A genetic Study of the Ghanaian Population Using 15 Autosomal STR Loci

Autosomal short tandem repeat (STR) population data collected from a well characterized population are needed to correctly assigning the weight of DNA profiles in the courtroom and widely used for ancestral analyses. In this study, allele frequencies for the 15 autosomal short tandem repeat (STR) loci included in the AmpFlSTR® Identifiler® plus kit (D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, VWA, TPOX, D18S51, D5S818, FGA) were obtained by genotyping 332 unrelated individuals of Ghanaian origin. Statistical tests on STR genotype data showed no significant departure from Hardy-Weinberg equilibrium (HWE). The overall match probability, combined power of exclusion and combined power of discrimination for these loci were 1 in 3.85 × 1017, 0.99999893 and 0.99999998, respectively. Polymorphic information content (PIC) greater than 0.70 was observed for all loci except TH01 and D13S317. These statistical parameters confirm that this combination of loci is valuable for forensic identification and parentage analysis. Our results were also compared with those for 20 other human populations analyzed for the same set of markers. We observed that the Ghanaian population grouped with other African populations in two-dimensional principal coordinate (PCO) and a neighbor-joining (N-J) data mapping and placed closest to Nigerians. This observation reflects cultural similarities and geographical factors, coupled with the long history of migration and trading activities between Ghana and Nigeria. Our report provides what we believe to be the first published autosomal STR data for the general Ghanaian population using 15 loci genotyped using the AmpFlSTR® Identifiler® plus kit methodology. Our data show that the loci tested have sufficient power to be used reliably for DNA profiling in forensic casework and help to elucidate the genetic history of people living in the country.

Distribution of 22 Single Nucleotide Polymorphisms in 13 Cytokine Genes in Malays, Chinese, and Indians in Peninsular Malaysia

Introduction: Cytokines are cell signaling glycoproteins that are particularly important in immunity and inflammatory responses. Therefore, variations, such as single nucleotide polymorphisms (SNPs), in genes encoding for cytokines may have important consequences for their roles in health. Materials and Methods: A total of 222 unrelated, healthy, and un-admixed Malays (n = 97), Chinese (n = 77), and Indians (n = 48) with a median age of 30 years old (range 21-50) were typed for 22 cytokine gene SNPs: IL-1α -889 T/C, IL-1β (-511 T/C, +3962 T/C), IL-1R pst1 1970 T/C, IL-1RA mspa1 11100 T/C, IL-4Rα +1902 G/A, IL-12 - 1188 C/A, IFN-γ +874 A/T, TGF-β (cdn 10 C/T, cdn 25 G/C), TNF-α (-308 A/G, -238 A/G) IL-2 (+166 G/T, -330 T/G), IL-4 (-1098 T/G, -590 T/C, -33 T/C), IL-6 (-174 C/G, nt565 G/A), and IL-10 (-1082 G/A, -819 C/T, -592 A/C). This involved using well-established polymerase chain reaction procedures with sequence-specific primers and restriction fragment length polymorphism methods. Results: The majority of the screened cytokine gene SNPs are polymorphic in all three ethnicities. Exceptions include TGF-β cdn 25 (G/C), IL-1β +3962 (T/C), and TNF-α -238 (A/G), which were all observed to be monomorphic in Malays, Chinese and Indians. Many of the analyzed cytokine gene SNP genotypes deviated from Hardy-Weinberg equilibrium and the three ethnic study groups were all well-separated from reference Asian, African and European populations in a principal component analysis plot. Conclusion: We successfully typed 22 SNPs in 13 cytokine genes from genetic material collected from unrelated and un-admixed Malay, Chinese and Indian individuals in Peninsular Malaysia. These new cytokine gene population datasets reveal interesting contrasts with other populations.

Correction to: Extended blood group profiles for Malays, Chinese, and Indians in Peninsular Malaysia

An amendment to this paper has been published and can be accessed via the original article.

Extended blood group profiles for Malays, Chinese, and Indians in Peninsular Malaysia

Background

Blood group antigens are immunogenic polymorphic molecules presented on the surface of RBCs. This study aimed to determine extended blood group profiles (ABO, Rhesus, Kell, Kidd, Duffy, MNS, Cartwright, Dombrock, Colton, Lutheran, and Vel) in Malays, Chinese, and Indians in Peninsular Malaysia.

Results

Here, ABO Type O, DCCee, MNs, and Fy (a+b−) were the most frequent major blood group phenotypes in all three ethnic groups. Other minor blood group systems distributed differently across these ethnic groups, except for the Kell, Lutheran, Cartwright, and Vel blood group systems, where only K−k+, Lu (8+14), Yt (a+b−), and Vel (+) phenotypes were observed. Exact tests of population differentiation generally showed no significant differences between Malays included in the present study vs. other ethnically similar datasets from previous surveys. However, many significant differences were recorded in comparison between blood group datasets from ethnically unrelated populations (Malays vs. Chinese vs. Indians) especially for Rhesus, Kidd, and Duffy blood group systems. A Principal component analysis (PCA) plot showed that population groups from the Peninsular Malaysia map closely together as compared with population groups from other geographical regions.

Conclusions

Overall, our present study has successfully provided an extended blood group profiles for Malays, Chinese, and Indians in Peninsular Malaysia. These new blood group datasets can be used as guidelines for donor recruitment and as reference standards for studying diseases associated with blood group systems.

The Prevalence of Transfusion-transmitted Infections among Blood Donors in Hospital Universiti Sains Malaysia

Objectives

Blood bank centers routinely screen for hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) to ensure the safety of blood supply and thus prevent the dissemination of these viruses via blood transfusion. We sought to evaluate the detection of transfusion-transmitted infection (TTI) markers using standard serological methods and nucleic acid testing (NAT) among blood donors in Hospital Universiti Sains Malaysia.

Methods

Donated blood units were assessed for the presence or absence of HBV, HCV, and HIV using two screening method: serology and NAT. Reactive blood samples were then subjected to serological confirmatory and NAT discriminatory assays.

Results

A total of 9669 donors were recruited from September 2017 to June 2018. Among these, 36 donors were reactive either for HBV, HCV, or HIV by serological testing and eight by NAT screening. However, only 10 (three for HBV and seven for HCV) donors tested positive using serological testing and five (two for HBV and three for HCV) by NAT discriminatory assays. Note that all five NAT positive donors detected in the NAT discriminatory assays were confirmed to be serologically reactive. Therefore, the prevalence of HBV, HCV, and HIV was 0.03%, 0.1%, and 0.0%, respectively, in our donor pool.

