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Biomedical subjects

M C Jones

Publications and source records attributed to M C Jones.

At least 73 records · Page 4Linked to original sources
PubMed1994

[Pathologic findings in diethylene glycol poisoning].

We are reporting the necropsy findings of 7 patients poisoned with diethylene glycol-contaminated propolis (a rubbery substance produced by bees from vegetal resins). Besides the well-known features of hydropic necrosis of centrolobular areas in the liver and renal tubules we found acute pancreatitis with diffuse enzymatic fat necrosis which in two of the cases was considered the secondary cause of death, and acute demyelinating lesions in the central and peripheral nervous system. Six out of the 7 cases showed glomerular PAS-positive arteriolar hyalinosis at the vascular pole, in two of them widely disseminated. Differing from the findings reported in ethylene glycol poisoning we could not find calcium oxalate crystals in any of the cases. The pancreatic, central and peripheral nervous system lesions as well as the glomerular arteriolar hyalinosis have not been previously described in the literature in relation with diethylene glycol poisoning.

Aged↗
PubMed1994

Incidence of renal anomalies in children prenatally exposed to ethanol.

OBJECTIVE: Based on a number of studies involving animals as well as human case reports indicating an association between prenatal ethanol exposure and renal malformations, it has been suggested that children with fetal alcohol syndrome (FAS) should be screened for renal anomalies. The purpose of this study was to evaluate a group of children prenatally exposed to alcohol to determine the incidence of renal anomalies and to evaluate the need for such a screening procedure. METHODS: Renal ultrasounds were performed on a total of 84 patients (68 children, 13 adolescents, and three adults). In addition to screening for malformations, renal size was studied. Data were analyzed using both chronologic and height-age as determinants of kidney size. PATIENTS: Of these 84 patients, 51 (61%) had FAS, and 33 (39%) had a history of prenatal ethanol exposure but did not have FAS. RESULTS: Three (3.6%) patients (one with FAS, two with prenatal ethanol exposure who did not have FAS) had significant renal abnormalities. This incidence was not significantly different from that found in ultrasound screening of newborns. The kidneys of children with both FAS and prenatal ethanol exposure who did not have FAS were significantly smaller than normal for both chronologic and height-age. When children were compared across chronologic ages, those with FAS had significantly smaller kidneys than those who had no evidence of FAS. After adjusting for height, the difference between these two groups was no longer significant. CONCLUSIONS: Based on these data, children prenatally exposed to ethanol do not need to be screened for renal anomalies.

Abnormalities, Drug-Induced↗
PubMed1993

Sagittal craniosynostosis, Dandy-Walker malformation, and hydrocephalus: a unique multiple malformation syndrome.

The Dandy-Walker malformation and craniosynostosis have each been described as isolated occurrences and as components of multiple malformation syndromes. The purpose of this report is to delineate the characteristics of a multiple malformation syndrome of Dandy-Walker malformation and sagittal craniosynostosis. The inheritance pattern appears to be autosomal dominant.

Abnormalities, Multiple↗
PubMed1993

Molecular cloning and sequencing of coat protein-encoding cDNA of rice tungro spherical virus--a plant picornavirus.

Rice tungro spherical virus (RTSV) was shown to have three coat protein (CP) species by high resolution NaDodSO4-PAGE and Western blot analyses. The sequence of a coat protein-expressing cDNA clone that was identified and selected from a RTSV cDNA library showed that the insert was composed of 2823 bp with only one large open reading frame (ORF) coding for 941 amino acids. The positions of the three coat proteins were located in the putative polyprotein by N-terminal microsequencing and were shown to start at amino acids 287, 495, and 698 for CP-1, CP-2, and CP-3, respectively. The coat proteins are expressed as a polyprotein at the 5' region of the viral RNA genome, and all are cleaved at glutamine carboxy termini, presumably by picornavirus 3C-type of protease(s). Sequence comparisons of coat proteins revealed that there are high amino acid homologies between CP-2 of RTSV and VP3s of encephalomyocarditis virus (EMCV) and Theiler's murine encephalomyelitis virus (TMEV). These results indicate that RTSV is a plant picornavirus.

Amino Acid Sequence↗
PubMed1993

Cognitive strategies and hypothesis testing during discrimination learning in Parkinson's disease.

