Optimization of the tyrosinase mRNA probe to detect circulating melanocytes with reverse transcription and polymerase chain reaction

It was recently suggested that reverse transcription polymerase chain reaction (RT-PCR)-based detection of tyrosinase messenger RNA (mRNA) in peripheral blood is useful in the early detection of circulating tumor cells, since tyrosinase is thought to be a melanocyte-specific marker. However, the sensitivity of detection of these cells in circulation is controversial, some authors reporting 0% effectiveness, others obtaining 100% efficacy. We developed a modification of a technique to process blood samples to detect tyrosinase mRNA, and tested the method with 50 samples from as many patients with histologically confirmed malignant melanoma in different stages. Whole blood was processed by discarding the plasma and extracting RNA from density gradient-isolated peripheral blood lymphocytes. The RNA samples were tested with a sensitive nested primer RT-PCR assay. Sensitivity was tested using RNA extracted from SK-mel-1 human melanoma cells diluted serially with peripheral blood obtained from healthy control subjects. A lymph node from a patient with confirmed disseminated melanoma served as the positive control. Our technique was able to detect tyrosinase mRNA in samples from the 37 patients with progressive metastatic melanoma. The test detected tyrosinase mRNA from both the melanoma cell line and the positive lymph node. Our method to extract RNA from whole blood improves the specificity and sensitivity of tyrosinase mRNA detection by RT-PCR. The test should be of use in determining the prognosis of patients with melanoma, and in deciding when to initiate early treatment in patients with malignant melanoma.

The subthalamic nucleus and tremor in Parkinson's disease

The role of the subthalamic nucleus (STN) in the origin of parkinsonian tremor is discussed. Previous studies in monkeys made parkinsonian by MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) administration suggested a direct participation of the STN in the pathophysiology of tremor. We recorded tremor-related activity in the STN in 12 patients with Parkinson's disease (PD) and found that microstimulation of the sensorimotor region of the nucleus, where these neurons are present, stopped the tremor with a very short latency. Long-term treatment by means of bilateral deep-brain stimulation (DBS) in the same 12 patients led to a significant reduction of tremor as well as other cardinal features of PD. This effect was blindly assessed at 3 months after implantation. In another group of seven patients, a unilateral lesion of the STN was performed. Both postural and resting tremor were significantly improved on the limbs contralateral to the lesion side. In three patients, tremor disappeared completely after 12 months of follow up. The electrophysiologic data and therapeutic effect of inactivating the STN strongly indicated that this structure is directly involved in the origin of parkinsonian tremor, as suggested by the MPTP model.

[Usefulness of anti-neutrophil cytoplasmic antibodies, anti-proteinase 3 and anti-myeloperoxidase in management of small vessel vasculitis]

BACKGROUND

Analysis of usefulness of antineutrophil cytoplasmic antibodies (AN-CA) as a marker of clinical activity in small vessel vasculitis.

PATIENTS AND METHODS

33 patients, 10 patients with Wegener's granulomatosis (WG) and 23 with microscopic polyangiitis (MPA) and rapidly progressive glomerulonephritis type III (RPGN III). The clinic and serologic follow-up was accomplished every 3 months during an average of 19 (SD, 24) months (range 3-52 months. The serologic follow-up included the determination of ANCA by indirect immunofluorescence (IFI) and ELISA, as well as the serum level of C reactive protein (RCP).

RESULTS

At the time of diagnosis all patients were ANCA positive by IFI and ELISA. The seroconversion of ANCA from positive to negative was produced in 30/33 patients (90%). Twenty-six out of these 30 patients (87%) achieved the seroconversion within the first 6 months. During the follow-up 4 patients had a major relapse, all with positive ANCA. In 2 patients, one of each group, seroconversion from negative to positive was not associated with clinical relapse of vasculitis.

CONCLUSION

ANCA should be used in conjunction with other indices of disease activity in patients with small vessel vasculitis.

[Coronary revascularization surgery with arterial grafts]

Coronary artery revascularization surgery is well established procedure throughout the world. The benefits are based on the blood perfusion through the implanted grafts distal to the coronary occlusions and continue as long as the grafts remains patent. The immediate success of this procedure is related to the surgical technique and the anatomical characteristics of the grafted coronary arteries. However, the long term results are mainly dependent on the type of grafts used. The modern era of myocardial revascularization started in the sixties with the use of saphenous vein grafts by Johnson and Favaloro. Alternative vascular conduits to the saphenous vein have been tried, and the internal mammary artery has become the first choice. In recent years, various publications have demonstrated the supremacy of the internal mammary artery over the saphenous vein when used as a single, bilateral, sequential of free graft. In order to obtain full myocardial revascularization, the use of alternatives to the internal mammary artery is required. The gastroepiploic artery, the inferior epigastric artery and the radial artery have been used as alternatives to the saphenous vein with the hope of obtaining long term results similar to the internal mammary artery.

Epilepsy surgery in the first three years of life

PURPOSE

Partial seizures in early postnatal life may be catastrophic and associated with poor long-term outcome. Epilepsy surgery can alleviate partial seizures in older children and adults, but there is little experience with surgical therapy in infancy apart from hemispheric epilepsy syndromes.

METHODS

We analyzed the results of cortical resection to treat medically refractory partial epilepsy in 31 children (16 boys, 15 girls) aged <3 years (mean, 18.3 months). Subjects were included only if seizure relief was the primary indication for surgery.

RESULTS

Follow-up of at least 1 year (mean, 4.6 years) in 26 patients revealed that 16 were seizure-free, 4 had >90% seizure reduction, and 6 had <90% reduction. There was no significant difference in seizure outcome between hemispherectomy/multilobar resections and lobar resections or temporal versus extratemporal resection. Seizure outcome was independent of the amount of cortex removed in nonlesional patients. Only the presence of a discrete lesion on preoperative neuroimaging correlated with a favorable outcome. Family perceptions of accelerated development in seizure-free patients were not confirmed on developmental assessment.

CONCLUSIONS

We conclude that cortical resection often benefits very young children with catastrophic partial seizures, but does not guarantee enhanced neurological development. The location and extent of the excised cortex may not be critical as long as the entire epileptogenic region and lesion are removed.

