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S Sharma

Publications and source records attributed to S Sharma.

At least 109 records · Page 6Linked to original sources
PubMed2004

Comparison of echo and MRI in the imaging evaluation of intracardiac masses.

We compared the efficacy of echocardiography (ECHO) and magnetic resonance imaging (MRI) for evaluating intracardiac masses. Over an 8-yr period, 28 patients, 21 males, 7 females, 16 days-60 years of age (mean 25 years) with a suspected intracardiac mass on ECHO (transthoracic in all; transesophageal in 9) underwent an MRI examination. Five patients had a contrast-enhanced MRI. ECHO and MRI were compared with respect to their technical adequacy, ability to detect and suggest the likely etiology of the mass, and provide additional information (masses not seen with the other technique, inflow or outflow obstruction, and intramural component of an intracavitary mass). With MRI, the image morphology (including signal intensity changes on the various sequences) and extracardiac manifestations were also evaluated. The diagnosis was confirmed by histopathology in 18, surgical inspection in 4, by follow- up imaging on conservative management in 5, and by typical extracardiac manifestations of the disease in 1 patient. Fifteen (54%) patients had tumors (benign 12, malignant 3), 5 had a thrombus or hematoma, and 4 each had infective or vascular lesions. Thirty-four masses (13 in ventricle, 11 septal, 7 atrial, 2 on valve and 1 in pulmonary artery) were seen on MRI, 28 of which were detected by ECHO. Transthoracic ECHO (TTE) and MRI were technically optimal in 82% and 100% of cases, respectively. Nine patients needed an additional transesophageal ECHO (TEE). Overall, MRI showed a mass in all patients, whereas ECHO missed it in 2 cases. In cases with a mass on both modalities, MRI detected 4 additional masses not seen on ECHO. MRI suggested the etiology in 21 (75%) cases, while the same was possible with ECHO (TTE and TEE) in 8 (29%) cases. Intramural component, extension into the inflow or outflow, outflow tract obstruction, and associated pericardial or extracardiac masses were better depicted on MRI. We conclude that MRI is advantageous over a combination of TTE and TEE for the detection and complete morphological and functional evaluation (hemodynamic effects) of cardiac masses.

Adolescent↗
PubMed2004

The upper limit of physiological cardiac hypertrophy in elite male and female athletes: the British experience.

Establishment of upper normal limits of physiological hypertrophy in response to physical training is important in the differentiation of physiological and pathological left ventricular hypertrophy. The genetic differences that exist in the adaptive response of the heart to physical training and the causes of sudden cardiac death in young athletes indicate the need for population-specific normal values. Between September 1994 and December 2001, 442 (306 male, 136 female) elite British athletes from 13 sports were profiled. Standard two-dimensional guided M-mode and Doppler echocardiography were employed to evaluate left ventricular morphology and function. Eleven (2.5%) athletes, competing in a range of sports including judo, skiing, cycling, triathlon, rugby and tennis, presented with a wall thickness >13 mm, commensurate with a diagnosis of hypertrophic cardiomyopathy. Eighteen (5.8%) male athletes presented with a left ventricular internal diameter during diastole (LVIDd) >60 mm, with an upper limit of 65 mm. Of the 136 female athletes, none where found to have a maximum wall thickness >11 mm. Left ventricular internal diameter was <60 mm in all female athletes. Systolic and diastolic function were within normal limits for all athletes. Upper normal limits for left ventricular wall thickness and LVIDd are 14 mm and 65 mm for elite male British athletes, and 11 mm and 60 mm for elite female British athletes. Values in excess of these should be viewed with caution and should prompt further investigation to identify the underlying mechanism.

Adolescent↗
PubMed2004

Frontotemporal dementia with Pick-type histology associated with Q336R mutation in the tau gene.

