Random quasi-phase-matched second-harmonic generation in periodically poled lithium tantalate.

We observe second harmonic generation via random quasi-phase-matching in a 2.0 mum periodically poled, 1-cm-long, z-cut lithium tantalate. Away from resonance, the harmonic output profiles exhibit a characteristic pattern stemming from a stochastic domain distribution and a quadratic growth with the fundamental excitation, as well as a broadband spectral response. The results are in good agreement with a simple model and numerical simulations in the undepleted regime, assuming an anisotropic spread of the random nonlinear component.

Chinese hamster ovary cells resistant to the topoisomerase II catalytic inhibitor ICRF-159: a Tyr49Phe mutation confers high-level resistance to bisdioxopiperazines.

Anticancer drugs targeted to the nuclear enzyme DNA topoisomerase II are classified as poisons that lead to DNA breaks or catalytic inhibitors that appear to completely block enzyme activity. To examine the effects of the bisdioxopiperazine class of catalytic inhibitors to topoisomerase II, we investigated a Chinese hamster ovary (CHO) subline selected for resistance to ICRF-159 (CHO/159-1). Topoisomerase IIalpha content in CHO/159-1 cells was reduced by 40-50%, compared to wild-type CHO cells, whereas the beta isoform was increased by 10-20% in CHO/159-1 cells. However, the catalytic activity of topoisomerase II in nuclear extracts from CHO/159-1 cells was unchanged, as was its inhibition by the topoisomerase II poison etoposide (VP-16). No inhibition of topoisomerase II catalytic activity by ICRF-187 was seen in CHO/159-1 cells up to 500 microM, whereas inhibition was evident at 50 microM in wild-type CHO cells. VP-16-mediated DNA single-strand breaks and cytotoxicity were similar in the two sublines. ICRF-187 could abrogate these VP-16 effects in the wild-type line but had no effect in CHO/159-1 cells. Western blots of topoisomerase IIalpha after incubation of CHO cells with ICRF-187 demonstrated a marked band depletion, whereas this effect was completely lacking in CHO/159-1 cells, and an equal effect of VP-16 was observed in both lines. These data imply that the CHO/159-1 topoisomerase IIalpha lacks sensitivity to bisdioxopiperazines and that the mechanism of resistance in this cell line does not confer cross-resistance to topoisomerase II poisons, suggesting that mutations conferring resistance to bisdioxopiperazines can occur at sites distinct from those responsible for resistance to complex stabilizing agents. Accordingly, CHO/159-1 cDNA showed two heterozygous mutations in the proximal NH2-terminal part of topoisomerase IIalpha (Tyr49Phe and delta 309Gln-Gln-Ile-Ser-Phe313), which is in contrast to those induced by topoisomerase II poisons, which cluster further downstream. Site-directed mutagenesis and transformation of the homologous Tyr50Phe coding mutation in human topoisomerase IIalpha in a temperature-conditional yeast system demonstrated a high-level resistance to ICRF-193, compared to cells expressing wild-type cDNA, but none toward the poisons VP-16 or amsacrine, thus confirming that the Tyr50Phe mutation confers specific resistance to bisdioxopiperazines. Thus, these results indicate that the region of the protein involved in ATP-binding also plays a critical role in sensitivity to bisdioxopiperazines, a result consistent with the known requirement for the formation of an ATP-bound closed clamp for bisdioxopiperazine activity. These results may enable a more precise understanding of the interaction of topoisomerase II-directed drugs with their target enzyme.

[Occurrence of Giardia cysts and Cryptosporidium oocysts in swimming pools in the province of Palermo, Italy]. / Presenza di cisti di Giardia e oocisti di Cryptosporidium in piscine della provincia di Palermo.