Conclusions

Both serological and NAT screening and confirmatory assays should be used routinely to reduce the risk of infection transmission via the transfusion of blood and blood components.

Assessment of QIAGEN™ Investigator® 24plex GO! kit workflow for autosomal STR profiling of forensic reference samples

Background

DNA profiling has proven to be a valuable technique for identification of individuals in crime. Currently, the technique targets several short tandem repeat (STR) regions in human genome. However, increasing number of samples submitted for STR analysis may lead to delays due to the limited number of experienced analysts who might be available at any given moment and the time taken to complete lengthy DNA profiling procedures. This study was conducted to test the specificity, repeatability, reproducibility and robustness of Investigator® 24plex GO! kit for genotyping of reference samples submitted to the Royal Malaysian Police Forensic DNA Laboratory for DNA database.

Material and methods

In this study, Investigator® 24plex GO! kit was used to directly amplify STR loci from buccal swab cell of reference samples that had previously been STR typed using GlobalFiler™ Express kit. Capillary electrophoresis was carried out on a 3500xL Genetic Analyser using POP-4® Polymer. Amplified products were assigned to particular STR alleles using the GeneMapper ID-X version 1.4 software.

Results

Our study shows that STR profiles generated using Investigator® 24plex GO! gave concordance results with those previously obtained using the GlobalFiler™ Express kit. In addition, quality sensors included in the kit are of particular importance for determining the effectiveness of the PCR reaction and help to indicate the nature and quantity of DNA template for PCR amplification.

Conclusion

The Investigator® 24plex GO! kit is reliable for STR typing of reference samples.

Autosomal STR Profiling and Databanking in Malaysia: Current Status and Future Prospects

Science and technology are extensively used in criminal investigation. From the mid- to late-1980s, one of the scientific discoveries that has had a particularly remarkable impact on this field has been the use of highly variable DNA sequence regions (minisatellites) in the human genome for individual identification. The technique was initially referred to as DNA fingerprinting, but is now more widely referred to as DNA profiling. Since then, many new developments have occurred within this area of science. These include the introduction of new genetic markers (microsatellites also known as short tandem repeats/STRs), the use of the polymerase chain reaction for target amplification, the development of DNA databases (databanking), and the advancement and/or improvement of genotyping protocols and technologies. In 2019, we described the progress of DNA profiling and DNA databanking in Malaysia for the first time. This report included information on DNA analysis regulations and legislation, STR genotyping protocols, database management, and accreditation status. Here, we provide an update on the performance of our DNA databank (numbers of DNA profiles and hits) plus the technical issues associated with correctly assigning the weight of evidence for DNA profiles in an ethnically diverse population, and the potential application of rapid DNA testing in the country. A total of 116,534 DNA profiles were obtained and stored in the Forensic DNA Databank of Malaysia (FDDM) by 2019, having increased from 70,570 in 2017. The number of hits increased by more than three-fold in just two years, where 17 and 69 hits between the DNA profiles stored in the FDDM and those from crime scenes, suspects, detainees, drug users, convicts, missing persons, or volunteers were recorded in 2017 and 2019, respectively. Forensic DNA analysis and databanking are thus progressing well in Malaysia and have already contributed to many criminal investigations. However, several other issues are discussed here, including the need for STR population data for uncharacterized population groups, and pilot trials for adopting rapid DNA profiling technology. These aspects should be considered by policy makers and law enforcement agencies in order to increase the reliability and efficiency of DNA profiling in criminal cases and in kinship analysis in Malaysia.

Dataset on 21 autosomal and two sex determining short tandem repeat loci in the Kedayan population in Borneo, Malaysia

This data article provides population frequencies for 21 autosomal and two sex determining short tandem repeat (STR) loci in unrelated Kedayan individuals. This article is related to the research paper entitled “Forensic parameters and ancestral fraction in the Kedayan population inferred using 21 autosomal STR loci” [1] where these same data were subjected to ancestry and forensic analyses. We have collected 200 blood samples consisting of 128 male and 72 female volunteer representatives from Kedayan people residing in various parts of Borneo. All 23 STR loci were simultaneously amplified using Globalfiler™ Express PCR and amplicons were separated using an ABI 3500xl Genetic Analyzer. The STR allele calls at each locus were called using GeneMapper^Ⓡ ID-X Software v1.4, while several algorithms in Arlequin software version 3.5 were used to estimate Hardy–Weinberg equilibrium (HWE) and linkage disequilibrium (LD) between pairs of STR loci.

Population dataset for 21 simple tandem repeat loci in the Akan population of Ghana

Short tandem repeat (STR) loci are widely used as genetic marker for ancestral and forensic analyses. The latter application includes for paternity testing and DNA profiling of samples collected from scenes of crime and suspects. This survey provides the first dataset for 21 STR loci across the Akan population in Ghana by genotyping of 109 unrelated healthy individuals using Investigator 24plex kit. None of the STR loci screened deviated from Hardy-Weinberg equilibrium after applying Bonferroni correction. Overall, 224 unique alleles were observed with allele frequencies ranging from 0.005 to 0.518. The combined match probability, combined power of exclusion and combined power discrimination were 1 in 4.07 × 10⁻²⁵, 0.999999999 and 1, respectively. Principal coordinate analysis carried out using 21 STR allele frequency data mapped the Akans with Nigerian subpopulation groups (Hausa, Igbo and Yoruba), but separated from Thais of Thailand, Chechen of Jordan and Tijuana of Mexico.

Population data for 23 Y chromosome STR loci using the Powerplex® Y23 STR kit for the Kedayan population in Malaysia

Genetic polymorphisms at 23 Y chromosome short tandem repeat (STRs) loci included in the Powerplex® Y23 PCR kit were successfully scored in 128 unrelated Kedayan individuals living in Sabah, East Malaysia. Complete haplotypes were recorded for all individuals and included 92 different types with 72 being unique to single male subjects. Three important forensic statistics were calculated from these data; haplotype diversity = 0.993, discriminating capacity = 0.719, and match probability = 0.015. The Kedayan appear to be most closely related to Malays and Filipinos in a multidimensional scaling plot and are separated from other mainland Asia populations including Thais and Hakka Han. These new data for Kedayan have been deposited in the YHRD database (accession number: YA004621). Our statistical analyses showed the reliability of Y-STR loci for geographically extended use in forensic casework and for studying human population history.

