Alkenyl group is responsible for the disruption of microtubule network formation in human colon cancer cell line HT-29 cells

Alk(en)yl trisulfides (R-SSS-R′) are organosulfur compounds produced by crushed garlic and other Allium vegetables. We found that these compounds exhibit potent anticancer effects through the reaction with microtubules, causing cell cycle arrest. Nine alk(en)yl trisulfides including dimethyl trisulfide, diethyl trisulfide, dipropyl trisulfide (DPTS), dibutyl trisulfide, dipentyl trisulfide, diallyl trisulfide (DATS), dibutenyl trisulfide, dipentenyl trisulfide and allyl methyl trisulfide were synthesized and added to cultures of HT-29 human colon cancer cells at a concentration of 10 μM. The trisulfides with alkenyl groups such as DATS, but not those with alkyl groups, induced rapid microtubule disassembly at 30–60 min as well as cell cycle arrest during the mitotic phase approximately at 4 h after the treatment. Both DATS-induced microtubule disassembly and the cell cycle arrest were cancelled by the simultaneous treatment of the cancer cells with 2 mM L-cysteine, glutathione (GSH) or N-acetyl-L-cysteine. Reciprocally, L-buthionine-(S,R)-sulfoximine (500 μM), an inhibitor of GSH synthesis, enhanced the power of DATS in inducing the cell cycle arrest. These results indicate that alk(en)yl trisulfide react with sulfhydryl groups in cysteine residues of cellular proteins such as microtubule proteins. Thus, the present study provides evidence that trisulfides with alkenyl groups have potent anticancer activities, at least in part, directed toward microtubules. These findings suggest that alkenyl trisulfides and their structurally related compounds may provide novel and effective anticancer agents.

Curtobacterium ammoniigenes sp. nov., an ammonia-producing bacterium isolated from plants inhabiting acidic swamps in actual acid sulfate soil areas of Vietnam

The ammonia-producing bacteria B55T, CA73, SA69 and SA72 were isolated from the waterweeds Ludwigia adscendens (B55T) and Eleocharis dulcis (CA73, SA69 and SA72) grown in highly acidic swamps (pH 2–4) in actual acid sulfate soil areas of Vietnam. The isolates were Gram-positive, irregular rod-shaped, non-spore-forming bacteria. On the basis of 16S rRNA gene sequence similarity, strain B55T was shown to belong to the genus Curtobacterium of the class Actinobacteria. Chemotaxonomic data (MK-9 as major isoprenoid quinone, d-ornithine as cell-wall diamino acid, acetyl as the acyl type of peptidoglycan) supported the affiliation of all four strains to this genus. Although their 16S rRNA gene sequence similarity was 99 % to species with validly published names within the genus, they formed a group that was distinct in the phylogenetic tree, and DNA–DNA relatedness values to these established species were less than 10 %. The results of physiological and biochemical tests and major fatty acids (cyclohexyl-C17 : 0, anteiso-C17 : 0 and cyclohexyl-C19 : 0) allowed phenotypic differentiation of these strains from the species of Curtobacterium with validly published names. Therefore, strains B55T, CA73, SA69 and SA72 represent a novel species, for which the name Curtobacterium ammoniigenes sp. nov. is proposed. The type strain is B55T (=NBRC 101786T=VTCC D6-11T=JCM 14609T).

Long-term remission of cyclic Cushing's disease that was diagnosed and treated surgically in non-active phase

Cyclic Cushing's disease is a rare clinical entity that is defined as a periodic excessive production of adrenocorticotropic hormone (ACTH) and cortisol. Only 42 cases with cyclic Cushing's disease have been reported in the literature. The diagnosis is very difficult because of the fluctuating secretion of ACTH and cortisol. We report a 78-year-old woman with a pituitary adenoma presenting with cyclic Cushing's disease. In the present case, several interesting issues are pointed out: 1) MRI study detected the presence of an adenoma and selective venous sampling in the cavernous sinus disclosed the hypersecretion of ACTH from a pituitary adenoma. These neuroimaging and endocrinological studies were helpful for the diagnosis, even in the remission phase. 2) The disease was in the long-term remission phase after transsphenoidal surgery despite the high recurrence rate in this clinical entity, although it recurred four years later. Even in the remission phase of cyclic Cushing's disease, meticulous endocrinological and neuroimaging examinations can reveal the presence of a pituitary adenoma, which should be treated surgically.

