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Biomedical subjects

J Keene

Publications and source records attributed to J Keene.

50 records · Page 3Linked to original sources
PubMed1991

Biochemical properties of the outer membrane of Treponema denticola.

The outer membranes (OMs) from serovars a, b, and c of Treponema denticola, originally isolated from periodontal patients, were prepared. Dialysis of the OMs against 20 mM MgCl2 yielded the aggregable (A) and the nonaggregable (NA) moieties of the OMs. The absence of muramic acid, adenosine triphosphatase, hexokinase, and nucleic acid as well as electron microscopy indicated that the OM preparations were homogeneous. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the A and NA moieties of the OMs showed approximately 25 Coomassie brilliant blue R-250 stain-positive bands or 47 silver-stained polypeptides. The relative molecular masses ranged between 14 and 97 kDa. The electrophoretic polypeptide profiles of the A and NA moieties shared many similarities among serovars a, b, and c. However, they exhibited variation in the overall pattern, intensity, or location of the polypeptide stained zones. This was especially true for serovar b. Two-dimensional electrophoretic studies showed an excess of 100 silver-stained spots with isoelectric points of 4.6 to 7.0 and relative molecular masses in the 14- to 97-kDa range. The OMs contained simple proteins, glycoproteins, and lipoproteins. The NA moieties of the OMs contained 4 to 6, 10 to 12, and 4 to 6 glycopeptides as well as two, seven, and two lipoprotein bands for serovars a, b, and c, respectively. The A moieties of the OMs showed 7 to 9, 11 to 13 and 5 to 6 glycopeptides as well as four, five, and three lipoprotein bands for serovars a, b, and c, respectively. Lipopolysaccharide was detected in the OMs of the three serovars following removal of proteins with proteinase K, pronase and silver staining of sodium dodecyl sulfate-polyacrylamide gels, or removal of lipopolysaccharide from the OMs by hot phenol extraction. The 66- and 53-kDa bands were present in serovars b and c, while a band with a relative molecular mass of 45 kDa was present only in serovar c. Endotoxin-like activity was also shown in the OMs of the three serovars by the Limulus amebocyte clotting assay and the chick embryo lethality test. This is the first report on selected biochemical properties of the OM macromolecules of three known serovars of T. denticola.

Bacterial Proteins↗
PubMed1985

Segmental spinal instrumentation without sublaminar wires.

We have developed a method of segmental spinal instrumentation that precludes the passage of sublaminar wires, thus reducing the likelihood of neurological complications. The technique utilizes the base of the spinous process as the purchase site for segmental fixation and a newly developed button-wire implant. The technique and early experience with this method are described.

Adolescent↗
PubMed1985

A simple radiographic diagnosis of occult blow-out fractures.

Standard radiographs of the orbit may not provide conclusive diagnosis of a blow-out fracture. Conventional and computed tomography have been employed effectively to resolve questionable cases. These imaging modalities generally are unavailable after hours and on weekends. The exaggerated Waters views are plain film radiographs easily and routinely obtainable that can demonstrate an occult fracture of the orbital floor.

Adult↗
PubMed1979

Relationship of seminal plasma testosterone and dihydrotestosterone to sperm count and motility in man.

A radioimmunoassay previously described for serum T and DHT was adapted for use in the measurement of these hormones in seminal plasma. The seminal plasmas of 273 semen specimens were assayed for T and DHT concentration. Mean levels of these hormones for various sperm count and sperm motility categories were determined. We found that: (1) the DHT level of the azoospermic group was significantly lower than all other groups; (2) the T level of the group whose mean sperm count exceeded 40 x 10(6)/ml was higher than that of all other groups; (3) the DHT level of the group with absent sperm motility was lower than the level of all other groups; and (4) changes in sperm motility were not accompanied by changes in T levels. We concluded that idiopathic male subfertility as evidenced by oligospermia, azoospermia, and decreased sperm motility may be related to insufficient androgen production due to a primary intratesticular defect.

Cell Count↗
PubMedDate not supplied

A retrospective radiographic survey of embedded primary molar roots in Saudi adult patients.

This retrospective study reports the radiographic prevalence of embedded primary molar roots within Saudi adult dentulous patients. Embedded roots of primary molars were viewed radiographically by evaluation of the records of 300 patients. Embedded primary molar roots were detected in 7 percent of the viewed patient radiographs. Fifty-five percent of the embedded roots demonstrated the concomitant existence of partial bony ankylosis. The remaining 45 percent of the embedded roots were surrounded by an intact lamina dura and periodontal ligament space. The frequency of occurrence demonstrated an age-based relationship, showing 9 percent prevalence in the older age-group (41-50 yr.) as compared to a 45 percent occurrence seen in the younger (15-20 yr.) group. Seventy-seven percent of the embedded roots were found within the mandible as compared with a 23 percent occurrence in the maxilla.

Adolescent↗