Biophysical characteristics of HIMAC clinical irradiation system for heavy-ion radiation therapy

PURPOSE

The irradiation system and biophysical characteristics of carbon beams are examined regarding radiation therapy.

METHODS AND MATERIALS

An irradiation system was developed for heavy-ion radiotherapy. Wobbler magnets and a scatterer were used for flattening the radiation field. A patient-positioning system using X ray and image intensifiers was also installed in the irradiation system. The depth-dose distributions of the carbon beams were modified to make a spread-out Bragg peak, which was designed based on the biophysical characteristics of monoenergetic beams. A dosimetry system for heavy-ion radiotherapy was established to deliver heavy-ion doses safely to the patients according to the treatment planning. A carbon beam of 80 keV/microm in the spread-out Bragg peak was found to be equivalent in biological responses to the neutron beam that is produced at cyclotron facility in National Institute Radiological Sciences (NIRS) by bombarding 30-MeV deuteron beam on beryllium target. The fractionation schedule of the NIRS neutron therapy was adapted for the first clinical trials using carbon beams.

RESULTS

Carbon beams, 290, 350, and 400 MeV/u, were used for a clinical trial from June of 1994. Over 300 patients have already been treated by this irradiation system by the end of 1997.

Decrease of the D3 dopamine receptor mRNA expression in lymphocytes from patients with Parkinson's disease

We investigated the dopamine receptor (DAR) mRNA expression in peripheral blood lymphocytes from 45 patients with Parkinson's disease (PD) and 21 age-matched controls using the quantitative reverse transcription and polymerase chain reaction method. Beta-actin mRNA was used as an internal control to evaluate the relative expression level of the DAR mRNA. There was a statistically significant decrease of the D3 dopamine receptor (D3R) mRNA expression in PD patients compared with that in controls. There was no change in expression of the D5 dopamine reception mRNA in PD patients. A further binding study showed reduction of the D3R binding sites in PD lymphocytes. The decrease of the D3R mRNA expression correlated with the degree of clinical severity in PD patients.

Treatment of Kearns-Sayre syndrome with coenzyme Q10

We studied the metabolism of coenzyme Q10 (CoQ) and the effects of CoQ therapy in five patients with Kearns-Sayre syndrome (KSS). Although the mitochondrial fraction was increased in muscles from KSS patients, CoQ content was slightly low. CoQ synthesis was normal in fibroblasts from KSS patients. Administration of 120 to 150 mg/d of CoQ improved abnormal metabolism of pyruvate and NADH oxidation in skeletal muscle. CoQ therapy decreased CSF protein concentration and CSF lactate/pyruvate ratio. ECG abnormalities and neurologic symptoms also improved.

Expression of the D3 dopamine receptor gene and a novel variant transcript generated by alternative splicing in human peripheral blood lymphocytes

The sequential reverse transcription and polymerase chain reaction amplified the mRNA coding for the D3 dopamine receptor (D3R) in human peripheral blood lymphocytes. Pharmacological analysis confirmed the binding of the D3R specific ligand to the lymphocytes. In addition, there was a novel shorter variant transcript of the D3R gene generated by alternative splicing in lymphocytes and brain. This variant, termed D3(TM4-del), has a 143 bp deletion and encodes a 138 amino acid protein containing the first three transmembrane domains of the native D3R.

Effect of serotonin on the differentiation of human monocytes into dendritic cells

