A study of embolizing materials for chemo-embolization therapy of hepatocellular carcinoma: effects of chitin concentration on cis-diamminedichloroplatinum(II) albumin microsphere properties and antitumor effect in VX2 hepatocellular carcinoma model rabbits

cis-Diamminedichloroplatinum(II) (CDDP) albumin microspheres were prepared with various chitin concentrations and microsphere CDDP contents, specific surface area, surface structure and other microsphere properties. CDDP release in vitro and the antitumor effect in VX2 tumor model rabbits were investigated. CDDP content was increased as the concentration of chitin increased; at a chitin concentration of 6.0% it was about 2 times that without chitin. Specific surface area also increased with chitin concentration. CDDP release rate from various microspheres in vitro was suppressed as chitin concentration increased. Thus, microsphere properties, especially surface structure, are affected by an increase in chitin concentration. In experiments in vivo, various microspheres were injected into the hepatic artery of VX2 hepatocellular carcinoma model rabbits, and the effects of the chitin concentration on the time course of blood platinum (Pt) level and the antitumor effect were assessed. The blood Pt concentration increased with increase in chitin concentration, with a maximum of 0.45 microgram/ml at a concentration of 6.0%, even 7 d following microsphere administration. Tumor growth was suppressed when the chitin concentration was increased. Tissue Pt concentrations also increased in the presence of chitin. These findings suggest that increasing the chitin concentration might promote microsphere decomposition and hence CDDP release in vivo, thus improving immunopotentiating activity and resulting in enhanced CDDP antitumor effect. The detailed mechanisms of the action, however remains to be studied.

[Clinical usefulness of 99mTc-ECD--a multicenter phase 3 study]

A phase 3 clinical study of a newly developed brain perfusion agent, 99mTc-L,L-ethyl cysteinate dimer (99mTc-ECD), was performed in 521 cases of cerebrovascular diseases and impairment of brain function to evaluate the safety, effectiveness and usefulness of the agent as a multi-center study involving 35 institutions in Japan. Out of 510 cases evaluated for the clinical usefulness, valuable information for clinical diagnosis was obtained in 486 cases (95.3%), and 444 cases (87.1%) were judged as "extremely useful" or "useful". Although the positive ratio of abnormalities detected by the agent was as same as that of 99mTc-hexamethylpropyleneamine oxime (99mTc-HM-PAO), the abnormal regions detected by the agent had tendency to be larger in size and to have higher contrast than those detected by 99mTc-HM-PAO. It is concluded that 99mTc-ECD is a safe and useful radiopharmaceutical as a brain perfusion agent for the diagnosis of cerebrovascular diseases and impairment of brain function.

Improvement of brain single photon emission tomography (SPET) using transmission data acquisition in a four-head SPET scanner

Attenuation coefficient maps (mu-maps) are a useful way to compensate for non-uniform attenuation when performing single photon emission tomography (SPET). A new method was developed to record single photon transmission data and a mu-map for the brain was produced using a four-head SPET scanner. Transmission data were acquired by a gamma camera opposite to a flood radioactive source attached to one of four gamma cameras in the four-head SPET scanner. Attenuation correction was performed using the iterative expectation maximization algorithm and the mu-map. Phantom studies demonstrated that this method could reconstruct the distribution of radioactivity more accurately than conventional methods, even for a severely non-uniform mu-map, and could improve the quality of SPET images. Clinical application to technetium-99m hexamethyl-propylene amine oxime (HMPAO) brain SPET also demonstrated the usefulness of this method. Thus, this method appears to be promising for improvement in the image quality and quantitative accuracy of brain SPET.

