α-Synuclein pathology in Drosophila melanogaster is exacerbated by haploinsufficiency of Rop: connecting STXBP1 encephalopathy with α-synucleinopathies

Syntaxin-binding protein 1 (STXBP1) is a presynaptic protein that plays important roles in synaptic vesicle docking and fusion. STXBP1 haploinsufficiency causes STXBP1 encephalopathy (STXBP1-E), which encompasses neurological disturbances including epilepsy, neurodevelopmental disorders, and movement disorders. Most patients with STXBP1-E present with regression and movement disorders in adulthood, highlighting the importance of a deeper understanding of the neurodegenerative aspects of STXBP1-E. An in vitro study proposed an interesting new role of STXBP1 as a molecular chaperone for α-Synuclein (αSyn), a key molecule in the pathogenesis of neurodegenerative disorders. However, no studies have shown αSyn pathology in model organisms or patients with STXBP1-E. In this study, we used Drosophila models to examine the effects of STXBP1 haploinsufficiency on αSyn-induced neurotoxicity in vivo. We demonstrated that haploinsufficiency of Ras opposite (Rop), the Drosophila ortholog of STXBP1, exacerbates compound eye degeneration, locomotor dysfunction, and dopaminergic neurodegeneration in αSyn-expressing flies. This phenotypic aggravation was associated with a significant increase in detergent-insoluble αSyn levels in the head. Furthermore, we tested whether trehalose, which has neuroprotective effects in various models of neurodegenerative disorders, mitigates αSyn-induced neurotoxicity exacerbated by Rop haploinsufficiency. In flies expressing αSyn and carrying a heterozygous Rop null variant, trehalose supplementation effectively alleviates neuronal phenotypes, accompanied by a decrease in detergent-insoluble αSyn in the head. In conclusion, this study revealed that Rop haploinsufficiency exacerbates αSyn-induced neurotoxicity by altering the αSyn aggregation propensity. This study not only contributes to understanding the mechanisms of neurodegeneration in STXBP1-E patients, but also provides new insights into the pathogenesis of α-synucleinopathies.

Bilateral choroid plexus resection in a 9p hexasomy/tetrasomy mosaic patient

Previous reports have shown that a gain of the chromosome 9 short arm (9p) is associated with choroid plexus hyperplasia (CPH). Furthermore, CPH can lead to communicating hydrocephalus; however, no cases of CPH with 9p gain requiring choroid plexus resection have been reported. Here, we describe the first case in which a 9p hexasomy/tetrasomy mosaic patient required choroid plexus resection for hydrocephalus. This finding suggested that the 9p copy number is correlated with CPH severity.

Leigh-like syndrome with progressive cerebellar atrophy caused by novel HIBCH variants

Pathogenic variants in the HIBCH gene cause HIBCH deficiency, leading to mitochondrial disorders associated with valine metabolism. Patients typically present with symptoms such as developmental regression/delay, encephalopathy, hypotonia and dystonia. Brain magnetic resonance imaging (MRI) shows bilateral lesions in the basal ganglia with/without brainstem involvement. Here, we report a case of a Japanese patient with Leigh-like syndrome caused by novel HIBCH variants. Long-term follow-up MRI revealed progressive cerebellar atrophy, which expands the phenotypic spectrum of HIBCH deficiency.

Myosin Va, a novel interaction partner of STXBP1, is required to transport Syntaxin1A to the plasma membrane

Syntaxin-binding protein 1 (STXBP1, also known as Munc18-1) regulates exocytosis as a chaperone protein of Syntaxin1A. The haploinsufficiency of STXBP1 causes early infantile-onset developmental and epileptic encephalopathy, known as STXBP1 encephalopathy. Previously, we reported impaired cellular localization of Syntaxin1A in induced pluripotent stem cell-derived neurons from an STXBP1 encephalopathy patient harboring a nonsense mutation. However, the molecular mechanism of abnormal Syntaxin1A localization in the haploinsufficiency of STXBP1 remains unknown. This study aimed to identify the novel interacting partner of STXBP1 involved in transporting Syntaxin1A to the plasma membrane. Affinity purification coupled with mass spectrometry analysis identified a motor protein Myosin Va as a potential binding partner of STXBP1. Co-immunoprecipitation analysis of the synaptosomal fraction from the mouse and tag-fused recombinant proteins revealed that the STXBP1 short splice variant (STXBP1S) interacted with Myosin Va in addition to Syntaxin1A. These proteins colocalized at the tip of the growth cone and axons in primary cultured hippocampal neurons. Furthermore, RNAi-mediated gene silencing in Neuro2a cells showed that STXBP1 and Myosin Va were required for membrane trafficking of Syntaxin1A. In conclusion, this study proposes a potential role of STXBP1 in the trafficking of the presynaptic protein Syntaxin1A to the plasma membrane in conjunction with Myosin Va.

Quantitative pretreatment EEG predicts efficacy of ACTH therapy in infantile epileptic spasms syndrome

OBJECTIVE

This study aimed to determine the correlation between outcomes following adrenocorticotrophic hormone (ACTH) therapy and measurements of relative power spectrum (rPS), weighted phase lag index (wPLI), and graph theoretical analysis on pretreatment electroencephalography (EEG) in infants with non-lesional infantile epileptic spasms syndrome (IESS).

METHODS

Twenty-eight patients with non-lesional IESS were enrolled. Outcomes were classified based on seizure recurrence following ACTH therapy: seizure-free (F, n = 21) and seizure-recurrence (R, n = 7) groups. The rPS, wPLI, clustering coefficient, and betweenness centrality were calculated on pretreatment EEG and were statistically analyzed to determine the correlation with outcomes following ACTH therapy.