Action of neltenexine on anion secretion in human airway epithelia

Neltenexine has been applied to human lung diseases such as chronic obstructive pulmonary disease (COPD) as a mucolytic agent. However, we have no information on the neltenexine action in bronchial epithelial cells. We studied the neltenexine action on the ion transport in human submucosal serous Calu-3 cells. Under a hyper-secreting condition caused by terbutaline (a beta2-adrenergic agonist), neltenexine diminished anion secretion by inhibiting the Cl- and HCO3- uptake via Na+/K+/2Cl- cotransporter and Na+/HCO3- cotransporter without blockade of the cystic fibrosis transmembrane conductance regulator (CFTR) channel, and also diminished anion secretion via stimulation of Cl-/HCO3- exchanger, which facilitates the extrusion of more CFTR-permeant anion, Cl-, with the uptake of less CFTR-permeant anion, HCO3-. Thus, neltenexine reduced the hyper-secretion to keep an appropriate fluid level in the airway, providing a possibility that neltenexine can be an effective drug in airway obstructive diseases by decreasing the airway resistance under a hyper-secreting condition.

Prognostic factors for ovulatory response with clomiphene citrate in polycystic ovary syndrome

OBJECTIVE

To evaluate prospectively the prognostic factors for ovulatory responses following clomiphene citrate (CC) administration in polycystic ovary syndrome (PCOS).

STUDY DESIGN

Fifty-nine infertile patients with a diagnosis of PCOS were recruited. Ovulation was induced using 100 mg/day CC administered daily from days 5 to 9 of the cycle. Endocrine and metabolic parameters between responder and non-responder groups were analyzed.

RESULTS

For a 75-g fasting glucose load (75-g OGTT), blood glucose levels at 60 and 120 min, the area under the curve (AUC) and blood insulin levels at 120 min in the non-responder group (n=25) were significantly higher than those in the responder group (n=34), although the measurements of fasting blood glucose and insulin were not significantly different between the two groups. In the receiver operating characteristic curves, the most appropriate cutoff point was 120 mg/dl for the blood glucose level at 120 min and 9000 for the blood glucose x insulin level at 120 min. There were no significant differences in the clinical characteristics or in the endocrine and metabolic parameters between conceived (n=9) and non-conceived groups (n=21).

CONCLUSION

The levels of blood glucose and blood glucose x insulin at 120 min after 75-g OGTT could be good biochemical markers of CC resistance in PCOS. No predictors of conception following CC therapy were identified by this study.

Ambroxol-induced modification of ion transport in human airway Calu-3 epithelia

Ambroxol is often used as a mucolytic agent in various lung diseases. However, it is unclear how ambroxol acts on bronchial epithelial cells. To clarify the action of ambroxol, we studied the effects of ambroxol on the ion transport in human Calu-3 cells, a human submucosal serous cell line, measuring the transepithelial short-circuit current and conductance across monolayers of Calu-3 cells. Ambroxol of 100 microM diminished the terbutaline (a beta2-adrenergic agonist)-stimulated Cl-/HCO3(-)-dependent secretion without any decreases in the conductance of cystic fibrosis transmembrane conductance regulator (CFTR) channel locating on the apical membrane. On the other hand, under the basal (unstimulated) condition ambroxol increased the Cl(-)-dependent secretion with no significant change in the apical CFTR channel conductance and decreased the HCO3- secretion associated with a decrease in the apical CFTR channel conductance. Ambroxol had no major action on the epithelial Na+ channel (ENaC) or the ENaC-mediated Na+ absorption. These results indicate that in Calu-3 cells: (1) under the basal (unstimulated) condition ambroxol increases Cl- secretion by stimulating the entry step of Cl- and decreases HCO3- secretion by diminishing the activity of the CFTR channel and/or the Na+/HCO3(-)-dependent cotransporter, (2) under the adrenergic agonist-stimulated condition, ambroxol decreases Cl- secretion by acting on the Cl-/HCO3- exchanger, and (3) ambroxol has a more powerful action than the adrenergic agonist on the Cl-/HCO3- exchanger, leading fluid secretion to a moderately stimulated level from a hyper-stimulated level.

