Disoriented collagen fibers and disorganized, fibrotic orbicularis oris muscle fiber with mitochondrial myopathy in non-syndromic cleft lip.

OBJECTIVE: This study aims to explore and compare the histopathology of upper cleft lip tissue in order to identify the abnormalities and orientation of muscle and collagen fibers in patients affected with non-syndromic cleft lip with or without cleft palate (NSCL±P) and normal controls. MATERIALS AND METHODS: Eight fresh lip tissues of consented patients with NSCL±P and two controls were fixed and stained with hematoxylin and eosin (H&E), Masson's trichrome (MT), and modified Gomori trichrome techniques. The images were captured and examined using imaging cellSens software (Olympus, Tokyo, Japan) and Mirax Scan (Carl Zeiss, Germany). The H&E stained tissues were analysed for muscle fiber size using image processing program (imageJ, USA). Histopathological appearance of epidermal and dermal layers including collagen orientation, as well as muscle fibers abnormalities were observed. RESULTS: Tissues stained with H&E exhibit pseudoepitheliomatous hyperplasia, epidermal and sebaceous glands hyperplasia. Morphometric analysis of muscle fibers showed the diameter was between 6.912 and 10.246 µm. Collagen fibers were densely packed in cleft tissue, but muscle fibers were sparse in MT stain. Modified Gomori trichrome stain revealed hypoplastic muscle with fibrosis, including ragged red fibers. CONCLUSION: Disoriented collagen fibers, significant sparse and disorganized orbicularis oris muscle fibers with classical myopathic appearances proved that cleft tissue had abnormal histology findings. These findings further support the mechanism of collagen and muscle fibers during embryonic development that causing cleft formation.

Mitochondrial diseases.

Mitochondrial disorders represent a major challenge in medicine. Most of the mitochondrial proteins are encoded by the nuclear DNA (nDNA), whereas a very small fraction is encoded by the mitochondrial DNA (mtDNA). Mutations in mtDNA or mitochondria-related nDNA genes can result in mitochondrial dysfunction. The disease usually affects multiple organs in varying locations and severity; however, there are some forms which affect a single organ. The diagnosis of mitochondrial disorders is based on clinical examination, biochemical and histopathologic examinations, functional studies, and molecular genetic testing. Neuropathologic alterations of the muscle are variable and can range from striking abnormalities, such as cytochrome oxidase-negative and ragged red fibers, to nonspecific or minimal changes. Neuropathologic alterations in the brain show common features in disorders with different genetic background. These are characterized by various degrees of vacuolation in the white and gray matter, regional neurodegeneration with reactive astrogliosis, loss of oligodendrocytes, presence of macrophages and microgliosis, capillary proliferation, and mineralization of vessel walls. The advent of molecular genetics, the discovery of biomarkers and new sequencing platforms to perform targeted exome and whole-genome sequencing have changed traditional approaches to diagnose mitochondrial diseases.

Muscle biopsy findings in a child with NALCN gene mutation.

Mutation in NALCN (Sodium leak channel, non-selective) gene in humans has been shown to present with a wide spectrum of clinical manifestations including neurodevelopmental impairment, hypotonia and congenital contractures. Distinctive features including episodic ataxia and neuroaxonal dystrophy have also been reported. In this case report, we describe the muscle biopsy findings of a 3-year-old boy who presented with congenital arthrogryposis, hypotonia and developmental delay who has a heterozygous de novo C.965T>C (p.1332T) variant in the NALCN gene found by expanded whole exome sequencing (WES). Distal arthrogryposis and ulnar deviation of hands were prominent findings, which have been shown to be associated with de novo heterozygous mutations in this gene. He also presented with brief paroxysmal episodes of tremulousness; however, he has not clearly had episodes of episodic ataxia. Initial work-up including extensive genetic and metabolic tests was normal except for mildly elevated multiple metabolites in urine, suggestive of mild dysfunction of multiple mitochondrial enzymes. Muscle biopsy findings revealed ragged red fiber changes on trichrome staining and an increased number of mitochondria with non-specific crystalloid like inclusions ultrastructurally. The biochemical and muscle biopsy findings are suggestive of a possible mitochondrial bioenergetic dysfunction. The association of NALCN gene with secondary mitochondrial dysfunction remains unclear.

