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Biomedical subjects

H M Meinck

Publications and source records attributed to H M Meinck.

At least 55 records · Page 3Linked to original sources
PubMed1997

Antibodies to the tyrosine phosphatase-like protein IA-2 are highly associated with IDDM, but not with autoimmune endocrine diseases or stiff man syndrome.

Antibodies to the 40 kD antigen (identified as tyrosine phosphatase IA-2) and glutamate decarboxylase (GAD65) are strongly associated with insulin dependent diabetes mellitus (IDDM). However, antibodies to GAD (GADA) can appear in the absence of IDDM, particularly in stiff man syndrome (SMS) and in some individuals with autoimmune polyendocrine syndrome type II (APS II) and organ specific autoimmune diseases. The aim of this study was to compare the specificity of IA-2 antibodies (IA-2A) and GADA for IDDM by determining their frequency in different patient groups. IA-2A were present in 64/114 (56%) IDDM patients and 9/19 (47%) APS II patients with IDDM but in only 4/28 (14%) SMS patients. 1/24 (4%) APS II patients without IDDM and 1/113 (0.9%) patients with organ specific autoimmune disease had low level IA-2A. In contrast GADA were present in 77/114 (68%) IDDM patients and 17/19 (89%) APS II patients with IDDM, but also in 25/28 (89%) SMS patients, 5/24 (21%) APS II patients without IDDM and 22/113 (19%) patients with organ specific autoimmune diseases. Furthermore, within the group of new onset IDDM, IA-2A seemed to be associated with ICA and age: 63% of ICA positive IDDM patients had IA-2A (74% had GADA) increasing to 77% in the group below 20 years of age (69% for GADA). Our results demonstrate that IA-2A may be more specific for IDDM than GADA, as the latter are also present in patients with SMS, APS II without IDDM and organ specific autoimmune diseases. IA-2A were less frequent in older patients with IDDM than GADA or ICA. A combination of IA-2A and GADA detected 84% of total and 93% of ICA positive IDDM patients.

Adolescent↗
PubMed1996

"Sunbath polyneuritis": subacute axonal neuropathy in perazine-treated patients after intense sun exposure.

This article aims at drawing attention to the peculiar association of intense exposure to sunlight and subacute development of sensory neuropathy which was seen in 7 psychiatric patients treated with the phenothiazine derivative, perazine. Three patients additionally developed bilateral VII nerve palsy. Symptoms followed a monophasic course with almost complete remission. Routine neurophysiology suggested axonal neuropathy confirmed by sural nerve biopsy in 1 patient. A toxic origin of neuropathy is supposed, possibly induced by phenothiazine photoproducts, which may cause cell damage via lipid peroxidation.

Adult↗
PubMed1996

Köbberling-Dunnigan syndrome: a rare cause of generalized muscular hypertrophy.

A 36-year-old woman presented with muscle hypertrophy (particularly of the calves) since puberty, occasional muscle cramps, a musculine habitus, and a loss of subcutaneous fat on limbs and trunk sparing her face, neck, and vulva. Multiple lipomas were found on her trunk, and acanthosis nigricans on her neck. Laboratory testing revealed hyperlipidemia and pathological glucose tolerance with hyperinsulinemia. Physical and laboratory findings are consistent with Köbberling-Dunnigan syndrome, a rare inherited form of lipoatrophy. The patient's mother had the same body habitus and insulin-dependent diabetes mellitus. These cases suggest that partial lipodystrophy also affects muscle and is a cause of genuine muscular hypertrophy.

Adult↗
PubMed1996

A transgenic rat model of Charcot-Marie-Tooth disease.

Charcot-Marie-Tooth disease (CMT) is the most common inherited neuropathy in humans and has been associated with a partial duplication of chromosome 17 (CMT type 1A). We have generated a transgenic rat model of this disease and provide experimental evidence that CMT1A is caused by increased expression of the gene for peripheral myelin protein-22 (PMP22, gas-3). PMP22-transgenic rats develop gait abnormalities caused by a peripheral hypomyelination, Schwann cell hypertrophy (onion bulb formation), and muscle weakness. Reduced nerve conduction velocities closely resemble recordings in human patients with CMT1A. When bred to homozygosity, transgenic animals completely fail to elaborate myelin. We anticipate that the CMT rat model will facilitate the identification of a cellular disease mechanism and serve in the evaluation of potential treatment strategies.

Animals↗
PubMed1996

Three familial cases presenting with an immobile spine. Rigid spine or Emery-Dreifuss syndrome?

A father and his two sons presented with slowly progressive muscular weakness, contractures of the spine, elbows and ankles, and cardiac conduction disturbances in the father. Clinical and histological findings are discussed in relation to the hitherto reported cases of autosomal dominant variant of the Emery-Dreifuss syndrome and the distinction from the rigid spine syndrome.

Adolescent↗
PubMed1996

Psychological factors in the diagnosis and pathogenesis of stiff-man syndrome.

