Xenomonitoring of Culex quinquefasciatus mosquitoes as a guide for detecting the presence or absence of lymphatic filariasis: a preliminary protocol for mosquito sampling

A protocol for the collection of resting, blood-engorged Culex quinquefasciatus Say and their examination for microfilariae has been developed as a way of detecting whether lymphatic filariasis (LF) occurs in a particular locality. The protocol was first implemented in a pilot study in Trinidad, West Indies. For gathering prevalence data, such xenomonitoring is a suitable alternative to the use of human bait, which is ethically questionable. The resting mosquitoes were collected, either indoors or outdoors, using electrical and mouth aspirators. A 'cocoeya broom', made from a bunch of the midribs of coconut-palm leaves, was found to be useful in flushing out the mosquitoes resting in hard-to-reach areas within bedrooms. The rationale behind the strategy and the five-step methodology, of householder notification, mapping, preparation of equipment, mosquito collecting and laboratory processing, are described. Data from the pilot study indicate that this xenomonitoring protocol may be applicable worldwide, albeit with modifications to take account of variations in the vector species involved and their ecology and resting behaviour.

Quantification of PCR amplification products of Brugia HhaI repeat DNA using a semiautomated Q-PCR system

The sensitive, rapid and species-specific diagnosis of Brugia infections in humans or animal models is important in determining the level of parasitemia and the efficacy of chemotherapy or vaccinations. The HhaI family of highly repeated DNA sequences from Brugia have been useful in polymerase chain reaction (PCR)-based diagnosis of brugian filarial infections in blood samples and in mosquitoes. A PCR assay was developed using a biotinylated primer, a non-biotinylated primer and a species-specific chemiluminescent probe [tris[2,2'bipyridine] ruthenium (II) chelate, TBR] to detect PCR amplified Hhal family repeats. Individual blood samples from jirds infected with Brugia malayi or B. pahangi and with different levels of microfilaremia were tested in this assay. Known concentrations of Brugia DNA and DNA from the blood of uninfected control jirds were used as positive and negative controls, respectively. The PCR products generated by this method were analyzed using a semi-automated quantitative (Q)-PCR system. The levels of parasite DNA can be calculated from the luminosity units generated. Significant amounts of parasite DNA were detected in blood samples from infected jirds, and these values were correlated with the levels of microfilaremia. In contrast, reductions in circulating microfilaria following treatment with ivermectin correlated with low levels of measurable DNA. Using this system, we were also able to detect HhaI repeat DNA in the spleens of B. pahangi- infected jirds at 56 days post-infection when circulating microfilariae were not readily detectable. The results indicate that the species-specific Hhal Q-PCR detection and quantification method is rapid and sensitive, is useful in the detection of Brugia DNA in blood and other tissues and is suited for use in clinical settings because it does not require radioactive isotopes and gel-based protocols.

The DNA sequence and comparative analysis of human chromosome 20

The finished sequence of human chromosome 20 comprises 59,187,298 base pairs (bp) and represents 99.4% of the euchromatic DNA. A single contig of 26 megabases (Mb) spans the entire short arm, and five contigs separated by gaps totalling 320 kb span the long arm of this metacentric chromosome. An additional 234,339 bp of sequence has been determined within the pericentromeric region of the long arm. We annotated 727 genes and 168 pseudogenes in the sequence. About 64% of these genes have a 5' and a 3' untranslated region and a complete open reading frame. Comparative analysis of the sequence of chromosome 20 to whole-genome shotgun-sequence data of two other vertebrates, the mouse Mus musculus and the puffer fish Tetraodon nigroviridis, provides an independent measure of the efficiency of gene annotation, and indicates that this analysis may account for more than 95% of all coding exons and almost all genes.

