Lignan glucosides from Acanthus ilicifolius

From the aerial part of Acanthus ilicifolius, two lignan glucosides, (+)-lyoniresinol 3a-[2-(3,5-dimethoxy-4-hydroxy)-benzoyl]-O-beta-glucopyranoside, and dihydroxymethyl-bis(3,5-dimethoxy-4-hydroxyphenyl) tetrahydrofuran-9(or 9')-O-beta-glucopyranoside have been isolated, together with eight known compounds. The structural elucidations were based on the analyses of physical and spectroscopic data.

Apoptosis signal-regulating kinase 1 (ASK1) is an intracellular inducer of keratinocyte differentiation

Cells differentiate in response to various extracellular stimuli. This cellular response requires intracellular signaling pathways. The mitogen-activated protein (MAP) kinase cascade is a core signal transduction pathway that determines the fate of many kinds of cell. MAP kinase kinase kinase activates MAP kinase kinase, which in turn activates MAP kinase. Apoptosis signal-regulating kinase (ASK1) was identified as a MAP kinase kinase kinase involved in the stress-induced apoptosis-signaling cascade that activates the SEK1-JNK and MKK3/MKK6-p38 MAP kinase cascades. Expression of the constitutively active form of ASK1 (ASK1-DeltaN) in keratinocytes induced significant morphological changes and differentiation markers, transglutaminase-1, loricrin, and involucrin. A transient increase in p21(Cip1/WAF1) reduced DNA synthesis, and cell cycle analysis verified the differentiation. p38 MAP kinase inhibitors, SB202190 and SB203580, abolished the induction of differentiation markers, transglutaminase-1, loricrin, and involucrin. In turn, the induction of differentiation with ceramide in keratinocytes caused an increase in ASK1 expression and activity. Furthermore, normal human skin expresses ASK1 protein in the upper epidermis, implicating ASK1 in in vivo keratinocyte differentiation. We propose that the ASK1-p38 MAP kinase cascade is a new intracellular regulator of keratinocyte differentiation.

Hemodynamic evaluation of left testicular varicocele by scrotal scintigraphy

OBJECTIVE

Scintigraphically assessed hemodynamics of left testicular varicoceles were correlated with spermatogenesis and the effect of varicocelectomy.

METHODS

Comparison of the time-activity curve (TAC) of the left hemiscrotum with those of the femoral artery and femoral muscle identified three types of scrotal TAC:TAC-1 peaked as rapidly as in the femoral artery; TAC-3, as slowly as in femoral muscle, and TAC-2, intermediate between these. Comparison of TAC of the left hemiscrotum before and after varicocelectomy was done. Testicular biopsy specimens and the effect of varicocelectomy on semen analyses were compared between the types of TAC.

RESULTS

60 patients were divided into 3 groups: 17 in TAC-1; 13 in TAC-2, and 30 in TAC-3. The TAC of the left scrotum showed the same TAC pattern as the left femoral muscle in each patient after varicocelectomy. Spermatogenesis deteriorated most in biopsy specimens from TAC-2 patients. Semen analysis showed improved total motile sperm counts in 58.8, 69.2 and 26.7% of TAC-1, TAC-2, and TAC-3 patients, respectively.

CONCLUSIONS

TAC-1 and TAC-2 patients were better candidates for varicocelectomy than TAC-3 patients. The hemodynamics of the internal spermatic veins and pampiniform plexus in TAC-3 patients might be different from those in TAC-1 and TAC-2 patients.

Effects of age and weaning on the immature rat uterotrophic assay using ethynylestradiol

The purpose of this study was to evaluate the most appropriate rat age for the start of administration, and the effect of weaning, in the immature rat uterotrophic assay using ethynylestradiol (EE). Animals weaned on postnatal day (PND) 20 were administered subcutaneously EE at doses of 0.06-6 micrograms/kg/day for 3 days beginning on PND 21, 23 or 25. EE at the same doses was also administered to rats weaned on PND 17 or 20 from PND 21 for 3 days. Although uterine weight was significantly increased in the rats given 0.6-6 micrograms/kg EE in both of the studies, the percentage increase relative to the control in each group given EE from PND 21 and weaned on PND 20 was higher than in those groups given EE from PND 23 or 25, and the group weaned on PND 17.