[A case of non-mucin-producing papillary adenocarcinoma with a 19-year clinical history before operation]

A 73-year-old woman was admitted to our hospital for investigation of an abnormal shadow in the right upper lung field. Every year she had a medical check up since 1983 and the abnormal shadow was repeatedly pointed out However, she had not undergone a detailed examination. When she had a medical check up in July 2001, the shadow slightly increased compared with the previous chest film. Chest CT showed the mass with a pleural indentation in the right S3a, measuring 4 x 4 cm in size. Despite examinations including bronchoscopy we could not make a definitive diagnosis. After we explained the situation to her, she decided to have an operation. The biopsy during the operation revealed adenocarcinoma and right upper lobectomy with nodal dissection was performed. The ultimate diagnosis was non-mucin-producing papillary adenocarcinoma. This stage IB case was pT2N0M0. We reported this case because it was a rare slow-growing papillary adenocarcinoma that did not produce mucin and had a 19-year clinical history before operation.

Comparison of artifacts on coronal reformation and axial CT pulmonary angiography images using single-detector and 4- and 8-detector multidetector-row helical CT scanners

RATIONALE AND OBJECTIVES

The aim of this study is to compare the degree of stair-step artifact on coronal reformation computed tomographic (CT) pulmonary angiography images obtained using single-detector helical CT (SDCT), four-detector (4-MDCT), and eight-detector multidetector-row CT (8-MDCT) and compare the degree of motion artifact on the corresponding axial CT images.

MATERIALS AND METHODS

Three groups of consecutive patients imaged by means of CT angiography for suspected pulmonary embolus were retrospectively identified by using CT records at our institution: (1) group A (n = 38), SDCT; (2) group B (n = 36), 4-MDCT; and (3) group C (n = 74), 8-MDCT. For each case, coronal multiplanar volume reformation maximal intensity projection images were created by using a standard technique. All images were reviewed in a randomized fashion by two thoracic radiologists who were blinded to the type of CT scanner. Stair-step artifact of pulmonary arteries on coronal reformation images was graded by consensus agreement using a four-point scale (0 = no artifact to 3 = severe artifact). Axial images were assessed for six parameters of motion artifact. The sum of these grades resulted in a total motion score, with a potential range of 0 (no motion) to 12 (severe motion). Statistical analysis was performed using the Mann-Whitney test.

RESULTS

Stair-step artifacts were significantly higher for SDCT (mean, 2.9; median, 3) compared with 4-MDCT (mean, 2.2; median, 2; P < .0001) and 8-MDCT (mean, 1.5; median, 1; P < .0001). Total motion scores were significantly higher for SDCT (mean, 9.3) compared with 4-MDCT (mean, 8.4; P = .03) and 8-MDCT (mean, 6.8; P < .0001).

CONCLUSION

Stair-step artifacts are significantly higher with SDCT compared with MDCT. For MDCT, eight-detector scanners produce images with significantly less artifact than four-detector scanners.

Interactions between clarithromycin and digoxin in patients with end-stage renal disease

OBJECTIVE

To report a significant increase in the serum levels of digoxin associated with the use of clarithromycin in six patients undergoing renal replacement therapy.

CASE SUMMARY

All six patients were males with end-stage renal disease and in need of renal replacement therapy. Four patients were anuric. The mean age was 78.8 +/- 5.8 (66-83) years. All patients except one, who was treated by hemofiltration, were treated by hemodialysis. All patients except one, who had been treated with metildigoxin (0.35 mg/week), were also taking digoxin (0.375 mg/week). Clarithromycin was administered at a dose of 200-400 mg/day for the treatment of bronchitis in all patients. The concomitant administration of clarithromycin increased serum digoxin levels from 1.8-4.0-fold in all cases. In two of six cases, a high probability of digoxin intoxication and suspicion of digoxin intoxication was evident. In three of six cases, serum digoxin levels increased within 12 days after the co-administration of clarithromycin, while in the other three cases, serum digoxin levels were increased 53-190 days after the administration of clarithromycin.

