A mayfly’s rapid transition toward unisexual populations

Sexual reproduction is overwhelmingly the most common reproductive mode among Metazoans, although it has been secondarily lost in some organisms. Ephoron shigae is a geographically parthenogenetic mayfly. Here, we provide details of the frequency of bisexual and parthenogenetic strains of E. shigae together with data on their sex ratios in the Abukuma-gawa River and one of its downstream tributaries, the Surikami-gawa River, in Japan. In a previous study in the 1990s, bisexual populations were observed in both rivers. The present study clearly shows that sex ratios have since changed to be almost entirely unisexual within the downstream area of the Abukuma-gawa River and the Surikami-gawa River. Our genetic analyses also show that these females are of a parthenogenetic strain, and that the original bisexual strains were overwhelmed within a period of <20 years. However, it was recently observed that many males and females of the bisexual strains continue to inhabit upstream areas of the Abukuma-gawa River. Therefore, we suggest that the parthenogenetic strains have increased in abundance primarily downstream. We show that a drastic change has occurred over a short period, involving the replacement of one strain and a corresponding change in reproductive mode along a riverine environment.

Carpal tunnel syndrome: a common initial symptom of systemic wild-type ATTR (ATTRwt) amyloidosis

BACKGROUND

Systemic wild-type ATTR (ATTRwt) amyloidosis is a prevalent aging-related disorder. However, a limited number of systemic ATTRwt amyloidosis patients have been diagnosed antemortem, and therefore, the prevalence of ATTRwt is underestimated. Here, we investigated clinical findings of a series of systemic ATTRwt amyloidosis patients with antemortem diagnosis.

METHODS

Thirty-one consecutive patients diagnosed with systemic ATTRwt amyloidosis at Shinshu University Hospital were included in this study. Systemic ATTRwt amyloidosis was diagnosed based on proven ATTR amyloid deposition in biopsy specimens and confirmation of wild-type TTR genotype.

RESULTS

The systemic ATTRwt amyloidosis patients consisted of 24 men and seven women, and mean age of onset was 69.8 ± 9.0 years. The most common initial symptom was carpal tunnel syndrome (CTS, 17 patients), followed by heart failure symptoms (14 patients). The mean age at diagnosis was 74.5 ± 8.3 years and the duration of illness from onset to diagnosis was 5.4 ± 4.4 years. Cardiogenic embolism and renal dysfunction are also frequently seen during the course of the disease.

CONCLUSIONS

CTS is the most common initial symptom of systemic ATTRwt amyloidosis. Our results suggest the possibility of systemic ATTRwt amyloidosis diagnosis at an early stage by carefully examining patients with CTS.

Unexpected monophyletic origin of Ephoron shigae unisexual reproduction strains and their rapid expansion across Japan

The burrowing polymitarcyid mayfly Ephoron shigae is distributed across Japan, Korea, northeast China and far east Russia. Some populations are bisexual, and others are unisexual, i.e. geographically parthenogenetic throughout Japan. In general, parthenogenetic organisms are often found in harsh environments, such as at high latitudes and altitudes, in xeric as opposed to mesic conditions, in isolated habitats such as islands and island-like areas, and at the peripheral regions of the taxon's range. In E. shigae, however, the distributions of bisexual and unisexual populations overlap broadly in their respective geographical ranges. In the analysis of mitochondrial 16S rRNA and COI, we revealed that unisexual populations were of monophyletic origin and recently differentiated somewhere in western Japan. In the nuclear DNA EFI-α analysis, parthenogenetic strains had two genotypes, i.e. the heterozygous genotype of E1/E3 and the homozygous genotype of E1/E1 or E3/E3, while specimens of bisexual lineage had 20 genotypes. These results are consistent with an automixis mode of reproduction for the parthenogenetic strains, and also support the monophyletic origin of the parthenogenetic strains. Furthermore, there would be no gene flow between the specimens of the bisexual lineage and those of the parthenogenetic strain.

Safety and efficacy of long-term diflunisal administration in hereditary transthyretin (ATTR) amyloidosis

BACKGROUND

A recent 2-year randomized controlled trial indicated that the transthyretin (TTR) tetramer stabilizer, diflunisal, inhibits polyneuropathy progression and preserves quality of life in hereditary ATTR amyloidosis. However, its long-term outcomes are unknown. Here, we report tolerance and efficacy of long-term diflunisal administration in hereditary ATTR amyloidosis.

METHODS

Diflunisal was administered orally at 500 mg/day to 40 Japanese hereditary ATTR amyloidosis patents who were not candidates for liver transplantation. The observation period ranged from 2 to 116 months (mean ± SD: 38.0 ± 31.2 months).

