A machine learning approach to assess changes in scoliosis

This paper presents a machine learning approach that can be used to evaluate the validity of the results obtained with an automated system to measure changes in scoliotic curves. The automated system was used to measure the inclinations of 141 vertebral endplates in spine radiographs of patients with scoliosis. The resulting dataset was divided into training and test set. The training set was used to configure three classifiers: a support vector classifier (SVC), a decision tree classifier (DT) and a logistic regression classifier (LR). Their performance was evaluated on the test set. The SVC had an accuracy of 86% discriminating Good Results (those in which the error was less than 3 degrees ) from Bad Results. This accuracy was better than that of the LR (76%) and DT (68%). The differentiation between Good and Bad Results using the proposed machine learning approach was achieved successfully.

Cytokine gene polymorphisms in Colombian patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) patients exhibit alterations in cytokine production that may be relevant to SLE pathogenesis. There is evidence that cytokine gene polymorphisms control cytokine production; thus, these polymorphisms may be associated with SLE or its clinical manifestations. To establish the association of tumor necrosis factor alpha (TNF-alpha), transforming growth factor (TGF) beta1, interleukin (IL)-10, and IL-6 gene polymorphisms in Colombian SLE patients and their clinical manifestations, 120 SLE patients and 102 healthy controls were studied. Single nucleotide polymorphisms were studied by sequence-specific primers polymerase chain reaction (SSP-PCR) at: TNFalpha-308 (G/A), TGFbeta1 codon 10 (C/T) and codon 25 (G/C), IL-10 -1082 (G/A), -819 (C/T) and -592 (C/A), and IL-6 + 174 (G/C). Human leukocyte antigen (HLA)-DRbeta1 was typed by SSP-PCR. SLE patients had increased frequency of allele C at TGFbeta1 codon 25 (P = 0.0001, odds ratio (OR): 4.25, 95% confidence interval (CI): 2.17-8.35) and allele A at TNFalpha-308 (P = 0.0004 OR: 3.9, 95% CI: 1.65-5.80) compared with healthy controls. There was higher frequency of GC genotype at TGFbeta1 codon 25 in SLE patients (P < 0.0001). Extended genotypic analysis showed that SLE patients have decreased frequency of TNFalphaLow/TGFbeta1High (0.50) compared with healthy controls (0.80) (P < 0.0001). No association was found between these polymorphisms and SLE clinical manifestations except for Sm and Ro autoantibodies that were associated with TNFalpha allele A. There is an association between TNFalpha-308A/TGFbeta1 codon 25C with SLE susceptibility in Colombian population. This association may result in a highly inflammatory response with a decrease regulatory function mediated by TNFalpha and TGFbeta1, respectively. The TNFalpha-308A/TGFbeta1 25C genotype may be one component of genetic susceptibility to SLE in Colombian population.

Automatic matching of spine images to assess changes in scoliosis

This paper presents an image matching approach that can be used to measure changes in scoliotic curves. The proposed approach uses a novel fuzzy logic controller to estimate all open parameters. Using fluoroscopy images of a spine phantom, it was found that, with minimal user interaction, the matching of spine images could be achieved with high accuracy (the average errors were around 0.03 mm) and high computational efficiency (requiring less than 1 minute for matching each vertebra).

Evaluating similarity metrics in an image matching tool for image guided spine surgery

This paper presents a comparison study of the effect of three similarity measures (mutual information, normalized mutual information, and mean squared error on the edges of the input image) in an image matching tool that can be used in image guided spine surgery. Using 3D rotational x-rays and magnetic resonance images of a spine phantom, it was found that the similarity measures had similar effect. Therefore, experiments with other datasets are needed before making conclusions about the suitability of these similarity metrics for image guided surgery.

Latin-American trial of orlistat for weight loss and improvement in glycaemic profile in obese diabetic patients

AIM

To determine if obese non-insulin-dependent diabetic patients lose more weight when treated for 24 weeks (6 months) with orlistat (120 mg t.i.d.), in conjunction with a hypocaloric diet plus behavioural counselling, than when treated by placebo (t.i.d.) plus similar instructions. The secondary objectives were to evaluate the effects on glucose profile and to determine the tolerability and safety of orlistat.

DESIGN

Double-blind, parallel, randomized, placebo-controlled, multicentre study.

SUBJECTS

Obese, non-insulin-dependent diabetic patients, aged 18-70 years old, with BMI > 27 kg/m2, evaluated at 10 Latin-American centres, in five countries. EFFICACY AND TOLERABILITY MEASUREMENTS: After screened, eligible patients passed by a 2-week placebo run-in period receiving a hypocaloric diet. On day 0, patients were randomized to orlistat or placebo for 24 weeks. At each visit, body weight, blood pressure and waist circumference were measured. At the screening visit, baseline visit (week 0), and at weeks 8, 16 and 24, a central laboratory was in charge of measuring fasting glucose and insulin, HbA1c, postprandial glucose and insulin, fasting total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides, and postprandial triglycerides. Other safety laboratory assessments were measured locally at the screening visit, baseline visit and at the end of the study. Adverse events were assessed at each visit from baseline.

RESULTS

After 24 weeks of treatment, the orlistat group lost an average of 4.7% of initial body weight vs. 3.0% in the placebo group (p = 0.0003). A greater weight loss was achieved in the orlistat compared with the placebo group (4.24 +/- 0.23 vs. 2.58 +/- 1.46 kg, p = 0.0003). Almost twice as many patients receiving orlistat (30% vs. 17%) lost > or = 5% of initial body weight (p = 0.003). Orlistat treatment plus diet compared to placebo plus diet was associated with significant improvement in glycaemic control, as reflected in decreases in HbA1c (p = 0.04), fasting plasma glucose (p = 0.036) and postprandial glucose (p = 0.05). Orlistat-treated patients had a mean decrease in glucose levels of 1.00 +/- 0.34 mmol/l [3.7%] vs. 0.01 +/- 0.30 mmol/l for placebo group, at week 24 and an absolute decrease of HbA1c of 0.61 +/- 0.15 vs. a decrease of 0.22 +/- 0.14% in the placebo group. Orlistat therapy also resulted in significantly greater improvements than placebo in lipid profile, with reductions in total cholesterol (p = 0.0001) and LDL-cholesterol (p = 0.002). Mild to moderate transient gastrointestinal events were reported, mainly with orlistat treatment, but their association with withdrawal from the study was low.

