Biomedical subjects

J Sotelo

Publications and source records attributed to J Sotelo.

At least 73 records · Page 4Linked to original sources

PubMed1995

A new shunt for hydrocephalus that relies on CSF production rather than on ventricular pressure: initial clinical experiences.

BACKGROUND: Ventricular shunting for hydrocephalus is one of the surgical procedures most frequently associated with complications. When the hydrocephalus is secondary to arachnoiditis the prognosis is usually poor. METHODS: Twenty-six patients with hydrocephalus secondary to chronic arachnoiditis due to meningeal cysticercosis were treated with a new ventriculoperitoneal shunt whose design is based on the rate of cerebrospinal fluid (CSF) production and shunt resistance rather than on ventricular pressure, which has been the principal parameter for most other shunting devices. RESULTS: The shunt has remained functional in 25 patients (96%). A peculiar response was documented in all cases by sequential CT scans; i.e.; the size of the ventricular cavities showed gradual reduction and about 1 month postsurgery the ventricles had returned to normal size. In all cases, fast clinical improvement was documented within the first 2 days after surgery with remission of all symptoms of intracranial hypertension. Improvement has continued for a mean follow-up of 9 +/- 2 months. In one case, the shunt was occluded a month after surgery, was withdrawn, and was replaced by a conventional shunt. CONCLUSIONS: Our initial results contrast with the experience with other shunts, which in these patients have a rate of 50% occlusion within the first 4 months after surgery. Although a long-term follow-up is mandatory, it seems that the treatment of hydrocephalus by a shunt devoid of valve mechanisms, with drainage capacity limited to physiological parameters of CSF production, could avoid the unacceptable high frequency of overdrainage and occlusion that are the main complications of shunting devices that operate in relation to ventricular pressure.

Adult↗

PubMed1995

Changes in brain, plasma and cerebrospinal fluid contents of beta-endorphin in dogs at the moment of death.

To investigate the possible participation of endogenous opioids in the cerebral events that take place at the moment of death we studied brain, cerebrospinal fluid and serum contents of beta-endorphin in dogs that were either conscious or unconscious at the moment of sudden death induced by cardiac arrest. Although with great interindividual variations, the animals that were conscious at the moment of cardiac arrest, presented a significant increase in beta-endorphin when compared with their own previous values (p < 0.05) or with the values found in animals that were deeply anaesthetized at the time of cardiac arrest. There seems to be a sudden increment of beta-endorphin in brain tissue and body fluids of dogs who are conscious at the moment of sudden death, this change was not observed in dogs that were anaesthetized prior to death. Brain opioids could participate in the sensations narrated by subjects in the so called near-death experience.

Animals↗

PubMed1995

Antigens from Taenia crassiceps cysticerci used in complement fixation, enzyme-linked immunosorbent assay, and western blot (immunoblot) for diagnosis of neurocysticercosis.

Antigens from Taenia solium cysticerci for the immunodiagnosis of cysticercosis are scarce and difficult to obtain. We studied the reliability of antigens from Taenia crassiceps cysticerci as a substitute for those from T. solium in three diagnostic tests: complement fixation, enzyme-linked immunosorbent assay, and Western blot (immunoblot). Precision rates of the three tests of 93, 99, and 96%, respectively, were found. Cysticerci from T. crassiceps can be easily obtained in large quantities and can be effectively used for the diagnosis of human neurocysticercosis.

Animals↗

PubMed1995

Diagnosis of American trypanosomiasis (Chagas' disease) by the new complement fixation test.

A new immunodiagnostic method of complement fixation was used for serodiagnosis of American trypanosomiasis; 92% sensitivity and 99% specificity were obtained, for an overall accuracy of 97%. This test can be used in field studies, obviating the use of most laboratory equipment and imported reagents; places where economic limitations hinder the use of other immunodiagnostic procedures; and in association with other tests for confirmation of the diagnosis.

Animals↗

PubMed1995

Is the frequency of multiple sclerosis increasing in Mexico?

Multiple sclerosis has steadily increased in Mexican mestizos from an apparently rare disorder in the 1970s to the second most frequent cause of admission to a neurology ward in the 1990s. Most patients belonged to high socioeconomic and educational groups. Familial incidence was low. Age at onset was younger than in other series and long term disability was milder than in patients from countries in which the disease is apparently more prevalent.