RESULTS

Diflunisal-related adverse events included deterioration of renal function and thrombocytopenia resulting in discontinuation of the drug in three patients. Orally administered diflunisal significantly increased serum TTR concentration (p = 0.001) and stabilized TTR tetramer structure in each patient. Longitudinal analyses of data collected at baseline, 24 months, and after 24 months confirmed sustaining effects of diflunisal on both neurological and cardiac functions. Notably, ulnar compound muscle action potential amplitude, cardiac wall thickness, and ejection fraction were not deteriorated after 24 months of treatment.

CONCLUSIONS

Diflunisal was tolerated well by most hereditary ATTR amyloidosis patients, although renal function and blood cell counts must be carefully monitored. Clinical effects of diflunisal were sustained after 2 years of treatment.

Effect of synovial transthyretin amyloid deposition on preoperative symptoms and postoperative recovery of median nerve function among patients with idiopathic carpal tunnel syndrome

BACKGROUND

The clinical characteristics of wild-type transthyretin amyloid deposition among patients with carpal tunnel syndrome (CTS) have not been well investigated.

METHODS

One-hundred and seven patients with idiopathic CTS who underwent carpal tunnel release were enrolled. They underwent physical examination of the hand, nerve-conduction study, and magnetic resonance imaging (MRI) study of the wrist, and completed a patient-oriented questionnaire. The tests, except for MRI, were repeated 1, 3, and 6 months postoperatively. Synovial tissue was obtained during surgery and analyzed by Congo red and immunohistochemical staining. Ordinal logistic regression analysis was used to evaluate the significance of different clinical and subjective findings between patients with and without amyloid deposition. Postoperative improvements were also compared.

RESULTS

Wild-type transthyretin amyloid deposition was observed for 38 patients. Greater symptom severity and 2-point discrimination scores, and larger cross-sectional areas of the carpal tunnel, were significantly correlated with a larger amount of preoperative amyloid deposition. However, the presence and amount of preoperative amyloid deposition did not affect postoperative improvements in physical findings and nerve-conduction studies.

CONCLUSIONS

Although transthyretin amyloid deposition can worsen CTS symptoms, postoperative improvements were similar for patients with and without this deposition.

High prevalence of ATTR amyloidosis in endomyocardial biopsy-proven cardiac amyloidosis patients

BACKGROUND

Cardiac amyloidosis had been considered to be an incurable disease; however, new disease-modifying therapeutic approaches have succeeded in ameliorating the disease. Therefore, early and precise diagnosis based on the amyloid precursor protein is extremely important.

OBJECTIVE

To determine the prevalence rates of systemic amyloidoses underlying cardiac amyloidosis.

METHODS

The types of amyloidosis in 53 consecutive patients with endomyocardial biopsy-proven cardiac amyloidosis were analyzed by Congo red and immunohistochemical staining. If staining for TTR was positive, direct DNA sequencing of the entire TTR gene was performed.

RESULTS

ATTR amyloidosis was the most common (32/53 patients, 60.4%). The ATTR amyloidosis subtypes were senile systemic amyloidosis (SSA) 11, familial ATTR 10, and genotype unknown 11. AL amyloidosis was the next most frequent (19/53, 35.8%).

CONCLUSIONS

ATTR amyloidosis, especially SSA, might be much more common than previously thought. With the development of new drugs targeting the ATTR amyloidosis, major efforts should be made to increase awareness of senile systemic amyloidosis among cardiologists.

Arterial thromboembolism in senile systemic amyloidosis: report of two cases

We describe a rare complication, systemic arterial thromboembolism, seen in two patients with senile systemic amyloidosis (SSA). Case 1 was a 73-year-old man who was tentatively diagnosed as having cardiac amyloidosis. Five months later, he was afflicted by severe left flank pain. CT disclosed renal infarction and then he received endomyocardial biopsy and the transthyretin (TTR) gene analysis, leading to the final diagnosis of SSA. Case 2 was an 88-year-old woman who had been definitively diagnosed as having SSA-related heart failure with atrial fibrillation two years before. She was transferred to the emergency room in our hospital and enhanced CT revealed complete occlusions of the left internal carotid and left vertebral arteries, both subclavian arteries, and the left renal and left internal iliac arteries. Paying much attention to intracardiac thrombosis might be necessary in taking care of SSA patients.

Two siblings diagnosed to have transthyretin-related familial amyloid cardiomyopathy around the same time at different hospitals

Mutation in the transthyretin (TTR) gene may clinically manifest as cardiomyopathy. Here, we describe 69-year-old and 72-year-old brothers who were diagnosed as having TTR-related familial amyloid cardiomyopathy by endomyocardial biopsy at different hospitals at around the same time. They were not from an endemic area of familial amyloid polyneuropathy. Genetic analysis showed a base change in the TTR gene leading to a p.Val30Met mutation in both patients. Screening of family members, as well as detailed family history taking, is important for the diagnosis of cardiomyopathy of unknown etiology.

