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Biomedical subjects

A L Williams

Publications and source records attributed to A L Williams.

At least 109 records · Page 6Linked to original sources
PubMed1980

Association of respiratory virus infections with sudden infant death syndrome.

From September, 1974, to September, 1979, 488 cases of sudden infant death syndrome (SIDS) in Melbourne were studied for evidence of viral infection. One hundred and eighty-eight infants (39%) yielded one or more viruses, with respiratory viruses being detected in 102 cases (21%). Further evidence of a respiratory virus association with SIDS was obtained by comparing the monthy respiratory virus isolation rates at the Royal Children's Hospital from 1973 to 1979 with the incidence of SIDS in the same period. A highly significant correlation was obtained between these isolation rates and the incidence of SIDS, which suggests that respiratory viruses play a role in SIDS in Melbourne.

Adenoviridae↗
PubMed1980

Biological Process for Converting Naphthalene to cis-1,2-Dihydroxy-1,2-Dihydronaphthalene.

A biological process for converting naphthalene to cis-1,2-dihydroxy-1,2-dihydronaphthalene (DHD) catalyzed by Pseudomonas putida strain 119 was optimized in flask experiments. These studies revealed the following: (i) P. putida 119 can propagate efficiently and produce DHD when supplied one of several carbon sources and naphthalene; (ii) maximum DHD production by P. putida 119 occurs in logarithmic-growth-phase cells and decreases at various rates in the stationary growth phase, depending upon the carbon source used; (iii) several analogs of salicylic acid can be used as effective inducers of naphthalene metabolism in P. putida cells growing on glucose; and (iv) the addition of chemical surfactants to naphthalene-cell (P. putida 119) mixtures stimulates DHD production.

Journal Article↗
PubMed1980

Microbial production of 4,4'-dihydroxybiphenyl: biphenyl hydroxylation by fungi.

Of 15 species of fungi examined for their ability to hydroxylate biphenyl, 10 produced 4-hydroxybiphenyl. Seven of the 10 also produced 4,4'-dihydroxybiphenyl. The most efficient strains, Absidia pseudocylindrospora NRRL 2770 and Absidia sp. NRRL 1341, were more closely examined to determine their growth characteristics and the kinetics of biphenyl hydroxylation in batch fermentation. In the absence of biphenyl, A. pseudocylindrospora 2770 and Absidia sp. 1341 grew about as rapidly and efficiently in a defined glucose minimal medium as in a complex medium. Substrate yield coefficients for glucose in both media were 0.4 to 0.5 g of biomass per g of glucose, and the specific growth rate was about 0.17 h (doubling time, about 4 h). In this unoptimized system, 10 to 15 g of biomass per liter (dry weight) could be produced, using a defined salt solution and glucose as sole carbon and energy source. In the presence of biphenyl, growth was inhibited, more so for strain 1341 than for strain 2770. However, the specific activity for biphenyl hydroxylation (milligrams of biphenol per gram of biomass) was about 3.5 times greater for strain 1341. Furthermore, biphenyl hydroxylation appeared to require the presence of an oxidizable carbon and energy source (and perhaps growth) to proceed and, at least for strain 1341, hydroxylation seemed to be more efficient in the complex medium.

Journal Article↗
PubMed1980

Computed tomography of the lumbar facet joints.

Lumbar facet joints are difficult to image with conventional radiographic techniques. A series of 100 consecutive cases of low back pain and sciatica was examined with CT. Abnormal facet joints were found in 65. Abnormalities demonstrated by CT included osteophyte formation, hypertrophy of articular processes, articular cartilage thinning, vacuum joint phenomenon, and calcification of the joint capsule. In patients with sciatic or low back pain, CT is indicated to demonstrate treatable abnormalities of the facet joints.

Humans↗
PubMed1980

Improving visualization of the anterior subarachnoid space during cervical gas myelography.

To improve definition of the spinal cord when it lies anteriorly, turning the patient from the lateral decubitus to the supine position and obtaining a horizontal-beam lateral radiograph of the cervical spine is recommended. Supine positioning permits improved visualization of the anterior subarachnoid space and evaluation of extradural lesions encroaching upon it, as well as abnormal fixation of the cord.

Humans↗
PubMed1980

Soft-tissue anatomy within the spinal canal as seen on computed tomography.

The CT appearance of the vascular, ligamentous, and neural tissues in the spinal canal was studied in 50 patients and 5 cadavers. In some patients, iodinated contrast medium was first injected into the ascending lumbar veins, nucleus pulposus, or theca. Positive identification of spinal soft tissues on the CT image was made by reference to cadaver dissections. The spinal cord, nerves, root sheaths, retrovertebral plexus, epidural and basivertebral veins, posterior longitudinal ligament and ligamentum flavum, intervertebral disks, and vertebral arteries can be demonstrated by CT, indicating its value in the diagnosis of disease of the cord, disk, and epidural space.