Adult↗

PubMed1995

Differences between ventricular and lumbar cerebrospinal fluid in hydrocephalus secondary to cysticercosis.

We studied ventricular and lumbar cerebrospinal fluid (CSF) in 16 patients with hydrocephalus secondary to meningeal cysticercosis, and samples were taken at the time of the surgical implantation of a ventricular shunt. All lumbar CSF samples revealed raised cell counts (mean, 72 +/- 28/mm3) and protein counts (mean, 78 +/- 12 mg/dl), as well as positive immune reactions to cysticerci antigens. In contrast, 50% of the ventricular CSF samples exhibited cell and protein counts within normal limits and five showed negative immune reactions to cysticerci antigens. Ample differences between ventricular and lumbar CSF were also observed in the contents of glucose and immunoglobulins G, A, and M. The biochemical and immunological composition of the CSF varied greatly along the cerebrospinal axis in patients with chronic arachnoiditis caused by cysticercosis. Our findings further support the premise of the subarachnoid space as an immunologically active substratum and provide information to explain the frequent occlusion of ventricular shunts in patients with hydrocephalus secondary to inflammatory disorders of the subarachnoid space.

Adult↗

PubMed1995

Reversibility of the alterations induced by chronic alcoholism and malnutrition in rats after alcohol withdrawal and proper nutrition.

OBJECTIVE: The specific influence of malnutrition on the cellular damage induced by alcoholism has been poorly defined; therefore, the possible degree of improvement that could be obtained after the institution of proper nutrition and after alcohol withdrawal remains unclear. We studied both conditions in several combinations, either after chronic alcoholism, chronic malnutrition or both, and after reversal of each condition or of both. METHOD: Using experimental models of alcoholism and malnutrition, we studied the alterations induced by each condition and on the combination of both in five histological locations and in 10 hematological and biochemical parameters; afterwards, we studied the possible restorative effect on each parameter after 4 months of alcohol withdrawal or proper nutrition or both. RESULTS: Our results showed that chronic alcoholism induced a mean of 31% deviation from values obtained in controls, malnutrition induced 17%, and alcoholism and malnutrition combined induced 52%. Upon the removal of the offending condition, alcohol withdrawal brought 13% improvement and proper nutrition 5% improvement; in the animals with alcoholism and malnutrition, alcohol withdrawal and proper nutrition brought 26% improvement, alcohol withdrawal but continuation of malnutrition 10% improvement, and continuation of alcoholism but proper nutrition led to a further 8% worsening from the alterations already found during alcoholism and malnutrition. CONCLUSIONS: Multivariate statistical comparisons demonstrated that chronic malnutrition produced an important, independent and difficult to reverse effect on the damage induced by alcoholism in several histological and physiological parameters.

Alcoholism↗

PubMed1994

Dengue virus infects mouse cultured neurons but not astrocytes.

Cultures of mouse brain cells containing a high proportion either neurons or astrocytes were inoculated with various strains of dengue virus. At analysis by double immunofluorescence, all strains of dengue virus studied were tropic for neurons. In no case were the astrocytes infected. Only approximately 10% of all neurons were infected, suggesting that the virus may enter the cell through a membrane receptor present only in a subgroup of neurons.

Animals↗

PubMed1994

Low contents of nerve growth factor in serum and submaxillary gland of diabetic mice. A possible etiological element of diabetic neuropathy.

Insulin and nerve growth factor are peptides that share several chemical and functional properties. While the total or relative deficiency of insulin causes diabetes, the possible disorders due to deficiency of nerve growth factor have not been clearly defined. However, the intense biological actions of nerve growth factor in the maintenance and growth of several neural cells make feasible its participation in the physiopathology of some diseases of the peripheral nervous system. We measured the contents of nerve growth factor in serum, submaxillary gland and sciatic nerve of mice with streptozotocin-induced diabetes. Nerve growth factor in diabetic mice was diminished in serum and submaxillary gland when compared with matched controls (P < 0.01). This finding further supports a similar observation in diabetic patients and suggests a possible etiological involvement of neural growth factor in the development of diabetic neuropathy.

Animals↗

PubMed1994

Detrimental effects of malnutrition on the damage induced by alcoholism: a study of animal models that simulate chronic alcoholism and malnutrition of large human groups.

