Efficacy and safety of fluticasone propionate hydrofluoroalkane inhalation aerosol in pre-school-age children with asthma: a randomized, double-blind, placebo-controlled study

OBJECTIVE

To evaluate the efficacy and tolerability of fluticasone propionate (FP) hydrofluoroalkane (HFA) in children age 1 to < 4 years with asthma.

STUDY DESIGN

Children were assigned (2:1) to receive FP HFA 88 mug (n = 239) or placebo HFA (n = 120) twice daily through a metered-dose inhaler with a valved holding chamber and attached facemask for 12 weeks. The primary efficacy measure was mean percent change from baseline to endpoint in 24-hour daily (composite of daytime and nighttime) asthma symptom scores.

RESULTS

The FP-treated children had significantly greater (P < or = .05) reductions in 24-hour daily asthma symptom scores (-53.9% vs -44.1%) and nighttime symptom scores over the entire treatment period compared with the placebo group. Daytime asthma symptom scores and albuterol use were slightly more decreased with FP than with placebo; however, the differences were not statistically significant. Increases in the percentage of symptom-free days were comparable. The percentage of patients who experienced at least 1 adverse event was similar in the 2 groups. Baseline median urinary cortisol excretion values were comparable between the groups, and there was little change from baseline at endpoint. FP plasma concentrations demonstrated that systemic exposure was low.

CONCLUSIONS

FP HFA 88 mug twice daily was effective and well tolerated in pre-school-age children with asthma.

Do seizures in patients with refractory epilepsy vary between wakefulness and sleep?

AIM

To determine the effects of sleep and wakefulness on seizures in patients with refractory epilepsy recorded while undergoing video-electroencephalography (EEG) telemetry.

METHODS

The video-EEG data of patients who had two or more seizures during video-EEG telemetry (n = 270) were reviewed. Fifty seven patients who had seizures both in wakefulness and sleep were identified. The video and ictal EEG data were reviewed, paying specific attention to type of seizures, duration, semiology, lateralisation and number of seizures.

RESULTS

Three hundred and sixty two seizures were recorded; 237 seizures while awake and 125 while sleeping. Secondary generalisation occurred more often in sleep than in wakefulness (p < 0.01). Overall, there was no significant effect of sleep on the duration of seizures or ictal EEG change. Sleep and awake seizures differed in only eight patients.

CONCLUSION

Secondary generalisation occurred more often in sleep than in wakefulness, perhaps due to the facilitated spread of seizures during sleep. For the most part, however, seizures recorded during sleep did not differ from those recorded during wakefulness.

Meloxicam effectively inhibits preterm labor uterine contractions in a chronically catheterized pregnant sheep model: impact on fetal blood flow and fetal-maternal physiologic parameters

OBJECTIVE

Preterm birth occurs in 5% to 10% of all pregnancies and is associated with considerable neonatal mortality and morbidity. Effective and safe drugs to prevent preterm labor are not currently available. We have hypothesized that the nonsteroidal anti-inflammatory drug meloxicam, a more selective cyclooxygenase-2 inhibitor will successfully inhibit labor but avoid the complications associated with inhibition of cyclooxygenase-1.

STUDY DESIGN

Preterm labor was induced in chronically catheterized sheep by RU486 administration. Animals were then randomized to receive maternal infusions of saline (n = 5) or meloxicam (n = 4) for 48 hours or until delivery when the animals were killed and tissues and blood samples collected.

RESULTS

Maternal infusion of meloxicam inhibited uterine contractions, increasing contraction duration, and attenuating frequency and amplitude. Saline-treated animals progressed to delivery. Administration of meloxicam was not associated with any change in fetal or maternal blood gas status, osmolality, arterial pressure, heart rate, or fetal blood flows.

CONCLUSION

Meloxicam may represent a potentially safe and effective tocolytic agent.

Efficacy and safety of inhaled fluticasone propionate chlorofluorocarbon in 2- to 4-year-old patients with asthma: results of a double-blind, placebo-controlled study

BACKGROUND

Current asthma guidelines recommend inhaled glucocorticoids administered via pressurized metered-dose inhaler (MDI) with a holding chamber as the preferred therapy for young children with asthma.

OBJECTIVE

To evaluate the efficacy and safety of fluticasone propionate chlorofluorocarbon MDI use in preschool-aged children with asthma.

