New allergens from hen's egg white and egg yolk. In vitro study of ovomucin, apovitellenin I and VI, and phosvitin

Three hen egg yolk proteins, apovitellenins I and VI and phosvitin, and one egg white protein, ovomucin, were purified and tested for their ability to bind IgE in the sera of patients hypersensitive to egg. All of the proteins bound IgE from the sera of egg-allergic individuals in the radioallergosorbent test, and they also inhibited binding of IgE to the parent fractions-either egg yolk (apovitellenins I and VI and phosvitin) or egg white (ovomucin). It appears that apovitellenins I and VI are major allergens for some of the individuals tested. This is the first report of the in vitro allergenicity of these proteins.

Immunohistochemical localization of c-erbB-2 in human breast carcinomas

This study was carried out to assess the utility of antibodies raised to synthetic peptides of the predicted sequence of the c-erbB-2 gene product to identify immunocytochemically those tumours overexpressing this putative transmembrane receptor. Staining with rabbit antiserum 21N gave the best correlation with gene amplification and did not stain the membrane of any of the normal tissues at the dilution which strongly stained the membrane of any of the normal tissues at the dilution which strongly stained the amplified tumours. No significant correlation was found with lymph node involvement, epidermal growth factor receptor status or with oestrogen receptor levels. Of the 12 out of 34 cases which demonstrated c-erbB-2 gene amplification in the primary tumour, two had lymph node metastases which were also positive immunocytochemically. Fourteen other cases which had lymph node metastases were negative in the primary tumour and in the metastases. These tumours all showed strong membrane positivity. A comparison of modified methacarn and formol saline fixation demonstrated an increased sensitivity with the former, but the staining pattern was unaltered. This small but extensively studied group of cases has indicated that increased c-erbB-2 protein can be identified routinely in fixed tissue sections, making it possible to carry out extensive studies to look for clinical correlates, but also to assess the stage in tumour progression at which the increased expression occurs and whether it correlates with any potentially premalignant condition.

A novel whey protein synthesized only in late lactation by the mammary gland from the tammar (Macropus eugenii)

A major whey protein which appears in milk from the tammar wallaby (Macropus eugenii) only during the second half of lactation (late lactation protein-A, LLP-A) was purified to apparent homogeneity by ion-exchange chromatography and gel filtration. An Mr of 21,600 +/- 2000 was calculated from its amino acid composition. A computer-based comparison of the sequence of the first 69 amino acid residues with the Atlas of Protein Sequence data base showed no significant homology with known proteins. Antiserum to LLP-A was prepared in rabbits, and single radial immunodiffusion was used to measure the amounts of LLP-A in milk during the first 40 weeks of lactation. LLP-A was first detected at 26 weeks; thereafter its concentration increased abruptly, to reach a maximum of 26 g/l at approx. 36 weeks of lactation. Explants prepared from mammary gland biopsies at 20 and 35 weeks of lactation were exposed to [3H]amino acids for 8 h; immunoprecipitation of tissue extracts showed that, whereas the rate of casein synthesis was the same at both stages of lactation, LLP-A was synthesized only by the 35-week mammary gland.

Allergenic cross-reactivity of egg-white and egg-yolk proteins. An in vitro study

The radioallergosorbent test (RAST) and RAST inhibition test were used to examine cross-allergenicity amongst the major hen's egg-white and egg-yolk proteins. Using ovalbumin as a reference allergen to compare cross-reactivity, it was apparent that the proteins conalbumin, ovomucoid and lysozyme substantially inhibited binding to ovalbumin discs of IgE in the sera of patients clinically hypersensitive to egg. The converse situation with conalbumin, ovomucoid and lysozyme on the discs and ovalbumin as the inhibitor also resulted in significantly decreased levels of IgE binding to the proteins on the discs. It was also demonstrated that cross-reactions occurred between ovalbumin and the yolk protein, apovitellenin I. Cross-reaction was also observed surprisingly when egg lysozyme was on the disc and the milk protein allergen alpha-lactalbumin was used as the inhibitor. The demonstration of cross-reaction between all of these proteins may signify that there are a number of common allergenic determinants on these egg proteins, thus providing a molecular basis for the phenomenon of cross-reactivity.

