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Biomedical subjects

F E Martinez

Publications and source records attributed to F E Martinez.

At least 19 recordsLinked to original sources
PubMed2005

Repercussions of castration and vasectomy on the ductal system of the rat ventral prostate.

Diseases, such as cancer and benign prostatic hyperplasia, are related to disruption of the mechanism regulating the balance between cell proliferation and apoptosis in prostatic cells. Since castration and vasectomy might alter that balance, this study evaluates the cell proliferation, apoptosis and height of the secretory epithelium of the ventral-prostate ductal system post-castration and vasectomy. Immunohistochemical (PCNA and Ki67), cytochemical (Fuelgen reaction) and morphometric investigation have been carried out. Cell proliferation indices decreased significantly in both regions of the ventral-prostate ductal system after castration compared to the sham-operated group. The apoptotic index increased significantly after 48 h, declining 7 days post-castration. The cell proliferation indices did not differ after 48 h significantly; however, they increased 7 days post-vasectomy in both regions. The apoptotic index did not differ significantly in either time post-vasectomy. Castration caused an imbalance in favor of apoptosis, whereas vasectomy caused an imbalance in favor of cell proliferation.

Animals↗
PubMed2005

Ultrastructural changes on the hard palatine mucosa of Calomys callosus after 120 days of experimental chronic alcoholism.

The present study analyzed the toxic effects of chronic alcohol ingestion on the ultrastructure of the lining epithelium of the hard palatine mucosa of the rodent Calomys callosus, in order to contribute to the understanding of the consequences of alcohol abuse for the morphology of the digestive system. Twenty-six adult animals aged three months were divided into two experimental groups. The control group received a solid diet and tap water, and the alcoholic group received the same solid diet and ethanol P.A. diluted 20% in water (v/v). After 120 days of treatment, all animals were anaesthetised, weighed and sacrificed. At the end of treatment, mean body weight did not differ between control and alcoholic animals. The epithelial cells of the alcoholic group showed many alterations such as the presence of lipid droplets, nuclei in corneum layer, nuclei with increase peripheral chromatin and greater electron density, altered mitochondria, and intense dilatation of the intercellular spaces. It was concluded that 20% ethanol provokes marked ultrastructural lesions in the hard palatine mucosa.

Alcoholism↗
PubMed2004

Amino acid composition of parturient plasma, the intervillous space of the placenta and the umbilical vein of term newborn infants.

The objective of the present study was to determine the levels of amino acids in maternal plasma, placental intervillous space and fetal umbilical vein in order to identify the similarities and differences in amino acid levels in these compartments of 15 term newborns from normal pregnancies and deliveries. All amino acids, except tryptophan, were present in at least 186% higher concentrations in the intervillous space than in maternal venous blood, with the difference being statistically significant. This result contradicted the initial hypothesis of the study that the plasma amino acid levels in the placental intervillous space should be similar to those of maternal plasma. When the maternal venous compartment was compared with the umbilical vein, we observed values 103% higher on the fetal side which is compatible with currently accepted mechanisms of active amino acid transport. Amino acid levels of the placental intervillous space were similar to the values of the umbilical vein except for proline, glycine and aspartic acid, whose levels were significantly higher than fetal umbilical vein levels (average 107% higher). The elevated levels of the intervillous space are compatible with syncytiotrophoblast activity, which maintain high concentrations of free amino acids inside syncytiotrophoblast cells, permitting asymmetric efflux or active transport from the trophoblast cells to the blood in the intervillous space. The plasma amino acid levels in the umbilical vein of term newborns probably may be used as a standard of local normality for clinical studies of amino acid profiles.

Amino Acids↗
PubMed2003

Ultrastructure of the urethra of the Mongolian gerbil.

OBJECTIVE: The urethra is the main port of entry of sexually transmitted pathogens. However, papers on the morphology of the urethra are scarce. The Mongolian gerbil is a rodent native of the Mongolia and China and has been utilized as a laboratory animal since the 1960s. This work describes the ultrastructure of the urethra of the Mongolian gerbil to provide data for future experimental studies. METHODS: The urethra of ten adult male gerbils was studied by transmission electron microscopy. RESULTS: The epithelium of the pelvic urethra possesses two cell types: I and II, without the formation of cellular layers, while the penile urethra possesses cellular layers: basal, intermediate and superficial. The urethra presents neurosecretory cells belonging to the amine precursor uptake and decarboxylation system. CONCLUSIONS: The urethral epithelium of the gerbil is a neurosecretory epithelium, part of the amine precursor uptake and decarboxylation system.

Animals↗
PubMed2003

Structure of the pelvic and penile urethra--relationship with the ducts of the sex accessory glands of the Mongolian gerbil (Meriones unguiculatus).

