Serum IgG subclass concentrations in healthy adults: a study using monoclonal antisera

IgG subclass concentrations have been measured in the sera of 172 healthy adults using monoclonal antisera. 'Normal ranges' are given. The findings were similar to those of previous studies of European populations but differed from the findings of the only other study of a large British population. In particular, low proportions of IgG4 in a British population have not been confirmed. IgG4 concentrations were higher in males than females (P = less than 0.00003) and IgG3 concentrations were higher in females than males (P = 0.034).

Purification and characterization of an inducible dissimilatory type sulfite reductase from Clostridium pasteurianum

An inducible sulfite reductase was purified from Clostridium pasteurianum. The pH optimum of the enzyme is 7.5 in phosphate buffer. The molecular weight of the reductase was determined to be 83,600 from sodium dodecyl sulfate gel electrophoresis with a proposed molecular structure: alpha 2 beta 2. Its absorption spectrum showed a maximum at 275 nm, a broad shoulder at 370 nm and a very small absorption maximum at 585 nm. No siroheme chromophore was isolated from this reductase. The enzyme could reduce the following substrates in preferential order: NH2OH greater than SeO3 (2-) greater than NO(2-) 2 at rates 50% or less of its preferred substrate SO3(2-). The proposed dissimilatory intermediates, S3O6 (2-) or S2O3(2-), were not utilized by this reductase while KCN inhibited its activity. Varying the substrate concentration [SO3(2-)] from 1 to 2.5 mumol affected the stoichiometry of the enzyme reaction by alteration of the ratio of H2 uptake to S2- formed from 2.5:1 to 3.1:1. The inducible sulfite reductase was found to be linked to ferredoxin which could be completely replaced by methyl viologen or partially by benzyl viologen. Some of the above-mentioned enzyme properties and physiological considerations indicated that it was a dissimilatory type sulfite reductase.

Systemic antibody deficiency in patients without serum immunoglobulin deficiency or with selective IgA deficiency

Serum IgG tetanus toxoid antibody (IgGTTab) concentrations were measured in patients with chronic chest infections or recurrent acute chest infections following immunization and compared with results obtained in a group of 43 controls. Apart from selective IgA deficiency in some patients, all had normal or high serum immunoglobulins. Using an enzyme linked immunosorbent assay (ELISA) for IgG TTab, antibody was present following one immunization in all controls who had previously been immunized and following two immunizations in those not previously immunized. Ninety-seven and a half per cent of controls had a serum antibody concentration of greater than 4 micrograms/ml. Following the same immunization schedule, eight of 45 (18%) patients with chronic chest infections and three of 11 (27%) patients with recurrent acute infections had a serum IgG TTab of less than 4 micrograms/ml. The three patients with a low IgG TTab concentration and recurrent acute infections all had selective IgA deficiency. Two of these patients have benefited from injections of normal human immunoglobulin. It is suggested that systemic antibody deficiency as a cause of chronic or recurrent respiratory tract infections cannot be excluded by measuring serum immunoglobulin concentrations alone and that it is of value to measure antibody responses following immunization.

Hypercalcaemia in a psychogeriatric population

Serum calcium concentration was estimated, via a multichannel analyser, in all patients admitted to a 25 bed psychogeriatric inpatient unit and associated day hospital. Case notes of 629 consecutive admissions over a 42 month period were studied, and the prevalence of hypercalcaemia found to be 0.7 per cent, close to that estimated for the general population. Cases of hypercalcaemia with psychiatric symptoms, undetected medically because of vague and non-specific physical symptoms, do not appear in excess in a psychogeriatric population.

On the absence of implicit sex-preference in Ghana

As part of a comparative analysis of uterine sibling groups to discover any evidence of ‘stopping rules’ related to actual preferences for children of one sex or another, the distribution of sequences of births by sex from a Ghanaian sample of 9392 mothers has been examined. No such rules can be detected.

Retinal changes in rats flown on Cosmos 936: A cosmic ray experiment

Ten rats, five centrifuged during flight to simulate gravity and five stationary in flight and experiencing hypogravity, orbited the Earth. No differences were noted between flight-stationary and flight-centrifuged animals, but changes were seen between these two groups and ground controls. Morphological alterations were observed comparable to those in the experiment flown on Cosmos 782 and to the retinal cells exposed to high-energy particles at Berkeley. Affected cells in the outer nuclear layer showed swelling, clearing of cytoplasm, and disruption of the membranes. Tissue channels were again found, similar to those seen on 782. After space flight, preliminary data indicated an increase in cell size in montages of the nuclear layer of both groups of flight animals. This experiment shows that weightlessness and environmental conditions other than cosmic radiation do not contribute to the observed damage of retinal cells.

