Successful selective production of vanillic acid from depolymerized sulfite lignin and its application to poly(ethylene vanillate) synthesis

Towards lignin upgrading, vanillic acid (VA), a lignin-derived guaiacyl compound, was produced from sulfite lignin for successfully synthesizing poly(ethylene vanillate), an aromatic polymer. The engineered Sphingobium sp. SYK-6-based strain in which the genes responsible for VA/3-O-methyl gallic acid O-demethylase and syringic acid O-demethylase were disrupted was able to produce vanillic acid (VA) from the mixture consisting of acetovanillone, vanillin, VA, and other low-molecular-weight aromatics obtained by Cu(OH)₂-catalyzed alkaline depolymerization of sulfite lignin and membrane fractionation. From the bio-based VA, methyl-4-(2-hydroxyethoxy)-3-methoxybenzoate was synthesized via methylesterification, hydroxyethylation, and distillation, and then it was subjected to polymerization catalyzed by titanium tetraisopropoxide. The molecular weight of the obtained poly(ethylene vanillate) was evaluated to be M_w = 13,000 (M_w/M_n = 1.99) and its melting point was 261°C. The present work proved that poly(ethylene vanillate) is able to be synthesized using VA produced from lignin for the first time.

Antifungal activity of simply fractionated organosolv lignin against Trametes versicolor

In an effort to achieve sustainable development goals, a reevaluation of the materials used in wooden buildings must be done, including the preservatives used to treat the materials. Since typical wood preservatives use toxic heavy metals, their handling and use can contaminate the environment. Therefore, substances such as lignin-derived components have been investigated as bio-based preservatives. Organosolv treatment is a promising technique for separating components of lignocellulosic biomass, which enables the utilization of each component. The present report describes components of lignocellulose with antifungal effects that were recovered after organosolv treatment using water and 1-butanol solvent at 473 K for 2 h, followed by simple solvent fractionation. The organosolv lignin was divided into three fractions: n-hexane soluble, ethyl acetate soluble, and ethyl acetate insoluble, yielding 23 wt%, 52 wt% and 13 wt%, respectively. Antifungal activity was determined using an agar plate method. White rot fungi (Trametes versicolor) was dispersed on the agar plate with a cellulose disc containing each lignin-derived fraction obtained from Japanese cedar. Results showed inhibition of fungal growth over the cellulose disc containing the n-hexane soluble fraction. To examine the effect in greater detail, the chemical structure of the n-hexane-soluble fraction on the antifungal activity was investigated. The content of phenolic hydroxyl group in n-hexane-soluble fraction was the highest (4.6 mmol/g), and the results from the chemical modification suggested that the functional group was required for antifungal action. In addition, the n-hexane-soluble fraction imparted some water resistance. The procedures used for cedar as a feedstock were applied to another type of biomass-bagasse-and its fractions showed antifungal activity similar to those of Japanese cedar.

POS0516 REDEFINING THE CLINICAL AND LABORATORY FEATURES OF RHEUMATIC PLEURAL EFFUSION: A 30-CASE SERIES

Background:

Rheumatoid pleural effusion (RPE) is a common extra-articular complication in patients with rheumatoid arthritis (RA). Previous studies have shown that RPE usually occurs in middle-aged men with rheumatoid factor (RF)-positive RA. RPE usually has features of pleural fluid acidosis, high lactate dehydrogenase (LDH) levels, and very low glucose levels(1). However, to the best of our knowledge, these findings were based on very few case series and reports, and most of these reports were published by the early 2000s(1, 2).

Objectives:

To investigate the clinical and laboratory characteristics and typical clinical courses of patients with RPE in a single centre of Japan since the beginning of the 21st century.

Methods:

Medical records of RPE patients were retrospectively reviewed between May 2006 and September 2020. RPE was identified by fulfilling these five conditions: (1) confirmation of the RA diagnosis; (2) having an exudative pleural effusion according to Light’s criteria; (3) negative results of pleural fluid culture; (4) negative results of pleural fluid cytology; and (5) exclusion of a parapneumonic effusion or empyema defined as no antibiotic use or ineffectiveness of antibiotics during the clinical course. Patients were divided into two groups according to their age at diagnosis: <60 years (Group A) and ≥60 years (Group B).

Results:

A total of 30 cases of RPE were included in the study. The median age was 71 years (interquartile range [IQR], 66–78 years). Of these patients, 16 (53%) were women. The median disease duration of RA was 98 months (IQR, 8–162 months). The two groups comprised six patients aged <60 years old and 24 patients ≥60 years. The median age was 54 years (IQR, 49–56 years) in Group A and 74 years (IQR, 69–78 years) in Group B. The median disease duration of RA was longer in Group B than that in Group A (132 vs. 3 months, p=0.008). Compared with Group A, Group B had fewer patients with fever (14% vs. 83%, p=0.003), and had lower serum C-reactive protein levels (3.3 vs. 11.1 mg/dL, p=0.03). Moreover, Group B was more likely to show mild inflammatory pleural fluids with higher pH (7.5 vs. 7.2, p=0.005) and lower LDH levels (155 vs. 1810 IU/L, p=0.046). Corticosteroids were started or increased in five (83%) and nine (38%) patients, and biologic disease-modifying anti-rheumatic drugs were started in one (17%) and two (8%) patients in groups A and B, respectively. One patient (16%) died within 5-years in Group A, and seven patients (29%) died in Group B.

Conclusion:

In contrast to previous studies, RPE was seen in older patients as well as middle-aged adults, and the pleural fluid analysis in older patients with RPE showed milder inflammation than the middle-aged patients.

References:

[1]Balbir-Gurman A, et al. Semin Arthritis Rheum. 2006 Jun; 35(6): 368-78.

[2]Faurschou P, et al. Thorax. 1985 May; 40(5): 371-5.

Table 1.

Comparison of clinical and laboratory findings between Group A and Group B.

Group A (n=6)Group B (n=24)P valueAge (years)54 [49-56]74 [69-78]Female2 (n=6, 33.3)14 (n=24, 58.3)0.38Disease duration of RA (months)3 [1-9]132 [44-199]0.008Fever ≥37.0°C5 (n=6, 83.3)3 (n=22, 13.6)0.003SerumCRP (mg/dL)11.1 [5.6-1.4]3.3 [0.9-10.5]0.03  RF (IU/mL)100 [19-816]63 [23-193]0.95  Anti-CCP ab positive5 (n=6, 83.3)12 (n=15, 80)1.00Pleural fluid analysispH7.2 [7.2-7.2]7.5 [7.4-7.5]0.005LDH (IU/L)1810 [594-2932]155 [123-346]0.046Glu (mg/dL)59 [10-123]105 [91-122]0.42Tp (g/dL)5.1 [4.9-5.6]4.6 [3.6-5.2]0.21Number of cells (/μL)5235 [3353-9300]3300 [1490-5008]0.27 Glu/serum Glu0.41 [0.09-0.99]1.05 [0.85-1.15]0.71Started or increased CS5 (n=6, 83.3)9 (n=24, 37.5)0.18Started bDMARDs1 (n=6, 16.6)2 (n=24, 8.3)0.50Died within 5 years1 (n=6, 16.6)7 (n=24, 29.1)1.00

Data are median [interquartile range], or number (total number, percent).

