bluuebunny/crossref_metadata_2025 huggingface dataset:
OsDREB genes in rice, Oryza sativa L., encode transcription activators that function in drought‐, high‐salt‐ and cold‐responsive gene expression
Authors: Dubouzet Joseph G. , Sakuma Yoh , Ito Yusuke , Kasuga Mie , Dubouzet Emilyn G. , Miura Setsuko , Seki Motoaki , Shinozaki Kazuo , Yamaguchi‐Shinozaki Kazuko
Published: March 2003

The transcription factors DREBs/CBFs specifically interact with the dehydration‐responsive element/C‐repeat (DRE/CRT) cis‐acting element (core motif: G/ACCGAC) and control the expression of many stress‐inducible genes in Arabidopsis. In rice, we isolated five cDNAs for DREB homologs: OsDREB1A, OsDREB1B, OsDREB1C, OsDREB1D, and OsDREB2A. Expression of OsDREB1A and OsDREB1B was induced by cold, whereas expression of OsDREB2A was induced by dehydration and high‐salt stresses. The OsDREB1A and OsDREB2A proteins specifically bound to DRE and activated the transcription of the GUS reporter gene driven by DRE in rice protoplasts. Over‐expression of OsDREB1A in transgenic Arabidopsis induced over‐expression of target stress‐inducible genes of Arabidopsis DREB1A resulting in plants with higher tolerance to drought, high‐salt, and freezing stresses. This indicated that OsDREB1A has functional similarity to DREB1A. However, in microarray and RNA blot analyses, some stress‐inducible target genes of the DREB1A proteins that have only ACCGAC as DRE were not over‐expressed in the OsDREB1A transgenic Arabidopsis. The OsDREB1A protein bound to GCCGAC more preferentially than to ACCGAC whereas the DREB1A proteins bound to both GCCGAC and ACCGAC efficiently. The structures of DREB1‐type ERF/AP2 domains in monocots are closely related to each other as compared with that in the dicots. OsDREB1A is potentially useful for producing transgenic monocots that are tolerant to drought, high‐salt, and/or cold stresses.
A Mak‐like kinase is a repressor of GAMYB in barley aleurone
Authors: Woodger Fiona J. , Gubler Frank , Pogson Barry J. , Jacobsen John V.
Published: March 2003

GAMYB is a gibberellin (GA)‐regulated activator of hydrolase gene expression in the aleurone layer of germinating cereal grains. Although it is clear that GAMYB expression is regulated by GA, more remains to be understood about how this transcription factor operates within the GA‐response pathway. In order to isolate new components from the GA‐response pathway, barley aleurone libraries were screened for GAMYB‐binding proteins using a recently developed yeast two‐hybrid system, which is compatible with the use of transcription factors as baits. We isolated a new member of the emerging Mak‐subgroup of cdc2‐ and MAP kinase‐related protein kinases. We have termed this GAMYB‐binding protein KGM (for kinase associated with GAMYB). Transient expression of KGM specifically repressed α‐amylase promoter activity at the level of GAMYB function but a mutation designed to de‐stabilise the activation loop of KGM alleviated this repression. We propose that KGM is a negative regulator of GAMYB function in aleurone that may prevent precocious hydrolase gene expression.
Phytochrome control of flowering is temperature sensitive and correlates with expression of the floral integrator FT
Authors: Halliday Karen J. , Salter Michael G. , Thingnaes Elin , Whitelam Garry C.
Published: March 2003

In Arabidopsis flowering is accelerated by reduced red:far‐red (R:FR) ratio which signals the presence of neighbouring vegetation. Hastened flowering is one component of the shade‐avoidance syndrome of responses, which alter many aspects of development in response to the threat of potential competition. Of the red/far‐red‐absorbing photoreceptors it is phyB that plays the most prominent role in shade‐avoidance, although other related phytochromes act redundantly with phyB. It is well established that the phyB mutant has a constitutively early flowering phenotype. However, we have shown that the early flowering phenotype of phyB is temperature‐dependent. We have established that this temperature‐sensitive flowering response defines a pathway that appears to be independent of the autonomous‐FLC pathway. Furthermore, we have demonstrated that the phytochromes control the expression of the floral promoter FT. We have also shown that other phyB‐controlled responses, including petiole elongation, are not sensitive to the same temperature change. This suggests that discrete pathways control flowering and petiole elongation, components of the shade‐avoidance response. This work provides an insight into the phytochrome and temperature interactions that maintain flowering control.
Retracted: An enhanced transient expression system in plants based on suppression of gene silencing by the p19 protein of tomato bushy stunt virus
Authors: Voinnet Olivier , Rivas Susana , Mestre Pere , Baulcombe David
Published: March 2003

