ABSTRACT
Current control measures for schistosomiasis have only been partially successful in endemic areas due to socioeconomic constraints. One possibility for controlling the disease is to aim at the miracidial stage of the trematode to avoid infecting intermediate snail hosts by introducing more attractive substances for miracidia in the environment. Here, we introduce an accumulation assay of Schistosoma mansoni miracidia using a square glass tube for analysis of the positive responses of miracidia toward several substances, including snail-conditioned water of Biomphalaria glabrata, Bulinus globosus and insusceptible snails collected in the Nagasaki area in Japan. The substances are not proteins because miracidia accumulated in boiled snail-conditioned water and the secretion or emission level of substances depended on the feeding conditions of Biomphalaria glabrata. The present study also showed that substances emitted from Biomphalaria glabrata with a molecular weight around 10 kDa accumulated Schistosoma mansoni miracidia. Further, we showed that Schistosoma mansoni miracidia did not accumulate in response to mono- or disaccharides tested in the study.
Subject(s)
Biomphalaria , Schistosoma mansoni , Animals , Biomphalaria/physiology , Host-Parasite Interactions , Schistosoma mansoni/physiology , Snails , WaterABSTRACT
Treatment using intramedullary nail (IMN) is challenging for atypical femoral incomplete fractures with the bowed femur. Although IMN is the first choice for atypical femoral fractures, there is often a mismatch between the shape of the femur and the implant. Therefore, for prophylactic surgery of atypical femoral incomplete fracture we used IMN with a chipping technique, which is used for non-unions of the longitudinal fracture. We report a case of an 87-year-old woman who presented with bilateral thigh pain that lasted 3 months and gradually worsened. She had a medication history of bisphosphonates for 10 years. In addition, radiography showed severe curvature in her femurs, with radiolucent fracture lines in the diaphysis. We obtained good results by using IMN with the chipping technique. Thigh pain was promptly relieved postoperatively. Four months after surgery, each bone had fused without the need for additional treatment. The chipping technique in prevention surgery of atypical femoral fracture can eliminate the mismatch with the implant by grinding the limited lesion, including the radiolucent fracture line. Moreover, it promotes bone healing.
ABSTRACT
Voiding function of Schistosoma haematobium infected students was evaluated in 45 schoolboys in Kwale district, Coast province, Kenya, using a questionnaire and uroflowmetry. Sixty-eight schoolboys who were S. haematobium negative were also examined. Symptoms related to the lower urinary tract were qualitatively assessed using the International Prostate Symptoms Score (I-PSS) questionnaire. The I-PSS showed that S. haematobium infected boys felt the need to strain to urinate and post voiding some urine still remained. To examine the disturbances revealed by I-PSS quantitatively, voiding was assessed by a portable uroflowmeter and a bladder scanner. Unexpectedly, no significant residual urine post voiding and no decline in urine flow rates were found in S. haematobium infected boys. However, volume-corrected maximum and average flow rates in S. haematobium infected boys were higher than in those not infected. These results suggest that cystitis associated with S. haematobium infection causes irritation and hypercontraction of the bladder.
Subject(s)
Cystitis/epidemiology , Cystitis/parasitology , Schistosoma haematobium/isolation & purification , Schistosomiasis haematobia/complications , Schistosomiasis haematobia/epidemiology , Students/statistics & numerical data , Urination , Adolescent , Animals , Anthelmintics/therapeutic use , Case-Control Studies , Chi-Square Distribution , Child , Cystitis/diagnosis , Cystitis/drug therapy , Cystitis/urine , Humans , Kenya/epidemiology , Male , Praziquantel/therapeutic use , Prevalence , Radiography , Risk Assessment , Risk Factors , Schistosomiasis haematobia/diagnosis , Schistosomiasis haematobia/drug therapy , Schistosomiasis haematobia/urine , Schools , Statistics, Nonparametric , Surveys and Questionnaires , Urinary Bladder/diagnostic imaging , UrodynamicsABSTRACT
BACKGROUND: Although insecticide-treated bed nets are effective tools, use often does not follow ownership. House structure and space arrangements may make the attempt to use bed nets difficult, especially for school age children. The objectives of this study were to explore whether an individual's sleeping arrangements and house structure affect bed net use in villages along Lake Victoria in western Kenya. METHODS: Sleeping arrangements of residents were directly observed for use of a bed net, use of a bed, and location. House size, number and types of rooms, bed availability, and residents' ages were estimated. The family heads and mothers were asked about the reason for not using bed nets. Individual bed net use was examined against age and sleeping arrangement. Net use at the household level was examined against four variables: bed availability, bed net availability, house size, and number of rooms. RESULTS: Bed net use by children between five and 15 years of age was lower than that among the other age classes. However, age was dropped from the final model, and sleeping arrangement was significantly associated with net use. Net use was significantly associated with bed availability, number of rooms and their interaction. CONCLUSION: Net use was affected by sleeping arrangement and availability of suitable locations for hanging nets, in addition to net availability. Most residents had likely not realized that sleeping arrangement was a factor in net use. The ease of hanging a net is particularly important for children.