Abbreviations: RA, rheumatoid arthritis; CRP, C-reactive protein; RF, rheumatoid factor; Anti-CCP ab, anti-cyclic citrullinated peptide antibodies; LDH, lactate dehydrogenase; Glu, glucose; Tp, total protein; CS, corticosteroid; bDMARDs, biologic disease-modifying anti-rheumatic drugs

Disclosure of Interests:

None declared

Cyclosporin A Treatment in Intrinsic Canine Atopic Dermatitis (Atopic-like Dermatitis): Open Trial Study

In this study, dogs were separated into two groups and treated with immunosuppressant (Cyclosporin A: CsA). The first group was the canine atopic dermatitis (CAD) group, which is similar to extrinsic atopic dermatitis (AD) in humans (treated with a CsA dose of 2.5-5.5 mg/kg, n=8), and the second group was the canine atopic-like dermatitis (ALD) group, which is similar to intrinsic AD in humans (treated with a CsA dose of 2.5-6.5 mg/kg, n=14). The canine atopic dermatitis extent and severity index (CADESI)-4 was evaluated before treatment (PRE) and after treatment (POST) to assess the effectiveness of CsA for the two groups. In the CAD group, CADESI-4 showed no change (PRE:79±29, POST:77±28) and out of the eight dogs, no dogs showed complete remission, three dogs showed partial remission, and five dogs showed no effect. Whereas in the ALD group, CADESI-4 showed a significant reduction (PRE: 61±42, POST: 32±25, p<0.01) and out of the 14 dogs, 11 dogs showed complete remission, two dogs showed partial remission, and one dog showed no effect. The results indicate that the immunosuppressant showed effectiveness for the dogs diagnosed with ALD. One dog had to be treated for a year and eight months, which was the longest period in the study, this dog presented with hyperplasia of the lymphoidgland and mammary tumor.

Rush sublingual immunotherapy in canine atopic dermatitis: a prospective pilot study

Twenty dogs with canine atopic dermatitis (CAD) were treated with rush sublingual immunotherapy (SLIT), with a 48 hour build-up phase and 6 months maintenance phase (treated by antigen once every 3-4 weeks). The canine atopic dermatitis extent and severity index (CADESI)-4 was evaluated before treatment (baseline) and after 6 months. An open, non-controlled, non-randomized pilot trial was conducted to assess the effectiveness and safety of rush SLIT for environmental allergen extracts (Dematophagoides pteronyssinus and D.farinae mix and other). Three dogs dropped out and 17 dogs finished the trial. CADESI-4 at baseline was 60.6±27.1 (range 17-107, n=17). After 6 months of SLIT treatment, CADESI-4 was 37.4±36.0 (range 5-152, n=17) (p <0.01), which was a 38.3% reduction. A significant improvement, defined as a CADESI-4 reduction of > 30%, was observed in 13 out of 17 dogs (76%). A moderate improvement, defined as a CADESI-4 reduction of ≦30%, was observed in 2 dogs (12%). In the other 2 dogs (12%), CADESI-4 worsened or showed no change. However, no severe adverse effects were observed during the trial.

Therefore, rush SLIT against environmental allergen extract for CAD showed effectiveness and safety as evidenced by the reduction of CADESI-4 after 6 months SLIT without severe adverse effects.

Accuracy of pre- and postcontrast 3D time-of-flight MR angiography in patients with acute ischemic stroke: correlation with catheter angiography

BACKGROUND AND PURPOSE

3D time-of-flight (TOF) MR angiography (MRA) is insensitive to slow flow; however, the use of MR imaging contrast agents helps to visualize slow-flow vessels and avoids overestimation of vascular occlusion. The purpose of this study was to correlate pre- and postcontrast 3D TOF MRA with the results of conventional angiography during endovascular reperfusion therapy and to determine the accuracy of postcontrast 3D TOF MRA.

MATERIALS AND METHODS

Thirteen patients who underwent endovascular reperfusion therapy for acute ischemic stroke were retrospectively analyzed. MR imaging techniques included single-slab 3D TOF MRA with and without contrast, as well as perfusion-weighted imaging. Angiography during reperfusion therapy was used as a standard of reference. Affected arteries were divided into segments either proximal or distal to the lesion, and pre- and postcontrast MRA signals were graded as absent, diminished or narrowed, or normal.

RESULTS

In 2 of 5 patients with arterial stenosis and 6 of 8 patients with complete occlusion, MRA signal intensity proximal to each lesion was absent, indicating a proximal pseudo-occlusion on precontrast MRA. Postcontrast MRA demonstrated an arterial signal intensity proximal to the stenotic or occlusive lesions in all 13 patients. Arterial signal intensity distal to the occlusion was identified on postcontrast MRA in 7 of 8 patients having complete occlusion, and the extent of occlusion on postcontrast MRA was similar to results of conventional angiography.

CONCLUSION

In this small series, postcontrast 3D TOF MRA more accurately delineated the extent of stenotic or occlusive arterial lesions than precontrast MRA.

Three-dimensional fast recovery fast spin-echo imaging of the inner ear and the vestibulocochlear nerve

The aim of this study was to assess the performance of three-dimensional fast recovery fast spin-echo (3DFRFSE) for imaging of the inner ear as well as the facial and vestibulocochlear nerves. We evaluated 3DFRFSE sequences, comparing it with 3D fast spin-echo (3DFSE) in a water phantom and in 12 normal volunteers. We also examined 66 patients using 3DFRFSE sequence and assessed the visualization of their pathologies. In a water phantom study, signal intensity (SI) on 3DFRFSE was higher than that on 3DFSE at the same TR ranging from 1,500 to 6,000 ms. In normal volunteers, 3DFRFSE with TR of 2,800 ms showed comparable SI, and signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) superior to those on 3DFSE with TR of 5,000 ms. In clinical setting, 3DFRFSE was useful in demonstrating anatomic details in the labyrinth and pathologic findings of inner ear. The 3DFRFSE can provide high-resolution heavily T2-weighted images (T2WI) with shorter scan time than 3DFSE without significant disadvantage. The 3DFRFSE is a beneficial technique for evaluation of lesions in the inner ear as well as the facial and vestibulocochlear nerves.

Risk factors for the development of bladder transitional cell carcinoma following surgery for transitional cell carcinoma of the upper urinary tract

To determine the risk factors for development of transitional cell carcinoma (TCC) of the bladder (BTCC) following surgery for TCC of the upper urinary tract (UUT-TCC) in patients without history of BTCC, 85 patients surgically treated for UUT-TCC (34 female, 51 male; median age 66, range 42-85 years) were reviewed retrospectively. The Cox proportional hazards model was used to assess the association of relevant clinicopathologic factors with BTCC-free survival in patients without a history of BTCC and TCC-specific survival in all. Median follow-up duration was 35 (range 1-193) months. Six patients (7%) had previous histories of BTCC, and 6 others (7%) had concurrent BTCC at the time of surgery for UUT-TCC. Of 70 patients who had no history of BTCC and underwent follow-up cystoscopy, 24 (34%) developed BTCC during follow-up after surgery. Univariate analysis identified female sex, postoperative systemic chemotherapy, and incomplete distal ureterectomy as significant risk factors for new development of BTCC. After multivariate analysis adjusted for age and pathological (p) T stage in the TNM classification, all three factors remained significant, with respective hazard ratios of 5.56 (95% confidence interval (CI), 1.99-15.6; p = 0.001), 3.19 (95% CI, 1.34-7.62; p = 0.009) and 2.99 (95% CI, 1.08-8.26; p = 0.03). Only pT stage was a significant independent risk factor for TCC-specific death. Female sex and postoperative systemic chemotherapy, as well as incomplete distal ureterectomy, are possible riks factors for development of BTCC following surgery for UUT-TCC.