The local cytokine environment and presence of stimulatory signals determine whether monocytes acquire dendritic cell (DC) or macrophage characteristics and functions. Because enhanced platelet activation is reported in patients with many allergic disorders, such as atopic dermatitis, platelet-derived factors may influence monocytic differentiation into DC. In this study we examined the effect of serotonin, a prototypic mediator of allergic inflammation released mainly by activated platelets at the inflammatory site, on the granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-4-driven differentiation of monocytes into monocyte-derived DC. Monocytes from healthy adult donors were cultured with GM-CSF and IL-4 in the presence or absence of serotonin, and the phenotypes and function of these cells were analysed. In the presence of serotonin, monocytes differentiated into DC with reduced expression of co-stimulatory molecules and CD1a, whereas expression of CD14 was increased. These serotonin-treated DC exhibited significantly reduced stimulatory activity toward allogeneic T cells. However, these cells showed enhanced cytokine-producing capacity, including IL-10 but not IL-12. There was no significant difference between both types of DC in phagocytic activity. Experiments using agonists and antagonists indicated that serotonin 5-hydroxytryptamine (5-HT) induced the alteration of their phenotype and reduction in antigen-presenting capacity were mediated via 5-HTR(1/7). It is therefore suggested that serotonin-driven DC may have a regulatory function in the inflammatory process.

Two novel variants of transthyretin identified in Japanese cases with familial amyloidotic polyneuropathy: transthyretin (Glu42 to Gly) and transthyretin (Ser50 to Arg)

Two mutant genes coding for two different variants of transthyretin were identified in two independent kindreds with familial amyloidotic polyneuropathy. A single base change from A to G was identified in exon 2 of transthyretin gene in two brothers from the first kindred. This base change led to replacement of glutamate by glycine at position 42 of 127-residue molecule. In a patient from the second kindred, T to G transversion in exon 3 of transthyretin gene led to replacement of Ser by Arg at position 50. The two mutants were discovered by randomly sequencing recombinant clones containing the entire length of each one of the four exons selectively amplified by polymerase chain reaction. The base change produced a new restriction site for Hae III and Cfr 13 I in the exon 2 and for Mva I in the exon 3, respectively. Restriction fragment length polymorphisms and allele-specific oligonucleotide hybridizations confirmed the base changes. The accurate detection of the new mutant genes is hereafter possible by these procedures.

Alzheimer-type pathology in a patient with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS)

A 53-year-old Japanese woman with a point mutation in mitochondrial DNA (tRNALeu(UUR), nt3243) consistent with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) and Alzheimer-type brain pathology is reported. This woman had suffered myopathy and psychosis without any clinical evidence of, stroke-like episodes during the last 10 years of her life, and had died after an accident. At autopsy 30 h post mortem, a part of the brain was snap frozen for biochemical and histochemical studies, and the remaining part was processed for a routine examination and electron microscopy. In the brain there were no ischemic lesions. Instead, primitive/diffuse senile plaques were found throughout the brain, predominantly in the frontal and temporal lobes, while Alzheimer neurofibrillary tangles were found only in the parahippocampal gyrus. These plaques were positive for beta-protein and mostly negative for tau protein, ubiquitin, neurofilaments, alpha-choline acetyltransferase, and acetylcholinesterase. Mutations in codon 331 of the ND2 gene as well as codons 693, 713 and 717 of the beta-amyloid precursor protein gene, known to be responsible for some cases of familial Alzheimer disease, were not found. Furthermore, coincidental Down syndrome was ruled out by chromosome analysis. The results suggest a possible correlation between this mitochondrial DNA abnormality and Alzheimer-type pathology.

Congenital malignant melanoma: a case report

Congenital malignant melanoma (MM) is an uncommon condition that is defined as MM recognized at birth. Its incidence is difficult to determine because of the small number of reported cases and because of problems associated with diagnosis. Generally, Spitz naevus and melanoma have many clinical and histopathological similarities, so it is difficult to differentiate between the two. We describe a rare case of congenital MM in which differential diagnosis from Spitz naevus was problematic. In addition, we review the literature and comment on the prognostic differences among the three types of congenital and infantile MM.

A novel mutant (transthyretin Ile-50) related to amyloid polyneuropathy. Single-strand conformation polymorphism as a new genetic marker

DNA sequence polymorphisms in transthyretin (TTR) genes were investigated by single-strand conformation polymorphism (SSCP) analysis of polymerase chain reaction products. The amplified DNA fragments that encode each exon of the normal TTR gene showed two bands, representing the two complementary single strands of DNA. In one patient with amyloid polyneuropathy, the exon 3 DNA showed a unique, aberrant migration pattern. Direct sequencing analysis of the amplified exon 3 revealed a single base change (G-to-T), resulting in a novel amino acid substitution (Ser-50----Ile). We also present the SSCP patterns for five known Japanese TTR variants.

