Identification and characterization by high-performance liquid chromatography/electrospray ionization mass spectrometry of a new variant hemoglobin, Mataro [beta134(H12) Val > Ala

This work illustrates the practical use of combined microbore reversed-phase high-performance liquid chromatography (RP-HPLC) with electrospray ionization mass spectrometry (ESI-MS) in protein identification. The approach consisted of the detection of the abnormal beta-globin chain by ESI-MS analysis of mixtures of intact globins, which simultaneously provided their molecular masses. Separation of the polypeptide globin chains was carried out using microbore C4 RP-HPLC on-line with ESI-MS. Direct peptide-mapping ESI-MS without previous chromatographic separation was performed in order to identify tryptic peptides from whole blood. For the sequence confirmation of the abnormal peptide containing the mutation point, C18 RP-HPLC tryptic separation of the globin mixture on-line with collision-induced dissociation (CID) fragmentation was done. The y series ions allowed the identification of the hemoglobin (Hb) variant as [beta134(H12) Val > Ala]. This new Hb was named Hb Mataró, after the city where it was detected.

Production and neurotropism of lentivirus vectors pseudotyped with lyssavirus envelope glycoproteins

We investigated the production efficiency and the gene transfer capacity in the central nervous system of HIV-1-based vectors pseudotyped with either the G protein of the Mokola lyssaviruses (MK-G), a neurotropic virus causing rabies disease, or the vesiculo-stomatitis G protein (VSV-G). Both envelopes induced syncitia in cell cultures. They were incorporated into vector particles and mature virions were observed by electron microscopy. Vector production was two- to sixfold more efficient with VSV-G than with MK-G. For equivalent amounts of physical particles, vector titration was 5- to 25-fold higher with VSV-G than with MK-G pseudotypes on cultured cells, and in vivo gene expression in mouse brain was more intense. Thus, VSV-G pseudotypes were produced more efficiently and were more infectious than MK-G pseudotypes. Tropism for brain cells was analyzed by intrastriatal injections in rats. Both pseudotypes preferentially transduced neurons (70-90% of transduced cells). Retrograde axonal transport was investigated by instilling vector suspensions in the rat nasal cavity. Both pseudotypes were efficiently transported to olfactive neuron bodies. Thus, although coating HIV-1 particles with rabdhovirus envelope glycoproteins enables them to enter neuronal cells efficiently, pseudotyping is not sufficient to confer the powerful neurotropism of lyssaviruses to lentivirus vectors.

Nearly all hereditary paragangliomas in the Netherlands are caused by two founder mutations in the SDHD gene

Hereditary paragangliomas or glomus tumors are usually benign slow-growing tumors in the head and neck region. The inheritance pattern of hereditary paraganglioma is autosomal dominant with imprinting. Recently, we have identified the SDHD gene encoding subunit D of the mitochondrial respiratory chain complex II as one of the genes involved in hereditary paragangliomas. Here, we demonstrate that two founder mutations, Asp92Tyr and Leu139Pro, are responsible for paragangliomas in 24 and 6 of the 32 independently ascertained Dutch paraganglioma families, respectively. These two mutations were also detected among 20 of 55 isolated patients. Ten of the isolated patients had multiple paragangliomas, and in eight of these SDHD germline mutations were found, indicating that multicentricity is a strong predictive factor for the hereditary nature of the disorder in isolated patients. In addition, we demonstrate that the maternally derived wild-type SDHD allele is lost in tumors from mutation-carrying patients, indicating that SDHD functions as a tumor suppressor gene.

New 1-aryl-3-(4-arylpiperazin-1-yl)propane derivatives, with dual action at 5-HT1A serotonin receptors and serotonin transporter, as a new class of antidepressants

In a search toward new and efficient antidepressants, 1-aryl-3-(4-arylpiperazin-1-yl)propane derivatives were designed, synthesized, and evaluated for 5-HT reuptake inhibition and 5-HT1A receptor antagonism. This dual pharmacological profile should lead, in principle, to a rapid and pronounced enhancement in serotoninergic neurotransmission and consequently to a more efficacious treatment of depression. The design was based on coupling structural moieties related to inhibition of serotonin reuptake, such as gamma-phenoxypropylamines, to arylpiperazines, typical 5-HT1A ligands. In binding studies, several compounds showed affinity at the 5-HT transporter and 5-HT1A receptors. Antidepressant-like activity was initially assayed in the forced swimming test with those compounds with Ki < 200 nM in both binding studies. Functional characterization was performed by measuring the intrinsic effect on rectal temperature in mice and also the antagonism to 8-OH-DPAT-induced hypothermia. The most efficacious compounds (12f, 23gE, 28a, and 28b) were further explored for their ability to antagonize 8-OH-DPAT-induced inhibition of forskolin-stimulated cAMP formation in a cell line expressing the 5-HT1A receptor. Furthermore, the antidepressant-like properties of 12f, 28a, and 28b, which exhibited 5-HT1A receptor antagonistic property in the latter study, were also evaluated in the learned helplessness test in rats. Among these three compounds, 28b (1-benzo[b]thiophene-3-yl)-3-[4-(2-methoxyphenyl)-1-ylpropan-1-ol) showed the higher affinity at both the 5-HT transporter and 5-HT1A receptors (Ki = 20 nM in both cases) and was also active in the other pharmacological tests. Such a pharmacological profile could lead to a new class of antidepressants with a dual mechanism of action and a faster onset of action.

