Urinaryα 1 as an index of proximal tubular function in early infancy

Urinary ₁-microglobulin (U-A₁M) was measured in healthy term infants on days 1, 4, 7, 14, 28, 90 and 180 of life. U-A₁M was high until day 14 and declined thereafter. It was significantly correlated with urinary ₂-microglobulin (U-B₂M) throughout the study, but not with serum A₁M on days 1 or 7. Similar to U-B₂M, U-A₁M in the clinically stable term infants with intrauterine growth retardation (n=4–7) was not elevated on days 1–7. In the sick infants who needed immediate resuscitatio at birth (n=4–8), U-A₁M as well as U-B₂M was high on days 1–7 and then decreased to normal levels, suggesting that U-A₁M can be used as a sensitive marker of acute proximal tubular damage and its recovery. These observations indicate that U-A₁M is a useful index of proximal tubular function in early infancy.     

Enflurane reduces the excitation and inhibition of dorsal horn WDR neuronal activity induced by BK injection in spinal cats

The effects of enflurane (0.5%, 1.5% and 2.5%) on the excitation and inhibition of dorsal horn wide dynamic range (WDR) neuronal activity induced by bradykinin (BK) injection was studied in spinal cats. Extracellular activity was recorded in the dorsal horn from single WDR neurons responding to noxious and non-noxious stimuli applied to the cutaneous receptive fields on the left hind paw foot pads of decerebrate, spinal cord transected (L_1–2) cats. When 10µg of BK was injected into the femoral artery ipsilateral to the recording site as the noxious test stimulus, 24 of 26 WDR neurons (92%) gave excitatory responses and 2 (8%) gave inhibitory resposes. On the other hand, when the injection of 10µg of BK into the femoral artery contralateral to the recording site was used as the noxious test stimulus, 7 of 12 WDR neurons (58%) gave inhibitory responses, 3 (25%) gave excitatory responses, and 2 (17%) showed no response. The excitatory neuronal activity in WDR neurons was not depressed by 0.5% or 1.5% enflurane but was depressed significantly by 2.5%. However, the inhibitory neuronal activity in WDR neurons was significantly depressed by 0.5%, 1.5% and 2.5% enflurane. We have found that enflurane reduces the excitation as well as the inhibition of dorsal horn WDR neuronal activity induced by BK injection. These results suggest that the reduction of excitatory and inhibitory responses produced by noxious stimulation is likely to be the fundamental basis of the enflurane-induced anesthetic state in terms of WDR neurons.(Nagasaka H, Nakajima T, Takano Y et al.: Enflurane reduces the excitation and inhibition of dosal horn WDR neuronal activity induced by BK injection in spinal cats. J Anesth 4: 102–109, 1990)     

New hepatocellular diffusion model for analysis of hepatobiliary transport processes of drugs

A new hepatocellular diffusion model was developed to kinetically evaluate the hepatobiliary transport processes of drugs in the perfusion system, based on the physiological structure of the liver. Since the equations describing the hepatocellular diffusion phenomena were derived as image forms in the Laplace domain, the fast inverse Laplace transform (FILT) was adopted to manipulate the image equations. Cefixime and cefpiramide were selected as model drugs. The concentrations in the perfusate and the excreted amounts into the bile were simultaneously measured at appropriate intervals after the rapid administration of each drug into the portal vein. The hepatocellular diffusion model was fitted to the biliary excretion profiles from rat livers, by means of a nonlinear least squares program, MULTI(FILT). According to this model, the hepatobiliary transport process of drug is kinetically separated into three steps, that is, the diffusion into and through the hepatocytes, the transfer from the hepatocytes into the bile canaliculi, and the movement through the bile canaliculi to the outlet of bile duct. These steps are characterized by the diffusion rate constant through hepatocytes (k_dif), the permeability rate constant into the bile canaliculi (k_bmc) and the transit time through the bile canaliculi to the outlet of bile duct ( ), respectively. It was demonstrated that k_dif of cefixime (0.023min¹) was significantly smaller than that of cefpiramide (0.044 min¹), while the differences in k_bmc and were not obvious between cefixime and cefpiramide. k_bmc and of both drugs were about 1.2 min¹ and about 1.0 min, respectively. These parameters were correlated to the excretion ratio into the bile (F_bile) and the mean transit time from the sinusoid through the hepatocytes to the outlet of bile duct ( ).     

Medical economics and quality of life: Analysis of factors that influence the perception of medical cost by post-surgical breast cancer patients

Recently, the importance of achieving a balance in terms of length of life (LL), quality of life (QOL) and medical costs has been emphasized in the evaluation of cancer treatment, and it is also said that the cost should be seen from the viewpoints of both the society and the patient. Few studies, however, have been performed to investigate how the patients bear the cost and the influence of this factor. Therefore, in the present study we examined the perception of medical care cost (PMC) in 83 non-recurrent post-surgical breast cancer patients. The factors that influence the PMC were analyzed by univariate and multivariate analyses using the variables representing QOL, sociodemographic and clinical characteristics, types of therapy, and various types of medical cost. First, the results of the relationship between the variables and the PMC revealed that the patients with better QOL, especially those with better social category QOL, tended to have a lower PMC. However, no other variable had any significant associations with the PMC. Second, the results of multiple regression analyses revealed that patients with better QOL, especially those with better social category QOL, in the elderly, and/or those with higher level of education tended to show a lower PMC. In conclusion, the results of the present study suggest that, when we consider evaluating the cost of cancer treatment for postsurgical breast cancer patients, we should take into account the patients' QOL, age, and their level of education.     