Initiation of locomotion from the mesencephalic locomotor region: effects of selective brainstem lesions

The effects of selected brainstem lesions on controlled treadmill locomotion produced by stimulation of the mesencephalic locomotor region (MLR) in postmamillary cats were determined in these experiments. The importance for the initiation of locomotion of projections from the MLR to rostral brainstem structures, described in a preceding paper, were examined by selective lesioning or by adjusting the level of the decerebration. The role played by the lateral vestibulospinal tract (LVST) in the initiation of locomotion was examined by lesioning Deiters' nucleus bilaterally. Contrary to previous claims, the results of the present experiments show that areas of the brainstem rostral to the MLR are not required for the initiation of locomotion by MLR stimulation. This finding eliminates the ventral tegmental area of Tsai and the substantia nigra, both implicated in the initiation of locomotion, as required participants in MLR stimulated locomotion. Bilateral Deiters' nucleus (DN) lesions did not significantly affect the initiation of locomotion from the MLR, nor did such lesions alter in a systematic fashion the amplitude or timing of EMG activity in flexor or extensor muscles of the hindlimb during MLR evoked walking. Joint angle changes during the locomotor cycle were also essentially unaltered by DN lesions. The significance of these findings regarding the brainstem structures which must be involved in the initiation of locomotion are discussed.

Fluorescent monitoring of proteins during sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting

Fluorescent labeling of proteins was found to be a very sensitive and reliable alternative to conventional methods for monitoring proteins on Western blots. Proteins were labeled with 2-methoxy-2,4-diphenyl-3(2H)-furanone (MDPF) before SDS-PAGE. After electrophoresis and subsequent electro-blotting the fluorescent-labeled proteins were visible upon ultraviolet illumination of the nitrocellulose membranes, and could be photographed to yield an accurate record of the blots before subsequent serological analysis. The sensitivity for detecting MDPF-labeled proteins on nitrocellulose was 100-200 ng, 50 to 100 fold less sensitive than on gels. Fluorescent-labeled TMV and MStpV capsid proteins that were blotted onto nitrocellulose still reacted in serological tests and were detected when present in quantities as low as 100 pg. Fluorescent labeling allows accurate photographic records of the SDS-gel, blot and probed blot using only one sample, and no subsequent staining steps are required.

Solubilisation of human erythrocyte band 4.1 protein in the non-ionic detergent Tween 20

Extraction of spectrin-depleted erythrocyte membranes with the non-ionic detergent Tween 20, in a 0.1 M glycine-NaOH buffer (pH 9.8) leads to the solubilization of band 4.1 and the sialoglycoproteins. The comigration of band 4.1 with the sialoglycoproteins in gel filtration and detergent-free electrophoresis indicated that these proteins may be associated as complexes of high molecular weight. Although treatment of intact membranes with Tween 20 under the same conditions does not lead to direct solubilization of proteins, severe disruption of the membranes was observed under phase contrast microscopy. Suspension of the treated membranes in 5 mM phosphate buffer (pH 8.0) leads to the solubilization of band 4.1, spectrin, actin and the sialoglycoproteins. High molecular weight complexes of band 4.1 and the sialoglycoproteins were isolated from these extracts, suggesting a possible interaction between band 4.1 and sialoglycoproteins which may be important for linking the cytoskeleton to the membrane.

Adipocyte insulin-binding species: the 40 A Stoke's radius protein

Several laboratories have demonstrated the presence of large (70 A) (1 A = 0.1 nm) and small (40 A) insulin receptors. This report provides evidence that the 40 A insulin receptor migrates on dodecyl sulfate - acrylamide gel electrophoresis as a 90 000 dalton protein and that this protein is a single polypeptide chain. 125I-labeled insulin was bound to plasma membranes from isolated rat adipocytes. Following removal of unbound 125I-labeled insulin, the mixture was exposed to disuccinimidyl suberate. Proteins tagged with 125I-labeled insulin were separated by dodecyl sulfate gel electrophoresis or Sepharose 6B chromatography. Autoradiography of the gels demonstrated several large (relative mass (Mr) greater than 300 000) and one small (Mr approximately 90 000) labeled protein in nonreduced membrane proteins. Dithiothreitol reduction decreased the large insulin-binding species to its known subunits, but the 90 000 dalton protein did not decrease in size. Triton X-100 solubilized plasma membranes were separated by Sepharose 6B chromatography. One labeled protein, with Kav = 0.57 elution position, on dodecyl sulfate gel electrophoresis migrated as a 90 000 dalton protein. Thus, rat adipocyte plasma membranes contain both an oligomeric insulin-binding species and a monomeric insulin-binding species. The relationship of the monomeric to the oligomeric insulin receptor is discussed.

