First test-day postcalving risk factors for clinical mastitis in southern Chile dairy farms: A retrospective cohort study.

We conducted a retrospective cohort study to evaluate risk factors associated with clinical mastitis in dairy cows in southern Chile between the first milk test after calving to 200 d in milk (DIM). Data from 8,772 cows were collected from June 2017 to November 2019 on 10 dairy farms selected by convenience in southern Chile. Data were analyzed using a multivariable mixed logistic regression using a manual backward selection process with logit link function and farm as a random effect. The dependent variable was clinical mastitis between the first milking sample collected by monthly milk sampling program up to 200 DIM. Days in milk, fat, urea, parity, season, and somatic cell counts were statistically associated with clinical mastitis in the first 200 d in milk. Cows with higher than average milk yield, parity, urea, and somatic cell count were at greater odds of being diagnosed with clinical mastitis compared with their respective referents. In contrast, higher milk fat was associated with lower odds of clinical mastitis. Significant interactions between days in milk with season and parity were observed, where for every 5-d increase in DIM, the odds of clinical mastitis decreased by different proportions depending on the interaction. Identified risk factors for clinical mastitis using first monthly milk sampling data can help dairy farmers in Chile implement herd-level mastitis prevention and control measures.

In vitro inactivation of Mycobacterium avium subsp. paratuberculosis (MAP) by use of copper ions.

BACKGROUND: Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of paratuberculosis, a contagious infectious disease that affects domestic and wild ruminants causing chronic inflammation of the intestine. MAP has proven to be very resistant to both physical and chemical processes, making it difficult to control this pathogen. Based on the recognized antimicrobial properties of copper, the objective of this study was to evaluate the effectiveness of copper ions to reduce MAP numbers and/or MAP viability in a fluid matrix. Besides, methicillin-resistant Staphylococcus aureus (MRSA), and Escherichia coli were used as controls of the effectiveness of copper ions. MAP-spiked PBS was subjected to copper ions treatment at 24 V for 5 min and the PBS suspensions were sampled before and after treatment. MAP viability and quantification were determined using three complementary techniques: a phage amplification assay, MGIT culture and qPCR. RESULTS: Moderate numbers (103 CFU ml-1) of the two control bacteria were completely eliminated by treatment with copper ions. For MAP, copper ions treatment reduced both the viability and numbers of this pathogen. Phage assay information quickly showed that copper ions (24 V for 5 min) resulted in a significant reduction in viable MAP. MGIT culture results over time showed statistically significant differences in time-to-detection (TTD) values between PRE and POST treatment. MAP genome equivalent estimates for PBS suspensions indicated that MAP numbers were lower in samples POST-treatment with copper ions than PRE-treatment. CONCLUSIONS: The use of copper ions resulted in a significant reduction of MAP in a liquid matrix, although some MAP survival on some occasions was observed.

GSK-3ß overexpression causes reversible alterations on postsynaptic densities and dendritic morphology of hippocampal granule neurons in vivo.

Adult hippocampal neurogenesis (AHN) is crucial for the maintenance of hippocampal function. Several neurodegenerative diseases such as Alzheimer's disease (AD) are accompanied by memory deficits that could be related to alterations in AHN. Here, we took advantage of a conditional mouse model to study the involvement of glycogen synthase kinase-3ß (GSK-3ß) overexpression (OE) in AHN. By injecting GFP- and PSD95-GFP-expressing retroviruses, we have determined that hippocampal GSK-3ß-OE causes dramatic alterations in both dendritic tree morphology and post-synaptic densities in newborn neurons. Alterations in previously damaged neurons were reverted by switching off the transgenic system and also by using a physiological approach (environmental enrichment) to increase hippocampal plasticity. Furthermore, comparative morphometric analysis of granule neurons from patients with AD and from GSK-3ß overexpressing mice revealed shared morphological alterations. Taken together, these data indicate that GSK-3ß is crucial for hippocampal function, thereby supporting this kinase as a relevant target for the treatment of AD.

Molecular and serological prevalence of Coxiella burnetii in bovine dairy herds in southern Chile: A PCR and ELISA-based assessment of bulk tank milk samples.