Retrospective psychological evaluation of nine patients with stiff-man syndrome (SMS), seven of whom evidenced autoimmune disease, revealed a characteristic set of psychological symptoms or features: Major stressful life events preceded the development of permanent symptoms by 6 months or less (seven patients); transient motor symptoms occurred in emotionally distressing situations months or even years before the onset of a permanent motor deficit (five patients); after onset, similar situations specifically precipitated or augmented stiffness and spasms (five patients). We also found task-specific fear resembling agoraphobia (six patients) and loss or invalidation of one or both parents, or loss of home, in childhood (seven patients). Eight patients were initially misdiagnosed as having psychogenic movement disorder. We conclude that the common misdiagnosis of SMS as a psychogenic movement disorder is due to the compelling association of a set of salient psychological features, bizarre and fluctuating motor symptoms, and lack of approved neurologic signs.

Adult↗
PubMed1996

A GLRA1 null mutation in recessive hyperekplexia challenges the functional role of glycine receptors.

Dominant missense mutations in the human glycine receptor (GlyR) alpha 1 subunit gene (GLRA1) give rise to hereditary hyperekplexia. These mutations impair agonist affinities and change conductance states of expressed mutant channels, resulting in a partial loss of function. In a recessive case of hyperekplexia, we found a deletion of exons 1-6 of the GLRA1 gene. Born to consanguineous parents, the affected child is homozygous for this GLRA1(null) allele consistent with a complete loss of gene function. The child displayed exaggerated startle responses and pronounced head-retraction jerks reflecting a disinhibition of vestigial brain-stem reflexes. In contrast, proprio- and exteroceptive inhibition of muscle activity previously correlated to glycinergic mechanisms were not affected. This case demonstrates that, in contrast to the lethal effect of a null allele in the recessive mouse mutant oscillator (Glra1 spd-ot), the loss of the GlyR alpha 1 subunit is effectively compensated in man.

Alleles↗
PubMed1995

Two sisters with Escobar syndrome.

We report on 2 sisters with an autosomal-recessive multiple pterygium syndrome, type Escobar, consisting of multiple pterygia with severe contractures, short stature, and minor facial and external genital anomalies. The striking finding was severe muscular atrophy. We speculate that a neuromuscular disorder is the underlying pathogenesis of Escobar syndrome.

Abnormalities, Multiple↗
PubMed1995

Stiff man syndrome: neurophysiological findings in eight patients.

The neurophysiological findings in eight patients with the stiff man syndrome (SMS), including four of six tested with autoantibodies against glutamic acid decarboxylase, are presented. Neurophysiological findings did not make it possible to discriminate between patients with and those without autoimmunity against GABAergic neurons. Investigation of mono- and polysynaptic reflexes revealed abnormal results in a variable number of SMS patients, the abnormalities largely corresponding to those seen in spastic paresis. A stereotyped motor response to electrical stimulation of peripheral nerves was recorded from the trunk muscles of all patients investigated. This response was termed spasmodic reflex myoclonus and consisted of a sequence of 1-3 synchronous myoclonic bursts, 60-70 ms after median nerve stimulation, followed by a tonic decrescendo activity over a number of seconds. The recruitment order of muscles along the neuraxis in spasmodic reflex myoclonus suggested that the latter was generated in the spinal cord and conveyed via propriospinal tracts. It is thought that spasmodic reflex myoclonus may serve not only as a diagnostic tool, but also as a key to understanding some aspects of the pathophysiology of both spasms and stiffness in SMS. It is speculated that stiffness is a fragment of spasms, both being generated by common neuronal mechanisms tentatively ascribed to interneurons in the spinal grey matter.

Electromyography↗
PubMed1995

Masseter inhibitory reflex threshold: a novel technique for electrophysiological investigation of trigeminal nerve lesions.

The masseter inhibitory reflex was investigated in 60 healthy volunteers, in 38 patients with trigeminal nerve branch lesions in the majority due to dental surgery, and in 9 patients with facial sensory loss and weakness caused by brain hemisphere lesions. The reflex threshold (TR) was almost symmetric both in normal subjects and in the patients with hemisphere lesions. In peripheral trigeminal hypaesthesia, elevation of TR on the lesioned side proved the most sensitive electrophysiological parameter. There was, moreover, some correspondence between the degree of sensory loss in hypaesthesic skin areas and elevation of TR, and recovery from the lesion was associated with TR normalization. Supratentorial lesions, in contrast, may influence the reflex pattern rather than reflex excitability.

Adolescent↗
PubMed1995

Inclusion body myositis presenting with isolated erector spinae paresis.

We report a 70-year-old patient who presented with a 4-year history of weakness of paravertebral muscles. Electrodiagnostic studies revealed a mixed neurogenic-myopathic pattern. Light microscopic examination revealed atrophic fibers with rimmed vacuoles; electron microscopy demonstrated cytoplasmic and intranuclear filaments measuring about 16 nm in width, consistent with the diagnosis of inclusion body myositis. Therapy with corticosteroids provided only a mild and transient benefit. Ten months after the initial evaluation, clinical and electrodiagnostic examination demonstrated mild progression of the disease.

Aged↗
PubMed1994

Stiff man syndrome: clinical and laboratory findings in eight patients.