[Case report of transthyretin Val30Met familial amyloid polyneuropathy presenting hydrocephalus]

A 70-year-old man was admitted to our hospital with visual loss, dysesthesia, gait disturbance, and urinary retention. A pacemaker was implanted 1 year ago for atrioventricular conduction block. Neurologic examination revealed mild cognitive impairment, near blindness with vitreous opacity, diffuse muscle weakness, loss of all sensory modalities with areflexia, and orthostatic hypotension. Head CT showed hydrocephalus. The Congo red staining of vitrectomized specimen and the biopsied sural nerve showed amyloid depositions. Gene analysis disclosed Val30Met missense mutation of transthyretin, which is responsible for familial amyloid polyneuropathy. His bed-ridden brother also had severe urinary dysfunction and orthostatic hypotension with hydrocephalus on MRI. These two sibling cases suggest correlation of the transthyretin Val30Met mutation with hydrocephalus, a rare phenotype of this disease.

High prevalence of wild-type transthyretin deposition in patients with idiopathic carpal tunnel syndrome: a common cause of carpal tunnel syndrome in the elderly

Carpal tunnel syndrome is the most common type of entrapment neuropathy. However, the cause of carpal tunnel syndrome remains unclear in most cases. Senile systemic amyloidosis, induced by wild-type transthyretin deposition, is a prevalent aging-related disorder and often accompanied by carpal tunnel syndrome. In this study, we measured the frequency of unrecognized wild-type transthyretin deposition in patients with idiopathic carpal tunnel syndrome. One hundred twenty-three patients with carpal tunnel syndrome, including 100 idiopathic patients, treated by carpal tunnel release surgery were analyzed. Tenosynovial tissues obtained at surgery were analyzed by Congo red and immunohistochemical staining. If staining for transthyretin was positive, the entire transthyretin gene was analyzed by direct DNA sequencing. We also analyzed tenosynovial tissues from 32 autopsy cases as controls. Thirty-four patients (34.0%) with idiopathic carpal tunnel syndrome showed amyloid deposition in the tenosynovial tissue, and all amyloid showed specific immunolabeling with antitransthyretin antibody. Direct DNA sequencing of the entire transthyretin gene did not reveal any mutations, indicating that all amyloid deposits were derived form wild-type transthyretin. Statistical analysis using logistic regression showed that the prevalence of transthyretin deposition in the idiopathic carpal tunnel syndrome group was significantly higher than that in controls (odds ratio, 15.8; 95% confidence interval, 3.3-5.7), and age and male sex were independent risk factors for transthyretin amyloid deposition. Our results demonstrate that wild-type transthyretin deposition is a common cause of carpal tunnel syndrome in elderly men. It is likely that many patients develop carpal tunnel syndrome as an initial symptom of senile systemic amyloidosis.

Diagnostic value of abdominal wall fat pad biopsy in senile systemic amyloidosis

Senile systemic amyloidosis (SSA) is a main cause of intractable heart failure in elderly individuals. To demonstrate transthyretin (TTR)-derived amyloid deposition endomyocardial biopsy has been commonly carried out in the patients with SSA, but this invasive biopsy technique cannot always be performed in aged patients with severe cardiac dysfunction. During the past 3 years, 11 patients with SSA (6 males and 5 females; ages from 70 to 97 years) were examined. All underwent skin biopsy from the abdominal wall and 8 showed TTR-immunoreactive amyloid deposition (sensitivity: 73%): amyloid deposits were seen mainly in the deep layer of subcutaneous fat tissue and showed a patchy distribution. They were weakly Congophilic, but were strongly immunolabeled by an anti-TTR antibody. The severity and pattern of amyloid deposition in this biopsy of SSA patients were considerably different from those obtained from age-matched patients with TTR-related familial amyloid polyneuropathy. Surgical skin biopsy including the deep subcutaneous fat pad can be performed safely at the bedside and is useful for the histopathological diagnosis of SSA.

Novel pathogenic mutations and copy number variations in the VPS13A gene in patients with chorea-acanthocytosis

Chorea-acanthocytosis (ChAc) is a rare autosomal recessive neurodegenerative disorder caused by loss of function mutations in the vacuolar protein sorting 13 homolog A (VPS13A) gene that encodes chorein. It is characterized by adult-onset chorea, peripheral acanthocytes, and neuropsychiatric symptoms. In the present study, we performed a comprehensive mutation screen, including sequencing and copy number variation (CNV) analysis, of the VPS13A gene in ChAc patients. All 73 exons and flanking regions of VPS13A were sequenced in 35 patients diagnosed with ChAc. To detect CNVs, we also performed real-time quantitative PCR and long-range PCR analyses for the VPS13A gene on patients in whom only a single heterozygous mutation was detected. We identified 36 pathogenic mutations, 20 of which were previously unreported, including two novel CNVs. In addition, we investigated the expression of chorein in 16 patients by Western blotting of erythrocyte ghosts. This demonstrated the complete absence of chorein in patients with pathogenic mutations. This comprehensive screen provides an accurate and useful method for the molecular diagnosis of ChAc.