METHODS

Randomized, double-blind, placebo-controlled, parallel-group study of 332 children aged 24 to 47 months with asthma. Fluticasone propionate chlorofluorocarbon, 44 or 88 microg twice daily, or placebo (chlorofluorocarbon propellant alone) administered for 12 weeks via MDI with a valved holding chamber and an attached face mask. The primary efficacy measure was average change in 24-hour daily asthma symptom scores. Safety assessments included adverse events, 12-hour urinary cortisol excretion, and growth.

RESULTS

Treatment failure (ie, asthma exacerbation) occurred in approximately half as many fluticasone propionate-treated patients (13%-14%) as placebo-treated patients (24%). Compared with placebo users, patients treated with fluticasone propionate, 88 microg twice daily, had a 13% greater improvement in the mean proportion of symptom- and albuterol-free days (P = .02); asthma symptom scores and albuterol use were also significantly reduced. Patients treated with fluticasone propionate, 44 microg twice daily, had greater improvements than placebo-treated patients; however, differences did not reach statistical significance. At end point, the growth velocities of fluticasone propionate-treated patients were within the range of those of placebo-treated patients. No clinically relevant changes in 12-hour overnight urinary cortisol excretion were observed.

CONCLUSION

Compared with placebo use, fluticasone propionate, 88 microg administered twice daily, significantly reduced asthma exacerbations, asthma symptoms, and rescue albuterol use and was well tolerated, with no clinically relevant systemic effects, as measured by growth velocity or 12-hour urinary cortisol excretion levels.

Fluticasone propionate HFA-134a pressurized metered-dose inhaler in adolescents and adults with moderate to severe asthma

In this randomized, double-blind, placebo-controlled trial, 397 patients with moderate to severe asthma, previously treated with bronchodilators alone, received fluticasone propionate 88, 220, or 440 microg twice daily, or placebo via metered dose inhaler (MDI) for 12 weeks. Mean change from baseline to endpoint in pre-dose percent predicted forced expiratory volume in one second (FEV1) was greater (p < 0.001) in each fluticasone propionate group (9.0%, 88 microg bid; 9.8%, 220 microg bid; 11.2%, 440 microg bid) versus placebo (3.4%). Morning and evening peak expiratory flow (PEF), asthma symptoms, and supplemental albuterol use also improved in all fluticasone propionate groups versus placebo. The incidence of adverse events and 24-hour urine cortisol excretion rates were similar between active treatments and placebo.

Fluticasone propionate hydrofluoroalkane inhalation aerosol in patients receiving inhaled corticosteroids

BACKGROUND

Inhaled corticosteroids (ICSs) delivered by metered-dose inhalers that contain chlorofluorocarbon propellants are being discontinued because of the harmful effects of chlorofluorocarbon on the ozone layer. Therefore, some metered-dose inhaler products are being reformulated with "ozone-friendly" hydrofluoroalkane propellants.

OBJECTIVE

To evaluate treatment with fluticasone propionate hydrofluoroalkane inhalation aerosol, 88, 220, and 440 microg twice daily, vs placebo in patients with asthma receiving an ICS.

METHODS

Randomized, double-blind, parallel-group, 12-week study.

RESULTS

Mean morning predose percent predicted forced expiratory volume in 1 second increased by 2.2%, 3.2%, and 4.6% in the fluticasone propionate, 88-, 220-, and 440-microg twice-daily, groups, respectively, compared with an 8.3% decrease for placebo (P < .001 vs placebo for all groups). Secondary pulmonary function end points and asthma symptoms showed similar improvements compared with placebo. Discontinuation from the study due to lack of efficacy was 50% in the placebo group and 11%, 10%, and 6% in the fluticasone propionate, 88-, 220-, and 440-microg twice-daily, groups, respectively. At week 12, the probability of remaining in the study was 0.89, 0.90, and 0.94 for the fluticasone propionate, 88-, 220-, and 440-microg twice-daily, groups, respectively, vs 0.45 for the placebo group (P < .001 for all). Changes in 24-hour urinary cortisol excretion rates were similar among treatment groups.