Mitochondrial diseases with the main manifestations of cardiomyopathy and respiratory muscle damage / 中华实用儿科临床杂志

Objective The 3243A ＞ G mutation in mitochondrial DNA is a common cause of the classical mitochondrial diseases characterized by neuro-muscular disorders.This study reports a rare case with the main manifestations of mitochondrial disease in children of mitochondrial cardiomyopathy and respiratory muscle damage.Methods The clinical characteristics,diagnosis and treatment,biochemical,pathological and genetic features of a 10-year-old girl were studied.Results The girl was admitted because of heart failure and respiratory failure at the age of 10.Ragged red fibers in skeletal muscles had been noticed.On her mitochondrial gene,3243A ＞ G mutation,Leu tRNA (UUR),was detected.The mutation rate in the peripheral blood cells was 94％.After the treatment with a high dose of creatine phosphate sodium,coenzyme Q10 and L-carnitine with assisted ventilation,the patient improved rapidly.The child was followed up for 2 years without recurrence.Meanwhile the growth,development and daily life were normal.Conclusions Cardiac and respiratory muscle impairments that appeared at the same time as the first manifestations of the children's mitochondrial disease is not common,and it is rare to have cardiomyopathy based mitochondrial gene 3243A ＞ G mutation is seldom seen clinically.Skeletal muscle biopsy and genetic test is the key for accurate diagnosis.Improving mitochondrial metabolism and assisted ventilation appear to be helpful treatments.

Localization of exogenous DNA to mitochondria in skeletal muscle following hydrodynamic limb vein injection.

Mitochondrial genetic disorders are a major cause of mitochondrial diseases. It is therefore likely that mitochondrial gene therapy will be useful for the treatment of such diseases. Here, we report on the possibility of mitochondrial gene delivery in skeletal muscle using hydrodynamic limb vein (HLV) injection. The HLV injection procedure, a useful method for transgene expression in skeletal muscle, involves the rapid injection of a large volume of naked plasmid DNA (pDNA) into the distal vein of a limb. We hypothesized that the technique could be used to deliver pDNA not only to nuclei but also to mitochondria, since cytosolic pDNA that is internalized by the method may be able to overcome mitochondrial membrane. We determined if pDNA could be delivered to myofibrillar mitochondria by HLV injection by PCR analysis. Mitochondrial toxicity assays showed that the HLV injection had no influence on mitochondrial function. These findings indicate that HLV injection promises to be a useful technique for in vivo mitochondrial gene delivery.

Epilepsia partialis continua in mitochondrial dysfunction: Interesting phenotypic and MRI observations.

An 11-year-old girl manifested with photophobia, ptosis, external ophthalmoplegia, hypotonia, weakness of proximal limb muscles, hyporeflexia, and generalized seizures (six months). Her elder sister had had uncontrolled seizures and photophobia and died at seven years of age. In the patient, serum lactate was high (55 mg/dl). Muscle biopsy revealed characteristic ragged red and ragged blue fibers, diagnostic of mitochondrial cytopathy. Sequencing of the complete mitochondrial genome of the DNA obtained from the muscle biopsy of the patient did not show any characteristic mutation. Four months later, the girl was admitted with a one-week history of epilepsia partialis continua (EPC). EEG revealed Periodic Lateralized Epileptiform Discharges (PLEDs), once in 2-4 seconds, over the right temporo-occipital leads. MRI revealed signal change of right motor cortex, which had restricted diffusion. MR spectroscopy (MRS) from this region revealed lactate peak. EPC remained refractory to multiple anti-epileptic drugs, immuno-modulators, coenzyme-Q, and carnitine. This thought provoking report expands the spectrum of mitochondrial cytopathies.

Kearns-Sayre Syndrome: 3 Case Reports and Review of Clinical Feature

Kearns-Sayre syndrome, first described by Kearns and Sayre in 1958, is a rare disorder consisting of ptosis, limited movement of both eyes and atypical retinal pigmentary change (salt-pepper like appearance). Most cases have shown an increase in the concentration of mitochondria and ragged-red fiber under Gomori-trichrome staining on muscle biopsy. Occasionally, it is combined with other neurologic and endocrinologic symptoms such as ataxia, dementia, diabetes, and hyperaldosteronism. We recently experienced three cases of male teenaged patients who expressed the clinical features of Kearns-Sayre syndrome.