Pneumatosis cystoides intestinalis in neuropsychiatric systemic lupus erythematosus with diabetes mellitus: case report and literature review

We report a patient with neuropsychiatric systemic lupus erythematosus (NPSLE) complicated by diabetes mellitus (DM) who showed pneumatosis cystoides intestinalis (PCI) while being treated with prednisolone (PSL) and an alpha-glucosidase inhibitor (αGI). The PCI was ameliorated with the cessation of the αGI and tapering of PSL in addition to transient fasting. Multiple factors, including NPSLE, DM, and medications, may have been involved in the pathogenesis of PCI in this patient.

A Young Man with Anti-NMDAR Encephalitis following Guillain-Barré Syndrome

A 19-year-old man developed rapidly progressive muscle weakness and dysesthesia in the extremities, and dyspnea after a flu-like episode. Nerve conduction studies showed reduced motor nerve conduction velocities with conduction block, and sensory nerve action potentials could not be evoked. The patient was diagnosed as having Guillain-Barré syndrome (GBS), and was treated with 2 cycles of intravenous immunoglobulin (IVIg) therapy and was assisted by mechanical ventilation. During the recovery course of the illness, he experienced several attacks of psychomotor agitation from the 37th hospital day, and generalized tonic convulsive seizures suddenly developed on the 42nd hospital day. Brain MRI showed high-intensity lesions in the bilateral thalamus and medial temporal lobes. The convulsions were controlled by continuous thiopental infusion (until the 50th hospital day) and mechanical ventilation (until the 84th hospital day). Intravenous methylprednisolone pulse therapy (1,000 mg/day) for 3 days followed by dexamethasone (16 mg/day) was added. After relief of convulsive seizures, prominent orolingual dyskinesia appeared, and on MRI marked atrophy of the bilateral medial temporal lobes was seen. Anti-N-methyl-D-aspartate receptor (NMDAR) antibodies in serum and cerebrospinal fluid were positive on the 92nd hospital day. Anti-NMDAR encephalitis usually affects young females but a small number of male cases with this disease have been reported. Our male patient was unique in having GBS, a post-infectious autoimmune disease, as a preceding disease, suggesting that anti-NMDAR encephalitis itself is caused by a parainfectious autoimmune mechanism.

Upper limb neuropathy such as carpal tunnel syndrome as an initial manifestation of ATTR Val30Met familial amyloid polyneuropathy

We report here two patients with amyloidogenic transthyretin (ATTR) Val30Met familial amyloid polyneuropathy (FAP) who developed numbness in both hands and were diagnosed as having bilateral carpal tunnel syndrome (CTS). In both patients systemic TTR amyloidosis consisting of polyneuropathy affecting both upper and lower limbs and/or autonomic dysfunction gradually appeared after surgery for CTS. Although CTS associated with TTR amyloidosis has been known as an initial symptom in some patients with ATTR non-Val30Met FAP and those with senile systemic amyloidosis, this is the first report of ATTR Val30Met FAP patients starting with upper limb neuropathy including CTS-like symptoms. It is also notable that both patients had no genealogical relationship with two Japanese endemic foci of this disease.

Intestinal angina due to atherosclerosis in a 45-year-old systemic lupus erythematosus patient

We report a patient with systemic lupus erythematosus (SLE) who developed progressive emaciation and postprandial abdominal pain with a 27-year history of corticosteroid treatment. The patient was diagnosed as having intestinal angina based on computed tomography that showed severe stenosis of the superior mesenteric artery (SMA) in addition to complete occlusion of the celiac and inferior mesenteric arteries. Histopathology of the SMA and abdominal aorta showed atherosclerosis with no vasculitis or thrombus formation. Intestinal angina should actively be considered as a possible cause of recurrent abdominal pain in SLE patients, particularly in those with a long history of disease.

Defect structures in nematic liquid crystals around charged particles

We numerically study the orientation deformations in nematic liquid crystals around charged particles. We set up a Ginzburg-Landau theory with inhomogeneous electric field. If the dielectric anisotropy epsilon 1 is positive, Saturn-ring defects are formed around the particles. For epsilon 1< 0 , novel "ansa" defects appear, which are disclination lines with their ends on the particle surface. We find unique defect structures around two charged particles. To lower the free energy, oppositely charged particle pairs tend to be aligned in the parallel direction for epsilon 1> 0 and in the perpendicular plane for epsilon 1< 0 with respect to the background director. For identically charged pairs the preferred directions for epsilon 1> 0 and epsilon 1< 0 are exchanged. We also examine competition between the charge-induced anchoring and the short-range anchoring. If the short-range anchoring is sufficiently strong, it can be effective in the vicinity of the surface, while the director orientation is governed by the long-range electrostatic interaction far from the surface.

