Complement activation in semisolid media: insolubilization of alternative pathway convertases in agar gels with C3 nephritic factor-containing sera

It was previously shown that when normal human serum and purified properdin or serum containing nephritic factor were allowed to diffuse toward each other in agar, a stainable precipitin line formed only in the presence of an intact alternative pathway. In the present study we have shown that when guinea pig erythrocytes were incorporated in agar and normal human serum was allowed to diffuse toward C3 nephritic factor-containing serum, a line of hemolysis appeared that coincided with the stainable line. The line of hemolysis only formed in the presence of C3, factor B and Mg++, as does the properdin or C3 nephritic factor-induced stainable line. When C2-deficient serum was incorporated in agar with guinea pig erythrocytes and serum samples containing nephritic factor were applied in wells, rings of lysis developed, the areas of which correlated significantly with nephritic factor activity. When partially purified nephritic factor (contaminated only with IgG) or serum containing nephritic factor was subjected to electrophoresis in agar-guinea pig erythrocyte gels and overlaid with normal human serum, bands of lysis developed that required factor B and C3. Lysis of guinea pig erythrocytes in this system appears to be due to insolubilization of alternative pathway convertases with activation of the membrane attack unit C5-C9.

Heterogeneity of nephritic factor and its identification as an immunoglobulin

Complement C3 nephritic factor (NeF) produces alternative pathway-meciated C3 cleavage by binding to and stabilizing the alternative pathway C3 convertase, C3bBb. Some studies have suggested that NeF is an immunoglobulin, while others conclude that it is a distinct serum protein. The heterogeneity of NeF was evaluated by electrophoresis and isoelectric focusing of NeF-containing serum followed by hemolytic demonstration of NeF activity in agar gel. With each method, diffuse cathodal zones or multiple bands of hemolysis developed, which revealed remarkable variations in patterns from patient to patient. NeF activity was absorbed by and eluted from insolubilized antibody to Fc and Fab fragments of IgG. Immunoabsorption of six NeF-containing sera with insolubilized anti-kappa and anti-lambda light chain antisera revealed that NeF had kappa antigenic determinants in three, lambda antigenic determinants in one, and both kappa and lambda antigenic determinants in two. These data indicate that NeF is an oligoclonal immunoglobulin. Because NeF binds to the alternative pathway C3 convertase, C3bBb, we suggest that it is an antibody to a conformational antigen of the C3-factor B complex, and thereby stabilizes this complex.

Mesangial proliferative glomerulonephritis with irregular intramembranous deposits. Another variant of hypocoplementemic nephritis

Two patients with a persistent mesangial proliferative glomerulonephritis and reduced serum C3 levels have been followed for six and 10 years. Both have had a mild course with normal renal function and spontaneous morphologic improvement. Levels of the fourth component (C4) and second component (C2) of complement, and properdin factor B have been normal; the third component (C3) of complement nephritic factor has not been detected. Ultrastructurally, irregular intramembranous electron-dense deposits are present, primarily within the lamina densa. These deposits are separated by varying lengths of normal-appearing glomerular basement membrane. Intramembranous and subendothelial electron-lucent areas, containing vesicles, are also seen. Subendothelial deposits, mesangial interposition, splitting of the glomerular basement membrane and ribbon-like intramembranous deposits are not found. The disease in these patients was clinically indistinguishable at onset from mrmbranoproliferative glomerulonephritis (MPGN). The possibility of a variant with mild clinical course, no progression and spontaneous morphologic improvement is important in planning and assessing treatment programs in this disease group.

Fundamental nature of human infant's brain asymmetry

Morphological speech zone asymmetry in man cannot be due to environmental or developmental factors after birth. The functional implication of such a finding is not yet clear. Morphological asymmetry of the human brain is paralleled by electrophysiological evidence of cerebral hemispheric asymmetries. The results of our analysis of 50 infants suggest that clear occipital-temporal coherency asymmetry similar, but not identical to the adult pattern, also exists at or near birth. These asymmetries are generated by stimuli with no verbal content and in infants who presumably have no or an undeveloped capability for language. It is suggested that language is only a part of much more fundamental asymmetries which include the processing of auditory and visual information. Our results, and those of other, are consistent with the assumption that the left hemisphere is more able to relate stimuli to past experience, either short or long-term, while the right hemisphere is more able to process, stimuli which are not easily identifiable or referable. These capabilities would not be based on language, and hence would be expected to develop independently and possibly before speech. The demonstration that reversing electrophysiological asymmetries can be generated with non-speech stimuli in the visual and auditory modalities, and in neonates, supports such an assumption.

