Scatter and attenuation correction in technetium-99m brain SPECT

We propose a practical method for scatter and attenuation compensation in 99mTc-ECD brain SPECT using a simultaneous emission CT (ECT) and transmission CT (TCT) acquisition system that includes the following major components: (a) triple-headed SPECT gamma camera equipped with fanbeam collimators; (b) external line sources containing 99mTc placed at the focal lines of the collimators; and (c) scatter correction by the triple-energy-window (TEW) method.

METHODS

Projection images were obtained over a 360 degrees rotation scan. After acquisition, scatter correction was performed using the TEW method, which corrected scattered photons pixel by pixel in the projection data. Scatter-corrected ECT images were compensated for attenuation using the TCT images with Chang's iterative method, and were converted to activity concentration (kBq/ml) images by obtaining a cross-calibration scan. After validating this method with phantom studies, it was applied to clinical brain imaging using a combination of 925 MBq 99mTc-ECD as a radiopharmaceutical and 222 MBq 99mTc as an external source. ECT and TCT data were acquired separately or simultaneously.

RESULTS

SPECT quantification and image quality were improved by performing this correction. The activity concentration images obtained with the simultaneous acquisition were almost identical to those obtained with the separate acquisition.

CONCLUSION

This method was clinically practical and cost-effective for reconstructing quantitative 99mTc brain SPECT images.

Unusual pKa of the carboxylate at the putative catalytic position of the thermophilic F1-ATPase beta subunit determined by 13C-NMR

Glutamic acid-190 in the beta subunit of F1-ATPase from thermophilic Bacillus PS-3 (TF1) was reported to be essential for the ATPase activity. The mutant TF1beta subunit in which Glu-190 had been substituted by cysteine was carboxymethylated with 13C-labeled monoiodoacetic acid. The pKa value of the carboxymethylene group at the 190 position was determined as 5.6 +/- 0.4 by 13C-NMR. On the basis of this value, the pKa of the carboxylate of Glu-190 of the TF1beta subunit was estimated to be 6.8 +/- 0.5. The unusually high pKa could play a role in the catalytic mechanism of F1-ATPase.

Effects of Chinese herbal medicine on sperm motility and fluorescence spectra parameters

Hochu-ekki-to is a Chinese herbal medicine that has been used for unexplained male infertility with some favorable clinical results. However, the detailed mechanisms of the effect of this medicine on male infertility have not been disclosed. This study investigated the effects of Hochu-ekki-to on sperm motility of human semen. Sixteen semen samples were obtained from 14 normal volunteers. Semen samples were incubated with 1, 10, and 100 micrograms/mL of Hochu-ekki-to solution in 5% CO2, 37 degrees C for 1-6 h, and the motility was compared with that of the control groups (the untreated semen and the semen incubated with phosphate-buffered saline). The motility of sperm in 10 and 100 micrograms/mL of Hochu-ekki-to solution for 1-6 h was significantly higher than that of the control groups. One microgram/milliliter of Hochu-ekki-to solution also maintained higher sperm motility after 4-6 h incubation compared with the control groups. Previous reports showed that sperm motility correlated significantly with fluorescence intensity peaks from both spermatozoa and semen plasma. However, the fluorescence intensity at 622 nm excited at 488 nm from spermatozoa fractions in each group was not significantly different. It would appear that the enhanced sperm motility induced by Hochu-ekki-to is mediated by improvement of the circumstances of semen rather than that of spermatozoa-related factors.

Detection of a new interstellar molecular ion, H2COH+ (protonated formaldehyde)

A new interstellar molecular ion, H2COH+ (protonated formaldehyde), has been detected toward Sgr B2, Orion KL, W51, and possibly in NGC 7538 and DR21(OH). Six transitions were detected in Sgr B2(M). The 1(1,0)-1(0,1) transition was detected in all sources listed above. Searches were also made toward the cold, dark clouds TMC-1 and L134N, Orion (3N, 1E), and a red giant, IRC + 10216, without success. The excitation temperatures of H2COH+ are calculated to be 60-110 K, and the column densities are on the order of 10(12)-10(14) cm-2 in Sgr B2, Orion KL, and W51. The fractional abundance of H2COH+ is on the order of 10(-11) to 10-(9), and the ratio of H2COH+ to H2CO is in the range 0.001-0.5 in these objects. The values in Orion KL seem to be consistent with the "early time" values of recent model calculations by Lee, Bettens, & Herbst, but they appear to be higher than the model values in Sgr B2 and W51 even if we take the large uncertainties of column densities of H2CO into account. We suggest production routes starting from CH3OH may play an important role in the formation of H2COH+.

