Minimally required heat doses for various tumour sizes in induction heating cancer therapy determined by computer simulation using experimental data.

PURPOSE: Although induction heating cancer therapy (IHCT) using magnetic nanoparticles can be a promising approach to treatment-less multi-nodular cancers, the objective requirement for successful clinical application has not clearly been elucidated. We intended to define objective heat doses suitable for IHCT, especially focusing on the sizes of liver cancer nodules. MATERIALS AND METHODS: Alternating magnetic fields were applied to three human pancreatic cancer cell lines, the intercellular space of those cell pellets were filled with magnetic nanoparticles, and confirmed the cytotoxic effect of IHCT. Subsequently, the temperatures of liver cancer nodules in IHCT were simulated using a computer software program and the required heat dose for various sized tumours were determined. RESULTS: Heating the cancer cells up to 50 degrees C for 10 min was sufficient for complete cell killing and the heat dose of 1.7 W/g(tumour) is required for 10 mm tumour. Larger tumours require a smaller heat dose, e.g. 20 mm and 40 mm tumours require 0.7 W/g(tumour) and 0.6 W/g(tumour), respectively, whereas smaller tumours require large amounts of heat, e.g. 5 mm and 1 mm tumours require 5.1 W/g(tumour) and 105 W/g(tumour), respectively. CONCLUSIONS: Integrating the presently available technologies, including high-quality magnetic nanoparticles (1000 W/g(material)) and effective drug delivery systems (1-2 mg(material)/g(tumour)), treatment of a 10 mm tumour seems possible. Since treatment of smaller tumours less than 5 mm require substantial heat dose, researchers involved in IHCT should target cancer nodules of 10 mm or more, and develop a heat delivery system providing a minimum of 1.7 W/g(tumour).

The measurement of small magnetic signals from magnetic nanoparticles attached to the cell surface and surrounding living cells using a general-purpose SQUID magnetometer.

Magnetic nanoparticles have recently been widely applied in the bio-medical field. Responding to the demand for a simple and sensitive magnetic assay system for bio-liquid samples, we employed a general-purpose superconducting quantum interference device (SQUID) magnetometer. Strips of filter paper were used as a liquid-specimen sample holder possessing a very small magnetic background signal. An aqueous solution of superparamagnetic iron-oxide nanoparticles (Resovist) was dropped in a tiny blot-like spot in the middle of the filter paper and the magnetization was measured. Magnetic moments of a dilution series of Resovist solutions versus the number of particles provided a linear graph, revealing that the magnetic moment per Resovist particle was 8.25 x 10(-17) emu. 1 x 10(5) cancer cells were incubated with Resovist, and the number of Resovist particles attached to the cell surface and surrounding a living cell was calculated to be 1.02 +/- 0.14 x 10(7) particles/cell. Our system using a commercial SQUID magnetometer should be more than enough to determine the number of magnetic nanoparticles biologically reacting with living cells, contributing to the application of magneto nanomaterials to the life-science field.

Alterations of host resistance to mouse typhoid infection by sex hormones.

The effect on mouse typhoid infection of a 3-day treatment of female virgin mice with 1 mg/day of female sex hormones (estrogen or progesterone), maintaining the same hormonal levels observed in pregnant mice for 30 days, was investigated in order to clarify the mechanisms of altered resistance during pregnancy. Estrogen-exposed mice were more susceptible to the intraperitoneal challenge with Salmonella typhimurium as compared with the vehicle control mice, while progesterone treatment increased the survival times of mice. Estrogen exposure increased the number of peritoneal cells after treatment, but the inflammatory cellular response after infection was significantly suppressed. Although the estrogen-treated and vehicle control mice had the same degrees of peritoneal cellular responses after infection, the death rates in the estrogen-treated mice were higher than those in the vehicle control mice against challenge with 1 LD50 of S. typhimurium. On the other hand, progesterone treatment resulted in the marked influx of peritoneal cells after treatment was terminated, and also it induced a significant increase in the number of peritoneal cells after infection. Although survival times in the progesterone group were higher than those in other groups, all progesterone-treated mice died after a challenge with 1,000 LD50 of S. typhimurium. These results suggest that progesterone enhances nonspecific resistance by increasing the influx of peritoneal cells after infection, while estrogen affects the acute inflammatory responses.

