easy in hypotensive settings.

A novel frameshift mutation in TRPV6 is associated with hereditary pancreatitis

Introduction: Hereditary pancreatitis (HP) is a rare debilitating disease with incompletely understood etio-pathophysiology. The reduced penetrance of genes such as PRSS1 associated with hereditary pancreatitis indicates a role for novel inherited factors. Methods: We performed whole-exome sequencing of three affected members of an Indian family (Father, Son, and Daughter) with chronic pancreatitis and compared variants with those seen in the unaffected mother. Results: We identified a novel frameshift mutation in exon 11 of TRPV6 (c.1474_1475delGT; p.V492Tfs*136), a calcium channel, in the patients. Functional characterization of this mutant TRPV6 following heterologous expression revealed that it was defective in calcium uptake. Induction of pancreatitis in mice induced Trpv6 expression, indicating that higher expression levels of the mutant protein and consequent dysregulation of calcium levels in patients with chronic pancreatitis could aggravate the disease. Discussion: We report a novel frameshift mutation in TRPV6 in an Indian family with HP that renders the mutant protein inactive. Our results emphasize the need to expand the list of genes used currently for evaluating patients with hereditary pancreatitis.

Snakebite Causing Facial and Lingual Tremors: A Case Report

Snakebite is a significant public health problem causing around 2.7 envenomations and 138,000 deaths globally. History may sometimes be unclear or misleading, which can cause a delay in diagnosis. Neuroparalytic, hemotoxic, and myotoxic are the common snake bite manifestations. Neuroparalytic snake bites rarely cause involuntary movements. Here we report a case of a 26-year-old female patient who sustained a snake bite and developed tremors in the face and tongue. She improved with mechanical ventilation, anti-snake venom, atropine-neostigmine, and calcium gluconate. She was discharged after seven days of hospital stay and now maintaining regular follow-up in the outpatient clinic.

Pneumothorax and Pneumomediastinum Complicating Organophosphate Poisoning: A Case Series of Complications Less Understood

Organophosphate compounds are used as insecticides in agricultural and domestic settings throughout the world. Acute organophosphorus (OP) poisoning is a major public health issue. Early diagnosis of OP poisoning and prompt atropinization can save lives. Respiratory failure may occur in patients with OP poisoning for many reasons, including aspiration of gastric contents, excessive secretions, pneumonia, and sepsis complicating acute respiratory distress syndrome. Till date, however, spontaneous pneumothorax and pneumomediastinum have not been reported in cases of OP poisoning. This report presents two similar cases of OP poisoning in which spontaneous pneumothorax and pneumomediastinum developed following OP ingestion.

Twelve Month Evaluation of a Novel Mineral Organic Adhesive Material Used to Stabilize Dental Implants Placed in Oversized Osteotomies in Vivo in an Animal Model

OBJECTIVES

To evaluate long-term in vivo stability of dental implants stabilized at time of placement in oversized osteotomies with a novel, self-setting, mineral-organic bone adhesive.

MATERIALS/METHODS

Canine (26) mandibular teeth were removed, and 3 oversized osteotomies prepared bilaterally. Implants were placed with either adhesive, particulate xenograft or with blood clot filling the implant/osteotomy gaps. Removal torque and histology were assessed.

RESULTS

The adhesive provided significant and clinically relevant immediate implant stability of 22.2N-cm (95%CI 5.3; 39.0) which continued throughout the early postoperative course and persisted through the nine- (155N-cm 95%CI 113; 197) and twelve-month (171N-cm 95%CI 134.2; 209.4) time points. This is in comparison to the blood clot of 1.4N-cm (95%CI 0.7; 2.1), 128.6N-cm (95%CI 66.8; 190.4), and 140.7N-cm (95%CI 78.8; 202.5) and particulate xenograft, 1.3N-cm (95%CI 0.6; 2.0), 132.1N-cm (95%CI 94.5; 169.7), and 101.5 (95%CI 59.5; 143.5) respectively. Histological examination shows the adhesive establishes intimate contact with the implant and bony walls and is replaced with new bone without compromising stability. Soft tissue does not penetrate the adhesive and marginal bone/biomaterial level is maintained. Control sites filled with xenograft or blood clot heal with reduced bone levels and, in some cases, xenograft particles were encapsulated in connective tissue.