CONCLUSION

Orlistat is a useful and an effective therapy in obese diabetic patients, promoting clinically significant weight loss and improved glycaemic control and lipid profile.

Adequacy and nutrition in the absence of residual renal function in peritoneal dialysis

With the aim of evaluating nutrition indices and dialysis adequacy level in patients who started peritoneal dialysis (PD) without residual renal function, we retrospectively studied 19 patients [8 men, 11 women; 3 with diabetes (15.8%); mean age: 44.5 +/- 10.74 years; 15 on continuous ambulatory peritoneal dialysis (CAPD), 3 on continuous cycling peritoneal dialysis (CCPD), 1 on nightly intermittent peritoneal dialysis (NIPD)]. The mean time spent by these patients on hemodialysis before PD was 62.7 +/- 54.7 months (range: 8.8-216 months), and the mean time on PD was 46.2 +/- 21.4 months (range: 10-75 months). In these patients, we measured weekly Kt/V urea, weekly creatinine clearance (CrC), normalized protein catabolic rate (nPCR), body surface area (BSA), urea distribution volume (V), serum albumin, body mass index (BMI), percent lean body mass (%LBM), infusion volume (liters per day), subjective global assessment (SGA), and peritoneal equilibration test (PET). Using the Student t-test at a significance level of p < 0.05, we compared initial body weight (INW), actual weight (AW), and ideal body weight (IBW) according to age, sex, and height. We analyzed actuarial and technique survival (Kaplan-Meier). In regard to patient survival, only death was considered the end point; for technique survival, only technique failure was considered the end point. Data are expressed as mean +/- standard deviation. Results were: Kt/V, 2.20 +/- 0.46 L weekly; CrC, 59.11 +/- 12 L weekly; nPCR, 1.08 +/- 0.25 g/kg daily; BSA, 1.67 +/- 0.2 m2; V, 33.34 +/- 7.12; serum albumin, 3.68 +/- 0.22 g/dL; BMI, 24.06 +/- 4.16; %LBM, 64.92 +/- 10.13; SGA, 94.7% well-nourished; AW, 65.37 +/- 13.88 kg; IBW, 67.21 +/- 10.5 kg (AW vs IBW: r = 0.69, p > 0.05); INW, 61.54 +/- 11.07 kg (INW vs AW: r = 0.92, p < 0.05; INW vs IBW: r = 0.71, p < 0.05). Distribution of transport status by PET was 15.8% high transport, 36.8% high-average transport, 36.8% low-average transport, and 10.5% low transport. Mean infusion volume was 10.41 +/- 1.36 L in 24 hours. Cumulative survival was 100%, 98%, and 82% after 1, 2, and 6 years respectively. Technique survival was 100% after 6 years. The adequacy results accord with Dialysis Outcomes Quality Initiative (DOQI) recommendations, and the nutrition indices and actuarial and technique survival are satisfactory for anuric patients.

Effect of various doses of recombinant human thyrotropin on the thyroid radioactive iodine uptake and serum levels of thyroid hormones and thyroglobulin in normal subjects

Recombinant human TSH (rhTSH), usually given as 0.9-mg doses im on 2 successive days, increases serum thyroglobulin (Tg) and radioactive iodine uptake (RAIU) in residual thyroid tissue in patients with thyroid cancer. We previously reported that a single, relatively low dose of rhTSH (0.1 mg im) is a potent stimulator of T(4), T(3), and Tg secretion in normal subjects. The present study describes the effects of higher doses of rhTSH on thyroid hormone and Tg secretion. Six normal subjects for each dose group, having no evidence of thyroid disease, received either 0.3 or 0.9 mg rhTSH by im injection. Serum TSH, T(4), T(3), and Tg concentrations were measured at 2, 4, and 8 h and 1, 2, 3, 4, and 7 days after rhTSH administration. The peak serum TSH concentrations were 82 +/- 18 and 277 +/- 89 mU/L, respectively, for the 0.3- and 0.9-mg doses of rhTSH. Serum T(4), T(3), and Tg concentrations increased significantly in subjects receiving 0.3 and 0.9 mg rhTSH, with significant increases in T(4) and T(3) being observed before significant increases in serum TG: Peak concentrations of serum T(4), T(3), and Tg, after 0.3 mg rhTSH administration, were 100 +/- 19, 131 +/- 14, and 1035 +/- 724% above individual baselines, respectively. Similarly, peak concentrations of serum T(4), T(3), and Tg, after 0.9 mg rhTSH administration, were 102 +/- 16, 134 +/- 7, and 1890 +/- 768% above individual baselines, respectively. These data, compared with previously reported data for the responses to 0.1 mg rhTSH, indicated that 0.1, 0.3, and 0.9 mg rhTSH had similar quantitative stimulatory effects on thyroid hormone and Tg secretion, except that the T(4) response was greater in groups receiving 0.3 and 0.9 mg rhTSH than in the group receiving 0.1 mg rhTSH. We also studied the effect of rhTSH on the thyroid RAIU in the group that received 0.9 mg rhTSH. The 6- and 24-h RAIU values were significantly higher after rhTSH (pre-rhTSH, 6-h value = 12.5 +/- 1.8%; 24 h value = 23 +/- 2.7%; post-rhTSH, 6 h value = 27 +/- 4.8%; 24-h value = 41 +/- 4.2%). The stimulating effects of 0.9 mg rhTSH on the 6- and 24-h RAIUs were similar. rhTSH is a potent stimulator of T(4), T(3), and Tg secretion and the RAIU in normal subjects. Single doses greater than 0.1--0.3 mg do not seem to further enhance thyroid hormone or Tg secretion.

