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Biomedical subjects

M Cruz

Publications and source records attributed to M Cruz.

At least 19 recordsLinked to original sources
PubMed1993

Susceptibility to demyelinating polyneuropathy in plasma cell dyscrasia may be influenced by amino acid position 9 of the HLA-DR beta chain.

Fifty-five patients with plasma cell dyscrasias were investigated by genomic typing for HLA-DR and -DQ genes by restriction fragment length polymorphism, neurophysiology and for presence of anti-myelin-associated glycoprotein (MAG) antibodies. In 26 patients, a polyneuropathy (PN) of demyelinating type was established. Among these individuals, an association was found with the presence of a tryptophan amino acid residue at position 9 of the DR beta chain (P < 0.01). This position is part of the first hypervariable region of the DR beta chain, and may be of importance in determining preferential peptide-binding capacity of the HLA-DR molecule. The presence of anti-MAG antibodies in 15 out of 17 patients with an IgM M-component and demyelinating PN (14 of these 15 individuals carrying a tryptophan at position 9) supports the pathogenic role of an autoimmune response against MAG. The finding of an HLA class II association may indicate a pathogenic role of T cell immunity in this condition.

Adult↗
PubMed1993

Vasopressin in cerebrospinal fluid of newborns with hypoxic-ischemic encephalopathy. Preliminary report.

Vasopressin in cerebrospinal fluid has been measured in 27 fullterm newborns with hypoxic-ischemic encephalopathy. These newborns were divided into three groups according to the degree of neurological involvement, and they have been compared with a control group of 10 newborns. Determinations of vasopressin in cerebrospinal fluid and plasma were done by RIA. The cerebrospinal fluid vasopressin in asphyxiated newborns was higher than in the control group (p < 0.001); the mean concentration in the group of newborns classified as moderate or severe hypoxic-ischemic encephalopathy was higher than in the control group (18.7 pg/ml vs 4.66 pg/ml), and also higher than in the group classified as mild (14.2 pg/ml). Cerebrospinal fluid vasopressin values have a direct relationship to the plasmatic values at 12 hours of life (r = 0.76; p < 0.001). We concluded that vasopressin values in cerebrospinal fluid at 12 hours increase according to the clinical severity of the neonatal hypoxic-ischemic encephalopathy and that they have a strong relationship with plasmatic vasopressin.

Asphyxia Neonatorum↗
PubMed1992

Immobilized pH gradient isoelectric focusing and immunoblotting for investigations of anti-Borrelia burgdorferi IgG antibodies.

Anti-Borrelia burgdorferi immunoglobulin G (IgG) responses in cerebrospinal fluid, serum, and joint fluid from Lyme disease patients were investigated by immobilized pH gradient (IPG) isoelectric focusing (IEF) in pH 4-10 and pH 4-7 gels. After focusing, the anti-B.-burgdorferi antibodies were blotted by affinity-driven transfer to antigen-coated polyvinylidene difluoride membranes (immunoblot) and the IgG antibodies were immunoenzymatically stained. IPG-IEF gels gave an excellent resolution of IgG and the immunoblot proved advantageous for the detection of anti-B. burgdorferi IgG antibodies. These antibodies, as judged from the electromigration characteristics, were found to contain oligoclonal as well as polyclonal subpopulations. This latter group included IgG antibodies that were inadequately resolved when separated by conventional carrier ampholyte IEF.

Antibodies, Bacterial↗
PubMed1992

Light chain distribution of anti-Borrelia burgdorferi IgG antibodies in Lyme arthritis.

Joint fluid (JF) and serum IgG from eight Lyme arthritis patients was investigated by isoelectric focusing, blotting to membranes of uncoated nitrocellulose (NC) as well as Borrelia (B.) burgdorferi antigen-coated NC (immunoblot) and immunoezymatic staining for visualization of the IgG isotype and characterization of the kappa/lambda light chain distribution. Oligoclonal bands of total IgG occurred in JF as well as in serum (3 cases) or in JF only (1 case); IgG lambda components were present in all four subjects and IgG kappa in three. IgG (Fc frag) reactive but kappa/lambda light chain negative oligoclonal bands were present in JF of one further patient. Additional investigations supported the interpretation that these components were free gamma chains. Oligoclonal anti-B. burgdorferi IgG antibodies occurred in JF as well as in serum (6 cases) or in JF only (1 case). There were complete identities, as defined by isoelectric points and light chain types, between JF and serum antibodies in an individual patient while identities between oligoclonal bands of total IgG and anti-B. burgdorferi IgG were infrequent. Antibodies of IgG kappa identity were present in all seven patients and six of them also had IgG lambda antibodies. The antibody response was, therefore, by definition oligo- and not monoclonal in 6 out of 7 patients. Furthermore, the anti-B. burgdorferi antibodies of IgG kappa identity only that were present in one case did not exhibit any completely characteristic monoclonal microheterogeneity.