Contribution of interferon gamma and membrane-associated interleukin 1 to the resistance to murine typhoid of Ityr mice.

Resistance of mice to Salmonella typhimurium in the early phase of infection is known to be controlled by the expression of chromosome 1 locus Ity. To clarify the mechanism by which the genetically resistant (Ityr) mice can overcome the first phase of salmonellosis, the early response in DBA/2 (Ityr) and BALB/c (Itys) mice was compared after a subcutaneous injection of S. typhimurium. In both strains, the growth of S. typhimurium was controlled in livers and Kupffer cells until day 3, but thereafter the bacteria multiplied rapidly in BALB/c mice. Over the first 2 days nonspecific responses (changes in levels of blood leukocytes, plasma iron, and alpha 1-antitrypsin) were not significantly different between the strains, and the capacity of Kupffer cells isolated from infected mice of both strains to produce interleukin 1 (IL-1) and tumor necrosis factor alpha (TNF-alpha) was of the same degree. Thereafter, only DBA/2 Kupffer cells were able to produce membrane-associated IL-1 (ma IL-1) as well as TNF-alpha. Moreover, only DBA/2 splenocytes were able to produce interferon gamma (IFN-gamma) upon stimulation with Salmonella antigens, although concanavalin A-stimulated splenocytes of both strains produced the same level of interleukin 2. Furthermore, administration of recombinant murine IFN-gamma and DBA/2 Kupffer cells of day 6 to BALB/c mice 3 days after infection resulted in a significant level of protection, whereas neither of these materials alone induced protection. Injection of anti-TNF-alpha antibodies did not affect the resistance of DBA/2 mice. Thus, these findings suggest that the early resistance of Ityr mice is partly attributable to their capacity to produce IFN-gamma and ma IL-1 after infection.

Induction of hypersensitivity to endotoxin in C3H/HeJ mice by immunization with L-form Salmonella typhimurium.

When endotoxin low-responder C3H/HeJ mice were immunized with L-form Salmonella typhimurium, the mice were more susceptible to a lethal challenge with S. typhimurium 1 week after immunization (1-week mice) than were the unimmunized controls. One-week immune mice produced overwhelming amounts of tumor necrosis factor-alpha (TNF-alpha) in the blood after infection, while 4-week immune mice produced lesser amounts of this cytokine with a 75% survival rate at 60 days postinfection. Pretreatment with anti-TNF-alpha antibody prevented 1-week immune mice from succumbing to acute illness. Endotoxin-stimulated peritoneal macrophages from 1-week immune mice produced higher amounts of TNF-alpha in vitro than did those from 4-week immune mice and they expressed larger amounts of TNF-alpha mRNA on Northern blot. The capacity of macrophages to produce TNF-alpha in vitro was correlated with the degree of colonization by the L form in the cells. These results suggest that the colonization by L-form S. typhimurium in macrophages alters the susceptibility to S. typhimurium of C3H/HeJ mice and that TNF-alpha might play a major role in this alteration of host resistance.

Murine tumorlytic factor, immunologically distinct from tumor necrosis factor-alpha and -beta, induced in the serum of mice treated with a T-cell mitogen of Corynebacterium kutscheri.

Murine tumorlytic factor (TF), immunologically distinct from murine tumor necrosis factor (TNF)-alpha and -beta, was purified to a homogeneity from the serum of mice injected with a T-cell mitogen of Corynebacterium kutscheri. The treated mouse serum was purified by Lentil lectin-Sepharose chromatography, DEAE-cellulose chromatography, preparative isoelectric focusing, and high-pressure liquid chromatography to the specific activity of 1.5 x 10(6) U/mg protein. TF was 42 kDa in its oligomeric form and 14 kDa in its monomeric form. TF activity was not impaired with hamster monoclonal antibody (mAb) to recombinant murine TNF-alpha and -beta and, reciprocally, rabbit antibody to TF neutralized the bioactivity of neither murine TNF-alpha nor -beta. TF was not precipitated with the mAb to murine TNF-alpha and -beta in Western blot analysis. The partial amino acid sequence of TF was at most 33% homologous to the 46-63 sequence of mouse TNF-beta. Thus, these results suggest that TF might be a novel tumorlytic factor which is immunologically distinct from mouse TNF-alpha and -beta.

