Archaeal lipids forming a low energy-surface on air-water interface.

Archaea or archaebacteria are the microorganism living in extreme environments such as hot springs and salt lakes. The membrane is featured universally by lipids which possess saturated polyisoprenoid chains in the hydrophobic moiety. This paper concerns the surface properties of Langmuir membranes made of archaeal lipid models (AL) bearing a phytanyl group or (3RS, 7R, 11R)-3,7,11,15-tetramethylhexadecyl group. All of the AL provide a Langmuir membrane on an air-water interface with an abnormally low surface tension (32-37 mN/m at 20-70 degrees C), while the conventional lipids having n-alkyl chains give membranes of 54-56 mN/m. The abnormally low energy surface of AL lipids is considered to arise from the bulky and fluid polyisoprenoid chain.

Changes in ascorbic acid content in primary cultured rat hepatocytes exposed to 2,2'-azobis (2-amidinopropane) dihydrochloride, a radical initiator.

Changes in ascorbate content in primary cultured rat hepatocytes exposed to oxidative stress derived from water soluble radical initiator 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) were examined. Cells were exposed to 0.05 and 5 mg/ml of AAPH as 'mild' and severe' oxidative stresses, respectively. Lipid peroxidation in hepatocytes was induced by 'severe' oxidative stress, but not by 'mild' oxidative stress. Ascorbate decreased at 6 hr after administration of both mild' and severe' oxidative stresses, and recovered to the control level after a further 6 hr. In cells treated with 'severe oxidative stress, however, total ascorbate (reduced form plus oxidized form) had increased 24 hr after administration. These results indicated that consumption alone did not account for the increase of ascorbate in hepatocytes under oxidative stress.

[A case of neurofibromatosis 2 combined with a vagal neurilemmoma in the mediastinum].

A 39-year-old man was referred to our hospital for further evaluation of an abnormal mediastinal shadow on chest X-ray film. CT scan of the chest showed a cyst-like tumor in the mediastinum. CT scan of the brain to investigate the impairment of hearing revealed bilateral cerebropontine angle tumors. Histological examination of both tumors revealed neurilemmoma. Neurofibromatosis 2 combined with a vagal neurilemmoma in the mediastinum is very rare.

Lasting increase in D1 dopamine receptors in the lateral part of the substantia nigra pars reticulata after subchronic methamphetamine administration.

To examine the possible involvement of D1 dopamine receptors in behavioral sensitization induced by subchronic methamphetamine (MAP) administration, regional D1 receptors labeled with [3H]SCH 23390 were examined using binding assay and quantitative autoradiography. Rats received 4 mg/kg/day MAP (i.p.) for 14 days, and were decapitated after an abstinence period of 24 h, 7 days or 21 days. In MAP-treated rats, a significant decrease in Kd in the mesolimbic area was observed 24 h but not 7 days after the last injection. Neither Kd nor Bmax changed in the striatum or medial prefrontal cortex of MAP-treated rats after any period of abstinence. Autoradiography revealed a significant increase in specific [3H]SCH 22390 binding in the lateral part of the substantia nigra pars reticulata (SNr) of MAP-treated rats. Since this increase lasted up to 21 days after cessation of subchronic MAP administration, it is suggested that lasting increase in the nigral D1 receptors may be associated with the biological changes underlying MAP-induced behavioral sensitization.

Effects of selective D-1 and D-2 dopamine antagonists on development of methamphetamine-induced behavioral sensitization.

The present study examined effects of selective antagonists of D-1 and D-2 dopamine receptors on the development of behavioral sensitization produced by repeated methamphetamine (MAP) administration. Male Sprague-Dawley rats were divided into four groups. Each group received a daily injection of saline (control group), 4 mg/kg MAP (MAP group), 1 mg/kg YM-09151-2 plus 4 mg/kg MAP (YM + MAP group) or 0.5 mg/kg SCH 23390 plus 4 mg/kg MAP (SCH + MAP group) for 14 days. During daily injection for 14 days, the MAP group exhibited a progressive augmentation in locomotor and stereotyped behavior, whereas the progression of such behaviors in the YM + MAP and SCH + MAP group was completely prevented. After an abstinence period of 7 days, all groups received a challenge of 2 mg/kg MAP. The MAP challenge reproduced hyperlocomotion and intense stereotyped behavior only in the MAP group. However, neither the YM + MAP group nor the SCH + MAP group showed stereotypy. The manner in which both groups showed only hyperlocomotion was similar to that observed in the control group. These results indicate that both selective D-1 antagonists and selective D-2 antagonists not only reverse MAP-induced motor effects at each injection but also prevent the development of behavioral sensitization induced by repeated MAP administration.

[Maternal beta-endorphin secretion during pregnancy--measurement of immunoreactive beta-endorphin in urine].

Gestational variations in maternal beta-endorphin (beta-end) secretion were investigated by simultaneous measurements of plasma and urinary immunoreactive beta-endorphin (ir-beta-end). Urinary ir-beta-end was extracted by using a Sep-Pak C18 column and was found to be stable for at least 24 hours at room temperature. Plasma and urine (2 hour collection) samples were obtained from 41 pregnant women and 7 non-pregnant women. Almost parallel increases in plasma and urinary ir-beta-end were observed during the course of pregnancy and there was a good correlation between them. Compared with non-pregnant values, significant increases (p less than 0.001) were observed after 36 weeks of gestation. We also studied chromatographic patterns of urinary extracts of non-pregnant and pregnant women. Both of them consist of 4 peaks and resemble each other. They were essentially similar to those of plasma extracts except for the third peak which appeared between the elution position of beta-lipotropin (beta-LPH) and beta-end. In conclusion, maternal beta-end secretions increase in late gestation not only in plasma but also in urine.