CONCLUSIONS

Implants placed in oversized osteotomies and lacking primary stability can be stabilized at placement with a novel, highly osteoconductive and resorbable adhesive. Gradual replacement of the biomaterial allows osseointegration without loss of stability through 12 months of follow-up. This novel adhesive has the potential to stabilize implants placed in sites with inadequate bony support.

An Unusual Case of Persistent Hypoglycemia in Scrub Typhus

Acute fever is a common worldwide issue among patients presenting to the emergency department. Main tropical fevers presenting as acute fever are malaria, dengue fever, typhoid, scrub typhus, and leptospirosis. Scrub typhus is a zoonotic disease caused by Orientia tsutsugamushi, which is endemic in many parts of India. Its clinical presentation varies significantly from undifferentiated fever and fever with thrombocytopenia to meningoencephalitis. Persistent hypoglycemia in scrub typhus has not yet been reported. Here we report a case of a 27-year-old male who presented with altered mental status after seven days of scrub typhus diagnosis. Diagnosis of hypoglycemia (random blood sugar of 37 mg/dL) was made at triage. Altered mental status responded to dextrose, but despite meals and treatment, hypoglycemia persisted. The cause for persistent hypoglycemia remained unexplained as most laboratory panels for hypoglycemia were either normal or did not fit into a particular cause.

Bone Regeneration in Maxillary Sinus Augmentation using Advanced Platelet-Rich Fibrin (A-PRF) and Plasma Rich in Growth Factors (PRGF): A Pilot Randomized Controlled Trial

The purpose of this pilot randomized controlled trial was to analyze and compare the effects of advanced platelet-rich fibrin (A-PRF) and plasma rich in growth factors (PRGF) combined with deproteinized bovine bone mineral (DBBM) on bone regeneration outcomes in maxillary sinus augmentation (MSA) procedures. A total of 15 patients in need of MSA were consecutively recruited. Maxillary sinuses were grafted with DBBM alone (control group), DBBM mixed with A-PRF (PRF group), or DBBM mixed with PRGF (PRGF group). After a 6-month healing period, bone core biopsy samples were collected prior to implant placement for histologic and histomorphometric analyses. The mean percentage of mineralized tissue (MT) was 20.33 ± 11.50 in the control group, 32.20 ± 7.29 for the PRF group, and 34.80 ± 6.83 for the PRGF group, with no statistically significant differences across the three groups (P > .05). The mean percentage of remaining bone grafting material (RBGM) was 24.00 ± 7.94 for the control group, 26.00 ± 7.78 for the PRF group, and 15.80 ± 8.23 for the PRGF group, with no statistically significant differences across the three groups (P > .05). Finally, the mean percentage of nonmineralized tissue (NMT) was 55.66 ± 7.77 for the control group, 41.40 ± 8.32 for the PRF group, and 49.60 ± 5.68 for the PRGF group, with no statistically signifcant differences across the three groups (P > .05). These findings suggest that the addition of A-PRF and PRGF to DBBM does not enhance new bone formation outcomes in maxillary sinus augmentation procedures. Neither of the two platelet concentrates were superior to the other in any of the variables assessed.

Receptor Guanylyl Cyclase C and Cyclic GMP in Health and Disease: Perspectives and Therapeutic Opportunities

Receptor Guanylyl Cyclase C (GC-C) was initially characterized as an important regulator of intestinal fluid and ion homeostasis. Recent findings demonstrate that GC-C is also causally linked to intestinal inflammation, dysbiosis, and tumorigenesis. These advances have been fueled in part by identifying mutations or changes in gene expression in GC-C or its ligands, that disrupt the delicate balance of intracellular cGMP levels and are associated with a wide range of clinical phenotypes. In this review, we highlight aspects of the current knowledge of the GC-C signaling pathway in homeostasis and disease, emphasizing recent advances in the field. The review summarizes extra gastrointestinal functions for GC-C signaling, such as appetite control, energy expenditure, visceral nociception, and behavioral processes. Recent research has expanded the homeostatic role of GC-C and implicated it in regulating the ion-microbiome-immune axis, which acts as a mechanistic driver in inflammatory bowel disease. The development of transgenic and knockout mouse models allowed for in-depth studies of GC-C and its relationship to whole-animal physiology. A deeper understanding of the various aspects of GC-C biology and their relationships with pathologies such as inflammatory bowel disease, colorectal cancer, and obesity can be leveraged to devise novel therapeutics.