In this report, we describe the clinical and neuropathological features of a case of familial frontotemporal dementia (FTD), with onset at 58 years of age and disease duration of 10 years, associated with a novel mutation, Q336R, in the tau gene (tau). In vitro studies concerning the properties of tau proteins bearing this mutation, with respect to microtubule assembly and tau filament aggregation, are reported. Clinically, the patient showed alterations in memory, language and executive functions and marked behavioural change consistent with FTD, although the extent of memory impairment was more than is characteristic of FTD. At autopsy, there was degeneration of the frontal and temporal lobes associated with the presence of hyperphosphorylated tau proteins in swollen (Pick) cells and intraneuronal inclusions (Pick bodies). By immunohistochemistry, the Pick bodies contained both 3-repeat and 4-repeat tau proteins although, because no fresh tissues were available for analysis, the exact isoform composition of the aggregated tau proteins could not be determined. Neurons within frontal cortex contained neurofibrillary tangle-like structures, comprising both straight and twisted tubules, or Pick bodies in which the filaments were short and randomly orientated. In vitro, and in common with other tau missense mutations, Q336R caused an increase in tau fibrillogenesis. However, in contrast to most other tau missense mutations, Q336R increased, not decreased, the ability of mutant tau to promote microtubule assembly. Nonetheless, this latter functional change may likewise be detrimental to neuronal function by inducing a compensatory phosphorylation that may yield increased intracellular hyperphosphorylated tau species that are also liable to fibrillize. We believe the mutation is indeed pathogenic and disease causing and not simply a coincidental rare and benign polymorphism. Since this mutation is segregating with the FTD clinical and neuropathological phenotype, it has not been found in unaffected individuals and it has novel functional properties in vitro which are likely to be detrimental to neuronal function in vivo.

Aged↗
PubMed2004

Urovirulence of Pseudomonas aeruginosa: planktonic cells vs. biofilm cells.

Planktonic and biofilm cells of a clinical urinary isolate of P. aeruginosa were compared in vitro for their ability to adhere to uroepithelial cells, interaction with macrophages, and for production of virulence factors like extracellular proteinase, elastase, hemolysin, phospholipase C and pyochelin. Biofilm cells showed increased adherence to UECs, which was coupled with reduced uptake and intracellular killing by macrophages. Overall there was a decrease in production of extracellular products by biofilm cells. Comparing the two cell forms for their ability to establish infection in an ascending model of acute pyelonephritis, significant enhancement of renal bacterial load, as well as more pronounced renal pathology developed with biofilm cells.

Animals↗
PubMed2004

Pericardial abscess occurring after tuberculous pericarditis: image morphology on computed tomography and magnetic resonance imaging.

AIM: To study the image morphology on computed tomography (CT) and magnetic resonance imaging (MRI) of pericardial abscess, an uncommon complication of tuberculous pericarditis. MATERIAL AND METHODS: In a 9-year period, 120 patients with clinical and imaging features of constrictive pericarditis were retrospectively reviewed. Of them, 13 patients (age range, 1-51 years; seven females, six males), who had a pericardial mass on echocardiography, and were subjected to CT (11 patients) and MRI (7 patients), were included as subjects of the present study. Five patients underwent both the investigations. The intra-lesional morphology, location, extent, mass effect on adjacent cardiac chambers, secondary effects on the atria and venae cavae, and pericardial thickness were studied. Histopathological confirmation of tubercular infection was available in nine patients. In the remaining four patients, the diagnosis was based on typical extra-cardiac manifestations of tuberculosis. RESULTS: A total of 15 abscesses were detected. CT showed a lesion with a hypodense core and an enhancing rim in all patients. On spin-echo T1-weighted MRI, 57% of the paients had a lesion with a hyperintense core, suggesting an exudative process. Seventy-one percent of patients showed a lesion with a hyperintense core on T2-weighted MRI, while one lesion was hypointense. Post-gadolinium MRI was performed in two patients and showed an enhancing rim in both, with enhancing septa in one. The predominant site of involvement was in the right atrioventricular (AV) groove (77%). Localized tamponade, suggested by the presence of mass effect on an adjacent cardiac chamber, was noted in nine (69%) cases, with proximal atrial dilatation in 78% of them. Four other patients (31%) had atrial dilatation without a localized mass effect. CONCLUSION: Pericardial abscess is an uncommon complication of constrictive pericarditis. Tuberculosis was responsible for abscess formation in all cases in this study. The majority of the lesions are located in the right AV groove with imaging features suggestive of localized tamponade. The presence of a hypointense core on T2-weighted MRI may suggest a tubercular aetiology.

Abscess↗
PubMed2004

Prevalence of polycystic ovaries and polycystic ovary syndrome in lesbian women compared with heterosexual women.

