First Report on Banana Weevil, Cosmopolites sordidus (Germar 1823) (Coleoptera: Curculionidae), an Exotic Economically Important Pest from Saudi Arabia

We report the first record of the occurrence of the banana weevil, Cosmopolites sordidus (Germar, 1823) (Coleoptera: Curculionidae), an economically important pest of bananas (Musa spp.), from Fifa Mountains in Saudi Arabia. Moreover, we recorded the first observation of damage caused to bananas by C. sordidus in a banana farm in Jazan Province, southwestern Saudi Arabia, in March 2022. Molecular characterization using DNA sequences of the mitochondrial COI gene confirmed the morphological identification of C. sordidus. This discovery is considered a warning notice to prevent the potential establishment and spread of this dangerous pest in the banana cultivation regions in Saudi Arabia. Therefore, it is recommended that detection and monitoring of banana weevil should be undertaken in Saudi banana farms in order to restrict the dissemination of this weevil to other banana cultivation areas.

Impact of resveratrol and zinc on biomarkers of oxidative stress induced by Trichinella spiralis infection

Trichinellosis is a re-emerging worldwide foodborne zoonosis. Oxidative stress is one of the most common detrimental effects caused by trichinellosis. In addition, Trichinella infection poses an infinite and major challenge to the host's immune system. Resistance and side effects limit the efficiency of the existing anti-trichinella medication. Given that concern, this work aimed to investigate the anti-helminthic, antioxidant, anti-inflammatory and immunomodulatory effects of resveratrol and zinc during both phases of Trichinella spiralis infection. Sixty-four Swiss albino mice were divided into four equal groups: non-infected control, infected control, infected and treated with resveratrol, and infected and treated with zinc. Animals were sacrificed on the 7th and 35th days post-infection for intestinal and muscular phase assessments. Drug efficacy was assessed by biochemical, parasitological, histopathological, immunological, and immunohistochemical assays. Resveratrol and zinc can be promising antiparasitic, antioxidant, anti-inflammatory, and immunomodulatory agents, as evidenced by the significant decrease in parasite burden, the significant improvement of liver and kidney function parameters, the increase in total antioxidant capacity (TAC), the reduction of malondialdehyde (MDA) level, the increase in nuclear factor (erythroid-derived 2)-like-2 factor expression, and the improvement in histopathological findings. Moreover, both drugs enhanced the immune system and restored the disturbed immune balance by increasing the interleukin 12 (IL-12) level. In conclusion, resveratrol and zinc provide protection for the host against oxidative harm and the detrimental effects produced by the host's defense response during Trichinella spiralis infection, making them promising natural alternatives for the treatment of trichinellosis.

Acetazolamide loaded-silver nanoparticles: A potential treatment for murine trichinellosis

Trichinellosis is a global food-borne disease caused by viviparous parasitic nematodes of the genus Trichinella. Due to the lack of effective, safe therapy and the documented adverse effects of traditional therapy, this study aimed to evaluate the therapeutic effect of acetazolamide-loaded silver nanoparticles (AgNPs) on murine trichinellosis. Fifty male Swiss albino mice were divided into five groups of ten mice each: Group I, normal control group; Group II, infected with T. spiralis and not treated; Group III, infected and given AgNPs; Group IV, infected and treated with acetazolamide; and Group V, infected and treated with acetazolamide-loaded AgNPs. Mice were infected orally with 250 larvae. The efficacy was assessed by counting T. spiralis adults and larvae, measuring serum total antioxidant capacity, and observing the histopathological and ultrastructural alterations. Acetazolamide-loaded AgNPs treatment exhibited the highest percentage of reduction (84.72% and 80.74%) for the intestinal adults and the muscular larvae of T. spiralis-infected animals, respectively. Furthermore, during the intestinal and muscular phases, the serum of the same group had the best free-radical scavenging capacity (antioxidant capacity), which reduced tissue damage induced by oxidative stress. Histopathologically, the normal intestinal and muscular architecture was restored in the group treated with acetazolamide-loaded AgNPs, in addition to the reduced inflammatory infiltrate that alleviated inflammation compared to infected animals. Our results confirmed the marked destruction of the ultrastructural features of T. spiralis adults and larvae. Acetazolamide-loaded AgNPs are a promising therapy against T. spiralis infection.

First Report of Basal Rot of Onion Caused by Fusarium oxysporum f. sp. cepae in Saudi Arabia

Onion (Allium cepa L.) is a globally important crop worldwide including Saudi Arabia. In November 2020, 2-month-old onion plants (cv. Redwing) in commercial fields within the Sajir area of Riyadh region (∼ 1.4 ha), showed symptoms of yellowing, wilting, stunting, bulb discoloration, rot in the basal parts of bulb and decrease in roots. In the advanced stages, the affected plants collapsed and died. The incidence of symptomatic plants ranged from 30 to 65% in the surveyed fields. To isolate the pathogen, symptomatic onion plants (n =20) were sampled. Diseased tissues from roots and bulbs were cut into small pieces (4 × 4 mm), sanitized with 1% sodium hypochlorite solution for 2 min, submerged in 70% alcohol for 20 s, then rinsed with sterile water, before plating on potato dextrose agar (PDA) medium. The plates were incubated at 25°C for 6 days. Subcultures of the mycelia grown out of the diseased tissues produced purplish pink fungal colonies on PDA. On carnation leaf agar, cultures were characteristic of Fusarium oxysporum as described by Leslie and Summerell (2006), with the presence of unicellular microconidia (3.8 to 7.8 × 1.7 to 2.5 μm, n= 50) without septa in false heads or short monophialides and slightly curved macroconidia (16.3 to 28 × 4.2 to 6.1 μm, n= 50) with two to four septa. Older mycelia developed many chlamydospores that were single or in short chains. To further confirm the pathogen identification, DNA was extracted from single-spore cultures of three representative isolates using the DNeasy Plant Mini kit (QIAGEN, Hilden, Germany). Three different fungal nuclear regions of internal transcribed spacer (ITS), elongation factor 1-α, (TEF1-α) and the second largest subunit of DNA-directed RNA polymerase II (RPB2) DNA were amplified by PCR and sequenced with the following primers: ITS4 and ITS5 (White et al. 1990); EF-1 and EF-2 (O'Donnell et al. 2008); and fRPB2-5F and fRPB2-7cR (Liu et al. 1999), respectively. Phylogenetic analysis based on the alignment of the ITS, TEF1-α, and RPB2 sequences using MEGA7 placed these isolates in the F. oxysporum clade. The ITS, TEF1-α, and RPB2 sequences of an isolate FOC-OR9 were submitted to GenBank (OL721757, OL764494, and OL764495 respectively). To confirm the forma specialis cepae, a fragment of the F. oxysporum f. sp. cepae gene Secreted In Xylem 3 (SIX3) was amplified by PCR (Kalman et al. 2020). The SIX3 amplicon (∼ 277-bp) was sent for sequencing, and the sequence was submitted to GenBank (OL828265). BLASTn analysis of the sequences showed 100% identity with F. oxysporum f. sp. cepae (KP746408). To fulfill Koch's postulates, pathogenicity tests were performed with healthy onion bulbs cv. "Redwing" of 100-150 g each. Prior to inoculation of onion bulbs, the dry bulb scales, one of the fleshy inner scales, as well as the roots were removed. Bulbs were then surface sterilized (as described above) and injected with 20 µl of a conidial suspension (106 spores/ ml) into the basal plate of each bulb and approximately 1 cm deep into the tissue. Six bulbs were inoculated for each isolate, placed in a mesh bag, and incubated at 28 °C in the dark. Six bulbs injected with sterile water and six non-inoculated bulbs served as controls. At the 4th week post inoculation, necrotic rot symptoms and brown discoloration were observed on the basal plates of these inoculated bulbs (similar symptoms to those observed in the field), while control treatments showed no symptoms. The pathogen was re-isolated from the basal plates onto PDA and identified morphologically and molecularly as F. oxysporum f. sp. cepae, thus fulfilling Koch's postulates. The test was repeated twice. This pathogen was previously reported causing onion basal rot in United Kingdom (Taylor, et al., 2013). To our knowledge, this is the first report of basal rot in onion caused by F. oxysporum f. sp. cepae in Saudi Arabia. It is recommended that preventive management should be considered as this disease may cause significant economic losses for onion growers in Saudi Arabia. Also, Fusarium mycotoxin contamination of onion bulb could pose a public health risk.