CONCLUSIONS

Fluticasone propionate hydrofluoroalkane, previously shown to be a clinically suitable alternative to fluticasone propionate chlorofluorocarbon, was effective and well tolerated. The ability to switch from fluticasone propionate chlorofluorocarbon and other chlorofluorocarbon-containing ICSs to fluticasone propionate hydrofluoroalkane without sacrificing asthma control or tolerability will facilitate a smooth transition to this nonchlorofluorocarbon-containing medicinal.

Rituximab treatment for glomerulonephritis in HCV-associated mixed cryoglobulinaemia: efficacy and safety in the absence of steroids

OBJECTIVE

Rituximab, an anti-CD20 monoclonal antibody, has been used in lupus nephritis and membranous idiopathic nephropathy and has proved effective in non-renal manifestations of type II mixed cryoglobulinaemia (MC) syndrome. We investigated the possible efficacy and safety of rituximab in the treatment of cryoglobulinaemic nephritis.

METHODS

Five patients with active, biopsy-proven, glomerulonephritis in hepatitis C virus (HCV)-related type II MC syndrome were treated with four weekly infusions of rituximab (375 mg/m2) in monotherapy, without steroids whenever possible. Rituximab was the first-line therapy in three cases.

RESULTS

A rapid and sustained renal response was observed in all patients, in one of them without retreatment up to the last follow-up (month 21+). Renal biopsy was repeated after 6 months in one patient and histopathological improvement was documented. Three patients relapsed, at months +5, +7 and +12 of follow-up, respectively. Two of them were then retreated with rituximab and again presented a rapid improvement in renal function. Maintenance therapy with rituximab was performed in two patients: nephritis remission was maintained in both. Fc-gamma receptor 3a (FcgammaRIIIa) genotype characterization was consistent with the clinical response observed. Rituximab also proved effective against other active MC manifestations, when present. No major side-effects occurred and steroids were not required in the follow-up.

CONCLUSIONS

Rituximab may provide effective and safe therapy in type II MC-related glomerulonephritis, possibly as first-line therapy, avoiding steroids and hazardous immunosuppressive treatment.

Application of SEBAL approach and MODIS time-series to map vegetation water use patterns in the data scarce Krishna river basin of India

Evapotranspiration (ET) from irrigated land is one of the most useful indicators to explain whether the water is used as "intended". In this study, the Surface Energy Balance Algorithm for Land (SEBAL) was used to compute actual ET from a Landsat7 image of December 29, 2000 for diverse land use in the Krishna Basin in India. SEBAL ETa varies between 0 to 4.7 mm per day over the image and was quantified for identified land use classes. Seasonal/annual comparison of ETa from different land uses requires time series images, processed by SEBAL. In this study, the Landsat-derived snapshot SEBAL ETa result was interpreted using the cropping calendar and time series analysis of MODIS imagery. The wastewater irrigated area in the basin has the highest ETa in the image, partly due to its advanced growth stage compared to groundwater-irrigated rice. Shrub and forests in the senescence phase have similar ETa to vegetable/cash crops, and ETa from grasslands is a low 0.8 mm per day after the end of the monsoon. The results indicate that wastewater irrigation of fodder and rice is sufficient to meet crop water demand but there appears to be deficit irrigation of rice using groundwater.

Magnetic correlations and the anisotropic Kondo effect in Ce1-xLaxAl3

By combining the results of muon spin relaxation and inelastic neutron scattering in the heavy fermion compounds Ce1-xLaxAl3 (0.0<or=x<or=0.2), we show that static magnetic correlations are suppressed above a characteristic temperature, T*, by electronic dissipation rather than by thermal disorder. Below T*, an energy gap opens in the single-ion magnetic response in agreement with the predictions of the anisotropic Kondo model. Scaling arguments suggest that similar behavior may underlie the "hidden order" in URu2Si2.

