Sofosbuvir and daclatasvir therapy in patients with hepatitis C-related advanced decompensated liver disease (MELD ≥ 15)

BACKGROUND

Antiviral therapy for hepatitis C has the potential to improve liver function in patients with decompensated cirrhosis.

AIMS

To examine the virological response and effect of viral clearance in patients with decompensated hepatitis C cirrhosis all with MELD scores ≥15 following sofosbuvir/daclatasvir ± ribavirin.

METHODS

We prospectively collected data on patients who commenced sofosbuvir/daclatasvir for 24-weeks under the Australian patient supply program (TOSCAR) and analysed outcomes including sustained viral response at 12 weeks (SVR12), death and transplant.

RESULTS

108 patients (M/F, 79/29; median age 56years; Child-Pugh 10; MELD 16; genotype 1/3, 55/47) received sofosbuvir/daclatasvir and two also received ribavirin. On intention-to-treat, the SVR12 rate was 70% (76/108). Seventy-eight patients completed 24-weeks therapy. SVR12 was achieved in 56 of these patients on per-protocol-analysis (76%). SVR12 was 80% in genotype 1 compared to 69% in genotype 3. Thirty patients failed to complete therapy. In patients achieving SVR12, median MELD and Child-Pugh fell from 16(IQR15-17) to 14(12-17) and 10(9-11) to 8(7-9), respectively (P<.001). In those who died, MELD increased from 16 to 23 at death (P=.036). Patients who required transplantation had a significantly higher baseline MELD (20) compared to those patients completing treatment (16) (P=.0010). The odds ratio for transplant in patients with baseline MELD ≥20 was 13.8(95%CI 2.78-69.04).

CONCLUSIONS

SVR12 rates with sofosbuvir/daclatasvir in advanced liver disease are lower than in compensated disease. Although treatment improves MELD and Child-Pugh in most patients, a significant proportion will die or require transplantation. In those with MELD ≥20, it may be better to delay treatment until post-transplant.

Methylphenidate amplifies long-term potentiation in rat hippocampus CA1 area involving the insertion of AMPA receptors by activation of β-adrenergic and D1/D5 receptors

Methylphenidate (MPH, Ritalin©) is widely used in the treatment of Attention Deficit Hyperactivity Disorder and recently as a drug of abuse. Although the effect of MPH has been studied in brain regions such as striatum and prefrontal cortex (PFC), the hippocampus has received relatively little attention. It is known that MPH increases the TBS-dependent Long Term Potentiation (LTP) in the CA1 area. However, the cellular and molecular mechanisms involved in this process are still unknown. Using field potential recordings and western blot analysis in rat hippocampal slices of young rats, we found that acute application of MPH enhances LTP in CA3-CA1 synapses in a dose-dependent manner with an EC50 of 73.44±6.32 nM. Using specific antagonists and paired-pulse facilitation protocols, we observed that the MPH-dependent increase of LTP involves not only β-adrenergic receptors activation but also post-synaptic D1/D5 dopamine receptors. The inhibition of PKA with PKI, suppressed the facilitation of LTP induced by MPH consistent with an involvement of the adenyl cyclase-cAMP-PKA dependent cascade downstream of the activation of D1/D5 receptors. In addition, samples of CA1 areas taken from slices potentiated with MPH presented an increase in the phosphorylation of the Ser845 residue of the GluA1 subunit of AMPA receptors compared to control slices. This effect was reverted by SCH23390, antagonist of D1/D5 receptors, and PKI. Moreover, we found an increase of surface-associated functional AMPA receptors. We propose that MPH increases TBS-dependent LTP in CA3-CA1 synapses through a polysynaptic mechanism involving activation of β-adrenergic and D1/D5 dopaminergic receptors and promoting the trafficking and insertion of functional AMPA receptors to the plasma membrane.

Methylphenidate has long-lasting metaplastic effects in the prefrontal cortex of adolescent rats