Violent crime datasets: Incidence and patterns in Malaysia from 2006 to 2017

This article provides violent crime data in Malaysia from 2006 to 2017. The violent crimes include murder, rape, gang robbery, robbery and voluntarily causing hurt cases. A total of 330,395 violent crime cases were reported in this 12 year period and the data were tabulated state by state for all thirteen states of Malaysia, including two states in Borneo (Sabah and Sarawak) and one federal territory (Kuala Lumpur). In general, violent crimes show a decreasing trend from 2006 to 2017 in Malaysia. However, armed gang robbery and armed robbery show a fluctuating pattern from 2008 to 2011. A similar pattern was also recorded for unarmed gang robbery from 2008 to 2010. The violent crime data deposited here are available for further analysis, e.g., for identifying risk factors such as demography, lifestyle, socio-economic status, government policies etc. which may be associated with violent crime incidence and pattern across the country.

Assessment of autosomal and male DNA extracted from casework samples using Casework Direct Kit, Custom and Maxwell 16 System DNA IQ Casework Pro Kit for autosomal-STR and Y-STR profiling

Short repetitive regions in autosomal and Y chromosomes known as short tandem repeats (STRs) are currently used for DNA profiling in crime investigations. However, DNA profiling requires a sufficient quality and quantity of DNA template, which is often not obtained from trace evidence or degraded biological samples collected at the scene of a crime. Here, we assessed autosomal and male DNA components extracted from crime scene and mock casework samples using the Casework Direct Kit, Custom and compared the results against those obtained by extraction of matching samples using well-established Maxwell 16 System DNA IQ Casework Pro Kit. The quantity and quality of extracted DNA obtained using both Casework Direct Kit, Custom and Maxwell 16 System DNA IQ Casework Pro Kit were analyzed using PowerQuant Systems followed by autosomal and Y-chromosome STR profiling using GlobalFiler Express PCR Amplification Kit and PowerPlex Y23 System, respectively. Our results showed that the Casework Direct Kit and Maxwell 16 DNA IQ Casework Pro Kit have more or less equal capacity to extract inhibitor free DNA, but that the latter produces slightly better quality and more DNA template and subsequently higher numbers of STR allele calls for autosomal and Y-STR analyses. Nonetheless, the Casework Direct Kit, Custom is the quicker and cheaper option for extraction of good, clean DNA from high content material and might best be used for extraction of reference samples. Such reference DNA samples typically come from buccal swabs or freshly drawn blood. So, in general, they can confidently be expected to have a high nucleic acid content and to be inhibitor-free.

Human neutrophil antigen frequency data for Malays, Chinese and Indians

BACKGROUND

Human neutrophil antigens (HNAs) are implicated in several clinical disorders and their allelic variations have been reported for many populations. This new study was aimed to report the genotype and alleles frequencies of HNA-1, -3, -4 and -5 loci in Malays, Chinese and Indians in Peninsular Malaysia.

METHODS

A total of 222 blood samples were collected from healthy, unrelated Malay, Chinese and Indian individuals. Their HNA-1, -3 and -4 and HNA-5 loci were genotyped using polymerase chain reaction-sequence specific primer (PCR-SSP) or PCR-restriction fragment length polymorphism (RFLP) assays.

RESULTS

All HNA loci are polymorphic, except for HNA -4. Geneotypes HNA-1a/1b, -3a/3b and -4a/4a were observed most frequently at these three loci in all three ethnic groups. In contrast, HNA-5a/5b and -5a/5a were observed as the predominant genotypes in Malays vs. Chinese and Indians, respectively. The Malays, Chinese and Indians shared HNA -3a (0.505-0.527), HNA -4a (1.000) and -5a (0.676-0.854) as the most frequent alleles. However, HNA-1a was found to be the most common in Malays (0.506) and Chinese (0.504) and HNA-1b for Indians (0.525).

CONCLUSION

Combined with HNA data that have been published for Malay subethnic and Orang Asli groups, this study provides the first fully comprehensive HNA dataset for populations to be found in Peninsular Malaysia. Overall, our findings provide further evidence of genetic complexity in the region. This now publicly available HNA dataset can be used as a reliable reference source for improving medical outcomes.

Population data of 23 Y chromosome STR loci for the five major human subpopulations of Ghana

In this study, 268 samples for unrelated males belonging to the five major human subpopulation groups in Ghana (Akan, Ewe, Mole-Dagbon, Ga-Dangme and Guang) were genetically characterised for 23 Y chromosome short tandem repeat (STR) loci using the Powerplex® Y23 STR kit. A total of 263 complete haplotypes were recorded of which 258 were unique. The haplotype diversity, discriminating capacity and match probability for the pooled population data were 0.9998, 0.9627 and 0.0039, respectively. The pairwise genetic distance (R_ST) for the Ghanaian datasets and other reference populations deposited in the Y-STR Haplotype Reference Database (YHRD) were estimated and mapped using multidimensional scaling (MDS) plot. The Guang and Ewe were significantly different from the Akan, Mole-Dagbon and Ga-Dangme. However, the five Ghanaian datasets were all plotted close together with other African populations in the MDS data mapping.

Transfusion Medicine and Molecular Genetic Methods

Transfusion procedures are always complicated by potential genetic mismatching between donor and recipient. Compatibility is determined by several major antigens, such as the ABO and Rhesus blood groups. Matching for other blood groups (Kell, Kidd, Duffy, and MNS), human platelet antigens, and human leukocyte antigens (HLAs) also contributes toward the successful transfusion outcomes, especially in multitransfused or highly immunized patients. All these antigens of tissue identity are highly polymorphic and thus present great challenges for finding suitable donors for transfusion patients. The ABO blood group and HLA markers are also the determinants of transplant compatibility, and mismatched antigens will cause graft rejection or graft-versus-host disease. Thus, a single and comprehensive registry covering all of the significant transfusion and transplantation antigens is expected to become an important tool in providing an efficient service capable of delivering safe blood and quickly locating matching organs/stem cells. This review article is intended as an accessible guide for physicians who care for transfusion-dependent patients. In particular, it serves to introduce the new molecular screening methods together with the biology of these systems, which underlies the tests.

