Adenosine A1-receptor agonist attenuates the light-induced phase shifts and fos expression in vivo and optic nerve stimulation-evoked field potentials in the suprachiasmatic nucleus in vitro

Adenosine is widely accepted to act as an inhibitory neuromodulator in the mammalian central nervous system. In the present study, we examined whether adenosine receptor agonist modifies the photic entraining responses in the rat suprachiasmatic nucleus both in vivo and in vitro. Light (200 lux, 15 min)-induced phase shifts of hamster wheel-running rhythms was attenuated by a systemic administration of A1-adenosine receptor agonist N6-cyclohexyladenosine (N-CHA) in a dose-dependent manner; 0.5 mg/kg N-CHA caused 60% inhibition of light-induced phase shifts. On the other hand, A2-adenosine receptor agonist N6-[2-(3,5-dimethoxyphenyl)-2-(2-methylphenyl)-ethyl]adenosine (DPMA) failed to inhibit light-induced phase shifts. Systemic administration of N-CHA but not of DPMA inhibited light (300 lux, 1 h)-induced Fos expression in the suprachiasmatic nucleus in a dose-dependent manner; 1 mg/kg N-CHA caused 73% inhibition of light-induced Fos expression. Bath application of N-CHA but not of DPMA inhibited optic nerve stimulation-evoked field potentials in rat suprachiasmatic nucleus slices. The present results suggest that activation of adenosine A1-receptor attenuates the photic input through the inhibition of retinohypotalamic pathway to the SCN.

Positions of disulfide bonds in yam (Dioscorea japonica) acidic class IL (class IV) chitinase

Yam acidic class I chitinase belongs to a low molecular weight subclass of class I (class IL; corresponds to class IV) chitinase. The positions of disulfide bonds in this chitinase were examined. Chitinase protein was digested with acid protease and thermolysin, and the resulting disulfide bond containing peptides were separated by reversed-phase HPLC and detected using the SBD-F (7-fluorobenzo-2-oxa-1,3-diazole-4-sulfonic acid ammonium salt) method. Four intradisulfide bonds containing peptides were purified and three disulfide bonds in the catalytic domain were identified as Cys-66 and Cys-115, Cys-128 and Cys-136, and Cys-218 and Cys-250. Location of disulfide bonds in the catalytic domain was identical to that of barley class II chitinase but different from rye class II chitinase at the C-terminal. Conservation of S-S bonds at the N-terminal half of the catalytic domain between class I and class II chitinases strongly suggests that this region is important for formation of the active site.

Will thallium-201 replace gallium-67 in salivary gland scintigraphy?

We investigated and compared findings on combined 99mTc pertechnetate-201Tl with those of [99mTc]pertechnetate-67Ga scintiscans to elucidate the advantages of 201Tl in detecting various salivary glands disorders.

METHODS

We studied 23 patients: 6 had sialadenitis, 12 had benign tumors and 5 had malignant tumors. All but four patients had undergone [99mTc]pertechnetate (before and after lemon stimulation), 201Tl (early and delayed) and 67Ga imaging.

RESULTS

Five of six sialadenitis patients showed various degrees of diffuse uptake of 99mTc. All six except one showed early uptake without retention of 201Tl on delayed imaging. The 67Ga scan showed uptake in all patients except one. Nine of 12 benign tumors showed a cold defect on 99mTc scans. Patients with Warthin's tumors and plasmacytoma showed increased 99mTc uptake at the tumor with retention. The 201Tl scan showed early uptake without retention in benign tumors except in three patients, two of whom had Warthin's tumor. Five of the benign tumors, however, were positive on 67Ga scan. None of the malignant tumors showed any uptake of 99mTc. The 201Tl scan showed uptake with tumor retention on delayed images in three patients; three other patients also had positive 67Ga scans. Overall, sensitivity and specificity of 201Tl in detecting malignant tumors were 60% and 73%, respectively, with a negative predictive value of 85%. Sensitivity and specificity for 67Ga were 60% and 47%, respectively, with a negative predictive value of 80%.

CONCLUSION

In view of sensitivity, specificity and convenience of 201Tl as well as future prospects for dual-isotope acquisition, 67Ga may be replaced by 201Tl in detecting salivary gland disorder.