Coxiella burnetii (C. burnetii) is a highly resilient zoonotic bacterium responsible for Q fever, a disease which occurs worldwide, with the exception of New Zealand. However, in Chile, the prevalence and impact of C. burnetii in cattle herds remain poorly understood due to limited research. This study aimed to assess the presence of C. burnetii in dairy cattle herds in southern Chile, using two diagnostic methods on bulk tank milk samples. The results of the study revealed a high prevalence of C. burnetii infection in the analyzed herds. Of the 271 milk tank samples tested, 76% (208/271, CI: 71.1-81.5) tested positive using ELISA, while 73% (200/271, CI: 68.0-78.8) tested positive using qPCR. These findings indicate a significant presence of C. burnetii in the cattle herds studied. Despite the high prevalence observed, no new Q fever outbreaks have been reported in the study area. This discrepancy highlights the need for further research to better understand the transmission dynamics, environmental factors, and livestock management practices associated with C. burnetii infection. These studies will contribute to the development of effective prevention and control strategies and promote public health regarding Q fever.

[Bacterial colonization in areas of burnt skin and healthy children younger than 15 years, seen COANIQUEM, Santiago, Chile]. / Colonización bacteriana de piel sana versus quemada de niños bajo 15 años tratados en COANIQUEM, Santiago de Chile.

UNLABELLED: Bacterial colonization in patients with burns skin without infection and outpatient management has been poorly studied. OBJECTIVE: To quantify and identify the type of bacteria that colonize healthy body areas homologous location of the skin in children from 1 to 15 years, seen COANIQUEM, Santiago, Chile. Per patient, we studied 204 samples from each zone. The isolated microorganisms were S. epidermidis 35, 3%; others Staphylococcus coagulase negative, 25.8%; S. aureus, 4.4%; and S. viridans group 1.4%. In the subgroup of children who had a count between 1 and 1000 cfu, there was a higher proportion of cfu in burned skin healthy skin (p = 0.0359). The association between depth of the lesion and the bacterial count obtained p = 0.034. CONCLUSION: In outpatient treatment, the microorganisms are expected in healthy skin, burned skin is evident in lower counts probably associated with epithelial damage.

[Bacteriological quality of air in a ward for sterile pharmaceutical preparations]. / Calidad microbiológica del aire de una unidad de preparados farmacéuticos estériles.

BACKGROUND: An extremely clean area is required for preparation of sterile pharmaceutical compounds, in compliance with international standards, to minimize the probability of microbial contamination. AIM: To evaluate the bacteriological quality of the air in the Sterile Pharmaceutical Preparation Unit of the University of Chile's Clinical Hospital and to set up alerts and action levels of bacterial growth. METHODS: We studied eight representative sites of our Unit on a daily basis from January to February 2005 and twice a week from June 2005 to February 2006. We collected 839 samples of air by impact in the Petri dish. RESULTS: 474 (56.5%) samples were positive; 17 (3.5%) of them had an inappropriate bacterial growth (2% of total samples). The samples from sites 1 and 2 (big and small biosafety cabinets) were negative. The countertop and transfer area occasionally exceeded the bacterial growth limits. The most frequently isolated bacteria were coagulase-negative staphylococci, Micrococcus spp and Corynebacterium spp, from skin microbiota, and Bacillus spp, an environmental bacteria. CONCLUSIONS: From a microbiological perspective, the air quality in our sterile preparation unit complied with international standards. Setting institutional alerts and action levels and appropriately identifying bacteria in sensitive areas permits quantification of the microbial load and application of preventive measures.

[Acute gastroenteritis caused by a Vibrio cholerae non-O1, non-O139 strain harboring a genetic region homologous to the VpaI-7 pathogenicity island]. / Gastroenteritis aguda causada por Vibrio cholerae no-O1, no-O139 que porta una región homologa a la isla de patogenicidad VpaI-7.

Pathogenic Vibrio cholerae isolates, the etiologic agents of cholera, generally express one of two O antigens (O1 or O139). Most environmental isolates are nonpathogenic and are referred to as "non-O1, non-O139". However some V. cholerae non-O1, non-O139 strains are clearly pathogenic and have caused outbreaks or sporadic cases of gastroenteritis and extraintestinal infections in humans. We report a case of acute gastroenteritis by a V. cholerae non-O1, non-O139 harboring a genetic region homologous to a segment of the VpaI-7 V. parahaemolyticus pathogenicity island.

