Effect of nifedipine and dipyridamole on K+ and NA stimulated 45Ca-uptake into rabbit aortic strips

The effect of dipyridamole (DPM), a purine nucleoside uptake inhibitor, on the K+ and noradrenaline (NA)-stimulated 45Ca-uptake into Rabbit aortic strips was studied and compared with that of nifedipine (NFD). DPM (10(-6) M) significantly (P < 0.02) inhibited 45Ca-uptake in aortic strips stimulated with K+ (10(-1) M). However, it had less significant effect on NA (10(-4) M)-stimulated 45Ca-uptake. The percentage inhibition was 80 and 57 in K+ and NA-stimulated 45Ca-uptake, respectively. Similarly, NFD (10(-7) M) caused significant (P < 0.01, P < 0.05) decrease in K+ (0.060 +/- 0.009) and NA (0.082 + 0.01, mM)-stimulated 45Ca-uptake. The percentage inhibition by NFD was 98 and 64 in K+ and NA-stimulated 45Ca-uptake, respectively. The results suggest that DPM inhibits Ca2+ influx occurring through Voltage Operated Calcium Channels (VOCCs) but it has little effect on Receptor Operated Calcium Channels (ROCCs).

Co-agglutination (Co-A) test for circulating antigen in hydatid disease

A co-agglutination (Co-A) test with Staphylococcus aureus (Cowan's strain I) bearing protein A coated with specific hydatid antibodies, was used to demonstrate circulating hydatid antigen in serum for the diagnosis of hydatid disease. The test had a sensitivity of 95% and specificity of 89% in detecting hydatid antigen in serum. A false positive reaction was observed with 18.5% of control sera from patients with various parasitic diseases. However, these all gave negative results when tested after further dilution. The test is reliable and rapid; the result could be obtained within 30-45 min of receipt of a serum sample. Since the test is simple and the reagents are inexpensive and easily available, it can be used in less well equipped laboratories in developing countries.

Prevalence of hookworm species in Pondicherry, India

A study was carried out to find out the hookworm species prevalent in Pondicherry, India, based on the identification of filariform larvae recovered from coproculture of hookworm positive stools. A total of 184 hookworm positive stools were cultured using the Harada-Mori coproculture method. The results of the study for the first time showed both hookworm species, Ancylostoma duodenale (60 cases) and Necator americanus (49 cases) to be present in Pondicherry. The former species was relatively more common than the latter. Three cases were infected with both species of hookworm.

Recent trends in the serodiagnosis of hydatid disease

Hydatid disease caused by Echinococcus granulosus is a zoonotic infection of cosmopolitan distribution. As the clinical manifestations of hydatid disease in man are variable, the diagnosis of the condition presents complex problems for clinicians. Since the parasitic diagnosis of the disease is difficult, the specific diagnosis of the condition relies heavily on immunodiagnostic tests. The recent approach to the diagnosis of hydatid disease in man is primarily based on: (1) a combination of two or three more serological tests to diagnose the condition, as a single test fails to detect all the cases, (2) detection of circulating hydatid antigen (CAg) in the serum by enzyme-linked immunosorbent assay (ELISA) and other assays, as the antigen detection system is useful in monitoring post-surgical and chemotherapeutic evaluation of the cases as well as in the prognosis of the condition and (3) demonstration of E. granulosus antigen in the cystic fluid to establish the etiology of the hydatid cyst. Hydatid disease is essentially a disease of poor people residing in rural areas, hence there is need for a simple, economic diagnostic immunoassay for use at the field level or in a rural health center with inadequate facilities. Counter-current-immunoelectrophoresis (CIEF) and bacterial co-agglutination (Co-A), have been standardized and evaluated in this laboratory for the first time for detection of CAg in cases of hydatid disease at the field level and rural health center.