New 3-[4-(aryl)piperazin-1-yl]-1-(benzo[b]thiophen-3-yl)propane derivatives with dual action at 5-HT1A serotonin receptors and serotonin transporter as a new class of antidepressants

A series of new 3-[4-(aryl)piperazin-1-yl]-1-(benzo[b]thiophen-3-yl)propane derivatives were synthesized in an attempt to find a new class of antidepressant drugs with dual activity at 5-HT1A serotonin receptors and serotonin transporter. Title compounds were evaluated for in vitro activity on 5-HT1A receptor and 5-HT transporter. They show high nanomolar affinity for both activities, and in particular, compounds 1-(5-chlorobenzo[b]thiophen-3-yl)-3-[4-(2-methoxyphenyl)piperazin-1-yl]propan-1-ol (7) and 1-(5-fluorobenzo[b]thiophen-3-yl)-3-[4-(2-methoxyphenyl)piperazin-1-yl]propan-1-ol (8) show values (nM) of K(i)=30 and 2.3 for 5-HT1A receptors and K(i)=30 and 12 for serotonin transporters, respectively. In GTPgammaS binding assays, compound 8 revealed antagonist properties to 5-HT1A receptors. Such a pharmacological profile could lead to potent antidepressant agents with new dual mechanism of action.

Human enteric viruses in Coquina clams associated with a large hepatitis A outbreak

An outbreak of hepatitis A, affecting 183 people, occurred in Valencia (Spain). Epidemiological evidence pointed to an association of the outbreak with consumption of Coquina clams (Donax sp), imported frozen from Peru. Shellfish were analysed for the presence of hepatitis A virus (HAV), enteroviruses, rotaviruses, astroviruses, caliciviruses and hepatitis E virus. HAV was detected in 75% of assayed shellfish samples. Other enteric viruses were occasionally found in the same samples. Molecular epidemiological analysis of fragments of the VP1/2A and the 5' end of the genome from shellfish and sera isolates, revealed the presence of six variants belonging to a single genotype.

[Assessment of the PCR-Southern blot technique for the analysis of viremia in patients with acute hepatitis A]

Assessment of viremia in hepatitis A virus (HAV) infection is not frequently performed with conventional methods because the techniques used are laborious, have low sensitivity are usually performed in feces. The aims of this study were to develop a polymerase chain reaction (PCR) and Southern blot technique to detect HAV-RNA in the serum of patients with acute HAV infection and to determine the relationship between HAV-RNA and anti-HAV IgM and alanine aminotransferase (ALT) levels. The presence of HAV-RNA was studied in 26 serum samples from 21 patients with acute hepatitis A. We also studied 11 samples from patients with acute hepatitis B and 15 samples from patients with non-A, non-E hepatitis. HAV-RNA was detected in 10 (38%) of the 26 serum samples from patients with acute hepatitis A. Simple PCR was positive in 5 samples and PRC-Southern blot was positive in 10. All the serum samples obtained during the first week of onset were HAV-RNA positive and 50% of those obtained during the second week were positive. None of the serum samples obtained after the second week of onset were HAV-RNA positive. None of the serum samples from the 11 patients with acute hepatitis B or from the 15 patients with non-A, non-E acute hepatitis were positive for HAV-RNA. No significant relationship was detected between HAV-RNA detection and an IgM anti-HAV or ALT positive result. In conclusion, the presence of HAV-RNA in acute hepatitis A is frequent but the PCR Southern blot technique is required for detection, which is transitory during the first weeks after onset.

Astrovirus detection in wastewater samples

Procedures for the detection of astroviruses in wastewater samples have been developed and evaluated. Following these methodologies, we investigated the occurrence of astroviruses in wastewater samples from three different sewage treatments plants located in Southern France and two in the Barcelona area. Some positive samples were genotyped by analysis of a fragment of the ORF1a by restriction fragment length polymorphism (RFLP) with endonuclease DdeI. The amplimers generated contain several sites for the DdeI restriction endonuclease, being the number and location of sites different between strains.

Cerebral autoregulation in subjects adapted and not adapted to high altitude

BACKGROUND AND PURPOSE

Impaired cerebral autoregulation (CA) from high-altitude hypoxia may cause high-altitude cerebral edema in newcomers to a higher altitude. Furthermore, it is assumed that high-altitude natives have preserved CA. However, cerebral autoregulation has not been studied at altitude.

METHODS

We studied CA in 10 subjects at sea level and in 9 Sherpas and 10 newcomers at an altitude of 4243 m by evaluating the effect of an increase of mean arterial blood pressure (MABP) with phenylephrine infusion on the blood flow velocity in the middle cerebral artery (Vmca), using transcranial Doppler. Theoretically, no change of Vmca in response to an increase in MABP would imply perfect autoregulation. Complete loss of autoregulation is present if Vmca changes proportionally with changes of MABP.

RESULTS

In the sea-level group, at a relative MABP increase of 23+/-4% during phenylephrine infusion, relative Vmca did not change essentially from baseline Vmca (2+/-7%, P=0.36), which indicated intact autoregulation. In the Sherpa group, at a relative MABP increase of 29+/-7%, there was a uniform and significant increase of Vmca of 24+/-9% (P<0.0001) from baseline Vmca, which indicated loss of autoregulation. The newcomers showed large variations of Vmca in response to a relative MABP increase of 21+/-6%. Five subjects showed increases of Vmca of 22% to 35%, and 2 subjects showed decreases of Vmca of 21% and 23%.

CONCLUSIONS

All Sherpas and the majority of the newcomers showed impaired CA. It indicates that an intact autoregulatory response to changes in blood pressure is probably not a hallmark of the normal human cerebral vasculature at altitude and that impaired CA does not play a major role in the occurrence of cerebral edema in newcomers to the altitude.

