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M Belo

Publications and source records attributed to M Belo.

At least 19 recordsLinked to original sources
PubMed2004

Intravenous r-TPA in vertebrobasilar acute infarcts.

Presented are the clinical data of 18 consecutive patients who were treated by IV recombinant tissue plasminogen activator (r-TPA) for suspected vertebrobasilar (VB) acute ischemia within 7 hours. The mean delay for treatment was 5 +/- 3.6 hours. Mean baseline NIH Stroke Scale score was 17 +/- 4. At 3 months, 10 patients were independent (modified Rankin Scale [mRS] score = 0 to 2), whereas 8 patients showed a poor outcome (mRs = 3 to 6). IV r-TPA in VB ischemia in a 7-hour window may be safe and efficient.

Aged↗
PubMed2004

[Cerebral venous thrombosis presenting as subarachnoid hemorrhage].

Headache of subacute onset, associated with other signs of increased intracranial pressure, represents the most frequent symptom of cerebral thrombophlebitis. We report a case of subarachnoid hemorrhage as a rare presentation of cerebral thrombophlebitis. Unfractionated intravenous heparin treatment resulted in resolution of subarachnoid hemorrhage on control brain CT scan and quick clinical recovery.

Adult↗
PubMed2003

Evidence of hemispheric specialization in marmosets (Callithrix penicillata) using tympanic membrane thermometry.

Recent studies have employed tympanic thermometry to assess lateralization of cognitive and emotional functions in primates. However, no studies using this technique have investigated the possibility of hemispheric specialization in New World monkeys. Therefore, the aim of the present study was to investigate tympanic membrane (TM) temperature asymmetries and their possible correlation with stress responses in marmosets (Callithrix penicillata). Infrared TM thermometry was completed bilaterally in 24 animals (14 males and 10 females) during a stressful situation of capture and restraint. There were no significant differences between gender. A significant negative correlation was observed between TM temperature of the right ear and the number of captures (r = -0.633; P<0.001). Subjects with a more frequent previous history of captures (5 to 9 captures; N = 11) showed lower TM temperature when compared to those with fewer previous captures (1 to 4 captures; N = 13). No differences were observed for the left TM temperature. These results suggest that under intense emotional challenge (capture and restraint) there is a stronger activation of the neural structures situated in the right brain hemisphere. Taken together, the data reveal for the first time evidence of hemispheric specialization in emotional physiological processing in a New World monkey.

Animals↗
PubMed1995

[Cysticercosis in patients with neurologic diseases in hospital milieu in Lomé, Togo].

The aim of this study was to determine the frequency and clinical presentation of cysticercosis in patients consulting in the neurology unit of the Lomé, Togo Teaching Hospital. Among the 2.064 patients examined, 38 had cysticercosis. All 38 were males, age ranged 18 to 50 years. Diagnosis was established on the basis of multiple subcutaneous cysticercosis (n = 33), cerebral cysticercosis scan findings (n = 5), serology (n = 7) and cerebrospinal fluid findings (n = 3) of specific antibodies using the ELISA method. Recurrent epileptic seizures occurred in 33 patients. Three other were in a confusional state, one had headaches and one had hemiplegy. The results of this study contrast with the reported scarcity of cerebral cysticercosis in hospitals in other West African countries.

Adult↗
PubMed1994

A study of peripheral tolerance through embryonic grafts of the bursal epithelial rudiment between MHC-distinct chick embryos.

We report here that different organ grafts are not equally competent to induce tolerance of the host even if they are performed early in development, i.e. before the host's immune system has started to develop. We have grafted the epithelio-mesenchymal rudiment of the bursa of Fabricius between histoincompatible chicken embryos at E5 and found that the transplant is normally colonized by hemopoietic cells from the host and that a normal contingent of B cells is eventually produced. The grafted bursa is tolerated after birth for a few weeks (> or = 4-8) but is in all cases rejected by an immune mechanism which cannot be assimilated to the physiological involution process which occurs at 4-5 months of age. Moreover, even in the first month after birth, when the bursa is still healthy, skin grafts of the same MHC haplotype are promptly rejected. These observations are in contrast with the outcome of allogeneic limb bud grafts which are permanently tolerated after birth although in an unperfect manner. We show in addition that, as was the case in xenogeneic grafts of limb buds and bursas of Fabricius from quail and chick embryos, the allogeneic in situ graft to thymic epithelium of the MHC haplotype of the bursal implant induces tolerance of the bursa. One common point of xenogeneic and allogeneic embryonic grafts of limb bud, bursa and even thymic rudiments is that none of them induced a complete state of tolerance, since proliferation responses were always obtained in vitro in one-way host-donor mixed leucocyte cultures.

Animals↗
PubMed1994

Quantitative and qualitative changes in intestinal immunoglobulin-bearing plasma cells in jejunal mucosa of 52 HIV-infected patients.