Methylphenidate (MPH) is widely used as a "nootropic" agent and in the treatment of disorders of attention, and has been shown to modulate synaptic plasticity in vitro. Here we present in vivo evidence that this MPH-induced metaplasticity can last long after the end of treatment. MPH (0, 0.2, 1 and 5mg/kg) was administered daily to male rats from postnatal day 42 for 15 days. The animals were tested daily in a radial maze. Long-term potentiation (LTP), a marker of neural plasticity, was induced in vivo in the prefrontal cortex after 2-3h, 15-18 days or 5 months without treatment. The behavioral performance of the 1mg/kg group improved, while that of animals that had received 5mg/kg deteriorated. In the 1 and 5mg/kg groups LTP induced 2-3h after the last MPH treatment was twice as large as in the controls. Further, 15-18 days after the last MPH administration, in groups receiving 1 and 5mg/kg, LTP was about fourfold higher than in controls. However, 5 months later, LTP in the 1mg/kg group was similar to controls and in the 5mg/kg group LTP could not be induced at all. No significant changes of LTP were seen in the low-dose group of animals (0.2mg/kg). Thus, firstly, doses of MPH that improve learning coincide approximately with those that augment LTP. Secondly, MPH-induced increases in LTP can last for several weeks, but these may disappear over longer periods or deteriorate at high doses.

Measurement of the proton-air cross section at √s=57 TeV with the Pierre Auger Observatory

We report a measurement of the proton-air cross section for particle production at the center-of-mass energy per nucleon of 57 TeV. This is derived from the distribution of the depths of shower maxima observed with the Pierre Auger Observatory: systematic uncertainties are studied in detail. Analyzing the tail of the distribution of the shower maxima, a proton-air cross section of [505±22(stat)(-36)(+28)(syst)] mb is found.

Measurement of the depth of maximum of extensive air showers above 10{18} eV

We describe the measurement of the depth of maximum, X{max}, of the longitudinal development of air showers induced by cosmic rays. Almost 4000 events above 10;{18} eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106{-21}{+35}) g/cm{2}/decade below 10{18.24+/-0.05} eV, and (24+/-3) g/cm{2}/decade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 g/cm{2}. The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.

Observation of the suppression of the flux of cosmic rays above 4 x 10 (19) eV

The energy spectrum of cosmic rays above 2.5 x 10;{18} eV, derived from 20,000 events recorded at the Pierre Auger Observatory, is described. The spectral index gamma of the particle flux, J proportional, variantE;{-gamma}, at energies between 4 x 10;{18} eV and 4 x 10;{19} eV is 2.69+/-0.02(stat)+/-0.06(syst), steepening to 4.2+/-0.4(stat)+/-0.06(syst) at higher energies. The hypothesis of a single power law is rejected with a significance greater than 6 standard deviations. The data are consistent with the prediction by Greisen and by Zatsepin and Kuz'min.

Upper limit on the diffuse flux of ultrahigh energy tau neutrinos from the Pierre Auger Observatory

The surface detector array of the Pierre Auger Observatory is sensitive to Earth-skimming tau neutrinos that interact in Earth's crust. Tau leptons from nu(tau) charged-current interactions can emerge and decay in the atmosphere to produce a nearly horizontal shower with a significant electromagnetic component. The data collected between 1 January 2004 and 31 August 2007 are used to place an upper limit on the diffuse flux of nu(tau) at EeV energies. Assuming an E(nu)(-2) differential energy spectrum the limit set at 90% C.L. is E(nu)(2)dN(nu)(tau)/dE(nu)<1.3 x 10(-7) GeV cm(-2) s(-1) sr(-1) in the energy range 2 x 10(17) eV< E(nu)< 2 x 10(19) eV.

Association between heroin dependence and 5-HT2A receptor gene polymorphisms

OBJECTIVE

To investigate the association between four polymorphisms of the 5-HT(2A) receptor and 5-HT transporter genes and heroin dependence.

METHODS

113 heroin- dependent patients (DSM-IV criteria) and 420 unrelated healthy controls from Asturias (Northern Spain) were genotyped using standard methods.

RESULTS

There was an apparent difference in the distribution of genotypes for A-1438G polymorphisms (p = 0.024, not significant after Bonferroni correction). The 5-HT(2A) -1438A allele was significantly more common in patients than controls [0.55 and 0.45, respectively; corrected p = 0.042, OR = 1.51 (95% CI = 1.13-2.03)]. An interaction was observed between A-1438G of 5-HT(2A) and 5-HTT polymorphisms. The association between the -1438AA vs. AG/GG genotypes and heroin dependence was enhanced in the presence of 12-repeat 5-HTT VNTR and short 5-HTTLPR alleles [24.8% in heroin-dependent patients vs. 12.6% in controls; corrected p = 0.045, OR = 2.28 (95% CI = 1.36-3.82)].

CONCLUSIONS

Our findings support a contribution of the 5-HT(2A) gene to susceptibility to heroin dependence, as well as a possible synergistic effect of 5-HT(2A) and 5-HTT genes on susceptibility to heroin dependence.