Abdominal hydatidosis in Pondicherry, India

A study during the period 1980-1987 revealed 71 surgically confirmed cases of abdominal hydatid disease. The majority of the patients were in 3rd, 4th and 5th decades (64.5%) with approximately equal incidence in both males and females. The commonest site of lesion was liver (56.4%), followed by peritoneal cavity (16.9%) and spleen (10.2%). Indirect hemagglutination serology test was found to be more sensitive (95.2%) than the traditional Casoni skin test in the diagnosis of abdominal hydatid disease. Ultrasonography was also found to be a useful procedure in the diagnosis of the condition. This study shows that there is a significant rise in the number of patients suffering from abdominal hydatid disease in this part of India.

Protein A-antibody mediated hemagglutination assay for serodiagnosis of amebic liver abscess

A successful modification of the indirect hemagglutination test to demonstrate antibodies for serodiagnosis of amebic liver abscess has been described in the present study. In the modified test, the protein A-IMA, Staphylococcus aureus (Cowan's strain I) bearing protein A (SAPA) cells were used to enhance hemagglutination of sensitized red cells. Use of SAPA cells markedly enhanced sensitivity of the test and greatly increased the titers obtained with most of the sera. At a diagnostic antibody titer of 1:128 and above, the protein A-IHA could detect 72 (100%) of amebic liver abscess (ALA) cases. Amongst the controls, no false positive reaction was observed in non-amebic liver disease controls. However 1(2%) of sera demonstrated false positive reactions from healthy controls. The protein A-IHA was highly sensitive when compared with that of the indirect hemagglutination (IHA) for serodiagnosis of amebic liver abscess. The novel immunoassay is simple, inexpensive and requires little technical skill. It has the potential for wide application in serodiagnosis of amebic liver abscess.

Adenosine- and alpha,beta-methylene ATP-induced differential inhibition of cholinergic and non-cholinergic neurogenic responses in rat urinary bladder

1. The effects of adenosine and alpha,beta-methylene adenosine triphosphate (alpha,beta-Me ATP) on single pulse-induced neurogenic responses and contractions caused by exogenously applied acetylcholine (ACh) and adenosine triphosphate (ATP) were examined in rat urinary bladder. 2. Application of single pulse stimulation (1 ms; 80 V) evoked a biphasic contractile response (abolished by tetrodotoxin, 0.5 x 10(-7) M) consisting of a fast (time to peak: 1.02 +/- 0.07 s) and a slow component (time to peak: 4.92 +/- 1.6 s). The selective inhibition of the slow component by atropine (3 x 10(-6) M) suggests the participation of both cholinergic and non-cholinergic neurotransmitters. 3. alpha,beta-Me ATP (5 x 10(-6) M) abolished ATP (10(-4) M)-induced contractions without altering those to ACh (10(-6) M). Further, the selective inhibition of the fast component of the neurogenic response by alpha,beta-Me ATP is suggestive of the contribution of endogenous ATP to the non-cholinergic component. 4. Adenosine (10(-8) M to 10(-4) M) caused dose-related differential inhibition of the fast (IC50, 1.04 +/- 0.25 x 10(-5) M) and slow (IC50, 2.18 +/- 0.69 x 10(-6) M) components, thereby further supporting two modes of neurotransmission in bladder. 5. Theophylline (10(-4) M) antagonized the inhibitory effects of adenosine on the non-cholinergic component, thereby implicating the participation of P1-purinoceptors in neuromodulation. In contrast, theophylline at this concentration enhanced the adenosine-induced inhibition of the cholinergic component. component. 6. The magnitude of ATP (10-4M)- and ACh (10-8M)-induced contractions were almost identical to those of the fast and slow components of the neurogenic response, respectively. Comparable reduction of ATP (30.2 + 3.4%) and ACh (100%) contractions to those of fast (44.2 + 6.5%) and slow (88.2 + 5.5%) components suggests the involvement of a postjunctional mechanism in adenosine-induced differential inhibition of neurogenic responses. 7. The lack of effect of erythro-6-amino-9-(2-hydroxy-3-nonyl) adenosine hydrochloride (10-6M) and dipyridamole (10-6M) suggests that endogenous adenosine plays little part in modulation of single pulseinduced neurogenic response. 8. The results of the present study suggest that fast and slow components of neurogenic response are mediated through ATP and ACh, respectively, possibly co-released from the same neurone in the rat bladder.

