Platelet antigen HPA-5b (Bra) in an Algerian population.
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Adult↗
Biomedical subjects
P Mercier
Publications and source records attributed to P Mercier.
Neonatal thrombocytopenia in HLA-DR, -DQ, -DP-typed mother due to rare anti-HPA-1b (PLA2) (Zwb) fetomaternal immunization.
A new case of rare neonatal alloimmune thrombocytopenia, due to an IgG anti-HPA-1b in a mother HPA-1 (a+, b-), was diagnosed using monoclonal antibody-specific immobilization of platelet antigens. Clinically, it was similar to the 2 previously reported observations and confirmed that, in this particular case of anti-HPA-1b, the treatment with random platelet pools may be as effective as selected single-donor platelet units when maternal platelets are unusable. The HLA-DR, -DQ, -DP genotypes of the family were obtained by PCR-SSO. The mother's typing, compared to the HLA-DR of the 6 similar cases reported in Europe, suggests that a combined effect of two rare HLA haplotypes might enhance this immunization.
Adult↗
Growth of neural crest cells in vitro is enhanced by extracts from Silky Fowl embryonic tissues.
In the Silky Fowl (SF) breed of chicken, most of the internal organs are infiltrated with melanocytes. Previous studies have shown that this generalized mesodermal pigmentation is not due to a cell autonomous abnormality of the melanocytes but to environmental factors able to promote both the homing of pigment cell precursors in abnormal embryonic sites and their proliferation and differentiation. To analyse the mode of these environmental cues, we tested the effect of SF embryo extract (SFEE) on cultured quail neural crest cells as compared with that of EE from normal chickens of the JA57 strain (JA57EE). We found that SFEE enhances crest cell proliferation as judged by 3H-TdR incorporation and cell counting. In contrast, no effect of SFEE was observed either on the proportion of cultured cells that are engaged into the melanocytic differentiation pathway or on the amount of melanin produced by each differentiated pigment cell. The simple observation, however, reveals that SFEE has a significant effect on pigmentation of the cultured quail neural crest cells. This effect has therefore to be accounted for by the general increase in cell number induced by SFEE. The question is raised as to whether the in vivo SF phenotype is generated exclusively by this mechanism.
Animals↗
Drug targeting into the central nervous system by stereotactic implantation of biodegradable microspheres.
Controlled drug release in the central nervous system through an implantable polymeric vector has been developed in recent years. For this purpose, different polymeric devices composed primarily of synthetic biocompatible and biodegradable polymers have been investigated. The first polymeric devices developed were macroscopic implants (monolithic devices), which required open surgery for implantation. Microencapsulation methods, however, allow the production of microparticles or nanoparticles loaded with neuroactive drugs. Because of their size, these micro- or nanoparticles may be easily implanted by stereotaxy in discrete, precise, and functional areas of the brain without causing damage to the surrounding tissue. Presently, this method is most frequently applied in the fields of neuro-oncology and neurodegenerative diseases, but neurologically, the potential applications of drug targeting by stereotactic implantation of drug-loaded particles are legion.
Biodegradation, Environmental↗
[Epidural hematoma. Myth and reality, based on 3 exemplary cases].
The acute epidural hematoma is a real surgical emergency with a good outcome if the operation is performed in reasonable delays. In 1994, too many young patients eventually died or were left with major disabilities, because of an unacceptable and almost always avoidable loss of time. We do emphasize some rules which have to be followed to avoid catastrophic events.
Accidents, Traffic↗
[Malignant astrocytoma of the cerebellum. Apropos of 10 cases. Review of the literature].
While reviewing a series of 138 cerebellar tumors operated upon between 1978 and 1991, the authors could only find 2 glioblastomas and 8 anaplastic astrocytomas, occurring in 4 children (3 to 14 years old) and 6 adults (23 to 48 years old). These 10 cases represent 2% of the all malignant gliomas population observed during the same period of time. Clinically speaking, nothing makes these tumors different from other cerebellar ones. However, with an heterogenous image and an irregular contrast enhancement, the CT (scan) appearance can lead to the diagnosis. 7 lesions develop within the cerebellar vermis (vermis cerebelli) and 3 develop within the cerebellar hemisphere. Total surgical resection is performed in 9 cases and subtotal resection in 1 case (because of the extension to the floor of the fourth ventricle). Adjunctive radiotherapy on their posterior cranial fossa is achieved in 8 cases. The 2 patients with a glioblastoma present with a recurrence of their tumor at 15 months and 6 years respectively, and eventually died. Out of the patients with an anaplastic astrocytoma, 4 are still alive without recurrence and with a median follow-up of 7 years. The pathogenesis of such lesions is discussed. An aggressive therapeutic management is suggested because of the possible prolonged survival rate.