1. The purpose of the present study was to evaluate the intestinal secretory immunity of HIV-infected patients. Jejunal biopsies were obtained with a Watson capsule from 52 HIV-infected patients and compared to a control group consisting of 12 healthy subjects, matched for age and sex. IgA- and IgM-containing plasma cells were studied by immunofluorescence by two independent observers who had no knowledge of the history of the slides. 2. The IgA and IgM plasma cell density was significantly decreased in HIV-infected patients when compared to the controls (31/52 for IgA and 42/52 for IgM in the HIV group and normal density in all controls). The depletion of intestinal plasma cells was an early feature of HIV disease and did not correlate with diarrhea, enteropathogens or mucosal atrophy. Although IgA plasma cell depletion has been described in HIV infection, this is the first report of IgM cell density reduction. 3. A peripheral fluorescence pattern was observed in the intestinal cells of HIV-infected patients, contrasting with the normal cytoplasmic fluorescence pattern seen in controls. The cells presenting a rim of peripheral fluorescence in HIV disease might correspond to immature B lymphocytes. 4. The intestinal plasma cell depletion may result in hampered mucosal defense in HIV disease, and is likely to be a direct consequence of T lymphocyte function impairment. 5. The data indicate that the intestinal secretory immune system is altered in AIDS and also in the early stages of HIV disease.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Antibody-dependent cellular cytotoxicity against HIV-1 in sera of immunized chimpanzees.

After immunization of chimpanzees against HIV antigens, antibodies that mediate antibody-dependent cellular cytotoxicity (ADCC) were evaluated and compared with anti-HIV-antibody levels detected by enzyme-linked immunosorbent assay (ELISA) and neutralizing antibody titers. Adult chimpanzees were immunized with different HIV-1 (LAV-BRU) antigen preparations: recombinant vaccinia virus (rVV) expressing gp160, p25 or p27nef; formalin- and beta-propiolactone-inactivated whole virus (inHIV); soluble recombinant gp160 either associated or not associated with other HIV proteins; a 25-mer peptide from the V3 region of gp120 coupled with KLH (V3-KLH). Immunization with the various rVV mixtures induced no or borderline ADCC increase above preimmune serum levels. Stronger and more sustained reactivity was elicited by inHIV. Purified HIV antigens elicited ADCC activity when the chimpanzees were naive; ADCC increased or remained at the same level when the animals had been preimmunized with rVV and/or inHIV. This type of reactivity apparently did not depend on whether gp160 alone or mixed with other proteins was used for immunization. The injection of V3-KLH resulted in only little, if any, recall ADCC response. ELISA antibody titers significantly correlated with ADCC and neutralizing antibody titers, but serum ADCC was independent of neutralizing antibody titers, an indication that the two latter serum activities are mediated by independent antibodies. Therefore, ADCC is elicited in the same manner as other antibody activities by the immunization of chimpanzees with inHIV or with purified recombinant HIV antigen preparations. The results obtained from the three chimpanzees of this series, which were subsequently challenged with infectious virus through the intravenous route, suggest that serum ADCC may be considered for vaccination purposes.

Amino Acid Sequence↗
PubMed1990

[Cysticercosis and neurocysticercosis: epidemiological survey in North Togo].

An epidemiologic survey was carried out by a team of medical doctors working in the Kozah district of North Togo during April 1987. It was designed to evaluate the incidence of epilepsy and cysticercosis, taking a sample population of 5,264 subjects aged over 15 years old. 81.7% of the population feed on pigs which are allowed to roam freely in the vicinity of people's habitations. Cysticercosis (123 cases; incidence 23.3 cases per thousand) was diagnosed when one of the following three tests gave a positive result:--serum sample greater than or equal to 0.400 OD with ELISA test (101 cas),--identification of a cysticercosis cyst on anatomopathological examination of subcutaneous cysts (12 cases),--presence of typical calcification patterns revealed by cranial or muscle X-rays (21 cases in 18 patients). General epilepsy or partial motor fits were entirely clinically diagnosed (88 cases; 16 per thousand of population). Cysticercosis proved to be the cause of 29.5% epileptic sufferers, onset occurring after the age of 50 in 66% of these patients.

Adolescent↗
PubMed1989

Thymic epithelium tolerizes chickens to embryonic graft of quail bursa of Fabricius.

We demonstrated previously that isotopic and isochronic grafts of the quail bursa of Fabricius rudiment performed at 5 days of incubation (E5) into chick embryos resulted in the development of a chimeric bursa whose chick host B lymphocytes and accessory cells differentiated in a foreign, quail epithelial environment. Such animals reject their grafted bursa by the age of 2-3 weeks post-hatching (1,2). Isotopic embryonic grafts of the thymus epitheliomesenchymal anlagen from the quail donor of the bursal rudiment were carried out at E4.5 (before their colonization by hemopoietic precursor cells), following partial or complete host thymectomy. The quail thymic epithelial stroma was accepted and invaded by chick hemopoietic precursor cells that further differentiated into lymphocytes and dendritic cells. Tolerance of the foreign bursa was induced in such thymobursal chimeras. This demonstrates that the thymic epithelium has the capacity to induce tolerance of xenogeneic rudiments when both grafts are implanted at early stages of embryonic development. We also report on the production of two birds in which removal of the chick host thymus was complete thus generating chimeras in which host T and B lymphocytes differentiated in a completely xenogeneic epithelial environment.

