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Biomedical subjects

R W Chun

Publications and source records attributed to R W Chun.

At least 19 recordsLinked to original sources
PubMed2001

Th1/Th2 predominance and proinflammatory cytokines determine the clinicopathological severity of IgA nephropathy.

BACKGROUND: IgA nephropathy is one of the most common forms of primary glomerulonephritis in adults. Its pathogenesis is complex. The nature of infiltrating and proliferating cells and of cellular mediators could contribute to the progression of IgA nephropathy towards end-stage renal failure. METHODS: To evaluate this hypothesis, we attempted to quantify the magnitude of intrarenal gene expression of various cytokines (IL-1 beta, TNF-alpha, IL-6, IL-15, IL-2, IFN-gamma, IL-10) and chemokines (IL-8, RANTES, MCP-1) in 48 renal core biopsy specimens, diagnosed as IgA nephropathy by immunofluorescence microscopy. Semi-quantitative reverse-transcriptase polymerase chain reaction using internal competitors was used for the quantification of gene transcripts. RESULTS: The expression of intrarenal gene transcripts of various cytokines and chemokines was closely interrelated, but not associated with the pathological grading system. The IFN-gamma/IL-10 ratio was higher in patients with renal dysfunction than in those with normal renal function (P=0.0483). Gene transcript levels of proinflammatory cytokines were related to the amount of proteinuria. In patients with severe glomerular sclerosis, the ratio of IFN-gamma/IL-10 gene transcripts was high (P=0.04). IL-10 gene transcript level was related to the severity of tubulointerstitial damage. The levels of gene expression of IL-10 (P=0.009), IFN-gamma (P=0.03), and TNF-alpha (P=0.005) were related to the degree of mesangial matrix expansion and the extent of intrarenal arteriolar changes correlated with the expression of the IL-8 gene transcript (r=0.43, P=0.004). CONCLUSIONS: We propose that Th1/Th2 predominance and the level of proinflammatory cytokines could determine the pathogenetic processes and the severity of the clinical manifestations of IgA nephropathy.

Adolescent↗
PubMed1999

La Crosse and other forms of California encephalitis.

The California serogroup viruses are mosquito viruses that cause human infections on five continents. They are maintained and amplified in nature by a wide variety of mosquito vectors and mammalian hosts; they thrive in a remarkably wide variety of microclimates (eg, tropical, coastal temperate marshland, lowland river valleys, alpine valleys and highlands, high boreal deserts, and arctic steppes). In 1993, California serogroup viruses caused 71% of all cases of arboviral illness in the United States, principally La Crosse encephalitis. The 30 to 180 annual cases of La Crosse encephalitis represent 8% to 30% of all cases of encephalitis, rendering this illness the most common and important endemic mosquito-borne illness in the USA. Subclinical or mild infections are much more common. Methods and results acquired from intense study of California serogroup viruses have been applied, with benefit, to the study of the ecology and pathogenesis of many more serious human arboviral illnesses. The evolutionary potential of viruses, with particular reference to the development of more virulent strains, has been studied more closely in the California serogroup viruses than in almost any other agent of human disease.

Animals↗
PubMed1999

The relationship between plasma leptin and nutritional status in chronic hemodialysis patients.

Leptin serves an important role in suppressing appetite in mice and is known to be elevated in chronic renal failure (CRF) patients. But clinical significance of leptin as an appetite-reducing uremic toxin, remains to be determined. So we studied the relationship between plasma leptin and nutritional status in 46 chronic hemodialysis (HD) patients. Pre HD leptin was measured and divided by body mass index (BMI) to give adjusted leptin levels. KT/Vurea (K, dialyzer urea clearance; T, duration of HD; V, volume of distribution of urea), C-reactive protein (CRP), plasma insulin and nutritional parameters such as serum albumin, normalized protein catabolic rate (nPCR), subjective global assessment (SGA), BMI and mid-arm muscle circumference (MAMC) were also measured. Mean plasma leptin levels were 8.13+/-2.91 ng/mL (male 3.15+/-0.70; female 14.07+/-6.14, p<0.05). Adjusted leptin levels were positively correlated with nPCR (male r=0.47, p<0.05; female r=0.46, p<0.05), SGA (male r=0.43, p<0.05; female r=0.51, p<0.05) and MAMC (male r=0.60, p<0.005; female r=0.61, p<0.05). They did not correlate with KT/Vurea, serum albumin, hematocrit, bicarbonate, insulin and CRP. Presence of DM and erythropoietin therapy had no effect on leptin levels. These results suggest that leptin is a marker of good nutritional status rather than a cause of protein energy malnutrition in chronic HD patients.