Immature rat uterotrophic assay of bisphenol A

We used the immature rat uterotrophic assay to determine the estrogenicity of bisphenol A (BPA). We administered BPA (in sesame oil) to rats subcutaneously (sc; 0, 8, 40, and 160 mg/kg/day) or orally (0, 40, 160, and 800 mg/kg/day) for 3 days beginning on postnatal day (PND) 18; rats were sacrificed 24 hr after the last administration. Uterine wet, blotted, and relative weights increased in all groups given BPA sc. After oral administration, uterine relative weight increased in 160 and 800 mg/kg BPA groups, and wet and blotted weights increased in the 800 mg/kg BPA group. Plasma concentrations of BPA at 1 hr after the last administration were detected in all groups given BPA sc and in groups given 160 and 800 mg/kg BPA orally, with a dose-response effect. The study was then reproduced under the same conditions. After sc injections, uterine wet and blotted weights increased in the 40 and 160 mg/kg BPA groups, and relative weight increased in all groups given BPA sc. By contrast, uterine wet, blotted, and relative weights increased only in the 160 and 800 mg/kg oral BPA groups. Also, to examine time-course changes in uterine weight, we administered BPA (in sesame oil) sc from PND 18 to PND 20 for 3 days at doses of 0, 8, 40, and 160 mg/kg/day; uterine weights were then measured at 6, 12, 18, and 24 hr after the last administration. Uterine wet, blotted, and relative weights increased in all BPA groups at 6 and 24 hr and in 40 and 160 mg/kg BPA groups at 12 hr. By contrast, at 18 hr, uterine wet, blotted, and relative blotted weights increased in all BPA groups and relative wet weight increased in 40 and 160 mg/kg BPA groups. The percentage increases in uterine wet and relative weights of 40 and 160 mg/kg BPA groups at 6 hr were higher than those at 24 hr relative to the controls, but the coefficient of variation in these weights in the group given 8 mg/kg BPA at 24 hr was smaller than that at 6 hr. These findings demonstrate BPA-induced uterotrophy in the immature uterotrophic assay in rats administered 8 mg/kg/day sc and in rats given 160 mg/kg/day orally, and suggest that the autopsy at 24 hr after the last administration is suitable.

Endosseous titanium implants as anchors for mesiodistal tooth movement in the beagle dog

The purpose of this study was to determine the anchorage potential of titanium implants (Branemark; 3.75 x 7 mm) with the use of a sectional arch wire technique for orthodontic mesiodistal tooth movement, as assessed by the osseointegration of implants and tooth movement. Two implants were surgically placed in healed mandibular extraction sites of the second and third premolars on each side in 4 adult male beagle dogs. The implants were surgically uncovered 18 weeks later, and second-stage abutments with soldered edgewise tubes were attached. Segmented edgewise rectangular archwires (0.017 x 0. 025 inch) with a T-loop or an L-loop were placed between the implants and the fourth premolars on both sides as the anchorage unit. One segment in each dog served as a loaded side, and the archwire was calibrated to produce 200 g of lateral force on the fourth premolar. The contralateral segment served as an unloaded side and was not subjected to orthodontic force. Sectional wires were activated biweekly 24, 28, 28, and 32 weeks, respectively, depending on the magnitude and the appearance of mesial tipping movement of the fourth premolar. After mandibular impressions were taken to measure the distance between the first molar and the fourth premolar, the animals were euthanized and dissected mandibles were prepared. The specimens were then embedded in polyester resin and cut to take backscattered electron images. On the basis of these images, the percentage of peri-implant bone volume was calculated and defined as an index of osseointegration. The differences between the initial and final fourth premolar to first molar distances varied (7.40, 8.85, 10.50, and 3.30 mm) on the loaded side, whereas the unloaded side showed no movement. Not only was there no statistical difference in the percent of peri-implant bone volume between the loaded and unloaded sides, but there was also no statistical difference between the compression and tension sides in both loaded and unloaded implants, which suggests that the implants maintained rigid osseointegration. In conclusion, the present study demonstrated that endosseous titanium implants can function as anchors for long-term orthodontic mesiodistal movement.