Transient gene expression is a fast, flexible and reproducible approach to high‐level expression of useful proteins. In plants, recombinant strains of Agrobacterium tumefaciens can be used for transient expression of genes that have been inserted into the T‐DNA region of the bacterial Ti plasmid. A bacterial culture is vacuum‐infiltrated into leaves, and upon T‐DNA transfer, there is ectopic expression of the gene of interest in the plant cells. However, the utility of the system is limited because the ectopic protein expression ceases after 2–3 days. Here, we show that post‐transcriptional gene silencing (PTGS) is a major cause for this lack of efficiency. We describe a system based on co‐expression of a viral‐encoded suppressor of gene silencing, the p19 protein of tomato bushy stunt virus (TBSV), that prevents the onset of PTGS in the infiltrated tissues and allows high level of transient expression. Expression of a range of proteins was enhanced 50‐folds or more in the presence of p19 so that protein purification could be achieved from as little as 100 mg of infiltrated leaf material. The effect of p19 was not saturated in cells that had received up to four individual T‐DNAs and persisted until leaf senescence. Because of its simplicity and rapidity, we anticipate that the p19‐enhanced expression system will have value in industrial production as well as a research tool for isolation and biochemical characterisation of a broad range of proteins without the need for the time‐consuming regeneration of stably transformed plants.
Arabidopsisgene expression changes during cyst nematode parasitism revealed by statistical analyses of microarray expression profiles
Authors: Puthoff David P. , Nettleton Dan , Rodermel Steven R. , Baum Thomas J.
Published: March 2003

With the availability of microarray technology, the expression profiles of thousands of genes can be monitored simultaneously to help determine the mechanisms of these biological processes. We conducted Affymetrix GeneChip microarray analyses of theArabidopsis–cyst nematode interaction and employed a statistical procedure to analyze the resultant data, which allowed us to identify significant gene expression changes. Quantitative real‐time RT‐PCR assays were used to confirm the microarray analyses. The results of the expression profiling revealed 128 genes with altered steady‐state mRNA levels following infection by the sugar beet cyst nematode (Heterodera schachtii; BCN), in contrast to only 12 genes that had altered expression following infection by the soybean cyst nematode (H. glycines; SCN). The expression of these 12 genes also changed following infection by BCN, i.e. we did not identify any genes regulated exclusively by SCN. The identification of 116 genes whose expression changes during successful cyst nematode parasitism by BCN suggests a potential involvement of these genes in the infection events starting with successful syncytium induction. Further characterization of these genes will permit the formulation of testable hypotheses to explain successful cyst nematode parasitism.
CYP79F1 and CYP79F2 have distinct functions in the biosynthesis of aliphatic glucosinolates in Arabidopsis
Authors: Chen Sixue , Glawischnig Erich , Jørgensen Kirsten , Naur Peter , Jørgensen Bodil , Olsen Carl‐Erik , Hansen Carsten H. , Rasmussen Hasse , Pickett John A. , Halkier Barbara A.
Published: March 2003

Cytochromes P450 of the CYP79 family catalyze the conversion of amino acids to oximes in the biosynthesis of glucosinolates, a group of natural plant products known to be involved in plant defense and as a source of flavor compounds, cancer‐preventing agents and bioherbicides. We report a detailed biochemical analysis of the substrate specificity and kinetics of CYP79F1 and CYP79F2, two cytochromes P450 involved in the biosynthesis of aliphatic glucosinolates in Arabidopsis thaliana. Using recombinant CYP79F1 and CYP79F2 expressed in Escherichia coli and Saccharomyces cerevisiae, respectively, we show that CYP79F1 metabolizes mono‐ to hexahomomethionine, resulting in both short‐ and long‐chain aliphatic glucosinolates. In contrast, CYP79F2 exclusively metabolizes long‐chain elongated penta‐ and hexahomomethionines. CYP79F1 and CYP79F2 are spatially and developmentally regulated, with different gene expression patterns. CYP79F2 is highly expressed in hypocotyl and roots, whereas CYP79F1 is strongly expressed in cotyledons, rosette leaves, stems, and siliques. A transposon‐tagged CYP79F1 knockout mutant completely lacks short‐chain aliphatic glucosinolates, but has an increased level of long‐chain aliphatic glucosinolates, especially in leaves and seeds. The level of long‐chain aliphatic glucosinolates in a transposon‐tagged CYP79F2 knockout mutant is substantially reduced, whereas the level of short‐chain aliphatic glucosinolates is not affected. Biochemical characterization of CYP79F1 and CYP79F2, and gene expression analysis, combined with glucosinolate profiling of knockout mutants demonstrate the functional role of these enzymes. This provides valuable insights into the metabolic network leading to the biosynthesis of aliphatic glucosinolates, and into metabolic engineering of altered aliphatic glucosinolate profiles to improve nutritional value and pest resistance.
Neonatal thrombocytopenia in two of six human platelet alloantigen (HPA) 5a‐positive children of an HPA‐5a‐immunized mother
Authors: Kekomäki  , Koskela  , Laes  , Teramo  , Kekomäki
Published: March 2003

We describe a human platelet alloantigen (HPA) 5a‐alloimmunized HPA‐5b5b mother. The children were obligatory heterozygotes for HPA‐5a but despite IgG class maternal anti‐HPA‐5a antibodies only two (second and fifth) of the six children developed neonatal thrombocytopenia. Throughout the 4‐year follow‐up the mother had anti‐HPA‐5a antibodies (confirmed in the 8th Platelet serology workshop of International Society of Blood Transfusion in 1996). Antibodies against glycoproteins (GP) IIbIIIa or IbIX were not detected. Differences in the children's HPA type (HPA‐1, ‐2, ‐3, ‐5) did not correlate with thrombocytopenia. We hypothesized that different expression of GPIaIIa recently associated with two silent polymorphisms (C807T and G873A) of GPIa could explain the unpredictable recurrence pattern of neonatal alloimmune thrombocytopenia (NAIT). Both parents were homozygous for the silent polymorphisms (C807 and G873) associated with the low expression of GP Ia. Thus, the inheritance pattern of the silent polymorphisms (C807T and G873A) did not help in predicting the recurrence risk of thrombocytopenia in the offspring. More detailed comprehension of the natural history of NAIT would be necessary to enable directing fetal blood sampling to the cases at the highest risk of thrombocytopenia.
Severe haemolysis after an ABO unmatched kidney transplant — a nonsecretor transplanted from a donor with high anti‐A titre
Authors: Sternberg  , Lee  , Croxton  , Mundy  , Morris  , Littlewood  , Murphy
Published: March 2003