Adolescent↗
PubMed1991

Antibodies to myelin-associated glycoprotein are found in cerebrospinal fluid in polyneuropathy associated with monoclonal serum IgM.

Antibodies to myelin-associated glycoprotein (MAG) have been demonstrated in the serum samples from about half the patients with polyneuropathy associated with serum IgM monoclonal component. We examined cerebrospinal fluid (CSF) and serum samples from 13 patients with this disease by enzyme-linked immunosorbent assay for anti-MAG IgM antibodies. We detected these antibodies in both CSF and serum samples in 10 of the patients; in three of them the antibodies were at higher levels in the CSF. The remaining three patients had anti-MAG IgM antibodies in the CSF only. Intrathecal production of anti-MAG IgM antibodies is thus common in polyneuropathy associated with IgM monoclonal component. In three patients, examined on two occasions from 1 to 7 years, high anti-MAG IgM antibody levels persisted in CSF and serum samples. Among 165 patients with other neurologic diseases, including 60 with multiple sclerosis and 60 control subjects with tension headache, anti-MAG IgM antibodies were detected in the CSF from three patients (two with multiple sclerosis, one with aseptic meningitis), and in the serum sample of one patient with multiple sclerosis. Whether the frequent occurrence of anti-MAG IgM antibodies in CSF and their intrathecal synthesis has pathogenetic relevance for the development of polyneuropathy associated with IgM monoclonal component is unsure.

Aged↗
PubMed1991

Cells secreting anti-MAG antibody occur in cerebrospinal fluid and bone marrow in patients with polyneuropathy associated with M component.

Occurrence and distribution of cells secreting antibodies against myelin associated glycoprotein (MAG) were studied in 9 patients with polyneuropathy associated with the monoclonal (M) component in serum. Utilizing an immunospot assay, we found that 4 of 7 patients with polyneuropathy associated with an IgM M component had cells secreting anti-MAG IgM antibody in cerebrospinal fluid (CSF) numbering between 1 per 212 and 1 per 3333 mononuclear cells. All 7 patients had cells secreting anti-MAG IgM antibody in bone marrow (median value 1 per 2000 cells). In contrast, peripheral blood from only 2 of these patients contained low numbers of such cells. One patient with polyneuropathy associated with an IgA M component had cells secreting anti-MAG IgA antibody in CSF, and 1 with an IgG M component had cells secreting anti-MAG IgG antibody in CSF; both patients also had anti-MAG IgM antibodies detectable in CSF only by ELISA. These 2 patients may thus have concurrent intrathecal production of antibodies of 2 different isotypes which are directed against the same or different epitopes of MAG. The production of antibodies directed against a component of myelin occurring in the immediate vicinity of the peripheral nervous system might be involved in the pathogenesis of the polyneuropathy.

Adult↗
PubMed1991

Lyme arthritis: oligoclonal anti-Borrelia burgdorferi IgG antibodies occur in joint fluid and serum.

The antibody response to Borrelia (B.) burgdorferi, and to measles virus as control antigen, was analysed by agarose isoelectric focusing (AIF) and immunoblot of joint fluid and serum from 10 patients with Lyme arthritis and 10 controls with rheumatoid arthritis. Among the Lyme arthritis patients, six had oligoclonal anti-B. burgdorferi IgG antibody bands in joint fluid and corresponding serum, one patient had oligoclonal antibody bands in joint fluid only and also an elevated B. burgdorferi-specific joint fluid to serum antibody ratio as evidence of intra-joint production of specific antibodies, and the remaining three patients were negative for oligoclonal-specific antibody bands. Absorption with B. burgdorferi antigen confirmed the specificity of the oligoclonal antibody bands. They comigrated only partially on AIF with oligoclonal bands of total IgG, and the specificity of most oligoclonal IgG in joint fluid and serum in Lyme arthritis remains undefined. Among the controls, no anti-B, burgdorferi IgG antibodies were detected by AIF and immunoblot. Instead, 9 of the 10 rheumatoid arthritis patients had oligoclonal anti-measles IgG antibody bands which were restricted to the joint fluid in three of them, indicating local production. We conclude that Lyme arthritis is often accompanied by an oligoclonal specific antibody response in joint fluid and serum simultaneously, and occasionally by intrasynovial synthesis of oligoclonal-specific antibodies.