The accumulation of putrescine and paraquat into lung slices taken from BHT treated mice

Putrescine and paraquat have been shown to accumulate in slices of mouse lung by a process which obeys saturation kinetics. The Vmax for the process was similar for both compounds (1.18 and 1.29 mumol/g wet wt/h) although the apparent Km for putrescine was 15 microM compared with 209 microM for paraquat. Mice were given a range of doses of BHT (i.p.) and the sequence and nature of the changes in morphology of the lung determined by light and electron microscopy. Lung slices were prepared from mice given BHT, and their ability to accumulate both paraquat and putrescine was determined. Within 4 days of dosing with 200 mg BHT/kg, there was marked cellular proliferation in the lung with an increase in the number of type II epithelial cells. Seven days after dosing the lungs had generally returned to their normal morphology with only occasional areas in some lungs showing evidence of damage. Between 1 day and 7 days after dosing, slices of mouse lung showed a reduced ability to accumulate paraquat or putrescine. This did not return to control values until 14 days. The greatest reduction in the accumulation of either compound was seen 4 days after dosing when the proliferation of the type II epithelial cells was most marked. Mice given 150 mg BHT/kg showed similar but less extensive morphological change and the ability of lung cells from these mice to accumulate paraquat or putrescine was not as severely reduced compared with mice given 200 mg BHT/kg. With doses of 100 mg BHT/kg the accumulation of paraquat and putrescine was only slightly reduced and there was a correspondingly minimal affect on lung morphology. The lungs of mice given 50 mg BHT/kg were unaffected as was their ability to accumulate either compound. The results from this study, when taken in the context of previously reported data, support the conclusion that paraquat is accumulated into the lung by a process responsible for the uptake of putrescine. In the rat, paraquat and putrescine are known to accumulate in alveolar type II cells and therefore it appears that the regenerating alveolar type II epithelial cell is functionally unable to accumulate these compounds and may be considered physiologically similar to type II epithelial cells in immature animals.

Adipocyte insulin-binding species: the size and subunit composition of the larger binding species

Several investigators have reported that there are both large and small insulin-binding proteins in plasma membranes; the larger protein demonstrates nonlinear Scatchard binding, and the smaller protein has linear binding. We now present evidence that the larger insulin-binding species consists of four proteins of different sizes. Rat epididymal adipocyte plasma membranes were prebound with 125I-insulin and then exposed to 1 mM disuccinimidyl suberate for 15 min at 2 degrees C. The membranes were solubilized in 0.1% Triton X-100 and applied to a Sepharose 6B column. Peaks of radioactivity from the column were dialyzed, lyophilized, and analyzed by dodecyl-sulphate gel electrophoresis (5%, 100/l; mono/bisacrylamide). Autoradiograms of the gels were scanned with a densitometer. The Sepharose chromatogram revealed four radioactive peaks: peak 1 at column void volume; peak 2, Kav = 0.27; peak 3, Kav = 0.77; and peak 4, Kav = 1.09. Dodecyl sulphate electrophoresis of fractions in peak 2 demonstrated four bands on autoradiography; peak 1 did not enter the gel and peaks 3 and 4 ran with the dye front. Molecular weight estimates of the four insulin-binding species in peak 2 were 600, 500, 420, and 350 K. On dithiothreitol reduction each insulin-binding species yielded subunits of Mr approximately equal to 135 and 18 K. The three largest binding species demonstrated an additional 45-K dalton protein on dithiothreitol reduction, and the 500-K and 420-K binding species also yielded a 49-K dalton protein. These results suggest that the large insulin-binding protein in rat epididymal adipocytes contains several insulin-binding species, and that these insulin-binding species differ in the number of and the type of subunits they contain. In addition, it may be postulated that the nonlinear Scatchard binding associated with the larger binding protein is a consequence of the heterogeneity of the insulin-binding species in this Sepharose peak.

Influence of streptozitocin-induced diabetes on glycosyltransferase activities in plasma and renal cortex

The collagen glucosyltransferase of renal cortex is increased in experimental diabetes and this increased may be partially reversed or prevented by insulin treatment. The absence of any consistent increase in the plasma collagen glucosyltransferase level in diabetes argues against the enzyme's having a significant role in the pathological thickening of capillary basement membranes. The biological significance of the increased renal glucosyltransferase activity in chemically-induced diabetes must therefore remain in doubt but it is possible that the high glucose concentration in the blood simply stimulates the synthesis of new enzyme protein in the kidney.

Synthesis and assay for activity of a proposed anorexogenic agent, L-pyroglutamyl-L-histidyl-glycine

L-Pyroglutamyl-L-histidyl-glycine has been reported to be an anorexogenic agent in female mice. In this report the synthesis of this tripeptide is described. The synthetic material was injected into female and male mice and into male rats. In no instance did the animals decrease their food intake. Further, the weights of peptide-treated animals were the same as those of control (saline-treated) animals. The results suggest that L-pyroglutamyl-L-histidyl-glycine is not an anorexogenic agent.

