RESUMEN

Chronic migraine is a disabling neurovascular disorder that ranks amongst the top causes of years lived with disability worldwide. The duration and the frequency of migraine affect cognitive and affective domains, inducing worsening of memory, executive functions, orientation and causing anxiety. Population-based studies report a worrying level of resistance to treatments. Therefore, this study aims: 1) to assess efficacy of monoclonal antibodies (mAbs) directed towards the calcitonin gene-related peptide (CGRP) or its receptor (CGRP-R) for chronic migraine resistant to current preventatives; 2) to design a clinical trial protocol to evaluate the efficacy and safety of combination therapy utilizing anti-CGRP/CGRP-R together with onabotulinumtoxin A in patients suffering from resistant chronic migraine; 3) to provide a molecular rationale for combination therapy. A controlled trial is warranted as pooled analysis of real-world data from our group highlighted that combined treatment provides ≥50% reduction vs. baseline (onabotulinumtoxin A) of monthly headache days (MHDs) in up to 58.8% of patients, but there has been only sparse application of this combined therapy to date. The mAbs chosen are: erenumab, because its combination effect with onabotulinumtoxin A improved symptoms in 65% of patients; eptinezumab, due to its faster action. The results highlight that early diagnosis of migraine improves therapeutic outcomes with mAbs alone, confirming their effectiveness and the need for an adequately powered clinical trial evaluating the safety and potential superior effectiveness of eptinezumab/erenumab and onabotulinumtoxin A together.

RESUMEN

Fragments of botulinum neurotoxin (BoNT) have been explored as potential targeting moieties and carriers of biomolecules into neurons, although with lower binding and translocation efficiency compared with intact proteins. This study exploits a detoxified recombinant form of full-length BoNT/B (BoTIM/B) fused with core streptavidin (CS-BoTIM/B) for lentiviral targeting to central and autonomic neurons. CS-BoTIM/B underwent an activity-dependent entry into cultured spinal cord neurons. Coupling CS-BoTIM/B to biotinylated lentivirus-encoding green fluorescent protein (GFP) endowed considerable neuron selectivity to the vector as evident from the preferential expression of the reporter in neurons co-cultured with skeletal muscle cells. CS-BoTIM/B-guided lentiviral transduction with the expression of a SNARE protein, SNAP-25 (S25), rendered non-susceptible to proteolysis by three BoNT serotypes, yielded a sizable decrease in cleaved S25 upon exposure of spinal cord neurons to these toxins. This was accompanied by synaptic transmission being spared from blockade by BoNT/A or BoNT/E, reflecting adequate translation and functional competence of recombinant multi-toxin-resistant S25. The augmented neurotropism conveyed on the lentivirus by CS-BoTIM/B was also demonstrated in vivo through enhanced expression of a reporter in intramural ganglionic neurons in the rat trachea, after injection of the targeted GFP-encoding lentivirus. Thus, a novel and realistic prospect for gene therapy of peripheral neuropathies is offered in this study through lentiviral targeting to neurons by CS-BoTIM/B.

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The degradation of aldicarb, and the metabolites aldicarb sulfoxide and aldicarb sulfone, was evaluated in cotton field soils previously exposed to aldicarb. A loss of efficacy had been observed in two (LM and MS) of the three (CL) field soils as measured by R. reniformis population development and a lack of cotton yield response. Two soils were compared for the first test-one where aldicarb had been effective (CL) and the second where aldicarb had lost its efficacy (LM). The second test included all three soils: autoclaved, non-autoclaved and treated with aldicarb at 0.59 kg a.i./ha, or not treated with aldicarb. The degradation of aldicarb to aldicarb sulfoxide and then to aldicarb sulfone was measured using high-performance liquid chromatography (HPLC) in both tests. In test one, total degradation of aldicarb and its metabolites occurred within 12 days in the LM soil. Aldicarb sulfoxide and aldicarb sulfone were both present in the CL soil at the conclusion of the test at 42 days after aldicarb application. Autoclaving the LM and MS soils extended the persistence of the aldicarb metabolites as compared to the same soils not autoclaved. The rate of degradation was not changed when the CL natural soil was autoclaved. The accelerated degradation was due to more rapid degradation of aldicarb sulfoxide and appears to be biologically mediated.