Subject(s)
Insecticide-Treated Bednets , Mosquito Nets/statistics & numerical data , Residence Characteristics , Sleep , Adolescent , Adult , Age Distribution , Child , Child, Preschool , Female , Humans , Infant , Kenya , Male , Middle Aged , Rural Population , Young AdultABSTRACT
BACKGROUND: The typical response to burn stress causes burn shock, followed by a diuretic phase; however, fluid management remains crucial in this phase in the treatment of the elderly, patients with preexisting cardiac or renal diseases, and patients developing acute renal failure. We studied the effects of human atrial natriuretic peptide (hANP), which is a renal vasodilator, natriuretic, and inhibitor of renin secretion, on renal function in these patients with burn injuries. METHODS: Thirty-three severely burned patients (44.8% +/- 20.6% total burn surface area) with prolonged cardiovascular overload and pulmonary edema after burn shock receiving a continuous infusion of hANP (0.025 microg/kg/min and 0.05 microg/kg/min, hANP group) were compared with control (no-hANP group, n = 25). Vital signs, urine output (UO) and blood gas analysis before and 72 hour after the start of hANP were recorded. Creatinine clearance, free water clearance, and fractional excretion of sodium were also calculated. RESULTS: Sixteen (48%) patients were elderly, over 80 years old. Twenty (60%) had preexisting cardiovascular disease, renal insufficiency, or diabetes. hANP infusion increased UO in 25 (66%) cases and improved oxygenation in 31 (82%) cases. Treatment with hANP increased creatinine clearance, fractional excretion of sodium, and UO, except in four cases that had already progressed to complete renal failure before the infusion of hANP. CONCLUSIONS: Intravenous hANP seems to be effective for postresuscitative pulmonary dysfunction and renal function after burn shock in the vulnerable elderly, or patients with preexisting disease, suggesting that it could be valuable in facilitating fluid management in the acute phase in severely burned patients.
Subject(s)
Atrial Natriuretic Factor/therapeutic use , Burns/drug therapy , Kidney/drug effects , Lung/drug effects , Shock, Traumatic/drug therapy , Age Factors , Aged , Aged, 80 and over , Blood Gas Analysis , Burn Units , Burns/complications , Burns/mortality , Case-Control Studies , Chi-Square Distribution , Dose-Response Relationship, Drug , Drug Administration Schedule , Female , Follow-Up Studies , Humans , Infusions, Intravenous , Injury Severity Score , Kidney Function Tests , Male , Middle Aged , Probability , Respiratory Function Tests , Respiratory Mechanics/drug effects , Risk Assessment , Shock, Traumatic/etiology , Shock, Traumatic/mortality , Statistics, Nonparametric , Survival AnalysisABSTRACT
Experimental vaccination with radiation-attenuated cercariae (RAC) confers possible practical levels of resistance to challenge infection by humoral and by cellular mechanism. Here, we aimed to identify possible vaccine antigens by using specific IgG antibody from RAC vaccinated miniature pig. Two milligrams of soluble egg antigen (SEA) or schistosomal worm antigen preparation (SWAP) was fractionated using two dimensional liquid chromatography (proteome PF 2D) consisted of high performance chromatofocusing (HPCF) and high resolution reversed phase chromatography (HPRP). Of the 42 HPCF fractions of SEA or SWAP, 26 (61.9%) or 15 (35.7%) showed positive dot blot reaction with RAC vaccinated serum respectively. The dot blot positive fractions were applied to the second HPRP column. One hundred and seven out of 26 x 96 of SEA fractions and 18 out of 15 x 96 SWAP fractions reacted with RAC vaccinated serum. From the positive fractions we chose 17 of SEA and 10 of SWAP that had no reactivity with normal cercariae infected (NCI) sera and had single peak of 214 nm; and automated N-terminal amino acid sequence based on in situ Edman Reaction was conducted. Four sequences were obtained and applied to the homology search in NCBI database. A total of eight candidate genes were listed up and their cDNA clones from schistosomula stage were obtained. Two of the recombinant proteins (AAW27472.1 and AXX25883.1) showed strong reactivity with the RAC vaccinated serum but marginal with NCI serum. This protocol using proteome PF 2D could be applicable in identifying immunoreactive proteins from crude extract for the development of vaccines or for diagnostics.
