[Acquired oculomotor paralysis in the adolescent]

INTRODUCTION

Acquired oculomotor palsy in juvenile age are most commonly due to head trauma, tumors, migraine, vasculopathies and demyelinating diseases.

CLINICAL CASES

We document three cases of paroxysmal oculomotor nerve palsy in childhood, illustrating the main clinical symptoms, neurological examination, MR images, diagnosis, treatment and evolution. Final diagnosis were: multiple sclerosis, pineoblastoma, and craniopharyngioma.

CONCLUSIONS

Sudden oculomotor nerve palsy occurring in youth in the absence of head trauma, viral infection or migraine access, firmly suggests a serious intracranial disease, and neuroimage studies should be quickly obtained to have an early diagnosis.

Primary HIV-1 drug resistance in Spain before and after the introduction of protease inhibitors

The prevalence of genotypic resistance to nucleoside analogues was examined in 150 naive individuals with chronic HIV-1 infection acquired before June 1996, when protease inhibitors began to be used in Spain, and in a group of 52 recent seroconverters infected since 1997. Overall, the prevalence of subjects carrying nucleoside-resistant genotypes was similar in both groups (12.6% and 15.4%, respectively). A polymorphism at codon 70 accounted for more than half of cases (63.1%) in naive individuals infected before protease inhibitors became available, in contrast most recent seroconverters carried genotypes with one or more key nucleoside resistance mutations, mainly associated with lack of sensitivity to zidovudine or lamivudine (prevalence 9.6% and 5.9%, respectively). When only key mutations were considered in each of the two periods, the prevalence of nucleoside-resistant genotypes was increased significantly among recent seroconverters (13.5% vs. 4.7%; P<0.05). The relatively high rate of resistance to nucleosides in Spain justifies the introduction of drug resistance testing in naive recent seroconverters before beginning antiretroviral therapy.

Suicide and Alzheimer's pathology in the elderly: a case-control study

BACKGROUND

The single most important risk factor for Alzheimer's pathology is age. Elderly individuals are also at increased risk for suicide, but comprehensive studies of the association between Alzheimer's pathology and suicide are lacking. We designed the current study to determine if Alzheimer's disease changes are overrepresented in elderly people committing suicide.

METHODS

The design is a case-control study. Cases (n = 28) were subjects older than 60 years of age who completed suicide. For each case, two age- and gender-matched individuals who died naturally were selected as control subjects (n = 56). Neuropathologic examination of hippocampal sections was performed blindly and included a modified Braak scoring system and semiquantitative assessment of neurofibrillary tangles, amyloid deposition, Lewy bodies, and Lewy-associated neurites. Data were analyzed by conditional logistic regression.

RESULTS

The brains of individuals who committed suicide had higher modified Braak scores than those of matching control subjects (p =.0028). The number of neurofibrillary tangles in CA1 was not an independent predictor of suicide status in the statistical analysis (p =.16), although the distribution was more highly skewed among the cases (75th percentile of 10.5 for cases, vs. 2 for control subjects).

CONCLUSIONS

Severe Alzheimer's disease pathology is overrepresented in elderly patients who complete suicide.

HIV-1 plasma viremia not increased in patients receiving highly active antiretroviral therapy after influenza vaccination

The effect of vaccinating patients with sustained undetectable HIV-1 viremia (VL) achieved with highly active antiretroviral therapy was prospectively investigated. During the 1998 influenza immunization period, 39 HIV-1-infected patients who showed a VL<20 copies/ml for at least 6 months before the study entry date were vaccinated for influenza. Twenty-two vaccinees were immunized at entry. Seventeen controls were followed for 4 weeks after entry, crossing over then to the vaccination group. The proportion of patients with undetectable VL was not significantly different between the vaccination and control groups 2 and 4 weeks after entry. Therefore, influenza immunization of patients with undetectable viremia achieved with highly active antiretroviral therapy does not seem to affect VL.

Low levels of HIV-1 plasma viral load in patients infected with HIV-1 subtype b and advanced immunosuppression

OBJECTIVES

Some HIV-1 infected patients show low levels of viraemia despite having advanced immunosuppression. Cases with falsely undetectable viraemia by conventional PCR have been reported when patients were infected with non-B subtypes. The aim of this study was to investigate whether this immunovirological discordance can be due to the presence of HIV-1 non-B subtypes, and whether a modified PCR procedure can yield different HIV viraemia values in these cases.