CONCLUSION

The simultaneous administration of clarithromycin caused an increase in digoxin levels in six patients undergoing renal replacement therapy. The increase in the serum digoxin can be attributed to the inhibition of P-glycoprotein in the intestine and/or bile capillary rather than the kidney by clarithromycin since renal function was dramatically impaired, and four of the patients were anuric. The issue of why serum digoxin levels were increased so late in three patients undergoing renal replacement is unclear. However, this interaction seemed to be clinically significant even in ESRD patients, whose renal function was highly impaired. The simultaneous use of digoxin and clarithromycin should be avoided even in patients undergoing renal replacement therapy whose renal function is impaired, since digoxin levels may increase unexpectedly.

Prefrontal Neuronal Activity Encodes Spatial Target Representations Sequentially Updated After Nonspatial Target-Shift Cues

We examined prefrontal neuronal activity while monkeys performed a sequential target-shift task, in which, after a positional cue indicated the initial saccade target among 8 peripheral positions, the monkeys were required to internally shift the target by one position on every flash of a target-shift cue. The target-shift cue appeared in the center 0 to 3 times within a single trial and was always the same in shape, size, and color. We found selective neuronal activity related to the target position: when the target-shift cue implied the target shift to particular peripheral positions, neurons exhibited early-dominant and late-dominant activity during the following delay period. The early-dominant target-selective activity emerged early in the delay just after the presentation of the target-shift cue, whereas the late-dominant activity gradually built up toward the end of the delay. Because the target-shift cue was not related to any specific target location, the early-dominant target-selective activity could not be a mere visual response to the target-shift cue. We suggest that the early-dominant activity reflects the transitory representation for the saccade target that was triggered by the nonspatial target-shift cue, whereas the late-dominant activity reflects the target representation in the spatial working memory or the preparatory set for the possible impending saccade, being repeatedly updated during sequential target shifts.

High-Resolution CT Using MDCT: Comparison of Degree of Motion Artifact Between Volumetric and Axial Methods

OBJECTIVE

The purpose of this study was to compare the degree of motion artifact on high-resolution CT images obtained using volumetric and axial (nonvolumetric) CT methods.

CONCLUSION

Volumetric high-resolution CT is associated with significantly greater motion artifact compared with axial noncontiguous high-resolution imaging.

Functional Magnetic Resonance Imaging of Macaque Monkeys Performing Visually Guided Saccade Tasks

The frontal and parietal eye fields serve as functional landmarks of the primate brain, although their correspondences between humans and macaque monkeys remain unclear. We conducted fMRI at 4.7 T in monkeys performing visually-guided saccade tasks and compared brain activations with those in humans using identical paradigms. Among multiple parietal activations, the dorsal lateral intraparietal area in monkeys and an area in the posterior superior parietal lobule in humans exhibited the highest selectivity to saccade directions. In the frontal cortex, the selectivity was highest at the junction of the precentral and superior frontal sulci in humans and in the frontal eye field (FEF) in monkeys. BOLD activation peaks were also found in premotor areas (BA6) in monkeys, which suggests that the apparent discrepancy in location between putative human FEF (BA6, suggested by imaging studies) and monkey FEF (BA8, identified by microstimulation studies) partly arose from methodological differences.

Frequency and Severity of Air Trapping at Dynamic Expiratory CT in Patients with Tracheobronchomalacia

OBJECTIVE

The purpose of this study was to compare the frequency and severity of air trapping in patients with and without tracheobronchomalacia using dynamic expiratory volumetric CT.

MATERIALS AND METHODS

The study group consisted of 20 subjects, including 10 patients with bronchoscopically proven tracheobronchomalacia and 10 control subjects of similar ages without tracheobronchomalacia. All 20 subjects underwent MDCT performed at the end of deep inspiration and during dynamic expiration. The images were analyzed at three lung levels, and the extent of air trapping was assessed visually using a 5-point scale. For each subject, a total air-trapping score was derived by summing the values for the three lung levels (possible range, 0-12). Statistical analysis was performed using the Mann-Whitney U test.

RESULTS

In the tracheobronchomalacia group, 10 (100%) of 10 patients showed air trapping, with a median score of 5 (range, 2-12). In the control group, six (60%) of 10 subjects showed air trapping, with a median score of 2 (range, 0-3). The median total air-trapping score was significantly higher (p < 0.001) for the tracheobronchomalacia group compared with the control group. Excessive central airway collapse (expiratory reduction in cross-sectional area of > 50%) was seen on CT scans in all tracheobronchomalacia patients but in none of the control subjects.