RESULTS

The rPS value was significantly higher in the delta frequency band in group R than in group F (p < 0.001). The wPLI values were significantly higher in the delta, theta, and alpha frequency bands in group R than in group F (p = 0.007, <0.001, and <0.001, respectively). The clustering coefficient in the delta frequency band was significantly lower in group R than in group F (p < 0.001).

CONCLUSIONS

Our findings demonstrate the significant differences in power and functional connectivity between outcome groups.

SIGNIFICANCE

This study may contribute to an early prediction of ACTH therapy outcomes and thus help in the development of appropriate treatment strategies.

Low-grade IVH in preterm infants causes cerebellar damage, motor, and cognitive impairment

BACKGROUND

Few studies have examined the effect of low-grade intraventricular hemorrhage (IVH) on the white matter in the cerebellum and its association with neurodevelopment. We evaluated cerebellar white matter at term-equivalent age (TEA) in preterm infants with low-grade IVH. Furthermore, we assessed neurodevelopmental outcomes at 3 years of age to examine the influence of low-grade IVH on neurodevelopment.

METHODS

Thirteen infants with low-grade IVH and 26 without IVH, born at <30 weeks' postmenstrual age (PMA), were enrolled in this study. Diffusion tensor imaging (DTI) parameters, including fractional anisotropy (FA) and apparent diffusion coefficient (ADC) in the middle and superior cerebellar peduncles (SCP), were measured. Neurodevelopmental outcomes at three years of age were assessed and the correlation between DTI parameters and developmental quotient (DQ) was analyzed.

RESULTS

Preterm infants with IVH showed lower FA values (P < 0.01) and higher ADC values (P < 0.05) in the SCP at TEA than the no-IVH group. Lower Postural-Motor and Cognitive-Adaptive DQ at 3 years of age were observed in the IVH compared to the no-IVH group. A significant correlation between the FA values in the SCP at TEA and the Posture-Motor DQ was observed at three years of age (P = 0.043, r = 0.50).

CONCLUSIONS

These data suggest that low-grade IVH in preterm infants affects the SCP at TEA and that impaired cerebellar white matter correlates with poor motor development at three years of age.

Phenotypes of SMA patients retaining SMN1 with intragenic mutation

BACKGROUND

Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder caused by homozygous deletion or intragenic mutation of the SMN1 gene. It is well-known that high copy number of its homologous gene, SMN2, modifies the phenotype of SMN1-deleted patients. However, in the patients with intragenic SMN1 mutation, the relationship between phenotype and SMN2 copy number remains unclear.

METHODS

We have analyzed a total of 515 Japanese patients with SMA-like symptoms (delayed developmental milestones, respiratory failures, muscle weakness etc.) from 1996 to 2019. SMN1 and SMN2 copy numbers were determined by quantitative polymerase chain reaction (PCR) method and/or multiplex ligation-dependent probe amplification (MLPA) method. Intragenic SMN1 mutations were identified through DNA and RNA analysis of the fresh blood samples.

RESULTS

A total of 241 patients were diagnosed as having SMA. The majority of SMA patients showed complete loss of SMN1 (n = 228, 95%), but some patients retained SMN1 and carried an intragenic mutation in the retaining SMN1 (n = 13, 5%). Ten different mutations were identified in these 13 patients, consisting of missense, nonsense, frameshift and splicing defect-causing mutations. The ten mutations were c.275G > C (p.Trp92Ser), c.819_820insT (p.Thr274Tyrfs*32), c.830A > G (p.Tyr277Cys), c.5C > T (p.Ala2Val), c.826 T > C (p.Tyr276His), c.79C > T (p.Gln27*), c.188C > A (p.Ser63*), c.422 T > C (p.Leu141Pro), c.835-2A > G (exon 7 skipping) and c.835-3C > A (exon 7 skipping). It should be noted here that some patients with milder phenotype carried only a single SMN2 copy (n = 3), while other patients with severe phenotype carried 3 SMN2 copies (n = 4).

CONCLUSION

Intragenic mutations in SMN1 may contribute more significantly to clinical severity than SMN2 copy numbers.

Impaired neuronal activity and differential gene expression in STXBP1 encephalopathy patient iPSC-derived GABAergic neurons

Syntaxin-binding protein 1 (STXBP1; also called MUNC18-1), encoded by STXBP1, is an essential component of the molecular machinery that controls synaptic vesicle docking and fusion. De novo pathogenic variants of STXBP1 cause a complex set of neurological disturbances, namely STXBP1 encephalopathy (STXBP1-E) that includes epilepsy, neurodevelopmental disorders and neurodegeneration. Several animal studies have suggested the contribution of GABAergic dysfunction in STXBP1-E pathogenesis. However, the pathophysiological changes in GABAergic neurons of these patients are still poorly understood. Here, we exclusively generated GABAergic neurons from STXBP1-E patient-derived induced pluripotent stem cells (iPSCs) by transient expression of the transcription factors ASCL1 and DLX2. We also generated CRISPR/Cas9-edited isogenic iPSC-derived GABAergic (iPSC GABA) neurons as controls. We demonstrated that the reduction in STXBP1 protein levels in patient-derived iPSC GABA neurons was slight (approximately 20%) compared to the control neurons, despite a 50% reduction in STXBP1 mRNA levels. Using a microelectrode array-based assay, we found that patient-derived iPSC GABA neurons exhibited dysfunctional maturation with reduced numbers of spontaneous spikes and bursts. These findings reinforce the idea that GABAergic dysfunction is a crucial contributor to STXBP1-E pathogenesis. Moreover, gene expression analysis revealed specific dysregulation of genes previously implicated in epilepsy, neurodevelopment and neurodegeneration in patient-derived iPSC GABA neurons, namely KCNH1, KCNH5, CNN3, RASGRF1, SEMA3A, SIAH3 and INPP5F. Thus, our study provides new insights for understanding the biological processes underlying the widespread neuropathological features of STXBP1-E.