The specific influence of malnutrition on the pathophysiological changes induced by chronic alcoholism is controversial; most studies are inconclusive because they have been made in chronic alcoholics that develop malnutrition as a complication of alcoholism. However, in vast human groups, alcoholism evolves in individuals that belong to a chronically undernourished population. In an attempt to simulate real-life conditions of malnutrition-alcoholism in humans, we studied in rats: (1) the effects of chronic malnutrition with tortilla, a corn bread that constitutes the main diet of large human groups; (2) the effects of chronic alcoholism with commercial brandy; and (3) the effects of chronic alcoholism and malnutrition combined. The damage induced either by alcoholism or that induced by malnutrition alone were of similar degree, whereas the combination of malnutrition and alcoholism led to a worsening of some parameters studied: body weight, leucocyte count and, more remarkably, in the tissue damage of several areas of the central nervous system.

Alcoholism↗

PubMed1993

Electroconvulsive shock does not modify striatal contents of dopamine in MPTP-treated mice.

It has been suggested that the therapeutic response to electroconvulsive therapy in depressed patients could be mediated by functional changes in the dopaminergic pathways; a favorable response to electroconvulsive therapy was also observed recently in patients with Parkinson's disease. To study a possible interference of electroconvulsive shock in the course of MPTP-induced parkinsonism in rodents, we measured the striatal content of dopamine in MPTP-treated mice that received electroconvulsive shock at various intervals in the course of MPTP neurotoxicity. Our results showed no immediate or delayed differences in striatal dopamine content of animals that received MPTP and electroconvulsive shock when compared with animals that received only MPTP, thus suggesting that the strong biological effects of MPTP and electroconvulsive shock on the brain may follow different biochemical mechanisms.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMed1993

Changes in the threshold of pentylenetetrazol-induced seizures in cats with a chronic granuloma in brain amygdala.

A parenchymal brain granuloma is the final consequence of a localized inflammatory reaction against an infectious agent, particularly parasites. In humans, these lesions are frequent causes of epilepsy. We studied the pattern of seizures induced by pentylenetetrazol (PTZ) in cats with a chronic granuloma induced 1 year earlier by injection of silicates into the brain amygdala. Compared with controls, the seizure threshold to myoclonic seizures was significantly decreased in cats with granuloma, while the threshold for tonic-clonic seizures was not altered. Thus, the difference in PTZ doses between the initial and final components of the seizure became significantly enlarged (P < 0.001). Our results indicate that a granulomatous lesion in amygdala facilitates the generation and propagation of myoclonic seizures, whereas other components of PTZ-induced seizures are not affected.

Amygdala↗

PubMed1993

Therapy for neurocysticercosis: a reappraisal.

Accepted approaches to therapy for the different forms of neurocysticercosis are reviewed. Therapy must be individualized according to the level of disease activity and the location of the parasite. Patients with inactive disease should receive only symptomatic treatment. In contrast, patients with parenchymal brain cysts must receive a course of anticysticercal drugs. Both albendazole and praziquantel are useful; however, recent evidence favors the former as the drug of choice for this form of the disease. Albendazole (but not praziquantel) is also effective in the treatment of giant subarachnoid cysts; such medical treatment obviates surgery in some cases. Patients with ventricular cysts may also benefit from medical therapy; however, surgery is the current approach to this type of lesion, as it is to spinal cysticercosis. Although intraocular cysts have classically been resected by surgery, a recent study indicates that albendazole is equally effective. For patients with mixed forms of neurocysticercosis, therapeutic measures related to--but not directly targeting--the disease (i.e., steroid administration for brain edema or shunt placement for hydrocephalus) should be contemplated before therapy with anticysticercal drugs is instituted.

Albendazole↗

PubMed1993

Pharmacokinetic comparison of two albendazole dosage regimens in patients with neurocysticercosis.

To evaluate two different dosage regimens for albendazole (7.5 mg/kg twice a day or 5.0 mg/kg three times a day), a study was performed in 10 patients with a diagnosis of parenchymal brain cysticercosis. Each patient received both regimens sequentially according to a randomized, crossover design. Blood and urine samples were taken once the drug steady state had been reached. Plasma levels of albendazole sulfoxide at steady state were determined using a HPLC method. In spite of a great intersubject variability observed with both regimens in the area under the curve (AUC) and in the minimum steady-state plasma concentration (Cp min ss), no statistically significant differences were found in these parameters. We suggest that a regimen of 7.5 mg/kg every 12 h can favorably replace the currently used regimen of 5 mg/kg every 8 h.