Angiographically verified progression of moyamoya disease in an adult. Case report

The authors present the case of a 37-year-old man with definite moyamoya disease in whom angiographic findings drastically changed. The patient presented with left hemiparesis due to lacunar infarction. Angiography initially disclosed a narrow right carotid artery (CA) siphon and severe stenosis of the horizontal segment of the left middle cerebral artery. Four years later, the patient experienced right-central facial paresis, which developed because of a small putaminal hematoma. Angiography results demonstrated occlusion of the internal CA siphons bilaterally, with moyamoya vessels. It therefore appears that in some adults, moyamoya disease is accompanied by very progressive vascular changes.

Exhaled nitric oxide level decreases after cardiopulmonary bypass in adult patients

OBJECTIVE

To measure exhaled nitric oxide (NO) and compare it with lung function after cardiopulmonary bypass (CPB) in adult patients. Pulmonary dysfunction is sometimes observed after CPB. Impaired production of NO may account for this dysfunction.

DESIGN

Prospective, single-center, observational study.

SETTING

University hospital operating room, intensive care unit.

PATIENTS

Sixteen adult patients undergoing cardiac surgery with CPB.

INTERVENTIONS

None except cardiac surgery with CPB.

MEASUREMENTS AND MAIN RESULTS

Exhaled NO was measured continuously by the chemiluminescence method and was expressed as the peak and mean NO concentrations, and the NO output (VNO). These parameters were calculated by averaging four sequential tidal NO values. The data were obtained serially from before CPB to 16 hrs after CPB. Lung function was evaluated by monitoring lung compliance, pulmonary artery pressure, and alveolar-arterial oxygen difference (P(A-a)O2). The cardiac index did not change except for a significant increase at 16 hrs compared with 6 hrs after CPB. Peak NO, mean NO, and VNO decreased from 15.4 +/- 2.0 ppb (before CPB) to 8.2 +/- 0.8 ppb (6 hrs after CPB), from 5.7 +/- 0.7 ppb to 2.8 +/- 0.6 ppb, and from 29.2 +/- 3.1 nL/min to 15.7 +/- 2.2 nL/min, respectively. These changes were associated with the increases in pulmonary artery pressure and alveolar-arterial oxygen difference, and the decrease in lung compliance. VNO recovered to the level measured before CPB 16 hrs after CPB, which was consistent with the physiologic recovery in pulmonary hypertension, lung compliance, and gas exchange.

CONCLUSION

Measurement of exhaled NO as VNO, which was associated with lung dysfunction, may be an indicator of lung injury in adult patients after cardiopulmonary bypass.

Combination of a teratoma and embryonal carcinoma of the testis in SD IGS rats: a report of two cases

Testicular tumors of germ cell origin are extremely rare in rats. We encountered 2 cases of teratoma and embryonal carcinoma in the testes of 8- and 10-week-old Sprague-Dawley IGS rats. A unilateral tumor mass with bilateral testicular atrophy was observed macroscopically in both cases. Microscopic examination revealed that the tumor mass had characteristic features of a teratoma and was composed of several types of differentiated cells and tissues at various stages of maturation. Embryonal carcinoma tissue, composed of undifferentiated cells with an embryonic and anaplastic appearance, was observed within the tumor mass. In addition, foci of intratubular teratomas and embryonal carcinomas were observed in the testis on the side without any obvious mass. No obvious germ cells were observed in the seminiferous tubules in the remnant nontumorous area. Furthermore, intratubular transition of cells was observed from the embryonal carcinoma tissue to the squamous epithelium. This finding indicates that an embryonal carcinoma differentiates toward a teratoma even at a very early stage of development of the germ cell tumor.