Significant deposition of wild type transthyretin-derived amyloid in the gastrointestinal tract of aged individuals

Two male patients aged 72 and 77 were found to have transthyretin (TTR) immunoreactive amyloid deposits in their gastrointestinal tracts when they underwent surgery for gastric and sigmoid colon cancer, respectively. They had no cardiac symptoms and there was no mutation in their TTR gene. Amyloid deposits were seen mainly on vascular walls in submucosal layers of the stomach and colon, while the muscularis mucosae, which is invariably affected in familial amyloid polyneuropathy (FAP), was completely free of amyloid deposition. The pattern of TTR-derived amyloid deposition in the gastrointestinal tract in SSA and in FAP are quite different.

Cortical petechial hemorrhage, subarachnoid hemorrhage and corticosteroid-responsive leukoencephalopathy in a patient with cerebral amyloid angiopathy

We describe a 69-year-old woman who developed subacute onset cognitive decline after hitting the left side of her head. Cerebral spinal fluid showed yellowish discoloration with highly elevated protein content. FLAIR MRI revealed diffuse high signal intensity in all cortical sulci, and leptomeningeal enhancement in the left cerebral hemisphere was seen in the T1 image after contrast administration. She was treated with a corticosteroid. Consciousness disturbance was temporarily relieved but again worsened, resulting in an apathetic state due to communicating hydrocephalus. A shunt tube was placed in her right lateral ventricle. A brain biopsy disclosed multiple cortical microbleeds and heavy deposition of Abeta-immuoreactive amyloid on vascular walls. Inflammatory mononuclear cells surrounded a few leptomeningeal vessels. After the operation her condition further deteriorated and she fell into a coma. MRI showed diffuse swelling of the right cerebral white matter. She again received high-dose corticosteroid and gradually recovered during the following 2 months. On MRI the vast majority of abnormal signals in the right cerebral white matter disappeared. An initial manifestation of this patient was possibly caused by multiple microhemorrhages from fragile cortical and subarachnoid vessels with Abeta-amyloid deposition, which was triggered by head trauma. CAA-related inflammation possibly worsened this condition. Additionally, surgical intervention for communicating hydrocephalus might have induced cerebral amyloid angiopathy (CAA)-related leukoencephalopathy in her right cerebral hemisphere. These CAA-derived manifestations are unusual and high-dose corticosteroids seems to be useful for vascular events in CAA patients.

An unusual case of Klippel-Trénaunay-Weber syndrome presenting with portosystemic encephalopathy

We report a unique male patient presenting with portosystemic encephalopathy (PSE) due to intrahepatic portohepatic venous (PHV) shunts. He was diagnosed as having Klippel-Trénaunay-Weber syndrome (KTWS) based on the findings of a hemitruncal port-wine stain with subcutaneous arteriovenous fistulae and varicose veins in the legs. However, limb-hypertrophy, which is one of the most cardinal manifestations of KTWS, was absent, and in KTWS, PSE is quite a rare clinical manifestation. Hence, the clinical picture of this patient was unusual. Our clinical observation suggests that KTWS can be one of the underlying disorders causing PSE.

Mutations of carnitine palmitoyltransferase II (CPT II) in Japanese patients with CPT II deficiency

Carnitine palmitoyltransferase II (CPT II) deficiency is an inherited disorder involving beta-oxidation of long-chain fatty acids. CPT II deficiency is a wide-spectrum disorder that includes a lethal neonatal form, an infantile form, and an adult-onset form. However, the ethnic characteristics and the relationship between genotype and clinical manifestation are not well understood. We investigated three non-consanguineous Japanese patients with CPT II deficiency and examined cell lines from 4 unrelated patients and 50 healthy donors. The CPT 2 gene was typed by direct DNA sequencing of polymerase chain reaction-amplified gene products. Case 1 (infantile form) was heterozygous for a phenylalanine to tyrosine substitution at position 383 (p.F383Y) and a novel valine to leucine substitution at 605 (p.V605L). Cases 2, 4, and 5 (infantile form) and case 3 (adult-onset form) were heterozygous for a single mutation at F383Y. Case 6 (adult-onset form) was compound heterozygous at the CPT 2 locus, with deletion of cytosine and thymine at residue 408, resulting in a stop signal at 420 (p.Y408fsX420), and an arginine to cysteine substitution at position 631 (p.R631C). Case 7 (adult-onset form) was homozygous for the p.F383Y mutation. In conclusion, we identified p.F383Y mutations in six of seven patients with CPT II deficiency and two novel variants of the coding gene: p.Y408fsX420 and p.V605L. These mutations differ from those in Caucasian patients, who commonly harbor p.S113L, p.P50H, and p.Q413fsX449 mutations; therefore, our data and those of other Japanese groups suggest that the p.F383Y mutation is significant in Japanese patients with CPT II deficiency.

