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A Leach

Publications and source records attributed to A Leach.

At least 37 records · Page 2Linked to original sources
PubMed1999

Six new Eimeria species from vespertilionid bats of North America.

Twenty species of bats (Molossidae, Vespertilionidae) were collected from California, New Mexico, Oregon, South Carolina, Utah, and Baja California Norte (Mexico), and 29 of 404 (7%) animals, including Antrozous pallidus, Eptesicus fuscus, Myotis auriculus, Myotis californicus, Myotis ciliolabrum, Myotis evotis, Myotis lucifugus, Myotis thysanodes, Myotis vivesi, Myotis volans, Myotis yumanensis, and Nycticeius humeralis were infected with Eimeria spp., which represent 6 new species. Sporulated oocysts of a new species from A. pallidus are subspheroidal, 24.8 x 21.6 (22-27 x 19-24) microm with a polar granule and a large globular residuum. The oocyst wall is sculptured, with 2 layers, approximately 1.5 thick. Ovoidal sporocysts are 11.5 x 7.8 (9-13 x 7-10) microm, with Stieda body and residuum of many large granules. Sporulated oocysts of a new species from M. californicus are subspheroidal, 20.7 x 18.2 (19-23 x 16-20) microm, with 1-7 tiny polar granules, but without oocyst residuum. The oocyst wall is rough, with 2 layers, approximately 1.4 thick. Ovoidal sporocysts are 11.2 x 7.3 (10-12 x 7-8) microm, with Stieda body and a globular residuum. Sporulated oocysts of a second new species from M. californicus are subspheroidal, 23.1 x 20.7 (20-26 x 19-23) microm, with residuum and 1 polar granule, but a micropyle is absent. The oocyst wall is rough with 2 layers, approximately 1.5 thick. Ovoidal sporocysts are 12.5 x 7.2 (11-14 x 7-8) microm, with a Stieda body and residuum. Sporulated oocysts of a new species from M. ciliolabrum are subspheroidal, 24.9 x 20.1 (18-27 x 17-23) microm, with 1-2 polar granules, but without micropyle and residuum. The oocyst wall is rough with 2 layers, approximately 1.5 thick. Ellipsoidal sporocysts are 12.5 x 9.0 (8-14 x 7-10) microm, with Stieda and substieda bodies and residuum. Sporulated oocysts of a new species from M. evotis are subspheroidal, 21.3 x 18.6 (20-24 x 15-20) microm, with a prominent polar granule, but without micropyle and residuum. The oocyst wall is smooth with 2 layers, approximately 1.0 thick. Ovoidal sporocysts are 12.2 x 8.0 (11-13 x 7.5-9) microm, with Stieda and substieda bodies and residuum. Sporulated oocysts of the new species from N. humeralis are subspheroidal, 22.4 x 18 (21-24 x 17-20) microm, with 1-3 polar granules, but residuum and micropyle are absent. The oocyst wall is lightly sculptured with 2 layers, approximately 1.4 thick. Ovoidal sporocysts are 10.9 x 7.7 (9-12 x 6-8) microm, with Stieda body and residuum. Sporulated oocysts of E. pilarensis Scott and Duszynski, 1997 and those of at least 12 other morphological forms were seen in the other infected bats; these latter forms were seen in too few numbers to be adequately described as new species.

Animals↗
PubMed1998

Antigenuria in Gambian infants following immunization with a Haemophilus influenzae type b polyribosylribitol phosphate-tetanus toxoid protein conjugate (PRP-T) vaccine.

During a Haemophilus influenzae type b (Hib)-conjugate vaccine trial, the prevalence and duration of antigenuria after vaccination was studied in 102 Gambian infants aged 51 to 175 days. Urine samples were collected at 0, 1, 3, 7, 14, 21 and 28 days postvaccination and tested for Hib antigen by latex agglutination using Biomérieux and Directigen reagent kits. Biomérieux positive reactions were found in 6 of 247 (2.4%) samples from vaccinated children and in 8 of 199 (4.0%) from nonvaccinated children (chi 2 = 0.47; 1 df; p = 0.5). In contrast, Directigen positive reactions were obtained with 86/242 samples (35.5%) from vaccinated children and from 28/190 (14.7%) from non-vaccinated children (chi 2 = 22.7; 1 df; p < 0.0001). The highest rate of antigenuria was detected in samples collected on Day 7 after vaccination when 24 of 30 (80%) were positive. Antigenuria following vaccination was frequent and may complicate the use of this test as a means of diagnosing invasive Hib disease in vaccinated children.

Antigens, Bacterial↗
PubMed1998

Causes of mortality in twins in a rural region of The Gambia, West Africa.