Effect of nutritional supplementation on quantities of glucose transporters 1 and 4 in sheep granulosa and theca cells

The stimulatory effect of nutritional supplementation on ovarian activity in sheep has been linked to an increase in glucose availability that, with insulin, directly decreases follicular steroidogenesis. Glucose uptake occurs by glucose transporters, but it is not known which glucose transporters are present in the sheep ovary or whether they are affected by nutritional stimulation. The aim of this study was to determine whether widely distributed glucose transporter 1 (GLUT1) or insulin-responsive GLUT4 are present in the granulosa or theca cells of sheep ovarian follicles, and whether their concentrations are affected by nutritional stimulation. Merino ewes (n = 49-51 per group) were stimulated nutritionally for 5 days before luteolysis with lupin grain or with one of two regimens of a glucogenic mixture, administered orally, which increases blood glucose concentrations towards the upper end of the normal range. Water was used as a control. Ovaries (n = 3 per group) were dissected and the granulosa cells and thecal shell from individual follicles were examined for glucose transporters using western blotting. GLUT1 concentration was 7-18 times higher in the granulosa than in the theca cells. GLUT4 was detected at a similar concentration in both types of cell. Nutritional treatment had no effect on the concentration of GLUT1 or GLUT4 in either tissue, and did not increase ovulation rate, despite increased concentrations of glucose and insulin. Concentrations of glucose transporters were not correlated with follicular concentrations of oestradiol or androstenedione. The presence of GLUT1 and GLUT4 in the granulosa and theca of sheep follicles indicates that the transporters have a role within the ovary in the modulation of follicular function.

Effect of nutritional supplementation on quantities of glucose transporters 1 and 4 in sheep granulosa and theca cells

The stimulatory effect of nutritional supplementation on ovarian activity in sheep has been linked to an increase in glucose availability that, with insulin, directly decreases follicular steroidogenesis. Glucose uptake occurs by glucose transporters, but it is not known which glucose transporters are present in the sheep ovary or whether they are affected by nutritional stimulation. The aim of this study was to determine whether widely distributed glucose transporter 1 (GLUT1) or insulin-responsive GLUT4 are present in the granulosa or theca cells of sheep ovarian follicles, and whether their concentrations are affected by nutritional stimulation. Merino ewes (n = 49-51 per group) were stimulated nutritionally for 5 days before luteolysis with lupin grain or with one of two regimens of a glucogenic mixture, administered orally, which increases blood glucose concentrations towards the upper end of the normal range. Water was used as a control. Ovaries (n = 3 per group) were dissected and the granulosa cells and thecal shell from individual follicles were examined for glucose transporters using western blotting. GLUT1 concentration was 7-18 times higher in the granulosa than in the theca cells. GLUT4 was detected at a similar concentration in both types of cell. Nutritional treatment had no effect on the concentration of GLUT1 or GLUT4 in either tissue, and did not increase ovulation rate, despite increased concentrations of glucose and insulin. Concentrations of glucose transporters were not correlated with follicular concentrations of oestradiol or androstenedione. The presence of GLUT1 and GLUT4 in the granulosa and theca of sheep follicles indicates that the transporters have a role within the ovary in the modulation of follicular function.

Moderate alcohol consumption and risk of heart failure among older persons

CONTEXT

Heavy consumption of alcohol can lead to heart failure, but the relationship between moderate alcohol consumption and risk of heart failure is largely unknown.

OBJECTIVE

To determine whether moderate alcohol consumption predicts heart failure risk among older persons, independent of the association of moderate alcohol consumption with lower risk of myocardial infarction (MI).

DESIGN

Prospective cohort study conducted from 1982 through 1996, with a maximum follow-up of 14 years.

SETTING AND PARTICIPANTS

Population-based sample of 2235 noninstitutionalized elderly persons (mean age, 73.7 years; 41.2% male; 21.3% nonwhite) residing in New Haven, Conn, who were free of heart failure at baseline. Persons who reported alcohol consumption of more than 70 oz in the month prior to baseline were excluded.

MAIN OUTCOME MEASURE

Time to first fatal or nonfatal heart failure event, according to the amount of alcohol consumed in the month prior to baseline.

