An experimental study on direct revascularization of bronchial circulation by microvascular anastomosis.

The effects of direct revascularization of the bronchial artery after bronchoplasty were estimated by laser Doppler velocimetry and india ink injection in dogs. Bronchoplastic surgery at the right main bronchus was performed in all dogs, and the bronchial artery was reconstructed using the internal thoracic artery in the reconstruction group. The mucosal blood flow was measured at the distal side of the anastomosis. India ink was injected into the aorta in the nonreconstruction group and into the internal thoracic artery in the reconstruction group. The peripheral blood flow had diminished immediately after surgeries to 59% of the baseline value and took 14 days to recover to the baseline value in the nonreconstruction group. However, in the reconstruction group, the blood flow recovered at once to 78% of the baseline value and had returned to that value in 5 days. Statistically significant differences were noted between the groups from just after operation to day 7. India ink data confirmed these findings. In the nonreconstruction group, no ink was observed in the peripheral bronchial vessels on day 3; it was noted in part of the vessels on day 7 and in most on day 14. On the other hand, a relatively large number of vessels were stained just after operation in the reconstruction group. Thus reconstruction of the bronchial artery by means of the anastomosis with the internal thoracic artery can be said to be a useful and effective method for preventing airway ischemia.     

Gallium scintigraphy in patients with adult T-cell leukemia lymphoma

Gallium scintigraphy was evaluated in 25 patients with adult T-cell leukemia lymphoma (ATLL). Anterior and posterior images were obtained at 72 h after administration of 3 mCi ⁶⁷Ga-citrate using a gamma camera (Maxi-Camera 400T, General Electric Co.) with a medium energy standard parallel hole collimator. Abnormally high accumulations were observed in 17 out of 25 cases (superficial lymph node, 8; hilar and mediastinal lymph node, 7; paraaortic lymph node, 2; lung, 9; liver, 1; bone, 1). There were 10 malignant lesions detected by ⁶⁷Ga scintigraphy in 9 out of 17 cases (superficial lymph node, 1; hilar and mediastinal lymph node, 6; paraaortic lymph node, 1; liver, 1; bone, 1). White blood cell count and serum LDH levels were raised in patients with abnormally high accumulations of ⁶⁷Ga. In conclusion, ⁶⁷Ga scintigraphy seemed to be a useful examination to detect malignant lesions in patients with ATLL.     

Metabolism of 99mTc-ethyl cysteinate dimer (99mTc-ECD) in blood--mainly in vitro]

Metabolism of 99mTc-ethyl cysteinate dimer (99mTc-ECD) in blood was studied mainly in vitro. When 99mTc-ECD was mixed with blood taken from 12 subjects, the octanol extraction ratio of ECD (y) decreased rapidly and the octanol extraction ratio-time profile well fitted a monoexponential curve (y = Ae-kt/1000, A, k: constant, t: time after mixing). The k value and hematocrit (Ht) were significantly correlated (k = 0.376Ht-3.27, r = 0.897, p less than 0.001), therefore, it was suggested that the majority of the enzyme which dissolves ECD exists in red blood cells. When ECD was mixed with blood, there were more hydrophilic products of ECD in plasma than those generated by the enzyme in plasma. In vivo input function of 99mTc-ECD was calculated by arterial blood sampling and octanol extraction. The duration of effective input was relatively short, which was attributed to rapid decrease of octanol extraction ratio in vivo.     

Effects of inhibitors of protein kinase C and Na+/H+ exchange on alpha 1-adrenoceptor-mediated inotropic responses in the rat left ventricular papillary muscle.

1. Alpha 1-adrenoceptor stimulation of rat left ventricular papillary muscle produced a triphasic inotropic response: an initial transient positive inotropic effect (PIE) followed by a transient negative inotropic effect (NIE) and a sustained PIE. 2. The protein kinase C inhibitor, staurosporine, at concentrations ranging from 30 nM to 100 nM inhibited the sustained PIE, but had no significant effect on the transient PIE and NIE. 3. H-7, 1-(5-isoquinoline sulphonyl)-2-methylpiperazine, a less specific inhibitor of protein kinase C than staurosporine, at a concentration of 100 microM inhibited both the transient NIE and the sustained PIE without affecting the transient PIE. 4. Amiloride, an inhibitor of Na+/H+ exchange, at concentrations ranging from 0.1 mM to 1 mM inhibited the sustained PIE and, at higher concentrations, also inhibited the transient NIE. 5. An amiloride analogue, 5-(N-methyl-N-isobutyl)amiloride (MIBA), inhibited only the sustained PIE with an IC50 of 0.3 microM which is approximately two orders of magnitude lower than amiloride. 6. The receptor-linked stimulation of Na+/H+ exchange through protein kinase C activation may be a mechanism for alpha 1-adrenoceptor-mediated sustained PIE.     

ELISA using monoclonal antibody to human serum arylesterase.

ELISA for determining arylesterase content in human serum has been developed by the one-step sandwich method using 2 monoclonal antibodies. While the content of arylesterase in healthy adults was 81 +/- 25 mg/l, a decrease was observed in patients with liver cirrhosis, where the mean +/- SD was 37 +/- 7 mg/l. ELISA of human serum arylesterase correlated with the activity determined by a specific substrate assay we devised recently.     

Serotype‐specific polysaccharide of Streptococcus mutans contributes to infectivity in endocarditis

Streptococcus mutans and other viridans streptococci have been implicated as major etiological agents of infective endocarditis. The serotype‐specific rhamnose‐glucose polysaccharide (RGP) of S. mutans has several biological functions that appear to be essential for the induction of infective endocarditis. The aim of this study was to examine the contribution of RGP to the infectivity of S. mutans in infective endocarditis using a rat model. The RGP‐defective mutant of S. mutans showed reduced ability to induce infective endocarditis compared to the parental strain. The ability of S. mutans to induce infective endocarditis was not consistent with the binding capacity of the organism to extracellular matrix proteins. The results suggest that S. mutans containing whole RGP is more virulent than the RGP‐defective mutant, and the RGP has an important role for the induction of infective endocarditis by S. mutans.     

Toluene vapor exposure and urinary excretion of hippuric acid among workers in China.

A factory survey was conducted in three provinces in China from 1985 to 1989. The time-weighted average toluene concentrations in breathing zone air were monitored by diffusive sampling, whereas hippuric acid (HA) concentrations in shift-end urine samples were measured by high performance liquid chromatography (HPLC). Exposed workers (456 men and women) were those for whom toluene (up to 548 ppm toluene) accounted for greater than or equal to 90% of total exposure (by vapor concentration in ppm), whereas 517 nonexposed controls were recruited from the same factories or from factories of the same region. There was a linear correlation between the intensity of toluene exposure and HA concentration in the shift-end urine. Comparison of the results with findings in the literature shows that the toluene-induced increase in urinary HA concentration among workers in China is significantly smaller than the published values, whereas HA concentrations in urine samples from nonexposed controls are comparable to the levels previously reported.