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C Díaz

Publications and source records attributed to C Díaz.

At least 163 records · Page 9Linked to original sources
PubMedDate not supplied

[Methods to assess the ex vivo growth capacity of mesothelial cells obtained directly from peritoneal effluent].

The anatomical and functional integrity of mesothelial cells (MC) is necessary for peritoneal membrane stability. At present, there is no satisfactory method to assess MC function and regenerative capacity in individual peritoneal dialysis (PD) patients. MC may be cultured from peritoneal biopsy specimens, but peritoneal biopsy is an invasive procedure that cannot be performed serially. The aim of this study is to explore the feasibility of serial culture of MC from the peritoneal effluent of PD patients. Fifty-two randomly selected PD patients were studied. MC were obtained from the peritoneal effluent of nocturnal 2.27% glucose exchanges and cultured in T25 tissue culture flasks. Subconfluent MC cultures were obtained in 80.7% of patients. At this stage, the percentage of cells in the tissue cultured flask characterized as MC by morphology and immunostaining had increased to 95.5%. MC were then subcultured in multi-well culture plates, where they showed exponential cell growth until day 16. Nine (17%) patients released low numbers of MC into the effluent and MC could not be cultured to subconfluence. One additional patient released and apparently adequate number of MC that repeatedly failed to reach confluence. Patients showed the same behavior in several cultures performed. In conclusion, peritoneal MC released into peritoneal effluent are accessible for profound analysis by a culture technique. This technique opens the possibility of serial follow-up of the biology of MC individual PD patients.

Cell Division↗
PubMedDate not supplied

[Simultaneous micro-transplantation of fetal mesencephalic cells to the striate and substantia nigra pars reticulata in hemi-parkinsonian rats. A study of behavior].

INTRODUCTION: Microtransplantation of fetal dopaminergic cells has been used over the past ten years with good results in models of Parkinson's disease. OBJECTIVE: To evaluate the effect of microtransplantation of fetal dopaminergic cells 'seeded' in the substantia nigra pars reticulata (SNpr) and striate (St) simultaneously. MATERIAL AND METHODS: The animals received a transplant or microtransplant of cells into the St and SNpr ipsilateral to the lesion in the substantia nigra pars compacta or to both regions. Depending on the site and technique used the following experimental groups were considered: I. Macrotransplantation to the St (n = 20); II. Microtransplant to the St (n = 20); III. Microtransplant to St + SNpr (n = 20); IV. Microtransplant to St + SNpr (n = 20); V. Macrotransplantation to SNpr (n = 20); VI. Microtransplantation to SNpr (n = 20); and VII. Control (lesion only) (n = 20). The rotations induced by D-amphetamine (5 mg/kg i.p.) and by apomorphine were studied 1, 2, 3 and 6 months and 3 and 6 months respectively after transplantation. Three months after transplantation we studied the motor asymmetry shown by the animals by means of the ladder test. RESULTS: The rotations were reduced in the groups with intrastriate transplantation. Comparison between the surgical techniques showed nonsignificant differences between them. The ladder test showed significant differences in use of the limbs in all experimental groups. Use of the left limb was significantly reduced in all groups. CONCLUSIONS: Modification of the rotations seems more sensitive to the site of transplant than to the technique used. It seems that the skills studied using the ladder test are not altered by the microtransplant technique.

Animals↗
PubMedDate not supplied

[Resistance to insecticides in Blattella germanica species strains from Santiago de Cuba].

A study was conducted on the level of resistance to seven insecticides, namely, 3 organophosphate compounds (malathion, chlorpyrifos and pirimiphos-methyl), one carbamate (propoxur) and 1 pyrethroid (cypermethrin, deltamethrin and lambdacialotrine) of three field-collected strains of Blattella germanica (Linnaeus, 1767) from Santiago de Cuba. These strains showed high resistance levels to malathion, cypermethrin, deltamethrin and lambdacialotrine and low resistance to pirimiphos-methyl, and also they were susceptible to chlorpyrifos and propoxur. The levels of resistance to tested organophosphate insecticides such as malathion and pirimiphos-methyl and to pyrethroid compounds like cypermethrin, deltamethrin and lambdacialotrine may be related to the increased production of esterases as a mechanism of resistance. The value of frequency of the resistant genes for enzyme acetylcholinesterase was very low, therefore, the modified acetylcholinesterase is not involved in resistance to insecticides tested in the studied strains from Santiago de Cuba.

