Subcutaneous wound infiltration of ketamine is superior to bupivacaine in terms of pain perception and opioid consumption after cesarean section: a double-blinded randomized placebo-controlled clinical trial

OBJECTIVE

The aim of the present study was to evaluate the analgesic efficiency of SC ketamine, either alone or in combination with bupivacaine, following CS by means of postoperative pain and opioid need.

PATIENTS AND METHODS

One hundred and twenty women were allocated into 4 groups in this prospective, double-blind, placebo-controlled, randomized trial. Group K (Ketamine, n=30) received SC 1 mg/kg ketamine. Group B (Bupivacaine, n=30) received SC 20 mL bupivacaine 0.5%. Group KB (Ketamine+Bupivacaine, n=30) received SC ketamine 1 mg/kg plus SC 20 mL bupivacaine 0.5%. Group P (Placebo, n=30) received SC 30 mL 0.9% saline (placebo).

RESULTS

VAS scores at resting and on coughing and analgesic consumptions were compared. Visual analogue scale (VAS) pain scores at rest and coughing, at 15 and 60 minutes, and 2, 6 and 12 hours, and total opioid necessity were measured. VAS scores at rest in Group P were higher than in Group KB at the 6th hour, while lower in Group K and Group KB than in Groups B or P at the 12th hour. Patients receiving placebo had higher coughing VAS scores than those receiving ketamine or ketamine+bupivacaine at 2nd, 6th and 12th hours. Patients in Groups P and B required higher doses of morphine than those in groups K or KB.

CONCLUSIONS

Subcutaneous ketamine, either alone or in combination with bupivacaine, provides a better postoperative pain relief and reduces postoperative opioid consumption when compared to use of bupivacaine alone.

The comparison of intraincisional bupivacaine infiltration and intravenous paracetamol administration for pain alleviation after cesarean section: a double-blinded randomized placebo controlled clinical trial

OBJECTIVE

This study aimed to compare the analgesic effect of subcutaneous (SC) bupivacaine and intravenous (IV) paracetamol on postoperative pain and opioid requisites in patients undergoing cesarean delivery.

PATIENTS AND METHODS

One hundred and five women were allocated into 3 groups in this prospective, double-blind, placebo-controlled, randomized trial. Group 1 received SC bupivacaine, Group 2 received IV paracetamol following surgery and every 6 hours for 24 hours in the postoperative period, Group 3 received SC 0.9% saline and IV 0.9% saline at similar periods. Visual analogue scale (VAS) pain scores at rest and coughing, at 15 and 60 minutes, and 2, 6 and 12 hours, and total opioid necessity were measured.

RESULTS

VAS scores at rest were higher in placebo group than in bupivacaine and paracetamol groups at 15 minutes (p=0.047) and 2 hours (p=0.004). VAS scores at coughing were higher in placebo group than in bupivacaine and paracetamol groups at 2 hour (p=0.001) and 6 hours (p=0.018). Placebo group needed higher (p<0.001) doses of morphine than paracetamol or bupivacaine groups.

CONCLUSIONS

Intravenous paracetamol decreases pain scores similar to SC bupivacaine in the postoperative period compared to placebo. Patients taking bupivacaine or paracetamol need fewer opioids than placebo.

ROS Induction Targets Persister Cancer Cells with Low Metabolic Activity in NRAS-Mutated Melanoma

Clinical management of melanomas with NRAS mutations is challenging. Targeting MAPK signaling is only beneficial to a small subset of patients due to resistance that arises through genetic, transcriptional, and metabolic adaptation. Identification of targetable vulnerabilities in NRAS-mutated melanoma could help improve patient treatment. Here, we used multiomics analyses to reveal that NRAS-mutated melanoma cells adopt a mesenchymal phenotype with a quiescent metabolic program to resist cellular stress induced by MEK inhibition. The metabolic alterations elevated baseline reactive oxygen species (ROS) levels, leading these cells to become highly sensitive to ROS induction. In vivo xenograft experiments and single-cell RNA sequencing demonstrated that intratumor heterogeneity necessitates the combination of a ROS inducer and a MEK inhibitor to inhibit both tumor growth and metastasis. Ex vivo pharmacoscopy of 62 human metastatic melanomas confirmed that MEK inhibitor-resistant tumors significantly benefited from the combination therapy. Finally, oxidative stress response and translational suppression corresponded with ROS-inducer sensitivity in 486 cancer cell lines, independent of cancer type. These findings link transcriptional plasticity to a metabolic phenotype that can be inhibited by ROS inducers in melanoma and other cancers.