Modification of a Kowa RC-2 fundus camera for self-photography without the use of mydriatics

Research on retinal circulation during space flight required the development of a simple technique to provide self monitoring of blood vessel changes in the fundus without the use of mydriatics. A Kowa RC-2 fundus camera was modified for self-photography by the use of a bite plate for positioning and cross hairs for focusing the subject's retina relative to the film plane. Dilation of the pupils without the use of mydriatics was accomplished by dark adaption of the subject. Pictures were obtained without pupil constriction by the use of a high speed strobe light. This method also has applications for clinical medicine.

Histochemical and immunohistochemical study of diffuse large-cell lymphomas

Ninety diffuse large-cell lymphomas (diffuse histiocytic lymphoma) were subclassified into B-cell, T-cell, and histiocytic types according to their enzyme histochemical and immunohistochemical characteristics. The B-cell type was characterized by presence of intracellular monoclonal immunoglobulin; negative or weakly positive diffuse acid phosphatase activity; and an occasional focal nodular pattern or preceding nodular lymphoma. The T-cell type was characterized by moderate, focal acid phosphatase activity; convoluted nuclear structure; and frequent preceding cutaneous manifestations. The histiocytic type was characterized by strong nonspecific esterases and diffuse acid phosphatase activity and presence of lysozyme and phagocytic activity. Most of the lesions (74 cases) were of the B-cell type. This group was further subdivided into follicular center cell type and B-cell immunoblastic sarcoma, according to the stage of cellular transformation. Preliminary clinical correlation suggests that the histiocytic type is most resistant to treatment. B-cell immunoblastic sarcomas were much more aggressive than neoplasms of the follicular center cell type.

Cosmic ray effects on the eyes of rats flown on Cosmos No. 782, experimental K-007

The eyes from six rats were fixed at the recovery site in Russia after they had circled the earth for 19.5 d in a 62.8 degree orbit. The eyes of six more flight rats were fixed 25 d later. These two preparations and eyes exposed to 1000 rad of neon and argon were compared to obtain data on possible radiation effects on the retina. Most of the flight eye tissue was normal; however, necrotic nuclei were found in the outer nuclear layer and channels were located in the outer segment area. Macrophages were seen between the pigment layer and outer segments. Comparison of the Day zero znd 25-d postflight eyes suggested some possible recovery. Light flashes seen by space travelers and damage from cosmic rays appear to arise from two different sites of interaction. The flashes are created by cosmic ray transversal of the outer segments while pathologic change, when it occurs, is quite possibly from interaction with some part of the nucleus. Nevertheless, direct interaction with other cellular components could also occur. Other factors, such as secondaries from spacecraft shielding, may play an important role.

The absent pulmonary valve syndrome. Considerations of management

The absent pulmonary valve syndrome consists of a severely hypoplastic pulmonary valve with anular stenosis, aneurysmal dilatation of the main pulmonary artery with one or both pulmonary branches also dilated, and a ventricular septal defect. From 1955 to 1975, 15 patients were seen at Texas Children's Hospital with this syndrome. Although anatomically similar to tetralogy of Fallot, the most significant symptoms during early infancy were secondary to bronchial compression resulting from the dilated pulmonary arteries and enlarged left atrium. Intracardiac repair performed on two infants at four months of age failed to ameliorate the respiratory symptoms and both died. Seven patients from 2.3 to 16 years of age were operated upon, with one late postoperative death. Five other patients have not yet received surgical intervention. We recommend vigorous continual respiratory therapy for for infants and small children and intracardiac repair in older children since repair in infancy does not relieve respiratory symptoms. We do not recommend a prosthetic pulmonary valve unless there is persistently elevated main pulmonary artery pressure.

Unilateral pulmonary vein atresia: Diagnosis and treatment

The clinical, hemodynamic, angiographic and pathologic features of unilateral pulmonary vein atresia in a 16 month old boy are described. The relevant findings were symptoms and signs of influenza, roentgenographic evidence of unilateral diffuse interstitial edema, prominent interlobar fissures and pleural effusion, absence of abnormal cardiac structure and prominent unilateral bronchial circulation. Angiocardiography was necessary for a definitive diagnosis and revealed the lack of a site of entry for venous blood from the right lung into the circulation. The patient was treated successfully by a right pneumonectomy. The histologic hallmark in this case was extensive intimal fibrosis of the pulmonary veins.

The Role of Compressional Viscoelasticity in the Lubrication of Rolling Contacts

A simple model for the time-dependent volume response of a liquid to an applied pressure step is used to calculate the variation with rolling speed of the traction coefficient in a rolling contact system. Good agreement with experimental results is obtained at rolling speeds above 50 in/sec. At lower rolling speeds a very rapid change in the effective viscosity of the lubricant is predicted. This behavior, in conjunction with shear rate effects, is shown to lead to large errors when experimental data are extrapolated to zero rolling speed.