A study of cis-diamminedichloroplatinum(II) suppositories for the treatment of rabbit uterine endometrial carcinoma

cis-Diamminedichloroplatinum (II) (cisplatin: CDDP) suppositories containing NaCl at different concentrations were prepared as a local chemotherapeutic agent for the treatment of uterine endometrial carcinoma and were administered to rabbits implanted with uterine VX2 tumor. The intrauterine CDDP histological level, as well as the antitumor effects and side effects of the suppositories to the liver and kidney were studied. The results showed high intrauterine tissue CDDP level in all suppository administrations. In particular, the NaCl-added suppositories enhanced the intrauterine CDDP level. As for antitumor effects, while the tumor growth rate of the NaCl-added suppository group was likely to be suppressed, the suppositories could not suppress tumor growth completely. The plasma platinum (Pt) level was 1.5 micrograms/ml or less and that of the liver and kidney was as low as 0.31 to 0.48 micrograms/g. No difference in levels depending on NaCl concentration was observed, nor was any abnormality found in the biochemical analysis including glutamate oxaloacetate transaminase (GOT) and blood urea nitrogen (BUN). Histopathological study revealed the degeneration of tumor cells in the NaCl-added suppository group. Minimal congestion and hemorrhage were observed in the endometria, possibly resulting from CDDP. By adding NaCl to CDDP suppositories, the uterine CDDP level and antitumor effects increased while no serious renal dysfunction was noted. Therefore, we conclude that NaCl-added CDDP suppositories are a useful local chemotherapy for endometrial carcinoma.

A study of embolizing materials for chemo-embolization therapy of hepatocellular carcinoma: antitumor effect of cis-diamminedichloroplatinum(II) albumin microspheres, containing chitin and treated with chitosan on rabbits with VX2 hepatic tumors

As an effective therapy for hepatocellular carcinoma, hepatic arterial chemo-embolization therapy has been widely used, and many embolizing materials have been extensively investigated. In the present study, we prepared various types of cis-diamminedichloroplatinum(II) (CDDP) albumin microspheres using chitin and chitosan, both of which have attracted considerable attention as new non-toxic biological polymer materials having favorable characteristics such as immune adjuvant activity, biological compatibility, and biodegradation. Hepatic artery of rabbit hepatic cancer models, which had transplanted VX2 tumors, were embolized with various types of microspheres. The anti-tumor effects and tumor-targeting of the microspheres, and the effects of the microspheres administration on the hepatic tissue were investigated. As a result, anti-tumor activity of the microspheres was increased by the addition of chitin-containing or chitosan treated materials; tumor growth rates of chitin addition and chitosan treated groups were approximately 160% and 120%, respectively, and were significantly lower than that of the non-treatment groups with a rate of approximately 580%. However, complete inhibition of tumor growth might have been impossible. Anti-tumor activity was increased by the addition of chitin-containing or chitosan treated materials. Whereas the growth inhibitory effect was insufficient, in order to potentiate anti-tumor activity, higher CDDP contents and sustained release of CDDP at a high level from microsphere and so on should be essentially improved for the near future. The CDDP level in hepatic tissue following the administration of microspheres was increased by adding chitin to the microspheres or by treating the microspheres with chitosan.(ABSTRACT TRUNCATED AT 250 WORDS)

[Phase 2 clinical study of 99mTc-ECD--a multicenter study]

A phase 2 clinical study of a newly developed brain perfusion agent, 99mTc-ECD, was performed in 166 cases of cerebrovascular diseases and impairment of brain function to evaluate effectiveness, usefulness, optimum dose and optimum timing of imaging as a multi-center study involving 10 institutions in Japan. All cases were judged as no problems on safety and any side effects due to the administration of the compound were not observed. Out of 163 cases evaluated for the clinical usefulness, valuable information for clinical diagnosis was obtained in 160 cases (98.3%), and 154 cases (94.5%) were judged as "extremely useful" or "useful". Although SPECT imaging was possible from 5 min after injection, images obtained between 60 and 90 min after injection showed relatively better image quality in many cases. Regarding standard administration dose, 400 to 800 MBq were considered to be appropriate. 99mTc-ECD is considered to be a promising radiopharmaceutical as a brain perfusion agent.