Dystonia, mental deterioration, and dyschromatosis symmetrica hereditaria in a family with ADAR1 mutation

A family with dystonia associated with dyschromatosis symmetrica hereditaria (DSH), mental deterioration, and tissue calcification is described. The proband possessed an adenosine deaminase acting on the RNA 1 gene (ADAR1) mutation Gly1007Arg. This ADAR1 mutation could disturb RNA editing at Q/R sites of glutamate receptor in the brain and increase Ca(2+) influx into neurons, which is thought to induce dystonia and mental deterioration. The observations in our family raise the possibility that the ADAR1 mutation might be a direct cause or a predisposing factor for heredodegenerative dystonia. Further investigation of ADAR1 mutations will shed light on the genotype-phenotype correlation in DSH.

Biopsy-proven tuberculous meningitis mimicking CNS sarcoidosis

We report a 31-year-old man with tuberculous meningitis (TM) mimicking CNS sarcoidosis. Although Mycobacterium tuberculosis (MTB) was not detected in CSF, the level of adenosine deaminase (ADA) in CSF was significantly raised. Brain biopsy showed caseous granuloma and a diagnosis of TM was made. The diagnosis of TM is often difficult and brain biopsy should be considered if MTB is not detected in the CSF. Evaluation of CSF ADA level could also strongly contribute to distinguishing TM from other meningitis. In addition to antituberculosis drugs, corticosteroid therapy was effective in our patient but careful reduction of its dosage was required.

Diflunisal stabilizes familial amyloid polyneuropathy-associated transthyretin variant tetramers in serum against dissociation required for amyloidogenesis

Transthyretin (TTR) tetramer dissociation, misfolding and misassembly are required for the process of amyloid fibril formation associated with familial amyloid polyneuropathy (FAP). Preferential stabilization of the native TTR tetramer over the dissociative transition state by small molecule binding raises the kinetic barrier of tetramer dissociation, preventing amyloidogenesis. Two NSAIDs, diflunisal and flufenamic acid, and trivalent chromium have this ability. Here, we investigated the feasibility of using these molecules for the treatment of FAP utilizing serum samples from 37 FAP patients with 10 different mutations. We demonstrated that the TTR heterotetramer structures in FAP patients serum are significantly less stable than that in normal subjects, indicating the instability of the variant TTR structure is a fundamental cause of TTR amyloidosis. We also demonstrated that therapeutic serum concentrations of diflunisal (100-200 microM) stabilized serum variant TTR tetramer better than those of flufenamic acid (35-70 microM). Trivalent chromium at levels obtained by oral supplementation did not stabilize TTR in a statistically significant fashion. Importantly, diflunisal increased serum TTR stability in FAP patients beyond the level of normal controls.

Ghrelin prevents development of diabetes at adult age in streptozotocin-treated newborn rats

AIMS/HYPOTHESIS

Ghrelin, a stomach-derived hormone, functions in multiple biological processes, including glucose metabolism and cellular differentiation and proliferation. In this study, we examined whether early treatment with ghrelin can regenerate beta cells of the pancreas in an animal model of diabetes mellitus, the n0-STZ model, in which neonatal rats are injected with streptozotocin (STZ) at birth.

METHODS

Following administration of ghrelin to n0-STZ rats from postnatal days 2 to 8, we examined beta cell mass, mRNA expression levels of insulin and of pancreatic and duodenal homeobox 1 (Pdx1) gene, and pancreatic morphology on days 21 and 70. In addition, we investigated the effects of ghrelin on beta cell replication.

RESULTS

By day 21, ghrelin treatment increased pancreatic expression of insulin and Pdx1 mRNA in n0-STZ rats. The number of replicating cells was also significantly increased in the ghrelin-treated n0-STZ model. At day 70, n0-STZ rats exhibited hyperglycaemia, despite slight increases in plasma insulin levels. Ghrelin treatment resulted in the improvement of plasma glucose levels, which were associated with normal plasma insulin levels. Pancreatic insulin mRNA and protein levels were significantly increased in ghrelin-treated n0-STZ model animals.

CONCLUSIONS/INTERPRETATION

These findings suggest that ghrelin promotes regeneration of beta cells in STZ-treated newborn rats. Thus, early administration of ghrelin may help prevent the development of diabetes in disease-prone subjects after beta cell destruction.

