Presence of multiple HIV type 1 subtypes among mothers and children in Japan.

We collected blood samples from 70 HIV-1-infected pregnant women and 76 babies born to HIV-1-infected women in Japan, from 1989 to 1999. To analyze the genetic diversity of HIV-1 among mothers and children, we sequenced the C2-V3 regions of HIV-1 gp120. Phylogenetic tree analysis of these regions revealed that multiple HIV-1 subtypes, A, B, D, E, and G, were circulating among mothers and children in Japan. Thus, the genetic heterogeneity of HIV-1 among mothers and children in Japan is steadily increasing, although the number of cases remains small. Perhaps the longest term survivor, an 11-year-old child with a vertical HIV-1 subtype G infection in Japan, is one of our subjects.

Three siblings of fatal infantile encephalopathy with olivopontocerebellar hypoplasia and microcephaly.

We report three male siblings born with fatal encephalopathy comprising microcephaly, myoclonus and muscle hypertonia. All three patients died during infancy. Postmortem examination on the brain revealed that all infants had neuronal loss in the cerebellar cortex, inferior olivary and pontine nuclei, which were more pronounced in the older subject than the younger ones. In addition, they were associated with polymicrogyria in the cerebral cortex of the insula, olivary and dentate nuclear dysplasia, and a hypoplastic corticospinal tract. The clinical and neuropathological findings in our cases were identical to those in fatal infantile encephalopathy with olivopontocerebellar hypoplasia and microencephaly [Albrecht et al., Acta Neuropathol 1993;85:394-399], but an association of malformations suggests a new genetic factor in pathogenesis of olivopontocerebellar hypoplasia.

[Pharmacokinetic, bacteriological and clinical studies on cefozopran in neonates].

The efficacy, safety and pharmacokinetics of cefozopran (CZOP) were evaluated in neonates and the following results were obtained: 1. Of the 12 patients treated with CZOP, judgment of clinical efficacy was evaluable in 10 patients (including 5 with pneumonia and 3 with urinary tract infections). The treatment was effective and the causative organism was eradicated in 100% of the patients. 2. No adverse signs and symptoms were recognized during the treatment with CZOP. A slight elevation of direct bilirubin was recognized as an abnormal alteration of laboratory test values in one patient. The value, however, returned to the normal range after the completion of treatment. 3. The pharmacokinetic evaluation was made in 3 of the 12 patients. The blood CZOP levels were recognized in proportion with the dosages. The elimination half lives (T 1/2) in those patients were 8.92, 2.90 and 2.76 hours. Prolongation of T 1/2 was recognized in the patient aged 0 day. It was possible to examine the urinary excretion only in one patient aged 18 days. The excretion rate of the drug was 68.6% of dose by 8 hours after administration. These results suggest that CZOP is a drug useful for treatment of infections in neonates as well, with high efficacy and safety.

[Pharmacokinetic, bacteriological and clinical studies on cefozopran in neonates and premature infants. A study of cefozopran in the perinatal co-research group].

The following results were obtained in pharmacokinetic, bacteriological and clinical investigations of a cephem antibiotic for injection, cefozopran (SCE-2787, CZOP), administered to neonates and premature infants. 1. Pharmacokinetics (1) Half-lives (T 1/2's) of CZOP in 0-day-old (less than 24 hours after birth) neonates and premature infants were longer than those in 1-day-old or older infants. When half-lives were compared between 0-day-old neonates and 0-day-old premature infants, longer half-lives were observed in premature infants. (2) When CZOP was intravenously administered to 1-day-old or older neonates and premature infants at a dose of 20 mg/kg, no differences were noted in blood concentrations between neonates and premature infants from 30 minutes to 6 hours after administration as well as T 1/2's. (3) Blood concentration of CZOP administered at doses of 10, 20 and 40 mg/kg were dose-dependent. (4) Urine excretion rates of CZOP administered to 1-day-old or older neonates and premature infants were approximately 30 to 60% in the first 6 hours after administration. Urine excretion rates in 0-day-old neonates and premature infants were low. 2. Clinical results (1) Of a total of 136 cases to which CZOP was administered, clinical efficacy evaluation was possible in 96 cases, and safety evaluation in 132 cases. (2) The clinical efficacy rates were 78.6% (22/28) in 28 cases in which causative organisms were detected (Group A), and 97.1% (66/68) in 68 cases in which no such organisms were detected (Group B), with the total efficacy rate (Groups A and B) of as high as 91.7% (88/96). (3) Bacteriological evaluations were made with 33 strains isolated from the 28 cases of Group A. Elimination rates for Gram-positive and Gram-negative bacteria were 88.2% (15/17) and 92.3% (12/13), respectively, with the total elimination rate of 90.0% (27/30). No microbial substitution was noted. (4) As an adverse reaction, diarrhea was noted in one case (0.8%). Abnormal laboratory test values were noted in 15 cases (12.3%) including eosinophilia, elevated GPT, and elevated gamma-GTP. All of these abnormalities were transitory, and none of them critical. As a result of above pharmacokinetic and clinical investigations, CZOP is considered to be highly useful in the treatment of indicated infections in neonates and premature infants. It appears that 20 mg/kg of CZOP can be administered by intravenous injection or intravenous drip infusion to neonates and premature infants aged 0-day (less than 24 hours after birth) once or twice daily, to those aged 1 (24 or more hours after birth) to 7 days twice or three times daily, and to those aged 8 or more days three to four times daily, and that the dose can be increased up to 40 mg/kg in cases of critical or intractable infections.