A case of severe haemolysis following an ABO unmatched renal transplant is reported in a group A nonsecretor who received a kidney from a group O living related donor. Following the haemolytic episode, group A donor units were incompatible and the patient was transfused with group O blood. Serological investigation of the recipient revealed anti‐A present in the serum and on the red cells. Investigation of the donor revealed the presence of high‐titre anti‐A. The association of such high‐titre donor antibody with haemolysis in ABO unmatched grafts has not been reported before. We discuss the risk factors for developing haemolysis in an ABO unmatched organ transplant and explore the possible relevance of such high donor antibody titre to recipients who are nonsecretors.
European study of the antenatal management of fetomaternal alloimmune thrombocytopenia (FMAIT)
Authors: Birchall J. , Murphy M. F. , Kaplan C. , Kroll H.
Published: March 2003

FMAIT occurs in ∼1 in 1200 births, of which 10–20% have serious bleeding, i.e. intracranial haemorrhage (ICH). Management of such pregnancies needs to balance the risk of bleeding against the known risk of fetal blood sampling (FBS).

S tudy 

This was a nonrandomised observational study of FMAIT due to anti‐HPA‐1a. All cases were managed by an initial FBS, then a) intravenous immunoglobulin (IVIgG), b) regular intrauterine platelet transfusions (IUT), c) neither of above, but FBS ± 1 IUT predelivery, d) no treatment. All babies with a previous sibling known to have platelets < 20 × 109/L or an ICH were considered high risk.

R esults 

43 pregnancies (44 babies) were analysable giving 49 results in total (more than 1 management in 5).

In (a) there was one case with ICH. The resultant platelet count was ≥ 50 × 109/L in 10 cases, and 6 of these were high risk (5 ICH, 1plts < 20 × 109/L). No significant side‐effects of treatment occurred. In (b) the number of high risk cases was greater than (a) and there were 2 cases of ICH. The pre‐IUT platelet count was < 20 × 109/L on at least 50% of occasions in 10 cases. Overall 12 babies needed to be delivered because of complications caused by FBS/IUT, 4 at less than 32 weeks gestation. There were few cases in (c) and no cases in (d).

C onclusions 

The incidence of ICH in the study group is less than the incidence of ICH in untreated siblings. However, complications from FBS/IUT were significant, and the platelet count was not consistently maintained at > 20 × 109/L. Further studies are required to define the optimal antenatal management of FMAIT.
Large‐scale HPA‐1 epidemiological study in scotland: an up‐date
Authors: Bessos H. , Fagge T. , Wilson D. , Duncan J. , Harkness M. , Rentoul F. , Ahya R. , Armstrong‐Fisher S. , Urbaniak S. , Turner M.
Published: March 2003

Neonatal alloimmune thrombocytopenia (NAIT) in the Caucasian population is mainly due to a mismatch in the HPA‐1 marker between mother and foetus. About 10% of pregnant HPA‐1b women develop anti‐HPA‐1a antibodies (ab) which may lead to NAIT with possible intracranial haemorrhage and death or life long morbidity. The ab development is significantly correlated with HLA‐DRB3*0101. Although the frequency of homozygous HPA‐1b varies between 1·5 and 4·5%, the frequency of HPA‐1 NAIT detection in our laboratories was very low suggesting either that the epidemiology was different in Scotland or that the disease was being under‐reported. In August 1999 we began a two year study of HPA‐1 NAIT involving 25 000 pregnant women in Scotland. The aim of the study is to determine the frequency of HPA‐1b homozygosity, monitor ab levels during pregnancy, and assess the cost effectiveness of routine screening across Scotland. The HPA‐1 antigen and antibody assays consist of internationally validated ELISAs (Bessos et al. Transfusion, 38, 73S, 1998). The laboratory and clinical data are being collated using a Microsoft Access database. Of 11,500women screened to date in 3 Scottish regions, 216 are HPA‐1b homozygous (1·9%): 136/6841(2%) in Edinburgh; 67/3973 (1·69%) in Aberdeen; and 13/686 (1·9%) in Glasgow. So far, 11/145 (about 8%) consented HPA‐1b women are ab positive, with ab titres ranging from 1 : 2 to 1 : 256, but staying low or decreasing during pregnancy. Two have had previously affected babies and are being managed according to current guidelines. One woman with no previously affected children but with an ab titre declining from 1 : 256 to 1 : 32 during pregnancy, delivered recently a severely thrombocytopenic baby whose platelet counts rose to 137 × 109/L 3 days later. The mother's ab titre two weeks postdelivery rose back to 1 : 128. Due to observed interregional differences, our results caution prudence in the interpretation of regional vs. national epidemiological studies. Moreover, the overall HPA‐1b frequency in Scotland appears to be considerably higher than earlier indications, suggesting that NAIT may be under‐reported.
Clinical management and outcome for mother and child in suspected cases of NAITP
Authors: Husebekk A. , Jaegtvik S. , Killie M. K. , Aune B. , Oian P. , Dahl L.B. , Skogen B. R.
Published: March 2003

Severe thrombocytopenia of the newborn is most often caused by alloantibodies to platelet antigens (a‐HPA 1a).

