A novel immunoglobulin superfamily receptor for cellular and viral MHC class I molecules

The human cytomegalovirus UL18 gene product is a homolog of cellular major histocompatibility (MHC) class I antigens. UL18 has been proposed to protect virus-infected cells against natural killer (NK) cell cytotoxicity by engaging NK cell killer inhibitory receptors (KIR) for MHC class I. UL18 binds to a novel immunoglobulin superfamily glycoprotein, designated Leukocyte Immunoglobulin-like Receptor (LIR-1). This protein is distinct from, but related to, known KIRs and binds cellular MHC class I antigens. The cytoplasmic domain of LIR-1 contains four putative immunoreceptor tyrosine-based inhibitory motifs. Upon tyrosine phosphorylation, LIR-1 associates with the tyrosine phosphatase SHP-1. In contrast to KIRs, LIR-1 is expressed predominantly on monocytic and B lymphoid cell types, suggesting a distinct biological function.

Mitochondrial dysfunction in autism spectrum disorders: a population-based study

A minority of cases of autism has been associated with several different organic conditions, including bioenergetic metabolism deficiency. In a population-based study, we screened associated medical conditions in a group of 120 children with autism (current age range 11y 5mo to 14y 4mo, mean age 12y 11mo [SD 9.6mo], male:female ratio 2.9:1). Children were diagnosed using Diagnostic and Statistical Manual of Mental Disorders criteria, the Autism Diagnostic Interview--Revised, and the Childhood Autism Rating Scale; 76% were diagnosed with typical autism and 24% with atypical autism. Cognitive functional level was assessed with the Griffiths scale and the Wechsler Intelligence Scale for Children and was in the normal range in 17%. Epilepsy was present in 19 patients. Plasma lactate levels were measured in 69 patients, and in 14 we found hyperlactacidemia. Five of 11 patients studied were classified with definite mitochondrial respiratory chain disorder, suggesting that this might be one of the most common disorders associated with autism (5 of 69; 7.2%) and warranting further investigation.

The MHC class I binding proteins LIR-1 and LIR-2 inhibit Fc receptor-mediated signaling in monocytes

The MHC class I binding proteins leukocyte immunoglobulin-like receptor (LIR)-1 and -2 recognize a similar broad spectrum of HLA-A, -B and -C alleles but are differentially expressed in lymphocytes, monocytes, and dendritic cells. In monocytes, phosphorylation of LIR-1 and LIR-2 results in the binding of the tyrosine phosphatase SHP-1. Coligation of either LIR with Fcgamma receptor I (CD64) inhibits tyrosine phosphorylation of the associated Fc receptor gamma chain and Syk molecules, as well as intracellular calcium mobilization. These findings suggest that LIR-1 and LIR-2 function as unique MHC class I receptors involved in the inhibition or down-modulation of monocyte activation signals, particularly those mediated through the receptors for IgG, IgE and IgA.

LIRs/ILTs/MIRs, inhibitory and stimulatory Ig-superfamily receptors expressed in myeloid and lymphoid cells

Cells exhibit a complex network of inhibitory and stimulatory signaling pathways, which interact with each other to maintain an homeostatic balance and modulate cellular responses to external stimuli. During most of the 1980s, a great effort was put into the characterization of stimulatory cell surface receptors for cytokines and growth factors. In the last decade, a large number of inhibitory receptors have been identified and it has become apparent that inhibitory signaling pathways are subject to intricate regulatory mechanisms. Inhibitory and stimulatory signaling pathways work in concert with each other to establish activation thresholds and provide sensitive tuning mechanisms that help control cellular responses. LIRs/ILTs/MIRs are a novel family of inhibitory and stimulatory receptors expressed both in myeloid and lymphoid cells. They contain two or four immunoglobulin-like domains in the extracellular region and their cytoplasmic domains are either very short and without any signaling motifs or are long and contain a variable number of immunoreceptor tyrosine-based inhibition motifs (ITIMs). LIRs within the first group send stimulatory signals by association with the FcR common gamma chain and LIRs within the second group deliver inhibitory signals by association with the protein tyrosine phosphatase SHP-1. This review summarizes our current knowledge on the LIRs, their ligands, and biological functions.