CONCLUSION

Air trapping was observed with a higher frequency and greater severity in patients with tracheobronchomalacia than in a control group of patients of similar ages without tracheobronchomalacia.

Plasma triglyceride-rich lipoprotein remnants as a risk factor of 'Pokkuri disease'

In our recent report, it remained unclear whether or not triglyceride-rich lipoprotein remnants (RLP) were associated with the risk of sudden coronary death in younger cases without coronary atherosclerosis that were detected in about 10% of all sudden coronary death cases in Japan. These cases were categorized as 'origin unknown, but suspected to be due to coronary spasm', the so called 'pokkuri disease' in Japan. The present study population consisted of 108 sudden death cases without coronary atherosclerosis [(pokkuri disease n=57) and non-cardiac sudden death (control n=51)] aged 20-69 years from Kanagawa prefecture in Japan. All individuals had died suddenly and unexpectedly, most had no significant history of medical conditions including cardiac symptoms and had not taken medications prior to death according to their medical records. All the autopsies were performed within 12 h after death. Plasma total cholesterol (TC), triglycerides (TG), phospholipids, RLP-C and RLP-TG, VLDL-C, LDL-C, HDL-C, apolipoproteins A-I, A-II, B, C-II, C-III, E, Lp (a) and homocysteine were measured in postmortem plasma samples. The TG-rich lipoprotein remnants measured as RLP-C and RLP-TG were significantly higher in pokkuri disease compared with controls both in fasting and postprandial states (P<0.05 and P<0.001), indicating that RLP-C and RLP-TG were the most significant risk factor in pokkuri disease among the parameters tested in this study. In conclusion the TG level in RLP (RLP-TG) appeared to be strongly associated with the risk of sudden death in the absence of coronary atherosclerosis (pokkuri disease).

A case of adenocarcinoma with mixed subtypes displaying ground-glass opacity on high-resolution CT

We report a case of adenocarcinoma with mixed subtypes with pleural dissemination and lymphatic permeation, although the CT results showed ground-glass opacity that led to the diagnosis of bronchioloalveolar carcinoma without foci of active fibroblastic proliferation.

Neural mechanisms of memory retrieval: role of the prefrontal cortex

In the primate brain, long-term memory is stored in the neocortical association area which is also engaged in sensory perception. The coded representation of memory is retrieved via interactions of hierarchically different cortical areas along bottom-up and top-down anatomical connections. The functional significance of the fronto-cortical top-down neuronal projections has been relevantly assessed in a new experimental paradigm using posterior-split-brain monkeys. When the splenium of the corpus callosum and the anterior commissure were selectively split, the bottom-up visual signal originating from the unilateral striate cortex could not reach the contralateral visual cortical areas. In this preparation, long-term memory acquired through visual stimulus-stimulus association learning was prevented from transferring across hemispheres. Nonetheless, following the presentation of a visual cue to one hemisphere, the prefrontal cortex could instruct the contralateral hemisphere to retrieve the correct stimulus specified by the cue. These results support the hypothesis that the prefrontal cortex can regulate memory recall in the absence of bottom-up sensory input. In humans, functional neuroimaging studies have revealed activation of a distributed neural network, including the prefrontal cortex, during memory retrieval tasks. Thus, the prefrontal cortex is consistently involved in retrieval of long-term memory in primates.

Short communication: mapping of somatosensory cortices with functional magnetic resonance imaging in anaesthetized macaque monkeys

Functional magnetic resonance imaging (fMRI) in macaque monkeys is emerging as a potent candidate to bridge the gap between data from human fMRI studies and data from anatomy, electrophysiology and lesion studies in monkeys. The primary (SI) and secondary (SII) somatosensory cortices are the principal regions for somatosensory information processing and contain systematic representations of the body surface map (somatotopy). To examine the functional organization of the somatosensory cortices in anaesthetized macaque monkeys with fMRI, we asked whether focal and differential activation could be observed in SI and SII in response to tactile stimulation with two parameters: body sides (right and left) and body regions (hand and face). We found that changes in stimulus parameters elicited differential focal activation in both SI and SII in two ways. First, the hand and face stimulation activated SI and SII in the contralateral, but not in the ipsilateral, hemisphere. Second, the hand and face stimulation differentially activated two adjacent regions in both SI and SII. These fMRI results appear to correlate with previous mapping studies by other methods in the macaque somatosensory cortices. This study shows the feasibility of fMRI studies in mapping multiple sensory areas in monkeys by which we can distinguish between adjacent functionally distinct regions.