Single and Combined Mutations of Acetylcholinesterase Gene Giving Resistance to Pirimiphos-Methyl in Musca domestica Slaughterhouse Populations

The house fly Musca domestica L. (Diptera: Muscidae) is a worldwide medical and veterinary pest, causing great economic losses. Organophosphate insecticides have been widely used to control house fly populations. The main objectives of the present study were to evaluate the resistance levels of M. domestica slaughterhouse populations, collected from Riyadh, Jeddah, and Taif, against the organophosphate insecticide pirimiphos-methyl and investigate the genetic mutations of the Ace gene associated with pirimiphos-methyl resistance. The obtained data showed that there were significant differences among pirimiphos-methyl LC₅₀ values of the studied populations, where the highest LC₅₀ was recorded for the Riyadh population (8.44 mM), followed by Jeddah and Taif populations (2.45 mM and 1.63 mM, respectively). Seven nonsynonymous SNPs were detected in the studied house flies. The Ile239Val and Glu243Lys mutations are reported for the first time, whereas Val260Leu, Ala316Ser, Gly342Ala, Gly342Val, and Phe407Tyr were previously reported in M. domestica field populations from other countries. Considering three mutations associated with insecticide resistance, at amino acid positions 260, 342, and 407 of acetylcholinesterase polypeptide, 17 combinations were recovered in this study. Three out of these seventeen combinations were frequently found both worldwide and in the three Saudi house fly field populations, as well as their pirimiphos-methyl-surviving flies. Overall, the single and combined Ace mutations are apparently associated with pirimiphos-methyl resistance, and the obtained data can be useful in managing house fly field populations in Saudi Arabia.

Molecular-Based Taxonomic Inferences of Some Spider Mite Species of the Genus Oligonychus Berlese (Acari, Prostigmata, Tetranychidae)

DNA barcoding technology using short DNA sequences has emerged as an efficient and reliable tool for identifying, confirming, and resolving closely related taxa. This study used ITS2-rDNA and mtCOI DNA sequences to confirm the identity of eight Oligonychus species, representing 68 spider mite samples, collected mainly from Saudi Arabia (SA) and some from Mexico, Pakistan, USA, and Yemen. The intraspecific nucleotide divergences of the studied Oligonychus species ranged from 0% to 1.2% for ITS2 and 0% to 2.9% for COI. However, the interspecific nucleotide divergences were distinctly higher than the intraspecific ones and ranged from 3.7% to 51.1% for ITS2 and 3.2% to 18.1% for COI. Furthermore, molecular data correctly confirmed the species identity of 42 Oligonychus samples lacking males, including a previously claimed sample of O. pratensis from SA. High genetic variations were detected in two Oligonychus species: O. afrasiaticus (McGregor) (nine ITS2 and three COI haplotypes) and O. tylus Baker and Pritchard (four ITS2 and two COI haplotypes). In addition, ITS2- and COI-based phylogenetic trees confirmed the subdivision of the genus Oligonychus. In conclusion, integrative taxonomic approaches are vital to resolve the closely related Oligonychus species, identify the samples lacking male specimens, and assess phylogenetic relationships within and among species.

Evidence for Reconsidering the Taxonomic Status of Closely Related Oligonychus Species in punicae Complex (Acari: Prostigmata: Tetranychidae)

To elucidate the taxonomic problems in species delineation within the Oligonychus punicae complex (O. punicae, O. mangiferus, and O. vitis) (Acari: Prostigmata: Tetranychidae), we performed morphological and molecular investigations on mite samples, collected from different hosts/countries. Thirty-nine samples of punicae complex, collected from Egypt, Pakistan, and Saudi Arabia (SA), did not show any considerable morphological differences in females and males. All 39 samples of the punicae complex resembled the original description of O. punicae, while the claimed Mexican O. punicae was distinctively different based on male aedeagus. Molecularly, the low nucleotide diversity ranged from 0% to 2.1% (ITS2-rDNA) and 0% to 1% (COI-mtDNA), and was observed among various DNA sequences of the punicae complex from Egypt, India, Israel, Pakistan, and SA, confirming their identity as one species. The high genetic divergence ranged from 17.2% to 18.8% (ITS2) and 9.2% to 10.2% (COI), observed between the claimed Mexican O. punicae and all other sequences of the punicae complex, indicating that the Mexican sample do not belong to O. punicae. Basing our findings on both morphological and molecular data, we can conclude that O. mangiferus and O. vitis are synonymized with O. punicae. Additionally, this study reveals that the claimed Mexican O. punicae needs to be re-identified.