Hypersensitivity of nucleus accumbens neurons to methamphetamine and dopamine following repeated administrations of methamphetamine

Methamphetamine (MAP) abuse is known to induce reverse tolerance in humans. Electrophysiological studies were performed to elucidate time-related changes in dopamine (DA) receptor sensitivities to DA and MAP after withdrawal following repeated MAP administrations. MAP (5 mg/kg) or physiological saline (1 ml/kg) was injected i.p. to rats once daily for 5 days. Single neuronal activities of nucleus accumbens (Acc) of 5-day MAP-administrated rats were extracellularly recorded with a glass microelectrode attached along a seven-barreled micropipette under chloral hydrate anesthesia. Each barrel was respectively filled with DA, MAP, haloperidol, glutamate and NaCl. Drugs were microiontophoretically applied to the immediate vicinity of Acc neurons receiving inputs from the parafascicular nucleus (Pf) of thalamus. Spikes elicited by Pf stimulation- and glutamate-induced firing were inhibited by iontophoretic application of either DA or MAP at doses of 20-40 nA in the saline-treated rats: EC50 for DA and MAP were 23.8 and 23.2 nA, respectively. At 24-30 hr after the final MAP administration, however, the inhibitory effects of both DA and MAP on Pf stimulation- and glutamate-induced firing of Acc neurons were less pronounced than those in the saline-treated animals. Furthermore, spontaneous firing was enhanced during haloperidol application. On day 5 postadministration, the inhibition of Acc neurons by DA or MAP was significantly more marked than that of saline-treated animals. On day 10 postadministration, the inhibition of Acc neurons by DA or MAP was comparable to that in controls. These results indicate that repeated administrations with MAP induce hyposensitivity and hypersensitivity of Acc neurons to DA and MAP at 24-30 hr and on day 5 postadministration, respectively.

Molecular switch of F0F1-ATP synthase, G-protein, and other ATP-driven enzymes

Exchange-out of amide tritium from labeled gamma-subunit of alpha 3 beta 3 gamma complex of F0F1-ATP synthase was not accelerated by ATP, suggesting that hemagglutinin-type transition of coiled-coil structure did not occur in gamma-subunit. Local topology of nucleotide binding site and "switch II" region of G-protein alpha resemble those of F1-beta subunit and other proteins which catalyze ATP-triggered reactions. Probably, binding of nucleotide to F0F1-ATP synthase induces conformational change of the switch II-like region with transforming beta subunit structure from "open" to "close" for and this transformation results in loss of hydrogen bonds with gamma subunit, thus enabling the gamma subunit to move.

Requirement of CD80 and CD86 molecules for antigen presentation by eosinophils

The authors analysed the antigen-presenting ability of eosinophils purified from peritoneal exudate cells of interleukin-5 (IL-5) transgenic mice. The granulocyte-macrophage colony-stimulating factor (GM-CSF)-treated eosinophils induced proliferative responses of primed lymph node T cells and thymus T cells to staphylococcal enterotoxin B (SEB), while untreated eosinophils induced little or no response. GM-CSF-treated eosinophils also induced proliferation of ovalbumin (OVA)-primed lymph node T cells to OVA. Although untreated eosinophils expressed no MHC class II molecule on the surface the eosinophils could be induced to express major histocompatibility complex (MHC) class II molecules when treated with GM-CSF. In the present study, anti-I-Ak monoclonal antibodies (MoAbs) strongly inhibited proliferation of thymus T cells and proliferation of OVA-primed lymph node T cells in response to OVA, but weakly inhibited proliferation of primed T cells in response to SEB. Furthermore, CD80 (B7-1) and CD86 (B7-2) were expressed on the surfaces of untreated eosinophils. The expression of those two molecules on the eosinophils was increased by incubation with GM-CSF. Moreover, anti-CD80 or anti-CD86 MoAbs blocked proliferative responses of primed lymph node T cells and thymus T cells to SEB, and also blocked responses of primed lymph node T cells to OVA. Thus, CD80 and CD86 play an important role in stimulation of T cells by eosinophils.