SIGNIFICANCE

Metabolic reprogramming in drug-resistant NRAS-mutated melanoma cells confers sensitivity to ROS induction, which suppresses tumor growth and metastasis in combination with MAPK pathway inhibitors.

Disrupted redox balance in utero-placenteal junction may be the main culprit in the occurrence of abruptio placenta

OBJECTIVE

To determine the oxidant/antioxidant balance and proinflammatory status in amniotic fluids collected during cesarean section of patients diagnosed with abruptio placenta.

PATIENTS AND METHODS

Twenty-five patients diagnosed with ablatio placenta with intact membranes who went to emergency cesarean section were included in the study. A diagnosis of AP was made in those who had at least one of the following criteria or, in suspicious cases, two findings. (i) Antepartum hemorrhage starting after 20 weeks of gestation, (ii) presence of retroplacental hematoma on ultrasonography, (iii) severe fetal distress or death, (iv) localized or diffuse uterine tenderness or pain. The control group consisted of 25 patients who presented for delivery, who were not diagnosed with AP, and whose membranes were intact. NF-κB, total oxidant capacity (TOC), total antioxidant capacity (TAC), and oxidative stress index (TOC/TAC=OSI) levels were measured in amniotic fluids collected during cesarean section from both groups.

RESULTS

Amniotic fluid TAS values of the AP group were significantly lower than the healthy controls (1.14±0.33 vs. 9.05.±3.40, p<0.01). Amniotic fluid TOS values were significantly increased in the AP group (36.1±8.10 vs. 11.4±2.77, p<0.02). OSI values were significantly higher in the AP group (31.6±9.03 vs. 1.26±0.02, p<0.01). Amniotic fluid NF-κB expression of the AP group was approximately 5 times higher than the control group (10.4±2.56 ng/mL vs. 1.86±0.30 ng/mL, p<0.01). High blood pressure and smoking history were significantly higher in the AP group. Gestational age and fetal birth weight of the AP group were lower than the control group.

CONCLUSIONS

Since the increase in amniotic fluid oxidant capacity and proinflammatory cytokine synthesis cannot be neutralized by the antioxidant system, hypoxic cell damage may lead to premature separation of the placenta.

Psoriasis patients' characteristics associated with high PASI response to tildrakizumab: an international dual center study

OBJECTIVE

Heterogeneous real-world evidence can complement the more strictly regulated clinical trial data. A benefit of this is the wide range of backgrounds, comorbidities and characteristics that can give additional insights into treatments. Observational, retrospective studies can help to fill in the mosaic that makes up a treatments landscape. Tildrakizumab, an interleukin 23p19 inhibitor, is approved for the treatment of plaque psoriasis and has been shown to be a safe and efficacious therapy in clinical trials and emerging real-world evidence. We aimed at confirming the efficacy of tildrakizumab in patients with plaque psoriasis in a dual center setting and identifying patients' characteristics leading to better treatment response.

PATIENTS AND METHODS

Patients with moderate to severe plaque psoriasis, eligible for systemic biological treatment, and treated with tildrakizumab were included in the study and the routine clinical parameters - Psoriasis Area and Severity Index (PASI), Dermatology Life Quality Index (DLQI), and safety - were retrospectively analyzed.

RESULTS

The combined cohorts included 89 patients, of which 64% were naïve to biologic therapies. At the time of analysis efficacy assessment was available for 39 patients after 12 months of treatment, 73 patients after 36 weeks, 79 patients after 16 weeks and 82 patients after 4 weeks. PASI and DLQI decreased significantly over time, with 52/73 (71.2%) patients achieving PASI 100 after 36 weeks. No severe side-effects were recorded in association with tildrakizumab.