Adolescent↗
PubMed1991

Multiple sclerosis: cells secreting antibodies against myelin-associated glycoprotein are present in cerebrospinal fluid.

We evaluated the B-cell response in cerebrospinal fluid (CSF) and blood by enumerating cells secreting antibodies to myelin-associated glycoprotein (MAG) and, for reference, to myelin basic protein (MBP), two myelin components which may constitute targets for autoimmune attack in multiple sclerosis (MS). Among 25 untreated MS patients, 12 had cells in CSF secreting anti-MAG IgG antibodies (mean value 1 per 1429 CSF cells) and three also had cells secreting anti-MAG antibodies of the IgM isotype but at lower levels. In CSF from 2 out of 10 MS patients examined, anti-MAG and anti-MBP IgG antibody-secreting cells were present concurrently. Antibody-secreting cells were less frequent in blood and bone marrow, reflecting compartmentalization to CSF. Anti-MAG antibody-secreting cells were found in CSF from only 1 out of 27 control patients. The intrathecal production of anti-MAG and anti-MBP antibodies may be important in the pathogenesis of MS.

Adult↗
PubMed1991

Immunological findings in 14 cases of Langerhans cells histiocytosis.

We have studied humoral and cell immunity in 14 children, from 2 months to 15 years old, diagnosed with Langerhans cells histiocytosis who had not received immunosuppressant nor immunopotentiating treatment. At the time of diagnosis, children were found in the following Greenberger clinical stages: stage II (5), stage III (6), stage IV (3). The children in stage II had moderate alterations in immunity, with an increase in IgG, IgM, IgA, increase in T4 lymphocytes and decrease in T8 lymphocytes; the clinical evolution was good. In stage III, normal immunoglobulins were noted in 2 children, an increase in IgG, IgM, IgA in 1; an increase in IgM in 1, a decrease in IgM in 1 and absence of IgA in 1. In all a decrease was found in T8 lymphocytes and the T4 lymphocytes were decreased in 3 and normal in 3; delayed immune response and response to mitogens was decreased in 3. These findings were related to a bad prognosis; 2 children died and another developed chronic disease. In stage IV serious alterations were detected in the immune system with a decrease in IgG, IgM, IgA, an increase in IgE, a decrease in T, B, T4 and T8 lymphocytes and very slight delayed immune response and response to mitogens; the children died.

Adolescent↗
PubMed1991

Clinical evaluation of albendazole and praziquantel in the treatment of cerebral cysticercosis.

One hundred consecutive patients presenting with symptoms and signs of neurocysticercosis, confirmed by neuroimaging techniques were randomly assigned to treatment with either praziquantel 50 mg/kg/day for 15 days or albendazole 15 mg/kg/day for 30 days. All patients were treated also with steroids for 42 days. Follow-up was for 90 days for response to treatment and for at least 1 year for recurrence. Although similar numbers of patients showed no improvement in neuroimaging criteria at 3 months, the response to albendazole was more pronounced with larger numbers showing marked improvement or disappearance of lesions. Similar findings were apparent, with resolution of the presenting neurological signs and symptoms being more frequent, in the albendazole group. Electroencephalographic changes were also normalized. The use of steroids eliminated the frequently observed headache that has been seen during the first few days of treatment and permitted severe cases to be treated. Both albendazole and praziquantel appear to be effective at the doses used, with albendazole showing a slightly better overall response.

Adult↗
PubMed1991

[Clinical diagnosis versus autopsy].