Paraquat Poisoning Associated With Daisley Barton Syndrome: A Case Report

Pesticides include insecticides, herbicides, and rodenticides. Pesticide poisoning can be intentional, accidental, or occupational. Around 385 million cases of unintentional acute pesticide poisoning occur annually worldwide, with approximately 11,000 fatalities. Herbicides are used to kill weeds and can include chlorophenoxy compounds, bipyridyls, urea-substituted herbicides, organophosphates, and glyphosate. Paraquat is a bipyridyl nonselective contact herbicide with high mortality rates upon exposure in humans. Paraquat poisoning causes acute lung injury, rarely leading to pneumothorax and pneumomediastinum, referred to as Daisley Barton Syndrome. We report a case of a 22-year-old female from Uttarakhand, India, who accidentally ingested paraquat. She was initially asymptomatic, but later developed lung, liver, and kidney injuries as well as pneumomediastinum and pneumothorax.

A Case of Chorea: A Rare and Unusual Complication of Hyperglycemia

We present a case of hemichorea in a patient with nonketotic hyperglycemia (NKH), a rare presentation of hyperglycemia. A 55-year-old female with diabetes presented to the emergency department with involuntary bilateral upper and lower limb movements for five days. The patient had a serum glucose level of 358 mg/dL (19.87 mmol/L) and improved after controlling blood sugar levels. When we encounter a case of chorea in the emergency department, high blood sugar levels are an essential underlying reversible etiology to be kept in mind.

Protons to Patients: targeting endosomal Na+ /H+ exchangers against COVID-19 and other viral diseases

While there is undeniable evidence to link endosomal acid‐base homeostasis to viral pathogenesis, the lack of druggable molecular targets has hindered translation from bench to bedside. The recent identification of variants in the interferon‐inducible endosomal Na⁺/H⁺ exchanger 9 associated with severe coronavirus disease‐19 (COVID‐19) has brought a shift in the way we envision aberrant endosomal acidification. Is it linked to an increased susceptibility to viral infection or a propensity to develop critical illness? This review summarizes the genetic and cellular evidence linking endosomal Na⁺/H⁺ exchangers and viral diseases to suggest how they can act as a broad‐spectrum modulator of viral infection and downstream pathophysiology. The review also presents novel insights supporting the complex role of endosomal acid‐base homeostasis in viral pathogenesis and discusses the potential causes for negative outcomes of clinical trials utilizing alkalinizing drugs as therapies for COVID‐19. These findings lead to a pathogenic model of viral disease that predicts that nonspecific targeting of endosomal pH might fail, even if administered early on, and suggests that endosomal Na⁺/H⁺ exchangers may regulate key host antiviral defence mechanisms and mediators that act to drive inflammatory organ injury.

A study of medical education technology (MET) guidelines implementation in poorly performing first year medical students

Introduction and Aim: MET guideline is a compulsory directive of MCI which has to be implemented in medical education training program in all medical colleges in the country.Idea for research was originated by better university result of last year in which group dynamics, PBL, SDL, group discussion was implemented.The present study was conducted to improve the performance of poor scoring medical students utilizing MET guidelines.   Materials and Methods: 24 Students were selected out of 150 students on the basis of poorscore between September to March from 1st year M.B.B.S. batch (2017-2018), T.S.M. Medical College and Hospital, Amausi, Lucknow. They were exposed to MET guidelines like group dynamics, PBL, SDL, group discussion etc. Their performance was observed in successive examinations.   Results: 92% students of study group showed improvement. But desired goal was achieved by 83% students.   Conclusion: Small group teaching and newer methods of teaching are helpful in improvingperformance(increase percentage of marks) of students.

