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Biomedical subjects

A H Cook

Publications and source records attributed to A H Cook.

5 recordsLinked to original sources
PubMed1999

Monitoring human blood dendritic cell numbers in normal individuals and in stem cell transplantation.

Dendritic cells (DC) originate from a bone marrow (BM) precursor and circulate via the blood to most body tissues where they fulfill a role in antigen surveillance. Little is known about DC numbers in disease, although the reported increase in tissue DC turnover due to inflammatory stimuli suggests that blood DC numbers may be altered in some clinical situations. The lack of a defined method for counting DC has limited patient studies. We therefore developed a method suitable for routine monitoring of blood DC numbers, using the CMRF44 monoclonal antibody (MoAb) and flow cytometry to identify DC. A normal range was determined from samples drawn from 103 healthy adults. The mean percentage of DC present in blood mononuclear cells (MNC) was 0.42%, and the mean absolute DC count was 10 x 10(6) DC/L blood. The normal ranges for DC (mean +/- 1.96 standard deviation [SD]) were 0.15% to 0.70% MNC or 3 to 17 x 10(6) DC/L blood. This method has applications for monitoring attempts to mobilize DC into the blood to facilitate their collection for immunotherapeutic purposes and for counting blood DC in other patients. In preliminary studies, we have found a statistically significant decrease in the blood DC counts in individuals at the time of blood stem cell harvest and in patients with acute illnesses, including allogeneic bone marrow transplant (BMT) recipients with acute graft-versus-host disease (aGVHD).

Adolescent↗
PubMed1994

Control of the vertical dimension in Class II correction using a cervical headgear and lower utility arch in growing patients. Part I.

A retrospective cephalometric study was performed comparing three groups of 30 growing patients with Class II, Division 1 malocclusions. Group 1 was treated with a cervical headgear/lower utility arch combination (CHG/LUA), group 2 was treated with a cervical headgear alone (CHG), and the third group was untreated. The average treatment time was 1 year, 6 months. No other appliances were used during this period. Maxillary and mandibular dental and skeletal treatment responses were compared with an analysis of variance (ANOVA) and a Scheffe's test. In addition, a multiple stepwise regression was performed to determine whether pretreatment measures of facial pattern were accurate predictors of mandibular rotational response. Both treatment groups demonstrated significant reduction in maxillary protrusion. The CHG-only group showed significantly greater anterior descent of the palatal plane as compared with the untreated group. The maxillary molars showed significant distal movement in both treatment groups without any extrusion beyond that seen with normal growth. The maxillary incisor demonstrated significant retroclination in the CHG-only group. There was no statistical difference among the groups for variables commonly used for measuring mandibular rotation or protrusion. The change in vertical position of the lower molar was not significantly different among the groups. A CHG as used in this study produced maxillary orthopedic and orthodontic changes without upper molar extrusion beyond that seen with normal eruption and in the absence of an opening rotation of the mandible, even in subjects with dolicocephalic facial patterns. The LUA did not appear to influence lower molar eruption or mandibular rotational response. None of the commonly used predictors of facial pattern, such as the Y-axis, XY-axis, or MP angle, accurately predicted mandibular rotational response. Further study would be necessary to ascertain whether this was a result of their invalidation as predictors, or a result of the treatment strategy employed.

Cephalometry↗
PubMed1994

The variability and reliability of two maxillary and mandibular superimposition techniques. Part II.

A retrospective cephalometric study was performed to evaluate the reliability and the validity of various maxillary and mandibular superimposition techniques. In the maxilla, Ricketts' position three and the "best fit" techniques were evaluated. In the mandible, Ricketts' position four and the Björk structural method were studied. All techniques proved to be statistically reproducible and reliable. It could not be determined which technique was most valid since a control, such as implants, was not available in the sample used. Both mandibular techniques yielded comparable descriptive analyses of mandibular dental changes. The maxillary superimposition techniques yielded different descriptions of maxillary dental changes which may be a result of the subjective manipulation required when using the best fit technique. Since none of the approaches appeared to be statistically superior, we recommend positions three and four because of their ease.

Adolescent↗