PubMed Health⌕ Search

Biomedical subjects

A Benitez

Publications and source records attributed to A Benitez.

At least 19 recordsLinked to original sources
PubMed2006

Labeling of antibiotics for infection diagnosis.

UNLABELLED: The high impact of infection on daily clinical practice has promoted research into better and more accurate diagnostic and therapeutic METHODS: Localizing inflammation/infection with nuclear medicine techniques began over 40 years ago. Today, (67)Ga-scintigraphy, (99m)Tc-nanocolloid, (111)In and (99m)Tc in vitro labeled leukocytes, and monoclonal antigranulocyte antibodies are widely available for this purpose. While these methods are useful for localizing inflammation, they cannot always differentiate septic from aseptic processes. The ideal properties of an agent for diagnosing infection include: high specificity, early diagnosis, rapid blood clearance, ease of preparation, low toxicity, biodistribution appropriate for the disease under study, absence of immunologic response and low cost. A novel approach to infection diagnosis is the use of radiolabelled antibiotics. Antibiotics localize in the infectious focus, where they are frequently taken up and metabolized by microorganisms. The majority of the various antibiotics studied so far are those of the quinolones group (ciprofloxacin, sparfloxacin, enrofloxacin, levofloxacin, norfloxacin and ofloxacin). More recently, the labeling of ceftizoxime, a semisynthetic third generation cephalosporin, has been reported. The relevant features of labeled antibiotics in research and/or clinical infection diagnosis are the focus of this article.

Animals↗
PubMed2005

Prostaglandins E(2) and F(2alpha) enhance differentiation of cementoblastic cells.

BACKGROUND: The prostaglandins (PG) E(2) and PGF(2alpha) are important cytokines in periodontal physiology and pathology. PGE(2) and PGF(2alpha) alter cell function by binding and activating the plasmamembrane G-protein-coupled PG receptors. In this study, we examined the PGE(2) and PGF(2alpha) effects on the immortalized cementoblastic OCCM cells. METHODS: Confluent OCCM cells were treated with PGE(2), PGF(2alpha), specific activators/inhibitors of the EP prostanoid receptors, a specific activator of the FP prostanoid receptor, and direct activators/inhibitors of the protein kinase C (PKC) signaling pathway. Mineral nodule formation was assessed by the von Kossa stain. RESULTS: PGE(2) and PGF(2alpha) significantly increased mineralization of OCCM cells. The EP1 and EP3 PG receptor activators 16,16-dimethyl-prostaglandin E(2) and sulprostone, also increased mineralization. In contrast, specific activators of the EP2 or the EP2/EP3/EP4 receptors did not have any effect. Fluprostenol, a specific activator of the FP receptor, significantly increased mineralization of OCCM cells. FP and EP (1 or 3) receptors signal through activation of the protein kinase C (PKC) pathway. Indeed, phorbol 12-myristate 13-acetate (PMA), a direct activator of the PKC pathway, significantly increase OCCM mineralization, while pre-treatment of OCCM cells with the PKC inhibitor GF109203x (bisindolylmaleimide) significantly decreased mineralization. CONCLUSION: We conclude that PGE(2) and PGF(2alpha) exert an anabolic effect on OCCM mineralization through activation of PKC signaling.

Calcification, Physiologic↗
PubMed2001

Neurodevelopment of neonates in neonatal intensive care units and growth of surviving infants at age 2 years.

SUMMARY: The presence of development disorders in neonates attended in a Neonatal Intensive Care Unit (NICU) is highly variable; the aim of this study, therefore, was to determine the evolution of somatic and neurosensory development in a group of neonates requiring treatment in the NICU and to analyse the perinatal and developmental aspects of children presenting abnormalities. PATIENTS AND METHODS: A total of 492 neonates (275 premature, 106 with birthweight < or =1500 g), who were treated in the NICU between January 1994 and December 1997, were followed-up until the age of 2 years. Data were obtained concerning birthweight, body length, head circumference, gestational age, normality of weight for gestational age, single/multiple birth, duration of stay in the NICU and the hospital, duration of mechanically assisted respiration and evolutive somatometry, neurological examination and the Brunet-Lezine development test, adjusted for the gestational age of the neonates, at 6, 12, 18 and 24 months. When abnormal results were detected, Early Attention (EA) programmes were applied. RESULTS: Somatometry at birth in relation to gestational age revealed a weekly weight gain of 8.6%, an increase in body length of 1% and in head circumference of 1% (p<0.001). The evolution of somatic development to the age of 2 years showed that neonates with a birthweight < or =1500 g did not reach the values of neonates with a greater birthweight. The prevalence of cerebral palsy among all neonates was 6.8%, 14.6% among those weighing < or =1500 g, 4% among those weighing 1501-2500 g and 5% among those weighing >2500 g. The overall rate of neurosensory injury was 10.5%. These neonates presented less somatic development than those did with no neurologic disorder. To sum up, most of the neonates attended in the NICU during the 1990s presented a normal pattern of development. Nevertheless, they should be the object of special attention during the first years of life, particularly those neonates with a birthweight < or =1500 g and those presenting neurosensory risk.