OBJECTIVE: To determine the prevalence of polycystic ovaries (PCO) and polycystic ovarian syndrome (PCOS) in lesbian women compared with heterosexual women undergoing fertility treatment. DESIGN: A prospective observational study. SETTING: The London Women's clinic and The Hallam Medical Center. Tertiary referral fertility setup. PATIENT(S): Six hundred eighteen women undergoing ovarian stimulation with or without IUI treatment between November 2001 and January 2003. Of these, 254 were self-identified as lesbians and 364 were heterosexual women. INTERVENTION(S): Baseline pelvic ultrasound examination and blood tests conducted to measure biochemical parameters such as FSH, LH, E(2), PRL, T, androstenedione (A), sex hormone-binding globulin (SHBG), and DHEAS were performed between day 2 and 3 of each woman's menstrual cycle. Tubal patency tests were performed by hysterosalpingography or laparoscopy. MAIN OUTCOME MEASURE(S): Biochemical parameters. RESULT(S): Eighty percent of lesbian women, compared with 32% of the heterosexual women, had PCO on pelvic ultrasound examination. Thirty-eight percent of lesbian women, compared with 14% of heterosexual women, had PCOS. There were no significant differences in the androgen concentrations between lesbian and heterosexual women with normal ovaries. However, lesbian women with PCO and PCOS had significantly higher androgen concentrations compared with heterosexual women with PCO and PCOS. Tubal disease was as common in lesbian women as in heterosexual women. CONCLUSION(S): There is a significantly higher prevalence of PCO and PCOS in lesbian compared with heterosexual women. Lesbian women with either PCO or PCOS had more pronounced hyperandrogenism than did heterosexual women with either PCO or PCOS.

Adult↗
PubMed2004

Spinal anesthesia for cesarean section following inadequate labor epidural analgesia: a retrospective audit.

BACKGROUND: High blocks have been reported when spinal anesthesia is used for cesarean section following inadequate labor epidural analgesia. We have therefore modified the practice at our institution to minimize this risk and conducted a retrospective observational study of outcome following the change of practice. METHOD: The records of 115 women with inadequate epidural labor analgesia who required cesarean section between July 1998 and January 2002 were studied. No epidural boluses were administered in the 30 min preceding spinal anesthesia and a reduced spinal dose, median (range) 9.38 mg (7.5-11.3 mg) of 0.75% hyperbaric bupivacaine and fentanyl 15 microg (10-25 microg) was used. Patients were left sitting for 2 min and then positioned supine with left uterine displacement and were closely monitored for symptoms or signs that would suggest a high block. RESULTS: No parturient developed a high spinal necessitating intubation, and there was no adverse neonatal outcome. CONCLUSION: These findings do not conclusively establish this method as safe, but should spinal anesthesia for cesarean section following suboptimal labor epidural analgesia be considered, avoiding epidural boluses immediately preceding spinal injection, using a lower spinal dose, and delayed supine positioning following spinal injection may be advisable.

Adult↗
PubMed2004

Pharmacological thrombolysis in Budd Chiari syndrome: a single centre experience and review of the literature.

BACKGROUND/AIMS: To review our experience of thrombolytic therapy in patients with acute Budd Chiari syndrome (BCS). METHODS: Records of 10 patients with BCS, treated by thrombolysis over a 12-year period were retrospectively analysed for demographics, clinical presentation/duration, primary disease, thrombolytic regimen, and follow-up. The same characteristics were also studied in previously reported patients. The agent used was recombinant tissue plasminogen activator (tPA) in all patients. RESULTS: Thrombolysis was used 12 times in 10 patients. Infusion was made systemically in three patients, into the hepatic artery in one patient, locally into a hepatic vein and/or IVC in four patients and locally within TIPS/portal vein in two patients. Only one infusion made systemically was partially successful. Adjunctive balloon angioplasty and/or stent insertion was undertaken for all eight procedures (in six patients) where local infusion was into the hepatic vein or TIPS. Six of these were ultimately successful (in five patients) and two were unsuccessful. Thrombolysis was more likely to be successful in the presence of a short history of thrombosis, when the thrombolytic agent was locally infused and when it was combined with a successful radiological procedure. Mean follow-up was 4.5 years (range 1-10 years). No serious bleeding complication occurred. CONCLUSIONS: We observed no benefit from thrombolysis when delivered systemically or arterially except in one case. Thrombolysis was useful in adjunctive management of BCS when the drug was infused locally into recently thrombosed veins that had appreciable flow following partial recanalisation. Thrombolysis was clearly of benefit in the repermeation of occluded/partially occluded hepatic veins/TIPS when early detection of new thrombus followed interventional procedures such as balloon angioplasty or stenting of hepatic veins.

Adolescent↗
PubMed2004

In vitro anti-resorptive activity and prevention of ovariectomy-induced osteoporosis in female Sprague-Dawley rats by ormeloxifene, a selective estrogen receptor modulator.