Clinical phenotypes of spinal muscular atrophy patients with hybrid SMN gene

BACKGROUND

Spinal muscular atrophy (SMA) is a neuromuscular disease caused by homozygous deletion of SMN1 exons 7 and 8. However, exon 8 is retained in some cases, where SMN2 exon 7 recombines with SMN1 exon 8, forming a hybrid SMN gene. It remains unknown how the hybrid SMN gene contribute to the SMA phenotype.

METHOD

We analyzed 515 patients with clinical suspicion for SMA. SMN1 exons 7 and 8 deletion was detected by PCR followed by enzyme digestion. Hybrid SMN genes were further analyzed by nucleotide sequencing. SMN2 copy number was determined by real-time PCR.

RESULTS

SMN1 exon 7 was deleted in 228 out of 515 patients, and SMN1 exon 8 was also deleted in 204 out of the 228 patients. The remaining 24 patients were judged to carry a hybrid SMN gene. In the patients with SMN1 exon 7 deletion, the frequency of the severe phenotype was significantly lower in the patients with hybrid SMN gene than in the patients without hybrid SMN gene. However, as for the distribution of SMN2 exon 7 copy number among the clinical phenotypes, there was no significant difference between both groups of SMA patients with or without hybrid SMN gene.

CONCLUSION

Hybrid SMN genes are not rare in Japanese SMA patients, and it appears to be associated with a less severe phenotype. The phenotype of patients with hybrid SMN gene was determined by the copy number of SMN2 exon 7, as similarly for the patients without hybrid SMN gene.

Complex hereditary spastic paraplegia associated with episodic visual loss caused by ACO2 variants

Most patients with homozygous or compound heterozygous pathogenic ACO2 variants present with muscular hypotonia features, namely, infantile cerebellar-retinal degeneration. Recently, two studies reported rare familial cases of ACO2 variants presenting as complex hereditary spastic paraplegia (HSP) with broad clinical spectra. Here, we report the case of a 20-year-old Japanese woman with complex HSP caused by compound heterozygous ACO2 variants, revealing a new phenotype of episodic visual loss during febrile illness.

A novel Drosophila model for neurodevelopmental disorders associated with Shwachman-Diamond syndrome

Genetic defects in ribosome biogenesis result in a group of diseases called ribosomopathies. Patients with ribosomopathies manifest multiorgan phenotypes, including neurological impairments. A well-characterized ribosomopathy, Shwachman-Diamond syndrome (SDS), is mainly associated with loss-of-function mutations in the causal gene SBDS. Children with SDS have neurodevelopmental disorders; however, the neurological consequences of SBDS dysfunction remain poorly defined. In the present study, we investigated the phenotype of Drosophila melanogaster following knockdown of CG8549, the Drosophila ortholog of human SBDS, to provide evidence for the neurological consequences of reduction in physiological SBDS functions. The pan-neuron-specific knockdown of CG8549 was associated with locomotive disabilities, mechanically induced seizures, hyperactivity, learning impairments, and anatomical defects in presynaptic terminals. These results provide the first evidence of a direct link between a reduction in physiological SBDS function and neurological impairments.

Intrathecal nusinersen treatment after ventriculo-peritoneal shunt placement: A case report focusing on the neurofilament light chain in cerebrospinal fluid

BACKGROUND

In July 2018, a rare and serious adverse effect (AE), namely, communicating hydrocephalus unrelated to meningitis or bleeding, was reported in relation to five patients treated with nusinersen for spinal muscular atrophy (SMA). Some patients were managed using a ventriculo-peritoneal shunt (VPS) implant and continued to receive nusinersen treatment. However, there is limited information concerning the effectiveness and safety of nusinersen treatment for patients with a VPS.

CASE REPORT

A female patient exhibited general hypotonia soon after birth and was diagnosed, using genetic analysis, with spinal muscular atrophy. She required permanent invasive ventilation from 2 months of age. She developed a progressive hydrocephalus and underwent placement of a VPS in infancy. Treatment with nusinersen was initiated when she was 7 years old. The neurofilament light-chain (NfL) concentration in the cerebrospinal fluid (CSF) decreased over time with nusinersen treatment. Twelve months have passed since the start of nusinersen treatment and no AEs have been observed.

CONCLUSION

Nusinersen treatment may be effective and safe, even after placement of a VPS. NfL levels in the CSF could be valuable markers of disease activity/treatment response even in advanced stages of SMA.

Early infantile-onset Leigh syndrome complicated with infantile spasms associated with the m.9185 T > C variant in the MT-ATP6 gene: Expanding the clinical spectrum

BACKGROUND

The mitochondrial DNA MT-ATP6 gene encodes the ATP6 subunit of the mitochondrial ATP synthase. The m.9185 T > C variant in MT-ATP6 has been reported to cause various neurological disorders including late-onset Leigh syndrome (LS). To our knowledge, there has been no reported case of infantile-onset LS associated with the m.9185 T > C variant. Herein, we report a patient with early-onset LS complicated with infantile spasms who exhibited profound developmental delay.

CASE REPORT

A 3-month-old Japanese girl presented with focal seizures. Brain magnetic resonance imaging (MRI) revealed bilateral lesions in the basal ganglia and cerebral peduncle. Laboratory evaluation demonstrated marked elevations of lactate and pyruvate in both venous blood and cerebrospinal fluid. At 6 months, she developed infantile spasms, which were ceased by adrenocorticotropic hormone therapy. At 2 years of age, she was bedridden due to hypotonic quadriplegia and was unable to make eye contact. Whole-exome sequencing identified apparently de novo homoplasmic m.9185 T > C variant in her blood.

CONCLUSION

This is the first case report describing early infantile-onset LS associated with the m.9185 T > C variant, and thereby broadens the phenotypic spectrum of m.9185 T > C-related disorders.