Cytotoxic isoflavans from Eysenhardtia polystachya

Two new cytotoxic isoflavans, (3S)-7-hydroxy-2',3',4',5', 8-pentamethoxyisoflavan (1) and (3S)-3',7-dihydroxy-2',4',5', 8-tetramethoxyisoflavan (2), were isolated from the bark and trunks of Eysenhardtia polystachya (Leguminosae), together with the known constituents stigmasterol, isoduartin, cuneatin, 7-hydroxy-2',4', 5'-trimethoxyisoflavone, and 3,4-dimethoxy-8, 9-(methylenedioxy)pterocarpan. The structures of 1 and 2 were elucidated on the basis of spectroscopic methods. The antimicrobial, cytotoxic, and insecticidal potential of some of these compounds were evaluated. The isoflavans 1, 2, and isoduartin (2', 7-dihydroxy-3',4',8-trimethoxyisoflavan) displayed moderate cytotoxic activity against KB cell lines.

Characterization of a new human embryonal rhabdomyosarcoma cell line, RMS-GR

A human tumor cell line designated RMS-GR was established from an embryonal rhabdomyosarcoma. The monolayer cells were polygonal, round or spindle-shaped. The RMS-GR cell line became stable with a doubling time of 42 h. Tumorigenicity of the cells was confirmed by heterotransplantion into nude mice. Electron microscopic images showed typical cytoplasmic inclusion of aggregated intermediate filaments and myofibril-like thin filaments. The expression of desmin, vimentin, actin and human myoglobin was recognized by cytofluorometric analyses, and a large fraction of CK-MM and small fractions of CK-BB and MCK-1 isoenzymes were found. Chromosomal analysis showed that the modal chromosome number was consistently near triploid with structural abnormalities mostly involving chromosomes 1, 3 and 8, and additional unidentified markers. No alteration of chromosome 2 was observed. The RMS-GR cell line may provide a system to identify genes which are involved in the pathogenic mechanism of rhabdomyosarcomas, and to investigate the modulation of myogenic differentiation.

Chondrolysis of the hip after transfer of the greater trochanter

Transfer of the greater trochanter is a surgical technique that is used for overgrowth of the greater trochanter arising from disturbance of the growth plate of the proximal femur. Few complications have been described, and to our knowledge, necrosis of the cartilage has not been reported. Herein we describe four cases of chondrolysis in three patients who underwent this surgical procedure. In our view, immobilization with plaster associated with the increased pressure produced by the descent of the gluteal attachment may have contributed to the development of chondrolysis.

Collagen-related markers of bone turnover reflect the severity of liver fibrosis in patients with primary biliary cirrhosis

The influence of a nonskeletal disease with increased connective tissue synthesis or degradation in the collagen-related markers of bone turnover has been evaluated in 34 women with primary biliary cirrhosis (PBC; age range 41-81 years), a disease with increased hepatic fibrosis, often associated with osteoporosis. Serum osteocalcin (BGP), and carboxy-terminal (PICP) and amino-terminal (PINP) propeptides of type I collagen were assessed as indexes of bone formation, whereas serum tartrate-resistant acid phosphatase (TRAP), and cross-linked carboxy-terminal telopeptide of type I collagen (ICTP), and urinary hydroxyproline (HYP), pyridinoline (PYR), deoxypyridinoline (DPYR), and type I collagen cross-linked N- (NTX) and C-telopeptide (CTX) were measured as markers of bone resorption. The histologic stage of the disease and serum amino-terminal propeptide of type III collagen (PIIINP) as an index of liver fibrogenesis were also evaluated. BGP levels were significantly lower, whereas PICP and PINP levels were higher in patients than in controls. Among the bone resorption markers, serum ICTP and urinary PYR, DPYR, HYP, NTX, and CTX levels were significantly higher in patients than in controls. Serum PIIINP levels were also increased in PBC patients. BGP did not correlate with PICP and PINP, but these markers of bone formation as well as ICTP, PYR, DPYR, and NTX correlated with serum PIIINP levels. Serum TRAP did not correlate with collagen-related markers of bone resorption. Moreover, patients with PIIINP and bilirubin above normal levels had higher PICP, PINP, ICTP PYR, DPYR, CTX, and NTX. These markers correlated with the histologic stage of the disease, but not with osteopenia measured by densitometric procedures in 22 patients. In conclusion, collagen-related markers of bone turnover do not reflect bone remodeling in PBC. The close association of these markers with PIIINP and the clinical and histologic stage of the liver disease suggests that they are influenced by liver collagen metabolism.

Therapeutic differentiation in a human rhabdomyosarcoma cell line selected for resistance to actinomycin D

Classical cytotoxic treatment of rhabdomyosarcoma (RMS) is accompanied often by significant morbidity and poor response. The use of cytotoxic agents may induce a multidrug resistance phenotype, which plays an important role in the sensitivity of tumoral cells to drugs. Using actinomycin D, a drug of choice in the treatment of RMS, we induced resistance in the TE.32.7 human RMS cell line. The TE.32.7-DAC-resistant cell line exhibited cross-resistance to vincristine and doxorubicin and showed mdr1/P-glycoprotein over-expression, suggesting that this mechanism was involved in the reduction in intracellular drug concentration and may be responsible for the failure of treatment of RMS with classical cycles of cytotoxics. Furthermore, this resistant cell line showed increased expression of the muscle differentiation markers desmin and alpha-actinin and ultrastructural changes which clearly indicated myogenic differentiation. Our findings suggest that, although this tumor is probably arrested along the normal myogenic pathway to maturation, induction of cell differentiation with anti-neoplastic drugs may be an alternative therapeutic approach. However, the failure of TE.32.7-DAC cells to completely re-enter the program of myogenic differentiation supports the hypothesis that multidrug resistance is a major obstacle in differentiation therapy for RMS.

Cape Town solution in prolonged myocardial preservation: structural and ultrastructural study

This study deals with myocardial preservation after 24 hours of continuous, hypothermic and oxygenated perfusion with Cape Town (CT) solution, focusing on the morphological changes produced by preservation and reperfusion, and their possible relationship to the composition of the solution and the immediate hemodynamic findings after orthotopic heart transplantation in dogs. After preservation, aside from mild or moderate mitochondrial changes, the most relevant lesions included edema and vasoconstriction. Reperfusion was followed by the development of areas of necrosis forming contraction bands and an increment in the mitochondrial damage; the intercalated disks conserved their normal structure; edema became more prominent and was invariably accompanied by hemorrhage; vasoconstriction was very pronounced and was accompanied on occasion by evidence of capillary rupture; and inflammatory cells were observed in the interstitium. These results indicate that colloid must be added to Cape Town solution and that reperfusion probably requires selective approaches to deal with vasoconstriction and inflammation.