Subject(s)
Antibodies, Helminth/immunology , Antigens, Helminth/immunology , Helminth Proteins , Proteome , Schistosoma japonicum/immunology , Schistosomiasis japonica/immunology , Vaccines, Attenuated , Animals , Antigens, Helminth/genetics , Antigens, Helminth/metabolism , Gamma Rays , Helminth Proteins/genetics , Helminth Proteins/immunology , Helminth Proteins/metabolism , Immunoglobulin G/immunology , Rabbits , Schistosoma japonicum/growth & development , Schistosoma japonicum/radiation effects , Schistosomiasis japonica/parasitology , Schistosomiasis japonica/prevention & control , Swine , Swine, Miniature , Vaccines, Attenuated/immunology , Vaccines, DNA/immunologyABSTRACT
A total of 14 Sri Lankan pregnant women, who were anti-Brugia pahangi urinary IgG4 positive, and their 14 newborn babies were followed up for the urinary antibody for 2 years by enzyme-linked immunosorbent assay. Eight babies showed positive IgG4 reaction, at least once within 4 months after birth. Urinary antibody titers of mothers and their babies measured around the perinatal period showed a significant positive correlation, suggesting that baby's IgG4 was transferred from the mother through the placenta. The IgG4 decreased gradually and became negative in all positive babies by day 339.3 after birth. The present result provides a basis to judge if a positive urine ELISA test among babies is due to a new filarial infection.
Subject(s)
Antibody Specificity , Brugia pahangi/immunology , Filariasis/immunology , Immunity, Maternally-Acquired , Immunoglobulin G/urine , Pregnancy Complications, Parasitic/immunology , Animals , Antibodies, Helminth/urine , Enzyme-Linked Immunosorbent Assay , Female , Filariasis/parasitology , Filariasis/urine , Follow-Up Studies , Humans , Immunity, Maternally-Acquired/immunology , Infant, Newborn , Pregnancy , Pregnancy Complications, Parasitic/parasitology , Sri LankaABSTRACT
The jird (Mongolian gerbil) is a highly susceptible experimental host for the lymphatic filarial nematode, Brugia pahangi. The chemotactic activity of serum from this host for B. pahangi infective larvae was compared in vitro to that of sera or hemolymph of a wide variety of other organisms including mammals, reptiles, fishes and invertebrates. The range of the Chemotactic Index (CI) was from 96.0 for the jird to 56.2 for a snail. An average of CI of saline control was 4.5. Significant chemotactic activity was present in many organisms, especially mammals, but was not closely related to either the phylogenetic position of the organism and to its known susceptibility as definitive host for B. pahangi. Migratory response was diminished in a consistent way by serial dilution of sera of humans, jirds and fetal bovine serum. Pre-incubation of larvae in fetal bovine serum inhibited migration, especially towards the sera of humans. Inhibition could be reversed by rinsing larvae in saline, longer rinse periods resulting in greater recovery of CI. These results are the first to suggest the activity of the specific amphid chemoreceptors in the chemotaxis of the infective larvae of B. pahangi.