Contrast Media↗
PubMed1980

Computed tomography in the diagnosis of herniated nucleus pulposus.

In this study, the effectiveness of computed tomography(CT) in diagnosing herniated nucleus pulposus was evaluated. Sixteen CT examinations which were interpreted as positive for a herniated disk, and were intraoperatively confirmed, were reviewed. In all 16 patients, CT demonstrated posterior protrusion of the disk and displacement of anterior epidural fat. Calcification within the protruding disk was noted in several patients, and an extruded disk fragment identified by CT in two. In all cases, the CT findings correlated closely with the surgical findings. This study suggests that CT accurately demonstrates disk herniation.

Adult↗
PubMed1980

The computed tomographic appearance of the spinal cord in diastematomyelia.

The myelographic and computed tomographic findings in 10 patients with diastematomyelia were reviewed. In all patients, including seven with osseous spurs, the hemicords were smaller than the normal cord above or below the cleft. The narrow hemicords distinguish diastematomyelia from diplomyelia.

Child↗
PubMed1980

Computed tomography of the optic chiasm.

Using a CT/T 8800 scanner, axial and coronal images of the optic chiasm were obtained in a cadaver, 41 normal individuals, and six patients with symptoms of chiasmal glioma. The size and shape of each chiasm were determined. The normal chiasm appeared to be U- or boomerang-shaped in axial sections, and U- or dumbell-shaped in coronal sections. The average normal chiasm diameters were 1.8 cm (transverse) by 0.8 cm (anteroposterior) by 0.4 cm (vertical). The chiasm was globular and larger than 0.6 cm (vertical dimension) in all cases of chiasmal glioma. The abnormal chiasm can be distinguished accurately from the normal chiasm by computed tomography.

Cranial Nerve Neoplasms↗
PubMed1980

Computed tomography in sciatica.

Lumber facet arthropathy and a herniated disk are two major causes of low back pain and sciatica. The authors evaluated the importance of computed tomography (CT) in 243 patients with low back pain and/or sciatica. Lumbar facet abnormalities were found in 139 patients (57%), and a herniated disk was found in 48 patients (20%). CT findings correlated precisely with surgical observations in cases involving a herniated disk and correlated well with the results of an intra-articular facet block in a small series of patients. CT can effectively diagnose and differentiate between lumbar facet arthropathy and a herniated disk.

Adult↗
PubMed1980

Tracheobronchitis and sudden infant death syndrome.

In many infants who have died suddenly and unexpectedly post mortem examination reveals the presence of a non-suppurative tracheobronchitis. The role of the tracheobronchitis in the sudden death of the infant is not known. Analysis of a series of sudden infant deaths indicates that these infants die at an older age, i.e. over three months, and most frequently in colder months of the year. If, as suggested, these deaths constitute a distinct group, investigations regarding the mode of death should be undertaken separately from that in younger infants in whom no such lesions are found.

Australia↗
PubMed1979

Computed tomography in Behçet disease.

In Behçet disease, CT may demonstrate low attenuation mass lesions with or without contrast enhancement. Since neurologic involvement may precede the typical dermatologic manifestations, Behçet disease should be included in the differential diagnosis of intracranial mass lesions. A case is presented with central nervous system involvement.

Adult↗
PubMed1979

The computed tomographic appearance of the normal pituitary gland and pituitary microadenomas.

With the use of axial and coronal computed tomography (CT), the authors compared the density, contrast enhancement, and dimensions of normal pituitary glands and pituitary microadenomas. The normal gland appears homogeneous, nearly isodense with brain tissue, and it enhances uniformly. Its upper surface is concave downward or flat and its height 2-7 mm. The cavernous sinuses, the third, fourth, and sixth cranial nerves, the infundibulum, and the adjacent carotid arteries are well demonstrated by CT. Abnormal height and upward convexity of the gland are reliable signs of prolactinoma; abnormal density and enhancement are suggestive signs. CT findings in prolactin- and ACTH-secreting tumors may differ. CT is more sensitive and more specific than polytomography in the diagnosis of pituitary adenoma.

Adenoma↗
PubMed1979

Arteriovenous malformation simulating a cyst on computed tomography.

Three cases are described in which an intracerebral arteriovenous malformation (AVM) was accompanied by a cystic component probably resulting from hemorrhage. The 3 patients gave a history of headaches. In cases of low-attenuating nonenhancing CT processes, an AVM must be considered.

Adult↗