Electrophysiologic assessment of calcium channel blockers in transplanted hearts: an experimental study

The effects of calcium channel blockers on automaticity, conduction, and refractoriness were studied in a model of heterotopic heart transplantation in dogs, which combined an innervated heart (recipient) and a denervated one (donor). Following the surgical procedure, 0.2 mg/kg verapamil (n = 10), 0.15 mg/kg diltiazem (n = 10), or 5 microg/kg + 30 microg/kg/h nifedipine (n = 10) was administered intravenously. In basal situation and after drug administration, each heart was assessed for AV interval, cycle length, sinoatrial conduction time, atrioventricular node antegrade block point, and atrioventricular node and ventricular refractory periods; electrocardiographic PR and QT intervals and QRS complexes; systemic arterial, pulmonary artery, central venous, and pulmonary capillary wedge pressures; and cardiac output. The depressor effects of these calcium channel blockers on automaticity, refractoriness, and conduction were more intense in the transplanted hearts, very possibly because of the absence of adrenergic reflexes mediated by the autonomic nervous system; in particular, verapamil produced a great depression of sinus automaticity in a large number of cases.

[Comparative study of secretory IgA]

OBJECTIVE

The aim of this study was measure and compare Secretory IgA levels in the respiratory tract.

DESIGN

Cross-sectional study.

SETTING

Neumology Department of General Hospital. La Raza Medical Center Mexico.

MATERIAL AND METHOD

There were 35 volunteers. Samples of sputum, washings nasopharyngeal and bronchial was obtained from thirty five patients with COPD. Measurement of SIgA levels was performed by nephelometric technique. Results is reported as ratio of SIgA concentration/Total proteins concentration named SIgA relative concentration. Correlation index was obtained of three type of samples.

RESULTS

The SIgA values of sputum, washings nasopharyngeal and bronchial was similar similar +/- 0.011, 0.064 +/- 0.007 and 0.082 +/- 0.017 respectively). Multiple correlation was r = 0.508 (p < 0.01).

Characterization of rat liver-specific methionine adenosyltransferase gene promoter. Role of distal upstream cis-acting elements in the regulation of the transcriptional activity

Methionine adenosyltransferase is a ubiquitous enzyme that catalyzes the only known route of biosynthesis of S-adenosylmethionine, the major methyl group donor in cell metabolism. In mammals, two different methionine adenosyltransferases exist: one is confined to the liver, and the other one is distributed in extrahepatic tissues. In the present study, we report the cloning of the 5'-flanking region of liver-specific methionine adenosyltransferase gene from rat. Two closely spaced sites for transcriptional initiation were identified by primer extension analysis. The major transcription start site was determined to be 29 nucleotides downstream from the putative TATA box. Transient transfection assays of constructs containing sequentially deleted 5'-flanking sequences fused to the luciferase gene showed that rat hepatic methionine adenosyltransferase promoter was able to efficiently drive reporter expression not only in liver-type cells (rat hepatoma H35 cells and human hepatoblastoma HepG2 cells) but also in Chinese hamster ovary cells. Two regions spanning nucleotides -1251 to -958 and -197 to +65 were found to be crucial for the promoter efficiency. The distal upstream region contains elements that positively regulate promoter activity in H35 and HepG2 cells but are ineffective in Chinese hamster ovary cells. Eight protein binding sites were characterized in both regions by DNase I footprinting analysis. Two of these elements, sites A and B, located in the distal region, were found to be essential for the regulation of promoter activity. Electrophoretic mobility shift assays and competition experiments showed that site A is recognized by an NF1 protein. Site B was able to interact with a member of HNF-3 family when nuclear extracts from rat liver and H35 cells were used in the in vitro assay, but an additional binding activity to an NHF1-like protein was obtained with the hepatoma cell extracts. It is suggested that this differential binding can contribute to the cell specificity of promoter function.

Stimulation of DNA synthesis by natural ceramide 1-phosphate

We found that natural (long-chain) ceramide 1-phosphate can be dispersed into aqueous solution when dissolved in an appropriate mixture of methanol/dodecane (49:1, v/v). This solvent mixture facilitates the interaction of this phosphosphingolipid with cells. Under these conditions, incubation of EGFR T17 fibroblasts with natural ceramide 1-phosphate caused a potent stimulation of DNA synthesis. This effect was accompanied by an increase in the levels of proliferating-cell nuclear antigen. Concentrations of natural ceramide 1-phosphate that stimulated the synthesis of DNA did not inhibit adenylate cyclase activity, nor did they stimulate phospholipase D. Natural ceramide 1-phosphate did not alter the cellular phosphorylation state of tyrosine residues or of mitogen-activated protein kinase. Furthermore, natural ceramide 1-phosphate failed to induce the expression of the proto-oncogenes c-myc and c-fos. Both the stimulation of DNA synthesis and the induction of proliferating-cell nuclear antigen by natural ceramide 1-phosphate were inhibited by natural ceramides. This work suggests that the use of methanol and dodecane to deliver natural ceramide 1-phosphate to cells may be useful for elucidation of the biological function(s) and mechanism(s) of action of ceramide 1-phosphate.

Etidronate versus fluoride for treatment of osteopenia in primary biliary cirrhosis: preliminary results after 2 years

BACKGROUND & AIMS

Because osteopenia increases morbidity of primary biliary cirrhosis (PBC), the effects of cyclical etidronate vs. sodium fluoride on bone mass were compared in patients with PBC.

METHODS

Thirty-two women with PBC were randomly assigned to receive etidronate (400 mg/day during 14 days every 3 months) or fluoride (50 mg/day, enteric-coated tablets). Bone mineral density of the lumbar spine and proximal femur were measured initially and every 6 months. Bone fractures were also evaluated.

RESULTS

Sixteen patients were allocated into each group, which were comparable with respect to the severity of PBC and osteopenia. Thirteen patients with etidronate and 10 patients with fluoride completed 2 years in the study. In the etidronate group, bone mineral density increased in the lumbar spine (P = 0.02) and did not change in the proximal femur. In the fluoride group, lumbar bone mineral density did not change but femoral bone mass decreased, particularly in the Ward's triangle. Two patients in the fluoride and none in the etidronate group developed new vertebral fractures, and the number of new nonvertebral fractures was similar in both groups. Neither treatment impaired liver function or cholestasis.