Cerebellar peduncle injury predicts motor impairments in preterm infants: A quantitative tractography study at term-equivalent age

PURPOSE

Cerebellar injury is well established as an important finding in preterm infants with cerebral palsy (CP). In this study, we investigated associations between injury to the cerebellar peduncles and motor impairments in preterm infants using quantitative tractography at term-equivalent age, which represents an early phase before the onset of motor impairments.

METHODS

We studied 64 preterm infants who were born at <33 weeks gestational age. These infants were divided into three groups: CP, Non-CP (defined as infants with periventricular leukomalacia but having normal motor function), and a Normal group. Diffusion tensor imaging was performed at term-equivalent age and motor function was assessed no earlier than a corrected age of 2 years. Using tractography, we measured fractional anisotropy (FA) and apparent diffusion coefficient (ADC) of the superior cerebellar peduncles (SCP) and middle cerebellar peduncles (MCP), as well as the motor/sensory tracts.

RESULTS

The infants in the CP group had significantly lower FA of the SCP and sensory tract than those in the other groups. There was no significant difference in FA and ADC of the motor tract among the three groups. Severity of CP had a significant correlation with FA of the MCP, but not with the FA of other white matter tracts.

CONCLUSION

Our results suggested that the infants with CP had injuries of the ascending tracts (e.g. the SCP and sensory tract), and that additional MCP injury might increase the severity of CP. Quantitative tractography assessment at term-equivalent age may be useful for screening preterm infants for prediction of future motor impairments.

A 5-Year Follow-Up of Triple-Seronegative Myasthenia Gravis Successfully Treated with Tacrolimus Therapy

Seronegative myasthenia gravis (MG) is a generalized form of MG that is diagnosed on the basis of clinical symptoms, electrophysiological testing, and pharmacological responses, in the absence of a seropositive status for anti-acetylcholine receptor (AChR) antibodies. Generalized MG that is seronegative for anti-AChR, anti-muscle-specific kinase (MuSK), and anti-low density lipoprotein receptor related protein 4 (Lrp4) antibodies is known as triple-seronegative MG. We here describe a case of triple-seronegative MG in an 8-year-old boy. His first symptom was dysphagia, at 3 years of age, and he subsequently developed ptosis, rhinolalia, and a waddling gait. A genetic analysis was conducted to exclude the possibility of congenital myasthenia syndrome due to the patient's resistance to steroid therapy. His condition was successfully managed with tacrolimus therapy over a 5-year follow-up period. Recently, several studies have reported the therapeutic utility of tacrolimus in juvenile seropositive MG; in contrast, a few reports have described tacrolimus treatment in cases of seronegative MG. Our findings suggest that tacrolimus therapy is a safe and effective option for the treatment of juvenile seronegative MG.

A Video Report of Brain-Lung-Thyroid Syndrome in a Japanese Female With a Novel Frameshift Mutation of the NKX2-1 Gene

Benign hereditary chorea is a rare autosomal-dominant disorder that is characterized by childhood-onset nonprogressive chorea and normal cognitive function. Defects in NKX2-1 on chromosome 14q13, which encodes thyroid transcription factor 1, produce a concurrent clinical manifestation of chorea, respiratory distress, and hypothyroidism known as “brain–lung–thyroid syndrome.” Here, the authors describe a video report of benign hereditary chorea in a Japanese female with a novel frameshift mutation of NKX2-1 (c.915_916insC) (p.Ala303ArgfsX132) that was initially misdiagnosed as ataxic cerebral palsy. In early infancy, especially before the appearance of chorea, benign hereditary chorea can be misdiagnosed as ataxic and dyskinetic cerebral palsy due to shared clinical features including motor delay, hypotonia, ataxic gait, and dystonia.

The shortest isoform of dystrophin (Dp40) interacts with a group of presynaptic proteins to form a presumptive novel complex in the mouse brain

Duchenne muscular dystrophy (DMD) causes cognitive impairment in one third of the patients, although the underlying mechanisms remain to be elucidated. Recent studies showed that mutations in the distal part of the dystrophin gene correlate well with the cognitive impairment in DMD patients, which is attributed to Dp71. The study on the expression of the shortest isoform, Dp40, has not been possible due to the lack of an isoform specific antibody. Dp40 has the same promoter as that found in Dp71 and lacks the normal C-terminal end of Dp427. In the present study, we have raised polyclonal antibody against the N-terminal sequence common to short isoforms of dystrophin, including Dp40, and investigated the expression pattern of Dp40 in the mouse brain. Affinity chromatography with this antibody and the consecutive LC-MS/MS analysis on the interacting proteins revealed that Dp40 was abundantly expressed in synaptic vesicles and interacted with a group of presynaptic proteins, including syntaxin1A and SNAP25, which are involved in exocytosis of synaptic vesicles in neurons. We thus suggest that Dp40 may form a novel protein complex and play a crucial role in presynaptic function. Further studies on these aspects of Dp40 function might provide more insight into the molecular mechanisms of cognitive impairment found in patients with DMD.

Development of corpus callosum in preterm infants is affected by the prematurity: in vivo assessment of diffusion tensor imaging at term-equivalent age

Callosal injury in preterm infants is a key factor affecting neurodevelopmental outcome. We investigated the characteristics of corpus callosum (CC) in preterm infants without apparent white matter lesions. We studied 58 preterm infants divided into three groups of 23-25, 26-29, and 30-33 wk GA. Diffusion tensor imaging (DTI) was obtained at term-equivalent age. The CC was parcellated into the genu, body, isthmus, and splenium. We measured fractional anisotropy (FA) and apparent diffusion coefficient (ADC) of each CC subdivision using tractography and manual region of interest analysis. The cross-sectional areas were also measured. At the isthmus and splenium in the 23-25 GA group, the FA was significantly lower and the size was also significantly reduced. Furthermore, the FA and cross-sectional areas in the posterior CC decreased linearly with decreasing GA. There were no differences in FA and cross-sectional areas in other CC subdivisions, and no differences in ADC in any CC subdivisions, among the GA groups. We demonstrated that preterm infants without apparent white matter lesions affect development of the posterior CC depending on the degree of prematurity.

