Immunoglobulins of the snake Psammophis sibilans. Studies using a monoclonal antibody

A mouse monoclonal antibody (mAb) raised against serum immunoglobulins (Ig) of the snake. Psammophis sibilans stained in indirect immunofluorescence a proportion of snake splenic and peripheral blood lymphocytes, whereas it did not react with thymocytes, erythrocytes, brain, heart, lung, liver or kidney cells. The mAb, designated SR-2, combined in enzyme-linked immunosorbent assay (ELISA) with serum proteins of each of 20 individual P. sibilans tested. On Western blots of P. sibilans reduced whole serum proteins, purified Ig, or anti-rat erythrocyte (RRBC) antibodies eluted from glutaraldehyde-fixed RRBC, mAb SR-2 identified two bands of apparent molecular weight (m.w.) of 60,000 and 51,000 daltons. These bands were due to distinct polypeptides and not resulting from heterogeneous glycosylation of a single polypeptide, as they both were readily detected after periodate oxidation or endoglycosidase-F treatment of serum proteins and isolated Ig. MAb SR-2 bound to CNBr-activated Sepharose 4B precipitated from P. sibilans 125I-labeled serum proteins under non-reducing conditions a band that did not enter 7.5 or 9-16% gel and one of about 150,000 daltons. Under reducing conditions, two heavy bands of approximately 63,000 and 50,000 daltons and two light chains of apparent mass 23,000 and 20,000 bands were precipitated. The data presented provide, for the first time, substantial information on the molecular characteristics of snake Ig.

Formation and proliferative effects of lipoxins in human bone marrow

Lipoxins A4 and B4 together with the all-trans lipoxin (LX) isomers were produced by normal human bone marrow cell suspensions after incubation with ionophore A23187. Both LXA4 and LXB4 enhanced the growth of myeloid progenitor cells in semisolid agar in the presence of suboptimal concentrations of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF). Lipoxin A4 at 10(-10) M stimulated the colony formation in 13 out of 15 tested human bone marrows with a mean (+/- SEM) increase of 47 +/- 11% (p = 0.001). A similar stimulatory effect was observed after addition of LXB4 (10(-10) M). The monohydroxyeicosatetraenoic acids 5-, 12- and 15-HETE did not affect colony growth. In addition, LXA4 (10(-8) M) efficiently counteracted the increased colony formation induced by leukotriene C4 (10(-10) M), suggesting an antagonistic relationship between these lipoxygenase products. The results support a role for lipoxins in the regulation of human myelopoiesis.

[Acute respiratory distress syndrome in the initial phase of myocardial infarction in adults]

Four patients developed an acute respiratory distress syndrome characterised by clinical and radiological signs of pulmonary oedema, a protein-rich oedema, severe hypoxemia refractory to oxygen therapy, contrasting with normal left ventricular filling pressures and indicating increased permeability of the alveolo-capillary membrane, 24 to 72 hours after the onset of acute myocardial infarction. After having excluded the usual causes of the acute respiratory distress syndrome, the authors suggest that acute myocardial infarction, especially when extensive, may cause a lesion of the alveolo-capillary membrane by an unknown mechanism. Treatment consisted in mechanical ventilation with positive expiratory pressures in 3 cases and with continuous positive pressure during spontaneous respiration in the third patient and in relay with controlled ventilation in the other two. These techniques of ventilation improved the hypoxemia and led to complete cure in all cases without evolution to pulmonary fibrosis. In addition to mechanical ventilation, all patients were given systematic antibiotic therapy because of the possibility of an infectious etiology while waiting for the results of microbiological and serological testing and because of the high risk of superinfection which plays an essential part in the outcome of the condition. The immediate response to treatment was favourable in all cases. One patient died suddenly of cardiogenic shock two weeks after this episode. The other patients are still alive 39, 38 and 20 months after infarction. The importance of the diagnosis of the acute respiratory distress syndrome in the acute phase of myocardial infarction resides in its therapeutic implications which are quite different to those of cardiogenic shock.(ABSTRACT TRUNCATED AT 250 WORDS)