RESULTS

Increasing alcohol consumption in the moderate range was associated with decreasing heart failure rates. For persons consuming no alcohol (50.0%), 1 to 20 oz (40.2%), and 21 to 70 oz (9.8%) in the month prior to baseline, crude heart failure rates per 1000 years of follow-up were 16.1, 12.2, and 9.2, respectively. After adjustment for age, sex, race, education, angina, history of MI and diabetes, MI during follow-up, hypertension, pulse pressure, body mass index, and current smoking, the relative risks of heart failure for those consuming no alcohol, 1 to 20 oz, and 21 to 70 oz in the month prior to baseline were 1.00 (referent), 0.79 (95% confidence interval [CI], 0.60-1.02), and 0.53 (95% CI, 0.32-0.88) (P for trend =.02).

CONCLUSIONS

Increasing levels of moderate alcohol consumption are associated with a decreasing risk of heart failure among older persons. This association is independent of a number of confounding factors and does not appear to be entirely mediated by a reduction in MI risk.

Detection of Brugia malayi in laboratory and wild-caught Mansonioides mosquitoes (Diptera: Culicidae) using Hha I PCR assay

An Hha 1 based polymerase chain reaction (PCR) assay developed for the detection of Brugia malayi, the causative agent of Brugian lymphatic filariasis, was evaluated for its sensitivity in the laboratory and for its usefulness in measuring changes in transmission of the disease in the field. Laboratory studies showed that the new assay was highly sensitive in comparison with the standard dissection and microscopy technique. The assay can detect as little as 4 pg of parasite DNA or a single microfilaria in pools of up to 100 mosquitoes. The optimum pool size for convenience was found to be 50 mosquitoes per pool. The efficacy of PCR assay was evaluated in filariasis control programmes in operation in endemic areas of Kerala State, South India. The infection rates obtained by the Hha I PCR assay and the conventional dissection and microscopy technique were 1.2% and 1.7% respectively in operational areas and 8.3% and 4.4% respectively, in check areas, which were not significantly different (P < 0.05). Thus, the Hha I PCR assay was found to be as sensitive as the conventional technique and hence it can be used as a new epidemiological tool for assessing parasite infection in field-collected mosquitoes.

SfiI endonuclease activity is strongly influenced by the non-specific sequence in the middle of its recognition site

The SfiI endonuclease cleaves DNA at the sequence GGCCNNNN NGGCC, where N is any base and downward arrow is the point of cleavage. Proteins that recognise discontinuous sequences in DNA can be affected by the unspecified sequence between the specified base pairs of the target site. To examine whether this applies to SFII, a series of DNA duplexes were made with identical sequences apart from discrete variations in the 5 bp spacer. The rates at which SFII cleaved each duplex were measured under steady-state conditions: the steady-state rates were determined by the DNA cleavage step in the reaction pathway. SFII cleaved some of these substrates at faster rates than other substrates. For example, the change in spacer sequence from AACAA to AAACA caused a 70-fold increase in reaction rate. In general, the extrapolated values for k(cat) and K(m) were both higher on substrates with inflexible spacers than those with flexible structures. The dinucleotide at the site of cleavage was largely immaterial. SFII activity is thus highly dependent on conformational variations in the spacer DNA.

The Effect of Reading Ability and Response Formats on Patients' Abilities to Respond to a Patient Satisfaction Scale

This study investigated the relationship between reading ability and patient satisfaction measured with a 5-point Likert scale, a yes/no/uncertain choice, and a pictorial format. The study sample included 48 patients, 16 patients with third to fifth grade reading levels and 32 patients with reading levels of sixth grade or above. The mean percent agreement among the positively worded items on all three scales exceeded 80% regardless of reading level and response format. All of the patients had difficulty with the negatively worded items in all three formats, with the percent agreement dropping to only 49% between the negative items on the yes/no/uncertain and pictorial formats in the lower reading group.

