Spinal organization and steroid sensitivity of motoneurons innervating the pubococcygeus muscle in the male rat

Male rat motoneurons innervating the pubococcygeus muscle were located in the ventral nucleus of lamina IX at the sixth lumbar (L6) and first sacral (S1) spinal cord segments. Retrograde labeling with horseradish peroxidase-wheat germ agglutinin was transported up to second-order dendrites and revealed that these motoneurons have a "U-shaped arborization" of dendrites toward the intermediolateral and intermediomedial nuclei area of lamina VII. This dendritic organization makes a wide "final common path" that probably integrates afferent information from several sources, accounting for the participation of the pubococcygeus muscle in autonomic and somatic processes, such as those related to micturition and reproduction. Castration produced a decrement in the morphometry of these motoneurons. A main effect was a decrement in dendritic length. Steroid replacement indicated that testosterone and estradiol, but not dihydrotestosterone, are able to induce a recovery of morphometric alterations. However, estrogen induced recovery after 2 weeks of treatment, whereas testosterone took 4 weeks. Thus, it is proposed that supraspinal aromatization of testosterone in the male central nervous system might be an important process for the appropriate organization of the pubococcygeus muscle motoneurons and that estradiol seems to need a shorter time of action than testosterone because of differential up-regulation and down-regulation of steroid receptors.

Filarial antibody responses in Wuchereria bancrofti transmission area are related to parasitological but not clinical status

In Wuchereria bancrofti transmission areas, three groups of individuals have been identified, according to the presence or absence of microfilariae or adult worm derived molecules in the blood compartment. These groups likely reflect individuals with different permissivity/resistance to the complete development of W. bancrofti cycle. The profile of filarial-specific immunoglobulins was analysed in W. bancrofti-exposed individuals in French Polynesia, according to the presence or absence of microfilariae (Mf) and adult worms, measured by Og4C3 circulating antigen. Individuals harbouring adult worms, have higher filarial-specific IgG4 but lower IgG3 and IgE levels, than adult worm-free individuals, independently of the presence of Mf. Low filarial-specific IgG1 and IgG2 levels were associated with the presence of Mf but independent of the presence/absence of adult worms. The filarial antibody responses were associated with the parasitological status of individuals but not with clinical symptoms such as hydroceles or limb lymphangitis or elephantiasis. The reduction of filarial-specific immunoglobulin levels was higher after treatment with diethylcarbamazine, than ivermectin, which likely reflects the better effect of the former on W. bancrofti adult worms. However, reduction of antibody levels was also observed in Mf-and adult worm-negative individuals. This could be due to the overall reduction of W. bancrofti transmission in the island where this study took place.

The immunodominant Brugia malayi paramyosin as a marker of current infection with Wuchereria bancrofti adult worms

The full-length cDNA sequence encoding Brugia malayi L3 paramyosin has been isolated by immunoscreening a cDNA library with a mouse antiserum raised against Wuchereria bancrofti L3 infective larvae. A recombinant truncated form of paramyosin was expressed as a glutathione S-transferase fusion protein and used to evaluate humoral responses of adults from a W. bancrofti-endemic area in French Polynesia according to their parasitological status. Immunoglobulin G4 (IgG4) preferentially bound to paramyosin in W. bancrofti-parasitized individuals, in contrast to unparasitized individuals, who harbored neither microfilaria nor Og4C3 adult worm circulating antigen. Reduction of the anti-paramyosin IgG4 titer following combined chemotherapy with diethylcarbamazine and ivermectin was significantly correlated with a reduction in the adult worm burden. This indicates that the presence of paramyosin-reactive IgG4 is associated with the presence of parasites and that reduction can be used as an immunological marker for W. bancrofti clearance.