Biomonitoring study of people living near or working at a municipal solid-waste incinerator before and after two years of operation

The authors conducted a biomonitoring study in the town of Mataró, Spain, of 104 subjects who lived near (i.e., within 0.5-1.5 km) an incinerator, 97 subjects who lived far (i.e., within 3.5 km-4.0 km) from an incinerator, and 17 workers at a new municipal solid-waste incinerator. The study commenced before the incinerator started functioning in 1995, and 2 y later (1977) the authors undertook the final part of the study. Dioxins, furans, and polychlorinated biphenyls were studied in pooled blood samples (n = 22), and individual blood and urine samples were analyzed for the detection of lead, chromium, cadmium, and mercury. In 1995, dioxin blood levels were low-both among those living close to the incinerator (mean = 13.5 ng international-dioxin toxic equivalents/kg fat) and among those living far away (mean = 13.4 ng international-dioxin toxic equivalents/kg fat). In 1997, dioxin and polychlorinated biphenyl levels had increased in both groups of residents by approximately 25% and 12%, respectively. (The increase in dioxin levels was about 10% when the authors took into account the mean of two repeated quality-control analyses.) Blood lead levels decreased, but no difference was observed for chromium, cadmium, and mercury. Minimal changes were seen among workers. Given the low dioxin stack emissions from this plant (mean = 2.5-0.98 ng international-dioxin toxic equivalents/m3) and that the blood dioxin levels did not depend on distance of residence from the incinerator, it would appear unlikely that the small increase in dioxin blood levels resulted from the incinerator's emissions.

[Norwalk virus-like food poisoning after eating oysters]

BACKGROUND

The aim of this study was to conduct a clinical-epidemiological and microbiological investigation into an outbreak of food-borne disease due to the consumption of oysters.

PATIENTS AND METHODS

A historic cohort study was conducted into the consumption of 15 food items and clinical symptoms. The influence of each foodstuff was assessed by Mantel-Haenzel stratified relative risk (RRM-H) at 95% confidence intervals, and was confirmed by dose-response analysis with a chi 2 test tendency. We investigated sample stools from 5 patients and 2 food-handlers.

RESULTS

The overall attack rate was 38.0% (19/50). The median period of incubation was 39.0 h (maxim 62 and minimum 3 h). The symptoms were: fever 17.6% (3/17), diarrhoea 57.9% (11/19), vomits 84.2% (16/19), nausea 89.5% (17/19) and abdominal pain 89.5% (17/19). In stratified analysis, the Mantel-Haenzel method revealed a statistically risk for oysters (RRM-H = 3.3; IC 95%: 1.1-8.7), while the RRM-H value for sea snails was not significant (RRM-H = 2.8; IC 95%: 0.9-41.1). For oyster consumption, the dose-response test was statistically significant (p = 0.005). Examination by electron microscopy revealed small round structured viruses compatible with Norwalk-like virus. The oyster contamination was reported to the public health authority.

CONCLUSIONS

This research highlights the usefulness of dose-response analysis in presenting epidemiological evidence, reveals the potential role of oyster consumption in food-borne disease such us Norwalk-like virus and show the need for monitoring production centres and oyster beds in order to prevent further cases of contamination.

Reversal of pathology in the entire brain of mucopolysaccharidosis type VII mice after lentivirus-mediated gene transfer

Gene transfer vectors derived from human immunodeficiency virus (HIV-1) efficiently transduce nondividing cells and remain stably integrated in their genome. Long-term expression of reporter genes has been documented after intracerebral injection of these vectors. Using a HIV-based vector, we looked for a reversal of brain damage in the beta-glucuronidase-deficient mucopolysaccharidosis type VII mouse, an animal model of human lysosomal storage diseases. The vector suspension was injected stereotactically in the brain of 10-week-old animals, an age at which storage lesions are patent in glia, perivascular cells, and neurons. Either a single intrastriatal injection or multiple injections in both cerebral hemispheres and in the cerebellum were performed. Local tolerance, enzyme delivery, and correction of storage lesions were investigated by comprehensive analysis of serial sections of the entire brain of mice killed 6 or 16 weeks postinjection. Histochemical staining detected enzyme activity in widely distributed areas, the size of which increased with time. Clearance of lysosomal storage extended far beyond enzyme-positive areas. In mice receiving multiple injections of the vector, complete correction or significant reduction of the pathology was observed in every section, suggesting disease regression in the entire brain. These results may have implications for the treatment of neurological symptoms in lysosomal storage diseases.

Improvement of erythropoiesis in beta-thalassemic mice by continuous erythropoietin delivery from muscle

beta-Thalassemias are highly prevalent genetic disorders that can cause severe hemolytic anemia. The main pathophysiologic feature of beta-thalassemia is the accumulation of unpaired alpha-globin chains in erythrocyte precursors and red blood cells (RBCs). This accumulation alters cell membrane function and results in early cell destruction and ineffective erythropoiesis. Correction of globin chain imbalance through the induction of fetal hemoglobin (HbF) synthesis is a tentative therapeutic approach for this class of diseases. In short-term in vitro or in vivo assays, recombinant human erythropoietin increases the frequency of erythroid precursors programmed to HbF in humans and to beta-minor globin in mice. In contrast, long-term treatment of beta-thalassemic patients did not induce HbF significantly. We took advantage of highly efficient adeno-associated virus-mediated (AAV-mediated) gene transfer into mouse muscle to induce a robust and sustained secretion of mouse erythropoietin in beta-thalassemic mice, which represent a suitable model for human beta-thalassemia intermedia. A 1-year follow-up of 12 treated animals showed a stable correction of anemia associated with improved RBC morphology, increased beta-minor globin synthesis, and decreased amounts of alpha-globin chains bound to erythrocyte membranes. More effective erythropoiesis probably accounted for a reduction of erythroid cell proliferation, as shown by decreased proportions of circulating reticulocytes and by reduced iron 59 ((59)Fe) incorporation into erythroid tissues. This study indicates that the continuous delivery of high amounts of autologous erythropoietin induced a sustained stimulation of beta-minor globin synthesis and a stable improvement of erythropoiesis in the beta-thalassemic mouse model. (Blood. 2000;95:2793-2798)

