Publications by authors named "Hector Sandoval"

Purpose: To evaluate the safety and refractive outcomes of eyes after intraocular lens (IOL) iris suture fixation (ISF).

Setting: Private practice, Los Angeles, California.

Design: Nonrandomized and unmasked retrospective chart review.

View Article and Find Full Text PDF

Purpose: To assess whether there are added risks when performing intraocular lens (IOL) exchange in the setting of an open posterior capsule (OPC) when compared with a closed posterior capsule (CPC) IOL exchange.

Setting: Private practice, Los Angeles, California.

Design: Nonrandomized and unmasked retrospective chart review.

View Article and Find Full Text PDF

We report the complete genome sequence of a field isolate of a novel bipartite secovirid infecting cassava in Colombia, provisionally named "cassava torrado-like virus" (CsTLV). The genome sequence was obtained using Oxford Nanopore Technology, and the 5' ends were confirmed by RACE. The RNA1 is 7252 nucleotides (nt) long, encoding a polyprotein of 2336 amino acids (aa) containing the typical "replication block", conserved torradovirus motifs, and a Maf/Ham1 domain, which is not commonly found in viral genomes.

View Article and Find Full Text PDF

B cells are responsible for protective antibody production after differentiation into antibody-secreting cells during humoral immune responses. From early B cell development in the bone marrow, to their maturation in the periphery, activation in the germinal center, and differentiation into plasma cells or memory B cells, B cells display ever-changing functions and properties. Autophagy and mitochondria play important roles in B cell development, activation, and differentiation to accommodate the phenotypic and environmental changes encountered over the lifetime of the cell.

View Article and Find Full Text PDF

Different macrophage subtypes have different morphologies/shapes and functions. Naïve M0 macrophages are elongated. Pro-inflammatory M1 that produce the bactericidal molecule iNos are round.

View Article and Find Full Text PDF

Background: Gastric cancer is the second leading cause of cancer death globally. In Honduras the incidence in the last decade was 39 and 21 per 100,000 inhabitants for men and women, respectively. In 2008 IARC (GLOBOCAN) placed Honduras as the country with the highest incidence of gastric cancer in Latin America.

View Article and Find Full Text PDF

We previously identified mutations in Nardilysin (dNrd1) in a forward genetic screen designed to isolate genes whose loss causes neurodegeneration in Drosophila photoreceptor neurons. Here we show that NRD1 is localized to mitochondria, where it recruits mitochondrial chaperones and assists in the folding of α-ketoglutarate dehydrogenase (OGDH), a rate-limiting enzyme in the Krebs cycle. Loss of Nrd1 or Ogdh leads to an increase in α-ketoglutarate, a substrate for OGDH, which in turn leads to mTORC1 activation and a subsequent reduction in autophagy.

View Article and Find Full Text PDF

Autophagy is a central lysosomal degradation pathway required for maintaining cellular homeostasis and its dysfunction is associated with numerous human diseases. To identify players in autophagy, we tested ∼1200 chemically induced mutations on the X chromosome in Drosophila fat body clones and discovered that shibire (shi) plays an essential role in starvation-induced autophagy. shi encodes a dynamin protein required for fission of clathrin-coated vesicles from the plasma membrane during endocytosis.

View Article and Find Full Text PDF

The ability to sense energy status is crucial in the regulation of metabolism via the mechanistic Target of Rapamycin Complex 1 (mTORC1). The assembly of the TTT-Pontin/Reptin complex is responsive to changes in energy status. Under energy-sufficient conditions, the TTT-Pontin/Reptin complex promotes mTORC1 dimerization and mTORC1-Rag interaction, which are critical for mTORC1 activation.

View Article and Find Full Text PDF

Two insults often underlie a variety of eye diseases including glaucoma, optic atrophy, and retinal degeneration--defects in mitochondrial function and aberrant Rhodopsin trafficking. Although mitochondrial defects are often associated with oxidative stress, they have not been linked to Rhodopsin trafficking. In an unbiased forward genetic screen designed to isolate mutations that cause photoreceptor degeneration, we identified mutations in a nuclear-encoded mitochondrial gene, ppr, a homolog of human LRPPRC.

View Article and Find Full Text PDF

Autophagy helps deliver sequestered intracellular cargo to lysosomes for proteolytic degradation and thereby maintains cellular homeostasis by preventing accumulation of toxic substances in cells. In a forward mosaic screen in Drosophila designed to identify genes required for neuronal function and maintenance, we identified multiple cacophony (cac) mutant alleles. They exhibit an age-dependent accumulation of autophagic vacuoles (AVs) in photoreceptor terminals and eventually a degeneration of the terminals and surrounding glia.