Sleep quality in a family with hereditary parkinsonism (PARK6)

OBJECTIVES

The autosomal recessive disorder PARK6 manifests as early-onset Parkinson's disease (PD) with a particularly mild progression. PARK6 is of particular scientific interest, since it is caused by loss-of-function mutations in the mitochondrial protein kinase PINK1 and may thus serve as a model for oxidative damage in PD and in other basal ganglia disorders. Sleep disturbances are very common in PD but have not yet been reported for PARK6 patients. The present study reports on sleep of a Spanish family with PARK6. Of the 5 siblings, 3 were homozygous and severely affected, and 2 were heterozygous and clinically asymptomatic. Research questions concerned possible differences in sleep recordings between homozygote and heterozygote siblings and similarities between PARK6 and sporadic PD sleep profiles.

METHOD

The data from detailed clinical interviews of the patients and their bedpartners are reported and compared with polysomnographic data from second-night recordings.

CONCLUSIONS

All siblings had good subjective and objective sleep quality. Restless legs syndrome and rapid eye movement (REM) sleep behaviour disorder (RBD) were not observed, suggesting that sleep disturbances are not commonly found in PARK6 patients. Good sleep quality and the absence of RBD might be a useful diagnostic guide in the differential diagnosis of sporadic PD versus PARK6.

Plasma aminopeptidase activities in Parkinson's disease

Parkinson's disease (PD) is an age-related neurodegenerative disease characterized by a progressive motor disorder, but frequently is accompanied by autonomic symptoms such as hypotension. Together with the decrease of dopamine, significant decreases in aminopeptidase activities have been reported in PD brains. However, up to date there are no studies about changes of aminopeptidase activities in plasma of PD patients. We studied plasma activities of alanyl-, aspartyl-(AspAP), cystinyl-(CysAP) and glutamyl-aminopeptidase (GluAP) in two groups of subjects: control (n=41) and PD (n=48). Plasma activities of AspAP, CysAP, and GluAP showed significant decreases of 24.9% (p<0.05), 39.4% (p<0.01) and 33.3% (p<0.01), respectively, in PD group. These aminopeptidases are involved in the metabolism of circulating peptides such as the ones of the renin-angiotensin system. The importance of aminopeptidases in striatal dopamine content and in neuroendocrine system in PD is discussed.

Serotonin gene polymorphisms in patients with panic disorder

INTRODUCTION

The objective is to investigate the possible association between four serotonin gene polymorphisms (T102C, A-1438G, 5-HTTLPR and VNTR-5HTT) and panic disorder (PD).

PATIENTS AND METHOD

92 PD outpatients (DSM-IV criteria) and 174 healthy volunteers from Asturias (control group) were included. Polymorphisms were determined after polymerase chain reaction amplification followed by digestion with restriction enzymes and electrophoresis on an agarose gel.

RESULTS

Both 5-HT2A polymorphisms are in complete linkage disequilibrium in our population. No statistically significant differences in genotype frequencies of serotonin gene polymorphisms (T102C, A-1438G, 5HTTLPR and VNTR-5HTT) were found between patients and control subjects. Allele frequencies did not differ between both groups. No differences were found according to gender.

CONCLUSIONS

The polymorphisms studied were not associated with PD in our population. However, larger patient samples are necessary to confirm or reject these findings.

Negative evidences in association between apolipoprotein E polymorphism and panic disorder

The aim is to investigate the association between apolipoprotein E (ApoE) and panic disorder (PD). Genotyping 92 PD patients [Diagnostic Statistic Manual IV (DSM IV) criteria] and 174 controls no differences were found between both groups. Variation in the ApoE-gene was not associated with the development of PD.

Dopaminergic function in a family with the PARK6 form of autosomal recessive Parkinson’s syndrome

A G309D mutation in the PINK1 gene in a consanguineous Spanish kindred with seven siblings, three of whom are clinically affected, has recently been shown to be a cause of the PARK6 form of autosomal-recessive Parkinson's syndrome. In this family, we studied pre- and postsynaptic dopaminergic function using 123I-FP-CIT- and 123I-iodobenzamide-SPECT to determine binding to the presynaptic dopamine transporter (DAT) and postsynaptic D2 receptors respectively. All three PARK6 patients showed reduced striatal DAT binding with posterior preponderance similar to sporadic idiopathic PD, but only one patient showed significant striatal asymmetry. In two of the siblings, DAT binding was markedly increased. IBZM-SPECT was normal in both patients and sibs. Our findings indicate that 123I-FP-CIT-SPECT shows similar DAT binding in PARK6 patients compared to idiopathic Parkinson's disease. The increased DAT binding in heterozygous PARK6 carriers may be a new very early preclinical finding, but its significance is still unclear.

