Usefulness of intravoxel incoherent motion MRI for visualizing slow cerebrospinal fluid motion

BACKGROUND

In the cerebrospinal fluid (CSF) dynamics, the pulsations of cerebral arteries and brain is considered the main driving force for the reciprocating bidirectional CSF movements. However, measuring these complex CSF movements on conventional flow-related MRI methods is difficult. We tried to visualize and quantify the CSF motion by using intravoxel incoherent motion (IVIM) MRI with low multi-b diffusion-weighted imaging.

METHODS

Diffusion-weighted sequence with six b values (0, 50, 100, 250, 500, and 1000 s/mm²) was performed on 132 healthy volunteers aged ≥ 20 years and 36 patients with idiopathic normal pressure hydrocephalus (iNPH). The healthy volunteers were divided into three age groups (< 40, 40 to < 60, and ≥ 60 years). In the IVIM analysis, the bi-exponential IVIM fitting method using the Levenberg-Marquardt algorithm was adapted. The average, maximum, and minimum values of ADC, D, D*, and fraction of incoherent perfusion (f) calculated by IVIM were quantitatively measured in 45 regions of interests in the whole ventricles and subarachnoid spaces.

RESULTS

Compared with healthy controls aged ≥ 60 years, the iNPH group had significantly lower mean f values in all the parts of the lateral and 3rd ventricles, whereas significantly higher mean f value in the bilateral foramina of Luschka. In the bilateral Sylvian fossa, which contain the middle cerebral bifurcation, the mean f values increased gradually with increasing age, whereas those were significantly lower in the iNPH group. In the 45 regions of interests, the f values in the bilateral foramina of Luschka were the most positively correlated with the ventricular size and indices specific to iNPH, whereas that in the anterior part of the 3rd ventricle was the most negatively correlated with the ventricular size and indices specific to iNPH. Other parameters of ADC, D, and D* were not significantly different between the two groups in any locations.

CONCLUSIONS

The f value on IVIM MRI is useful for evaluating small pulsatile complex motion of CSF throughout the intracranial CSF spaces. Patients with iNPH had significantly lower mean f values in the whole lateral ventricles and 3rd ventricles and significantly higher mean f value in the bilateral foramina of Luschka, compared with healthy controls aged ≥ 60 years.

Immune-related aseptic meningitis diagnosed by Cube FLAIR on enhanced magnetic resonance imaging for a lung cancer patient administered atezolizumab: A case report

Immune checkpoint inhibitors (ICIs) can cause immune-related adverse events (irAEs), such as neurological toxicity. A 46-year-old man was diagnosed with squamous cell lung cancer. Lung cancer recurred 3 years after he experienced left segmental lung rejection. Therefore, he received atezolizumab as fourth-line chemotherapy. He experienced fever, headache, and decreased consciousness 10 days after the first dose of atezolizumab. Plain head computed tomography and cerebrospinal fluid examination showed no significant findings. Magnetic resonance imaging (MRI) with a Gadolinium (Gd)-enhanced Cube fluid-attenuated inversion recovery (FLAIR) sequence showed nodular abnormalities with contrast enhancement. Thus, aseptic meningitis caused by ICIs was suspected. His consciousness level gradually improved with glucocorticoid therapy. Moreover, most nodular abnormalities observed on cerebral MRI disappeared concurrently. Thus, Gd-enhanced Cube FLAIR sequence has the unique ability to reveal immune-related aseptic meningitis.

MRI-based assessment of acute effect of head-down tilt position on intracranial hemodynamics and hydrodynamics

PURPOSE

To quantify the acute effect of the head-down tilt (HDT) posture on intracranial hemodynamics and hydrodynamics.