Unexpectedly high incidence of visceral AA-amyloidosis in slaughtered cattle in Japan

Experimental mouse AA amyloidosis can be transmissible by dietary ingestion of amyloid fibrils and it is well known that AA amyloidosis occasionally develops in aged cattle. Bovine liver and intestine have conventionally been used in Oriental foods, and the incidence of visceral AA amyloidosis in slaughtered cattle was evaluated. Renal tissues from 302 aged cattle older than 4 years were obtained from a local abattoir. Amyloid deposition was microscopically examined and amyloid protein was immunochemically determined. Renal amyloid deposition was seen in 15 out of 302 cattle with no previous history of diseas, an incidence of 5.0%. Amyloid protein in these cattle was AA and they had pathological findings in their visceral organs on gross examination. The incidence of visceral AA amyloidosis in slaughtered cattle in this study was disturbingly high compared with those (0.4-2.7%) previously reported from Japan and other foreign countries. AA amyloidosis is a life-threatening complication in patients with chronic inflammatory diseases and these patients at risk should avoid ingesting food that may possibly contain AA amyloid fibrils. More detailed information on cattle amyloidosis is required to guarantee the safety of our food.

Skin Metabolism in Transdermal Therapeutic Systems

Skin has at least two barriers with protective functions: the stratum corneum physical barrier and a biochemical barrier in the epidermis and dermis. Numerous chemical and physical enhancers exist for transdermal therapeutic systems; some cause irritation, and possibly influence enzyme deactivation. Knowledge of enzymatic skin reactions is important for developing safe and efficacious transdermal systems for treatment not only of skin diseases but also for systemic application. This paper overviews the effects of (a) chemical enhancers and additives, (b) drug structure, and (c) physical enhancement on skin metabolism.

Multiple brain tumors of diffuse large B cell lymphoma in a patient with Waldenström's macroglobulinemia/ lymphoplasmacytic lymphoma: PCR and DNA sequence analysis show evidence of differences in clonality of the two B cell malignancies

Multiple brain tumors of diffuse large B cell lymphoma (DLBL) were observed in a 75-year-old man with Waldenström's macroglobulinemia (WM). Paravertebral and multiple subcutaneous nodules occurred in succession and he died 4 months after onset. We investigated B cell monoclonality by means of polymerase chain reaction (PCR) analysis and sequencing of the immunoglobulin heavy chain of paraffin-embedded sections. The PCR product of the brain tumors showed a different rearrangement pattern from those of the other sections. The co-occurrence of DLBL with WM is rare, and some investigators have examined the clonality of the two malignancies. This case is important because DLBL brain tumors co-occurred with WM, enabling us to prove that DLBL and WM have different clonality.

Pharmacokinetic model for in vivo/in vitro correlation of intravitreal drug delivery

A pharmacokinetic model of intravitreal drug delivery has been developed for describing the elimination and distribution of ocular drugs in the posterior segments of the eye. The model, based on Fick's second law of diffusion, assumes the cylindrical vitreous body with three major pathways for elimination: the posterior aqueous chamber, the retina/choroids/sclera (RCS) membrane and the lens posterior capsule. The model parameters such as the diffusion coefficient and the partition coefficient of the drug in the vitreous body and its surrounding tissues, the posterior lens capsule and the retina/choroids/sclera membrane, can be determined from in vitro membrane penetration experiments using respective rabbit tissues. The time course of in vivo mean concentration of the drug in the rabbit vitreous body following intravitreal drug delivery well agreed with the profile calculated from the present pharmacokinetic model for both membrane-controlled polymeric devices and biodegradable rod-matrix systems. The pharmacokinetic model suggests that the major route of elimination of drug molecules released from the vitreous implant is through the posterior aqueous humor because of the absence of a barrier membrane. However, the elimination through the RCS membrane cannot be overlooked because of the large diffusion area of the RCS membrane. The vitreous body concentration of the drug released from biodegradable vitreous implants can be predicted from the in vivo release rate-time profile by the present pharmacokinetic model.

Association of Graves' disease with Evans' syndrome in a patient with IgA nephropathy

A 20-year-old woman with IgA nephropathy was admitted to Jikei University Hospital for the treatment of rapid deterioration of renal function after receiving 131I-therapy against hyperthyroidism on October 23,1999, and hemodialysis was started. On admission, she was diagnosed as having Evans' syndrome in addition to known Graves' disease. Renal biopsy revealed end-stage renal damage, then, hemodialysis was maintained. Treatment for Evans' syndrome was also started and her general condition gradually improved. The present case implied that "Graves' disease" and "Evans' syndrome" could represent some of the manifestations of an underlying immunological disorder in the patient.

