Vitamin D, bone mineral density and risk of fracture in people with intellectual disabilities.

BACKGROUND: People with intellectual disabilities (IDs) have very high rates of osteoporosis and fractures, to which their widespread vitamin D deficiency and other factors could contribute. We aimed to assess in people with IDs previously treated for vitamin D deficiency (1) long-term adherence to vitamin D supplementation and (2) bone mineral density (BMD), as an indicator for risk of fractures, according to vitamin D supplementation and other factors. METHOD: We recorded height, weight, medical, pharmacological, dietary and lifestyle assessment. Blood sample were taken for vitamin D and related analytes. dual-energy X-ray absorptiometry for BMD was performed. RESULTS: Of 51 study participants (mean [standard deviation, SD] age 51.5 [13.6] years, 57% male), 41 (80.4%) were taking vitamin D and 10 were not. Mean [SD] serum vitamin D was 81.3 [21.3] vs. 25.2 [10.2] nmol/L (P < 0.0001), respectively. Thirty-six participants underwent a dual-energy X-ray absorptiometry scan, which showed osteoporosis in 23.7% and osteopenia in 52.6%. Participants on vitamin D had higher BMD than those who were not, a statistically significant difference when confounders (lack of mobility and hypogonadism) were removed. BMD was significantly different according to mobility, particularly in wheelchair users, in whom hip BMD was 33% lower (P < 0.0001) than in participants with normal mobility. Participants still taking vitamin D showed a 6.1% increase in BMD at the spine (P = 0.003) after mean [SD] 7.4 [1.5] years vitamin D treatment. CONCLUSIONS: In people with IDs and previous vitamin D deficiency, BMD increases on long-term vitamin D supplementation. However, additional strategies must be considered for osteoporosis and fracture prevention in this population.

Muscle fibre type changes in hypothyroid myopathy.

Changes in muscle fibre type in hypothyroid myopathy were studied by serial percutaneous needle biopsy of vastus lateralis before and during treatment with L-thyroxine. A type II fibre atrophy and loss was found, which correlated with the clinical and biochemical evidence of a myopathy. The type II fibre atrophy was corrected by L-thyroxine but type II fibre loss was still apparent in severely myopathic patients up to two years after starting treatment. The pathogenesis and significance of type II fibre atrophy and loss are discussed in relation to prognosis.

Information processing in anxiety: a pilot study of the effect of manipulating 5-HT function.

We gave the indirect 5-HT agonist, D-fenfluramine (30 mg), the 5 -HT antagonist methysergide (2 mg) and placebo to 11 patients with an anxiety disorder and 12 controls in a double-blind, balanced-order, cross-over design. Compared to controls, patients had significantly higher anxiety ratings, were slower in naming colours in computerized Stroop tests and showed greater interference for anxiety-related words. Patients tended to have a lower critical flicker fusion threshold (CFFT) than controls and in the subjects taken as a whole there was a significant inverse correlation between CFFT and Spielberger state (r=-0.54, p<0.01) and trait anxiety (r=-0.55, p<0.01). Neither drug had significant effects on anxiety ratings or on Stroop interference. D-Fenfluramine significantly increased CFFT (p < 0.02) and methysergide non-significantly reduced CFFT with no significant differences between patients and controls. 5-HT may be involved in lower-level visual information processing but we found no evidence for its direct involvement in the attentional bias for anxiety-related information in the emotional Stroop.

Tracheoplasty for congenital complete tracheal rings.

OBJECTIVE: To better appreciate the complex nature of the pediatric patient with tracheal stenosis due to congenital complete tracheal rings, we evaluated clinical presentation, methods of evaluation, necessity for surgical repair, associated anomalies, and outcome. DESIGN: Retrospective study. PATIENTS: Eighteen patients with long-segment tracheal stenosis due to congenital complete tracheal rings were evaluated at Cincinnati (Ohio) Children's Hospital Medical Center between 1985 and 1991. Three patients did not require surgical intervention. Fifteen patients underwent tracheoplasty with cardiopulmonary bypass through a midline sternotomy. RESULTS: The patients with congenital complete tracheal rings usually present with respiratory compromise in the first year of life. In the majority of patients, a diagnosis was made based on the symptoms and findings of an endoscopic examination with the aid of plain film roentgenography. In selected patients, computed tomography or magnetic resonance imaging was used. We evaluated symptoms, length of stenosis, type of repair, duration of intubation, and complications, as well as the mortality associated with this procedure. CONCLUSIONS: The technique of tracheoplasty has evolved at our institution, including the use of a posterior tracheal division, anterior castellated division, autologous pericardial patch grafting, and cricoid split with intubation for 7 to 21 days. We found the mortality associated with this procedure quite high at 47%, compared with previously published reports with mortality figures between zero and 77%.