21 samples of waters of 7 swimming pools in the province of Palermo were investigated for the presence of Giardia cysts and Cryptosporidium oocysts. Some chemio-physical parameters (chlorine, temperature, turbidity and pH) were also evaluated as well as the presence of bacterial indicators of faecal (total coliforms, Escherichia coli and enterococci), mucocutaneous and environmental (Staphylococcus aureus and Pseudomonas aeruginosa) contamination. All samples were negative for bacterial indicators of faecal contamination; 3 were positive for the presence of coagulase-negative staphylococci, 1 was positive for Alcaligenes spp. and 2 for Pseudomonas aeruginosa. 8 samples proved to be positive for Giardia and 6 also for Cryptosporidium. All but one of them were coming from waters of 2 swimming pools of the same recreational center. In all samples the concentration of Giardia was substantially higher than that of Cryptosporidium. This study shows that the disinfection and filtering plants are not always suitable to ensure a good level of the quality of the waters of swimming pools and suggests that should be necessary to check them also for the presence of protozoa like Giardia and Cryptosporidium, which may be responsible for gastroenteritis.

[Development of a technique for recovering Giardia cysts and Cryptosporidium oocysts from fresh vegetables]. / Descrizione di una tecnica per la ricerca di cisti di Giardia e di oocisti di Cryptosporidium in vegetali freschi contaminati sperimentalmente.

Techniques described for recovering Giardia and Cryptosporidium (oo)cysts from fruit and vegetables are generally inadequate and present variable recovery efficience and elevated costs. The aim of our study was to evaluate the recovery efficiency of a simple and economic technique to apply either to berry vegetables, like tomatoes and peppers, or to large leave vegetables, like lettuce and chicory. The method include contamination and further elution of the vegetables. Then sedimentation of (oo)cysts by centrifugation of the eluate of vegetables and their visualization by means of direct immunofluorescence. The higher recovery values for both protozoa were obtained in large leave vegetables with mean data above 70% for Giardia and 76% for Cryptosporidium, whereas the values observed in the berry vegetables were above 43% for Giardia and above 37% for Cryptosporidium on average.

Argentine Randomized Study: Coronary Angioplasty with Stenting versus Coronary Bypass Surgery in patients with Multiple-Vessel Disease (ERACI II): 30-day and one-year follow-up results. ERACI II Investigators.

OBJECTIVE: The purpose of this study was to compare percutaneous transluminal coronary revascularization (PTCR) employing stent implantation to conventional coronary artery bypass graft surgery (CABG) in symptomatic patients with multivessel coronary artery disease. BACKGROUND: Previous randomized studies comparing balloon angioplasty versus CABG have demonstrated equivalent safety results. However, CABG was associated with significantly fewer repeat revascularization procedures. METHODS: A total of 2,759 patients with coronary artery disease were screened at seven clinical sites, and 450 patients were randomly assigned to undergo either PTCR (225 patients) or CABG (225 patients). Only patients with multivessel disease and indication for revascularization were enrolled. RESULTS: Both groups had similar clinical demographics: unstable angina in 92%; 38% were older than 65 years, and 23% had a history of peripheral vascular disease. During the first 30 days, PTCR patients had lower major adverse events (death, myocardial infarction, repeat revascularization procedures and stroke) compared with CABG patients (3.6% vs. 12.3%, p = 0.002). Death occurred in 0.9% of PTCR patients versus 5.7% in CABG patients, p < 0.013, and Q myocardial infarction (MI) occurred in 0.9% PTCR versus 5.7% of CABG patients, p < 0.013. At follow-up (mean 18.5 +/- 6.4 months), survival was 96.9% in PTCR versus 92.5% in CABG, p < 0.017. Freedom from MI was also better in PTCR compared to CABG patients (97.7% vs. 93.4%, p < 0.017). Requirements for new revascularization procedures were higher in PTCR than in CABG patients (16.8% vs. 4.8%, p < 0.002). CONCLUSIONS: In this selected high-risk group of patients with multivessel disease, PTCR with stent implantation showed better survival and freedom from MI than did conventional surgery. Repeat revascularization procedures were higher in the PTCR group.

[Occurrence of Giardia and Cryptosporidium in wastewater, surface water and ground water samples in Palermo (Sicily)]. / Presenza di Giardia e Cryptosporidium in reflui civili e in campioni d'acqua superficiale e profonda del territorio palermitano.

