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The PCR technique was applied to the diagnosis of tuberculosis in live cattle, and both skin-test-negative and skin-test-positive animals were studied. DNA was taken from various sources including specimens of lymph node aspirates, milk, and nasal swabs. After slaughter and visual inspection, tissues such as lymph nodes, lungs, and udders from tuberculin reactors were tested by the same technique. Specific oligonucleotide primers internal to the IS6110 insertion element were used to amplify a 580-bp fragment. A 182-bp fragment was obtained by designating a nested PCR from the first amplification product. This fragment was cloned and sequenced, and after being labeled it was employed in dot blot hybridization. A total of 100 cattle were tested, and PCR analysis was performed using nasal swab, milk, and lymph node aspirate. Sixty skin-test-positive cows were also tested to detect mycobacterial DNA in tissue samples from lymph nodes, lungs, and udders, and the infection was confirmed in all of the animals. Using PCR analysis of tissue samples from slaughtered animals as a "gold standard" we calculated 100% values for sensitivity, specificity, and positive and negative predictive values for milk and lymph node aspirate samples. The respective values for nasal swab samples were 58, 100, 100, and 28%. The respective values for all of the samples were 74, 100, 100, and 35%, while for visual inspection the values were 81, 100, 100, and 58%, respectively. PCR analysis of specimens of lymph node aspirates, milk, and nasal swabs from skin-test-negative animals showed that 52% of these skin test results were false negatives. These animals, not being removed from the farms, represent a potential source of further infection.

An antiserum against a hsp of the 70-kDa family was prepared, by means of a fusion protein, which was able to detect a constitutive 75-kDa hsc in the sea urchin P. lividus. This hsc was present both during oogenesis and at all developmental stages. A two-dimensional electrophoresis has revealed four isolectric forms of this 75-kDa hsc. The amino acid sequence of the fragment used to prepare the anti-hsp70 antibodies revealed a 43% identity with the corresponding part of sea urchin sperm receptor, and in mature eggs a brighter immunofluorescence was seen all around the cell cortex where the receptor for sea urchin sperm is localized. In oocytes the hsp75 was localized in the cytoplasms but not in the nuclei. In the embryos a higher hsp75 concentration was found in the portion facing the lumen of the cells which invaginate at gastrulation.

Adenine arabinoside monophosphate (ara-AMP) is a potent antiviral agent against hepadnaviruses but its use in the treatment of chronic hepatitis B is hampered by severe neurotoxic side effects, which are dose dependent. In order to reduce these adverse reactions and to adopt the lysosomotropic approach to antiviral chemotherapy, ara-AMP was coupled to lactosaminated human serum albumin (L-HSA), a neoglycoprotein which specifically penetrates hepatocytes. In mice with Ectromelia virus hepatitis, ara-AMP coupled with L-HSA was selectively delivered to liver cells in which it was released in a pharmacologically active form. Moreover in woodchucks with WHV hepatitis and in patients with chronic HBV infection, coupled ara-AMP inhibited hepadnavirus replication at a dose (1.5 mg/kg/day) 3-6 times lower than the free drug. A clinical study using a 28-day period of treatment with conjugated ara-AMP at 1.5 mg/kg/day has now been started. In the first 6 patients the treatment has been completed. The conjugate inhibited virus growth without producing any side effects. L-HSA-ara-AMP conjugate must be given by intravenous infusion. New hepatotropic conjugates of ara-AMP have been recently prepared which could be administered by bolus intravenous injection or by intramuscular route. These complexes might assure a better compliance in patients with hepatitis B virus infection for a long lasting liver targeted antiviral treatment.

Background: Anti-hepatitis e antigen-positive chronic hepatitis B is a progressive liver disease associated with precore mutant hepatitis B virus (HBV) and poor response to interferon. Therefore, precore mutant HBV may behave as an interferon-resistant virus. The relations between the prevalences of wild-type and precore mutant HBVs in baseline viremias and response to interferon were analyzed., Methods: Sera from 115 patients (59 treated and 56 untreated, followed up for 30 months) were tested using a quantitative oligonucleotide hybridization assay., Results: Spontaneous or interferon-induced recoveries were observed in 28.5% (6 of 21) and 47.3% (18 of 38) or in 0% (0 of 35) and 19% (4 of 21) of the patients with wild-type prevalent or mutant prevalent HBVs, respectively. Relapses occurred in 85.7% (12 of 14) and 19.4% (4 of 21) of treated patients with prevalent precore mutant and prevalent wild-type HBV, respectively (P = 0.0001). High precore mutant HBV levels (> 20% of total viremia) were associated with the lack of permanent response to interferon (P = 0.01)., Conclusions: Precore mutant HBV can influence the response to interferon when it reaches significant serum levels (> 20% of total viremia). Therefore, chronic hepatitis B should be treated as early as possible in its natural history before precore mutant HBV is selected as a prevalent virus.

A patient with Corrected Transposition of the Great Arteries (CTGA), mild incompetence of left A-V valve, complete atrioventricular block without associated anatomic lesions, in whom a bicameral permanent pace maker has been implanted, is described. The procedure of implantation did not present any particular problem; the stability of the electrocatheters was good. The exercise tolerance with DDD mode stimulation was normal and definitively better as compared to that achieved with ventricular stimulation at progressively higher stimulation frequency. The patient is now well and attending a normal physical activity.