Animals↗
PubMedDate not supplied

[Idiopathic membranous nephropathy in an elderly patient with type 2 diabetes mellitus].

We report an 85 years-old patient with type 2 diabetes mellitus and both clinical and biochemical nephrotic syndrome. The renal biopsy showed membranous nephropathy at stage I-II. There was no evidence of malignancy. The patient was treated with steroids, and two months later the proteinuria had not improved. The objects under discussion are the factors that should lead to suspect the existence of glomerulonephritis, other than diabetic glomerulosclerosis, suggesting the need for kidney biopsy. We also focus on the prognostic and therapeutic relevance, as well as on the common pathogenic aspects.

Adrenal Cortex Hormones↗
PubMedDate not supplied

[Course of insecticide resistance in Culex quinquefasciatus (Diptera: Culicidae) in a region of La Habana].

The use of malathion to control mosquitoes in Cuba during 7 years until 1986 selected 2 resistance mechanisms: that of elevated activity of nonspecific esterases and that of altered acetylcholinesterase (Ache) in Culex quinquefasciatus (Say). In Havana, specifically in the area under study (Quibú River), malathion was replaced by cypermethrin in 1987 and cycles of treatment with cypermethrin have been intensively used since 1987 up to now when the populations of Aedes or Culex increase. In Culex quinquefasciatus (Say) from the Quibú River the resistance levels, mainly to malathion, declined significantly from 1986 to 1997. An increase of resistance to pyrethroid was observed during that period of 11 years. The mechanism of elevated esterases rose to a frequency of 1 and there was also an increase in the frequency of the mechanism of Ache. The esterase B1, responsible for the resistance to malathion, but not to pyrethroid, was selected in this population until 1986. Starting from the use of pyrethroid for the control in this area, 2 new phenotypes of esterases named A6 and B6, apparently related to pyrethroid resistance, were selected.

Aedes↗
PubMedDate not supplied

[Adaptation of microtitration plate methods for quantification of the activity of esterases and glutathione-s-transferase in Aedes aegypti].

The detection techniques for the activity of non-specific esterases and glutathione-s-transferase in Culex quinquefasciatus were modified to detect such enzymes in Aedes aegypti(L). The optimal concentration values of substrate (saturating concentration) and the optimum reading time for reaction were determined for each enzyme by using 4 Aedes aegypti strains: one from Cuba 2 from Venezuela and one susceptible reference strain. The frequency of non-specific esterases turned out to be 0.76 in MIRANDA 0.42 in ARAGUA and 1 in SANTIAGO DE CUBA in which the highest frequency value of this mechanisms was reached. The frequency of glutathione-s-transferase mechanism was 0.45 in ARAGUA 0.043 in MIRANDA and 1 in SANTIAGO DE CUBA. For the first time in Cuba a set of biochemical techniques was available for detecting the resistance mechanisms of Aedes aegypti which made it possible to create sound foundations for the easy rapid detection of the resistance of this species the main dengue vector in the Americas.

Aedes↗
PubMedDate not supplied

[High esterases as mechanism of resistance to organophosphate insecticides in Aedes aegypti strains].

Five strains of Aedes aegypti L. one from Cuba and 4 from Venezuela were evaluated to determine their resistance to organophosphate insecticides (temephos, chlorpiriphos and pirimiphos methyl). In the Venezuelan strains only APURE showed resistance to temephos. In TACHIRA and MIRANDA moderate resistance values were noted (FR50 5 to 10x) for chlorpiriphos and high levels of resistance (FR > 10x) to this insecticide were found in ARAGUA. All the Venezuelan strains showed high levels of resistance to pirimiphos methyl. The Cuban strain from Santiago de Cuba revealed moderate resistance to temephos and pirimiphos methyl, but high resistance to chlorpiriphos. The results of the biochemical tests proved the presence of esterase and glutathione-s-transferase at high frequency in almost every strain. By the polyacrilamide gel electrophoresis, a strongly stained band was observed in all the strains with a Rf value of 0.779; it was named esterase A4 and was not seen in the susceptible reference strain. The meaning of this esterase in the resistance to organophosphate insecticides is yet to be determined. Resistance to these insecticides in Aedes aegypti is a serious problem for the control of this species therefore integrated management strategies were proposed to prevent or delay the appearance of this species in Cuba and Venezuela.