Alternatives in the management of aneurysmal bone cysts of the mandible.

Aneurysmal bone cyst (ABC) is an unusual expansile lesion of bone which may arise within the mandible on rare occasions. This lesion may arise with very few signs or symptoms. Surgical treatment consists of complete excision or curettage. The recurrence rate may be high in lesions which are incompletely excised. Three cases of aneurysmal bone cysts in children will be presented, demonstrating the wide variation of clinical presentation. One case required an extensive mandibular resection, necessitating the first reported microvascular mandible reconstruction for this entity in a pediatric patient.

Abnormalities of the bony thorax causing tracheobronchial compression.

A number of intrathoracic and extrathoracic causes of airway obstruction have been well documented in the literature. At times, tracheal compression may be caused by abnormalities of the bony thorax whose previously unrecognized significance can result in unexpected difficulties when extubation is attempted following a routine intubation. Alternatively, patients may develop progressive distress secondary to their skeletal abnormalities. We report on cases illustrating anomalies of the manubrium, sternum and spine which have caused significant, occasionally life-threatening, tracheal and bronchial narrowing including pectus excavatum and scoliosis. A protocol is presented detailing the appropriate methods of diagnosis and treatment of these types of deformities.

The role of computed tomography in the diagnosis of subperiosteal abscess of the orbit.

Periorbital cellulitis is a frequent complication of sinusitis in children. Subperiosteal abscess (SPA), however, is an uncommon sequela and may lead to serious complications if not promptly and adequately treated. A series of 13 consecutive patients who underwent orbital computed tomographic (CT) scans from January 1, 1986, to June 30, 1989, to investigate the possibility of SPA were reviewed. As demonstrated in this series, the diagnosis of subperiosteal abscess remains a clinical one that may be supported, but not determined, by an orbital CT scan. Cautious interpretation of these studies is advocated. Aggressive surgical therapy in appropriate clinical situations will lead to more rapid resolution of the disease process and fewer complications.

Biology undergraduates' misconceptions about genetic drift.

This study explores biology undergraduates' misconceptions about genetic drift. We use qualitative and quantitative methods to describe students' definitions, identify common misconceptions, and examine differences before and after instruction on genetic drift. We identify and describe five overarching categories that include 16 distinct misconceptions about genetic drift. The accuracy of students' conceptions ranges considerably, from responses indicating only superficial, if any, knowledge of any aspect of evolution to responses indicating knowledge of genetic drift but confusion about the nuances of genetic drift. After instruction, a significantly greater number of responses indicate some knowledge of genetic drift (p = 0.005), but 74.6% of responses still contain at least one misconception. We conclude by presenting a framework that organizes how students' conceptions of genetic drift change with instruction. We also articulate three hypotheses regarding undergraduates' conceptions of evolution in general and genetic drift in particular. We propose that: 1) students begin with undeveloped conceptions of evolution that do not recognize different mechanisms of change; 2) students develop more complex, but still inaccurate, conceptual frameworks that reflect experience with vocabulary but still lack deep understanding; and 3) some new misconceptions about genetic drift emerge as students comprehend more about evolution.

Active learning not associated with student learning in a random sample of college biology courses.

Previous research has suggested that adding active learning to traditional college science lectures substantially improves student learning. However, this research predominantly studied courses taught by science education researchers, who are likely to have exceptional teaching expertise. The present study investigated introductory biology courses randomly selected from a list of prominent colleges and universities to include instructors representing a broader population. We examined the relationship between active learning and student learning in the subject area of natural selection. We found no association between student learning gains and the use of active-learning instruction. Although active learning has the potential to substantially improve student learning, this research suggests that active learning, as used by typical college biology instructors, is not associated with greater learning gains. We contend that most instructors lack the rich and nuanced understanding of teaching and learning that science education researchers have developed. Therefore, active learning as designed and implemented by typical college biology instructors may superficially resemble active learning used by education researchers, but lacks the constructivist elements necessary for improving learning.

Diagnostic Criteria for Psychiatric Disorders for Use with Adults with Learning Disabilities/Mental Retardation (DC-LD) and the diagnosis of anxiety disorders: a review.

BACKGROUND/METHODS: During the development of Diagnostic Criteria for Psychiatric Disorders for Use with Adults with Learning Disabilities[DC-LD] a literature review of diagnostic issues in anxiety disorders in adults with intellectual disability (ID) was undertaken using electronic and hand searching of journals. RESULTS: Relevant general concepts in the general population are reviewed briefly before those related specifically to adults with ID. The literature relating to the diagnosis of specific anxiety disorders is reviewed, although with the exception of obsessive compulsive disorder this consists mainly of case reports. Difficulties in the use of diagnostic systems developed for the general population for the diagnosis of anxiety disorders in adults with ID are frequently commented upon. CONCLUSIONS: It is concluded that anxiety disorders are well recognized in adults with ID, although their prevalence is uncertain, and that the use of modified diagnostic criteria may aid further research in this area.