RESUMEN

The possible impact of Rotylenchulus reniformis below plow depth was evaluated by measuring the vertical distribution of R. reniformis and soil texture in 20 symptomatic fields on 17 farms across six states. The mean nematode population density per field, 0 to 122 cm deep, ranged from 0.4 to 63 nematodes/g soil, and in 15 fields more than half of the R. reniformis present were below 30.5 cm, which is the greatest depth usually plowed by farmers or sampled by consultants. In 11 fields measured, root density was greatest in the top 15 cm of soil; however, roots consistently penetrated 92 to 122 cm deep by midseason, and in five fields in Texas and Louisiana the ratio of nematodes to root-length density within soil increased with depth. Repeated sampling during the year in Texas indicated that up to 20% of the nematodes in soil below 60 cm in the fall survived the winter. Differences between Baermann funnel and sugar flotation extraction methods were not important when compared with field-to-field differences in nematode populations and field-specific vertical distribution patterns. The results support the interpretation that R. reniformis below plow depth can significantly impact diagnosis and treatment of cotton fields infested with R. reniformis.

RESUMEN

Rotylenchulus reniformis is rapidly becoming the most economically important pest associated with cotton in the southeastern United States. Incentive programs have been implemented to support sampling of production fields to determine the presence and abundance of R. reniformis. These sampling programs have dramatically increased the number of soils samples submitted to nematology laboratories during autumn. The large numbers of samples overwhelm most labs and require placement in cold storage until extraction. Therefore, the objective of this study was to examine the length of time soils infested with R. reniformis can be stored before nematode extraction without compromising the accuracy of estimates of population densities. A sandy loam and a silty loam were the two cotton production soils used in this study. Rotylenchulus reniformis numbers decreased 61%during the first 180 days of storage in both soils. Rotylenchulus reniformis numbers from the initial sampling through 180 days decreased as a linear function. The decline of R. reniformis numbers during storage was estimated as 0.28% of the population lost daily from the maximum population through 180 days. The diminution of nematode numbers from 180 through 1,080 days in storage continued, but at a slower rate. Numbers of R. reniformis declined to less than 89%, 93%, and 99% of the initial population within 360, 720, and 1,080 days, respectively, of storage. The reduction of R. reniformis numbers over 180 days can be adjusted, allowing a more accurate estimation of R. reniformis levels in soil samples stored at 4 degrees C.

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It has been hypothesized Rotylenchulus reniformis (Rr) has a competitive advantage over Meloidogyne incognita (Mi) in the southeastern cotton production region of the United States. This study examines the reproduction and development of Meloidogyne incognita (Mi) and Rotylenchulus reniformis (Rr) in separate and concomitant infections on cotton. Under greenhouse conditions, cotton seedlings were inoculated simultaneously with juveniles (J2) of M. incognita and vermiform adults of R. reniformis in the following ratios (Mi:Rr): 0:0, 100:0, 75:25, 50:50, 25:75, and 0:100. Soil populations of M. incognita and R. reniformis were recorded at 3, 6, 9, 14, 19, 25, 35, 45, and 60 days after inoculations. At each date, samples were taken to determine the life stage of development, number of egg masses, eggs per egg mass, galls, and giant cells or syncytia produced by the nematodes. Meloidogyne incognita and R. reniformis were capable of initially inhibiting each other when the inoculum ratio of one species was higher than the other. In concomitant infections, M. incognita was susceptible to the antagonistic effect of R. reniformis. Rotylenchulus reniformis affected hatching of M. incognita eggs, delayed secondary infection of M. incognita J2, reduced the number of egg masses produced by M. incognita, and reduced J2 of M. incognita 60 days after inoculations. In contrast, M. incognita reduced R. reniformis soil populations only when its proportion in the inoculum ratio was higher than that of R. reniformis. Meloidogyne incognita reduced egg masses produced by R. reniformis, but not production of eggs and secondary infection.