Serum Leptin Correlates with Obesity But Does Not Differ Between Gestational Diabetes and Normal Glucose Tolerance during 24-28 Weeks of Gestation

Leptin is an adipocytokine secreted by adipocytes which positively correlates with obesity. It is considered as a potential mediator for precipitating Gestational diabetes mellitus (GDM) which is more evident during 24-28 weeks of gestation. This study was conducted to see serum leptin level during 24-28 weeks of gestation in GDM at the Department of Endocrinology, BSMMU, Bangladesh from March 2019 to August 2020. Pregnant women (N=108) were challenged with 75gm oral glucose (OGTT) at 24-28 weeks of gestation and divided into GDM [n=45, age: 27.80±3.98 years, mean±SD; BMI: 27.88 (24.46-30.43) kg/m², median Interquartile range (IQR)] and normal glucose tolerance [NGT; n=62, age: 26.19±5.30 years, mean±SD; BMI: 25.80 (23.65-28.42) kg/m², median (IQR)] on basis of WHO-2013 diagnostic criteria. Fasting serum leptin and glucose were measured by ELISA and glucose oxidase method respectively. No statistically significant difference was found between GDM and NGT for leptin [26.05(16.92-50.55) vs. 23.50(14.95-38.30) median (IQR), p=0.360]. It was also not different statistically between GDM and NGT either for age groups (p=NS for all) or for Asian categories of BMI subgroups (p=NS for all). However, it was higher in subjects with BMI ≥23kg/m² than that with BMI ≤23kg/m² for both GDM [16.65 (6.39, 35.75) vs. 28.35 (19.60, 51.10) median (IQR), p=0.114] and NGT [14.65(9.19, 19.60) vs. 26.00 (17.30, 43.40) median (IQR), p=0.002]. It was also statistically similar in the GDM subgroups divided by Asian BMI cut-off (p=NS). BMI correlated with leptin in NGT (r=0.495, p<0.001) but not in GDM (r=0.177, p=0.251) and regression analysis revealed BMI (kg/m²) as predictor for high leptin (p=0.008). ROC curve analysis for leptin showed AUC for GDM was 0.553 (p=0.360) suggesting it as a poor predictor. It is concluded that fasting leptin in 24-28 weeks of gestation better relates with BMI but does not differ between GDM and NGT anddoes not seem to be a good predictor for GDM. Further study is required to make a comment on its prediction over GDM.

Molecular Phylogenetics and Population Genetics of the Dengue Vector Aedes aegypti From the Arabian Peninsula

Aedes aegypti mosquito is the principal dengue vector in the Kingdom of Saudi Arabia (KSA); however, no study has addressed its ecology and population structure yet. Therefore, we report on Ae. aegypti phylo- and population genetics using three DNA markers: COI, ND4, and rDNA-ITS2. Sampling the immature stages of Ae. aegypti revealed that water storage tanks (34.3% of habitats) were the most productive and contained 33% of immatures stages. Other important habitats included containers for wastewater drainage (including air-conditioning and water cooler trays) and containers associated with ornamentation. Shallow water leakage spots (2.7% of habitats, 8% of immatures) can be considered rare-but-epidemiologically-important containers. Neighbor-joining (NJ) phylogenetic analysis of Ae. aegypti identified 8, 14, and 9 haplotypes of COI, ND4, and ITS2, respectively, and revealed high levels of genetic variation in Ae. aegypti populations of KSA. Global distribution of haplotypes also indicated multiple gene introductions into these populations, with high levels of intra-population genetic variation and continuous gene exchange. The neutrality values indicated a deficiency of alleles and suggested that the KSA Ae. aegypti loci tested did not follow a neutral model of molecular evolution. Fst values and AMOVA indicated that most of the genetic variation in the KSA Ae. aegypti populations is due to intra- rather than inter-population differences. This is the first comprehensive report on the phylo- and population genetics of Ae. aegypti from the Arabian Peninsula. This information expands our understanding of the ecology and population dynamics of this important arboviral vector for informed control efforts.

Molecular and physiological characterization of Fusarium strains associated with different diseases in date palm

Several species of Fusarium cause serious diseases in date palm worldwide. In the present work, 14 SSR markers were used to assess the genetic variation of Fusarium strains isolated from diseased trees in Saudi Arabia. We also studied the effect of different temperatures on mycelial growth of these strains. The pathogenicity of four strains of F. proliferatum was also evaluated on local date palm cultivars. Eleven SSR markers amplified a total of 57 scorable alleles from Fusarium strains. Phylogenetic analysis showed that F. proliferatum strains grouped in one clade with 95% bootstrap value. Within F. proliferatum clade, 14 SSR genotypes were identified, 9 of them were singleton. Four out of the five multi-individual SSR genotypes contained strains isolated from more than one location. Most F. solani strains grouped in one clade with 95% bootstrap value. Overall, the SSR markers previously developed for F. verticillioides and F. oxysporum were very useful in assessing the genetic diversity and confirming the identity of Saudi Fusarium strains. The results from the temperature study showed significant differences in mycelial growth of Fusarium strains at different temperatures tested. The highest average radial growth for Fusarium strains was observed at 25°C, irrespective of species. The four F. proliferatum strains showed significant differences in their pathogenicity on date palm cultivars. It is anticipated that the assessment of genetic diversity, effect of temperature on hyphal growth and pathogenicity of potent pathogenic Fusarium strains recovered from date palm-growing locations in Saudi Arabia can help in effectively controlling these pathogens.

Phylogenomic Analysis of a 55.1-kb 19-Gene Dataset Resolves a Monophyletic Fusarium that Includes the Fusarium solani Species Complex

Scientific communication is facilitated by a data-driven, scientifically sound taxonomy that considers the end-user's needs and established successful practice. In 2013, the Fusarium community voiced near unanimous support for a concept of Fusarium that represented a clade comprising all agriculturally and clinically important Fusarium species, including the F. solani species complex (FSSC). Subsequently, this concept was challenged in 2015 by one research group who proposed dividing the genus Fusarium into seven genera, including the FSSC described as members of the genus Neocosmospora, with subsequent justification in 2018 based on claims that the 2013 concept of Fusarium is polyphyletic. Here, we test this claim and provide a phylogeny based on exonic nucleotide sequences of 19 orthologous protein-coding genes that strongly support the monophyly of Fusarium including the FSSC. We reassert the practical and scientific argument in support of a genus Fusarium that includes the FSSC and several other basal lineages, consistent with the longstanding use of this name among plant pathologists, medical mycologists, quarantine officials, regulatory agencies, students, and researchers with a stake in its taxonomy. In recognition of this monophyly, 40 species described as genus Neocosmospora were recombined in genus Fusarium, and nine others were renamed Fusarium. Here the global Fusarium community voices strong support for the inclusion of the FSSC in Fusarium, as it remains the best scientific, nomenclatural, and practical taxonomic option available.

