[Prenatal diagnosis. II. Importance of ultrasonographic markers in prenatal diagnosis of chromosome abnormalities]

The Medical Genetic Unit of the University of Zulia (MGUUZ) has developed a Prenatal Diagnosis Program (PDP) since January-1993, in which Genetic Risk Factors are determined in couples who request prenatal genetic counseling. In this program, different prenatal diagnostic procedures are performed to detect congenital defects during intrauterine life. One of these procedures is the Fetal Sonogram (FS). FS is a non invasive technique which permits the prenatal diagnosis of many genetic dysmorphic syndromes. Through the search of abnormal specific characteristics in the fetus, chromosomopathies may be suspected. These findings are named "Echosonographic Markers of Chromosomal Abnormalities" (EMCA). During three years (January-1993 to December-1996), patients attended in the PDP included 321 pregnant women in which 312 FS were performed. Abnormal outcomes were 22 (17 with isolated congenital malformations and 5 with EMCA). Only one fetus with chromosome abnormality (46,XX21q-) could not be detected by FS. The goals of this paper are: 1) to report 5 patients with sonographic markers suggestive of chromosomal abnormalities and 2) to show the FS usefulness in prenatal diagnosis of chromosompathies. We conclude that, in the search of the EMCA the FS should be offered systematically to all pregnant women without recognizable genetic risk. They are the main group with optimal reproductive age and in consequence, with the possibility of having a relatively major number of conception outcomes with congenital defects, with or without chromosomic etiology. The majority of those defects can be detected by FS and could allow us to select the patients in which the use of an invasive prenatal diagnostic procedure could be justified.

Synthesis and antiallergic activity of pyridothienopyrimidines

The synthesis of a series of pyridothienopyrimidines and their evaluation as inhibitors or inducers of the release of histamine from rat mast cells is reported. The activity was measured after immunological stimulation with ovoalbumin and chemical stimulation with polymer 48/80 and the drugs adryamicin and vinorelbine. The experiments were carried out with and without preincubation of the stimulus with the cells before addition of the drug. Several pyridothienopyrimidines show inhibitory IC50 values in the range 2-25 microM, indicating they are up to 100 times more potent than cromoglycate (DSCG) and 10 times greater than Ketotifen. Compound 9l is a potent inhibitor in all the conditions tested and shows IC50 = 9-25 microM. Pyridothienopyrimidines 4l and 9e are very strong inducers of histamine release in the immunological (4l, 170-230%) and chemical (9e, 100-150%) assays, respectively. Compounds 4l and 9i are cytotoxic in vitro (IC50 = 0.1-0.2 microgram/mL) against P-388, A-549, HT-29, and MEL-28 tumor cell lines.

Radiation exposure to medical staff in interventional and cardiac radiology

The aim of this work has been to determine typical occupational dose levels in interventional radiology and cardiology installations and to relate doses to patient and occupational dosimetry through the dose-area product. An experimental correlation between environmental dosimetric records and dose-area products in the centres studied was established. The study covered a sample of 83 procedures performed by 10 specialists in six laboratories. The radiologists and cardiologists monitored wore nine thermoluminescent chips next to eyes, forehead, neck, hands, left shoulder, left forearm and left arm during each single procedure. In addition, direct reading electronic devices for environmental dosimetry were placed in the C-arm of the X-ray system, to estimate roughly the occupational radiation risk level. Typical shoulder doses derived from electronic dosimetry range between 300 and 500 muSv per procedure, assuming no lead protective screens were used. Using these values and patient dose-area data from two laboratories, averaged ratios of 84 and 120 muSv per 1000 cGy cm2 are obtained for cardiology procedures. Finally, occupational dose reductions of approximately 20% when using highly filtered X-ray beams with automatic tube potential (kV) reduction (available in some facilities), and by a factor of about three when using ceiling mounted screens, have been found.

Lens injuries induced by occupational exposure in non-optimized interventional radiology laboratories

Several cases of ophthalmologically confirmed lens injuries, caused by occupational radiation exposure, have occurred in two X-ray rooms devoted to vascular and visceral interventional radiology procedures. Both laboratories were equipped with overcouch X-ray systems not designed for interventional radiology and without specific tools for radiation protection of the eyes. Typical workloads ranged from between two and five procedures per day. For the two radiologists affected, estimates for the dose to eye lens ranged from 450 to 900 mSv per year, over several years. Once the incidents had been detected, the X-ray systems in both rooms were removed and new equipment specifically designed for interventional radiology was installed, including suspended shielding screens. Since these lens injuries were only detected accidentally, measures to avoid similar occurrences in the future are discussed.

Preliminary investigation of the association of oral lichen planus and hepatitis C

OBJECTIVE

The aim of this investigation was to determine if an association exists between hepatitis C virus and oral lichen planus.

STUDY DESIGN

Three groups of subjects were selected: 505 patients with hepatitis C virus infection (group 1), 100 patients with oral lichen planus (group 2), and a randomly selected control group (age- and gender-matched) of 100 healthy subjects (group 3). The prevalence of oral lichen planus was determined in groups 1 and 3, and the prevalence of hepatitis C virus infection was established in groups 2 and 3.