Adolescent↗

PubMed1992

The course of seizures after treatment for cerebral cysticercosis.

BACKGROUND: Worldwide, cerebral cysticercosis is one of the most common causes of seizure disorders. Modern cysticidal drugs can usually eliminate the parasite from the brain, but there have been doubts as to whether such treatment improves the seizure disorder. METHODS: We studied 240 patients with seizures and cysticercosis of the brain parenchyma. Of these patients, 118 received cysticidal therapy (albendazole, praziquantel, or both) for lesions without inflammation on imaging studies (group 1); 49 patients with similar lesions either were not offered or refused cysticidal medication (group 2). Another 58 patients with inflammation around cysts (making spontaneous resolution more likely) also did not receive cysticidal medication (group 3), whereas cysticerci were removed surgically in 15 patients (group 4). The 240 patients were followed for a mean (+/- SE) of 92 +/- 7 months. RESULTS: In the patients treated with cysticidal medications, there was an 82 percent reduction in the mean number of brain cysts (from 5.0 to 0.9) and a 95 percent reduction in the mean frequency of seizures (from 11.3 to 0.6 per year; P less than 0.001). After three years of follow-up, 64 patients in group 1 (54 percent) were seizure-free. By contrast, the untreated patients (group 2) averaged 10.9 seizures per year; none were seizure-free. Among those with inflamed cysts (group 3), there was a 74 percent reduction in the frequency of seizures (from 7.5 to 2.7 per year), and 18 patients (31 percent) became seizure-free. After surgical treatment (group 4), there was an 87 percent reduction in the frequency of seizures (from 12.8 to 1.7 per year), and six patients (40 percent) became seizure-free. CONCLUSIONS: After medical treatment of neurocysticercosis, there is usually remission or marked improvement in the associated seizure disorder.

Adult↗

PubMed1992

Albendazole therapy for giant subarachnoid cysticerci.

Albendazole is considered to be the drug of choice for treatment of parenchymal brain cysticercosis. Its efficacy, however, for treatment of subarachnoid cysticerci has not been established, to our knowledge. In this study, we treated four patients who had giant subarachnoid cysticerci with albendazole at daily doses of 15 mg/kg of body weight for 8 days. Computed tomographic studies showed that all cysts disappeared 3 months after the end of treatment. This was associated with marked clinical improvement in every case. Our results indicated that albendazole is highly effective for treatment of this form of the disease.

Adult↗

PubMed1992

Immunodiagnosis of neurocysticercosis. Disappointing performance of serology (enzyme-linked immunosorbent assay) in an unbiased sample of neurological patients.

To ascertain the reliability of serological diagnosis of neurocysticercosis in the everyday a priori situation of neurological consultation, the enzyme-linked immunosorbent assay test was used to predict the eventual diagnosis of neurocysticercosis in an unselected sample of 1064 consecutive neurological cases. Results showed 69% sensitivity and 71% specificity of the enzyme-linked immunosorbent assay test for the diagnosis of neurocysticercosis. In sharp contrast with publications that have proclaimed the excellent diagnostic performance of immunodiagnostic tests, our results suggest that identification of serum antibodies with standard enzyme-linked immunosorbent assay techniques is of little value when applied to a large and heterogeneous group of neurological patients in an endemic area of cysticercosis, and our results urge a reevaluation of currently used immunodiagnostic tests that are practiced in the serum of suspected cases.

Central Nervous System Diseases↗

PubMed1992

Clinical pharmacokinetics of albendazole in patients with brain cysticercosis.

Albendazole pharmacokinetics were studied in eight patients who were receiving albendazole in doses of 15 mg/kg per day for 8 days as treatment of brain cysticercosis. Albendazole was not detected in plasma, but its main metabolite albendazole sulphoxide could be measured. Maximum plasma levels for albendazole sulphoxide ranged from 0.45 to 2.96 micrograms/mL. The half-life of albendazole sulphoxide was between 10 and 15 hours. A double peak was found in three patients. Mean residence time values were from 14 to 20 hours. Plasma levels of albendazole sulphoxide at the steady state showed great intraindividual variability. The results suggest that albendazole can be administered twice daily rather than three times as is currently done.

Administration, Oral↗