[Intraarterial urokinase infusion therapy with superselective catheterization for acute occlusive cerebrovascular disease]

Intraarterial urokinase infusion therapy with superselective catheterization was performed on 11 patients for acute occlusive cerebrovascular disease. The subjects were five men and six women with a mean age of 70 years (range, 48-83 years). Nine of 11 patients had middle cerebral artery occlusion and two had basilar artery occlusion. The interval from onset to infusion ranged from 3.5 to 9 hours, and the total dosage of urokinase from 24 x 10(4) to 150 x 10(4) IU. Recanalization of the occluded artery was achieved in nine patients (82%), and favorable clinical outcome was achieved in seven patients (64%). Six of whom were discharged with no neurologic deficits. Hemorrhagic infarction occurred in two patients without clinical deterioration. Our observations suggest that intraarterial urokinase infusion therapy with superselective catheterization may be very useful in the acute stage of occlusive cerebrovascular disease.

Enhancing effect of sodium chloride on in vitro adsorption of paraquat onto activated carbon

The enhancing effect of sodium chloride addition on the adsorption of paraquat onto activated carbon was discussed from the standpoints of equilibrium amount adsorbed and adsorption rate in vitro. The amount of paraquat adsorbed was increased by the addition of sodium chloride. The amount adsorbed with 0.1% addition was about five times greater than that in sodium chloride-free solution at an equilibrium concentration of 1 mg/L. The adsorption rate of paraquat onto activated carbon was also accelerated by sodium chloride addition. Kinetic constants in 0.1% and 0.9% sodium chloride solution were about 1.4 and 2.0 times greater, respectively, than that in sodium chloride-free solution. It was confirmed that paraquat removal by activated carbon was enhanced by sodium chloride addition. The reason was assumed to be the interrupted dissociation of paraquat in solution caused by sodium chloride addition.

Application of Hilbert transform to radionuclide-gated cardiac studies: analysis of asynchronous emptying and filling in various heart diseases

Fourier phase analysis has generally been used to investigate asynchronous emptying and filling in various heart diseases. A potential limitation of this form of analysis is curve fitting error, since a truncated Fourier series may not adequately describe the shape of a time-volume curve (TVC) and thus may produce errors in indices calculated from the fit. To overcome this problem, we developed a new method using Hilbert transform. Using Hilbert transform, the instantaneous phase (IP) curve was calculated directly from the TVC obtained from multigated cardiac blood pool images. Four parameters [time to maximum IP [T(max)], time to 0 in IP[T(0)], time to minimum IP[T(min)], and time from 0 to minimum IP [T(min-0)]] were extracted from the IP curves for each pixel, and functional images were constructed in 40 patients with ischemic heart disease (IHD), 16 with hypertrophic cardiomyopathy (HCM), 3 with dilated cardiomyopathy (DCM), and 7 normal controls (N). The standard deviations (SD) of these parameters were then calculated for the left ventricle. In IHD patients with a left ventricle ejection fraction (LVEF) of less than 50% and in DCM, the SDs of all parameters were significantly higher than in group N. In IHD patients with an LVEF of greater than 50%, the SDs of T(min), T(0), and T(min-0) were significantly higher than in group N, but there was no significant difference in the SD of T(max). In HCM patients, the SDs of T(min) and T(min-0) were significantly higher than in group N, suggesting the presence of asynchronous filling. In conclusion, this method appears to be promising for the quantitative analysis of asynchronous emptying and filling in various heart diseases.