Association of GH polymorphisms with growth traits in buffaloes

Members of the somatotrophic axis, especially GH and IGF1, are essential for growth. The association between GH polymorphisms and growth traits was numerously studied in cattle; however, no data are available for such association studies in buffalo. Therefore, this study was conducted to screen for polymorphisms in the GH gene and to study their putative association with growth traits in 200 Egyptian buffaloes. Polymerase chain reaction single-strand conformation polymorphism and sequencing were applied to look for polymorphisms in 3 loci spanning all exons and introns of buffalo GH. The C (MspI+) >T (MspI-) SNP in intron3, which is well known in cattle, was not detected in the examined buffaloes. However, 2 missense mutations were detected in exon5: one previously detected p.Leu153Val SNP, with very low frequencies for the mutant (Val) allele and one novel p.Asn174His SNP. At weaning age, the p.Leu153Val SNP was significantly associated with weaning body weight and gain with the positive effect of the wild allele (Leu) and higher GH serum, mRNA, and protein levels in animals with Leu/Asn and Leu/His haplotypes. At yearling age, the 2 SNPs associated with yearling weight and gain with positive effect for the mutant (Val and His) alleles with increased GH, and IGF1 serum, mRNA, and protein and GHR mRNA and protein levels in animals with Val/Asn haplotype. Therefore, the selection of Egyptian buffaloes with the Val/Asn haplotype could improve the growth traits of Egyptian buffaloes at yearling age which is the target age for perfect growing.

Molecular and phenotypic variations in Eutetranychus orientalis (Klein) populations from Saudi Arabia

The oriental red spider mite, Eutetranychus orientalis (Klein) is a major pest of citrus in many countries including Saudi Arabia (SA). The morphological variations among the different populations of E. orientalis were reported. In the present study, phenotypic variations based on 40 different morphological characteristics were evaluated in 10 E. orientalis populations collected from different hosts and regions of SA. Further, ITS2-rDNA sequences were used to confirm the identity of these phenotypically varying populations. Phenotypic variations in all populations were found in the shape and length of dorsal setae, striation pattern between setae d1 and e1, and leg chaetotaxy. The rDNA sequence analysis of these morphologically varying populations resulted in 10 different ITS2 Saudi haplotypes. The phenotypic and genetic variations were more related to the host plants rather than their geographic distribution. The E. orientalis population collected from Phoenix dactylifera was phenotypically distinct and genetically divergent. The populations collected from citrus species were also more phenotypically and genetically related to each other than to populations collected from non-citrus host plants. The haplotypes recovered from Ziziphus sp., Morus sp., and Azadirecta indica from different regions were grouped in the same sub-clade. Further, the ITS2 haplotypes of Saudi E. orientalis recovered from Citrus reticulata from Riyadh and Al Ula were 100% identical to the ITS2 haplotypes recovered from Citrus sp. from Israel. It is concluded that phenotypic variations exist among different populations of E. orientalis inhabiting different host plants. This species should be identified carefully by considering phenotypic intraspecific variations.

Management of Asiatic Citrus Canker Under Field Conditions in Saudi Arabia Using Bacteriophages and Acibenzolar-S-Methyl

Applications of formulated bacteriophages with skim milk and sucrose or nonformulated bacteriophages combined with acibenzolar-S-methyl (ASM) were compared with copper bactericides applications for suppressing Asiatic citrus canker (ACC) caused by Xanthomonas citri subsp. citri (Xcc) on leaves under greenhouse and field conditions in Saudi Arabia. Bacteriophages were applied one day prior to inoculation of Mexican lime (Citrus aurantifolia) plants with Xcc, then twice a week until the end of the trials. Copper hydroxide was applied once prior to inoculation and then every seven days afterward, whereas ASM was applied one week prior to inoculation and then every 21 days afterward. Under greenhouse conditions, the incidence of ACC on leaves was reduced significantly from 75.2 to 12.8% or 18.3% for plants treated with copper hydroxide or bacteriophages in combination with ASM, respectively. Applications of formulated phages in combination with ASM as soil drench under field conditions significantly decreased disease incidence by 14.8% (Trial 1) and 16.8% (Trial 2) compared with untreated control plants. Overall, the Xcc-inoculated plants treated with bacteriophages + ASM combination showed significant ACC reduction under greenhouse and field conditions. The bacteriophages + ASM combination tested in these trials can be an effective tool in the integrated management programs of Asiatic citrus canker disease.

Mitochondrial Molecular Markers for Resistance to Bayoud Disease in Date Palm

Bayoud disease, caused by Fusarium oxysporum f. sp. albedinis, is a very serious and destructive disease to date palm. Screening of date palm germplasm for resistance to bayoud disease is a crucial step to avoid or alleviate the disease consequences. Fortunately, it was discovered that there are two mitochondrial plasmid-like DNA molecules associated with susceptibility or resistance to bayoud disease. In this chapter, we present a fast, simple, and reliable technique to screen date palm germplasm for the presence of these mitochondrial molecular markers associated with susceptibility or resistance to bayoud.

Efficacy of Vitamin C in Lowering Serum Uric Acid

The objective of the study was to determine the efficacy of vitamin C in reducing serum uric acid (UA). This study was a double-blind placebo-controlled randomized trial conducted in the Department of Rheumatology, Bangabandhu Sheikh Mujib Medical University (BSMMU) Dhaka, Bangladesh from July 2007 and August 2008. Study participants were included from out patient department (OPD) of Rheumatology of BSMMU suffering from various Rheumatological problems other than gouty arthritis. All of the participants were non-smokers, non-alcoholics, and randomized to take either placebo or vitamin C (500 mg/day) for 12 weeks. A total of 98 subjects were enrolled in the study; 71 completed the trial, with 34 in the placebo group and 37 receiving vitamin C. Serum uric acid levels were not significantly reduced in the experimental group and they increased in the placebo group. In the vitamin C group, the mean change was -0.32mg/dl [95% confidence interval -0.73, 0.77], whereas in the placebo group, the mean change was +0.12mg/dl [95% confidence interval was -0.22, 0.47]. Subgroups were defined by sex, body mass index, and quartiles of baseline serum uric acid levels. In a subgroup analysis, vitamin C lowered serum uric acid significantly in those who had comparatively higher baseline uric acid levels. Although vitamin C did not lower serum uric acid significantly, participants with higher baseline serum uric acid levels experienced a significant uric acid lowering effect, but as the sample size was very small, it is difficult to draw any definitive conclusion.

Allelic variation of melanocortin-1 receptor locus in Saudi indigenous sheep exhibiting different color coats

Objective

This study was designed to characterize the DNA polymorphisms of the melanocortin-1 receptor (MC1R) gene in indigenous Saudi Arabian sheep breeds exhibiting different color coats, along with individuals of the Sawaknee breed, an exotic sheep imported from Sudan.