[89Sr Therapy for pain relief in patients with bone metastases]

Radioactive strontium chloride (89Sr) was administered for pain relief in 6 patients with bone metastases (4 prostate cancer and 2 breast cancer patients). Out of 6 patients, 2 showed apparent relief of bone pain and improvement of QOL, and 3 showed slight relief of the pain with or without improvement of QOL; that is, 83% was effective. Side effects were seen in 2 patients; transient deterioration of bone pain in one patient and bone marrow suppression in the other patient. The patient who showed bone marrow suppression had rather more lesions of bone metastasis (diffuse metastasis) and least urinary excretion of the radioactivity. Urinary excretion for 2 days varied 5 to 40% of the administered dose and was less in the patients with more metastatic lesions.

Microglial activation by epileptic activities through the propagation pathway of kainic acid-induced hippocampal seizures in the rat

We studied the distribution of activated microglia in the brain during kainic acid-induced acute hippocampal seizures in rats. Although no microglial activation was observed 4 h after seizure induction, activation was detected in the primary focus and also in other selected structures in the limbic and non-limbic structures after 8 and 24 h, in the absence of any obvious morphological changes in the neurons. The structures with activated microglia were highly consistent with those included in the propagation pathways of the hippocampal seizures. These findings thus suggest that the microglial cells are activated through the propagation pathways by the seizure activities that propagate transynaptically from the primary focus, even without any apparent neuronal injury.

Studies on the magnitude and the mechanism of cough potentiation by angiotensin-converting enzyme inhibitors in guinea-pigs: involvement of bradykinin in the potentiation

One adverse effect of the angiotensin-converting enzyme (ACE) inhibitors used for treatment of hypertension and congestive heart failure is the production of dry coughs. Imidapril is a new type of ACE inhibitor with a very low incidence of coughs. The magnitude and the mechanism of cough potentiation of imidapril and other ACE inhibitors has been studied in guinea-pigs. In normal guinea-pigs single and repeated dosing of imidapril at 0.1 to 100 mg kg-1 had no effect on capasaicin- or citric acid-induced coughs. Single and repeated dosing of enalapril and captopril at 10 to 30 mg kg-1, respectively, significantly increased the number of capsaicin-induced coughs. Repeated dosing of 1 mg kg-1 enalapril also significantly augmented the capsaicin cough. In bronchitic guinea-pigs imidapril also had no effect on the coughs induced by the two stimulants. Enalapril and captopril significantly increased the number of coughs induced not only by capsaicin but also by citric acid. Lower doses of enalapril were enough to augment the capsaicin-induced coughs, whereas medium to large doses failed to augment the cough irrespective of the protocol of administration. Bradykinin-induced discharges of the vegal afferents from the lower airway were significantly increased by enalaprilat but not by imidaprilat. Capsaicin-induced discharges of the afferents were, on the other hand, significantly depressed by enalaprilat, but not by imidaprilat. Interestingly, enalaprilat depression of the discharges was significantly reversed by Hoe-140, a bradykinin B2 receptor blocker. In guinea-pigs pretreated with a low dose of enalapril, arterial infusion of bradykinin significantly potentiated the coughs induced by capsaicin. The results indicated that imidapril was less potent than enalapril and captopril in potentiating cough responses induced by capsaicin and citric acid in guinea-pigs, and further suggest that bradykinin might be a key substance in the mechanism of the potentiation of coughs associated with ACE inhibitors.

Progressive expression of immunomolecules on activated microglia and invading leukocytes following focal cerebral ischemia in the rat

