Nucleotide sequence of a cloned hepatitis B virus genome, subtype ayr: comparison with genomes of the other three subtypes

The entire nucleotide sequence of genomic DNA was determined for hepatitis B virus (HBV) of subtype ayr, which had been derived from the blood of a Japanese asymptomatic carrier. The genome was 3215 nucleotides long, and differed in DNA sequence by 10% from that of subtypes adw or ayw, but by only 2% from that of subtype adr. Amino acid sequences coded for by the S, C, P and X genes, as well as by the pre-S region, closely resembled those of subtype adr, indicating that the evolution of HBV/ayr from HBV/adr was more recent than the differentiation of the other three subtypes. In the product of the S gene, the mutually exclusive subtypic determinants of the surface antigen, d and y, were associated with variation of amino acid residues at only the 68th and 122nd positions from the N terminus, in contrast to the variation at as many as seven positions for the other set of subtypic determinants, w and r. Sequences representing high local hydrophilicity in the product of the S gene were involved in subtypic variation, although such sequences in the pre-S region were shared by HBV genomes of the various subtypes. In particular, a hydrophilic sequence of 19 amino acid residues, coded for by the pre-S(2) region and implicated in the presumed hepatotropism of HBV, was possessed in common by HBV/adr, HBV/ayr and HBV/ayw, and differed in HBV/adw by only one residue at the 9th position. This amino acid sequence appears to be a promising candidate for a synthetic peptide vaccine.

[Concentrations of cefmenoxime in human bone marrow blood and osseous tissue]

One gram of cefmenoxime (CMX) was administered to each of 10 patients by a one shot intravenous injection at the beginning of surgery. At 30, 60, 90, 120 minutes after the administration, concentrations of CMX in venous blood, bone marrow blood and bone tissue were assayed by the agar-well method. CMX was smoothly transmigrated after the injection from venous blood to bone marrow blood and bone tissue, and effective concentrations higher than MIC80 values were maintained for several hours. CMX, therefore, appears to be a useful drug for the prophylaxis and the treatment of postoperative infections.

Color functional images of the cerebral blood flow

Functional gamma imaging, in color, was established for regional cerebral blood flow (rCBF) using 133Xe. During 10 min after intracarotid injection of 133Xe in saline, 60 picture frames of the 133Xe clearance curve for the entire hemisphere were obtained. After nine-point smoothing, the rCBF for each of the 4,096 picture elements was calculated by two methods: the half-time method and the height-over-area method. Both the 133Xe clearance half-times and the calculated CBF values were displayed, using 13 steps of color, as functional CBF images of the brain. Images of peak count and total count were also displayed on the same frame of the color television. Forty-six studies, performed on 37 patients with various cerebral disorders, were divided into two types: diffuse and focal. In the diffuse type, a decrease in CBF was noted in cases of normal-pressure hydrocephalus; successful ventriculoperitoneal shunt operations were followed by recovery of CBF. Occlusion of the middle cerebral artery showed up as a wedge-shaped area of decreased CBF, even when the conventional brain scan looked normal. Increased perfusion to a tumor was frequently associated with decreased CBF in the rest of the lateral hemisphere; such a decrease could be improved by surgical removal of the tumor.

[Regional cerebral blood flow in senile patients with meningiomas (author's transl)]

We investigated the regional cerebral blood flow of 4 meningioma patients who were all of ages over 60 years old. The average age of the patients was 68 years. Cerebral blood flow was determined by the 133Xe clearance method of Lassen and Ingvar. By extra-cranial recording of the radioactivity from the freely diffusible inert gas 133Xe, which dissolved in saline, was injected into the internal carotid artery, a clearance curve was obtained from the cerebral hemisphere. This curve could be resolved into two monoexponential clearance functions that corresponed to the flow in the grey and white matter. Graphical analysis of the original curve allowed the estimation of the relative weight of these two tissue components as well as of the mean cerebral blood flow. In three patients, regional cerebral blood flow was measured both pre- and post-operatively and these values were compared. Focal rCBF disturbances could be detected in agreement with the tumor location as verified directly or by other diagnostic procedures. That is, a relative hyperemia was detected at the areas corresponding to the tumor site. Mean fg (the flow in the grey matter) of four patients was 77.3 +/- 14.0 ml/100 g/min on the tumor areas, 48.1 +/- 6.6 ml/100 g/min on the peritumoral regions, 63.1+/- 4.1 ml/100 g/min on the non-tumoral regions. CBFr (average cerebral blood flow) of non-tumoral areas in the four patient was 36.6 +/- 2.4 ml/100 g/min and that of the peri-tumoral area, 33.1 +/- 7.9 ml/100g/min. These figures are moderately smaller than that of the normal one. A comparison between the neurological features and regional flow values noted in patients who had a removal of menigiomas indicated that the flow values of non-tumoral area increased markedly a month after operation, instead of only slight or no improvement in neurological features. Although our cases with rCBF studies are still too few to warrant conclusions, it seems that post-operative follow-up of mean cerebral blood flow changes might be rather greater help in the assessment of prognosis after operation of meningiomas than fg (the flow in the grey matter).