Serum bilirubin concentration is modified by UGT1A1 haplotypes and influences risk of type-2 diabetes in the Norfolk Island genetic isolate

Background

Located in the Pacific Ocean between Australia and New Zealand, the unique population isolate of Norfolk Island has been shown to exhibit increased prevalence of metabolic disorders (type-2 diabetes, cardiovascular disease) compared to mainland Australia. We investigated this well-established genetic isolate, utilising its unique genomic structure to increase the ability to detect related genetic markers. A pedigree-based genome-wide association study of 16 routinely collected blood-based clinical traits in 382 Norfolk Island individuals was performed.

Results

A striking association peak was located at chromosome 2q37.1 for both total bilirubin and direct bilirubin, with 29 SNPs reaching statistical significance (P < 1.84 × 10⁻⁷). Strong linkage disequilibrium was observed across a 200 kb region spanning the UDP-glucuronosyltransferase family, including UGT1A1, an enzyme known to metabolise bilirubin. Given the epidemiological literature suggesting negative association between CVD-risk and serum bilirubin we further explored potential associations using stepwise multivariate regression, revealing significant association between direct bilirubin concentration and type-2 diabetes risk. In the Norfolk Island cohort increased direct bilirubin was associated with a 28 % reduction in type-2 diabetes risk (OR: 0.72, 95 % CI: 0.57-0.91, P = 0.005). When adjusted for genotypic effects the overall model was validated, with the adjusted model predicting a 30 % reduction in type-2 diabetes risk with increasing direct bilirubin concentrations (OR: 0.70, 95 % CI: 0.53-0.89, P = 0.0001).

Conclusions

In summary, a pedigree-based GWAS of blood-based clinical traits in the Norfolk Island population has identified variants within the UDPGT family directly associated with serum bilirubin levels, which is in turn implicated with reduced risk of developing type-2 diabetes within this population.

Electronic supplementary material

The online version of this article (doi:10.1186/s12863-015-0291-z) contains supplementary material, which is available to authorized users.

Allele frequencies of human platelet antigens in Banjar, Bugis, Champa, Jawa and Kelantan Malays in Peninsular Malaysia

OBJECTIVES

The major aims of this study are to characterise and compile allelic data of human platelet antigen (HPA)-1 to -6 and -15 systems in five Malay sub-ethnic groups in Peninsular Malaysia.

BACKGROUND

HPAs are polymorphic glycoproteins expressed on the surface of platelet membranes and are genetically differentiated across ethnogeographically unrelated populations.

METHODS

Blood samples were obtained with informed consent from 192 volunteers: Banjar (n = 30), Bugis (n = 37), Champa (n = 51), Jawa (n = 39) and Kelantan (n = 35). Genotyping was done using polymerase chain reaction-sequence specific primer method.

RESULTS

In general, frequencies of HPAs in the Malay sub-ethnic groups are more similar to those in Asian populations compared with other more distinct populations such as Indians, Australian Aborigines and Europeans.

CONCLUSIONS

This study provides the first HPA datasets for the selected Malay sub-ethnic groups. Subsequent analyses including previously reported HPA data of Malays, Chinese and Indians revealed details of the genetic relationships and ancestry of various sub-populations in Peninsular Malaysia. Furthermore, the comprehensive HPA allele frequency information from Peninsular Malaysia provided in this report has potential applications for future study of diseases, estimating risks associated with HPA alloimmunization and for developing an efficient HPA-typed donor recruitment strategy.

Molecular approaches to transfusion medicine in Polynesians and Maori in New Zealand

In recent years, with the application of genotyping technology, there has been a substantial increase in the number of reported blood group alleles. This survey was designed to evaluate new molecular blood group genotyping methods and compile reference blood group data sets for Polynesian and Maori subjects. Subsequent analyses of these results were used to calculate probability of random match, to trace Polynesian ancestry and migration patterns and to reveal past and present episodes of genetic admixture. Genomic DNA samples from Maori and Polynesian subjects were drawn from the Victoria University of Wellington DNA Bank and genotyped using combination of commercial PCR-SSP kits, hybridization SNP assay services or sequence-based typing. This survey also involves compilation of serological ABO and Rhesus blood group data from RakaiPaaka Iwi tribal members for comparison with those generated during our molecular blood group study. We observed perfect consistency between results obtained from all molecular methods for blood group genotyping. The A, O, DCcEe, DCCee, MNs, K-k+, Jk(a+b-), Jk(a+b+), Fy(a+b-), Fy(a+b+), Di(a+b-), Co(a+b-) and Do(a-b+) were predominant blood group phenotypes in both Polynesians and Maori. Overall, our survey data show only small differences in distributions of blood group phenotypes between Polynesian and Maori groups and their subgroups. These differences might be associated with selection, population history and gene flow from Europeans. In each case, we estimate that patients with certain blood groups have a very low probability of an exact phenotypic match, even if the patients were randomly transfused with blood from donors of their own ethnicity. The best way to avoid haemolytic transfusion reaction in such cases is to perform a pretransfusion cross-match and recruit increased numbers of donors with rare phenotype profiles. The conclusion of this study is that application of molecular method covering as many known variants as possible may help to improve the accuracy blood group genotyping and potentially conserve the routine requirements of transfusion centres.

Human platelet antigens frequencies in Maori and Polynesian populations

BACKGROUND

Allele frequencies of human platelet antigens (HPA) reflect population history and possibility of platelet-specific alloimmunization. Here, we report on screening of variants at HPA loci for Polynesian and Maori subjects.

OBJECTIVES

Our aims are to evaluate new HPA genotyping methods, compile and analyse new HPA datasets for these subjects, use HPA data for tracing ancestry, migration patterns, genetic admixture and its potential influence on health.

MATERIALS AND METHODS

A total of 75 Maori and 25 Polynesian DNA samples were genotyped using commercial BAGene HPA-TYPE DNA-SSP kits, BLOODchip hybridization SNP assays and DNA sequence based typing.

RESULTS

Genotyping was successful and cross validation of PCR-SSP and BLOODchip gave 100% agreement. Among the HPA loci tested, only six are dimorphic (HPA-1 to -3, -5, -6 and -15) and all others are monomorphic. The Polynesians and Maori have the 'a' allele form as the most common for all loci except HPA-15.

CONCLUSIONS

The newly observed HPA data as well as principal coordinate analysis clearly indicate genetic contributions from both, Asia and Australasia in Maori and Polynesian populations together with recent admixture with Europeans. In addition, different prevalences of HPA alleles among Polynesian, Maori and European populations contribute towards different risk profiles for platelet-specific alloimmunization. This is the first report for these populations and our findings are of direct practical relevance for blood transfusion centres, the management of pregnancies, assessment of neonatal alloimmune thrombocytopenia and management of multi-transfused patients.