CONCLUSIONS

We confirmed the safety and efficacy of tildrakizumab in a real-world clinical setting. A higher proportion of patients naïve to biologics achieved a greater PASI response than patients who had previously been treated with biologics. The same was true for older patients and patients with a shorter history of disease.

The Resolution Rate of Pulmonary Embolism on CT Pulmonary Angiography: a Prospective Study

PURPOSE

To prospectively assess the rate of clot resolution from CT pulmonary angiography (CTPA) in patients with acute pulmonary embolism (PE).

MATERIALS AND METHODS

This prospective cohort study included 290 patients (136 men, 154 women; mean age, 51.9 years) with acute PE. All patients had a CTPA at the presentation and had at least one follow-up within 6 months (mean 72.7 days). Sixty-four percent of patients had follow-up scans for research purposes within a pre-determined period (between 28 and 184 days; mean, 78.27 days) and 36 % had (between 2 and 184 days; mean, 62.78 days) for a clinical indication. The volume of each clot was measured using a semi-automated quantification program. The resolution rate was evaluated by interval-censored analysis.

RESULTS

The overall estimated probability of complete resolution was 42 % at 7 days, 56 % at 10 days, and 71 % at 45 days. Achieving complete resolution was significantly faster in patients with peripheral clots (HR: 1.78; CI: 1.05-3.03, p = 0.032) but slower in patients with consolidation and history of venous thromboembolism (VTE), (HR: 0.37; CI: 0.18-0.79, p = 0.01 and HR: 0.57; CI: 0.35-0.91, p = 0.019, respectively). Although the patients with cancer showed a faster resolution rate (HR: 1.67; CI: 1.05-2.68, p = 0.032), the mortality rate was significantly higher than non-cancer patients.

CONCLUSION

The resolution rate of clot burden in acute PE was associated with patients' clinical presentation variables and CTPA imaging biomarkers. This information may be incorporated into designing a prediction rule and determining the appropriate duration of anticoagulation therapy in patients with acute PE.

Evolving Role and Translation of Radiomics and Radiogenomics in Adult and Pediatric Neuro-Oncology

Exponential technologic advancements in imaging, high-performance computing, and artificial intelligence, in addition to increasing access to vast amounts of diverse data, have revolutionized the role of imaging in medicine. Radiomics is defined as a high-throughput feature-extraction method that unlocks microscale quantitative data hidden within standard-of-care medical imaging. Radiogenomics is defined as the linkage between imaging and genomics information. Multiple radiomics and radiogenomics studies performed on conventional and advanced neuro-oncology image modalities show that they have the potential to differentiate pseudoprogression from true progression, classify tumor subgroups, and predict recurrence, survival, and mutation status with high accuracy. In this article, we outline the technical steps involved in radiomics and radiogenomics analyses with the use of artificial intelligence methods and review current applications in adult and pediatric neuro-oncology.

Clinicopathological and Genomic Profiles of Atypical Fibroxanthoma and Pleomorphic Dermal Sarcoma Identify Overlapping Signatures with a High Mutational Burden

Atypical fibroxanthoma (AFX) and pleomorphic dermal sarcoma (PDS) are rare tumors developing in chronically sun-exposed skin. Clinicopathological features are similar, but they differ in prognosis, while PDS has a more aggressive course with a higher risk for local recurrence and metastases. In current clinical practice, they are diagnosed by exclusion using immunohistochemistry. Thus, stringent diagnostic criteria and correct differentiation are critical in management and treatment for optimal outcomes. This retrospective single-center study collected clinicopathological data and tumor samples of 10 AFX and 18 PDS. Extracted genomic DNA from tumor specimens was analyzed by a next-generation sequencing (NGS) platform (FoundationOne-CDx™). Among 65 identified mutations, TP53 inactivating mutations were observed in all tumor specimens. In both AFX and PDS, the known pathogenic gene alterations in CDKN2A, TERT promoter, and NOTCH1 were frequently present, along with high mutational burden and stable Micro-Satellite Instability status. The mutational profiles differed only in ASXL1, which was only present in AFX. Further differences were identified in likely pathogenic and unknown gene alterations. Similarities in their genomic signatures could help to distinguish them from other malignancies, but they are not distinguishable between each other using the FoundationOne-CDx™ NGS panel. Therefore, histological criteria to determine diagnosis remain valid. For further insight, performing deep tumor profiling may be necessary.