Differentiation between high-grade glioma and metastatic brain tumor using single-voxel proton MR spectroscopy

The purpose of this study was to clarify the efficacy of single-voxel proton magnetic resonance spectroscopy (MRS) in differentiating high-grade glioma from metastasis. Thirty-one high-grade gliomas (11 anaplastic gliomas and 20 glioblastomas) and 25 metastases were studied. Proton MRS was performed using point-resolved spectroscopy with echo times (TEs) of both 136 and 30 ms. The peaks for lipid were evaluated at short TE, and those for N-acetyl-aspartate (NAA), creatine (Cr), and choline-containing compounds (Cho) were assessed at long TE. All the tumors exhibited a strong Cho peak at long TE. Twenty-one of 25 metastases showed no definite Cr peak. The remaining 4 metastases showed NAA and Cr peaks; however, the presence of NAA and relatively high NAA/Cr ratio (1.58+/-0.56) indicated normal brain contamination. All the gliomas, except for a single glioblastoma, showed a Cr peak with (n=16) or without (n=14) NAA. At short TE all metastases and glioblastomas showed definite lipid or lipid/lactate mixture, but anaplastic gliomas showed no definite lipid signal. Intratumoral Cr suggests glioma. Absence of Cr indicates metastasis. Definite lipid signal indicates cellular necrosis in glioblastoma and metastasis, and no lipid signal may exclude metastases.

Local thrombolysis for acute ischemic stroke based on findings of diffusion and perfusion MRI

SUMMARY

Cerebral per fusion and cerebral tissue integrity were studied in 13 patients with acute embolic stroke in the territory of the internal carotid artery by diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) within six hours after onset. PWI/DWI mismatch lesion was depicted in six patients. MCA was occluded in five of six patients, who underwent local thrombolytic therapy. In three cases, complete restoration of the cerebral circulation was obtained and enlargement of irreversible brain damage compared to initial DWI lesion was prevented. Seven patients without PWI/DWI mismatch did not undergo thrombolytic therapy. Spontaneous reopening of occluded MCA was verified with subsequent cerebral angiography in one of seven patients. CT depicted symptomatic intracerebral hemorrhage in this patient. It is concluded that DWI and PWI in combination are useful in selection of patients for thrombolytic therapy.

Hypothalamic cholinergic regulation of body temperature and water intake in rats

Without disturbing the behavior of unanesthetized rats, the perfusion of neostigmine through microdialysis probe into the anterior hypothalamus (AH), paraventricular nucleus (PVN) and lateral ventricle (LV) decreased body temperature and increased water intake. On the other hand, the perfusion into the supraoptic nucleus (SON) increased the body temperature. The perfusion of neostigmine increased the extracellular concentration of acetylcholine in the perfusion sites except LV. Changes, both decrease and increase, in body temperature and increase in water intake were correlated with increases in c-fos-like immunoreactivity (Fos-IR) in the hypothalamus, pons and medulla. Distinct Fos-IR was found in the PVN, SON, median preoptic nucleus (MnPO), locus coeruleus (LC), area postrema and nucleus of the solitary tract (NTS). Co-administration of atropine with neostigmine completely suppressed the changes in the body temperature, water intake and Fos-IR, all of which were induced by the neostigmine perfusion into AH, PVN and SON. In the LV-perfused rats, on the other hand, co-administration of atropine and neostigmine only partially prevented body temperature reduction and still induced significant hypothermia. These results suggest that muscarinic receptor activation in specific regions of the hypothalamus and the activation of LC and NTS are implicated in the regulation of body temperature and water intake. Other receptor processes are involved in the LV-induced changes.

Development of obesity and neurochemical backing in aurothioglucose-treated mice

To clarify the neurochemical backing of aurothioglucose (ATG)-induced obesity in mice, we investigated lesion sites, hypothalamic neurotransmitters and c-Fos-like immunoreactivity (Fos-IR). At day 2 after ATG, tissue loss or cells death was observed in several parts of the ventral area of the ventromedial hypothalamic nucleus (VMH), and the dorsal area of arcuate nucleus and in the nucleus of the solitary tract (NTS). However, the greater part of the VMH was retained. Body weight began to increase in week 1. Hypothalamic serotonin (5-HT) and the metabolites were increased at day 2. The contents of acetylcholine, norepinephrine and dopamine in the hypothalamus showed no significant change. In week 1, the area shown tissue loss was compacted and plugged up. In the control group, most obvious c-Fos-like immunoreactive region was paraventricular nucleus (PVN). At day 2, Fos-IR was observed around destroyed regions in the hypothalamus and NTS, but few Fos-IR was found in the other regions including PVN. The Fos-IR around destroyed regions diminished after week 1. In week 3, Fos-IR in the PVN increased. These results suggest that the development of ATG-induced obesity cannot be attributed to solely VMH destruction. The restoration processes of the neuronal dysfunction involving PVN seem to play an important role in the development of obesity. NTS lesion and 5-HT system might contribute to decrease in food intake for several days after ATG.

Opposite regulation of body temperature by cholinergic input to the paraventricular nucleus and supraoptic nucleus in rats

Hypothalamic cholinergic system plays an important role in the regulation of body temperature and fluid balance. We have previously shown that cholinergic stimulation of the anterior hypothalamus and preoptic area was accompanied by a fall in body temperature, increased water intake, and increased Fos protein in the paraventricular nucleus (PVN) and supraoptic nucleus (SON). In the present study, to estimate the role played by cholinergic input to the PVN and SON in thermoregulation and water intake, we used microdialysis for cholinergic stimulation with neostigmine and analysis of the nucleus, and also investigated immunoreactivity for c-Fos protein in the brain. This stimulation increased extracellular concentration of acetylcholine in these nuclei. Stimulation of the PVN decreased body temperature and increased water intake. On the other hand, stimulation of the SON increased body temperature. Both in PVN-stimulated and SON-stimulated rats, c-Fos-like immunoreactivity (Fos-IR) was evident in the PVN, SON and certain regions including locus coeruleus (LC), area postrema and nucleus of the solitary tract (NTS). Addition of atropine to the dialysis medium attenuated the increase of Fos-IR and suppressed the cholinergic stimulation-induced responses in body temperature and water intake. These results suggest that cholinergic muscarinic mechanisms in PVN and SON play an opposite function in the regulation of body temperature. The same neuronal pathway including LC and NTS may participate in an advance both in hypothermia and in hyperthermia.