Diagnosis of Wuchereria bancrofti infection by the polymerase chain reaction using urine and day blood samples from amicrofilaraemic patients

A sensitive and specific polymerase chain reaction (PCR) based on a highly repeated deoxyribonucleic acid (DNA) sequence (188 bp; SspI repeat) was tested for the detection of Wuchereria bancrofti DNA in blood and urine samples collected during the day from individuals in Coque, Recife, Brazil, an endemic area for W. bancrofti. All microfilaraemic individuals were also positive by PCR, irrespective of the samples used. The PCR system was capable of detecting W. bancrofti DNA in amicrofilaraemic individuals: c. 93% were positive by PCR when day blood samples were used and 59.7% when urine samples collected at 07:00 were used. Thus, nocturnally periodic W. bancrofti infection can be detected in blood samples collected during the day, which is convenient for large-scale screening. In addition, non-invasive urine collection provided suitable samples for PCR, which is clearly advantageous for preliminary mass diagnosis.

[Proximal femoral fractures in patients over 75 years. Vital and functional prognosis of a cohort of 78 patients followed during 2.5 years]

PURPOSE OF THE STUDY

The purpose of this study was to highlight factors influencing vital and functional prognosis at 2.5 years of elderly people being treated for a proximal femoral fracture.

MATERIAL

The study was based on 78 patients more than 75 years old admitted to the orthopedic department for emergency treatment. After post-operative care, patients were transferred to a geriatric readaptation unit. The average patient age at the time of surgery was 85 years.

METHODS

This was a retrospective study. Survival graphs were established for the entire population as well as for the sub-populations characterized by a studied parameter. Mortality factors were compared via a univariable analysis. A multivariable logistical regression analysis isolated the factors explaining mortality at 12, 18, and 30 months and survival at 30 months, as well as factors explaining functional prognosis at 1 year.

RESULTS

The overall mortality rate was 41 per cent, 48.5 per cent of deaths occur within the first year. Factors which are harmful for vital prognosis are the following: high degree of dependence before the fracture, the existence of a neuropsychiatric pathology, and age factor (more than 85 years). 61.5 per cent of surviving patients were independent for daily activities. 77 per cent of surviving patients lived in their usual place of residence. Factors which were harmful for functional prognosis were the following: type of the fall, symptomatic of an underlying pathological state, and existence of a neuropsychiatric pathology. Nutrition was also a predictive factor concerning the patient's out come.

DISCUSSION

The average age of the studied population was higher than in most studies in literature. The treatment is mainly based on hip arthroplasty. The group of patients of over 85 have the highest mortality rate. However, a better survival rate at 18 months has been observed for patients older than 90 years. The delay before surgical care was significantly negative if longer than 6 days. However, a delay of 3 to 6 days was not significantly harmful for survival. Within the studied population, the maximum autonomy gain was observed during the first 6 months. The type of non-accidental fall, symptomatic of an associated pathology, was a factor for functional prognosis which has not been often mentioned. So was the biological deficit of nutrition. Social status acted as an indicator of functional status evolution.

CONCLUSION

Therapeutic choices can only be guided by assessments of patients' vital and functional prognosis. A sophisticated or even expensive device should be demanded for patients with favorable prognosis. For patients with precarious functional and vital prognosis, priority should be given to less invasive techniques with immediate walking. The cost of the device should be correlated with patient's functional investment.

Synthesis and ESR study of new dihydroxamic acid siderophores S as scavengers of hydroxyl radicals

Five new dihydroxamic acid ligands (L) (8, 10a, 10b, 10c and 13) have been synthesised and characterised as potential chelating agents for iron (Fe3+). The log stability constants of Fe2L3 and FeL+ from Fe3+ and L2- have been estimated to be log beta = 61.96 and log beta 1 = 22.8 respectively. The ability of these compounds to scavenge hydroxyl radicals (oOH) responsible for cell damage have been studied by esr spectroscopy.