RESUMEN

The microbial degradation of aldicarb was examined in the greenhouse using soil from four cotton fields with a history of aldicarb use. The addition of aldicarb at 0.59 kg a.i./ha to natural soil increased Rotylenchulus reniformis numbers 6.6% in one soil and decreased R. reniformis numbers only 25.8% in another soil as compared to the corresponding natural soil without aldicarb. The use of increasing rates of aldicarb did not increase the efficacy of aldicarb in these soils. Rotylenchulus reniformis numbers were reduced 39.8, 22.6, and 6.8%, and increased 5.7% for aldicarb applied at 0.29, 0.59, 0.85, and 1.19 kg a.i./ha, respectively, in one natural soil. In another natural soil, R. reniformis numbers were reduced 42.5 and 21.9% for aldicarb applied at 0.29 and 1.19 kg a.i./ha, respectively, but increased 19.1 and 10.6% for aldicarb applied at 0.59 and 0.85 kg a.i./ha, respectively. Autoclaving the soils restored aldicarb toxicity in both soils, and R. reniformis numbers were reduced 96 and 99%, respectively, as compared to autoclaved soil without aldicarb. Bacterial populations were greater in the natural soils where aldicarb did not reduce R. reniformis numbers relative to the same soils that were autoclaved. However, no bacterial species was consistently associated with aldicarb degradation.

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In May 2000, seedling death in grain sorghum (Sorghum bicolor L.) was reported in fields located in the delta region of Mississippi, following a wet planting season when precipitation and relative humidity were 50 and 10.5% greater, respectively, than the 5-year average. Seedlings exhibited various symptoms, including necrosis of the leaf tip and blade, collar rot, root rot, and streaking of the vascular system at the soil line that resulted in plant death. Tissue sections from plants with collar and root rot were plated aseptically on potato dextrose, V8, and cornmeal agars. Pythium ultimum was the only pathogenic fungus isolated and appeared on 63% of tissue sections. Recovered isolates exhibited similar growth and morphology in vitro and were stimulated to produce fruiting structures by the grass leaf-baiting method. Isolates produced primary terminal globose oogonia, 19 µm in diameter. Oospores were aplerotic and approximately 16.4 µm in diameter, with a 2.1-µm-thick wall. Antheridia were monoclinous or diclinous and short-stalked, with 1 to 2 antheridia per oogonium. Zoospores were produced only in sterile water grass blade cultures and were reniform and biciliate, erupting from spherical vesicles in groups of 15 to 30. Pathogenicity tests were conducted in a controlled growth chamber. P. ultimum was increased on sterile common millet seed and incorporated into sterile field soil at an 0.5% (vol/vol) ratio. Noninfested millet seed was incorporated into field soil as a control. Soil was placed in pots, planted with five-grain sorghum seed, and placed in a growth chamber at 5°C, with a 12-h photoperiod. Treatments were replicated five times, and the experiment conducted twice. At 21 days after planting, the inoculated grain sorghum plants developed collar and root rot, with some leaf necrosis, similar to symptoms observed in the field. Symptoms did not develop on the control plants. Reisolations of P. ultimum on corn meal agar and by the grass-baiting method were successful. P. ultimum commonly is in Mississippi soils and is pathogenic to a number of agronomic crops, although it has not been reported previously as a pathogen on grain sorghum in Mississippi.