Economic aspects of village health

Given the poor quantity and quality of medical care in most villages in the developing countries, the economic determinants of village health are the supply of labour, the cash flow associated with that labour and the availability of land. The paper examines these in the three classical 'time periods', arguing that inability to meet labour peaks is of great significance in explaining seasonal shortage of food and chronic shortage of cash. It also explains community indifference to upkeep of social overhead capital. Substitution of capital goods for labour is socially differentiated, not least by labour availability, and leads inevitably to a regressive distribution of land and the creation or enlargement of a class of landless labourers. Under certain limited conditions this class may enjoy a rising real income with associated health-promotive expenditures. The more normal case, however, is extreme poverty, whether rural or urban, with all that that implies for the undermining of health. Land reform therefore becomes a necessary precondition of health promotion.

Combined hyperlipidemia and hypertriglyceridemia in renal allograft recipients. Comparison with non-renal combined hyperlipidemic or hypertriglyceridemic patients and normal subjects

In order to investigate the degree of similarity between renal transplant and non-renal combined hyperlipidemic and hypertriglyceridemic patients, serum and lipoprotein lipid compositions were compared in transplant and non-renal combined hyperlipidemic and in transplant and non-renal hypertriglyceridemic patients, and normal subjects. Although certain similarities were demonstrated, combined hyperlipidemia in transplants differed from that in non-renal patients in a number of respects: (1) LDL-triglyceride levels were increased to a greater extent in transplant than in non-renal patients in females, while LDL-phospholipid was elevated in male transplants only; (2) HDL-cholesterol levels were raised in transplants relative to non-renal patients in females, and relative to both non-renal patients and normal subjects in males; (3) a number of differences in lipoprotein-lipid ratios between transplant and non-renal patients were demonstrated for all three lipoprotein fractions. In hypertriglyceridemia, changes in lipoprotein-lipid levels were similar in transplant and non-renal patients with the exception of HDL-cholesterol levels, which were decreased in non-renal patients only. Furthermore, the ratio of esterified to free cholesterol in LDL and HDL was decreased in non-renal but not in transplant patients. The data presented demonstrate that, despite certain similarities, a number of the lipoprotein-lipid changes observed in transplant combined hyperlipidemia and in transplant hypertriglyceridemia differ from those observed in non-renal patients with similarly elevated serum lipids.

Factors influencing the response latencies of subnormal children in naming pictures

The times taken to name 56 drawings of objects on five separate occasions were analysed for 21 ESN(M) and 21 ESN(S) children, matched for picture-naming vocabulary. The ESN(S) group not only had a higher mean response latency but also showed greater inter- and intra-subject variance. Nine objects were selected whose names have a Thorndike-Lorge language frequency of 50 words per million or greater, and nine others were selected with a frequency of less than 50 words per million. Each object was drawn in two ways, one giving a two-dimensional outline with the addition of important detail, the other drawing also incorporating cues indicating the depth of the object. An analysis of variance of the children's latencies in naming the selected 36 pictures of 18 objects over five trials indicated that the method of drawing had no effect upon naming latencies. Pictures with high-frequency names were named faster than those with lower frequency names, the ESN(S) group showing a greater rate of increase in naming latency for the lower frequency words than the ESN(M) children. Results were discussed in terms of the Oldfield and Lachman models of lexical memory storage and of the search processes required for the retrieval of names.

Hypercholesterolemia in renal allograft recipients. Comparison with non-renal hypercholesterolemia and normal subjects

In order to investigate the degree of similarity between renal transplant and non-renal hypercholesterolemia, serum and lipoprotein lipid compositions were compared in female transplant hypercholesterolemic patients (serum cholesterol greater than 240 mg/100 ml, serum triglyceride less than 150 mg/100 ml) and female non-renal hypercholesterolemic and normal subjects. A number of lipid abnormalities were demonstrated: (1) Serum and LDL cholesterol and phospholipid levels were significantly elevated in both transplant and non-renal hypercholesterolemic patients; (2) Serum triglyceride, VLDL choelsterol, triglyceride and phospholipid, and LDL and HDL triglyceride were significantly increased in transplant hypercholesterolemic patients. Changes of this nature are usually found in hypertriglyceridemia, and were not observed in non-renal hypercholesterolemic subjects. Finally, a number of changes in the ratio of esterified to free cholesterol and in the ratios of other lipoprotein-lipids, most of which did not correspond to any changes found in the common non-renal hyperlipidemias, were also demonstrated.