Cross-Sectional Serosurvey of Companion Animals Housed with SARS-CoV-2–Infected Owners,Italy

We conducted a serologic survey among dogs and cats in Italy to detect antibodies against severe acute respiratory syndrome virus 2 (SARS-CoV-2). We found that SARS-CoV-2 seroprevalence was higher among cats (16.2%) than dogs (2.3%). In addition, seroprevalence was higher among animals living in close contact with SARS-CoV-2–positive owners.     

Ultrasound-Guided Periprosthetic Biopsy in Failed Total Hip Arthroplasty: A Novel Approach to Test Infection in Patients With Dry Joints

BackgroundTo diagnose periprosthetic joint infection (PJI) preoperatively, ultrasound-guided joint aspiration (US-JA) may not be performed when effusion is minimal or absent. We aimed to report and investigate the diagnostic performance of ultrasound-guided periprosthetic biopsy (US-PB) of synovial tissue to obtain joint samples in patients without fluid around the implants.MethodsOne-hundred nine patients (55 men; mean age: 68 ± 13 years) with failed total hip arthroplasty (THA) who underwent revision surgery performed preoperative US-JA or US-PB to rule out PJI.ResultsSixty-nine of 109 patients had joint effusion and underwent US-JA, while the remaining 40 with dry joint required US-PB. Thirty-five of 109 patients (32.1%) had PJI, while 74/109 (67.9%) had aseptic THA failure. No immediate complications were observed in both groups. Technical success of US-PB was 100%, as the procedure was carried on as planned in all cases. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of US-JA were 52.2%, 97.8%, 92.3%, 80.3%, and 82.6%, while for US-PB, they were 41.7%, 100%, 100%, 80%, and 82.5%, respectively, with no significant difference (P = .779). Using the final diagnosis as reference standard, we observed a moderate agreement with both US-JA (k = 0.56) and US-PB (k = 0.50).ConclusionWe present a novel US-guided technique to biopsy periprosthetic synovial tissue of failed THA to rule out PJI. We found similar diagnostic performance as compared with traditional US-JA. This supports future larger studies on this procedure that might be applied in patients without joint effusion.     

Mycobacterium ulcerans-specific immune response after immunisation with bacillus Calmette-Guérin (BCG) vaccine

BackgroundBacillus Calmette–Guérin (BCG) vaccine provides partial protection against Buruli ulcer caused by Mycobacterium ulcerans in epidemiological studies. This study aimed to quantify M. ulcerans-specific immune responses induced by BCG immunisation.MethodsIntracellular cytokine analysis of in-vitro experiments done 10 weeks after BCG immunisation in 130 Australian infants randomised to one of three BCG vaccine strains given either at birth (BCG-Denmark, BCG-Japan, or BCG-Russia) or at two months of age (BCG-Denmark).ResultsProportions of polyfunctional CD4⁺ T-cells were higher in M. ulcerans-stimulated compared to unstimulated control samples. These proportions were not influenced by the vaccine strain or timing of the immunisation. The M. ulcerans-specific immune responses showed similar patterns to those observed in M. tuberculosis-stimulated samples, although they were of lower magnitude.ConclusionsOur data show that BCG immunisation induces M. ulcerans-specific immune responses in infants, likely explaining the cross-protective effect observed in epidemiological studies. (ACTRN12608000227392)     

Pathophysiology of muscle tone

Pathophysiology of muscle tone is discussed on the basis of recent knowledge about motor system organization. Decerebrate rigidity, "pyramidal" spasticity and extrapyramidal rigidity served as models of muscle tone alterations in lateral and ventral motor system lesions.     