Adolescent↗
Are the calcium antagonists really useful in cerebral aneurysmal surgery? A retrospective study.
From 1983 to 1990, 234 patients with one or several cerebral arterial aneurysms were surgically treated in our department. Since 1983, we have been performing surgery as early as possible. As soon as the subarachnoid hemorrhage diagnosis is confirmed by computed tomography (or if unconfirmed, by lumbar puncture), we assume that each patient may have an aneurysm. Between 1987 and 1990, 111 patients were treated by vascular volume expansion (maintenance of central venous pressure above 5 cm H2O with 4% albumin or Ringer-lactate or, if necessary, with 20% albumin), which we supplemented with calcium antagonists (nimodipine in 60 patients and nicardipine in 51 patients). Two months after being discharged, each patient is examined by a neurosurgeon and, on the same day, is subjected to a neuropsychological evaluation and a computed tomographic scan of the brain. A few months after this consultation, a working-position/family-activities questionnaire is issued to the patient. All of the results studied on the basis of postoperative mortality, second-month computed tomographic scan ischemia, neuropsychological evaluation, and return to work show no significant difference between the groups with or without calcium antagonists or between the nimodipine and nicardipine subgroups.
Activities of Daily Living↗
Novel markers of melanocyte differentiation in the avian embryo.
In order to produce markers of melanoblasts and melanocytes, we immunized a mouse with trunk neural crest cells differentiated into melanocytes in culture. We obtained three monoclonal antibodies which react both with pigmented and unpigmented cells in epidermis and in neural crest cultures. These markers are characteristic of distinct differentiation steps. One of them, melanoblast/cyte early marker (MelEM) monoclonal antibody (Mab) detects melanoblasts as soon as they have reached the subectodermal mesenchyme, while the two others, Mel1 and Mel2 Mabs, detect antigens present in melanosomes and promelanosomes later in the differentiation process. Moreover, MelEM is a specific marker of melanoblasts/cytes deriving exclusively from neural crest and not of those from the neural retina. The antigen recognized by MelEM Mab is a protein of M(r) 26,000. The epitopes recognized by Mel1 and Mel2 Mabs are carbohydrate moieties carried by glycoproteins of M(r) 123,000 and 85,000, respectively.
Animals↗
Invasive character of an intradural spinal meningioma in early childhood.
The authors report the case of a 2-year-old baby girl with an intradural meningotheliomatous meningioma of the cauda equina which recurred three times. Despite four operative procedures and localized radiotherapy, the lesion kept on growing to reach the retroperitoneal space. Extensive laminectomy and associated radiotherapy were probably responsible for a spinal dislocation which had to be operated on. The child was left paraplegic with major bladder dysfunction after all procedures. This is the first reported case of well-documented "malignant" evolution of a spinal meningioma.
Female↗
Autoimmune polyendocrine failure--type 1 (insulin-dependent) diabetes mellitus and hypothyroidism--after allogeneic bone marrow transplantation in a patient with lymphoblastic leukaemia.
In this report we describe a patient who, after allogeneic bone marrow transplantation from her HLA-identical sister, developed polyendocrine failure in the form of Type 1 (insulin-dependent) diabetes mellitus and hypothyroidism. This was the result of the transfer of donor lymphoid cells which were activated by allogeneic bone marrow transplantation. The full chimerism of the recipient was demonstrated by restriction fragment length polymorphism analysis from nucleated blood cells and fibroblast DNA. During the 9-year follow-up, the donor developed hypothyroidism and signs of pre-Type 1 diabetes. This clinical observation resembles the adoptive transfer of diabetes observed in non-obese-diabetic mice and BB rats and confirms the role of immune processes in the pathogenesis of this disease.
Adolescent↗
[A rare etiology of spinal cord compression: Gaucher disease].
Gaucher's disease is a sphingolipidosis transmitted as an autosomal trait. Bone lesions are frequent in type 1 of the disease (i.e. the adult type without neurological manifestation). We report the case of a 70-year old woman suffering from spinal lesions with vertebral collapse and spinal cord compression. Our diagnosis was based on the finding in bone samples of Gaucher cells looking like large macrophages, and on the enzymatic assay of glucocerebrosidase. New treatments, such as replacement of the deficient enzyme by placental glucocerebrosidase, are currently being evaluated.
Aged↗
[HLA-DRB1 and HLA-DQB1 polymorphism in Algerians from Algiers].
