Effect of histamine and substance P on the rabbit and human iris sphincter muscle

Background and methods: In an attempt to clarify the functional action of histamine and substance P on atropine-resistant miosis, we isolated rabbit and human iris sphincter muscles and investigated their mechanical properties using the isometric tension recording method. Results: Substance P dose-dependently contracted the rabbit iris sphincter, but had no effect on the human iris sphincter. In the rabbit iris sphincter, histamine reduced the amplitude of twitch contraction evoked by field stimulation but had no effect on carbachol-induced contraction. Thioperamide, but not mepyramine or cimetidine, partially antagonized the histamine-induced reduction in the amplitude of twitch contractions. In the human iris sphincter, on the other hand, histamine dose-dependently provoked contraction and the amplitude of histamine-induced contraction was affected neither by atropine nor by indomethacin. Conclusions: These results provide evidence that histamine has strong contractile effect on the human iris sphincter muscle; the rabbit iris sphincter muscle, however, apparently lacks functional histamine receptors. In rabbits, exogenously applied histamine only activates H₃ receptors located on the cholinergic nerve terminal, hence the excitatory neuro-effector transmission is suppressed. Thus, histamine may have an important roles in atropine-resistant miosis in humans, but not in rabbits.     

Hyaluronic acid: a specific prognostic indicator of hepatic damage in biliary atresia

BACKGROUND/PURPOSE: Hepatic fibrosis can progress in biliary atresia (BA) and is associated with capillarization of hepatic sinusoids. The significance of serum hyaluronic acid (HA) as a noninvasive indicator of histological sinusoidal endothelial cell (SEC) damage and hepatic fibrosis in BA, is investigated. METHODS: A total of 28 postoperative BA patients (mean age, 11.0+/-3.7 years) and 20 normal controls (mean age, 10.5+/-2.8 years) were studied. BA patients were divided into group I, good liver function (n = 8); group II, moderate liver dysfunction (n = 10); and group III, severe liver dysfunction (n = 10). Serum HA was determined using a one-step sandwich enzyme immunoassay, and liver histological damage was confirmed immunohistochemically using an antibody against factor VIII-related antigen (FVIIIRAg), which is specific for detecting damaged SEC. RESULTS: Serum HA was significantly higher (P < .0001) in group III (84.6+/-36.5 ng/mL) than in group I (15.9+/-6.9 ng/mL) or group 11 (28.7+/-10.7 ng/mL). Although immunoreactive products of FVIIIRAg were abundant in group III, they were not detected in SEC from group II. CONCLUSION: Serum HA may be of value for monitoring postoperative BA patients as a noninvasive indicator of SEC damage and progressive hepatic fibrosis.     

Delivery of a normal newborn after intensive medical treatment for an acute exacerbation of ulcerative colitis during pregnancy: A case report

(Received for publication on Sept. 21, 1998; accepted on May 27, 1999)     

Supplement of liver enzyme by intestinal and kidney transplants in congenitally enzyme-deficient rat

Gunn rats have a congenital deficiency of bilirubin-uridine diphosphate glucuronyltransferase (B-UDP-GT) activity and are unable to glucuronidate bilirubin in the bile, resulting in unconjugated hyperbilirubinemia. Other than the liver, several organs, including small bowel and kidneys, are known to have B-UDP-GT activity in normal rats. We performed total- or partial-small-bowel transplantation as well as kidney transplantation for Gunn rats in congenic combination and compared the effects of these procedures. Serum total bilirubin (TBil) levels significantly decreased from 7.84 +/- 0.24 mg/dl to 2.19 +/- 0.43 mg/dl 2 weeks after total-small-bowel transplantation (n = 12). Correlation of hyperbilirubinemia was roughly proportional to the length of the transplanted small bowel. There were no difference in metabolic correction between jejunal and ileal transplantation. Serum TBil levels significantly decreased from 7.83 +/- 0.21 mg/dl to 2.24 +/- 0.98 mg/dl 2 weeks after kidney transplantation (n = 5). In conclusion, small-bowel and kidney transplantation were effective in correcting metabolic abnormality in Gunn rats for the period of 4-6 months. Estimated total B-UDP-GT activity supplemented by small-bowel or kidney transplantation was about 1/5-1/4 of the minimal requirement for the complete normalization of serum total bilirubin levels.     

Relationship between inositol 1,4,5-trisphosphate receptor isoforms and subcellular Ca2+ signaling patterns in nonpigmented ciliary epithelia.