Inhibition by a putative antipsychotic quinolinone derivative (OPC-14597) of dopaminergic neurons in the ventral tegmental area

The effects of the newly synthesized quinolinone derivative, OPC-14597 (7-{4-[4-(2,3-dichlorophenyl)-1-piperazinyl]butyloxy}-3, 4-dihydro-2(1 H)-quinolinone), on dopaminergic neuronal activity in the ventral tegmental area were examined using both in vivo microiontophoretic methods in chloral hydrate-anesthetized rats and the tight-seal whole-cell patch-clamp technique in thin-slice preparations of the rat brain. Neurons in the ventral tegmental area were classified as type I or type II according to their responses to antidromic stimulation of the nucleus accumbens, probably corresponding to dopaminergic and non-dopaminergic neurons, respectively. Antidromic spikes elicited by nucleus accumbens stimulation were inhibited by microiontophoretic application of dopamine and OPC-14597 in type I, but not in type II neurons. Although the OPC-14597-induced inhibition was antagonized by simultaneous application of domperidone (5-chloro-1-[1-[3-(2,3-dihydro-2-oxo-1 H-benzimidazo-1-yl)-propy]-4-piperidinyl]-1,3-dihydro-2H- benzimidazol-2-one; dopamine D2 receptor antagonist), SCH 23390 (R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4, 5-tetrahydro-1 H-3-benzazepine hydrochloride; dopamine D1 receptor antagonist) had no such effect. Spontaneous firing of type I neurons was also inhibited by iontophoretically applied OPC-14597 and dopamine, whereas that of type II neurons was unaffected. The inhibitory effect of OPC-14597 on the spontaneous firing of type I neurons was antagonized by domperidone, but not by SCH 23390. In a whole-cell patch-clamp study using a thin-slice preparation of the rat brain, bath application of OPC-14597 induced hyperpolarization accompanied by inhibition of spontaneously occurring action potentials in the large neurons (> 20 microns in diameter) in a concentration-dependent manner. These results suggest that OPC-14597 acts on dopaminergic neurons in the ventral tegmental area as a dopamine D2 receptor agonist to inhibit neuronal activities, probably by increasing membrane potassium conductance.

Catalytic activities of alpha3beta3gamma complexes of F1-ATPase with 1, 2, or 3 incompetent catalytic sites

In order to know how many functional catalytic sites are necessary for ATPase activity of F1-ATPase from a thermophilic Bacillus PS3, a new method of isolating homogeneous preparations of the alpha3beta3gamma complex with 1, 2, or 3 incompetent catalytic sites was developed. Ten glutamic acids (Glu.Tag) were linked to the C terminus of the catalytically incompetent beta(E190Q) subunit. The Glu.Tag itself did not affect ATPase activity of the complexes. Two kinds of alpha3beta3gamma complexes, one containing beta(wild-type) and the other Glu.Tag-linked beta(E190Q), were mixed, urea-denatured, and dialyzed, and alpha3beta3gamma complexes were reconstituted. Each of the complexes containing a different number of Glu.Tag-linked beta(E190Q) was separated by anion-exchange chromatography and analyzed. The results were as follows. 1) Normal steady-state ATPase activity requires three intact catalytic sites. 2) Chase-acceleration, a catalytic cooperativity, requires at least two intact catalytic sites. 3) Single-site catalysis can be mediated by a single intact catalytic site alone. Rescrambling of subunits between complexes could occur when the complex was aged under certain conditions, and this might be one of the reasons for previous contradictory results (Miwa, K., Ohtsubo, M., Denda, K., Hisabori, T., Date, T., and Yoshida, M.(1989) J. Biochem. (Tokyo) 106, 730-734).

[A case report of concomitant UFT-E and CDDP against lung epidermoid carcinoma]

A 52-year-old male with the chief complaint of hemo-sputum was diagnosed after detailed examination as epidermoid carcinoma in the right upper lobe bronchus through the bifurcation. Thoracotomy revealed infiltration of carcinoma into the right main pulmonary artery and the superior vena cava, which could not be excised. Subsequent postoperative radiotherapy (69 Gy) showed NC. Then concomitant administration of UFT-E and a low dose of CDDP was started on an outpatient basis. After the third course of treatment (six weeks per course), a significant reduction was noted in the size of the carcinoma. Bronchoscopy revealed CR with the elimination of carcinoma to mere traces. Besides the myelosuppression seen at the end of the second course of treatment, which resulted in a two-week hospitalization for blood transfusion, no adverse effect prevented the patient from continuing the outpatient treatment courses and from returning to work. We consider that the treatment was very successful not only for its effectiveness in reducing the carcinoma but also for the high QOL achieved.