Mutations in SDHD, a mitochondrial complex II gene, in hereditary paraganglioma

Hereditary paraganglioma (PGL) is characterized by the development of benign, vascularized tumors in the head and neck. The most common tumor site is the carotid body (CB), a chemoreceptive organ that senses oxygen levels in the blood. Analysis of families carrying the PGL1 gene, described here, revealed germ line mutations in the SDHD gene on chromosome 11q23. SDHD encodes a mitochondrial respiratory chain protein-the small subunit of cytochrome b in succinate-ubiquinone oxidoreductase (cybS). In contrast to expectations based on the inheritance pattern of PGL, the SDHD gene showed no evidence of imprinting. These findings indicate that mitochondria play an important role in the pathogenesis of certain tumors and that cybS plays a role in normal CB physiology.

Screening for BRCA2 mutations in 81 Dutch breast-ovarian cancer families

We have analysed 81 families with a history of breast and/or ovarian cancer for the presence of germline mutations in BRCA2 with a number of different mutation screening techniques. The protein truncation test (PTT) for exons 10 and 11 detected four different frame-shifting mutations in six of these families. Four of the remaining 75 families had given positive linkage evidence for being due to BRCA2. In these families the entire coding region was analysed by single-strand conformational polymorphism, leading to the detection of a non-sense and a splice-site mutation in two of them. While these studies were in progress, Southern analysis of BRCA1 revealed that in our study-population of 81 families, 15 families were segregating either the exon 13 or exon 22 deletion in BRCA1 (Petrij-Bosch et al (1997) Nat Genet 17: 341-345). This prompted us to examine BRCA2 in the remaining 58 families by Southern analysis, using two different restriction enzymes. No aberrations were found in the restriction patterns. Thus, contrary to BRCA1, large genomic rearrangements within the BRCA2 gene do not represent a major mutation mechanism among Dutch breast cancer families.

Long-term and significant correction of brain lesions in adult mucopolysaccharidosis type VII mice using recombinant AAV vectors

Most lysosomal storage diseases, including mucopolysaccharidosis, affect the central nervous system (CNS). They often induce severe and progressive mental retardation. Replacement therapy by purified enzyme infusions is a promising approach for the treatment of peripheral organs but without effect on CNS pathology because the enzyme cannot cross the blood-brain barrier. Intracranial injection of recombinant adeno-associated virus (AAV) vectors offers an alternative for sustained local enzyme delivery from genetically engineered cells. We stereotactically injected an AAV vector containing the human beta-glucuronidase cDNA into the striatum of adult mice severely affected by mucopolysaccharidosis type VII at the time of treatment. Six weeks later, beta-glucuronidase activity in the injected hemisphere was comparable to that of heterozygous mice, which have a normal phenotype. Areas staining positive for enzyme activity enlarged with time, representing more than 10% of the hemisphere volume by 16 weeks. A complete reversion of lysosomal storage lesions was evident in these areas, as well as in most neurons located in surrounding negative areas and in the noninjected hemisphere. Thus, a single intracerebral injection of AAV vectors could achieve a broad and sustained lysosomal enzyme delivery, allowing for stable reversion of storage lesions in a significant fraction of the adult brain.

A high-resolution physical map of human chromosome 21p using yeast artificial chromosomes

The short arm of human chromosome 21 (21p) contains many different types of repetitive sequences and is highly homologous to the short arms of other acrocentric chromosomes. Owing to its repetitive nature and the lack of chromosome 21p-specific molecular markers, most physical maps of chromosome 21 exclude this region. We constructed a physical map of chromosome 21p using sequence tagged site (STS) content mapping of yeast artificial chromosomes (YACs). To this end, 39 STSs located on the short arm or near the centromere of chromosome 21 were constructed, including four polymorphic simple tandem repeats (STRs) and two expressed sequence tags (ESTs). Thirty YACs were selected from the St. Louis YAC library, the chromosome 21-enriched ICRF YAC library, and the CEPH YAC and megaYAC libraries. These were assembled in a YAC contig map ranging from the centromere to the rDNA gene cluster at 21p12. The total size of the region covered by YACs is estimated between 2.9 and 5 Mb. The integrity of the YAC contig was confirmed by restriction enzyme fingerprinting and fluorescence in situ hybridization (FISH). One gap with an estimated size of 400 kb remained near the telomeric end of the contig. This YAC contig map of the short arm of human chromosome 21 constitutes a basic framework for further structural and functional studies of chromosome 21p.

Group D adenoviruses infect primary central nervous system cells more efficiently than those from group C

Group C adenovirus-mediated gene transfer to central nervous system cells is inefficient. We found that wild-type group D viruses, or recombinant adenovirus type 2 (Ad2) (group C) modified to contain Ad17 (group D) fiber, were more efficient in infecting primary cultures of neurons. Together with studies on primary vascular endothelial cells and tissue culture cell lines, our results indicate that there is not a universally applicable adenovirus serotype for use as a gene transfer vector.