PURPOSE: Subcellular Ca2+ signaling patterns, such as Ca2+ waves, gradients, and oscillations, are an important aspect of cell regulation, but the molecular basis for these signaling patterns is not understood. Because Ca2+ release patterns differ among isoforms of the inositol 1,4,5-trisphosphate (InsP3) receptor, the relationship between the distribution of these isoforms and subcellular Ca2+ signaling patterns in nonpigmented epithelial (NPE) cells was investigated. METHODS: The distributions of the types I, II, and III InsP3 receptors were determined in NPE cells by immunofluorescence, and subcellular Ca2+ signaling patterns in these cells were examined by confocal line scanning microscopy. RESULTS: The type I InsP3 receptor was concentrated at the basal pole of NPE cells, whereas the type III receptor was localized to the apical pole. The type II InsP3 receptor was not expressed in detectable amounts. Acetylcholine induced increases in Ca2+ that were mediated by InsP3, and these Ca2+ increases began as Ca2+ waves that were initiated at the apical pole, in the region of the type III InsP3 receptor. Acetylcholine occasionally induced sustained or repetitive Ca2+ increases that were prominent at the basal pole, in the region of the type I InsP3 receptor, but only subtle or absent apically. CONCLUSIONS: Because the type I InsP3 receptor is thought to be responsible for repetitive Ca2+ release events, and the type III InsP3 receptor instead is suited to initiate Ca2+ signals, the subcellular distribution of these two isoforms corresponds to the Ca2+ signaling patterns observed in this cell type. Differential subcellular expression of InsP3 receptor isoforms may be an important molecular mechanism by which NPE cells organize their Ca2+ signals in space and time.     

Effects of intravenously administered lidocaine on pulmonary vagal afferents and phrenic nerve activity in cats

The ability of lidocaine to suppress activity of single vagal afferent fiber and that of phrenic nerve was studied in 20 cats anesthetized with pentobarbital. Slowly adapting stretch receptors (SAR, n = 16) and rapidly adapting stretch receptors (RAR, n = 7) were identified by their discharge pattern to pulmonary inflation. Intravenous lidocaine (1mg·kg^–1 or 2mg·kg^–1) produced a suppression of SAR activity but not of RAR activity. Suppression of phrenic nerve activity lasted much longer than that of SAR. These findings indicate that iv lidocaine acts more dominantly on CNS than on peripherals. We conclude that iv lidocaine prevents cough and hemodynamic changes caused by airway manipulation mainly through its action on CNS and not on peripherals (peripheral nerves or their receptor).(Aoki M, Harada Y, Namiki A, et al.: Effects of intravenously administered lidocaine of pulmonary vagal afferents and phrenic nerve activity in cats. J Anesth 6: 395–400, 1992)     

Plasma vasopressin response to contrast medium during cardiac catheterization in infants and children

Fifteen infants and children (M = 7, F = 8), aged from 0 to 13 years, who underwent cardiac catheterization and cardioangiography under ketamine-diazepam anesthesia were the subjects of this study. The effect of a contrast medium, isolamate sodium (66.8%) on the plasma somolality and vasopressin concentration was studied. The plasma osmolality was significantly elevated after contrast medium administration (289 ± 3 vs. 303 ± 8mosmol·kg^–1) as well as plasma vasopressin (from 2.1 ± 0.9 vs. 4.7 ± 2.0 micro-unit·ml^–1).It is concluded that the administration of contrast medium for cardioangiography causes elevation of plasma osmolality, which leads to the elevation of plasma vasopressin concentration.(Yamashita M, Horigome H, Kudo T, et al.: Plasma vasopressin response to contrast medium during cardiac catheterization in infants and children. J Anesth 5: 203–204, 1991)     

Macroscopic assessment of nodal metastasis is not reliable in colon cancer

Background Japanese surgeons have to macroscopically assess nodal metastasis from colon cancer according to the general rules established in Japan. Adjuvant therapy is sometimes started after macroscopic assessment of nodal metastasis. Macroscopic assessment, however, is difficult in many cases. Methods We evaluated the reliability of macroscopic assessment of nodal metastasis in colon cancer by (1) comparing the number of nodes picked up macroscopically with that of nodes recognized microscopically, and (2) by comparing the number of metastatic nodes found between macroscopic and microscopic examination. Results The number of nodes found during macroscopic examination was equal to that found in microscopic examination in only 52 of 206 cases (25%). Although 120 of 206 cases (58%) were judged macroscopically to have metastatic nodes, 61 had no metastatic nodes found microscopically. Sensitivity and specificity for the recognition of cases with nodal metastasis was 85.5% and 55.5%, respectively. The number of metastatic nodes in macroscopic examination was equal to that in microscopic examination in 90 cases (44%). Conclusion Because macroscopic assessment of nodal metastasis is not reliable, physicians should not rely on macroscopic assessment to indicate the need for further therapy, such as adjuvant chemotherapy. The recommendation for macroscopic assessment of nodal metastasis should be eliminated from the general rules in Japan.     

Subependymoma of the septum pellucidum: Characterization by PET

We report the evaluation of a subependymoma of the septum pellucidum by positron emission tomography (PET) with analysis of ₁₈F-fluorodeoxyglucose (FDG)kinetics. The tumor showed exceedingly low rates of glucose metabolism (rCMRG1) and kinetic constants (K1, K2, and K3). This hypometabolism indicates low cellular density and slow growth.