Increased plasma LIGHT levels in patients with atopic dermatitis

LIGHT [the name of which is derived from 'homologous to lymphotoxins, exhibits inducible expression, competes with herpes simplex virus glycoprotein D for herpes simplex virus entry mediator (HVEM), and expressed by T lymphocytes'], is a member of the tumour necrosis factor superfamily that is involved in various inflammatory diseases. We aimed to estimate the relevance of plasma LIGHT levels as a biomarker for atopic dermatitis (AD). In order to understand the putative role of LIGHT in AD pathogenesis, we also investigate the effects of LIGHT on a monocytic cell line, human acute monocytic leukaemia cell line (THP-1). We examined plasma LIGHT levels, total serum IgE, serum value of CCL17 and peripheral blood eosinophil counts in patients with AD and healthy subjects. The effects of LIGHT on activation and apoptosis in THP-1 cells were also investigated. The plasma concentrations of LIGHT in AD patients were significantly higher than those in healthy individuals and the concentrations decreased as the symptoms were improved by treatment. The LIGHT plasma concentrations correlated with IgE levels and the Severity Scoring of AD (SCORAD) index. In addition, LIGHT stimulation increased expression of CD86 and induced production of interleukin-1β in THP-1 cells. Apoptosis was inhibited, the Bcl-2 level increased and the caspase-3 level decreased in THP-1 cells stimulated with LIGHT, compared to unstimulated control cells. These results suggest that plasma LIGHT levels may be one of the promising biomarkers for AD.

The role of interleukin-16 in murine contact hypersensitivity

Contact hypersensitivity (CHS) is a T-cell-mediated skin inflammatory response. It is controversial whether CD4(+) T cells play an enhancing or regulatory role in the pathogenesis of CHS. Because interleukin (IL)-16 is a chemoattractant cytokine for CD4-expressing cells, we investigated the involvement of IL-16 in the CHS reaction. IL-16 production was induced in the epidermis and dermis during the elicitation phase of the CHS response with trinitrochlorobenzene. In the sensitization phase, the single application of haptens such as trinitrochlorobenzene and oxazolone also induced IL-16, whereas primary irritants or vehicle control did not. IL-16 was produced mainly by CD11c-negative cells in the epidermis during the elicitation phase. Furthermore, treatment of sensitized mice with anti-IL-16 neutralizing MoAb enhanced the ear swelling and reduced the number of infiltrating CD4(+) T cells. These data indicate that IL-16 plays a role in CHS, whereby IL-16 induces CD4(+) T cells and these CD4(+) T cells subsequently exhibit down-regulating properties.

Histamine prevents apoptosis in human monocytes

BACKGROUND

As chronic atopic dermatitis (AD) is associated with activation of circulating and infiltrating monocytes, monocytes are considered to play a pivotal role in the establishment of chronic lesions in AD. Histamine is an important mediator of inflammatory and allergic responses. Although new immunomodulatory functions of histamine have recently become apparent, the effect of histamine on the life span of monocytes remains unclear.

OBJECTIVE

In the present study, we investigated the effect of histamine on the life span of human monocytes from normal healthy donors and patients with AD.

METHODS

Monocyte apoptosis was induced by serum deprivation, CD95/Fas ligation, or dexamethasone in the presence of histamine, and measured using annexin V-and propidium iodide-staining. Bcl-2 protein and activated caspase-3 were determined by flow cytometry. We also examined the effect of soluble, histamine-induced factors produced by monocytes on apoptosis. Furthermore, we examined whether monocytic apoptosis is dependent on the cAMP pathway.