This paper reports the investigation carried out on the occurrence of Cryptosporidium and Giardia (oo)cysts in water samples of two municipal treatment plants, and in surface water and ground water wells of the province of Palermo. The wastewater samples taken before and after treatment process were assayed over the course of one year Giardia cysts were detected in all samples throught the year at higher concentration levels than Cryptosporidium oocysts, with a peak observed in spring. The overall removal efficiency of (oo)cysts in the treatment plants was about of 90%. Their presence were also searched in surface waters (three artificial lakes and one river); (oo)cysts were detected in one lake at very low concentration; on the contrary, both parasites were found at high concentration levels in all the samples collected throught one year from the water of the river. The pattern of occurrence of both parasites appears temporally related to the level of rainfall trend. Cryptosporidium and Giardia were also found in ground water wells; their presence occurred only in waters taken from wells at a depth lower than 31 meters with concomitant presence of faecal bacteria. These results may provide further insight into the possible source of Cryptosporidium and Giardia in natural environmental and stress the potential risk associated with the use of waters for recreational and agricultural purposes.

A novel mutation in the Notch3 gene in an Italian family with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy: genetic and magnetic resonance spectroscopic findings.

BACKGROUND: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary syndrome caused by mutations of the Notch3 gene, usually localized to exons 3 and 4. OBJECTIVES: To report a novel pathogenetic mutation occurring in exon 6 of the Notch3 gene, a location not previously recognized in patients with CADASIL, and to report the results of magnetic resonance spectroscopy in CADASIL. METHODS: Mutation analysis of the Notch3 gene was performed in 2 patients belonging to a large kindred manifesting CADASIL, as well as in 7 clinically unaffected members of the family and 200 control chromosomes. Proton magnetic resonance spectroscopy was used to estimate metabolite resonance intensities in the 2 affected subjects. RESULTS: Sequence analysis of the Notch3 gene showed a new missense mutation CGC-->TGC in codon 332 of exon 6, resulting in the replacement of an arginine residue with a cysteine. This mutation was never observed in the 7 unaffected members of the family and the 200 control chromosomes examined. Proton magnetic resonance spectroscopy showed a diffuse decrease in cerebral N-acetylaspartate, indicating the presence of widespread axonal damage. CONCLUSIONS: Our findings emphasize the role of direct DNA sequence analysis for the diagnosis of CADASIL. Moreover, the results of proton magnetic resonance spectroscopy suggest that widespread axonal damage may be an early finding of the disease.

Randomized trial comparing two different high doses of methylprednisolone in MS: a clinical and MRI study.

OBJECTIVE: To assess the efficacy of two different high doses of intravenous methylprednisolone (IVMP) for the treatment of relapses in MS. BACKGROUND: IVMP is the treatment of choice for MS relapses, but it is unknown whether its effects are dose related. METHODS: We conducted a double-blind, randomized study. Follow-up included serial clinical and MRI recordings at baseline and at 7, 15, 30, and 60 days after the beginning of treatment. Outcome measures were the number of brain and cervical spinal cord MRI contrast-enhancing lesions, and the Expanded Disability Status Scale score. RESULTS: Both treatment regimens improved clinical scores and reduced the number of MRI enhancing lesions during the follow-up period. The higher dose of IVMP was significantly more effective than the lower dose in reducing the number of MRI contrast-enhanced lesions at 30 and 60 days, mainly by decreasing the rate of new lesion formation. CONCLUSIONS: The higher dosage of IVMP has a more powerful and prolonged action in maintaining blood-brain barrier integrity after a clinical relapse.

Kufs' disease presenting as late-onset epilepsia partialis continua.

A 64-year-old woman, who had no personal or family history of neurologic diseases, had an 18-month history of epilepsia partialis continua (EPC) associated with a moderate intellectual deterioration and subtle extrapyramidal rigidity. There was no photosensitive response. A thorough laboratory investigation was unremarkable. A biopsy of the rectal mucosa revealed abundant fingerprint profiles diagnostic of Kufs' disease (KD). Our case expands the clinical picture of KD and suggests that such a diagnosis should be considered in adult-onset EPC.

Pharmacodynamics of the long-duration response to levodopa in PD.