Records from 910 autopsies performed at a university hospital in Salvador, Bahia, Brazil were examined in order to assess the accuracy of clinical diagnoses of the patients' underlying causes of death. This study found inaccurate clinical diagnoses in 31% of the cases. The overall rate of diagnostic error appeared to remain fairly stable from 1970 to 1982, being highest for older patients. Thirty-six percent of the 263 cancer deaths were incorrectly diagnosed, and a number of pathologies considered relatively easy to diagnose were not always correctly identified--the underlying cause of death being incorrectly diagnosed in many of the fatalities caused by such ailments as arterial hypertension, chronic obstructive lung disease, pneumonia/bronchopneumonia, and schistosomiasis. Quite aside from their direct medical implications, diagnostic errors of the magnitude observed in this and other studies seriously jeopardize the quality of vital statistics and such statistics' usefulness for improving public health.

Adolescent↗
PubMed1991

Clinical diagnosis versus autopsy.

Records from 910 autopsies performed at a university hospital in Salvador, Bahia, Brazil, were examined in order to assess the accuracy of clinical diagnoses of the patients' underlying causes of death. This study found inaccurate clinical diagnoses in 31% of the cases. The overall rate of diagnostic error appeared to remain fairly stable from 1970 to 1982, being highest for older patients. Thirty-six percent of the 263 cancer deaths were incorrectly diagnosed, and a number of pathologies considered relatively easy to diagnose were not always correctly identified. Quite aside from their direct medical implications, diagnostic errors of the magnitude observed in this and other studies seriously jeopardize the quality of vital statistics and such statistics' usefulness for improving public health.

Adolescent↗
PubMed1990

Oligoclonal Borrelia burgdorferi-specific IgG antibodies in cerebrospinal fluid in Lyme neuroborreliosis.

Cerebrospinal fluid (CSF) and serum from 45 patients with lymphocytic meningoradiculitis were examined by isoelectric focusing combined with immunoblotting to detect Borrelia burgdorferi-specific oligoclonal immunoglobulin G (IgG) bands. In pretreatment samples, 35 patients (78%) showed B. burgdorferi-specific oligoclonal IgG in CSF indicative of intrathecal antibody production. At 2, 3-6, and 6 weeks after onset, respectively, such bands were present in 5 (42%) of 12, 21 (88%) of 24, and in all of 9 patients (100%). Up to 1 year after therapy, specific oligoclonal bands in CSF tended to remain unchanged despite clinical recovery. B. burgdorferi-specific oligoclonal bands in serum were found in 7 patients. These bands had identical migration patterns as in CSF, but were fewer in number and in some patients showed a temporal evolution different from their CSF counterpart. Not all oligoclonal IgG in CSF reacted with B. burgdorferi. The 41-kDa flagellar antigen was shown to be a major antigen in the intrathecal immune response. The demonstration of B. burgdorferi-specific oligoclonal IgG in CSF is a sensitive and reliable indicator of Lyme neuroborreliosis.

Adolescent↗
PubMed1990

Correlation between homologous and heterologous enzyme immunoassays for progesterone determinations in milk from cows.

Two enzymeimmunoassays, homologous and heterologous, have been used for measuring progesterone in unextracted bovine milk using HRP as the enzyme label. Antibody raised by immunization of the rabbit against 11 alpha-hemisuccinate-BSA was used for the homologous system (EIA-11 alpha) and 7 alpha-carboxyethylthioether-BSA (EIA-7 alpha) for the heterologous. The progesterone derivatives used for the enzyme-hormone conjugates were 11 alpha-hemisuccinate and 6 beta-OH-hemisuccinate respectively. Milk progesterone in 60 samples measured by EIA-11 alpha and EIA-7 alpha were highly correlated (r = 0.93). Both systems were further compared with a conventional direct progesterone radioimmunoassay (RIA) in regular use for the same samples showing a good correlation. The sensitivity estimated was much higher in the EIA-7 alpha (0.5 pg/well) than in the EIA-11 alpha (32 pg/well).

Animals↗
PubMed1990

[The study of the human genome in pediatrics today].

The author studies the present of genetic diseases, its great importance in the modern pediatrics and the main basic concepts. Also he reviews gene's function and constitution, DNA probes genoma, genetic code, gene mapping and others current problems in genetics: diagnostic applications, infectious diseases, prevention of inherited diseases, genetic counseling, prenatal sex determination by DNA probes, cell gene therapy and finally the ethical issues.

Child↗