Multiplex polymerase chain reaction for detection of Dirofilaria immitis (Filariidea: Onchocercidae) and Wuchereria bancrofti (Filarioidea: Dipetalonematidae) in their common vector Aedes polynesiensis (Diptera: Culicidae)

In French Polynesia, Aedes polynesiensis (Marks) is the vector of the human filarial parasite Wuchereria bancrofti (Cobbold) and dog heartworm, Dirofilaria immitis (Leidy). A multiplex polymerase chain reaction (PCR) assay was designed to screen pools of field-collected Ae. polynesiensis for the presence of both parasites simultaneously using primers specific for each parasite. The sensitivity of detection on purified DNA was 1 and 10 pg, equivalent to 0.1 and 1 L3 larva per pool for W. bancrofti and D. immitis, respectively. Codetection was performed at an hybridization temperature of 58 degrees C to avoid competition between heterologous DNA and primers that was observed at 55 degrees C. In addition, D. immitis was detected by PCR in the blood of infected dogs.

New tools for diagnosis and monitoring of bancroftian filariasis parasitism: The polynesian experience

Bancroftian filariasis is endemic in French Polynesia and control programs with diethylcarbamazine, started in the 1950s, led to a sharp reduction of the microfilaria prevalence. Consequently, the control program was interrupted in 1982. Ten years later, however, the incidence of the parasitism again reached pre-control levels (20-30% microfilaremia in some islands), indicating that the adult worms (for which no diagnostic tool was available) had persisted. Apart from research on chemotherapy strategies, the Institut Malardé has been actively involved in developing and evaluating more-powerful diagnostic tools than the unique detection of microfilariae by blood smear examination. These include: (1) the detection of adult worm circulating antigens in humans, and (2) the detection of Wuchereria bancrofti larvae in mosquitoes, using DNA probes. In this paper, Luc Nicolas reviews the available diagnostic tools to detect W. bancrofti and their implementation in epidemiological areas, based on the Polynesian experience.

A universally applicable internal standard for PCR detection of Wuchereria bancrofti in biological samples

A PCR-based assay have been previously described to detect Wuchereria bancrofti in mosquitoes and in human blood samples. However, the efficiency of PCR amplification may vary between samples depending on the presence of PCR inhibitors, leading sometimes to false negative results. To overcome this drawback, an internal standard plasmid (pWB11) was constructed. It can be added to each PCR reaction for coamplification along with the target W. bancrofti DNA (Sspl DNA repeat) using the same pair of primers. PCR products from W. bancrofti DNA or from pWB11 are 34 bp different in size and can be visualized either on agarose gel or by DNA ELISA using two different oligonucleotides probes.

Detection of Loa loa-specific DNA in blood from occult-infected individuals

Accurate and specific diagnosis of human loiasis is of crucial importance in an endemic area where two-thirds of infected individuals are without circulating microfilariae (occult loiasis). By using the polymerase chain reaction (PCR) and specific primers to the repeat 3 region (15r3) of the gene coding for Loa loa 15-kDa polyprotein antigen, DNA was amplified from total blood lysate of occult-infected subjects. A 396-bp DNA fragment was specifically detected. We tested the specificity of this method by qualitative hybridization to PCR products using blood lysates of the following subjects: (1) from Gabon (80 individuals residing in L. loa endemic area where loiasis exists sympatrically with Mansonella perstans); (2) from Togo (12 individuals infected with Onchocerca volvulus and M. perstans); (3) from Tahiti (12 individuals infected with Wuchereria bancrofti); and (4) from Mali (12 individuals infected with O. volvulus and M. perstans). Samples from Gabon included 60 L. loa amicrofilaremics and 20 L. loa occult-infected subjects. Qualitative hybridization carried out at 50 degrees C on PCR products, using a 15r3-specific oligonucleotide probe, revealed hybridization with L. loa-infected samples from Gabon and four samples from Togo after 2 days exposure to the film. The positive samples from Togo were characterized by the use of nested PCR. Three nested PCR products have been sequenced. No differences were observed between the three sequences and they are 99.72% identical to L. loa 15r3. None of bancroftian-infected individuals from Tahiti, nor O. volvulus- and M. perstans-infected individuals from Mali reacted after 1 week's exposure (overexposure) to the film. This allows us to conclude first that our 15r3 PCR assay is specific for L. loa and secondly that L. loa infections occur in Togo. The sensitivity of this 15r3 PCR assay was further investigated with occult patients and field-collected amicrofilaremic samples. We found that 19 of the 20 occult-infected individuals were positive on Southern hybridization, whereas 35/60 amicrofilaremics were positive. These results have shown that the sensitivity of this assay in detecting unequivocal, parasitologically proven occult loiasis was 95%, while the specificity with regard to the sympatric M. perstans was 100%.