Depression in Parkinson's disease is related to a genetic polymorphism of the cannabinoid receptor gene (CNR1)

Depression is a common symptom in Parkinson's disease (PD) and it is present in up to 40% of the patients. The cause of depression in PD is thought to be related to disturbance of monoamine neurotransmission. The endogenous cannabinoid system mediates different brain processes that play a role in the control of behaviour and emotions. Cannabinoid function may be altered in neuropsychiatry diseases, directly or through interactions with monoamine, GABA and glutamate systems. For this reason, we have investigated whether there is a genetic risk factor for depression in PD linked to the polymorphisms of CB1 receptor gene. Depression was more frequent in patients with PD than in controls with osteoarthritis. The presence of depression did not correlate with the stage of the disease but it was more frequent in patients with pure akinetic syndrome than in those with tremoric or mixed type PD. The CB1 receptor gene polymorphism (AAT)n is considered to modify the transcription of the gene and, therefore, it may have functional relevance. We analysed the length of the polymorphic triplet (AAT)n of the gene that encodes CB1 (CNR1) receptor in 89 subjects (48 PD patients and 41 controls). In patients with PD, the presence of two long alleles, with more than 16 repeated AAT trinucleotides in the CNR1 gene, was associated with a reduced prevalence of depression (Fisher's exact test: P=0.003). This association did not reach significant differences in the control group, but the number of control individuals with depression was too small to allow for statistical analysis. Since the alleles with long expansions may have functional impact in cannabinoid neurotransmission, our data suggest that the pharmacological manipulation of cannabinoid neurotransmission could open a new therapeutic approach for the treatment of depression in PD and possibly in other conditions.

Detection of circulating antigens in experimental anisakiasis by two-site enzyme-linked immunosorbent assay

A two-site enzyme-linked immunosorbent assay (ELISA) based on the avidin-biotin system was developed to study circulating antigens in the sera of rats orally or intraperitoneally infected with L3 larvae of Anisakis simplex s.l. Somatic and excretory-secretory antigens were detected from 24 h post-infection in all infected rats. A direct relationship between the number of larvae inoculated and the concentration of antigens in the sera was demonstrated; however, the amount of antigen decreased with the course of the infection. Comparative analysis revealed that intraperitoneal inoculation is most appropriate for detecting excretory-secretory antigens in serum. The minimum concentrations of A. simplex antigen detectable were approximately 2.5 microg/ml for somatic and excretory-secretory antigens. This antigen detection assay may have application in the diagnosis of anisakiasis.

[Critical period of cortical plasticity]

INTRODUCTION AND DEVELOPMENT

Alterations of sensory experience cause large-scale re-arrangements of cortical connectivity only early in life. After a critical period that roughly ends by puberty, comparable modifications requires more invasive manipulations, including deafferentation and cortical lesions. At a cellular level, the elementary mechanisms responsible for synaptic modification appear to be available throughout life. Thus, in adults, experience dependent plasticity might be constrained additional factors, like the maturation of inhibition or changes in the extra cellular matrix. Such view is consistent with a limited, but not absent, modifiability of adult cortical circuits. This view also has interesting therapeutical implications.

CONCLUSION

In this scenario, manipulation of these limiting factors, for example reducing synaptic inhibition, might be a useful strategy to enhance plasticity and to restore function in the adult cortex.

Apolipoprotein E genotype and schizophrenia: further negative evidence

OBJECTIVE

To investigate the association between apolipoprotein E (ApoE) genotype and schizophrenia.

METHOD

We genotyped 106 schizophrenic out-patients [Diagnostic Statistic Manual IV (DSM-IV) criteria] and 250 healthy volunteers (hospital staff and blood donors) from Asturias (Northern Spain). The ApoE genotypes (epsilon2, epsilon3, epsilon4-alleles) were determined after polymerase chain reaction (PCR) amplification, followed by digestion with the restriction enzyme Cfol and electrophoresis on a 4% agarose gel.

RESULTS

No significant differences in ApoE-allele frequencies between patients and controls was found, although an increased 64-frequency was recorded in patients compared with controls [9.0% vs. 6.2%, P = 0.124; odds ratio (OR) = 1.49; 95% confidence interval (CI) = 0.82-2.70]. ApoE-genotype frequencies did not differ between both groups. The mean age of onset for schizophrenic patients that carried the epsilon4-allele was not significantly different from that of patients without this allele.

