Biallelic somatic inactivation of the mismatch repair gene MLH1 in a primary skin melanoma

Inactivation of mismatch repair (MMR) genes has been linked to the hereditary nonpolyposis colon cancer syndrome and to a subset of sporadic cancers. A phenotypic characteristic of tumors with defective MMR is microsatellite instability (MSI). Although MSI has been reported in a proportion of cutaneous melanomas, inactivation of MMR genes in this tumor type has not been detected thus far. We recently described a human melanoma cell line, PR-Mel, and a cutaneous metastasis from the same patient, which displayed a MMR defect, and showed high MSI. Here we report that in the PR-Mel cell line both MLH1 alleles are somatically inactivated. One allele is lost through a chromosomal deletion of the region 3p21-24, whereas the remaining allele harbors a G --> A transition at position -1 of the acceptor splice site of intron 15, leading to the in-frame skipping of exon 16. The primary melanoma of the PR patient shows loss of heterozygosity at the BAT21 microsatellite marker, located in the MLH1 gene, and does not express the MLH1 and PMS2 proteins. Moreover, it harbors the same mutation detected in the PR-Mel cells. These results demonstrate that biallelic inactivation of MLH1 had occurred in the primary melanoma of the PR patient and suggest that disruption of MMR might have had a role in the development of the melanoma. This is the first report in which genetic defects leading to disruption of MMR function in a human melanoma have been identified.     

Mouse blastocysts release a lipid which activates anandamide hydrolase in intact uterus

Anandamide (N-arachidonoylethanolamine, AEA) is a major endocannabinoid, known to impair mouse pregnancy and embryo development and to induce apoptosis in blastocysts. Here we show that mouse blastocysts rapidly (within 30 min of culture) release a soluble compound, that increases by approximately 2.5-fold the activity of AEA hydrolase (fatty acid amide hydrolase, FAAH) present in the mouse uterus, without affecting FAAH gene expression at the translational level. This "FAAH activator" was produced by both trophoblast and inner cell mass cells, and its initial biochemical characterization showed that it was fully neutralized by adding lipase to the blastocyst-conditioned medium (BCM), and was potentiated by adding trypsin to BCM. Other proteases, phospholipases A(2), C or D, DNAse I or RNAse A were ineffective. BCM did not affect the AEA-synthesizing phospholipase D, the AEA-binding cannabinoid receptors, or the selective AEA membrane transporter in mouse uterus. The FAAH activator was absent in uterine fluid from pregnant mice and could not be identified with any factor known to be released by blastocysts. In fact, platelet-activating factor inhibited non-competitively FAAH in mouse uterus extracts, but not in intact uterine horns, whereas leukotriene B(4) or prostaglandins E(2) and F(2)alpha had no effect. Overall, it can be suggested that blastocysts may protect themselves against the noxious effects of uterine endocannabinoids by locally releasing a lipid able to cross the cell membranes and to activate FAAH. The precise molecular identity of this activator, the first ever reported for FAAH, remains to be elucidated.     

Role of immune-derived diffusible mediators in AIDS-associated neurological disorders

Neurologic abnormalities are common in HIV-1 infected patients and often represent the dominant clinical manifestation of pediatric AIDS. Although the neurological dysfunction has been directly related to CNS invasion by HIV-1, the pathogenesis of neurologic disorders remains unclear. This review will first discuss the spectrum of potential interactions between HIV-1 and neural (neuronal and glial) cells, in the face of experimental data. Next, we will focus on the role of immune-derived cytokines and other soluble compounds which have been proposed to act as neurotoxic mediators and appear to play a role in the pathogenesis of AIDS-associated neurodegeneration.     

Ultrasonography in the early diagnosis of psoriasis-associated enthesopathy

The aim of the present study was to detect entheseal abnormalities by means of ultrasonography (US) in patients with psoriasis. We evaluated 24 patients with psoriasis who underwent clinical and ultrasonographic examination of both lower limbs at the calcaneal insertions of the Achilles tendons and at the flexor and extensor tendons of all fingers of the hand. Fourteen patients with psoriatic arthritis were used as controls. US was performed using a real-time scanner (ATL SDI 3000) with a 5-12 MHz linear array transducer. Longitudinal and transverse scans of the talocrural joints, Achilles tendons and both the flexor and extensor tendons of the fingers of both hands were obtained at rest and during active and passive movements. On clinical examination no entheseal site was abnormal, but on US examination 33% of patients showed abnormalities. In particular, six psoriasis patients (25%) who were asymptomatic showed effusion around the extensor tendon of the first digit of the left hand and around the extensor tendon of the third and fourth digits of both hands; two patients (8.3%) showed a hypoechoic nodular formation of the flexor tendon sheath of the left hand. We conclude that entheseal abnormalities not detected at clinical examination were present in 33% of patients with psoriasis who underwent US examination. Therefore, we suggest the routine use of ultrasonography in the early diagnosis and in treatment and follow-up of patients with tendon enthesopathy, since these factors may have implications for therapy.     