Analysis of roles of natural killer cells in defense against Plasmodium chabaudi in mice

Mice that have recovered from a primary infection with Plasmodium chabaudi have been shown to resist a secondary infection. In the present study the authors investigated how natural killer (NK) cells were involved in this resistance. Spleen cells from P. chabaudiprimed C57BL/6 mice could transfer protection against P. chabaudi infection into naive syngeneic mice, but spleen cells from unprimed mice could not. T-enriched cells purified from primed spleen cells could also transfer such protection. Transfer of NK cells from primed spleen cells failed to protect against challenge infection. However, depletion of NK cells in host mice by injection of an anti-NK1.1 monoclonal antibody resulted in higher mortality relative to controls. The possible protective roles of NK cells in P. chabaudi infection are discussed.

Bronchiolitis obliterans organizing pneumonia associated with systemic lupus erythematosus with antiphospholipid antibody

Bronchiolitis obliterans organizing pneumonia (BOOP) is a pathologic entity characterized by the formation of fibrous tissue plugs within terminal bronchioles and alveolar ducts. Although BOOP has been associated with several connective tissue disorders, there are rare reports of BOOP in patients with systemic lupus erythematosus (SLE). We present a patient with SLE accompanying antiphospholipid antibody who developed recurrent respiratory symptoms and radiographic abnormalities. The diagnosis of BOOP was confirmed by transbronchial lung biopsy. This case suggests that not only SLE, but also the presence of antiphospholipid antibody, may be associated with the development of BOOP.

[-Clinical features of 10 cases of tuberculous meningitis--with special reference to patient's delay and doctor's delay]

We retrospectively evaluated the clinical findings of 10 cases of tuberculous meningitis who had been admitted to our department from 1987 to 1994. Four patients were male and six were female. All of them were Japanese, and their age ranged from 17 to 74 years old. Regarding the patient's delay, nine patients visited a doctor in 1 to 20 days after the onset of headache, and one patient visited a doctor in 14 days after the onset of general malaise. It is suggested that the patient's delay could not be longer than 3 weeks because of progressively worsening symptoms of tuberculous meningitis such as severe headache and fever. The time interval between the first contact of the patient to a doctor and the commencement of antituberculous therapy (doctor's delay), ranged from 14 to 66 days. When the diagnosis of meningitis was obtained based on the findings of the cerebrospinal fluid (CSF), focal neurological signs including psychological symptoms, cranial nerve palsies and seizure were noted besides meningeal signs or the disturbance of consciousness in 4 patients. The CSF revealed an increase in cell counts with mononuclear cell dominance in 9 patients, but the findings typical for tuberculous meningitis such as increase in total protein content and a decrease in glucose concentration were obtained in only 5 patients. Mycobacterium tuberculosis had not been detected in all cases when the antituberculous chemotherapy was started. Later, it was found to be positive in the CSF sample from only three patients by culture or polymerase chain reaction (PCR) method. When the antituberculous therapy was completed, meningitis was cured without remaining any symptom or sign in all patients. All patients had no active pulmonary tuberculosis when the meningitis was diagnosed, and only one of them had sequels of lung tuberculosis. Four patients had the past history of tuberculosis, and 1 had the familial history of pulmonary tuberculosis. At the first contact to a doctor, seven patients were diagnosed as having common cold or headache related with fever because of the lack of typical signs of meningitis. Similarly three other patients were initially diagnosed as having meningitis due to viral infection or unknown etiology. In summary, it was difficult to obtain the solid diagnosis of tuberculous meningitis at the initial stage of this disease, since the symptoms and signs at its onset often similar to those of common cold or non-specific headache. Therefore, when we see the patients with subacute onset of headache and fever followed by the meningeal signs, tuberculous meningitis should always be included in the list of diseases requiring differential diagnosis. In addition, when tuberculous meningitis is suspected, the antituberculous therapy should be started without any delay.

Cross-reactive idiotypes on rabbit anti-SEA antibodies stimulate anti-idiotype spleen and lymph node cell responses of mice infected with Schistosoma mansoni

