High-dose valacyclovir to prevent congenital cytomegalovirus transmission in pregnancy: is it possible to reduce major side effects?

Linked article: This Correspondence comments on D'Antonio et al. Click here to view the article.

Genotypic testing on HIV-1 DNA as a tool to assess HIV-1 co-receptor usage in clinical practice: results from the DIVA study group

PURPOSE

We have developed a sequencing assay for determining the usage of the genotypic HIV-1 co-receptor using peripheral blood mononuclear cell (PBMC) DNA in virologically suppressed HIV-1 infected patients. Our specific aims were to (1) evaluate the efficiency of V3 sequences in B versus non-B subtypes, (2) compare the efficiency of V3 sequences and tropism prediction using whole blood and PBMCs for DNA extraction, (3) compare the efficiency of V3 sequences and tropism prediction using a single versus a triplicate round of amplification.

RESULTS

The overall rate of successful V3 sequences ranged from 100 % in samples with >3,000 copies HIV-1 DNA/10(6) PBMCs to 60 % in samples with <100 copies total HIV-1 DNA /10(6) PBMCs. Analysis of 143 paired PBMCs and whole-blood samples showed successful V3 sequences rates of 77.6 % for PBMCs and 83.9 % for whole blood. These rates are in agreement with the tropism prediction obtained using the geno2pheno co-receptor algorithm, namely, 92.1 % with a false-positive rate (FPR) of 10 or 20 % and of 96.5 % with an FPR of 5.75 %. The agreement between tropism prediction values using single versus triplicate amplification was 98.2 % (56/57) of patients using an FPR of 20 % and 92.9 % (53/57) using an FPR of 10 or 5.75 %. For 63.0 % (36/57) of patients, the FPR obtained via the single amplification procedure was superimposable to all three FPRs obtained by triplicate amplification.

CONCLUSIONS

Our results show the feasibility and consistency of genotypic testing on HIV-1 DNA tropism, supporting its possible use for selecting patients with suppressed plasma HIV-1 RNA as candidates for CCR5-antagonist treatment. The high agreement between tropism prediction by single and triple amplification does not support the use of triplicate amplification in clinical practice.

Dimensional and microbiological in vitro analysis of a dental implant locking taper connection

The present study was carried out to compare the differences in contact, height and contact area between the implant-abutment interface and the implant-healing cap interface of an implant system featuring a locking tapered connection by using X-ray micro-tomography. It was also conducted to test in vitro whether the implant-healing cap tapered interface is capable of preventing bacterial leakage from the implant well to the external environment. The images of the samples, acquired by the X-ray micro-tomography, after being processed with a dedicated software, showed a greater contact height (CH) in the implant-abutment sample (3.57 mm) compared to the implant-healing cap sample (2.52 mm). This was also true for the contact area that was equal to 40.63 mm2 in the implant-abutment sample and 25.14 mm2 in the implant-healing cap sample. No bacteria were detected both in the nutrient of the test group and of the negative control after 24 h. An increased contact height and contact area in a tapered connection, between the implant and the abutment, have demonstrated to offer mechanical and biological advantages, in a implant-healing cap tapered connection. The major concern regards the microbiological aspects of this connection. The implant-healing cap tapered connection provides an hermetic barrier to microbial passage in vitro, even though such connection features lower contact height and contact area compared to the implant-abutment connection of the same implant system.

The heme oxygenase/biliverdin reductase system: a potential drug target in Alzheimer’s disease

Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by the progressive loss of cognitive function, the inability to perform the activities of daily living and psychiatric symptoms. The formation of toxic aggregates of amyloid-beta-peptide (Abeta), through the activities of beta - and gamma- secretases, is considered as the earlier event in the pathogenesis of the disease. The deposition of both Abeta and the following hyperphosphorylation of tau protein, trigger an exaggerate immune-inflammatory response culminating with the production of excess reactive oxygen and nitrogen species responsible for damage on cellular nucleic acids, proteins and lipids. One of the mechanisms used by neural cells to counteract oxidative/nitrosative damage in AD is the enhancement of the cell stress response. Among the main components of the cell stress response is the heme oxygenase/biliverdin reductase (HO/BVR) axis, which catalyzes the degradation of heme which is toxic if produced in excess or under redox unbalanced conditions. However, the HO/BVR system and its by-products, carbon monoxide and bilirubin, have also been shown to be neuroprotective by activating pro-survival pathways and scavenging free radicals. Nevertheless, recent research demonstrated as both the inducible isoform of HO, known as HO-1, and BVR undergo oxidative/nitrosative/phosphorylative post-translational modifications in AD brain which alter the ability of HO-1 and BVR to activate the cell stress response. In this light, naturally occurring substances or drugs (e.g. statins) that prevent the post-translational modifications leading to a controlled up-regulation of the HO/BVR system have been proposed as potential new tools for the treatment of AD.

