Expression of keratin K2e in cutaneous and oral lesions: association with keratinocyte activation,proliferation, and keratinization

The cytoskeleton in keratinocytes is a complex of highly homologous structural proteins derived from two families of type I and type II polypeptides. Keratin K2e is a type II polypeptide that is expressed in epidermis late in differentiation. Here we report the influence of keratinocyte activation, proliferation, and keratinization on K2e expression in samples of cutaneous and oral lesions. The normal expression of K2e in the upper spinous and granular layers of interfollicular epidermis is increased in keloid scars but showed distinct down-regulation in psoriasis and hypertrophic scars where keratinocytes are known to undergo activation. Unlike normal and psoriatic skin, K2e expression in hypertrophic and keloid scars began in the deepest suprabasal layer. In cutaneous basal and squamous cell carcinomas, K2e was absent in most tumor islands but the overlying epidermis showed strong expression. No significant K2e expression in nonkeratinized or keratinized oral epithelia, including buccal mucosa, lateral border of tongue and gingiva was detected. In oral lichen planus K2e expression was undetectable, but in benign keratoses of lingual mucosa induction of K2e along with K1 and K10 was observed. In mild-to-moderate oral dysplasia with orthokeratinization, K2e was highly expressed compared with parakeratinized areas but in severe dysplasia as well as in oral squamous cell carcinoma, K2e expression was undetectable. Taken together, the data suggest that K2e expression in skin is sensitive to keratinocyte activation but its up-regulation in oral lesions is a reflection of the degree of orthokeratinization.     

Slow frequency-dependence of action potential afterhyperpolarization in bullfrog sympathetic ganglion neurones

The afterhyperpolarization (AHP) which follows the action potential (AP) in bullfrog sympathetic ganglion B-cells involves activation of Ca²⁺-sensitive K⁺ conductances following Ca²⁺ influx via Ca²⁺ channels. The duration of AHPs evoked at 2-s stimulus intervals were 70.05±3.76% of those evoked at 90-s stimulus intervals (n=35). Since there was no consistent effect of ryanodine (5 M), ruthenium red, (300 M) or dantrolene Na (35 M) on this frequency dependence, it is unlikely to result from release of Ca²⁺ from intracellular stores. Ca²⁺ currents (I _Ca, studied by means of the whole-cell patch-clamp technique, exhibited a slow frequency dependence as a result of a slow inactivation process which was independent of Ca²⁺-induced I _Ca inactivation and I _Ca run-down. There was excellent correlation (r=0.964) between the estimated changes in Ca²⁺ influx and the expected activation of the Ca²⁺-sensitive K⁺ current, I _AHP. This result is consistent with the hypothesis that the frequency dependence of the AHP is a consequence of the slow inactivation of I _Ca.     

Physical growth and age at eruption of deciduous and permanent teeth in well-nourished Indian girls from birth to 20 years

The results of a cross-sectional anthropometric survey of 1,643 well-nourished girls, from birth to 20 years, from the city of Delhi (India) are reported. The standardized measurements of body weight, height/crown–heel length, sitting height/crown–rump length, biacromial and bicristal diameters, head circumference, chest girth, upper arm girth, calf girth and skinfolds at biceps, triceps, and subscapular regions were taken for each subject. Medians fall between the 10th and 25th percentiles of National Center for Health Statistics (NCHS) reference data for height and the 10th and 50th percentiles for weight. The mean height and weight of the present girls are above the national reference values given by Indian Council of Medical Research (ICMR). Means and standard deviations of the weight/height ratio and body mass index (BMI) are also presented. The height/weight ratio increases continuously with age to 18 years. The mean values of the BMI, however, decrease to 6 years, rising afterward to adulthood. Median ages of eruption of deciduous and permanent teeth are presented. The first deciduous tooth to emerge in present girls is mandibular I₁ at 7.6 months. The sequence of emergence based on ascending median ages is I₁, I₂, M₁, C, and M₂ for both maxillary as well as mandibular deciduous teeth. The permanent set of dentition starts with the emergence of mandibular M₁ at 5.75 years. Despite the rapid physical growth of American and British girls, the present girls are ahead in dental emergence and show earlier emergence of maxillary and mandibular permanent premolars, suggesting a genetic basis for the emergence of deciduous and permanent teeth. Partial correlation coefficients with age constant between height and the number of erupted deciduous and permanent teeth are positive and significant, reflecting an association, to some degree, with height and weight. © 1992 Wiley-Liss, Inc.     

