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Biomedical subjects

R Montalvo

Publications and source records attributed to R Montalvo.

13 recordsLinked to original sources
PubMed1999

Preparing teeth to receive a removable partial denture.

The success or failure of a removable partial denture is dependent on many factors. To achieve success, the practitioner must develop and sequence a sound treatment plan based on clinical and radiographic evidence. These findings must be carefully considered in prosthesis design and mouth preparation. Particular attention must be given to the proper placement of guiding planes and well-made rest seats and the use of surveyed crowns on abutment teeth. This article describes the rationale, importance, and clinical procedures for abutment preparation for removable partial dentures.

Crowns↗
PubMed1998

Alcohol and the pancreas.

Alcoholic pancreatitis may be one of the most serious adverse consequences of alcohol abuse. Its diagnosis, as it has for many years, depends primarily on clinical acumen in interpreting properly the symptoms and signs of abdominal distress, buttressed by elevated pancreatic enzymes (amylase and lipase). More recently, the use of computerized tomography (CT) in selected situations has been both of confirmatory and prognostic value. Severity of abnormality by CT correlates reasonably well with a variety of clinical-laboratory clusters (APACHE system, Ranson's criteria, etc.) and aids in therapy. The pathogenesis of alcoholic pancreatitis is not fully defined. The ultimate picture is one of tissue autolysis by activated proteolytic enzymes. The triggers for such activation, however, are still not known. They are represented by three main theories: (1) large duct obstruction and/or increased permeability relative to pancreatic secretion, (2) small duct obstruction due to proteinaceous precipitates, and (3) a direct toxic-metabolic effect of ethanol on pancreatic acinar cells. While not mutually exclusive, we favor the last hypothesis as being most consistent with the effects of ethanol on other organ systems. The direct effects of ethanol and/or its metabolites may be mediated, at least in part, via oxidative stress or the generation of fatty acid ethyl esters. Autolysis (regardless of proximate mechanism(s)) leads to inflammation likely mediated via release of various cytokines. It also should be appreciated that "acute" pancreatitis (the topic of this chapter) likely represents an acute process within a chronic pancreatic exposure and injury from alcoholic abuse. The key question of why pancreatitis develops in only a small number of alcohol abusers is not resolved. Therapy depends on the severity of alcoholic pancreatitis, which is defined by clinical-laboratory and often CT criteria. Mild pancreatitis usually resolves acutely with alcohol abstention and supportive therapy. Severe pancreatitis has a significant morbidity and mortality, mainly related to the degree of pancreatic necrosis and infection. It requires meticulous combined medical-surgical care.

APACHE↗
PubMed1998

Morbidity and mortality in the wilderness.

The medical literature is limited regarding current wilderness morbidity and mortality statistics. Available studies concentrate on selected wilderness activities. This study retrospectively examines wilderness injuries, illnesses, and mortality based on case incident report files from eight National Park Service parks within California over a three-year period. Data were extracted regarding type of illness or injury, body area affected, age, gender, month in which the event occurred, and activity in which the victim was involved at the time of the event. The overall occurrence of nonfatal events was 9.2 people per 100,000 visits. More than 70% of all nonfatal events were related to musculoskeletal or soft-tissue injury. The most frequently involved body area was the lower limbs (38%). Seventy-eight mortalities occurred during the three years studied, resulting in an overall mortality rate of 0.26 deaths per 100,000 visits. Men accounted for 78% of the deaths. Heart disease, drowning and falls were the most common causes of death. The information and statistics on morbidity and mortality in California wilderness areas that this study provides may be used to guide future wilderness use, education, and management. A standardized, computerized database would greatly facilitate future evaluations, decisions, and policies.

California↗
PubMed1997

Acute acalculous cholecystitis in patients with acute traumatic spinal cord injury.