The polymorphism of HLA-DRB1 and HLA-DQB1 genes in 100 unrelated Algerians from Alger was investigated using PCR amplification and oligonucleotide typing. Compared to western Europeans, this population shows a higher haplotypic frequency of HLA DRB1*03-DQB1*0201 (21.5%) and a lower haplotypic frequency of DRB1*0101-DQB1*0501 (2%). Two unexpected haplotypes are observed: DRB1*07-DQB1*0301 and DRB1*0406-DQB1*0402. DRB1*0402 is the most common subtype in the DRB1*04 group. Furthermore, we detected a rare DQB1*0305 allele, only found in a Sardinian subject until today.
Algeria↗
Acute insulin response to glucose and glucagon in subjects at risk of developing type I diabetes.
OBJECTIVE: To determine if knowledge of characteristics of insulin response to various secretagogues during the preclinical phase of type I diabetes may facilitate the diagnosis of subjects at risk. RESEARCH DESIGN AND METHODS: A test consisting of sequential intravenous challenge with glucose (0.3 g/kg) and glucagon (1 mg, 10 min after the end of glucose injection) was performed on 171 ICA- relatives of type I diabetic patients, 18 ICA+ relatives of type I diabetic patients, and 5 transiently hyperglycemic subjects. Acute response to glucose was expressed as the sum of plasma insulin at 2 and 5 min and response to glucagon as the increase in plasma insulin after 10 min. RESULTS: Responses below the lower 95% confidence interval in the ICA- population (40 and 43 microU/ml for glucose and glucagon, respectively) were considered abnormal. The two values were correlated (r = 0.62). Abnormalities coexisted in 2.3% of the ICA- group, 11% of the ICA+ group, and 100% of the transiently hyperglycemic group. All the relatives who subsequently developed diabetes or hyperglycemic subjects who required insulin exhibited combined abnormalities. Some ICA- and ICA+ relatives were tested repeatedly over a follow-up period of 1.5-4 yr. Although the intraindividual coefficient of variation for the two responses was high (28 and 30%), values tended to run parallel in both ICA+ and ICA- relatives. In 2 patients monitored for 2 and 4 yr before diabetes developed, both responses declined at the same rate. In terms of prediction of diabetes, sensitivity of combined abnormalities was high (100%). But compared with the intravenous glucose tolerance test, improvement of specificity by the double challenge was not statistically significant. CONCLUSIONS: Both insulin responses to glucose and glucagon are related. They depend on the secretory capacity of beta-cells and simultaneously become abnormal in the prediabetic phase.
Adolescent↗
Anomalies of the A1 segment.
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Cerebral Arteries↗
[Macroscopic vascularization of the adult sternum. Implications of removal of the internal thoracic arteries].
The most of the arterial vascularisation of the adult sternum is on the dependence of the internal thoracic arteries. The best results of the aorto-coronary by-pass starting from this arteries are however subjected to more infectious complications. The study of this arterial supply, in "surgical" conditions, after sternotomy and ablation of one or two internal thoracic arteries show this devascularization. The residual arterial supply is only constituted by thin branches coming from intercostal arteries.
Adult↗
[Metastases in the cauda equina in visceral cancers. Apropos of 2 cases].
Two new cases of cauda equina metastases from visceral cancers are reported. This diagnosis is only infrequently considered in patients with intra-dural lesions visualized by magnetic resonance imaging or saccoradiculography. The diagnosis is especially difficult in patients with no known primary cancer. Diagnosis rests on surgery during which only a biopsy is performed. Treatment is symptomatic and focuses on relieving pain. Prognosis is bleak.
Adenocarcinoma↗
[Arterial vascularization of the colon. The middle mesenteric artery].
In its modal disposition, the arterial vascularisation of the colon is on the dependence of the superior and inferior mesenteric arteries anastomosed by the way of "arcade de Riolan". Some more exceptional schemes can complicate this distribution: arteria colica media, medium mesenteric artery, intermesenteric arcus. This rare arterial dispositions can have a big practical importance, in the case of colic transposition, and more recently in the case of the utilization of the right gastroepiploic artery for coronary by-pass.
Arteries↗
[Osteosarcoma of the sacrum. Apropos of a case in a 14 year-old girl].
The authors report a case of sacral osteosarcoma, which is a rare and dreaded tumor. Sciatica was the first manifestation. Patients with refractory sciatica and normal plain films and computed tomography studies of the lumbar spine should undergo magnetic resonance imaging to look for a sacral lesion.
Adolescent↗