The urethra is the main place of entry for sexually transmitted pathogens. However, there is little literature on the morphology of the urogenital system, principally the urethra and ducts of the sex accessory glands. The Mongolian gerbil is an insectivorous, herbivorous and monogamous rodent with nocturnal habits; it has been used successfully as a laboratory animal since the 1960s. Therefore, the objective of the present paper was to describe the structure and ultrastructure of the urethra and its relations to the ducts of the accessory sex glands of the Mongolian gerbil (Meriones unguiculatus), contributing to the understanding of the reproductive biology of the rodent and aiming to provide data for future experimental studies. Conventional techniques of light and scanning electron microscopy were utilized. The urethra and ducts of the accessory sex glands are similar to those of the albino rat and the mouse. However, there is variation in drainage type among accessory sex glands for the inner urethra. The ducts of the seminal vesicle, the ductus deferens, drain their contents independently into the ampullary duct that opens in the urethra. The ducts of the prostate, coagulating and bulbourethral glands drain their contents independently into the urethra.

Animals↗
PubMed2003

Ultrastructural and morphometric analysis on the ovary of Wistar rats after chronic ethanol ingestion.

In the present study, seventy-two adult rats (Rattus norvegicus albinus) aged three months were used. The animals were divided into two groups (control and alcoholic). The control group received a solid diet (Purina rat chow) and tap water ad libitum. The alcoholic group received the same solid diet and sugar-cane liquid (trade 51, 41% Gay Lussac--GL) diluted 30% GL. At the end of 90, 180 and 270 days of treatment, ten rats of each group were anaesthetized with ethyl ether and sacrificed. The ovaries were collected, fixed, included and submitted to analysis by both light and electron microscopy. The alcoholic group showed increase in the number of corpora lutea at both 180 and 270 days of treatment, atresic follicles at 270 days of treatment, decreased diameter of corpora lutea at 180 and 270 days of treatment, the granulosa layer of the antral follicles at 180 days of treatment, and gradual regression of the theca antral follicles. Furthermore, an increase in diameter and posterior regression of the antral follicle were observed, as well as vacuolation, increased lipid droplets in the granulosa cell at 90 days and in the theca at 180 and 270 days of treatment and gradually in the interstitial cell. The rats showed ovarian alterations after ingestion of alcohol. There was a correlation between exposure time to the drug and the injury observed.

Alcohol-Induced Disorders↗
PubMed2003

Morphology of the vas deferens in an ethanol-drinking strain of rats (UChA and UChB).

Chronic alcoholism alters reproduction and therefore may be responsible for alterations of vas deferens, which are the subject of this analysis in UCh ethanol-drinking rats. The proximal and distal segments of the vas deferens of 20 animals were submitted to macroscopic, light microscopy, electron microscopy and morphometric analysis. The UCh rats showed atrophy of the epithelium of the vas deferens and alterations of the hypothalamus-pituitary axis. Ethanol induces changes in the epithelium of the vas deferens and hypothalamus-pituitary axis of UCh rats.

Alcohol Drinking↗
PubMed2002

Kinetics of spermatogenesis in the Mongolian gerbil (Meriones unguiculatus).

The Mongolian gerbil (Meriones unguiculatus) is a small rodent native to the arid regions of Mongolia and Northeastern China. The present study provides descriptions of both the cellular associations of the seminiferous-epithelium cycle and relative frequencies of stages in the gerbil. Based on the development of the acrosomic system and the nuclear morphology changes using the PAS-H staining technique, the transformation of spermatids into spermatozoa was divided into 15 steps. The first 12 steps were used to identify 12 stages or cellular associations and the other three steps were spread among the first six stages of the cycle of the seminiferous epithelium. The relative frequencies found for stages I through XII were: 13.15; 8.06; 8.98; 6.48; 5.37; 6.71; 7.36; 7.45; 7.27; 5.83; 11.53 and 11.81, respectively. Stage I had the highest frequency while stage V proved the lowest frequency among the XII stages. The pattern of spermatogenesis is similar to those of rodents used as laboratory animals. The present description is the first for this rodent and provides the foundation for a variety of future studies of the testis in this animal.

Animals↗
PubMed2002

Morphological effects on the hard palatine mucosa of Calomys callosus submitted to experimental chronic alcoholism.

The morphological effects of ethanol ingestion on the hard palatine mucosa of adult male Calomys callosus were observed. Twenty rodents were divided into two experimental groups: the control group received solid diet, Purina rat chow, and tap water ad libitum; the alcoholic group received the same solid diet and ethanol P.A. diluted 20% in water (v/v). After 270 days of treatment, all animals were sacrificed and the hard palatine mucosa were prepared for TEM and SEM methods. The epithelial cells of the alcoholic group showed some alterations like cytoplasmatic lipid droplets, pycnotic nucleus and increased mitochondrial size. The lamina propria also presented intense lipid droplets accumulation. The morphological changes suggested that chronic ethanol consumption was able to modify the integrity of the mucosa.