Three cases of disputed paternity in dogs resolved by the use of DNA fingerprinting

DNA fingerprinting with the probes 33.15 and alpha-globin 3'HVR has been used to resolve three cases of disputed paternity in dogs. For each pedigree it was necessary to establish which bands in the DNA fingerprints of the offspring were of paternal origin, and then establish which putative sire carried all these bands. In the first case, a litter of Rhodesian Ridgebacks, twelve DNA bands were informative in establishing paternity. In the second case, a litter of Afghan hounds, five DNA bands established paternity, Lastly, in a litter of Border collies, five DNA bands established paternity. In each case a single dog only sired the entire litter.

Phylogeography of the New Zealand cicada Maoricicada campbelli based on mitochondrial DNA sequences: ancient clades associated with cenozoic environmental change

New Zealand's isolation, its well-studied rapidly changing landscape, and its many examples of rampant speciation make it an excellent location for studying the process of genetic differentiation. Using 1520 base pairs of mitochondrial DNA from the cytochrome oxidase subunit I, ATPase subunits 6 and 8 and tRNA(Asp) genes, we detected two well-differentiated, parapatrically distributed clades within the widespread New Zealand cicada species Maoricicada campbelli that may prove to represent two species. The situation that we uncovered is unusual in that an ancient lineage with low genetic diversity is surrounded on three sides by two recently diverged lineages. Using a relaxed molecular clock model coupled with Bayesian statistics, we dated the earliest divergence within M. campbelli at 2.3 +/- 0.55 million years. Our data suggest that geological and climatological events of the late Pliocene divided a once-widespread species into northern and southern components and that near the middle of the Pleistocene the northern lineage began moving south eventually reaching the southern clade. The southern clade seems to have moved northward to only a limited extent. We discovered five potential zones of secondary contact through mountain passes that will be examined in future work. We predict that, as in North American periodical cicadas, contact between these highly differentiated lineages will exist but will not involve gene flow.

Maori origins, Y-chromosome haplotypes and implications for human history in the Pacific

An assessment of 28 pertinent binary genetic markers on the non-recombining portion of the Y chromosome (NRY) in New Zealand Maori and other relevant populations has revealed a diverse genetic paternal heritage of extant Maori. A maximum parsimony phylogeny was constructed in which nine of the 25 possible binary haplotypes were observed. Although approximately 40% of the samples have haplotypes of unequivocal European origin, an equivalent number of samples have a single binary haplotype that is also observed in Indonesia and New Guinea, indicative of common indigenous Melanesian ancestry. The balance of the lineages has either typical East Asian signatures or alternative compositions consistent with their affinity to Melanesia or New Guinea. Molecular analysis of mtDNA variation confirms the presence of a single predominant characteristic Southeast Asian (9-bp deletion in the Region V) lineage. The Y-chromosome results support a pattern of complex interrelationships between Southeast Asia, Melanesia, and Polynesia, in contrast to mtDNA and linguistic data, which uphold a rapid and homogeneous Austronesian expansion. The Y-chromosome data highlight a distinctive gender-modulated pattern of differential gene flow in the history of Polynesia.

Evaluating hypotheses on the origin and evolution of the New Zealand alpine cicadas (Maoricicada) using multiple-comparison tests of tree topology

The statistical testing of alternative phylogenetic trees is central to evaluating competing evolutionary hypotheses. Fleming proposed that the New Zealand cicada species Maoricicada iolanthe is the sister species to the major radiation of both low-altitude and montane Maoricicada species. However, using 1,520 bp of mitochondrial DNA sequence data from the cytochrome oxidase subunit I, tRNA aspartic acid, and the ATPase subunit 6 and 8 genes, we inferred that both M. iolanthe and another low-altitude species, Maoricicada campbelli, are nested within the montane Maoricicada radiation. Therefore, we examined the stability of the inferred phylogenetic placement of these two species using the newly developed Shimodaira-Hasegawa test (SH test) implemented in a maximum-likelihood framework. The SH test has two advantages over the more commonly used Kishino-Hasegawa (KH) and Templeton tests. First, the SH test simultaneously compares multiple topologies and corrects the corresponding P: values to accommodate the multiplicity of testing. Second, the SH test is correct when applied to a posteriori hypotheses, unlike the KH test, because it readjusts the expectation of the null hypothesis (that two trees are not different) accordingly. The comparison of P: values estimated under the assumptions of both the KH test and the SH test clearly demonstrate that the KH test has the potential to be misleading when the issue of comparing of a posteriori hypotheses is ignored and when multiple comparisons are not taken into account. The SH test, in combination with a variety of character-weighting schemes applied to our data, reveals a surprising amount of ambiguity in the phylogenetic placement of M. iolanthe and M. campbelli.

Exploring among-site rate variation models in a maximum likelihood framework using empirical data: effects of model assumptions on estimates of topology, branch lengths, and bootstrap support

We have investigated the effects of different among-site rate variation models on the estimation of substitution model parameters, branch lengths, topology, and bootstrap proportions under minimum evolution (ME) and maximum likelihood (ML). Specifically, we examined equal rates, invariable sites, gamma-distributed rates, and site-specific rates (SSR) models, using mitochondrial DNA sequence data from three protein-coding genes and one tRNA gene from species of the New Zealand cicada genus Maoricicada. Estimates of topology were relatively insensitive to the substitution model used; however, estimates of bootstrap support, branch lengths, and R-matrices (underlying relative substitution rate matrix) were strongly influenced by the assumptions of the substitution model. We identified one situation where ME and ML tree building became inaccurate when implemented with an inappropriate among-site rate variation model. Despite the fact the SSR models often have a better fit to the data than do invariable sites and gamma rates models, SSR models have some serious weaknesses. First, SSR rate parameters are not comparable across data sets, unlike the proportion of invariable sites or the alpha shape parameter of the gamma distribution. Second, the extreme among-site rate variation within codon positions is problematic for SSR models, which explicitly assume rate homogeneity within each rate class. Third, the SSR models appear to give severe underestimates of R-matrices and branch lengths relative to invariable sites and gamma rates models in this example. We recommend performing phylogenetic analyses under a range of substitution models to test the effects of model assumptions not only on estimates of topology but also on estimates of branch length and nodal support.