Frequency, Treatment and Outcome of Immune-Related Toxicities in Patients with Immune-Checkpoint Inhibitors for Advanced Melanoma: Results from an Institutional Database Analysis

Immune checkpoint inhibitors (ICIs) can induce immune-related adverse events (irAEs), which may result in treatment discontinuation. We sought to describe the onset, frequency, and kinetics of irAEs in melanoma patients in a real-life setting and to further investigate the prognostic role of irAEs in treatment outcomes. In this retrospective single-center cohort study, we included 249 melanoma patients. Onset, grade, and resolution of irAEs and their treatment were analyzed. A total of 191 (74.6%) patients in the non-adjuvant and 65 (25.3%) in the adjuvant treatment setting were identified. In the non-adjuvant setting, 29 patients (59.2%) with anti-CTLA4, 43 (58.1%) with anti-PD1, and 54 (79.4%) with anti-PD1/anti-CTLA4 experienced some grade of irAE and these had an improved outcome. In the adjuvant setting, the frequency of irAEs was 84.6% in anti-CTLA4 and 63.5% in anti-PD1, but no correlation with disease relapse was observed. Patients with underlying autoimmune conditions have a risk of disease exacerbation. Immunomodulatory agents had no impact on treatment efficacy. IrAEs are correlated with increased treatment efficacy in the non-adjuvant setting. Application of steroids and immunomodulatory agents, such as anti-TNF-alpha or anti-IL6, did not affect ICI efficacy. These data support irAEs as possible prognostic markers for ICI treatment.

Imaging findings of a rare pararectal splenosis and literature review

Pararectal splenosis is an extremely rare lesion caused by ectopic auto-transplantation of splenic tissue after splenic trauma or splenectomy. It is often asymptomatic and detected incidentally during radiologic evaluation. We present a 24-year-old male with pararectal splenosis. The patient had a history of splenectomy and presented with complaints of abdominal discomfort and chronic constipation. Contrast-enhanced computed tomography (CT) revealed multiple well-enhanced masses located in the abdominal cavity and one mass in pararectal area. Additionally, the pararectal lesion showed diffusion restriction on diffusion-weighted magnetic resonance imaging (DW-MRI). In this case report, we aim to highlight the significance of taking a detailed medical history; and using DW-MRI for diagnosis of splenosis by presenting a case in a rare location.

Comparison of the effects of dexmedetomidine and remifentanil on potential extreme haemodynamic and respiratory response following mask ventilation and laryngoscopy in patients with mandibular fractures

OBJECTIVE

The safety profile and efficacy were compared for remifentanil and dexmedetomidine with respect to haemodynamic and respiratory response during mask ventilation and laryngoscopy in patients with mandibular fractures.

PATIENTS AND METHODS

Seventy patients undergoing elective mandibular fracture surgery were randomly assigned to the remifentanil group (Group R, n = 35) or the dexmedetomidine group (Group D, n = 35). The primary outcomes were preoperative pain scores caused by jaw movement; haemodynamic response; intubation score; and side effects, such as the incidence of oxygen desaturation and muscle rigidity. Other side effects, such as tachycardia, bradycardia, hypertension and hypotension, were also compared.

RESULTS

Preoperative pain scores caused by jaw movement were significantly high for both groups, but there were no statistically significant differences between the groups. The incidence of oxygen desaturation and muscle rigidity was significantly lower in Group D than in Group R (p = 0.025). No significant differences existed between the groups in terms of intubation score, haemodynamics, and other side effects (p > 0.05).

DISCUSSION

Dexmedetomidine and remifentanil had equal effectiveness on the control of haemodynamic response due to mask ventilation and intubation in patients with mandibular fractures. However, at the doses used in this study, dexmedetomidine had a significant advantage over remifentanil in terms of respiratory stability.