Post-operative recovery after inguinal herniotomy in ex-premature infants: comparison between sevoflurane and spinal anaesthesia

We prospectively studied the post-operative recovery profile of 28 ex-premature infants undergoing inguinal herniotomy. All infants had a post-conceptual age of less than 46 weeks at the time of surgery and were randomized to receive either sevoflurane (group 1, 14 patients) or spinal anaesthesia (group 2, 14 patients). All patients received supplemental caudal analgesia before skin incision. Cardiorespiratory function was continuously recorded in all patients before and after surgery. A blinded observer analysed each paired recording for predefined episodes of apnoea, hypoxaemia or bradycardia and the reports were used to compare the two groups. Spinal anaesthesia was attempted unsuccessfully in four patients in group 2. Five patients in group 1 demonstrated an 'excess' number of episodes (median 4, range 3-12) of clinically silent post-operative cardiorespiratory complications. ('Excess' in our study was defined as a 3-fold or greater increase in the number of post-operative episodes of bradycardia or apnoea relative to pre-operative occurrence). Three of these patients had pre-existing abnormal respiratory function and accounted for 80% of the episodes (26/32) of post-operative bradycardia and all five episodes of post-operative apnoea identified. All episodes of bradycardia and apnoea were temporally unrelated. None of the remaining patients in group 2 demonstrated an unacceptable number of post-operative cardiorespiratory complications. Our limited study suggests that general anaesthesia with an inhalational agent such as sevoflurane may induce or unmask abnormalities of cardiopulmonary function in predisposed infants. Spinal anaesthesia may be preferable but it is potentially stressful for the infant and associated with a clinically significant failure rate.

MYO1, a novel, unconventional myosin gene affects endocytosis and macronuclear elongation in Tetrahymena thermophila

Targeted gene disruption was used to investigate the function of MYO1, an unconventional myosin gene in Tetrahymena thermophila. Phenotypic analysis of a transformed strain that lacked a functional MYO1 gene was conducted at both 20 degrees C and 35 degrees C. At either temperature the delta MYO1 strain had a smaller cytoplasm/nucleus ratio than wild type. At 20 degrees C, delta MYO1 populations had a longer doubling time than wild type, lower saturation density, and a reduced rate of food vacuole formation. However, at 35 degrees C, these characteristics were comparable to wild type. Although micronuclear division and cytokinesis appeared normal in delta MYO1 cells, failure of the macronucleus to elongate properly resulted in unequal segregation of macronuclear DNA in cells maintained at either 20 degrees C or 35 degrees C.

Identification of potential vaccine and drug target candidates by expressed sequence tag analysis and immunoscreening of Onchocerca volvulus larval cDNA libraries

The search for appropriate vaccine candidates and drug targets against onchocerciasis has so far been confronted with several limitations due to the unavailability of biological material, appropriate molecular resources, and knowledge of the parasite biology. To identify targets for vaccine or chemotherapy development we have undertaken two approaches. First, cDNA expression libraries were constructed from life cycle stages that are critical for establishment of Onchocerca volvulus infection, the third-stage larvae (L3) and the molting L3. A gene discovery effort was then initiated by random expressed sequence tag analysis of 5,506 cDNA clones. Cluster analyses showed that many of the transcripts were up-regulated and/or stage specific in either one or both of the cDNA libraries when compared to the microfilariae, L2, and both adult stages of the parasite. Homology searches against the GenBank database facilitated the identification of several genes of interest, such as proteinases, proteinase inhibitors, antioxidant or detoxification enzymes, and neurotransmitter receptors, as well as structural and housekeeping genes. Other O. volvulus genes showed homology only to predicted genes from the free-living nematode Caenorhabditis elegans or were entirely novel. Some of the novel proteins contain potential secretory leaders. Secondly, by immunoscreening the molting L3 cDNA library with a pool of human sera from putatively immune individuals, we identified six novel immunogenic proteins that otherwise would not have been identified as potential vaccinogens using the gene discovery effort. This study lays a solid foundation for a better understanding of the biology of O. volvulus as well as for the identification of novel targets for filaricidal agents and/or vaccines against onchocerciasis based on immunological and rational hypothesis-driven research.