The presence of alloantibodies may be suspected in newborns with signs or symptoms of thrombocytopenia. When a‐HPA 1a is detected in a pregnant woman, there is no general agreement on follow up in pregnancy or about time and mode of delivery. The aim of the present study was to identify pregnancies at risk, follow the women with a‐HPA 1a antibodies determinations and clinical evaluations and plan the delivery as safe as possible with respect to severe bleedings.

R esults The frequency of HPA 1bb was found to be 2·1% (n=17,000) and in 12·0% of the HPA 1bb women, anti‐HPA 1a antibodies were detected. Fourteen babies were born with thrombocytopenia of < 35 × 109 L−1 and transfused. There was a clear correlation between antibody level in the mother and the severity of thrombocytopenia in the newborns. Beside from one clinical insignificant intracranial bleeding (ICH) detected by CT, all the children were healthy.

D iscussion Based on earlier publications, 5–6 babies in our material should have had ICH with neurological sequels. We believe that the combination of early detection of antibodies, close clinical follow up, termination of the pregnancy at week 38 by Caesarean section and immediate compatible platelet transfusion may explain the profitable clinical outcome for the babies. This relatively simple regimen is beneficial for improvement of perinatal morbidity and mortality.
Genetic changes in D weak Spanish donors
Authors: Torres P. , García F. , Jurado M. , Calle C. , Rodriguez M. A.
Published: March 2003

I ntroduction 

Recently some mutations were described in RHD gene associated to D weak. We have studied these changes in our blood donors.

M aterial and M
ethod 

56 D weak samples from our donors were studied in the following way: DNA extraction with DNAzol, PCR‐SSP of some fragments of RHD gene and digestion with Alw44I, Sac I, Alu l, Msp l restriction enzymes (F. Wagner, Blood 1999; 93: 385–393). In two samples with fenotipe ce, exons 4 and 5 of gene RHD were sequenced. In 6 samples, which seemed to be antigen D variant, all the exons of the RHD gene were amplified by PCR‐SSP. We also sequenced exons 4, 5 and 7 of the RHD gene and exon 5 of RHCE gene in one case. In two other cases, DVl atipical variants, RNA was extracted from reticulocytes and then cDNA of RHD gene was sequenced.

R esults 

28 samples have fenotype cEe and in all of them the mutation described in nucleotide 1154(G‐C) was detected. Of 17 samples with fenotype Cce 15 showed the described mutation in nucleotide 809(T‐G) and the remaining 2 showed a mutation in nucleotide 8(C‐G) as was previously pointed out. Two samples have ce fenotype and mutations in nucleotides 602(C‐G) and 667(T‐G). No mutations were located in 3 donors carrying Cce fenotype.

Six of our cases belong to antigen D variants; one case is a caucasian cDe donor with a DAR variant with ceAR. Another case, cDEe fenotype, is a type l DVI variant. Two other CcDe fenotypes are DVl atypical variants due to the fact that they present a sustitution of RHD gene exons 3,4 and 5 for those corresponding to the RHCE gene. The study of the last two variants is being completed at present.

C onclusions 

1. We confirm in our study that D weak is associated to changes, previously described by Wagner et al. in RHD gene. 2. There is a strong correlation between haplotypes and genetic mutations. 3. The most frecuent haplotype associated to D weak in our donors is cDE(R2) showing a mutation in nucleotide 1154. 4. A DAR variant with ceAR has been detected in a caucasian donor. 5. We find ourselves in the position to confirm the existence of a new type of D Vl variant.
Apparent cross‐reactivity of heparin‐dependent platelet antibodies with danaparoid in a PF4 ELISA
Authors: Lucas G. F. , Griffiths R. E. , Chown S.
Published: March 2003

A 60‐year‐old previously fit woman presented with deep vein thrombosis. She had a history of 2 pregnancies, no transfusions and a platelet count of 241×109/l. She was treated with intravenous unfractionated heparin and, after 10 days, her platelet count dropped to 30×109/l. The patient had not been previously exposed to heparin. There was no evidence for disseminated intravascular coagulation and a clinical diagnosis of heparin induced thrombocytopenia was made. Heparin was discontinued and danaparoid was administered. Over the next 10 days, her platelet count returned to normal. Laboratory investigation using a solid phase PF4‐heparin ELISA assay (GTI‐PF4) revealed the presence of heparin dependent antibodies. These antibodies were only partially inhibited by the addition of excess heparin (100 & 200iu) which suggested that heparin independent anti‐PF4 antibodies were also present. Substitution of excess danaparoid for heparin in the GTI‐PF4 kit also resulted in partial inhibition of antibody binding and suggested that the antibodies might cross‐react with danaparoid. Investigation using an annexin V flow cytometric assay confirmed the presence of heparin dependent platelet antibodies but the addition of excess heparin completely inhibited antibody binding. There was no evidence that the antibodies were cross‐reactive with danaparoid in the annexin V assay. The clinical outcome in this case suggests that the results of the annexin V assay may provide more accurate information about the cross‐reactivity of heparin dependent antibodies with heparin analogues than solid phase PF4‐heparin ELISA assays.
A comparison of biochemical and functional alterations of rat and human erythrocytes stored in CPDA‐1 for 29 days: implications for animal models of transfusion
Authors: D'almeida M. S. , Jagger J. , Duggan M. , White M. , Ellis C. , Chin‐Yee I. H.
Published: March 2003