Pituitary control of blood coagulation in the rat.

Assay of prothrombin time, activated partial thromboplastin time and activity in the thrombotest in the rat showed that at 14 days of age, male and female rats had similar activities but female rats of 21-84 days of age had higher blood coagulation activities than male rats. Coagulation in mature female animals was not affected by the stage of the oestrous cycle. Hypophysectomy of prepubertal (21 days old) or adult (56 days old) male or female animals resulted in lower activity (prolongation of clotting time). A pituitary gland implanted ectopically under the kidney capsule of hypophysectomized animals resulted in shorter clotting times than in hypophysectomized animals not so treated. Pituitary glands from female donors were more effective in recipients of both sexes than those from males. These results demonstrate a sexual differentiation in activity of coagulation factors in the rat and suggest that the involvement of the hypothalamic-hypophysial-gonadal axis in the regulation of blood coagulation.

Usefulness of the PAL test in the diagnosis of lung cancer.

Usefulness of a simple microagglutination test for diagnosis of malignant diseases was evaluated in the diagnosis of lung cancer. The test was not specific, being positive in 82% of malignant and 55% of nonmalignant cases. It was shown that poly-L-lysine-induced agglutination of lymphocytes reflects rather changed serum than cell properties and cannot be taken as a method for detection of sensitized cells.

Comparison of long-term therapeutic effect of an ACE inhibitor, temocapril, with that of a diuretic on microalbuminuria in non-diabetic essential hypertension.

Many investigators have reported that angiotensin-converting enzyme (ACE) inhibitors have antiproteinuric effects and retard the progression of renal impairment in diabetic patients. On the other hand, those effects of ACE inhibitors have not been well established in patients with essential hypertension. This study was conducted to prospectively evaluate whether an ACE inhibitor, temocapril, could modify the urinary microalbumin excretion rate (UAE) in hypertensive outpatients who had no signs of renal impairment. To compare the long-term effect of temocapril with that of a diuretic on UAE, hypertensive patients treated with a diuretic (trichlormethiazide) were enrolled in a prospective study if they had normal serum creatinine levels and no overt proteinuria during a 3-month screening period. A urinary microalbumin-to-urinary-creatinine ratio (mg albumin/mmol Cr) was used as an estimate of UAE. Patients visited the hospital monthly to determine blood pressure (BP) and UAE. After baseline observation during the treatment with the diuretic, the subjects were randomly divided into two groups. In group A, the diuretic was switched to temocapril, 2 to 4 mg once daily for 12 months. In group B, the subjects continued to receive the diuretic for an additional 12 months. Seventy-six outpatients (41 men and 35 women; mean age, 59.0+/-1.4 years) with essential hypertension entered the study. The effects of temocapril on BP appeared to be clinically similar to those of the trichlormethiazide, but the use of temocapril significantly decreased UAE. In group A (n=37), UAE decreased significantly (p<0.01) from the baseline value of 4.19+/-0.37 mg albumin/mmol Cr to 2.47+/-0.29 and 2.68+/-0.28 mg albumin/mmol Cr at the 6th and 12th month of temocapril therapy, respectively. In contrast, in group B (n=39) UAE was unchanged (baseline, 4.16+/-0.63 mg albumin/mmol Cr; 6 months, 4.92+/-0.72; 12 months, 4.71+/-0.74). These results indicate that long-term therapy with temocapril may be superior in reducing UAE than is diuretic therapy in patients with essential hypertension who had no signs of renal impairment.

Long-term therapy with an ACE inhibitor, temocapril, reduces microalbuminuria in essential hypertension.

