Design, synthesis, and conformational analysis of 3-cyclo-butylcarbamoyl hydantoins as novel hydrogen bond driven universal peptidomimetics.

A collection of systematically substituted 3-cyclo-butylcarbamoyl hydantoins was synthesized by a regioselective multicomponent domino process followed by easy coupling reactions. Calculations, NMR studies and X-ray analysis show that these scaffolds are able to project their side chains similar to common secondary structures, such as the α-helix and ß-turn, with favourable enthalpic and entropic profiles.

Synthesis, benzodiazepine receptor binding and molecular modelling of isochromeno[4,3-c]pyrazol-5(1H)-one derivatives.

A series of isochromeno[4,3-c]pyrazole-5(1H)-one derivatives 7b-h were prepared and tested at 10 µM for their ability to displace specific [(3)H]flunitrazepam from bovine brain membranes. The substitution pattern of the above derivatives was shown to influence the receptor affinity. The most active compound of the series was 7e, showing a 54% inhibition of [(3)H]flunitrazepam binding. Compounds 7a-d,i were compared with the known isomers chromeno[4,3-c]pyrazole-4(1H)-ones 14a-d,i, showing that the isochromene/chromene isomerism influences the activity.

Proprotein convertase subtilisin/kexin type 9 (PCSK9): from structure-function relation to therapeutic inhibition.

AIMS: This short review aims at summarizing the current information on Proprotein Convertase Subtilisin/Kexin type 9 (PCSK9) structure and function focusing also on the therapeutic possibilities based on the inhibition of this protein. DATA SYNTHESIS: PCSK9 has been recently discovered as the third gene involved in autosomal dominant hypercholesterolemia. PCSK9 binds and favors degradation of the low-density lipoprotein receptor (LDLR) and thereby modulates the plasma levels of LDL-cholesterol (LDL-C). Some of the natural occurring PCSK9 mutations increase the protein function (gain of function) and cause hypercholesterolemia, whereas loss of function mutations associate with hypocholesterolemia. Since the loss of a functional PCSK9 in humans is not associated with apparent deleterious effects, this protease is an attractive target for the development of lowering plasma LDL-C agents, either alone or in combination with statins. CONCLUSION: Inhibition of PCSK9 is emerging as a novel strategy for the treatment of hypercholesterolemia and data obtained from pre-clinical studies show that use of monoclonal antibodies, antisense oligonucleotides and short interfering RNA are effective in reducing LDL-C, clinical studies, accompanied by a better understanding of PCSK9 biology, are now necessary to address whether these new compounds will have a future in clinical practice.

Structure of S35C flavodoxin mutant from Desulfovibrio vulgaris in the semiquinone state.

The crystallographic structure of an engineered flavodoxin mutant from Desulfovibrio vulgaris has been analysed. Site-directed mutagenesis was used to substitute serine 35 with a cysteine to provide a possible covalent linkage. The crystal structure of the semiquinone form of this mutant is similar to the corresponding oxidation state of the wild-type flavodoxin. Analysis of the structural changes reveals the interaction between N(5)H of the flavin and the carbonyl O atom of Gly61 to be critical for modulation of the electrochemical properties of the protein.

Structural characterization of a dipeptide compound with immunostimulant activity: 3-(5-thioxo-L-prolyl)-L-thiazolidine-4-carboxylic acid.

The structural characteristics of an immunostimulating agent (3-(5-thioxo-L-prolyl)-L-thiazolidine-4-carboxylic acid) have been established using a combination of 1H and 13C NMR spectroscopy, molecular mechanic calculations (in vacuo and in solution) and X-ray crystallographic analyses. Conformational calculations and NMR spectra identify two classes of conformers, cis and trans, around the peptide bond between the rings, while in the solid state only the cis form has been found.

Field application of lysosomal destabilisation indices in the mussel Mytilus galloprovincialis: biomonitoring and transplantation in the Lagoon of Venice (north-east Italy).

