Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0026827 (hypotonia)
 5,860 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Physiological and clinical aspects are discussed in this review on calcium-phosphate metabolism in pre-term infants. Calcium accumulation in the bone mass of the foetus is related to the gestational age, and mainly occurs during the last weeks of gestation. Therefore, after birth, hypocalcemia is more frequent in pre-term than term infants. However, clinical symptoms of hypocalcemia, e.g. attacks of apnea, hyperexcitability and hypotonia, are rarely observed. Such symptoms depend upon the serum concentration of ionized calcium and this concentration is influenced by various metabolic factors. During the first two weeks of life phosphate is elevated in comparison to later periods. In spite of sufficient vitamin D supplementation low serum phosphate levels occur due to insufficient supply of phosphate. This correlates with evidence of rickets. An increased alkaline phosphatase activity can be considered an early and sensitive indicator. Pre-term infants develop rickets more frequently than term infants due to calcium-phosphate deficiency. Vitamin D supplementation alone is insufficient and should be combined with phosphate, as had been stated previously.
 ...
PMID:[Calcium-phosphate metabolism in pre-term infants]. 685 46

Twenty pre-eclamptic mothers treated with MgSO4 and their newborn infants were studied prospectively to determine the clinical and biochemical effects of hypermagnesemia. Maternal serum magnesium concentration rose to 4.4 mg/dl at delivery and was accompanied by a fall in maternal serum calcium concentration during labor. Neonatal serum Mg concentration remained elevated for the first 72 hours of life (mean at 72 hours = 3.0 mg/dl). Serum Mg concentration was higher in premature infants and in babies with birth asphyxia and/or hypotonia. Serum Ca concentration was higher and serum PTH was lower in hypermagnesemic study infants when compared to a retrospectively selected, matched froup of control infants. We speculate that elevated serum Mg values in these infants result in a shift of Ca from bone to plasma, and that elevated Mg and Ca concentrations further suppress neonatal parathyroid function.
 ...
PMID:Neonatal hypermagnesemia: effect on parathyroid hormone and calcium homeostasis. 735 3

The clinical and radiological picture observed in a female patient with cholelithiasis urgently hospitalised for abdominal occlusion is described. Radiological examination of the digestive tract disclosed a bilio apico-bulbar fistula and ectasis and hypotonia of the jejuno-ileal loops. A large calculus composed of calcium salts and cholesterine buried in a sigmoid loop was spontaneously passed by the patient during the examination. This resulted in regression of the symptoms of pain and occlusion. Cholangiocholecystography and examination of the digestive tract 3 months later showed a normal gallbladder picture, and disappearance of the fistula.
 ...
PMID:[Unusual case of biliary ileus]. 746 6

1. The effects of some alpha-adrenergic agonists and antagonists on electrically-evoked contractions and tension of chick expansor secundariorum muscle (ESM), and dependence of these events on extracellular calcium was investigated. 2. Both train and continuous electrical stimulation can produce regular contractions in preparations obtained from 40-60 day old chicks. 3. Clonidine had a biphasic action on the contractions produced by train electrical stimulation. In concentrations ranging from 10(-8) to 3 x 10(-7) M, clonidine decreased the contraction amplitude, but in higher concentrations, it caused an increase in both the muscle tension and the contraction amplitude. These effects were reversed by application of yohimbine although yohimbine by itself had no effect on the contractions. 4. Introduction of calcium free isotonic high potassium medium decreased muscle tone which was followed by further dose-dependent increase in tension, along with the addition of cumulative doses of CaCl2 (ED50 = 2.8 x 10(-3) M). 5. Nifedipine reduced the amplitude of ESM contractions produced by continuous electrical stimulation in a dose dependent manner (IC50 = 6.7 x 10(-7) M). 6. Methoxamine induced a completely dose dependent increase in muscle tension which was dependent on extracellular calcium and was inhibited by nifedipine. In the presence of 10(-8) M nifedipine, ED50 of methoxamine stimulatory effect increased from the control value of 2.2 x 10(-7) to 8.4 x 10(-7) M).(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:The role of calcium and alpha-adrenoceptors in contractile response of chick expansor secundariorum muscle to field stimulation. 751 4