Hypothalamic neuroactivity in specific processes and central regulation of body temperature and water intake

The method described was designed to elucidate the role of a particular neuronal system or specific nucleus in the central nervous system (CNS) in controlling physiological and biological functions. The neurochemical aspects of the CNS regulatory mechanism and related networks remain to be further investigated. There is little information available about the relationship between neuroactivity in the specific brain nuclei and physiological or biological responses in mammals. An adequate analysis of this relationship provides valuable insight to clarify which nucleus and what types of neurons are truly involved in the excitation of physiological events and its regulation. In the present study, we used microdialysis for stimulation of the anterior hypothalamus (AH) and simultaneous analysis of cholinergic activity, and we investigated c-Fos-like immunoreactivity (Fos-IR) in the brain in the same animal following microdialysis. The nuclear protein c-Fos, the product of c-fos oncogene, has been used as a marker of neuronal activity at the cellular level in the brain. Various physiological and pharmacological stimuli have been shown to induce Fos-IR in specific neuronal populations located in various regions of the brain. However, there are few studies investigating the responses produced by c-Fos expression in specific regions in same animals. We showed the involvement of hypothalamic cholinergic mechanisms in the thermoregulatory and water regulatory processes using the above procedures.

Changes in presynaptic proteins, SNAP-25 and synaptophysin, in the hippocampal CA1 area in ischemic gerbils

A general consensus exists that the presynaptic terminals in the hippocampal CA1 area are resistant to ischemic stress in spite of the loss of their target cells (CA1 pyramidal neurons). We have verified this by immunostaining and Western immunoblotting using the antibodies for presynaptic proteins, synaptosomal-associated protein of 25 kDa (SNAP-25) and synaptophysin in gerbils after bilateral carotid artery ligature. In the immunohistochemical analysis, decreases in SNAP-25 and synaptophysin immunoreactivities in the strata radiatum and oriens, especially around the apical dendrite of CA1 neurons, and disappearance of SNAP-25 immunoreactivity in the alveus were observed on day 2 after ischemia. On days 7 and 14, SNAP-25-positive granular materials were expressed in the CA1 area, and intense synaptophysin immunoreactivity around surviving CA1 neurons was observed. Western immunoblot analysis revealed significant decreases of SNAP-25 and synaptophysin (about 60% of control levels) on day 2, and then increase of their proteins (130--140% of control levels) on day 14. These results indicate that presynaptic degeneration occurs in the hippocampal CA1 area after ischemia, and it precedes the delayed neuronal death of CA1 neurons. The presynaptic terminal damage may be responsible for some pathological changes in ischemic brains.

Cholinergic input to the supraoptic nucleus increases Fos expression and body temperature in rats

To examine the role played by cholinergic input and processes in the supraoptic nucleus (SON) in the control of body temperature and water intake in rats, we used microdialysis to stimulate and analyze SON without disturbing the behavior of unanesthetized rats. After microdialysis, we also investigated immunoreactivity for c-Fos protein in the brain as an index of neuronal activation. Stimulation with neostigmine, an acetylcholine esterase inhibitor, through the microdialysis probe increased the extracellular concentration of acetylcholine in the SON. This cholinergic stimulation dose-dependently increased body temperature but did not significantly change the water intake. The stimulation markedly increased c-Fos-like immunoreactivity (Fos-IR) in the SON and certain hypothalamic areas, including the paraventricular nucleus (PVN) and median preoptic nucleus (MnPO). Fos-IR was also evident in certain regions of the pons and brainstem, including the locus ceruleus (LC), area postrema (AP), and nucleus of the solitary tract (NTS). Addition of atropine, a muscarinic receptor antagonist, to the dialysis medium containing neostigmine attenuated the increase of Fos-IR and suppressed the neostigmine-induced responses in body temperature. These results suggest that cholinergic input and activation of the muscarinic cholinoceptive neurons in the SON contribute to the regulation of body temperature. Activation of noradrenergic pathways in the brainstem including LC and NTS may be involved in the thermoregulation mechanism.

Diagnostic potential of short echo time MR spectroscopy of gliomas with single-voxel and point-resolved spatially localised proton spectroscopy of brain

Accurate neuroimaging grading of gliomas is useful for management, but techniques such as MRI and CT are not sufficiently reliable. Necrosis is a consistent, decisive prognostic factor and the key diagnostic criterion for glioblastoma multiforme. MR spectroscopy (MRS) allows noninvasive measurement of metabolites in brain tumours and mobile lipids reflect necrosis. However, short echo-time (TE) spectroscopy has been required for reliable assessment of lipids, since their relaxation times are very short. Recent advances have made it possible to perform short-TE MRS. We attempted to evaluate the significance of short TE spectroscopy as part of routine imaging for diagnosis and grading of gliomas. We performed TE 30 ms MRS in 25 patients with gliomas (grade II six; grade III three; grade IV, 16) and in 19 areas of healthy white matter using proton brain examination/single voxel (PROBE/SV) and point-resolved spatially localised spectroscopy (PRESS). With short-TE spectroscopy, lipid signals were detected in all 16 tumours of grade IV, one grade II (P = 0.0002) and none of grade III (P = 0.001). TE 136 ms MRS, carried out in 20 of these cases, showed lipid signals in only four of 14 grade IV tumours and in none of the other six. N-acetylaspartate/choline (NAA/Cho) ratios were always more than 1.0 in healthy tissues and less than 1.0 in all but one of the gliomas. The mean creatine (Cr)/Cho ratio in each tumour grade was significantly lower than in the healthy tissues. The mean Cr/Cho ratio was also significantly lower in grade IV than in grade II tumours (P < .0005). Considerable overlap in Cr/Cho ratio was observed between grade II and grades III and IV gliomas at long but less so at short-TE MRS. We conclude that short-TE MRS with PROBE/SV and PRESS is of value in grading gliomas.

Deep vein thrombosis during chemotherapy in a patient with advanced testicular cancer: successful percutaneous thrombectomy under temporary placement of retrievable inferior vena cava filter

A 27-year-old man with advanced testicular cancer experienced two events of deep vein thrombosis (DVT) during three cycles of cisplatin-based combination chemotherapy; the first thrombotic event occurred in the inferior vena cava (IVC) following the initial two cycles of chemotherapy and the second thrombotic event occurred in the right iliac vein following the third cycle. For both thrombotic events, he was successfully managed with thrombolytic therapy and percutaneous thrombectomy using a transcatheter hydraulic thrombectomy device under temporary placement of a retrievable IVC filter. Stasis of the IVC due to compression by a retroperitoneal lymphadenopathy of 7 cm in diameter, which was demonstrated on computed tomographic scans at presentation, was considered a major cause of DVT during chemotherapy. Patients with bulky retroperitoneal disease causing stasis of major veins are at high risk of DVT associated with chemotherapy and thromboprophylaxis should be strongly considered during their chemotherapy.

