The role of flow cytometric immunophenotyping in improving the diagnostic accuracy in referred fine-needle aspiration specimens

Flow cytometric (FCM) immunophenotyping has an important role in the diagnostic work up of fine-needle aspiration (FNA) specimens obtained from lymphoid lesions. The objective of the present study was to evaluate the feasibility of this method with respect to referred FNA specimens. One hundred and two FNA specimens referred to our laboratory for FCM analysis during the last 3 years were studied. Specimens were sent, accompanied by cytological smears, from 11 distant hospitals by ordinary mail. The evaluation of potential B-cell monoclonality, the main diagnostic issue to be resolved using FCM, was possible in 86 of these 102 cases. The remaining 16 samples could not be analyzed or adequately interpreted because of sparse or necrotic material. A monoclonal B-cell population was found in 17/86 satisfactory cases, of which 16 were histologically confirmed. Eight cases contained cells positive for the epithelial marker Ber-EP4 and were diagnosed accordingly as carcinomas. FCM analysis of specimens obtained with a clinical question of Hodgkin lymphoma or T-cell lymphomas did not yield definitive data. The time lapse between sampling and analysis (12-84 hr) did not affect the results. This probably was due to the fact that all aspirates were taken in Roswell Park Memorial Institute (RPMI) cell medium, supplemented with 50% fetal calf serum. In conclusion, this retrospective study establishes that it is possible, in the majority of cases, to refer FNA material for FCM immunophenotyping by mail, and that results regarding B-cell clonality in the case of small-cell lymphomas are reliable also after a transportation period of 3-4 days. Carcinoma may be similarly diagnosed and a diagnosis of lymphoma may be excluded in reactive proliferations. Cases with only a few atypical cells or specimens from patients suspected of having Hodgkin lymphoma or T-cell lymphomas are not suitable for analysis by FCM.     

Maximal COX-2 and ppRb expression in neurons occurs during early Braak stages prior to the maximal activation of astrocytes and microglia in Alzheimer's disease

Neuronal expression of cyclooxygenase-2 (COX-2) and cell cycle proteins is suggested to contribute to neurodegeneration during Alzheimer's disease (AD). The stimulus that induces COX-2 and cell cycle protein expression in AD is still elusive. Activated glia cells are shown to secrete substances that can induce expression of COX-2 and cell cycle proteins in vitro. Using post mortem brain tissue we have investigated whether activation of microglia and astrocytes in AD brain can be correlated with the expression of COX-2 and phosphorylated retinoblastoma protein (ppRb). The highest levels of neuronal COX-2 and ppRb immunoreactivity are observed in the first stages of AD pathology (Braak 0–II, Braak A). No significant difference in COX-2 or ppRb neuronal immunoreactivity is observed between Braak stage 0 and later Braak stages for neurofibrillary changes or amyloid plaques. The mean number of COX-2 or ppRb immunoreactive neurons is significantly decreased in Braak stage C compared to Braak stage A for amyloid deposits. Immunoreactivity for glial markers KP1, CR3/43 and GFAP appears in the later Braak stages and is significantly increased in Braak stage V-VI compared to Braak stage 0 for neurofibrillary changes. In addition, a significant negative correlation is observed between the presence of KP1, CR3/43 and GFAP immunoreactivity and the presence of neuronal immunoreactivity for COX-2 and ppRb. These data show that maximal COX-2 and ppRb immunoreactivity in neurons occurs during early Braak stages prior to the maximal activation of astrocytes and microglia. In contrast to in vitro studies, post mortem data do not support a causal relation between the activation of microglia and astrocytes and the expression of neuronal COX-2 and ppRb in the pathological cascade of AD.     

Anatomical study of five prenataly diagnosed sternopagus twins

Summary Among conjoined twins (1 out 50000 births), thoracopagus occurs most frequently and is generally lethal. Our anatomical study of five sets of sternopagus twins (3 female, 2 male) was performed to determine the ability of prenatal sonography to detect these anomalies. Autopsy in four cases revealed identical malformations: common sternum, single malformed heart, joined hepatic parenchyma, and a common small bowel leading to a cystic dilatation situated on the ileal segment at the end of the superior mesenteric artery. The diagnosis of conjoined twins was made in all cases by prenatal sonography at the mean time of 24.6 gestation weeks (range 19–34). The malformations detected by prenatal sonography were a single cardiac mass (all cases), joined hepatic parenchymas (3 cases), and an ileal cystic dilatation (1 case). Pregnancy was terminated in four cases. In one case cesarean delivery was performed, and the infants died 48 hours later. Prenatal sonography currently seems to be the best examination for diagnosis of sternopagus twins and the detection of lethal malformations thus allowing interruption of pregnancy.