GalNAc-alpha-O-benzyl inhibits NeuAcalpha2-3 glycosylation and blocks the intracellular transport of apical glycoproteins and mucus in differentiated HT-29 cells.

Exposure for 24 h of mucus-secreting HT-29 cells to the sugar analogue GalNAc-alpha-O-benzyl results in inhibition of Galbeta1-3GalNAc:alpha2,3-sialyltransferase, reduced mucin sialylation, and inhibition of their secretion (Huet, G., I. Kim, C. de Bolos, J.M. Loguidice, O. Moreau, B. Hémon, C. Richet, P. Delannoy, F.X. Real., and P. Degand. 1995. J. Cell Sci. 108:1275-1285). To determine the effects of prolonged inhibition of sialylation, differentiated HT-29 populations were grown under permanent exposure to GalNAc-alpha-O-benzyl. This results in not only inhibition of mucus secretion, but also in a dramatic swelling of the cells and the accumulation in intracytoplasmic vesicles of brush border-associated glycoproteins like dipeptidylpeptidase-IV, the mucin-like glycoprotein MUC1, and carcinoembryonic antigen which are no longer expressed at the apical membrane. The block occurs beyond the cis-Golgi as substantiated by endoglycosidase treatment and biosynthesis analysis. In contrast, the polarized expression of the basolateral glycoprotein GP 120 is not modified. Underlying these effects we found that (a) like in mucins, NeuAcalpha2-3Gal-R is expressed in the terminal position of the oligosaccharide species associated with the apical, but not the basolateral glycoproteins of the cells, and (b) treatment with GalNAc-alpha-O-benzyl results in an impairment of their sialylation. These effects are reversible upon removal of the drug. It is suggested that alpha2-3 sialylation is involved in apical targeting of brush border membrane glycoproteins and mucus secretion in HT-29 cells.

[Neonatal meningitis caused by atypical Streptococcus pneumoniae: case report and review]. / Meningitis neonatal por Streptococcus pneumoniae atípico: Reporte de un caso y revisión.

Streptococcus pneumoniae is a rarely recognized cause of neonatal sepsis and/or meningitis, but it is associated with substantial morbidity and mortality. Traditionally, S. pneumoniae is identified in the laboratory by demonstrating susceptibility to optochin. However, the emergence of optochin-resistant organisms makes definite identification difficult when only phenotypic tests are taken as markers. We present the case of a severe early-onset neonatal meningitis due to an atypical strain of S. pneumoniae. Laboratory methods utilized to certify this species diagnosis are discussed.

[Leuconostoc infections in patients with short gut syndrome, parenteral nutrition and continuous enteral feeding]. / Infección por Leuconostoc en pacientes con síndrome de intestino corto, nutrición parenteral y alimentación enteral continua.

Leuconostoc is a gram-positive cocci, quite ubiquitous in nature. It is used in wine industry, and for aroma and texture of dairy products. Occasionally it has been isolated from humans in cases of bacteremia, catheter associated infections, sepsis, meningitis, pneumonia, UTI, osteomyelitis and hepatic dysfunction. Short bowel syndrome, patients with CVC and patients with gastrostomy undergoing enteral feeding, are described amongst the factors associated with this infection. The isolation of a gram-positive cocci, that does not hydrolyze arginine and that is resistant to vancomycin leads to this diagnostic possibility. Antibiotic treatment: penicillin or ampicillin.

Differential distribution of sialic acid in alpha2,3 and alpha2,6 linkages in the apical membrane of cultured epithelial cells and tissues.

We used lectin cytochemistry and confocal microscopy to examine the distribution of sialic acid in epithelial cells. Maackia amurensis lectin and Sambuccus nigra agglutinin were used to detect alpha2,3 and alpha2,6 sialic acid, respectively. In Caco-2, HT-29 5M12, and MCF-7 cells, which express sialic acid mainly in one type of linkage, the majority of the signal was observed in the apical membrane. In cells that bound both lectins, alpha2,3 sialic acid was distributed apically, whereas alpha2,6 sialic acid showed a broader distribution. In IMIM-PC-1 cultures, alpha2,3 sialic acid was detected mainly in the apical membrane, whereas alpha2,6 sialic acid was more abundant in the basolateral domain of polarized cells. In these cells, treatment with GalNAc-O-benzyl led to reduced alpha2,3 levels and to an increase and redistribution of alpha2,6 to the apical domain. Similarly, sialic acid was predominantly expressed apically in all epithelial tissues examined. In conclusion, (a) sialic acid is mainly distributed to the apical membrane of epithelial cells, (b) there is a hierarchy in the distribution of sialic acids in polarized epithelial cells, i.e., alpha2,3 is preferred to alpha2,6 in the apical membrane, and (c) IMIM-PC-1 cells are a good model in which to study the regulation of the levels and distribution of sialic acids.