The clinical, biochemical, neuroimaging and neurophysiological findings of eight patients with stiff man syndromes (SMS) [four of six being tested with autoantibodies against glutamic acid decarboxylase (GAD)] are presented. In two patients (one GAD-positive, one GAD-negative), transient oculomotor disturbances suggested progressive encephalomyelitis with rigidity and myoclonus (PERM) as differential diagnosis. The catalogue of characteristic clinical symptoms of SMS is extended by three new symptoms: (1) an aura-like feeling reported by five patients to precede spontaneous spasmodic attacks; (2) a stereotyped motor pattern seen in seven patients during spasmodic jerks, consisting of brief opisthotonos, stiffening of the slightly abducted legs and inversion of the plantar-flexed feet; (3) a paroxysmal fear when crossing a free space unaided, or even thinking of it. Clinical findings did not enable us to discriminate between patients tested GAD-positive or GAD-negative. Cerebrospinal fluid contained elevated immunoglobulin levels or cell counts, or both, in the majority of patients. Autopsy of one patient revealed scattered lymphocyte cuffs around leptomeningeal, intracerebral and particularly intraspinal vessels, suggesting a mild inflammatory process. Whether SMS and PERM are closely related is discussed; they are possibly both manifestations of a spectrum of encephalomyelopathies having autoimmunity against GABAergic neurons in common.

Adult↗
PubMed1993

The synaptic vesicle-associated protein amphiphysin is the 128-kD autoantigen of Stiff-Man syndrome with breast cancer.

Stiff-Man syndrome (SMS) is a rare disease of the central nervous system (CNS) characterized by progressive rigidity of the body musculature with superimposed painful spasms. An autoimmune origin of the disease has been proposed. In a caseload of more than 100 SMS patients, 60% were found positive for autoantibodies directed against the GABA-synthesizing enzyme glutamic acid decarboxylase (GAD). Few patients, all women affected by breast cancer, were negative for GAD autoantibodies but positive for autoantibodies directed against a 128-kD synaptic protein. We report here that this antigen is amphiphysin. GAD and amphiphysin are nonintrinsic membrane proteins that are concentrated in nerve terminals, where a pool of both proteins is associated with the cytoplasmic surface of synaptic vesicles. GAD and amphiphysin are the only two known targets of CNS autoimmunity with this distribution. This finding suggests a possible link between autoimmunity directed against cytoplasmic proteins associated with synaptic vesicles and SMS.

Autoantigens↗
PubMed1993

[Acute myoglobinuric kidney failure in McArdle's syndrome. The diagnostic significance of 31P nuclear magnetic resonance spectroscopy].

A 44-year-old man developed acute renal failure, associated with reddish brown urine, after severe physical exertion. Since childhood his physical capacity was known to be limited. Muscular indurations, cramps and pains had occurred after muscular work. Serum creatinine level on the day before hospitalization was 10.0 mg/dl, creatine-kinase activity 3,790 U/l, lactate dehydrogenase activity 670 U/l, myoglobin level 701 ng/ml. Cause of the rhabdomyolysis was thought to be McArdle's disease (glycogen storage disease type V: abnormal skeletal muscle glycogen utilization). 31P-magnetic resonance spectroscopy, which gives characteristic spectra with anaerobic muscle work, provided the diagnosis, which was confirmed by measurement of myophosphorylase activity in a muscle biopsy (zero activity). After two dialysis sessions and alkalinization of the urine diuresis again occurred and the retention indicators fell to normal in the course of the subsequent 18 months. Creatinine kinase activity remained elevated.

Acute Kidney Injury↗
PubMed1993

Cytoplasmic islet cell antibodies recognize distinct islet antigens in IDDM but not in stiff man syndrome.

Cytoplasmic islet cell antibodies are well-established predictive markers of IDDM. Although target molecules of ICA have been suggested to be gangliosides, human monoclonal ICA of the immunoglobulin G class (MICA 1-6) produced from a patient with newly diagnosed IDDM recognized glutamate decarboxylase as a target antigen. Here we analyzed the possible heterogeneity of target antigens of ICA by subtracting the GAD-specific ICA staining from total ICA staining of sera. This was achieved 1) by preabsorption of ICA+ sera with recombinant GAD65 and/or GAD67 expressed in a baculovirus system and 2) by ICA analysis of sera on mouse pancreas, as GAD antibodies do not stain mouse islets in the immunofluorescence test. We show that 24 of 25 sera from newly diagnosed patients with IDDM recognize islet antigens besides GAD. In contrast, GAD was the only islet antigen recognized by ICA from 7 sera from patients with stiff man syndrome. Two of these sera, however, recognized antigens besides GAD in Purkinje cells. In patients with IDDM, non-GAD ICA were diverse. One group, found in 64% of the sera, stained human and mouse islets, whereas the other group of non-GAD ICA was human specific. Therefore, mouse islets distinguish two groups of non-GAD ICA and lack additional target epitopes of ICA besides GAD. Longitudinal analysis of 6 sera from nondiabetic ICA+ individuals revealed that mouse-reactive ICA may appear closer to clinical onset of IDDM in some individuals. Mouse-reactive ICAs, however, remained absent in 36% of the patients at diagnosis of IDDM.

Adolescent↗