Kinetic behavior of technetium-99m-HMPAO in the human brain and quantification of cerebral blood flow using dynamic SPECT

The kinetic behavior of 99mTc-hexamethylpropyleneamine oxime (HMPAO) in the human brain was investigated in 11 patients with various brain diseases (176 regions), using dynamic SPECT and a four-compartment model with five parameters (K1: rate constant for the transport of HMPAO from blood to brain, K2: backdiffusion from brain to blood, K3: conversion to a hydrophilic form in the brain, K5: conversion to a nondiffusible form in the blood, and fa: fraction of radioactivity attributable to the vascular compartment). Although K1 correlated well with cerebral blood flow (CBF) measured by the 133Xe inhalation method (Xe-CBF) (r = 0.888), its value was underestimated by 28.9% +/- 11.9%, indicating a low extraction fraction (E) for HMPAO. From E = K1/CBF, a regression equation of E = 0.857 - 0.00335. Xe-CBF was obtained. Significant correlations were observed for K2 versus Xe-CBF (r = 0.679), for K3 versus Xe-CBF (r = 0.483), for K3/(K2 + K3) versus Xe-CBF (r = -0.487), for K3/K2 versus Xe-CBF (r = -0.501), and for K2 + K3 versus Xe-CBF (r = 0.655), but not for K1/K2 versus Xe-CBF (r = 0.005). Thus, this model was useful for elucidating the kinetic behavior of HMPAO in the human brain, and correction for E appears to be indispensable for accurate CBF quantification using HMPAO.

Assessment of systolic thickening with thallium-201 ECG-gated single-photon emission computed tomography: a parameter for local left ventricular function

We measured left ventricular (LV) systolic thickening expressed as a systolic thickening ratio in 28 patients, using 201Tl ECG-gated SPECT. Five normals, 15 patients with prior myocardial infarction, 5 with hypertrophic cardiomyopathy, and 3 with dilated cardiomyopathy were studied. The systolic thickening ratio was calculated as [(end-systolic--end-diastolic pixel counts) divided by end-diastolic pixel counts], using the circumferential profile technique of both end-diastolic and end-systolic short axial images. Functional images of the systolic thickening ratio were also displayed with the "bull's-eye" method. The mean systolic thickening ratio thus calculated were as follows: normals, 0.53 +/- 0.05 (mean +/- 1 s.d.); non-transmural prior myocardial infarction, 0.33 +/- 0.09; transmural prior myocardial infarction, 0.14 +/- 0.05; hypertrophic cardiomyopathy in relatively nonhypertrophied areas, 0.56 +/- 0.11; hypertrophic cardiomyopathy in hypertrophied areas, 0.23 +/- 0.07; and dilated cardiomyopathy, 0.19 +/- 0.02. The systolic thickening ratio analysis by gated thallium SPECT offers a unique approach for assessing LV function.

Digestibility and energy availability of Wakame (Undaria pinnatifida) seaweed in Japanese

The digestibilities of nutrients and energy in Wakame were measured in healthy adult males. A test diet was given for 5 days after 5 days on a basal diet which supplied 40 g/day of protein and 45 kcal/kg/day of energy. The test diet was identical with the basal diet except that Wakame was incorporated. Digestibility was calculated by the difference of fecal output between the test period and the basal period. However the digestibility of its nutrient component was found to be different at each intake level. Therefore the present study simply lists the calculated figures. The results obtained were follows: 1) Composition of Wakame was protein: 20.5%, fat: 1.7%,. Total carbohydrate: 45.1%, gross energy content: 322 kcal/100g. 2) Digestibility of protein was 70.1 +/- 14.0%. 3) Digestibility of fat was 97.5 +/- 59.0%. 4) Digestibility of carbohydrate was 55.8 +/- 14.6%. 5) The ratio of the total available energy to intake energy (Net Energy Availability) was 62.4 +/- 19.4%. Wakame contains proteins and available carbohydrates, and may be consumed as a protein source as well as a good source of vitamins and minerals.

ECG-gated thallium-201 myocardial SPECT in patients with old myocardial infarction compared with ECG-gated blood pool SPECT

We evaluated one of the merits of ECG-gated thallium-201 single photon emission computed tomography (g-T1 SPECT), i.e., the ability to appreciate left ventricular (LV) wall motion. LV wall motion assessed by g-T1 SPECT and by ECG-gated Blood Pool SPECT (g-BP SPECT) was classified into three grades and compared segment by segment. T1-201 uptake by g-T1 SPECT was also classified into three grades and compared with those of wall motion in g-BP SPECT. Fifty patients with prior myocardial infarction were injected intravenously at rest with 111 to 185 M Bq (3 to 5 mCi) of Tl-201. The left ventricular regions were divided into anterior, septal, inferior and lateral segments (50 patients X 4 segments = 200 segments in total). The grades of wall motion and Tl-201 uptake detected by g-Tl SPECT correlated well with those of wall motion in g-BP SPECT (94.5% and 85%, respectively). With g-Tl SPECT it was possible to evaluate left ventricular wall motion, providing clear perfusion images.