[In Tunisia: description of a health education program based on socio-cultural realities]

Structured within the framework of the National Programme for the Fight Against Diarrhoea in Tunisia, (PNLAD) the goal of the LAD Project is to improve the understanding and in-home treatment of diarrhoea by mothers. The programme consists of three elements: education of the mothers through health centers and preschool institutions, training of health care and social workers, and a mass media campaign. This article discusses the education programme for mothers through preschool institutions. Before embarking on its education programme, the project team conducted a preliminary study in order to establish what level of knowledge of diarrhoea existed among the general population and what current treatment methods were used. The study consisted of small discussion groups composed of mothers, grandmothers, and fathers. In evaluating current notions regarding diarrhoea, the study noted the various vocabulary used and its meaning for both diarrhoea and dehydration. It also examined the general beliefs of what caused diarrhoea and what people believed would cure and/or prevent the disease. As far as treatment methods were concerned, it was important to understand the origins of the various remedies, the level of awareness of the formal and informal health channels that existed and the different kinds of treatment based on diet, mother's milk, liquids, saline/sugar solutions and medication. The second key aspect of the programme concerned the kind of educational materials and teaching methods used. Both had to be geared towards the teaching of adults while insuring a real exchange of knowledge and experience between the population and the development personnel.(ABSTRACT TRUNCATED AT 250 WORDS)

HIV infection surveillance in Mogadishu, Somalia

A group of 89 prostitutes and 45 patients attending sexually transmitted disease clinics in Mogadishu, Somalia were examined for evidence of HIV infection. Both groups reported more than 1 sexual partner routinely and had sexual contacts with prostitutes. There was a significant amount of sexually transmitted diseases (STDs) in these two groups, with 11.2% and 6.7% respectively being culture positive for N. gonorrhoea. Among the prostitutes, 28.1% were positive for antibodies to T. pallidum while only 4.4% of the STD patients were positive. One isolate of N. gonorrhoea was resistant to penicillin. All study participants were negative for antibodies to HIV suggesting an extremely low prevalence of HIV in high risk behaviour groups in the capital city of Somalia.

The use of the bromine partition test in the diagnosis and prognosis of tuberculous meningitis

The bromine partition test was successfully used to differentiate cases of proven tuberculous meningitis from patients with aseptic and non-tuberculous meningitis. Forty patients, 22 males and 18 females aged 5 to 30 years (mean 13.5 +/- 6.2), were included in the study. Nineteen patients were confirmed to have tuberculous meningitis, 12 had aseptic meningitis, and 9 bacterial meningitis. All patients received 0.6 mci/kg of bromine 82 administered through a nasogastric tube as ammonium bromide dissolved in 5 ml of isotonic sodium chloride. The serum to CSF bromine ratio was then calculated 48 hours after the dose. The test was then repeated 8 days later in patients with bacterial meningitis and 8, 90, and 180 day later in patients with tuberculous meningitis. The test was very useful in quickly differentiating cases of aseptic from bacterial and tuberculous meningitis and was also a useful prognosticator in patients with severe tuberculous meningitis.

Effect of gamma irradiation on the rate of cyst development of E. granulosus larvae in Swiss albino mice

White albino mice Mus Musculus albinus were intraperitoneally inoculated with aseptical normal and gamma irradiated protoscolices of E. granulosus at dose level of 40, 60, 80 and 100 Kr. Mice, either normaly infected or infected with irradiated protoscolices and sacrificed at intervals of 4, 6, 8, 10, 12, 14 and 16 weeks, showed a marked increase in the percentage of cyst number in the liver than in the peritoneal cavity or around spleen, although by increasing the dose level to 100 Kr. no cyst were developed around the spleen. Meanwhile the % of developing cyst in the peritoneal cavity was time and dose level dependent. The mean cyst diameter showed a progressive increase with the increase of infection time and a successive decrease by increasing the dose level of gamma irradiation. An increase in the number of cyst was observed particularly in normal mice where a marked increase was noted on the 8th week post infection while a successive decrease in the mean number of cyst was observed by increasing the dose level of gamma irradiation.