Interleukin-10 modulates the severity of hypersensitivity pneumonitis in mice

Hypersensitivity pneumonitis (HP) is an inflammatory lung disease characterized by granuloma formation. We recently showed that interferon-gamma (IFN-gamma) is essential for inflammation and granuloma formation in HP. Interleukin-10 (IL-10) counteracts many of the biologic effects of IFN-gamma, suggesting that IL-10 modulates inflammation and granuloma formation in HP. We compared the expression of HP in C57BL/6 mice that lack IL-10 (IL-10 knockout [KO]) with that in wild-type (WT) littermates. IL-10 KO and WT mice were exposed to the thermophilic bacteria Saccharopolyspora rectivirgula or to saline alone for 3 wk. The IL-10 KO mice had higher cell counts in their bronchoalveolar lavage fluid (2.85 +/- 0. 43 x 10(6)) than did WT mice (1.4 +/- 0.3 x 10(6)/ml; P < 0.03), with a more prominent neutrophil response. They also had greater inflammation after antigen exposure than did the WT mice (P < 0. 0001). There was increased upregulation of IFN-gamma, IL-1, and tumor necrosis factor-alpha (TNF-alpha) mRNAs in the lungs of IL-10 KO mice. Adenovirus-mediated gene transfer of IL-10 to the liver of IL-10 KO mice reduced the inflammation from that seen in WT mice. These studies show that IL-10 has important anti-inflammatory properties in HP, and that lack of this cytokine leads to a more severe granulomatous inflammatory response.

Enhancement of the immunogenicity of a synthetic peptide bearing a VP3 epitope of hepatitis A virus

The immune responses elicited in mice by different forms of the VP3(110-121) B-epitope of the hepatitis A virus (HAV) were studied. Different forms of incorporation in liposomes were tested, encapsulation, rather than surface exposure, being the best antigenic preparation. Three larger peptides of the VP3 epitope, two of them containing a hepatitis B virus T-epitope, and a third containing a putative T-epitope of HAV (VP3(102-121)) were assayed. While this latter T-epitope induced an enhancement of the response against the VP3 B-epitope, the artificially coupled T-epitopes failed to induce a significant increase. The administration of two multiple antigenic peptide (MAP) constructs, the first containing the VP3(110-121) and VP1(11-25) HAV sequences and the second only the VP1(11-25) sequence, also suggested the presence of a T-epitope, since the response against the VP1 peptide was increased in the first construct.

Human enteric viruses in the water environment: a minireview

Water virology started around half a century ago, with scientists attempting to detect poliovirus in water samples. Since that time, other enteric viruses responsible for gastroenteritis and hepatitis, among a great variety of virus strains, have replaced enteroviruses as the main target for detection in the water environment. Technical molecular developments, polymerase-chain reaction (PCR) amplification being the method of choice, enable the detection of fastidious health-significant viruses. However, shortcomings of molecular procedures include their potential incompatibility with concentration methods, indispensable to reduce the water sample volume to assay for viruses, the inability to discern between infectious and non infectious material. On the other hand, these procedures are restrained to sophisticated laboratories and detection of alternative indicator organisms has been proposed. Bacterial indicators fail to give a reliable clue of the virological quality of water. Selected bacteriophage groups appear as a better choice for their use as virus indicators.

Effects of keratinocyte and hepatocyte growth factor in vivo: implications for retrovirus-mediated gene transfer to liver

We have previously shown that intravenous administration of keratinocyte growth factor (KGF) induces hepatocyte proliferation, allowing for efficient and noninvasive in vivo gene transfer with high-titer retroviral vectors in mice. The distinctive periportal distribution of transduced cells led us to investigate the ability of virus-sized particles to perfuse the liver adequately after growth factor treatment. We found that perfusion was adequate, and that transduction was limited to the periportal region because only those cells were stimulated to divide. Cells in this region also showed increased expression of Ram-1, the receptor for the murine Moloney leukemia virus (MoMLV) amphotropic envelope, after KGF treatment. In further studies we found that recombinant hepatocyte growth factor (HGF) induces a different population of hepatocytes to divide and upregulate Ram-1. The differential pattern of induction suggested that combining KGF and HGF would improve gene transfer efficiency further. Indeed, simultaneous delivery of both growth factors leads to an overall increase in the number of proliferating cells. Importantly, when coupled with MoMLV delivery, efficiency of gene transfer increased. These results confirm the utility of growth factors for noninvasive hepatic gene transfer in mice, and demonstrate how experiments to define the mechanism of transduction can be taken advantage of to develop improved gene transfer protocols.

Flow cytometry detection of infectious rotaviruses in environmental and clinical samples

A method for the detection of infectious human rotaviruses based on infection of CaCo-2 cells and detection of infected cells by indirect immunofluorescence and flow cytometry (IIF-FC) has been developed. The technique was validated by performing a seminested reverse transcription-PCR assay with sorted cell populations. The efficiency of the procedure has been compared with that of the standard method of infection of MA104 cells and ulterior detection by IIF and optical microscopy (IIF-OM) and with that of infection of MA104 cells and detection by IIF-FC. The limit of sensitivity for the detection of the cell-adapted strain Ito(r) P13, expressed as the most probable number of cytopathogenic units, was established as 200 and 2 for MA104 and CaCo-2 cells, respectively, by the IIF-FC method. The ratio of infectious virus particles to total virus particles for a wild-type rotavirus was determined to be 1/2 x 10(6) and 1/2 x 10(4) for IIF-OM with MA104 cells and IIF-FC with CaCo-2 cells, respectively. The use of IIF-FC with CaCo-2 cells was tested with fecal and water samples and proved to be more effective than the standard procedure for rotavirus detection.