View Article and Find Full Text PDF

Reactive oxygen species (ROS) and mitochondrial defects in neurons are implicated in neurodegenerative disease. Here, we find that a key consequence of ROS and neuronal mitochondrial dysfunction is the accumulation of lipid droplets (LD) in glia. In Drosophila, ROS triggers c-Jun-N-terminal Kinase (JNK) and Sterol Regulatory Element Binding Protein (SREBP) activity in neurons leading to LD accumulation in glia prior to or at the onset of neurodegeneration.

View Article and Find Full Text PDF

Mitochondrial fusion and fission affect the distribution and quality control of mitochondria. We show that Marf (Mitochondrial associated regulatory factor), is required for mitochondrial fusion and transport in long axons. Moreover, loss of Marf leads to a severe depletion of mitochondria in neuromuscular junctions (NMJs).

View Article and Find Full Text PDF

Invertebrate model systems are powerful tools for studying human disease owing to their genetic tractability and ease of screening. We conducted a mosaic genetic screen of lethal mutations on the Drosophila X chromosome to identify genes required for the development, function, and maintenance of the nervous system. We identified 165 genes, most of whose function has not been studied in vivo.

View Article and Find Full Text PDF

Forward genetic screens using chemical mutagens have been successful in defining the function of thousands of genes in eukaryotic model organisms. The main drawback of this strategy is the time-consuming identification of the molecular lesions causative of the phenotypes of interest. With whole-genome sequencing (WGS), it is now possible to sequence hundreds of strains, but determining which mutations are causative among thousands of polymorphisms remains challenging.

View Article and Find Full Text PDF

Parkinson's disease (PD) is a common neurodegenerative disease, yet the underlying causative molecular mechanisms are ill defined. Numerous observations based on drug studies and mutations in genes that cause PD point to a complex set of rather subtle mitochondrial defects that may be causative. Indeed, intensive investigation of these genes in model organisms has revealed roles in the electron transport chain, mitochondrial protein homeostasis, mitophagy, and the fusion and fission of mitochondria.

View Article and Find Full Text PDF

Rhodopsin mistrafficking can cause photoreceptor (PR) degeneration. Upon light exposure, activated rhodopsin 1 (Rh1) in Drosophila PRs is internalized via endocytosis and degraded in lysosomes. Whether internalized Rh1 can be recycled is unknown.

View Article and Find Full Text PDF
Article Synopsis
  • - Vesicular trafficking is essential for regulating Notch signaling, crucial for cell fate and development of sensory organs.
  • - The gene tempura encodes a protein that forms a novel complex, which modifies Rab proteins (Rab1 and Rab11) to ensure their proper location within the cell.
  • - Impairments in Rab1 and Rab11 due to tempura loss disrupt the secretion of Scabrous and Delta, leading to issues in Notch signaling and sensory organ development.
View Article and Find Full Text PDF

Mitochondrial complex I (CI) is an essential component in energy production through oxidative phosphorylation. Most CI subunits are encoded by nuclear genes, translated in the cytoplasm, and imported into mitochondria. Upon entry, they are embedded into the mitochondrial inner membrane.

View Article and Find Full Text PDF

Rhodopsins (Rhs) are light sensors, and Rh1 is the major Rh in the Drosophila photoreceptor rhabdomere membrane. Upon photoactivation, a fraction of Rh1 is internalized and degraded, but it remains unclear how the rhabdomeric Rh1 pool is replenished and what molecular players are involved. Here, we show that Crag, a DENN protein, is a guanine nucleotide exchange factor for Rab11 that is required for the homeostasis of Rh1 upon light exposure.

View Article and Find Full Text PDF

Notch signaling affects many developmental and cellular processes and has been implicated in congenital disorders, stroke, and numerous cancers. The Notch receptor binds its ligands Delta and Serrate and is able to discriminate between them in different contexts. However, the specific domains in Notch responsible for this selectivity are poorly defined.

View Article and Find Full Text PDF

The resting energy expenditure (REE) and substrate utilization are computed by indirect calorimetry technique (ICT). The REE represents 80-85% of the total energy expenditure (TEE) but only accounts for the 7% of the actual body weight (ABW). The TEE is produced by the organs plus muscles, whereas the REE accounts only for the main organs.

View Article and Find Full Text PDF