RESULTS

Histamine prevented monocytic apoptosis induced by serum deprivation, CD95/Fas ligation, or dexamethasone in a dose- and time-dependent fashion. The inhibitory effects of histamine on monocytic apoptosis were blocked by an H2R antagonist, and mimicked by an H2R agonist. Histamine also up-regulated the expression of Bcl-2 and Mcl-1, and inhibited the activation of caspase-3. The culture supernatants from histamine-treated monocytes inhibited monocytic apoptosis, which was partly reversed by the removal of IL-10. Monocytes cultured with anti-IL-10 mAb and histamine did not exhibit an inhibitory effect on apoptosis. The histamine-induced anti-apoptotic effect was attenuated when monocytes were cultured in the presence of a cAMP inhibitor.

CONCLUSIONS

These results indicate that the H2R signals induced by histamine allow monocytes to prolong their life span and infiltrate to the site of inflammation. This process may contribute to the establishment of chronic allergic disorders, such as AD.

The fluid-attenuated inversion-recovery pulse sequence in assessment of central nervous system involvement in myotonic dystrophy

We compared the fluid-attenuated inversion recovery (FLAIR) sequence with conventional spin-echo (SE) imaging for detection of involvement of the central nervous system in five patients with myotonic dystrophy (MD). The diagnosis was made based on clinical features and DNA analysis. All patients showed abnormal high-intensity lesions in the white matter on T2-weighted images, although these were more clearly visible using FLAIR.

Design of synchrotron light source and its beamline dedicated to dual-energy x-ray computed tomography

A synchrotron light source dedicated to medical applications has been designed at National Institute of Radiological Sciences. The storage ring, with circumference of 80 m, is designed for acceleration of 2.3 GeV and a stored current of 420 mA. It is equipped with two multipole wigglers to produce sufficient photon flux in a hard x-ray region required for medical applications. The purposes of the synchrotron light source are clinical performance of medical diagnoses clinically and research and development relating with medical applications. One of the most interesting applications for us is dual-energy x-ray computed tomography (CT). It gives the information about electron density of human tissue. The information plays an important role in advancing heavy-ion radiotherapy of cancers. Electron density can be derived from attenuation coefficients measured by different energy x rays. In this paper, a practical method of the dual-energy x-ray CT with synchrotron radiation is proposed with the theoretical consideration. The primitive experiment using monochromatic x rays emitted from radioisotopes proved the procedure of analysis mentioned here effective to derive electron densities from linear attenuation coefficients for two x rays of a different energy. The beamline dedicated to dual-energy x-ray CT is also proposed. It has a multipole wiggler as a light source and it mainly consists of a dual crystal monochromator and a rotating filter for attenuating photon flux of x rays and two-dimensional detector.

Lethality of single-track events: comparison between calculations and experimental data

Recent results on cell killing by microbeams were analysed using three parameters (k, L, L1), where k is the mean number of lethal particles per cell nucleus, L [keV/microm] is the track-average LET (linear energy transfer) in cells, and L1 [keV/microm] is a critical value for inducing lethal damage by a single track. Analysis showed that calculations are consistent with two data sets. The existence of a quadratic dependence on LET of cellular effects is confirmed in the high-LET region between 30 and 500 keV/microm. L1 approximately 150 keV/microm was found to give the best fit and the sensitive area of the cell nucleus was determined as approximately 50 microm2 for Chinese hamster V79 cells. In microbeam experiments with several MeV alpha-particles, the relationship between k and L for V79 cells can be expressed as L = approximately 150(k)-1/2. For a given survival level, the difference in the required dose (or L) between the microbeam and broad-beam experiments is also analytically described.

Dosimetry and measured differential W values of air for heavy ions

Heavy-ion irradiation systems were designed and constructed at two cyclotron facilities in Japan for use in various fields of radiation physics and radiation biology. A 135 MeV/u carbon beam as well as 12 MeV/u carbon and helium-3 beams were first used in experiments. We have established a systematic method for heavy-ion dosimetry at both high and low incident energies involving measurements of fluences. We also obtained differential W values (w) of air for those beams by comparing the results of fluence measurement dosimetry with ionization chamber dosimetry. The differential W values of air were found to be 36.2 +/- 1.0, 34.5 +/- 1.0, and 33.7 +/- 0.9 eV for 6.7 MeV/u carbon ions, 10.3 MeV/u 3He ions, and 129.4 MeV/u carbon ions, respectively. The w value for high-energy heavy ions approaches the W value for high-energy electron or photon beams. In ionization chamber dosimetry for a heavy-ion beam, we found a track-size effect. A difference in the track sizes of heavy ions in the gas and solid phases affected the output current of the ion chamber in the case of high-energy heavy ions.