The genomes of Onchocerca volvulus

Onchocerca volvulus, the filarial parasite that causes onchocerciasis or river blindness, contains three distinct genomes. These include the nuclear genome, the mitochondrial genome and the genome of an intracellular endosymbiont of the genus Wolbachia. The nuclear genome is roughly 1.5x10(8) bp in size, and is arranged on four chromosome pairs. Analysis of expressed sequence tags from different life-cycle stages has resulted in the identification of transcripts from roughly 4000 O. volvulus genes. Several of these transcripts are highly abundant, including those encoding collagen and cuticular proteins. Analysis of several gene sequences from O. volvulus suggests that the nuclear genes of O. volvulus are relatively compact and are interrupted relatively frequently by small introns. The intron-exon boundaries of these genes generally follow the GU-AG rule characteristic of the splice donor and acceptors of other vertebrate organisms. The nuclear genome also contains at least one repeated sequence family of a 150 bp repeat which is arranged in tandem arrays and appears subject to concerted evolution. The mitochondrial genome of O. volvulus is remarkably compact, only 13747 bp in size. Consistent with the small size of the genome, four gene pairs overlap, eight contain no intergenic regions and the remaining gene pairs are separated by small intergenic domains ranging from 1 to 46 bp. The protein-coding genes of the O. volvulus mitochondrial genome exhibit a striking codon bias, with 15/20 amino acids having a single codon preference greater than 70%. Intraspecific variation in both the nuclear and mitochondrial genomes appears to be quite limited, consistent with the hypothesis that O. volvulus has suffered a genetic bottleneck in the recent past.

The filarial genome project: analysis of the nuclear, mitochondrial and endosymbiont genomes of Brugia malayi

The Filarial Genome Project (FGP) was initiated in 1994 under the auspices of the World Health Organisation. Brugia malayi was chosen as the model organism due to the availability of all life cycle stages for the construction of cDNA libraries. To date, over 20000 cDNA clones have been partially sequenced and submitted to the EST database (dbEST). These ESTs define approximately 7000 new Brugia genes. Analysis of the EST dataset provides useful information on the expression pattern of the most abundantly expressed Brugia genes. Some highly expressed genes have been identified that are expressed in all stages of the parasite's life cycle, while other highly expressed genes appear to be stage-specific. To elucidate the structure of the Brugia genome and to provide a basis for comparison to the Caenorhabditis elegans genome, the FGP is also constructing a physical map of the Brugia chromosomes and is sequencing genomic BAC clones. In addition to the nuclear genome, B. malayi possesses two other genomes: the mitochondrial genome and the genome of a bacterial endosymbiont. Eighty percent of the mitochondrial genome of B. malayi has been sequenced and is being compared to mitochondrial sequences of other nematodes. The bacterial endosymbiont genome found in B. malayi is closely related to the Wolbachia group of rickettsia-like bacteria that infects many insect species. A set of overlapping BAC clones is being assembled to cover the entire bacterial genome. Currently, half of the bacterial genome has been assembled into four contigs. A consortium has been established to sequence the entire genome of the Brugia endosymbiont. The sequence and mapping data provided by the FGP is being utilised by the nematode research community to develop a better understanding of the biology of filarial parasites and to identify new vaccine candidates and drug targets to aid the elimination of human filariasis.

A double-blind, placebo-controlled study of the safety, tolerability and pharmacokinetics of CP-101,606 in patients with a mild or moderate traumatic brain injury