Variants of the serotonin transporter gene (SLC6A4) significantly contribute to hyperserotonemia in autism

The role of the serotonin system in the etiology and pathogenesis of autism spectrum disorders (ASD) is not clearly defined. High levels of platelet serotonin (5-HT) have been consistently found in a proportion of patients, and it is known that specific 5-HT transporter gene (SLC6A4) variants modulate transporter reuptake function, therefore possibly influencing the occurrence of hyperserotonemia in a subset of autistic patients. We have examined the association of platelet serotonin levels with two SLC6A4 polymorphisms, 5-HTT gene-linked polymorphic region (HTTLPR) in the promoter and intron 2 variable number of tandem repeats (VNTR), in a sample of 105 ASD patients, their parents, and 52 control children. Quantitative transmission disequilibrium test (QTDT) results showed a significant effect on 5-HT levels of each SLC6A4 marker (P=0.017 for HTTLPR; P=0.047 for intron 2 VNTR) and of haplotypes of the two markers (P=0.017), with a major contribution of the L.Stin2.10 haplotype (P=0.0013). A 5-HT mean value in the range of hyperserotonemia was associated with the homozygous L.Stin2.10 haplotype (H (1,N=97)=7.76, P=0.0054), which occurred in 33% of hyperserotonemic patients against 6% of patients with normal 5-HT levels (Fisher's exact test: P=0.013, OR=8). Allele interaction at the HTTLPR locus was found, with a significant dominance variance effect on 5-HT levels. We found no transmission disequilibrium of any of the SLC6A4 variants in ASD. Our results show that the SLC6A4 gene is a significant factor in the determination of 5-HT levels, and that specific SLC6A4 variants are associated with an increased risk for hyperserotonemia in our sample of autistic patients. The biological mechanism, however, is unlikely to involve the SLC6A4 gene solely. The associated SLC6A4 alleles likely interact with other genes or environmental factors to produce the abnormally high 5-HT levels observed in this subset of autistic patients, who possibly represent a separate etiological group.

Saliva in the Diagnosis of COVID-19: A Review and New Research Directions

This review presents literature that highlights saliva's utility as a biofluid in the diagnosis and monitoring of COVID-19. A systematic search was performed in 5 electronic databases (PubMed, Embase, LILACS, Scopus, and Web of Science). Studies were eligible for inclusion if they assessed the potential diagnostic value and/or other discriminatory properties of biological markers in the saliva of patients with COVID-19. As of July 22, 2020, a total of 28 studies have investigated the presence of SARS-CoV-2 RNA in saliva. Several of those studies confirmed reliable detection of SARS-CoV-2 in the saliva of patients with COVID-19. Saliva offered sensitivity and specificity for SARS-CoV-2 detection comparable to that of the current standard of nasopharyngeal and throat swabs. However, the utility of saliva in diagnosing COVID-19 infection remains understudied. Clinical studies with larger patient populations that measure recordings at different stages during the disease are still necessary to confirm the accuracy of COVID-19 diagnosis with saliva. Nevertheless, the utility of saliva as a diagnostic tool opens the possibility of using rapid and less invasive diagnostic strategies by targeting bioanalytes rather than the pathogen.