Inhibition of contractions and 45Ca influx by adenosine in rabbit aorta

The effects of adenosine on contractility and 45Ca-uptake in rabbit aorta have been examined and compared with those of nifedipine. Both adenosine (10(-5) M) and nifedipine (10(-8) M) inhibited contractions caused by CaCl2 (0.1-10 mM) in K(+)-depolarized preparations. Nifedipine (10(-7) M) significantly inhibited the contractions of noradrenaline (NA) at all doses (10(-8)-10(-4) M), while adenosine inhibited the contractions induced only by lower doses of NA (10(-8) and 10(-7) M) without affecting those at higher doses (greater than 10(-7) M). Adenosine (10(-8) M) and nifedipine (10(-7) M) inhibited K(+)-stimulated 45Ca-uptake by aortic strips by 75 and 100%, respectively. Similarity, NA (10(-4) M)-stimulated 45Ca influx was inhibited by about 70% by both these agents. The results suggest that adenosine inhibits inward Ca2+ movement involving both voltage-operated and receptor-operated calcium channels in rabbit aortic smooth muscle.

Rapid indirect haemagglutination (rapid-IHA) using sensitized chick cells for serodiagnosis of amoebiasis at primary health centre level

A successful modification of the indirect haemagglutination (IHA) test as a simple and rapid diagnostic procedure for serodiagnosis of amoebiasis at a primary health centre (PHC) level laboratory has been described in the present study. In this modified IHA test, the chick red blood cells (RBC), stabilized by the double aldehyde method, could be sensitized with amoebic antigen and then stored at 4 degrees C for up to 45 days for their subsequent use, as ready-made reagent directly in the IHA, without loss of sensitivity. The chick red cells settled quickly and their haemagglutination pattern could be determined within 30 to 45 min of incubation at room temperature with test sera. The IHA using double-aldehyde stabilized (DAS) chick cells, showed equal sensitivity and specificity with that of IHA using human O cells in diagnosing cases with different manifestations of amoebiasis. With the use of stored sensitized DAS chick cells directly in the IHA, the test could be performed and results obtained within 60 to 90 min of receipt of the sera to be tested. This makes IHA a simple and rapid procedure for its adaptation at a PHC level laboratory for the serodiagnosis of amoebiasis.

A study on laboratory diagnosis of liver abscess in Pondicherry

A study was carried out to evaluate the role of laboratory investigations for diagnosis of liver abscess from the year 1976 to 1981. Bacteriological, parasitological, serological, haematological, histopathological studies and liver function tests were carried out in 240 confirmed cases of liver abscess during the study period. Out of 219 cases, pus culture for pyogenic bacteria was positive in 68 cases (including 27 cases of secondary bacterial infection of amoebic liver abscess) and sterile in 151 cases. Ent histolytica was demonstrated in pus of 24 cases. The diagnostic titre of 1:128 and above was detected in 137 sera by isohaemagglutination test. The liver function tests were of limited value. Albumin globulin ratio was altered in 91.25% cases and there was moderate increase in the levels of alkaline phosphatase. Histopathological studies demonstrated Ent histolitica in 2 cases only. Changes characteristic of pyogenic liver abscess were observed in 6 cases. Rest showed no specific changes.