Double-blind trial of cholestyramine in post-vagotomy diarrhoea

The effect of cholestyramine in post-vagotomy diarrhoea has been assessed under double-blind conditions. Cholestyramine produced a significant improvement in frequency, urgency, and consistency of stool as well as episodic diarrhoea. Faecal bile acid excretion was significantly higher in the post-vagotomy group when compared with normal controls. These findings confirm the effectiveness of cholestyramine and support the concept of a bile acid mediated aetiology in post-vagotomy diarrhoea.

Frequency and etiology of gross hematuria in a general pediatric setting

Since the frequency of gross hematuria in general, unselected, pediatric outpatient settings has not been reported, we reviewed all patients with this symptom or sign at a pediatric emergency walk-in clinic during 24 consecutive months. Of a total of 128,395 patient visits, gross hematuria was proven in 158 (1.3/1,000 visits). Fifty-six percent of all patients had readily apparent causes for their gross hematuria. Twenty-six percent of all hematuric patients had documented urinary tract infections, but only 9% had apparent glomerular disease.

Effect of iron and protein deficiency on the expulsion of Nippostrongylus brasiliensis from the small intestine of the rat

The relationship between iron deficiency and protein deficiency and infestation of the rat with the nematode Nippostrongylus brasiliensis was investigated. There was a significant delay in the expulsion of N. brasiliensis from the small intestine of both iron deficient and protein deficient animals and those with a combined deficiency of iron and protein. Iron repletion returned the time of worm expulsion to normal and this would appear to be related to iron deficiency per se rather than to anaemia. Antibody initiated damage to worms was normal in the control animals and in animals with nutritional deficiencies. This suggests that the defect in worm expulsion occurs either in the cell-mediated immune system or in one of the other mediators of expulsion. Extrapolation to the human situation has important therapeutic implications in that iron and protein deficiency may play an important role in the perpetuation of helminth infestations. Thus, to be successful antihelminth therapy should be accompanied by iron and protein supplementation.

Evaluation of the Honeywell ACS 1000

The Honeywell ACS 1000, an automated computerized scanning system, is evaluated against the recommended manual method for WBC differentials. Over 400,000 data points were gathered by both methods during an 11-month study, employing routine peripheral blood smears and critically characterized control preparations. These data were found to exhibit an effective increase in throughput, precision, comparable accuracy, and a reduction in operator fatigue. In addition, the instrument demonstrates application to the improvement of quality control, teaching, and continuing education.

Lateralisation of speech dominance by spectral analysis of evoked potentials

A computerised evoked potential test for the lateralisation of speech dominance was compared with the intracarotid sodium amylobarbitone test in 22 epileptic patients. Based on spectral analysis, the computer test correctly predicted the speech dominance of 15 of 16 left speech dominant and five of six right speech dominant patients. This non-invasive test is simple, quick, and innocuous and can be easily implemented on a small laboratory computer.

Follow-up studies on liver disease associated with HBsAg carriers

Eight male subjects who were initially studied in 1972 with liver biopsy because of HBsAg carrier status were re-studied two years later with liver biopsy, clinical examination and standard liver function tests. Three of the eight subjects remained antigen positive and had continuing liver disease, this being either chronic active hepatitis or chronic persistent hepatitis. two subjects became HBsAg negative and their liver biopsies returned to normal. One subject became HBsAg negative but his biopsy disclosed chronic active hepatitis with cirrhosis in the presence of normal liver function tests. While persistence of the antigenaemia is associated with persisting liver disease, the converse is not true in that the disappearance of the antigen does not necessarily imply an improvement in liver disease. Liver biopsy remains the only reliable means of assessing liver disease as biochemical tests of liver function and the clinical findings may be of little value.