Recent advances in the pathophysiology, diagnosis and treatment of hereditary hemochromatosis and other iron overload syndromes

Recent years have witnessed tremendous advances in the fields of pathophysiology, diagnosis and management of hereditary hemochromatosis (HH) and other iron overload syndromes, the dreadful consequences of which are fully preventable by early diagnosis and treatment. Missense mutations in HFE, a newly discovered gene encoding for a major histocompatibility class-I like molecule, have been found to be strictly associated with most cases of HH. The mechanisms by which a dysfunctional HFE molecule determines increased absorption of iron in HH are on the way to be fully clarified, due to the availability of a knockout mouse model. Epidemiologic studies have shown that HH is one of the most common human hereditary disorders. The possibility to identify HFE heterozygotes by means of a simple genetic test have prompted studies on the association between HFE mutations and iron overload syndromes different from HH. In the era of the historic completion of the human genome projects, genetic testing for HH may soon qualify for being adopted in universal population screening policies. In the present paper, the recent advances in the fields of genetics and pathophysiology of HH and other iron overload syndromes will be summarized. Furthermore, its clinical features, pathology and treatment will be reviewed, and the emerging issues of cost-effective diagnosis and of possible population screening strategies will be succintly discussed.

The midline thalamus: alterations and a potential role in limbic epilepsy

PURPOSE

In limbic or mesial temporal lobe epilepsy, much attention has been given to specific regions or cell populations (e.g., the hippocampus or dentate granule cells). Epileptic seizures may involve broader changes in neural circuits, and evidence suggests that subcortical regions may play a role. In this study we examined the midline thalamic regions for involvement in limbic seizures, changes in anatomy and physiology, and the potential role for this region in limbic seizures and epilepsy.

METHODS

Using two rat models for limbic epilepsy (hippocampal kindled and chronic spontaneous limbic epilepsy) we examined the midline thalamus for evidence of involvement in seizure activity, alterations in structure, changes in the basic in vitro physiology of the thalamic neurons. We also explored how this region may influence limbic seizures.

RESULTS

The midline thalamus was consistently involved with seizure activity from the onset, and there was significant neuronal loss in the medial dorsal and reuniens/rhomboid nuclei. In addition, thalamic neurons had changes in synaptically mediated and voltage-gated responses. Infusion of lidocaine into the midline thalamus significantly shortened afterdischarge duration.

CONCLUSIONS

These observations suggest that this thalamic region is part of the neural circuitry of limbic epilepsy and may play a significant role in seizure modulation. Local neuronal changes can enhance the excitability of the thalamolimbic circuits.

Spatio-temporal imaging of focal interictal epileptiform activity using EEG-triggered functional MRI

EEG-triggered, blood oxygen level-dependent functional MRI (BOLD-fMRI) was used in 24 patients with localization-related epilepsy and frequent interictal epileptiform discharges (spikes) to identify those brain areas involved in generating the spikes, and to study the evolution of the BOLD signal change over time. The location of the fMRI activation was compared with the scalp EEG spike focus and the structural MR abnormality. Twelve patients (50%) had an fMRI activation concordant with the EEG focus and structural brain abnormalities where present (n = 7). In 2 other patients, the fMRI activation was non-concordant with electroclinical findings. The remaining 10 patients (41.7%) showed no significant fMRI activation. These patients had significantly lower mean spike amplitudes compared to those with positive fMRI results (p = 0.03). The time course of the BOLD response was studied in 3 patients and this revealed a maximum signal change 1.5 to 7.5 sec after the spike. In conclusion, EEG-triggered fMRI can directly identify the generators of interictal epileptiform activity, with high spatial resolution, in selected patients with frequent spikes. The superior spatial resolution obtainable through EEG-triggered fMRI may provide an additional non-invasive tool in the presurgical evaluation of patients with intractable focal seizures.

Design of an intensive epilepsy monitoring unit

Video-electroencephalography (EEG) telemetry is a crucial component in the comprehensive evaluation of patients with epilepsy. The reasons for patients needing to be monitored fall broadly into three groups: presurgical assessment (36% of our patients), diagnostic assessment (52%), and sleep disorders (12%). Video EEG can be used to differentiate unusual epilepsies from pseudo seizures or other causes of paroxysmal neurological events. The design of a unit depends on the case mix of patients expected to be referred. The key elements to a successful unit are a reliable, flexible, easy-to-use recording system and a team of dedicated, experienced staff, both nursing and technical. The unit at the National Hospital is a six-bed ward with 7 nurses to provide 24-hour coverage, 5 technicians working in shifts, and physics support. A minimum of two staff are on duty at all times. It operates on a five-day week with a throughput of approximately 500 patients per year. It is vital that investigations are performed as efficiently and effectively as possible, and the patient's safety and wellbeing is paramount at all times. Drug reduction is likely to be used to precipitate seizures, especially in those being considered for epilepsy surgery, and this poses a risk of provoked secondary generalized seizures. Continuous supervision of patients, and the ability to respond rapidly to a seizure, are therefore essential. We adopt a standardized easy-to-follow drug-reduction protocol, similar to that used by other centers.