The expectations of patients undergoing revision hip arthroplasty

Sixty patients were prospectively assessed using the Western Ontario and McMaster Osteoarthritis Index (WOMAC) scale for osteoarthritis of the hip and the Short Form 36 (SF-36) general health status scale as well as the expectation WOMAC, which asked patients to estimate how they expected to feel 6 months after revision hip arthroplasty. There was a wide range of expectations, but we were unable to find any significant correlation between the patients' preoperative pain and stiffness levels and their expectations for pain and stiffness after revision hip arthroplasty. There was no significant correlation between the SF-36 scores and the patients' expectations. Our findings suggest that the expectations of patients awaiting revision hip arthroplasties are high and are not related closely to the level of preoperative disability.

Microsatellites: consensus and controversy

Microsatellite DNA loci have recently been adopted for many biological applications. Comparative studies across a wide range of species has revealed many details of their mutational properties and evolutionary life cycles. Experience shows that a full understanding of these processes is essential to ensure the effective use of microsatellites as analytical tools. In this article, we review the controversies that have arisen as biologists have taken up this new technology and the emerging consensus that has resulted from their debates. We point to the need for comparative DNA sequencing studies to produce input data for a new generation of theoretical models of microsatellite behaviour. We conclude by presenting our own conceptual model, 'Snakes and Ladders', as an aid to theory development.

An assessment of the use of intravesical potassium in the diagnosis of interstitial cystitis

PURPOSE

We evaluated the use of intravesical potassium in the diagnosis of interstitial cystitis.

MATERIALS AND METHODS

A blinded test assessment on 39 consecutive subjects attending our urology clinic for the evaluation of symptoms consistent with interstitial cystitis was performed. The pain response to intravesical potassium and water as a control was measured. The response rate was compared to the results of cystoscopy using standard outcome measures associated with diagnostic test assessment.

RESULTS

The probability of having interstitial cystitis given a positive intravesical potassium test was 66%. This finding added no new useful information and would not be helpful with clinical decisions as the probability of having interstitial cystitis in this population was already 56% before the test. Similarly, if the test was negative then 46% or nearly half of the subjects were still likely to have interstitial cystitis. Therefore, a negative test would have no ability to rule out disease nor would it be useful in making clinical decisions about how to proceed with evaluation or therapy. Test characteristics were considered poor with a sensitivity of 69.5% and a specificity of 50%. Likelihood ratios (positive 1.39, negative 0.61) also indicated poor inclusion and exclusion capabilities.

CONCLUSIONS

The general use of intravesical potassium as a diagnostic test for interstitial cystitis is not validated. The diagnosis of interstitial cystitis must depend on the clinical presentation and endoscopic findings based on National Institutes of Health criteria.

The albumin of the brown trout (Salmo trutta) is a glycoprotein

The albumin from an Atlantic salmonid, the brown trout (Salmo trutta), is 1730 Da higher in molecular mass than the albumin from a Pacific salmonid, the chinook salmon (Oncorhynchus tshawytscha), at 65230 Da. Digestion with neuraminidase revealed that purified brown trout albumin contained sialic acid while chinook salmon albumin did not. Concanavalin A-sepharose affinity chromatography was used to purify a glycopeptide from a total tryptic digest of brown trout albumin. The mass of this glycopeptide (3815 Da) was determined by mass spectrometry, and the sequence largely confirmed by N-terminal sequencing. The identified sequence of IAHCCNQSYSM-, contains an Asn-Gln-Ser glycosylation site and is identical to residues 475-485 derived from the cDNA of the albumin from the Atlantic salmon, the closest relative of the brown trout. Glycosylation of albumin is very unusual, and has not been identified in either reptilian or mammalian albumins. The finding of a glycoalbumin in salmonids, ancient members of the teleost fish subclass, coupled with evidence of albumin glycosylation in the oldest vertebrates, agnathans, as well as amphibians, suggests that albumin was originally a glycoprotein, but lost this modification sometime between the divergence of amphibians and reptiles.

Purification and partial amino acid sequences of two distinct albumins from turtle plasma

Two putative albumins, denoted Alb-1 (apparent molecular mass of 67 kDa) and Alb-2 (68 kDa), were purified from plasma of the emydid turtle (Trachemys scripta). Concentrations in serum or plasma were determined by radioimmunoassay using 125I-labeled Alb-1. In juvenile turtles (less than 2 years of age), serum concentrations of Alb-1 and Alb-2 were 2.72 +/- 0.23 mg/ml and 1.68 +/- 0.22 mg/ml, respectively, while concentrations in plasma pooled from adult turtles were 4.2 mg/ml and 2.6 mg/ml, respectively. The two albumins are immunologically distinct from one another as determined by both radioimmunoassay with 125I-labeled Alb-1 and Western blot analysis with antichicken albumin antiserum. Determination of the amino acid compositions of Alb-1 and Alb-2, and of albumin purified from plasma of the common snapping turtle (Chelydra serpentina), suggested that Alb-1 is more similar to albumins of other animals than is Alb-2. This was also indicated by Western blot analysis and by determining the N-terminal amino acid sequences of Alb-1 (40 residues) and Alb-2 (15 residues). Thus, it appears that two distinct forms of albumin are synthesized by T. scripta, possibly as a result of gene duplication and divergence.

Purification, partial characterization and peptide sequences of vitellogenin from a reptile, the tuatara (Sphenodon punctatus)

Vitellogenin (Vg), a major precursor to egg yolk proteins, was purified from plasma of an estradiol-treated female tuatara (Sphenodon punctatus) by MgCl2-EDTA precipitation and DEAE-cellulose chromatography. The amino acid composition of tuatara Vg is similar to that of other vertebtate Vgs and contains a large proportion of serine (13.7 mol/100 mol of total amino acid). The amino acid sequences of the N-terminus of mature Vg (33 residues) and of several trypsin- and CNBr-generated peptides were determined. Six peptide sequences obtained from tuatara Vg could be aligned with Vg sequences from other vertebrates. Reduced and non-reduced forms of tuatara Vg have the same apparent molecular mass (approximately 218 kDa) when resolved by SDS-PAGE, indicating that inter-chain disulfide bonds are not a feature of the molecule in this species. Western blot analysis with anti-tuatara Vg antiserum indicated that at least some epitopes are shared among Vgs of turtle, alligator and tuatara.

