Are animal models useful for understanding the pathophysiology of lysosomal storage disease?

Spontaneously occurring genetic lysosomal storage diseases are as rare in other mammalian species as in man. However, the advent of gene targeting technology has revolutionized the state of animal models of genetic diseases. Nearly all lysosomal storage diseases known in man have been duplicated in the mouse. The technology now allows, not only complete inactivation of endogenous genes, but also the introduction of essentially any type of mutation. These animal models can overcome many of the limitations inherent in studies of human patients - rarity of the disease, extremely complex genetic background and logistical and ethical constraints in the design and execution of experiments with human subjects. For example, genetic manipulations of germ cells or cross-breeding experiments between two mutants are readily feasible with animal models. Two major areas of the utility of animal models are the clarification of the pathophysiology/pathogenetic mechanism of disease and the exploration of therapeutic approaches. Examples of experiments using animal models of lysosomal storage disease are presented, primarily from studies undertaken in our own laboratory.
Conclusion : Animal models have proved invaluable in extending our knowledge of the lysosomal storage diseases and exploring potential therapies.     

Pelvic lipomatosis: clinical review and report of 4 new cases

First described by the end of the fifties, pelvic lipomatosis is an uncommon disease that develops as a result of an excessive proliferation of benign fat tissue within the perivesical and perirectal spaces. The compressive effect on the urinary, and to a lesser degree, the digestive and vascular structures result in the well-known symptoms. Diagnosis is reached through X-ray studies, primarily computerised tomography. Contribution of four new cases in young males diagnosed through imaging studies as well as biopsies in three of them. Evolution has been varying, with medical control of symptoms in two cases and renal function impairment due to upper obstructive uropathy in the other two.     

Hemoglobin and albumin adducts of benzene oxide among workers exposed to high levels of benzene

Benzene oxide (BO) reacts with cysteinyl residues in hemoglobin (Hb) and albumin (Alb) to form protein adducts (BO-Hb and BO-Alb), which are presumed to be specific biomarkers of exposure to benzene. We analyzed BO-Hb in 43 exposed workers and 42 unexposed controls, and BO-Alb in a subsample consisting of 19 workers and 19 controls from Shanghai, China, as part of a larger cross-sectional study of benzene biomarkers. The adducts were analyzed by gas chromatography-mass spectrometry following reaction of the protein with trifluoroacetic anhydride and methanesulfonic acid. When subjects were divided into controls (n = 42) and workers exposed to < or =31 (n = 21) and >31 p.p.m. (n = 22) benzene, median BO-Hb levels were 32.0, 46.7 and 129 pmol/g globin, respectively (correlation with exposure: Spearman r = 0.67, P < 0.0001). To our knowledge, these results represent the first observation in humans that BO-Hb levels are significantly correlated with benzene exposure. Median BO-Alb levels in these 3 groups were 103 (n = 19), 351 (n = 7) and 2010 (n = 12) pmol/g Alb, respectively, also reflecting a significant correlation with exposure (Spearman r = 0.90, P < 0.0001). The blood dose of BO predicted from both Hb and Alb adducts was very similar. These results clearly affirm the use of both Hb and Alb adducts of BO as biomarkers of exposure to high levels of benzene. As part of our investigation of the background levels of BO-Hb and BO-Alb found in unexposed persons, we analyzed recombinant human Hb and Alb for BO adducts. Significant levels of both BO-Hb (19.7 pmol/g) and BO-Alb (41.9 pmol/g) were detected, suggesting that portions of the observed background adducts reflect an artifact of the assay, while other portions are indicative of either unknown exposures or endogenous production of adducts.      

Increased aneusomy and long arm deletion of chromosomes 5 and 7 in the lymphocytes of Chinese workers exposed to benzene

Two of the most common cytogenetic changes in therapy- and chemical- related leukemia are the loss and long (q) arm deletion of chromosomes 5 and 7. The detection of these aberrations in lymphocytes of individuals exposed to potential leukemogens may serve as useful biomarkers of increased leukemia risk. We have used a novel fluorescence in situ hybridization (FISH) procedure to determine if specific aberrations in chromosomes 1, 5 and 7 occur at an elevated rate in the blood cells of workers exposed to benzene. Forty-three healthy workers exposed to a wide range of benzene concentrations (median 31 p.p.m., 8 h time-weighted average) and 44 unexposed controls from Shanghai were studied. Whole blood was cultured and metaphase spreads were harvested at 72 h. Benzene exposure was associated with increases in the rates of monosomy 5 and 7 but not monosomy 1 (P < 0.001, P < 0.0001 and P = 0.94, respectively) and with increases in trisomy and tetrasomy frequencies of all three chromosomes. Long arm deletion of chromosomes 5 and 7 was increased in a dose-dependent fashion (P = 0.014 and P < 0.0001) up to 3.5-fold in the exposed workers. These results demonstrate that leukemia-specific changes in chromosomes 5 and 7 can be detected by FISH in the peripheral blood of otherwise healthy benzene-exposed workers. We suggest that aberrations in chromosomes 5 and 7 may be useful biomarkers of early biological effect for benzene exposure.      