Relationship between antiretroviral plasma concentration and emergence of HIV-1 resistance mutations at treatment failure

PURPOSE

The relationship between antiretroviral pharmacokinetic exposure and acquisition of human immunodeficency virus-1 (HIV-1) drug resistance mutations (DRM) is not fully understood. The aim of this study was to investigate whether antiretroviral plasma concentration could predict the emergence of DRM at treatment failure.

METHODS

The study cohort comprised retrospectively selected patients with failing antiretroviral regimens for whom a protease inhibitor (PI) or non-nucleoside reverse transcriptase inhibitor (NNRTI) trough concentration measurement (TDM) had been obtained before failure, a genotypic resistance test (GRT1) had been performed before the TDM, and a genotypic resistance test (GRT2) had been performed at therapeutic failure. Drug levels were classified as undetectable/detectable or subtherapeutic/therapeutic according to limits of quantification of a high-performance liquid chromatography-ultraviolet assay or pre-defined efficacy thresholds, respectively. The number of DRM acquired at treatment failure was evaluated by comparing the results of the GRT2 and GRT1.

RESULTS

A total of ten and 57 failure episodes occurred among our patients on NNRTI-based and PI-based regimens, respectively, and included in the evaluation. PI concentration was subtherapeutic in 28.1% of patients, among which the levels were undetectable in 21.1%. Twenty-five (43.9%) patients acquired at least one new PI-DRM according to the GRT2. Patients with undetectable PI levels showed a lower emergence of PI-DRM (minor + major) than those with detectable levels (8.3 vs. 53.3%, p = 0.007). Multivariate analysis confirmed that undetectable PI levels were independent negative predictors of DRM selection. NNRTI measurements were subtherapeutic in 2/10 (20%) patients. NNRTI-DRM were acquired by all patients regardless of NNRTI levels.

CONCLUSIONS

A PI measurement showing undetectable drug levels prior to treatment failure predicted the lack of emergence of PI-DRM at failure. These results suggest that PI levels can help clinicians interpret the reasons for treatment failure and guide the type of interventions needed.

Oxidative profile in patients with colon cancer: effects of Ruta chalepensis L

AIM

To verify the involvement of free radicals in tumor progression and to investigate the effects of an ethanolic extract of Ruta Chalepensis L. and of rutin in blood of patients with colon cancer.

MATERIALS AND METHODS

Leaves of Ruta Chalepensis L. were collected in the area around Catania (Italy). For the preparation of the ethanol extract of leaves, an exhaustive extraction of 100 g of the drug was carried out in Soxhlet with 800 ml of 95% ethanol. Fifty-six patients with colorectal cancer were randomly selected for this study; among these, 34 were affected by an early stage (T1 N0 M0 according to scale), while 22 were affected by an advanced stage (T4, N1-2, M0) of cancer. Data obtained from these patients were compared with those of a control group consisting of 20 healthy subjects. Plasma of each sample was used for determining non-proteic antioxidant capacity, thiol groups, lipid hydroperoxides and nitrite/nitrate levels, evaluated by spectrophotometric tests. In addition, percentage of haemolysis was evaluated incubating (for 2 hours at 37 degrees C) erythrocyte suspension with a free radical donor (50 mM 2,2'-azobis-amidino propane chloridrate), in the presence or absence of ethanolic extract of Ruta Chalepensis L. (250 microg/ml) or rutin (1 mM).