Iron fortification of milk powder

The bioavailability of an iron-fortified full cream milk preparation was studied and found to be effective for supplementation of the diet with iron. It consequently could be of value in the prophylaxis against iron deficiency and serve as an additional source of dietary protein.

Evaluation of an improved Reagent Strip system for measuring blood glucose

Using a new, synthetic whole-blood control and an improved reflectance meter, the within-run precision of Dextrostix Reagent Strips for quantitative determination of blood-glucose levels is compared with three common manual methods (hexokinase, o-toluidine, and glucose oxidase), and one automated method (neocuproine-AutoAnalyzer). In addition, the strip is compared on a day-to-day basis with the o-toluidine method. Dextrostix, used with the new instrument and control, provides results that compare very well with the other methods for within-run precision, and with the o-toluidine method for day-to-day results.

Constancy and linearity of the metabolic clearance of adrenocorticotropin in dogs

The study of the turnover characteristics of adrenocorticotropin (ACTH) has been facilitated by (1) a sensitive bioassay for ACTH in plasma based upon the response of suspended adrenal cells to ACTH and (2) a technique for preserving the ACTH in small plasma samples. The metabolic clearance rate (MCR) of ACTH was determined by intravenous step infusions of ACTH into dogs lightly anesthetized with Nembutal, without blockade of ACTH secretion; in these dogs the endogenous plasma ACTH level was negligible. The infusion rates ranged from 0.25 to 3.0 mU/kg∙min, yielding plasma ACTH plateau concentrations of 1.8 to 37 mU/100 ml. In no dog did the MCR correlate significantly with plasma concentration, nor did the MCR differ significantly from dog to dog. The 34 successful plateaux yielded a mean MCR of 9.54 ± 0.24 ml/kg∙min. Linear regression of MCR versus concentration yielded a correlation coefficient of −0.00026. The findings showed that the disappearance of ACTH from blood is not dose-dependent and varies negligibly with time or among animals. Hence the measured MCR may be used to convert concentrations of ACTH in plasma into turnover rates.

Liver disease and cell-mediated immunity in hepatitis-associated antigen (HAA) carriers

As the incidence of liver disease in hepatitis-associated antigen (HAA) carriers has not been defined and it has been postulated that continuing liver disease is associated with incompetence of the cell-mediated immune system, a prospective study was undertaken to examine both these points.An increased incidence of HAA carriers was found in a prison population (1.3%). Eighteen of these subjects gave informed consent to further study with liver function tests, liver biopsy, and testing of cell-mediated immunity with dinitrochlorobenzene (DNCB) skin sensitization. Liver function tests were normal in 10 subjects, mildly abnormal in six (SGPT < 100 IU/litre), and abnormal in two. Serum proteins were normal in all. Liver biopsy showed that five subjects had chronic aggressive hepatitis, three of whom had normal liver function tests. Eight subjects had persistent hepatitis, three with normal liver function tests. The remainder had acute hepatitis (1), evidence of residual hepatitis (1), or non-specific changes (2). Only one subject had normal histology. Drug addicts, who comprised 56% of the group, had more severe liver disease then those who were not addicts. The hypothesis that persisting liver disease is associated with impaired cell-mediated immunity was not confirmed in that nine of the 12 subjects with persistent or chronic aggressive hepatitis had a positive response to dinitrochlorobenzene skin sensitization, thus implying normal cell-mediated immunity. The findings of this study suggest that in the presence of continuing antigenaemia liver biopsy is mandatory in order to disclose treatable liver disease.

Effect of pressure on the integrity of the duct-acinar system of the pancreas

India ink introduced into the pancreatic ducts of the cat can escape into the interstitium at pressures below the maximum secretory pressure of the pancreas. The ink appears to leave through clefts between the acinar cells.

Adaptation of intestinal lactase in the rat

A study was undertaken to adapt intestinal lactase activity in adult rats. After 5 to 8 weeks on a 30% lactose diet, a significant increase in jejunal lactase activity was observed. A similar, but smaller rise was found using a 30% glucose diet.

Effects of ethyl alcohol on sphincteric resistance at the choledocho-duodenal junction in man

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