Sulphure in epidermal keratohyalin granules: a quantitative assay by x-ray microanalysis

The elemental composition of different types of keratohyalin granules from the epidermis of newborn and adult rats was studied by means of an EMMA-4 analytical electron microscope, equipped with an energy-dispersive X-ray spectrometer. An absolute quantitation of the sulphur concentration in keratohyalin granules was performed. The results demonstrate that epidermal keratohyalin granules are chemically heterogeneous. A type of keratohyalin granule present in the nuclei and cytoplasm of epidermal cells from both newborn and adult rats - termed single granules - is rich in sulphur, having a content of 2-5-3-6%. Other types of keratohyalin granules, which differ in newborn and adult rats, contain a sulphur-poor component; they often have a sulphur-rich component as well. The sulphur-poor keratohyalin contains 0-6-0-9% sulphur. It is suggested that the sulphur-rich keratohyalin granules are the source of the peripheral envelope protein of cornified cells.     

A comparative study of passive haemagglutination methods for the detection of hepatitis B surface antigen in routine hospital practice

Two passive haemagglutination methods for detecting HBsAg were compared. In general, the method using turkey erythrocytes was found preferable to the method employing sheep cells since it is more rapid and more sensitive, and less frequently gave rise to false positive reactions with sera from staff, blood donors, and patients not receiving haemodialysis. The turkey cell test gives rise to more false positive screen tests than the sheep cell test when monitoring renal dialysis patients since approximately 10% of the sera of these patients were found to contain turkey cell agglutinins, but this presents no particular difficulty if the recommended absorption procedures are used.     

The prevalence of hepatitis B surface antigen in commercially prepared plasma products

Commercially available lots of plasma derivatives prepared between 1957 and 1975 were tested for hepatitis B surface antigen (HBsAg) by radioimmunoassay. In all, 69 per cent of lots of plasma protein fraction, 40 per cent of factor IX concentrate, 20 per cent of normal serum albumin, 13 per cent of antihemophilic factor, 3 per cent of fibrinogen, and 0.7 per cent of immune serum globulin lots tested were HBsAg-positive. There was great variation in the prevalence of HBsAg-positive lots of each product among the different manufacturers, reflecting not only differences in methods of processing plasma, but also differences in donor populations. Those manufacturers relying upon volunteer donor plasma or placental source material demonstrated lower rates of HBsAg-positive lots of final products than those relying upon commercial donor plasma. There was a marked decrease in the prevalence of positive lots during the period 1971 to 1973, coincident with the onset of routine plasma donor screening for HBsAg. However, current requirements for plasma screening have not resulted in totally HBsAg-free plasma products. Use of more sensitive and more reliable tests for HBsAg will probably reduce contamination of plasma pools with HBsAg to undetectable levels. Despite HBsAg-status, however, the "high-risk" plasma products (fibrinogen, antihemophilic factor, factor IX concentrate) must still be considered capable of transmitting hepatitis and used only with the strictest indications.     

Tracheal obstruction associated with a fungus ball. A case of primary tracheal candidiasis

A case of transient filling defects in the renal pelves and ureters, secondary to spontaneously occurring acquired anticoagulants, is presented. The relationship of this entity to hemophilia, immunologic disorders, such as systemic lupus erythematosis, and normal post partum patients is discussed. The differential diagnosis for filling defects in the renal pelvis is reviewed.     

Villous papilloma of the rectum presenting as infective gastro-enteritis

Three elderly patients have recently been admitted as emergencies to the Infection Unit of the Aberdeen Hospitals as presumed cases of infective gastro-enteritis. Investigation revealed the presence of a villous papilloma of the rectum in each case.     

The sedimentation equilibrium of heterogeneously associating systems and mixtures of non-interacting solutes: analysis without determination of molecular weight averages

In 8 healthy subjects (group A) and 4 subjects with respiratory symptoms (group B), the lung pressure-volume curve (P-V curve), maximum expiratory flow-volume curve (MEFVC) and respiratory resistance (Rrs) at all vital capacities were measured. To avoid laryngeal artifact on a mouth pressure, an intratracheal catheter was used for measurement of Rrs which was obtained with 3 cycles/sec oscillatory forced pressure. Group B did not show a different elastic recoil from group A. In comparison of the maximum expiratory flow (Vmax) at 80, 70, 60 and 50% of the total lung capacity (TLC). Vmax of group B showed lower values than that of group A. Rrs was almost the same in both groups from 70% TLC upwards, but Rrs of group B was higher than that of group A from 65%TLC downwards. Since the lung elastic recoil pressures (Pst (1)) in the two groups were not different and Rrs's were different significantly only at low lung volumes, the decrease in Vmax of group B was supposed to be due to the increased Rrs which might reflect small airway obstruction.     