[Deletions of mitochondrial DNA in Kearns-Sayre syndrome]

Single large-scale deletions of mitochondrial DNA (mtDNA) are found in 70 to 80% of Kearns-Sayre syndrome (KSS) patients. Most deletions are flanked by direct repeats up to 13 nucleotides in length. The incidence of ragged-red fibers and cytochrome c oxidase-negative fibers in muscle is correlate with the amount of deleted mtDNA. Recently, study with 'cybrid' cell lines, which have different proportions of deleted mtDNA, showed that accumulation of deleted mtDNA to over 60% of the total mtDNA resulted in progressive inhibition of overall mitochondrial translation, as well as, reduction of cytochrome c oxidase activity. These results suggest that deletion of mtDNA alone is sufficient for the mitochondrial dysfunction in KSS.

[DNA tests for mutant genes coding for transthyretins Gly42, Arg50 and Cys114 in Japanese cases of familial amyloid polyneuropathy]

Four different genes encoding variant transthyretins (TTR) have been known in Japanese cases with familial amyloidotic polyneuropathy (FAP); TTR Met30, Gly42, Arg50 and Cys114. First three mutant genes can be detected by restriction fragment length polymorphism using NsiI, Cfr13I and MvaI, respectively. Since a single base change responsible for TTR Cys114 produces no new restriction site, RFLP is not directly applicable for the detection of this gene. In this study, TTR Cys114 gene was amplified by polymerase chain reaction using mismatch primer to produce a new restriction site for HgiAI. The enzyme digestion of the product resulted in the appearance of extra fragments in the presence of the normal fragment. The accurate detections of all the four mutant genes are hereafter possible by these procedures.

Analysis of relative biological effectiveness of high energy heavy ions in comparison to experimental data

We report that the relative biological effectiveness (RBE) of accelerated heavy ions for inactivation of cells can be analyzed by using the quadratic dependence on the linear energy transfer (LET) of the cellular effect. For high-LET radiation in low-dose regions, the inactivation cross section (sigma) can be approximately expressed as sigma max [1-exp[-k.(LET/Li)2]; here, k is the number of heavy-ions traversed in a cell nucleus and Li is a geometrical parameter related to the DNA structure, which depends on cell type. This original expression was first presented by Powers et al [Int. J. Radiat. Biol. 14 (1968)]. Using this expression and the Poisson distribution for the stochastic property of particle hitting, the mortality of cell populations was calculated. The numerical results were compared to the RBE values recently obtained with Chinese hamster V79 cells, and an Lt value of 152 keV/micron was found to give the best fit. At LETs of between 30 and 500 keV/micron, the D10 values (10% survival dose) agreed with the experimental data within an error range of -15%-(+8%).

Neurovascular complications of antiphospholipid syndrome: a narrative review

BACKGROUND

 Antiphospholipid syndrome (APS) is a systemic autoimmune disorder characterized by thrombosis, pregnancy complications, and other nonthrombotic manifestations in the presence of antiphospholipid antibodies. Neurovascular complications, including ischemic stroke, cerebral venous thrombosis and cognitive impairment, pose significant challenges in management.

OBJECTIVE

 To comprehensively review relevant and updated clinical aspects of neurovascular manifestations of APS.

METHODS

 We conducted a narrative review using the PubMed, EMBASE, and Cochrane Library databases with medical terms related to APS and its neurovascular manifestations. English-language studies, published between January 1, 2015, and March 2024, were included. Key publications outside this timeframe were also considered. Studies with higher levels of evidence, such as randomized controlled trials and meta-analyses, were prioritized for inclusion.