Little is known about birth or mortality rates of twins in The Gambia. There are no reports of the causes of death among twins in sub-Saharan Africa. We identified twin births and deaths from a community-based study which had been carried out in a large rural region of The Gambia over a 5-year period from 1989 to 1993. The overall twinning rate excluding stillbirths was 14.3 (95% CI 12.9, 15.8) per 1000 live deliveries. This was significantly lower among the Mandinka ethnic group (8.8 per 1000) than among the Serahulis (15.1 per 1000) or Fulas (18.3 per 1000). The early-neonatal, late-neonatal and post-neonatal twin mortality rates were 114.0, 45.9 and 64.2 per 1000 live twin births, respectively. In comparison, the early-neonatal, late-neonatal and post-neonatal mortality rates of singletons were 18.6, 16.0 and 41.1 per 1000, respectively. In the post-neonatal period, malnutrition was more frequently a cause of death among twins than among singletons (7.8 per 1000 twin births vs 2.0 per 1000 singleton births; p = 0.0008). Appropriate strategies for preventing malnutrition are required for this high-risk group.

Birth Rate↗
PubMed1998

Early detection of differences in surgical outcome for cleft lip and palate.

This study examined the dento-alveolar relationships of 5-year-old children born with a unilateral cleft lip and palate with primary surgical repair performed in one of two centres (Bristol or Oslo). The Bristol sample comprised 46 sets of study models and the Oslo CLP Growth Archive provided 54 cases with a very similar sex distribution. We used a recently developed 5-year-old index to measure differences in outcome between the two centres. The Oslo sample were assessed as having up to 57 per cent in the ideal groupings (1 and 2), in the Bristol group this was only 35 per cent. Bristol had up to 46 per cent of cases assessed in the worst groups (4 and 5). The comparative figure from the Oslo group was 15 per cent. These results suggest that it is possible to detect differences in surgical outcome at 5 years of age.

Age Factors↗
PubMed1997

Follow-up of Gambian children recruited to a pilot safety and immunogenicity study of the malaria vaccine SPf66.

A pilot safety and immunogenicity trial of the malaria vaccine SPf66 was undertaken in The Gambia in 1993. One hundred and fifty infants aged 6-11 months were immunized with either 0.5 mg or 1.0 mg of SPf66 produced either in Colombia or in the USA or with a control vaccine. Children who received SPf66 experienced more clinical attacks of malaria than did children in the control group during the first period of surveillance and the difference in incidence between children who had received high dose Colombian vaccine and the control children was statistically significant at the 5% level. During the 1995 malaria transmission season, 127 children from the original cohort of 150 were observed. During 18 weeks of intensive surveillance, the incidence of clinical malaria was again higher among children who had received SPf66 than among children who had received inactivated polio vaccine (6.23 vs 4.89 clinical attacks per 1000 days at risk), the effect being most marked among children who were in the high dose groups, but differences between groups were now no longer statistically significant.

Child↗
PubMed1997

Changes in the pattern of infant and childhood mortality in upper river division, The Gambia, from 1989 to 1993.

A surveillance system was used to detect births and deaths in children in a large, rural, West African population from 1989 to 1993. Cause of death was investigated using post-mortem questionnaires. Overall infant (age 0-11 months) and child (age 1-4 years) mortality rates of 80.1 and 18.8 per 1000 per year were recorded. These were reasonably consistent over the period of surveillance. The most frequent cause of death in infants was acute respiratory infection (ARI), whereas in children it was malaria: these two conditions accounted for 41% of the deaths in children under 5 years old. Other leading causes of death were acute gastroenteritis, malnutrition, and septicaemia. Deaths attributed to ARI decreased over the 5-year period, but mortality rates from other causes were either unchanged or increased slightly. Mortality from all causes peaked in the rainy season and was slightly higher in villages which were part of a primary health care programme than in those which were not. There were also no differences between male and female mortality rates beyond one year of age. Despite the introduction of a number of health interventions, there has been no major change in the overall pattern of mortality in children in a rural area of The Gambia. Malaria and ARI remain the main causes of death.

Acute Disease↗
PubMed1997

Induction of immunologic memory in Gambian children by vaccination in infancy with a group A plus group C meningococcal polysaccharide-protein conjugate vaccine.

Two hundred twenty-one Gambian children vaccinated previously with one, two, or three doses of a meningococcal conjugate vaccine or two doses of polysaccharide vaccine before the age of 6 months were revaccinated at the age of 18-24 months with either meningococcal polysaccharide, conjugate, or inactivated polio vaccines. Children who had previously received one, two, or three doses of conjugate vaccine had significantly (P < .001) higher anti-group C meningococcal antibody levels following revaccination than did children vaccinated with a polysaccharide vaccine for the first time. Children vaccinated previously with two doses of polysaccharide vaccine had a lower group C antibody response than did control children. Group A antibody responses following revaccination of children who had previously received polysaccharide or conjugate vaccine were not significantly higher than those in control children. Thus, immunologic memory was probably induced by the group C but not by the group A component of the conjugate vaccine.