[A new method for pharmacokinetic analysis of 99mTc-GSA using two-compartment and two-parameter model]

Technetium-99m-diethylenetriaminepentaacetic acid-galactosyl-human serum albumin (99mTc-GSA) is a liver scintigraphy agent which binds to asialoglycoprotein receptor in hepatocyte. Twenty-six patients with liver dysfunction were examined with 99mTc-GSA liver scintigraphy using two-compartment and two-parameter model (2C2P model). The 99mTc-GSA was assumed to move within two compartments (whole blood and liver). k1 and k2 were parameters which represented transfer rate constant from blood to liver, and from liver to blood, respectively. Two differential equations based on 2C2P model were integrated, so that k1, k2, k1/k2 and VLmg were estimated from the time-activity curves of the heart and liver. VLmg was computed as maximum amount of 99mTc-GSA binding to liver. The results were compared with the liver function tests and the conventional 99mTc-GSA indices: HH15, LHL15, and LU15. k1/k2 and VLmg values had positive correlation with the result of the serum liver function tests, Plt., T.Bil., ChE, GOT, LDH, ALP and gamma GTP. It is concluded that this new method using 2C2P model is not invasive and simplest in the 99mTc-GSA liver scintigraphies, and may be useful in evaluating liver function.

NMR structure of ribonuclease HI from Escherichia coli

The solution structure of ribonuclease HI (RNase HI) from Escherichia coli (E. coli), a protein of 155 residues, was determined. Three-dimensional nuclear Overhauser enhancement spectroscopy (NOESY) was used to obtain 1,424 distance constraints between individually assigned polypeptide chain hydrogen atoms. Supplemental geometric constraints of 90phi angles and 12chi1 angles, and the distance constraints of 66 hydrogen bonds were experimentally derived. Using the DADAS90 program that calculates structures in dihedral angle space, 15 structures satisfying almost all constraints were obtained. The average root mean square deviation (RMSD) from the mean structure was 0.75 A for backbone atoms. The RMSD for backbone atoms between the representative NMR structure with the smallest constraint violation and crystal structures was within 1.2 A. Although the NMR and crystal structures thus resemble one another, a significant discrepancy was observed in a region termed 'basic protrusion.' The discrepancy observed in NMR experiments is explained by fluctuation in this region.

[Effects of infusion methods of propofol on quality of sedation and ease of sedation control during gynecological laparotomy under spinal anesthesia]

Twenty patients were prospectively and randomly studied to investigate effects of infusion methods of propofol on quality of sedation and ease of sedation control during gynecological laparotomy under spinal anesthesia. After establishment of spinal anesthesia, patients were randomly assigned to one of the following two groups, i.e. conventional continuous infusion group (Cont group) and target-controlled infusion group (TCI group). In the Cont group, propofol was started at a rate of 6 mg.kg-1.hr-1 until response to command disappeared. In the TCI group, the initial target concentration of propofol was set at 1.2 micrograms.ml-1 until response to command disappeared. Thereafter infusion rate or target concentration was adjusted to maintain Mackenzie's score at 3 or 4. Predicted concentration of propofol was 1.2 +/- 0.01 micrograms.ml-1 at induction of sedation and 1.2 +/- 0.11 micrograms.ml-1 during stable sedation in the TCI group. Satisfaction VAS, anxiety VAS, discomfort VAS, sedation score and times of changing infusion condition were similar in both groups. Total dose of propofol was significantly less in the TCI group. In conclusion, quality of sedation and ease of control of sedation were comparable in both groups and continuous infusion method is simple.

Iridoid and megastigmane glycosides from Phlomis aurea

From the leaves of Phlomis aurea, two new iridoids of unique structures named 3-epiphlomurin (1) and phlomurin (2), a new megastigmane glucoside phlomuroside (3) and a new benzyl alcohol glycoside having the structure benzyl alcohol-O-beta-xylopyranosyl-(1-->2)-beta-glucopyranoside (4) have been isolated together with four known iridoids auroside, lamiide, 8-epiloganin and ipolamiide, two known phenolic glycosides acteoside (verbascoside) and syringin, one known phenylethanoid glycoside 2-phenylethyl-O-beta-xylopyranosyl-(1-->2)-beta-glucopyranoside, one known lignan liriodendrin and three known flavonoids chrysoeriol-7-O-beta-glucopyranoside, acacetin-7-O-beta-glucopyranoside and luteolin-7-O-beta-glucopyranoside. The structures of the isolated compounds were verified by means of mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectral analyses.