CP-101,606 is a postsynaptic antagonist of the glutamate-mediated NR2B subunit of the N-methyl-D-aspartate (NMDA) receptor. When administered intravenously (i.v.) at the time of injury, CP-101,606 is neuroprotective in animal models of traumatic brain injury (TBI) and ischemia. Minimal adverse effects have been observed in normal human volunteers given i.v. doses of up to 3 mg/kg/hr for 72 hours. The objective of the present clinical trial was to assess the safety, pharmacokinetics, and tolerability of CP-101,606 infused for various times in patients who had suffered either an acute moderate or mild TBI (Glasgow Coma Score 9-14) or hemorrhagic stroke. Patients began receiving treatment within 12 hours of brain injury. A total of 53 subjects (45 with TBI and 8 with stroke) were randomized in a double-blind fashion to receive CP-101,606 or placebo (4 drug: 1 placebo). Drug/placebo was administered by i.v. infusion (0.75 mg/kg/hr) for 2 hours and then stopped (n = 25) or continued for 22 hours (n = 4) or 70 hours (n = 24) at a rate of 0.37 mg/kg/hr. Mean plasma drug concentrations were well above the predicted therapeutic concentration of 200 ng/ml within two hours of initiating treatment and were sustained as long as drug was infused. All the patients tolerated their drug/placebo treatment, and there were no clinically significant cardiovascular or hematological abnormalities in either group. A Neurobehavioral Rating Scale, used to detect personality changes and behavioral disturbances, indicated that all subjects showed an improvement from their postinjury, predosing baseline but did not significantly differ from each other with respect to type of head injury and/or treatment with drug or placebo. Modified Kurtzke Scoring also showed a similar pattern of improvement irrespective of type of head injury or drug/placebo treatment. This study suggests that CP-101,606, infused for up to 72 hours has no psychotropic effects and is well-tolerated in patients who have sustained a mild or moderate TBI or hemorrhagic stroke.

An open-label study of CP-101,606 in subjects with a severe traumatic head injury or spontaneous intracerebral hemorrhage

CP-101,606 is a postsynaptic antagonist of N-methyl-D-aspartate (NMDA) receptors bearing the NR2B subunit. When administered intravenously (i.v.), it decreases the effects of traumatic brain injury (TBI) and focal ischemia in animal models. Therapeutic plasma concentrations (200 ng/ml) in animals, have been well tolerated in healthy human volunteers. The purpose of the present dose escalation study was to assess the safety, tolerability, and pharmacokinetics of CP-101,606 in subjects who had suffered either an acute severe TBI (Glasgow Coma Scale 3-8) or spontaneous intracerebral hemorrhage. Thirty patients, 20 with a TBI and 10 with a stroke, were enrolled in the trial and began receiving an i.v. infusion of CP-101,606 for 2 hours, 24 hours, or 72 hours within 12 hours of brain injury. For the first two hours, the drug was given a rate of 0.75 mg/kg/hr and then stopped (n = 17) or continued for 22 (n = 2) or 70 hours (n = 11) at 0.37 mg/kg/hr. Plasma and cerebrospinal fluid (CSF) were collected at serial times during and after treatment. There were no consistent changes in blood pressure or pulse nor any clinically significant hematological or electrocardiogram (ECG) abnormalities attributable to CP-101,606. No adverse events or behavioral changes were considered to be related to the drug. Plasma concentrations of CP-101,606 over 200 ng/ml were rapidly achieved in the blood and CSF within two hours and were sustained there as long as the drug was infused. CSF concentrations were slightly higher than that in plasma by the end of infusion suggesting good penetration of CP-101,606 into the CSF. Outcome in the severe TBI patients, as measured by the Glasgow Outcome Score at six months, suggested that a two-hour infusion yielded a range of scores similar to contemporary patients with a severe TBI treated at our hospital while the outcomes of the patients treated with either a 24- or 72-hour infusion were better on average. Thus, these results indicate that CP-101,606 infused for up to 72 hours is well tolerated, penetrates the CSF and brain, and may improve outcome in the brain-injured patient.

Parental smoking practices and caries experience in pre-school children

Voluntary and involuntary smoking influence general health. Links between voluntary smoking and oral health are confirmed for periodontal diseases and oral cancer/precancer. Since recent reports have suggested an association between parental smoking and caries experience in young children, this study aimed to explore varying patterns of parental smoking, adjusted for social class, with caries prevalence, using data derived from the UK National Diet and Nutrition Survey (1995). Data analysis was confined to 749 children aged 3.0-4.5 years, to avoid confounding effects of unerupted teeth. Bivariate analysis indicated that the prevalence of maternal rather than paternal smoking was significantly related to caries and substantially attenuated social class differences. The reported number of cigarettes smoked was not important. To compensate for the association between social class and maternal smoking, data were dichotomised by social class (manual/non-manual). With caries prevalence as the dependent variable, logistic regression analysis recorded maternal smoking as a significant independent variable in each case, with odds ratios of 1.55/1.96, respectively. The process was repeated for the combined dataset, using the more extensive (six) social class categories. This further analysis yielded an odds ratio for maternal smoking of 1.54 compared with 1.46 for social class. Nutrition status (as growth parameters) and dietary intake (as household spending on confectionery) were not significant independent variables in these equations. The rationale for these findings is discussed. Further research is required to determine mechanisms underlying these observations. It is concluded that maternal smoking is a significant factor to be considered as an additional risk indicator beyond social class when predicting caries risk in young children.