This study investigated the nature and extent of impairments in the use of hypotheses and cognitive strategies in medicated subjects with idiopathic Parkinson's disease (PD) and matched control subjects. PD subjects did not differ from controls in solving one- or two-dimensional discrimination learning problems, but showed impairment on four-dimensional problems which did not appear to be attributable to memory deficits. They achieved fewer correct solutions, used fewer hypotheses, and were less likely to use appropriate lose-shift strategies following negative feedback. The pattern of findings was similar to those previously reported for subjects with frontal lobe lesions.

Aged↗
PubMed1993

Prenatal diagnosis of a giant intracranial teratoma associated with pulmonary hypoplasia.

We present a case in which an intracranial tumour replacing all intracranial contents was diagnosed by sonography at 31 weeks' gestation. The patient was delivered by caesarean section and died shortly after delivery. At necropsy, the tumour was found to be a teratoma with no recognisable normal brain tissue present. Additional findings at necropsy included pulmonary and adrenal hypoplasia. The diagnosis and prognosis of intracranial teratomas diagnosed in utero, and the association of this tumour with pulmonary hypoplasia, are discussed.

Abnormalities, Multiple↗
PubMed1993

An immunohistological study of epidermal growth factor receptor and neu receptor and neu receptor expression in proliferative glomerulonephritis.

Many forms of glomerulonephritis including IgA nephropathy are characterized by mesangial cellular proliferation. Since epidermal growth factor is a potent mitogen for cultured human mesangial cells, we have attempted to localize and quantify the expression of its receptor in normal and abnormal renal biopsies using immunohistochemistry. Using a particular antibody (Amersham, clone EGFR1), the epidermal growth factor receptor (EGF-R) was shown to be predominantly localized in the mesangium of the glomerulus. Visual estimates of intensity of staining suggested that expression of this receptor may be increased in some IgA disease patients with mesangial proliferative glomerular lesions. The neu receptor which has a 50% homology with EGF-R was, however, absent from the glomerulus and cultured mesangial cells did not express detectable levels. Expression of EGF-R by cultured mesangial cells, as assessed by immunostaining, was weak and it was not possible to induce detectable upregulation using different cytokines. The factors leading to increased expression of EGF-R in glomerulonephritis, therefore, remain unknown. Our findings suggest that signalling via EGF-R may play a role in the pathogenesis of proliferative glomerulonephritis. Despite its homology with EGF-R, the neu receptor is unlikely to have similar importance.

Cells, Cultured↗
PubMed1993

Facial clefting. Etiology and developmental pathogenesis.

This article has provided an overview of normal and abnormal facial morphogenesis and the factors that govern this process. Etiologic heterogeneity among patients encountered in treatment clinics has been emphasized. The implications of this information with respect to treatment, reproductive counseling, and prenatal diagnosis have been reviewed.

Child↗
PubMed1992

Deletions and microdeletions of 22q11.2 in velo-cardio-facial syndrome.

Velo-cardio-facial syndrome (VCFS), an autosomal dominant disorder, is characterized by cleft palate, cardiac defects, learning disabilities and a typical facial appearance. Less frequently, VCFS patients have manifestations of the DiGeorge complex (DGC) including hypocalcemia, hypoplastic or absent lymphoid tissue and T-cell deficiency suggesting that these 2 conditions share a common pathogenesis. Here, we report the results of cytogenetic and molecular studies of 15 VCFS patients. High-resolution banding techniques detected an interstitial deletion of 22q11.21-q11.23 in 3 patients. The remaining 12 patients had apparently normal chromosomes. Molecular analysis with probes from the DiGeorge Chromosome Region (DGCR) within 22q11 detected DNA deletions in 14 of 15 patients. In 2 families, deletions were detected in the affected parent as well as the propositus suggesting that the autosomal dominant transmission of VCFS is due to segregation of a deletion. Deletions of the same loci previously shown to be deleted in patients with DGC explains the overlapping phenotype of VCFS and the DGC and supports the hypothesis that the cause of these two disorders is the same.

Chromosome Banding↗
PubMed1992

Paraplegia and congenital contractures as a consequence of intrauterine trauma.