In order to evaluate the involvement of inflammatory reactions following focal cerebral ischemia in the rat, we immunohistochemically visualized microglial cells and blood-borne leukocytes (neutrophils and monocytes) using various antibodies directed against immunomolecules expressed on these cells. Focal cerebral ischemia was produced by intraluminal occlusion of the right middle cerebral artery for 1 h. The brains were perfusion-fixed at 4 h, 1 day, 3 days, 7 days and 14 days after ischemia. Frozen brain sections were prepared and stained with monoclonal antibodies to complement receptor type 3 (OX42), major histocompatibility complex (MHC) class I and class II antigens (OX18 and OX6, respectively), a pan-macrophage/monocyte marker (ED1), intercellular adhesion molecule-1 (ICAM-1), LFA-1 alpha chain (CD11a) and beta chain (CD18), and T cells (CD5). In ischemic areas where infarction developed later, microglial cells were destroyed (beginning at 4 h), neutrophils migrated (1-3 days), and then monocytes/macrophages infiltrated and covered the entire lesions (3-14 days). The invading leukocytes expressed CD11 and CD18 adhesion molecules on their cell surface while ICAM-1 was expressed on endothelial cells. In surrounding areas, in contrast, there was a rapid activation of microglia showing morphological changes and upregulation of OX42 immunoreactivity (4 h-7 days), especially in the transitional rim of the infarct (7 days). ED1 and MHC antigens were expressed on both activated microglia and invading leukocytes. Thus, developing infarction was accompanied by accumulation of inflammatory cells of both intrinsic (microglia) and extrinsic (leukocytes) origins. Thus, results suggest that the relative importance of each source is determined by the time after ischemia and the site within the lesion, and that the expression of immunological molecules plays an important role in eliciting such inflammatory reactions.

Involvement of p53 in DNA strand break-induced apoptosis in postmitotic CNS neurons

The tumour suppressor p53 gene serves as a critical regulator of the cell cycle and of apoptosis following the exposure of normal cells to DNA damage. To examine the role of p53 in postmitotic CNS neurons, we cultured cerebellar neurons from normal wild-type mice and mutant p53-null mice under various conditions inducing neuronal death. When cerebellar neurons from 15- to 16-day postnatal wild-type mice were treated with ionizing radiation or DNA-damaging agents, massive neuron death occurred after 24-72 h. In contrast, neurons from p53-/- mice evidently resisted gamma-irradiation and some DNA-damaging agents, such as etoposide and bleomycin. On the other hand, low-K+ medium-induced apoptosis of cerebellar neurons was not affected by p53 status. Neither cell cycle progression nor DNA synthesis occurred during cell death induced by gamma-irradiation and low-K+ medium, as well as in normal cultures of p53+/+ and p53-/- neurons. These results suggest that p53 is required for the apoptotic death of postmitotic cerebellar neurons induced by DNA strand breaks.

Uptake of technetium-99m-tetrofosmin, technetium-99m-MIBI and thallium-201 in tumor cell lines

We investigated the kinetics, cellular uptake and intracellular distribution of 99mTc-tetrofosmin in tumor cell lines and compared them with those of 99mTc-MIBI and 201TI.

METHODS

At specific intervals after incubation with radiotracers, cellular uptake was determined. Cells were also treated with nigericin, carbonyl cyanide m-chloro-phenylhydrazone (CCCP) and ouabain to determine their effects on the uptake of the tracers.

RESULTS

Each tracer showed similar uptake kinetics in both cell lines, and a steady-state was maintained for at least 4 hr. Nigericin stimulated the uptake of both 99mTc-tetrofosmin and 99mTc-MIBI in HBL-2 cells, although it inhibited their uptake in SW-13 cells. Nigericin also inhibited 90% of 201TI uptake in both cell lines. Addition of CCCP caused 73%-97% release of accumulated 99mTc-MIBI from both cell lines with or without nigericin pretreatment, indicating that most of the accumulated 99mTc-MIBI was related to mitochondria. The effect of CCCP on accumulated 99mTc-tetrofosmin was less marked than that on 99mTc-MIBI in both cell lines, indicating that only a part of accumulated 99mTc-tetrofosmin, was related to mitochondria. Ouabain preincubation inhibited 74%-77% and 51%-53% of 201TI uptake in HBL-2 and SW-13 cells, respectively, as well as inhibited 22%-31% uptake of 99mTc-tetrofosmin in both HBL-2 and SW-13 cells. Uptake by the dead cells of either cell line was negligible for each tracer.

CONCLUSION

Technetium-99m-tetrofosmin uptake depends on both cell membrane and mitochondrial potentials. Only a small fraction of 99mTc-tetrofosmin accumulates inside the mitochondria, while most 99mTc-MIBI accumulates inside the mitochondria. Thallium-201 uptake is partly independent of the Na+, K+ pump.