The present study was conducted to prospectively evaluate whether a new ACE inhibitor, temocapril, could modify urinary microalbumin excretion rate (UAE) in a group of hypertensive outpatients who had no evidence of renal impairment. Sixty-three outpatients (32 men and 31 women; mean age, 59.9 +/- 1.5 yr) with essential hypertension entered the study, all having been treated for at least 6 mo with dihydropyridine calcium-channel blockers (CCBs: nitrendipine, nisoldipine, or amlodipine). Their blood pressures (BPs) had been controlled to adequate levels with the CCBs. None had overt proteinuria (determined by Albustix) or abnormal serum creatinine levels. After 3 mo of baseline observation under the previous treatment, the subjects were randomly divided into two groups. In group A (n = 31), the previously used CCBs were switched to temocapril, 2 to 4 mg once daily for 12 mo, and BP was controlled at a level equivalent to that during CCB treatment. In group B (n = 32), the subjects were maintained on their previous treatment for a further 12 mo. The effect of temocapril on BP appeared to be clinically similar to that of the previously used CCBs, but it significantly decreased UAE as compared with the previous therapy. In group A, UAE decreased significantly (p < 0.01) from the baseline value of 38.9 +/- 5.1 mg/g creatinine (Cr) to 22.2 +/- 4.2 and 25.3 +/- 5.6 mg/g Cr at the 6th and 12th months of temocapril therapy, respectively. In contrast, in group B UAE was unchanged (baseline 39.8 +/- 6.6 mg/g Cr; 6 mo, 44.6 +/- 6.8; 12 mo, 45.9 +/- 7.7). In group A, 17 of 31 patients (54.8%) had abnormal UAE levels (> or = 29.5 mg/g Cr) during previous therapy with CCBs, but 6 mo after switching to temocapril 25 of these patients (80.6%) had normal UAE (< 29.5 mg/g Cr). In group B, 15 of 32 patients (46.9%) had abnormal UAE levels during the observation period, and these abnormal UAE levels remained unchanged; 17 of the 32 patients (53.1%) had abnormal UAE levels after a further 6 mo of continued CCBs therapy. We conclude that long-term therapy with temocapril may provide renal protection by reducing UAE even in hypertensive patients with no evidence of renal impairment.

Isolation of a cytotoxin from L-form Salmonella typhimurium.

A cytotoxic protein was isolated from the sodium dodecyl sulphate (SDS)-solubilized extract of the stable L forms of Salmonella typhimurium by ion-retardation chromatography, ion-exchange chromatography, isoelectric focusing and gel filtration. The purified toxin, with a molecular mass of 32 kDa and with isoelectric point of 6.4, was thermolabile and trypsin-sensitive. Against mouse macrophages, its cytolytic effect was detectable in vitro at concentrations higher than 0.7 micrograms/ml, with a complete lysis obtained at 5 micrograms/ml. In contrast, it stimulated C3H/HeJ macrophages in the dose range of 0.1-0.5 micrograms/ml to allow the cell to respond to endotoxin, resulting in the significant production of tumor necrosis factor alpha. By Northern blot analysis, this effect was detectable at a dose as low as 0.01 micrograms/ml. These findings suggest that the transformation of bacillary S. typhimurium into L forms in vivo may induce alterations in host resistance against murine typhoid.

Hepatotoxic activity of Campylobacter jejuni.

Hepatotoxic factor(s) were isolated from whole-cell lysates of Campylobacter jejuni GIFU 8734 and purified by chromatography. A single intravenous injection of 10 micrograms of this factor reproducibly produced hepatitis in mice, as determined by histology and liver function tests. The hepatic lesions were very similar to those evoked by C. jejuni infection. Tissue-culture studies with mouse hepatocytes demonstrated that low concentrations of the factor caused release of hepatic enzymes into the medium without appreciable cytolysis. High concentrations of the factor induced cytolysis. These effects were neutralised by antiserum to the factor, but not by antisera to the lipopolysaccharide of C. jejuni or to the heat-labile enterotoxin of Escherichia coli. Among 20 clinical isolates of C. jejuni, only four evoked hepatitis in mice and produced the hepatotoxic factor.

Mononuclear cell response in the liver of mice infected with hepatotoxigenic Campylobacter jejuni.