The novel gene, gamma2-COP (COPG2), in the 7q32 imprinted domain escapes genomic imprinting

The gene MEST (or PEG1) on chromosome 7q32 is paternally expressed in human fetal tissues as a result of genomic imprinting. Since some imprinted genes are clustered, we speculated that an imprinted gene cluster might exist at 7q32. We have sought to isolate additional human genes close to MEST and to characterize their allelic expression patterns. Here, we report the biallelic expression of the gene, gamma2-COP (coatomer protein complex, subunit gamma 2, HUGO-approved symbol COPG2), and monoallelic expression of the transcript, CIT1, which is located in intron 20 of gamma2-COP. Recently, gamma2-COP was reported to be a novel imprinted gene that overlaps the 3'-untranslated region (3'-UTR) of MEST in a tail-to-tail orientation. However, our results revealed biallelic expression in all fetal tissues and adult blood lymphocytes. On the other hand, CIT1 was an antisense transcript of gamma2-COP intron 20 and was expressed from the paternal allele in all fetal tissues examined. Adult blood lymphocytes showed biallelic expression. We identified additional MEST 3'-UTR sequence, which overlaps the last four exons and introns of gamma2-COP. This additional MEST 3'-UTR may complicate analysis of gamma2-COP imprinting. Our data indicate that the region containing MEST at 7q32 is an imprinted domain, but gamma2-COP adjacent to MEST escapes genomic imprinting.

Administration of opiate receptor antagonist inhibits mucosal atrophy of the gut in fasting rats

OBJECTIVE

The objective of this study was to determine whether the opiate mu receptor antagonist naloxone would prevent atrophy of the gut in 24-h-fasted rats.

METHODS

Male Sprague-Dawley rats (n = 76, body weight 200-225 g) were catheterized in the jugular vein on Day 0. The rats were fed standard rat chow for 4 days. On Day 4, the diet was changed to the standard liquid diet, and the rats were allowed free access to the liquid diet. On Day 7, the rats were randomized into five groups: (1) free fed, (2) free fed plus naloxone, (3) pair fed, (4) fasting, (5) free fed plus morphine, (6) fasting plus naloxone. Either naloxone (0.16 mg/kg/h) or morphine (0. 21 mg/kg/h) was continuously infused via venous catheter for 24 h. On Day 8, 24 h after fasting or free feeding, the animals were sacrificed.

RESULTS

Twenty-four hours of fasting caused atrophy of the jejunum and elevated morphine levels in the brain (free fed, 931. 3 +/- 122.3 fmol/g, vs fasting, 1419.0 +/- 150.0, P < 0.05). Morphine infusion reduced villus height, mucosal weight, and protein content in jejunum as compared with the free fed rats receiving saline. Administration of naloxone caused an increase in villus height (fasting, 587.0 +/- 25.8 microm, vs fasting plus naloxone, 670.0 +/- 17.4, P < 0.05), mucosal weight (fasting, 17.4 +/- 1.8 mg/cm, vs fasting plus naloxone, 22.6 +/- 1.9, P < 0.05), and protein content (fasting, 13.5 +/- 0.7 microg/cm, vs fasting plus naloxone, 16.7 +/- 0.6, P < 0.05) in jejunum.

CONCLUSION

Mucosal atrophy of the jejunum is caused by endogenous opioid in fasting rats.

Major metabolites of ginseng sapogenins formed by rat liver microsomes

Incubation of ginseng sapogenins with microsomes from rat liver resulted in formation of their 20,24-epoxides as major metabolites. Identification of the metabolites was performed by HPLC, FAB-MS and EI-MS.

Flow cytometric differentiation of Asian and Western types of multiple sclerosis, HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and hyperIgEaemic myelitis by analyses of memory CD4 positive T cell subsets and NK cell subsets