MATERIALS AND METHODS

We evaluated the intracranial physiological parameters, blood flow-related parameters, and brain morphology in the HDT (-6° and -12°) and the horizontal supine (HS) positions. Seven and 15 healthy subjects were scanned for each position using 3.0 T magnetic resonance imaging system. The peak-to-peak intracranial volume change, the peak-to-peak cerebrospinal fluid (CSF) pressure gradient (PG_p-p ), and the intracranial compliance index were calculated from the blood and CSF flow determined using a cine phase-contrast technique. The brain volumetry was conducted using SPM12. The measurements were compared using the Wilcoxon signed-rank test or a paired t-test.

RESULTS

No measurements changed in the -6° HDT. The PG_p-p and venous outflow of the internal jugular veins (IJVs) in the -12° HDT were significantly increased compared to the HS (P < 0.001 and P = 0.025, respectively). The cross-sectional areas of the IJVs were significantly larger (P < 0.001), and the maximum, minimum, and mean blood flow velocity of the IJVs were significantly decreased (P = 0.003, < 0.001, and = 0.001, respectively) in the -12° HDT. The mean blood flow velocities of the internal carotid arteries were decreased (P = 0.023). Neither position affected the brain volume.

CONCLUSION

Pressure gradient and venous outflow were increased in accordance with the elevation of the intracranial pressure as an acute effect of the HDT. However, the CSF was not constantly shifted from the spinal canal to the cranium.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:565-571.

Efficacy and safety of osteoporosis medications in a rat model of late-stage chronic kidney disease accompanied by secondary hyperparathyroidism and hyperphosphatemia

This study showed that bisphosphonate was safe and effective for the treatment of bone disorders in stage 4 chronic kidney disease (CKD) rats. Intermittent teriparatide therapy showed an anabolic action on bone even under secondary hyperparathyroidism conditions without having an adverse effect on mineral metabolism in late-stage CKD.

INTRODUCTION

Patients with late-stage CKD are at high risk for fragility fractures. However, there are no consensus on the efficacy and safety of osteoporosis medications for patients with late-stage CKD. In the present study, we aimed to examine the efficacy and safety of alendronate (ALN) and teriparatide (TPD) for treating bone disorder in late-stage CKD with pre-existing secondary hyperparathyroidism using a rat model of CKD.

METHODS

Male 10-week-old Sprague-Dawley rats were subjected to a 5/6 nephrectomy or sham surgery and randomized into the following four groups: sham, vehicle (saline subcutaneous (sc) daily), ALN (50 μg/kg sc daily), and TPD (40 μg/kg sc daily). Medications commenced at 24 weeks of age and continued for 4 weeks. Micro-computed tomography, histological analysis, infrared spectroscopic imaging, and serum assays were performed.

RESULTS

Nephrectomized rats developed hyperphosphatemia, secondary hyperparathyroidism (SHPT), and high creatinine, equivalent to CKD stage 4 in humans. ALN suppressed the bone turnover and increased the degree of mineralization in cortical bone, resulting in an improvement in the mechanical properties. TPD further increased the bone turnover and significantly increased the degree of mineralization, micro-geometry, and bone volume, resulting in a significant improvement in the mechanical properties. Both ALN and TPD had no adverse effect on renal function and mineral metabolism.

CONCLUSIONS

BP is safe and effective for the treatment of bone disorders in stage 4 CKD rats. Intermittent TPD therapy showed an anabolic action on bone even under SHPT conditions without having an adverse effect on mineral metabolism in late-stage CKD.

Autoimmune arthritis deteriorates bone quantity and quality of periarticular bone in a mouse model of rheumatoid arthritis

This study showed that autoimmune arthritis induces especially severe osteoporosis in the periarticular region adjacent to inflamed joints, suggesting that arthritis increases the fragility fracture risk near inflamed joints, which is frequently observed in patients with RA.

INTRODUCTION

Periarticular osteoporosis near inflamed joints is a hallmark of early rheumatoid arthritis (RA). Here we show that rheumatic inflammation deteriorates the bone quality and bone quantity of periarticular bone, thereby decreasing bone strength and toughness in a mouse model of RA.