Methods

The complete coding region of MC1R gene including parts of 3′ and 5′ untranslated regions was amplified and sequenced from three the indigenous Saudi sheep; Najdi (generally black, n = 41), Naeimi (generally white with brown faces, n = 36) and Herri (generally white, n = 18), in addition to 13 Sawaknee sheep.

Results

Five single nucleotide polymorphisms (SNPs) were detected in the MC1R gene: two led to nonsynonymous mutations (c.218 T>A, p.73 Met>Lys and c.361 G>A, p.121 Asp>Asn) and three led to synonymous mutations (c.429 C>T, p.143 Tyr>Tyr; c.600 T>G, p.200 Leu>Leu, and c.735 C>T, p.245 Ile>Ile). Based on these five SNPs, eight haplotypes representing MC1R E^d and E⁺ alleles were identified among the studied sheep breeds. The most common haplotype (H3) of the dominant E^d allele was associated with either black or brown coat color in Najdi and Sawaknee sheep, respectively. Two other haplotypes (H6 and H7) of E^d allele, with only the nonsynonymous mutation A218T, were detected for the first time in Saudi indigenous sheep.

Conclusion

In addition to investigating the MC1R allelic variation in Saudi indigenous sheep populations, the present study supports the assumption that the two independent nonsynonymous Met73Lys and Asp121Asn mutations in MC1R gene are associated with black or red coat colors in sheep breeds.

Systematic review and meta-analysis of the performance of clinical risk assessment instruments for screening for osteoporosis or low bone density

We performed a systematic review and meta-analysis of the performance of clinical risk assessment instruments for screening for DXA-determined osteoporosis or low bone density. Commonly evaluated risk instruments showed high sensitivity approaching or exceeding 90% at particular thresholds within various populations but low specificity at thresholds required for high sensitivity. Simpler instruments, such as OST, generally performed as well as or better than more complex instruments.

INTRODUCTION

The purpose of the study is to systematically review the performance of clinical risk assessment instruments for screening for dual-energy X-ray absorptiometry (DXA)-determined osteoporosis or low bone density.

METHODS

Systematic review and meta-analysis were performed. Multiple literature sources were searched, and data extracted and analyzed from included references.

RESULTS

One hundred eight references met inclusion criteria. Studies assessed many instruments in 34 countries, most commonly the Osteoporosis Self-Assessment Tool (OST), the Simple Calculated Osteoporosis Risk Estimation (SCORE) instrument, the Osteoporosis Self-Assessment Tool for Asians (OSTA), the Osteoporosis Risk Assessment Instrument (ORAI), and body weight criteria. Meta-analyses of studies evaluating OST using a cutoff threshold of <1 to identify US postmenopausal women with osteoporosis at the femoral neck provided summary sensitivity and specificity estimates of 89% (95%CI 82-96%) and 41% (95%CI 23-59%), respectively. Meta-analyses of studies evaluating OST using a cutoff threshold of 3 to identify US men with osteoporosis at the femoral neck, total hip, or lumbar spine provided summary sensitivity and specificity estimates of 88% (95%CI 79-97%) and 55% (95%CI 42-68%), respectively. Frequently evaluated instruments each had thresholds and populations for which sensitivity for osteoporosis or low bone mass detection approached or exceeded 90% but always with a trade-off of relatively low specificity.

CONCLUSIONS

Commonly evaluated clinical risk assessment instruments each showed high sensitivity approaching or exceeding 90% for identifying individuals with DXA-determined osteoporosis or low BMD at certain thresholds in different populations but low specificity at thresholds required for high sensitivity. Simpler instruments, such as OST, generally performed as well as or better than more complex instruments.

Characterization of Novel Trichoderma asperellum Isolates to Select Effective Biocontrol Agents Against Tomato Fusarium Wilt

The use of novel isolates of Trichoderma with efficient antagonistic capacity against Fusarium oxysporum f. sp. lycopersici (FOL) is a promising alternative strategy to pesticides for tomato wilt management. We evaluated the antagonistic activity of 30 isolates of T. asperellum against 4 different isolates of FOL. The production of extracellular cell wall degrading enzymes of the antagonistic isolates was also measured. The random amplified polymorphic DNA (RAPD) method was applied to assess the genetic variability among the T. asperellum isolates. All of the T. asperellum isolates significantly reduced the mycelial growth of FOL isolates but the amount of growth reduction varied significantly as well. There was a correlation between the antagonistic capacity of T. asperellum isolates towards FOL and their lytic enzyme production. Isolates showing high levels of chitinase and β-1,3-glucanase activities strongly inhibited the growth of FOL isolates. RAPD analysis showed a high level of genetic variation among T. asperellum isolates. The UPGMA dendrogram revealed that T. asperellum isolates could not be grouped by their anta- gonistic behavior or lytic enzymes production. Six isolates of T. asperellum were highly antagonistic towards FOL and potentially could be used in commercial agriculture to control tomato wilt. Our results are consistent with the conclusion that understanding the genetic variation within Trichoderma isolates and their biochemical capabilities are required for the selection of effective indigenous fungal strains for the use as biocontrol agents.

Antimicrobial resistance and in vitro biofilm-forming ability of Enterococci spp. isolated from urinary tract infection in a tertiary care hospital in Dhaka

The biofilm mode of life conveys a survival advantage to the microorganism associated with it. Biofilm on an indwelling urinary catheter consists of adherent microorganisms, their extra cellular products, and host components deposited on the catheter and thus biofilm on urinary catheters results in persistent infections that are resistant to antimicrobial therapy. This study was done during the period of January 2010 to December 2010. Fifty nine enterococci isolated from 1203 urine samples were speciated by conventional microbiological methods and examined for their ability to form biofilm by microtitre plate assay and antimicrobial susceptibility testing by disc diffusion method for 10 clinically relevant antibiotics respectively. Biofilm producing Enterococci were more frequently found in catheterized than in non catheterized patient (p<0.004). Enterococcus faecium showed increased resistantance to multiple antibiotic than Enterococcus faecalis. Significant relationship was found between biofilm production with antibiotic resistance to amoxicillin, co-trimoxazole, ciprofloxacin, gentamycin, cefotaxime, and cefuroxime. This study demonstrated a high propensity among the isolates of Enterococci to form biofilm and a significant association of biofilms with multiple drug resistance. DOI: http://dx.doi.org/10.3329/bmrcb.v40i1.20320 Bangladesh Med Res Counc Bull 2014; 40: 6-9

Performance of risk assessment instruments for predicting osteoporotic fracture risk: a systematic review

We systematically reviewed the literature on the performance of osteoporosis absolute fracture risk assessment instruments. Relatively few studies have evaluated the calibration of instruments in populations separate from their development cohorts, and findings are mixed. Many studies had methodological limitations making susceptibility to bias a concern.