Clothing microclimate temperatures during thermal comfort in boys, young and older men

To examine the effects of age-related differences in thermoregulatory function on the clothing microclimate temperature (Tm) and Tm fluctuations while maintaining thermal comfort in daily life, 5 boys (group B, 10-11 years), 5 young men (group Y, 20-21 years) and 5 older men (group O, 60-65 years) volunteered to take part in this study. The subjects were asked to maintain thermal comfort as closely as possible in their daily lives. Tm (temperatures between the skin surface and the innermost garment) at four sites (chest, back, upper arm, and thigh), skin temperature on the chest (Tchest) and ambient temperature (Ta) were measured over a period of 8-12 h from morning to evening on one day in each of the seasons, spring, summer, autumn, and winter. Records of ability to maintain thermal comfort and of adjustment of their clothes were kept by each subject. Ta during periods of thermal comfort did not differ among the groups in any of the seasons. In group Y, Tm was significantly lower at the thigh than at the other sites in spring, autumn, and winter (P < 0.05) and fluctuations (CV) of Tm were significantly larger at the thigh than at other sites in autumn and winter (P < 0.05). Similar tendencies were observed for Tm and CV of Tm in group B. However, Tm and CV of Tm in group O did not differ by site except for the autumn Tm. Group O had a smaller CV at the thigh in winter (P < 0.05), compared to groups B and Y, suggesting a smaller regional difference in Tm fluctuation in group O. Group O adjusted their clothes even on the lower limbs (together with upper body) in order to maintain thermal comfort in accordance with changes in Ta, while groups B and Y did so only on their upper bodies. These results suggest that compared to boys and young men, lower thermoregulatory function in older men may affect Tm and CV of Tm as a result of clothing on lower limbs being adjusted differently in order to maintain thermal comfort.

Tl-201 uptake and retention in a Warthin's tumor

We report scan findings of Tl-201 in a case of histologically proved Warthin's tumor. Dual isotopes acquisition was performed in a case of left parotid Warthin's tumor. Both early and delayed Tc-99m-pertechnetate (Tc-99m) images showed increased uptake at the tumor. Tl-201 scan also showed an increase of uptake on the early image and retention on the delayed image. The uptake ratios of Tl-201 were 3.0 (early) and 2.3 (delayed). Scan findings of Tl-201 in a case of Warthin's tumor were similar to those of Tc-99m, and the interpretation of Tl-201 images should be accompanied with Tc-99m images.

Ninjurin, a novel adhesion molecule, is induced by nerve injury and promotes axonal growth

Peripheral nerve injury results in axonal degeneration and in phenotypic changes of the surrounding Schwann cells, whose presence is critical for nerve regeneration. Using differential screening strategies, we identified a novel protein, termed ninjurin (for nerve injury-induced protein), that is up-regulated after axotomy in neurons and in Schwann cells surrounding the distal nerve segment. Ninjurin is located on the cell surface, is capable of mediating homophilic adhesion, and promotes neurite extension of dorsal root ganglion neurons in vitro. Ninjurin is also expressed in a number of other tissues, predominantly in epithelial cells. These results suggest that ninjurin plays a role in nerve regeneration and in the formation and function of other tissues.

Regional age-related alterations in cholinergic and GABAergic receptors in the rat brain

The age-related changes of cholinergic and gamma-aminobutyric acid (GABA)ergic receptors were studied in 3-week- and 6-, 12-, 18- and 24-month-old Fisher 344 male rat brains using receptor autoradiography. [3H]Quinuclidinyl benzilate (QNB), [3H]hemicholinium-3 (HC) and [3H]muscimol were used to label acetylcholine receptors, acetylcholine reuptake sites and GABAA receptors, respectively. In immature rats (3-week-old), [3H]QNB and [3H]muscimol binding showed a significant increase in most brain areas, compared to adult young animals (6-month-old), whereas [3H]HC binding exhibited a significant increase only in the dentate gyrus, substantia nigra and cerebellum. In contrast, [3H]QNB and [3H]HC binding showed no significant changes in all brain areas during aging. On the other hands, [3H]muscimol binding showed a significant reduction in the substantia nigra and cerebellum of adult mature rats (12-month-old). Thereafter, the age-related reduction in [3H]muscimol binding was observed in all brain areas of aged rats (24-month-old). Our results demonstrate that the GABAergic system is susceptible to aging processes in the central nervous system, whereas the cholinergic system is unaltered by aging. Furthermore, our results suggest significant regional changes in both GABAergic and cholinergic systems in the brain even 3 weeks after birth. These findings suggest that the disturbance in GABAergic-cholinergic interactions may play a key role in age-related neurological deficits and cognitive dysfunction.