[Annulo-aortic ectasia]

On the basis of a literature review and the study of 18 cases, the authors examine annuloaortic ectasia, which involves dilatation of the fibrous ring of the heart at the aortic orifice, marked by aortic regurgitation and dystrophic aneurysm of the ascending aorta. The authors noted a predominantly muscular disorder (14 males, 4 females) often detected from an assessment of aortic regurgitation without clinical, radiologic or specific electrical features. The value of echocardiography and Doppler echocardiography is clearly apparent from the diagnosis of the disease, monitoring of progress, selection of patients for invasive pre-operative explorations and post-operative surveillance. The developing gravity of this disease is stressed, rapid repercussions in the left ventricle intervening more than complications due to ectasia itself. This indicates the urgency of complete replacement of the whole ascending aorta and of the aortic valve with reimplantation of coronary arteries as in the Bentall or Bentall-Cabrol surgical intervention, seven cases of which have been reported with satisfactory results.

Correction of reentrant atrioventricular tachycardia by surgical ablation of accessory pathways

Patients with reentrant atrioventricular (AV) tachycardia have an accessory connection in addition to the normal conduction pathway, AV node and His-Purkinje system. This pathway predisposes some patients to recurrent, disabling supraventricular tachyarrhythmias. Although it is found with other associated cardiac conditions, most patients are healthy with no underlying structural heart disease. Interest has developed in surgically dividing the accessory pathway in patients with arrhythmias poorly controlled with medications or at risk for potentially fatal tachyarrhythmias. Surgery is safe and effective and should be considered for patients with rapid AV conduction during atrial fibrillation, those refractory to pharmacologic therapy, and young patients who otherwise would require lifelong antiarrhythmic therapy. This report describes surgical correction of reentrant AV tachycardia in five patients ranging in age from six months to 23 years.

Cytokines and immunoglobulin in rheumatic heart disease: production by blood and tonsillar mononuclear cells

Rheumatic fever and rheumatic heart disease are considered to result from abnormal immune responses after Group A streptococcal pharyngitis. Production of interleukin 1 (IL-1), tumor necrosis factor-alpha (TNF), interleukin 2 (IL-2) and immunoglobulin (Ig) by blood and tonsillar mononuclear cells from rheumatic or healthy children was measured after stimulation in vitro by pokeweed mitogen (PWM) or the streptococcal extracellular product, blastogen A (BLA). Tonsillar cells from patients with rheumatic heart disease produced significantly less IL-1, TNF, IL-2, and Ig than control tonsillar cells. In contrast, blood mononuclear cell cultures from rheumatic children produced more TNF and IL-2 than controls. Our findings suggest that abnormal regulation of cytokine and Ig production may contribute to the pathogenesis of acute rheumatic fever and rheumatic heart disease.

Antibody to carbohydrate and polypeptide epitopes on the surface of schistosomula of Schistosoma mansoni in Egyptian patients with acute and chronic schistosomiasis