Subject(s)
Chemotaxis/physiology , Gerbillinae/parasitology , Hemolymph/parasitology , Host-Parasite Interactions , Serum/parasitology , Adult , Animals , Brugia pahangi/growth & development , Brugia pahangi/pathogenicity , Brugia pahangi/physiology , Cattle , Female , Gerbillinae/blood , Gerbillinae/urine , Hemolymph/physiology , Humans , Larva/pathogenicity , Larva/physiology , Male , Serum/physiology , Sweat/parasitology , Sweat/physiology , Urine/parasitology , Urine/physiologyABSTRACT
BACKGROUND: Secondary abdominal compartment syndrome (ACS) is a lethal complication after resuscitation from burn shock, even after abdominal decompression (AD) is performed. This study investigated increased susceptibility to multiple organ dysfunction syndrome (MODS) in extensively burned patients with ACS. METHODS: Patients admitted to our burn unit between 2002 and 2005 with burns affecting 40% or more of the total body surface area without severe inhalation injury were analyzed. Hemodynamic parameters, blood gas analysis, and intrabladder pressure as intra-abdominal pressure were recorded. Serum interleukin (IL)-8 and IL-6 concentrations were measured in 20 of these patients. Lung injury score and Sequential Organ Failure Assessment scores were serially determined. RESULTS: Fourteen of 38 patients developed intra-abdominal hypertension in 22.9 +/- 8.9 hours postburn. Hemodynamic parameters in these 14 patients, including peak intra-abdominal pressure (46.6 +/- 11.2 to 19.8 +/- 9.9 cm H2O), peak inspiratory pressure (51.4 +/- 10.5 to 31.8 +/- 7.0 cm H2O), and abdominal perfusion pressure (51.3 +/- 18.3 to 73.9 +/- 13.6 mm Hg), were improved immediately after AD. Despite AD, lung injury score and Sequential Organ Failure Assessment scores increased significantly 2 and 3 days postburn in patients who required AD. Plasma concentration of IL-8 was elevated in intra-abdominal hypertension patients 3 days postburn. CONCLUSION: Intra-abdominal hypertension induced acute lung injury and MODS with IL-8 elevation, even though AD improved hemodynamic parameters in extensively burned patients.
Subject(s)
Burns/complications , Compartment Syndromes/etiology , Multiple Organ Failure/etiology , Respiratory Distress Syndrome/etiology , Abdominal Cavity , Compartment Syndromes/blood , Compartment Syndromes/surgery , Decompression, Surgical , Humans , Interleukin-8/blood , Multiple Organ Failure/blood , Respiratory Distress Syndrome/bloodABSTRACT
Japan controlled its major parasitic diseases by the 1970s. Based on this experience, the Government of Japan proposed the Global Parasite Control Initiative in 1998 and established three research and training centres around the world. The Asian Centre of International Parasite Control (ACIPAC) is the first such centre, and completed five years of activities focused on school-health-based parasite control in the Greater Mekong Subregion in 2005. The lessons learned and experiences gained by ACIPAC should be applied to all health promotion programmes worldwide.
Subject(s)
Health Education/methods , Parasitic Diseases/prevention & control , Schools , Animals , Asia, Southeastern , Child , Child, Preschool , Humans , International Cooperation , JapanABSTRACT
A single-dose treatment with diethylcarbamazine (DEC) reduced microfilaria (mf) counts of Brugia pahangi by >90% at 30 min post-treatment in Mongolian jirds (Meriones unguiculatus). The reduction was followed by a rapid increase in microfilaremia, with the count reaching pretreatment level in 3 hr. The mechanisms behind this temporary reduction of mf were investigated. Without treatment, mf accumulated in the lungs. At 30 min post-treatment, they had moved from the lungs and accumulated in the muscle. At the same time, electron microscopy revealed many mf in the muscle interstitium. DEC concentrations at 30 min were much lower in the muscle (12.2 microg/g of tissue) than in the lungs, liver, and kidneys (19.8-40.7 microg/g), all of which declined to < 0.6 microg/g by 3 hr. The presence of mf in the muscle would be advantageous for avoiding high DEC concentrations, and their extravascular location could prevent attack by host effector cells.