Intragastric inoculation with hepatotoxigenic strains of Campylobacter jejuni led to the death of mice during the late phase of infection. Histological study disclosed a massive infiltration of mononuclear cells in the liver, mimicking intrahepatic hypersensitivity. Neither enterotoxigenic nor enteroinvasive Escherichia coli induced such a lesion. However, the same histopathological change was induced by injecting the hepatotoxic factor of hepatotoxigenic C. jejuni intravenously on two occasions separated by 14 days. Neither a single injection of an increased dose of the hepatotoxic factor nor two injections, the second of which was heat-inactivated, induced this change. Pre-treatment with rabbit antibody to the hepatotoxic factor inhibited the development of the hepatic lesion. These results suggest that C. jejuni-induced hepatic lesions in mice may be caused, at least in part, by the active moiety of the hepatotoxic factor. The possible mechanisms by which the toxic factor induces hepatitis as a consequence of hypersensitivity are discussed in relation to Guillain-Barré syndrome and Reiter's syndrome associated with C. jejuni enteritis.

Virulence of transparent and opaque colony types of Neisseria gonorrhoeae for the genital tract of mice.

The virulence of transparent (Tr) and opaque (Op) colony types of Neisseria gonorrhoeae in the genital tract of female mice was evaluated at two stages of oestrous. Isogenic pairs of Tr and Op variants were isolated from N. gonorrhoeae strain 57-120. Both variants exhibited a T2 morphology, but only the Op variant possessed protein II (P.II) in outer-membrane fractions. When administered by intravaginal inoculation Op gonococci were highly infective only for mice in late pro-oestrous, whereas Tr gonococci were virulent for mice at both late pro-oestrous and dioestrous. Gonococci recovered from the uterus were of both Tr and Op phenotypes in equal proportions when mice were infected at dioestrous with Tr cells. In contrast, greater than 90% of recovered colonies were of Op phenotype when mice were infected at late pro-oestrous with either Op or Tr cells. These results indicate that the virulence of gonococci for the genital tract of female mice differs from that for the chicken embryo. Furthermore, gonococcal survival in the female genital tract might be attributable to phase variation from Tr to Op phenotypes.

Prevalence and clinical presentation of glucose-6-phosphate dehydrogenase deficiency in Pakistani Pathan and Afghan refugee communities in Pakistan; implications for the use of primaquine in regional malaria control programmes.

Glucose-6-phosphate dehydrogenase (G-6-PD) deficiency surveys in Afghan refugees and a local community in the North-West Frontier Province, Pakistan, showed that this trait was most common among Pathan and Uzbak refugees (15.8% and 9.1% respectively). The prevalence among Pakistani Pathans was 7.0%, and that in Tajik and Turkoman refugees was 2.9% and 2.1% respectively. Hospital studies showed that the type of G-6-PD deficiency in Pathans could cause severe haemolytic crises. The potentially fatal side effects of primaquine treatment in the Pathan communities, and the high risk of re-infection, render the anti-relapse treatment policy for Plasmodium vivax obsolete. However, epidemic conditions of P. falciparum malaria may justify the use of primaquine as a gametocidal drug, administered as a single dose, during the transmission season. These findings necessitate revision of the recommendations for the use of primaquine in the area.

Determination of the chiral structure of [Formula: see text] using anomalous x-ray scattering near the Cs K absorption edge.

A structural study of [Formula: see text], grown from aqueous solution, was performed using anomalous x-ray scattering near the Cs K absorption edge to determine an absolute configuration of constituent atoms. The sense of the helical structure of the [Formula: see text] chain was found to be predominantly right-handed through a comparison of observed Bragg Bijvoet ratios with calculated ones. Assuming that [Formula: see text] consists of the two domains (i.e. right- and left-handed helices), we estimate that the volume fraction for the right-handed helix is [Formula: see text].

[Optimization of arbitrarily primed polymerase chain reaction (AP-PCR)-based DNA fingerprinting of Mycobacterium tuberculosis and its clinical application].