INTRODUCTION

The aim of this study was to systematically review the literature on the performance of osteoporosis clinical fracture risk assessment instruments for predicting absolute fracture risk, or calibration, in populations other than their derivation cohorts.

METHODS

We performed a systematic review, and MEDLINE, Embase, Cochrane Library, and multiple other literature sources were searched. Inclusion and exclusion criteria were applied and data extracted, including information about study participants, study design, potential sources of bias, and predicted and observed fracture probabilities.

RESULTS

A total of 19,949 unique records were identified for review. Fourteen studies met inclusion criteria. There was substantial heterogeneity among included studies. Six studies assessed the WHO's Fracture Risk Assessment (FRAX) instrument in five separate cohorts, and a variety of risk assessment instruments were evaluated in the remainder of the studies. Approximately half found good instrument calibration, with observed fracture probabilities being close to predicted probabilities for different risk categories. Studies that assessed the calibration of FRAX found mixed performance in different populations. A similar proportion of studies that evaluated simple risk assessment instruments (≤5 variables) found good calibration when compared with studies that assessed complex instruments (>5 variables). Many studies had methodological features making them susceptible to bias.

CONCLUSIONS

Few studies have evaluated the performance or calibration of osteoporosis fracture risk assessment instruments in populations separate from their development cohorts. Findings are mixed, and many studies had methodological limitations making susceptibility to bias a possibility, raising concerns about use of these tools outside of the original derivation cohorts. Further studies are needed to assess the calibration of instruments in different populations prior to widespread use.

Effect of tonsillectomy on humoral immunity

Tonsils are one of the important secondary lymphoid organ in immune system. It remains controversial whether tonsillectomy results in decreased serum immunoglobulin level. The purpose of this study was to observe the effect of tonsillectomy on humoral immunity parameters among the patients with tonsillar disease. Total group A 70 patients up to the age of 18 years, who were enrolled for tonsillectomy and 30 age matched children group B were included for comparative study. Serum IgG, IgM and IgA levels were measured in all 70 patients before tonsillectomy and in 56 patients who came for 1st follow-up after one month and 30 patients who came for 2nd follow up after three months of tonsillectomy. Serum IgG, IgM and IgA levels were also measured in group B children. Serum IgG, IgM and IgA levels in patients of group A did not show any significant difference in comparison to group B. One month after tonsillectomy the level of IgG was slightly decreased and IgM and IgA were increased compared to preoperative value but not statistically significant. All IgG, IgM and IgA were also not significantly altered in comparison to group B. Three months after tonsillectomy serum IgG, IgM and IgA level were found decreased in comparison to pre operative value and group B, among which difference of only IgG was significant. After tonsillectomy humoral parameters were found reduced but overall impact on humoral immune status was not significantly altered.

Fusarium verticillioides from finger millet in Uganda

Finger millet (Eleusine coracana) is a subsistence crop grown in Sub-Saharan Africa and the Indian Sub-continent. Fusarium species occurring on this crop have not been reported. Approximately 13% of the Fusarium isolates recovered from finger millet growing at three different locations in eastern Uganda belong to Fusarium verticillioides, and could produce up to 18,600 µg/g of total fumonisins when cultured under laboratory conditions. These strains are all genetically unique, based on AFLP analyses, and form fertile perithecia when crossed with the standard mating type tester strains for this species. All but one of the strains is female-fertile and mating-type segregates 13:20 Mat-1:Mat-2. Three new sequences of the gene encoding translation elongation factor 1-α were found within the population. These results indicate a potential health risk for infants who consume finger millet gruel as a weaning food, and are consistent with the hypothesis that F. verticillioides originated in Africa and not in the Americas, despite its widespread association with maize grown almost anywhere worldwide.

Disease Severity and Microsclerotium Properties of the Sorghum Sooty Stripe Pathogen, Ramulispora sorghi

Ramulispora sorghi causes sooty stripe of sorghum. Disease severity in irrigated and dryland plots was measured for 25 susceptible sorghum genotypes during the 2007 and 2008 growing seasons using a rating scale based upon percent leaf area infected. Disease severity ratings were approximately 1.4 points higher (P < 0.0001) on the rating scale in the irrigated plots than dryland plots for 2007 and 2008. Sooty stripe lesions were collected from each sorghum genotype in irrigated plots and assessed for mean microsclerotium production within lesions, microsclerotium size, and sporogenic germination, with significant differences apparent between genotypes for microsclerotium size (P = 0.01) and sporogenic germination (P = 0.01). There was no relationship between disease severity and microsclerotium production within leaf lesions, microsclerotium size, or sporogenic germination; however, there was a positive and significant correlation between microsclerotia production within a lesion and microsclerotium size (R² = 0.19, P < 0.0001). Although microsclerotia from sorghum lesions varied in structural characteristics and their ability to produce spore masses, these qualities were dependent upon the sorghum genotype from which the microsclerotia were derived, because the R. sorghi population was genetically uniform as determined by internal transcribed spacer sequences and random amplified polymorphic DNA polymerase chain reaction.

Genomic and resistance gene homolog diversity of the dominant tallgrass prairie species across the U.S. Great Plains precipitation gradient

BACKGROUND

Environmental variables such as moisture availability are often important in determining species prevalence and intraspecific diversity. The population genetic structure of dominant plant species in response to a cline of these variables has rarely been addressed. We evaluated the spatial genetic structure and diversity of Andropogon gerardii populations across the U.S. Great Plains precipitation gradient, ranging from approximately 48 cm/year to 105 cm/year.

METHODOLOGY/PRINCIPAL FINDINGS

Genomic diversity was evaluated with AFLP markers and diversity of a disease resistance gene homolog was evaluated by PCR-amplification and digestion with restriction enzymes. We determined the degree of spatial genetic structure using Mantel tests. Genomic and resistance gene homolog diversity were evaluated across prairies using Shannon's index and by averaging haplotype dissimilarity. Trends in diversity across prairies were determined using linear regression of diversity on average precipitation for each prairie. We identified significant spatial genetic structure, with genomic similarity decreasing as a function of distance between samples. However, our data indicated that genome-wide diversity did not vary consistently across the precipitation gradient. In contrast, we found that disease resistance gene homolog diversity was positively correlated with precipitation.

SIGNIFICANCE

Prairie remnants differ in the genetic resources they maintain. Selection and evolution in this disease resistance homolog is environmentally dependent. Overall, we found that, though this environmental gradient may not predict genomic diversity, individual traits such as disease resistance genes may vary significantly.