Subject(s)
Brugia pahangi/drug effects , Diethylcarbamazine/pharmacology , Filaricides/pharmacology , Lung/parasitology , Muscle, Skeletal/parasitology , Animals , Blood Vessels/parasitology , Blood Vessels/ultrastructure , Brugia pahangi/physiology , Brugia pahangi/ultrastructure , Diethylcarbamazine/blood , Diethylcarbamazine/pharmacokinetics , Disease Models, Animal , Filaricides/blood , Filaricides/pharmacokinetics , Gerbillinae , Heart/parasitology , Kidney/metabolism , Kidney/parasitology , Liver/metabolism , Liver/parasitology , Lung/metabolism , Male , Microfilariae/drug effects , Microfilariae/physiology , Microfilariae/ultrastructure , Microscopy, Electron, Transmission , Muscle, Skeletal/metabolism , Muscle, Skeletal/ultrastructure , Myocardium/metabolismABSTRACT
BACKGROUND: Secondary abdominal compartment syndrome is a lethal complication after resuscitation from burn shock. Hypertonic lactated saline (HLS) infusion reduces early fluid requirements in burn shock, but the effects of HLS on intraabdominal pressure have not been clarified. METHODS: Patients admitted to our burn unit between 2002 and 2004 with burns > or =40% of the total body surface area without severe inhalation injury were entered into a fluid resuscitation protocol using HLS (n = 14) or lactated Ringer's solution (n = 22). Urine output was monitored hourly with a goal of 0.5 to 1.0 mL/kg per hour. Hemodynamic parameters, blood gas analysis, intrabladder pressure as an indicator of intraabdominal pressure (IAP), and the peak inspiratory pressure were recorded. Pulmonary compliance and the abdominal perfusion pressure were also calculated. RESULTS: In the HLS group, the amount of intravenous fluid volume needed to maintain adequate urine output was less at 3.1 +/- 0.9 versus 5.2 +/- 1.2 mL/24 h per kg per percentage of total body surface area, and the peak IAP and peak inspiratory pressure at 24 hours after injury were significantly lower than those in the lactated Ringer's group. Two of 14 patients (14%) in the HLS group and 11 of 22 patients (50%) developed IAH within 20.8 +/- 7.2 hours after injury. CONCLUSION: In patients with severe burn injury, a large intravenous fluid volume decreases abdominal perfusion during the resuscitative period because of increased IAP. Our data suggest that HLS resuscitation could reduce the risk of secondary abdominal compartment syndrome with lower fluid load in burn shock patients.
Subject(s)
Abdomen , Burns/complications , Compartment Syndromes/prevention & control , Lactic Acid/therapeutic use , Saline Solution, Hypertonic/therapeutic use , Shock, Traumatic/therapy , Adolescent , Adult , Aged , Compartment Syndromes/etiology , Drug Combinations , Female , Humans , Isotonic Solutions/therapeutic use , Lactic Acid/administration & dosage , Male , Middle Aged , Ringer's Lactate , Saline Solution, Hypertonic/administration & dosage , Shock, Traumatic/etiologyABSTRACT
Abdominal compartment syndrome (ACS) is rarely reported as a complication of severe burn. This study clarified the risk of burned patients with and without ACS, especially regarding the resuscitation fluid volume. Extensively burned patients admitted to our burn unit from January 2003, through to June 2004, were examined. Vital signs, blood gas analysis, bladder pressure to estimate intra-abdominal pressure (IAP), peak inspiratory pressure (PIP), resuscitation fluid volume, and urine output (UO) were analyzed. Intra-abdominal hypertension (IAH) was defined as an IAP of more than 30 cm of H2O. Eight of 48 patients suffering from a more than 30% total burn surface area developed ACS in 18.3+/-4.9 h. In these patients, IAP (49+/-12 cmH2O), PIP (50+/-16 cmH2O), heart rate (115+/-8/min), and PaCO2 (54.6+/-10.1 mmHg) were higher than normal, and their resuscitation volume was 0.40+/-0.11 L/kg. Also, a significant correlation between the IBP, PIP and resuscitation volume was observed. Most patients with severe burns required more than 300 mL/kg of resuscitation fluid for the first 24 h after injury that led to ACS and had higher HR, IBP, PIP and PaCO2 despite arterial pressure showing no significant difference.