Adult↗
PubMed1983

Reenactment of the triggering situation for the diagnosis of epilepsy.

When a fixed set of ambient circumstances is associated with convulsive or nonconvulsive paroxysmal attacks, reenactment of the situation should be considered as a possible shortcut for reaching a diagnosis. Reenactment determined the diagnosis in 30 of 32 patients with paroxysmal disorders. The referral diagnosis was correct in only 13 of the 32 patients. To be appropriately executed, the reenactment should entail polygraphic recording of at least EEG, ECG, and respiration. Vertex electrodes should be included to avoid overlooking of cortical electrodecremental event. If unsuccessful at the first attempt, reenactment should be repeated.

Adolescent↗
PubMed1983

Clinical aspects of La Crosse encephalitis: neurological and psychological sequelae.

Only rarely will a child continue to have focal neurologic findings, such as paresis, for as long as 8 years after LAC encephalitis. Most of the other focal neurologic findings, such as Babinski reflexes, pathologic reflexes, aphasias, choreas, dysarthrias and ataxias, resolve completely. Abnormal electroencephalographic findings during the acute period were note in 86-100% of the cases. On 1-8 year follow-up, EEG abnormalities were noted in approximately 33% of the subjects tested. Seizures are present at high frequency during acute illness and recurrent seizures may occur in 6-13% of the cases 1-8 years after infection. The cognitive and intellectual functioning of children following LAC encephalitis is not significantly different from that of the normal population. As a group, LAC encephalitis victims also function in the normal range in terms of their academic performances. There are individuals, however, who will have suffered permanent destructive lesions resulting in lowered IQ and lowered school performance. Behavioral abnormalities are difficult to measure and when present, difficult to ascribe to a definitive cause.

Adolescent↗
PubMed1982

Lateral cervical meningocele.

Although lateral meningoceles have been described in the thorax, they have not been previously reported in the neck. We describe an infant who was born with a lateral meningocele in the cervical posterior triangle that was felt clinically to be cystic hygroma. Surgical excision was complicated by a cerebral spinal fluid fistula and subsequent meningitis. Problems that this patient presented and potential complications in management are discussed. Although the clinical manifestations of lateral meningoceles and extradural cysts are quite different, there are many anatomic similarities between these entities and other cervical masses that confuse diagnosis and nosology. Their differential diagnosis is reviewed.

Cervical Vertebrae↗
PubMed1982

Hypomelanosis of Ito (incontinentia pigmenti achromians)--a clinicopathologic study: macrocephaly and gray matter heterotopias.

We studied a boy with macrocephaly, hypotonia, pigmentary retinopathy, unilateral whorled hypopigmented skin lesions, and seizures. Skin biopsy confirmed the clinical diagnosis of hypomelanosis of Ito. Postmortem examination at age 22 months revealed a severe neuronal migrational defect that altered the cerebral cortex architecture of white matter. There were many gray matter heterotopias characterized by altered neurons and giant cells. Electronmicroscopy revealed the astrocytic nature of the giant cells. Embryologic migration of both melanoblasts from neural crest and cortical neurons occurs in the second trimester, suggesting a common mechanism for the developmental pathology of skin and brain.

Brain↗
PubMed1980

Familial infantile myasthenia.

Familial infantile myasthenia is a rare type of myasthenia that usually occurs in connection with respiratory depression. The condition is characterized by (1) absence of myasthenia in the mother, (2) occurrence of a similar disorder among siblings, (3) respiratory depression at birth, (4) episodic weakness and apnea during the first two years of life, and (5) improvement with age. Since the condition responds to anticholinesterase medication, early diagnosis is important. Familial infantile myasthenia is a potential cause of sudden infant death and should be considered in infants with unexplained respiratory distress.

Adolescent↗
PubMed1980

The Dubowitz syndrome: further observations.

An autosomal recessive disorder characterized by intrauterine growth retardation, postnatal retardation, microcephaly, sparse hair, toe syndactyly, and characteristic facial appearance is now recognized as the Dubowitz syndrome. Five addition additional cases of the Dubowitz syndrome are reported, including 2 with documented vascular abnormalities.

Face↗
PubMed1979

Brainstem auditory evoked response in adrenoleukodystrophy.