RESULTS

Non-proteic antioxidant capacity was significantly lower in cancerous patients than in healthy subjects (p < 0.001). This decrease was stage-related. In fact, non-proteic antioxidant capacity resulted lower in advanced than in early colorectal cancer (p < 0.001). The same significant stage-related decrease was observed in plasma thiol groups (p < 0.001). Coherently with the decrease in non-proteic antioxidant capacity and thiol groups, higher levels of lipid hydroperoxides and nitrite/nitrate were observed in patients with colorectal cancer with respect to healthy subjects (p < 0.001) and the increase in these markers of oxidative stress was related to the cancer stadiation. Neoplastic patients also showed an increased percentage of oxidative hemolysis respect to controls and the haemolytic damage was correlated with the stage of colon cancer. Both the extract of Ruta Chalepensis L. and rutin were able to protect erythrocytes from oxidative stress induced by the free radical donor, but the extract of Ruta Chalepensis L. was more effective than rutin. This protective effect was significant only in erythrocytes from patients with early colorectal group, whereas no significant modification was induced by Ruta Chalepensis L. or rutin in red blood cells from advanced colorectal cancer patients exposed to the same experimental conditions.

CONCLUSION

Oxidative stress correlates with colon cancer stadiation and both the extract of Ruta chalepensis and rutin are able to protect red blood cells from radical-induced damage. However, their effects are significant in early stages of cancer. So these natural antioxidants might be usefull to prevent carcinogenesis and/or tumor progression.

Examination of periodontal pathogens in stenotic valve specimens and in whole blood samples in patients affected by aortic valve stenosis and chronic periodontitis

Periodontitis may be a risk factor for atherosclerosis and coronary heart disease. The influence of periodontal pathogens in cardiovascular diseases needs further investigation. Therefore, the aims of this clinical study are: to test the presence of periodontal bacteria DNA in aortic valves and to assess the concomitant presence of the same periodontal bacteria DNA in whole blood samples in patients affected by aortic valve stenosis and chronic periodontitis. Nineteen consecutive patients (12 males and 7 females, age: 49-85 years) were enrolled in this study after having been subjected to a complete periodontal evaluation to confirm the diagnosis of chronic periodontitis. All patients were scheduled for aortic valve replacement surgery. After clinical and microbial periodontal examination, the aortic valve tissue specimens were obtained by excision during valve replacement surgery and the patients were subjected to the whole blood sampling before the surgery. The polymerase chain reaction technology was used to detect the putative periodontal pathogens Tannerella forshytia, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Fusobacterium nucleatum, Campylobacter rectus, Eikenella corrodens and Treponema denticola. Neither the 19 aortic valve specimens nor the blood samples were positive for the genoma of the selected periodontal pathogens. The selected periodontal pathogens did not colonize the aortic valve of patients affected by stenosis and bacterial genoma was not present in whole blood samples. A high blood pressure at the aortic valve may prevent the adhesion and proliferation of bacterial colonies.

Recurrent Intraventricular Hemorrhages Caused by an AVM Detected by Angiography with Initially Normal Angiogram

Primary intraventricular haemorrhage (PIVH) is an uncommon type of non-traumatic cerebral haemorrhage limited to the ventricular system arising in adults and children, with diverse aetiology and variable course. Vascular malformations account for 34% of PIVH, whereas no cause is found in 21–47%. When a primary intraventricular haemorrhage is detected in a young patient an underlying lesion such as an arteriovenous malformation (AVM) must be ruled out. The diagnosis may be suspected when there is sudden onset of headache, nausea and vomiting with or without a reduced level of consciousness. Nevertheless, even if clinical features suggest the diagnosis of PIVH, cerebral computed tomography (CT) scan is required for confirmation, and magnetic resonance imaging (MRI) and catheter angiography are necessary to establish the aetiology. We describe a case of isolated recurrent intraventricular haemorrhages caused by AVM detected by diagnostic intracranial angiography with no abnormality demonstrated on angiography four years earlier.

Pro-metastatic signaling by c-Met through RAC-1 and reactive oxygen species (ROS)