Antibodies, Bacterial↗
PubMed1997

A glycoprotein pneumococcal conjugate vaccine primes for antibody responses to a pneumococcal polysaccharide vaccine in Gambian children.

BACKGROUND: Streptococcus pneumoniae is a major cause of acute respiratory infections and acute bacterial meningitis in children. Pneumococcal polysaccharide vaccines are poorly immunogenic in this highly vulnerable group, but protein polysaccharide conjugate vaccines are likely to be more effective. OBJECTIVES: To determine whether immunization of infants with a pneumococcal conjugate vaccine induces immunologic memory. METHODS: Eighty-four Gambian children, who had been vaccinated previously with two or three doses of a pentavalent pneumococcal conjugate vaccine (CRM197) or with a Haemophilus influenzae type b (Hib) conjugate vaccine were immunized when approximately 2 years old with a 23-valent pneumococcal polysaccharide vaccine, and a blood sample was obtained 10 days later. Pneumococcal antibody titers in prevaccination and postvaccination sera were measured by enzyme-linked immunosorbent assay and by an opsonophagocytic assay. RESULTS: On revaccination with a pneumococcal polysaccharide vaccine, children who had previously received pneumococcal conjugate vaccine had higher antibody concentrations to each of the five polysaccharide components of the conjugate vaccine than did control children. For type 6B polysaccharide, which is poorly immunogenic in young children, postvaccination antibody concentrations were 0.37, 27.6 and 50.9 microg/ml in children who had received no previous pneumococcal immunization or two or three doses of conjugate vaccine, respectively. Type 14 antibodies produced after revaccination were of high avidity and had opsonic activity. CONCLUSION: Vaccination of young infants with two or three doses of a pneumococcal conjugate vaccine primes the immune system to respond strongly and rapidly on subsequent exposure to pneumococcal polysaccharide.

Antibodies, Bacterial↗
PubMed1997

A two-phase, double-blind randomized study of three haloperidol plasma levels for acute psychosis with reassignment of initial non-responders.

To clarify the plasma level/therapeutic response relationship of haloperidol (HPDL) we used a prospective double-blind design in 95 acutely psychotic patients. After drug washout, patients were randomly assigned to a low, middle or high plasma level range for 2 weeks (phase A), and then 50% of the initial non-responders were randomly reassigned into the putative therapeutic range for an additional 2 weeks (phase B). There were no significant differences in clinical outcome between the three plasma level ranges in phase A. However, in phase B initial non-responders displayed greater improvement in the middle range than in the low or the high ranges. No further benefit was observed when plasma levels were raised to or maintained in the high range.

Acute Disease↗
PubMed1996

Pilot trial of a pentavalent pneumococcal polysaccharide/protein conjugate vaccine in Gambian infants.

BACKGROUND: Invasive pneumococcal disease is a major cause of mortality and morbidity in young children in developing countries. Pneumococcal polysaccharide/protein conjugate vaccines, which are likely to be immunogenic in the very young, offer a potential way for preventing these infections. Therefore a pilot safety and immunogenicity study of a five-valent conjugate vaccine has been undertaken in an area of rural Africa where invasive pneumococcal disease is prevalent. METHODS: Thirty Gambian infants were vaccinated with 3 doses of a five-valent pneumococcal conjugate vaccine containing 5 micrograms of type 6B, 14, 18, 19F and 23F polysaccharides conjugated to the diphtheria toxin mutant protein CRM197 at the ages of 2, 3 and 4 months; 30 infants received 2 doses at the ages of 2 and 4 months and 30 infants who received three doses of a Haemophilus influenzae type b vaccine acted as controls. Local and systemic reactions were recorded after vaccination and antibody titers were measured by an enzyme-linked immunosorbent assay. RESULTS: No serious local or systemic reactions to vaccination were recorded. Antibody responses to each component of the vaccine were demonstrated. One month after immunization with three doses of vaccine, antibody titers were 3 to 11 times higher than before vaccination (postvaccination titers ranged from 2.49 micrograms/ml for type 19 polysaccharide to 7.59 micrograms/ml for type 14). Elevated titers were well-maintained during the subsequent 4 months. Three doses of vaccine induced higher titers than did two doses. Antibody titers increased 2- to 3-fold over the period of immunization in children who received H. influenzae type b vaccine. CONCLUSIONS: A five-valent pneumococcal conjugate vaccine proved safe and immunogenic in Gambian infants. However, a vaccine containing a larger number of serotypes will be necessary to achieve a maximal clinical impact.

Antibodies, Bacterial↗
PubMed1995

Efficacy trial of malaria vaccine SPf66 in Gambian infants.