OBJECTIVE: To determine the latency, magnitude, and duration of the long-duration response (LDR) to levodopa in PD in relationship to the administration of levodopa at different interdose intervals. METHODS: In six patients with PD, two different 15-day treatment regimens were used in which the drug was administered with interdose intervals of 24 or 8 hours. RESULTS: The LDR built up within a few days with either regimen, but a faster rate of administering levodopa shortened the latency to the appearance of a sustained LDR. Once a sustained response had been reached, the magnitude of the LDR showed a stable ceiling effect that was independent of the levodopa schedule. After discontinuation of treatment, the decay of the LDR was similar for both regimens. CONCLUSIONS: The system underlying the LDR to levodopa may be completely saturated when a sustained response has been fully developed. The intervals between doses of levodopa shorter than the interval effective to reach a sustained LDR should not be used in the clinical management of patients with PD because the antiparkinsonian benefit deriving from the LDR is already maximal and briefer intervals do not provide a greater benefit.

The long-duration response to L-dopa in the treatment of early PD.

OBJECTIVE: To investigate the long-duration response (LDR) to L-dopa resulting from different regimens of L-dopa. BACKGROUND: In clinical practice, L-dopa is usually administered without considering the LDR due to the drug. Moreover, it has not been established whether in early PD a multiple daily intake of small doses of L-dopa may induce a sustained LDR. METHODS: Twenty-four patients with early PD underwent a double-blind, crossover trial, comparing three different 15-day treatment periods with L-dopa: treatment A (250 mg every 24 hours); treatment B (250 mg every 8 hours); and treatment C (125 mg every 8 hours). After completion, 20 patients underwent a subsequent open-label randomized trial with prolonged treatments (250 mg every 24 hours or 125 mg every 8 hours) up to 3 months. LDR was measured at the end of each treatment. RESULTS: All patients achieved a sustained LDR after treatments A and B, whereas only 17% of patients reached a sustained LDR after treatment C. Overall, the LDRs resulting from treatments A and B had similar magnitude and were larger than the LDR deriving from treatment C. After 3 months of prolonged treatments, only three of 10 patients treated with 125 mg every 8 hours increased their LDR, whereas all 10 patients treated with 250 mg every 24 hours had a maximal and stable LDR. CONCLUSIONS: Sustained LDR to L-dopa is dependent on the amount of the single doses of the drug. A regimen scheduling small, divided doses during the day, as done in clinical practice, is a questionable therapy for the achievement of a sustained LDR.

Loss of long-duration response to levodopa over time in PD: implications for wearing-off.

OBJECTIVE: To determine the modifications of the long-duration response to levodopa in PD over a 1-year period. BACKGROUND: The development of predictable motor fluctuations in PD has been attributed mainly to modifications over time of the short-duration response to levodopa, whereas the role of the long-duration response has not been widely investigated. METHODS: In 17 patients with PD the authors examined prospectively both the short-duration response and the long-duration response to levodopa under standardized conditions on two different occasions separated by a period of approximately 1 year (11.7 +/- 3.6 months). RESULTS: At the end of the follow-up period, the short-duration response increased in magnitude but did not change significantly in duration. A total of 24% of patients lost the long-duration response 1 year after their first examination, but a sustained long-duration response could be reestablished by shortening the interdose interval for levodopa intake. Moreover, the duration of the long-duration response after discontinuation of treatment became significantly shorter during 1 year. CONCLUSION: Modifications of the long-duration response may have a pivotal role in generating a fluctuating response, and suggest that therapeutic strategies based on maintenance of the long-duration response should be sought to avoid the appearance of motor fluctuations.

Genetic heterogeneity in autosomal recessive hereditary motor and sensory neuropathy with focally folded myelin sheaths (CMT4B).

Hereditary motor and sensory neuropathy with focally folded myelin sheaths, or Charcot-Marie-Tooth disease neuropathy type 4B (CMT4B), is a distinct clinical and genetic entity belonging to the heterogeneous group of autosomal recessive demyelinating neuropathies. We previously described a large pedigree with CMT4B and found evidence of linkage to chromosome 11q23. We now describe a second, unrelated family in which two individuals were affected with CMT4B. We exclude the disease locus segregating in this smaller pedigree from the 11q23 region as well as from most of the regions where other CMT loci have been mapped. We thus provide evidence for a second locus causing the CMT4B phenotype.

Dopamine D2 receptor gene polymorphism and the risk of levodopa-induced dyskinesias in PD.