125I-Schistosoma mansoni schistosomulum surface antigens were immunoprecipitated with human antibodies from individual Egyptian patients diagnosed as being either acutely or chronically infected with S. mansoni. Both sets of patients were found to have IgG antibodies in their sera capable of immunoprecipitating the major Mr greater than 200, 38 and 32K antigens. However, the immunoprecipitation of the Mr greater than 200K antigen was found to constitute a significantly greater proportion of the total precipitate achieved with acute sera than with chronic sera. The Mr 38 and 32K antigens were more variably precipitated by the acute sera than the chronic sera but the proportion of the total precipitation that these two antigens constituted was not found to be significantly different between the two sets of sera. Immunoprecipitation with pooled antibodies absorbed with egg and adult worm homogenates which had been treated to remove either carbohydrate or polypeptide epitopes demonstrated that the Mr greater than 200K antigen was the principal target of egg-cross-reactive anti-carbohydrate antibody amongst the antigens detected. The Mr 38 and 32K antigens were found to be precipitated by antibodies to protease-sensitive and periodate-insensitive polypeptide epitopes. These results are consistent with egg-cross-reactive anti-carbohydrate IgG antibody making a greater contribution to schistosomulum surface recognition in acute infection than in chronic infection. Indeed the presence of a higher level of egg-cross-reactive and anti-carbohydrate antibody directed against schistosomulum surface epitopes in an acute serum pool than in a chronic serum pool was confirmed by measurement of antibody binding to whole schistosomula.

A substrate amplification system for enzyme-linked immunoassays. II. Demonstration of its applicability for measuring anti-DNA antibodies

We have recently described a substrate amplification system, based on the method of Self, which increases the sensitivity of alkaline phosphatase (AP)-dependent enzyme-linked immunosorbent assays (ELISA) by a factor of 30-50. This increase is achieved by having AP, the primary enzyme, produce an activator for a secondary enzyme-substrate system, within which marked amplification occurs. We have now demonstrated that this amplification method can be applied to the measurement of human antibodies to DNA. The sensitivity is greater by a factor of 10 than the conventional method, which uses p-nitrophenyl phosphate (p-NPP) as substrate. On replicate assays the method is reproducible, with a coefficient of variation of less than 0.1. This great increase in sensitivity should be of value in conserving specimens of serum and in screening monoclonal antibodies.

Optimization of symptomatic therapy in Parkinson's disease

A third-order nonlinear mathematical model of the dose-effect relationship of levodopa, one of the most common drugs used for the symptomatic therapy of Parkinson's disease, is derived with the aid of a visual tracking based method which allows the measurement of some Parkinsonian symptoms quantitatively and objectively. The parameters of this model are identified for each subject separately due to the large interpatient variability in response to treatment. The model is then used to optimize the dosage regimen for each patient individually (according to the clinical particularities and needs of each patient) with respect to an objective function which includes the symptoms dynamically and the total amount of levodopa which is to be administered. Encouraging clinical results of this control engineering approach to therapy optimization are presented. The advantages and drawbacks of this approach are discussed and further research directions are indicated.

A substrate amplification system for enzyme-linked immunoassays. Demonstration of its general applicability to ELISA systems for detecting antibodies and immune complexes

Self recently described a substrate system for alkaline phosphatase (AP)-dependent ELISAs which markedly increased sensitivity, compared to using p-nitrophenyl phosphate. This increase is achieved by having AP, the primary enzyme, produce an activator for a secondary enzyme-substrate system, within which marked amplification occurs. We adapted this technique to study antibodies to casein, bovine serum albumin, ovalbumin, and cardiolipin in the sera of patients with systemic lupus erythematosus (SLE) and normal individuals. The new substrate system yielded titres 30-50-fold higher than those with p-nitrophenyl phosphate (Sigma 104, p-NPP). In addition, when used in a solid-phase C1q binding assay we were able to use a 1 : 100,000 dilution of AP-conjugated anti-human IgG with the amplified substrate, compared to the 1 : 1000 dilution needed with p-NPP. This system is extremely valuable because of its flexibility. It can either be very sparing of limited samples, or if the added sensitivity is not needed, 100-fold less AP conjugate may be used. Thus rare or expensive conjugates can be significantly conserved.

