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Biomedical subjects

C M Hall

Publications and source records attributed to C M Hall.

At least 19 recordsLinked to original sources
PubMed1992

Two unusual cases of nephrocalcinosis in infancy.

Nephrocalcinosis is uncommon in childhood, the main causes are renal tubular acidosis, hyperparathyroidism and medullary sponge kidney. It is also seen where there is hypercalcaemia or hypercalciuria of any aetiology; We report nephrocalcinosis in an 18-month-old infant with metaphyseal chondrodysplasia type Jansen and also in a neonate with McCune Albright syndrome who displayed atypical skeletal appearances and had multiple ovarian cysts.

Female↗
PubMed1992

Effects of NSAIDs on beagle crevicular cyclooxygenase metabolites and periodontal bone loss.

This investigation focuses on the changes in the concentrations of cyclooxygenase (CO) products present within the crevicular fluid in naturally-progressing periodontitis in the beagle and the effects of various non-steroidal anti-inflammatory drugs (NSAIDs) on these metabolite levels and disease progression. Six groups of 5-6 beagles with periodontitis were followed for 6 months to determine the pretreatment rate of radiographic bone loss. At baseline, groups of animals were placed on soft chow to promote disease progression. Groups were treated with either placebo, three different formulations of systemic ibuprofen, systemic naproxen or topical flurbiprofen. During the 6-month treatment phase, crevicular fluid (CF) samples and radiographs were taken at regular intervals. Radioimmunoassay of CF samples from untreated animals demonstrated a steady increase in prostaglandin E2 (PGE2) over baseline values. At 1 month, CF-PGE2 levels increased 2-fold over baseline and, by 6 months, had reached a 5- to 6-fold elevation. Crevicular fluid thromboxane B2 (CF-TxB2) levels rapidly reached a 4- to 5-fold peak over baseline at 1 month and subsequently dropped to a 2-fold elevation for the remainder of the study. The rate of bone loss (BLOSS) in untreated animals increased 38% during the 6-month period, as compared to baseline pretreatment BLOSS rates. Overall, there was a significant depression in the CF levels of both PGE2 and TxB2 in all NSAID-treated groups. All NSAID treatments significantly retarded BLOSS, ranging from 21.0-36.9% of the control BLOSS rate. Furthermore, CO activation represents a major regulatory step in bone destruction and may thereby serve as an important site for pharmacological modulation.

Administration, Oral↗
PubMed1991

A new lethal sclerosing bone dysplasia.

A neonate is described with a lethal sclerosing bone dysplasia associated with prenatal fractures and craniofacial abnormalities including microcephaly, exophthalmos, hypoplastic nose and mid-face, small jaw and nodular hyperplasia of the gums. Parental consanguinity suggests that an autosomal recessive mutation is the likely aetiology.

Bone Diseases, Developmental↗
PubMed1991

Clavicular overgrowth in association with cystic hygroma.

Cystic hygroma is a rare congenital abnormality of the lymphatic system of the neck which is now considered to form part of a spectrum of lymphangiomatous malformations. Lytic bone lesions are described in systemic lymphangiomatosis and bony overgrowth (hemihypertrophy) in association with angiomatous malformations of the limbs. Two infants with ipsilateral clavicular overgrowth adjacent to cystic hygromas are reported. This association has not been recorded previously; the possible etiology is discussed.

Clavicle↗
PubMed1991

Expression of neuronal intermediate filament proteins ON1 and ON2 during goldfish optic nerve regeneration: effect of tectal ablation.