Coordinate regulation of endothelin and adrenomedullin secretion by oxidative stress in endothelial cells

To elucidate the significance of oxidative stress in the modulation of endothelial functions, we examined the effects of H(2)O(2) on the expression of two endothelium-derived vasoactive peptides, endothelin (ET) and adrenomedullin (Am), and their interaction. H(2)O(2) dose dependently suppressed ET secretion and ET-1 mRNA expression in bovine carotid endothelial cells (ECs). Menadion sodium bisulfate, a redox cycling drug, also decreased ET secretion in a dose-dependent manner. Catalase, a H(2)O(2) reductase, and dl-alpha-tocopherol (vitamin E) significantly inhibited H(2)O(2)-induced suppression of ET secretion. Downregulation of ET-1 mRNA under oxidative stress was regulated at the transcriptional level. In contrast, H(2)O(2) increased Am secretion (and its mRNA expression) accompanied by the augmentation of cAMP production. Am, as well as 8-bromo-cAMP and forskolin decreased ET secretion in a dose-dependent fashion. Furthermore, an anti-Am monoclonal antibody that we developed abolished H(2)O(2)-induced suppression of ET secretion at 6-24 h after the addition of H(2)O(2). H(2)O(2) increased the intracellular Ca(2+) concentration ([Ca(2+)](i)). Moreover, treatment with ionomycin, a Ca(2+) ionophore, and thapsigargin, an inhibitor of endoplasmic reticulum ATPase, decreased ET secretion dose dependently for 3 h. These results suggest that the production of ET was decreased via activation of the Am-cAMP pathway and by the elevation of [Ca(2+)](i) under oxidative stress. These findings elucidate the coordinate expression of two local vascular hormones, ET and Am, under oxidative stress, which may protect against vascular diseases.

An experimental approach to study the binding properties of vitamin E (alpha-tocopherol) during hairless mouse skin permeation

An experimental approach to study the binding properties of vitamin E has been developed. Total vitamin E solubility in the skin was determined by a partition study, followed by in vitro skin permeation studies with whole skin and stripped skin. The amount of freely diffusable vitamin E in the diffusion process was determined from the permeation profiles of whole skin and stripped skin by employing a bi-layer model. The concentrations of vitamin E in the stratum corneum and viable dermis were determined separately. By subtracting this amount from the total concentration of vitamin E in the skin, as determined by the solubility study, the amount of bound vitamin E was determined. After skin permeation reached a steady state, the donor solution was removed and the permeation study continued (desorption study). During the entire period of the desorption experiment, the amount of vitamin E in the receptor solution hardly increased and remained constant. After the desorption experiment, vitamin E still remaining in the skin was determined by extracting with tissue solubilizer, SOLABLE, and is considered as the amount of vitamin E strongly bound in the skin. The concentrations of bound vitamin E determined by permeation and desorption studies coincided relatively well. To further investigate skin binding of vitamin E, a differential scanning calorimetry study was performed. Vitamin E-treated stratum corneum showed phase transitions at 76 and 85 degrees C, associated with lipid transitions. The thermal transitions associated with the lipid transition suggested interactions of vitamin E with lipid components of the skin. During skin permeation, vitamin E forms a very strong reservoir in the skin tissue and this amount of vitamin E, about 30%, exists as a bound-form with the lipid components of the stratum corneum.

Positional dissociation between the genetic mutation responsible for pseudohypoparathyroidism type Ib and the associated methylation defect at exon A/B: evidence for a long-range regulatory element within the imprinted GNAS1 locus

Pseudohypoparathyroidism type Ib (PHP-Ib) is a paternally imprinted disorder which maps to a region on chromosome 20q13.3 that comprises GNAS1 at its telomeric boundary. Exon A/B of this gene was recently shown to display a loss of methylation in several PHP-Ib patients. In nine unrelated PHP-Ib kindreds, in whom haplotype analysis and mode of inheritance provided no evidence against linkage to this chromosomal region, we confirmed lack of exon A/B methylation for affected individuals, while unaffected carriers showed no epigenetic abnormality at this locus. However, affected individuals in one kindred (Y2) displayed additional methylation defects involving exons NESP55, AS and XL, and unaffected carriers in this family showed an abnormal methylation at exon NESP55, but not at other exons. Taken together, current evidence thus suggests that distinct mutations within or close to GNAS1 can lead to PHP-Ib and the associated epigenetic changes. To further delineate the telomeric boundary of the PHP-Ib locus, the previously reported kindred F, in which patient F-V/51 is recombinant within GNAS1, was investigated with several new markers and direct nucleotide sequence analysis. These studies revealed that F-V/51 remains recombinant at a single nucleotide polymorphism (SNP) located 1.2 kb upstream of XL. No heterozygous mutation was identified between exon XL and an SNP approximately 8 kb upstream of NESP55, where this affected individual becomes linked, suggesting that the genetic defect responsible for parathyroid hormone resistance in kindred F, and probably other PHP-Ib patients, is located >or=56 kb centromeric of the abnormally methylated exon A/B. A region upstream of the known coding exons of GNAS1 is therefore predicted to exert, presumably through imprinting of exon A/B, long-range effects on G(s)alpha expression.