We examined the alterations of memory CD4(+) T cell subsets bearing surface receptors linked to either Th1 or Th2 cytokine production as well as natural killer (NK) cell subsets by three color flow cytometry in the peripheral blood from 36 patients with clinically definite multiple sclerosis (MS), 27 patients with HAM/TSP, 13 patients with hyperIgEaemic myelitis who had mite antigen-specific IgE and 25 healthy controls (HC). The patients with MS were clinically classified into an optico-spinal form of MS (Asian type, MS-A) and the conventional form of MS (Western type, MS-W). MS-A showed a significant increase of CD4(+)CD45RA(-)CCR5(+) cells (Th1 cells) through the relapse and remission phases in comparison to HC, while MS-W showed a significant increase of CD4(+)CD45RO(+)CD62L(-) cells (Th1 cells) only at the relapse phase. HAM/TSP showed a significant increase of CCR5(+) and CD62L(-) memory CD4(+) T cells as well as CD30(+) memory CD4(+) T cells (Th2 cells) in comparison to HC. On the other hand, a selective increase of CD4(+)CD45RO(+)CD30(+) cells was found in hyperIgEaemic myelitis. The percentage of mature NK cells (CD3(-)CD16(+)CD56(+) cells) as well as double negative T cells (CD3(+)CD4(-)CD8(-) cells) decreased significantly in HAM/TSP in comparison to HC. Our findings therefore suggest a flow cytometric analysis of Th1/Th2-associated markers on memory CD4(+) T cells as well as NK cell subsets to be useful for differentiating various inflammatory neurologic conditions.

Minor phenolics from Crinum bulbispermum bulbs

From the bulbs of Crinum bulbispermum Milne, four new minor compounds were isolated viz. 4-hydroxy-2',4'-dimethoxydihydrochalcone (1), 4,5-methylenedioxy-4'-hydroxy-2-aldehyde[1,1'-biphenyl] (4), hippacine (6), and 4'-hydroxy-7-methoxyflavan-3-ol (7). In addition, four known compounds were isolated and identified as 2(S),3',4'-dihydroxy-7-methoxy flavan (2), isolarrien (3), isoliquiritigenin (5) and liquiritigenin (8). The structures of the isolated compounds were established by spectral evidence.

Minimum 10-year outcome of decompressive laminectomy for degenerative lumbar spinal stenosis

STUDY DESIGN

A retrospective follow-up study was conducted in patients who underwent decompressive laminectomy for degenerative lumbar spinal stenosis.

OBJECTIVES

To describe the long-term outcome of decompressive laminectomy performed for degenerative lumbar spinal stenosis, and to investigate preoperative factors that influenced outcomes, especially risk factors predisposing patients to poor results.

SUMMARY OF BACKGROUND DATA

The success rate of surgical treatment of decompressive laminectomy for lumbar spinal stenosis varies. Long-term follow-up investigations have indicated deterioration of outcome; however, the causes of deterioration have not been fully investigated, and there have been no reports with a minimum 10-year follow-up.

METHODS

Of 151 patients who underwent decompressive laminectomy from 1980 through 1989, 37 were followed up for a minimum of 10 years. The mean age at surgery was 60.9 +/- 8. 2 years (range, 43-76), and the average follow-up period was 13.1 +/- 2.1 years (range, 10.1-17.4). The results were evaluated by the criteria of the Japanese Orthopedic Association Lumbar Score, and the outcome was classified as excellent at more than 75% improved score; good, 50-75%; fair, 25-49%; and poor, 0-24% or less. Information about impairment of activities of daily living was also obtained at follow-up. Associations between preoperative clinical and radiographic variables and clinical outcome were evaluated statistically.

RESULTS

In all patients, the average score improvement of 55.2 +/- 31.6% was regarded as acceptable. The postoperative score and percentage of improvement of low back pain were lower than those of leg pain and walking ability. No impairment in activities of daily living was found in 62.2% of the patients. Rate of improvement was evaluated as excellent in 13 (35.1%), good in 8 (21.6%), fair in 8, and poor in 8 patients. Three patients required additional surgery because of disc herniation at the laminectomied segments. The patients with multiple laminectomy (P = 0.034) and more than 10 degrees preoperative sagittal rotation angle (P = 0.018) showed a significantly poorer outcome than the remainder of the patients.

CONCLUSIONS

Long-term follow-up showed that even without spinal fusion, more than half the patients were evaluated as excellent or good. Patients with more than a 10 degrees sagittalrotation angle who need multiple laminectomy, should be given information about the possibility of earlier deterioration of the outcome, and alternative or additional treatment such as concomitant spinal fusion with decompression may be considered.