Antiosteoporotic activity of ormeloxifene, a multifunctional SERM, using inhibition in parathyroid hormone (PTH) induced resorption of 45Ca from prelabeled chick and rat fetal limb bones in chase cultures and modulation of certain biochemical markers of bone turnover and bone mineral density (BMD) in ovariectomized adult female rats, was investigated. Ormeloxifene concentration-dependently inhibited PTH-induced resorption of 45Ca from chick fetal femora with treated/control (T/C) ratio of 0.71, 0.32 and 0.20 at 50, 100 and 200 microM concentration, in comparison to 0.49, 0.53 and 0.95 in case of CDRI-85/287 (a pure antiestrogen), tamoxifen and ethynylestradiol (100 microM), respectively. Using rat fetal limb bones, ormeloxifene (100 microM) exhibited T/C ratio of 0.67, in comparison to 1.43 with PTH alone. Heat-killed bones exhibited negligible resorption (2.9%; T/C: 0.098) in response to PTH. In adult female rats, ormeloxifene (1.25 and 12.5 mg/kg per day) inhibited ovariectomy-induced increase in serum total and bone-specific alkaline phosphatase and osteocalcin and urine calcium/creatinine ratio to almost intact control level. Ovariectomy was accompanied by marked decrease in bone mineral density of isolated femur and tibia, being maximum in femur neck (28.3%; P < 0.01) and midshaft (23.7%; P < 0.01), but only marginal (6.7%; P > 0.05) in region proximal to tibio-fibular separation point. Decrease in BMD based on T-/Z-score, too, was >2.5 S.D. than mean value of normal young adult/age-matched females. This was prevented by ormeloxifene and the effect, though apparently more in females supplemented with higher dose of ormeloxifene, was not always significantly different and clear dose-response was not evident until BMD data was evaluated on T-/Z-score basis. The analysis also demonstrated much higher threshold level of tibia than femur and more so for their mid-shafts. Increase in BMD of isolated bones was also observed in ormeloxifene-treated intact females, without significantly altering biochemical markers of bone turnover or uterine weight. Findings suggest potential of ormeloxifene in management of post-menopausal osteoporosis and beneficial effect on BMD in women taking this SERM for contraception or any hormone-related clinical disorder.

Animals↗
PubMed2004

Prevention of tissue injury in an ascending mouse model of chronic pyelonephritis--role of free radical scavengers.

The role of free radical scavengers in preventing the tissue injury using a non obstructive, ascending mouse model for chronic pyelonephritis was assessed. The parameters taken into consideration are Luminol Dependent Chemiluminescence (LDCL), histopathology and some biochemical investigations. We have observed that both catalase and Dimethyl-Sulfoxide (DMSO, free radical scavengers) were able to prevent the free radical mediated tissue injury and ultimate renal scarring, irrespective of the bacterial strain studied.

Animals↗
PubMed2004

A unique strain of Leptospira isolated from a patient with pulmonary haemorrhages in the Andaman Islands: a proposal of serovar portblairi of serogroup Sehgali.

Leptospirosis is endemic in the Andaman Islands, often occurring as outbreaks during the post-monsoon period. Pulmonary involvement is common and associated with high morbidity and mortality. During the investigation of an outbreak in North Andaman in 1996 an isolate was recovered from the blood of a patient with fever, headache, body aches and haemoptysis with respiratory distress as presenting symptoms. The isolate was characterized using the cross-agglutination absorption test (CAAT) and monoclonal antibodies (mAbs). The isolate showed typical morphology and characteristic motility of the genus Leptospira. Growth was inhibited at 13 degrees C and in the presence of 8-azaguanine. The isolate could not be identified with grouping sera representing 25 serogroups, CAAT and mAbs. A new serovar of a new serogroup is proposed. Genetic characterization using polymerase chain reaction (PCR) followed by sequencing of the PCR product and randomly amplified polymorphic DNA fingerprinting (RAPD) showed that the isolate was genetically similar to L. interrogans sensu stricto.

Adult↗
PubMed2004

Leptospirosis among schoolchildren of the Andaman & Nicobar Islands, India: low levels of morbidity and mortality among pre-exposed children during an epidemic.