METHODS

Female BALB/c mice and SKG mice, a mutant mouse model of autoimmune arthritis on the BALB/c background, were used. At 12 weeks of age, BALB/c mice underwent either Sham surgery or bilateral ovariectomy (OVX), and SKG mice underwent intraperitoneal injection of mannan to induce arthritis. Eight weeks later, the mice were killed and the femurs and tibias were subjected to micro-computed tomography, Fourier transform infrared (FTIR) spectroscopic imaging, X-ray diffraction, histology, and mechanical testing.

RESULTS

SKG mice developed significant trabecular bone loss in both the distal metaphysis of the femur and the lumbar vertebral body, but the extent of the bone loss was more severe in the distal metaphysis. Neither SKG nor OVX mice exhibited changes in the geometry and matrix properties of the diaphysis of the femur, whereas SKG mice, but not OVX mice, did exhibit changes in these properties in the distal metaphysis of the femur. Bone strength and fracture toughness of the distal metaphysis of the tibia adjacent to the inflamed ankle joint were significantly decreased in SKG mice.

CONCLUSIONS

Autoimmune arthritis induces periarticular osteoporosis, characterized by deterioration of cortical bone geometry and quality as well as by trabecular bone loss, leading to severe bone fragility in periarticular bone adjacent to inflamed joints.

Anomalous vertebral and posterior communicating arteries as a risk factor in instrumentation of the posterior cervical spine

We investigated the incidence of anomalies in the vertebral arteries and Circle of Willis with three-dimensional CT angiography in 55 consecutive patients who had undergone an instrumented posterior fusion of the cervical spine. We recorded any peri-operative and post-operative complications. The frequency of congenital anomalies was 30.9%, abnormal vertebral artery blood flow was 58.2% and vertebral artery dominance 40%. The posterior communicating artery was occluded on one side in 41.8% of patients and bilaterally in 38.2%. Variations in the vertebral arteries and Circle of Willis were not significantly related to the presence or absence of posterior communicating arteries. Importantly, 18.2% of patients showed characteristic variations in the Circle of Willis with unilateral vertebral artery stenosis or a dominant vertebral artery, indicating that injury may cause lethal complications. One patient had post-operative cerebellar symptoms due to intra-operative injury of the vertebral artery, and one underwent a different surgical procedure because of insufficient collateral circulation. Pre-operative assessment of the vertebral arteries and Circle of Willis is essential if a posterior spinal fusion with instrumentation is to be carried out safely.

Involvement of Flt-1 tyrosine kinase (vascular endothelial growth factor receptor-1) in pathological angiogenesis

Vascular endothelial growth factor (VEGF) and its two receptors, Fms-like tyrosine kinase 1 (Flt-1) (VEGFR-1) and KDR/Flk-1 (VEGFR-2), have been demonstrated to be an essential regulatory system for blood vessel formation in mammals. KDR is a major positive signal transducer for angiogenesis through its strong tyrosine kinase activity. Flt-1 has a unique biochemical activity, 10-fold higher affinity to VEGF, whereas much weaker tyrosine kinase activity compared with KDR. Recently, we and others have shown that Flt-1 has a negative regulatory function for physiological angiogenesis in the embryo, possibly with its strong VEGF-trapping activity. However, it is still open to question whether the tyrosine kinase of Flt-1 has any positive role in angiogenesis at adult stages. In this study, we examined whether Flt-1+ could be a positive signal transducer under certain pathological conditions, such as angiogenesis with tumors overexpressing a Flt-1-specific, VEGF-related ligand. Our results show clearly that murine Lewis lung carcinoma cells overexpressing placenta growth factor-2, an Flt-1-specific ligand, grew in wild-type mice much faster than in Flt-1 tyrosine kinase domain-deficient mice. Blood vessel formation in tumor tissue was higher in wild-type mice than in Flt-1 tyrosine kinase-deficient mice. On the other hand, the same carcinoma cells overexpressing VEGF showed no clear difference in the tumor growth rate between these two genotypes of mice. These results indicate that Flt-1 is a positive regulator using its tyrosine kinase under pathological conditions when the Flt-1-specific ligand is abnormally highly expressed. Thus, Flt-1 has a dual function in angiogenesis, acting in a positive or negative manner in different biological conditions.