METHODS

Fifteen HIV-infected patients either naive for antiretroviral drugs or under treatment, with HIV plasma viraemia below 1000 copies/mm(3)and CD4+ cell counts lesser than 500 or 300 cells/mm(3), respectively, were included. Serotyping, genotyping and HIV plasmatic viraemia determinations were performed in all individuals.

RESULTS

In five out of six treatment-naive patients the virus was categorized as non-B subtype by serotyping, although only one case was confirmed by genotyping as HIV-2. Eight out of nine patients under antiretroviral therapy were subtype B carriers by serotyping and confirmed by genotyping. The remaining patient was determined as a subtype A carrier by both procedures. A modified PCR procedure (Amplicor HIV Monitor Test version 1.5) did not yield higher viral load levels than the former version.

CONCLUSIONS

The presence of HIV-1 subtypes non-B can explain a minority of cases of this immunovirological discordance, but in most of them the reason is still unknown. Likewise, a PCR procedure adapted for detecting HIV-1 non-B subtypes fails to find higher plasma viraemia in patients with such a discordance.

Life-supporting human complement regulator decay accelerating factor transgenic pig liver xenograft maintains the metabolic function and coagulation in the nonhuman primate for up to 8 days

BACKGROUND

It is not known whether the pig liver is capable of functioning efficiently when transplanted into a primate, neither is there experience in transplanting a liver from a transgenic pigs expressing the human complement regulator human complement regulator decay accelerating factor (h-DAF) into a baboon. The objective of this study was to determine whether the porcine liver would support the metabolic functions of non-human primates and to establish the effect of hDAF expression in the prevention of hyperacute rejection of porcine livers transplanted into primates.

METHODS

Five orthotopic liver xenotransplants from pig to baboon were carried out: three from unmodified pigs and two using livers from h-DAF transgenic pigs.

FINDINGS

The three control animals transplanted with livers from unmodified pigs survived for less than 12 hr. Baboons transplanted with livers from h-DAF transgenic pigs survived for 4 and 8 days. Hyperacute rejection was not detected in the baboons transplanted with hDAF transgenic pig livers; however, it was demonstrated in the three transplants from unmodified pigs. Baboons transplanted with livers from h-DAF transgenic pigs were extubated at postoperative day 1 and were awake and able to eat and drink. In the recipients of hDAF transgenic pig livers the clotting parameters reached nearly normal levels at day 2 after transplantation and remained normal up to the end of the experiments. In these hDAF liver recipients, porcine fibrinogen was first detected in the baboon plasma 2 hr postreperfusion, and was present up to the end of the experiments. One animal was euthanized at day 8 after development of sepsis and coagulopathy, the other animal arrested at day 4, after an episode of vomiting and aspiration. The postmortem examination of the hDAF transgenic liver xenografts did not demonstrate rejection.

INTERPRETATION

The livers from h-DAF transgenic pigs did not undergo hyperacute rejection after orthotopic xenotransplantation in baboons. When HAR is abrogated, the porcine liver maintains sufficient coagulation and protein levels in the baboon up to 8 days after OLT.

Hole dynamics in noble metals

Hole dynamics in noble metals (Cu and Au) is investigated by means of first-principles many-body calculations. While holes in a free-electron gas are known to live shorter than electrons with the same excitation energy, our results indicate that d holes in noble metals exhibit longer inelastic lifetimes than excited sp electrons, in agreement with experiment. The density of states available for d-hole decay is larger than that for the decay of excited electrons; however, the small overlap between d and sp states below the Fermi level increases the d-hole lifetime. The impact of d-hole dynamics on electron-hole correlation effects is also addressed.