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Etude anatomique de cinq jumeaux conjoints sternopages de diagnostic anté-natal

Résumé Les jumeaux conjoints représentent 1 pour 50000 naissances, les thoracopages sont les plus fréquents et présentent le plus souvent des malformations léthales. Une étude anatomique des malformations rencontrées chez les jumeaux conjoints sternopages a été effectuée dans le but d'évaluer l'intérêt de l'échographie anté-natale pour le diagnostic de ces malformations. Nous avons étudié anatomiquement cinq jumeaux conjoints (3 féminins, 2 masculins). Un examen nécropsique a été réalisé quatre fois, montrant dans tous les cas les mêmes malformations: sternum commun, coeur unique malformatif, union des parenchymes hépatiques, grèle commun aboutissant à une poche kystique située sur le segment iléal de l'intestin grèle, à la terminaison de l'artère mésentérique supérieure. Le diagnostic de jumeaux conjoints avait dans tous les cas été porté en anté-natal par les échographies, à un terme moyen de 26,6 semaines d'aménorrhée (extrèmes 21–26). Les malformations retrouvées par les échographies étaient: dans tous les cas une masse cardiaque unique, trois fois une union des parenchymes hépatiques, une fois une poche kystique du grèle. Le diagnostic avait conduit quatre fois à une interruption médicale précoce de la grossesse. Dans un cas une césarienne avait été pratiquée, les enfants étaient morts 48 heures après. L'échographie anté-natale nous semble actuellement le meilleur examen pour faire le diagnostic de jumeaux conjoints et rechercher des malformations léthales conduisant à une interruption de la grossesse.

     

RPGRIP1: a novel ciliary gene involved in cerebellar disorders

The ciliary gene RPGRIP1L is mutated in cerebello-oculo-renal syndrome (Joubert syndrome type B) and Meckel syndrome
Delous et al. (2007)
Nature Genetics 39: 875–881
Mutations in the gene encoding the basal body protein RPGRIP1L, a nephrocystin interactor, cause Joubert syndrome
Arts et al. (2007)
Nature Genetics 39: 882–888     

Familial hypouricaemia associated with renal tubular uricosuria and uric acid calculi: case report

We describe a patient with the rare combination of uric acid calculi, familial hypouricaemia, and increased renal urate clearance.     

Preimplantation genetic diagnosis of spinal muscular atrophy

After Duchenne muscular dystrophy, spinal muscular atrophy (SMA) is the most common severe neuromuscular disease in childhood. Since 1995, homozygous deletions in exon 7 of the survival motor neuron (SMN) gene have been described in >90-95% of SMA patients. However, the presence of a highly homologous SMN copy gene complicates the detection of exon 7 deletions. This paper describes the adjustment and evaluation of an established SMN exon 7 polymerase chain reaction (PCR) protocol at the single cell level, and the first preimplantation genetic diagnosis (PGD) of SMA with this PCR protocol. To determine PCR efficiency and allelic loss, 200 leukocytes of normal individuals, SMA carriers and patients, and 25 blastomeres were tested. The PCR efficiency of the SMN exon 7 and the adjacent copy gene sequence, tested in the leukocytes, were 90% and 91% respectively. No allelic loss was detected. One out of 25 blastomeres tested revealed a negative PCR signal for the SMN exon 7 sequence. All 25 showed the copy gene sequence. PGD of SMA was offered to a couple with an affected child homozygous for the SMN exon 7 deletion. After intracytoplasmic sperm injection, four and five embryos could be genotyped for the SMN exon 7 in two cycles respectively. After embryo transfer in the second PGD cycle an ongoing gemelli pregnancy was achieved. This study demonstrates that PGD for SMA is feasible when a previous child is homozygous for the SMN exon 7 deletion.