[Drug Compliance Scale. I. Development of the Drug Compliance Scale]

The failure of patients to comply with treatment regimens recommended by their physicians is a significant clinical problem. Researches on the assessment of compliance have, however, been precluded by methodological difficulties such as lack of adequate measures. The purpose of this study was to develop a self-administered questionnaire to evaluate drug compliance. First, questionnaire containing a 52-items complied by two doctors, a pharmacist and a nurse, was tested on 81 outpatients, all volunteers, attending the departments of psychosomatic medicine and internal medicine. Four items were temporarily removed for later analysis because they directly inquired about drug compliance (drug compliance items). The other 48 items were analyzed and three factors consisting of 26 items were further studied: expectation on taking medicine, rejection to taking medicine and seeking knowledge of drugs. Chronback's alpha coefficients representing internal consistency of the three factors were sufficiently high (ranging from .75 to .84). Furthermore, we preformed a simplified pill count to validate the 4 drug compliance items. There was a weak to moderate correlation between the result of pill count and each of 4 drug compliance items. A new self-administered questionnaire of 30 items was thus developed and named the Drug Compliance Scale.

[Drug Compliance Scale. II. Psychological factors affecting drug compliance in the department of psychosomatic medicine]

The purpose of this study was to investigate psychological factors affecting drug compliance in the department of psychosomatic medicine. Seventy-four outpatients were asked to answer a battery of self-administered questionnaire including the Drug Compliance Scale (DCS) that we had recently developed and other questionnaire evaluating psychological and vegetative symptoms, self-efficacy and attributional styles on the promotion of health and personality closely related to interpersonal relationships. Results of path analysis indicated that attributional styles and self-efficacy mainly affected three factors of DCS such as expectation on taking medicine, rejection to taking medicine and seeking knowledge of drugs, through which they influenced drug compliance, and also indicated that personality and self-efficacy mainly affected the stability of mood state, suggesting a further influence on drug compliance.

Flt-1 lacking the tyrosine kinase domain is sufficient for normal development and angiogenesis in mice

Receptor tyrosine kinases Flt-1 and Flk-1/KDR, and their ligand, the vascular endothelial growth factor (VEGF), were shown to be essential for angiogenesis in the mouse embryo by gene targeting. Flk-1/KDR null mutant mice exhibited impaired endothelial and hematopoietic cell development. On the other hand, Flt-1 null mutation resulted in early embryonic death at embryonic day 8.5, showing disorganization of blood vessels, such as overgrowth of endothelial cells. Flt-1 differs from Flk-1 in that it displays a higher affinity for VEGF but lower kinase activity, suggesting the importance of its extracellular domain. To examine the biological role of Flt-1 in embryonic development and vascular formation, we deleted the kinase domain without affecting the ligand binding region. Flt-1 tyrosine kinase-deficient homozygous mice (flt-1(TK-/-)) developed normal vessels and survived. However, VEGF-induced macrophage migration was strongly suppressed in flt-1(TK-/-) mice. These results indicate that Flt-1 without tyrosine kinase domain is sufficient to allow embryonic development with normal angiogenesis, and that a receptor tyrosine kinase plays a main biological role as a ligand-binding molecule.