An Economic Analysis of Water and Sanitation Infrastructure Improvements in the Colonias of El Paso County, Texas

The authors conducted a cost-benefit analysis of a project to improve water supply and sanitation infrastructure in a rural community (colonia) along the United States-Mexico border. The present value of total costs in the scenario without improvements was $42,937,507, compared with net costs with improvements of $34,600,800. It is estimated that improved access to safe drinking water and solid waste sanitation prevented 155 cases of hepatitis A and 5,165 cases of gastrointestinal illness over 26 years and saved $846,541 in associated health care costs, approximately 10% of the total estimated savings. The majority of benefits was in the form of time savings and increased land values. The authors did not consider the value of improving environmental conditions for future generations and preventing communicable disease epidemics associated with poor sanitation. Accurate value estimates for these benefits might strengthen the argument for undertaking similar infrastructure-improvement projects in the colonias and in other underdeveloped rural areas of the United States. cost-benefit analysis; water supply and sanitation; health care costs; disease-prevention effectiveness Hanley & Belfus, Inc. Int J Occup Environ Health 1077-3525 2 3 1996 July/September Decreases in Subpopulations of T Lymphocytes and Natural Killer Cells in the Blood of Retired Chromate Workers 222 225 EN Takeshi Tanigawa Shunichi Araki Department of Public Health, Faculty of Medicine, University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo 113, Japan. Akinori Nakata Takaharu Araki Susumu Sakurai To examine the effects of past exposure to chromates on lymphocyte subpopulations in man, the authors measured subpopulations of T lymphocytes and natural killer (NK) cells by flow cytometry together with B lymphocytes in blood samples from 27 male workers and 22 healthy controls. All subjects were nonsmokers. The numbers of CD4+CD45RA+ (suppressor-inducer), CD8+ (suppressor/cytotoxic) and total T lymphocytes, CD16+CD57+ NK cells, and total lymphocytes in the blood of chromate workers were significantly smaller than those in the blood of healthy controls (analysis of covariance with age as a covariate). It is suggested that suppressor-inducer and suppressor/cytotoxic T lymphocytes and NK cells with intermediate NK cell activity are most susceptible to the effects of past exposure to chromates as compared with other lymphocyte subpopulations such as B and CD4+CD29+ T lymphocytes.

Age-related change of mineral content in the human thoracic aorta and in the human cerebral artery

The relative contents (RCs) of mineral elements in aortae and cerebral arteries from 23 subjects, with ages ranging between 45 and 99 yr, were analyzed by inductively coupled plasma atomic emission spectrometry. The RCs of calcium, phosphorus, and magnesium in the aortae increased markedly after the age of 70. While the RC of sulfur in aortae decreased gradually after that age. It was found that accumulation of calcium and phosphorus occurred primarily in the tunica media of aorta, and secondarily in the tunica intima. Furthermore, the RCs of calcium, phosphorus, and magnesium in cerebral arteries increased markedly after the age of 70, whereas the RC of sulfur in cerebral arteries decreased after age 70. It was found that accumulation of calcium and phosphorus in the cerebral arteries were 30 and 60%, respectively, lower than those in the aortae with ages ranging between 45 and 99 yr.

N (epsilon)-(carboxymethyl)lysine protein adduct is a major immunological epitope in proteins modified with advanced glycation end products of the Maillard reaction