Compartmentalization of cells bearing "rheumatic" cell surface antigens in peripheral blood and tonsils in rheumatic heart disease

Monoclonal antibodies that recognize "rheumatic" antigens of peripheral blood non-T cells were used to study the compartmentalization of such cells in peripheral blood and tonsils of individuals with rheumatic heart disease (RHD) and suitable control subjects. The peripheral blood of most (71%) of the 42 individuals with RHD contained cells reacting with monoclonal antibody 83S19.23 or 256S.10, whereas these cells were present in only 17% of the 41 control subjects (P less than .02). However, none of 21 individuals with RHD had such cells in their tonsils, although they were present in the tonsils of 50% of the 40 control subjects (P less than .03). These results may reflect a failure in RHD or organ-specific homing of cells with the epitopes recognized by the antibodies. The presence of these cells in tonsils may be important in the immune response to streptococcal pharyngeal infection, and their absence in RHD may be involved in the unusual immune responses characteristic of this disease.

Lymphocyte subpopulations in rheumatic heart disease

Monoclonal antibodies and indirect immunofluorescence techniques were used to compare the distribution of lymphocyte subpopulations of tonsil and peripheral blood from patients with rheumatic heart disease and age and socioeconomically matched patients undergoing tonsillectomy for chronic recurrent tonsillitis, but who had no evidence of rheumatic fever or rheumatic heart disease. The proportions of B cells (BA-1+), total T cells (Lyt-3), inducer/helper T cells (T4+) and cytotoxic/suppressor T cells (T8) were determined. No significant differences were apparent between rheumatic heart disease and control groups in resting cells from tonsils or blood. Cells undergoing proliferation in response to streptococcal blastogen A were identified by similar techniques. These tonsillar preparations from patients with rheumatic heart disease generated a smaller proportion of T8+ cultured cells and a greater T4/T8 ratio of cultured cells in response to group A streptococcal blastogen A than did nonrheumatic subjects.

Dynamics of the ureterovesical junction: interaction between diuresis and detrusor instability at the ureterovesical junction in pigs

In pigs under general anesthesia, the mutual relation between ureterovesical flow and detrusor activity was evaluated with juxtavesical ureteral perfusion pressure measurements and cystometry. At constant bladder filling volume ureterovesical perfusion could provoke detrusor activity, which was positively related to the perfusion rate, and which disappeared after perfusion was stopped. During such involuntary detrusor activity ureterovesical perfusion pressure might increase significantly more than intravesical pressure. It is concluded that ureterovesical flow causes distension of detrusor muscle bundles around the ureteric hiatus, which may trigger local and general detrusor activity in an unstable bladder. During such detrusor activity, due to forces in the bladder wall, resistance to outflow from the upper urinary tract could be significantly more impaired than is reflected by the increase of intravesical pressure at cystometry. The clinical implications are discussed.

Solution of the multiple dosing problem using linear programming

A system theoretical approach to drug concentration-time data analysis is introduced after the discussion of some relevant concepts as they are used in system theory. The merits of this approach are demonstrated in multiple dosing problem. It is shown that dosage minimization without stringent constraints does not result in the desired therapeutic effect. In a different optimization the discrepancy between the actual and the desired time-histories of the relevant substance's plasma concentration is minimized. It is shown that both of these optimizations can be reduced to linear programming problems which are easily solvable with today's computers. These methods are demonstrated in a case study of dopaminergic substitution in Parkinson's disease where computer simulations show them to yield excellent results. Finally, the limits of this approach are also discussed.

Interruption of the inferior vena cava for the prevention of recurrent pulmonary embolism

Pulmonary embolism in high-risk patients may be minimized by inferior vena caval interruption by ligation, plication, intraluminal filters, or intraluminal balloons. Vena caval filter implantation is the least traumatic of all surgical methods of preventing pulmonary embolism. These nonocclusive methods are preferred to minimize the possible sequelae of venous insufficiency. The prevention of septic emboli requires complete ligation of the inferior vena cava. The transvenous approach to caval interruption by intraluminal filters is particularly useful in severely ill patients. When major surgical procedures are performed for the purpose of caval interruption, the intra-abdominal approach has greater associated mortality and morbidity than does the retroperitoneal approach. The Mobin-Uddin and Kim-Ray Greenfield filters are at present the most frequently used modalities for prevention of fatal pulmonary embolism when intervention is required. In large series of patients where intraluminal caval filters have been utilized, there has been an operative mortality of under 1 per cent, with an incidence of recurrent emboli of under 2 per cent, and an incidence of venous stasis sequelae of approximately 20 per cent. Some clinicians prefer the Greenfield filter over the Mobin-Uddin umbrella because of greater ease and flexibility of placement. In general, however, both transvenous intraluminal filters have been used effectively with acceptable mortality and morbidity, and the device used might properly be determined by the experience of the surgeon.

