University of Puerto Rico, Medical Sciences Campus

About: University of Puerto Rico, Medical Sciences Campus is a education organization based out in San Juan, Puerto Rico, United States. It is known for research contribution in the topics: Population & Medicine. The organization has 1711 authors who have published 1496 publications receiving 27756 citations.

Disparities in asthma medication dispensing patterns: the case of pediatric asthma in Puerto Rico.

Abstract: This study was supported by NIH Grant # 5P60 MD002261-02 funded by the National Center for Minority Health and Health Disparities.

Cocaine alters GABAB‐mediated G‐protein activation in the ventral tegmental area of female rats: Modulation by estrogen

Abstract: In female rats, estrogen has been reported to enhance cocaine sensitization. Here we investigated the effect of estrogen and cocaine treatments on GABAB-stimulated [35S]GTPγS binding. Ovariectomized rats without (OVX) and with estrogen treatment (OVX-EB) were pretreated with saline or cocaine (15 mg/kg, i.p.) for 5 days and after 1 week of withdrawal challenged with cocaine. One hour after the final injection, animals were sacrificed, brains immediately frozen, and stored at −70°C for subsequent cryosectioning. In vitro functional autoradiography was performed using baclofen (300 μM), a GABAB receptor agonist, to stimulate [35S]GTPγS binding in tissue sections at the level of the ventral tegmental area (VTA). OVX-EB rats showed lower levels of [35S]GTPγS binding in the VTA (−15%) and entorhinal cortex (EC) (−60%). The effect of cocaine on GABAB-mediated G-protein activation varied with the presence of estrogen. Repeated cocaine administration reduced [35S]GTPγS binding in the VTA and EC of OVX rats and increased it in OVX-EB. Thus, our data suggest that estrogen reduces GABAB-mediated G-protein activation in female rats. The results also show that estrogen strongly influences cocaine-induced alterations in GABAB function in the VTA and EC of female rats. Synapse 54:30–36, 2004. © 2004 Wiley-Liss, Inc.

Tunicamycin-induced ER stress in breast cancer cells neither expresses GRP78 on the surface nor secretes it into the media

Abstract: GRP78 (an Mr 78 kDa calcium dependent glucose binding protein) is located in ER lumen. It functions as ER chaperone and translocates proteins for glycosylation at the asparagine residue present in the sequon Asn-X-Ser/Thr. Paraffin sections from N-glycosylation inhibitor tunicamycin treated ER-/PR-/HER2+ (double negative) breast tumor in athymic nude mice exhibited reduced N-glycan but increased GRP78 expression. We have evaluated the effect of tunicamycin on cellular localization of GRP78 in metastatic human breast cancer cells MDA-MB-231 (ER-/PR-/HER2-). Tunicamycin inhibited cell proliferation in a time and dose-dependent manner. Nonmetastatic estrogen receptor positive (ER+) MCF-7 breast cancer cells were also equally effective. GRP78 expression (protein and mRNA) was higher in tunicamycin (1.0 μg/mL) treated MCF-7 and MDA-MB-231 cells. GRP78 is an ER stress marker, so we have followed its intracellular localization using immunofluorescence microscopy after subjecting the cancer cells to various stress conditions. Unfixed cells stained with either FITC-conjugated Concanavalin A (Con A) or Texas-red conjugated wheat germ agglutinin (WGA) exhibited surface expression of N-glycans but not GRP78. GRP78 became detectable only after a brief exposure of cells to ice-cold methanol. Western blotting did not detect GRP78 in conditioned media of cancer cells whereas it did for MMP-1. The conclusion, GRP78 is expressed neither on the outer-leaflet of the (ER-/PR-/HER2-) human breast cancer cells nor it is secreted into the culture media during tunicamycin-induced ER stress. Our study therefore suggests strongly that anti-tumorigenic action of tunicamycin can be modeled to develop next generation cancer therapy, i.e., glycotherapy for treating breast and other sold tumors.

Long-term effects of tetanus toxoid inoculation on the demography and life expectancy of the Cayo Santiago rhesus macaques

Abstract: Tetanus was a major cause of mortality in the free-ranging population of rhesus monkeys on Cayo Santiago prior to 1985 when the entire colony was given its first dose of tetanus toxoid. The immediate reduction in mortality that followed tetanus toxoid inoculation (TTI) has been documented, but the long-term demographic effects of eliminating tetanus infections have not. This study uses the Cayo Santiago demographic database to construct comparative life tables 12 years before, and 12 years after, TTI. Life tables and matrix projection models are used to test for differences in: (i) survival among all individuals as well as among social groups, (ii) long-term fitness of the population, (iii) age distribution, (iv) reproductive value, and (v) life expectancy. A retrospective life table response experiment (LTRE) was performed to determine which life cycle transition contributed most to observed changes in long-term fitness of the population post-TTI. Elimination of clinical tetanus infections through mass inoculation improved the health and well-being of the monkeys. It also profoundly affected the population by increasing survivorship and long-term fitness, decreasing the differences in survival rates among social groups, shifting the population's age distribution towards older individuals, and increasing reproductive value and life expectancy. These findings are significant because they demonstrate the long-term effects of eradicating a major cause of mortality at a single point in time on survival, reproduction, and overall demography of a naturalistic population of primates.

Low-cost Method for Obtaining Medical Rapid Prototyping Using Desktop 3D printing: A Novel Technique for Mandibular Reconstruction Planning

Abstract: Background Three-dimensional (3D) printing is relatively a new technology with clinical applications, which enable us to create rapid accurate prototype of the selected anatomic region, making it possible to plan complex surgery and pre-bend hardware for individual surgical cases. This study aimed to express our experience with the use of medical rapid prototype (MRP) of the maxillofacial region created by desktop 3D printer and its application in maxillofacial reconstructive surgeries. Material and methods Three patients with benign mandible tumors were included in this study after obtaining informed consent. All patient's maxillofacial CT scan data was processed by segmentation and isolation software and mandible MRP was printed using our desktop 3D printer. These models were used for preoperative surgical planning and prebending of the reconstruction plate. Conclusions MRP created by desktop 3D printer is a cost-efficient, quick and easily produced appliance for the planning of reconstructive surgery. It can contribute in patient orientation and helping them in a better understanding of their condition and proposed surgical treatment. It helps surgeons for pre-operative planning in the resection or reconstruction cases and represent an excellent tool in academic setting for residents training. The pre-bended reconstruction plate based on MRP, resulted in decreased surgery time, cost and anesthesia risks on the patients. Key words:3D printing, medical modeling, rapid prototype, mandibular reconstruction, ameloblastoma.