Loss of myocyte enhancer factor 2 expression in osteoclasts leads to opposing skeletal phenotypes

Osteoclasts are multinuclear cells that resorb bone. Osteoclast differentiation is regulated by multiple transcription factors which may be acting in a single or multiple factor complex to regulate gene expression. Myocyte enhancer factor 2 (MEF2) is a family of transcription factors whose role during osteoclast differentiation has not been well characterized. Because MEF2A and MEF2D are the family members most highly expressed during osteoclast differentiation, we created conditional knockout mice models for MEF2A and/or MEF2D. In vitro cultures of A- and D-KO osteoclasts were smaller and less numerous than wild type cultures, while AD-KO osteoclasts were almost completely devoid of TRAP positive mononuclear cells. Female A-KO mice are osteopetrotic while male A- and D-KO mice of either sex had no significant in vivo skeletal phenotype, suggesting a sex-specific regulation of osteoclasts by MEF2A. Lastly, in vivo male AD-KO mice are osteopenic, indicating while MEF2 is required for M-CSF and RANKL-stimulated osteoclastogenesis in vitro, osteoclasts can form in the absence of MEF2 in vivo via a RANKL-alternative pathway.

Endosomal Acid-Base Homeostasis in Neurodegenerative Diseases

Neurodegenerative disorders are debilitating and largely untreatable conditions that pose a significant burden to affected individuals and caregivers. Overwhelming evidence supports a crucial preclinical role for endosomal dysfunction as an upstream pathogenic hub and driver in Alzheimer's disease (AD) and related neurodegenerative disorders. We present recent advances on the role of endosomal acid-base homeostasis in neurodegeneration and discuss evidence for converging mechanisms. The strongest genetic risk factor in sporadic AD is the ε4 allele of Apolipoprotein E (ApoE4), which potentiates pre-symptomatic endosomal dysfunction and prominent amyloid beta (Aβ) pathology, although how these pathways are linked mechanistically has remained unclear. There is emerging evidence that the Christianson syndrome protein NHE6 is a prominent ApoE4 effector linking endosomal function to Aβ pathologies. By functioning as a dominant leak pathway for protons, the Na⁺/H⁺ exchanger activity of NHE6 limits endosomal acidification and regulates β-secretase (BACE)-mediated Aβ production and LRP1 receptor-mediated Aβ clearance. Pathological endosomal acidification may impact both Aβ generation and clearance mechanisms and emerges as a promising therapeutic target in AD. We also offer our perspective on the complex role of endosomal acid-base homeostasis in the pathogenesis of neurodegeneration and its therapeutic implications for neuronal rescue and repair strategies.

Molecular diagnosis and clinico-hemato-biochemical alterations and oxidant-antioxidant biomarkers in Babesia-infected dogs of Mizoram, India

BACKGROUND & OBJECTIVES

Babesiosis is a tick transmitted disease, infecting a wide variety of wild and domestic animals, as well as humans. This study was designed to investigate molecular diagnosis and clinic-hemato-biochemical and oxidant/antioxidant status in dogs of Mizoram, India.

METHODS

A total 1200 dogs screened for babesiosis during 2017-18 and 53 dogs suspected for babesiosis by clinical signs and were confirmed by molecular diagnosis. Clinical signs were recorded; also blood samples were taken to investigate hematologic changes, serum biochemical variations and oxidative stress biomarkers.

RESULTS

The overall incidence of babesiosis in dogs of Aizawl, Mizoram, India during the study period recorded was 1.25% (15/1200) and 28.3% cases confirmed from 53 suspected dogs (15/53). The most commonly observed clinical signs were fever, emaciation, depression and icterus and lymphadenopathy. Significant reduction in PCV, HB, RBCs, MCHC, total protein, and albumin along with significant increase in MCV, WBCs, monocytes and BUN were the most consistent hemato-biochemical changes. Oxidant/antioxidant assessment showed significant reduction in superoxide dismutase, catalase and total anti-oxidant (TAC) along with significant increase in lipid peroxidase (LPO) activities.

INTERPRETATION & CONCLUSION

The findings of this study demonstrated that the main causative agent of babesiosis in dogs in Mizoram Province is Babesia gibsoni which caused significant alteration of hemato-biochemical and oxidant-antioxidant status in dogs.