Organ distribution of quantum dots after intraperitoneal administration, with special reference to area-specific distribution in the brain

Quantum dots (QDs) are well known for their potential application in biosensing, ex vivo live-cell imaging and in vivo animal targeting. The brain is a challenging organ for drug delivery, because the blood brain barrier (BBB) functions as a gatekeeper guarding the body from exogenous substances. Here, we evaluated the distribution of bioconjugated QDs, i.e., captopril-conjugated QDs (QDs-cap) following intraperitoneal injection into male ICR mice as a model system for determining the tissue localization of QDs, employing ICP-MS and confocal microscopy coupled with spectrometric analysis. We have demonstrated that intraperitoneally administered QDs-cap were delivered via systemic blood circulation into liver, spleen, kidney and brain at 6 h after injection. QDs-cap were located predominantly inside the blood vessels in the liver, kidney and brain, but a few were distributed in the parenchyma, especially noteworthy in the brain. Careful studies on acute as well as chronic toxicity of QDs in the brain are required prior to clinical application to humans.

Total sleep deprivation induces an acute and transient increase in NK cell activity in healthy young volunteers

STUDY OBJECTIVES

To investigate the effects of one night's total sleep deprivation (TSD) on NK cell activity, with rigorous control of circadian phase of sampling points as well as physical exercise level in association with sleep deprivation.

DESIGN

The mean sleep onset time of each subject before starting the study was defined as his 0000 h. This study was composed of a Sleep-Sleep session (sleep times, 00:00 h - 08:00 h and 24:00 h - 32:00 h) and a Sleep-Wake session (sleep time, 00:00 h - 08:00 h) with TSD (24:00 h - 32:00 h) placed in a cross-over design with 2-week interval between each session. In each session, the subjects were rested in the supine position under dim light from - 06:00 h to 36:00 h (for 42 hours).

SETTING

University-based sleep and chronobiology laboratory

PARTICIPANTS

10 healthy adult men (mean age, 20.9 y; age range, 19-23 y)

INTERVENTIONS

NA.

MEASUREMENTS AND RESULTS

NK cell activity was measured every 4 hours from 12:00 h. NK cell activity during TSD (at 28:00 h) has been revealed to significantly increase (p=0.01) compared with the corresponding value in the Sleep-Sleep session. This effect was weaker at their usual waking time 32:00 h (p=0.07), and disappeared until 36:00 h (4 hours after awakening). The circadian rhythm phases (dim light melatonin onset time) were coincident between the 2 sessions.

CONCLUSIONS

The present findings suggest that one night TSD induces an acute and transient increase in NK cell activity that is not influenced by the effects of circadian rhythm or the amount of physical exercise undertaken during TSD.

[Influences of uncommon isoenzymes on determination of alkaline phosphatase activity by dry-chemistry analyzers]

Dry-chemistry(DC) analysis may be influenced by some matrix effects for measuring uncommon isoenzyme forms. Placental and intestinal alkaline phosphatase(AP) are overestimated by the VITROS DC, compared with results obtained with the wet-chemistry(WC) method of Bretaudiere, et al. using 2-amino-2-methyl-1-propanol (AMP) buffer, however, no such discrepancy between AP results in any DC method and that with a routine WC method recommended by Japanese Society of Clinical Chemistry in that 2-ethylaminoethanol(EAE) buffer is used, has been demonstrated. The type of buffer used affects differently the rates of AP isoenzymes activities. We therefore examined whether the presence of uncommon AP isoenzyme forms in serum caused aberrant DC results for AP in comparison with a routine WC method using EAE buffer. Here, serum samples with only liver AP and bone AP(n : 32); high-molecular-mass AP(n : 11); placental AP(n : 12); intestinal AP(n : 13) and immunoglobulin (Ig) bound AP(n : 12) were analyzed for total AP activity on three different DC analyzers: VITROS 700XR, FUJIDRYCHEM 5000, SPOTCHEM 4410 and a WC analyzer: HITACHI 7350. Values obtained in all of the DCs for sera containing only liver/bone AP agreed with those with the WC method. For sera containing placental AP, the VITROS values were higher than those with the WC method, while the FUJIDRYCHEM values and the SPOTCHEM values were lower. The VITROS values and the FUJIDRYCHEM values for sera containing intestinal AP were lower than those with the WC method, while the SPOTCHEM values were higher. All of the DCs did not affect high-molecular-mass AP and Ig bound liver/bone AP types of macro AP, but underestimated Ig bound intestinal type. Ig bound intestinal AP may be sieved by DC multilayer elements.

[Evaluation of direct identification testing from positive blood culture bottles with MicroScan rapid identification panels]

We evaluated the direct identification method from growth-positive blood culture bottles using MicroScan Rapid ID panels (DADE BEHRING) for the purpose of rapid identification. The inoculum for Rapid ID panels were prepared using an isolation method from blood culture bottles by VACUTAINER (BD). McF 1.0 had a better result than McF 0.5 as the inoculum concentration for Rapid ID panels. Rapid ID panel identification results were effected by blood contamination for > or =0.3% of S. aureus and 0.9% of a strain of E. coli. Blood contamination from the bottle may cause an issue to the identification results. The accuracy of this direct identification testing was 72.0% (36 out of 50) for gram positives organisms and 88. 9% (80 out of 90) for gram negatives organisms. Although some strains including S. pyogenes, coagulase-negative staphylococci and non-Fermentative Gram Negative Rods had not identified correctly, this method provides a preliminary result within 3 hours and provides a fast turn around time. In conclusion, this method was considered as an effective method for routine testing.