A physical map of the human genome

The human genome is by far the largest genome to be sequenced, and its size and complexity present many challenges for sequence assembly. The International Human Genome Sequencing Consortium constructed a map of the whole genome to enable the selection of clones for sequencing and for the accurate assembly of the genome sequence. Here we report the construction of the whole-genome bacterial artificial chromosome (BAC) map and its integration with previous landmark maps and information from mapping efforts focused on specific chromosomal regions. We also describe the integration of sequence data with the map.

Biodegradable PLGA microspheres loaded with ganciclovir for intraocular administration. Encapsulation technique, in vitro release profiles, and sterilization process

PURPOSE

The purpose of this work was to obtain a sterilized formulation consisting of biodegradable microspheres of poly (DL-lactide-co-glycolide) (PLGA) for intraocular sustained release of ganciclovir.

METHODS

Microspheres were prepared using a dispersion of ganciclovir in fluorosilicone oil (FSiO) that was further dispersed in an acetone solution of PLGA [50/50 and inherent viscosity 0.41 dl/g], and emulsified in silicone oil with a surfactant. Once prepared, the formulation was exposed with an effective gamma radiation dose of 2.5 megarads. The release rate data of ganciclovir from the sterilized and nonsterilized batches were compared using the similarity factor (f2).

RESULTS

The dispersion of the drug in FSiO contributed to achieving a drug payload of up to 95% of the theoretical in the 300-500 microm microspheres. Ten mg released ganciclovir in vitro at 1.3 microg/h for the first 21 days, but decreased to approximately 0.2 microg/h from day 25 until the end of the release study (42 days). No significant differences in the amounts of encapsulated drug (alpha = 0.05) were observed between the sterilized and nonsterilized microspheres. Furthermore, dissolution profiles of formulations behaved similarly before and after gamma radiation exposure.

CONCLUSIONS

The technique of microsphere preparation described resulted in high ganciclovir loading (95%) and prolonged drug release. The ganciclovir formulation behaved similarly before and after the sterilization process.

Ablation of idiopathic ventricular tachycardia by bipolar radiofrequency current application between the left aortic sinus and the left ventricle

BACKGROUND

Failure to ablate idiopathic ventricular outflow tract tachycardia by radiofrequency current is not uncommon and suggests that non-standard approaches may be required to map and suppress idiopathic ventricular tachyarrhythmias in some patients.

METHODS AND RESULTS

Left and right ventricular activation and pace mapping proved inadequate for radiofrequency application in a patient with idiopathic ventricular outflow tract tachycardia. Presystolic activity was recorded at the left aortic sinus of Valsalva, and the QRS complex recorded at this location during pacing showed few differences compared with that recorded during tachycardia. Radiofrequency current application at this site transiently suppressed the tachycardia. Following new mapping of the left ventricle outflow tract, radiofrequency application just below the aortic valve in close proximity to the previous aortic application site transiently abolished the arrhythmia. Finally, bipolar radiofrequency application between the distal electrode of the aortic catheter and the distal electrode of a second catheter placed in the left ventricular subaortic area permanently suppressed the tachycardia.

CONCLUSION

Bipolar radiofrequency application between the aortic sinus of Valsalva and the left ventricle could be an alternative approach in occasional patients with idiopathic ventricular outflow tract tachycardia resistant to conventional left ventricular and aortic root unipolar radiofrequency application.

Respiratory distress secondary to both amphotericin B deoxycholate and lipid complex formulation

A 73-y-old female with a history of adenocarcinoma of colon and refractory anemia developed febrile neutropenia following chemotherapy. Therapy with iv infusion of amphotericin B deoxycholate (AmBd) was initiated on day 8 of hospital admission. Premedications included acetaminophen, diphenhydramine and meperidine. Patient developed rigor, chill and elevated temperature approximately 100 min into the infusion. The infusion was temporarily discontinued and rigors subsided following administration of 25 mg meperidine im. Infusion was continued after cessation of the rigors with no further sequelae. During each infusion of AmBd over the next 3 d, the patient developed rigor, chill and elevated temperature which was managed with meperidine. However, on day 4 she developed respiratory distress, bronchospasm and visible cyanosis with oxygen saturation of 88% while on 2 L oxygen. The infusion was stopped and the symptoms subsided with administration of albuterol via nebulizer. Amphotericin lipid formulation infusion was reinstituted after 3 d because of the patient's worsening clinical status. However, the patient developed severe respiratory distress approximately 130 min into the infusion. The infusion was discontinued and she was treated with albuterol via nebulizer. Itraconazole therapy was instituted without any adverse sequelae. Clinicians should be aware of this potential adverse event since it can occur with all formulation of amphotericin.

Hematology of natural bovine trypanosomosis in the Brazilian Pantanal and Bolivian wetlands

We report hematological changes observed in natural cases of bovine trypanosomosis due to Trypanosoma vivax in beef and dairy cattle from Bolivian wetlands and Pantanal, Brazil. The main hematologic changes produced by T. vivax infections were anemia and severe leucopenia. The cattle presented macrocytic hypochromic anemia. The leukocyte changes were characterized by relative lymphocytosis and monocytosis and decrease in the neutrophil counts. The clinical signs were lachrymation, progressive weakness, marked weight loss, inappetence, diarrhea and abortions during the third trimester of pregnancy.

A Huntington's disease CAG expansion at the murine Hdh locus is unstable and associated with behavioural abnormalities in mice

Huntington's disease (HD) is a dominant disorder characterized by premature and progressive neurodegeneration. In order to generate an accurate model of the disease, we introduced an HD-like mutation (an extended stretch of 72-80 CAG repeats) into the endogenous mouse Hdh gene. Analysis of the mutation in vivo reveals significant levels of germline instability, with expansions, contractions and sex-of-origin effects in evidence. Mice expressing full-length mutant protein display abnormal social behaviour in the absence of acute neurodegeneration. Given that psychiatric changes, including irritability and aggression, are common findings in HD patients, our data are consistent with the hypothesis that some clinical features of HD may be caused by pathological processes that precede gross neuronal cell death. This implies that effective treatment of HD may require an understanding and amelioration of these dysfunctional processes, rather than simply preventing the premature death of neurons in the brain. These mice should facilitate the investigation of the molecular mechanisms that underpin the pathway from genotype to phenotype in HD.