Overexpression of neutrophil neuronal nitric oxide synthase in Parkinson's disease

Much evidence supports a role of nitric oxide (.NO) and peroxynitrite (ONOO(-)) in experimental and idiopathic Parkinson's disease (PD); moreover, an overexpression of neuronal nitric oxide synthase (nNOS) was recently reported in the basal ganglia of PD patients. In accord, we previously found a 50% increased.NO production rate during the respiratory burst of circulating neutrophils (PMN) from PD patients. As PMN express the nNOS isoform, the objective of the present study was to ascertain whether this increased.NO production is representative of nNOS gene upregulation. PMN were isolated from blood samples obtained from seven PD patients and seven age- and sex-matched healthy donors; nNOS mRNA was amplified by reverse transcriptase-polymerase chain reaction and the products were hybridized with a probe for nNOS. Nitrotyrosine-containing proteins and nNOS were detected by Western blot and NO production rate was measured spectrophotometrically by the conversion of oxymyoglobin to metmyoglobin. The results showed that both.NO production and protein tyrosine nitration were significantly increased in PMN isolated from PD patients (PD 0.09 +/- 0.01 vs 0.06 +/- 0.008 nmol min(-1) 10(6) cells(-1); P < 0.05). In addition, five of the seven PD patients showed about 10-fold nNOS mRNA overexpression; while two of the seven PD patients showed an expression level similar to that of the controls; detection of nNOS protein was more evident in the former group. In summary, it is likely that overexpression of nNOS and formation of ONOO(-) in PMN cells from PD patients emphasizes a potential causal role of.NO in the physiopathology of the illness.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a recently described neurovascular disease affecting young to middle age individuals. The disease is caused by mutations in the Notch3 gene located in the short arm of chromosome 19. Clinically, the disease is characterized by migrainous headaches (with or without aura), mood disturbances, focal neurologic deficits, transient ischemic attacks, strokes, and dementia. Pathologically, the disease is characterized by a stereotypic degeneration of the arterial walls (especially in the intracranial compartments) with deposition in the media of a nonatheromatous, nonamyloidotic substance that under the electron microscope (EM) appears as a granular osmiophilic material (GOM), pathognomonic for the disease. The nature of the GOM is undetermined and the pathogenesis remains to be elucidated. A review of current literature in English language is presented on the clinical, radiologic, pathologic, and genetic features of CADASIL.

4-Alkylidenyl glutamic acids, potent and selective GluR5 agonists

Twenty-four 4-alkylidene glutamic acids were synthesised and tested as potential subtype selective GluR5 and 6 ligands. It was found that a critical size of alkylidene group gave potent and selective GluR5 receptor agonists. LY339624 had Kis of 0.0326 and >100 microM on GluR5 and 6 receptors, respectively.

Electron wave function at a vicinal surface: switch from terrace to step modulation

The Cu(111) surface state has been mapped for vicinal surfaces with variable step densities by angle-resolved photoemission. Using tunable synchrotron radiation to vary the k dependence perpendicular to the surface, as well as the (k) dependence, we find a switch between two qualitatively different regimes at a miscut of 7 degrees (17 A terrace width). For larger miscut angles the step modulation of the wave function dominates, and for smaller miscut angles the terrace modulation dominates. These observations resolve an apparent inconsistency between prior photoemission and STM results.

Effects of sub-chronic combined treatment with pergolide and caffeine on contralateral rotational behavior in unilateral 6-hydroxydopamine-denervated rats

We studied the synergistic effects of pergolide and bromocriptine with caffeine on turning behavior in 6-OHDA denervated rats. Both pergolide and bromocriptine were synergistic with caffeine, and prevented tolerance to caffeine-induced turning. When caffeine was removed, tolerance to bromocriptine effects was observed for 1 day only, while no tolerance was observed to pergolide. These results suggest that caffeine could be useful in the treatment of Parkinson's disease, preferentially as an adjuvant of mixed dopaminergic agonists like pergolide.

Factors affecting establishment of a gypsophyte: the case of Lepidium subulatum (Brassicaceae)