Haemato-biochemical alterations and oxidative stress associated with naturally occurring porcine circovirus2 infection in pigs

Porcine circovirus2 (PCV2) infection in pigs is one of the major causes of economic loss to the farmers in terms of low production, slow growth and increase post-weaning mortality rate. The effect of PCV2 infection on haemogram, serum biochemical profile and oxidant/anti-oxidant status is not well established in pigs. In the present study, haemogram, serum biochemical profile and oxidant/anti-oxidant status were assessed in pigs confirmed positive for PCV2 infections as evidenced by commercially available enzyme-linked immunosorbent assay kit (n = 151) and polymerase chain reaction (PCR) (n = 42) among a total of 306 number of pigs included in the study. Non-infected healthy pigs (n = 6) served as healthy control. The total erythrocyte count (TEC), haemoglobin (Hb), packed cell volume (PCV), total leukocyte count (TLC), differential leukocyte count (DLC) and thrombocyte count were measured. The levels of total protein, albumin, globulin, total bilirubin, direct bilirubin, blood urea nitrogen (BUN), creatinine and glucose and enzymes viz. alanine transaminase (ALT), aspartate transaminase (AST), gamma-glutamyl transferase (GGT) and alkaline phosphatase (ALP) were measured. Oxidative stress indicators such as plasma malondialdehyde (MDA) and total anti-oxidant activity (TAOA) were measured using commercially available kits. The mean values of TLC, lymphocytes and thrombocyte count were significantly (P < 0.05) low in PCV2-infected pigs. The levels of globulin, AST, GGT, BUN and creatinine were significantly increased (P < 0.05) whereas levels of albumin and glucose significantly (P < 0.05) decreased in PCV2-infected pigs. The significant increase (P < 0.05) in MDA level and significant decrease (P < 0.05) in TAOA level were noticed in PCV2-infected animals as compared with healthy control. The present study supports immunosuppression, possible multiple organ damage and oxidative stress associated with naturally occurring PCV2 infection in pigs. Timely vaccination and managemental practices can reduce PCV2 infection in farms. In spite of many research studies, there is still paucity of detailed systemic study on haemato-biochemical alteration and oxidative stress associated with PCV2 infection.

Cyclic nucleotides, gut physiology and inflammation

Misregulation of gut function and homeostasis impinges on the overall well-being of the entire organism. Diarrheal disease is the second leading cause of death in children under 5 years of age, and globally, 1.7 billion cases of childhood diarrhea are reported every year. Accompanying diarrheal episodes are a number of secondary effects in gut physiology and structure, such as erosion of the mucosal barrier that lines the gut, facilitating further inflammation of the gut in response to the normal microbiome. Here, we focus on pathogenic bacteria-mediated diarrhea, emphasizing the role of cyclic adenosine 3',5'-monophosphate and cyclic guanosine 3',5'-monophosphate in driving signaling outputs that result in the secretion of water and ions from the epithelial cells of the gut. We also speculate on how this aberrant efflux and influx of ions could modulate inflammasome signaling, and therefore cell survival and maintenance of gut architecture and function.

Accuracy of two dental age estimation methods in the Indian population - A meta-analysis of published studies

BACKGROUND

Dental age estimation using radiographic methods have gained considerable attention in the recent past. Although several such methods exist, Demirjian's method and Willems' method are very popular and have been used extensively. Whether these methods are applicable to the Indian population is not known.

METHODS

A search of Pubmed, Embase and Google Scholar search engines was done using specific keywords to identify studies using Demirjian's and Willems' methods in the Indian population. Studies published up to July 2018 were considered, and after thorough review, 20 eligible studies were identified. Meta-analysis of data obtained from these articles was conducted on 3668 children for Demirjian's method and 3144 children for Willems' method. The weighted mean differences for both of these methods at 95% confidence intervals were assessed to identify the accuracy of each method in predicting the chronological age.

RESULTS

Demirjian's method was found to consistently overestimate the age in Indian population, irrespective of the gender. The overestimation was in the order of few months. Willems' method resulted in underestimation of the age, although this was comparatively minimal in the order of 30 to 40 days.

CONCLUSION

Willems' method produced more accurate age which was very close to the chronological age, both in boys and girls. In contrast, Demirjian's method suffered from marked overestimation. Willems' method appears to be more suited to use in the Indian population.