RESULTS

The prevalence of oral lichen planus was 3.36% (n = 17) in group 1 and 1% (n = 1) in the control group; the prevalence of hepatitis C virus infection was 23% (n = 23) in group 2, and 5% (n = 5) in the control group. No significant differences were observed in the incidence of oral lichen planus in group 1 between those patients who received interferon and those who did not. The 17 patients in group 1 who manifested oral lichen planus and hepatitis C virus infection simultaneously exhibited a marked tendency to have only reticular lesions (70.6%), with involvement of the buccal mucosa in 88.2% of these patients, the tongue in 29.4%, and the gingiva in 11.8%. Analyzing a randomized subgroup of 143 patients from group 1 (subgroup 1) that was matched by age and gender with groups 2 and 3, we found that the incidence of oral lichen planus in patients with hepatitis C virus infection (subgroup 1) was greater than in the control group (5.59% vs 1%), though this was not statistically significant (chi2 = 0.119; p = 0.06). In contrast, group 2 exhibited a statistically significant higher incidence of hepatitis C virus infection (23%) than the controls (5%; chi2 = 0.259, p = 0.0002).

CONCLUSIONS

The prevalence of hepatitis C virus infection in patients with oral lichen planus was greater than in the control series. In our opinion this observation warrants the investigation of potential concomitant hepatitis C virus infection in patients with oral lichen planus.

Well differentiated gastric adenocarcinoma with rhabdoid areas: a case report with immunohistochemical analysis

We describe the case of a 73-year-old patient with gastric adenocarcinoma composed of histologically well differentiated glandular areas, extensive rhabdoid zones and regions depicting a transition between these two constituents. The rhabdoid component showed typical features such as abundant eosinophilic cytoplasm, eccentric nuclei, prominent nucleoli, intense positive immunohistochemical cytoplasmic reaction for vimentin and less evident immunohistochemical for cytokeratin and epithelial membrane antigen (EMA). Our findings strongly suggest that the rhabdoid areas probably represent a phenotypic variant of a gastric adenocarcinoma, otherwise fairly well differentiated, a combination that to the best of our knowledge has not been previously reported.

Caprine arthritis-encephalitis in an indigenous Spanish breed of dairy goat

The presence of caprine arthritis and encephalitis (CAE) in Spain has never been officially acknowledged but it is suspected. Goats have been imported from other European countries with a high prevalence of the disease, mainly France, and they might have introduced the disease into the indigenous goat population. A serological survey of caprine arthritis and encephalitis virus antibodies was carried out in 22 volunteer dairy Murciano-Granadina goat herds; 2513 lactating goats were tested with an agar gel immunodiffusion test, and 12.1 per cent were found to be positive. Five of the herds were free of infection, six had a low prevalence of the disease, five had a medium prevalence and six had a high prevalence. Five seropositive goats with clinical signs of CAE were studied. Macroscopic and microscopic lesions similar to those described for CAE were detected in all five goats and a cytopathic effect typical of CAE virus was observed in primary explant cultures from four of them.

Characterization of melittin effects in synaptosomes

The effects of melittin at increasing concentrations on: [3H]GABA release from mouse brain synaptosomes; on the radioactivity released from [3H]arachidonic acid labeled synaptosomal membranes; on synaptosomes ultrastructure and on the leakage of the cytoplasmic marker, lactate-dehydrogenase (LDH) was investigated. Melittin 0.3, 1, 3, 7, and 10 microM progressively increases [3H]GABA release, but the efficacy of melittin is decreased when the amount of tissue exposed to a constant concentration of the toxin increases. The release of [3H]GABA induced by melittin below 3 microM is Ca2+ dependent, but not that induced by the higher concentrations. The Ca2+ dependent fraction of the [3H]GABA released by 0.3 microM melittin is selectively inhibited by 10 microM quinacrine and 1 microM nordihydroguaiaretic acid (NDGA) and facilitated by 3 microM indomethacin, whereas the Ca2+ independent fraction of the [3H]GABA released by melittin is not. In the presence of Ca2+, melittin 0.3, 1 and 10 microM progressively increases [3H]arachidonic acid release over control release, but the effectiveness of melittin is also decreased as the amount of tissue increases. No apparent changes in synaptosomes ultrastructure are observed in 0.3 microM treated synaptosomes, but a noticeable disorganization is produced in 10 microM melittin-treated synaptosomes, independently on the presence of external Ca2+. LDH activity only increases over control activity in the supernatant solutions of 10 microM melittin treated synaptosomes, also in a Ca2+ independent manner. Our interpretation of these results is that the Ca2+-dependent, pharmacologic sensitive component of melittin-induced release of [3H]GABA, unmasked when 0.3 microM melittin was used, involves the activation of a Ca2+-dependent type of membrane PLA2. The Ca2+-independent release of [3H]GABA is in contrast, highly probable to be due to the membrane perturbation produced by complex melittin/lipid interactions.