Cell proliferation in carcinoma in bilharzial bladder: influence of pre-operative irradiation and clinical implications

Cell proliferation in carcinoma in the bilharzial bladder was studied in 92 patients in terms of the in vitro labeling index (LI), cell density (CD) and labeled cell density (LCD) using the in vitro 3H-Tdr technique. Cell proliferation was much greater in high than in low grade tumors and in deep than in superficial parts of the tumor, but was much less dependent on cell type; transitional cell cancer had the highest activity followed by squamous cell and adenocarcinoma. The probability of local recurrence after cystectomy decreased markedly when the LI exceeded 5.0%. The influence of the following three pre-operative radiotherapy regimens was studied: split-course (SC): the initial course consisted of 20 Gy in 10 treatments with a similar course was given after one week, hyper-fractionation using 17 treatments 0.6 Gy each on two successive days, this 2-day course of 20 Gy was repeated after one week, and concentrated irradiation consisting of two treatments, 6.0 Gy each with a gap of one week. Cystectomy was performed 14-20 days after treatment in all groups. Preoperative irradiation was generally associated with an increased probability of local control. The unfavorable influence of a high pretreatment LI was not noted after pre-operative irradiation. The CD was also reduced in proportion to the pretreatment LI. It is proposed that the response to irradiation was proportional to the initial proliferation activity and hence the prognostic significance of tumor grade and pretreatment LI was masked. Postirradiation tumor volume reduction was a strong predictor of treatment outcome. Concentrated irradiation was the least efficient pre-operative irradiation regimen and was associated with the least tumor volume reduction.

Increased sodium-lithium countertransport in college students with elevated blood pressure

Blood pressure screening was carried out on a university campus to identify early hypertension or high-normal BP in young adults. Compared with normotensive control subjects of a similar age, drawn from the same population, persons identified as being at the upper end of the BP distribution had significantly increased levels of sodium-lithium countertransport. This difference persisted when other potential confounding variables, eg, overweight, sex, ethnicity, sodium excretion, and age, were taken into account. A positive family history was associated with slightly higher levels of sodium-lithium countertransport, although the effect could be explained by higher present levels of BP. These data suggest that abnormalities of cation transport are present early in the course of the development of hypertension. Measurement of transport levels may provide an estimate of risk of hypertension and allow identification of susceptible persons.

Non invasive evaluation of left ventricular performance in 294 diabetic patients without clinical heart disease

The authors studied the modification of systolic time intervals (STI), pre-ejection period (PEP) and left ventricular ejection time (LVETc), before and after isometric exercise, in 294 diabetic patients without clinical evidence of cardiomyopathy and in good metabolic control compared to 132 normal subjects. The study was aimed at detecting preclinical alterations of left ventricular function. Diabetic patients considered together did not show any difference in STI in basal conditions or after isometric exercise compared to normal subjects. When diabetic patients were divided into sub-groups according to their treatment, the insulin-treated diabetics showed modification of STI after isometric exercise, which indicated an alteration of left ventricular function. Also subjects treated with oral hypoglycemic agents showed similar but less evident changes. In diabetic patients on diet only and in those with duration of diabetes of 6 months or less, STI was identical to that of normal subjects. These data do not explain the pathogenesis of myocardial involvement, although they are in accordance with studies which have laid emphasis on the alteration of compliance of the diabetic heart.