Analysis of the factors influencing the quality of life of patients with advanced or recurrent breast cancer

To investigate the factors influencing the quality of life (QOL) of Japanese patients with advanced or recurrent breast cancer, a newly developed QOL questionnaire, The QOL Questionnaire for Cancer Patients Treated with Anticancer Drugs (QOL-ACD), was answered by 23 patients, and a multiple regression analysis was performed. The demographic and medical factors relating to the overall QOL score and to the four categories of the QOL-ACD, namely (1) activity, (2) physical condition, (3) psychological condition, and (4) social relationships, were analyzed. The results indicated that skin metastasis, a heavier body weight, and bone metastasis had a strong negative influence on the overall QOL scroe, whereas endocrine therapy, the existence of a primary lesion, and more extensive first surgery had a strong positive influence on it. With regard to the analysis of the four categories, endocrine therapy was found to be positively related to all four categories. The multiple correlation coefficient (R) between the estimated overall QOL score and the observed overall QOL score was about 0.77. The results of this analysis showed that endocrine therapy can improve the QOL of patients with advanced or recurrent breast cancer, and that the QOL-ACD questionnaire could prove extremely useful for predicting the QOL of individual patients and for aiding clinicians in deciding on the most appropriate type of therapy for each patient.     

Role of disturbance of ependymal ciliary movement in development of hydrocephalus in rats

We have developed a new in vitro method of quantitatively analyzing ciliary movement in the ependymal wall of the aqueduct in rats. An axial slice of the midbrain containing ependymal wall was placed in a culture dish filled with a culture medium containing latex beads 1 m in diameter at a concentration of 10⁷ beads/ml. The movement of the beads caused by flow of culture medium generated by the to-and-fro ciliary movement was recorded by a high speed video system attached to an inverted phase-contrast microscope. Ciliary movement was expressed by the speed of the latex beads (m/s). Aqueductal ciliary movement in congenitally hydrocephalic HTX rats, congenitally hydrocephalic WIC-Hyd rats, and other normal rats was evaluated. The results suggest that in congenitally hydrocephalic WIC-Hyd rats the degree of hydrocephalus related strongly to the degree of ciliary dyskinesia, but in congenitally hydrocephalic HTX rats it did not. Considering this discrepancy, we attempted to see whether or not hydrocephalus was caused by artificial disturbance of ependymal ciliary movement in vivo. We found that continuous infusion of metavana date, an inhibitor of ciliary movement, into the III ventricle of normal Sprague-Dawley rats for 7 days induced dilatation of the ventricular system. Although the question whether or not disturbance of aqueductal ependymal ciliary movement is related to the development of human congenital hydrocephalus is debatable, the results of the present in vitro and in vivo experimental investigations appear to suggest that the disturbance of ciliary movement in the aqueduct could at least be one of the factors contributing to the inducement of hydrocephalus in experimental conditions.     

Application of Akaike's information criterion (AIC) in the evaluation of linear pharmacokinetic equations

According to linear pharmacokinetics, the time course of plasma concentration of a drug, C_p,is expressed by a sum of exponential functions, C_p= _i=1 ⁿ a_i .This article describes a statistical technique to estimate the number of exponential terms, n,for the time course of drug by the application of Akaike's information criterion (AIC). Plasma concentrations of ethoxybenzamide, sulfisoxazole, bishydroxycoumarin, and diazepam measured following bolus intravenous injection were used as clinical examples for this method. Selection of models is compared between the AIC method and an Ftest method at significance levels of 5% and 1%.     

Adolescent smoking behavior in Japan, 1996.

We conducted second nationwide survey on smoking behavior among Japanese high school students. The survey was a cross-sectional sampling survey. The survey's targets were junior and senior high schools throughout Japan. Sample schools were selected by stratified cluster sampling. Self-administered anonymous questionnaires were sent to sample schools for all students to fill out. 65.6% of the junior high schools and 67.0% of the senior high schools were responded to this survey. A total of 117,325 students responded and 115,814 questionnaires were subjected to analysis. 7.5% of boys and 3.8% of girls in the 1st grade of junior high school were classified as current smokers, compared with 36.9% of boys and 15.6% of girls in 3rd grade of senior high school. Less than 1% of boys and girls in the 1st grade of junior high school were classified as daily smokers, this figure increased markedly by the 3rd grade of senior high school to reach 25.4% of boys and 7.1% of girls. Of students in the 3rd grade of senior high school, 21.2% of boys and 9.9% of girls had tried smoking before 13 year of age. Cigarette consumption also increased with age, although the proportion of those smoking 20 or more cigarettes per day did not. The major source for cigarettes among current smokers was vending machines. This survey revealed that smoking prevalence among Japanese high school students has already reached quite high level. Comprehensive energetic measures for control minor smoking are necessary in Japan.     

Tumor lysis syndrome in widely metastatic small-cell lung cancer

Tumor lysis syndrome is a rare complication of nonhematologic malignancies that results from massive necrosis of neoplastic cells after chemotherapy. This syndrome consists of life-threatening metabolic derangements, including severe hyperphosphatemia, hyperkalemia, hyperuricemia, and hypocalcemia, and may result in renal failure and death if not recognized early and treated appropriately. We report a case of tumor lysis syndrome after induction chemotherapy in a patient with widely metastatic smallcell lung cancer. This case emphasizes the importance of awareness and early treatment of this syndrome.