Genetic variation of southern hemisphere fur seals (Arctocephalus spp.): investigation of population structure and species identity

We have examined phylogenetic and geographic patterns of variation in the mitochondrial cytochrome b gene of Southern Hemisphere fur seals (Arctocephalus spp.). Our survey of 106 individuals from four putative species reveals three distinct patterns of variation reflecting ancient, recent historic, and contemporary gene flow. For the combined samples of Subantarctic (Arctocephalus tropicalis) and Antarctic (Arctocephalus gazella) fur seals, we find low levels of sequence diversity and reciprocal paraphyly of hapiotypes (where representative haplotypes of a species are found to occur infrequently in another species and vice versa). For the Australian and Cape fur seal subspecies (Arctocephalus pusillus doriferus and A. p. pusillus, respectively), we find low levels of sequence diversity but significant differences in the regional distribution of haplotypes that are consistent with, but not conclusive of, the current subspecies definition based on nonmolecular data. For the New Zealand fur seal (Arctocephalus forsteri), we find high levels of average sequence diversity because of the survival of two divergent lineages of mitochondrial hapiotypes with differences approaching that found in interspecific comparisons of other mammals. The two divergent clades are distributed sympatrically in some regions, but the overall geographic structure of the variation is significant across the range of this species. These new molecular data are inconsistent with current taxonomic definitions of species within the Southern Hemisphere fur seals and argue for reevaluation of these "species" definitions. For management purposes, the definition of evolutionarily significant units (Ryder 1986) and genetic management units (Moritz 1994) in relation to these species may also be evaluated in light of this molecular genetic information.

Simulated dose reduction in conventional chest CT: validation study

PURPOSE

To validate a technique of computer-simulated dose reduction for conventional chest computed tomography (CT).

MATERIALS AND METHODS

In 27 patients, CT scans were obtained at 200, 100, and 40 mAs at two levels. The raw data from the 200-mAs scan were modified on a computer workstation to simulate the increased noise present on 100- and 40-mAs scans. Real and simulated 100- and 40-mAs images were independently assessed in random order for overall image quality and radiologic findings by four subspecialty-trained chest radiologists who were blinded to the technique. The four observers were given paired real and simulated images. They were asked to identify the real image and note any difference in diagnostic quality.

RESULTS

No difference was seen in overall image quality or radiologic findings between real and simulated images (P > .05). In the paired comparison, 433 of 864 (50.1%) real images were correctly identified.

CONCLUSION

Computer modification of 200-mAs raw scan data to simulate 100- and 40-mAs noise levels produces reconstructed images indistinguishable from real 100- and 40-mAs scans. This technique provides realistic reduced-dose images without patient radiation exposure and with identical image registration and motion artifact.

Identification and partial characterization of alpha 2-macroglobulin from the tuatara (Sphenodon punctatus)

alpha 2-Macroglobulin (alpha 2-M), a large molecular mass proteinase-binding protein, was identified in plasma from tuatara (Sphenodon), a rare reptile endemic to New Zealand. In this genus, alpha 2-M constitutes 11-13% of total plasma protein (approximately 2.2-3.9 mg/mL). Analysis of blood samples collected at approximately monthly intervals from individual tuatara indicated that the plasma level of alpha 2-M remains fairly constant. The subunits of tuatara alpha 2-M have an apparent molecular mass of approximately 160 kDa as determined by SDS-polyacrylamide gel electrophoresis and the intact protein is an oligomer that contains inter-chain disulfide bonds. N-terminal sequence analyses of tuatara alpha 2-M revealed a distinct similarity to alpha-macroglobulins of other vertebrates and that at least two types of alpha 2-M subunits are present in plasma of tuatara.

New Zealand population data at five VNTR loci: validation as databases for forensic identity testing

Databases were developed for three New Zealand ethnic groups (Caucasian, Maori and Polynesian), at five VNTR loci (D1S7, D2S44, D4S139, D5S110 and D12S11), and validated for interpretation of forensic identity tests. A +/-2.8% sliding window was used to define the alleles at each locus and allelic frequency distributions were obtained for each locus. The conservative nature of the sliding window approach for forensic casework was demonstrated. Tests for independence of alleles within and between loci showed good agreement with the expectation of independence. Although Polynesians are known to have reduced genetic diversity at some VNTR loci, this was found not to be a concern for the present methodology. Procedures for the analysis and reporting of DNA profile results used by New Zealand forensic scientists are therefore appropriate.

Assessment of the appropriateness of services provided by a multidisciplinary meningomyelocele clinic

Since 1969, the Meningomyelocele Clinic at British Columbia's Children's Hospital has been serving the needs of children with spina bifida. In 1994, the clinic provided urgent and routine multidisciplinary clinical assessments to 330 patients and families. The purpose of this study was to assess, from the patients' and families' perspective, the appropriateness of the frequency of routine clinic visits and the value of the health services provided. Sixty-five patients/families were interviewed and completed a questionnaire developed by the clinic. Current visit frequency and services provided appear to meet the patient/family needs. The medical and nursing contributions were seen as valuable resources for the patient/families resulting in most patient/families feeling well informed about spina bifida.

Inference of population subdivision from the VNTR distributions of New Zealanders

A population sample from people of diverse ethnic origins living in New Zealand serves as a database to test methods for inference of population subdivision. The initial null hypothesis, that the population sample is homogeneous across ethnic groups, is easily rejected by likelihood ratio tests. Beyond this, methods for quantifying subdivision can be based on the probability of drawing alleles identical by descent (FST), probabilities of matching multiple locus genotypes, and occurrence of unique alleles. Population genetic theory makes quantitative predictions about the relation between FST, population sizes, and rates of migration and mutation. Some VNTR loci have mutation rates of 10(-2) per generation, but, contrary to theory, we find no consistent association between the degree of population subdivision and mutation rate. Quantification of population substructure also allows us to relate the magnitudes of genetic distances between ethnic groups in New Zealand to the colonization history of the country. The data suggests that the closest relatives to the Maori are Polynesians, and that no severe genetic bottleneck occurred when the Maori colonized New Zealand. One of the central points of contention regarding the application of VNTR loci in forensics is the appropriate means for estimating match probabilities. Simulations were performed to test the merits of the product rule in the face of subpopulation heterogeneity. Population heterogeneity results in large differences in estimates of multilocus genotype frequencies depending on which subpopulation is used for reference allele frequencies, but, of greater importance for forensic purposes, no five locus genotype had an expected frequency greater than 10(-6). Although this implies that a match with an innocent individual is unlikely, in a large urban area such chance matches are going to occur.