OBJECTIVE: To investigate whether polymorphisms in the genes for dopamine receptors D1 and D2 are associated with the risk of developing peak-dose dyskinesias in PD. BACKGROUND: Peak-dose dyskinesias are the most common side effects of levodopa therapy for PD. The identified predictors may only partially account for the risk of developing peak-dose dyskinesias because a substantial proportion of patients never develop peak-dose dyskinesias. Genetic factors could play a role in determining the occurrence of peak-dose dyskinesias. METHODS: A case-control study of 136 subjects with sporadic PD and 224 population control subjects. We studied three polymorphisms involving the dopamine receptor D1 gene and one intronic short tandem repeat polymorphism of the dopamine receptor D2 gene. RESULTS: The polymorphisms of the dopamine receptor D1 gene were not associated with the risk of developing PD or peak-dose dyskinesias. The 15 allele of the polymorphism of the dopamine receptor D2 gene was more frequent in parkinsonian subjects than in control subjects. More important, the frequency of both the 13 allele and the 14 allele of the dopamine receptor D2 gene polymorphism was higher in nondyskinetic than in the dyskinetic PD subjects. The risk reduction of developing peak-dose dyskinesias for PD subjects carrying at least 1 of the 13 or 14 alleles was 72% with respect to the PD subjects who did not carry these alleles. CONCLUSIONS: Certain alleles of the short tandem repeat polymorphism of the dopamine receptor D2 gene reduce the risk of developing peak-dose dyskinesias and could contribute to varying susceptibility to develop peak-dose dyskinesias during levodopa therapy.

Autosomal recessive hereditary motor and sensory neuropathy with focally folded myelin sheaths: clinical, electrophysiologic, and genetic aspects of a large family.

We describe 10 patients from a large family with early onset motor and sensory neuropathy. Six were still living at the time of the study. In all cases, early motor milestones had been achieved. Mean age at onset of symptoms was 34 months; these included progressive distal and proximal muscle weakness of lower limbs. Pes equinovarus developed in all patients during childhood. Slight facial weakness was present in four patients, and one of them also had bilateral facial synkinesia. Intellectual function was normal in all cases. There was no evidence of thickened peripheral nerves. All three adult patients (mean age, 27 years) were seriously handicapped and wheelchair-bound. Death occurred in the fourth to fifth decade of life and the duration of the illness varied from 27 to 39 years. Motor nerve conduction velocities ranged from 15 to 17 m/sec in the upper limbs of the youngest patients, and were undetectable in the adult patients. Sensitive action potentials were almost always absent. In all patients, auditory evoked potentials showed abnormally delayed interpeak I-III latencies. The most prominent pathologic finding was a highly unusual myelin abnormality consisting of irregular redundant loops and folding of the myelin sheath. The genealogic study gave strong evidence of autosomal-recessive inheritance. The molecular analysis failed to demonstrate either duplication in the chromosome 17p11.2-12, point mutations in the four exons of the PMP-22 (17p11.2) and the six exons of the Po (1q21-q25) genes, or linkage to chromosome 8q13-21.1.

A new locus for autosomal dominant nocturnal frontal lobe epilepsy maps to chromosome 1.

BACKGROUND: Autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) is caused by mutations in the alpha4 subunit of the neuronal nicotinic acetylcholine receptor (CHRNA4) gene, mapping on chromosome 20q13.2. A second ADNFLE locus was mapped on chromosome 15q24. OBJECTIVE: To report a new third ADNFLE locus on chromosome 1 in a large Italian family. METHODS: The authors performed a clinical and genetic study in a large, three-generation ADNFLE family from southern Italy, including eight affected individuals and three obligate carriers. RESULTS: The age at onset of seizures was around 9 years of age and all affected individuals manifested nocturnal partial seizures of frontal lobe origin. Interictal awake and sleep EEG recordings showed no definite epileptiform abnormalities in most patients. Ictal video-EEG showed that the attacks were partial seizures with a frontal lobe semiology. Intellectual and neurologic examinations, and brain CT or MRI results were always normal. Carbamazepine was effective in all treated patients. Exclusion mapping of the known loci linked to ADNFLE-ENFL1, and ENFL2, on chromosomes 20q13.2 and 15q24-was performed on the pedigree before starting the genome-wide linkage analysis. The whole genome scan mapping allowed the identification of a new ADNFLE locus spanning the pericentromeric region of chromosome 1. CONCLUSIONS: The authors provided evidence for a third locus associated to autosomal dominant nocturnal frontal lobe epilepsy on chromosome 1. Among the known genes mapping within this critical region, the ss2 subunit of the nicotinic receptor (CHRNB2) represents the most obvious candidate.