CONCLUSIONS

Cyclical etidronate is more effective and better tolerated than sodium fluoride in preventing bone loss in PBC.

Biochemical markers of bone turnover in Camurati-Engelmann disease: a report on four cases in one family

Moderate increases in "classical" biochemical markers of bone turnover have been described only in some patients with Camurati-Engelmann disease. However, the determination of the following "new" markers has not been previously performed: serum osteocalcin (BGP), bone alkaline phosphatase (BAP), carboxyterminal propeptide of type I procollagen (PICP), aminoterminal propeptide of type I procollagen (PINP), tartrate-resistant acid phosphatase (TRAP), telopeptide carboxyterminal of type I collagen (ICTP), urinary pyridinoline (PYR), crosslinked N-telopeptides of type I collagen (NTX), and Crosslaps (CL). Such a determination may improve the evaluation of the disease activity. To evaluate the usefulness of biochemical markers of bone turnover reflecting Camurati-Engelmann disease activity we measured the levels of all these markers in four affected patients. The results were compared with bone scintigraphic indices of disease activity. Except for PICP and TRAP, bone formation and resorption markers were abnormal in all patients and were related to bone scan indices of disease activity. Among the markers of bone formation PINP, BAP, and BGP showed the highest values, whereas NTX and CL were the most sensitive markers of bone resorption. These results suggest that the determination of NTX or CL, and PINP or either BAP and BGP, associated with bone scan evaluation, provides the best assessment of Camurati-Engelmann disease activity.

Actinomycin D treatment leads to differentiation and inhibits proliferation in rhabdomyosarcoma cells

Human embryonal cell line RD is derived from rhabdomyosarcoma, a tumor of childhood that arises from rhabdomyoblasts probably arrested somewhere along their pathway to maturation. Because actinomycin D is a drug of choice in the treatment of rhabdomyosarcomas, and because it has been used to induce differentiation as an alternative therapy for myeloproliferative syndromes, we treated RD cells with different concentrations of actinomycin D and evaluated the effects on growth and differentiation. Actinomycin D treatment in vitro caused time- and dose-dependent growth inhibition. Interestingly, RD cells treated with low doses (2.85 and 5.7 nmol/L) of actinomycin D for 6 days showed morphologic and phenotypic differentiation, with increased expression of desmin, alpha-actinin, and tropomyosin. However, treatment with 11.4 nmol/L actinomycin D strongly inhibited growth and had cytotoxic effects that prevented the cells from attaining myogenic differentiation. We conclude that exposure of this human embryonal rhabdomyosarcoma cell line to low concentrations of actinomycin D released the neoplastic cells from their blockade, allowing them to recover normal myogenic development. We suggest a potential role for differentiation therapy in the treatment of rhabdomyosarcomas.

[Contribution of thalamic somatosensory evoked potentials to stereotaxic thalamometry]

INTRODUCTION

In order to use short latency somatosensory thalamic evoked potentials (PES) to locate therapeutic targets in functional surgery, thalamic PES were recorded during stereotactic thalamotomy in 25 patients with Parkinson's disease, using a concentric bipolar semi-micro-electrode, 4 mm in diameter. In the 72 trajectories planned. 628 registers were made, obtaining 314 PES in 55 trajectories. These recordings were divided into 5 groups, according to the electrical variables evaluated in each case (absolute latency, inter-peak latency, absolute amplitude and number of phases).

MATERIAL AND METHODS

The electrophysiological characteristics of the PES groups obtained, and the spatial representation of these in a tridimensional system of coordinates, is shown. We analyze the sequence of the groups of potentials in each of the trajectories followed.

CONCLUSIONS

We consider that the limit between adjacent nuclear edges, ventral intermediate (Vim)-ventro-caudal (Vc), may be represented by the transition of potentials in group 1 to potentials in group 4 and/or potentials of group 3 to those of group 2. This study shows that thalamic PES are useful for locating targets during stereotactic thalamotomy.

Comparative plasma disposition kinetics of ivermectin, moxidectin and doramectin in cattle

The persistence of the broad-spectrum antiparasitic activity of endectocide compounds relies on their disposition kinetics and pattern of plasma/tissues exchange in the host. This study evaluates the comparative plasma disposition kinetics of ivermectin (IVM), moxidectin (MXD) and doramectin (DRM) in cattle treated with commercially available injectable formulations. Twelve (12) parasite-free male Hereford calves (180-210 kg) grazing on pasture were allocated into three groups of four animals each. Animals in each group received either IVM (Ivomec 1%, MSD AGVET, Rahway, NJ, USA), MXD (Cydectin 1%. American Cyanamid, Wayne, NJ, USA) or DRM (Dectomax 1%, Pfizer Inc., New York, NY, USA) by subcutaneous injection at a dose of 200 micrograms/kg. Jugular blood samples were collected from 1 h up to 80 days post-treatment, and plasma extracted, derivatized and analysed by high performance liquid chromatography (HPLC) using fluorescence detection. The parent molecules were detected in plasma between 1 h and either 70 (DRM) or 80 (IVM and MXD) days post-treatment. The absorption of MXD from the site of injection was significantly faster (absorption half-life (t1/2ab) = 1.32 h) than those of IVM (t1/2ab = 39.2 h) and DRM (t1/2ab = 56.4 h). MXD peak plasma concentration (Cmax) was reached significantly earlier (8.00 h) compared to those of IVM and DRM (4-6 days post-treatment). There were no differences on Cmax values: the area under the concentration-time curve (AUC) was higher for IVM (459 ng.d/mL) and DRM (627 ng.d/mL) compared to that of MXD (217 ng.d/mL). The mean plasma residence time was longer for MXD (14.6 d) compared to IVM (7.35 d) and DRM (9.09 d). Unidentified metabolites were detected in plasma: they accounted for 5.75% (DRM), 8.50% (IVM) and 13.8% (MXD) of the total amount of their respective parent drugs recovered in plasma. The comparative plasma disposition kinetics of IVM, MXD and DRM in cattle, characterized over 80 days post-treatment under standardized experimental conditions, is reported for the first time.