Aberrant neuronal physiology in the basal nucleus of the amygdala in a model of chronic limbic epilepsy

Limbic epilepsy is a chronic condition associated with a broad zone of seizure onset and pathology. Studies have focused mainly on the hippocampus, but there are indications that changes occur in other regions of the limbic system. This study used in vitro intracellular recording and histology to examine alterations to the physiology and anatomy of the basal nucleus of the amygdala in a rat model of chronic limbic epilepsy characterized by spontaneously recurring seizures. Epileptic pyramidal neuron responses evoked by stria terminalis stimulation revealed hyperexcitability characterized by multiple action potential bursts and no evident inhibitory potentials. In contrast, no hyperexcitability was observed in amygdalar neurons from kindled (included as a control for seizure activity) or control rats. Blockade of ionotropic glutamate receptors unmasked inhibitory postsynaptic potentials in epileptic pyramidal neurons. Control, kindled and epileptic inhibitory potentials were predominantly biphasic, with fast and slow components, but a few cells exhibited only the fast component (2/12 in controls, 0/3 in kindled, 3/10 in epileptic). Epileptic fast inhibitory potentials had a more rapid onset and shorter duration than control and kindled. Approximately 40% of control neurons exhibited spontaneous inhibitory potentials; no spontaneous inhibitory potentials were observed in neurons from kindled or epileptic rats. A preliminary histological examination revealed no gross alterations in the basal amygdala from epileptic animals. These results extend previous findings from this laboratory that hyperexcitability is found in multiple epileptic limbic regions and may be secondary to multiple alterations in excitatory and inhibitory efficacy. Because there were no differences between control and kindled animals, the changes observed in the epileptic animals are unlikely to be secondary to recurrent seizures.

Serum iron indices as a measure of iron deposits in chronic hepatitis C

Serum iron indices are believed to be elevated in patients with hepatitis C virus (HCV) infection in connection to the presence of hepatic inflammation, though this hypothesis has never been formally tested. We studied 69 consecutive, unselected anti HCV antibody positive patients, aged 14 to 70 years. Iron, transferrin saturation and ferritin were measured in fasting serum samples. Histologically detectable iron (HDI) as well as histologic grading and staging were estimated semiquantitatively in liver biopsy samples. The median values for serum iron, transferrin saturation and serum ferritin were 24 micromol/l (range, 8-61), 29 percent (range, 6-77) and 170 microg/l (range, 1-954), respectively. At univariate analysis, all three serum iron indices were positively correlated with grading and staging scores, as well as with HDI in the liver; only serum iron was positively correlated with transaminases. At multivariate analysis, independent associations were found between serum iron and the grading score; ferritin and sinusoidal and portal HDI; transferrin saturation and total hepatic HDI. In conclusion, in hepatitis C, serum iron reflects the degree of current hepatic inflammation and necrosis, whereas the extent of progressive deposition of iron in sites of fibrosis is best reflected by serum ferritin. Transferrin saturation is the best predictor of the status of hepatic iron deposits.

Modeling pollutant release from a surface source during rainfall runoff

Though runoff from manure spread fields is recognized as an important mode of nonpoint-source pollution, there are no models that mechanistically describe transport from a field-spread manure-type source. A mechanistic, physically based model for pollutant release from a surface source, such as field-spread manure, was hypothesized, laboratory tested, and field-applied. The primary objective of this study was to demonstrate the potential applicability of a mechanistic model to pollutant release from surface sources. The laboratory investigation used stable sources and a conservative "pollutant" (KCl) so that the dynamic effects of source dissolution and chemical transformations could be ignored and transport processes isolated. The field investigation used runoff and soluble reactive phosphorus (SP) data collected from a dairy-manure-spread field in the Cannonsville watershed in the Catskills region of New York State. The model predictions corroborated well with observations of runoff and pollutant delivery in both the laboratory and the field. "Pollutant" release from surface sources was generally predicted within 11% of laboratory KCl measurements and field SP observations. Laboratory flume runoff predictions with 15 and 26% errors for 25 and 15 mm h(-1) simulated rainfall intensity experiments, respectively, represented root mean square errors of less than 0.2 mLs(-1). A 26% error was calculated for overland flow predictions in the field, which translated into approximately a 39 mLs(-1) error. Results suggest that the hypothesized model satisfactorily represents the primary mechanisms in pollutant release from surface sources.