Long-term incubation of proteins with glucose leads to the formation of advanced glycation end products (AGE). Recent immunological studies have suggested the potential role of AGE in atherosclerosis, aging, and diabetic complications. We previously prepared a monoclonal (6D12) as well as a polyclonal anti-AGE antibody and proposed the presence of a common AGE structure(s) that may act as a major immunochemical epitope [Horiuchi, S., Araki, N., & Morino, Y. (1991) J. Biol. Chem. 266, 7329-7332]. The purpose of the present study was to determine the major epitope. Amino acid analysis of AGE-proteins indicated that N(epsilon)-(carboxymethyl)lysine (CML) was a major modified lysine residue. Immunologic studies demonstrated the positive reaction of 6D12 not only to all CML-modified proteins tested, but also to BSA modified with several aldehydes known to generate a CML-protein adduct, and a linear correlation between the CML contents of CML-BSA and their immunoreactivity to 6D12 up to approximately 8 mol/mol of protein. Further experiments with CML analogs revealed that the epitope of 6D12 is a CML-protein adduct with an important carbonyl group. In contrast to 6D12, our polyclonal anti-AGE antibody showed a significant but much weaker immunoreactivity to CML-BSA, suggesting that the polyclonal antibody contains two populations, one reactive to CML (CML-PA) and the other unreactive to CML (Non-CML-PA). Non-CML-PA separated from CML-PA by CML-BSA affinity chromatography did not react with all CML-modified preparations, but retained its property to react commonly with AGE preparations obtained from proteins, lysine derivatives, and monoaminocarboxylic acids. Therefore, it is clear that a CML-protein adduct is a major immunological epitope in AGE structures, but there still exist other major epitope(s) expressed commonly in AGE-proteins.

Effects of cerebral ischemia on dopamine receptors in the gerbil striatum

Dopamine D1 and D2 receptors and uptake sites were studied in the gerbil striatum and frontal cortex 1 h to 7 days after 10 min of cerebral ischemia caused by occlusion of the bilateral common carotid arteries. [3H]SCH23390 ([N-methyl-3H]R[+]-8-chloro-2, 3,4,5-tetrahydro-3-methyl-5-phenyl-7-ol-benzazepine), [3H]nemonapride and [3H]mazindol were used as markers of dopamine D1 receptors, D2 receptors and uptake sites, respectively. A significant reduction in [3H] SCH23390 binding was found in the striatum from 48 h after ischemia. In contrast, during the recirculation periods, [3H]nemonapride and [3H]mazindol binding was mostly unaffected in this region which was the most vulnerable to ischemia. The frontal cortex, where ischemic neuronal damage was mild, also showed no significant changes in [3H]SCH23390, [3H]nemonapride and [3H]mazindol binding after ischemia. Thus, cerebral ischemia that was associated with cell loss in the striatum resulted in a selective reduction of dopamine D1 receptors and not D2 receptors. No changes in dopamine D1 or D2 receptors were observed in frontal cortex. If massive dopamine release occurs with cerebral ischemia, it is not reflected by modification in the number of uptake sites located on dopamine terminals.

First-trimester prenatal molecular diagnosis of infantile hypophosphatasia in a Japanese family

We obtained a prenatal molecular diagnosis during the first trimester in a Japanese woman whose first child (the proband) had been a compound heterozygote for infantile hypophosphatasia. We examined chorionic villus DNA samples obtained at 10 weeks of gestation for the base substitutions detected in the proband DNA using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) and PCR-allele-specific oligonucleotide (ASO) analysis. The genotype of the fetus was the same as that of the proband. The same mobility shift patterns of single strand conformation polymorphism (SSCP) bands were observed in the fetus and the proband. This molecular approach to prenatal diagnosis appears to be more accurate than the enzymatic method and also more accurate and more rapid than the conventional RFLP method.

Uptake and washout of I-123-MIBG in neuronal and non-neuronal sites in rat hearts: relationship to renal clearance

We investigated the uptake and washout of I-123-metaiodobenzylguanidine (MIBG) in neuronal (both intra- and extravesicular) and non-neuronal sites in the heart and its relationship to renal clearance. Acute renal failure was induced in rats by ligating the renal vessels, and the findings were compared with those of sham-operated rats. Each group consisted of control, reserpine-treated and 6-hydroxydopamine (6-OHDA)-treated subgroups. Rats were sacrificed at 10 minutes and 4 hours after injection of MIBG. MIBG activity was calculated in specimens of heart, spleen, lung and blood. At 10 minutes, no significant difference in MIBG uptake in the heart was observed among the subgroups or between sham-operated and renal failure rats despite a significantly higher blood MIBG activity in the latter. At 4 hours, however, the hearts of both reserpine-treated and 6-OHDA-treated rats showed significantly lower MIBG uptake than control rats. Furthermore, the hearts of renal failure rats showed higher MIBG uptake in the control and reserpine-treated rats than in the corresponding subgroups in sham-operated rats. Intra and extravesicular neuronal uptake of MIBG in the heart were estimated using control, reserpine-treated and 6-OHDA-treated rats. Vesicular uptake values were similar in both the sham-operated group (0.51% ID/g) and the renal failure group (0.44% ID/g). But extravesicular neuronal uptake values were quite different in the renal failure group (0.86% ID/g) and the sham-operated group (0.19% ID/g). In conclusion, uptake to and washout from extravesicular neuronal sites may depend on the concentration of MIBG in the blood or the state of renal clearance, but vesicular uptake may be independent of these factors.