Leptospirosis is an important public health problem in the Andaman Islands. The disease is being increasingly reported among children and adolescents in recent times. An attempt was made to find out the level of exposure to leptospires, to estimate the incidence of infection and to identity the risk factors for acquiring infection among children. A sample of 1544 schoolchildren was selected. Presence of anti-leptospiral antibodies was tested using the microscopic agglutination test (MAT). Students were interviewed for behavioural factors. In total, 341 (221 seronegative and 120 seropositive) students were followed up clinically and serologically during a subsequent outbreak. An overall seropositivity rate of 23.6% (95% CI 21.54-25.81) was observed. Infection rate was 33.5% among seronegatives whereas re-infection rate was 16.7% among seropositives during the outbreak that occurred 1 month after the first sample collection. Morbidity and mortality were found to be higher among seronegative individuals than seropositives. More than 90% of leptospiral infections were found to be subclinical or unnoticed. The high level of exposure among the children results in high infection rates and because they have less previous exposure than adults, they do not have sufficient protection to resist clinical illness during outbreaks.

Adolescent↗
PubMed2004

Genetic polymorphism of the CYP1A1, CYP2E1, GSTM1 and GSTT1 genes and lung cancer susceptibility in a north indian population.

CYP1A1, CYP2E1, GSTM1 and GSTT1 polymorphisms were evaluated in north Indian lung cancer patients and controls. The estimated relative risk for lung cancer associated with the CYP1A1*2C allele was 2.68. Apart from the CYP1A1*2C genotype, there was no attributable risk in relation to other genotypes when analyzed singly. However, in the presence of a single copy of the variant CYP1A1 (CYP1A1*1/2A) and null GSTT1 genes, there was a three-fold increased risk for lung cancer; when stratified histologically the relative risk increased to 3.7 in case of SQCC. Similarly individuals carrying the mutant CYP1A1*2C genotype and single copy of the variant CYP1A1 Mspl allele, had a relative risk of 2.85 for lung cancer. In case of the GSTM1 and CYP1A1 genotypes, null GSTM1 and variant Msp1 alleles had two-fold elevated risk for SQCC. On the other hand CYP1A1*2C and null GSTM1 genotype had a 3.5-fold elevated risk for SCLC. Stratified analysis indicated a multiplicative interaction between tobacco smoking and variant CYP1A1 genotypes on the risk for SQCC and SCLC. The heavy smokers (BI > 400) with CYP1A1*2C genotype were at a very high risk to develop SCLC with an OR of 29.30 (95% CI = 2.42-355, p = 0.008). Taken together, these findings, the first to be analyzed in north Indian population, suggest that combined GSTT1 , GSTM1 and CYP1A1 polymorphisms could be susceptible to lung cancer induced by bidi (an Indian cigarette) smoking.

Alleles↗
PubMed2004

Left ventricular morphology and function in female athletes: a meta-analysis.

The purpose of the present study was to examine the impact of physical training upon cardiac structure and function, and identify physiologic upper limits in female athletes. Meta-analytical techniques were applied to 13 published echocardiographic studies examining cardiac structure and function in female athletes. The study group included 890 athletes and 333 controls. For comparison of sporting discipline, studies were partitioned into 3 categories (endurance, strength/sprint, team). Significant (p < 0.05) effect sizes were observed for all structural measures between athletes and controls. Significant effect size differences existed between sporting groups for LVIDd and LVM only, with endurance and team game athletes demonstrating the largest effect sizes compared to strength trained athletes. No significant effect of training was observed for left ventricular diastolic or systolic function, with the exception of stroke volume where a significant effect size difference was observed between athletes and controls with no observed difference between sporting groups. Maximum reported upper limits for LV wall thickness and LVIDd in female athletes were 12 mm and 66 mm respectively. Chronic exercise training results in cardiac enlargement in female athletes. The nature of physiologic adaptation is similar to that observed in male athletes. LV wall thickness values greater than 12 mm in female athletes should be viewed with caution and indicate a more comprehensive evaluation to establish a physiological or pathological basis for the observed left ventricular enlargement.

Adaptation, Physiological↗
PubMed2004

Pharmacokinetic study of 11-Keto beta-Boswellic acid.

