Gene expression profiling of the ageing rat vibrissa follicle.

BACKGROUND: The application of gene expression profiling to the study of chronological ageing has the potential to illuminate the molecular mechanisms underlying a complex and active process. For example, ageing of the skin and its constituent organs has myriad phenotypic consequences, and a better understanding of the means by which these changes arise has important corollaries for intervention strategies. OBJECTIVES: We used a transcriptional profiling approach to investigate changes in gene expression associated with ageing of the large vibrissa follicle of the Wistar rat. METHODS: Follicle mRNA isolated from male Wistar rats at 1 and 18 months of age was hybridized to Clontech Atlas 1.2 Rat cDNA macroarrays. Confirmation of array results was provided by the use of Northern blotting and immunohistochemistry. RESULTS: Seven transcripts displayed at least a 1.6-fold increase in expression with age, of which APOD (2.5-fold), GSTM2 (2.0-fold) and NPY (1.8-fold) showed the greatest increases. Decreased expression was found in 19 transcripts, most notably in ALOX12 (13.3-fold) and GAP43 (12.6-fold) expression. CONCLUSIONS: Follicular ageing is characterized by transcriptional changes associated with diverse aspects of keratinocyte metabolism, proliferation and development.

Id proteins are dynamically expressed in normal epidermis and dysregulated in squamous cell carcinoma.

Helix-loop-helix genes regulate many developmental pathways, and growing evidence associates dysregulated expression with tumorigenesis. We observed Id-1, Id-2, and Id-3 mRNA expression in proliferating human keratinocytes in vitro with subsequent down-regulation with differentiation. Immunohistochemical analysis of human tissue sections identified cytoplasmic Id-1 expression and nuclear Id-2 and Id-3 expression in the proliferating layers of the epidermis. Furthermore, we observed a columnar pattern of Id-2 and Id-3 staining, which may relate to the epidermal proliferative unit. In squamous cell carcinoma of the head and neck, Id protein immunoreactivity was observed in the majority of malignant keratinocytes in the most poorly differentiated sections, with reduced staining in well-differentiated disease.

Infrared imaging of pharmaceutical materials undergoing compaction.

The goal of this study was to use infrared thermography as a new technique to investigate the heat released during compaction and consolidation of pharmaceutical powders and granules. Real-time temperature measurements without physical contact with tablets were provided by a highly sensitive (+/- 0.1 degrees C at 30 degrees C) infrared camera (Agema Infrared Systems, Model 470 with CM-SOFT software). High-resolution images were captured at the takeoff point, i.e., less than 1 sec after compaction, stored on floppy disks, and then analyzed on a regular PC equipped with a VGA color monitor. Thermal surface profiles of tablets were obtained with high geometric and temperature resolution. Reproducibility of the camera readouts was better than 3%. The model granulation used was a direct compression blend of microcrystalline cellulose, spray-dried lactose, and magnesium stearate. This blend was compressed using an instrumented Korsch PH106 rotary press fitted with 1 station of 19.1 x 7.9-mm (0.750 x 0.312-in.) capsule-shaped tools. The effects of compaction force (6-20 kN), rate (130- to 360-msec contact time), and lubricant level (0.5 and 1.0%) on postcompaction temperature rise, caused by heat released during compaction, were investigated. The presence and location of nonhomogeneous heat distribution were assessed as well. Results have shown that the heat released during compaction increases with compaction force. Tablet surface temperatures of 33.8 +/- 0.7 degrees C were observed at 20 kN compaction force in contrast to 29.5 +/- 0.3 degrees C at 6.7 kN.(ABSTRACT TRUNCATED AT 250 WORDS)

Pleurectomy through the triangle of auscultation for treatment of recurrent pneumothorax in younger patients. Evaluation of 60 consecutive cases.

Sixty patients, aged 14 to 35 years, with recurrent pneumothorax were treated with pleurectomy through the triangle of auscultation, with no chest wall muscle transection. The advantages of this approach over a full thoracotomy are that with no muscle transection, a shorter postoperative recovery is expected and, subsequently, early return to normal activity is achieved. The scar may also be more cosmetically acceptable. There was no postoperative mortality, and only one patient required reoperation because of bleeding. The technique is simple, and exposure is adequate. If necessary, this limited thoracotomy can be converted to a full thoracotomy with no difficulty.

Effect of compressional force on tablets containing cellulosic disintegrators I: Dimensionless disintegration values.

Spray-dried lactose tablets containing cellulosic disintegrators or microcrystalline cellulose were compressed at different compressional forces. USP disintegration times were measured as a function of pH and compressional force. Two dimensionless quantities were derived from the experimentally determined disintegration times, and their utility in the study of tablet formulations was demonstrated. These dimensionless quantities were used to assess the effect of compressional force and pH on disintegration behavior as well as to compare disintegrator efficiency. Two internally cross-linked sodium carboxymethylcellulose disintegrators were found to be the most efficient; their efficiency increased with increasing compressional force at all pH values.