. Animal models of transfusion are employed in many research areas yet little is known about the storage‐related changes occurring in the blood used in these studies. This study assessed storage‐related changes in red blood cell (RBC) biochemistry, function and membrane deformability in rat and human packed RBCs when stored in CPDA‐1 at 4 °C over a 4‐week period. Human blood from five volunteers and five bags of rat RBC concentrates (five donor rats per bag) were collected and stored at 4 °C. RBC function was assessed by post‐transfusion viability and the ability to regenerate adenosine triphosphate (ATP) and 2,3‐diphosphoglycerate (DPG) when treated with a rejuvenation solution. Membrane deformability was determined by a micropipette aspiration technique. ATP in rat RBCs declined more rapidly than human RBCs; after 1 week rat ATP fell to the same level as human cells after 4 weeks of storage (rat, 2·2 ± 0·2 µmol g−1 Hb; human, 2·5 ± 0·3 µmol g−1 Hb). Baseline DPG concentrations were similar in rat and human RBCs (16·2 ± 2·3 µmol g−1 Hb and 13·7 ± 2·4 µmol g−1 Hb) and declined very rapidly in both species. Human RBCs fully regenerated ATP and DPG when treated with a rejuvenation solution after 4 weeks of storage. Rat RBCs regenerated ATP but not DPG. Post‐transfusion viability in rat cells was 79%, 26% and 5% after 1, 2 and 4 weeks of storage, respectively. In rats, decreased membrane deformability became significant (− 54%) after 7 days. Human RBC deformability decreased significantly by 34% after 4 weeks of storage. The rejuvenation solution restored RBC deformability to control levels in both species. Our results indicate that rat RBCs stored for 1 week in CPDA‐1 develop a storage lesion similar to that of human RBCs stored for 4 weeks and underscores significant species‐specific differences in the structure and metabolism of these cells.
The relationship between ABO histo‐blood group, factor VIII and von Willebrand factor
Authors: O'Donnell J. , Laffan M. A.
Published: March 2003

. ABO histo‐blood group is a major determinant of plasma levels of factor VIII (FVIII) and von Willebrand factor (vWF). Blood group O individuals have significantly (approximately 25%) lower plasma levels of both glycoproteins. This association is of clinical significance. Low plasma levels of either FVIII or vWF have long been established as causes of excess bleeding. Conversely, there is accumulating evidence that elevated FVIII–vWF levels may represent an important risk factor for ischaemic heart disease and venous thromboembolic disease. In spite of the well‐documented association between ABO blood group and FVIII–vWF levels, the underlying mechanism remains unknown. However, it has been established that the ABO effect is primarily mediated through a direct functional effect of the ABO locus on plasma vWF levels.

Theoretically, ABO blood group may alter the rate of vWF synthesis or secretion within endothelial cells. Alternatively, ABO group may affect vWF plasma clearance rates. ABH antigenic determinants have been identified on the N‐linked oligosaccharide chains of circulating vWF and FVIII, according to the blood group of the individual. It remains unclear whether these carbohydrate structures are responsible for mediating the effect of ABO blood group on plasma vWF levels.
Electron‐microscopic examination of Rickettsia tsutsugamushi‐infected human liver
Authors: Pongponratn Emsri , Maneerat Yaowapa , Chaisri Urai , Wilairatana Polrat , Punpoowong Benjanee , Viriyavejakul Parnpen , Riganti Mario
Published: March 2003

SummaryA 33 year‐old Thai woman was diagnosed with scrub typhus infection according to clinical symptoms, eschar lesions compatible with the disease, and specific antibody to Rickettsia tsutsugamushi detected by indirect immunoperoxidase. Percutaneous transhepatic needle biopsies were taken before and 7 days after treatment with tetracycline to study the pathology of the liver. The liver tissue was evaluated by light microscopy, using H & E and Pinkerton's stains, and by transmission electron microscopy (TEM). Before treatment it showed reactive hepatitis. Rickettsia organisms within the hepatocytes and sinusoids detected by Pinkerton's stain appeared as tiny bright‐red organisms. By TEM, the rod‐shaped double‐membrane Rickettsiae appeared intact in the cytoplasm of Kupffer's cells and hepatocytes. After tetracycline treatment, moderate levels of acidophilic and ballooning liver cells were observed. The degree of cytoplasmic organelle damage varied, including fatty metamorphosis, depletion of glycogen granules, loss of the mitochondrial cristae, dilatation of endoplasmic reticulum and cytoplasmic vacuolation. Rickettsia organisms cannot be visualized by Pinkerton's stain but were detected by TEM, in markedly vacuolated hepatocytes, in congested sinusoids and in Kupffer's cells. Intranuclear Rickettsia were discovered in the endothelial nucleus, showing various degrees of injury. Some were mildly degenerated, while others exhibited clumping of nucleoprotein at the cytoplasm periphery and large vacuolation centrally. Many indented organisms were found, and binary fission during Rickettsiae multiplication was always affected. Electron‐microscopic examination of hepatic injury associated with scrub typhus is rare. This is the first ultrastructural localization of Rickettsiae in the infected human liver.
Low overall mortality of Turkish residents in Germany persists and extends into a second generation: merely a healthy migrant effect?*
Authors: Razum Oliver , Zeeb Hajo , Akgün H. Seval , Yilmaz Selma
Published: March 2003