Antibodies to Schistosoma mansoni soluble egg antigens (SEA) generated in outbred rabbits from two different sources were used to study cross-reactive idiotype/anti-idiotype (Id/anti-Id) interactions in S. mansoni-infected mice in two different locations. Immunoaffinity purified rabbit polyclonal anti-SEA antibody preparations (RabId) were predominantly Ig by SDS-PAGE and demonstrated anti-SEA activity by ELISA and Western blot. RabId prepared from three separate rabbits and used at 40 micrograms/ml in vitro stimulated lymphocyte proliferative responses of spleen cells from mice with eight week infections (Mean +/- SEM [E-C]) of 3869 +/- 764, 18594 +/- 3046 and 8962 +/- 1734 cpm. Spleen cells from uninfected mice exposed to the same RabId preparations in vitro had respective [E-C] values of 206 +/- 144, 494 +/- 154 and 363 +/- 180. Lymph node cells from mice infected for 8 weeks demonstrated [E-C] of 123 +/- 400, 5073 +/- 828 and 2361 +/- 656 upon exposure to these 3 RabId preparations. Lymph node cells from uninfected mice had [E-C] of 220 +/- 76, 194 +/- 82 and 143 +/- 72 when exposed to these RabId. Maximum in vitro proliferative response to Ig from unimmunized rabbits was 761 +/- 400 by spleen cells from mice with eight week infections. These data indicate the presence of cross-reactive Id on rabbit anti-SEA antibodies from different rabbits that can stimulate in vitro lymphoproliferative responses of spleen or lymph node cells from S. mansoni-infected mice.

[A case of posttraumatic spinal pseudomeningocele which caused spinal cord compression 20 years after injury]

We reported an extremely rare case of posttraumatic spinal pseudomeningocele which caused spinal cord compression 20 years after getting injury, and demonstrated that sequelae of an injury may occur many years after the original wound. A 39-year-old man, who got left cervical root avulsion due to a traffic accident when he was 17 years old, began to complain of progressive muscle atrophy and weakness of left lower extremity 1 year ago. Myelography demonstrated pseudomeningocele at left C6-C8 level, and MRI and CT myelography revealed that the pseudomeningocele extends through the intervertebral foramen and compresses the spinal cord to the right side in the spinal canal. Bilateral functional compression of spinal cord dorsal and lateral column was also verified with SEP and MEP electrophysiologically.

Fluorescence spectra from human semen and their relationship with sperm parameters

Fluorescence spectra of human semen, seminal plasma, and spermatozoa were investigated. A total of 51 semen samples were obtained from 45 men, including 40 suspected subfertile men and 5 normal volunteers. Fluorescence spectra excited at 488 nm for each component in 10 mM phosphate-buffered saline (PBS) were scanned in a range of 500 to 700 nm. Under these conditions, emission peaks from each component were observed at 622 nm. The intensity of emission peaks from spermatozoa at 622 nm correlated strongly with the concentration of spermatozoa (r = .837, p = .0001). Sperm motility also correlated significantly with fluorescence intensity emission peaks from spermatozoa (r = .369, p = .019) and semen plasma (r = .356, p = .024). To clarify the origin of emission peak of 622 nm with 488 nm excitation, some components in seminal plasma were dissolved in PBS and the fluorescence spectra were measured. The standard single solutions in PBS, such as citric acid, zinc, calcium, and riboflavin (vitamin B2), did not yield an emission peak of 622 nm with 488 nm excitation. However, blood plasmas and albumin revealed similar fluorescence peaks at 622 nm. Thus, the fluorescence spectra may originate from some protein complex.

Increased expression of cathepsins E and D in reactive microglial cells associated with spongiform degeneration in the brain stem of senescence-accelerated mouse

Senescence-accelerated mouse (SAM) P8 and P10 exhibit a spongy degeneration, especially in the brain stem, and a brain atrophy mainly in the frontal portion of the cerebral cortex, respectively, with advancing age. In an attempt to clarify the role of two distinct intracellular aspartic proteinases, cathepsins E (CE) and D (CD), in these age-related pathological changes, accumulation and localization of these enzymes were investigated in the brain stem and the cerebral cortex of SAMP8 and P10 and in the senescence-resistant control SAMR1 with four different age groups (1 week and 2, 6, and 12 months). In the brain stem of SAMP8, a marked spongy degeneration was observed at more than 2 months of age. The same degree of spongy degeneration was also observed in the brain stem of age-matched SAMP10 but not SAMR1. The nonlysosomal enzyme CE was barely detectable in the brain stem of all three strains at 1 week of age, but it was markedly accumulated in the brain stem of SAMP8 and P10 at 2 months of age. The lysosomal enzyme CD was found in relatively high concentration in the brain stem of all three strains at 1 week of age. At 2 months of age, CD contents were significantly increased in the brain stem of SAMP8 and P10 compared with those of age-matched SAMR1. At the light-microscopic level, increased immunoreactivities for CE in the brain stem of 2-month-old SAMP8 and P10 were found in reactive microglial cells clustered at the spongy areas but not in microglial cells with resting or ramified morphology and astrocytes. The increased immunoreactivity for CD was observed mainly in reactive astrocytes and partially in reactive microglial cells. Immunoblotting analyses revealed that CE in the brain stem of 2-month-old SAMP10 consisted of only the mature form of 42 kDa, whereas CD in this tissue is composed of mainly the mature form of 44 kDa and partially its degradation products. On the other hand, there was a marked brain atrophy mainly in the frontal portion of the cerebral cortex of 6-month-old SAMP10 but not in age-matched SAMP8 or SAMR1. Although CE was not detectable even in the atrophied cortical area of SAMP10, CD contents in the cerebral cortex slightly increased with senescence in all three strains.(ABSTRACT TRUNCATED AT 400 WORDS)