Immunological evidence of an early seroconversion to oncogenic Merkel cell polyomavirus in healthy children and young adults

Oncogenic Merkel cell polyomavirus (MCPyV) provokes a widespread and asymptomatic infection in humans. Herein, sera from healthy children and young adults (HC, n = 344) aged 0–20 years old were evaluated for anti-MCPyV immunoglobulin G (IgG) and IgM antibodies employing a recently developed immunoassay. Serum MCPyV IgG data from healthy subjects (HS, n = 510) and elderlies (ES, n = 226), aged 21–65/66–100 years old, from our previous studies, were included. The anti-MCPyV IgG and IgM rates in HC sera were 40.7% and 29.7%, respectively. A lower prevalence of anti-MCPyV IgGs was found in HC aged 0–5 years old (13%) compared to 6–10 (52.3%), 11–15 (60.5%) and 16–20 years old (61.6%) cohorts. Age-stratified HCs exhibited similar anti-MCPyV IgM rates (27.9%–32.9%). Serological profiles indicated that anti-MCPyV IgGs and IgMs had low optical densities (ODs) during the first years of life, while IgM ODs appeared to decrease throughout young adulthood. A lower anti-MCPyV IgGs rate was found in HC (40.7%) than HS (61.8%) and ES (63.7%). Upon the 5-years range age-stratification, a lower anti-MCPyV IgGs rate was found in the younger HC cohort aged 0–5 years old compared to the remaining older HC/HS/ES cohorts (52.3%–72%). The younger HC cohort exhibited the lowest anti-MCPyV IgG ODs than the older cohorts. Low anti-MCPyV IgMs rates and ODs were found in the 21–25 (17.5%) and 26–30 (7.7%) years old cohorts. Our data indicate that, upon an early-in-life seroconversion, the seropositivity for oncogenic MCPyV peaks in late childhood/young adulthood and remains at high prevalence and relatively stable throughout life.     

Reduction of urinary 8-epi-prostaglandin F2α during cyclo-oxygenase inhibition in rats but not in man

1. 8-epi-prostaglandin (PG) F_2α, a major F₂ isoprostane, is produced in vivo by free radical-dependent peroxidation of lipid-esterified arachidonic acid. Both cyclo-oxygenase isoforms (COX-1 and COX-2) may also form free 8-epi-PGF_2α as a minor product. It has been recently seen in human volunteers that the overall basal formation of 8-epi-PGF_2α in vivo is mostly COX-independent and urinary 8-epi-PGF_2α is therefore an accurate marker of ‘basal'' oxidative stress in vivo.
2. To test the validity of this marker in the rat, we evaluated in vivo the effect of COX inhibition on the formation of 8-epi-PGF_2α vs prostanoids. Two structurally unrelated COX inhibitors (naproxen: 30 mg kg⁻¹ day⁻¹; indomethacin: 4 mg kg⁻¹ day⁻¹) were given i.p. to rats kept in metabolic cages. In vivo formation of 8-epi-PGF_2α was assessed by measuring its urinary excretion. Prostanoid biosynthesis was assessed by measuring urinary excretion of major metabolites of thromboxane (TX) and prostacyclin (2,3-dinor-TXB₁ and 2,3-dinor-6-keto-PGF_1α). All compounds were selectively measured by immunopurification/gas chromatography-mass spectrometry.
3. Naproxen reduced urinary excretion of 2,3-dinor-TXB₁ and 2,3-dinor-6-keto-PGF_1α but, unexpectedly, also that of 8-epi-PGF_2α (82, 49 and 52% inhibition, respectively). Indomethacin had a similar effect (77, 69 and 55% inhibition). Esterified 8-epi-PGF_2α in liver and plasma remained unchanged after indomethacin.
4. These findings prompted us to re-assess the contribution of COX activity to the systemic production of 8-epi-PGF_2α in man. We gave naproxen (1 g day⁻¹) to healthy subjects (four nonsmokers and four smokers). Urinary 8-epi-PGF_2α remained unchanged in the two groups (9.63±0.99 before vs 10.24±1.01 after and 20.14±3.00 vs 19.03±2.45 ng h⁻¹ 1.73 m⁻²), whereas there was a marked reduction of major urinary metabolites of thromboxane and prostacyclin (about 90% for both 11-dehydro-TXB₂ and 2,3-dinor-TXB₂; >50% for 2,3-dinor-6-keto-PGF_1α).
5. To investigate whether rat COX-1 produces 8-epi-PGF_2α more efficiently than human COX-1, we measured the ex vivo formation of 8-epi-PGF_2α and TXB₂ simultaneously in whole clotting blood. Serum levels of 8-epi-PGF_2α and TXB₂ were similar in rats and man.
6. We conclude that a significant amount of COX-dependent 8-epi-PGF_2α is present in rat but not in human urine under normal conditions. This implies that urinary 8-epi-PGF_2α cannot be used as an index of near-basal oxidant stress in rats. On the other hand, our data further confirm the validity of this marker in man.