Birth Weight↗
PubMed1999

Evaluation of dream content in combat-related PTSD.

Nightmares that replicate traumatic events are among the criteria that define posttraumatic stress disorder (PTSD); however, there has been limited systematic assessment of the content of dreams in PTSD. A PTSD dream rating instrument was developed to operationalize features attributed to dreams associated with combat-related PTSD that incorporated dimensions from the dream content analysis literature, and its reliability was assessed. Then the instrument was used to characterize dream reports in 18 Vietnam combat veterans diagnosed with PTSD. Approximately half of the group's target dreams contained features characteristic of combat, and all but 3 (17%) were moderately to highly threatening. Fifty-three percent were set at least partially in the present and 79% contained distorted elements. We therefore conclude that target dreams of combat veterans with PTSD vary with regard to replication of trauma and elements normally associated with dreaming, but typically are threatening.

Adult↗
PubMed1998

Prevalence of malaria parasitemia and accuracy of microscopic diagnosis in Haiti, October 1995.

In October 1995 the Ministry of Public Health and Population in Haiti surveyed 42 health facilities for the prevalence and distribution of malaria infection. They examined 1,803 peripheral blood smears from patients with suspected malaria; the overall slide positivity rate was 4.0% (range, 0.0% to 14.3%). The rate was lowest among 1- to 4-year-old children (1.6%) and highest among persons aged 15 and older (5.5%). Clinical and microscopic diagnoses of malaria were unreliable; the overall sensitivity of microscopic diagnosis was 83.6%, specificity was 88.6%, and the predictive value of a positive slide was 22.2%. Microscopic diagnoses need to be improved, and adequate surveillance must be reestablished to identify areas where transmission is most intense. The generally low level of malaria is encouraging and suggests that intensified control efforts targeted to the areas of highest prevalence could further diminish the effect of malaria in Haiti.

Adolescent↗
PubMed1998

[Efficiency of oxidant gas generator cells powered by electric or solar energy].

Diseases caused by microbial contaminants in drinking water continue to be a serious problem in countries like Mexico. Chlorination, using chlorine gas or chlorine compounds, is one of the best ways to treat drinking water. However, difficulties in handling chlorine gas and the inefficiency of hypochlorite solution dosing systems--due to sociopolitical, economic, and cultural factors--have reduced the utility of these chlorination procedures, especially in far-flung and inaccessible rural communities. These problems led to the development of appropriate technologies for the disinfection of water by means of the on-site generation of mixed oxidant gases (chlorine and ozone). This system, called MOGGOD, operates through the electrolysis of a common salt solution. Simulated system evaluation using a hydraulic model allowed partial and total costs to be calculated. When powered by electrical energy from the community power grid, the system had an efficiency of 90%, and in 10 hours it was able to generate enough gases to disinfect about 200 m3 of water at a cost of approximately N$8 (US $1.30). When the electrolytic cell was run on energy supplied through a photoelectric cell, the investment costs were higher. A system fed by photovoltaic cells could be justified in isolated communities that lack electricity but have a gravity-fed water distribution system.

Chlorine↗
PubMed1997

Sequential computerized tomography changes and related final outcome in severe head injury patients.