Subject(s)
Abdomen , Burns/complications , Compartment Syndromes/etiology , Fluid Therapy/methods , Resuscitation/methods , Adolescent , Adult , Aged , Aged, 80 and over , Body Surface Area , Compartment Syndromes/drug therapy , Female , Humans , Male , Middle AgedABSTRACT
BACKGROUND: Abdominal compartment syndrome (ACS) can become fatal; however, it has rarely been described as a complication of burn injury. This study clarified the physiologic results of abdominal decompression (AD) for ACS in patients with burn injury in detail. METHODS: Extensively burned patients admitted to our burn unit between January 2003 and February 2004 were prospectively monitored by pulmonary artery catheter. Physiologic parameters from the catheter, blood gas analysis, intrabladder pressure as a parameter of intra-abdominal pressure (IAP), peak inspiratory pressure, and urine output (UO) were compared before and after escharotomy as AD in patients with ACS. RESULTS: Eight of 36 patients who had sustained more than 30% total body surface area burn developed ACS requiring AD in 18.3 +/- 4.9 hours. AD significantly decreased IAP (52 +/- 9 cm H2O vs. 26 +/- 7 cm H2O), peak inspiratory pressure (53 +/- 13 cm H2O vs. 35 +/- 6 cm H2O), heart rate, and Paco2, and increased cardiac index (1.6 +/- 0.7 L/min/m2 vs. 2.5 +/- 0.9 L/min/m2), abdominal perfusion pressure (50 +/- 11 mm Hg vs. 72 +/- 17 mm Hg), UO (0.45 +/- 0.46 mL/h/kg vs. 2.0 +/- 2.1 mL/h/kg), and oxygen delivery index (290 +/- 195 mL/m2/min vs. 455 +/- 218 mL/m2/min). Impaired oxygen consumption index increased (86 +/- 43 mL/m2/min vs. 153 +/- 58 mL/m2/min) after AD. CONCLUSION: In patients with severe burn injury, elevated IAP makes pulmonary artery wedge pressure and UO unreliable indices of preload or intravascular volume, and decreases abdominal perfusion in the resuscitation period. AD in these patients significantly improves the ventilation, hemodynamic parameters, and oxygen metabolism.
Subject(s)
Abdomen/physiopathology , Burns/physiopathology , Compartment Syndromes/physiopathology , Compartment Syndromes/surgery , Decompression, Surgical , Viscera/blood supply , Adolescent , Adult , Aged , Aged, 80 and over , Burns/complications , Compartment Syndromes/etiology , Female , Humans , Middle Aged , Oxygen Consumption , Pressure , Prospective Studies , Radiography, AbdominalABSTRACT
Anti-filarial effects of diethylcarbamazine (DEC), tetracycline (TC) and the combination on Brugia pahangi adult females were studied in 7-day cell-free culture, in terms of microfilaria release, parasite motility, MTT assay for parasite viability and embryogram. TC 50 microg/ml (TC50) effectively reduced microfilaria release from day 1 of culture. Combined with DEC 100 microg/ml (DEC100) or DEC 500 microg/ml (DEC500), microfilaria release reduced further and synergistically. TC50 also reduced motility, but DEC100 and DEC500 did not. The combination of TC50 and DEC500 reduced motility synergistically. The MTT assay supported the results of motility study in general. The embryogram showed that only DEC500 reduced the total number of intrauterine embryos, especially ova, indicating that DEC500 inhibited early embryogenesis. TC50 did not affect the total number of embryos, but resulted in apparent accumulation of microfilariae in the uterus, suggesting that the drug inhibited release of microfilariae in this in vitro system. These results clarified different anti-female mechanisms between DEC and TC. A PCR-based study showed that endosymbiont bacteria, Wolbachia, in B. pahangi females decreased significantly after TC treatment. However, this study could not determine whether the effects of TC were direct or Wolbachia-mediated.