Role of preoptic and anterior hypothalamic cholinergic input on water intake and body temperature

To elucidate the role played by cholinergic mechanism in the preoptic area (POA) and anterior hypothalamus (AH) in the control of body temperature and water intake of rats, we used microdialysis without disturbing the behavior of unanesthetized animals. After microdialysis, we also investigated immunoreactivity for c-Fos protein in the hypothalamus. Stimulation with neostigmine, an acetylcholine esterase inhibitor, through microdialysis probe increased extracellular concentration of acetylcholine (ACh) in the POA and AH, and was accompanied by a dose-dependent fall in body temperature and increased water intake. Addition of atropine, a muscarinic receptor antagonist, to the dialysis medium containing neostigmine suppressed the neostigmine-induced changes in rectal temperature and water intake. Neostignime markedly increased c-Fos-like immunoreactivity (Fos-IR) in certain hypothalamic areas, including the paraventricular nucleus, supraoptic nucleus and median preoptic nucleus. This increase was also attenuated by atropine. These results suggest that cholinergic inputs and activation of muscarinic processes in POA and AH induced a decline in body temperature and increased water intake.

Effects of an oriental herbal medicine, "Saiboku-to", and its constituent herbs on Compound 48/80-induced histamine release from peritoneal mast cells in rats

Effects of a traditional oriental herbal medicine, "Saiboku-to" and its constituent herbs on Compound 48/80-induced histamine release from peritoneal mast cells in rats were investigated. Saiboku-to inhibited Compound 48/80-induced degranulation of and histamine release from the mast cells, suggesting that Saiboku-to not only possesses anti-histamine release effect from mast cells, but also contains active herbs with this effect. Significant inhibitions were found in 4 of 10 constituent herbs of Saiboku-to: Magnoliae Cortex, Perillae Herba, Bupleuri Radix and Hoelen. In the dose-response curves of the four herbs, the logarithmic linearity was observed for each herb, and 50% inhibitory concentration, the IC50 values, were calculated to be 56.8 microg/ml for Magnoliae Cortex, 175.8 microl/ml for Perillae Herba, 356.6 microg/ml for Bupleuri Radix, and 595.8 microg/ml for Hoelen. One mg/ml of Saiboku-to showing 75% inhibition of Compound 48/80-induced histamine release level from mast cells contains 88.5 microg of Magnoliae Cortex (it was estimated from the dose-response curve that this dose inhibits 62.68% of the Compound 48/80-induced histamine release level), 58.8 microg of Perillae Herba (21% inhibition), 205.9 microg of Bupleuri Radix (35.24% inhibition), and 147.1 microg of Hoelen (11.15% inhibition). From these results, it is suggested that the anti-histamine release effect of Saiboku-to, which contains 10 herbs, may be due mainly to the effect of Magnoliae Cortex and the synergism of the 3 other herbs.

A putative chemoattractant receptor, C5L2, is expressed in granulocyte and immature dendritic cells, but not in mature dendritic cells

Leukocyte chemoattractants are involved in the inflammatory response act via G protein-coupled receptors. We report the cloning of a novel human gene encoding the putative orphan receptor, C5L2, belonging to a subfamily of C3a, C5a and formyl Met-Leu-Ph receptors that are related to the chemokine receptor family. C5L2 transcript levels were abundant in granulocytes and immature dendritic cells but not in mature dendritic cells. We speculate that this receptor may regulate the activation of immature dendritic cells and play a role in the chemoattraction of leukocytes to inflammatory regions.

Learning and memory in mice treated with choline oxidase, a hydrolytic enzyme for choline

Learning and maintenance of memory in mice intraperitoneally (IP) injected with choline oxidase (ChO, 6 units/g), a hydrolytic enzyme for choline (Ch), were assessed by means of a step-through passive-avoidance task. The ChO treatment induced a hydrolysis of free Ch in plasma, which in turn, induced a decrease in cerebral acetylcholine (ACh) release. In the learning test, the ChO-treated mice showed significant inhibition to learn the avoidance from electric shock. In the retention test, the impairment of the memory once established was not produced by posttreated ChO. We concluded that the decreased cerebral cholinergic neurotransmission induced by ChO retarded acquisition of passive-avoidance learning more readily than the maintenance of memory.

Neurochemical determination of the location of NMDA and GABA receptors on rat striatal cholinergic neurons

This paper reports on the protocol for neurochemical determination of the location of various receptors on cholinergic neurons in various brain regions. We applied this protocol to investigate whether NMDA and GABA receptors are located on rat striatal cholinergic neurons. When striatal cholinergic neurons were selectively destroyed by intrastriatal injection of cholinergic neurotoxin, ethylcholine mustard aziridinium ion (AF64A), the number of NMDA and GABA(A) receptors decreased. However, no significant changes were observed on the number of GABA(B) receptors. These results suggest that NMDA and GABA(A), but not GABA(B) receptors are located on cholinergic neurons in the striatum. These results also indicate the usefulness and scientific applicability of the present protocol.

Measurement of circulating T cell subsets positive for Fas antigen (CD95) in patients with alcoholic hepatitis

T cell subsets positive for Fas antigen in peripheral blood of patients with alcoholic hepatitis were measured, using monoclonal antibodies in two colour immunofluorescence assay with flowcytometry. 1) In the patients with alcoholic hepatitis, the ratio of mean +/- standard deviation (M +/- SD) of CD4+ cells positive for CD95 (Fas antigen) in peripheral blood lymphocytes of patients with alcoholic hepatitis tended to increase, but the ratio of CD95-positive cells in CD4+ cells of peripheral blood was almost the same, compared with those of healthy controls. In the alcoholics (overdrink) who did not show alcoholic hepatitis with or without apparent alcoholic damage, the ratio of CD95-positive CD4+ cells in peripheral blood lymphocytes was within normal range, while CD95-positive cells in CD4+ cells of peripheral blood tended to decrease. 2) In the alcoholic hepatitis, the ratios of CD8+ cells positive for CD95 and CD95-positive cells in CD8+ cells of peripheral blood decreased significantly, and in the alcoholics (overdrink) they also tended to decrease. 3) The fluorescence intensity of CD95 on CD4+ cells in peripheral blood of the alcoholics (overdrink) decreased apparently, although the one on CD8+ cells did not. 4) The ratios of T cell subsets, that is, CD4+ and CD8+ cells, positive for HLADR in peripheral blood of the patients with alcoholic hepatitis increased significantly, respectively. These results showed that the ratio of CD8+ cells positive for Fas antigen in peripheral blood of the patients with alcoholic hepatitis decreased. It was suspected that this finding might be due to the direct effect of intaken alcohol to T cell subsets rather than hepatitis, and/or the result of immunological homeostasis in alcoholic hepatitis.

[Presurgical mapping with functional MRI: comparative study with transcranial magnetic stimulation and intraoperative mapping]

PURPOSE

The accuracy of preoperative mappings in patients with brain tumors near the central sulcus using functional magnetic resonance imaging (fMRI) or transcranical magnetic stimulation (TCS) was evaluated by comparative reference to intraoperative mapping.

METHODS

The thumb movement was evoked by TCS for the mapping of the motor cortex. After the placement of the marker determined by TCS on the scalp, fMRI under motor tasks consisting of repetitive grasping was performed. For motor cortex activation, an axial oblique plane to maximize gray matter sampling in the rolandic cortex was employed in order to compare these different mapping techniques more precisely. Sixteen patients with brain tumors were included in this study.