Induction of LH surge with estradiol benzoate and its clinical significance in anovulatory women.

In order to investigate the hypothalamic function of anovulatory women serial determinations of the serum gonadotropins (LH and FSH) were made over a period of 120 h following the intramuscular injection of 1 mg of estradiol benzoate (E.B.). Ten women with normal menstrual cycles and 57 anovulatory women were subjected to this study. The positive release of LH in serum (exceeding at least 150% of basal level) in response to E.B. was noted in follicular phase of the cycles, but not in luteal phase, and in 31 of 57 patients the release came between 48 to 96 h after the E.B. injection. The LH surge after E.B. injection was difficult to provoke when the basal serum LH and estradiol (E2) levels were low: less than 10 mIU/ml and 50 pg/ml, respectively. Thirteen of 27 patients, who showed LH surge, ovulated because of Clomid. Only three of 17 patients, who did not show LH surge, ovulated as a response to Clomid. Ten of 14 patients, who showed LH surge after E.B. but did not ovulate after Clomid, revealed a polycystic ovarian disease (PCO), and the responsiveness to both E.B. and Clomid improved after wedge-resection of the ovaries. These results suggest that the serum E2 level is closely correlated to the ability for LH-RH production in the hypothalamic "surge center," and that the E.B. provocation test is useful for investigating the hypothalamic function of anovulatory women and for diagnosing preoperatively the PCO resistant to Clomid treatment.

Hypothalamic function of secondary anovulatory women.

In order to investigate the hypothalamic function of the women suffering from ovulatory defect, serial determinations of the serum gonadotropins (LH and FSH) were made over a period of 120 hrs following the intramuscular injection of estradiol benzoate (E.B.) 1 mg. Ten normal cycling women and 57 anovulatory women, excluding premature ovarian failure, were subjected to this study. The positive release of LH in serum (exceeds at least 150% of basal level) to E. B. were noted in follicular phase of the normal cycles, but not in luteal phase, and in 31 of 57 anovulatory women the release occurred between 48 to 96 hrs after the E.B. injection. The LH surge after EB. was difficult to provoke when the basal serum LH and estradiol (E2) levels were low as less than 10 mIU/ml and 50 pg/ml, respectively. Thirteen of 27 women, who showed LH surge, ovulated by Clomid. Only 3 of 17 women, who did not show LH surge to E.B., ovulated as a response to Clomid. Ten of 14 cases, who showed LH surge to E.B. but not ovulated by Clomid, revealed polycystic ovarian disease (PCO), and the responsiveness to E.B. and Clomid improved after wedge-resection of the ovaries. These results suggest that the serum E2 level is closely correlated with the ability for LH-RH production in hypothalamic "surge center" either primarily or secondarily, and that E.B. provocation test is useful to investigate the hypothalamic function of anovulatory patients and to preoperatively diagnose the PCO patients refractory to Clomid treatment.

Detection of subclinical abortion in infertile women by beta-hCG radioimmunoassay.

Serum hCG was measured by specific beta-hCG radioimmunoassay during the late luteal phase in 58 infertile women recording the basal body temperature. As control, serum hCG was also measured during the 5th to 17th day after the basal body temperature shift in 18 normal pregnancy. In all normal pregnancy cases serum hCG was detected after the 9th day from basal temperature shift. Serum hCG was detected during the late luteal phase in 6 cases, including 2 cases succeeded in pregnancy in corresponding cycle, out of 58 infertile women. In spite of the hCG detection, the hyperthermic phase on BBT chart was not significantly prolonged in remaining 4 cases, in which the next menses took place as usual. Thus, so called subclinical abortion was suspected in these 4 cycles. This result suggests subclinical abortion might occur in infertile women. When hCG is detected during the late luteal phase, intensive treatment for the defective luteal function may salvage the endangered pregnancy. Since the incidence of hCG detection in this study was rather smaller than the previous reports, the major portion of causes of infertility might exist earlier or around the time of implantation of fertilized ovum.

[A simple method for estimating the day of ovulation by basal body temperature chart (author's transl)].

A new method for estimating the day of ovulation was assessed. The method is as follows; The range of hypothermic phase presumed 0.1 degrees C around mean basal body temperature of early 10 menstrual days. The day of ovulation was estimated by searching for the day which is followed by at least 4 consecutive days of rising temperature within the range of hypothermic phase. The accuracy of this method was assessed by comparing the basal body temperature and urinary luteinizing hormone (LH) peak day. The estimated day fell within 2 days during which the ovulation will occur most probably in 36 cycles (69%) and fell within 4 days around most expectable ovulation time in 46 cycles (88%). This result provide some insight into the limitation of the basal body temperature which is influenced by factors other than progesterone in determining the time of ovulation. But our simple objective method is useful in some cases than any other method determined by vague criteria.

PIP: A new method for estimating the day of ovulation was assessed. The method is as follows. The range of the hypothermic phase was during the 1st 10 menstrual days with a mean basal body temperature (BBT) of 0.1 degrees Celsius. The day of ovulation was estimated by searching for the day which is followed by at least 4 consecutive days of rising temperature within the range of the hypothermic phase. The accuracy of the method was assessed by comparing the BBT and urinary luteinizing hormone peak day. The estimated day fell within 2 days during which the ovulation would most probably occur in 36 cycles (69%) and fell within 4 days around the expected time of ovulation in 46 cycles (88%). This result provides some insight into the limitation of the BBT which is influenced by factors other than progesterone in determining ovulation. But our simple objective method is useful in some cases when compared with other methods determined by vague criteria. (author's modified)