Goldfish retinal explants were used to study optic tectum participation in the regulation of intermediate filament protein synthesis in retinal ganglion cells during optic nerve regeneration. Retinas were explanted at various times after removal of the contralateral optic tectum. The synthesis of the intermediate filament proteins ON1 and ON2 in the cultures was quantitated by labeling with [35S]methionine, followed by two-dimensional gel electrophoresis, autoradiography, and densitometry. Neuritic growth from the explants was quantitated based on fiber length and density. In retinal explants placed in culture after 23 days of optic nerve regeneration, the synthesis of ON1 and ON2 was reduced when the tectum had been ablated. In contrast, synthesis of these proteins in explants placed in culture at an earlier stage of regeneration was not affected by tectal ablation. At all time points tested, neuritic outgrowth from retinal explants was stimulated by tectal ablation. These findings indicate that the synthesis of the ON1 and ON2 intermediate filament proteins during regeneration is not directly regulated by axonal volume. Further, our findings suggest that interaction between growing axons and tectum is important for sustained expression of these proteins during the later stages of optic nerve regeneration.

Animals↗
PubMed1991

Mesenchymal hamartoma of the chest wall in infancy.

Two cases of mesenchymal hamartoma of the chest wall are presented. The clinical presentation, radiological and histological features of this rare tumour are discussed. The management, which may be conservative or surgical depends on the clinical symptoms, and this is also discussed.

Child, Preschool↗
PubMed1991

Inhibition of alveolar bone loss in beagles with the NSAID naproxen.

The non-steroidal anti-inflammatory drug(NSAID) naproxen was studied in 11 beagle dogs over a 13-month period to determine its effect on the progression of periodontitis. Following a 6-month pretreatment period, 5 dogs received naproxen daily at a dosage of 2.0 mg/kg for 1 month, then 0.2 mg/kg for 6 months. Six control dogs received a gelatin capsule daily as placebo. Standardized radiographs were used to measure the rate of bone loss during the pretreatment and treatment periods. In the control dogs, the rate of bone loss was seen to increase during the treatment period although the increase was not statistically significant. In dogs treated daily with naproxen, the rate of bone loss in the treatment period was significantly less at 4 months of treatment; however, at 7 months the difference, though lower than pretreatment rate, was not significant. When the percent change in rate of bone loss during the overall 7-month treatment period was compared with pretreatment rate, the control dogs demonstrated a 38% increase in rate of bone loss during the treatment period contrasting with a 61% decrease in bone loss rate in naproxen-treated dogs. The data indicate that the non-steroidal anti-inflammatory drug naproxen can significantly inhibit alveolar bone loss in beagles. At 4 months of treatment the rate of bone loss in the naproxen-treated dogs was significantly less than pretreatment, but at 7 months of treatment the rate was no longer statistically significantly less than baseline. This probably reflects a dose response to naproxen treatment for, after 30 days of the treatment period, the naproxen dosage was reduced 10-fold due to tolerance by the beagle.

Alveolar Bone Loss↗
PubMed1991

Microtia and short stature: a new syndrome.

Bilateral microtia, absent patellae, short stature, poor weight gain, and characteristic facial features are described in two female sibs. Other skeletal anomalies included complete habitual dislocation of the elbow, slender ribs and long bones, abnormal modelling of the glenoid fossae with hooked clavicles, and clinodactyly. Bone age was significantly delayed and there was flattening of the epiphyses. This unusual combination of features has many similarities to the syndrome described by Hurst et al.

Abnormalities, Multiple↗
PubMed1991

Sibs with mental retardation, supraorbital sclerosis, and metaphyseal dysplasia: frontometaphyseal dysplasia, craniometaphyseal dysplasia, or a new syndrome?

A brother and sister are presented with unusual facies, bilateral mixed hearing loss, mental retardation, and widespread radiological abnormalities. The clinical and radiological evidence for and against the two most likely diagnoses of frontometaphyseal dysplasia and craniometaphyseal dysplasia is considered.

Abnormalities, Multiple↗
PubMed1990

Neuronal intermediate filament expression during neurite outgrowth from explanted goldfish retina: effect of retinoic acid.