[Clinico-pathological correlation in the main types of dementia]

INTRODUCTION

Dementia has became a serious health problem in developed countries. The objective of this study was to establish the possible correlation between the initial clinical diagnosis and the anatomopathological criteria. Pathological confirmation of the cases clinically diagnosed as Alzheimer disease/senile dementia Alzheimer type (AD/SDAT) and multi-infarct dementia (MID) was carried out.

MATERIAL AND METHODS

Twelve brains from demented patients were studied. Brains were removed at post-mortem intervals of 1-3 hours to guarantee an adequate conservation of the tissue. The brains were weighed, fixed for 4 weeks in 10% buffered neutral formalin and coronally sectioned at intervals of approximately 1 cm. Bilateral sections of neocortex from frontal, temporal, parietal lobes, cingulate gyrus, amygdala, hippocampus, thalamus, cerebellum and unilateral sections of locus ceruleus and substantia nigra were taken. Five micrometer sections of the paraffin embedded material were stained by the following methods: hematoxylin-floxine, Congo red and Bielschowsky silver impregnation.

RESULTS

Our neuropathological results showed a high correlation with the initial clinical classification and confirmed the diagnosis of AD/ SDAT in 6 cases, MID in 3 cases and mixed dementia in 1 case. Two cases did not exhibited morphological evidence of dementia.

CONCLUSIONS

We concluded that the methodology applied for the morphologic diagnosis of dementia was feasible, useful and reproducible. Further studies will be necessary using a larger number of sample.

Surgical treatment of Parkinson's disease

At present, there are three major surgical approaches to Parkinson's disease (PD): (1) Ablative surgery (i.e. pallidotomy, thalamotomy); (2) deep brain stimulation (DBS) of the thalamus, internal globus pallidus (GPi) and subthalamic nucleus (STN); and (3) grafting fetal mesencephalic cells into the striatum. As a result of increasing understanding of the pathophysiology of the basal ganglia and the demonstration of surgical alleviation of experimental parkinsonism, surgery has regained a paramount importance in the management of PD. The aim of pallidotomy and DBS is to reduce the excessive inhibitory output from the GPi and substantia nigra reticulata (SNr). Pallidotomy and DBS of the STN or GPi aim to reverse the pathophysiological consequences of dopamine deficiency in PD, and should be considered entirely symptomatic treatments. The ideal candidates for pallidotomy are young patients in good general health in whom dyskinesias are the main reasons for disability. Patients with severe bilateral problems uncontrollable with present pharmacological tools are candidates for DBS. As yet, there are no formal data to help decide how to choose between GPi and STN stimulation. In our practice, patients are allocated to GPi stimulation when 'on' dyskinesias are extremely severe. In most other instances, we prefer to perform STN stimulation. At present there is almost no reason to decide for the thalamic stimulation since tremor is equally arrested by STN stimulation, which in addition improves all other features of PD. Equally the only indication for thalamotomy would be a patient with long-standing tremor as the main clinical manifestation, which can not be controlled with drugs. The proportion of patients in whom the thalamus will be the preferable target for either DBS or thalamotomy is small (less than 5%). Grafting aims to repair the nigrostriatal pathway and restore dopaminergic function in the striatum. In the future implants containing not only dopaminergic cells but also growth factors and a variety of other substances could become a method to not only functionally compensate the biochemical abnormalities of PD but also to arrest its progression. This technique is limited to a few centres around the world owing to the technical, logistical and ethical problems of obtaining and handling embryonic cells. At present, grafting of dopaminergic cells is perhaps best suited for patients with young-onset PD (less than 45 years old) who are at high risk of developing complications within a short time of beginning pharmacological treatment and in whom the idea of making lesions or implanting electrodes into the brain for decades seems less appealing. Consideration of surgery in any given patient should be weighed against the risks (about 1% mortality and 2-6% of severe morbidity-hemiplegia, cognitive deficit, speech problems, etc.) associated with these techniques. The development of better imaging methods and the growing expertise of multidisciplinary teams will undoubtedly make surgery for PD safer and more effective in the future.

Structural and ultrastructural study of the myocardium after 24-hour preservation in University of Wisconsin solution

This study deals with myocardial preservation after 24 hours of continuous perfusion with University of Wisconsin (UW) solution, focusing on the morphological changes produced by preservation and reperfusion, and their possible relationship to the composition of the solution and the immediate hemodynamic findings after orthotopic heart transplantation in dogs. Following preservation, the histological images of the myocardium were normal in almost every case. After revascularization, although 50% of the hearts recovered preoperative functional levels, there were relevant histological changes in all of them. These changes consisted of interstitial edema, damage to at least 50% of the mitochondria, presence of contraction bands, loss of intercellular junction structure and vasoconstriction. According to these results, the association of continuous perfusion and UW solution appears to be effective during the ischemic period of prolonged myocardial preservation, but not during reperfusion. Perhaps the proportion of viable hearts could be increased by preventing vasoconstriction.

Glucocorticoid regulation of hepatic S-adenosylmethionine synthetase gene expression

The effects of glucocorticoids on the regulation of rat liver S-adenosylmethionine synthetase were studied in vivo and in two culture systems. Livers from adrenalectomized animals were examined for enzyme activity, immunoreactive protein, and messenger RNA (mRNA) content. All three parameters showed a similar trend, i.e. they decreased 3-fold after adrenalectomy and increased over the control values upon triamcinolone replacement. These results suggested that glucocorticoid regulation of hepatic S-adenosylmethionine synthetase was mediated at the mRNA level. Triamcinolone and dexamethasone increased S-adenosylmethionine synthetase mRNA content in a time- and dose-dependent manner in both rat hepatoma H35 cells and primary cultures of adult rat hepatocytes. The kinetics of mRNA induction were identical in both culture systems, indicating that the hormone-mediated response is independent of the differentiated state of the cell. Insulin blocked the inducing effect of glucocorticoids on S-adenosylmethionine synthetase mRNA in a dose-dependent manner. On the other hand, the triamcinolone-dependent increase in mRNA levels was completely abolished by treatment with actinomycin D, whereas cycloheximide did not affect this response. The transcription rate of the gene, as measured by run-on assay, increased 3-fold after hormone addition. Transient transfections of H35 cells with 1.4 kilobases of the 5'-flanking region of the hepatic S-adenosylmethionine synthetase gene fused to a luciferase reporter gene showed that promoter activity is also increased 3-fold after triamcinolone treatment, suggesting that this promoter region contains the sequence elements necessary to confer glucocorticoid responsiveness. In addition to the transcriptional control of the hepatic S-adenosylmethionine synthetase gene, our results suggest that glucocorticoids may be acting at a posttranscriptional level.