A different placement of the stone; rhinolithiasis

INTRODUCTION

Rhinolithiasis is a rare disease and formed by mineralization in the nasal cavity. Precipitated calcareous material on intranasal foreign substances forms the rhinoliths. It is start time could have since childhood.

MATERIALS AND METHODS

In this article, we present eight cases of rhinolithiasis who admitted to our Clinic between January 2001 and December 2010 with unilateral chronic nasal discharge, nasal obstruction and oral malodor.

CONCLUSIONS

Rhinolithiasis mostly manifests itself with unilateral purulent rhinorrhea, nasal obstruction and facial pain symptoms. We aimed to discuss these entity with similar cases in the literature.

Multiple dural arteriovenous fistulas involving the cavernous sinus, transverse sinus, sigmoid sinus and spinal drainage: CT angiography findings in 14-year-old boy

Dural arteriovenous fistulas (DAVF) are rare and constitute 10% to 15% of all intracranial arteriovenous malformations. Only few cases of DAVFs are reported in children. Here is the first case report describing CT angiographic findings in a 14 year old child having multiple DAVFs involving spinal canal, both cavernous and cerebral sinuses.

The incidence of non-proliferative and precancerous lesions of reduction mammoplasty: evaluation of 273 cases

BACKGROUND

Reduction mammoplasty (RM) is one of the most commonly performed plastic surgery procedures to treat symptomatic macromasty or to correct asymmetry. Occult breast carcinomas were rarely defined in RM specimens. There are few studies aiming to define the incidence of non-proliferative and precancerous lesions.

MATERIAL AND METHODS

We evaluated the pathological findings of the RM specimens that have been submitted to our Center for the last 6 years (2005-2011).

RESULTS

A total of 273 cases with bilateral RM were enrolled to the study. Of them, 229 cases had pathological changes. Eight cases (2.9%) had atypical ductal/lobular hyperplasia. One case (0.3%) had lobular carcinoma in situ; however, no invasive breast carcinoma was detected. Other pathological findings included fibrocystic changes, fibrosis, adenosis, fibroadenoma (without complex features), mastitis and duct ectasia.

CONCLUSIONS

Pathological examination of the RM specimens is quite important to define the lesions precancerous of breast carcinoma. Unknown occult breast lesions could be identified and early interventions may be taken into account.

Vaccination coverage in the South-East Anatolian Project (SEAP) region and factors influencing low coverage

OBJECTIVES

To determine the vaccination coverage of children living in the South-east Anatolian Project (SEAP) region; whether the vaccination coverage was similar to formal reports, other studies and other countries; and which factors influence vaccination, in order to indicate how vaccination coverage can be improved.

STUDY DESIGN

A descriptive cross-sectional study conducted in nine provinces of the SEAP region in order to determine public health problems and their causes.

METHODS

A population-based sample of 1150 houses was selected from rural and urban areas of the SEAP region and visited by the researchers. Questionnaires were applied in 2001 and 2002.

RESULTS

In the SEAP region, only 30% of children had received a complete set of vaccines. The vaccination coverage was 76.7% for Bacille Calmette-Guérin; 62.0% for the third doses of diphtheria, tetanus toxoid, pertussis and polio vaccine; 62.7% for measles; 44% for the third dose of hepatitis B vaccine in children aged 12-23 months; and 13.3% for the second dose of tetanus toxoid in women who gave birth in the last 5 years. In logistic regression analysis, residence type, number of siblings, birth interval, follow-up visits of midwives, and maternal level of education were found to influence whether children were completely vaccinated.

CONCLUSIONS

The findings of this study indicate that vaccination coverage is not acceptable in the SEAP region. Efforts must focus on family planning services, education of women, follow-up visits and strengthening health facilities, especially in rural regions, to improve vaccination.