Summaryobjective To test the hypothesis that as a minority with lower socio‐economic status, Turkish residents in Germany might experience a higher mortality than Germans.

methods All‐cause mortality rates by age group and sex of Turkish and German adults for the time period 1980–94 were calculated from death registry data and mid‐year population estimates.

results The age‐adjusted mortality rate (per 100000) of Turkish males aged 25–65 years resident in Germany was 299 in 1980 and 247 in 1990, consistently half that of German males. The mortality of Turkish females in Germany was 140 in 1990, half that of German females. Mortality of Turkish males/females in Ankara was 835 and 426 in 1990.

conclusion In view of the socio‐economic status of Turkish residents in Germany the large mortality difference compared to Germans is unexpected. It cannot be fully explained by a selection at the time of hiring (healthy migrant effect) because it lasts over decades and extends into the second generation. A healthy worker effect is unlikely because Turkish residents have a lower employment rate than Germans. There is little evidence for movement of gravely ill persons back to Turkey. An ‘unhealthy re‐migration effect’ in which socially successful migrants with a lower mortality risk stay in the host country while less successful ones return home even before becoming manifestly ill would partly explain our findings.
Maternal anthropometry‐based screening and pregnancy outcome: a decision analysis
Authors: Kramer Michael S. , Jere Haas  , Kelly Alan
Published: March 2003

Summary
objective To assess the impact of screening and intervention based on maternal height, prepregnancy weight and weight during weeks 16–19 or 24–27 in reducing adverse pregnancy outcomes (IUGR, preterm birth and assisted delivery) in developing country settings.methods Decision analysis based on a recent multicentre WHO collaborative study of maternal anthropometry and pregnancy outcomes and meta‐analyses of controlled clinical trials of balanced energy/protein supplementation (for IUGR and preterm birth) and support from caregivers during labour (for assisted delivery). Subjects for the analysis comprised pregnant women from Cali, Colombia (1989, n= 4598); urban and rural Pune, India (1990, n= 4307); and urban and rural Myanmar (1981–82, n= 3542) followed until delivery.results Seven to 45% of pregnant women had positive screens, with preventive fractions (PFs) ranging from 0.034 to 0.109 for IUGR, 0.027–0.082 for preterm birth and 0.011–0.105 for assisted delivery. Screening prevention ratios (SPRs = ratios of the number of women treated to the number of cases of adverse outcome prevented) are high in all three study settings for preterm birth and assisted delivery (range 22.8–115.7) and low in settings with a high prevalence of the adverse outcome and high specificity of the anthropometric measure (India for IUGR, range 7.0–8.0). Sensitivity analyses demonstrate a marked linear fall in PF and an exponential rise in the SPR as the relative risk associated with intervention increases (i.e. as the protective benefit of intervention decreases) from 0.60 to 0.95.conclusions A maternal anthropometry‐based ‘risk approach’ is unlikely to result in a major reduction in adverse pregnancy outcomes in developing country settings. For risk‐free and inexpensive interventions (e.g. caregiver support during labour), a better strategy would be to forego screening and instead treat all pregnant women.
Implications for school‐based health programmes of age and gender patterns in the Tanzanian primary school
Authors: Lansdown R. G. , Bundy D. A. P. , Eberstein T. , Hall A. , Kihamia C. M. , Yona E. , Issae W. , Mwanri L. , Magingo J.
Published: March 2003

This paper examines children's potential access to school health services by analysing data on the demographic structure, enrolment patterns and reported causes of early school‐leaving in 347 schools in Tanga Region, Tanzania served by a school‐based health programme. The analysis indicates that net enrolment ratios have risen over the previous 6 years, particularly among children under 10 years. However, in 1994 children were still much older than expected for a basic school population: 81% were adolescents ($10 years) and the mean age was 12 years. These data suggest that schools can provide equitable access to health education and school‐based health services for a majority of children, even in a low‐income country, and that the primary school population is predominantly adolescent and would benefit from health programmes targeted at that age group.
Host haematological factors influencing the transmission of Plasmodium falciparum gametocytes to Anopheles gambiae s.s. mosquitoes
Authors: Drakeley C. J. , Secka I. , Correa S. , Greenwood B. M. , Targett G. A. T.
Published: March 2003

Summary We investigated the relationship between selected host haematological and parasitological parameters and the density and infectivity of Plasmodium falciparum gametocytes. 143 individuals (age range 1–62 years) attending an outpatient clinic in Farafenni, The Gambia, who had peripheral blood gametocytaemia were recruited (mean gametocyte density 123.7/μl, range 5–17,000/μl). Of the parameters measured, packed cell volume (PCV), reticulocyte count (RetC) and lymphocyte count (LyC) were significantly associated with gametocyte density (r=− 0.17, P < 0.05; r= 0.21, P < 0.01; r= 0.18, P < 0.05, respectively). Data from membrane feeding experiments in which 15 or more mosquitoes were dissected showed that 60.7% (53/87) of gametocyte carriers infected one or more mosquitoes. Gametocyte density was strongly correlated with transmission success (TS) (r= 0.3, P < 0.005) and, in successful infections, with both mosquito prevalence (MP) (r= 0.36, P < 0.005) and mean oocyst burden (MOB) (r= 0.65, P < 0.0001). None of the other factors measured were significantly associated with any of these indices in bivariate analysis. Regression modelling showed that both gametocyte density and PCV were positively associated with gametocyte carrier infectivity to mosquitoes (LRχ2= 100.7 and 47.2, respectively) and, in successful infections, with MOB (β= 0.16, t = 4.9, P < 0.001; β= 0.02, t = 2.3, P < 0.05, respectively). The positive association with PCV suggests that blood meal quality influences infection probably as a nutritional requirement, however, as this effect was most apparent at high gametocyte densities, its epidemiological significance is questionable. Though the haematological parameters associated with gametocyte density are a direct consequence of asexual infection, they may also represent an adaptive mechanism for optimization of sexual stage development.
Viewpoint: Management of malaria – working with the private sector
Authors: Brugha Ruairi , Chandramohan Daniel , Zwi Anthony
Published: March 2003