Aedes↗
PubMedDate not supplied

[Effects of simultaneous transplant of foetal mesencephalic cells in the striatum and the subthalamic nucleus of hemiparkinsonian rats].

INTRODUCTION: The main strategy followed in neural transplants as a method of treatment for Parkinson s disease, both experimental and clinical, has been to introduce foetal mesencephalic cells into the target area: the striatum. However, when the dopaminergic cells in the substantia nigra degenerate, not only is the dopaminergic innervation of the striatum affected but also other nuclei: globus pallidus, substantia nigra, substantia nigra pars reticulata and subthalamic nucleus. A series of data from pharmacological and physiological studies offer strong evidence that the dopamine released in these nuclei may play an important role in regulating the output nuclei of the basal ganglia. AIM: To evaluate the effect of transplanting foetal mesencephalic cells on the behaviour of 6 OH DA rats when introduced into the striatum and the subthalamic nucleus. MATERIALS AND METHODS: 6 OH DA was used to induce lesions in the substantia nigra of rats, which were divided into several experimental groups. The rotating activity induced by D amphetamine (5 mg/kg, intraperitoneally) and apomorphine (0.05 mg/kg, subcutaneously) was evaluated before and three months after the transplant in all the experimental groups, except in the control group of healthy rats. The hemiparkinsonian rats received a total of 350,000 foetal ventral mesencephalic cells, which were implanted within small deposits in the striatum (8) and in the subthalamic nucleus (4). RESULTS AND CONCLUSIONS: Rotation induced by both drugs was significantly lower (p= 0.05) in animals that had had dopaminergic cells transplanted into the striatum body. No significant improvement in this behaviour was to be found when transplants were limited to just the subthalamus or, simultaneously, also to the striatum. A significant increase in rotating behaviour induced by apomorphine was observed in the group which received a transplant in just the subthalamus.

Adrenergic Agents↗
PubMedDate not supplied

[Segmentary organisation of the efferents of the vestibular complex in chicken embryos: is this an example of the general case?].

INTRODUCTION: In this paper we present, from the perspective of the embryological segmentary layout of the hindbrain, the topographic layout of the vestibular projection neurons that sustain the vestibulospinal, vestibulo ocular and vestibulocerebellous efferents, in correlation with the classic vestibular nuclei. AIMS: Four vestibular nuclei are usually described superior, lateral, medial and inferior. These originate in at least nine successive rhombomeric segments or pseudosegments, which suggests the possibility of a more precise analysis of their neuronal populations and of their respective connections and functions. It has recently been observed that the vestibular projection neurons identified for a particular target tend to appear aggregated in discrete accumulations, which have been proved to correlate either with rhombomeric units, where they apparently develop, or with internal subdivisions within them. Each projection has its own particular organisation. Comparing them with the resulting connective mosaic in different species shows that various aspects of this organisation are conserved throughout evolution in vertebrates. It is argued that certain genes that control the development of the rhombomeric units in the brain stem may determine, among other aspects, the specific properties of the different neuronal subpopulations related with their axonal navigation and synaptogenesis. CONCLUSIONS: This type of analysis furthers our understanding of how the functional circuitry of a complex system, such as the vestibular system, is generated and is a line of reasoning that in principle can be applied to the whole neural tube.

Animals↗
PubMedDate not supplied

[Microbiologic study of bacteremia and fungemia in chronic hemodialysis patients].

Microbiologic study of bacteremia and fungemia in chronic hemodialysis patients. Bloodstream infections are the second cause of death in patients in chronic hemodialysis (CHD), and the knowledge of the epidemiology is useful to establish proper empiric therapies. The aim of this study was to evaluate the frequency and distribution of microorganisms, in bacteremia and fungemia in 530 patients in CHD. Two hundred and forty eight blood culture series from 114 patients with suspected bacteremia were processed; 44% of them were positive from which 71% (n=78) were clinically significative and belonged to 58 patients. Sixty eight percent of these isolates were gram-positive cocci (n:53), and 22% gram-negative rods (n:17). Staphylococcus aureus was the most prevalent pathogen showing 23% of methicillin-resistance. Candida spp. was the fourth pathogen most common in frequency.