Biodegradable poly(DL-lactic-co-glycolic acid) microspheres containing tetracaine hydrochloride. In-vitro release profile

Tetracaine does not result in effective treatment of intractable pain caused by trigeminal neuralgia because of its short duration of effect. In a sustained release system a controlled delivery of the drug at the site of administration, would avoid successive administrations. Tetracaine hydrochloride (HCl) has been encapsulated using a technique based on the evaporation of solvent from an O/O emulsion, using poly(DL-lactic-co-glycolic acid) (PLGA) 50:50. Microspheres were separated into three fractions: 106-212, 212-300 and 300-425 microns. The effects of two variables of the manufacturing method (volume of the inner phase of the emulsion and volume of surfactant added to the external phase) on the drug loading into microspheres, dissolution profiles and SEM characterization of the microspheres were evaluated. Microspheres containing tetracaine hydrochloride (up to 94% referred to the theoretical) released the drug, in-vitro, over 35 days. Tetracaine HCl was delivered according to zero order kinetics from day 5 until the end of the release assay. The rate of drug release depended mainly on the viscosity of the discontinuous phase and on the size of microparticles. Microsphere size resulted more homogeneous when using the highest volume of the surfactant, being almost 80% of microparticles within the range 212-300 microns.

Characterization of the Huntington's disease (HD) gene homologue in the zebrafish Danio rerio

The Huntington's disease (HD) gene contains a trinucleotide repeat that is expanded and unstable in patients with the disease (HDCRG, 1993). As the first step toward investigating a potential role for this gene in early vertebrate development, we isolated the homolog of the Huntington's disease (ZHD) cDNA in zebrafish. This cDNA encodes a predicted protein product of 3121 amino acids with 70% identity to human huntingtin. The first exon is predicted to encode four glutamines, followed by only one proline, demonstrating that the polymorphic polyproline stretch found in mammalian HD sequences is absent in the fish. We sequenced approximately 900bp upstream from the predicted start codon and found that it lacks a TATA box, CCAAT box, or Sp1 binding sites. Western blot analysis revealed that the protein is expressed at a high level in late embryonic development and at moderate levels in the adult head.

Percutaneous mitoxantrone injection for primary and secondary liver tumors: preliminary results

PURPOSE

To determine the effects of percutaneous intratumoral chemotherapy with mitoxantrone (PIM) in the palliative treatment of malignant liver lesions.

METHODS

We treated 15 progressive lesions in nine patients in whom either previous therapy failed or serious complications developed as a result. Seven lesions were metastatic and eight were due to foci of hepatocellular carcinoma. Under computed tomography (CT) guidance, we percutaneously injected 10-20 mg of mitoxantrone mixed with 0.5 ml of contrast medium into the tumor, performing one to three treatments at intervals of 1 month.

RESULTS

There were no complications. The morphologic responses of the tumors after treatment were: minor response in one case, no change in 11 cases, progressive disease in three cases. Mitoxantrone induced tumor necrosis with no viable cancer tissue in eight of 11 biopsies. Recurrence was observed in nine of the treated lesions 2-9 months after treatment. New lesions were observed in five of nine patients 1-9 months after treatment.

CONCLUSION

In patients with malignant liver lesions with no other therapeutic possibilities, minimally invasive intratumoral mitoxantrone injection was carried out safely with good tumor delivery of chemotherapy, and tumor necrosis was demonstrated at biopsy. We feel this approach warrants further investigation.

Traumatic spinal cord injury complicating ankylosing spondylitis

The aim of this paper is to review the incidence and characteristics found in traumatic spinal cord injury (SCI) occurring in patients with long-standing ankylosing spondylitis (AS). The incidence of patients with traumatic SCI admitted to our unit from January 1984 to February 1996 was 2% (15 out of 893). They were all men with a mean age of 56 years. Most frequently the etiology of the lesion was a motor vehicle accident and the injury was mainly due to a hyperextension mechanism. Acute spinal fracture occurred in 13 patients, all involving the cervical region. No fracture was observed in two patients with thoracic neurological level. Three patients presented with an interval free period of neurological symptoms in whom a spinal epidural hematoma was visualized with magnetic resonance imaging. On admission eight patients were diagnosed as having complete SCI and the other seven an incomplete SCI. In the acute phase, respiratory complications were most frequent, causing six patients to die. Treatment was conservative in 14 patients. Multidisciplinary management of these patients should be implemented in an institution equipped with both a Spinal Injury Unit and an Intensive Care Unit.

Biometrical alterations of Trypanosoma evansi isolate in laboratory rodents

Biometrical alterations in a horse Trypanosoma evansi isolate were observed when passaged in laboratory rodents. The major parasite transformation observed was the increase in the total length as a consequence of an increase in some parasite measurements. These transformations probably occurred as a consequence of a host change from horse to rodents. No kinetoplastic forms were observed.

Current status of injectable hormonal contraception, with special reference to the monthly method

Injectable contraceptives are a valid option in every family planning program. Contraceptives which are administered every 2 or 3 months, containing only progestogen agents (DepoProvera, Noristerat) have proven efficacious and do not show long-term safety problems. They differ from other contraceptives in their long lasting action and by not presenting the contraindications of the estrogens. Their most prominent side-effect is the irregularity of cyclic bleeding. Although bleeding irregularities are not life threatening, many users stop the treatment for that reason. Monthly contraceptives comprising progestogens and estrogens, maintain or improve the high efficacy of the earlier forms and have the added benefit of allowing bleeding to resemble the physiologic one. This increases acceptability and the continuation rate. There is no long-term inconvenience. At this point, the greatest experience is with the formulation known as Topasel or Perlutal. Other formulations (Cyclofem, Mesigyna) are beginning to be commercialized and their characteristics must still be confirmed through daily use. Indications, contraindications, precautions and warnings for the use of monthly injectable contraceptives are basically identical to those of the combined oral contraceptives, as are the side-effects. Efficacy, though, proves to be superior, which can be correlated to a simpler method of use and less risk of error when using it. Main motivation factors are: efficacy, simplicity in usage, reversibility and confidentiality.

