Autosomal dominant retinitis pigmentosa (adRP): exclusion of a gene from three mapped loci provides evidence for the existence of a fourth locus.

Retinitis Pigmentosa (RP) is a group of inherited retinopathies which affect approximately 1 in 4,000 individuals. The disorder can be classified on the basis of inheritance; dominant, recessive and X-linked forms have been well documented. The existence of genetic heterogeneity within autosomal dominant RP (adRP) had been previously demonstrated. As a result of extensive linkage studies in 2 large Irish families and 1 American pedigree three adRP genes have been mapped. adRP genes have been localised to chromosome 3q close to the rod photoreceptor gene, rhodopsin; to chromosome 6p close to another transmembrane photoreceptor gene, peripherin/RDS and to the pericentric region of chromosome 8, although the causative gene in this region has not yet been identified. Here we report the results of a linkage study in a Spanish family, who exhibit an early-onset form of adRP. The adRP gene segregating in this family has been excluded from the three known adRP loci on chromosomes 3q, 6p and 8 using a series of both intragenic microsatellite markers from the rhodopsin and peripherin/RDS genes and markers flanking the three known loci. These results provide definitive evidence for the existence of a fourth adRP locus, further emphasising the genetic heterogeneity that exists within adRP.     

HPLC purification of the main allergen of Parietaria judaica pollen

A two-step purification procedure of Par j I from the whole Parietaria judaica pollen extract is described. The first step consisted of gel filtration HPLC using a TSKG 3000 SW column, and 0.1% trifluoroacetic acid as the eluant. By this method, proteins were separated from the highly colored material present in the extract. Then, Par j I-containing fractions were chromatographed on a reversed-phase HPLC column (Vydac C4) using an acetonitrile gradient. This second step yielded pure Par j I as assessed by SDS-PAGE and CIE. Previously reported microheterogeneity was still observed, but amino acid analysis of various RP-HPLC fractions suggested that the heterogeneity of Par j I might not be due to changes in its primary structure. Allergenic activity of Par j I was shown to be retained after the purification procedure by several immunochemical techniques.     

Predicting difficult orotracheal intubation in pharyngo-laryngeal disease: preliminary results of a composite index

PURPOSE: Prediction of difficulty in orotracheal intubation (DI) in patients undergoing laryngeal microsurgery should help reduce the morbidity-mortality associated with this clinical situation. To establish a simple score to predict this difficulty, we studied 11 variables and their association with DI in these patients. METHODS: The study included 181 patients. The variables evaluated were: Mallampati grade, thyromental distance, mouth opening, temporomandibular joint movement, tooth morphology, maxillary deficiency, head and neck movement, receding mandible, body mass index, and clinical symptoms of laryngeal and supraglottic disease. To establish the score, regression coefficients of the statistically significant variables were used on adjusted logistic regression analysis. RESULTS: DI was present in 50 patients (28%) and orotracheal intubation was impossible in four (2%). Except for obesity, all the variables evaluated were predictive of DI. A simple predictive test was established based on logistic regression analysis including all the variables except temporomandibular joint movement. To determine the optimum cut-off for the new test, a receiver operating characteristic curve analysis was applied. A score > or = 5 in the proposed test provided a sensitivity of 94% and a specificity of 76%. CONCLUSION: The index we describe is aimed at predicting DI in a very specific population with a high risk of this complication. This index uses a series of variables which may be measured easily during the preoperative period and provides an excellent predictive capacity with a high sensitivity and specificity when the index is > or = 5.     

Acute carotid obliteration: a new vascular manifestation in POEMS syndrome

The case of a 65-year-old woman with polyneuropathy, organomegaly, skin changes and monoclonal gammopathy of IgG-lambda type is described. This patient developed an acute carotid obliteration during oral anticoagulation and despite absence of vascular risk factors. Macroangiopathy has been described as a rare systemic manifestation of POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal spike and skin changes), affecting the coronary and lower limbs arteries. To our knowledge, this is the second case of POEMS syndrome with a cerebrovascular manifestation.     

Ultrasonography and computed tomography in adrenal myelolipoma

We report 2 cases of adrenal myelolipoma with sonographic and computerized tomographic findings. Characteristic radiologic signs of this rare clinical entity must be known to avoid unnecessary surgical procedures.     

Effect of ethanol on proteolysis in isolated liver cells

Ethanol, when tested alone, inhibited proteolysis by about 20%; however, no effect was detected when it was combined with exogenous oxidizable fuels which inhibited proteolysis by themselves. Ethanol was effective in inhibiting proteolysis in the presence of protease inhibitors like ammonia, leupeptin or methylamine, indicating that its mechanism of action involves a non-lysosomal pathway of degradation. Ethanol oxidation is mandatory for it to have effect on proteolysis, however, its action is not related to an increased state of reduction of the NAD system. In contrast to other reductants of the NAD system, ethanol effect is accompanied by a rise in the phosphorylation state of the adenine nucleotides, suggesting that its action might be related to the cellular energy state.     

Application of quantitative fluorescent PCR with short tandem repeat markers to the study of aneuploidies in spontaneous miscarriages

BACKGROUND: Aneuploidies involve approximately 80% of chromosomal anomalies found in spontaneous miscarriages. Since cytogenetic studies show high rates of failure, we have incorporated the quantitative fluorescent polymerase chain reaction (QF-PCR) technique to the study of numerical chromosome anomalies in miscarriages. METHODS: Multiplex and simple QF-PCR assays have been performed on 160 miscarriage and 34 parental DNA samples analysing specific short tandem repeat (STR) markers for chromosomes 2, 7, 13, 15, 16, 18, 21, 22 and X. Cases successfully karyotyped were used as controls in our study. RESULTS: While maternal contamination could be detected in such cases, a molecular result was obtained for 94% of miscarriages without a cytogenetic one. Thirty-six per cent of them were diagnosed with numerical chromosome anomalies. Parental origin of the extra chromosome and the error stage of meiosis could be also determined. CONCLUSIONS: QF-PCR represents a useful and reliable tool to diagnose aneuploidies in spontaneous miscarriages. It provides information about parental and meiotic origin of anomaly, allowing an appropriate genetic counselling.