The restriction of vascular plants to gypsum-rich soils under arid or semiarid climates has been reported by many authors in different parts of the world. However, factors controlling the presence of gypsophytes on these soils are far from understood. We investigated the establishment of Lepidium subulatum, a gypsophyte, in a nondisturbed semiarid gypsum-soil landscape in central Spain, both from spatial and temporal perspectives. Over 1400 seedlings were tagged, and their growth and survival were monitored for a 2-yr period. Several biotic and abiotic variables were measured to determine the factors controlling the emergence and early survival. These variables included the cover of annual plants, bryophytes, lichens, litter, gypsum crystals, bare fraction and cover of each perennial plant, and several soil properties (gravel, fine gravel, and fine-earth fraction, conductivity, pH, gypsum content, organic matter and penetrometer soil resistance). Our results support the linkage of gypsophily with some physical properties of the surface crust. Seedlings tended to establish on the gypsum surface crust, and their survival was size dependent, probably as a consequence of the necessity of rooting below the surface crust before summer drought arrives. However, once seedlings emerged, a higher survival rate occurred on the alluvial soils of the piedmont-slope boundary where soil crusts are absent or thinner. We conclude that Lepidium subulatum may be considered a refuge model endemic with a distribution range that occupies a reduced fraction of a wider habitat from which it is probably excluded by competition.

Lack of synergism between caffeine and SKF 38393 on rotational behavior in 6-hydroxydopamine-denervated rats

We have recently shown a synergistic effect between caffeine and the dopamine D(2) receptor agonist, bromocriptine, on contralateral rotational behavior in unilaterally 6-hydroxydopamine-denervated rats. In addition, we found that bromocriptine prevented caffeine-induced tolerance to this behavior following repeated treatment. In the present study, we investigated whether or not the dopamine D(1) receptor agonist, (+/-)-phenyl-2,3,4, 5-tetrahydro-(1H)-3-benzazepine-7,8-diol (SKF 38393), presented similar characteristics. Different groups of rats received simultaneous injections of either vehicle plus vehicle, caffeine (40 mg/kg) plus vehicle, SKF 38393 (0.5, 1, 2, and 4 mg/kg) plus vehicle, or caffeine plus SKF 38393 (0.5, 1, 2, and 4 mg/kg) for 5 consecutive days, and both ipsilateral and contralateral rotational behavior was measured. Results showed that, on the first day of treatment, caffeine produced significantly more rotational behavior than did a low dose of SKF 38393 (0.5 mg/kg), and significantly less turning than at higher doses (2 and 4 mg/kg). Combined treatment with caffeine and a high dose of SKF 38393 (4 mg/kg) produced significantly more rotational behavior than did caffeine plus vehicle. With repeated administration, caffeine produced sustained tolerance to its effects on rotational behavior, whereas SKF 38393 did not. In the groups treated with low doses of SKF 38393 (0.5, and 1 mg/kg) plus caffeine, tolerance was observed while in the groups that received high doses of SKF 38393 (2 and 4 mg/kg) plus caffeine, no tolerance was observed to rotational behavior. These results suggest that maximal stimulation of dopamine D(1) receptors may be needed to prevent the tolerance effects of caffeine in this animal model. This finding may have clinical relevance to the therapeutic treatment of Parkinson's disease.

4-Alkyl- and 4-cinnamylglutamic acid analogues are potent GluR5 kainate receptor agonists

Enantiomerically pure (2S,4R)-4-substituted glutamic acids were prepared and tested for homomeric GluR5 and GluR6 kainate subtype receptor affinity. Some of the 4-cinnamyl analogues showed high selectivity and potency (K(i) < 25 nM) for the GluR5 receptors. The greatest selectivity and potency were achieved with the 3-(2-naphthyl)prop-2-enyl compound. This compound, LY339434, has negligible activity at the AMPA and kainate receptors GluR1, -2, -4 and -6. Although, LY339434 shows agonist activity at NMDA receptors in cultural hippocampal neurons (approximate EC(50) of 2.5 microM), we consider that LY339434 should be a useful pharmacological tool for the investigation of the functional role of GluR5 kainate receptors.

Celiac disease and TNF promoter polymorphisms

The possibility that genetic susceptibility to celiac disease (CD) might be influenced by tumor necrosis factor (TNF) genes polymorphism has repeatedly been put forward. To date, this has only been investigated in case-control studies and results have been contradictory. In order to avoid any possible ethnic mismatching between patients and controls, we have approached this problem studying 71 celiac families, establishing the parental haplotypes and comparing CD versus control haplotypes (the so-called AFBAC or affected family-based controls). We used DNA-based methods to screen for HLA-DRB1, -DQA1, and -DQB1 alleles, TNFalpha promoter polymorphims and TNFa and b microsatellites. The guanine-to-adenine polymorphism at position -308 of the TNFalpha gene promoter region was found associated with CD as the TNF-308A allele appeared significantly increased in frequency in CD haplotypes, and this was shown to be independent of the association between CD and the DRB1*0301,DQA1*0501,DQB1*0201 alleles. Our results indicate that at least another gene, in addition to the known association of CD with HLA class II, has a susceptibility role in this disease. This should be either TNFalpha or another polymorphic gene in the telomeric end of the HLA class III region.