The influence of risk factors on the severity of anti-tuberculosis drug-induced hepatotoxicity.

BACKGROUND: Hepatotoxicity is one of the most serious adverse effects of anti-tuberculosis drugs (ATD). Although many risk factors have been associated with ATD-induced hepatotoxicity, their influence on hepatitis severity has not been studied systematically. OBJECTIVES: To evaluate whether the presence of hepatotoxicity risk factors (advanced age, chronic liver disease, abuse of alcohol or other drugs or malnutrition) influences the severity of ATD-induced hepatotoxicity. DESIGN: A prospective cohort study of 471 active tuberculosis patients treated with isoniazid, rifampicin and pyrazinamide and followed in a tuberculosis clinic between January 1998 and July 2002. Incidence of hepatotoxicity and its severity according to the presence or absence of ATD-induced hepatitis risk factors was evaluated. RESULTS: The incidence of ATD-induced hepatotoxicity (serum transaminase > 3 x the upper limit of normal [ULN]) was 18.2% (42/231 patients) in the risk factor group and 5.8% (14/240 patients) in the non-risk factor group (OR 3.5; 95% CI 1.9-6.7; P < 0.001). Severe hepatotoxicity (transaminase > 10 x ULN) occurred in 6.9% (16/231) of the risk factor group and in 0.4% (1/240) (OR 17.7; 95% CI 2.3-135; P < 0.001) of the group without risk factors. CONCLUSIONS: ATD-induced hepatitis is significantly more frequent and more severe in patients with hepatotoxicity risk factors.

[A multicenter study of infection with human immunodeficiency virus type-2 (HIV-2) in Spain (1991). The Spanish Group for the Study of HIV-2]. / Estudio multicéntrico de la infección por el virus de la inmunodeficiencia humana tipo 2 (VIH-2) en España (1991). Grupo Español para el Estudio del VIH-2.

BACKGROUND: To January 1991 thirteen cases of HIV-2 infection had been reported in Spain. Paradoxically, neighboring countries, i.e. France and Portugal, have reported more than one thousand cases, and are the most HIV-2 prevalent areas outside West Africa. We report the results of a prospective, nationwide study on the prevalence of HIV-2 infection conducted in Spain in 1991. In addition, an evaluation of testing methodologies is made. METHODS: Sera collected from 8,073 individuals at high-risk for HIV infection were screened by a combined HIV-1 plus HIV-2 ELISA. Reactive samples were further evaluated by three tests, as HIV-1 Western blot (WB), HIV-2 specific WB, and a synthetic peptide assay immuno-dot (Pepti-lav, Pasteur). RESULTS: Fifteen (0.18%) individuals met criteria of HIV-2 infection in both specific WB and SPA. Four (27%) of them showed reactivity to both HIV-1 and HIV-2, and the dual infection was confirmed by polymerase chain reaction (PCR) in 2 out of 3 available samples. The SPA showed higher sensitivity and specificity than WB in the diagnosis and distinction of HIV-1 and HIV-2 infections. CONCLUSIONS: To January 1992, 28 cases of HIV-2 infection have been described in Spain. All but two were African immigrants. The first cases of HIV-1 plus HIV-2 coinfection have been identified. In HIV high-risk populations, SPA may provide an excellent alternative to WB to confirm ELISA reactive samples.

[Evaluation of various criteria for the interpretation of western blot for the diagnosis of human immunodeficiency virus infection. Spanish Group for the Study of HIV-2]. / Evaluación de diferentes criterios de interpretación del Western blot para el diagnóstico de la infección por el virus de la inmunodeficiencia humana. Grupo Español para el Estudio del VIH-2.