Memory retrieval under the control of the prefrontal cortex

Memory retrieval is a process wherein a distributed neural network reactivates the brain's representation of past experiences. Sensory long-term memory is represented among a population of neurones in the modality-specific posterior association cortex. The coded representation of memory can be retrieved by interactions of hierarchically different cortical areas along bottom-up and top-down anatomical connections. We examined the function of the prefrontal cortex in memory retrieval by two different approaches. Firstly, a meta-analysis of brain imaging studies revealed that the prefrontal cortex is reliably activated by memory retrieval in humans. Secondly, in order to determine the causal relationship between the prefrontal activations and memory retrieval, we designed a new experimental paradigm using posterior-split-brain monkeys. Following section of the splenium of the corpus callosum and the anterior commissure, visual stimulus-stimulus association learning within one hemisphere did not transfer to the other. Nevertheless, when a visual cue was presented to one hemisphere, the prefrontal cortex could instruct the contralateral hemisphere to retrieve the correct stimulus specified by the cue. These findings suggest that the prefrontal cortex can regulate the recall of long-term memory in the absence of bottom-up sensory inputs.

Bronchopulmonary arterial anastomosis at the precapillary level in human lung. Visualization using CT angiography compared with microangiography of autopsied lung

PURPOSE

To investigate the interrelationships between the bronchial and pulmonary circulations including the existence of precapillary bronchopulmonary arterial anastomoses.

MATERIAL AND METHODS

CT of bronchial arteriography (BAG-CT) was performed in 10 patients and BAG-CT during a pulmonary artery block test (PA-block) in 5 patients with lung cancer. Bronchial and pulmonary circulations were evaluated in 5 autopsied normal lungs by injecting silicone rubber with different colors into the bronchial and pulmonary arteries.

RESULTS

BAG-CT correlated well with the findings at silicone rubber injection into lung autopsy samples. BAG-CT demonstrated inflow of contrast medium into the pulmonary artery during PA-block in all cases, while no inflow was observed before and following reversal of PA-block. Mixed silicone rubber was observed in the lobar to subsubsegmental bronchial arteries in all cases and in the subsubsegmental pulmonary artery in one case.

CONCLUSION

Precapillary bronchopulmonary arterial anastomoses may exist at the level of the lobar bronchi to the periphery. If either the pulmonary or bronchial circulation is disturbed, flow occurs inside the anastomoses to supplement the other flow, especially flow from the bronchial to the pulmonary arteries via the anastomoses, which occurs within 30 min.

Top-down signal from prefrontal cortex in executive control of memory retrieval

Knowledge or experience is voluntarily recalled from memory by reactivation of the neural representations in the cerebral association cortex. In inferior temporal cortex, which serves as the storehouse of visual long-term memory, activation of mnemonic engrams through electric stimulation results in imagery recall in humans, and neurons can be dynamically activated by the necessity for memory recall in monkeys. Neuropsychological studies and previous split-brain experiments predicted that prefrontal cortex exerts executive control upon inferior temporal cortex in memory retrieval; however, no neuronal correlate of this process has ever been detected. Here we show evidence of the top-down signal from prefrontal cortex. In the absence of bottom-up visual inputs, single inferior temporal neurons were activated by the top-down signal, which conveyed information on semantic categorization imposed by visual stimulus-stimulus association. Behavioural performance was severely impaired with loss of the top-down signal. Control experiments confirmed that the signal was transmitted not through a subcortical but through a fronto-temporal cortical pathway. Thus, feedback projections from prefrontal cortex to the posterior association cortex appear to serve the executive control of voluntary recall.

Prediction of preterm delivery by combined use of simple clinical tests

OBJECTIVE

To investigate the usefulness of 4 clinical tests in detecting both the major symptoms (premature uterine contractility and cervical change) and causes (intrauterine infection) of preterm delivery (PTD). These were performed simultaneously on 683 pregnant women at 26 to 28 weeks of gestation.