CONCLUSION

Variation in the ApoE gene was not associated with the development of schizophrenia in our population. ApoE-genotypes did not modify the age of onset of the disease.

Developmental inhibitory gate controls the relay of activity to the superficial layers of the visual cortex

A developmental reduction in the radial transmission of synaptic activity has been proposed to underlie the end of the critical period for experience-dependent modification in layers II/III of the visual cortex. Using paired-pulse stimulation, we investigated in visual cortical slices how the propagation of synaptic activity to the superficial layers changes during development and how this process is affected by sensory experience. The results can be summarized as follows. (1) Layers II/III responses to repetitive stimulation of the white matter become increasingly depressed between the third and sixth week of postnatal development, a time course that parallels the end of the critical period. (2) Paired-pulse depression is reduced after dark rearing and also by blocking inhibitory synaptic transmission. (3) Paired-pulse depression and its regulation by age and sensory experience is more pronounced when stimulation is applied to the white matter than when applied to layer IV. Together, these results are consistent with the idea that the maturation of intracortical inhibition reduces the capability of the cortex to relay incoming high-frequency patterns of activity to the supragranular layers.

[Radioguided surgery of hyperparathyroidism. A case report]

Primary hyperparathyroidism is the main cause of hypercalcemia in ambulatory patients. Classic surgical resolution of this disease includes bilateral cervical exploration with exhibition of the four parathyroid glands and evaluation of the suspicious gland with a rapid biopsy. We report a 79 years old female with a primary hyperparathyroidism in whom the adenoma causing the disease was located with the help of an intraoperative gamma-probe that detected the zone of higher radiation counting of Tc99m Sestamibi, that was injected preoperatively. The patient was discharged with normal serum calcium and phosphate levels.

Platelet activating factor increases ciliary activity in the hamster oviduct through epithelial production of prostaglandin E2

We investigated the signal transduction mechanisms associated with an increase in ciliary beat frequency (CBF) produced by platelet activating factor (PAF) in oviductal ciliated cell cultures. In the range of concentrations similar to that produced by preimplantation embryos, PAF increased the CBF in a dose-dependent manner. The addition of PAF and prostaglandin E2 (PGE2) to the cultures produced a synergic increase of ciliary beating, suggesting that PAF and PGE2 signal transduction pathways may be associated. To demonstrate this hypothesis, cyclooxygenase-2 (COX-2) was selectively blocked by a specific inhibitor, NS-398, and the PAF-induced CBF increase was abolished. Moreover, a phospholipase A2 (PLA2) inhibitor, AACOCF3, blocks the PAF-induced CBF increase. PGE2 production by oviductal epithelial cells is stimulated by PAF, and WEB-2086, a PAF-receptor blocker, specifically blocks the PAF-induced PGE2 production. Using the fluorescent indicator fura-2, we measured the effect of PAF on intracellular Ca2+ concentration ([Ca2+]i) in individual ciliated cells. PAF induced a transient increase of [Ca2+]i that was blocked by WEB-2086 or by removal of extracellular Ca2+. We propose a mechanism for PAF-mediated signal transduction in the ciliated cells of the oviductal epithelium. Minimal doses of PAF trigger Ca2+ mobilization in tandem with increased PLA2 activity and a COX-2-mediated increase in PGE2. Local PGE2 production by the oviductal mucosa suggests the presence of an autocrine loop controlling ciliary activity.

Functional cross talk after activation of P2 and P1 receptors in oviductal ciliated cells

The presence of ATP and adenosine receptors and their role in controlling ciliary activity in oviductal ciliated cells was studied by measuring the ciliary beat frequency (CBF) in oviductal tissue cultures. ATP, adenosine, and related compounds increased the CBF in a dose-dependent manner. We established that P2 receptors of subtype 2Y(2) and P1 receptors of subtype A(2a) mediated the responses to ATP and adenosine, respectively. We found evidence to suggest that stimulation of ciliary activity by ATP requires D-myo-inositol 1,4, 5-trisphosphate [Ins(1,4,5)P(3)] metabolism, intracellular Ca(2+) mobilization, and protein kinase C activation. On the other hand, the adenosine effect is mediated by activation of a G(s) protein-dependent pathway that enhances cAMP intracellular levels. To study the interaction between P2 and P1 receptors, cells were stimulated simultaneously with both agonists. We observed a synergistic increase of the CBF even at agonist concentrations (100 nM) that did not produce a significant response when added separately to the culture. Furthermore, a blocker of the cAMP pathway produced a reduction of the ATP response, whereas a blocker of the Ins(1,4,5)P(3) pathway also produced an inhibition of the adenosine response. Our evidence demonstrates that both ATP and adenosine receptors are present in a single ciliated cell and that a mechanism of cross talk could operate in the transduction pathways to control ciliary activity.