Prevalence of genotypic resistance to nucleoside analogues and protease inhibitors in Spain. The ERASE-2 Study Group

OBJECTIVE

To examine the prevalence of resistance mutations to nucleoside reverse transcriptase inhibitors (NRTI) and protease inhibitors (PI) in a representative HIV-1 population in Spain.

METHODS

A cross-sectional study was conducted including 601 HIV-infected patients who attended 20 Spanish hospitals in June 1998. Drug resistant mutations were examined using hybridization line probe assays (LiPA). The 6 bp insert at position 69 and the codon 75 mutant were examined by sequencing analysis in specimens lacking reactivity to 69/70 and 74 bands on LiPA, respectively.

RESULTS

Primary resistance to NRTI was recognized in nine out of 52 (17%) naive individuals, whereas primary resistance to PI was found in seven out of 126 (6%) PI-naïve patients. The codons most frequently involved in NRTI resistance were at positions 70 (66%), 184 (44%), 215 (33%), and 41 (11%), whereas the most common PI resistance mutation was at codon 82 (6/7 subjects). In pre-treated patients, the overall prevalence of resistant genotypes was 72.9% for NRTI and 27.2% for PI. The most frequent NRTI mutations occurred at codons 184 (38.5%), 215 (30.1%), and 41 (22.5%), whereas the most frequent PI mutations in pre-treated subjects were found at positions 82 (15.8%) and 84 (11.4%). Overall, patients who began triple combinations as initial therapy showed a lower number of key resistance mutations than those who began highly active antiretroviral therapy (HAART) after being exposed to NRTI for a period of time (mean number of mutations, 0.1 versus 1.8, P< 0.05). Codon 75 mutant was found in three out of 387 patients (0.7%), whereas no insertions at codon 69 were recognized.

CONCLUSION

The prevalence of primary genotypic resistance to NRTI and PI in Spain was 17% and 6%, respectively. Zidovudine, lamivudine, indinavir and ritonavir were the drugs most frequently affected. These data support the use of resistance testing prior to the introduction of first-line antiretroviral therapies in Spain. Among pre-treated subjects, drug resistance genotypes were less prevalent in those who began HAART as initial therapy.

Presence of genotypic resistance in nucleoside analogue-treated HIV-1-infected patients with undetectable viral load

Patients harbouring drug-resistance viruses usually suffer a rise in serum viraemia after a variable period of time. We have investigated the relationship between the appearance of resistant genotypes and the viral load of each patient after treatment. Our objective was to assess the association between human immunodeficiency virus (HIV) RNA plasma levels and the number of drug resistance-associated point mutations after treatment. A total of 150 patients from three reference centres in Spain (Madrid, Barcelona and Seville) from a previous study (Erase Study) were included. Patients had at that time undergone antiretroviral treatment with nucleoside analogues for at least 1 year (zidovudine/didanosine; zidovudine/zalcitabine; zidovudine/zalcitabine/lamivudine; zidovudine/didanosine/lamivudine). In this study, plasma viraemia in these patients was quantified and a line probe assay was used to determine the genotype of the virus. Viral load was significantly higher in patients harbouring virus with more than three mutations than in those individuals who harboured wild-type strains (P < 0.05). Surprisingly, when patients with viral load < 500 copies/ml (13/150) were analysed, only two carried wild-type strains, whereas three had virus with more than three point mutations. The viral load of six samples was assayed using an ultrasensitive test (detection limit < 20 copies/ml). Of the three samples where viral load was < 20 copies/ml, one patient harboured wild-type virus, whereas two carried mutant virus strains. These results suggest that even in patients with undetectable viral loads by conventional methods, viral replication may continue and mutations develop. Therefore, standard values of plasma viraemia for measuring the effectiveness of the treatment should be reconsidered when patients are on antiviral regimens of just two or three nucleoside analogues.