Molecular cloning and biological characterization of NK cell activation-inducing ligand, a counterstructure for CD48

Using the monoclonal antibody C1.7, which recognizes a signaling, membrane-bound molecule on human NK and a proportion of CD8(+) T cells, we cloned a novel molecule we refer to as NK cell activation-inducing ligand (NAIL). It is a 365-amino acid protein that belongs to the immunoglobulin-like superfamily with closest homology to murine 2B4, and human CD84 and CD48. Using a soluble NAIL-Fc fusion protein, we determined the counterstructure for NAIL, CD48, which it binds with high affinity. Stimulation of human B cells with recombinant NAIL in the presence of a suboptimal concentration of human CD40 ligand or IL-4 resulted in increased proliferation. Treatment of human dendritic cells with soluble NAIL-leucine zipper protein resulted in an increased release of IL-12 and TNF-alpha. Using recombinant CD48 protein, we demonstrated the ability of this molecule to increase NK cell cytotoxicity and induce IFN-gamma production. We also showed that 2B4 binds to mouse CD48, suggesting that interaction of these receptors may play a similar role in both species. Taken together these results indicate that the NAIL-CD48 interaction may be an important mechanism regulating a variety of immune responses.

One-stage posterolateral decompression and stabilization for primary and metastatic vertebral tumors in the thoracic and lumbar spine

During the past decade, anterior approaches to the spine have been shown to be much more effective than laminectomy for the relief of pain and neurological deficits due to vertebral metastases. Laminectomy has failed because it does not allow adequate decompression of epidural lesions anterior to the thecal sac. In an effort to combine the advantages of the posterior approach with an adequate decompression, a one-stage posterolateral decompression-stabilization procedure was performed on nine patients with thoracolumbar spine tumors. The approach has been used for decompression and stabilization after thoracolumbar burst fractures. Marked lasting improvement was seen in all six patients with preoperative neurological deficits and in four patients with severe back pain and/or radiculopathy. Three nonambulators and two marginal ambulators could walk postoperatively without assistance. Of five patients who were working preoperatively, four returned full-time to their prior occupations. Three patients had serious complications, including one early postoperative death. No patient deteriorated neurologically due to the procedure. Although the series is small, it demonstrates that adequate one-stage decompression-stabilization of spinal epidural lesions is possible via the posterolateral approach and should be considered in certain cases as an alternative to the anterior approach.

A novel mouse model for neurotrophic keratopathy: trigeminal nerve stereotactic electrolysis through the brain

PURPOSE

To develop a mouse model of neurotrophic keratopathy by approaching the trigeminal nerve through the brain and to evaluate changes in corneal cell apoptosis and proliferation.

METHODS

Six- to 8-week-old male C57BL/6 mice underwent trigeminal stereotactic electrolysis (TSE) to destroy the ophthalmic branch of the trigeminal nerve. Clinical follow-up using biomicroscopy of the cornea was performed at days 2, 4, 5, and 7. To confirm the effectiveness of the procedure, we examined the gross nerve pathology, blink reflex, and immunohistochemistry of the corneal nerves. TUNEL-positive apoptotic and Ki-67-positive proliferating corneal cells were evaluated to detect changes from the contralateral normal eye.

RESULTS

TSE was confirmed by gross histology of the trigeminal nerve and was considered effective if the corneal blink reflex was completely abolished. TSE totally abolished the blink reflex in 70% of mice and significantly reduced it in the remaining 30%. Animals with absent blink reflex were used for subsequent experiments. In these mice, a progressive corneal degeneration developed, with thinning of the corneal epithelium and eventually perforation after 7 days. In all mice, 48 hours after TSE, corneal nerves were not recognizable histologically. Seven days after TSE, an increase in cellular apoptosis in all the corneal layers and a reduction in proliferation in basal epithelial cells were detected consistently in all mice.

CONCLUSIONS

TSE was able, in most cases, to induce a disease state that reflected clinical neurotrophic keratitis without damaging the periocular structures. Moreover, corneal denervation led to increased apoptosis and reduced proliferation of epithelial cells, formally implicating intact nerve function in regulating epithelial survival and turnover.

Stereotypies in Rett syndrome: Analysis of 83 patients with and without detected MECP2 mutations

BACKGROUND

Hand stereotypies are considered a hallmark of Rett syndrome (RTT) and are usually described as symmetric movements at the midline. However, related pathologies may show the same type of involuntary movement. Furthermore, patients with RTT also have stereotypies with other localizations that are less well characterized.