Since the number of outbreaks of pulmonary tuberculosis is increasing in Japan, epidemiological analysis is important to prevent the disease. Since Mycobacterium tuberculosis lacks the variety of biotypes among strains, genetical analysis is considered to be a promising measure to differentiate various of this pathogen. We applied arbitrarily primed polymerase chain reaction (AP-PCR)-based DNA fingerprinting to clinically isolated strains of M. tuberculosis. Although genetic analyses of M. tuberculosis by AP-PCR were reported by several investigators, reproducibilities of their results were not sufficient to be widely accepted as a reliable epidemiological tool. To attain high reprodicibulity, we attempted to optimize AP-PCR conditions including primers and annealing temperature, and to purity of DNA preparations. In this study, high reproducibility was attained by using the mixed primers of 1309F and 92R, and DNA preparations with an absorbance ratio (A260/A280) of higher than 1.50. Twenty two clinical isolates, including strains isolated from one incidence of nosocomial infection and from that of intrafamilial infection were analyzed by the optimized method; consequently they were grouped into 16 types. This AP-PCR method requires only one week subculture of M. tuberculosis and less than 24 hours for analysis. This AP-PCR method allowed us to obtain the highly reproducible results within a considerably short term, which would be applicable to clinical epidemiological investigation.

[The 5th report on long-term chemotherapy using erythromycin (EM) for chronic lower airway infection--cases followed over 7 years].

Clinical studies were made over 7 years on 9 cases to whom long-term chemotherapy with EM was administered for chronic airway infection. 1) Clinical effectiveness: Highly effective in 8 cases; Improvement in QOL was observed in 8 cases. Bacteriological effect: In 7 cases, pathogenic bacteria disappeared. 2) No side effects were observed. 3) Changes in PaO2 levels with the passage of time: In most cases, PaO2 reached a plateau within 1 year. Although in some cases, there was subsequent elevation. 4) The frequency of catching cold over the 7 years period was low with an average of 1.2 times/year per subject. In only 2 cases were subject hospitalized due to acute exacerbation triggered by a cold. 5) Mucociliary transport improved in 7 out of 8 cases examined. However, only 4 of these recovered normal transport. The effect of EM in the other cases in which clinical improvement was not demonstrated was deemed slightly effective. On the basis of the above findings, it was suggested that long-term chemotherapy using EM was clinically efficacious. This is based on the fact that its efficacy, including amelioration of QOL appeared within one year of the initiation of therapy, and continued without decline for over 7 years.

[A clinical study of chronic lower respiratory tract infections with Pseudomonas aeruginosa by transtracheal aspiration].

We investigated the yearly changes of the incidence of Pseudomonas aeruginosa (P. aeruginosa) isolated from chronic lower respiratory tract infections (CLRTI), and also performed a clinical study on CLRTI with P. aeruginosa by transtracheal aspiration (TTA) to clarify the recent trend of P. aeruginosa infection in CLRTI and the predisposing clinical factors to the acute exacerbation. The isolation rate of P. aeruginosa among the total isolated bacteria in CLRTI between December 1978 and March 1983 was 8.4%, but it increased to 23.1% between April 1988 and March 1993. In 69 episodes (40 cases) of P. aeruginosa isolated from CLRTI between April 1983 and March 1993, monomicrobial infections of P. aeruginosa were 42 episodes (60.9%) and polymicrobial infections were 27 episodes (39.1%). When the diseases were classified into acute exacerbated and non-exacerbated phases, polymicrobial infections were seen more in the former phase, and the principal organisms detected with P. aeruginosa were Haemophilus influenzae and Streptococcus pneumoniae. In the acute exacerbated cases, predisposing conditions concerning the exacerbation were divided into four patterns: 1. polymicrobial infections with H. influenzae or S. pneumoniae, 2. after acute upper respiratory tract infections due to viral superinfection, 3. early phase from bacterial replacement by P. aeruginosa, 4. immunocompromised states such as adrenal corticosteroid administration or systemic underlying diseases. These results suggest that the importance of P. aeruginosa in CLRTI is increasing year by year and we must pay attention to the fact that P. aeruginosa alone may also cause acute exacerbation in the latter 2 patterns of the condition.