Blood levels of polychlorinated dibenzodioxins, polychlorinated dibenzofurans and polychlorinated biphenyls in the general population of a Spanish Mediterranean city

Polychlorinated dibenzodioxins (PCDDs), Polychlorinated dibenzofurans (PCDFs) and Polychlorinated biphenyls (PCBs) are among the most toxic environmental pollutants. We determined blood levels of these compounds in a population sample of the city of Mataró, Spain. Blood samples were drawn from a randomly selected sample of 198 subjects, of both genders, aged 18 to 69 years. These samples were pooled into 10 groups for laboratory analysis. For males, total level of PCDDs was 505.7 ppt, of PCDFs was 26.7 ppt, and the international toxic equivalent (I-TEQ) was 12.5. For females the levels were 739 ppt, 28.8 ppt and 14.71-TEQ, respectively. The most important contributors to the total I-TEQ were HexaCDD, PentaCDD and PentaCDF. The blood concentration of total PCBs was 2.02 mg/l in males, and 1.58 mg/l in females. Levels of PCDDs, PCDFs and PCBs increased by age in both sexes. The levels of PCDDs and PCDFs in residents of this Mediterranean city are among the lowest observed in industrialized countries.

A new continuous epitope of hepatitis A virus

A new continuous epitope of hepatitis A virus (HAV) was defined in the VP3 protein. Convalescent sera recognised the synthetic peptide 3110-3121 (FWRGDLVFDFQV). The replacement of the arginine, glycine, or aspartic acid at positions 112, 113, or 114, respectively by other amino acids induced the loss of synthetic peptide recognition by human convalescent sera, thereby confirming the presence of an epitope in the original VP3(110-121) sequence. Shorter VP3 peptides such as VP3(110-119). VP3(110-117), and VP3(110-116) and a tandem repeat of VP3(111-116) failed to react with convalescent sera, indicating the importance of the entire peptide in the epitope structure. The maximum inhibition of human convalescent binding to HAV by the VP3(110-121) peptide was around 60%, and 50% inhibition was achieved at a peptide concentration of 2.3-2.4 micrograms/ml. Antibodies generated by this peptide bound to intact HAV and neutralised its infectivity. Antipeptide antibodies inhibited convalescent serum binding to HAV. Monoclonal antibodies H7C27 and MAK-4E7 inhibited completely binding of the antipeptide antibodies to HAV.

Solid phase synthesis and immunogenicity of a VP3 peptide from hepatitis A virus

The synthesis of a peptide belonging to the VP3 capsid protein of Hepatitis A virus has been accomplished by the continuous flow Fmoc-polyamide solid phase method. The use of methoxytrimethylbenzenesulphonyl (Mtr) and pentamethylchromansulphonyl (Pmc) as arginine side-chain protecting groups in the presence of tryptophan without lateral protection or protected with t-Boc is discussed. The synthetic VP3 peptide has been administered to mice in different forms: (i) free, (ii) coupled to keyhole limpet hemocyanin, (iii) encapsulated in multilamellar (MLV) liposomes, and (iv) incorporated to a tetrameric branched lysine core. The immune response induced by these preparation is reported.

Disinfection of human enteric viruses on fomites

The virucidal action of several commercially available disinfectant preparations was assayed against hepatitis A virus and human rotavirus dried on polystyrene. Overall, the level of virus disinfection achieved was very poor, usually inducing less than 3 log titre reduction. Suspension tests performed with the same disinfectants showed different virus inactivation rates, thus failing to provide a reliable indication of the actual virus disinfection on fomites. In our studies, bacteriophages of Bacteroides fragilis proved to be a simple, cheap and reliable screening tool for the evaluation of virus disinfection on non-porous surfaces. The same conclusion cannot be drawn for poliovirus.

Astrovirus survival in drinking water

A method based on infection of CaCo-2 cultured cell monolayers (CC) and reverse transcription-PCR (RT-PCR) was developed for the specific detection of infectious astrovirus. The procedure was validated by titrating poliovirus stocks in parallel in CaCo-2 cells by determining the most probable number of cytopathogenic units and by cell culture and subsequent RT-PCR (CC-RT-PCR). CC-RT-PCR was then employed to measure the persistence of astrovirus suspended in dechlorinated tap water. After 60 days, the decay of astrovirus infectivity was 2 log units at 4 +/- 1 degrees C and 3.2 log units at 20 +/- 1 degrees C, while after 90 days, the titer reduction was 3.3 and 5 log units at 4 +/- 1 degrees C and 20 +/- 1 degrees C, respectively. Astrovirus decay in the presence of free chlorine (FC) was monitored by CC-RT-PCR. Residual infectivity was found after 2 h in the presence of 1 mg of FC/liter. Under these conditions, astrovirus shows a log titer reduction (LTR) or 4, while 0.5 mg of FC/liter induced an LTR of 2.4. The possibility of acquiring data on the survival of fastidious viruses in the environment opens new perspectives on the epidemiology of some significant infections transmitted by the fecal-oral route.

Proliferation induced by keratinocyte growth factor enhances in vivo retroviral-mediated gene transfer to mouse hepatocytes

Retroviral gene transfer to liver without prior injury has not yet been accomplished. We hypothesized that recombinant human keratinocyte growth factor would stimulate proliferation of hepatocytes and allow for efficient in vivo gene transfer with high titer murine Moloney retroviral vectors. This report shows that 48 h after intravenous injection of keratinocyte growth factor, hepatocyte proliferation increased approximately 40-fold compared to non-stimulated livers. When keratinocyte growth factor treatment was followed by intravenous injection of high titer (1 x 10(8) colony forming units/ml) retrovirus coding for the Escherichia Coli beta-galactosidase gene, there was a 600-fold increase in beta-galactosidase expression, with 2% of hepatocytes transduced. Thus, by exploiting the mitogenic properties of keratinocyte growth factor, retrovirus-mediated gene transfer to liver may be accomplished in vivo without the use of partial hepatectomy or pretreatment with other toxins to induce hepatocyte cell division.