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A survey was conducted in northeastern Louisiana to determine the frequency and abundance of plant-parasitic nematodes associated with cotton. In fall 1997 and 1998, more than 600 soil samples were collected from cotton fields representing 6,200 ha, which is 5.3% of the cotton production hectarage in this region. Composite soil samples were collected from 10 ha in each field. Nematodes were extracted by gravity screening and sucrose centrifugation, identified to genus, and quantified. Nine genera of plant-parasitic nematodes were identified. Rotylenchulus reniformis was found in 67% of the fields sampled, with an average population of 12,959 juveniles and vermiform adult stages per 500 cm(3) of soil. Meloidogyne incognita was identified in 25% of the fields sampled, with an average population of 998 juveniles per 500 cm(3) of soil. Hoplolaimus spp. were identified in 3%, or 155 ha, with an average population of 282 juveniles and adult stages per 500 cm[sup3] of soil. Rotylenchulus reniformis and M. incognita occurred at population levels above reported economic thresholds in 49% and 21% of the fields, respectively.

RESUMEN

The efficacy of foliar applications of oxamyl were evaluated for the management of Rotylenchulus reniformis on cotton in Mississippi. Two tests were established in Tallahatchie County on a fine sandy loam soil (56.8% sand, 37.8% silt, 5.3% clay, pH 5.4, and 0.3% OM) naturally infested with R. reniformis. Oxamyl was applied as a foliar spray at 0.14, 0.27, or 0.53 kg a.i./ha to cotton plants that had reached the sixth true leaf growth stage. A second oxamyl application was applied 14 days after the first treatment at the same rates. All oxamyl treatments also received aldicarb at 0.59 kg a.i./ha at planting. Controls consisted of aldicarb alone, disulfoton (which is not a nematicide), and an untreated control. Oxamyl reduced R. reniformis numbers at 79 and 107 days after planting in Test 1 and at 62 and 82 days after planting in Test 2 compared to aldicarb at 0.59 kg a.i./ha alone and the controls that received neither material. Average reniform population densities in oxamyl-treated plots were 24.5% and 30% lower than with aldicarb alone and the controls. Cotton plant height was greater in plots that received oxamyl at all rates than in the controls. Cotton in oxamyl plus aldicarb and aldicarb alone treatments produced more bolls per plant and had a greater total boll weight than disulfoton and the untreated control. Seed cotton yields were greater in oxamyl-treated plots than for disulfoton-treated and the untreated control.

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We investigated mortality in Anopheles farauti mosquitoes, a major coastal malaria vector in the south-west Pacific, fed on a volunteer who had taken a 250 micrograms/kg dose of ivermectin. High mortality was recorded in mosquitoes feeding during the first week after treatment of the volunteer, for instance 100-80% failed to survive 3 days. A long-term residual effect of ivermectin in the blood was indicated by a small but significantly higher mortality in mosquitoes fed 6 weeks after ivermectin was taken. These effects were included in malaria transmission models that incorporated host choice and host-induced mortality parameters. For the zoophilic An. farauti, ivermectin treatment of animals resulted in a greater reduction in malaria than ivermectin treatment of humans alone, whereas for an anthropophilic vector, treatment of humans was more important. This suggests that ivermectin treatment of animals could have an important role in malaria control where An. farauti is the vector. Improvement in the health of humans and domestic animals through control of parasitic worms and mites might encourage community participation in strategies involving ivermectin.

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Botulinum neurotoxin (BoNT) types A and B selectively block exocytosis by cleavage of SNAP-25 and synaptobrevin, respectively; in humans, many months are required for full recovery from the resultant neuromuscular paralysis. To decipher the molecular basis for such prolonged poisoning, intoxication in adreno-chromaffin cells was monitored over 2 months. Exocytosis from BoNT/B-treated cells resumed after 56 days because of the appearance of intact synaptobrevin. However, inhibition continued in BoNT/A-treated cells, throughout the same interval, with a continued predominance of cleaved SNAP-25-(1-197) over the intact protein. When recovery from poisoning was attempted by transfection of the latter cells with the gene encoding full-length SNAP-25-(1-206), no restoration of exocytosis ensued even after 3 weeks. To ascertain if this failure was because of the persistence of the toxin's protease activity, the cells were transfected with BoNT/A-resistant SNAP-25 constructs; importantly, exocytosis was rescued. C-terminal truncation of the toxin-insensitive SNAP-25 revealed that residues 1-201, 1-202, 1-203 afforded a significant return of exocytosis, unlike shorter forms 1-197, -198, -199, or -200; accordingly, mutants M202A or L203A of full-length SNAP-25 rescued secretion. These findings give insights into the C-terminal functional domain of SNAP-25, demonstrate the longevity of BoNT/A protease, and provide the prospect of a therapy for botulism.