METHODS

We analyzed stereotypies in 83 patients with RTT, 53 with and 30 without a mutation detected in the MECP2 gene. Patients were observed and videotaped always by the same pediatric neurologist. Stereotypies were classified, and data were submitted to statistical analysis for comparison of mutation-positive and -negative patients and analysis of their evolution with the disease.

RESULTS

All the patients showed hand stereotypies that coincided with or preceded the loss of purposeful hand movements in 62% of the patients with MECP2 mutations. The hair pulling stereotypy was more frequent in the group with detected mutations, whereas hand washing was not. Hand gaze was absent in all RTT patients with MECP2 mutations. Patients with MECP2 mutations also had more varied stereotypies, and the number of stereotypies displayed by each patient decreased significantly with age in this group. In all patients, stereotypies other than manual tended to disappear with the evolution of the disease.

CONCLUSIONS

Although symmetric midline hand stereotypies were not specific to patients with an MECP2 mutation, some of the other stereotypies seemed to be more characteristic of this group. In patients younger than 10 years and meeting the necessary diagnostic criteria of Rett syndrome, the association of hand stereotypies without hand gaze, bruxism, and two or more of the other stereotypies seemed to be highly indicative of the presence of an MECP2 mutation.

Human cytomegalovirus, MHC class I and inhibitory signalling receptors: more questions than answers

The human cytomegalovirus UL18 protein, an MHC class I homologue, has been shown to bind to leucocyte immunoglobulin-like receptor (LIR)-1, a member of a family of nine closely related immunoglobulin superfamily receptors expressed on leucocytes. The LIRs are related to the natural killer (NK)-cell immunoglobulin-like receptors and to several other immunoreceptors. Three groups of LIR molecules have been defined: those containing cytoplasmic domain inhibitory signalling motifs, those with short cytoplasmic domains and a charged residue within the transmembrane domain, and a secreted molecule. LIR-1 and LIR-2 bind to a broad spectrum of cellular MHC class I antigens, including HLA-A, -B and -C alleles. LIR-2 is expressed by all monocytes and dendritic cells, whereas LIR-1 is additionally expressed by B cells and subsets of T and NK cells. Upon tyrosine phosphorylation, LIR-1 and LIR-2 associate with the tyrosine phosphatase, SHP-1, and have been shown to inhibit Fc gamma RI signalling when co-crosslinked in monocytes. Evidence for and against a role of UL18 as an inhibitor of NK-cell function is discussed, as are possible functional outcomes of UL18-LIR-1 interactions in monocytic cells.

Long-term Phase 1/2 intraspinal stem cell transplantation outcomes in ALS

Objective

Intraspinal human spinal cord‐derived neural stem cell (HSSC) transplantation is a potential therapy for amyotrophic lateral sclerosis (ALS); however, previous trials lack controls. This post hoc analysis compared ambulatory limb‐onset ALS participants in Phase 1 and 2 (Ph1/2) open‐label intraspinal HSSC transplantation studies up to 3 years after transplant to matched participants in Pooled Resource Open‐Access ALS Clinical Trials (PRO‐ACT) and ceftriaxone datasets to provide required analyses to inform future clinical trial designs.

Methods

Survival, ALSFRS‐R, and a composite statistic (ALS/SURV) combining survival and ALS Functional Rating Scale revised (ALSFRS‐R) functional status were assessed for matched participant subsets: PRO‐ACT n = 1108, Ph1/2 n = 21 and ceftriaxone n = 177, Ph1/2 n = 20.

Results

Survival did not differ significantly between cohorts: Ph1/2 median survival 4.7 years, 95% CI (1.2, ∞) versus PRO‐ACT 2.3 years (1.9, 2.5), P = 1.0; Ph1/2 3.0 years (1.2, 5.6) versus ceftriaxone 2.3 years (1.8, 2.8), P = 0.88. Mean ALSFRS‐R at 24 months significantly differed between Ph1/2 and both comparison cohorts (Ph1/2 30.1 ± 8.6 vs. PRO‐ACT 24.0 ± 10.2, P = 0.048; Ph1/2 30.7 ± 8.8 vs. ceftriaxone 19.2 ± 9.5, P = 0.0023). Using ALS/SURV, median PRO‐ACT and ceftriaxone participants died by 24 months, whereas median Ph1/2 participant ALSFRS‐Rs were 23 (P = 0.0038) and 19 (P = 0.14) in PRO‐ACT and ceftriaxone comparisons at 24 months, respectively, supporting improved functional outcomes in the Ph1/2 study.