Melatonin secretion rhythm disorders in patients with senile dementia of Alzheimer's type with disturbed sleep-waking

BACKGROUND

There is growing evidence that the dysregulation of circadian rhythms may play an important role in irregular sleep-waking in demented elderly. In this study, we investigated daily variation of the pineal hormone melatonin, which has been reported to possess hypnogenic and synchronizing effects, in patients with senile dementia of Alzheimer's type.

METHODS

Serum melatonin secretion rhythms in inpatients with senile dementia of Alzheimer's type (SDAT group, n = 10, average age = 75.7 years) with disturbed sleep-waking and nondemented elderly (ND group, n = 10, age = 78.3 years) without clinical sleep disorders in the same facility were monitored under a dim light condition without excessive physical exercise.

RESULTS

The SDAT group showed a significantly higher degree of irregularities in actigraphically recorded rest-activity (R-A) rhythm during the 7-day baseline period compared with the ND group. The SDAT group simultaneously showed significantly reduced amplitude, larger variation of peak times, and diminished amount of total secretion in the melatonin secretion rhythm compared with the ND group. There were significantly positive correlations between the severity of R-A rhythm disorder and the reduced amplitude as well as diminished amount of total melatonin secretion.

CONCLUSIONS

The SDAT patients with disturbed sleep-waking possessed melatonin secretion rhythm disorders that may play an important role in irregular sleep-waking in demented elderly.

[Effect of macro-creatine kinase in serum on dry chemistry methods results for total creatine kinase activity]

Most enzymes in serum that are measured in clinical laboratories can occur in macro-molecular forms in a significantly number of patients. Within dry chemistry (DC) multilayer film, physical barriers may prevent contact macro-molecular enzyme forms with the active reagent ingredients. Here, serum samples with macro-creatine kinase (macro-CK) type 1: CK-immunoglobulin complex or type 2: oligomer mitochondrial CK (CKm) were analyzed for total CK activity on three different DC analyzers: VITROS 700XR, FUJIDRYCHEM 5000, SPOTCHEM SP4410 and a classic wet chemistry (WC) analyzer: HITACHI 7350. Macro-CKs were detected and identified by electrophoresis on cellulose acetate. Serum with high amounts of oligomer CKm gave CK values by all of DC methods significantly lower than that by the WC method (p < 0.05). Oligomer CKm gradually converts into monomer forms in serum after storage. With increase in day after storage at 4 degrees C, there was a gradual shift in which percent of total CK activity for oligomer CKm decreased while the ratio of total CK activity, DC method/WC method increased. The principle of analytical method for CK activity determination is commonly to all of the DC methods, the WC method and the electrophoretic analysis. These suggest that oligomer CKm is sieved by DC multilayer film elements. In contrast, each of DC method produced highly corrected CK activities for sample containing CK-immunoglobulin complex. This difference in the effects of macro-CKs may depend upon physicochemical characteristics of analytical DC elements.

Determination of uric acid in scalp hair for non-invasive evaluation of uricemic controls in hyperuricemia

The uric acid concentration in blood has been widely accepted as a diagnostic indicator of hyperuricemia and gout, and its assay method is well established. In the present study, we developed a simple and rapid method for the determination of uric acid in hair, which can be obtained non-invasively. The concentration (nmol/mg hair) of uric acid extracted from 10-20 mg hair with 0.1 M potassium hydroxide was determined by an enzymatic method using uricase. The concentration of uric acid (nmol/mg hair, mean+/-S.D.: 0.49+/-0.157, n=16) in hair from hyperuricemic patients was significantly higher than that (0.26+/-0.107, n=8) in healthy volunteers (p<0.01). The within-run and between-day precision (CVs) of the assay was 9.6-10.3% (n=10 each) and 11.6-16.3% (n=7 each), respectively. The concentration (nmol/mg hair, y) of uric acid in hair correlated well with that in serum (mg/l, x): y=0.09x-0.12 (r=0.75, Syx=0.122, n=23). Changes in the concentration of uric acid in the hair of antihyperuricemic drug-treated patient paralleled that in serum, suggesting that the concentration of uric acid in hair is a reliable indicator of the metabolic control in hyperuricemia.

Preparation of useful synthetic intermediates of Taxol analogs, cyclooctenone derivatives

Stereoselective syntheses of omega-(alpha-bromoketo) octanals and nonanal with oxygenated functions and formation of the corresponding eight-membered carbocyclic aldols by subsequent samarium(II)-mediated cyclization are demonstrated. Cyclooctenones deoxygenated at the C2 or C10 position in the taxane framework are prepared by dehydration of the above aldols.

[Determination of uric acid in scalp hair for non-invasive estimation of uricemic control in hyperuricemia]

Uric acid in blood has been widely accepted as a reliable indicator of hyperuricemia and gout, and its assay method has been established. In the present study, we developed a simple and non-invasive rapid method for the determination of uric acid in hair. Concentration(nmol/mg hair) of uric acid extracted from 10-20 mg of hair(95% < extractability; 0.1N KOH, 37 degrees C, 2 hr) was determined by an enzymatic method using uricase. The concentration of uric acid(nmol/mg hair, mean +/- SD: 0.489 +/- 0.157, n = 16) in hair from hyperuricemic patients was significantly higher than that(0.258 +/- 0.107, n = 8) from healthy volunteers(p < 0.01). Within-run and between-day precisions(reproducibilities, CVs) for the assay were 9.6-10.3%(n = 10 each) and 11.6-16.3%(n = 7 each), respectively. The concentration(y, nmol/mg hair) of uric acid in hair correlated well with that in blood(x, g/l): y = 8.770x-0.123(r = 0.746, Syx = 0.122, n = 23). Changes in the concentration of uric acid in hair of hyperuricemic patient treated with allopurinol paralleled to those in blood. In conclusion, it was confirmed that the concentration of uric acid in hair reflected that in blood, suggesting that measuring uric acid in hair can be available for the metabolic control in hyperuricemia.