Regulation of the goldfish neuronal intermediate filament proteins ON1 and ON2 was investigated in a retinal explant system. The synthesis of these proteins in explanted retina decreased with increasing time in culture, despite continuing neurite outgrowth. Thus, ON1/ON2 neurofilament expression is regulated independently from neurite outgrowth. During regeneration of the goldfish optic nerve in vivo, the expression of these proteins increased during the later phase of the process, when growing axons make contact with the optic tectum. The declining synthesis of ON1 and ON2 during neurite outgrowth in culture suggests that factors extrinsic to the retina are necessary to support synthesis of these proteins. Treating retinal explants with retinoic acid stimulated the synthesis of the ON1/ON2 proteins in a dose-dependent manner. This stimulation was effective during a period of declining synthesis of the ON1/ON2 proteins, restoring their synthesis towards initial levels of expression. These results show that retinoic acid serves as a modulator of neurofilament expression in this in vitro model of nerve regeneration.

Animals↗
PubMed1990

Yunis-Varon syndrome with severe osteodysplasty.

We report two male sibs and two female sibs from separate families, both with normal parents, who had a lethal condition with features of the Yunis-Varon syndrome and radiological signs of severe osteodysplasty. Autosomal recessive inheritance is likely in both families. The additional features described represent further delineation of the phenotype of the Yunis-Varon syndrome.

Bone Diseases, Developmental↗
PubMed1990

The Baller-Gerold syndrome: phenotypic and cytogenetic overlap with Roberts syndrome.

A case is reported where the major clinical features of craniostenosis and radial aplasia led to an initial diagnosis of Baller-Gerold syndrome. Mild fibular hypoplasia on skeletal survey led to review of the diagnosis and the similarity of the facial phenotype to that of Roberts syndrome was noted. Chromosome analysis showed the premature centromere separation characteristic of this condition. This case raises the question as to whether the Baller-Gerold syndrome can be considered as a distinct entity. It is suggested that cases diagnosed as having Baller-Gerold syndrome should have cytogenetic analysis and that known Roberts syndrome survivors are reviewed for signs of craniostenosis.

Adult↗
PubMed1989

Changes in cyclooxygenase metabolites in experimental periodontitis in Macaca mulatta.

The four principal metabolites of cyclooxygenase (CO) were examined during the progression of experimental periodontitis in the rhesus monkey Macaca mulatta. Thirty-two monkeys were divided in four disease-matched groups. Three groups were treated with flurbiprofen, a potent CO inhibitor, at either 0.027, 0.27 or 7.1 mg/kg/day delivered systemically by a subcutaneously-implanted osmotic mini-pump. We have previously described the findings indicating that flurbiprofen treatment significantly retarded clinical attachment loss (ALOSS), redness and radiographic bone loss (BLOSS). This investigation focuses on the changes in CO metabolites which occur during disease progression of ligature-induced periodontitis and on the dose-response relationship of flurbiprofen, as it relates to disease inhibition and the suppression of ARA metabolites within the crevicular fluid (CF). In untreated animals there was a statistically significant 3-fold increase in CF levels of prostaglandin E2 (PGE2) and thromboxane B2 (TxB2) at 3 months, as compared to baseline, which positively correlated with increases in redness, bleeding, ALOSS and BLOSS. CF-PGE2 and TxB2 levels reached a 6-fold peak at 6 months and returned to baseline by 12 months. Flurbiprofen (Fb) prevented the 3-month rise in TxB2, but did not affect the increase in PGE2. At 6 months, Fb administration caused a dose-dependent inhibition of both PGE2 and TxB2. Probit analysis of the dose-response data revealed that the concentration of Fb which caused a 50% inhibition of CF-TxB2 level (the IC50 value for TxB2 synthesis) was approximately two logs lower than the IC50 value for PGE2 synthesis, i.e. TxA2-IC50 = 0.013 vs. PGE2-IC50 = 1.35 mg flurbiprofen/kg/d. The slopes of the PGE2 and TxB2 inhibition curves were identical, consistent with a similar mechanism or singular enzyme for the site of action of Fb inhibition of CO activity. However, the kinetics and sensitivity of Fb inhibition were significantly different for the CO activity responsible for TxB2 and PGE2 synthesis, perhaps due to different compartmentalization of CO within different cell types.

Animals↗