RESULTS

In nine patients, fMRI disclosed activation in one restricted gyrus or in the localized area around one restricted sulcus. Of these nine patients, preoperative TCS mapping corresponded closely with fMRI in six, while in the remaining three, the TCS marker fell between 1 and 2 cm apart from the fMRI-activated area. However, in these three patients, intraoperative electrocortical stimulation corresponded with the preoperative mapping with fMRI. In six patients, contigucus two gyri were activated by motor tasks. The TCS marker was disclosed on one of the two activated gyri. Of these six patients, the position of the TCS marker and fMRI-activated site corresponded with each other in four cases. They were found on the same gyrus but there was 1.0-2.0 cm distance between them in two cases. Intraoperative somatosensory evoked potential was monitored in two of these six cases. They corresponded well with the mapping by fMRI and TCS together. In only one patient, no significant activation area was obtained by fMRI because of excessive head motion during motor tasks. The TCS marker in this patient was identical with intraoperative electro-cortical stimulation mapping.

CONCLUSION

For presurgical planning in patients with brain tumor near the central sulcus, comparative evaluation with fMRI and TCS is applicable and provides accurate functional mapping.

Daily time budgets of long-distance commuting workers in Tokyo megalopolis

In Tokyo Megalopolis, long-distance commuting between residences in the suburbs and work places in the centre of the city was examined. Using a questionnaire, heads of household in two suburbs were asked about the influences of long commuting hours on their daily time budgets. The results showed that on workdays, the workers who spent longer commuting rose and left home for work earlier, and came back home and retired later; accordingly, both time spent on in-home activities on workdays and hours slept on the day before a workday were shorter. Comparison of time budgets between the subjects who work 5 and 6 days per week revealed more vulnerable influences of long commuting hours in the former than the latter. The expected health consequences of these findings are discussed from a biosocial/human ecological viewpoint.

Phytoalexins from hairy roots of Hyoscyamus albus treated with methyl jasmonate

The treatment of hairy roots of Hyoscyamus albus with copper sulfate (Cu2+) and methyl jasmonate (JAMe) produced several phytoalexins having the vetispyrane skeleton. Lubimin and solavetivone were isolated after treatment with Cu2+. Seven sesquiterpenoid phytoalexins were isolated from the culture medium after treatment with JAMe, including lubimin, solavetivone, 3-hydroxysolavetivone and four new compounds (1-4). Structures of the new compounds were elucidated to be (3R,4S,5R,7S,9R)-3-hydroxy-9-tigloyloxysolavetivone (1), (3R,4S,5R,7S,9R)-3-hydroxy-9-(3-methylbutenoyloxy)-solavetivone (2), (3R,4S,5R,7S,9R)-3-hydroxy-9-isobutanoyloxysolavetivone (3); and (3R,4S,5R,7S,9R)-3,9-dihydroxysolavetivone (4). The induction pattern of phytoalexins in hairy roots treated with JAMe was different in those treated with Cu2+, and co-treatment with JAMe and Cu2+ gave only solavetivone.

Stimulation of rat hypothalamus by microdialysis with K+: increase of ACh release elevates plasma glucose

The effects of stimulation of the ventromedial hypothalamus (VMH) or lateral hypothalamus (LH) with potassium chloride through a microdialysis probe were studied. The concentrations of ACh and norepinephrine (NE) in the dialysate obtained from the hypothalamic nuclei and plasma glucose concentration were measured. Stimulation of the hypothalamic nuclei, VMH and LH, with potassium increased the plasma glucose level as well as the extracellular concentrations of ACh and choline. Addition of atropine, a muscarinic ACh receptor antagonist, into the potassium solution reduced the increase in the level of plasma glucose. Cholinergic stimulation of these nuclei with neostigmine increased the extracellular concentrations of ACh and plasma glucose. Stimulation of the nuclei with potassium also increased the release of NE. However, stimulation of the VMH or LH with NE and/or pargyline, a monoamine oxidase inhibitor, through the dialysis probe membrane did not significantly increase the plasma glucose concentration. These results suggest that activation of the muscarinic cholinergic or ACh-receptive neurons in the hypothalamic nuclei, VMH and LH, contribute to the elevation of plasma glucose level.

The role of nitric oxide in striatal acetylcholine release induced by N-methyl-D-aspartate

Effect of nitric oxide (NO) on striatal acetylcholine (ACh) release induced by N-methyl-D-aspartate (NMDA) was investigated in freely moving rats by means of microdialysis. NMDA caused a significant increase in ACh release in the striatum, which was blocked by the specific NMDA receptor antagonists, (+/-)-3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP) and (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine hydrogen maleate (MK-801), indicating that agonist-evoked increase in ACh release in the striatum was through an NMDA receptor-mediated mechanism. NG-monomethyl-L-arginine acetate salt (L-NMMA; a NO synthase inhibitor) facilitated NMDA-evoked increase in ACh release, while L-arginine (the precursor of NO) inhibited the ACh release. The increase by L-NMMA of ACh release induced by the NMDA was also blocked by L-arginine. These results suggest that NO induced by NMDA receptor-mediated mechanism in cholinergic neurons may mediate an inhibitory regulation of ACh release.

Direct regulation of acetylcholine release by N-methyl-D-aspartic acid receptors in rat striatum

The aziridinium ion of ethylcholine (AF64A), a cholinergic neurotoxin, was injected into the right striatum of a rat. The unilateral injection of 10 nmol AF64A reduced the activity of choline acetyltransferase (CAT) and the tissue content of acetylcholine (ACh) in the striatum. The striatal contents of dopamine (DA), norepinephrine (NE), 5-hydroxyindoleacetic acid (5-HIAA) and gamma-aminobutyric acid (GABA) were unchanged. These results suggest that the cholinospecificity in the striatal lesion was induced by the 10 nmol dose of AF64A. The number of N-methyl-D-aspartic acid (NMDA) receptors in the striatum treated with 10 nmol AF64A was determined by a specific binding assay using [3H](+/-)-3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid ([3H]CPP), a selective ligand for NMDA receptors. The number of the NMDA receptors decreased significantly in the injected area. On the other hand, in a microdialysis using normal rats, the perfusion of 50 microM NMDA into the striatum increased ACh release. The perfusion of 100 microM MK801 which is the specific and non-competitive NMDA receptor antagonist, decreased the basal levels of ACh release and blocked NMDA-elicited ACh release. Taken together, the present results strongly suggest that a population of NMDA receptors exists on cholinergic interneurons within the striatum, and it directly regulates ACh release.

[Non-Hodgkin's lymphoma of the spermatic cord: a case report]

A 77-year-old man presented with a 2-week history of a painless lump in the left groin. He underwent left radical orchiectomy under a diagnosis of left spermatic cord tumor. The specimen revealed a 5 x 3 cm solid tumor arising in the spermatic cord at the level of the symphysis pubis. On microscopic examination, the tumor was classified as a diffuse, large cell non-Hodgkin's malignant lymphoma in the Working Formulation, involving a small portion of the upper pole of the left testis. Immunohistochemical stains were positive for LCA and L26. Gallium scan showed increased activity along the left testicular artery in the abdomen. The patient underwent 6 cycles of chemotherapy consisting of cyclophosphamide, vindesine, pirarubicin, prednisone and subsequently the addition of etoposide, which resulted in only temporary improvement. He died with extensive disease 10 months after surgery.