Transurethral radiofrequency thermal ablation of prostatic tissue: a feasibility study in humans

OBJECTIVES

To evaluate the feasibility and efficacy of ablating prostatic tissue by inducing thermal lesions using radiofrequency (RF) energy delivered transurethrally through electrodes mounted on a Foley-like catheter.

METHODS

Twenty male patients, candidates for radical cystoprostatectomy to treat bladder carcinoma, underwent RF prostate ablation 1 to 8 days before surgery (mean 2.8). Stainless steel, internally cooled, 2-cm-long electrodes mounted on a Foley-like catheter were used to deliver RF energy to the prostatic tissue. Semicircular electrodes were used in 10 patients (group A) and circular electrodes were used in the remaining 10 patients (group B). The urethral, rectal, and prostatic tissue temperatures were recorded. Histologic step sections were performed on whole mounts of the prostates to define the volume of the thermal lesions.

RESULTS

The mean RF energy delivered was 36.5 kJ (range 26.4 to 53.1) in group A and 82.3 kJ (range 38 to 149) in group B. The intraprostatic temperatures were between 44 degrees C and 80 degrees C in group A and between 60 degrees C and 119 degrees C in group B. The urethral and rectal temperatures never exceeded 42 degrees C. No major complications occurred. After the RF procedure, 5 patients who received more than 75 kJ of energy could not void and required catheterization. The mean prostate volume was 11.54 cm(3) for group A and 24.02 cm(3) for group B. The mean volumes of the thermal lesions and their relative percentages in relation to the whole prostate in groups A and B were, respectively, 1.69 cm(3) and 15% and 6.91 cm(3) and 29% (P = 0.049). Analysis of variance showed a significant correlation between the thermal lesion volume and the energy delivered, regardless of the electrode shape (P = 0.001).

CONCLUSIONS

Satisfactory thermal ablation of prostatic tissue can be achieved using RF electrodes mounted on a Foley-like catheter. The procedure is effective, simple, and safe and, therefore, can be used in pilot clinical studies on patients with benign prostatic hyperplasia.

Ectoparasites of the island fox on Santa Cruz Island

The ectoparasite fauna for island foxes (Urocyon littoralis) on Santa Cruz Island (California, USA) in April (wet season) and September (dry season) 1998 was evaluated. Three taxa of ectoparasites were identified. These were fleas (Pulex irritans), lice (Neotrichodectes mephitidis), and ticks (Ixodes pacificus). Ectoparasite abundances varied seasonally. Typical of insular endemic species, island foxes may be especially vulnerable to the introduction of novel disease organisms and their vectors.

Fixation-off sensitivity as a model of continuous epileptiform discharges: electroencephalographic, neuropsychological and functional MRI findings

A case of fixation-off sensitivity (FOS) in an asymptomatic adult is presented and studied as a model for continuous epileptiform discharges. Video-electroencephalographic (EEG) revealed continuous bilateral occipital spike wave discharges during elimination of central vision, which were shown to be associated with transitory cognitive impairment demonstrated by neuropsychological testing. Functional MRI showed activation of parieto-occipital and frontal brain areas during the fixation-off discharges. This localization was confirmed with 64-channel EEG source analysis. The applied methods provided additional information on the pathophysiology of epileptiform discharges.