Relationship between biochemical markers of bone turnover and bone scintigraphic indices in assessment of Paget's disease activity

OBJECTIVE

To evaluate the relationship between biochemical markers of bone turnover and bone scan indices of disease activity, as well as to analyze their variations based on skeletal involvement, in Paget's disease.

METHODS

Serum samples were obtained from 51 patients with Paget's disease to determine the levels of total alkaline phosphatase (total AP), bone alkaline phosphatase (bone AP), propeptide carboxyterminal of type I procollagen (PICP), propeptide aminoterminal of type I procollagen (PINP), osteocalcin, tartrate-resistant acid phosphatase, and telopeptide carboxyterminal of type I collagen. Urine samples were analyzed for levels of hydroxyproline (HYP), pyridinoline (PYR), deoxypyridinoline (DPYR), C-terminal telopeptide of type I collagen (CTx), and N-terminal telopeptide of type I collagen (NTx). In addition, 2 semiquantitative scintigraphic indices, disease activity (AI) and disease extent (EI), were obtained. Pagetic skeletal locations were evaluated individually, with special attention to skull involvement.

RESULTS

All biochemical markers correlated with the AI and the EI. Serum PINP, bone AP, and total AP showed the highest proportions of increased values among the bone formation markers (94%, 82%, and 76%, respectively). Among the bone resorption markers, urinary NTx showed the highest proportion of increased values in patients with Paget's disease (96%), compared with PYR (69%), DPYR (71%), CTx (65%), and HYP (64%). In patients with mild disease activity, serum PINP was the marker with the highest proportion of increased values (71%). In contrast, serum PICP and urinary CTx were the most discriminative markers for skull involvement. Except for higher values for most of the biochemical markers of bone turnover in flat bones, no major differences in other skeletal locations were observed.

CONCLUSION

The determination of serum PINP as a marker of bone formation and urinary NTx as a marker of bone resorption provided the best biochemical profile to ascertain the extent and activity of Paget's disease. In patients with skull involvement, serum PICP and urinary CTx were shown to be the most discriminative markers.

Recombinant rat liver S-adenosyl-L-methionine synthetase tetramers and dimers are in equilibrium

Rat liver S-adenosyl-L-methionine synthetase is present in two oligomeric forms, tetramers and dimers, with different substrate kinetics and regulation. In vivo the relative amounts of both forms may change in some instances. The basis of this regulatory mechanism is not known. When rat liver cDNA was used to express the protein in Escherichia coli the two oligomeric forms were found. Gel filtration chromatography of the purified recombinant enzyme suggested that these two isoforms might be in equilibrium. This was confirmed by kinetic experiments which showed that the specific activity of the enzyme was dependent on the protein concentration. From these experiments, apparent equilibrium constants of (5.6 +/- 0.4) x 10(5) M-1 and (3.5 +/- 0.9) x 10(5) M-1 were obtained at 2mM and 60 microM methionine concentrations, respectively. Using hydrophobic chromatography on phenyl-Sepharose to separate the tetrameric and dimeric forms, an equilibrium constant of (4.9 +/- 0.7) x 10(5) M-1 was calculated. A rate constant for the dissociation of the tetramer of k-1 = (8.1 +/- 0.4) x 10(-4) s-1 at 4 degrees C was also calculated using the same approach. In summary, we have shown that the rat liver S-adenosyl-L-methionine synthetase produced in bacterial cells is present in two oligomeric forms, tetramers and dimers, which are in equilibrium. This system might be useful for studying the dynamics and the regulation of the distribution of oligomeric forms in the mammalian liver.

Developmental toxicity of dimethyl sulfate by inhalation in the rat

Dimethyl sulfate (DMS; CAS No. 77-78) is a colorless, oily liquid which is used as a chemical intermediate and as a reactant in producing polyurethane resins. In this study, groups of pregnant Crl:CD BR rats were exposed, nose-only, to either 0.1, 0.7 or 1.5 ppm DMS by inhalation for 6 hr/day from Days 7 through 16 of gestation (day in which copulation plug was detected was designated Day 1G). A control group of pregnant rats was exposed simultaneously to air only. All female rats were euthanized on Day 22G and the fetuses were examined. A suppression of both food consumption and the rate of body weight gain was seen in the 0.7 and 1.5 ppm groups. No unusual clinical signs were seen in rats exposed to DMS. None of the reproductive parameters was altered in any of the groups and no statistically significant fetal effects were detected. DMS is not a developmental toxin in the rat following inhalation exposures up to 1.5 ppm during the period of major organogenesis.

Radiologic study of patellar height in Osgood-Schlatter disease

There are contradictory reports regarding patellar position in the Osgood-Schlatter disease. We present a prospective statistical study of 17 patients with Osgood-Schlatter disease and 12 adolescents without anterior knee pain. The Caton-Deschamps index was assessed on strictly the lateral radiograph of the knee. The findings indicate a strong association between Osgood-Schlatter disease and patella alta. This increase in patellar height would require an increase in the force needed from the quadriceps to achieve full extension. This mechanism could be responsible for the apophyseal lesion.

Bilateral simultaneous spontaneous quadriceps tendons rupture. A case report studied by magnetic resonance imaging

A rare case of bilateral, simultaneous, and spontaneous rupture of the quadriceps tendon in a previous healthy young man is presented. Magnetic resonance imaging (MRI) defined accurately the features of the tear showing different levels of rupture on each side. This finding was especially helpful in preoperative planning.

S-adenosylmethionine synthesis: molecular mechanisms and clinical implications

Methionine adenosyltransferase (MAT) is an ubiquitous enzyme that catalyzes the synthesis of S-adenosylmethionine from methionine and ATP. In mammals, there are two genes coding for MAT, one expressed exclusively in the liver and a second enzyme present in all tissues. Molecular studies indicate that liver MAT exists in two forms: as a homodimer and as a homotetramer of the same oligomeric subunit. The liver-specific isoenzymes are inhibited in human liver cirrhosis, and this is the cause of the abnormal metabolism of methionine in these subjects.