NGF delays rather than prevents the cholinergic terminal damage and delayed neuronal death in the hippocampus after ischemia

Cerebral ischemia induces damage of cholinergic terminals in the hippocampus, which preceded the delayed neuronal death (DND) of the CA1 pyramidal cells. We investigated the effects of nerve growth factor (NGF) on the cholinergic terminal damage after ischemia. Continuous NGF infusion (0.5 microg/7 days) into the lateral ventricle before and after 5 min ischemia prevented a decrease in choline acetyltransferase (ChAT)-immunoreactivity and disturbance of acetylcholine (ACh) release on the 4th day after ischemia, but not on day 7, i.e., NGF infusion caused delay in the progress of the cholinergic terminal damage. These findings show that the cholinergic terminal damage may result from deficiency of endogenous NGF in an ischemic brain. In addition, we investigated whether NGF would prevent the DND after ischemia. NGF infusion also caused delay in the progress of the DND until day 14. Our results suggested that the neuroprotective effect of NGF on the DND may be secondarily yielded by maintenance of communication between cholinergic terminal and the target CA1 cell, and that prevention of cholinergic terminal damage may be useful for the treatment of cerebrovascular disease.

High forskolin production in hairy roots of Coleus forskohlii

Hairy roots of Coleus forskohlii were induced by infection with the Agrobacterium rhizogenes MAFF 03-01724 strain. Growth and forskolin production of two hairy root clones cultured in various liquid media were examined. Hairy root clone B9 grew well in woody plant liquid medium and showed a high forskolin yield (ca. 1.3 mg/ 100 ml flask) after 5 weeks of culture. The time course of growth and forskolin production of the clone B9 cultured in woody plant liquid medium was also examined. Rapid growth started at week 2 and continued until week 5. The highest forskolin yield (ca. 1.6 mg/100 ml flask) was obtained at week 5. Productivity was much higher than that previously reported.

Changes in presynaptic protein NACP/alpha-synuclein in an ischemic gerbil hippocampus

We observed temporal changes in NACP (precursor protein of non-Abeta component of Alzheimer's disease amyloid), a presynaptic protein a.k. a. alpha-synuclein, in the hippocampus after 5 min ischemia. Intense NACP immunoreactivity was seen transiently around cerebral blood vessels in the CA1 subfield on day 4, and NACP-positive unusual tubal and chain-like structures developed on month 6. We suggest that the changes in NACP may play an important role in the ischemic pathogenesis.

Stable isotope methodology for kinetic studies of interconversion of cortisol and cortisone in a human subject

Oral administration of 5 mg each of deuterium-labeled cortisol ([1,1,19,19,19-2H5]cortisol, cortisol-d5) and cortisone-d5 ([1,1,19,19,19-2H5]cortisone) to a human subject on two different occasions four weeks apart provided a useful means of characterizing the kinetics of the interconversion of cortisol and cortisone. From the data on plasma concentration measurements of cortisol-d5, cortisone-d5, cortisone-5, endogenous cortisol and endogenous cortisone by gas chromatography-mass spectrometry, it was demonstrated that (1) the plasma concentration ratio of cortisone-d5 to cortisol-d5 approached a plateau 4-5 h following either the cortisol-d5 or cortisone-d5 administration and the plateau values for the cortisone-d5 and cortisol-d5 administration were almost identical (about 0.43) and (2) dosing with only 5 mg of the deuterium-labeled steroids suppressed the plasma concentrations of endogenous cortisol and cortisone.

Relations between the extracellular concentrations of choline and acetylcholine in rat striatum

Changes in extracellular levels of acetylcholine (ACh) and choline (Ch) in the striatum of rats were examined by in vivo microdialysis after intraperitoneal injections of drugs. A dopamine D2 antagonist, sulpiride (20 mg/kg), and a muscarinic antagonist, atropine (3.5 mg/ kg), increased ACh levels and decreased Ch levels. On the contrary, the D2 agonist (+/-)-2-(N-phenylethyl-N-propyl)amino-5-hydroxytetralin (N-434; 5 mg/kg) and an anesthetic, pentobarbital (50 mg/kg), decreased ACh levels and increased Ch levels. Perfusion of 10 microM hemicholinium-3 (HC-3), a Ch uptake inhibitor, through the striatum induced a complete inhibition of ACh release and increased Ch levels in all drug-treated groups. The degree of relative increase in the level of Ch induced by HC-3 differed among the drug-pretreated groups; compared with the control group, the relative increase was larger in the sulpiride- and atropine-treated groups and smaller in the N-434 and pentobarbital-treated groups. Thus, we demonstrated reciprocal relations between extracellular concentrations of Ch and ACh after treatments by drugs. The data suggest that in the striatum, which is rich in cholinergic innervation, the extracellular Ch concentration is to a large extent determined by activity of the cholinergic transmission reflected in high-affinity choline uptake.

Effects of ventromedial hypothalamus stimulation on glycogenolysis in rat liver using in vivo microdialysis

In vivo microdialysis was applied to study the effects of ventromedial hypothalamus (VMH) stimulation on liver glycogenolysis under anesthesia. We examined glucose output and norepinephrine (NE) outflow from the liver through analysis of glucose and NE in the liver dialyzate. Stimulation of the VMH increased glucose output and NE outflow from the liver and increased the plasma glucose level. Similar results were obtained on hepatic nerve stimulation. Bilateral adrenalectomy did not abolish the glycogenolysis induced by VMH stimulation. NE outflow increased to a much greater extent in adrenalectomized rats. These data show that VMH stimulation causes glycogenolysis and glucose output from the liver mainly via the hepatic nerves, and that microdialysis is a simple and useful method for the study of liver metabolism in vivo.

Neural mechanism of pupillary dilation elicited by electro-acupuncture stimulation in anesthetized rats

The neural mechanisms to reflex dilation elicited by electro-acupuncture stimulation were investigated in anesthetized rats. Two needles, with 160 microns diameter and about 5 mm apart, were inserted into the skin and underlying muscle of a hindpaw. Repetitive 20 Hz, 0.5 ms electrical pulses at various intensities were used for stimulation for 30s. The pupil size was magnified about 44 times via a microscope and was continuously recorded on a videotape. Electro-acupuncture stimulation at more than 0.5 up to 6 mA induced stimulus intensity-dependent pupil dilation. These responses were abolished by the severance of the sciatic and saphenous nerve of the stimulated hindlimb. Compound action potentials were recorded from the distal cut end of the tibial of a saphenous nerve following electro-acupuncture stimulation of the hindpaw. The mean threshold of the compound action potentials of the myelinated fibers in saphenous nerves was 0.18 mA, while that of unmyelinated fibers was 3.0 mA. The mean threshold of the compound action potentials of the myelinated fibers in the tibial nerve was 0.20 mA of unmyelinated fibers was 3.3 mA. Severance of bilateral trunks did not affect the response, while severance of the third cranial nerves abolished the responses. In conclusion, electro-acupuncture stimulation applied to the hindpaws of the anesthetized rats induced excitation of myelinated or of both myelinated and unmyelinated afferent fibers of the tibial and saphenous nerve, and involved a reflex response of pupil dilation through the third cranial parasympathetic efferent nerve.