The authors analysed the serial computerized tomography (CT) findings in a large series of severely head injured patients in order to assess the variability in gross intracranial pathology through the acute posttraumatic period and determine the most common patterns of CT change. A second aim was to compare the prognostic significance of the different CT diagnostic categories used in the study (Traumatic Coma Data Bank CT pathological classification) when gleaned either from the initial (postadmission) or the control CT scans, and determine the extent to which having a second CT scan provides more prognostic information than only one scan. 92 patients (13.3% of the total population) died soon after injury. Of the 587 who survived long enough to have at least one control CT scan 23.6% developed new diffuse brain swelling, and 20.9% new focal mass lesions most of which had to be evacuated. The relative risk for requiring a delayed operation as related to the diagnostic category established by using the initial CT scans was by decreasing order: diffuse injury IV (30.7%), diffuse injury III (30.5%), non evacuated mass (20%), evacuated mass (20.2%), diffuse injury II (12.1%), and diffuse injury I (8.6%). Overall, 51.2% of the patients developed significant CT changes (for worse or better) occurring either spontaneously or following surgery, and their final outcomes were more closely related to the control than to the initial CT diagnoses. In fact, the final outcome was more accurately predicted by using the control CT scans (81.2% of the cases) than by using the initial CT scans (71.5% of the cases only). Since the majority of relevant CT changes developed within 48 hours after injury a pathological categorization made by using an early control CT scan seems to be most useful for prognostic purposes. Prognosis associated with the CT pathological categories used in the study was similar independently of the moment of the acute posttraumatic period at which diagnoses were made.

Adolescent↗
PubMed1985

Effect of streptozotocin-diabetes and insulin treatment on regulation of Leydig cell function in the rat.

The present study was performed to further clarify the possible role played by insulin deficiency on the steroidogenic capacity of the rat testis. Sprague-Dawley rats weighing 250-300 g were used in all experiments. Diabetes was induced by i.p. injection (40 mg/kg b.w.) of streptozotocin and was monitored at 2-day intervals by measuring body weight and serum glucose, glucosuria and ketonuria levels. The effect of insulin therapy on pituitary LH content and plasma LH concentrations, as well as on the cyclic AMP level in interstitial cell incubation medium and plasma testosterone concentrations, was measured 30 days after the induction of diabetes by radioimmunoassay. Streptozotocin-induced diabetes resulted in significantly reduced pituitary LH (16%, P less than 0.025) and plasma LH (34%, P less than 0.02); insulin treatment completely restored these levels. Similarly, the cyclic AMP content of interstitial cell incubation medium and the plasma testosterone concentrations were dramatically decreased in the diabetic state (50%, P less than 0.005 and 63%, P less than 0.025, respectively) and combined treatment with insulin plus hCG appeared slightly more effective than treatment with either of these hormones alone, suggesting a possible synergistic action. It is concluded that decreased testicular steroidogenesis in the diabetic rat may represent, at least in part, a direct consequence of insulin deficiency at the hypothalamic and/or pituitary levels. However, our findings would also be consistent with other reports suggesting that insulin may play a direct role in the rat testis.

Animals↗
PubMed1982

Effect of streptozotocin diabetes on the pituitary-testicular axis in the rat.

The pituitary-testicular axis was investigated in the streptozotocin diabetic male rat to determine the relationship between hormonal alterations and steroidogenic activity. Male Sprague-Dawley rats weighing 250-300 g were used in all experiments. Diabetes was induced by intraperitoneal injection (40 mg/kg body wt.) of streptozotocin and they were studied with non-diabetic controls. The observations on these animals were compared to those from diabetic rats treated with 1-5 IU protamine zinc insulin. Steroidogenic activity was determined by measuring the per cent of [4-14C]-cholesterol converted to [4-14C]-pregnenolone and [4-14C]-progesterone. Plasma concentrations of LH, FSH and prolactin were measured by RIA. Streptozotocin induced diabetes resulted in significantly reduced plasma LH (34%, p less than 0.20) and prolactin (53%, p less than 0.001) but did not modify FSH concentrations. Insulin treatment completely and partially restored abnormal LH and prolactin release. The activity of the enzyme cleaving the side-chain of cholesterol (rate limiting step in steroidogenesis) was considerably reduced in the diabetic state (59%, p less than 0.002) and insulin treatment restored it to even supranormal levels (not significant). Our findings suggest that insulin may play a physiological and differential role in regulating the secretory activity of the anterior pituitary. The insulin is needed for normal LH and prolactin release and Leydig cells function but its role in FSH release and Sertoli cells function is not clear.

Animals↗
PubMed1976

Shipping fever pneumonia in yearling feedlot cattle.