Moderately obese, insulin-resistant women exhibit abnormal vascular reactivity to stress

To define the hemodynamic implications of insulin resistance (IR), we compared 10 normotensive, insulin-resistant women who had abnormal glucose tolerance tests with 10 age-matched healthy normotensive women with normal glucose tolerance tests with respect to mental arithmetic and handgrip responses. Hemodynamic variables obtained at baseline and during stress included heart rate, blood pressure, cardiac output, and systemic vascular resistance. The IR group weighed more (84 versus 66 kg). Screening BP was similar (123/72 versus 120/68 mm Hg, P=NS) between groups although baseline diastolic BP at testing day was higher in the IR group than control group (75 versus 65 mm Hg, P<.05). The IR group showed a significantly greater increase in systolic (18% versus 10%, P<.O1) and diastolic (24% versus 12%, P<.01) blood pressure responses to mental stress than the control group. During mental stress, the control group demonstrated increased cardiac output (1.4 L/min) and decreased systemic vascular resistance (-120 dyne x s x cm[-5]), whereas IR subjects demonstrated increased systemic vascular resistance (119 dyne x s x cm(-5); group difference, P<.02) with only a small increase in cardiac output (0.5 L/min). Handgrip also caused a greater increase in systemic vascular resistance in the IR group (252 versus 64 dyne x s x cm(-5), P<.05), with a correspondingly greater increase in blood pressure than control subjects. Baseline blood pressure was correlated with weight (r=.41, P<.02) and stress blood pressure with fasting insulin (r=.51, P<.001) and glucose-to-insulin ratio (r= -.55, P<.001). We conclude that insulin resistance is associated with an exaggerated blood pressure response to stress; an enhanced vasoconstriction to stress may mediate this response. This hyperreactivity may be a marker for future hypertension in obese, normotensive, hyperinsulinemic individuals.

Chromosomal mapping of two members of the human dynein gene family to chromosome regions 7p15 and 11q13 near the deafness loci DFNA 5 and DFNA 11

We mapped expressed tagged sequences (ESTs) corresponding to two human dynein heavy chain genes: beta heavy chain of the outer dynein arm and heavy chain isotype 1B (DYH1B), by using somatic cell hybrids and radiation hybrid panels. The EST for the beta heavy chain of the outer dynein arm mapped to chromosome region 7p15, and the EST for DYH1B mapped to 11q13.5. Two loci for nonsyndromic forms of deafness, DFNA5 and DFNA11, have previously been mapped to these two chromosomal regions. Including the gene for the axonemal light chain, hp28, we have mapped three different dynein genes near loci for different forms of nonsyndromic deafness. The hypothesis that mutations in some dynein genes are associated with nonsyndromic deafness should now be tested.

Recombinant human thyrotropin is a potent stimulator of thyroid function in normal subjects

Recombinant human TSH (rhTSH) is known to stimulate 131I uptake and thyroglobulin (Tg) release from the postoperative remnant and metastases in thyroid cancer patients, but its effects on serum thyroid hormone and Tg concentrations in normal subjects have not been reported. Before using rhTSH in the management of thyroid disorders other than cancer, the thyroid response to rhTSH in normal subjects must be assessed. Six subjects, two men and four women, without evidence of thyroid disease, including normal serum free T4 index and TSH concentrations and negative tests for antithyroid peroxidase and Tg, were studied. Each received 0.1 mg rhTSH, im, 11% of the lowest dose that has been administered to thyroid cancer patients. Blood was obtained before; 2, 4, and 8 h after; and 1, 2, 3, 4, 7, and about 3 weeks after rhTSH administration. Serum TSH significantly increased at 2 h (mean +/- SE, 2.4 +/- 0.9 to 40.7 +/- 7.4 mU/mL), peaked at 4 h (50.9 +/- 9.3), remained significantly elevated for 1 day, and was significantly below baseline (0.8 +/- 0.5) 7 days after rhTSH administration. Serum T3 increased significantly at 4 h (115 +/- 4 to 190 +/- 14 ng/dL), peaked at 24 h (217 +/- 23 ng/dL), and remained significantly elevated for 3 days (151 +/- 12 ng/dL). Serum T4 increased significantly at 8 h (7.3 +/- 0.2 to 9.8 +/- 0.4 micrograms/dL), peaked at 24 h (11.2 +/- 0.5 micrograms/dL), and remained significantly elevated for 4 days (9.4 +/- 0.5 micrograms/dL). Serum Tg did not change for the first 8 h, increased significantly at 1 day (15.9 +/- 3.9 to 34.7 +/- 6.0 ng/mL), peaked at 2 days (44.2 +/- 7.0 ng/mL), and remained significantly elevated for 4 days (37.7 +/- 13.7 ng/mL). All values returned to baseline at 3 weeks. TSH antibodies were not detected at 3 weeks. A single dose of 0.1 mg rhTSH is a potent stimulator of thyroid function in normal subjects. rhTSH may be a useful agent to test thyroid reserve and for use in clinical settings that require direct thyroid stimulation.

Mutations in the gene encoding cystatin B in progressive myoclonus epilepsy (EPM1)

Progressive myoclonus epilepsy of the Unverricht-Lundborg type (EPM1) is an autosomal recessive inherited form of epilepsy, previously linked to human chromosome 21q22.3. The gene encoding cystatin B was shown to be localized to this region, and levels of messenger RNA encoded by this gene were found to be decreased in cells from affected individuals. Two mutations, a 3' splice site mutation and a stop codon mutation, were identified in the gene encoding cystatin B in EPM1 patients but were not present in unaffected individuals. These results provide evidence that mutations in the gene encoding cystatin B are responsible for the primary defect in patients with EPM1.