Application of a polymerase chain reaction-ELISA to detect Wuchereria bancrofti in pools of wild-caught Anopheles punctulatus in a filariasis control area in Papua New Guinea

Chemotherapy-based eradication programs are aimed at stopping transmission of Wuchereria bancrofti by its obligatory mosquito vector. This study compares one year post-treatment W. bancrofti infection rates of Anopheles punctulatus, the main vector of lymphatic filariasis in Papua New Guinea, using traditional dissection techniques and a polymerase chain reaction (PCR)-based ELISA of a parasite-specific Ssp I repeat. A total of 633 mosquitoes in 35 batches were dissected. Six batches contained W. bancrofti-infected mosquitoes, giving a minimum infection rate of 0.9%. This value was not different than the actual infection rate, which was 9 (1.4%) of 633 mosquitoes (P = 0.48). The DNA was extracted from 47 pools containing a mean of 13.2 mosquitoes per pool. A total of 621 mosquitoes were processed for the PCR-ELISA, including 486 caught by human bait and 135 by light trap, which included both dead and live mosquitoes. Of 23 pools of alcohol-preserved human-bait mosquitoes, seven were positive by the PCR-ELISA, giving an infection rate identical to that obtained by dissection of individual mosquitoes (1.4%). The minimum infection rates for pools of light-trap mosquitoes found dead and alive were 2.7% (2 of 74) and 4.9% (3 of 61), respectively. These values did not differ from each other (P = 0.84), but the overall infection rate of light-trap mosquitoes was greater than that of mosquitoes captured by human bait (3.7% versus 1.4%; P = 0.09). These data indicate that the PCR-ELISA of a W. bancrofti Ssp I repeat using pools of mosquitoes is comparable to traditional dissection techniques for monitoring transmission intensity following introduction of mass chemotherapy. This approach may also be useful for rapid and cost-effective assessment of transmission in endemic areas where the frequency of overt lymphatic pathology is low.

Detection of DNA of nocturnally periodic Brugia malayi in night and day blood samples by a polymerase chain reaction-ELISA-based method using an internal control DNA

An internal control was used in a polymerase chain reaction (PCR)-ELISA-based technique to detect the Hha I repeat of the filarial parasite Brugia malayi. A single microfilaria added to 200 microl of blood was reliably detected. The assay was evaluated on field samples from persons living in an area endemic for Anopheles-transmitted, nocturnally periodic B. malayi in central Sulawesi, Indonesia. Examination of night blood of 138 individuals for the presence of microfilariae by filtration revealed 44 microfilaria carriers. All microfilaria carriers were also positive in the PCR-ELISA and, in addition, 14 more samples were proven to contain parasite DNA. The sensitivity of both methods was compared on night and on day blood samples collected from 113 persons. Whereas 37 microfilaria carriers were identified by filtration of night blood, no microfilariae were observed in the corresponding day blood samples. The PCR-ELISA result was positive in all 37 night blood samples of microfilaria carriers and in an additional 13 night blood samples without microfilariae. Parasite DNA was detected in 31 day blood samples of microfilaria carriers and in 3 day blood samples of amicrofilaremic persons. Assuming a sensitivity of the PCR-ELISA on night blood of 100%, the sensitivity of night blood filtration is 74% and that of the PCR-ELISA on day blood is 68%. These data suggest that the described PCR-ELISA method is capable of detecting infections with nocturnally periodic B. malayi in day blood samples. Therefore, this method may facilitate both the identification of endemic areas and the monitoring of control programs.