Pathologic Findings of Mitochondrial Myopathy

Mitochondrial myopathy (MM) has been applied to muscle disease in which mitochondria have abnormal structure, function or both. To characterize the pathologic findings of MM, we examined the ultrastructural and histochemical findings of 24 cases of MM. The ultrastructures of the MM were characterized by abnormal mitochondria in number (pleoconia) and size (megaconia), and showed predominant accumulation of mitochondria in the subsarcolemmal space of myofibers in all cases. Mitochondria contained abnormally shaped cristae (concentric form and gyriform) in 79% of cases. Paracrystalline inclusion which was known to be a characteristics of MM were seen only in 7 cases (29%). Electron dense deposits were more frequently found (77%) in abnormal mitochondria of chronic progressive external opthalmoplegia and Kearn-Sayre syndrome. But, other findings were not specific for the specific clinical entities. On succinate dehydrogenase (SDH) stain, ragged red fibers (RRF) showed more intense positivity than modified Gomori-trichrome stain and definite strong reactive products were present along the periphery of myofibers which showed normal findings on modified Gomori-trichrome stain. In conclusion, ultrastructural findings such as mitochondria showing pleoconia with megaconia, and bizarre shaped cristae may be helpful for the diagnosis of MM and SDH stain is more useful for identification of RRF than modified Gomori-trichrome stains.

A Case of Kearns-Sayre Syudrome

Kearns-Sayer syndrome, a rare mitochondrial disorder, is composed of chronic progressive external ophthalmoplegia, atypical retinal pigmentation and complete heart block, and also causes numerous neurologic or endocrinologic symptoms. On muscle biopsy, a "ragged red fiber" was seen with Gomori trichrome stain, On electron microscopy, aggregations of abnormal mitochondria were demonstrated, confirming the diagnosis of mitochondrial myopathy. We report a case of Kearns-Sayer syndrome we have experienced.

A Case of Chronic Progressive External Ophthalmoplegia

Chronic progressive external ophthalmoplegia(CPEO) is rare syndrome, which is characterized by slowly progressive blepharoptosis, paralysis of extraocular muscle and has involvement of other organs, particularly the retina, heart, endocrine gland, and bony skeleton. Histological examination of muscle showes characteristic ragged red fibers. Electron microscopy reveals a number of abnormal mitochondria which contain paracrystalline inclusion bodies. We experienced a 50-year-old female with CPEO, that was pathologically proven by electron microscopy and bilateral levator levator advancements were given for ptosis.

Clinical Manifestations of Mitochondrial Diseases

According to the recently published reports about mitochondrial diseasbl the clinical manifestations are more various than expected. There have been no clinical studies covering whole spectrum of mitochond7iral disease except a few case reports in our country. The authors performed this studies to understand the various clinical and laboratory findings of mitochondrial disease and the usefulness of current tools for the diagnosis of mitochondrial diseases. We reviewed retrospectively the clinical, laboratory and pathologic findings of mitochondrial disease. The diagnosis of mitochondrial disease was based on clinical manifestations, 'ragged-red fiber' in Gomori stainging, and/or abnormal mitochondrial morphologies on electron microscopy. Twenty one patients were diagnosed as mitochondrial disease. Their clinical diagnosis included 7 MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes); 3 MERRF (myoclonic epilepsy with ragged red fibers); 2 KSS (Kearns-Sayre syndrome); 7 CPEO (chronic progressive external ophthalmoplegia); and 2 mitochondrial myopathy. The usefulness of electrodiagnostic studies, such as EMG, NCV and FEG, were limited in some patients. The muscle biopsy showed ragged red fibers in 10 of 15 sampled examined. Eleven patients had abnormal serum lactic acid level. The authors found that the mitochondrial disease revealed broad clinical spectrum and clinically available diagnostic tests, such as serum lactate and light microscopic examination showed limited value. Therefore, to evaluate the mitochondrial dysfunction with systemic involvement may be desirable to depend on sensitive and specific methods including succinate dehydrogenase (SDH) staining, electron microscopy and biologic studies of mitochondrial DNA.

A case of MELAS syndrome

MELAS syndrome is a rare but distinct clinical entity belonging to a group of mitochondrial encephalomyopathies characterized by the tetrad of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes. We experienced a case of MELAS syndrome in an 8 year-old boy who showed headache, pain of the eyeball, vomiting, stroke-like episodes such as visual disturbance and dysarthria, myoclonic seizure, confusion, and walking disturbance. His serum lactate level was elevated up to 48 mg/dl. MRI findings showed high signal intensities T2-weighted image and low signal intensities in T1-weighted image in the right thalamus and parietooccipital lobe and bilateral symmetric high signal intensity in T1-dweighted image in the basal ganglia. We have seen the dispersed ragged-red fibers with modified Gomori trichrome staining on light microscope, and abundant and dysmorphic mitochondria on electon microscope in the specimen of muscle biopsy. esis of SLE.