Prevalence of hepatitis B surface antigen, hepatitis B e antigen and antibody, and antigen subtypes in atomic bomb survivors

On the basis of previous studies showing an association between hepatitis B surface antigen (HBsAg) positivity and radiation exposure in atomic bomb (A-bomb) survivors, we investigated further the active state of hepatitis B virus (HBV) infection by incorporating tests for hepatitis B e antigen (HBeAg) and hepatitis B e antibody (anti-HBe) and HBsAg subtypes into our biennial health examinations. Among 6548 A-bomb survivors for whom HBsAg was assayed between July 1979 and July 1981, 129 persons were HBsAg positive. HBeAg and anti-HBe were measured in 104 of these persons and subtypes of HBsAg in 98 persons. Among those exposed to radiation (average liver dose 0.58 Sv), the odds ratio of HBsAg positivity tended to increase with radiation dose (P for trend = 0.024). The P values for association between the prevalence of HB e antigen and radiation dose and between the prevalence of anti-HBe and radiation dose were 0.094 and 0.17, respectively. The HB antigen subtype adr was predominant over other subtypes in both Hiroshima and Nagasaki, but the distribution of subtypes did not seem to differ in relation to radiation dose. These results suggested that A-bomb survivors remain in an active state of HBV infection and that the mechanism(s) of seroconversion may be impaired.

Reversible structural changes of octacalcium phosphate and labile acid phosphate

Acid phosphate is one of the major impurities incorporated into bioapatites, and its quantity and environment in forming mineral have been used as diagnostic probes to pursue acidic precursor(s). Currently, little is known about the structural feature of nonstoichiometric octacalcium phosphate (OCP), which has been advocated to be, most plausibly, mineral salt initially formed during amelogenesis. In the present report, we attempt to define the state of acid phosphate in OCP crystals which were Ca-deficient and contained 40% total phosphate as acid phosphate. We assessed fractions of acid phosphate in discrete environments by extracting the crystals in either deionized water, 10 mmol/L NaOH solution (initial pH 11), or 150 mmol/L Tris buffer at pH 7.4. Solid samples before and after the treatments were examined by chemical analyses and x-ray diffraction. The results indicated that successive extractions with use of the alkaline solution brought about a reversible change (not hydrolysis) in the interior structure of OCP, which accompanied a marked decrease in acid phosphate. A substantial part of the lost acid phosphate was restored during subsequent treatments at neutral pH, and, intriguingly, this restoration accompanied a re-ordering of OCP structure. The data suggested that the acid phosphate in OCP is separated into three pools: (a) a stable pool corresponding to roughly 50 to 60% of the total acid phosphate, (b) a reversibly exchangeable pool corresponding to 25 to 30% of the acid phosphate which may exist either in the water layer or on crystal surfaces, and (c) an unstable (or irreversibly lost) pool corresponding to 15 to 20% of the acid phosphate, a part of which might be explained by the presence of excess hydrogen in OCP. The present work supports the concept that protons and, to a lesser magnitude, phosphate species can diffuse into and out of the OCP lattice prior to initiation of its hydrolytic transition into apatite.

Mechanism of haematuria in lupus nephritis

Images

Ultraweak biophoton emission imaging of transplanted bladder cancer

Biophoton emission or spontaneous ultraweak light emission has been observed from almost all living organisms, with intensities ranging from 10(-19) to 10(-16) W/cm2. The measurement of biophoton emission offers the attractive possibility of noninvasive monitoring of the underlying physiological function of a living system. In the present study, ultraweak biophoton emission from mice with transplanted bladder cancer was detected by a two-dimensional photon-counting system. Photon counts were observed to be 1.51-4.73 times higher from the regions of untreated tumor than from normal regions. Our study suggests that this novel technique may be applicable to the diagnosis of superficial tumors.