Alcoholism↗
PubMed2001

Structure and ultrastructure of the ventral prostate of isogenic mice (C57B1/6J) submitted to chronic alcohol ingestion.

Morphological and functional alterations caused by chronic alcohol ingestion in testes and accessory sex organs have been studied both in man and in laboratory animals. The aim of the present study was to examine the possible occurrence of deleterious effects of chronic alcohol ingestion on the secretory epithelium of the ventral prostate of mice. Twenty-four adult male C57BL/6J mice were divided into three groups. The alcohol-treated group was allowed to drink only 6% (v/v) ethanol, the isocaloric group received a diet of water/sucrose with a calorie content equivalent to a 6% alcohol solution and the control group received water. Both groups were fed ad libitum with solid Purina rat chow. After 120 days, animals from each group were anesthetized with ethyl ether, weighed and processed for light and transmission electron microscopy. The results demonstrated reduction in the glandular epithelium cell height and disorganization of the Golgi complex. Moreover, abundant membrane-bound structures, most likely representing cytoplasmic material, were observed, as well as accumulation of dense bodies. Statistical analysis showed that bodyweight gain was similar for both groups. In conclusion, chronic alcohol ingestion has harmful effects on the secretory epithelium cells of the ventral lobe of the prostate of mice after 120 days of treatment.

Alcoholism↗
PubMed2001

Age-dependent changes in the regulation of cyclooxygenases in the gastrointestinal tract after gram-negative endotoxemia.

BACKGROUND: Cyclooxygenases (COXs) modulate prostaglandin synthesis in the gastrointestinal tract. Prostaglandins have been shown to have a cytoprotective effect on bowel mucosa in adults, but no similar data are available in neonates. Thus, the purpose of the current study was to evaluate age-dependent changes in gastrointestinal tract COX regulation after Escherichia coli lipopolysaccharide exposure in rats. METHODS: Stomach, small bowel, and large bowel COX-1 and COX-2 mRNA levels (reverse transcription polymerase chain reaction technique) and protein content (Western blot) were obtained from neonates (younger than 3 days old) and adult rats 18 hours after exposure to E. coli O111:B4 lipopolysaccharide toxin. Untreated animals served as controls. RESULTS: Stomach, small bowel, and large bowel tissue COX-1 mRNA levels in the newborn were significantly lower (P < 0.01) than in the adult. No age-dependent differences were found for COX-2 mRNA levels. After lipopolysaccharide exposure, no significant changes in COX-1 levels were seen at either age, whereas COX-2 mRNA levels were increased only in the stomach for both ages. Western blot analysis of small bowel tissue for COX-1 and COX-2 showed no lipopolysaccharide-induced changes in protein content, but the COX-1 content was significantly lower in the newborn (P < 0.01). CONCLUSIONS: In the rat, COX expression in the gastrointestinal tract is regulated in an age-dependent fashion. Lower COX-1 expression and a lack of observable increase in COX-2 mRNA levels in the newborn small bowel after endotoxemia may render the bowel more susceptible to bowel injury early in life.

Age Factors↗
PubMed2001

[Nutrition of the preterm infants]

OBJECTIVE: To review the recent medical literature on nutrition of preterm infants, focusing on practical aspects that are relevant to pediatricians and neonatologists. SOURCES: An extensive review of the related literature using Medline, Cochrane Database of Systematic Reviews and Best Evidence was performed. SUMMARY OF THE FINDINGS: There is compelling evidence that early nutritional practices may affect short-term growth and developmental outcome in preterm infants. In addition, these practices have a determinant role in adult health. We still have to learn a lot about the safety and effectiveness of nutrient administration in preterm infants; about techniques targeted at assessing the effect of different nutritional strategies; and about the long term effects of these regimens on developmental outcome, growth and disease. CONCLUSIONS: Despite recent advances in neonatal nutrition, basic and clinical research is still necessary so that the nutritional needs of preterm infants can be better defined and adequately provided.

Journal Article↗
PubMed2001

Morphology of the seminal vesicle of Calomys callosus submitted to experimental chronic alcoholism.

The objective of the present study was to assess the possible toxic effects of chronic alcohol ingestion on the ultrastructure of the lining epithelium of the seminal vesicle of the rodent Calomys callosus, in order to contribute to the understanding of the consequences of alcohol abuse for the morphology of the male reproductive apparatus. Twenty six adult animals aged three months were divided into two experimental groups. The control group received a solid diet (Purina chow) and tap water, and the alcoholic group received the same solid diet and ethanol P.A. diluted 20% in water (v/v). After 210 days of treatment, all animals were anaesthetised, weighed and sacrificed. At the end of treatment, mean body and seminal vesicle weight did not differ between control and alcoholic animals. The epithelial cells of the alcoholic group showed many alterations such as the presence of lipid droplets of different sizes, nuclei with increased peripheral chromatin and greater electrondensity, megamitochondria, and intense dilatation of the cisterns of the granular endoplasmic reticulum. It was concluded that 20% ethanol provokes marked ultrastructural lesions in the seminal vesicle.