Scintigraphic evaluation of myocardial uptake of thallium 201 and technetium 99m pyrophosphate utilizing a rat model of chronic doxorubicin cardiotoxicity

To evaluate the usefulness of myocardial scintigraphy as a monitoring tool for chronic doxorubicin (DXR) cardiotoxicity, a rat model was used to investigate the relationship between the myocardial uptake of thallium 201 (Tl) or rechnetium 99m pyrophosphate (99mTc-PPi) and histological changes of the heart. Although there was no significant difference in myocardial Tl uptake between control and DXR-treated rats at an early phase after Tl injection, late-phase Tl uptake was significantly higher in the DXR-treated rats than in the control rats, indicating a slow wash-out of Tl from the myocardium. The wash-out rate calculated from scintigraphic examination of DXR-treated rats was significantly decreased with increasing degree of cardiomyopathy. Since the Tl wash-out rate was sharply decreased even in animals with minimal histological changes, it may be a possible monitoring tool for the early detection of chronic DXR cardiotoxicity. On the other hand, myocardial 99mTc-PPi images could be obtained only in rats with severe myocardial changes and hence would not useful for early detection.

Adsorption removal of benzalkonium chloride by granular activated carbon for medical waste water treatment

The adsorption removal of benzalkonium chloride disinfectant by granular activated carbon is discussed. The adsorption isotherm of benzalkonium chloride was expressed by the Freundlich equation. A significant correlation was found between the amount of benzalkonium chloride adsorbed in less than 1000 ppm of equilibrium concentration and the micropore volume of activated carbon. As for the adsorption rate, a change in intraparticle diffusiveness was found with increasing adsorption ratio. No significant correlation between the values of intraparticle diffusiveness and the properties of activated carbon was found. It was concluded that the micropore volume of activated carbon was the dominant factor in the adsorption removal of benzalkonium chloride by granular activated carbon.

[A case of a gastric cancer patient with high serum pepsinogen levels at relapse]

A rare case of a 68-year-old female cancer patient with an extremely high serum level of pepsinogens (PG) at relapse is presented. She had stage 3 Borrmann 3 type gastric cancer which was a poorly differentiated adenocarcinoma. Her postoperative serum PG levels had been within normal limits (23.0 ng/ml for PG-I and 3.2 ng/ml for PG-II), but at the time of the peritoneal relapse they were 5,630 ng/ml and 3,380 ng/ml, respectively. After was chemotherapy initiated, her serum PG levels decreased in parallel with an improvement of her clinical status. Immunohistochemical examination with monoclonal antibodies revealed PG-I and PG-II production in the primary and the metastatic lesions.

[Prevention of vitamin K deficiency in the early neonatal period--prophylactic oral administration of VK to the mother]