A field study was carried out in the Lagoon of Venice (north-east Italy) with the aim of evaluating the potential use of lysosomal destabilisation as a biomarker of anthropogenic stress in the autochthonous mussel Mytilus galloprovincialis. Two different approaches were adopted in biomonitoring six sites in the Lagoon, evaluating indigenous populations of mussels and organisms transplanted from a reference site and checked at several points in time. Lysosomal membrane stability was investigated by means of two tests: neutral red retention assay (NRRA) for evaluating haemocyte lysosomes and lysosomal latency test (LLT) for digestive cell lysosomes. Results indicate that the lysosomal response measured in haemocytes according to NRRA is a more valuable biomarker of anthropogenic stress in the framework both of passive and active biomonitoring in marine coastal environments.

Mediastinitis due to cryptococcal infection: a new clinical entity in the HAART era.

OBJECTIVES: Highly active antiretroviral therapy (HAART) produces a rapid decline in plasma HIV-1 RNA levels with concomitant immune reconstitution. Probably due to the enhanced immune function, shortly after starting HAART, some latent opportunistic infections precipitated. The aim of this study was to illustrate the results of a survey on Cryptococcus associated mediastinitis occurring after HAART introduction, carried out at a referral centre of Infectious Diseases in the north-east of Italy, between October 1999 and October 2000. METHODS: All consecutive HIV-positive patients, naive to HIV-protease inhibitor therapy, and diagnosed with culture-proven cryptococcal infection were included in the study. Clinical and immuno-virological parameters before HAART and subsequently for 12 months were evaluated. RESULTS: Three of five patients were diagnosed with cryptococcal mediastinitis within a median time of 90 days (range, 60-150) after commencing HAART and fluconazole prophylaxis. Diagnosis was established by lymph node biopsy alone. Clinical improvement was documented when systemic anti-fungal therapy was combined with surgical drainage of the suppurative lesions. The role of immune restoration was confirmed by the significant increase in CD4 cell count, the reduction of HIV-RNA to undetectable levels and the prominent inflammatory reactions of lymph nodes. CONCLUSIONS: Our report suggests that HIV-positive patients with prior cryptococcal systemic infection may present a re-exacerbation of atypical cryptococcosis as a manifestation of immune restoration, even when fluconazole prophylaxis is ongoing.

[Occupational injuries with biological risk at a hospital]. / Infortuni occupazionali a rischio biologico in un'Azienda Ospedaliera.

A ten years retrospective study was carried out among the personnel of Padua Hospital to determine the rate of occupational exposure to blood and body fluids. 4738 injuries occurred between 1990 and 1999: 78% were percutaneous injuries 22% blood contacts. No case of operating room transmission of blood-borne infection was documented but it is clear that the risk is not zero and the number of injuries indicate the need for further training and reinforcement of universal precautions to reduce occupational exposures.

Acquired immunodeficiency syndrome-related Kaposi's sarcoma regression after highly active antiretroviral therapy: biologic correlates of clinical outcome.

BACKGROUND: Kaposi's sarcoma (KS) is the most common cancer seen in subjects with acquired immunodeficiency syndrome (AIDS). KS etiology and pathogenesis are still ill defined, and no definite improvement in survival has been obtained with current chemotherapeutic regimens. This open prospective study was aimed at evaluating the clinical response of AIDS-related KS to highly active antiretroviral therapy (HAART), a combination of protease and reverse transcriptase inhibitors, as well as the relationship between clinical response, human immunodeficiency virus type 1 (HIV-1) burden, and antibody titer against human herpesvirus 8 (HHV8) proteins. PATIENTS AND METHODS: Fourteen KS patients were studied; 12 were in the poor-risk group. At given intervals, the patients underwent clinical examination, and their CD4(+) cell counts, plasma HIV-1 RNA levels, and antibody titers to lytic-phase ORF65 and latent-phase HHV8 proteins were determined. RESULTS: When last seen, the overall clinical response rate was 86% (median follow-up, 22 months); 10 complete and two partial responses were achieved, and two patients showed disease progression. All patients with complete or partial response showed a consistent decrease in HIV-1 RNA levels, with a corresponding increase in CD4(+) cell counts; HIV-1 RNA levels in the two progressors remained persistently high, despite a change in HAART. HHV8 ORF65 antibody titers were generally higher in patients with extensive skin or mucosal/visceral involvement versus patients with limited disease; no differences in latent-phase HHV8 antibody titers were observed in relation to tumor burden. CONCLUSION: The findings indicate that antiretroviral therapy with protease inhibitors is effective for AIDS-related KS; the clinical response was correlated with a decrease in plasma HIV-1 RNA levels and an increase in CD4(+) lymphocytes, whereas antibody levels to the lytic-phase HHV8 protein were influenced by the extent of tumor involvement.