Cultural barriers to successful communication during orthodontic care

OBJECTIVE

To determine to what extent barriers related to culture and language, and how inappropriate expectations might impede orthodontic care, among Pakistani Muslims when compared to white Caucasians from similar socio-economic backgrounds in Bradford, UK.

DESIGN

Semi-structured interviews.

SETTING

Dentists were interviewed in the clinic. Parents and children were interviewed separately in the waiting room or in adjacent rooms depending on availability.

PARTICIPANTS

Four dentists working in the Community and Hospital Dental Services, 30 children and 10 parents of white and Pakistani origin.

RESULTS

Among the white Caucasian groups, three-way communication involving parents, children and dentist enhanced understanding, supported orthodontic treatment and reinforced the need for good home care. Among Pakistani families communication was primarily two-way, involving the dentist and the child. Parents and families had limited understanding of the process and were unable to offer a comparable level of support that would benefit their children most. This can place additional burdens on the Pakistani child patient and requires a very positive approach from the dental team.

CONCLUSIONS

There is a clear need for chairside support, through patient advocates or interpreters, as well as the provision of appropriate educational material to match parents' educational needs on behalf of their children.

Diagnostic delays in head and neck cancers

Head and neck cancers are a significant and worsening health problem in the UK. In the absence of screening, minimising diagnostic delay after the onset of symptoms improves prognosis. Delay, from the patient's initial experience of symptoms to the ultimate diagnosis, consists of two elements--the delay prior to presenting to a clinician plus that due to the health professional consulted. This study aimed to establish the period of delay between recognition of the initial tumour symptoms and the formal diagnosis among a sample of patients recently diagnosed with head and neck cancer. Using a semistructured questionnaire, 133 men and 55 women were interviewed by a research nurse, and the results were related to the clinical findings. Tumour size at diagnosis was classified according to T1 (22%), T2 (29%), T3 (27%) and T4 (22%). Of the 186 patients with complete hospital records, 48 (26%) were diagnosed with cancer of the lip and oral cavity (CLOC). From the onset of symptoms to the patients' initial decision to seek professional advice, the median period was 4 weeks among those with CLOC and 3 weeks for those with other head and neck cancers (OHNC). The distribution was highly skewed with delays beyond 6 months occurring among 9% of the OHNC group, compared with 3% of CLOC. From the onset of symptoms to a consultant appointment, the median delay was 8 weeks for OHNC, but 12 weeks for CLOC, with delays beyond 6 months of 13% in each group, respectively. First symptoms included 'change in voice' (26%), 'pain' (27%), 'lump' or 'growth' (12%) as well as dysphagia, 'infection', 'sore throat', 'ulcers' or 'abscess'. No significant association was found between the nature of the first symptoms and the urgency with which patients interpreted their symptoms, nor was this related to diagnostic delay, sex, age or social class. It is concluded that there is substantial variation in time to clinical presentation, particularly for OHNC, although professional delay for the majority of these cases was minimal. For patients with CLOC there was less variation in patient delay, but clinician delay was relatively longer.

Patient's perceptions of an anesthesia preoperative computerized patient interview

Our desire to elicit a more complete medical history from our patients led to the implementation of a preoperative computerized interview. We previously demonstrated the effectiveness of the interview by computing its mean completion time for the overall patient population (n = 120), and further examined the effects of age, gender, and educational level. In this study, we investigated patient perception of the interview itself. Before and after taking the computer interview, we asked the patients to complete a paper and pencil questionnaire comprised of sixteen questions, expressing their feelings toward the computer interview. Responses elicited prior to taking the computer interview were compared with those obtained afterward. The Stuart-Maxwell test was used to determine statistically significant differences in answers before and after the interview. Initial questionnaire responses reflected a positive attitude toward computer usage which became even stronger after the interview. The only negative responses elicited were really more "doctor positive" than "computer negative." We conclude that patients looked favorably upon participating in a computerized medical interview provided that physician-patient contact is maintained.