A Ca2+-ATPase Regulates E-cadherin Biogenesis and Epithelial-Mesenchymal Transition in Breast Cancer Cells

Progression of benign tumors to invasive, metastatic cancer is accompanied by the epithelial-to-mesenchymal transition (EMT), characterized by loss of the cell-adhesion protein E-cadherin. Although silencing mutations and transcriptional repression of the E-cadherin gene have been widely studied, not much is known about posttranslational regulation of E-cadherin in tumors. We show that E-cadherin is tightly coexpressed with the secretory pathway Ca²⁺-ATPase isoform 2, SPCA2 (ATP2C2), in breast tumors. Loss of SPCA2 impairs surface expression of E-cadherin and elicits mesenchymal gene expression through disruption of cell adhesion in tumorspheres and downstream Hippo-YAP signaling. Conversely, ectopic expression of SPCA2 in triple-negative breast cancer elevates baseline Ca²⁺ and YAP phosphorylation, enhances posttranslational expression of E-cadherin, and suppresses mesenchymal gene expression. Thus, loss of SPCA2 phenocopies loss of E-cadherin in the Hippo signaling pathway and EMT-MET transitions, consistent with a functional role for SPCA2 in E-cadherin biogenesis. Furthermore, we show that SPCA2 suppresses invasive phenotypes, including cell migration in vitro and tumor metastasis in vivo. Based on these findings, we propose that SPCA2 functions as a key regulator of EMT and may be a potential therapeutic target for treatment of metastatic cancer. IMPLICATIONS: Posttranslational control of E-cadherin and the Hippo pathway by calcium signaling regulates EMT in breast cancer cells.

Histomorphometric Analysis of Maxillary Sinus Grafts: A Pilot Study

PURPOSE

This pilot study evaluated and compared the degree of new bone formation following maxillary sinus graft (MSG) using three different bone graft materials.

MATERIAL AND METHODS

Patients with an edentulous posterior maxilla (unilateral or bilateral) were included in this study and underwent a two-stage procedure. Each sinus was randomly assigned one of the three graft materials: anorganic bovine bone mineral (ABBM), anorganic equine bone mineral (AEBM), or mineralized cancellous bone allograft (MCBA). Bone core samples were obtained from the lateral wall of the grafted sites at least 8 months after MSG. Bone quality was evaluated during bone core retrieval. The samples were histomorphometrically analyzed using Kruskal-Wallis and Dunn-Bonferroni tests at the significance level of α = .05.

RESULTS

A total of 28 sinuses (14 unilateral and 7 bilateral) from 21 subjects, with a mean age of 61.5 (range, 33-75) years, were included in the study. Twenty-eight bone cores (ABBM [n = 9], AEBM [n = 9], and MCBA [n = 10]) were obtained at a mean healing time of 9.1 (range, 8-12) months. Six maxillary sinus membrane perforations (≤ 5 mm) were noted and repaired during surgery (21.4%). Histomorphometric analysis of the harvested bone cores revealed statistically significant differences in the percentage of vital bone (VB%), residual bone materials (RBM%), and connective tissue/marrow (CT%) among the different graft materials (Kruskal-Wallis; P < .05). The VB% in the MCBA group (32.0% ± 12.4%) was significantly greater than those in the ABBM (10.9% ± 8.9%) and AEBM (9.1% ± 5.9%) groups (P < .05). The RBM% in the MCBA group (5.5% ± 5.7%) was, however, significantly less than those in the ABBM (34.3% ± 12.1%) and AEBM (38.9% ± 5.3%) groups (P < .05). There were no significant differences in VB% and RBM% between ABBM and AEBM (P = 1.0). Newly formed bone and residual graft materials were integrated into the surrounding tissue with no sign of inflammation or foreign-body reaction.

CONCLUSION

Within the confines of the study, MCBA has significantly greater new bone formation than ABBM and AEBM. AEBM showed comparable histomorphometric results in all parameters (VB%, RBM%, CT%) to ABBM.

NHA2 promotes cyst development in an in vitro model of polycystic kidney disease

KEY POINTS

Significant and selective up-regulation of the Na⁺ /H⁺ exchanger NHA2 (SLC9B2) was observed in cysts of patients with autosomal dominant polycystic kidney disease. Using the MDCK cell model of cystogenesis, it was found that NHA2 increases cyst size. Silencing or pharmacological inhibition of NHA2 inhibits cyst formation in vitro. Polycystin-1 represses NHA2 expression via Ca²⁺ /NFAT signalling whereas the dominant negative membrane-anchored C-terminal fragment (PC1-MAT) increased NHA2 levels. Drugs (caffeine, theophylline) and hormones (vasopressin, aldosterone) known to exacerbate cysts elicit NHA2 expression. Taken together, the findings reveal NHA2 as a potential new player in salt and water homeostasis in the kidney and in the pathogenesis of polycystic kidney disease.