We studied the effect of vitamin K(MK-4) on the prevention of vitamin K deficiency in the early neonatal period. MK-4 (20 mg/day) was given orally for 1-7 days to 183 pregnant women at 37-39 weeks gestation. In the MK-4 treated group, there were no cases of melena neonatorum but there were 9 cases in the untreated group (9/757, 1.2%). To investigate the influence of MK-4 administration on liver function and the VK dependent coagulation system, maternal and umbilical venous blood were taken to measure T-Bil, GOT, GPT, gamma-GTP, LDH, and II, VII, X activity and HPT. There was no significant difference between these values in MK-treated and untreated groups. MK-4 concentrations were measured in the maternal and umbilical venous blood of 68 subjects. The level of MK-4 in umbilical venous blood was less than 0.1 ng/ml in 17 of 21 subjects not treated with MK-4 but it was over 0.1 ng/ml in 30 of 47 MK-4 treated subjects. However, no MK-4 was detected in 6 of 8 subjects who were treated for 1 day. The level of MK-4 in maternal blood was less than 0.1 ng/ml in 12 of 21 untreated subjects but it was 0.19-92.6 ng/ml in all of the 47 MK-4 treated subjects. The mean MK-4 concentration in cord blood as a percentage of that in maternal blood was 17.9%. These findings indicate that MK-4 is effectively transported from maternal to fetal blood through the placenta and its administration to pregnant women is useful in preventing melena neonatorum.

Study on digestibility and energy availability of daily food intake in Japanese (Part 3. Cereals)

Four male Japanese were fed a semisynthetic diet including egg and soy powder as protein source for seven days (Basal-diet period), and in the following seven days 200 g of polished rice, wheat flour and buckwheat flour added at the expense of part of the corn starch and sugar in the basal diets (Test-diet period). Urine and feces were collected throughout both periods and the contents of nitrogen, fat and energy in these excreta were determined. Digestibility of protein (N), fat and carbohydrate (by difference) was calculated. The protein digestibilities of the polished rice (in the form of cooked grains), wheat flour (in the form of cooked powder) and buckwheat flour were 89.6 +/- 5.0%, 93.4 +/- 2.9% and 85.1 +/- 2.5%, respectively. The fat digestibilities of the polished rice, wheat flour and buckwheat flour were 93.6 +/- 1.8%, 70.8 +/- 13.5% and 103.1 +/- 8.4%, respectively showing relatively large variation (This results may be caused by an errors in measurement). The carbohydrate digestibility was close to 100%. The net energy availabilities of the polished rice, wheat flour and buckwheat flour were 100.6 +/- 1.4%, 96.5 +/- 1.1% and 96.0 +/- 1.1%, respectively.

A method for computing the derivative of noisy time-activity curves and its application to radioisotope dynamic analysis

A method for computing the slope or the derivative of time-activity curves containing statistical fluctuations is described. The algorithm presented employs digital differentiation as a digital filter. In designing an effective differentiating filter the Chebyshev-type min-max method and Remez exchange algorithm are used to minimise the weighted Chebyshev error. The validity of this method has been investigated using computer-based Monte Carlo simulation. Renogram curve analysis is presented as an example of an application of this method to radioisotope dynamic analysis. The ratio of the bilateral slopes of the renogram's second segments estimated using this method correlated well with the renal plasma flow ratio (r = 0.97, n = 16). The functional images of the slope of the renogram's second segments have been constructed and ascertained to be clinically useful. This method is considered to provide a powerful tool for extraction of quantitative information both in research and in routine nuclear medicine clinical work, and may be useful in various other fields.

[The role of gallium-67 citrate scintigraphy in gastro-intestinal malignant lymphoma]

To evaluate the clinical usefulness of gallium-67 scintigraphy in the detection of the gastrointestinal (GI) non-Hodgkin's lymphoma (NHL) and in the assessment of the therapeutic effects, gallium-67 scintigraphy was reviewed on 24 cases (25 lesions; stomach in 20, ileum in 2, and terminal ileum and/or cecum in 3). Twenty-three out of the 25 lesions (92.0%) were detected by gallium-67 scintigraphy, while barium study could detect all of the 25 lesions. The sizes of the gallium-67 negative 2 lesions were the smallest of all (2.5 and 3.0 cm). The tumor size was considered to the most important factor in the detection by gallium-67 scintigraphy, while the histological classification and the location of the tumor were not related to its detectability. Findings in follow-up gallium-67 scintigraphy after therapy on 10 cases were correlated well with the therapeutic effects. These data suggest that gallium-67 scintigraphy is useful for the detection of GI involvement of NHL and for the assessment of therapeutic effects.