RESULTS

 Stroke is a prevalent complication in APS, with arterial thrombosis being a predominant mechanism. Despite recent trials, direct oral anticoagulants (DOACs) have not shown superiority over vitamin K antagonists (VKAs) for secondary prevention in this population. Cerebral venous thrombosis (CVT), although rare, can also occur in APS, and while DOACs have shown promise as a treatment in a general population, caution is warranted due to potential harm. Cognitive impairment affects a considerable proportion of APS patients, with thrombotic and nonthrombotic mechanisms contributing to its pathophysiology. Future research should focus on optimal management strategies for cognitive impairment and the efficacy of anticoagulation and immunosuppression.

CONCLUSION

 Understanding the complex interplay of neurovascular manifestations in APS is essential for guiding clinical decisions and improving patient outcomes. Despite advancements, some challenges remain in establishing effective preventive and treatment measures, highlighting the need for further research in this field.

impact of dapagliflozin on left ventricular diastolic function in diabetic patients with heart failure complicating cardiovascular risk factors

Funding Acknowledgements

Type of funding sources: None.

Background

Type 2 diabetes mellitus (T2DM) is a well-known risk factor for heart failure (HF), even in patients without a structural heart disease or a symptom of HF. Diabetes-related cardiomyopathy is presented as an left ventricular (LV) diastolic dysfunction, which, like cardiovascular disease, is a contributor of the development of HF in both patients with reduced ejection fraction (HFrEF) and with preserved ejection fraction (HFpEF). Furthermore, comorbid factors other than T2DM also have been identified as high risk factors for of progression to HF. Dapagliflozin is a sodium glucose cotransporter type 2 (SGLT2) inhibitor, and represents a new class of anti-hyperglycemic agents for T2DM. A result from a recent large clinical trial showed that dapagliflozin reduced risk of worsening HF or death from cardiovascular causes for patients with HFrEF compared to those who received a placebo, regardless of the presence or absence of T2DM. However, the effect of SGLT2 inhibitors on LV diastolic function in T2DM patients with HF who had cardiovascular risk factors other than T2DM remains uncertain.

Purpose

Our purpose was to investigate the impact of dapagliflozin on LV diastolic function in T2DM patients with stable HF complicating cardiovascular risk factors.

Methods

We analyzed data from our previous prospective multicenter study, which investigate the effect of dapagliflozin on LV diastolic function of 53 T2DM patients with stable HF at five institutions in Japan. Patients who had been taking at least one antidiabetic drugs other than SGLT2 inhibitor started the administration of dapagliflozin. Cardiovascular risk factors other than T2DM was determined as age, gender, hypertension, dyslipidemia, history of cardiovascular events and overweight.

Results

E/e′ significantly decreased from 9.3 to 8.5 cm/s 6 months after administration of dapagliflozin (p = 0.020) as previously described. Multivariate logistic regression analysis showed that dyslipidemia was the only independent determinant of an improvement of E/e’ among cardiovascular risk factors. Furthermore, relative changes in E/e’ from baseline to 6 months after administration of dapagliflozin seen in HFpEF patients with dyslipidemia were significantly larger than those in HFpEF patients without dyslipidemia (-15.2% vs. 29.6%, p = 0.014), but such a difference was not observed in non-HFpEF patients. In addition, relative changes in high-density lipoprotein cholesterol (HDL-C) from baseline to 6 months after administration of dapagliflozin had significant correlation with those in E/e’ (r=-0.300, p = 0.038). However, such correlations were not observed in low-density lipoprotein cholesterol (LDL-C) and triglyceride (r = 0.05, p = 0.72 and r = 0.05, p = 0.73). Conclusion: Dapagliflozin was more beneficial effect on LV diastolic function for T2DM patients with stable HF, especially those with complicating dyslipidemia. Our findings may thus offer a new insight into the management of T2DM patients with HF.

Abstract Figure.