ABSTRACT

Autosomal dominant polycystic kidney disease (ADPKD) is caused by mutations in PKD1 and PKD2 encoding polycystin-1 (PC1) and polycystin-2 (PC2), respectively. The molecular pathways linking polycystins to cyst development in ADPKD are still unclear. Intracystic fluid secretion via ion transporters and channels plays a crucial role in cyst expansion in ADPKD. Unexpectedly, we observed significant and selective up-regulation of NHA2, a member of the SLC9B family of Na⁺ /H⁺ exchangers, that correlated with cyst size and disease severity in ADPKD patients. Using three-dimensional cultures of MDCK cells to model cystogenesis in vitro, we showed that ectopic expression of NHA2 is causal to increased cyst size. Induction of PC1 in MDCK cells inhibited NHA2 expression with concordant inhibition of Ca²⁺ influx through store-dependent and -independent pathways, whereas reciprocal activation of Ca²⁺ influx by the dominant negative membrane-anchored C-terminal tail fragment of PC1 elevated NHA2. We showed that NHA2 is a target of Ca²⁺ /NFAT signalling and is transcriptionally induced by methylxanthine drugs such as caffeine and theophylline, which are contraindicated in ADPKD patients. Finally, we observed robust induction of NHA2 by vasopressin, which is physiologically consistent with increased levels of circulating vasopressin and up-regulation of vasopressin V2 receptors in ADPKD. Our findings have mechanistic implications on the emerging use of vasopressin V2 receptor antagonists such as tolvaptan as safe and effective therapy for polycystic kidney disease and reveal a potential new regulator of transepithelial salt and water transport in the kidney.

Histone deacetylase-mediated regulation of endolysosomal pH

The pH of the endolysosomal system is tightly regulated by a balance of proton pump and leak mechanisms that are critical for storage, recycling, turnover, and signaling functions in the cell. Dysregulation of endolysosomal pH has been linked to aging, amyloidogenesis, synaptic dysfunction, and various neurodegenerative disorders, including Alzheimer's disease. Therefore, understanding the mechanisms that regulate luminal pH may be key to identifying new targets for managing these disorders. Meta-analysis of yeast microarray databases revealed that nutrient-limiting conditions inhibited the histone deacetylase (HDAC) Rpd3 and thereby up-regulated transcription of the endosomal Na⁺/H⁺ exchanger Nhx1, resulting in vacuolar alkalinization. Consistent with these findings, Rpd3 inhibition by the HDAC inhibitor and antifungal drug trichostatin A induced Nhx1 expression and vacuolar alkalinization. Bioinformatics analysis of Drosophila and mouse databases revealed that caloric control of the Nhx1 orthologs DmNHE3 and NHE6, respectively, is also mediated by HDACs. We show that NHE6 is a target of the transcription factor cAMP-response element-binding protein (CREB), a known regulator of cellular responses to low-nutrient conditions, providing a molecular mechanism for nutrient- and HDAC-dependent regulation of endosomal pH. Of note, pharmacological targeting of the CREB pathway to increase NHE6 expression helped regulate endosomal pH and correct defective clearance of amyloid Aβ in an apoE4 astrocyte model of Alzheimer's disease. These observations from yeast, fly, mouse, and cell culture models point to an evolutionarily conserved mechanism for HDAC-mediated regulation of endosomal NHE expression. Our insights offer new therapeutic strategies for modulation of endolysosomal pH in fungal infection and human disease.