Acute acalculous cholecystitis (AAC) is a very serious complication which can be found in patients with multiple serious traumatic lesions ('polytrauma'). Very few patients have been reported in the literature with an acute spinal injury and associated AAC. We report seven patients with polytrauma and acute spinal cord injury who developed AAC. All had no complaint of the principal warning symptom: right upper quadrant abdominal pain. All presented with a palpable mass in this site and the laboratory results were compatible with cholestasis. The diagnosis of AAC was confirmed both by ultra sound and CT scanning. We discuss the possible precipitating factors and the treatment. One hundred and ninety one patients were admitted to the Intensive Care Unit in our Hospital with SCI over a period of 2 years, all of these in the acute stage. AAC was diagnosed in seven patients among them. Our purpose is to call attention to this clinical condition which can complicate the outcome of patients with multiple trauma and acute spinal cord injury. To date AAC in this group of patients has been infrequently described in the available literature.

Abdominal Pain↗
PubMed1993

In situ hybridization localization of choline acetyltransferase mRNA in adult rat brain and spinal cord.

The cellular distribution of choline acetyltransferase (ChAT) mRNA within the adult rat central nervous system was evaluated using in situ hybridization. In forebrain, hybridization of a 35S-labeled rat ChAT cRNA densely labeled neurons in the well-characterized basal forebrain cholinergic system including the medial septal nucleus, diagonal bands of Broca, nucleus basalis of Meynert and substantia innominata, as well as in the striatum, ventral pallidum, and olfactory tubercle. A small number of lightly labeled neurons were distributed throughout neocortex, primarily in superficial layers. No cellular labeling was detected in hippocampus. In the diencephalon, dense hybridization labeled neurons in the ventral aspect of the medial habenular nucleus whereas cells in the lateral hypothalamic area and supramammillary region were more lightly labeled. Hybridization was most dense in neurons of the motor and autonomic cranial nerve nuclei including the oculomotor, Edinger-Westphal, and trochlear nuclei of the midbrain, the abducens, superior salivatory, trigeminal, facial and accessory facial nuclei of the pons, and the hypoglossal, vagus, and solitary nuclei and nucleus ambiguous of the medulla. In addition, numerous cells in the pedunculopontine and laterodorsal tegmental nuclei, the ventral nucleus of the lateral lemniscus, the medial and lateral divisions of the parabrachial nucleus, and the medial and lateral superior olive were labeled. Occasional labeled neurons were distributed in the giantocellular, intermediate, and parvocellular reticular nuclei, and the raphe magnus nucleus. In the medulla, light to moderately densely labeled cells were scattered in the nucleus of Probst's bundle, the medial vestibular nucleus, the lateral reticular nucleus, and the raphe obscurus nucleus. In spinal cord, the cRNA densely labeled motor neurons of the ventral horn, and cells in the intermediolateral column, surrounding the central canal, and in the spinal accessory nucleus. These results are in good agreement with reports of the immunohistochemical localization of ChAT and provide further evidence that cholinergic neurons are present within neocortex but not hippocampus.

Animals↗
PubMed1992

Sleep apnea prosthesis for dentate patients.

This article describes clinical and laboratory techniques for the fabrication of a sleep apnea prosthesis for a dentate patient. The treatment objective is to posture the mandible at an increased vertical and protrusive position to diminish or eliminate the collapse of the base of tongue into the oropharynx. During fabrication of the prosthesis, cephalograms are used to evaluate spatial change between the base of the tongue and the posterior pharyngeal wall.

Acrylic Resins↗
PubMed1989

Stabilized record base for maxillary removable partial denture obturator.

Accurate maxillomandibular jaw relation records are enhanced by a stabilized framework used to support the occlusal rim and recording medium. Stability of the framework is often lost on the defect side because of the size of the surgical defect and/or number of missing teeth. This article introduces a technique that uses a record base stabilized with a soft resilient material that permits easy removal and replacement of the framework on the altered master cast without damage.

Acrylic Resins↗
PubMed1965

Radiolysis of estrone and estradiol.

Gamma irradiation of estrone and estradiol in 1 Naqueous sodium hydroxide results in the formation of 2-hydroxyestrone and 2-hydroxyestradiol, respectively. Estrolactone (16a-oxa-D-homoestrone) was not encountered.

Chemical Phenomena↗