The difference between registered natural head position and estimated natural head position in three dimensions

This study determined the intra-rater and inter-rater reliability of re-orientating three-dimensional (3D) facial images into the estimated natural head position. Three-dimensional facial images of 15 pre-surgical class III orthognathic patients were obtained and automatically re-orientated into natural head position (RNHP) using a 3D stereophotogrammetry system and in-house software. Six clinicians were asked to estimate the NHP of these patients (ENHP); they re-estimated five randomly selected 3D images after a 2-week interval. The differences in yaw, roll, pitch, and chin position between RNHP and ENHP were measured. For intra-rater reliability, the intra-class correlation coefficient (ICC) values ranged from 0.55 to 0.77, representing moderate reliability for roll, yaw, pitch, and chin position, while for inter-rater reliability, the ICC values ranged from 0.38 to 0.58, indicating poor to moderate reliability. The median difference between ENHP and RNHP was small for roll and yaw, but larger for pitch. There was a tendency for the clinicians to estimate NHP with the chin tipped more posteriorly (6.3 ± 5.2 mm) compared to RNHP, reducing the severity of the skeletal deformity in the anterior–posterior direction.     

Cosmetic arm lengthening with monorail fixator

Upper limb length discrepancy is a rare occurrence. Humerus shortening may need specialized treatment to restore the functional and cosmetic status of upper limb. We report a case of humerus lengthening of 9 cm with a monorail external fixator and the result was observed during a 2-year follow-up. Humerus lengthening needs specialized focus as it is not only a cosmetic issue but also a functional demand. The monorail unilateral fixator is more functional and cosmetically acceptable, and thus becomes an effective treatment option.     

An assessment of the quality of care provided to orthognathic surgery patients through a multidisciplinary clinic

The quality of care delivered to 74 patients undergoing orthognathic surgery was assessed using a patient satisfaction questionnaire and data collected from hospital case records. Surgical complications, hospital services, patient satisfaction, and impact on quality of life, were the main aspects considered. The majority of patients reported that their treatment objectives had been achieved and that they were satisfied with the quality of care provided. The main concern of the patients regarding the clinic was the waiting time before an appointment could be offered. Eating and breathing difficulties and low mood after surgery were the main reported complications. Sixty-three patients experienced post-operative weight loss. The importance of a nutritious, high calorie soft diet should be emphasised and the use of menthol inhalations following maxillary osteotomies should be considered more frequently. Clinicians should be aware of post-operative low mood, which may require psychological support. We developed a sensitive assessment battery with comprehensive parameters to audit quality of orthognathic surgery service, and recommend that a similar approach should be considered by teams which undertake management of orthognathic patients.     

Investigations into the use of an ultrasonic chisel to cut bone. Part 2: Cutting ability

OBJECTIVES: Ultrasound may offer a possible alternative to rotary instruments for removing bone. This study was undertaken to analyse in vitro the various factors that influence the cutting of bone by an ultrasonic chisel. STUDY DESIGN: A block of bovine femur was moved in a longitudinal direction under a stationary ultrasonic chisel. The force and depth of the cut was recorded for cutting rates of 28-112 mm/min and with increasing rake angles of 0 to +20 degrees. The pressure exerted by the chisel was recorded for different cutting rates. RESULTS: When the cutting rate increases there is a corresponding increase in the downward force which is followed by a decrease in the force at rates greater than 56 mm/min. The depth of the cut increases up to a rate of 56 mm/min after which it decreases. Both the longitudinal and downward forces do not change when the rake angle changes from 0 to +10 degrees. The downward force decreases when the rake angle increases from +10 to +20 degrees. CONCLUSIONS: The bone is cut slowly with the ultrasonic chisel, but this would assist in precision. Where such an instrument is used for cutting bone the clinicians should be aware that both low forces and cutting rates are required, and the instrument should be held at a low rake angle.