Interpretation

Comparison of Ph1/2 studies to historical datasets revealed significantly improved survival and function using ALS/SURV versus PRO‐ACT controls. While results are encouraging, comparison against historical populations demonstrate limitations in noncontrolled studies. These findings support continued evaluation of HSSC transplantation in ALS, support the benefit of control populations, and enable necessary power calculations to design a randomized, sham surgery‐controlled efficacy study.

Down-regulation of leucocyte immunoglobulin-like receptor expression in the synovium of rheumatoid arthritis patients after treatment with disease-modifying anti-rheumatic drugs

OBJECTIVES

To compare the expression of leucocyte immunoglobulin-like receptors (LILRs) also known as ILTs and LIRs in rheumatoid arthritis (RA) synovial membrane before and after treatment with disease-modifying anti-rheumatic drugs (DMARDs) and investigate regulation of LILR-expression and function in vitro.

METHODS

A study was performed on serial synovial biopsies obtained from 10 RA patients before and after treatment with DMARDs. Expression of the activating LILRA2 (ILT1 or LIR-7) and inhibitory LILRB2 (ILT4 or LIR-2) and LILRB3 (ILT5 or LIR-3) was evaluated by immunohistochemical staining, and quantified by a validated scoring system. Peripheral blood mononuclear cells and in vitro derived macrophages were used to determine effects of DMARDs on expression and function of LILRs.

RESULTS

Abundant expression of LILRB2, B3 and A2 was found in synovial tissue of all patients before treatment. Number of inflammatory cells expressing both inhibitory and activating LILRs dramatically decreased in patients who responded to treatment, but remained high in those who did not. However, treatment of macrophages with DMARDs in vitro did not down-regulate LILR expression. On the other hand, reduction in LILR expression in RA synovia was associated with decreased inflammatory infiltrates in those who responded to treatment. Cross-linking of LILRA2 on macrophages caused substantial production of tumour necrosis factor (TNF-alpha) in a dose- and time-dependent manner that was strongly inhibited by dexamethasone.

CONCLUSIONS

We show that expression of LILRs in RA synovium was significantly reduced only in patients who responded to treatment. However, clinical responses may not be due to direct effects of DMARDs on LILR expression but due to partial inhibition of LIRA2-mediated TNF-alpha production by steroids leading to suppression of inflammation.

Profiles of NK, NKT cell activation and cytokine production following vaccination against hepatitis B

Human natural killer (NK) cells (CD56+ CD3-) represent crucial components of the innate immune system especially against viral infections and because their activation can modulate the outcome of the adaptive immune response. NKT cells (CD56+CD3+), a lymphocyte T population characterized by expression of surface markers of NK cells, are known to be abundant in the liver and their activation could be associated with hepatic injury. Using three-color flow cytometry to measure surface receptors and intracellular cytokines, we have explored early activation signals and cytokine production in NK and NKT cells within a group of hepatitis B vaccinated and non-vaccinated individuals. A specific increase of the CD56bright cell population, the activation receptor CD69 and IFN-gamma, was observed in NK cells following incubation with recombinant HBsAg in responders to vaccination. Comparable results were observed in NKT cells showing an increment of CD69, CD25, IL-2 and IFN-gamma expression in responder subjects. These parameters were statistically diminished in non-responder individuals (p<0.05) in both groups of cells. These results demonstrate a diminished activation of these cells in non-responders to the vaccine, suggesting that NK and NKT cells play an important role in the immune response following hepatitis B vaccination.