Hypoxanthine-guanine phosphoribosyltransferase (HPRT) expression in the central nervous system of HPRT-deficient mice following adenoviral-mediated gene transfer

In this study we show that recombinant adenovirus can augment hypoxanthine-guanine phosphoribosyltransferase (HPRT) levels in the central nervous system (CNS) of HPRT-deficient mice. Recombinant adenovirus containing the cDNA for rat HPRT (rHPRT) expressed from the Rous sarcoma virus LTR (RSV LTR) was constructed (AdRSVrHPRT). AdRSVrHPRT was injected into the right caudate nucleus of 7-week-old HPRT-deficient mice. Brains were analyzed for gene transfer, transgene expression and function by DNA PCR, in situ RNA hybridization, and enzyme bioactivity. The results show that rHPRT cDNA delivered by an adenoviral vector can augment HPRT levels in brain tissue and documents the utility of gene transfer to restore HPRT activity in an HPRT-deficient CNS.

Detection of infectious astroviruses in water

Volume 62, no. 5, p. 1811, column 2, line 2: Reference "(16)" should read "(15)." Page 1812, column 1, line 17: "Willcocks and Carter (15)" should read "Willcocks et al. (14)." [This corrects the article on p. 1811 in vol. 62.].

[Organizational models for the hematology areas of the district hospitals of Catalonia]

PURPOSE

The haematological assistance in Catalonia is based upon the district hospitals, in the first step, and the stage III hospitals located usually in higher population nuclei, in the second step. The purpose of this work was to analyse the resources of the "primary haematological assistance" network provided by the district hospitals, to evaluate them and to propose a model for their organisation.

MATERIAL AND METHODS

An enquiry was carried out to all members of the Grup de Treball d'Hospitals Comarcals de Catalunya (Catalonia's District Hospitals Task Force). The evaluable data included demographic figures of the population assisted, personnel of each haematological area, organising structure, clinical activity, cytomorphology, blood banks, laboratories and continuous formation activities.

RESULTS

The enquiry was answered by 15 of the 21 district hospitals (71.4%) with haematologists in Catalonia. The population assisted in those hospitals is 2,100,000 (ranging between 55,000 an 450,000). All centres are integrated in the National Health network. Eleven of the hospitals analysed have only one haematologist (73.3%). If his dedication is 100% of the time, this would represent a doctor for 105,000 people. The time devoted to work is 690 hours a week for all the population, with a mean of 3,043. Four patients assisted per hour. The total number of hospital beds is 3,353 (50-450), with a mean number of 1 haematologist for every 167.6 beds. The number of patients hospitalized due to blood diseases ranges between 3 and 13 per month. Six of the 15 centres are adjunct to the outpatient clinic. Two centres have a blood bank and 7 have developed an autotransfusion programme. All the centres but one perform oral anticoagulant treatment follow-up, the number of patients assisted ranging from 20 to 210 per week. None of the hospitals has a separate Haematology Service; in most of them haematology is structurally and functionally dependent from Laboratories and in some there is a mixed Laboratory/Internal Medicine functional organisation, depending of the Medical Direction. No haematologist is ever on call specifically for his specialty. Continuous formation activities are carried out in 9 of the 15 centres (60%).

COMMENT

Several measures are proposed to improve the haematological assistance, acting on different levels: continuous formation, patient flows and circuits, resident doctors training, anticoagulant treatment network, organisation models, credit cards from the Spanish Association of Haematology.

Non isotopic automatable molecular procedures for the detection of enteroviruses

Five microwell non isotopic hybridization assays, based on colorimetric immunoenzymatic reading, were developed and evaluated for the rapid and automatable detection of enteroviruses. Virus nucleic acids and/or capture probes were covalently bound to microtiter wells, and digoxigenin-11-dUTP was used as label for the detection of hybridized material. Among these procedures, a reverse transcriptase polymerase chain reaction (RT-PCR) hybridization assay was the most sensitive, enabling the detection of 10 MPNCU of poliovirus, and offering detection specificity for other enteroviruses, such as coxsackieviruses and echoviruses. The second most sensitive method was a complementary hybridization assay, simultaneously using three detection probes, one from the 5' end and two from the 3' end of poliovirus genome, offering a sensitivity for poliovirus detection of 5 x 10(3) MPNCU.

Late presentation of congenital muscular torticollis: a non-dystonic cause of torticollis

We describe three patients with a late presentation of congenital muscular torticollis to emphasize that this non-dystonic type of torticollis has to be considered in the differential diagnosis of cervical dystonia, even in adult patients. Surgery is the treatment of choice. Postoperatively, two of our patients had a transient lesion of the accessory nerve. We assume that in our patients the accessory nerve was embedded in the fibrous tissue around the affected muscle. To prevent damage to the accessory nerve, the incision has to be made distally at about 1 cm above the clavicle.

Integration of 30 CA-repeat markers into the cytogenetic, genetic and YAC maps of human chromosome 21

The number of polymorphic DNA markers developed for the whole human genome during the last 2 years has been vastly increased. For this reason, the genetic map is continuously improving, but the cytogenetic and physical maps are not progressing at the same speed. Therefore, there is a need to integrate genetic, cytogenetic and physical mapping data. We have developed and localized on the breakpoint map of human chromosome 21 thirty microsatellite markers. Twenty of them have been used in the construction of a genetic map of chromosome 21, which contains a total of 44 markers. This map has 39 uniquely placed loci at 23 anchor points, ordered with odds of at least 1,000:1. The sex average length of the map is 64.4 cM, with the male and female lengths being 49.4 and 79.2 cM, respectively. Twenty-six of these newly developed markers have been localised on the CEPH/Généthon and Joint YAC Screening Effort YACs. Although these microsatellites were found uniformly spread along chromosome 21, the detection of various markers in the same or adjacent YACs suggests that CA-repeat microsatellites are clustered in several regions. The localization of these markers on the cytogenetic, genetic and YAC maps has provided a refined location for them and is a step further towards the construction of an integrated map of HC21.