Secretory pathway Ca2+ -ATPases promote in vitro microcalcifications in breast cancer cells

Calcification of the breast is often an outward manifestation of underlying molecular changes that drive carcinogenesis. Up to 50% of all non-palpable breast tumors and 90% of ductal carcinoma in situ present with radiographically dense mineralization in mammographic scans. However, surprisingly little is known about the molecular pathways that lead to microcalcifications in the breast. Here, we report on a rapid and quantitative in vitro assay to monitor microcalcifications in breast cancer cell lines, including MCF7, MDA-MB-231, and Hs578T. We show that the Secretory Pathway Ca²⁺ -ATPases SPCA1 and SPCA2 are strongly induced under osteogenic conditions that elicit microcalcifications. SPCA gene expression is significantly elevated in breast cancer subtypes that are associated with microcalcifications. Ectopic expression of SPCA genes drives microcalcifications and is dependent on pumping activity. Conversely, knockdown of SPCA expression significantly attenuates formation of microcalcifications. We propose that high levels of SPCA pumps may initiate mineralization in the secretory pathway by elevating luminal Ca²⁺ . Our new findings offer mechanistic insight and functional implications on a widely observed, yet poorly understood radiographic signature of breast cancer.

Functional analysis of Na+/H+ exchanger 9 variants identified in patients with autism and epilepsy

Na⁺/H⁺ exchanger isoform 9, NHE9, finely tunes the pH within the endosomal lumen to regulate cargo trafficking and turnover. In patients with autism, genetic approaches have revealed deletions, truncations and missense mutations in the gene encoding NHE9 (SLC9A9). To help establish causality, functional evaluation is needed to distinguish pathogenic mutations from harmless polymorphisms. Here, we evaluated three previously uncharacterized NHE9 variants, P117T, D496N, and Q609K reported in patients with autism and epilepsy. We show that NHE9-DsRed localizes to recycling endosomes in HEK293 cells where it significantly alkalinizes luminal pH, and elevates accumulation of transferrin. All three NHE9 variants were expressed and localized to endosomal compartments, similar to wild-type NHE9. In contrast to previously characterized NHE9 variants, we observed no loss-of-function with respect to endosomal pH homeostasis and transferrin endocytosis. These findings suggest that the three NHE9 substitutions analyzed in our study are either benign polymorphisms or may have a cell-type specific or regulatory function not detected in our cell culture model. Our findings highlight the importance of combining the use of cellular studies of function with sequencing technologies that capture genomic variation in patients.

A Step-by-Step Description of PDL-Mediated Ridge Preservation for Immediate Implant Rehabilitation in the Esthetic Region

The aim of this study was to present in detail the clinical steps of the root-membrane technique. This technique combines the benefits of conventional root submergence via intentional maintenance of a root fragment for ridge preservation with those of immediate implant placement for functional rehabilitation of the treated site. A case study of a tooth diagnosed with a horizontal root fracture is used to illustrate this technique step by step. The clinical application of the root-membrane technique not only allowed for immediate placement in a site with compromised buccal plate but also facilitated excellent clinical stability of soft tissue contours during the 3 years of follow-up.

Fatal chilli bite

A healthy 2-year-old girl bit a green chilli accidentally following which she had many bouts of vomiting. She became unconscious and was immediately admitted to hospital. In spite of all medical intervention, she died after one day. The autopsy confirmed that the death was caused by respiratory failure due to acute respiratory distress syndrome following aspiration of gastric contents into tracheobronchial tree. Aspiration of gastric contents resulting in acute respiratory distress syndrome and death is not uncommon; however, death following the accidental bite of a chilli is rarely reported in medical-legal literature.

Postextraction ridge preservation and augmentation with mineralized allograft with or without recombinant human platelet-derived growth factor BB (rhPDGF-BB): a consecutive case series

In an attempt to reduce postextraction alveolar bone resorption, ridge preservation and augmentation procedures have become standard-of-care treatment following tooth removal. This consecutive case series compares histologic and histomorphometric bone regenerative findings at 4 months following grafting for ridge preservation and augmentation in intact sockets and sockets with buccal wall defects. Sites were treated with mineralized allograft alone (control) or in combination with 0.3 mg/mL recombinant human platelet-derived growth factor BB (rhPDGF-BB) (test). Sites were allowed to heal for 4 months and then re-entered for trephine core biopsy and implant placement. At the end of 4 months, the mean percent remaining mineralized allograft was statistically significantly less in the test group than in the control group. The difference in mean percent vital bone between the groups showed a strong trend toward greater bone formation for the test group (41.8%) compared to the control group (32.5%) at the end of 4 months. Addition of growth factor signaling molecules to current grafting procedures may lead to accelerated bone regeneration, making it possible to successfully place implants at earlier time points.