Increased Fas-mediated apoptosis in polymorphonuclear cells from HIV-infected patients

Neutrophils represent an important line of innate host defence against invading microorganisms and their functional detriment during HIV infection, including accelerated spontaneous cell death, has been shown to contribute to AIDS development. Neutrophils are susceptible to apoptosis via Fas and an interaction between Fas and FasL was suggested originally as a mechanism to explain constitutive neutrophil apoptosis. We have explored some intracellular pathways leading to PMN apoptosis from 28 HIV-infected patients and 24 healthy volunteers. As previously reported, accelerated spontaneous apoptosis was observed in HIV+ patients, but this did not correlate with viral load. Furthermore, an increase in the level of spontaneous apoptosis was detected in neutrophils from HIV-infected patients following inhibition of ERK, suggesting an impairment of this kinase pathway during the early stages of infection which may contribute to PMN dysfunction. An elevated susceptibility to undergo apoptosis was observed following cross-linking of Fas, which correlated both with viral load and co-expression of Fas/FasL surface molecules. Different mechanisms for spontaneous and Fas-induced apoptosis are proposed which together contribute to the neutropenia and secondary infections observed during the progression to AIDS.

The leukocyte immunoglobulin-like receptors (LIRs): a new family of immune regulators

Identification of a counterstructure for the human cytomegalovirus-encoded major histocompatibility complex class I-related gene product, UL18, has led to the discovery of a novel family of immunoreceptors, termed leukocyte immunoglobulin-like receptors (LIRs). The LIRs are differentially expressed in cells of the dendritic cell, monocytic and lymphocytic lineages, and appear to mediate diverse roles in immune regulation. This review summarizes the expression, distribution, and signaling capacities of the LIRs and discusses possible roles of the LIRs in both inhibition and activation of the cellular responses.

Hematogenous septic ankle arthritis

Ankle infection is a serious problem with limited published information on microbiology and associated morbidities. We describe the laboratory findings, microbiology, and occurrence of adjacent osteomyelitis in patients with hematogenous septic ankle arthritis. We retrospectively reviewed 30 patients with hematogenous septic arthritis of the ankle admitted over a 10-year period. Twenty-two patients were male and eight female. The mean age was 46 years (range, 23-67 years). C-reactive protein and erythrocyte sedimentation rate were elevated in all patients, but the peripheral white blood cell count was elevated in only 47% of patients. Staphylococcus aureus (S. aureus) was the most common pathogen, isolated in 13 (54%) of the 24 patients with positive cultures; four of these isolates (four of 24; 17% of positive cultures) were oxacillin-resistant. Four (17%) of the 24 patients with positive cultures had a mycobacterial infection. We identified adjacent osteomyelitis in 30% of patients, which was considerably associated with the presence of patient comorbidities. S. aureus is the most common pathogen in septic ankle arthritis and empiric antibiotic therapy is recommended. Adjacent osteomyelitis may be present and a high index of suspicion is necessary in patients with comorbidities.

LEVEL OF EVIDENCE

Level III, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Treatment of diabetic foot complications with hyperbaric oxygen therapy: a retrospective experience

BACKGROUND

The aim of this study is to evaluate the role of hyperbaric oxygen in the treatment of diabetic foot ulcers.

METHODS

We performed a retrospective observational study of all patients with diabetic foot ulcers treated at the Institution's hyperbaric chamber between January 2010 and August 2012. Patient data was obtained upon patient hospital visit and prospective clinical record consultation.

RESULTS

Twenty-six foot lesions including 13 foot ulcers Wagner grade 2 or greater and 13 amputation stump ulcers were submitted to hyperbaric oxygen therapy between January 2010 and August 2012 in our Institution. Of these, 23 foot lesions completed treatment and complete epithelialization of the primary lesion was achieved in 15 (65%). The mean healing period since the first hyperbaric oxygen therapy session was 16 weeks. Above-ankle amputations were performed in 3 limbs and transmetatarsal amputations in 2 limbs.