Protein synthesis by membrane-bound and free ribosomes of secretory and non-secretory tissues.

1. Methods for the separation of membrane-bound and free ribosomes from rat brain (cortex) and skeletal muscle were described and the preparations characterized by chemical analysis and electron microscopy. The attachment of ribosomes to membranes is not an artifact of the separation procedure. 2. The rate of incorporation of l-[(14)C]leucine into protein in vitro by the membrane-bound and free ribosomes from these two predominantly non-protein-secreting tissues is compared with that by similar preparations from rat liver. With all three tissues the initial rate was higher for the membrane-bound preparations. 3. By using the technique of discharging nascent polypeptide chains by incubation with puromycin followed by treatment with sodium deoxycholate (Redman & Sabatini, 1966), a major difference was observed for the vectorial discharge of nascent protein synthesized both in vivo and in vitro on membrane-bound ribosomes from liver, on the one hand, and brain and muscle, on the other. Whereas a large part of nascent protein synthesized on membrane-bound liver ribosomes was discharged into the membranous vesicles (presumably destined for export from the cell), almost all nascent protein from membrane-bound ribosomes from brain and muscle was released directly into the supernatant. Incorporation of [(3)H]puromycin into peptidyl-[(3)H]puromycin confirmed these findings. There was thus no difference between membrane-bound and free ribosomes from brain on the one hand, and from free polyribosomes from liver on the other, as far as the vectorial release of newly synthesized protein was concerned. 4. Incubation with puromycin also showed that the nascent chains, pre-formed in vivo and in vitro, are not involved in the attachment of ribosomes to membranes of the endoplasmic reticulum. 5. The differences in vectorial discharge from membrane-bound ribosomes from liver as compared with brain and muscle are not due to the different types of messenger RNA in the different tissues. Polyphenylalanine synthesized on incubation with polyuridylic acid was handled in the same way as polypeptides synthesized with endogenous messenger. 6. It is concluded that there is a major difference in the attachment of ribosomes to the membranes of the endoplasmic reticulum of secretory and non-secretory tissues, which results in a tissue-specific difference in the vectorial discharge of nascent proteins.

Protein synthesis by membrane-bound and free ribosomes of the developing rat cerebral cortex.

1. Rates of RNA and protein synthesis were measured in rat cerebral-cortex slices, and compared with amino acid incorporation into protein by membrane-bound and free ribosomes from the same tissue, in the first 3 weeks of life. 2. A rapid age-dependent decline in the incorporation of labelled precursors into both RNA and protein was observed, which was more marked for amino acid incorporation into protein. 3. Although membrane-bound ribosomes comprise only a small fraction of total ribosomes, they were more active in incorporating amino acids into protein than were free ribosomes, especially immediately after birth. The decline in activity with age was more marked in the membrane-bound fraction than in free ribosomes. This loss of activity was largely independent of alterations in soluble factors or endogenous mRNA content and appeared to involve some alteration of the function of the ribosome itself, with relatively small alterations in the ratio of membrane-bound to free ribosomes. 4. Thyroidectomy, performed soon after birth, had no effect on the incorporation of radioactive precursors into RNA or protein by either slices or the cell-free preparations during the first 3-4 weeks of life.

Complications of adenotonsillectomy in children under 3 years of age.

Adenotonsillectomy in children may be performed safely on an outpatient basis in the majority of cases without an increase in complication rates. However, very young children comprise a unique patient subpopulation with regard to adenotonsillar surgery. Surgical indications in older children tend to be dominated by chronic recurrent infections, whereas younger children usually require surgery for chronic upper airway obstruction related to adenotonsillar hypertrophy. This study was undertaken to evaluate the adenotonsillectomy patient population under 3 years of age. Complication rates related to airway problems, hemorrhage, and dehydration were determined. Children under 3 years of age demonstrated an increased incidence of postoperative airway complications, manifested by oxygen desaturation and transient upper airway obstruction. It is recommended that adenotonsillectomy be performed on such patients on an inpatient basis with close postoperative monitoring including pulse oximetry.

Primary mucinous adenocarcinoma of the eyelid.

Primary mucinous adenocarcinoma of the skin is a rare entity arising from eccrine sweat glands with a propensity for local recurrence and metastasis. This tumor has been widely reported in the ophthalmology literature, but not to our knowledge in the otolaryngology literature. A case of a 48-year-old man with a mucinous adenocarcinoma extensively involving the right eyelid and orbit necessitating craniofacial resection is presented together with a discussion of the pathology, clinical features, and management.