[The ABO blood groups-dependent reference intervals for serum alkaline phosphatase isozymes and total activity in individuals 20-39 years of age]

Reference intervals of the activity of serum alkaline phosphatase isozymes (AP-IZ: high molecular-, liver-, bone- and intestinal-types) were determined according to the ABO (blood type) system in 200 healthy subjects aged 20-39 years. AP activity was determined according to the JSCC method. AP-IZ was stained by the formazan method after isolation by TITANIII-Lipo plate electrophoresis. For the electrophoresis, treated serum with neuraminidase and untreated one were concomitantly used for detecting liver AP and bone AP respectively. As a result of comparison of mean AP-IZ activity among the groups divided according to the ABO system, total AP, intestinal AP and liver AP activities in the type B and O persons were significantly higher than in the type A and AB persons. It is well known that the activities of total AP and intestinal AP in type B and O persons are higher than in type A and AB persons, but there have been no reports showing that the activity of liver AP in type B and O persons is higher than in type A and AB persons. Furthermore, in the type B and O persons there was a low correlation (r = 0.195, p < 0.05) between the activities of liver AP and intestinal AP. The present assessment included subjects in the age group (20-39 years) considered not to show fluctuations in the activity of bone AP, which is influenced by age. The above findings should be investigated in regard to other age groups.

[Modification of enzyme molecules due to naturally-occurring immunoglobulins linking]

The appearance of circulating enzyme-linked immunoglobulin complexes (E-Ig), that are thought to be formed because of specific interaction between circulating immunoglobulins and normal serum isoenzymes. The presence of E-Ig in an individual is regarded as a benign phenomenon, although the presence of E-Ig may result in altered enzyme activity in serum and interfere with the measurement of isoenzymes, and is thus of diagnostic importance. The present paper deals with the isoenzyme specificities of immunoglobulins isolated from E-Igs and electrophoretically abnormal enzyme components due to E-Igs. The immunoglobulins react with a single isoenzyme, certain isoenzymes only or all the isoenzymes of a given enzyme. E-Igs thus formed are themselves heterogeneous, giving rise to many different electrophoretically abnormal enzyme components.

[Serum IgD concentrations in normal individuals 20-39 years of age]

Immunoglobulin D(IgD) concentration in serum of normal individuals varies widely, and the reference interval for the concentrations remains to be defined. In the present study, IgD concentrations were determined in serum from 637 normal individuals 20-39 years of age by the latex nephelometric immunoassay. The IgD concentrations ranged from < 0.20 to 71.5mg per deciliter, and the median and the 95% range as reference intervals were 1.99 and < 0.20 to 17.3mg/dl, respectively. There was difference of serum IgD concentration between female 20-29 years of age and female 30-39 years of age (p < 0.05), but not on sex. The correlation between serum IgD concentration and serum IgA concentration was significant (p < 0.001).

The first report of a case with acute myocardial infarction showing familial deficiency of creatine kinase

A 46-year-old male patient was diagnosed as suffering from acute myocardial infarction, but his serum creatine kinase (CK) level was extremely low and no CK isozymes were detected in the serum. The total CK activities in the skeletal muscle amounted to only 2% of that of the control. Electrophoresis of the CK isozymes in the skeletal muscle showed that CK-MM was absent but the CK-BB and abnormal isozyme bands were present. There was no evidence of myocardial ischemia, although the exercise treadmill test revealed ST segment depression in the chest leads. One of the patient's sisters had an extremely low serum CK level suggesting inheritance of this abnormality. This is the first report of a case showing familial deficiency of CK.

Separation and characterization of sialic acid-containing salivary-type amylase from patients' sera with immunoglobulin A-type myeloma

Isoamylases, with an abnormal anodic migration, were detected by an electrophoretic technique in the sera from two patients with immunoglobulin A-type myeloma. The abnormal isoamylase bands migrate towards the anode faster than the salivary isoamylase (S2) band and were stained more strongly than the S2 sub-band. The abnormal isoamylase could be separated from patients' sera by using size-exclusion high-performance liquid chromatography. The serum abnormal isoamylases were showed to be sialic acid residues containing amylase, after the study of treatment with neuraminidase (EC 3.2.1.18), and to be salivary-type amylase, after the study of reaction with human salivary monoclonal antibody. The abnormal bands were not detected in the saliva from one patient. The two patients had no detectable malignancies except myeloma. These findings strongly suggest that the sialic acid-containing salivary-type amylases were produced ectopically from myeloma cells. In this regard the ectopic amylase production by myeloma cells is discussed.

Electrophoretic analysis of enzyme-linked immunoglobulins and their clinical significance

The appearance of circulating enzyme-linked immunoglobulin complexes (E-Ig) is common for most enzymes used in clinical biochemical tests. The presence of E-Ig may result in altered enzyme activity in serum and interfere with the measurement of isoenzymes, and is thus of diagnostic importance. E-Ig can be identified by confirming that the binding protein is an immunoglobulin by its reaction with specific anti-human immunoglobulin antibodies. Currently, the presence of E-Ig in an individual is regarded as a benign phenomenon, not indicative of any particular disease process. However, it is becoming clear that E-IgG are closely associated with autoimmune states.