Summary Recent reviews have demonstrated that a substantial proportion of cases of malaria are managed in the private sector, and international policy initiatives routinely emphasize the need for malaria control programmes to collaborate with the private sector. However, information on how to develop successful partnerships between the public and private sectors remains limited. This paper reviews the current knowledge about the management of malaria by private providers, considers the potential of different strategies for influencing the quality of care provided, and identifies processes for facilitating public‐private sector collaborations. We contend that public sector‐led interventions, such as training of private providers or the distribution of prepackaged antimalarials through the private sector, are unlikely to scale up to sustainable national level programmes if they do not take into account a wide range of needs and concerns, represented by private provider organizations and other interest groups, including service users. These groups should be involved at key stages including the design and piloting of interventions, through to the dissemination and implementation of findings. Research priorities are outlined for the development of tools to facilitate public‐private partnerships for improving the management of malaria.
Mechanism(s) of attenuation of Theileria annulata vaccine cell lines
Authors: Hall Roger , Ilhan Tulin , Kirvar Erol , Wilkie Gwen , Preston Patricia M. , Darghouth Mohamed , Somerville Robert , Adamson Rachel
Published: March 2003

Summary Attenuated vaccines are an important means of controlling Theileria annulata infection of cattle. Production is by prolonged cultivation of macroschizont‐infected cells. The mechanism of attenuation remains unclear. There are three general nonmutually exclusive possibilities: Selection of avirulent subpopulations, genome rearrangements and alterations in gene expression. Several groups, including ours, have provided evidence that the population structure usually tends to simplify during attenuation. Our data on the T. annulata (Ta) Ankara cell line show that attenuation is not necessarily accompanied by the population becoming clonal. We have been unable to detect large DNA rearrangements. Evidence for alterations in host and parasite gene expression during attenuation is available. With respect to the host we have shown that attenuation is accompanied by loss of expression of parasite induced matrix metalloproteinases (MMPs). However, in different lines different protease activities are involved. In the T. annulata Ode line we have shown that 8 activities (including MMP9) are downregulated and that this correlates with a loss of metastatic behaviour. This has previously been shown in vitro using reconstituted basement membrane (Matrigel™) and is demonstrated in vivo using scid mice in this study. Thus part of the pathology, namely the ability to disseminate, mediated by host MMPs, is lost upon attenuation. Re‐isolation experiments have shown that the reduction/loss of MMP is a stable transferable trait. A logical extension is that loss of MMP activity (and virulence in general) must be at the most fundamental level a genetic trait of the parasite. Evidence for loss of parasite gene expression is implied by the loss of the ability to differentiate into merozoites on attenuation. Specific evidence for loss of parasite gene expression has been obtained using differential RNA display. We view virulence as a multifactorial phenomenon involving interacting subpopulations of cells and attenuation is a threshold effect whereby the number of virulence factors is reduced below a critical level. On this basis there will be many different ways to achieve attenuation.
The performance of school‐based questionnaires of reported blood in urine in diagnosing Schistosoma haematobium infection: patterns by age and sex
Authors: Guyatt Helen , Brooker Simon , Lwambo Nicholas J. S. , Siza Julius E. , Bundy Donald A. P.
Published: March 2003

Summary

This study investigates the performance of school‐based questionnaires of reported blood in urine as an indicator of the prevalence of Schistosoma haematobium infection in schools and the presence of infection in individuals. In most schools (87%), the prevalence of reported blood in urine underestimates the prevalence of S. haematobium infection. Predictive value analysis suggests that a threshold of 30% reported blood in urine would identify most of the high prevalence schools (i.e. those with 50% or more children infected with S. haematobium). Although the prevalence of S. haematobium infection was greater in males than females, girls reported a lower prevalence of blood in urine than boys even at comparable levels of infection. Reported blood in urine in females was more specific (identifying 10% more uninfected girls than the sign in boys), but was far less sensitive (identifying less than 20% of infected girls than boys). The sensitivity of reported blood in urine was also related to age, being significantly lower in girls over 14 years of age. The proportion of infected children who reported blood in urine was also lower in schools where the prevalence of reported blood in urine is less than 30%. The results suggest that the selective treatment of children based on reported blood in urine in low prevalence schools would miss a high proportion of infected children, particularly girls. It remains unclear whether other rapid assessment techniques, such as the use of reagent strips, would offer greater cost‐effectiveness.
Control of urinary schistosomiasis: an investigation into the effective use of questionnaires to identify high‐risk communities and individuals in Niger State, Nigeria
Authors: Mafe M. A. , von Stamm T. , Utzinger J. , N'goran E. K.
Published: March 2003