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A premature boll rot has been observed with increasing frequency in association with cotton (Gossypium hirsutum) in the Delta region of Louisiana-Mississippi. The initial developing cotton boll, sepals, and peduncle rapidly become necrotic and mummified. A dark brown to black lesion approximately 1 cm in length develops at the base of the peduncle, extending down the petiole below the diseased cotton boll. The diseased boll and peduncle remain attached to the petiole, hanging by a small portion of peduncle tissue. In an initial survey, the symptomatic boll rot was observed in 95% of the cotton fields in the Delta in 1996. A Phomopsis sp. was isolated from 58% of the diseased bolls, 42% of the cotton boll peduncles, and 52% of the leaf petioles collected from three cotton varieties. Fusarium spp. and Alternaria alternata were isolated from the diseased bolls with a frequency of 18 and 11%, respectively. Phomopsis sp. mycelium is dense, immersed, septate, and hyaline to pale brown in color. Stromata are pulvinate, less than 5 mm in diameter and form in a ring pattern. Pycinidia are erumpet, dark brown to black, separate or aggregated, and globose with ostiolate necks. Conidia are unicellular and hyaline, with alpha conidia oblong-elliptical and biguttulate while beta conidia are filiform and hamate in shape. The ratio of alpha to beta spores varies depending on the age of the culture. Pathogenicity tests with the sterile toothpick inoculation technique were conducted in a field planted with cotton cv. DPL 50. Developing cotton bolls approximately 5 to 8 mm in diameter were inoculated with either sterile toothpicks or toothpicks infested with a Phomopsis sp. Characteristic symptoms identical to the original boll rot were observed on 80% of the inoculated bolls 7 days after inoculation. A Phomopsis sp. was reisolated from the diseased bolls, completing Koch's postulates. No symptoms developed nor was the pathogen reisolated from the controls.

RESUMEN

Types A and E botulinum neurotoxin (BoNT) are Zn2+-requiring endoproteases which cleave nine and twenty-six residues, respectively, from the C-terminus of synaptosomal-associated protein of Mr = 25 kDa (SNAP-25). Involvement of SNAP-25 in the exocytosis of large dense-core vesicles in bovine adrenochromaffin cells was examined by measuring cleavage of SNAP-25 in relation to the levels of Ca2+-evoked catecholamine release from cells exposed to BoNT/A or /E, either before or after permeabilization. The dose-dependency of inhibition of exocytosis correlated closely with the extents of SNAP-25 cleavage in cells permeabilized and then treated with BoNT/E. In intact cells exposed to 66 nM BoNT/A, virtually all of the SNAP-25 was truncated, accompanied by a near-complete inhibition of exocytosis; however, after their permeabilization a significant level of secretion was recorded upon Ca2+-stimulation. Importantly, this BoNT/A-resistant release from the permeabilized cells was dramatically lowered by subsequently adding BoNT/E, which further truncated the SNAP-25 fragment (lacking the C-terminal nine residues) that had been produced earlier by BoNT/A. Moreover, anti-SNAP-25 IgG decreased the BoNT/A-insensitive exocytosis. When permeabilized cells were exposed to either neurotoxin, both blocked MgATP-dependent secretion but only BoNT/E attenuated the energy-independent phase. These distinct inhibitory effects of the two neurotoxins demonstrate that residues 197-205 at the C-terminus of SNAP-25 are absolutely essential for exocytosis from intact cells whereas even after their removal a significant proportion of the exocytotic response can be elicited from permeabilized cells, but this is reliant on amino acids 180-196. Moreover, the latter but not residues 197-205 are implicated in a late, MgATP-independent step of exocytosis, which is blocked by BoNT/E but nonsusceptible to BoNT/A.

