Chromosome 13 poly(ADP-ribose) polymerase polymorphisms and lung cancer risk

A 193 base pair repeat polymorphism in the human poly(ADP-ribose) polymerase (PADPRP) pseudogene found on chromosome 13 has been associated with lung cancer, endemic Burkitt lymphoma, B-cell lymphoma, breast cancer and colorectal carcinoma. We investigated the frequency of the PADPRP genetic polymorphism in a hospital-based case-control study of lung cancer for 54 cases and 47 controls. There was a statistically significant difference in allelic frequency between Caucasians and African Americans (p<0.001). For African Americans, the odds ratio for lung cancer and the 'B' allele was 2.38 (95% C.I.=0.73, 7.69) and for Caucasians 0.44 (95% C.I.=0.11, 1.77). The results for the African Americans, however, were not in Hardy-Weinberg equilibrium, although the Caucasians were. Thus, this study, albeit small, does not find that the PADPRP pseudogene duplicated region located on chromosome 13 is a risk factor for lung cancer.     

Clinical management of retinoblastoma

There have been many recent advances in the diagnosis and management of children with retinoblastoma. Regarding diagnosis, the judicial use of ancillary studies, particularly B-scan ultrasonography, has been instrumental in supplementing the diagnosis when opaque media preclude a clear view of the underlying neoplasm. Computed tomography and magnetic resonance imaging are important in the early detection of associated pinealoblastoma, which occurs as part of the recently described syndrome of "trilateral retinoblastoma." With regard to management, the technique of enucleation continues to improve and the scleralized hydroxyapatite implant is now available to provide a better cosmetic appearance and better motility of the artificial eye. Methods have been described for harvesting fresh tumor tissue immediately after enucleation for special DNA studies. Recent reports have documented a decreasing frequency of enucleation and an increasing tendency to use eye-preserving methods of management. Plaque radiotherapy, which provides more localized irradiation to the specific tumor, is gradually supplanting external beam irradiation for localized retinoblastoma that does not exhibit extensive vitreous seeding. The indications and contraindications for cryotherapy and photocoagulation have been more clearly delineated. The role of chemotherapy is being evaluated in the treatment of primary retinoblastoma and for metastatic disease. New breakthroughs in genetic research are being applied to clinical genetic counseling. The prognosis for life and for preservation of vision has improved greatly in recent years.     

Pathophysiological role of calpain in experimental demyelination

Calcium-activated neutral proteinase (calpain) has been extensively studied over the past three decades such that many enzymatic and structural properties of this enzyme are well understood. However, the pathophysiological roles of calpain remain poorly defined. In addition to recent studies delineating a role for calpain in various pathological conditions, this proteinase has been implicated in the degradation of myelin proteins in autoimmune demyelinating diseases such as multiple sclerosis and experimental allergic encephalomyelitis (EAE). In EAE, calpain translational expression is significantly increased in activated glial/inflammatory cells that participate in myelinolysis while calpain substrates (axonal and myelin proteins) are lost. Thus, since all major myelin proteins are calpain substrates, early studies suggest calpain may play an important role in demyelination of the central nervous system.     

Infantile spasms: the development of nonverbal communication after epilepsy surgery

The postoperative development of nonverbal communication was studied in 29 children, aged 18.2 (SD = 11.54) months, who underwent multilobar resection or hemispherectomy for intractable symptomatic infantile spasms (IS). Using the Early Social Communication Scale, the IS subjects had little, if any, social interaction, joint attention or behavior regulation before surgery. After a mean follow-up of 24 months, most of the children continued to have delayed nonverbal communication skills compared to normal children. Seizure-related, surgical and cognitive factors were unrelated to the postsurgical development of nonverbal communication. The children with right-sided surgery had a statistically significant increase in the use of social interaction but not in other gestural behaviors. Removal of the frontal lobe was not related to the nonverbal communication outcome. The study's findings suggest that impaired use of nonverbal communication might be a feature of surgically treated children with medically intractable IS. Copyright Copyright 1999 S. Karger AG, Basel     

Long-term outcome and cost-effectiveness of parenteral nutrition for acute gastrointestinal failure

Although there are several published audits of long-term home parenteral nutrition for chronic gastrointestinal failure, there is little data concerning the long-term outcome following prolonged in-patient parenteral nutrition for an episode of acute gastrointestinal failure. Between 1983 and 1 July 1993, 162 patients received total parenteral nutrition (TPN) in our unit for acute gastrointestinal failure for a total of 4997 patient days and using 192 central venous catheters. Over the 10 years there were 11 mechanical complications resulting in one death. Although the overall catheter infection rate was 5.7%, in the last 4 years it was 0%, associated with a reduction in the frequency of site dressing and change of giving set from three times to once weekly. All patients had lost more than 10% of their body weight before TPN. In the non-malignant group, fed for more than 21 days (mean 50 days), the 10-year survival was 74% at a cost of 4723 pounds sterling per year of life saved. In the malignant group, the 5-year survival was 27% at a cost of 8351 pounds sterling per year of life saved. These costs compare favourably with other technologies, such as dialysis for acute renal failure. Better patient selection, fewer complications and lower costs are obtained when this treatment is carried out by an expert team.     

Circumscribed choroidal hemangiomas: long-term visual prognosis

Twenty-one patients with a circumscribed choroidal hemangioma in one eye were followed for various intervals ranging from three years to over nine years after diagnosis. Eighteen of the 21 were treated with xenon arc and/or argon laser photocoagulation to the hemangioma in an attempt to reduce or eliminate a secondary retinal detachment at some point during the follow-up period. Only four of the 21 had visual acuity of 6/12 or better in the involved eye at the time of the most recent follow-up, and 15 of the 21 had visual acuity of 6/60 or worse. Persistent nonrhegmatogenous retinal detachment involving the fovea and degenerative changes in the macular retina secondary to prior retinal detachment accounted for most of the visual impairment in these 21 eyes.     

Bilateral progressive essential iris atrophy and keratoconus with coincident features of posterior polymorphous dystrophy: a case report and proposed pathogenesis.

We report the first case known to us of an apparent bilateral association of essential iris atrophy (EIA) and keratoconus (KC), with coincident features of posterior polymorphous dystrophy (PPD). Based on this case and the published natural history and findings of both the irido corneal endothelial (ICE) syndrome and PPD, we propose a new hypothesis for the pathogenesis of the ICE syndrome with associated KC and/or PPD. We suggest that, similar to the genetics of retinoblastoma, the predisposition for either the ICE syndrome or for PPD is inherited as an inactive allele, the so-called "first hit." Inactivation of the second allele, or "second hit," which could occur at any time, might be the product of the background mutation rate or of an environmental trigger. Dedifferentiation or an abnormality in normal development could occur after the first or second hit, resulting in varying clinical patterns. We also concur with other investigators that PPD could be part of the spectrum of the ICE syndrome, owing to similarities in their clinical presentations, histopathology, specular and electron microscopy, and natural history.