Overexpression of the c-Met/hepatocyte growth factor receptor(HGF-R) proto-oncogene and abnormal generation of intracellular oxygen species (reactive oxygen species (ROS)) have been linked, by independent lines of evidence, to cell transformation and to malignant growth. By comparing two subpopulations of the B16 mouse melanoma (B16-F0 and B16-F10) endowed with different lung metastasis capacities (low and high, respectively) we found that both the expression/phosphorylation of c-Met and the steady-state levels of ROS positively correlated with metastatic growth. shRNA-mediated downregulation of c-Met in F10 cells led to a parallel decrease in the generation of oxygen species and in metastatic capacity, suggesting that oxidants may mediate the pro-metastatic activity of the HGF receptor. c-Met activation by a ligand elicits the formation of oxidant species through the oxidase-coupled small GTPase Rac-1, a relevant downstream target of the HGF-R. Moreover, cell treatment with the catalytic ROS scavengers EUK-134 and EUK-189 attenuates Met signaling to ERKs and inhibits the anchorage-independent growth of F10 cells, consistent with a critical role for oxygen species in HGF signaling and in aggressive cell behavior. Finally, genetic manipulation of the Rac-ROS cascade at different levels demonstrated its crucial role in the pro-metastatic activity of c-Met in vivo. Thus, we have outlined a novel cascade triggered by c-Met and mediated by ROS, linked to metastasis and potentially targetable by new antimetastatic, redox-based therapies.

Bacterial and viral DNA in periodontal disease: a study using multiplex PCR

Recent studies have suggested an association between periodontal disease and the presence of Herpesviruses, in particular: Epstein-Barr virus (EBV) and Human Cytomegalovirus (CMV) (Contreras et al., 1999--Contreras et al., 2000--Slots et al., 2000--Ting et al., 2000). In the work reported in this paper, we use a multiplex Polymerase Chain Reaction (PCR) to compare the presence of Herpesviruses and putative bacterial pathogens in patients with periodontal disease and in healthy individuals. Direct detection of microorganisms with PCR is shown to offer significant advantages in terms of time, effort and cost. The study detected no statistically significant differences between the prevalence of EBV and CMV in patients and controls. The failure to replicate previous findings may be due to differences in the age composition and the geographical and social origins of the study groups. The study detected a significant excess of HSV-1 in periodontal patients. This suggests that the role of Herpesviruses in the pathogenesis of periodontal disease deserves further investigation. The bacterial assay confirmed the results of previous studies showing a strong association between periodontitis and the presence of A. actinomycetemcomitans, P. gingivalis and P. intermedia.

Benign adult familial myoclonic epilepsy: genetic heterogeneity and allelism with ADCME

Benign adult familial myoclonic epilepsy (BAFME) has been mapped to chromosome 8q24; however, genetic heterogeneity has been recently suggested. The authors report a clinical and electrophysiologic study of two Italian BAFME families showing linkage to chromosome 2p11.1-q12.2. Their report supports the evidence of non-Japanese families with BAFME and suggests a possible allelism with the recently described autosomal dominant cortical myoclonus and epilepsy syndrome.

Role of the JAK/STAT signal transduction pathway in the regulation of gene expression in CNS

Over the last 20 years the JAK/STAT signal transduction pathway has been extensively studied. An enormous amount of data on different cell signal transduction pathways is now available. The JAK/STAT signal transduction pathway is one of the intracellular signaling pathways activated by cytokines and growth factors that was first studied in the hematopoietic system, but recent data demonstrate that this signal transduction is also greatly utilized by other systems. The JAK/STAT pathway is a signaling cascade that links the activation of specific cell membrane receptors to nuclear gene expression. This review is focused on the role of JAK/STAT signal transduction pathway activation in the central nervous system (CNS).

Familial infantile myoclonic epilepsy: clinical features in a large kindred with autosomal recessive inheritance

PURPOSE

To describe the clinical features of a large kindred with familial infantile myoclonic epilepsy (FIME) with autosomal recessive inheritance, and to discuss the nosology of the early infantile myoclonic epilepsies (IMEs).

METHODS

The family descends from the intermarriage of two couples of siblings. In a previous study, we mapped the genetic locus to chromosome 16p13. We analyzed results of family records and personal history, psychomotor development, neurologic examination, epilepsy features, and EEG recordings for each subject.

RESULTS

FIME has a strong penetrance (eight affected of 14 subjects) and a homogeneous clinical picture. Like the benign form of infantile myoclonic epilepsy (BIME), FIME is a true idiopathic IME with unremarkable history, no neurologic or mental impairment, good response to treatment, and normal interictal EEG pattern. Conversely, onset with generalized epileptic seizures without fever (four patients) or with fever (one patient), frequency and duration of the myoclonic seizures, occurrence of generalized tonic--clonic seizures (GTCSs) in all patients and persistence of seizures into adulthood are characteristics of the severe infantile myoclonic epilepsy (SIME).