Low sample volume causes differentiation in human rhabdomyosarcoma cell line RD subjected to electroporation

Gene transfection has been accomplished with a variety of techniques such as DEAE dextran, calcium phosphate coprecipitation, protoplast fusion, liposomes, microinjection and recombinant bacteriophages. However, transfection by electroporation, consisting of the reversible permeabilization of cell membranes after exposure to a pulsed electric field, has been shown to be the most rapid, simple and efficient method for the stable incorporation of genes in different cell lines. We studied rhabdomyosarcoma cells subjected to electroporation in two different vol. [400 microliters (group 1) and 150 microliters (group 2] of 140 mM NaCl/15 mM Hepes buffer, pH 7.2) and evaluated the effects of electroporation volume on growth and differentiation. Low sample volumes induced a terminal process of morphological and ultrastructural myogenic differentiation in rhabdomyosarcoma cells, which concluded with cell death. Our results suggest that in electroporation low sample vol. of rhabdomyosarcoma cells induced morphological and phenotypic differentiation, with increased expression of desmin, alpha-actinin and tropomyosin.

Increased sensitivity to oxidative injury in chinese hamster ovary cells stably transfected with rat liver S-adenosylmethionine synthetase cDNA

Chinese hamster ovary cells were stably transfected with rat liver S-adenosylmethionine synthetase cDNA. As a result, S-adenosylmethionine synthetase activity increased 2.3-fold, an effect that was accompanied by increased S-adenosylmethionine, a depletion of ATP and NAD levels, elevation of the S-adenosylmethionine/S-adenosylhomocysteine ratio (the methylation ratio), increased DNA methylation and polyamine levels (spermidine and spermine), and normal GSH levels. By contrast, the transfected cells showed normal growth curves and morphology. Exposure to an oxidative stress by the addition of H2O2 resulted in a greater consumption of ATP and NAD in the transfected cells than in the wild-type cells. In turn, cell killing by H2O2 was greater in the transfected cells than in the wild-type cells. This killing of Chinese hamster ovary cells by H2O2 involved the activation of poly(ADP-ribose) polymerase with the resultant loss of NAD and ATP. 3-Aminobenzamide, an inhibitor of poly(ADP-ribose) polymerse, but not the antioxidant N,N'-diphenylphenylenediamine, prevented the killing of Chinese hamster ovary cells by H2O2 and maintained the contents of NAD and ATP. The results of this study indicate that a moderate activation of the synthesis of S-adenosylmethionine leads to ATP and NAD depletion and to a greater sensitivity to cell killing by oxidative stress.

Preoperative clinical, EEG, and imaging findings do not predict seizure outcome following temporal lobectomy in childhood

Although certain clinical, electroencephalographic (EEG), magnetic resonance imaging (MRI), and pathologic findings in adults with intractable temporal lobe epilepsy predict seizure outcome following temporal lobectomy, predictors of seizure outcome have not been studied systematically in pediatric temporal lobectomy series. We retrospectively analyzed preoperative clinical, EEG, and neuroimaging findings with reference to seizure outcome (seizure free or non-seizure free) in 33 children (mean age, 9.3 years) who underwent tailored temporal lobe resections for intractable temporal lobe epilepsy. Trends were apparent with (1) younger age at seizure onset, younger age at surgery, shorter duration of epilepsy, localized unilateral temporal lesions on MRI, and right-sided surgery more frequently associated with a seizure-free outcome, and (2) significant prior history, daily preoperative seizures, generalized motor seizures, mental retardation, and localized unilateral temporal epileptiform EEG activity more frequently associated with a non-seizure-free outcome. However, none of these findings, alone or in combination, correlated with postoperative seizure status at a statistically significant level. Submitting the four variables generally considered to be most predictive of favorable outcome (ie, normal intelligence, unilateral ictal and interictal EEG discharges, and focal temporal MRI lesion) to a multiple-cutoff procedure did not predict seizure freedom. Our data indicate that predictors of outcome of temporal lobectomy in adults may not apply in children, perhaps due to inherent neurobiologic differences in the etiology and expression of temporal lobe epilepsy, and should therefore not be used as sole determinants of surgical candidacy in children.

Maxillary growth in children after early facial bipartition

Facial osteotomies performed in young children are frequently associated with growth deficiencies, especially at the middle third of the face. This problem may be more severe when the initial deformity is associated with alveolar and palatal clefts. Orbital hypertelorism is a major congenital malformation requiring early correction. The resection of the ethmoid tissues located between the orbit and the medialization of the orbital skeleton through the intracranial approach modifies the exaggerated interorbital distance but does not correct the vertical shortness at the midline of the face. Also this procedure interferes with the sagittal growth of the maxilla possibly resulting from the horizontal osteotomy across the maxillae. The medial rotation of the two halves of the face performed by the intracranial approach or the subcranial approach simultaneously corrects the orbital hypertelorism and elongates the nose and the central segment of the face. Our experience with this procedure in infants and young children is analyzed. A series of nine patients with orbital hypertelorism associated with median and paramedian clefts underwent correction by hemifacial rotation. All patients were monitored from 6 to 10 years (mean, 7 years) and demonstrated normal sagittal growth of the maxillae.

Differential expression pattern of S-adenosylmethionine synthetase isoenzymes during rat liver development

The pattern of expression of liver-specific and extrahepatic S-adenosylmethionine (SAM) synthetase in developing rat liver was established by determining steady-state levels of the respective messenger RNAs (mRNAs) and protein content. Levels of liver-specific SAM synthetase mRNA increased progressively from day 20 of gestation, increased 10-fold immediately after birth, and reached a peak at 10 days of age, decreasing slightly by adulthood. Conversely, mRNA levels of extrahepatic isoenzyme decreased toward birth, increased threefold in the newborn, and decreased further in the postnatal life, reaching a minimum in the adult. Similar expression profiles were observed in isolated hepatocytes, indicating that both mRNAs are differentially regulated in the same cell type. Western blot analysis showed that levels of immunoreactive liver-specific isoenzyme followed a trend similar to the mRNA, indicating that developmental regulation of this enzyme is mediated at the mRNA level. Developmental patterns of expression of albumin and alpha-fetoprotein (AFP) mRNAs were closely related to those for liver-specific and extrahepatic isoenzymes, respectively. Therefore, it is suggested that liver-specific SAM synthetase may be a marker for hepatocyte differentiation. Incubation of primary cultures of hepatocytes from 21-day-old fetuses with permeant cyclic adenosine monophosphate (cAMP) analogues elicited an up-regulation of the mRNA for the liver-specific isoenzyme with a concomitant down-regulation of the extrahepatic message, suggesting a physiological role for the increased postnatal glucagonemia in the control of this isoenzyme switching. In contrast with the isoenzyme expression profiles, the levels of SAM, the product of SAM synthetase reaction, were determined to be greater during gestation than in immediate postnatal periods. These results indicate that synthesis and utilization of SAM may be regulated differentially in fetal and adult hepatocytes.