The clinical courses of 8 term infants with focal cerebral infarction or neonatal stroke were studied to determine whether such infants can be identified by current markers of perinatal distress, and whether changes in cerebral blood flow velocity (CBFV) occur during the acute phase of the disease. CBFV was measured from the middle cerebral artery (MCA) and anterior cerebral artery (ACA) utilizing duplex Doppler. Seven of the 8 patients required no resuscitation in the delivery room; 1 infant required brief bag and mask ventilation. No infant had evidence of severe fetal acidemia (i.e., cord pH < 7). All 8 infants were initially admitted to the newborn nursery. Infants were identified on the basis of abnormal clinical findings observed during the first 48 hours: seizures (n = 6) and hypotonia and apnea (n = 2). Serum electrolytes, calcium, magnesium, and glucose levels were normal, and the sepsis evaluation including a spinal tap was sterile in all patients. Neuroimaging revealed nonhemorrhagic left focal MCA infarction (n = 6) and right focal MCA infarction (n = 2). Duplex Doppler demonstrated transient ipsilateral decreases in CBFV as compared to the contralateral unaffected side at clinical presentation in 4 infants. In 2 of these infants the decrease in CBFV involved both the MCA and ACA, and in 2 infants, only the MCA vessels. These side-to-side differences were not present at subsequent CBFV measurements. The data indicate that infants who develop neonatal stroke cannot be distinguished from infants who do not develop the lesion by current markers of perinatal distress.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Neonatal stroke: clinical characteristics and cerebral blood flow velocity measurements. 770 86

A 72-year-old woman was referred to hospital for obnubilation with general muscle weakness and hypotonia. Biology showed hypocalcemia, hypophosphatemia, increased serum creatine kinase and alkaline phosphatase levels. Brain CT scan, cerebrospinal fluid examination, and electromyogram were normal. Clinical status and electroencephalogram were consistent with non-convulsive generalized status epilepticus. The treatment included clonazepam and CaCl2 and consciousness returned to normal. A treatment with multivitamin infusion containing vitamin D2 was given for 3 weeks. Muscle weakness improved partially. Serum vitamin D3 level was low and osteomalacic myopathy was diagnosed. A treatment was given with 25OH vitamin D3, 50 micrograms per day. Two months later, serum vitamin D3 and creatine kinase levels were normal and the patient could walk without help. We conclude that vitamin D status should be monitored in elderly patients with muscle symptoms and abnormal calcium status. Osteomalacic myopathy should be considered in critically ill patients with muscle symptoms of an unclear cause.
 ...
PMID:Muscle weakness in intensive care patients: initial manifestation of vitamin D deficiency. 770 75

The oculocerebrorenal (Lowe) syndrome is an X-linked recessive disorder characterized by congenital cataracts, hypotonia, developmental delay, poor growth and renal tubular dysfunction. Although the disorder has been mapped to chromosome Xq24-26, the underlying metabolic defect remains unknown. The renal component of the Lowe syndrome comprises tubular dysfunction, that is tubular proteinuria and generalized aminoaciduria progressing to the renal Fanconi syndrome, with later glomerular disease. Clinical problems typically include polyuria, acidosis, hypophosphatemia with rickets and eventually end stage renal disease. Hypercalciuria and its sequelae (nephrocalcinosis and nephrolithiasis) have not been described as cardinal features of the untreated disorder although they reportedly complicate vitamin D and calcium therapy of rickets. We discuss 5 boys with congenital cataracts, hypotonia, developmental delay, failure to thrive and the renal Fanconi syndrome who were diagnosed with the Lowe syndrome and in whom hypercalciuria was documented at diagnosis. We conclude that hypercalciuria and its sequelae may occur commonly in patients with the Lowe syndrome as a component of tubular dysfunction or a complication of therapy.
 ...
PMID:Hypercalciuria and nephrocalcinosis in the oculocerebrorenal syndrome. 786 19