Summary Schistosomiasis is a public health problem in Nigeria. Although there is a national programme for its control, there is the need for reliable and simple means of rapidly diagnosing communities to provide a detailed map on the distribution of the disease in the country, in order to prioritize control activities, as well as to monitor the effectiveness of control operations. A rapid assessment technique using school questionnaires was tested in Borgu Local Government Area (LGA), Niger State, north‐western Nigeria. Following a series of focus group discussions, the questionnaires were adapted before they were administered through the school system to 60 primary schools in Borgu LGA. Correctly completed questionnaires were returned from 58 schools (97%) within 4 weeks. Questionnaires were validated by reagent stick tests performed by trained teachers. Their results proved to be reliable compared to those obtained by our research team in 20 randomly selected schools. Overall prevalences of microhaematuria at 1+ and 2+ levels were 45.7% and 27.1%, respectively. Highly significant correlations were obtained between school prevalence of microhaematuria and reported schistosomiasis, as well as reported blood in urine. The diagnostic performance of the questionnaires at the 2+ level of microhaematuria was very good. The design of our study also allowed data analysis on an individual level, and multivariate analysis revealed highly significant odds ratios for reported schistosomiasis and reported blood in urine to detect an individual with urinary schistosomiasis. Our results are in good agreement with reports from other African countries, and questionnaires can be recommended for rapid identification of communities at highest risk of urinary schistosomiasis in Nigeria, so that scarce resources of the national control programme can be used most effectively.
Review: Domestic hygiene and diarrhoea – pinpointing the problem
Authors: Curtis Valerie , Cairncross Sandy , Yonli Raymond
Published: March 2003

Summary Improving domestic hygiene practices is potentially one of the most effective means of reducing the global burden of diarrhoeal diseases in children. However, encouraging behaviour change is a complex and uncertain business. If hygiene promotion is to succeed, it needs to identify and target only those few hygiene practices which are the major source of risk in any setting. Using biological reasoning, we hypothesize that any behaviours which prevent stools from getting into the domestic arena, the child's main habitat, are likely to have a greater impact on health than those practices which prevent pathogens in the environment from being ingested. Hence safe stool disposal, a primary barrier to transmission, may be more important than hand‐washing before eating, which constitutes a secondary barrier, for example. We review the epidemiological evidence for the effect of primary and secondary barrier behaviours and suggest that it supports this conclusion. In the absence of local evidence to the contrary, hygiene promotion programmes should give priority to the safe disposal of faecal material and the adequate washing of hands after contact with adult and child stools.
Development of rapid assessment procedures for the delimitation of lymphatic filariasis‐endemic areas
Authors: Srividya A. , Lall R. , Ramaiah K. D. , Ramu K. , Hoti S. L. , Pani S. P. , Das P. K.
Published: March 2003

Summary Lymphatic filariasis caused by Wuchereria bancrofti is a major public health problem in 73 tropical and subtropical countries including India. Delimitation of endemic areas is essential to plan control operations. The current method of night blood survey (NBS) for delimitation is cumbersome, time‐consuming and expensive. Therefore, there is a need to develop assessment procedures which can rapidly delimit endemic areas. For this purpose we evaluated three procedures: direct interviewing of key informants using structured questionnaires, an indirect method of a self‐administered questionnaires to key informants and physical examination by health workers for the presence of chronic filarial disease. Thirty rural communities in a filariasis‐endemic region in Cuddalore district in Tamil Nadu State in southern India constituted the study population. The determination of filariasis endemicity in the village communities assessed by the above procedures was compared in terms of rapidity, specificity, sensitivity and cost with the microfilaria rate and disease rate obtained by night blood sample survey and clinical examination by physicians. Prevalence score, control preference score and weighted mean number of cases with filarial disease per village were calculated using the key informant questionnaire techniques. While the prevalence and control preference score showed low sensitivity and moderate specificity, weighted mean number of cases showed high sensitivity and moderate specificity in identifying endemic villages. The prevalence of disease as determined by the physical examination of a sample population by health workers was highly sensitive in identifying communities endemic for filariasis. The degree of association between the disease rates estimated by physician and trained health workers was significant (r = 0.56; P < 0.05). These observations suggest that the weighted mean number of cases per village obtained through key informant techniques may be considered at a primary level to crudely identify endemic areas, followed by physical examination by health workers for filariasis, since it is relatively cheap and rapid.
Causes of low attendance at National Immunization Days for polio eradication in Bushenyi District, Uganda
Authors: Nuwaha F. , Mulindwa G. , Kabwongyera E. , Barenzi J.
Published: March 2003

Summary The purpose of this study was to investigate the factors influencing attendance for polio National Immunization Days (NIDs) using the Attitudes‐Social‐influence‐self‐Efficacy (ASE) model as a guiding theoretical framework. The data was collected in Bushenyi district of south‐western Uganda in 6 focus group discussions about outcomes of attendance at NIDs, about who decides on attendance, and about attendance barriers and supports. The purpose of NIDs – eradicating polio – was not known to the informants. The main reason mentioned for attending NIDs and other immunization was to weaken childhood diseases or to strengthen the children's capability in fighting diseases, whether they are immunizable or not. However, it was strongly believed that the previous NIDs had caused a severe malaria epidemic with a very high mortality, and this led to most parents not attending the next. Sources of social influence were mostly opinion and local leaders in communities, health workers, friends and relatives. Opinion leaders who did not immunize their children were said to hinder attendance at NIDs by other lay people. NIDs cards, on the other hand, were regarded as valuable means of support for attendance. Thus to improve immunization coverage, there is need for issuing NIDs cards, for using health education to change the belief that NIDs cause malaria, and to encourage local leaders to attend NIDs.