Genomic organization of the flt-1 gene encoding for vascular endothelial growth factor (VEGF) receptor-1 suggests an intimate evolutionary relationship between the 7-Ig and the 5-Ig tyrosine kinase receptors

The flt-1 tyrosine kinase gene encodes a high affinity receptor for Vascular Endothelial Growth Factor, and belongs to the so-called '7-Ig' or flt gene family which has characteristics of 7-Immunoglobulin (Ig)-like domains in the extracellular region. This is structurally distantly related to 5-Ig domain-containing receptors such as Fms/Kit/PDGF-R. However, the whole genomic organization for any 7-Ig receptor gene has not been determined yet. To examine the genomic structure of flt-1 and the evolutionary relationship between genes of the 7-Ig and 5-Ig receptor families, we isolated the mouse genomic DNAs carrying all exons of the flt-1 gene. The mouse flt-1 gene consisted of 30 exons, whose exon-intron boundaries were highly related to those in the 5-Ig receptor genes, except for the amino terminal region. The sequences corresponding to the first and second Ig-domains in the flt-1 gene were encoded by four exons, whereas this region was encoded by only two exons in the 5-Ig receptor genes. These results raise the interesting possibility that deletion or insertion mutations of introns in one of these receptor genes took place in the evolutionary generation of the other receptor genes.

Enhancement of in vitro spontaneous IgE production by topical steroids in patients with atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is an inflammatory skin disease. Although topical steroids are widely used for AD, management of severe AD is not satisfactory because of relapse or occasional aggravation of symptoms. Moreover, glucocorticoids induce in vitro IgE production. On the other hand, topical sodium cromoglycate (SCG) solution is a safe and effective treatment for AD.

METHODS

We treated 43 patients with AD with SCG solution (n = 21) or with topical steroids, beclomethasone dipropionate (BD) ointment (n = 22). After 2 weeks, clinical evaluation and spontaneous immunoglobulin production by peripheral blood B cells or surface IgE+ B cells from patients in the SCG and BD groups were assessed.

RESULTS

Both SCG and BD treatment remarkably improved eczema. However, although SCG treatment decreased spontaneous IgE production by B cells without affecting production of IgG, IgM, or IgA, BD treatment selectively increased spontaneous IgE production. SCG treatment also decreased IgE production by surface IgE+ B cells, whereas BD treatment increased it.

CONCLUSION

Topical steroid treatment increases in vitro spontaneous IgE production by B cells. This indicated that topical steroids may decrease inflammation; however, a large-scale study on the effect of topical steroids on IgE production in vitro and in vivo may be necessary.

Effect of topical cromoglycate solution on atopic dermatitis: combined treatment of sodium cromoglycate solution with the oral anti-allergic medication, oxatomide

The effect of topically applied sodium cromoglycate solution in moderate to severe atopic dermatitis (AD) in children aged 4-14 years was studied in a double-blind, placebo-controlled, randomized group-comparative trial. One group of patients was treated with topical sodium cromoglycate solution and oral oxatomide whereas the other group was treated with topical placebo solution and oral oxatomide. After 4 weeks, AD improved significantly in the group treated with the sodium cromoglycate solution and oxatomide combination while marginal improvement was noted in the placebo. In addition, spontaneous IgE production from peripheral blood mononuclear cells decreased significantly in the sodium cromoglycate group but not in the placebo group. These results suggest that sodium cromoglycate solution may be very effective in combination with anti-allergic medication in the treatment of moderate to severe AD in children.

New suppressor mutation sur0B of spo0B and spo0F mutations in Bacillus subtilis

Two extragenic suppressor mutations, sur0B20 and sur0F1, which restore the sporulation of spo0B or spo0F mutants of Bacillus subtilis to the wild-type level, were obtained. These suppressor mutations were located in the spo0A gene. Their location is close to that of the sof-1 mutation, which suppresses spo0B, spo0E and spo0F mutations. However, spo0 strains bearing the sur0B20 mutation differed in several phenotypic characteristics from spo0 mutants bearing the sof-1 suppressor. Nucleotide sequence analysis revealed that the sur0B20 and sur0F1 mutations resulted in Glu14 to Val and Asn12 to Lys conversion, respectively, in the spo0A gene. This result indicates that sur0B20 is a new suppressor of spo0b and spo0F mutations, whereas sur0F1 is identical to sof-1.