Identification of a 130-kDa albumin in tuatara (Sphenodon) and detection of a novel albumin polymorphism

Electrophoretic, immunochemical, and protein sequence analyses were performed on plasma albumin of the tuatara (Sphenodon), a rare reptile endemic to New Zealand. The analyses revealed that, unlike other terrestrial vertebrates, tuatara do not seem to possess a 60- to 75-kDa plasma albumin. The common form of plasma albumin in this genus has an apparent molecular mass of 130 kDa, making it by far the largest albumin reported for any terrestrial vertebrate. Starch gel electrophoresis of samples from tuatara on 24 of the 30 islands inhabited by this genus resolved two forms of the 130-kDa albumin (albumins A and C). A third albumin of approximately 170 kDa (albumin B), reflecting a novel alloalbuminemia, was found in tuatara in three geographically isolated populations. Albumin A appears to be restricted to populations at the southern extremity of the tuatara's distribution, while albumin C was found in all but four (southern) populations. Possible explanations for the origin and distribution of these albumins are discussed.

Use of spectral analysis to test hypotheses on the origin of pinnipeds

The evolutionary origin of the pinnipeds (seals, sea lions, and walruses) is still uncertain. Most authors support a hypothesis of a monophyletic origin of the pinnipeds from a caniform carnivore. A minority view suggests a diphyletic origin with true seals being related to the mustelids (otters and ferrets). The phylogenetic relationships of the walrus to other pinniped and carnivore families are also still particularly problematic. Here we examined the relative support for mono- and diphyletic hypotheses using DNA sequence data from the mitochondrial small subunit (12S) rRNA and cytochrome b genes. We first analyzed a small group of taxa representing the three pinniped families (Phocidae, Otariidae, and Odobenidae) and caniform carnivore families thought to be related to them. We inferred phylogenetic reconstructions from DNA sequence data using standard parsimony and neighbor-joining algorithms for phylogenetic inference as well as a new method called spectral analysis (Hendy and Penny) in which phylogenetic information is displayed independently of any selected tree. We identified and compensated for potential sources of error known to lead to selection of incorrect phylogenetic trees. These include sampling error, unequal evolutionary rates on lineages, unequal nucleotide composition among lineages, unequal rates of change at different sites, and inappropriate tree selection criteria. To correct for these errors, we performed additional transformations of the observed substitution patterns in the sequence data, applied more stringent structural constraints to the analyses, and included several additional taxa to help resolve long, unbranched lineages in the tree. We find that there is strong support for a monophyletic origin of the pinnipeds from within the caniform carnivores, close to the bear/raccoon/panda radiation. Evidence for a diphyletic origin was very weak and can be partially attributed to unequal nucleotide compositions among the taxa analyzed. Subsequently, there is slightly more evidence for grouping the walrus with the eared seals versus the true seals. A more conservative interpretation, however, is that the walrus is an early, but not the first, independent divergence from the common pinniped ancestor.

Plasma concentrations of vitellogenin and sex steroids in female tuatara (Sphenodon punctatus punctatus) from northern New Zealand

Vitellogenesis in tuatara (Sphenodon punctatus) on Stephens Island, New Zealand, at the southern (coolest) end of the geographical range of this species involves a prolonged period of about 3 years of the average 4-year reproductive cycle. These studies used a semiquantitative electrophoretic assay for vitellogenin (Vg). In the present study an ELISA was used to measure plasma levels of Vg in 138 female northern tuatara (S.p. punctatus) on 11 islands at the warmest end of the tuatara's range. Blood samples were collected in late summer-early autumn, just prior to the expected time of ovulation in those females that would nest the following spring. Plasma Vg levels ranged from nondetectable to 2.9 mg/ml but were not significantly correlated with plasma estradiol, testosterone, or progesterone levels. There was also no significant correlation among the three sex steroids. Plasma Vg and hormone levels were further examined as to whether females were ovulating. Incipient ovulation was inferred using endocrinological criteria derived from studies of tuatara on Stephens Island (i.e., elevated plasma testosterone). Plasma levels of Vg differed significantly between inferred ovulators and nonovulators when data for all islands were combined, although similar ranges were observed in the two groups of females (inferred ovulators: nondetectable to 2382 micrograms/ml, mean = 505 +/- 75; inferred nonovulators: nondetectable to 2864 micrograms/ml, mean = 460 +/- 63). Plasma levels of estradiol, but not progesterone, differed significantly between inferred ovulators and nonovulators when data for all islands were combined. Mean levels in inferred ovulators were: estradiol, 157 +/- 16 pg/ml (vs. 34 +/- 5 pg/ml in inferred nonovulators); progesterone, 1.1 +/- 0.2 ng/ml (vs. 0.7 +/- 0.1 ng/ml in inferred nonovulators); and testosterone, 5.6 +/- 0.5 ng/ml (vs. 0.2 +/- 0 ng/ml in inferred nonovulators). Only 37% of the females sampled met the minimum hormonal criteria indicative of ovulation. This suggests that, as in S. punctatus on Stephens Island, female S.p. punctatus on northern islands do not ovulate each year.

A short-term study of nitrofurantoin prophylaxis in children managed with clean intermittent catheterization

OBJECTIVE

Because there is no evidence for the effectiveness of antibiotic prophylaxis in children with neurogenic bladder, the value of once-daily nitrofurantoin macrocrystals was assessed in a selected population with neurogenic bladder due to meningomyelocele. METHODS AND TRIAL POPULATION: Children with significant urinary tract abnormalities other than neurogenic bladder were excluded. A urinary tract "infection" was defined as > or = 10(8) colony forming units of bacteria/L of urine together with pyuria of > or = 50 x 10(6) leukocytes/L, and/or symptoms consistent with an urinary tract infection. Fifty-six children participated in a 24-week double-blinded, placebo-controlled cross-over study. The infection status was assessed at two weekly intervals or if relevant clinical manifestations occurred.

RESULTS

For the whole trial the average percentage of "infections" per urine sample for each patient was reduced from 39% on placebo to 19% on single daily dose prophylaxis (P < .0003). For the first 12 weeks of the trial corresponding figures were 45% on placebo and 22% on prophylaxis (P < .0018). There was evidence for a marked carryover protective effect of nitrofurantoin into the placebo arm of the trial.

CONCLUSION

Nitrofurantoin is an effective prophylactic agent during a 3-month period. Long-term studies are needed to confirm the reasonable expectation of a beneficial effect on urinary tract damage.