CONCLUSIONS

Clinical overlap probably exists among the myoclonic epilepsies of infancy. FIME differs from other forms of IME in its phenotypic features. The peculiar mode of inheritance is explained by the genetic background of the family. Genetic studies suggest linkage to chromosome 16 in familial cases of true IME.

JAK/STAT signaling pathway mediates cytokine-induced iNOS expression in primary astroglial cell cultures

The production of nitric oxide by the calcium-independent inducible nitric oxide synthase (iNOS) in glial cells has been implicated in the neuropathogenesis of various diseases. It is well known that in response to lipopolysaccharide (LPS) and cytokines, such as IFN-gamma, glial cells are induced to synthesize large amount of nitric oxide (NO) (Bolaños et al., 1996; Nicoletti et al., 1998). The signaling transduction pathways for iNOS transcription in astroglial cells have however not yet been established. Because IFN-gamma receptor chains are associated with Janus tyrosine kinases (JAK1 and JAK2) (Darnell et al., 1994), we analyzed the involvement of the JAK/STAT signal transduction pathway in iNOS expression. Our study shows increased JAK2 and STAT1 alpha/beta tyrosine phosphorylation in primary astroglial cell culture after treatment with IFN-gamma and LPS. A temporal correlation was observed between JAK2 and STAT1 alpha/beta tyrosine phosphorylation, the appearance of interferon-regulatory factor-1 (IRF-1) mRNA and the iNOS expression. Inhibition experiments showed that JAK2 and STAT1 alpha/beta tyrosine phosphorylation were necessary for IFN gamma-mediated iNOS induction in astroglial cells. We conclude that JAK2 and STAT1 alpha/beta tyrosine phosphorylation is an early event involved in the expression of iNOS in astroglial cells.

Molecular characterization of the plasma membrane H(+)-ATPase, an antifungal target in Cryptococcus neoformans

The Cryptococcus neoformans PMA1 gene, encoding a plasma membrane H(+)-ATPase, was isolated from a genomic DNA library of serotype A strain ATCC 6352. An open reading frame of 3,380 nucleotides contains six introns and encodes a predicted protein consisting of 998 amino acids with a molecular mass of approximately 108 kDa. Plasma membranes were isolated, and the H(+)-ATPase was shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be slightly larger than the S. cerevisiae H(+)-ATPase, consistent with its predicted molecular mass. The plasma membrane-bound enzyme exhibited a pH 6.5 optimum for ATP hydrolysis, K(m) and V(max) values of 0.5 mM and 3.1 micromol mg(-1) min(-1), respectively, and an apparent K(i) for vanadate inhibition of 1.6 microM. ATP hydrolysis in plasma membranes and medium acidification by whole cells were inhibited by ebselen, a nonspecific H(+)-ATPase antagonist which was also fungicidal. The predicted C. neoformans protein is 35% identical to proton pumps of both pathogenic and nonpathogenic fungi but exhibits more than 50% identity to PMA1 genes from plants. Collectively, this study provides the basis for establishing the Cryptococcus H(+)-ATPase as a viable target for antifungal drug discovery.

Efficacy of oral cochleate-amphotericin B in a mouse model of systemic candidiasis

Amphotericin B (AMB) remains the principal therapeutic choice for deep mycoses. However, its application is limited by toxicity and a route of administration requiring slow intravenous injection. An oral formulation of this drug is desirable to treat acute infections and provide prophylactic therapy for high-risk patients. Cochleates are a novel lipid-based delivery system that have the potential for oral administration of hydrophobic drugs. They are stable phospholipid-cation crystalline structures consisting of a spiral lipid bilayer sheet with no internal aqueous space. Cochleates containing AMB (CAMB) inhibit the growth of Candida albicans, and the in vivo therapeutic efficacy of CAMB administered orally was evaluated in a mouse model of systemic candidiasis. The results indicate that 100% of the mice treated at all CAMB doses, including a low dosage of 0.5 mg/kg of body weight/day, survived the experimental period (16 days). In contrast, 100% mortality was observed with untreated mice by day 12. The fungal tissue burden in kidneys and lungs was assessed in parallel, and a dose-dependent reduction in C. albicans from the kidneys was observed, with a maximum 3.5-log reduction in total cell counts at 2.5 mg/kg/day. However, complete clearance of the organism from the lungs, resulting in more than a 4-log reduction, was observed at the same dose. These results were comparable to a deoxycholate AMB formulation administered intraperitoneally at 2 mg/kg/day (P < 0.05). Overall, these data demonstrate that cochleates are an effective oral delivery system for AMB in a model of systemic candidiasis.