Suppressive effects of vietnamese ginseng saponin and its major component majonoside-R2 on psychological stress-induced enhancement of lipid peroxidation in the mouse brain

We investigated the in vivo effects of Vietnamese ginseng saponin (VG saponin) and its major component majonoside-R2 (MR2) on psychological stress-induced enhancement of lipid peroxidation in the mouse brain. Psychological stress exposure using a communication box system for 4 h significantly increased the content of thiobarbituric acid reactive substance (TBARS), an index of lipid peroxidation activity, in the brain. Pretreatment with VG saponin (15-25 mg/kg, PO) and MR2 (1-10 mg/kg, IP) significantly attenuated the psychological stress-induced increase in TBARS content in the brain. The aglycone of MR2 (MR2-aglycone: 1.2 mg/kg, IP), at the equivalent dose of MR2 (i.e., 3 mg/kg, IP), also produced the suppressive effect on the increase in the TBARS content. The in vivo suppressive effect of MR2 was dose dependently attenuated by flumazenil (3 and 10 mg/kg, IP), a benzodiazepine receptor antagonist, and pregnenolone sulfate (10 mg/kg, IP), a neurosteroidal negative allosteric modulator of GABA(A) receptors. These findings suggest that VG saponin and its major component MR2 have preventive effects on the psychological stress-induced brain cell membrane damage, and that the effect of MR2 is partly due to enhancement of GABA(A)-ergic systems in the brain.

Pharmacokinetics and metabolism of 123I-BMIPP fatty acid analog in healthy and CD36-deficient subjects

Some have suggested that CD36, which is a multifunctional receptor with a molecular weight of 88 kDa, functions as a long-chain fatty acid (LCFA) transporter. We recently reported on a complete myocardial accumulation defect of the radiolabeled LCFA analog (123)I-15-(p-iodophenyl)-(R,S)-methylpentadecanoic acid (BMIPP) in patients with CD36 deficiency. In this study, we investigated the pharmacokinetics of BMIPP in patients with a myocardial accumulation defect of BMIPP accompanied by CD36 deficiency.

METHODS

Five patients (3 men, 2 women) with CD36 deficiency and 3 healthy men were investigated. Serial myocardial images were obtained every 70 s for 20 min (dynamic acquisition) and at 30, 60, 120, 180, and 240 min (static acquisition) after an intravenous bolus injection of 148 MBq BMIPP. Whole-body imaging was performed 60 min after injection. Plasma levels of BMIPP and its final metabolite, piodophenylacetic acid, at 2, 5, 10, 30, 60, 120, and 240 min after administration were determined.

RESULTS

In the CD36-deficient patients, myocardial images could not be obtained for up to 240 min after administration, and cardiac pool images showing only the cardiac chambers were obtained. The heart-to-mediastinum ratio was significantly lower in the CD36-deficient patients than in the healthy volunteers (1.71 +/- 0.11 versus 2.95 +/- 0.22, P < 0.05). Hepatic uptake of BMIPP was nearly double in CD36-deficient patients. The elimination of BMIPP from the circulation was retarded in the CD36-deficient patients.

CONCLUSION

We suggest that CD36 deficiency leads to decreased myocardial accumulation of BMIPP and retardation of BMIPP elimination from the circulation. The accumulation defect is probably caused by a defect in LCFA uptake into the myocardium through CD36.

DNA recognition by beta-sheets

The modes of DNA recognition by beta-sheets are analyzed by using the known crystal and solution three-dimensional structures of DNA-protein complexes. Close fitting of the protein surface and the DNA surface determines the binding geometry. Interaction takes place so that essentially the N-to-C direction of the beta-strands either follows or crosses the DNA groove. Upon following the major groove a two-stranded antiparallel beta-sheet dives into the groove and contacts DNA bases with its convex side facing the DNA, while upon following the minor groove, it binds around the sugar-phosphate backbones, with its opposite concave side shielding the DNA. In order for the beta-strands crossing the minor groove to interact with the DNA, the dinucleotide steps need to almost totally helically untwist and roll around major groove. The beta-sheet, on the other hand, needs to adopt a concave curvature on the binding surface in the direction that follows the DNA minor groove, and a convex surface in the direction that bridges the sugar-phosphate backbones across the groove. The result is to produce a hyperbolic paraboloidal DNA-binding surface.