Cerebral venous thrombosis and isolated intracranial hypertension without papilledema in CDH.

BACKGROUND: There is evidence that patients with chronic daily headache (CDH) may have isolated intracranial hypertension without papilledema (IHWOP). Recent studies have emphasized that isolated IH may be due to cerebral venous thrombosis (CVT). OBJECTIVE: To detect the occurrence of CVT in patients with CDH. METHODS: The authors investigated the occurrence of CVT in 114 consecutive patients with CDH by using MR venography (MRV). A portion of these patients underwent a lumbar puncture (LP) to measure CSF pressure. MRV and LP were also performed in 28 age-matched control subjects. RESULTS: In all the control subjects, both MRV and CSF pressure were normal. One hundred three of the 114 patients with CDH had normal MRV. Twenty-seven (Group 1) of these 103 patients underwent LP, and all of them had normal CSF pressure. Eleven (9.6%) of the 114 patients with CDH had CVT of one or both transverse sinuses. Six of these 11 patients had flowing abnormalities of one transverse sinus (Group 2), whereas the remaining five patients showed involvement of both transverse sinuses (Group 3). The CSF pressure of Group 2 was higher than that of either Group 1 or the control subjects, and one of the six patients showed isolated IHWOP. Patients of Group 3 displayed the highest CSF pressure, and four of five had isolated IHWOP. The headache profiles of patients with CDH and CVT did not differ from those of patients with CDH but normal MRV. CONCLUSIONS: CVT, as detected by MRV, occurred in 9.6% of patients who presented with CDH. Almost half of the patients with CVT had isolated IHWOP. These results suggest that MRV may be a useful tool for selecting patients with CDH who should have LP to exclude isolated IHWOP.

Clinical and genetic study of a large Charcot-Marie-Tooth type 2A family from southern Italy.

The authors report a large pedigree from southern Italy with Charcot-Marie-Tooth disease type 2A (CMT2A). The clinical picture was uniform and characterized by distal muscular weakness and atrophy in the lower limbs, reduced or absent tendon reflexes mainly in the lower limbs, and mild sensory impairment in the feet. Significant linkage to the CMT2A locus on chromosome 1p35-p36 was detected. Based on informative recombination in affected individuals, the authors mapped the CMT2A gene between D1S160 and D1S170.

The parkin gene is not involved in late-onset Parkinson's disease.

Mutations in the parkin gene have been reported in patients with early onset PD. The authors investigated the parkin gene in 118 patients who had an onset of PD after age 45 years: 95 subjects were sporadic patients and 23 subjects were from 18 families with a probable autosomal recessive inheritance. No pathogenetic mutations in the parkin gene were detected either in familial or in sporadic patients. Moreover, no differences were found between patients and 100 age-matched normal controls in the allele and genotype frequencies of four exonic parkin polymorphisms.

Effects of different antihypertensive drugs on left ventricular function.

Left ventricular hypertrophy (LVH) is a response by the heart to haemodynamic overload. It is frequently observed in hypertension as a consequence of work overload secondary to an increased systemic resistance. This increase is not the only cause of LVH; there are other factors which can have a significant effect on its incidence. LVH in arterial hypertension acts initially as a useful compensatory mechanism against increased peripheral resistance. However after a certain amount of time it produces changes of variable intensity which have important consequences for the heart and some of them impair cardiac performance: 1. It affects both systolic and diastolic ventricular function; 2. It reduces coronary reserve; 3. It increases the incidence of angina and heart failure; 4. It increases the incidence of ventricular arrhythmias and sudden death. It therefore seems reasonable to include the reduction of LVH among the basic aims of antihypertensive treatment. Antisympathetic drugs (methyldopa, prazosin, urapidil), adrenergic beta-blockers, calcium antagonists and the converting enzyme inhibitors have proven to have a variable degree of efficacy in effecting a regression of LVH.