Alcoholism↗
PubMed2000

Urethane suppresses rat lung inducible cyclooxygenase and nitric oxide synthase mRNA levels.

OBJECTIVE AND DESIGN: The purpose of the present study was to evaluate the effect of urethane, pentobarbital sodium and ketamine-xylazine anesthesia upon constitutive and inducible cyclooxygenase (COX-1; COX-2) and nitric oxide synthase (eNOS; iNOS) mRNA levels in the lung. METHODS: mRNA levels were determined by the semiquantitative RT-PCR technique. TREATMENT: Urethane (1.1 g/kg ip), Pentobarbital Sodium (40 mg/kg ip), and ketamine (85 mg/kg) - xylazine (15 mg/kg, im). Non-anesthetized animals served as controls. MATERIAL: Sprague-Dawley rat lungs RESULTS: Urethane significantly decreased COX-1 and COX-2 mRNA levels to 30% of control values. This agent had no effect upon eNOS, but completely suppressed iNOS mRNA levels. Pentobarbital sodium and ketamine had no effect on the mRNA levels for COX-1 and COX-2 the lung. CONCLUSIONS: Urethane has a suppressive effect on COX and iNOS RNA message in the lung and for this reason it should be avoided as an anesthetic when lung inflammatory processes are experimentally evaluated in the rat.

Anesthetics, Dissociative↗
PubMed2000

Ultrastructural study of acrosome formation in mongolian gerbil (Meriones unguiculatus).

Spermatogenesis is a complex and very well organized process lasting from 30 to 75 days in mammals. The spermatogenic process has been described mainly in laboratory mammals, such as the rat, while correspondent studies in wild animals are scarce. The gerbil (Meriones unguiculatus) is a small rodent native of the arid regions of Mongolia and China. Few reports are available on reproduction in the male Mongolian gerbil. The present study provides the first description of the ultrastructural alterations in spermatid cytoplasm and nucleus, with particular reference to acrosome formation in gerbils. The testes were processed by conventional transmission electron microscopy technique. Based on the development of the acrosomal system and changes in nuclear morphology, the transformation of spermatids in spermatozoon was divided into 15 steps. There were four phases in the spermiogenesis process in the gerbil: Golgi, cap, acrosomal and maturation phases. This provides the foundation for a variety of future studies of the spermiogenesis of this animal.

Acrosome↗
PubMed2000

Ultrastructural study of the ventral lobe of the prostate of mice with streptozotocin induced diabetes (C57BL/6J).

Morphological and functional changes caused by diabetes in the accessory sex organs and especially the prostate have been reported by several investigators. The aim of the present study was to examine the possible deleterious effects of experimentally induced diabetes on the secretory epithelium of the ventral prostate of mice. Sixteen adult male C57BL/6J mice were divided into two groups. The diabetic group received a streptozotocin injection of 75 mg/kg, while the control group received only 0.1 ml citrate buffer, i.p. After 30 days, the diabetic state was ascertained, the animals were sacrificed and the ventral lobe of the prostate was collected for histological and ultrastructural examination. The results showed reduction in glandular epithelium cell height, increased numbers of cytoplasmic vacuoles and thickening of the extracellular matrix. In conclusion, experimental diabetes has harmful effects on the secretory epithelial cells of the ventral lobe of the prostate of mice.

Animals↗
PubMed2000

Cutaneous application of vegetable oil as a coadjutant in the nutritional management of preterm infants.

BACKGROUND: The cutaneous application of vegetable oil as a therapeutic practice and dietary coadjuvant has been described mainly in adult patients at risk for essential fatty acid deficiency. In the current study, the effects of cutaneous soybean oil application on somatic growth and plasma linoleic and arachidonic acid levels were examined in enterally fed preterm newborns. METHODS: Sixty consecutive preterm infants were chosen from patients admitted to the nursery. Infants were randomly assigned to one of two groups: the oil group, which was treated cutaneously with soybean oil, or the control group, which received no cutaneous treatment. RESULTS: After 30 days, a significant increase in anthropometric parameters was observed in infants who received cutaneous oil, mainly in infants small for gestational age. An increase in linoleic acid level and a decrease in arachidonic acid level were seen in both groups but do not justify the difference found in growth rates in the control and oil groups. CONCLUSIONS: Preterm infants treated cutaneously with soy oil showed better somatic growth than the control group. The factors leading to the present results, especially the response of the infants who were small for gestational age merit further evaluation.

Administration, Cutaneous↗