Zinc and copper modulate differentially the P2X4 receptor

The rat ATP P2X4 receptor was expressed in Xenopus laevis oocytes to assess the effect of zinc and copper as possible regulators of purinergic mechanisms. ATP applied for 20 s evoked an inward cationic current with a median effective concentration (EC50) of 21.4+/-2.8 microM and a Hill coefficient (nH) of 1.5+/-0.1. Coapplication of ATP plus 10 microM zinc displaced leftward, in a parallel fashion, the ATP concentration-response curve, reducing the EC50 to 8.4+/-1.8 microM (p < 0.01) without altering the receptor nH. The zinc potentiation was fast in onset, easily reversible, and voltage-independent and did not require metal preexposure. The zinc EC50 was 2-5 microM, with a bell-shaped curve. At concentrations of 100-300 microM, zinc produced less potentiation, and at 1 mM, it inhibited 50% the ATP current. The effect of zinc was mimicked by cadmium. In contrast, copper inhibited the ATP-evoked currents in a time- and concentration-dependent fashion, reducing the maximal current (Imax) without altering the EC50. The copper-induced inhibition was slow in onset, slowly reversible, and voltage-independent. Whereas coapplication of 300 microM copper plus ATP reduced Imax to 36.2+/-5%, the coapplication of, or 60-s preexposure by, 10 microM copper reduced Imax to 79+/-9.2% (p < 0.05) and 39.6+/-8.7% (p < 0.01), respectively. The inhibition was noncompetitive in nature and mimicked by mercury. Cobalt, barium, and manganese did not modify significantly the ATP-evoked current, demonstrating metal specificity. The simultaneous 1-min preapplication of both metals revealed that the 10 microM zinc-induced potentiation was obliterated by 10 microM copper, whereas 30 microM copper not only reduced the potentiation, but inhibited the ATP response. Following coapplication of both metals for 20 s with ATP, at least 100 microM copper was required to counteract the 10 microM zinc-induced potentiation. The simultaneous preincubation with both metals provided evidence for a noncompetitive interaction. We hypothesize the existence of metal binding site(s), which are most likely localized in the extracellular domain of the P2X4 receptor structure. These sites are selective and accessible to extracellular metal applications and bind micromolar concentrations of metals. The present results are compatible with the working hypothesis that trace metals, such as copper and zinc, are physiological modulators of the P2X4 receptor. The modulation of brain purinergic transmission by physiologically and toxicologically relevant trace metal cations is highlighted.

Cold-hot mismatch between Tc-99m HMPAO-labeled leukocytes and Tc-99m ciprofloxacin in axial skeleton infections: a report of three cases

Radiolabeled leukocyte scintigraphy is a well-established technique for the diagnosis of inflammation and infection with a typical presentation of a hot spot within the abnormal areas. However, in some cases of osteomyelitis of the axial skeleton, a cold defect pattern has been described. Tc-99m ciprofloxacin is a new agent claimed to be specific for imaging sites containing viable bacteria. In this report, we present three cases of proved bacterial infection of the axial skeleton with a mismatch pattern between Tc-99m ciprofloxin and tagged leukocytes. Although Tc-99m-labeled leukocyte scanning showed a cold defect, probably caused by bone marrow replacement, the Tc-99m ciprofloxacin consecutively revealed a hot spot at the site of infection. These data suggest that Tc-99m ciprofloxacin should be a better agent than radiolabeled leukocytes for detecting osteomyelitis of the axial skeleton.

BDNF regulates the maturation of inhibition and the critical period of plasticity in mouse visual cortex

Maturation of the visual cortex is influenced by visual experience during an early postnatal period. The factors that regulate such a critical period remain unclear. We examined the maturation and plasticity of the visual cortex in transgenic mice in which the postnatal rise of brain-derived neurotrophic factor (BDNF) was accelerated. In these mice, the maturation of GABAergic innervation and inhibition was accelerated. Furthermore, the age-dependent decline of cortical long-term potentiation induced by white matter stimulation, a form of synaptic plasticity sensitive to cortical inhibition, occurred earlier. Finally, transgenic mice showed a precocious development of visual acuity and an earlier termination of the critical period for ocular dominance plasticity. We propose that BDNF promotes the maturation of cortical inhibition during early postnatal life, thereby regulating the critical period for visual cortical plasticity.