Toxic epidermal necrolysis induced by nevirapine therapy: description of two cases and review of the literature.

We describe two cases of toxic epidermal necrolysis developed during an antiretroviral therapy regimen containing nevirapine. It seems likely that the poor adherence to the dose escalation regimen of nevirapine has caused this life-threatening disease. A complete and written information on the scheduled antiretroviral therapy is mandatory, above all for individuals coming from developing countries where language barriers have not yet been successfully overcome.

Leuconostoc species: a case-cluster hospital infection.

Leuconostoc species are members of the Streptococcacae family. They are generally regarded as non-pathogenic culture contaminants and are thought to be an uncommon cause of infection. We present a study of a case-cluster nosocomial infection due to Leuconostoc spp. Three patients were hospitalized at the time of the infection with significant underlying diseases and all had a compromised skin and mucous barriers. Two had received previous antibiotic therapy. This report highlights the importance of Leuconostoc spp. as an emerging pathogen, even though the modes of transmission and reservoirs of Leuconostoc spp. are as yet unknown.

Chemo-immunotherapy of advanced AIDS-related Kaposi's sarcoma.

AIMS AND BACKGROUND: Kaposi's sarcoma (KS) is the most common neoplastic complication of HIV infection and AIDS. Multiple cytotoxic chemotherapy regimens have been used with various response rates. We have evaluated the efficacy and toxicity of low-dose chemotherapy in patients with poor-prognosis AIDS-related KS and the role of interferon alpha (IFN-alpha) in complete responders. METHODS: Twenty-five previously untreated patients with advanced KS received bleomycin (BL) 10 mg/m2 and vinblastine (VB) 6 mg/m2 on days 1 and 15 every two weeks. After six cycles, patients in complete remission received IFN-alpha (3 million U s.c. 3 times/week) combined with antiretroviral therapy. All patients were evaluated for toxicity using the World Health Organization (WHO) toxicity schedule. Both Eastern Cooperative Oncology Group (ECOG) and AIDS Clinical Trials Group (ACTG) response criteria were used to evaluate response and survival. RESULTS: The overall response rate was 84% (95% confidence interval, 51-117%) with six complete remissions (24%) and 15 partial remissions (60%) by ECOG criteria, and 92% (95% confidence interval: 58-128%) with 17 partial remissions (68%) by ACTG criteria. The median duration of response on IFN-alpha treatment was 4.5 months (range, 2-10). The overall median survival duration for all 25 patients was 9 months (range 2-39). Grade 3-4 anemia was observed in five patients and grade 3-4 neutropenia in two patients. No other clinically significant (> or = grade 3) toxicities were observed. CONCLUSIONS: Combination of BL and VB is effective and well tolerated, even if new therapeutic options are developing. This disease remains a challenging problem, so larger studies using the combination of chemotherapy and/or IFN-alpha with antiretroviral treatment are warranted.

Regression of AIDS-related Kaposi's sarcoma following antiretroviral therapy with protease inhibitors: biological correlates of clinical outcome.