Changes in core histone variant composition in differentiating neurons: the roles of differential turnover and synthesis rates

The core histone classes H2A, H2B, H3, and H4 are the main group of proteins responsible for the folding of DNA in nucleosomes. Each of the core histone classes except H4 is composed of nonallelic variants. The core histone variant composition changes during postnatal development in rat cerebral cortex neurons; H2A.1, H2B.1, H3.1 and H3.2 decay exponentially, whereas H2A.2, H2A.x, H2B.2, and H3.3 accumulate. H2A.z is the only variant that remains constant. We have studied the synthesis of core histone variants in cortical neurons and their neuroblasts by in vivo labeling with [14C]lysine. The variant synthesis pattern of neuroblasts has been determined by labeling gravid rats during the period of proliferation of the brain cortical neurons of the fetuses, and synthesis in neurons has been studied by postnatal labeling. The incorporation of H2A.1 is about twice that of H2A.2, both in neurons and neuroblasts. Despite its higher synthesis rate, the proportion of H2A.1 decreases during postnatal development indicating that the turnover of H2A.1 is faster than that of H2A.2. Differential turnover and a change in synthesis rate are both involved in determining the relative concentrations of H2B.1 and H2B.2 in neurons. H3.1 and H3.2 are synthesized in neuroblasts, but not in neurons, and are thus replaced by H3.3 in neuronal chromatin. The fact that the synthesis pattern of immature neurons from newborns does not differ from that of mature neurons indicates that the changes in the synthesis pattern of core histones occur at the arrest of cell proliferation and are unrelated to the state of differentiation of the cells.

A new human gene from the Down syndrome critical region encodes a proline-rich protein highly expressed in fetal brain and heart

Down syndrome is a major cause of mental retardation and congenital heart defects. While most of the affected individuals have three copies of chromosome 21, patients with partial trisomy 21 have also been described. These rare cases define a minimal region for the Down syndrome phenotype encompassing about 3 Mb around D21S55. By using a new method for the identification of coding sequences (Alu-splice PCR) we have identified a new gene, DSCR1, from region 21q22.1-q22.2. DSCR1 encodes a novel protein which has an acidic domain, a serine-proline motif, a putative DNA binding domain and a proline-rich region with the characteristics of a SH3 domain ligand. These features suggest that DSCR1 could be involved in transcriptional regulation and/or signal transduction. DSCR1 is highly expressed in human brain and heart, and increased expression in the brains of young rats compared with adults suggests a role for DSCR1 during central nervous system development. Structural characteristics, together with its particular expression in brain and heart, encourage us to suggest that the overexpression of DSCR1 may be involved in the pathogenesis of Down syndrome, in particular mental retardation and/or cardiac defects.

Genotyping of rotaviruses isolated from sewage

Rotaviruses from environmental samples have been genotyped by a seminested reverse transcription PCR assay with serotype-specific primers derived from variable regions of gene 9, which produce different characteristic segment sizes for serotypes 1 to 4. The method enabled the detection and identification of type 1, 2, and 3 group A rotaviruses in sewage.

Anti-hepatitis A virus antibody response elicited in mice by different forms of a synthetic VP1 peptide

Peptide VP1 (11-25) of the capsid of hepatitis A virus was synthesized by the Fmoc-polyamide solid phase method, and administered to mice in different forms: (1) free, (2) encapsulated in multilamellar liposomes, (3) coupled to keyhole limpet hemocyanin (KHL), and (4) incorporated into a tetrameric branched lysine core. The highest anti-VP1 peptide responses were generated by synthetic peptides entrapped into liposomes and coupled to KLH. No anti-HAV response was generated with the free peptide, while all the other forms induced both anti-HAV and HAV-neutralizing antibodies. Maximum neutralization indices were observed in ascites from mice treated with liposome-entrapped and KLH peptides.

Characterisation of three microsatellite polymorphisms (D21S1262, D21S1419 and D21S1421) from band 21q22.1

We have isolated three clones, containing highly polymorphic CA-repeat sequences, from a human chromosome 21 phage library (LA21NS01). These clones have been localised to band q22.1 by using a chromosome 21 somatic cell hybrid panel. D21S1262 is located between breakpoints 6918-8a1 and 3x2S, and D21S1419 and D21S1421 are localised between breakpoints JC6-A and MRC2G. Their observed heterozygosities range between 0.75 and 0.85 as shown by unrelated reference parents from the Centre d'Etude du Polymorphisme Humain. These highly polymorphic markers should be useful for improving the analysis of this region of chromosome 21, which contains important genes such as SOD1, GART and IFNAR.

Retroviral properties inherent to viral erythrocytic infection in sea bass

The characterization of the aetiological agent of viral erythrocytic infection (VEI) of sea bass suggests a retroviral origin of the disease. RNA from viral erythrocytic infection virus (VEIV) and DNA from blood and organs of VEI-affected fish hybridized to a specific retrovirus cDNA probe. Sequences homologous to retrovirus genome were also detected in non-infected SBL cells (a sea bass cell line), however, Southern blot analysis showed that the DNA restriction patterns in VEI-affected erythrocytes differed from those of SBL cells. RNA-dependent DNA polymerase activity was detected in VEI-affected sea bass blood. This reverse transcription was strongly Mn(2+)-dependent and is the first report of its occurrence in a marine fish and in fish blood samples. Nucleic acid sequences homologous to retrovirus RNA were detected in chromatographic fractions exhibiting reverse transcriptase activity and the presence of virus-like particles, 125-150 mm in diameter. The density of VEIV in sucrose was 1.17-1.18 g/cm3. The symptomatology of VEI is not far from those described for some retroviral diseases.