Cutaneous sporotricosis

Sporotrichosis, a deep fungal infection caused by Sporothrix schenckii, is a rare disease. Infection acquired by traumatic implantation of fungus to the skin. Our patient a 40 years old woman presented with multiple erythematous, ulcerated, crusted nodules of different size and shape situated over the right little finger to upper arm along the course of the lymphatic in a linear fashion. Microscopic examination and culture of the discharge from the skin lesion was done. Sporothrix schenckii was detected on microscopic examination (Yeast form) and on culture (Mycelial form). The patient was treated with Itraconazole at a dose of 100 mg twice in a day for 6 months. She was clinically cured of the disease by 6 months and then the treatment was stopped. We do not commonly encounter sporotrichosis in our practice. We are therefore, prompted to report the case.

Relatedness of Macrophomina phaseolina isolates from tallgrass prairie, maize, soybean and sorghum

Agricultural and wild ecosystems may interact through shared pathogens such as Macrophomina phaseolina, a generalist clonal fungus with more than 284 plant hosts that is likely to become more important under climate change scenarios of increased heat and drought stress. To evaluate the degree of subdivision in populations of M. phaseolina in Kansas agriculture and wildlands, we compared 143 isolates from maize fields adjacent to tallgrass prairie, nearby sorghum fields, widely dispersed soybean fields and isolates from eight plant species in tallgrass prairie. Isolate growth phenotypes were evaluated on a medium containing chlorate. Genetic characteristics were analysed based on amplified fragment length polymorphisms and the sequence of the rDNA-internal transcribed spacer (ITS) region. The average genetic similarity was 58% among isolates in the tallgrass prairie, 71% in the maize fields, 75% in the sorghum fields and 80% in the dispersed soybean fields. The isolates were divided into four clusters: one containing most of the isolates from maize and soybean, two others containing isolates from wild plants and sorghum, and a fourth containing a single isolate recovered from Solidago canadensis in the tallgrass prairie. Most of the sorghum isolates had the dense phenotype on media containing chlorate, while those from other hosts had either feathery or restricted phenotypes. These results suggest that the tallgrass prairie supports a more diverse population of M. phaseolina per area than do any of the crop species. Subpopulations show incomplete specialization by host. These results also suggest that inoculum produced in agriculture may influence tallgrass prairie communities, and conversely that different pathogen subpopulations in tallgrass prairie can interact there to generate 'hybrids' with novel genetic profiles and pathogenic capabilities.

Typhoid Fever

Typhoid fever is one of the most common febrile illnesses encountered by the physicians in Bangladesh. Diagnosis is not difficult but has lately become a challenge due to changed clinical pattern of the disease, lack of adequate facilities for blood, stool, urine culture, excessive reliance on nonspecific Widal test and non availability of any reliable rapid diagnostic tests. Further, the indiscriminate and injudicious use of antibiotics for treating fever in undiagnosed febrile illnesses early has created problems to the physicians to reach to a diagnosis later on. This has also led to the emergence of high level resistance to many of the commonly used antibiotics in our country. Ciprofloxacin is often used empirically for treating the disease though there is already a high level resistance. In case the organism is in-vitro sensitive to ciprofloxacin but resistant to nalidixic acid, a much higher dose of drug is required to maintain the MIC which is 10 times higher than usual. Third generation cephalosporins (ceftriaxone and cefixime) are still the effective drugs for treating typhoid fever. The drug needs to be used in proper dose and duration to prevent emergence of resistance. Azithromycin though advocated by many as an alternative to ciprofloxacin in resistant cases, has recently lost its credibility due to emergence of resistance. We should not rely on Widal test in diagnosing typhoid fever. In a suspected case, the patient should not be prescribed any antibiotic without sending blood sample for culture sensitivity.

Genetic Structure of Atmospheric Populations of Gibberella zeae

ABSTRACT Gibberella zeae, causal agent of Fusarium head blight (FHB) of wheat and barley and Gibberella ear rot (GER) of corn, may be transported over long distances in the atmosphere. Epidemics of FHB and GER may be initiated by regional atmospheric sources of inoculum of G. zeae; however, little is known about the origin of inoculum for these epidemics. We tested the hypothesis that atmospheric populations of G. zeae are genetically diverse by determining the genetic structure of New York atmospheric populations (NYAPs) of G. zeae, and comparing them with populations of G. zeae collected from seven different states in the northern United States. Viable, airborne spores of G. zeae were collected in rotational (lacking any apparent within-field inoculum sources of G. zeae) wheat and corn fields in Aurora, NY in May through August over 3 years (2002 to 2004). We evaluated 23 amplified fragment length polymorphism (AFLP) loci in 780 isolates of G. zeae. Normalized genotypic diversity was high (ranging from 0.91 to 1.0) in NYAPs of G. zeae, and nearly all of the isolates in each of the populations represented unique AFLP haplotypes. Pairwise calculations of Nei's unbiased genetic identity were uniformly high (>0.99) for all of the possible NYAP comparisons. Although the NYAPs were genotypically diverse, they were genetically similar and potentially part of a large, interbreeding population of G. zeae in North America. Estimates of the fixation index (G(ST)) and the effective migration rate (Nm) for the NYAPs indicated significant genetic exchange among populations. Relatively low levels of linkage disequilibrium in the NYAPs suggest that outcrossing is common and that the populations are not a result of a recent bottleneck or invasion. When NYAPs were compared with those collected across the United States, the observed genetic identities between the populations ranged from 0.92 to 0.99. However, there was a significant negative correlation (R = -0.59, P < 0.001) between genetic identity and geographic distance, suggesting that some genetic isolation may occur on a continental scale. The contribution of long-distance transport of G. zeae to regional epidemics of FHB and GER remains unclear, but the diverse atmospheric populations of G. zeae suggest that inoculum may originate from multiple locations over large geographic distances. Practically, the long-distance transport of G. zeae suggests that management of inoculum sources on a local scale, unless performed over extensive production areas, will not be completely effective for the management of FHB and GER.

Cephalosporium maydis is a distinct species in the Gaeumannomyces-Harpophora species complex

Cephalosporium maydis is an important plant pathogen whose phylogenetic position relative to other fungi has not been established clearly. We compared strains of C. maydis, strains from several other plant-pathogenic Cephalosporium spp. and several possible relatives within the Gaeumannomyces-Harpophora species complex, to which C. maydis has been suggested to belong based on previous preliminary DNA sequence analyses. DNA sequences of the nuclear genes encoding the rDNA ITS region, β-tubulin, histone H3, and MAT-2 support the hypothesis that C. maydis is a distinct taxon within the Gaeumannomyces-Harpophora species complex. Based on amplified fragment length polymorphism (AFLP) profiles, C. maydis also is distinct from the other tested species of Cephalosporium, Phialophora sensu lato and members of Gaeumannomyces-Harpophora species complex, which supports its classification as Harpophora maydis. Oligonucleotide primers for H. maydis were developed that can be used in a PCR diagnostic protocol to rapidly and reliably detect and identify this pathogen. These diagnostic PCR primers will aid the detection of H. maydis in diseased maize because this fungus can be difficult to detect and isolate, and the movement of authentic cultures may be limited by quarantine restrictions.