The clinical response of AIDS-related Kaposi's sarcoma (KS) to highly active antiretroviral therapy (HAART), a combination of human immunodeficiency virus type 1 (HIV-1) protease and reverse transcriptase inhibitors, was studied in 11 patients, all but one with progressive KS. CD4+ cell counts, plasma HIV-1 RNA levels, and antibody titres to lytic ORF65 and latency-associated human herpes virus type 8 (HHV-8) proteins were determined in sequential samples. Six complete and three partial clinical responses were achieved in a median time of 6 and 3 months, respectively, and confirmed after a median time of 16 months on HAART. 2 patients showed disease progression. A consistent decrease in HIV-1 RNA levels, paralleled by an increase in CD4+ cell counts, was observed in all patients who showed complete or partial clinical response; HIV-1 RNA levels remained persistently high in the two patients who progressed, despite a change in HAART. HHV-8 antibody titres were generally higher in patients with mucosal/visceral involvement compared with patients with limited disease; a decrease in ORF65 antibody titre was significantly associated with a clinical response. These results indicate that HAART is effective for AIDS-related KS; the clinical response correlates with a decrease in plasma HIV-1 RNA levels, an increase in CD4+ lymphocytes, and a decrease in antibodies to ORF65 HHV-8 protein.

Transient tonic pupils in botulism type B.

We report a 29-year-old woman who developed unilateral unreactive mydriasis and cycloplegia after 5 days of persistent constipation. During the next hours the patient complained of dry mouth and difficulties in swallowing food; iris and ciliary muscle palsies spread over the second eye. Ocular motility was normal and there were no clinical signs of neuromuscular involvement. Conventional electromyography and evoked muscle action potentials following repetitive nerve stimulation were normal; single-fiber electromyography showed normal jitter and absence of blocking. The diagnosis of botulism was considered as most likely, and the patient was given botulinum antitoxin. The post-treatment course was characterized by bilateral tonic pupillary reaction to near, sectoral iris contractions to light and pupillary constriction to 2 mm in 40 min following topical instillation of 0.1% pilocarpine. Ocular manifestations completely disappeared within 5 weeks. Botulism type B toxin was demonstrated in the pretreatment stool of the patient but not the serum.

Epidemiology of hepatitis A in northern Italy: a seven-year survey.

During a seven-year survey of acute symptomatic viral hepatitis in Padua (Northern Italy), the epidemiological features of hepatitis A were evaluated in 207 consecutive patients (120 males, mean age 22.7 +/- 11.4 years). The annual attack rate of the disease decreased significantly (p less than 0.05) between 1978 and 1979 (0.11/1000 inhabitants) and 1981 and 1984 (0.04-0.03/1000 inhabitants), mainly due to its declining prevalence in the pediatric age. In parallel with the shifting of hepatitis A towards adulthood, single sources of infection, mainly associated with adult life-style such as foreign travel and raw shellfish ingestion, have become more and more prominent. The spread of drug abuse has not influenced the epidemiology of hepatitis A in our area.

Epidemiological aspects on acute viral hepatitis in northern Italy.

Incidence and epidemiological features of acute hepatitis types A, B and non-A non-B have been evaluated in 332 consecutive patients hospitalized in Padova, Italy. Hepatitis B was diagnosed in 59% of cases and was frequently related to drug addition, health care work and household contact with HBsAg-positive subjects. Hepatitis A represented 22% of cases and its peak incidence occurred in the second decade. Non-A non-B hepatitis affected 15% of patients including not only transfusion or drug related forms, but also sporadic cases that prevailed among elderly women.

Clinical-electroencephalographic correlations in measles: a long range study of 18 subjects.

EEGs of 18 cases of measles (uncomplicated, with seizures, with encephalitides) were obtained through an underground cable connection between the Infections Diseases Department and the EEG unit. The varions EEG features of the disease have been studied during the evolution of the illness. An occasional EEG does not offer specific information on either the severity or the evolution of the disease. Marked EEG abnormalities appeared in the encephalitic group. The Authors emphasize the importance of serial prolonged EEG follow-up of measles in order to define precisely the stage and the evolution of the disease.