The I-Ag7 MHC class II molecule linked to murine diabetes is a promiscuous peptide binder

Susceptibility to insulin-dependent diabetes mellitus is linked to MHC class II genes. The only MHC class II molecule expressed by nonobese diabetic (NOD) mice, I-Ag7, shares a common alpha-chain with I-Ad but has a peculiar beta-chain. As with most beta-chain alleles linked to diabetes susceptibility, I-Ag7 contains a nonaspartic residue at position beta57. We have produced large amounts of empty I-Ag7 molecules using a fly expression system to characterize its biochemical properties and peptide binding by phage-displayed peptide libraries. The identification of a specific binding peptide derived from glutamic acid decarboxylase (GAD65) has allowed us to crystallize and obtain the three-dimensional structure of I-Ag7. Structural information was critical in evaluating the binding studies. I-Ag7, like I-Ad, appears to be very promiscuous in terms of peptide binding. Their binding motifs are degenerate and contain small and/or small hydrophobic residues at P4 and P6 of the peptide, a motif frequently found in most globular proteins. The degree of promiscuity is increased for I-Ag7 over I-Ad as a consequence of a larger P9 pocket that can specifically accommodate negatively charged residues, as well as possibly residues with bulky side chains. So, although I-Ad and I-Ag7 are structurally closely related, stable molecules and good peptide binders, they differ functionally in their ability to bind significantly different peptide repertoires that are heavily influenced by the presence or the absence of a negatively charged residue at position 57 of the beta-chain. These characteristics link I-Ag7 with autoimmune diseases, such as insulin-dependent diabetes mellitus.

GABA receptor antagonists modulate postmitotic cell migration in slice cultures of embryonic rat cortex

Recent studies indicate that GABA acts as a chemoattractant during rat cortical histogenesis. In vivo, GABA localizes in appropriate locations for a chemoattractant, along migratory routes and near target destinations for migrating cortical neurons. In vitro, GABA induces dissociated embryonic cortical neurons to migrate. Here, embryonic rat cortical slices were cultured in the presence or absence of GABA receptor (GABA-R) antagonists to assess GABA's effects on neuronal migration in situ. Gestational day 18 (E18) cortical slices were incubated overnight in bromodeoxyuridine (BrdU)-containing medium to label ventricular zone (vz) cells as they underwent terminal mitosis. The slices were then cultured in BrdU-free medium with or without GABA-R antagonists. In control slices, most BrdU(+) cells were observed in the cortical plate (cp) after 48 h. In contrast, cultures maintained in either saclofen (a GABA(B)-R antagonist) or picrotoxin (a GABA(A/C)-R antagonist) had few BrdU-labeled cp cells. However, the effects of the two antagonists were distinct. In the picrotoxin-treated slices, nearly half of all BrdU(+) cells remained in the vz and subventricular zone (svz), whereas saclofen treatment resulted in an accumulation of BrdU(+) cells in the intermediate zone (iz). Bicuculline, a GABA(A)-R antagonist, did not block, but rather enhanced migration of BrdU(+) cells into the cp. These results provide evidence that picrotoxin-sensitive receptors promote the migration of vz/svz cells into the iz, while saclofen-sensitive receptors signal cells to migrate into the cp. Thus, as cortical cells differentiate, changing receptor expression appears to modulate migratory responses to GABA.

Evidence for elevated telomerase activity in small cell carcinoma of the bladder

Telomerase activity was found to be elevated using a quantitative assay on snap-frozen protein extracts of exfoliated cells in urine and bladder washings and tumor tissue obtained from a male patient with small cell carcinoma of the bladder. To the best of our knowledge, this is the first demonstration of elevated values of telomerase activity in genitourinary small cell carcinoma and is in keeping with the findings in primary lung locations.

Ureteral obstruction after kidney transplantation secondary to bone metaplasia

We report a case of ureteral obstruction after kidney transplantation caused by localized bone metaplasia in the donor ureter. Surgical treatment consisted of removal of the involved ureteral segment, which was located 3 cm above the bladder and creation of a spatulated end-to-end anastomosis. Although bone metaplasia has been observed in the ureteral wall of some animal species secondary to experimental ischemia and microtrauma, it is exceedingly rare in humans and has never before been documented after kidney transplantation.

Focal xanthogranulomatous pyelonephritis with associated bone metaplasia

Focal xanthogranulomatous pyelonephritis of the left lower pole was accidentally discovered in a 34-year-old woman at sonography. The patient had no history of stones and urinary tract infection and both conventional radiology and CT scan revealed radiated calcifications within a well-circumscribed mass. Surgical treatment consisted of enucleoresection of the lesion, and histopathology revealed a nucleus of bone metaplasia. To the best of our knowledge, metaplastic bone formation has never been documented before with xanthogranulomatous pyelonephritis.