Mapping of a locus for a familial autosomal recessive idiopathic myoclonic epilepsy of infancy to chromosome 16p13

Myoclonic epilepsies with onset in infancy and childhood are clinically and etiologically heterogeneous. Although genetic factors are thought to play an important role, to date very little is known about the etiology of these disorders. We ascertained a large Italian pedigree segregating a recessive idiopathic myoclonic epilepsy that starts in early infancy as myoclonic seizures, febrile convulsions, and tonic-clonic seizures. We typed 304 microsatellite markers spanning the 22 autosomes and mapped the locus on chromosome 16p13 by linkage analysis. A maximum LOD score of 4.48 was obtained for marker D16S3027 at recombination fraction 0. Haplotype analysis placed the critical region within a 3.4-cM interval between D16S3024 and D16S423. The present report constitutes the first example of an idiopathic epilepsy that is inherited as an autosomal recessive trait.

Human herpesvirus 8 seroprevalence and evaluation of nonsexual transmission routes by detection of DNA in clinical specimens from human immunodeficiency virus-seronegative patients from central and southern Italy, with and without Kaposi's sarcoma

In order to investigate the seroprevalence of human herpesvirus 8 (HHV-8) infection in central and southern Italy, sera from human immunodeficiency virus (HIV)-seronegative subjects, with and without Kaposi's sarcoma (KS), were analyzed by immunofluorescence assay, using BC-3, a cell line latently infected with HHV-8. High titers of antibody against HHV-8 lytic and latent antigens were detected in all 50 KS patients studied, while in 50 HIV-seronegative subjects without KS, 32 (64%) were found positive for HHV-8 antibodies. Titers in the sera of these patients were lower than those for KS patients. This data suggests that HHV-8 infection is not restricted to KS patients and that the prevalence of HHV-8 infection in the general population may be correlated with differing rates of prevalence of KS in different parts of the world. In view of these findings, possible nonsexual transmission routes were evaluated. Nested PCR was used to test for the presence of HHV-8 DNA in saliva, urine, and tonsillar swabs from KS and non-KS patients. In KS patients, 14 out of 32 tonsillar swabs (43.7%), 11 out of 24 saliva samples (45.8%), and just 2 out of 24 urine samples (8.3%) tested positive for HHV-8 DNA. In the control group, on the contrary, none of the 20 saliva and 20 urine specimens was positive for HHV-8 DNA; only 1 out of 22 tonsillar swabs gave a positive result. This data supports the hypothesis that HHV-8 infects the general population in a latent form. The reactivation of viral infection may result in salivary shedding of HHV-8, contributing to viral spread by nonsexual transmission routes.

Human herpesvirus 8 in Italian HIV-seronegative patients with Kaposi sarcoma

OBJECTIVE

To evaluate the prevalence of human herpesvirus 8 (HHV-8) DNA detection in a large series of human immunodeficiency virus-seronegative patients with and without Kaposi sarcoma (KS) from the central and southern regions of Italy where classic KS is prevalent.

DESIGN

Samples of lesional, peripheral unaffected, and distant normal skin and peripheral blood mononuclear cells (PBMCs) from 33 patients with KS and PBMCs from 42 control subjects were analyzed using single and nested polymerase chain reaction techniques for the presence of HHV-8 DNA.

PATIENTS

A total of 33 patients with KS not related to acquired immunodeficiency syndrome (26 patients with classic KS and 7 patients with iatrogenic KS) were studied. Furthermore, 2 control groups were enrolled. The first group consisted of 13 healthy volunteers, the second of 29 patients affected by different dermatological diseases.

RESULTS

Human herpesvirus 8 sequences were found in 100% of lesional and perilesional specimens, in 33% of the distant normal skin samples, and in 69.6% of the PBMCs from patients with KS. A possible correlation between HHV-8 DNA in PBMCs and the clinical stage of the disease was observed. Moreover, the prevalence of viral DNA in PBMCs from the total control group was 23.8%. No viral DNA was detected in tissue biopsy specimens taken from the control group.

CONCLUSIONS

Our data suggest that HHV-8 could be a widespread virus, at least in Mediterranean regions where KS is more prevalent, such as southern and central Italy. As with other herpesviruses, it may be present lifelong in latent form somewhere in the body and may contribute to the pathogenesis of KS when other predisposing conditions are present.