Behaviour of Toxoplasma gondii RH Ankara strain tachyzoites during continuous production in various cell lines

Toxoplasma gondii is an obligate intracellular protozoan parasite. The objective of the present study was to examine the behaviour of Toxoplasma gondii RH Ankara strain tachyzoites in a cell culture environment. The study represents the first step in determining whether T. gondii RH Ankara strain tachyzoites, grown in cell culture, are of sufficient quality to allow cessation of in vivo tachyzoite production for diagnostic assays. In the present study, T. gondii RH Ankara strain tachyzoites were continuously produced in myeloma X63.Ag8.653, HeLa, Hep-2, and Vero cell cultures for 2 months. The average size of the tachyzoites was 3×5·7 μm prior to the first inoculation but after continuous production, a marked decrease was noted in average tachyzoite size. The smallest tachyzoite size, was 1×2·1 μm after 2 months, in myeloma cell cultures even though the yield of tachyzoites increased. With other cell cultures, tachyzoite yields were not as high as myeloma cell culture although decrease in size was less. The smallest decrease in tachyzoite size, averaging 2×3·8 μm after 2 months, was observed in tachyzoites produced in HeLa cell cultures. A virulence assay in small groups of BALB/c mice, using tachyzoites derived from cell cultures, was also conducted. The preliminary results of the virulence assay suggest that as the size of the tachyzoites decreased, the virulence in mice decreased. Future research will focus on the effect of the size of cell culture-derived T. gondii RH Ankara strain tachyzoites on the virulence, protein expression, and the reliability of diagnostic assays. Ultimately, the behaviour of tachyzoites from various T. gondii strains will be observed in cell culture to determine if size is altered.

Production of monoclonal antibodies against a 19-kD recombinant Plasmodium vivax MSP1 for detection of P. vivax malaria in Turkey

Plasmodium vivax malaria, which is transmitted to humans by mosquitoes, is one of the most important parasitic diseases in Turkey. The major protein on the surface of asexual erythrocytic stage merozoites of P. vivax (Pv) is 200 kD and called major merozoite surface protein-1 (PvMSP1). Polyclonal antibodies against the 19-kD C-terminal fragment of PvMSP1 (PvMSP1(19)) are protective in monkey models of P. vivax and associated with protection in field studies. In this research, monoclonal antibodies were produced against PvMSP1(19). A total of 214 IgG(1) antibody-releasing hybridomas were obtained and three monoclonal antibodies were produced (PvMSP1(19).1, PvMSP1(19).2, and PvMSP1(19).3) and selected for further study. They have now been purified from ascitic fluid on a Staphylococcus protein A affinity column. These are the first monoclonal antibodies produced against P. vivax in Turkey and the first monoclonal antibodies produced against this recombinant PvMSP1(19) in the world. The monoclonal antibodies will be used to study the epidemiology of P. vivax in patients with malaria in Turkey, and to develop better strategies for early diagnosis and treatment of the disease in our population.

Endometrial laser intrauterine thermotherapy: the first series of 100 patients observed for 1 year

OBJECTIVE

To describe a new instrument (GyneLase) that offers a new approach (endometrial laser intrauterine thermal therapy [ELITT]) to treatment of menorrhagia and to evaluate the efficacy of ELITT in the management of dysfunctional uterine bleeding.

DESIGN

Prospective study.

SETTING

University hospital.

PATIENT(S)

100 premenopausal women with dysfunctional uterine bleeding were observed for 1 year.

INTERVENTION(S)

Intrauterine laser thermotherapy with a diode laser.

MAIN OUTCOME MEASUREMENT(S)

Amenorrhea rate after 1 year.

RESULT(S)

The amenorrhea rate after 1 year of follow-up was 71%, and the rate of amenorrhea/severe hypomenorrhea rate was >90%; these rates are much higher than those in the literature after such procedures as electrosurgery or intrauterine thermal balloon therapy. The ELITT procedure is an inherently safe and simple alternative, providing controlled and effective treatment of the entire endometrium. In contrast to traditional endometrial ablation using a neodymium yttrium-aluminum-garnet laser, the ELITT procedure does not require intensive training or hysteroscopic control; it is also far less risky, because the power used per unit area is 1,000 times lower.

CONCLUSION(S)

The ELITT procedure is a new nonhysteroscopic technique for endometrial ablation. The technique is very safe and offers the highest amenorrhea rate to date in the literature.

