Usefulness of linkage disequilibrium of KM-19 and XV-2c DNA probes for genetic counselling in a high-risk CF family

A French couple with an individual risk of carrying the cystic fibrosis (CF) mutation of 1/2 sought genetic counselling. From the DNA haplotypes generated by XV-2c and KM-19 RFLPs, it could be deduced that only one subject was a carrier, lowering the risk of having a CF baby from 1/16 to 1/200. The strong linkage disequilibrium between these RFLPs and the CF allele observed in France reduced the risk to 1/1600.     

Metaphyseal anadysplasia in two sisters

Metaphyseal anadysplasia is a rare form of metaphyseal chondrodysplasia with well-defined radiological abnormalities. The prognosis is good as the natural course results in regression of the lesions with normal stature in adulthood. The few reported cases, exclusively in male children, indicated possible X-linked recessive transmission. The documentation of two affected sisters suggests genetic heterogeneity or another mode of inheritance. Received: 6 April 1998 Accepted: 30 December 1998     

The increase in bladder carcinoma cell population induced by the free beta subunit of human chorionic gonadotrophin is a result of an anti-apoptosis effect and not cell proliferation

Ectopic production of free beta human chorionic gonadotrophin (hCGbeta) by bladder carcinoma is well described and occurs in approximately 35% of cases. hCGbeta secreting tumours are more aggressive, radioresistant and have a greater propensity to metastasize. We proposed that the ectopic production of hCGbeta was contributing in an autocrine fashion to the radioresistance and metastatic potential of such secreting tumours. Though we demonstrated that the addition of hCGbeta to the culture media of bladder, cervical and endometrial carcinoma cell lines brought about an increase in cell populations this was not accompanied by a significant increase in the rate of replication. Since a cell population size is a balance of mitosis and mortality, we proposed that hCGbeta was inhibiting apoptosis. Here we have demonstrated that following incubation with recombinant hCGbeta, bladder carcinoma cells refrain from undergoing apoptosis. Quantitation of apoptotic bodies was carried out by immunoassay and corrected to cell number as determined by MTT assay. In each cell line, addition of hCGbeta reduced the number of apoptotic bodies dose-dependently, indicating a diminished apoptotic rate. Furthermore, TGFbeta1-induced apoptosis could be dose-dependently inhibited by co-incubation with hCGbeta. We propose, therefore, that such a decline in apoptosis may account for the cell population increase previously reported. It may also explain the radioresistance and aggressive nature of hCGbeta-secreting tumours and the poor prognosis associated therein.     

Recurrence of pulmonary embolism during anticoagulant treatment: a prospective study.

The risk of early recurrence of pulmonary embolism in patients with venous thromboembolic disease treated by anticoagulants is not well established. To determine the risk linked to contemporary proximal deep venous thrombosis, a prospective study was organised to give clinical and scintigraphic surveillance to 50 patients with angiographically proved pulmonary embolism plus phlebographically proved proximal deep vein thrombosis during the first 15 days of anticoagulant treatment. Perfusion lung scans were performed initially and on days 3, 7, and 15. Only two patients had a recurrence of pulmonary embolism during this period; both episodes were revealed by new symptoms, and one recurrence was fatal. The systematic performance of angiography in four patients found to have new scintigraphic defects led to the diagnosis of "spurious scintigraphic recurrence" in three of them. It is concluded that (a) adjusted anticoagulant treatment showed an effectiveness of 96% for preventing early recurrence of pulmonary embolism in this group of supposed high risk patients, and (b) in patients with recent pulmonary embolism new defects on systematic perfusion lung scans are not specific indicators of recurrent pulmonary embolism.     

Chemotherapy and delivery in the treatment of primary brain tumors

Malignant astrocytomas are aggressive neoplasms with a dismal prognosis despite optimal treatment. Maximal resective surgery is traditionally complemented by radiation therapy. Chemotherapy is typically used on patients with tumor recurrence, when their functional status is congruent with further treatment. The classic agents used are nitrosoureas, but temozolomide is gradually taking a more prominent role recently. New agents, biological modifiers, are increasingly used in clinical trials in an effort to affect the intrinsic biologic aberrations harboured by tumor cells. These drugs comprise differentiation agents, anti-angiogenic agents, matrix-metalloproteinase inhibitors and signal transduction inhibitors, among others. The issue of chemotherapy delivery is also crucial. Classically, agents are administered either intravenously or orally. In an effort to circumvent the obstacle imposed by the blood-brain barrier, investigators are actively working on more invasive methods of delivery, namely intra-arterial infusion with or without blood-brain barrier disruption or direct intra-cerebral administration, with clysis or drug-impregnated wafers. This article reviews the standard cytotoxic agents that have been used to treat malignant astrocytomas, and the different combination regimen offering promise. In addition, recent advances with biological modifiers are also discussed, along with alternate methods to deliver the agents more efficiently across the blood-brain barrier.