Clozapine therapy in patients with neurologic illness

OBJECTIVE

This review will analyze the use of clozapine in patients with neurologic illness.

METHODS

A review of the literature was performed. Attention is focused particularly on patients with seizure disorder, head injury, mental retardation, Parkinson's disease, Huntington's disease, tardive dyskinesia, and selected other neurological disorders.

RESULTS

This review discusses clinical difficulties/issues associated with clozapine therapy in patients with a variety of neurological disorders.

CONCLUSION

Although clozapine therapy should be reserved for those patients who are refractory to conventional psychotropic medications, when used appropriately it may offer a safe and effective way of improving quality of life for patients with behavioral symptoms and neurologic illness.

The utility of placing sphenoidal electrodes under the foramen ovale with fluoroscopic guidance

Although sphenoidal electrodes are widely used to detect epileptiform activity, there is no agreement on an optimal target to which electrodes should be aimed. The purpose of this study was to determine whether fluoroscopic guidance is a reliable method for placing electrodes directly below the foramen ovale and whether such positioning enhances their capacity to detect epileptiform activity when compared to similar electrodes placed blindly into the infratemporal fossa. We examined the surface/sphenoidal EEG recordings of 17 patients with intractable partial seizures of anterotemporal origin, after fluoroscopically placed sphenoidal electrodes (FPSE) had been inserted to lie just below the foramen ovale. A criterion for eligibility was a previous prolonged video/EEG monitoring with blindly placed sphenoidal electrodes (BPSE) that failed to detect seizures with a focal onset. No blindly placed electrode, for which there was radiographic documentation, reached the foramen ovale. Fluoroscopic guidance assured accurate targeting. FPSE detected a unilateral anterotemporal interictal focus in four patients in whom BPSE had failed to record any interictal spikes and detected bitemporal independent interictal foci in one patient in whom BPSE had identified only unilateral spikes. In nine other patients, the spike count obtained with FPSE recordings increased by > 100% when compared to that obtained with BPSE recordings. FPSE recorded seizures with an anterotemporal focal onset pattern in 10 patients in whom BPSE had recorded seizures with a regional, lateralized, or nonlocalized onset pattern. In nine of these 10 patients, this was adequate to recommend surgery and avoid invasive monitoring. Fluoroscopic guidance assures accurate targeting of the foramen ovale. When compared to BPSE, FPSE resulted in better detection of interictal and ictal epileptiform activity of mesial-basal-temporal origin.

Human nasal mucosal changes after exposure to urban pollution

Millions of people worldwide are living in areas where ozone (O3) concentrations exceed health standards (an hourly average of 235 micrograms/m3/0.12 ppm, not to be exceeded more than once per year). Ozone induces acute nasal inflammatory responses and significant epithelial lesions in experimental animals and humans. To determine the nasal effects of a 15-day exposure to an urban polluted atmosphere with O3 as the main pollutant, we studied a population of healthy, young males newly arrived to southwest metropolitan Mexico City (SWMMC). The study included 49 non-smoking residents in an unpolluted port, Veracruz City; 14 subjects stayed in the port and served as controls, while 35 subjects traveled to SWMMC and had serial nasal lavages at different times after arriving in SWMMC. Subjects had exposures to ambient O3 an average of 10.2 hr/day, with a total cumulative O3 exposure of 10.644 ppm.hr. Nasal inflammatory responses, polymorphonuclear leukocyte PMN-CD11b surface expression, rhinoscopic changes, and respiratory symptoms were evaluated. Exposed subjects had massive nasal epithelial shedding and significant responses in PMN nasal influx (p < 0.00001) and in PMN-CD11b expression (p < 0.05). Cumulative O3 exposure correlated with respiratory symptoms, PMNs (rs = 0.2374, p < 0.01), and CD11b (rs = 0.3094, p < 0.01); 94% of exposed subjects experienced respiratory symptoms, and 97% left the city with an abnormal nasal mucosa by rhinoscopy. Nasal epithelial changes persisted 2 weeks after the exposed subjects returned to their nonpolluted environment. Exposure to an urban polluted atmosphere induces significant and persistent nasal epithelial alterations in healthy subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Oral diclofenac combined with intra-portal pirarubicin: increased efficacy on liver VX2 tumour and hepatotoxicity in rabbits

VX2 is a carcinoma established in rabbits and producing an autocrine growth factor, prostaglandin E2. Pirarubicin is a potent anti-VX2 agent. We investigated whether the oral intake of enprostil--a synthetic prostaglandin E2--or of diclofenac--a potent non-steroidal anti-inflammatory drug--increases the efficacy and decreases the hepatotoxicity of pirarubicin when injected in the portal trunk. Enprostil increased the number of hepatic tumoral nodules and induced hepatic alterations, especially venous dilatation. Paradoxically the combination of enprostil and pirarubicin was at least as effective as pirarubicin or diclofenac on VX2 cells. However, the toxicity was increased, especially with respect to sclerosing cholangitis. Diclofenac proved to be as effective as pirarubicin, and the addition of oral diclofenac to local pirarubicin injection increased its antitumoral effect (P < 0.02). However, the combination of diclofenac and pirarubicin was more toxic than pirarubicin alone and induced centrolobular necrosis and sclerosing cholangitis.

[Intra-arterial hepatic chemotherapy. Experience of 200 cases]

OBJECTIVES

This retrospective study had three aims: a) to investigate whether one catheter, whatever the number of hepatic arteries, associated with miscellaneous arterial ligations, produced the same results as the implantation of multiple catheters, b) to study the survival rate after intra-arterial chemotherapy, and c) based on a multifactorial study of prognostic factors, to define the best indications of this treatment in the future.