Clinical, laboratory, and electrophysiological data, including brainstem auditory evoked responses, are reported in a case of adrenoleukodystrophy. A striking asymmetry was noted in wave VI of the brainstem auditory evoked potential, followed by absence of any recognizable wave on the abnormal side. The presumed site of origin of wave VI is the medical geniculate body, a structure severely involved in adrenoleukodystrophy. It is suggested that the brainstem auditory evoked response may promise noninvasive diagnostic aid in this disorder and that absence of wave VI may emerge as a clinically useful finding in diseases of the central nervous system.

Adrenal Gland Diseases↗
PubMed1979

Benign subdural collections of infancy.

During the past two years we studied six infants with subdural collections of fluid. All patients had macrocrania and excessive transillumination of the head. Rapid head growth was common but five patients were otherwise asymptomatic. Subdural taps performed on five children confirmed the presence of abnormal fluid over the cerebral convexities. Subdural fluid in four patients was compatible with effusion and in another with a hematoma. Computerized tomographic evaluation of all infants showed ventricular enlargement, wide cerebral sulci, decreased density in the anterior temporal regions, large sylvian cisterns, prominent interhemispheric fissures, and decreased density over the cerebral convexities. The CT findings resembled cerebral atrophy but psychomotor development and neurologic examinations have been norma.

Child Development↗
PubMed1978

Familial and acquired paroxysmal dyskinesias. A proposed classification with delineation of clinical features.

On a clinical basis the paroxysmal dyskinesias can be classified into two distinct categories--familial and acquired. The former begins in childhood and the dyskinesia may or may not be induced by sudden movements (kinesigenic or nonkinesigenic forms). In the familial kinesigenic form, the movements are brief, usually occur daily, and respond readily to anticonvulsants. This form has an autosomal dominant or recessive mode of inheritance. In the familial nonkinesigenic form, the movements are of longer duration, occur less frequently, and rarely respond to anticonvulsants. This form has a clear autosomal dominant mode of inheritance. The etiology is obscure. The acquired form of paroxysmal dyskinesia has a later onset and is an expression of an underlying neurological or metabolic disease. Some cases of acquired paroxysmal dyskinesia are manifestations of unusual forms of epilepsy. In these cases the differential diagnosis may be extremely difficult and must be based on EEG findings during an ictal episode.

Adolescent↗
PubMed1978

Cerebellar medulloblastoma. An analysis of four cases of extraneural metastasis.

In four of 28 patients (14%) with medulloblastoma who were treated at the University of Wisconsin, Madison, over a 20-year period, extraneural metastases developed. In an effort to delineate the causal factors involved in extraneural metastases, salient features of patients with metastases and without metastases were compared. Suboccipital craniectomy, radiation therapy, and patient longevity were not well correlated with metastases. However, subarachnoid tumor spread was a consistent precursor. A ventriculoatrial shunt may have been a factor in one patient and a serious infection that preceded diffuse metastasis may have been a factor in another patient. Half of the patients with metastases were found to have the desmoplastic variety of medulloblastoma while only one of 24 patients without metastases had this tumor type.

Cerebellar Neoplasms↗
PubMed1978

Clinical and extraneural histologic diagnosis of neuronal ceroidlipofuscinosis.

Neuronal ceroid-lipofuscinosis is manifested by visual and intellectual deterioration and seizures. Autofluorescent lipopigments are found in neural and many nonneural tissues, with characteristic staining and ultrastructural properties. Presumptive diagnosis can usually be made on the basis of history, physical examination, and electrodiagnostic tests, but in the absence of a specific biochemical defect, histologic confirmation is essential. A 6-year-old boy with the clinical appearance of the juvenile form of the disease had sea-blue histiocytes in the bone marrow, and curvilinear profiles in ultrastructural inclusions in skin biopsy tissue, cultured skin fibroblasts, and bone marrow cells.

Ceroid↗
PubMed1977

EEG recognition of Aicardi's syndrome.

Thirty-two EEGs from six cases of Aicardi's syndrome were reviewed. A characteristic EEG pattern was found in all cases. This consists of multifocal epileptiform abnormalities occurring on a burst-suppression pattern showing complete asynchrony between the two hemispheres. This pattern has been described so far only in Aicardi's syndrome. These characteristic EEG features are more readily found early in the course of the disease and occur less frequently six months after from the onset of symptoms, at which time they are often replaced by multiple epileptic foci on a severely disorganized background. The EEG sleep pattern was profoundly altered in all stages of the disease. The EEG is considered a helpful tool in the diagnosis of Aicardi's syndrome.

Bone and Bones↗