Reduction of Wuchereria bancrofti adult worm circulating antigen after annual treatments of diethylcarbamazine combined with ivermectin in French Polynesia

Circulating filarial antigen (CFA), determined with Og4C3 ELISA, is a marker of Wuchereria bancrofti adult worm infection. The reduction of CFA over 2 years was determined in 185 microfilaremic and 111 amicrofilaremic but CFA+ adults given an annual dose of either diethylcarbamazine (DEC) or ivermectin or the two combined. Reduction of CFA level was good with DEC but weak with ivermectin and followed the same pattern in amicrofilaremic and microfilaremic groups. Combinations and DEC alone had a similar impact on CFA level. CFA clearance was observed in amicrofilaremic but not in microfilaremic persons in all DEC-containing treatments. However, the highest clearance rate was observed in persons treated with DEC at 6 mg/kg combined with ivermectin. Continuous reduction of CFA level after repeated treatments shows that elimination of W. bancrofti infection, monitored by CFA clearance, might be achieved within a few years with annual treatments of DEC combined with ivermectin.

A polymerase chain reaction assay for the detection of Wuchereria bancrofti in blood samples from French Polynesia

A polymerase chain reaction (PCR) assay based on a highly repeated deoxyribonucleic acid (DNA) sequence found in Wuchereria bancrofti (the SspI repeat) has been developed to address the shortcomings of traditional diagnostic methods. In this field study in a W. bancrofti endemic region of French Polynesia, 373 human blood samples were collected and 100 microL of blood were screened by the SspI PCR assay and 1 microL by membrane filtration. The SspI PCR assay detected 99 of 113 blood samples in which microfilariae had been detected by filtration (sensitivity of 88%) with a specificity of 100%. All the samples missed by the SspI PCR assay had less than 8 microfilariae per mL of blood. To evaluate the efficacy of screening larger blood samples by PCR, both 100 microL and 500 microL samples from 50 patients with very low-level microfilaraemia were screened by the SspI PCR assay; the sensitivity increased from 60% to 84% when using the larger volume of blood. Finally, an enzyme-linked immunosorbent assay-based version of the SspI PCR assay was used to screen blood from 12 patients following treatment with diethylcarbamazine, ivermectin, or both. These results showed that the PCR assay closely paralleled the presence or absence of microfilariae in the blood and that no increase in the DNA level was seen immediately following drug treatment.

Cloning and expression of the first anaerobic toxin gene from Clostridium bifermentans subsp. malaysia, encoding a new mosquitocidal protein with homologies to Bacillus thuringiensis delta-endotoxins

A gene (cbm71) encoding a 71,128-Da mosquitocidal protein (Cbm71) was obtained by screening a size-fractionated XbaI digest of total genomic DNA from Clostridium bifermentans subsp. malaysia CH18 with two gene-specific oligonucleotide probes. The sequence of the Cbm71 protein, as deduced from the sequence of cbm71, corresponds to that of the 66-kDa protein previously described as one of the mosquitocidal components of C. bifermentans subsp. malaysia. Cbm71 shows limited similarities with Bacillus thuringiensis delta-endotoxins, especially in the four first conserved blocks. However, Cbm71 was not immunologically related to any of the Cry toxins and thus belongs to a novel class of mosquitocidal protein. The cbm71 gene was expressed in a nontoxic strain of B. thuringiensis, and Cbm71 was produced during sporulation and secreted to the supernatant of culture. Trichloroacetic-precipitated supernatant preparations were toxic for mosquito larvae of the species Aedes aegypti, Culex pipiens, and Anopheles stephensi.