Hepatitis C virus RNA quantification in right and left lobes of the liver in patients with chronic hepatitis C

Quantification of hepatitis C virus RNA in liver tissue is likely to be useful in the study of the natural history, pathogenesis, progression and treatment of hepatitis C virus-associated liver disease. Quantitative measurements of hepatitis C virus RNA in liver biopsy samples using the branched DNA (bDNA) signal amplification assay were carried out. The aims of this study were threefold: first, to assess the level of hepatitis C virus RNA in biopsy samples from the right and left lobes of the liver; second, to evaluate the correlation between hepatitis C virus RNA levels in serum and liver; and third, to investigate the relationship between serum and liver hepatitis C virus RNA levels and the severity of hepatic histology in non-cirrhotic patients with chronic hepatitis C. There was a strong correlation (r = 0.92, P < 0.01) between hepatitis C virus RNA levels in the right and left lobes of the liver as well as a strong correlation between hepatitis C virus RNA levels in liver and serum (r = 0.82, P < 0.01). However, there was no significant correlation between the severity of hepatic histology and levels of hepatitis C virus RNA in serum and liver among patients with chronic active hepatitis classified according to Knodell's hepatic activity index (KI). Our results indicate that hepatitis C virus RNA quantification from a single liver biopsy is representative of both lobes in patients with chronic hepatitis, and suggest that serum hepatitis C virus RNA levels are a meaningful reflection of hepatitis C virus RNA levels in the liver.

Inverse expression of mdr 1 and c-myc genes in a rhabdomyosarcoma cell line resistant to actinomycin d

Cytotoxic agents used in cancer therapy may induce differentiation in tumour cells with no proliferative potential. However, chemotherapy can also induce multidrug resistance, a formidable obstacle to the successful treatment of tumours. Both events were recently shown to occur in a rhabdomyosarcoma cell line (RD-DAC) resistant to actinomycin D, a drug of choice in the treatment of these tumours. To analyse this connection, cell line RD cultures were investigated with progressive concentrations of actinomycin D and it was shown that a minimum dose (1.2 x 10(-6) mM) of the drug was necessary to increase mdr 1 mRNA in RD-DAC. The mechanism of mdr 1 overexpression was an increase in the number of copies of the mdr 1 gene, although the mRNA levels were not correlated with mdr 1 amplification. Drug resistance mediated by mdr 1 overexpression coincided with the development of myogenic differentiation in RD-DAC and with a decrease in c-myc mRNA levels, whereas levels of N-myc mRNA showed no modulation. These findings suggest that factors implicated in cell proliferation and differentiation, such as c-myc, may be responsible for the control of genes related to the development of multidrug resistance in rhabdomyosarcomas. Modulation of these factors may determine the sensitivity of rhabdomyosarcoma cells to drugs and may play an important role in triggering the differentiation programme found in these resistant rhabdomyosarcoma cells.

Experimental study of the antithrombogenic behavior of Dacron vascular grafts coated with hydrophilic acrylic copolymers bearing salicylic acid residues

The objective of the present work was study of the behavior of active coatings of hydrophilic acrylic polymers bearing salicylic acid residues linked covalently to the macromolecular chains, after their application to woven and knitted Dacron vascular grafts. In vitro tests were carried out under dynamic flow conditions using equipment especially designed to reproduce physiologic conditions, to determine the retention of the coating using a saline solution. Ex vivo tests were carried out in an extracorporeal circuit using the dog as an animal model. The study of the deposition of platelets was followed by labeling of autologous platelets with 111In-oxine, as well as by analysis of the surfaces of the prostheses by scanning electron microscopy. An application of thin coatings of hydrophilic acrylic copolymers improves the antithrombogenicity of the vascular grafts with respect to the uncoated prosthesis. The presence of relatively small amounts of units bearing salicylic acid residues in the copolymer chains (5-20 wt %) gives good results when they are applied to woven and knitten Dacron meshes which have been quantified by analysis of the percentage of radiotracer on the surface of the vascular grafts tested in ex vivo experiments. The salicylic acid residues are released slowly to the medium by hydrolysis of the reversible covalent bonds of this compound to the acrylic macromolecular chains, which provides an additional antiaggregating effect for platelets. The polymeric coating forms a thin active film which improves the antithrombogenic properties of the surface of woven or knitted Dacron vascular grafts in ex vivo experiments.

Bioactive polyacetylenes from Bidens pilosa

From the methanolic extract of the whole plants of Bidens pilosa the new beta-D-glucopyranosyloxy-3-hydroxy-6(E)-tetradecen-8, 10,12-triyne besides a known polyine has been isolated and identified mainly by IR and NMR methods. The new compound showed overgrowing action against normal and transformed human cell lines in culture.

Language cortex representation: effects of developmental versus acquired pathology

Relatively little is known about language cortex representation in patients with developmental pathology and epilepsy. We report the results of mapping language by electrical stimulation of chronically implanted subdural electrodes in 34 patients (mean age, 12.2 years) evaluated for epilepsy surgery, 28 of whom had magnetic resonance imaging or histological evidence of developmental tumors or cortical dysplasia. Language cortex was identified in the temporal or frontal lobe of 19 patients (left hemisphere in 17, right hemisphere in 2), and overlapped or bordered the epileptogenic region in 12. Language cortex was not found in the frontal or temporal lobe of 15 patients (left hemisphere in 4, right hemisphere in 11) and was presumed to be contralateral to grid placement. Three patients with left-hemisphere perinatal or postnatal cerebral insults before the age of 5 years had no language in the left hemisphere, while 3 patients with insults between the ages of 6 and 16 years had preserved left-hemisphere language. Developmental lesions and early-onset seizures do not displace language cortex from prenatally determined sites, whereas lesions acquired before the age of 5 years may cause language to relocate to the opposite hemisphere, but only when language cortex is destroyed.