BACKGROUND: The Western blot (WB) is the most commonly used test to confirm the presence of antibodies against the human immunodeficiency virus type 1 (HIV-1). Different criteria of interpretation of the band profile have been proposed with there being no unanimity as to its reliability. The sensitivity and specificity of several criteria proposed for the interpretation of WB were evaluated and the individual significance of the reactivity of each band of the WB was analyzed. METHODS: The presence of antibodies against HIV-1 was prospectively studied in 8,073 samples of subjects with risk of infection. A total of 1,993 (25%) were reactive by ELISA and 1,261 were analyzed by WB, with a semiquantitative reading of the bands with a point scale from 0 to 2 being performed. The final interpretation of the WB (negative, doubtful, or positive) was carried out following 5 recommendations of usage. A test designed with synthetic peptides (Pepti-lav) was used as a reference and in discordant cases, other more specific serologic tests and/or genetic analysis by polymerase chain reaction (PCR) were performed. RESULTS: In order of frequency, the greater sensitivity was found to be for the CRSS (Consortium for Retrovirus Serology Standardization) criteria (97.9%), OMS (96.6%), CDC (Center for Disease Control) (95.9%), ARC (American Red Cross) (95.6%) and FDA (99.8%). The greatest specificity was for the criteria of the OMS, and FDA (99.8%). In order of frequency, the most frequent bands in HIV-1 + individuals were gp160 (99%), gp120, p24, p31, p55, p68, gp41, and p17 (68%). In non infected individuals, the recognized bands were, in decreasing order, p24, p17, p55, p68, p31, and glucoproteins. CONCLUSIONS: Different criteria of interpretation of the Western blot provide different degrees of sensitivity and specificity. The Western blot is a non standardized, expensive, laborious technique of subjective interpretation which provides an appreciable number of undetermined results.

[Essential thrombocythemia: a 35-year experience and review of the literature]. / Trombocitemia esencial: experiencia de 35 años y revisión de la literatura.

Essential thrombocythemia (ET) is a clonal myeloproliferative disorder characterized by an uncontrolled rise in peripheral blood platelet count. The aim of this report was to determine the clinical and laboratory data of this disease in a 35 years revision. Of the patients with the diagnosis of ET, we selected those who fulfilled five of the six diagnostic criteria proposed by the Poli Vera Study Group. We found 14 cases (10 female and 4 male) with a median age of 54.5 years (range 29-74). The most frequent initial clinical finding was hemorrhage and in four cases the diagnosis was preoperative. Median platelet count was 1,355 x 10(9)/L (range 600 to 3,750). One case had iron deficiency which was corrected before ET was diagnosed. None has evolved to acute leukemia. Initially, most of the cases were treated with busulphan and two received alpha-interferon which was promptly changed to busulphan because of secondary effects. Three patients have died due to hemorrhagic complications and one due to thrombosis. ET has a low frequency in our country and must be considered an exclusion diagnosis. Iron deficiency may mask the diagnosis specially in the cases with a platelet count not very high. Treatment can provide in general a long survival of good quality of life.

[Intestinal hemorrhage for 21 years in a case of blue nevus syndrome]. / Sangrado intestinal de 21 años en un caso de síndrome de nevo azul.

OBJECTIVE: To report a case of gastrointestinal bleeding due to a blue rubber bleb nevus syndrome undiagnosed for 21 years. CASE: A woman of 28 years of age suffered chronic gastrointestinal bleeding starting at seven years of age. During these 21 years she received various treatment with oral and parenteral iron and, in addition, four blood transfusions. We found her to be anemic with 7.8 g/dL of hemoglobin (HB), iron deficient and with skin lesions in tongue, right hand and lower extremities. A skin biopsy diagnosed the lesions as cavernous hemangiomas. Multiple intestinal hemangiomas seen by radiologic, endoscopic and colonoscopic studies, established the diagnosis. She was treated with oral iron; three months later she was asymptomatic and with higher levels of HB (9.1 g/dL). CONCLUSION: The rarity of the syndrome and the fact that, as far as we know, it is the first case reported in Mexico, probably led to a delay in its diagnosis and to potentially dangerous therapy in this patient in spite of the fact that the diagnosis was not difficult.