METHODS

Two hundred catheters were surgically implanted to perform intrahepatic arterial chemotherapy in patients with multiple unresectable isolated liver tumors. The origins of these tumours were colorectal cancer in 152 cases, neuroendocrine tumour in 13 cases, hepatocellular carcinoma in 9 cases, and miscellaneous tumours in 22 cases. The hepatic arteries were ligated in 32% of the cases. Resection of the primary or local recurrence was performed at the same time in respectively 41% and 16% of the cases.

RESULTS

The use of only one catheter was always possible, and the ligations of miscellaneous accessory hepatic arteries did not modify the therapeutic results. There were no postoperative deaths. Numerous complications occurred during local chemotherapy, mainly digestive and hepatobiliary complications (38.5% of the cases). Early discontinuation of local chemotherapy was due to the occurrence of thrombosis of the hepatic artery in 23% of the cases (after a mean delay of 5.2 months) and to the occurrence of digestive or hepato-biliary complications in 11% of the cases. The rate of objective response was 44%, with 22 complete and 62 partial responses on morphologic examination. The crude survival rates were 65 +/- 3% at 1 year, 33 +/- 4% at 2 years and 5 +/- 2% at 5 years, with a median survival of 16 months. The median survival was different according to the primary tumour (34 months for neuroendocrine tumours, 17 months for colorectal tumours and 12 months for hepatocellular and miscellaneous carcinomas). For the 152 colorectal cancers, a multifactorial study identified 2 main independent adverse prognostic factors: an involvement of the liver greater than 50% (P = 0.006) and circulating carcinoembryonic antigen > 100 ng/L (P = 0.001).

Mdr1 gene-expression in a multidrug-resistant human non-hodgkins-lymphoma xenograft model

In order to investigate the biology of tumor cells which express MDR1 gene and to test the activity of different P-glycoprotein blocking agents in vivo, we established a nude mice model. Five Non Hodgkin's Lymphoma (NHL) tumor specimens were xenografted to nude mice. One of them, obtained from a chemotherapy-refractory patient gave rise to a mice transplantable model. This tumor xenograft model, IGR-NHL-90, showed overexpression of the human MDR1 gene. In this tumor model, histology, mitotic index, phenotypic and karyotypic traits remained stable at subsequent passages. The in vitro resistance of vincristine was reversed by verapamil for these NHL tumor cells, suggesting that the MDR1 resistance is a relevant mechanism in this model. In the absence of chemotherapy a higher biological aggressivity of the heterotransplanted NHL was noted in subsequent nude mice passages. This was associated with decreased passage time and higher MDR1 m-RNA transcript levels. Thus IGR-NHL-90 may represent a suitable material to study regulation of MDR1 gene transcription in vivo and also to test the activity of various P-glycoprotein reversing agents with concurrent chemotherapy.

GLOBOSA: a homeotic gene which interacts with DEFICIENS in the control of Antirrhinum floral organogenesis

GLOBOSA (GLO) is a homeotic gene whose mutants show sepaloid petals and carpelloid stamens. The similarity of Glo mutants to those of the DEFICIENS (DEFA) gene suggests that the two genes have comparable functions in floral morphogenesis. The GLO cDNA has been cloned by virtue of its homology to the MADS-box, a conserved DNA-binding domain also contained in the DEFA gene. We have determined the structure of the wild type GLO gene as well as of several glo mutant alleles which contain transposable element insertions responsible for somatic and germinal instability of Glo mutants. Analyses of the temporal and spatial expression patterns of the DEFA and GLO genes during development of wild type flowers and in flowers of various stable and unstable defA and glo alleles indicate independent induction of DEFA and GLO transcription. In contrast, organ-specific up-regulation of the two genes in petals and stamens depends on expression of both DEFA and GLO. In vitro DNA-binding studies were used to demonstrate that the DEFA and GLO proteins specifically bind, as a heterodimer, to motifs in the promoters of both genes. A model is presented which proposes both combinatorial and cross-regulatory interactions between the DEFA and GLO genes during petal and stamen organogenesis in the second and third whorls of the flower. The function of the two genes controlling determinate growth of the floral meristem is also discussed.

Effect of the serotonin agonist, MK-212, on body temperature in schizophrenia

The effects of 6-chloro-2-(1-piperaziny)pyrazine (MK-212), a centrally acting 5-HT1C/5-HT2 agonist, on body temperature and behavior were assessed using a single-blind cross-over design in 23 schizophrenic patients and 22 normal controls. Body temperature was assessed before drug administration and at 30-min intervals for 3 hr. Each subject was administered placebo or MK-212. MK-212 significantly elevated temperature in normal controls. There was no overall MK-212-induced increase in temperature compared to placebo in the schizophrenic patients; however, 13 of 23 (56.5%) patients had a larger increase in temperature after MK-212 than placebo, 3 of 23 (13.1%) had no change, whereas the temperature change after placebo was greater than after MK-212 in 7 of 23 (30.4%) patients. MK-212 produced significant increases in nausea, feeling strange, and arousal but these effects did not differ between groups. These results are consistent with decreased 5-HT2 receptor responsivity in some patients with schizophrenia.

Low prevalence of microalbuminuria in normotensive patients with insulin-dependent diabetes mellitus

We studied the prevalence of microalbuminuria (urinary albumin excretion rate [UAER] greater than 20 micrograms/min less than or equal to 200 micrograms/min) as determined in a single, timed, overnight urine collection in 156 normotensive (BP less than 140/90), Albustix negative subjects with type 1 diabetes and its association with arterial blood pressure, the duration of diabetes, levels of glycosylated hemoglobin, body mass index, daily insulin dose and serum cholesterol. Nineteen subjects (12.2%) had a UAER in the microalbuminuric range. The microalbuminuric patients had a significantly longer duration of diabetes, 21 +/- 2 vs 15 +/- 1 years (P less than 0.01), higher diastolic blood pressure, 80 +/- 2 vs 76 +/- 1 mmHg (P less than 0.05) and serum cholesterol concentration, 206 +/- 11 vs 186 +/- 3 mg/dl (P less than 0.05) than did the normoalbuminuric subjects. There were no differences between the normoalbuminuric and microalbuminuric subjects in terms of age, systolic blood pressure, body mass index, daily insulin dose or glycosylated hemoglobin levels. These data indicate that the prevalence of microalbuminuria in type 1 diabetes has probably been overestimated in previous studies due to the inclusion of patients with hypertension. Thus, microalbuminuria, rather than being a predictor of the development of diabetic renal disease, may indicate the presence of diabetic nephropathy with rising blood pressure levels. Further investigation is needed to clarify the relationship between microalbuminuria and coronary risk factors such as serum cholesterol and diastolic blood pressure levels.