During each week of 1974, we surveyed, for illnesses and deaths, a continually changing population of yearling feedlot cattle that, for the year, totaled 407,000 animals. About 5.1% of the cattle sickened and, of these, 18.9% died. From the 3,943 fatalities, 1,988 necropsies were made. About 75% of the clinical diagnoses and 64% of the necropsy diagnoses were respiratory tract diseases; of the fatalities from respiratory tract diseases, 75% were attributed to shipping fever pneumonia. Nearly 72% of fatal cases of shipping fever pneumonia occurred during the first 45 days on feed. In the lungs of most cattle with shipping fever pneumonia, bronchiolitis, fibrinous exudate, colonies of microorganisms, lymphatic clots, intravascular clots, thromboses, and foci of necrosis were found. Pasteurella spp, Mycoplasma spp, and infectious bovine rhinotracheitis virus were isolated from pneumonic tissues. It was hypothesized that pathogenic Pasteurella spp and other microorganisms in nasal secretions transfer from the nasopharynx into the lungs by draining along the tracheal floor into ventral bronchi, bronchioles, and alveoli, and that pasteurella endotoxin, formed in infected lobules, thromboses and occludes lymphatics, capillaries, and veins and thereby causes ischemic necrosis.

Animals↗
PubMed1976

Atypical interstitial pneumonia in yearling feedlot cattle.

During each week of 1974, we surveyed, for illnesses and deaths, a constantly changing population of yearling feedlot cattle that, for the year, totaled 407,000 animals. From 3,943 fatalities, 1,988 necropsies were made; of this number, 106 (5.3%) had atypical interstitial pneumonia. The death rate was higher during summer and fall than during the other seasons and was evenly distributed throughout each of the 4 stages of fattening. Gross pulmonary lesions involved both lungs and were prominent throughout the caudal (diaphragmatic) lobes. Epithelialization, hemorrhage, fibrin, hyaline membranes, emphysema, bronchiolitis, and interstitial edema were common, whereas chromatin strands, bronchiolar edema, interstitial emphysema, and obliterating bronchiolitis were less common histopathologic features.

Animals↗
PubMed1976

Brisket disease in yearling feedlot cattle.

During all of 1974, we surveyed, for illnesses and deaths, about 407,000 yearling feedlot cattle maintained at 1,600 m altitude. Of 1,988 cattle necropsied, 116 (5.8%) had brisket disease. The malady occurred during all seasons but was most common throughout fall and winter. The gross changes were hypertrophy and dilatation of the right ventricle and generalizaed passive congestion. The postulated causative factors were high genetic susceptibility, rapid growth rate, previous mountain grazing, and hypoventilation with airway hypoxia.

Animals↗
PubMed1976

Fetal abomasal ulcers in yearling feedlot cattle.

During all of 1974, we surveyed, for illnesses and deaths, about 407,000 yearling feedlot cattle. From the 3,943 dead cattle, 1,988 necropsies were made; of this number, 31 (1.6%) had ulcers with fatal perforations or hemorrhages; a similar additional number of necropsied cattle had innocuous ulcers as incidental findings. Ulcers developed during all seasons and all stages of fattening, but were more common during the first 45 days of winter-initiated fattening than during other times. Perforations of the abomasal wall resulted in spillage of abomasal contents into the abdominal cavity and the development of peritonitis.

Abomasum↗
PubMed1976

Bronchiectasis in yearling feedlot cattle.

Thoughout all of 1974, we surveyed, for illnesses and deaths, about 407,000 yearling feedlot cattle. From the 3,943 dead cattle, 1,988 necropsies were made; of the cattle necropsied, 32 (1.6%) had bronchiectasis. In this disease, the permanently dilated small bronchi and bronchioles, located in ventral parts of the lungs, were filled with accumulations of exudate and microorganisms, including Pasteurella hemolytica, Pasteurella multocida, Corynebacterium pyogenes, Escherichia coli, Salmonella anatum, Staphylococcus spp, and Mycoplasma arginini.

Animals↗
PubMed1976

Embolic pulmonary aneurysms in yearling feedlot cattle.

Throughout all of 1974, we surveyed, for illnesses and deaths, about 407,000 yearling feedlot cattle. Of 1,988 cattle necropsied, 25 (1.3%) had ruptured pulmonary aneurysms and an additional 4 had gross pulmonary emboli without rupture. The emboli originated from thrombi in the caudal vena cava where that vessel closely applies to the left border of the liver and where parenchymal abscesses had developed. The emboli had lodged in the pulmonary artery, weakened its wall, and led to saccular aneurysms. Infection weakened and blood pressure ruptured the saccule and opened the adjacent bronchi. Extravasated blood dissected the tunica adventitia, formed hematomas, poured into the bronchus, and was expelled from the larynx. A portion was swallowed into the rumen, and some was coughed and blown from the nose and mouth. Deaths were attributed to exsanguination and pulmonary incapacitation.

Aneurysm↗