A polymerase chain reaction assay to determine infection of Aedes polynesiensis by Wuchereria bancrofti

The sensitivity of a previously described polymerase chain reaction (PCR) assay was improved to detect a single mosquito, infected by as few as 1-2 microfilariae of Wuchereria bancrofti, among 20-50 uninfected mosquitoes. Wild-caught Aedes polynesiensis were used to compare assessment of infection by dissection of individuals with the PCR assay of pools of mosquitoes. The PCR assay was at least as sensitive as dissection for detection of mosquitoes infected with W. bancrofti.

[Combinations of ivermectin and diethylcarbamazine for improved control of lymphatic filariasis]

Since 1993, a three arm double-blind controlled trial was implemented in French Polynesia to compare the efficacy of single doses of diethylcarbamazine (DEC) 6 mg/kg vs. ivermectin (IVR) 400 micrograms/kg vs. the combination IVR 400 + DEC 6 for treatment of Wuchereria bancrofti mf carriers. Of the 57 treated male patients, three groups of 19 were randomly selected and allocated to one of the three treatments. Twelve months after the first then the second treatment (M12 then M24) respectively, 3 (16%) then 10 (53%), 3 (16%) then 5 (26%), 7 (27%) then 10 (53%) of patients were mf negative in groups DEC 6, IVR 400 and IVR+DEC. Mf percent return was significantly lower in the group IVR+DEC (2% at M12 then M24) than for the groups DEC 6 (15% at M12 then 4% at M24) and IVR 400 (12% at M12 then 10% at M24). The combination IVR+DEC showed promising results for an annual strategy; to achieve the best results from a control program it is necessary to associate IVR+DEC.

Evaluation of entomopathogenic bacteria against Aedes polynesiensis, the vector of lymphatic filariasis in French Polynesia

Thirteen strains among 3 species of entomopathogenic bacteria were tested against 3 medically important mosquito species in French Polynesia. Two strains of Bacillus thuringiensis were highly toxic to Aedes polynesiensis, Aedes aegypti, and Culex quinquefasciatus. Six of 7 strains of Bacillus sphaericus tested were highly toxic to Cx. quinquefasciatus but not to the Aedes spp. Clostridium bifermentans serovar. malaysia was more toxic to Ae. polynesiensis than to the other 2 species. Entomopathogenic bacteria merit field testing for larval mosquito control in French Polynesia.

Advantages of an annual single dose of ivermectin 400 micrograms/kg plus diethylcarbamazine for community treatment of bancroftian filariasis

In 1994 and 1995, 2 supervised single dose treatments for bancroftian filariasis were given to all inhabitants ( > 3500) aged > or = 3 years on a Polynesian island. This island is divided into 4 political zones. Each zone was treated with a different dosage of the combination ivermectin (IVR) and diethylcarbamazine (DEC) as follows: (1) IVR 400 micrograms/kg plus DEC 6mg/kg, (2) IVR 400 micrograms/kg alone, (3) DEC 6 mg/kg alone (4) IVR 400 micrograms/kg plus DEC 3 mg/kg. 1717 inhabitants (aged > or = 20 years) had venous blood sampled when treated. The reductions in microfilaraemia prevalence rates one year after treatment were, respectively, 32%, 11%, 14% and 32%. The reductions in microfilaraemia levels one year after treatment were, respectively, 96%, 80%, 82% and 95%. Stool specimens from 82 children aged 6 years were examined for intestinal nematodes just before and just after treatment. IVR 400 micrograms/kg significantly reduced the prevalence and intensity of trichiuriasis. The combination IVR + DEC is a powerful tool for the control of lymphatic filariasis. Further studies are required to determine the appropriate presentation of DEC (salt and/or tablets), the frequency of treatment, and the duration of the control programme necessary to eradicate this disease.