CONCLUSION

Hyperbaric oxygen may be associated with ulcer healing in selected diabetic foot ulcers with impaired cicatrization.

Expression of activating and inhibitory leukocyte immunoglobulin-like receptors in rheumatoid synovium: correlations to disease activity

Rheumatoid arthritis (RA) is a heterogeneous chronic inflammatory joint disease characterized by excessive activation of inflammatory cells of which the underlying mechanisms are not fully elucidated. Perturbed expression and function of immune regulatory molecules called leukocyte immunoglobulin-like receptors (LILRs) may contribute to uncontrolled inflammation. LILRs primarily expressed on the surface of leukocytes are emerging as critical regulators of the threshold and amplitude of leukocyte activation. Inhibitory LILRs (LILRBs) contain cytoplasmic tails with immunoreceptor tyrosine-based inhibitory motifs that provide negative signals. Activating LILRs (LILRAs) have short cytoplasmic domains lacking signaling motifs but transmit activating signals by linking to immunoreceptor tyrosine-based activation motifs of the FcR γ-chain. Here we show that activating LILRA2, A5 and inhibitory LILRB2, B3 were abundantly expressed in synovial tissue of > 75% RA patients. Expression of LILRA2, A5, and B3 significantly correlated to disease activity. In contrast, LILRA1 and B4 were expressed in a subset of patients and no B1 or B5 expression was detected. LILRA2 and A5 were mainly expressed by synovial macrophages and endothelial cells but not lymphocytes, whereas B2 and B3 were expressed by macrophages and lymphocytes. Increase in the number of macrophages expressing activating LILRs and macrophages and lymphocytes expressing inhibitory LILRs suggest a crosstalk between these cells that may regulate the levels of cellular activation and disease severity, while differences in expression pattern may contribute to disease heterogeneity.

Kaposi's sarcoma-associated herpesvirus infection and Kaposi's sarcoma in Brazil

Kaposi's sarcoma (KS) became a critical health issue with the emergence of acquired immunodeficiency syndrome (AIDS) in the 1980s. Four clinical-epidemiological forms of KS have been described: classical KS, endemic KS, iatrogenic KS, and AIDS-associated KS. In 1994, Kaposi's sarcoma-associated herpesvirus (KSHV) or human herpesvirus type 8 was identified by Chang and colleagues, and has been detected worldwide at frequencies ranging from 80 to 100%. The aim of the present study was to evaluate the frequency of KSHV infection in KS lesions from HIV-positive and HIV-negative patients in Brazil, as well as to review the current knowledge about KS transmission and detection. For these purposes, DNA from 51 cases of KS was assessed by PCR: 20 (39.2%) cases of classical KS, 29 (56.9%) of AIDS-associated KS and 2 (3.9%) of iatrogenic KS. Most patients were males (7.5:1, M/F), and mean age was 47.9 years (SD = +/- 18.7 years). As expected, HIV-positive KS patients were younger than patients with classical KS. On the other hand, patients with AIDS-associated KS have early lesions (patch and plaque) compared to classical KS patients (predominantly nodular lesions). This is assumed to be the result of the early diagnose of KS in the HIV-positive setting. KSHV infection was detected by PCR in almost all cases (48/51; 94.1%), irrespectively of the clinical-epidemiological form of KS. These results show that KSHV is associated with all forms of KS in Brazilian patients, a fact that supports the role of this virus in KS pathogenesis.

Acquired procedural dyscalculia associated to a left parietal lesion in a child

We report the case of an 11-year-old boy who developed an anarithmetia in association with a left temporo-parietal tumor. His oral and written language were normal as well as his ability to judge magnitudes, process numbers, read operation signs and retrieve number facts. He had a specific difficulty in performing the procedures of subtraction, especially when it involved borrowing. These skills had been mastered before the present illness. This case shows that the components of calculation can be dissociated by brain lesions sustained during childhood, while arithmetic abilities are being acquired, thus reinforcing findings from developmental dyscalculias, that suggest a modular organisation of those skills during development.