Multiple kinship in two Spanish regions: new model relating multiple and simple consanguinity

The structure of the different categories of multiple consanguineous marriages (MCMs) and their historical variation patterns are analyzed in the Spanish dioceses of Alava (Basque Country) and Sigüenza-Guadalajara (Castile). Consanguineous marriages, up to third cousins, were taken from ecclesiastical dispensations, and the periods studied were 1831-1980 for Alava and 1861-1980 for Sigüenza-Guadalajara. Significant differences exist in the MCM rates in the two Spanish areas. In this study a model is proposed to prove that in a general population there may be dependence between MCM rates for specific relationships and the frequencies of those types of relationships in the form of simple consanguineous marriages (SCMs). The effects of avoidance and preferentiality and of underreporting are discussed to explain the deviations between observed and expected consanguineous marriage frequencies. A limit to the weight of remote consanguinity on the population inbreeding coefficient F is determined. The relationship between FT/FS and ms values from our two Spanish populations are fitted to curvilinear regressions. FT is the total population inbreeding coefficient, FS is the contribution to FT from SCMs, and ms is the relative observed frequency of SCMs in the general population.

[Parathyroid scintigraphy with Tc99m Sestamibi]

BACKGROUND

Parathyroid scintigraphy with Tc99m Sestamibi, a tracer that is taken up by hyperfunctioning parathyroid tissue, has a high yield in the diagnosis of abnormal parathyroid growths.

AIM

To assess the usefulness of parathyroid scintigraphy with Tc99m Sestamibi in patients with suspected hyperparathyroidism.

PATIENTS AND METHODS

We analyzed retrospectively 29 patients with suspected hyperparathyroidism, in whom a scintigraphy with Tc99m Sestamibi was performed.

RESULTS

Twenty four of 25 patients in whom hyperfunctioning parathyroid tissue was evidenced with scintigraphy, were operated. Histological diagnosis of the excised parathyroid gland, showed 23 adenomas and 1 hyperplasia. Anatomical location disclosed by scintigraphy was concordant with surgical findings in all cases, including a mediastinic adenoma. Of the four patients with negative scintigraphic findings, two had transitory PTH elevations and in two the presence of adenoma or hyperplasia could not be demonstrated with other diagnostic procedures.

CONCLUSIONS

Parathyroid scintigraphy with Tc99m Sestamibi had an 86% sensitivity for the detection of hyperfunctioning parathyroid tissue in patients with elevated PTH.

New method for comparing levels of microdifferentiation: application to migration matrices of two populations from the Basque Country (Spain)

Population microdifferentiation rates can be obtained by various coefficients. Despite differences in the formulations of these coefficients, the obtained values lead to convergent empirical interpretations. One of the most widely used coefficients is Wright's FST. Insofar as all these statistics depend on the number of subpopulations r and their effective size Ne, they are far from easy to compare and interpret. Here, we propose a new method for comparing microdifferentiation rates: a measurement referred to as -log(p), inferred from the relationship between the statistics FST and chi 2. The most interesting quality of -log(p) is that it is independent of r and Ne so that its use facilitates comparisons between populations with different characteristics. Using parent-offspring migration matrices, we estimated the values of -log(p) for two populations in the Basque Country: Lanciego and Orozco. The obtained values were compared with the -log(p) for other world populations whose microdifferentiation rates had already been calculated by other researchers using different data sources. Both Basque populations showed low -log(p) values, as did most of the considered continental populations, whereas island and nonmodern populations showed higher values. This implies microdifferentiation only in island and nonmodern populations, although the secular trend of this process in some populations, such as the Aland Islanders and the Papago, leads to isolation breakdowns.