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Seppic MONTANIDE ISA 720 is a metabolizable oil adjuvant that has given good results in animals with recombinant malarial antigens. Twelve human volunteers were given increasing intramuscular doses of MONTANIDE ISA 720, ranging from 0.6 to 1.8 ml. The adjuvant was well tolerated with only minor local effects, including tenderness, local swelling and discomfort on use. MONTANIDE ISA 720 may prove to be an acceptable and effective adjuvant for use in people.

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Botulinum neurotoxin (BoNT) types A and B are Zn2+-requiring endoproteases which potently block neurotransmitter release by cleavage of a 25-kDa synaptosomal-associated protein (SNAP-25) and synaptobrevin, respectively. Synaptobrevin is important for the exocystosis of catecholamines from dense-core granules and evidence is presented here for the involvement of SNAP-25 in this process in neuroendocrine cells. The effects of BoNT/A and BoNT/B on regulated secretion were compared in intact bovine chromaffin cells to investigate the consequences of cleavage of the different targets. Catecholamine secretion elicited by Ba2+, by elevated K+ concentrations or by nicotine was prevented by each toxin. A very good correlation was observed between the extents of SNAP-25 cleavage or synaptobrevin cleavage and inhibition of secretion by BoNT/A or BoNT/B, respectively, which indicates the importance of SNAP-25 and synaptobrevin in regulated exocytosis. Despite truncation of almost the entire SNAP-25 pool by exposure of the cells to BoNT/A, a residual fraction of secretion persisted that was induced by 20microM Ca2+ (and to a lesser extent by 1 mM Ba2+) following permeabilisation. Addition of more BoNT/A failed to reduce this level of secretion. Inclusion of Mg.ATP, which greatly enhanced secretion from permeabilised cells, was required for Ca2+-stimulated or Ba2+-stimulated BoNT/A-resistant secretion. Furthermore, synaptobrevin is essential for this response because the response was not observed in BoNT/B treated cells. In view of the ability of BoNT/E to abolish secretion from permeabilised cells and to delete 26 amino acids from the C-terminus of SNAP-25, it can be deduced that cleavage of only nine residues by BoNT/A does not prevent the resultant truncated form exhibiting attenuated activity under the conditions created by permeabilisation. This identification of a novel component of secretion from permeabilised cells should facilitate investigation of the functional interaction of SNAP-25 with other proteins involved in regulated exocytosis.

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The seven types (A--G) of botulinum neurotoxin (BoNT) are Zn2+ -dependent endoproteases that potently block neurosecretion. Syntaxin is presently thought to be the sole substrate for BoNT/C1, and synaptosomal-associated protein of Mr = 25 000 (SNAP-25) is selectively proteolyzed by types A and E. In this study, the effects of C1 on Ca2+ -regulated exocytosis of dense core granules from adreno-chromaffin cells were examined together with its underlying molecular action. Intact chromaffin cells were exposed to the toxin, and catecholamine release therefrom was then measured in conjunction with the monitoring of syntaxin cleavage by Western blotting. A good correlation was obtained between degradation of syntaxin 1A/B and reduction in Ca2+- or Ba2+-dependent secretion. However, blotting with antibodies against a C-terminal peptide of SNAP-25 revealed the additional disappearance of immunoreactivity, with the same toxin concentration dependency as syntaxin breakdown. Notably, the cleaved SNAP-25 product was similar in size to that produced by BoNT/A; however, contamination of BoNT/C1 by serotypes A or E was eliminated. Therefore, it is concluded that syntaxin 1A/B and SNAP-25 are cleaved in intact cells poisoned with only C1. Notably, C1 treatment of chromaffin cells abolished Ca2+ -evoked secretion following digitonin permeabilization, compared with partial inhibition by BoNT/A, suggesting the importance of syntaxin for catecholamine release. Unexpectedly, C1 failed to proteolyze a soluble recombinant SNAP-25, even though it served as an efficient substrate for BoNT/A. These interesting observations suggest that C1 can only efficiently cleave SNAP-25 in intact cells, possibly due to the existence therein of a unique conformation and/or the participation of accessory factors.