Detection and typing of herpes simplex viruses by using recombinant immunoglobulin fragments produced in bacteria

Thirty-seven bacterial clones producing human recombinant monoclonal antibody Fab fragments (rFabs) reactive to herpes simplex virus (HSV) antigens were selected from a human combinatorial antibody library constructed in a phage-display vector by a panning procedure against an HSV lysate. Thirty-four of the HSV-specific rFabs were able to specifically recognize HSV-infected cells in indirect immunofluorescence (IF) assays; of these, 25 recognized cells infected by either HSV type 1 (HSV-1) or HSV-2, while 9 recognized only HSV-1-infected cells. One HSV type-common rFab (rFab H37) and one HSV-1-specific rFab (rFab H85) were further evaluated as reagents for viral detection and typing by IF staining in 134 HSV-positive (72 HSV-1 and 62 HSV-2) viral cultures from clinical specimens. The results obtained with these two rFabs were fully consistent with those obtained with a commercial preparation of fluorescein-labeled anti-HSV type-specific murine monoclonal antibodies. The detection sensitivity with the type-common rFab in indirect IF assays was higher overall than that provided by the type-specific murine monoclonal antibodies. Preparations of rFabs suitable for IF staining can be easily and inexpensively obtained in a clinical microbiology laboratory from Escherichia coli cultures. Similar HSV-specific rFabs, therefore, could be advantageous for in vitro diagnostic purposes.

Incidence and lifetime prevalence of Bell's palsy in two Sicilian municipalities. Sicilian Neuro-Epidemiologic Study (SNES) Group

INTRODUCTION

In a door-to-door two-phase survey of common neurologic diseases conducted in two Sicilian municipalities, we investigated the incidence and the lifetime prevalence of Bell's palsy (BP).

MATERIAL & METHODS

During phase I, we administered a screening instrument for facial palsy to 11,901 adult persons. During phase 2, study neurologists using specified diagnostic criteria evaluated those subjects who screened positive.

RESULTS

We found 73 subjects who had experienced BP during their life. The lifetime prevalence as of November 1, 1987, was 642.8 cases per 100,000 population age 15 years and above. The prevalence increased with age and was similar in men and women. Eighteen episodes of BP occurred in the three years preceding the prevalence day. The average annual incidence rate was 52.8 new episodes per 100,000 population age 15 years and above. Incidence increased with age.

CONCLUSION

Comparison with other incidence studies suggests some geographic variability.

Engineering human monoclonal antibody fragments: a recombinant enzyme-linked Fab

A new plasmid vector, pCRP, allowing the expression of human recombinant monoclonal antibody Fab fragments fused with a bacterial acid phosphatase has been constructed. pCRP can accept heavy- and light-chain cDNAs cloned from combinatorial antibody libraries displayed on filamentous phages with the pCombIII system and is able to direct expression to soluble Fabs in which the carboxy-terminus of the heavy chain is fused to the amino-terminus of the mature PhoN nonspecific acid phosphatase of Providencia stuartii. Using the pCRP vector, we expressed two different human recombinant Fabs cloned from combinatorial libraries (one anti-tetenus toxoid and the other anti-HIV-1 gp120) fused with the acid phosphatase. In both cases chimeric antibodies were obtained which retained the antigen-binding ability and the enzymatic activity. Similar Fab-enzyme fusions can be successfully used, even unpurified, in enzyme immunoassays.

Autosomal recessive motor and sensory neuropathy with excessive myelin outfolding in two siblings

Two siblings, a 35-year-old male and a 37-year-old female, offspring of first cousins, presented with a hereditary motor and sensory neuropathy with type I clinical features which began to manifest at about age 10 years. Nerve biopsy in the proband showed it to be a type characterized by excessive myelin outfolding. Morphometric study revealed hypomyelination with focal thickenings due to outfoldings. Clinical, electrophysiological and morphological findings are virtually identical to those described by Ohnishi et al. The peculiarity of the neuropathological picture suggests a particular form of hereditary motor and sensory neuropathy.