[Regulation of T cell antigen receptor alpha chain gene expression].

A T cell antigen receptor (TcR) gene is considered to be a model system for studies of developmentally-regulated, lineage-specific gene expression. For the TcR alpha gene expression, it has been shown that the enhancer region located at 3.0 kb in mouse or 4.5 kb in human downstream of TcR C alpha gene is essential. The enchancer is demonstrated to contain at least four nuclear protein binding sites called T alpha 1-T alpha 4. In this report, we analysed the molecular requirement for murine TcR alpha gene enhancer function by using in vitro mutagenesis system and CAT assay, and obtained the following results: 1. The T alpha 2 element, especially ACATCC sequence, is important for enhancer activity, because the mutation in the sequence completely abolished the activity. 2. The sequence TCTGG near by the ACATCC sequence seems also important for the enhancer function, since the mutation lost the half of the activity. 3. The ets1, which is known to bind the ACATCC site, upregulates the enhancer activity of the reporter gene containing the concatemers of T alpha 2 region. The results indicate that ets1 has a trans-activating activity to the T alpha 2 region of TcR alpha chain enhancer.

Monoclonal antibody against murine T cell receptor V alpha 14 cross-reacts with human CD3 epsilon and detects disulfide-linked dimeric form.

A monoclonal antibody against V14+ alpha-chain of murine T cell receptor (TCR) was established by fusing spleen cells from a rat immunized with a soluble chimeric TCR/IgG3 protein containing murine TCR V alpha 14J alpha 281 in place of the VHDHJH of an IgG3. lambda 1, and subjected to screening on a human transfectant (Jurkat variant) expressing the murine V14J281 alpha-chain. The anti-mouse V alpha 14 antibody precipitated TCR alpha beta molecules from Triton X-100-solubilized extracts of 125I-labeled murine thymocytes and spleen cells. Unexpectedly, the antibody showed cross-reactivity to the human CD3 epsilon molecule and detected a disulfide-linked 20 kDa dimeric form of human CD3 epsilon, which is a novel family component of the CD3 complex and is associated closely with the CD3 zeta-zeta homodimer as well as TCR alpha beta or TCR gamma delta.

Autoreactive T-cell clones which suppress cytotoxic T cell responses.

Autoreactive T-cell clones (Thy 1+, CD4+, CD3+) which suppress generation of cytotoxic T lymphocytes (CTL) were established in long-term in vitro culture by stimulation with GM3-liposomes or soluble melanoma (B16) antigen composed of GM3. The T-cell receptors (TCR) of two representative clones analyzed used the same TCR alpha- and V13+ beta-chains. The clones produce only interferon gamma(IFN-gamma) but not interleukins (IL)2 and 4, despite their CD4+ phenotype, suggesting that they are not a typical TH1 or TH2 type. The clones are effectively stimulated by IFN-gamma treated (I-Ab/GM3+) B16 melanoma or I-Ab-transfected GM3+ L cells, but not by GM3-/I-Ab mutant melanoma, EL 4, or I-Ad/k-transfected L cells. This strongly suggested the involvement of GM3/class II in T-cell recognition. Antigen specificity was required for stimulation of the clones. However, once stimulated, they suppressed CTL generation in an antigen non-specific fashion. As class II+ B16 melanoma cells effectively function as antigen-presenting cells to stimulate the autoreactive suppressor T cell (Ts) clones of this type, this negative circuit between class II+ tumor cells and IFN-gamma-producing Ts would be a possible mechanism whereby tumor cells could escape the immune system.