     

Characterization of the Ca2+ responses evoked by ATP and other nucleotides in mammalian brain astrocytes

1. This study was aimed at characterizing ATP-induced rises in cytosolic free calcium ion, [Ca²⁺]_i, in a population of rat striatal astrocytes loaded with the fluorescent Ca²⁺ probe Fura2, by means of fluorescence spectrometry.
2. ATP triggered a fast and transient elevation of [Ca²⁺]_i in a concentration-dependent manner. The responses of the purine analogues 2-methylthio-ATP (2-meSATP), adenosine-5′-O-(2-thiodiphosphate) (ADPβS), as well as uridine-5′-triphosphate (UTP) resembled that of ATP, while α,β-methylene-ATP (α,β-meATP) and β,γ-methylene-ATP (β,γ-meATP) were totally ineffective.
3. Suramin (50 μM) had only a minor effect on the ATP response, whereas pyridoxal phosphate-6-azophenyl-2′,4′-disulphonic acid (PPADS) (5 μM) significantly depressed the maximum response.
4. Extracellular Ca²⁺ did not contribute to the observed [Ca²⁺]_i rise: removing calcium from the extracellular medium (with 1 mM EGTA) or blocking its influx by means of either Ni²⁺ (1 mM) or Mn²⁺ (1 mM) did not modify the nucleotide responses.
5. Furthermore, after preincubation with 10 μM thapsigargin, the nucleotide-evoked [Ca²⁺]_i increments were completely abolished. In contrast, 10 mM caffeine did not affect the responses, suggesting that thapsigargin-, but not caffeine/ryanodine-sensitive stores are involved.
6. Both application of the G-protein blocker guanosine-5′-O-(2-thiodiphosphate) (GDPβS) (1 mM) and preincubation with pertussis toxin (PTx) (350 ng ml⁻¹) partially inhibited the nucleotide-mediated responses. Moreover, the phospholipase C (PLC) inhibitor U-73122, but not its inactive stereoisomer U-73343 (5 μM), significantly reduced the ATP-evoked [Ca²⁺]_i rise.
7. In conclusion, our results suggest that, in rat striatal astrocytes, ATP-elicited elevation of [Ca²⁺]_i is due solely to release from intracellular stores and is mediated by a G-protein-linked P2Y receptor, partially sensitive to PTx and coupled to PLC.

     

Potential of Gene Therapy in Bone Marrow Transplantation

Gene therapy, initiated as a treatment for inherited disorders such as adenosine deaminase deficiency, is now a promising therapeutic strategy for malignancies and other acquired diseases. In particular, in the field of bone marrow transplantation (BMT) for haematological malignancies, the gene transfer of the suicide gene HSV-TK into donor lymphocytes allows control of the severe complication graft-versus-host disease (GvHD). The transfer of the HSV-TK suicide gene confers selective sensitivity to the drug ganciclovir, allowing in vivo elimination of the donor T-cells if severe GvHD occurs. In Italy, the first pilot study on delayed infusion of genetically engineered donor lymphocytes after T-depleted allogeneic BMT documented efficacy of engineered donor lymphocytes in terms of anti-tumour activity and efficiency of the suicide system. GvHD developed in 3 out of 8 patients and was successfully treated by ganciclovir administration.