Comprehensive analysis of neurotransmitters and their metabolites including acetylcholine and choline in rat brain nuclei

We have designed this method for the comprehensive and adequate analysis of neurotransmitters and metabolites including acetylcholine (ACh) and choline in specific brain nuclei. In physiological and pharmacological studies, the role of specific neurotransmitters in the central nervous system (CNS) has often been studied by microinjection of their agonist and antagonist into the target regions, with the action and role of the transmitter in question being deduced in a relatively straightforward manner from the results. However, none of these studies have investigated fluctuation in neurotransmitter and metabolite contents in response to a variety of stimuli in vivo. No comprehensive analysis of neurotransmitters in small specific area in the CNS has been undertaken due to the difficulties of proper analysis of ACh and choline. Different types of neuronal systems in the CNS affect each other. Thus, it is not necessarily clear that different types of neurons do in fact respond to an administered agonist and antagonist. For example, dopaminergic neuron mediated control of cholinergic interneuron in the striatum and dopaminergic regulation of cortical ACh release have been documented. Similarly, the cholinergic system affects dopaminergic and noradrenergic neurons. Intraventricular administration of an ACh esterase inhibitor, neostigmine, increases dopamine and noradrenaline release in the hypothalamus. So, an adequate comprehensive analysis of the transmitters and the metabolites in the same tissue sample provides valuable aid to clarify what types of neurons truly respond to the administered drugs and the excitation of physiological events. For an appropriate analysis we employed a microwave device, which made the estimation of ACh and choline possible. In addition to this, we employed a punch technique for the microdissection of the specific nuclei and area from the brain slice.

Suppression of cholinergic activity via the dopamine D2 receptor in the rat striatum

The effect of dopamine (DA) D2 receptor on extracellular choline (Ch) and acetylcholine (ACh) levels in rat caudate-putamen (striatum) was investigated by means of microdialysis. The systemic, intraperitoneal (i.p.), injection of (+/-)-2-(N-phenylethyl-N-propyl) amino-5-hydroxytetralin (N-434), a specific DA D2 receptor agonist decreased striatal ACh release in a dose-dependent manner and the i.p. injection of sulpiride, a specific DA D2 receptor antagonist, increased the ACh release in a dose-dependent manner. In contrast, extracellular Ch levels were increased by the agonist and decreased by the antagonist. An increased Ch uptake was observed in sulpiride-treated rats and a decreased Ch uptake was observed in N-434-treated rats. The effects of the D2 agonist on extracellular Ch, ACh and Ch uptake were completely antagonized by the D2 antagonist. These results suggest clearly an inhibition of ACh release by D2 receptor activation, contrasting with previous findings on DA-ACh interaction. The inverse relationship between extracellular Ch and ACh reflects a change in the Ch uptake owing to a change in cholinergic neuron activity via the D2 receptor mechanisms.

Regulation of dopamine D1 and D2 receptors on striatal acetylcholine release in rats

The effects of dopamine (DA) D1 and D2 receptors on striatal acetylcholine (ACh) releases were investigated by in vivo microdialysis. All drugs were applied via dialysis membrane directly to the striatum. The levels of ACh release were increased by 10(-4) M SKF38393, a D1 receptor agonist. Although 10(-4) M SCH23390, a D1 receptor antagonist, exhibited an increase in the levels of ACh release, the agonist (10(-4) M) induced-increase in the levels of ACh release was suppressed by coperfusion of the antagonist (10(-4) M). In contrast, the levels of ACh release were decreased by the D2 receptor agonist, N-434, in a dose-dependent manner (10(-4) M to 10(-7) M) and increased by the D2 receptor antagonist, sulpiride, in a dose-dependent manner (10(-5) M to 10(-7) M). The agonist (10(-5) M) induced-decrease in the levels of ACh release was suppressed by coperfusion of the antagonist (10(-4) M). Coperfusion of D1 (10(-4) M) and D2 (10(-5) M) agonists blocked both effects of respective drug alone. In order to clarify the effect of endogenous DA, two drugs with different mechanisms for enhancing DA concentration in the synaptic cleft, the DA release-inducer methamphetamine, and the DA uptake inhibitor nomifensine were perfused separately. Both (10(-4) M to 10(-5) M) produced a dose- and a time-dependent decrease in the levels of ACh release. Significant higher levels of ACh release were observed in the striatum of the 6-hydroxydopamine (8 micrograms/10 microliters)-treated rats with significant depletion of striatal DA content. These results suggest that in striatal DA-ACh interaction ACh release, as cholinergic interneuron's activity, is tonically inhibited via the D2 receptor, mainly by dopaminergic input, and the D1 receptor probably modifies the effect of the D2 receptor indirectly.

Hypothalamic cholinergic activity and 2-deoxyglucose-induced hyperglycemia

To clarify the role of the hypothalamic cholinergic system in the regulation of peripheral glucose metabolism, we investigated hypothalamic cholinergic activities after administration of 2-deoxyglucose (2-DG). Intravenous administration of 2-DG (500 mg/kg) caused neuroglycopenia and marked hyperglycemia; the level of plasma glucose increased to 210% of the initial levels of 20 min. For evaluation of the cholinergic activity, we employed a microwave device and subsequently analyzed the contents of acetylcholine (ACh) and choline after microdissection of the hypothalamic nuclei, ventromedial hypothalamic nucleus (VMH), lateral hypothalamus (LH), and paraventricular nucleus (PVN). In addition, we analyzed fluctuation of extracellular levels of ACh using in vivo brain microdialysis. A decrease in the ACh content, and a corresponding increase in the choline content, was observed in those hypothalamic nuclei min after administration of 2-DG. In the microdialysis perfusate, on the other hand, extracellular level of ACh was increased by 2-DG administration. These data show that ACh release, which is cholinergic activity, was increased after 2-DG administration. Our results suggest the involvement and importance of the hypothalamic cholinergic system in 2-DG-induced hyperglycemia.

Effects of MK-801 and pentobarbital on cholinergic terminal damage and delayed neuronal death in the ischemic gerbil hippocampus

The present study covers both the effects of MK-801, a noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist, and pentobarbital on cholinergic terminal damage and delayed neuronal death (DND) in ischemic gerbil. To study the above effects, in vivo microdialysis, immunohistochemical, and morphological techniques were used. MK-801 (3 mg/kg) or pentobarbital (50 mg/kg) were injected intraperitoneally 1 h or 30 min before 5 min ischemia, respectively. Each estimation was then carried out 4, 7, or 14 days after ischemia. Ischemia induced a significant decrease in acetylcholine (ACh) release and a disappearance of choline acetyltransferase (ChAT)-immunoreactivity in the hippocampus in addition to inducing DND. On day 4, MK-801 protected ischemia-induced DND in the hippocampal CA1 subfield. However, MK-801 had no effect against the decrease in ACh release in spite of protection of the decrease in ChAT-immunoreactivity. On day 7 and 14, no protective effect of MK-801 was observed in all estimations. It became clear that the mechanism of cholinergic terminal dysfunction is different from that involved in pyramidal cell death, i.e., excitative neurotoxicity induced by overabundant extracellular glutamate. Pentobarbital also provided protection against DND. However, protective effects of pentobarbital on the decrease in ACh release and the low ChAT-immunoreactivity were incomplete. Our present study indicated a limitation on the efficacy of NMDA receptor antagonist and barbiturate against cerebral ischemia.