Combination ivermectin plus diethylcarbamazine, a new effective tool for control of lymphatic filariasis

In 1993, a three arm double-blind controlled trial was implemented in French Polynesia, to compare the tolerance and efficacy of single doses of the combination ivermectin (IVR) 400 micrograms.kg-1 plus diethylcarbamazine (DEC) 6mg.kg-1 vs IVR 400 micrograms.kg-1 or DEC 6 mg.kg-1 alone, for treatment of Wuchereria bancrofti carriers. Of the 57 treated male patients in whom microfilaremia (mf) densities ranged from 22 to 4,709 mf/ml, three groups of 19 were randomly selected, and allocated to one of the three treatments. Twelve months after treatment 37%, 16% and 16% of patients were mf negative in groups DEC, IVR and IVR plus DEC respectively. Mf percent return to pretreatment level was significantly lower in the group IVR + DEC (1.9%) than for DEC 6 (14.7%) or IVR 400 (11.6%). Antigenemia percent return to pretreatment level was lower in the groups IVR + DEC or DEC 6 than for IVR 400. The combination IVR + DEC proved to be the most effective on macrofilariae and microfilariae (antigenemia and mf negative patients). The combination will be a very powerful tool for control of lymphatic filariasis. An annual filariasis day could be the most cost-effective strategy for administration of the drugs.

Role of the exosporium in the stability of the Bacillus sphaericus binary toxin

The persistence of toxicity of the Bacillus sphaericus 1593 binary toxin was compared when produced in B. sphaericus, inside the exosporium, or in a recombinant B. thuringiensis strain, outside the exosporium. The stability of the toxin crystal was affected by temperature and quality of the water, but not by the location of the production in the bacterial cell.

Clostridium bifermentans serovar malaysia: characterization of putative mosquito larvicidal proteins

The toxicity of Clostridium bifermentans serovar malaysia to mosquito larvae is due to protein toxins, belonging to a novel class of insecticidal toxins. Toxic extracts contains three major proteins of 66, 18 and 16 kDa. The 18-kDa and 16-kDa proteins are probably involved in toxicity. They are synthesised during sporulation, concomitant with activity. They are absent from non-toxic strains of C. bifermentans and are present at very low levels in non-toxic C. bifermentans serovar malaysia cultures produced at 42 degrees C. The 66-kDa protein is present throughout the growth phases of C. bifermentans serovar malaysia, and an immunologically related 66-kDa protein is present in non-toxic C. bifermentans strains.

Respective role of the 42- and 51-kDa components of the Bacillus sphaericus toxin overexpressed in Bacillus thuringiensis

The 42- and 51-kDa protein genes of Bacillus sphaericus 1593 have been subcloned independently downstream from the cytA gene promoter of Bacillus thuringiensis serovar israelensis and introduced into a non-mosquitocidal strain of Bacillus thuringiensis. Consequently, each protein was overproduced and accumulated as inclusion bodies which were purified. For the first time, the 42-kDa protein inclusions alone were found to be toxic to Culex pipiens larvae (LC50 at 48 h 300 ng ml-1); in contrast, the 51-kDa protein inclusions were not. Moreover, a synergistic effect between these two components was observed.

Characterization and toxicity to mosquito larvae of four Bacillus sphaericus strains isolated from Brazilian soils

Four Bacillus sphaericus strains, S1, S2, S5, and L2, isolated from Brazilian soils, were found to be toxic to larvae of the mosquitoes Culex pipiens and Anopheles stephensi at a level similar to that of strain 2362 which is now used operationally. Like strain 2362, the four strains belonged to the serotype H5 and produced major proteins of apparent molecular weights of 125, 110, 56, and 43 kDa. These latter two proteins were immunologically related to toxins of the same molecular weight as B. sphaericus 2362. Although the four Brazilian strains were very similar to strain 2362, gas chromatography analysis of the fatty acids revealed that these strains were different from strain 2362 and from each other, except for a possible similarity between strains S1 and S5.

Cellular fatty acid analysis as a potential tool for predicting mosquitocidal activity of Bacillus sphaericus strains

Gas-liquid chromatography of fatty acid methyl esters and numerical analysis were carried out with 114 Bacillus sphaericus strains. Since only two clusters harbored mosquitocidal strains, this technique could be developed in screening programs to limit bioassays on mosquito larvae. It also allows differentiation of highly homologous strains.