Radioquimioterapia de la enfermedad limitada del carcinoma pulmonar de célula pequeña. ¿Tratamiento concomitante en protocolos asistenciales?

Purpose We retrospectively reviewed our institution’s database to investigate the outcome and impact of combined radiochemotherapy (RT/CT; concomitant or in sequence) in localised small-cell lung cancer (L-SCLC). Material and methods Between January 1995 to November 1999, 79 patients with L-SCLC received combined RT/CT at our Institution. RT was delivered concurrently or sequentially following the CT. Patients with treatment response received additional prophylactic cranial irradiation (PCI). Results Of the patients treated, 54% had received concurrent CT/RT compared to 46% receiving RT following the CT. PCI was administered to 80% of the patients. Complete response was observed in 66% of patients. With a median follow up of 30 months, median overall survival was 15.9 months; 14.3 months for patients who received RT following CT and 21.6 months for those receiving concurrent CT/RT. The type of schedule of combined radiochemotherapy was an independent prognostic factor for survival free of local recurrence, as was additional PCI for distant metastasis-free survival. Conclusions Our results are similar to those reported previously in the literature. The main point of interest is that our patients were non-selected. We strongly support the use of concurrent CT/RT so as to achieve results comparable to the best in the literature.

     

Interobserver agreement in the diagnosis of pulmonary embolism with helical CT

PURPOSE: Our objective was to asses the interobserver agreement in the detection of pulmonary embolism (PE) with contrast-enhanced helical CT at the main pulmonary, lobar and segmental arteries. A prospective study was carried out in 51 patients with suspected PE. Finally, 29 patients were diagnosed of PE. SUBJECTS AND METHODS: All patients were studied with helical CT. Images (5 mm collimation, 1.5 pitch factor, 3 mm reconstruction interval) were obtained after bolus contrast injection (120 ml, 4 ml/s, 15 s delay time). All cases were blinded and independently interpreted in three ways: two radiologists with different level of expertise and two expert radiologists reading by consensus. Agreement was evaluated by means of the kappa test. RESULTS: Kappa values for thrombi detection expressed an excellent agreement at the main (between 0.802 and 0. 946), lobar (between 0.915 and 0.958) and segmental (between 0.879 and 0.718) levels. For all vessels, mean kappa values were similar and excellent for all three combinations of readers. Arteries with more discrepancies were located mainly at the anterior and posterior areas of the upper lobes. CONCLUSIONS: The high degree of agreement shown in this study indicates that helical CT is a reproducible test in the diagnosis of PE to the segmental level. Isolated readings and levels of expertise do not influence agreement.     

Early pregnancy losses in in vitro fertilization and oocyte donation

Objective: To evaluate prospectively the incidence of early pregnancy losses (before menstruation occurs) in IVF and ovum donation cycles.

Design: Prospective case-control study.

Setting: Tertiary care, university-associated center.

Patient(s): One hundred forty-five patients undergoing IVF and 92 undergoing oocyte donation were recruited. The control group for IVF consisted of 15 ovum donors who had no ET and were instructed to avoid intercourse. The control group for oocyte donation included 10 women undergoing a mock cycle of steroid replacement.

Intervention(s): Starting on day 6 after ET, the women were instructed to collect the first urine sample of the day every 2 days. Each patient collected six different specimens of urine (days 6, 8, 10, 12, 14, and 16 after ET for cases or the same days without ET for controls.

Main Outcome Measure(s): β-HCG was measured with a standardized microparticle enzyme immunoassay, and IVF reproductive outcome was assessed.

Result(s): For IVF, positive implantation was registered in 88 of 145 cycles of embryo replacement (60.7%). Only 30 (20.7%) resulted in viable pregnancies, whereas the remaining 58 miscarried. Forty-two of these miscarriages (72.4%) were early pregnancy losses and 13 (22.4%) were classified as clinical abortions. In ovum donation, positive implantation was recorded in 64 of 92 cycles of ET (69.6%). A total of 30 (32.6%) ended in viable pregnancies, whereas the remaining 34 (37.0%) were miscarriages. Early pregnancy loss accounted for 70.6% of pregnancy losses, whereas biochemical pregnancies and clinical abortions accounted for 11.8% and 17.6%, respectively.

Conclusion(s): Our results demonstrate that patients undergoing assisted reproductive technology have an increased rate of early pregnancy loss compared with fertile patients. In addition, these data indicate that implantation is more frequently impaired in IVF than in oocyte donation cycles, resulting in a high incidence of early pregnancy loss. This suggests that implantation may be subjected to abnormal conditions in assisted reproduction.