Chromosome location of a family of genes encoding different acidic ribosomal proteins in Saccharomyces cerevisiae

DNA probes from the genes encoding the acidic ribosomal proteins L44, L44' and L45, as well as from reporter genes for chromosomes IV, VII, XII and XV, have been hybridised to Southern blots of Saccharomyces cerevisiae DNA resolved by pulsed field gel electrophoresis. The protein L44' and protein L45 genes have been found to hybridise to chromosome IV, identified by the CAT1 gene probe, while the protein L44 probe hybridises with a band containing chromosomes VII and XV, identified by the ATPase 1 and HIS3 genes respectively.

Isolated symptomatic peripheral neuropathy in type 1 insulin-dependent diabetes mellitus

Diabetic neuropathy is probably the most frequent of the chronic complications of diabetes, and is usually found in association with diabetic retinopathy and/or nephropathy. We report seven patients with long-standing insulin-dependent diabetes mellitus in whom symptomatic peripheral neuropathy was the first and only documented complication. The diagnosis of peripheral symmetrical neuropathy was based on the presence of symptoms and abnormal physical findings, confirmed with abnormal electrophysiological and/or vibratory and thermal threshold measurements. Diabetic retinopathy and nephropathy were absent. We conclude that in some type 1 insulin-dependent diabetic patients, similar to what has been reported in type 2 non-insulin-dependent diabetes, peripheral neuropathy may be the first chronic complication to become manifest. This observation provides additional evidence to suggest that each of the diabetic complications may have a different pathogenic mechanism.

Mossy fiber synaptic reorganization in the epileptic human temporal lobe

The distribution of the mossy fiber synaptic terminals was examined using the Timm histochemical method in surgically excised hippocampus and dentate gyrus from patients who underwent lobectomy of the anterior part of the temporal lobe for refractory partial complex epilepsy. The dentate gyrus of epileptic patients demonstrated intense Timm granules and abundant mossy fiber synaptic terminals in the supragranular region and the inner molecular layer. In contrast, the dentate gyrus of presenescent nonepileptic primates demonstrated no Timm granules in the supragranular region. In nonepileptic senescent primates, occasional very sparse supragranular Timm granules were results are morphological evidence of mossy fiber synaptic reorganization in the temporal lobe of epileptic humans, and suggest the intriguing possibility that mossy fiber sprouting and synaptic reorganization induced by repeated partial complex seizures may play a role in human epilepsy.

Clozapine: new research on efficacy and mechanism of action

Clozapine can produce greater clinical improvement in both positive and negative symptoms than typical antipsychotic drugs in neuroleptic-resistant schizophrenic patients. The clinical response may occur rapidly in some patients but is delayed in others. Clozapine has also been reported to produce fewer parkinsonian symptoms, to involve a lower risk of producing tardive dyskinesia, and to produce no serum prolactin elevations in man. It seems likely that these effects are the result of a common biological mechanism or related mechanisms, rather than unrelated effects. Other atypical antipsychotic drugs, such as melperone and fluperlapine, share at least some of these properties. A relatively low affinity for the D-2 dopamine (DA) receptor and high affinity for the 5-HT2 receptor, producing a high 5-HT2/D-2 ratio, best distinguishes atypical antipsychotics like clozapine from typical antipsychotic drugs. Through its weak antagonist action on D-2DA receptors and a potent inhibitory effect on 5-HT2 receptors, as well as its ability to increase DA and 5-HT2 release, clozapine may be able to permit more normal dopaminergic function in the anterior pituitary, the mesostriatal, mesolimbic and mesocortical regions. The numerous advantages of clozapine over typical neuroleptics are consistent with the primary importance of DA to the pathophysiology of schizophrenia. The secondary but still significant role of 5-HT in the action of clozapine may either be direct or via the effect of 5-HT on dopaminergic mechanisms. Some aspects of schizophrenia could be due to a dysregulation of the interaction between serotonergic and dopaminergic neurotransmission.

Effect of nifedipine on sphincter of Oddi motor activity: studies in healthy volunteers and patients with biliary dyskinesia

The effect of nifedipine on sphincter of Oddi (SO) motor activity was determined by endoscopic manometry. Sphincter of Oddi pressures and motor function were compared in 21 healthy volunteers and in 9 patients with SO dyskinesia. The effects of sublingual doses of 10 or 20 mg of nifedipine were compared with placebo. Neither placebo nor 10 mg of nifedipine produced any effect on SO motor activity. In healthy volunteers 20 mg of nifedipine produced a moderate but significant decrease in basal SO pressure from 12.0 to 6.7 mmHg as well as in the amplitude, duration, and frequency of phasic contractions. In patients with SO dyskinesia 20 mg of nifedipine also resulted in a significant but more profound decrease of the basal SO pressure from 47.1 to 17.3 mmHg as well as in a decrease of amplitude, duration, and frequency of the phasic contractions. Neither placebo nor 10 or 20 mg of nifedipine has any effect on the sequence of phasic contractions. In summary, nifedipine may have a possible therapeutic role in the treatment of SO dyskinesia.

Variable rRNA gene copies in extreme halobacteria

Using PFG electrophoresis techniques, we have examined the organization of rRNA gene in halobacterium species. The results show that the organization of rRNA genes among closely related halobacteria is quite heterogeneous. This contrasts with the high degree of conservation of rRNA sequence (1). The possible mechanism of such rRNA gene amplification and its evolutionary implications are discussed.