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Experiments were conducted to assess the effects of the entomopathogenic nematode Steinernema carpocapsae and Spodoptera exigua multinucleocapsid nuclear polyhedrosis virus (SeMNPV), alone and in combinations, on mortality of the beet armyworm, S. exigua, larvae on soybean. In 1991 tests, field-grown soybean plants were treated with S. carpocapsae at 0.3 and 0.6 nematodes/cm(2) of leaflet, SeMNPV at 20 and 40 polyhedral inclusion bodies (PIB)/cm(2), and all possible combinations. Treated leaflets were collected from plants and bioassayed with 5-day-old larvae. The combination of S. carpocapsae at 0.6 nematodes/cm(2) + SeMNPV at 40 PIB/cm(2) produced significantly higher larval mortality (61.7%) compared with either S. carpocapsae (24.8-35.1%) or SeMNPV (26.5-33.7%) alone. In 1992, similar tests were repeated using S. carpocapsae at 0.2 and 0.5 nematodes/cm(2), and SeMNPV at 14 and 35 PIB/cm(2). The combination of 0.5 nematodes/cm(2) + 35 PIB/cm(2) resulted in significantly higher larval mortality (64.0%) than either pathogen alone (41.5-49.0%). Steinernema carpocapsae and SeMNPV produced additive effects on beet arlnyworm mortality. Persistence of S. carpocapsae was 12-24 hours and SeMNPV was 96-120 hours on soybean.

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An outbreak of 12 cases of meningitis, 11 caused by Neisseria meningitidis serogroup C, occurred at Doomadgee from September, 1990, to April, 1991. The incidence of meningitis was 17.55/10(3) person-years. Only children aged 1-10 years were affected. In October, 1990, or shortly thereafter, 473/509 children aged between 1 and 15 years inclusive had one dose of Mencevax AC. From the time of vaccination until April, 1991, a further eight cases occurred, six in vaccinated children. Vaccine efficacy in 1-15 year olds was calculated as 77%. Despite this, in April, 1991, the prevalence of antibody to group C polysaccharide in vaccinated children (78%) was not significantly different from that in unvaccinated children and adults. 46 nonresponders were revaccinated, and, in February, 1992, 78% had antibodies to group C polysaccharide. In April, 1991, an estimated 3.0% of the population had group C organisms, carriage being directly related to household crowding. In June, 1991, 2 months after mass prophylaxis with rifampicin, none of these individuals were carriers. In October, 1991, the carriage rate of group C organisms was 0.64%. There have been no further cases caused by the epidemic strain. Although uncrowded housing is a basic need, mass chemoprophylaxis and two doses of vaccine for children should be used in similar outbreaks.

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The effects of the blue form of Fusarium solani, the causal agent of sudden death syndrome (SDS), on Heterodera glycines were examined in the greenhouse. Roots of soybean cv. Coker 156 were inoculated with either H. glycines alone or F. solani + H. glycines in combination. Population levels of H. glycines were reduced 47% in the presence of F. solani. Life-stage development of H. glycines increased 3% in 30 days in the presence of F. solani. Fusarium solani colonized epidermal and cortical cells adjacent to developing juveniles of H. glycines and the nematode-induced syncytia within the soybean root tissue. At 40 days after inoculation, F. solani was isolated from 37% of the cysts in soil recovered from the F. solani + H. glycines combination treatment. Fusarium solani significantly affected H. glycines population density, life-stage development, and succeeding populations.