Patient dosimetry in interventional radiology using slow films

A method for the evaluation of patient doses in interventional radiology procedures is presented and discussed. The method requires the analysis of slow non-screen films such as those used in radiotherapy. Dose area product and patient skin dose can be estimated with fair accuracy depending on the interventional procedure type. The agreement between the slow film method and diamentor measurement is better than 5% after the application of appropriate corrections. The cost is reasonable (pounds 5 per film) making it a worthwhile option in patient dosimetry, especially when the X-ray equipment does not include any fixed dose-area measuring device. Additional valuable information which may be applied to optimization of procedures (e.g. irradiated areas, number and types of projections check of appropriate use of beam limiting devices) is achieved by examining the different irradiation fields on the film.

Dated co-occurrence of Homo erectus and Gigantopithecus from Tham Khuyen Cave, Vietnam

Tham Khuyen Cave (Lang Son Province, northern Vietnam) is one of the more significant sites to yield fossil vertebrates in east Asia. During the mid-1960s, excavation in a suite of deposits produced important hominoid dental remains of middle Pleistocene age. We undertake more rigorous analyses of these sediments to understand the fluvial dynamics of Pleistocene cave infilling as they determine how skeletal elements accumulate within Tham Khuyen and other east Asian sites. Uranium/thorium series analysis of speleothems brackets the Pleistocene chronology for breaching, infilling, and exhuming the regional paleokarst. Clast analysis indicates sedimentary constituents, including hominoid teeth and cranial fragments accumulated from very short distances and under low fluvial energy. Electron spin resonance analysis of vertebrate tooth enamel and sediments shows that the main fossil-bearing suite (S1-S3) was deposited about 475 thousand years ago. Among the hominoid teeth excavated from S1-S3, some represent Homo erectus and Gigantopithecus blacki. Criteria are defined to differentiate these teeth from more numerous Pongo pygmaeus elements. The dated co-occurrence of Homo erectus and Gigantopithecus blacki at Tham Khuyen helps to establish the long co-existence of these two species throughout east Asia during the Early and Middle Pleistocene.

Dose-area product values in frequently performed complex paediatric radiology examinations

Mean values of the dose-area product for barium meal, micturating cystourethrography and intravenous urography examinations from three health centres and for four age groups are presented in this study. Values measured are between 13% and 86% higher than results previously reported, which justifies the importance of applying procedures which reduce risks to patients.

Image quality and dose in lumbar spine examinations: results of a 5 year quality control programme following the European quality criteria trial

The large dose values found for lumbar spine examinations in a centre participating in the European quality criteria trial have been investigated within a 5 year quality control programme. Actions focused mainly on optimizing the focus-to-film distance, tube potential (kV), film optical density and X-ray beam filtration. These actions lead to overall dose reductions of up to 75% in lumbo-sacral joint examinations and prove the need for a regular survey of patient skin doses.

Patient dose values in interventional radiology

Large exposures incurred in interventional radiology procedures make it advisable to establish reference dose values. These dose values should be quoted in quantities representative of the radiological risk to the patient. In Spain, measurement methods were developed to comply with the European Directive on Patient Protection. Dose-area product and, when feasible, surface dose using thermoluminescent dosimetry chips were measured. Both approaches are discussed, as well as their potential use in patient protection programmes. Initial results are presented for a sample of 680 patients in 10 hospital centres in Spain. Mean, median and range are reported for some specific procedures. Mean values of 8750, 6651, 6663, 9292 and 6816 cGy cm2 are reported for percutaneous transluminal coronary angioplasty, coronary angiography, low extremity, renal and cerebral arteriographies, respectively.

Evaluation of tungsten and lead surgical gloves for radiation protection

We present experimental results on the radiation protection offered by some types of gloves commercialized for use in operating rooms where x rays are used and in interventional radiology rooms. Some gloves with lead as the attenuating element and others containing tungsten were evaluated. The composition of some gloves was determined by x-ray fluorescence analysis. Attenuations for direct beam and for scattered radiation were obtained with different quality x-ray beams. The results obtained are compared with data supplied by the manufacturers. We have also simulated numerically the attenuation of x-ray spectra of different kVp and filtrations to establish the possible advantages of tungsten as an attenuating element. It is concluded that the use of tungsten as an attenuating element is clearly more advantageous than lead in the whole range of energies used in diagnostic radiology since gloves with tungsten offer the same protection while also allowing much better tactile perception than gloves with lead.

Radiation doses to paediatric patients undergoing micturating cystourethrography examinations and potential reduction by radiation protection optimization

Dose-area product values were measured in paediatric micturating cystourethrography examinations in two dedicated facilities. The results are compared, taking into account features of the X-ray rooms and differences in examination protocol. Several optimization procedures were simulated or implemented, in order to estimate the dose savings which could be attained. Potential savings identified in the dose-area values reach about 85% for both centres.