[The effect of controlled release of DOPA and carbidopa on clinical response and plasma pharmacokinetics of DOPA in parkinsonian patients]

This is a multicentric double blind comparison of the effects of standard and slow release levodopa + carbidopa formulations in patients with Parkinson's disease. Sixty four patients with simple fluctuations were included and 43 finished the study. The study had three phases: a) optimal dose findings phase with standard levodopa + carbidopa; b) open label, cross over study with the two formulations, and c) double blind, parallel investigation. The following results were obtained. There was not a difference in the severity of disability according to UPDRS, part 3, scores though the subjective impressions of patients were in favor of standard formulations. The Sustained release levodopa + carbidopa produced significant improvement of dystonia in off period, pain due to akinesia in off and the number of hours in off and the quality and latency of sleep. In addition there was a tendency in favor of slow release compounds for early morning akinesia, global effect and impression of the examining physician. Low protein diet improved the kinetics of levodopa and the clinical response with both formulations. The clinical usefulness of standard and slow release levodopa + carbidopa formulation should be weighted according to individual problems of patients with Parkinson's disease.

Senile chorea: a multicenter prospective study

Senile chorea (SC) is characterized by the presence of late onset, generalized chorea with no family history and no dementia. It is unclear whether it is a distinct clinical entity or represents late onset Huntington's disease (HD) with an undetected family history. In order to clarify this issue, we carried out a prospective, multicenter study of suspected cases of SC. Since 1994 we identified six cases that met clinical criteria for SC. Their study included routine lab tests, cerebral MRI, neuropsychological assessment, and lastly gene IT15 analysis. An abnormal expansion of the (CAG)n repeat was found in three patients. Although there were no criteria for dementia, most neuropsychological tests revealed mild to moderate deficits, particularly in visuospatial and prefrontal tasks, m all six patients, those that were finally diagnosed as having late onset "sporadic" HD, but also in patients that finally had SC. This study provides further evidence on the existence of SC; however, the distinction from late onset "sporadic" HD seems not to be possible on clinical grounds unless a genetic study is carried out. Some cases of suspected "SC" have late onset "sporadic" HD.

Calcium mediates the activation of the inhibitory current induced by odorants in toad olfactory receptor neurons

In toad olfactory neurons, a putrid odorant mixture inducing inhibitory responses increases Ca2+-activated K+ conductance, developing a hyperpolarizing receptor potential. Removal of extracellular Ca2+ or exposure to nifedipine reversibly reduced the inhibitory response, suggesting that odorants induce a Ca2+ influx. We show evidence for an odorant-induced Ca2+ current. Using confocal microscopy, it is shown that odorants induce a nifedipine-sensitive elevation of Ca2+ in the apical end of the cell. These results suggest an inhibitory mechanism in which an apical Ca2+ influx causes an increase in internal Ca2+, opening Ca2+-activated K2+ channels that lead to membrane hyperpolarization.

Postpartum bilateral subdural hematomas following spinal anesthesia: case report

BACKGROUND

Intracranial subdural hematoma is an exceptionally rare complication of spinal anesthesia. We report a case of this infrequent event and consider the influence of cerebral atrophy as a predisposing factor.

METHODS AND RESULTS

This 18-year-old woman with severe headaches was admitted to the hospital 42 days after delivery. She had a history of normal pregnancy and uneventful labor and delivery. The epidural anesthesia was satisfactory. Computed tomography showed bilateral chronic subdural hematomas that were surgically removed. An early follow-up scan showed marked resolution of the hematomas and a small sized brain with large subarachnoid space. A late follow-up scan confirmed the diagnosis of brain atrophy.

CONCLUSIONS

Persistence of headache and gradual progression despite treatment must be regarded as a sign of intracranial complication following spinal anesthesia. In this case, cerebral atrophy is considered to be a contributory factor for the development of subdural hematoma following dural puncture.

Inbreeding patterns in the Gredos Mountain Range (Spain)

The relationships among the frequency of consanguineous marriages, inbreeding coefficient, period, village size, and altitude are analyzed for three rural valleys belonging to the Sierra de Gredos (central Spain). These valleys occupy an area of about 30 x 80 km2, and the average total number of inhabitants for the period 1877-1970 was 58,621. Information about a sample of 23,744 weddings celebrated between 1875 and 1974 was obtained from 48 village parish registers. The mean inbreeding level up to second cousins for the whole area was 0.0012. A high percentage of inbreeding variation (83%) can be explained by each village's census size, resulting in a different interslope consanguinity pattern consisting of higher inbreeding levels in most northern localities in the Gredos mountains. This north-south geographic trend is consistent with results on blood polymorphisms from the same area (Mesa et al. 1994).

Chemical reception in vertebrate olfaction: evidence for multiple transduction pathways

Odorant detection takes place at the receptor neurons of the olfactory epithelium and odorant discrimination relies in an important degree on these chemosensory cells. Here we review the evidence for the participation of multiple transduction pathways in the mechanisms of odor recognition in olfactory neurons.