We present a newborn infant with paraplegia and contractures of the lower limbs, consistent with neurologic injury rather than malformation. The mother was involved in a severe motor vehicle accident during the sixth month of pregnancy. We propose that this infant's injuries are a result of that accident.

Accidents, Traffic↗
PubMed1992

Severe insulin resistance and diabetes mellitus in mandibuloacral dysplasia.

Mandibuloacral dysplasia (MAD) is a syndrome with onset in midchildhood. The predominant characteristics of MAD include flexion contractures; mandibular hypoplasia; loss of body fat; atrophic, speckled skin; and progressive osteolysis of the clavicles. We studied three males with MAD. Each had lipodystrophy of the extremities, with sparing of the face and neck. All had moderate hyperlipidemia. In response to oral glucose, each had a diabetic response, with peak insulin levels between 2870 and 22,960 pmol/L. Insulin-stimulated glucose disposal was determined in two patients with MAD. At an insulin infusion rate of 120 mU/m2 per minute, glucose disposal was less than 25% of that measured at similar levels of insulinemia in nondiabetic control subjects, indicating marked insulin resistance in patients with MAD. The insulin resistance occurred without obesity, excessive levels of counterregulatory hormones, or anti-insulin-receptor antibodies. We suggest that MAD is a previously undescribed form of lipodystrophic insulin-resistant diabetes mellitus.

Abnormalities, Multiple↗
PubMed1992

The sonographic appearances in postpartum thyroiditis.

During the postpartum period about 50% of women with circulating thyroid autoantibodies develop a transient autoimmune thyroiditis. To determine the sonographic appearances in postpartum thyroiditis (PPT), serial ultrasound (US) scans of the thyroid were performed in 135 postpartum women who were divided into three clinical groups: Group 1, 37 antibody positive subjects who developed PPT; Group 2, 28 antibody positive subjects in whom thyroid function remained normal; Group 3, 70 antibody negative controls. Thyroid hypoechogenicity was observed in 14/31 patients (45%) who were scanned between 4 and 8 weeks postpartum and who subsequently developed PPT (Group 1) compared with 4/24 patients (17%) in Group 2 (P less than 0.05) and 1/65 patients (1.5%) in Group 3 (P less than 0.001). In antibody positive patients, the positive predictive value of an abnormal scan during this period was 78%. Between 15 and 25 weeks postpartum thyroid hypoechogenicity was present in 32/37 patients (86%) in Group 1 compared with 11/28 patients (39%) in Group 2 (P less than 0.001) and 2/70 patients (3%) in Group 3 (P less than 0.001). Sonographic abnormality persisted beyond 32 weeks postpartum in 36/41 antibody positive patients (87%) who had exhibited thyroid hypoechogenicity earlier during the study and who had late scans. The characteristic US appearance in PPT is thyroid hypoechogenicity. The role of sonography in the prediction, diagnosis and follow up of patients with PPT is discussed.

Autoantibodies↗
PubMed1992

Cued speech.

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Cues↗
PubMed1991

An analysis of the sequence of an infectious clone of rice tungro bacilliform virus, a plant pararetrovirus.

The nucleotide sequence of an infectious clone of rice tungro bacilliform virus (RTBV) DNA has been determined. The circular genome has 8002 bp and one strand contains four open reading frames (ORFs). One ORF is potentially capable of encoding a protein of 24 kD (P24) and has no initiation (ATG) codon. The other three ORFs potentially encode proteins of 12 kD, 194 kD and 46 kD (P12, P194, P46) respectively. The functions of P24, P12 and P46 are unknown. Comparative analyses with retroviruses and Commelina yellow mottle virus suggest that the 194 kD putative product is a polyprotein that is proteolytically cleaved to yield the virion coat protein, a protease and replicase (reverse transcriptase and RNase H) characteristic of retroelements. The DNA sequence reveals other features which strongly support our belief that RTBV is a pararetrovirus. These include sequences at the mapped positions of two discontinuities in the virion DNA which are complementary to tRNA metinit and purine-rich, and may be the priming sites for minus- and plus-strand DNA synthesis respectively. As the positions of likely transcriptional signals suggest, a full-length viral transcript is observed by northern analysis. The predicted folding of the 645 bp 5'-region of this RNA resembles that of caulimoviruses. Comparisons with other reverse transcribing elements are discussed.

Amino Acid Sequence↗