Participatory practices at work

This article discusses workplace participatory practices: the reciprocal process of engaging in and learning through work. The reciprocity between the affordance of the workplace (its invitational qualities) and individuals' engagement in the workplace is proposed as a means of understanding how learning through work proceeds. How workplaces invite individuals or cohorts of individuals to participate in and learn through work can be understood in terms of how they are afforded opportunities to engage in activities and interactions that are central to the values and practices (i.e. continuity) of the work practice. These affordances are shaped by workplace norms, practices and affiliations (e.g. cliques, associations, occupational groupings, employment status) and are often characterised by contestation and inequitable distribution. Access to opportunities for practice, and therefore learning, is directed towards sustaining the work practice and/or the interests of particular individuals and groups. Nevertheless, how individuals engage in and learn from work is also shaped by their agencies, which are a product of their values, subjectivities and identities. These reciprocal processes of participation in workplaces are illuminated through an analysis of the micro-social processes that shape the participatory practices of three workers over a six-month period: a union worker, a grief counsellor and a school-based information technology consultant. The findings illuminate the bases for participation, performance and learning for each of the three workers.     

Use of novel sensors combining local positioning and acceleration to measure feeding behavior differences associated with lameness in dairy cattle

Time constraints for dairy farmers are an important factor contributing to the under-detection of lameness, resulting in delayed or missed treatment of lame cows within many commercial dairy herds. Hence, a need exists for flexible and affordable cow-based sensor systems capable of monitoring behaviors such as time spent feeding, which may be affected by the onset of lameness. In this study a novel neck-mounted mobile sensor system that combines local positioning and activity (acceleration) was tested and validated on a commercial UK dairy farm. Position and activity data were collected over 5 consecutive days for 19 high-yield dairy cows (10 lame, 9 nonlame) that formed a subset of a larger (120 cow) management group housed in a freestall barn. A decision tree algorithm that included sensor-recorded position and accelerometer data was developed to classify a cow as doing 1 of 3 categories of behavior: (1) feeding, (2) not feeding, and (3) out of pen for milking. For each classified behavior the mean number of bouts, the mean bout duration, and the mean total duration across all bouts was determined on a daily basis, and also separately for the time periods in between milking (morning = 0630–1300 h; afternoon = 1430–2100 h; night = 2230–0500 h). A comparative analysis of the classified cow behaviors was undertaken using a Welch t-test with Benjamini-Hochberg post-hoc correction under the null hypothesis of no differences in the number or duration of behavioral bouts between the 2 test groups of lame and nonlame cows. Analysis showed that mean total daily feeding duration was significantly lower for lame cows compared with non-lame cows. Behavior was also affected by time of day with significantly lower mean total duration of feeding and higher total duration of nonfeeding in the afternoons for lame cows compared with nonlame cows. The results demonstrate how sensors that measure both position and acceleration are capable of detecting differences in feeding behavior that may be associated with lameness. Such behavioral differences could be used in the development of predictive algorithms for the prompt detection of lameness as part of a commercially viable automated behavioral monitoring system.     

Sensory characterization of human milk

Fore and hind milks from a single morning feed collected from 24 nursing mothers over 3 consecutive d were evaluated for sweetness, viscosity, and mouthcoat by a trained adult panel using magnitude estimation. Milks were perceived as sweet, thin, and low in mouthcoat. Hind milks were slightly more viscous and mouthcoating than fore milks. The higher fat content in hind milk was associated with higher estimation of physical viscosity. Milk fat content decreased as maternal age increased. Significant differences occurred between milks in lactose, fat, and protein contents. By use of a sweetness power function curve, the sweetness intensity of human milk was estimated as equivalent to a 2.12% sucrose solution.