Animals↗
PubMed1989

Epidemiological study of neuro-cysticercosis in northern Togo (West Africa).

In april 1987, an epidemiologic study in Northern Togo was carried out in order to evaluate the prevalence of cysticercosis and epilepsy. The survey also aimed to investigate possible connections between these two illnesses. The study encompassed 5264 subjects over 15 years old, selected using random sampling techniques; 125 cases of cysticercosis were diagnosed (2.4% of sample population); 12 by anatomo-pathological examination of cysts 18 (14.4%) based on skull and muscle x-ray calcifications and 104 patients were identified using ELISA tests on 1527 serum samples (optical density greater than or equal to 0.4). Among 88 epileptic patients (prevalence = 16.7 per thousand), 27 also suffered from cysticercosis (38.7% of all epileptic patients, 21.6% of cysticercosis patients and 0.51% of the total population).

Adolescent↗
PubMed1987

A novel method to bursectomize avian embryos and obtain quail----chick bursal chimeras. II. Immune response of bursectomized chicks and chimeras and post-natal rejection of the grafted quail bursas.

Two methods to bursectomize chick embryos before hemopoietic cell seeding of the bursa of Fabricius were compared in this work: section of the tail region at E3 including the presumptive bursal territory, and selective removal of the bursa at E5. Hatching ability is better with the former method, but survival rate and effectiveness of bursectomy are favored with the second, novel technique. Moreover, selective removal of the bursa at E5 can be followed by in situ engraftment of a quail bursa and construction of quail-chick bursal chimeras. The immune response of bursaless birds and bursal chimeras has been studied. Total absence of the bursa does not prevent a few B cells from differentiating and nonspecific Ig (IgM and/or IgG) from being secreted. As reported previously, bursaless birds, however, are unable to mount an immune response by producing specific antibodies. This immune function is restored by the graft of a quail bursa. The microenvironment of the bursa, although heterospecific, allows the expansion of the B cell population and generates the repertoire of the B cell antigen receptors. This process takes place during late embryonic and early postnatal life because the grafted quail bursal stroma is subjected to immune rejection from 2 to 3 wk after birth in all chimeras, which are, however, perfectly immunocompetent.

Age Factors↗
PubMed1985

A novel method to bursectomize avian embryos and obtain quail----chick bursal chimeras. I. Immunocytochemical analysis of such chimeras by using species-specific monoclonal antibodies.

Chick embryos were bursectomized at 5 days of incubation according to a novel surgical technique described in this article. This method yields birds that are able to hatch and are devoid of the physiologic deficiencies resulting from the previously used method, which involved resection of the cloacal and posterior embryonic region. The bursectomized embryos were grafted in situ with a quail bursa of the same age, which thereafter became chimeric through chick host hemopoietic cell invasion. By means of species-specific antibodies, the chimeric condition revealed 1) that the bursal epithelium expresses a unique antigenic determinant (MB1 determinant), until now considered to be an exclusive feature of blood vessel endothelium and hemopoietic cells, and 2) that this determinant appears in bursal epithelium at the time and site of hemopoietic cell invasion. The other point arising from this work concerns the apparent constitutive Ia expression by perifollicular blood capillary endothelial cells in normal and chimeric bursas.

Animals↗
PubMed1975

Origin of hemopoietic stem cells in embryonic bursa of Fabricius and bone marrow studied through interspecific chimeras.

The histogenesis of the bursa of Fabricius and of bone marrow was studied by a biological cell marking technique based on differences in the nuclear structure of two species of birds, Japanese quail (Coturnix coturnix japonica) and chick (Gallus gallus). In quail cells the nucleus contains a large amount of heterochromatin associated with the nucleolus. That makes it possible to distinguish them from chick cells after Feulgen-Rossenbeck staining and by electron microscopy. By grafting bursal rudiments and limb buds of quail into chick and inversely it was possible to demonstrate that the whole hemopoietic population of the bursa of Fabricius and of bone marrow is derived from bloodborne extrinsic stem cells. Neither endoderm nor mesoderm of the bursal rudiments is capable of differentiating into lymphoid cells. Combinations of quail bursal endoderm with chick homologous mesenchyme showed that the reticular cells of the follicles are the only endodermal derivatives of the bursa. The mesenchymal bursal component gives rise to the interfollicular connective cells. The contribution to bone marrow histogenesis of cells of vascular and blood origin, on one hand, and of the elements of the cartilaginous model, on the other hand, was analyzed. It appeared that osteoblasts, osteocytes, and stromal cells of marrow are derived from the perichondrium. In contrast, the endothelium of the vascular buds and the hemopoietic cells which invade the diaphysal cartilage during the endochondral ossification process do not belong to the mesenchymal bone primordium but have a fully extrinsic origin.

Animals↗