METHODS

The following four tests were performed at study entry: 1) uterine contractility by the nipple stimulation test (NST); 2) cervical length (CL) measured by transvaginal ultrasonography; 3) measurement of granulocyte elastase in cervical secretion; and 4) measurement of oncofetal fibronectin in vaginal secretion. Pregnancy outcomes were followed up and recorded for the 683 women.

RESULTS

Those women with a CL <25 mm showed a significantly higher PTD rate than those with a CL > or =30 mm (13.3 vs. 2.3%). This difference was dominant in primiparous women. Those women with a CL of 25 to 29 mm formed a potentially high-risk group in which a positive NST was associated with a high incidence of PTD. In contrast, granulocyte elastase in cervical secretion had no predictive efficacy for PTD during these weeks of gestation. The oncofetal fibronectin test had a very low (0.5%) positivity rate and proved to be unsuitable for routine clinical use.

CONCLUSION

The data demonstrated the usefulness of the uterine contraction induction test by nipple stimulation (NST) and cervical length (CL) measurement by transvaginal ultrasonography. The combined evaluation of the NST, CL measurement, and fibronectin assay, when necessary, was useful for the prediction of PTD.

Effect of troglitazone on endocrine and ovulatory performance in women with insulin resistance-related polycystic ovary syndrome

OBJECTIVE

To investigate the effect of troglitazone, a new antidiabetic agent that improves insulin resistance, on endocrine, metabolic, and ovulatory performance in women with insulin resistance-related polycystic ovary syndrome (PCOS).

DESIGN

Prospective clinical study.

SETTING

Infertility outpatient clinic, Niigata University Hospital, Niigata, Japan.

PATIENT(S)

Thirteen women with PCOS and insulin resistance.

INTERVENTION(S)

Troglitazone (400 mg/d) was administered for 12 weeks.

MAIN OUTCOME MEASURE(S)

Insulin and other hormone (gonadotropins, androgens) levels; various parameters relating to glucose and lipid metabolism before, during, and after troglitazone administration; and ovulation rate.

RESULT(S)

The mean (+/-SD) fasting insulin concentration was significantly reduced, from 18.3+/-8.9 to 10.5+/-7.1 microU/mL. The LH level was reduced from 9.7+/-3.4 to 4.8+/-3.9 mIU/mL and the testosterone level was reduced from 0.9+/-0.5 to 0.5+/-0.3 ng/mL in accordance. Atherosclerotic lipid levels also were normalized. Before troglitazone administration, the ovulation rate during clomiphene citrate therapy was 34.9% per cycle (15/43). This increased significantly to 72.7% (8/11) during troglitazone coadministration. Further, an ovulation rate of 42.3% (11/26) was achieved with troglitazone alone.

CONCLUSION(S)

In women with PCOS and insulin resistance, the reduction of hyperinsulinemia that is produced by troglitazone improves the hyperandrogenism that characterizes PCOS, restoring ovulation.

Polycystic ovary syndrome. Insulin resistance and ovulatory responses to clomiphene citrate

OBJECTIVE

To evaluate insulin secretion detected on oral glucose tolerance testing in relation to clomiphene citrate (CC) responses in women with polycystic ovary syndrome (PCOS).

STUDY DESIGN

A total of 37 PCOS women were enrolled. Plasma baseline levels of gonadotropins, sex hormone binding globulin, androstenedione, dehydroepiandrosterone sulfate and testosterone (T) were determined. Insulin and glucose serum concentrations were analyzed in all samples after a 75-g oral glucose tolerance test. A dose of 100 mg/d of CC was given for ovulation induction. Ovulation was detected by ultrasonographic observation in conjunction with a serum progesterone level.

RESULTS

During three consecutive cycles of CC administration, two or more anovulatory cycles were observed in 12 of 37 PCOS women (defined as CC nonresponders). The serum T level and the area under the curve (AUC) of insulin were significantly higher in CC nonresponders. The receiver operating characteristic curve of the AUC of insulin provided the most appropriate cutoff point for the prediction of CC resistance.

CONCLUSION

We found higher androgen secretion and insulin resistance in CC nonresponders. The AUC of insulin was the most reliable method for the prediction of CC resistance associated with insulin resistance.

Prednisolone plus low-dose aspirin improves the implantation rate in women with autoimmune conditions who are undergoing in vitro fertilization

OBJECTIVE

To evaluate the effect of prednisolone plus low-dose aspirin (PSL/LDA) in women with autoimmune conditions who were enrolled in an IVF-ET program.

