Harmonic Potential Theorem: Extension to Spin-, Velocity-, and Density-Dependent Interactions.

One of the few exact results for the description of the time evolution of an inhomogeneous, interacting many-particle system is given by the harmonic potential theorem (HPT). The relevance of this theorem is that it sets a tight constraint on time-dependent many-body approximations. In this contribution, we show that the original formulation of the HPT is valid also for the case of spin-, velocity-, and density-dependent interactions. This result is completely general and relevant, among the rest, for nuclear structure theory both in the case of ab initio and of more phenomenological approaches. As an example, we report on a numerical implementation by testing the small-amplitude limit of the time-dependent Hartree-Fock-also known as the random phase approximation-for the translational frequencies of a neutron system trapped in a harmonic potential.

Nerve growth factor protects human keratinocytes from ultraviolet-B-induced apoptosis.

Ultraviolet radiation is a potent inducer of apoptosis, whereas autocrine nerve growth factor protects human keratinocytes from programmed cell death. To evaluate the role of nerve growth factor in the mechanisms of ultraviolet B-induced apoptosis, cultured human keratinocytes were ultraviolet B irradiated following pretreatment with K252, a specific inhibitor of the tyrosine kinase high-affinity nerve growth factor receptor. Here we report that the addition of K252 significantly enhanced keratinocyte apoptosis. We then transfected normal human keratinocytes with pNUT-hNGF. Nerve growth factor overexpressing keratinocytes secreted the highest amounts of nerve growth factor in culture supernatants, were more viable, and had a higher rate of proliferation than mock-transfected cells. Whereas ultraviolet B radiation downregulated nerve growth factor mRNA and protein as well as the tyrosine kinase high-affinity nerve growth factor receptor in normal keratinocytes, it failed to do so in nerve growth factor-transfected cells. Moreover, nerve growth factor overexpressing keratinocytes were partially resistant to apoptosis induced by increasing doses of ultraviolet B at 24 and 48 h. These results indicate that downregulation of nerve growth factor function plays an important part in the mechanisms of ultraviolet B-induced apoptosis in human keratinocytes. In addition, ultraviolet B caused a decrease in BCL-2 and BCL-xL expression in mock-transfected keratinocytes, but not in nerve growth factor overexpressing cells. Finally, nerve growth factor prevented the cleavage of the enzyme poly(ADP-ribose) polymerase induced in human keratinocytes by ultraviolet B. These results are consistent with a model whereby the autocrine nerve growth factor protects human keratinocytes from ultraviolet B-induced apoptosis by maintaining constant levels of BCL-2 and BCL-xL, which in turn might block caspase activation.

[Short-term study of proglumetacin]. / Studio a breve termine della proglumetacina.

Twenty-five patients with joint rheumatoid pain were treated as outpatients during 15 days with 450 mg/day fo proglumetacin. Efficacy was "good" or "very good" in 64% of the patients. No case of clinically significant side-effects was observed.

Targeting the human DEAD-box polypeptide 3 (DDX3) RNA helicase as a novel strategy to inhibit viral replication.

Compounds currently used for the treatment of HIV-1 Infections are targeted to viral proteins. However, the high intrinsic mutation and replication rates of HIV-1 often lead to the emergence of drug resistant strains and consequent therapeutic failure. On this basis, cellular cofactors represent attractive new targets for HIV-1 chemotherapy, since targeting a cellular factor that is required for viral replication should help to overcome the problem of viral resistance. We and others have recently reported the identification of compounds suppressing HIV-1 replication by targeting the cellular DEAD-box helicase DDX3. These results provide a proof-of-principle for the feasibility of blocking HIV-1 infection by rendering the host cell environment less favorable for the virus. The rationale for such an approach and its implications in potentially overcoming the problem of drug resistance related to drugs targeting viral proteins will be discussed in the context of the known cellular functions of the DEAD-box helicase DDX3.

The synovial plica syndrome of the knee. Pathology, differential diagnosis and treatment.

The authors describe the "Synovial Plica Syndrome", one of the lesser known and therefore often overlooked painful conditions of the knee. It is due to the persistence of remnants of the embryonic synovial septa which are normally innocuous but in certain circumstances (usually of mechanical origin) can undergo inflammatory changes resulting in fibrosis. This produces a clinical picture with characteristic and distinctive features. The anatomical and pathogenic aspects are described and the differential diagnosis and possible lines of treatment are discussed and illustrated. If the diagnosis is made early, the results of treatment are excellent.

Biochemical changes in the articular cartilage of the patella and femoral condyles in the lateral hyperpatellar syndrome.

The biochemical changes in the articular cartilage of the femoral condyles and the patella were studied during the earliest stage of patello-femoral arthrosis, with particular reference to chondromalacia of the patella in the "lateral hypertension syndrome", with the object of comparing them with the results obtained by Boni et al. (1977) in the initial phases of experimental arthrosis induced in rabbits by means of vitamin A. The biochemical determinations were done on samples of cartilage removed at operation from the medial and lateral femoral condyles and the medial and lateral patellar articular facets in ten patients. The biopsy samples were fixed in 80% alcohol and dried in the oven at 50 degrees C for twenty-four hours. The hexosamine and hydroxyproline content was then determined. This investigation demonstrated significant biochemical changes in this syndrome in the four areas examined. The data obtained indicate that only the mucopolysaccharide component of the joint cartilage is involved at this stage. The most interesting finding was marked diminution in the galactosamine/glucosamine ratio, which was markedly diminished - the opposite of what occurs in established arthrosis. These data appear to be identical with those found in the early phases of vitamin A induced arthrosis in experimental rabbits. The diminution of hexosamine content and the diminished galactosamine/glucosamine ratio were more marked in the femoral condyles, which appeared to have few lesions macroscopically. These changes were also present in both articular facets of patella, but were less marked, probably because the degeneration was more advanced in those areas, thus more closely resembling frank arthrosis.

The tarsal and calcaneal tunnel syndromes.

This paper concerns 22 cases of compression of the posterior tibial nerve and its branches in the tarsal and calcaneal tunnels, all of which were treated by surgical decompression. The evaluation of both the operative findings and the results after a follow-up period ranging from 4 months to 2 years confirms the validity of neurolysis and emphasizes the role of the abductor hallucis muscle in the compression of the terminal branches of the posterior tibial nerve in the calcaneal tunnel.

A comparison between conservative treatment and operative treatment (capsulosyndesmorrhaphy) in severe acute capsuloligamentous lateral lesions of the ankle joint.

The authors report 31 cases of acute severe capsuloligamentous lateral lesions of the ankle joint, 12 of which were treated surgically and 18 with a below knee plaster cast. An evaluation of the results at an average 20 months follow-up showed the superiority of the conservative method.