Ángulo de convexidad facial y proyección del mentón en pacientes en postoperatorio de rinoseptoplastia / Angle facial convexity and projection of the chin in patients undergone of rhinoplasty

Introducción: La relación de la nariz con la morfología facial no es solo estructural. Numerosos estudios sugieren la relación entre la función respiratoria nasal y el de-sarrollo craneofacial. Objetivo: Determinar la mejoría en el ángulo de convexidad facial y proyección del mentón en pacientes en postoperatorio de rinoseptoplastia. Diseño: Estudio observacional analítico tipo corte transversal. Metodología: Mues-tra de 43 pacientes, 26 de género femenino y 17 masculino, entre 12 y 43 años, sometidos a rinoseptoplastia con evolución postoperatoria mínima de 3 meses. Se analizaron las variables de edad, sexo, ángulo de convexidad facial de Legan y proyección del mentón según González Ulloa antes y después de la cirugía, así como tiempo postquirúrgico. Resultados: El ángulo de convexidad facial se redujo 3,72°+2,19. En la técnica de González Ulloa, se evidenció avance del pogonion 2,53 mm+ 1,60. De los 43 pacientes, un 72%, mostró cambios favorables en el án-gulo de convexidad facial y en la proyección del mentón. Los mejores resultados se evidenciaron en menores de 16 años y evolución postquirúrgica mayor a 1 año. Discusión: A diferencia de otras investigaciones, observamos cambios significativos en pacientes adultos. Tal hecho nos lleva a otras interrogantes sobre mecanismos adicionales que pudieran influir en los patrones de crecimiento facial. Conclusiones: La rinoseptoplastia al considerarse un procedimiento que mejora la función respira-toria nasal, favorece cambios neuromusculares y endocrinos que permiten un mejor desarrollo del perfil facial en especial del tercio inferior.

Introduction: The relation between the nose and the facial morphology is not only structural. Numerous studies have demonstrated also a relationship between nasal respiratory function and craniofacial development. Objective: To determine the im-provement in the angle of facial convexity and chin projection in patients in the postoperative period of rhinoseptoplasty. Design: Cross-sectional study. Methods: 43 patients were selected. 26 women and 17 men between 12 and 43 years old, undergoing Rhinoplasty with minimum 3 months of postoperative evolution. We analyzed the variables of age, sex, Legan's angle of facial convexity and projection of the chin according to Gonzalez Ulloa before and after surgery, as well as post-surgical time. Results: The angle of facial convexity was reduced X + D.S 3.72 ° + 2.19. The technique of González Ulloa showed progress of the pogonion X + D.S 2.53 mm + 1.60. Of the 43 patients, 72%, showed positive changes at the angle of facial convexity and the projection of the Chin. Best results were apparent in children under 16 years and more than 1 year postsurgical evolution. Discussion: Unlike other research, we observe significant changes in adult patients. This fact leads to other questions about additional mechanisms that might influence the facial growth patterns. Conclusions: Rhinoseptoplasty is a procedure that improves the nasal respiratory function, favors neuromuscular and endocrine changes that allow better development of the facial profile especially in the lower third.

The Armc10/SVH gene: genome context, regulation of mitochondrial dynamics and protection against Aß-induced mitochondrial fragmentation.

Mitochondrial function and dynamics are essential for neurotransmission, neural function and neuronal viability. Recently, we showed that the eutherian-specific Armcx gene cluster (Armcx1-6 genes), located in the X chromosome, encodes for a new family of proteins that localise to mitochondria, regulating mitochondrial trafficking. The Armcx gene cluster evolved by retrotransposition of the Armc10 gene mRNA, which is present in all vertebrates and is considered to be the ancestor gene. Here we investigate the genomic organisation, mitochondrial functions and putative neuroprotective role of the Armc10 ancestor gene. The genomic context of the Armc10 locus shows considerable syntenic conservation among vertebrates, and sequence comparisons and CHIP-data suggest the presence of at least three conserved enhancers. We also show that the Armc10 protein localises to mitochondria and that it is highly expressed in the brain. Furthermore, we show that Armc10 levels regulate mitochondrial trafficking in neurons, but not mitochondrial aggregation, by controlling the number of moving mitochondria. We further demonstrate that the Armc10 protein interacts with the KIF5/Miro1-2/Trak2 trafficking complex. Finally, we show that overexpression of Armc10 in neurons prevents Aß-induced mitochondrial fission and neuronal death. Our data suggest both conserved and differential roles of the Armc10/Armcx gene family in regulating mitochondrial dynamics in neurons, and underscore a protective effect of the Armc10 gene against Aß-induced toxicity. Overall, our findings support a further degree of regulation of mitochondrial dynamics in the brain of more evolved mammals.