Serological survey of hydatid disease in Pondicherry, India

A serological survey was carried out to determine the frequency of distribution of hydatid antibodies in Pondicherry during 1981 to 1984. 1325 apparently normal sera and 109 sera from clinically suspected hydatid disease cases were screened by the indirect haemagglutination (IHA) test. Results showed a diagnostic titre of 1:128 or higher in 6 normal sera and 27 sera of suspected hydatid cases. An antibody titre of 1:64 was observed in 8.17 per cent of the sera screened by this test.

Sensitized chick cells in the indirect haemagglutination test for echinococcosis

An indirect haemagglutination (IHA) test was performed with chick red blood cells (RBC) on sera from 26 confirmed cases of echinococcosis and 45 control sera. The results were compared with those obtained in an IHA test with sheep RBC on the same batches of sera; both tests were equally sensitive. The chick cells settled quickly and the results could be determined within 30-45 min. Heterophilic antigen was not a problem. This study also showed that chick cells stabilised by the double-aldehyde method, could be sensitised with the antigen and then stored at 4 degrees C for up to 31 days before use in the IHA test without loss of sensitivity. The use of sensitised double-aldehyde stabilised (DAS) chick cells in IHA tests provides a rapid diagnostic test in echinococcosis.

Enhancement of sensitivity of the haemagglutination test for echinococcosis by use of Staphylococcus aureus protein A

A modification of the indirect haemagglutination test is described for the serodiagnosis of echinococcosis. In the modified test the Cowan I strain of Staphylococcus aureus, which contains protein A, was used to enhance haemagglutination of sensitised red cells. The test was performed in parallel with the indirect haemagglutination test on 31 sera from surgically-confirmed cases of hydatid disease and on 45 sera from healthy blood donors. Use of S. aureus protein A enhanced the sensitivity of the test and greatly increased the titres obtained with most of the sera. None of the sera from healthy blood donors exhibited a titre greater than 64, whereas all but two of the sera from cases of hydatid disease exhibited titres greater than 128. The immunoassay is simple, inexpensive and requires little technical skill. It has the potential for wide application in the serodiagnosis of echinococcosis.

Management of 240 cases of liver abscess

The clinical features and surgical management of 240 cases of liver abscess admitted during a period of five years are presented. Incidence of liver abscess was 0.20 per cent of hospital admissions. A peak age incidence in the 4th decade, male preponderance, pain and fever were the striking features. The majority of the abscesses were localised to a single lobe (90.0%). The abscess was sited in the right lobe in 75.1 per cent, in the left lobe in 18.3 per cent and in both lobes in 6.7 per cent. Elevation and limitation of movement of the right dome of the diaphragm was present in 89.5 per cent of cases. Depending upon therapeutic response, aspiration or/and surgical drainage was undertaken. Aspiration was done in 169 patients and surgical drainage in 63 patients. Management of pyogenic liver abscess included early operative intervention preceded by appropriate antibiotic therapy. Surgical intervention is required less often in amoebic abscess and is recommended only after amoebicidal therapy. Open drainage is recommended for the cases associated with complications, left lobe abscess and big abscess.

Evaluation of stabilised cells in the indirect haemagglutination test for echinococcosis

We have evaluated the use of sheep red-blood cells stabilised in various ways in indirect haemagglutination tests on the sera of 21 surgically confirmed cases of echinococcosis, and on control sera. Tests with Double-Aldehyde-Stabilised cells-treated sequentially with pyruvic aldehyde, tannic acid and glutaraldehyde-were more sensitive than tests with the cells treated only with formaldehyde, glutaraldehyde or pyruvic aldehyde, and subsequently tanned.

Hydatid disease in Pondicherry

An analysis of hospital and laboratory records for the period of 1971-1979 revealed 45 confirmed cases of hydatid disease. The majority were young adult (21-30 years) labourers. The commonest site of lesion was lower lobe of the left lung with the liver occupying second place. A few uncommon sites of involvement were also observed. Casoni's test was positive in 48% of cases. Eosinophilia was a usual associated finding. This report shows Pondicherry to be endemic for hydatid disease.