Subject(s)
Anti-Bacterial Agents/pharmacology , Brugia pahangi/drug effects , Diethylcarbamazine/pharmacology , Filaricides/pharmacology , Tetracycline/pharmacology , Animals , Anti-Bacterial Agents/administration & dosage , Brugia pahangi/embryology , Brugia pahangi/microbiology , Brugia pahangi/physiology , Culture Media , Diethylcarbamazine/administration & dosage , Drug Therapy, Combination , Female , Filaricides/administration & dosage , Microfilariae/drug effects , Microfilariae/microbiology , Parasitic Sensitivity Tests , Symbiosis , Tetracycline/administration & dosage , Wolbachia/drug effectsABSTRACT
As part of a search for good animal models for human schistosomiasis, two miniature pigs of the CLAWN strain (C-1, C-2) were inoculated percutaneously with 200 Schistosoma japonicum cercariae of the Chinese strain, and the subsequent infection was monitored parasitologically, pathologically and serologically. Egg excretion into feces began at 5 weeks post-infection (p.i.) and became pronounced from 8 weeks to 17-20 weeks p.i. The average number of eggs in 1 g feces of each pig at the peak period between 8 and 20 weeks were 288 and 277, respectively. C-1 and C-2 were killed and perfused at 27 and 47 weeks p.i. and adult worm numbers recovered were 35 and 15, respectively. C-2 had at least four pairs of viable mature worms but no detectable fecal eggs for a month before perfusion, suggesting that any produced eggs were not excreted into the feces during this period. Egg deposits associated with inflammatory reactions were observed by histological examination of the liver, spleen, pancreas, mesenteric lymph nodes, lung, and small intestine. This suggests that reduced fecal excretion of eggs into the feces did not correlate to reduced parasite numbers in the chronic phase of schistosomiasis. This is the first report showing the miniature pig to be a potential model for human S. japonicum infection.
Subject(s)
Disease Models, Animal , Schistosoma japonicum/pathogenicity , Schistosomiasis japonica/pathology , Swine, Miniature , Animals , Antibodies, Helminth/blood , Feces/parasitology , Female , Humans , Male , Parasite Egg Count , Schistosoma japonicum/immunology , Schistosomiasis japonica/parasitology , SwineABSTRACT
This study examined the possible involvement of cyclic adenosine monophosphate (cAMP) in the control of ciliary action of Schistosoma mansoni miracidia. Miracidia immobilized in hypertonic NaCl solution were treated with 3 compounds that are known to increase intracellular cAMP concentrations. Forskolin, at a concentration of 50 microM, induced 50.1% of the miracidia to swim in hypertonic solution. The corresponding values obtained for 3-isobutyl-1-methylxanthine (IBMX) at 1 mM and 8-bromo-cAMP at 10 mM were 42.2 and 50.4%, respectively. The motility-enhancing effect of these compounds was dose dependent. Nevertheless, the swimming speed of miracidia activated in this way was only 10% of that observed in artificial pond water (APW). Cholera toxin had no apparent effect on miracidia swimming in hypertonic NaCl solution. Likewise, swimming in APW treated with forskolin at 50 microM, IBMX at 1 mM, or 8-bromo-cAMP at 10 mM did not induce any apparent change in motility. Miracidia swimming in APW were then treated with 3 compounds that decrease the intracellular concentration of cAMP. MDL-12,330A, at a concentration of 250 microM, caused a dramatic decrease in swimming over a period of 1 hr. Likewise, SQ22536 and imidazole, at concentrations of 20 and 50 mM, respectively, caused 36.5 and 73.4% decreases in swimming under the same conditions. Finally, inhibitors of cAMP-dependent protein kinase, i.e., PKI(14-22)amide, H89, and H88, completely inhibited miracidia swimming in APW at concentrations of 25, 50, and 100 microM, respectively. These results suggest that cAMP and cAMP-dependent protein kinase are involved in osmosis-controlled ciliary motion of schistosome miracidia.
Subject(s)
Cyclic AMP/physiology , Schistosoma/physiology , 1-Methyl-3-isobutylxanthine/pharmacology , 8-Bromo Cyclic Adenosine Monophosphate/pharmacology , Animals , Cilia/physiology , Colforsin/pharmacology , Cyclic AMP-Dependent Protein Kinases/antagonists & inhibitors , Dose-Response Relationship, Drug , Fresh Water/parasitology , Movement/drug effects , Movement/physiology , Osmolar Concentration , Phosphodiesterase Inhibitors/pharmacology , Saline Solution, Hypertonic , Schistosoma/drug effects , Schistosoma/ultrastructureABSTRACT
Cercariometry provided information on diurnal fluctuation, seasonal and spatial distribution of cercariae in the suitable natural water bodies. There was an apparent mismatch between the results of cercariometry and snail sampling. Water, which cercariometry showed to contain cercariae was potentially infective, although the resultant worm load of sentinel rodents may not bear a linear relationship with cercarial density. Cercariometry has some weakness in practices and analysis of data, however, it provides the valuable information on the active transmission sites of schistosomiasis.