DESIGN

A retrospective clinical study.

SETTING

In vitro fertilization unit, Niigata University Hospital, Niigata, Japan.

PATIENT(S)

Three hundred seven women who underwent IVF-ET between January 1996 and December 1997.

INTERVENTION(S)

Prednisolone (10 mg/d) and aspirin (81 mg/d) were administered to the women with autoantibodies who chose to participate.

MAIN OUTCOME MEASURE(S)

Pregnancy and implantation rates with IVF-ET.

RESULT(S)

Women undergoing IVF who had positive antinuclear antibodies, with or without antiphospholipid antibodies, had significantly lower pregnancy and implantation rates than did women without autoantibodies (14.8% versus 21.7% and 6.8% versus 10.4%, respectively). The administration of PSL/LDA to women with antinuclear antibodies significantly improved the outcome of IVF-ET (40.6% pregnancy rate and 20.3% implantation rate).

CONCLUSION(S)

A high proportion of women who are undergoing IVF-ET have autoantibodies, which are associated with poor IVF outcomes. The administration of PSL/LDA to these women may improve their implantation rate.

Fatal bilateral adrenal hemorrhage following acute toluene poisoning: a case report

CASE REPORT

A 19-year-old woman was admitted to the emergency center with the development of quadriparesis after prolonged inhalation of lacquer thinner (67% toluene). Laboratory findings were compatible with a distal renal tubular acidosis manifest as metabolic acidosis, hypokalemia, and hyperchloremia. Despite potassium replacement, her condition deteriorated drastically 30 hours later. Blood pressure became refractory to vasopressors, temperature was persistently above 40 degrees C, and death occurred 56 hours later. At autopsy, adrenal insufficiency secondary to bilateral adrenal hemorrhage was diagnosed. Bilateral adrenal hemorrhage should be considered as a potential cause of sudden clinical deterioration during treatment of serious toluene intoxication.

Callosal window between prefrontal cortices: cognitive interaction to retrieve long-term memory

A perceptual image can be recalled from memory without sensory stimulation. However, the neural origin of memory retrieval remains unsettled. To examine whether memory retrieval can be regulated by top-down processes originating from the prefrontal cortex, a visual associative memory task was introduced into the partial split-brain paradigm in monkeys. Long-term memory acquired through stimulus-stimulus association did not transfer via the anterior corpus callosum, a key part interconnecting prefrontal cortices. Nonetheless, when a visual cue was presented to one hemisphere, the anterior callosum could instruct the other hemisphere to retrieve the correct stimulus specified by the cue. Thus, although visual long-term memory is stored in the temporal cortex, memory retrieval is under the executive control of the prefrontal cortex.

Consolidation of visual associative long-term memory in the temporal cortex of primates

Neuropsychological theories have proposed a critical role for the interaction between the medial temporal lobe and the neocortex in the formation of long-term memory for facts and events, which has often been tested by learning of a series of paired words or figures in humans. We have examined neural mechanisms underlying the memory "consolidation" process by single-unit recording and molecular biological methods in an animal model of a visual pair-association task in monkeys. In our previous studies, we found that long-term associative representations of visual objects are acquired through learning in the neural network of the anterior inferior temporal (IT) cortex. In this article, we propose the hypothesis that limbic neurons undergo rapid modification of synaptic connectivity and provide backward signals that guide the reorganization of neocortical neural circuits. Two experiments tested this hypothesis: (1) we examined the role of the backward connections from the medial temporal lobe to the IT cortex by injecting ibotenic acid into the entorhinal and perirhinal cortices, which provided massive backward projections ipsilaterally to the IT cortex. We found that the limbic lesion disrupted the associative code of the IT neurons between the paired associates, without impairing the visual response to each stimulus. (2) We then tested the first half of this hypothesis by detecting the expression of immediate-early genes in the monkey temporal cortex. We found specific expression of zif268 during the learning of a new set of paired associates in the pair-association task, most intensively in area 36 of the perirhinal cortex. All these results with the visual pair-association task support our hypothesis and demonstrate that the consolidation process, which was first proposed on the basis of clinico-psychological evidence, can now be examined in primates using neurophysiolocical and molecular biological approaches.