Application of Tc-99m-tetrofosmin as a tumor imaging agent: comparison with Tl-201

Tc-99m-tetrofosmin SPECT was performed on 6 occasions in 4 patients with hypopharyngeal carcinoma, lung carcinoma, esophageal carcinoma and maxillary plasmocytoma and compared with Tl-201 SPECT. All lesions accumulated both Tc-99m-tetrofosmin and Tl-201. Early uptake ratios of Tc-99m-tetrofosmin were about 2 but those of Tl-201 were much higher (more than 3). Washout rates of Tc-99m-tetrofosmin were higher than those of Tl-201. There was a good positive correlation between the early uptake ratio of Tc-99m-tetrofosmin and that of Tl-201. The delayed uptake ratio and washout rate showed poor correlation. In conclusion, early uptakes of both the agents were similar but their retention patterns were different. Tc-99m-tetrofosmin may be used for tumor imaging though more studies are required to evaluate diagnostic accuracy and the significance of delayed images.

Different age-related changes in NMDA and glycine receptors in the rat brain

We investigated the age-related changes of N-methyl-d-aspartate (NMDA) and strychnine-insensitive glycine receptors in the brain from Fischer rats aged 3 weeks (immature), 6 months (adult), 12 months (mature), 18 months (middle-aged) and 24 months (aged) using receptor autoradiography. [(3)H]MK-801 and [(3)H]glycine were used to label the NMDA receptor and the glycine receptor, respectively. In immature rats, [(3)H]MK-801 binding showed a significant decline only in the nucleus accumbens, whereas [(3)H]glycine binding exhibited a significant increase in the frontal cortex, parietal cortex, striatum and thalamus as compared with young rats. In mature, middle-aged and aged rats, [(3)H]MK-801 binding showed no significant change in the brain. In contrast, [(3)H]glycine binding showed a conspicuous reduction in the striatum and hippocampal CA3 sector and thalamus from mature rats. Thereafter, the age-related reduction in [(3)H]glycine binding was observed in all brain areas of middle-aged and aged rats. These results demonstrate that the glycine receptor in the rat brain is far more susceptible to aging processes than the NMDA receptor. Furthermore, they suggest the conspicuous differences in the developmental pattern between NMDA and glycine receptors in the rat brain after birth. These findings suggest that glycine receptor in the brain is primarily and severely affected in aging processes and this may lead to age-related neurological deficits.

[A case of multiple myeloma associated with abnormal plasma cells and M-protein in pleural effusion]

A 77-year-old woman with hypertension was admitted to our hospital because of exertional dyspnea end peripheral edema. Chest X-ray showed cardiomegaly, pulmonary congestion and right pleural effusion. Hypertensive heart failure was diagnosed and treated, and right pleural effusion disappeared in 2 weeks. Abnormalities on laboratory data, i.e. anemia and increased ESR et al. continued after the improvement of heart failure. Serum IgG was elevated (2570 mg/dl), while IgA and IgM were decreased. Immunoelectrophoresis indicated the presence of monoclonal IgG-lambda in the serum. Bone marrow puncture revealed an increase in atypical plasma cells (38.4%). Multiple myeloma was diagnosed from these findings and treated with melphalan and prednisolone. But increases in atypical plasma cells (43.2%) and serum IgG (2573 mg/dl) continued. During treatment, right pleural effusion increased again. Thoracocentesis showed bloody effusion with numerous atypical plasma cells, and the presence of monoclonal IgG-lambda was indicated by immunoelectrophoresis. The patient died of renal and heart failure 2 months after the onset of malignant pleural effusion. Cytological examination and immunoelectrophoresis are necessary for pleural effusion in multiple myeloma.