INTRODUCTION: Boswellia serrata has been used in traditional medicine for treatment of inflammatory diseases since antiquity. However human kinetic studies are lacking for this. Hence to better elucidate its effects in humans and determine its optimal dosing, this study was planned. MATERIAL AND METHODS: Twelve healthy adult men volunteers were given capsule Wok Vel containing 333 mg of Boswellia Serrata Extract, orally, after a seven days washout period. Venous blood samples were drawn through indwelling canula from each volunteer prior to drug administration and at 30, 60, 120, 150, 180, 210, 240, 300, 360, 480, 600, 720, 840 minutes after drug administration. Plasma obtained after centrifuge was analyzed to measure concentration of 11-Keto beta-Boswellic Acid (KBA) by HPLC. Various kinetic parameters were then calculated from the plasma concentrations. RESULTS: The results are expressed as mean +/- Standard Error of Mean. The peak plasma levels (2.72 x 10(-3) +/- 0.18 micromoles/ml) of BSE were reached at 4.5 +/- 0.55 h. The concentration declined with a mean elimination half life of 5.97 +/- 0.95 h. The apparent volume of distribution averaged 142.87 +/- 22.78 L and the plasma clearance was 296.10 +/- 24.09 ml/min. The AUC(0-infinity) was 27.33 x 10(-3) +/- 1.99 micromoles/ml h. CONCLUSION: Elimination half life of nearly six hours suggests that the drug needs to be given orally at the interval of six hours. The plasma concentration will attain the steady state after approximately 30 hours. BSE is a safe drug and well tolerated on oral administration. No adverse effects were seen with this drug when administered as single dose in 333 mg.

Administration, Oral↗
PubMed2004

Study on prevention of two-stage skin carcinogenesis by Hibiscus rosa sinensis extract and the role of its chemical constituent, gentisic acid, in the inhibition of tumour promotion response and oxidative stress in mice.

We designed the present study to investigate the role of gentisic acid in the chemopreventive activity of Hibiscus rosa sinensis extract on 7,12-dimethyl benz(a)anthracene (DMBA)/croton oil-mediated carcinogenesis in mouse skin via 12-O-tetradecanoyl phorbol-13-acetate (TPA)-induced tumour promotion response and oxidative stress. Single topical application of DMBA followed by twice weekly applications of croton oil after one week for 20 weeks resulted in 100% incidence of tumours in animals in 15 weeks. However, application of H. rosa sinensis extract 30 minutes prior to the application of croton oil twice weekly for 20 weeks caused significant reduction in the number of tumours per mouse and the percentage of tumour-bearing mice. Also, the latency period for the appearance of the first tumour was delayed on H. rosa sinensis pretreatment. A single topical application of TPA caused significant depletion in reduced glutathione (GSH) content, activities of its metabolizing and antioxidant enzymes, while malondialdehyde (MDA) formation, H2O2 content, ornithine decarboxylase (ODC) activity and DNA synthesis were significantly increased. Interestingly, pretreatment of H. rosa sinensis extract (3.5 mg and 7 mg/kg body weight) and gentisic acid (2.0 microg and 4.0 microg/0.2 ml acetone per animal) restored the levels of GSH, and its metabolizing and antioxidant enzymes (P<0.05). There was also a statistically significant reduction in MDA formation and H2O2 content (P<0.05) at both doses. Although inhibition of ODC activity by gentisic acid was not dose-dependent, thymidine incorporation in DNA (P<0.05) was dose-dependently recovered by the plant extract and its chemical constituent. We therefore propose that gentisic acid has a role in the modulatory activity of H. rosa sinensis extract.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2004

A protective merozoite protein of Plasmodium falciparum shares an epitope with surface antigens of Paramecium.

A Plasmodium falciparum cDNA expression clone, lambdaPf9, had been identified earlier as a protective epitope, using anti-lambdaPf9 antibodies and combinatorial phagotopes. A segment of the Pf9 gene showed homology with Paramecium immobilization surface antigens such as 51B, 51A and 156G. A synthetic Pf9-peptide was designed from this region, and specific antibodies were raised. Each of these anti-Pf9 antibodies and combinatorial reagents, as well as anti-Paramecium 51B antibodies, recognized the Pf9-peptide on ELISA, and the same protein band in parasite immunoblots. The P. falciparum protein was released from the merozoite membrane fraction on treatment with PI-PLC, indicating the presence of a GPI anchor. Anti-Pf9-peptide antibodies specifically inhibited the growth of P. falciparum in culture. Immunofluorescence assays showed the reactivity of anti-Pf9-peptide sera with P. falciparum merozoites and gametocytes, as well as on the surface of Paramecium tetraurelia. The Pf9-peptide was able to induce proliferation of splenic lymphocytes obtained from mice infected with the rodent malarial parasites Plasmodium berghei and Plasmodium yoelii. These results point towards Plasmodium Pf9 as a conserved novel protective protein, sharing an epitope with Paramecium surface antigens.

Amino Acid Sequence↗