Argentina↗
PubMedDate not supplied

[Xerosis caused by abuse of vasoconstrictor eye drops: apropos of a case].

This is the case of a 63 year old patient with chronic conjunctivitis on chronic local phenylephrine instillation for the last 13 years. We have observed that the protracted use of vasoconstrictor eyedrops can induce conjunctival xerosis and that its simple withdrawal can result in marked symptomatic improvement leaving behind only degenerative cicatricial changes.

Dose-Response Relationship, Drug↗
PubMedDate not supplied

[Study of the bronchial provocation test with Alternaria in the diagnosis of childhood asthma: sensitivity, specificity, reproducibility].

The results of the cutaneous tests with fungus, and the repercussion of the fungal allergens in asthma via inhalatory route has been a controversial subject for many years. The lack of characterization, purification and standardization of the allergens make the results of the cutaneous tests highly variable. The diagnostic value of the bronchial provocation test (BPT) in asthma, associated with suspicious fungal hypersensitivity, correctly performed with adequate controls and concentrations of non-irritant fungal allergens has been emphasized by various authors. The motive of the present study to demonstrate, by means of the BPT with Alternaria, if the lung is the target organ of hypersensitivity demonstrated by cutaneous tests and RAST, comparing the obtained results by the Score of FOUCARD (fig. 1), with the result of the inhalatory test. The specificity and reproductibility of the BPT was likewise verified according to the employed allergen and its non-unspecific irritant concentrations to the airway. Twenty patients of both sexes, with ages ranging between 7 and 14 years, distributed in two groups, were studied and diagnosed as having bronchial asthma. Group I: Fourteen patients diagnosed with asthma, for hypersensitivity to Alternaria with Score of FOUCARD equal or greater than 5 (Table I). Group II: Control group composed of 6 patients with negative allergological findinds to Alternaria with bronchial hyperreactivity demonstrated in for cases by BPT positive against Dermatophagoides and in two cases with positive methacholine test (PC20 less than 8 mg./ml.). The inhalation of the allergen was performed following the described method by Cockcroft.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

[Factors modifying late bronchial response in the bronchial provocation test in asthmatic children].

When the test of bronchial provocation with inhalant allergens is performed in atopic asthmatics, we may find an immediate response (IR), a late response (LR) or a dual response (IR-LR). The immediate response occurs between 10 to 30 minutes after the allergenic exposition and it is resolved spontaneously in about one to two hours. A proportion of these patients, estimated around 47-73% presented a LR. The LR is manifested 3 or 5 hours after the inhalation test, maximum at 6-12 hours and may persist until 24 hours. The late response serves as a clinical model of asthma because the bronchial response is more prolonged and severe than the immediate response. This is best controlled with corticosteroids while bronchial reversibility is difficult with sympathomimetics only, a fact commonly observed in the natural course of asthma. The early response was observed to be in relation with multiple factors more predictable than the late response. The object of this work was to evaluate if the LR was related with factors such as the degree of obstruction previous to the test, the intensity of immediate bronchial response and the maximum dose of inhaled allergen. The present study was performed in 34 children of both sexes with ages ranging between 6 and 14 years, diagnosed with bronchial asthma caused by Dermatophagoides (26 patients), and Alternaria (8 patients) through the score of Foucard with positive bronchial provocation test with the allergen. The BPT was performed according to the method described for Cockcroft, utilizing a continuous pressured nebulizer, inhaling for two minutes at current volume. We employed the De Villbis 646 model nebulizer with flow of air at 6 l/min and output at 0.13-0.16 ml/min. The inhaled concentrations of allergen progressively increased by ten fold, in Dermatophagoides 0.01; 0.1; 1 and 10 BU/ml, and for Alternaria 1/1,000,000, 1/100,000 and 1/10,000 P/V. Ten minutes after each dose a spirometric function with pneumoscreen Jaeger was performed. If the FEV1 was decreased by 20% from the control value, we considered the IR positive. The late response was evaluated through an hourly control of the peak respiratory flow rate (PEFR) with a Mini Wright within a 24 hours period after the test, respecting nocturnal sleep. We considered positive (LR) if PEFR fall was equal or superior to 40% of the basal value and the presence of bronchial symptoms.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