Enzyme-linked immunoglobulins and their clinical significance

Most of the enzymes used in routine biochemical tests have been detected in circulating enzyme-linked immunoglobulin (Ig) complexes (E-Ig). The complexes often cause unexplained hyperenzymemia and give anomalous patterns on isozyme electrophoresis. However, E-Ig does not appear to be associated with any pathological conditions. The present study was undertaken to determine the clinical characteristics of patients with E-Ig. More than 42,000 patients selected at random and 10,000 blood donors were screened for lactate dehydrogenase (LDH)-linked Ig complexes (LDH-Ig), amylase (Amy)-linked Ig complexes (Amy-Ig), alkaline phosphatase (AP)-linked Ig complexes (AP-Ig) and creatine kinase (CK)-linked Ig complexes (CK-Ig). LDH-Ig and Amy-Ig were screened by electrophoresis for routine isozyme analysis and identified by precipitin reactions. AP-Ig and CK-Ig were screened and identified by counter immunoelectrophoresis. The incidence of all E-Ig ranged from 0.18% to 0.61% in patients and from 0.03% to 0.23% in blood donors. The incidence curves of E-Ig were age-related, generally increasing with age. The curves of E-IgG's for different enzymes resembled each other in shape but those of E-IgA's did not. A positive correlation between E-IgG and autoimmune diseases was present. Consequently, it is concluded that both autoimmune diseases and age are the common clinical factors involved in E-IgG. No specific diseases were found for cases with E-IgA. However, it is suggested that some CK-IgA, but not all, is caused by elevated serum CK activity.

[Urinary excretion of cadmium, copper and zinc in workers exposed to cadmium]

Changes in urinary cadmium, copper and zinc excretion in workers who had considerable exposure to cadmium oxide fumes were investigated over a 5-year period following the cessation of exposure. The 22 male subjects aged 22 to 55 had been welders on automobile parts for periods ranging from 7 months to 23 years, using silver solder which contained cadmium. They were divided into three groups according to levels of urinary cadmium in the first medical examination in 1975: 5 in the high excretion group, 11 in the moderate group, and 6 in the low group. Renal tubular dysfunctions were indicated in most workers in the high excretion group but not in the other two groups. The high and moderate groups showed a rapid decrease in the levels of urinary-excreted cadmium, with biological half-times of 1.42 and 1.21 years, respectively. Excreted cadmium levelled off in the two groups about 1.7 and 1.5 years after the last exposure. Urinary copper excretion in the high cadmium excretion group was about twice that in the moderate and low groups, the difference being statistically significant in comparison with the controls. Urinary zinc excretion was high in all subjects immediately after cessation of exposure but decreased rapidly. After three years it was found that the reduction of urinary zinc was greatest in the high cadmium group. Urinary cadmium showed significant correlations with both copper and zinc. Urinary copper showed a negative correlation with zinc excretion in the high cadmium excretion group and a significant positive correlation in the other two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

[Pulmonary functions observed by means of flow-volume curve in welders exposed to ozone (author's transl)]

Pulmonary functions were observed by the flow-volume curve method on 68 healthy welders who had been exposed to comparatively high levels of ozone while engaged in arc welding process shielded by inert gas. The welders between 20 and 29 years of age were selected as subjects and classified into five groups according to ozone concentrations of the workshops. Results of pulmonary function tests were analyzed with reference to working experiences, dust concentrations of the workshops, smoking habits and air pollution levels of the location of factories. An attempt were made to evaluate the possible effects of prolonged exposure to ozone produced by welding upon the health or workers. The results obtained were as follows. 1. Values of both peak flow rate and maximum expiratory flow rate at 75% of vital capacity (V75) were decreased slightly in welder groups, but relationships between the observed values and ozone concentrations were not recognized. 2. Values of maximum expiratory flow rate at 25% of vital capacity (V25) of welders who had been exposed to ozone in concentration of 1.05 ppm or more were decreased significantly compared with groups exposed to ozone under 1.05 ppm. 3. In addition, values of both V25 and forced vital capacity (FVC) of the workers who had been engaged in welding for 4 years or more were significantly lower than those of the workers for less than 4 years of exposure. However, the relationship between the lung function values and smoking habits were not significant in both groups. 4. The decreases in V25 values were observed in several workers who had been exposed even to 0.46 ppm or higher (but under 1.05 ppm) ozone concentrations. 5. Relationships between the lung function values and either smoking habits or air pollutant levels of locations were not significant in all groups.

[Experimental pneumoconiosis induced by cemented tungsten and sequential concentrations of cobalt and tungsten in the lungs of the rat (author's transl)]

Experimental pneumoconiosis was induced by intratracheal injection of dusts of presintered cemented tungsten carbide, G2 (WC : Co=98 : 2) and TX20 (WC : Co : TiC : TaC=64 : 16 : 6 : 14) into the lungs of rats in order to document the pathological changes in lung tissues associated with environmental cobalt and tungsten. The following results were obtained. 1) Six months after the administration of G2 and TX20 dusts, marked fibrotic foci were noted and tungsten was detected in the lung tissues of all of the experimental animals. 2) Twelve months after the administration of both dusts, both the fibrotic changes and the tungsten levels were reduced in both test groups, but the reduction was more notable in the G2 group. The cases with fibrotic changes were relatively concomitant with the cases in which tungsten was detected. 3) On examination of tissue levels of cobalt derived from the dust, the cobalt levels in the lungs and bone tissues were less influenced by the dust of the G2 group at any point of investigation, whereas only the pulmonary cobalt levels at six months after the administration of the TX20 group showed a remarkable influence from the dust cobalt (p less than 0.01). 4) In the cases where tungsten was detected six months after the administration of both groups and twelve months after the administration of the TX20 group, pulmonary cobalt levels had not reached the value that should have been gained by the addition of expected values (dust cobalt levels calculated from the tungsten levels) to the control values. 5) The above results indicate that both G2 and TX20 dusts induced marked fibrotic changes in rat pulmonary tissues. However, these changes were reversible to some extent. In addition, a portion of the dust cobalt was dissolved in the body fluid and disappeared from the pulmonary fields.