SPf66 malaria vaccine is a synthetic protein with aminoacid sequences derived from pre-erythrocytic and asexual blood-stage proteins of Plasmodium falciparum. SPf66 was found to have a 31% protective efficacy in an area of intensive malaria transmission in Tanzanian children, 1-5 years old. We report a randomised, double-blind, placebo-controlled trial of SPf66 against clinical P falciparum malaria in Gambian infants. 630 children, aged 6-11 months at time of the first dose, received three doses of SPf66 or injected polio vaccine (IPV). Morbidity was monitored during the following rainy season by means of active and passive case detection. Cross-sectional surveys were carried out at the beginning and at the end of the rainy season. An episode of clinical malaria was defined as fever (> or = 37.5 degrees C) and a parasite density of 6000/microL or more. Analysis of efficacy was done on 547 children (316 SPf66/231 IPV). No differences in mortality or in health centre admissions were found between the two groups of children. 347 clinical episodes of malaria were detected during the three and a half months of surveillance. SPf66 vaccine was associated with a protective efficacy against the first or only clinical episode of 8% (95% CI -18 to 29, p = 0.50) and against the overall incidence of clinical episodes of malaria of 3% (95% CI -24 to 24, p = 0.81). No significant differences in parasite rates or in any other index of malaria were found between the two groups of children. The findings of this study differ from previous reports on SPf66 efficacy from South America and from Tanzania. In The Gambia, protection against clinical attacks of malaria during the rainy season after immunisation in children 6-11 months old at time of the first dose was not achieved.

Animals↗
PubMed1995

A trial of a group A plus group C meningococcal polysaccharide-protein conjugate vaccine in African infants.

The safety and immunogenicity of a group A plus group C meningococcal polysaccharide-CRM197 conjugate vaccine was evaluated in 304 8- to 10-week-old Gambian infants. Infants were immunized with one, two, or three doses of conjugate vaccine or with two doses of a meningococcal A plus C polysaccharide vaccine. The conjugate vaccine produced few systemic side effects, and local reactions were similar to those produced by the polysaccharide vaccine. Postvaccination group A meningococcal polysaccharide antibody levels, measured by ELISA, increased progressively after one, two, or three doses of conjugate vaccine. However, one dose of conjugate vaccine given at the age of 6 months induced a higher group C meningococcal antibody response than did two doses of conjugate vaccine given at 2 and 6 months. Two doses of conjugate vaccine induced higher levels of antibody than did two doses of polysaccharide vaccine. Thus, this new meningococcal conjugate vaccine proved to be safe and immunogenic.

Antibodies, Bacterial↗
PubMed1995

A pilot safety and immunogenicity study of the malaria vaccine SPf66 in Gambian infants.

A pilot safety and immunogenicity trial of the malaria vaccine SPf66 has been undertaken in 150 Gambian infants. No significant systemic side effects were recorded but modest local reactions were seen after the administration of a third 1.0 mg dose. SPf66 produced in Colombia was more immunogenic than SPf66 produced in the USA and a 1.0 mg dose of each vaccine gave higher antibody levels than a 0.5 mg dose. However, antibody levels fell rapidly after administration of the third dose of vaccine and showed little change over the following malaria transmission season. The incidence of clinical malaria was higher among children who received SPf66 than among children who received inactivated polio vaccine, the effect being most marked among children who received 1.0 mg Colombian SPf66. As the trial was not designed to measure the effect of SPf66 on morbidity from malaria, the significance of this finding is uncertain.

Animals↗
PubMed1994

Initial and recurrent bleeding are the major causes of death following subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: The goal of this study was to determine the causes of mortality and morbidity after subarachnoid hemorrhage. METHODS: We identified all first-ever spontaneous subarachnoid hemorrhages that occurred in the nearly 1.3 million population of greater Cincinnati during 1988. RESULTS: Thirty-day mortality for subarachnoid hemorrhage was 45% (36 of 80 cases). Of the 36 deaths, 22 (61%) died within 2 days of onset; 21 of these deaths were due to the initial hemorrhage, and one death was due to rebleeding documented by computer tomography. Nine of the remaining 14 deaths after day 2 were caused by the initial hemorrhage (2 cases) or rebleeding (7 cases). Volume of subarachnoid hemorrhage was a powerful predictor of 30-day morality (P = .0001). Only 3 of the 29 patients with a volume of subarachnoid hemorrhage of 15 cm3 or less died before 30 days. Two of these 3 patients died from documented rebleeding; the third had 87 cm3 of additional intraventricular hemorrhage. Delayed arterial vasospasm contributed to only 2 of all 36 deaths. CONCLUSIONS: Most deaths after subarachnoid hemorrhage occur very rapidly and are due to the initial hemorrhage. Rebleeding is the most important preventable cause of death in hospitalized patients. In a large representative metropolitan population, delayed arterial vasospasm plays a very minor role in mortality caused by subarachnoid hemorrhage.

Aged↗