Predicted creatinine clearance to assess glomerular filtration rate in chronic renal disease in humans

The work was designed to assess the suitability of both measured endogenous creatinine clearance (CCR) and predicted creatinine clearance (P-CCR) to evaluate GFR in chronic renal disease (CRD) by utilizing the renal clearance of inulin (CIN) as gold standard. A total of 124 subjects were studied (62 healthy, 62 with CRF). CCR significantly overestimated GFR in healthy subjects as well as in CRF, whereas P-CCR was identical to GFR. The CCR/CIN ratio which calculates the fractional creatinine clearance and provides a rough estimation of the contribution of creatinine secretion in explaining the differences between CCR and GFR was increased in CRD and especially in CRD of glomerular origin. The ration P-CCR/CIN was significantly lower than CCR/CIN in healthy subjects and in patients with CRD of glomerular origin. The data are against the use of CCR in assessing GFR in healthy subjects and in patients with CRD.

A family with tomaculous neuropathy mimicking Charcot-Marie-Tooth disease

The appearance of Guillain-Barré syndrome in a 9-year-old girl led to the detection of a hereditary neuropathy in her family. This neuropathy showed clinical and electrophysiological characteristics of Charcot-Marie-Tooth disease. Only nerve biopsy performed in a sister of the proband allowed diagnosis of tomaculous neuropathy which presented unusual clinical, electrophysiological and bioptic aspects.

Hereditary motor and sensory neuropathy type I and motor neuron disease. An unusual association

A 34-year-old man experienced progressive muscle weakness and wasting in the shoulder girdle later spreading distally to the upper limbs. Neurological examination revealed signs of pyramidal and bulbar involvement as well as widespread fasciculations. Pes cavus and distal hypoesthesia were also observed. MCV and nerve biopsy findings were consistent with HMSN-I, while EMG pattern suggested a MND. The association of HMSN-I with MND has not been previously described in literature.

The application of F wave measurements in hepatic patients

The ulnar and tibial nerve F response latencies were analyzed to study the proximal motor conduction velocity in 15 patients with liver disease. The results were compared with those obtained from 15 normal subjects. The tibial MNCV (P less than 0.01) and FWCV from spinal cord to elbow and knee for ulnar and tibial nerves (P less than 0.001) were significantly reduced in patients compared to the controls. Minimum, mean and maximum F latencies showed significant differences for ulnar (P less than 0.001) and tibial (P less than 0.01) nerves in patients with respect to the controls. The mean F determination compared to the minimum F and delta F did not improve disease identification. The conduction abnormality in hepatic patients appeared to be present only in the proximal segment of the ulnar nerve, whereas it was more uniformly distributed along the entire length of the tibial nerve. This demonstrates that the peripheral nerve involvement in hepatic disease is more diffusely present than can be determined by conventional conduction study only.

[Clinical application of the F-wave in various pathological conditions of the peripheral nervous system]

Using the latencies of M response and F-wave, motor nerve conduction was assessed along the entire course of the nerves in various diseases occurring at different levels of the peripheral nervous system. Idiopathic polyneuritis, motor neuron disease, radiculopathies and carpal tunnel syndrome were studied.

Analysis of F-wave in metabolic neuropathies: a comparative study in uremic and diabetic patients

Motor nerve conduction study along the entire length of the ulnar and tibialis posterior nerves was carried out in 30 diabetics compared with 30 uremic patients and 30 control subjects. The conduction in the proximal and the distal nerve segments was evaluated by the determination of the M and F latencies, MNCV (between the stimulus sites), FWCV (between the spinal cord and the stimulus sites), and F-ratio (conduction time ratio of proximal to distal segment). In both groups of patients the lower limbs appear much more involved than the upper, where the ulnar nerve is more commonly affected in uremic than in diabetic patients. In diabetic neuropathy the motor conduction abnormalities are diffuse over the total length of the nerve, but more marked distally in the ulnar nerve.

A case of Dejerine-Sottas disease with prominent ataxia and brain stem involvement. A clinical, electrophysiological, otoneurologic, and ultrastructural study

A case is presented of Dejerine-Sottas disease in a 12-year-old boy in which clinical signs made diagnosis of Friedreich's ataxia seem plausible. Based on marked slowing of motor conduction velocity, the sural nerve biopsy findings of a hypertrophic neuropathy with hypo- and demyelination of the nerve fibres, as well as the clinical history, the diagnosis of Dejerine-Sottas disease was made. ABR examination suggested involvement of brain stem at the roots and/or nuclei of the eighth cranial nerve, without involvement of higher structures.