To investigate whether prolonged severe swelling would cause irreversible injury to neurons, we exposed hippocampal tissue slices to hypotonic solutions (142 mosmol/kg) and followed the recovery of evoked responses for 5 h. Orthodromically evoked responses increased during hypotonia, except during recurrent waves of spreading depression (SD). After restoring normal osmotic pressure (pi o), evoked potentials became profoundly depressed. Following 30 min exposure, nearly maximal orthodromic responses recovered completely but responses to submaximal stimuli remained depressed, indicating elevated threshold. Following 60 min exposure, orthodromic transmission remained depressed. In slices from young animals, antidromic population spikes recovered completely, but in slices from older rats they remained partly depressed. Withdrawing calcium and raising magnesium concentration before and during hypotonic exposure resulted in modest but significant improvement of the recovery of synaptically transmitted responses, but made no difference for antidromic responses. With [Ca2+]o reduced and [Mg2+]o elevated, electrographic seizures replaced the episodes of SD during low pi o treatment. We conclude that even 60 min of severe hypotonic swelling did not kill CA1 pyramidal cells in tissue from young rats, but in its aftermath synaptic transmission was disrupted. Uptake of calcium may have played a minor role in the impairment of synaptic transmission. We propose hypothetically that post-hypotonic shrinkage of dendrites disrupted the integrity of excitatory synapses.
 ...
PMID:The extent and mechanism of the loss of function caused by strongly hypotonic solutions in rat hippocampal slices. 855 31

The severe neonatal centronuclear/myotubular myopathy (XLMTM) is an X-linked disorder characterized by generalized muscle weakness, hypotonia and serious respiratory insufficiency. The gene for this disease has been assigned to the long arm of chromosome X in the Xq28 band. Ca2+ ATPase isoform-3 (ATP2B3) has also been mapped to the human Xq28 region. Moreover, it is expressed in fetal but not in adult muscle, suggesting the developmental regulation of gene transcription. These findings render the ATP2B3 gene as an interesting candidate gene for XLMTM. Four families and 7 unrelated XLMTM patients have been analysed by using cDNA and genomic probes of ATP2B3. No large deletions or duplications have been found but a new EcoRI polymorphism has been identified. In addition, the DNA of an XLMTM male deletion patient has been hybridized with the ATP2B3 gene sequences. Our results therefore support the exclusion of ATP2B3 as the causal disease gene of XLMTM. The isolation of the MTM1 gene has recently been reported by another group. However, our approach has led to the detection of a new polymorphism that is an informative marker for linkage and mutation studies in other Xq28-mapped neurological or neuromuscular disorders.
 ...
PMID:Detection of a new polymorphism in the plasma-membrane Ca2+ ATPase isoform-3 gene and its exclusion as a candidate for X-linked myotubular myopathy (MTM1). 893

Hypoxia-ischemia damages selected regions of the immature at different ages. Prior to 32 weeks gestation the periventricular white matter is selectively vulnerable but in the last trimester the basal ganglia become especially vulnerable to injury. Hypoxia-ischemia causes injury by activating a series of biochemical events that unfolds over a period of hours to days following the initial insult and we are investigating the ways in which age modifies these events. The cascade includes release of glutamate, overstimulation of excitatory amino acid receptors and raised intracellular levels of calcium. Clinically this series is manifested by hypoxic-ischemic encephalopathy (HIE), a syndrome that includes coma, seizures, a burst suppression EEG, respiratory depression and severe hypotonia. Clinical studies have established a relationship between the severity of neonatal encephalopathy and later manifestations of brain damage or cerebral palsy. Potential neuroprotective therapies need to be effective when given after the insult but the 'therapeutic time window' for most N-methyl-D-aspartate (NMDA) glutamate antagonists is limited after injury. Using a model of hypoxic-ischemic injury and neonatal rats and hypothermic-circulatory arrest in dogs, we found that immunohistochemical staining for neuronal nitric oxide synthase (nNOS) is markedly increased from 6 to 24 h after the insult in the basal ganglia and cortex. The induction of nNOS preceded the time of maximal neuronal necrosis and during the time when many apoptotic nuclei were appearing. We have also found that a brief period of 2 h of mild hypothermia (32 degrees C) following hypoxia-ischemia in neonatal rats delayed neuronal necrosis by more than a week. We are determining whether this delay is related to a change in nNOS activation. Induction of nNOS in the post-insult period may contribute to expression of injury and signs of encephalopathy following a hypoxic-ischemic insult.
 ...
PMID:Hypoxic and ischemic disorders of infants and children. Lecture for 38th meeting of Japanese Society of Child Neurology, Tokyo, Japan, July 1996. 918 71


<< Previous 1 2 3 4 5 6 7 8 Next >>