Seroprevalence of Kaposi's sarcoma-associated herpesvirus/human herpesvirus 8 in several regions of Italy

OBJECTIVE: To study the seroprevalence of Kaposi's sarcoma-associated herpesvirus/human herpesvirus type 8 (KSHV/HHV-8) in 779 Italian blood donors. STUDY DESIGN/METHODS: Sera were tested for antibodies to a latency-associated nuclear antigen (LANA) and a capsid related protein encoded by ORF65. RESULTS: Among all Italian donors, 17.7% and 18.7% had antibodies to LANA and ORF65 protein, respectively, and 24.1% had antibodies to at least one antigen. KSHV/HHV-8 seroprevalence was higher in the Po valley and in Sardinia than close to the sub-Alpine Veneto region, Tuscany, or Apulia. KSHV/HHV-8 seroprevalence was almost equally distributed between men and women but increased in the older age groups. CONCLUSIONS: The regional differences and age distribution in seroprevalence agree partially with the incidence of classic KS in Italy. The rarity of classic KS in KSHV/HHV-8-infected subjects and the equal gender distribution of seroprevalence suggest that other cofactors may contribute to KS development in human immunodeficiency virus type 1 (HIV-1)-uninfected individuals.     

Osteointegration of hydroxyapatite-coated and uncoated titanium screws in long-term ovariectomized sheep.

This study was designed to evaluate the osteointegration of HA-coated and uncoated titanium screws in the cortical bone of long-term (24 months) ovariectomized sheep (OVX group) compared to sham-aged sheep (Control group). At 12 weeks after implantation, the screws were tested biomechanically (extraction torque) and histomorphometrically (affinity index: AI) in both femoral and tibial diaphyses. Cancellous bone status was assessed by iliac crest biopsy. BMD of the L5 vertebra and a histomorphological study of the femoral and tibial shafts were performed to acquire data on cortical bone. A significant difference was found between the OVX and Control groups for BMD (p<0.0005), and a significant reduction in the cancellous bone area was observed in the OVX group. Femoral and tibial cortical bone parameters showed significant differences between the groups. The type of material selected (femurs: p<0.0005; tibiae: p<0.0005) and ovariectomy (femurs: p<0.005; tibiae: p<0.005) had a significant effect on the extraction torque. AI results were related to the presence or absence of ovariectomy (p<0.05) and strictly depended on the material implanted in the femur and tibia (p<0.0005). In conclusion, at implantation OVX sheep showed a significant loss of trabecular and cortical bone versus sham-aged sheep. The biomechanical and histomorphological results achieved suggest employing HA-coated screws in the presence of osteopenic cortical bone.     

Circulating gamma/delta T lymphocytes from systemic sclerosis (SSc) patients display a T helper (Th) 1 polarization

Systemic sclerosis (SSc) is a connective tissue disease in which immune system activation is evidenced by high levels of different cytokines in the sera and/or in the supernatants of cultured peripheral blood mononuclear cells (PBMC) and by the presence of specific autoantibodies. gamma/delta T cells accumulate in the lung and the skin of SSc patients suggesting their potential role in the development and maintenance of the disease. The aim of this study was to assess cytokine production and cytotoxic activity of circulating gamma/delta T lymphocytes obtained from SSc patients and to evaluate their potential role during this disorder. Our results showed that both the proportion and the absolute number of IFN-gamma gamma/delta-producing cells (i.e. displaying a Th1 polarization) in SSc was significantly higher than either the proportion and the absolute number of IL-4 gamma/delta-producing cells in SSc or the proportion and the absolute number of IFN-gamma gamma/delta-producing cells in healthy controls (P < 0.05 for both groups). Furthermore, the cytotoxic activity of enriched gamma/delta T cells was significantly increased in SSc patients compared with controls. The results concerning the Vdelta1+ T cell subset paralleled those of total gamma/delta T lymphocytes. In contrast, alpha/beta T cells from SSc and control subjects displayed Th2 cytokine production. All these findings were independent of both disease subset and clinical status. Our data demonstrate that, although SSc is generally considered a Th2 autoimmune disease, Th1 polarization of gamma/delta T cells and an increase in their cytotoxic activity is observed in SSc, suggesting that gamma/delta T cells could have a relatively autonomous role in the pathogenesis in this disease.     

The effect of lengthening the gastrocnemius muscle in chronic therapy resistant plantar fasciitis

BackgroundThe aetiology of chronic therapy resistant plantar fasciitis (CTRPF) is multifactorial with more focus in recent times on the gastroc-soleus complex. This study evaluates the effect of lengthening the gastrocnemius muscle in CTRPF.MethodsAll patients with CRTPF complaints for at least one year underwent the same standard conservative treatment prior to surgery. 32 patients failed this treatment and underwent gastrocnemius recession. Silfverskiöld test, questionnaires and plantar pressure measurements were obtained at 5 visits.ResultsOne year follow up showed a significantly increase in dorsiflexion of the ankle (16 degrees), a decrease in VAS; 78 (SD: 19) to 20 (SD: 24) and significant improved functional scores. Plantar pressure measurements showed an increase of pressure under the medial proximal part of the midfoot and the 1 st metatarsal and a decrease under the hallux.ConclusionsA gastrocnemius recession results in a significant gain in dorsiflexion, altered loading of the foot and good clinical outcome in patients with CTRPF.Level of EvidenceLevel 2