Endometrial laser intrauterine thermo-therapy (ELITT): a revolutionary new approach to the elimination of menorrhagia

Various non-hysteroscopic procedures have been developed in the attempt to treat dysfunctional uterine bleeding that fails to respond to medical treatment efficiently and easily. Among these procedures is low-dose laser radiation of the endometrium with the diode source, which is characterized by the highest incidence of amenorrhea.

Effect of octreotide (Sandostatin 201-995) on bile flow and bile components

Octreotide (Sandostatin 201-995) has an inhibitory effect on gastric, intestinal, and pancreatic secretions and hepatic and splachnic blood flow. We examined the effects of octreotide on bile flow and bile components in 10 patients with T-tube choledochostomy. A Fogarty balloon catheter was inserted distal to the T-tube of these patients for measurement of bile flow and bile components. Bile samples were obtained to analyze bile acid, phospholipid, lipoprotein, and cholesterol, and bile flow measurements were performed every 15 min for a period of 90 min before study and after normal saline and octreotide administrations. While octreotide had an inhibitory effect on bile flow, the concentrations of bile acid, phospholipid, and lipoprotein in bile were increased with octreotide.

Humoral immune responses against Plasmodium vivax MSP1 in humans living in a malaria endemic area in Flores, Indonesia

The aim of this study was to evaluate the relationship among age, parasitemia status, spleen size, hematocrit, and antibody levels to Plasmodium vivax merozoite surface protein 1 (MSP1) in individuals chronically exposed to P. vivax. Subjects were recruited from the population of three adjacent villages on the Island of Flores in Indonesia where malaria transmission is hyperendemic and tropical splenomegaly syndrome is highly prevalent. Subjects were evaluated for spleen size, hematocrit, presence of parasitemia, and presence of antibodies to a recombinant peptide consisting of 90 amino acids from the carboxy terminus of MSP1. Fifty-seven percent of 2-4 year olds, 45% of 5-9 years old, and 7% of > or = 15 years old were parasitemic; 99% of the > or = 15 years old had splenomegaly, and 31% of them had Hackett 4 or 5 spleens. The frequency of antibody positivity to MSP1 antigen in ELISA increased with age reaching a maximum of 89% in > or = 20 years old. The frequency of antibody positivity to MSPI also increased with spleen size, and with a decline in the prevalence of parasitemia.

Monoclonal antibodies of three different immunoglobulin G isotypes produced by immunization with a synthetic peptide or native protein protect mice against challenge with Plasmodium yoelii sporozoites

Passive transfer of monoclonal antibodies (MAbs) against malaria circumsporozoite (CS) proteins protects animals against malaria. Active immunization with synthetic or recombinant peptides induces a level of polyclonal antibodies to sporozoites comparable to those found after passive immunization but does not provide comparable protection. In the Plasmodium yoelii system, synthetic or recombinant peptide-induced antibodies have never been shown to protect. The current studies were designed to determine whether immunogen structure (native protein versus synthetic peptide) or immunoglobulin G (IgG) subclass of antibodies was responsible for the absolute differences between protective, passively transferred MAbs and nonprotective, actively induced polyclonal antibodies. In this study we produced two MAbs, QGP-S1 (IgG1) and QGP-S2 (IgG2b), by immunization with a synthetic peptide based on the P. yoelii CS major repeat, (QGPGAP)4, conjugated to keyhole limpet hemocyanin. These MAbs were compared tp NYS1 (IgG3), an anti-CS protein MAb previously produced by immunization with irradiated P. yoelii sporozoites, which recognizes (QGP GAP)2. QGP-S1 and QGP-S2 passively transferred protection. However, when compared with NYS1, there was a hierarchy of protection, NYS1 > QGP-S1 > QGP-S2. There was no correlation between antibody level at challenge as determined by immunofluorescent antibody test against sporozoites or enzyme-linked immunosorbent assay against (QGPGAP)2 or apparent antibody avidity for (QGPGAP)2 by sodium thiocyanate elution assay. The data demonstrate that a synthetic peptide can induce protective antibodies and that a specific antibody subclass is not required for protection. Work to determine whether antibody affinity or fine specificity can explain the hierarchy of protection among the MAbs is under way.