Amplified Fragment Length Polymorphism Diversity in Cephalosporium maydis from Egypt

ABSTRACT Cephalosporium maydis, the causal agent of late wilt of maize, was first described in Egypt in the 1960s, where it can cause yield losses of up to 40% in susceptible plantings. We characterized 866 isolates of C. maydis collected from 14 governates in Egypt, 7 in the Nile River Delta and 7 in southern (Middle and Upper) Egypt, with amplified fragment length polymorphism (AFLP) markers. The four AFLP primer-pair combinations generated 68 bands, 25 of which were polymorphic, resulting in 52 clonal haplotypes that clustered the 866 isolates into four phylogenetic lineages. Three lineages were found in both the Nile River Delta and southern Egypt. Lineage IV, the most diverse group (20 haplotypes), was recovered only from governates in the Nile River Delta. In some locations, one lineage dominated (up to 98% of the isolates recovered) and, from some fields, only a single haplotype was recovered. Under field conditions in Egypt, there is no evidence that C. maydis reproduces sexually. The nonuniform geographic distribution of the pathogen lineages within the country could be due to differences in climate or in the farming system, because host material differs in susceptibility and C. maydis lineages differ in pathogenicity.

Comparison of PCR method with the culture method for identification of gonococci from endocervical swabs

Gonococcal infection remains still a major cause of morbidity among sexually active individuals. Diagnosis of the infection in a female case is more difficult than that in a male. This was a prospective study among 269 female commercial sex workers (CSWs) to screen them for gonococcal infection, comparing the rapid method of identification of gonococci by polymerase chain reaction (PCR) with the selective culture method. A total of 92 (34.2%) CSWs were identified positive for Neisseria gonorrhoeae by combination of the two methods. The PCR method identified 87 of the specimens to harbour cppB gene of N. gonorrhoeae, whereas culture method identified 83 specimens showing colonies of gonococci. Taking into consideration of the total positive cases (92), the PCR method showed a sensitivity of 94.57%, whereas sensitivity of culture method was 90.22%. The selective culture method appears to be the most applicable in the identification of gonococci from clinical specimens, particularly in the less resourceful countries like Bangladesh.

Primary drug resistance pattern of mycobacterium tuberculosis in Dhaka, Bangladesh

One thousand two hundred and eighty one clinically suspected untreated patients with pulmonary tuberculosis were studied from an urban tuberculosis clinic in Dhaka. Majority of the 1281 patients (77.6%) were from the age group of 14 to 44 years. Sputum, 106 (8.3%) were found positive for mycobacteria (both by Ziehl-Neelsen smear staining and culture to consider those as confirmed cases of mycobacterial infection. Out of these 106 cases, 101 (95.3%) were identified as M. tuberculosis and the rest 5 (4.7%) as Non-tuberculous Mycobacteria (NTM). Among the 101 M. tuberculosis strains, 30 (29.7%) were resistant to at least one drug; 16 (15.8%); to isoniazid, 11 (10.9%) to rifampicin, 07 (6.9%) to streptomycin, 03 (2.9%) to ethambutol and 04 (3.9%) to pyrazinamide. Multi-drug resistant tuberculosis (MDR-TB) was found in 5 (4.95%) cases. 5 (4.95%) cases were resistant to two drugs and 3 (2.97%) cases to three drugs. Ciprofloxacin was tested against 30 strains of M. tuberculosis; 2 (6.67%) of which were resistant. This is the first report of ciprofloxacin resistant Mycobacterium tuberculosis from Bangladesh. All the 5 strains of NTM tested for said 5 anti-tuberculous drugs, were found resistant to more than one.

Effect of endodontic irrigation solutions on microhardness of root canal dentine

OBJECTIVES

This study was undertaken to evaluate the effect of several endodontic irrigation solutions on the microhardness of root canal dentine.

METHODS

Eighteen freshly extracted maxillary incisors were used in this experiment. The crowns of teeth were sectioned at the cemento-enamel junction. The root canals were instrumented to an apical size #50 file, and irrigated with saline solution. The prepared roots were divided equally into two groups each of nine roots. Each root was sectioned transversely into cervical, middle and apical segments. The three sections of each root were separately mounted in a metal chuck with acrylic resin. The coronal dentine surfaces of the root segments were polished. The microhardness of the dentine was measured for the purposes of control data at 500 microns and 1 mm from the pulpo-dentinal interface. The canal portions in the root segments included in the first group were irrigated with 3% H2O2 and 5% NaOCl solutions used alternatively, while 17% EDTA solution was the irrigation used in the second group. One millilitre of each solution/segment was applied for 60 s exposure time. After irrigation, dentine microhardness was re-assessed and compared with the control values obtained before the irrigation treatment. Data were statistically analysed using ANOVA and Scheffe's test.

RESULTS

The results showed that, irrigation with either H2O2/NaOCl or EDTA decreased the microhardness value of root dentine. Irrigation with EDTA gave more reduction of dentine hardness compared to H2O2/NaOCl irrigation. The reduction of KHN of dentine following the irrigation treatment was statistically significant (p < 0.05) at both levels of hardness measurement.

CONCLUSIONS

Both H2O2/NaOCl and EDTA irrigating solutions significantly reduced the microhardness of root canal dentine.

Third stage of labor: analysis of duration and clinical practice

OBJECTIVES

Our purpose was to record gestational age-specific data for third-stage duration of labor, frequencies of retained placentas (undelivered at 30 minutes), manual removal of the placenta, and hemorrhage.

STUDY DESIGN

Included were 45,852 singleton deliveries > or = 20 weeks' gestation from 1984 to 1992. Odds ratios, 95% confidence intervals, and actuarial life analysis with censoring of cases with manual placenta removal were performed.

RESULTS

The frequency of retained placentas (2.0% overall) was markedly increased among gestations < or = 26 weeks (odds ratio 20.8, 95% confidence interval 17.1 to 25.4) and < 37 weeks (odds ratio 3.0, 95% confidence interval 2.6 to 3.5) compared with term. The frequency of manual removal (3.0% overall) was increased among gestations < or = 26 weeks (odds ratio 9.2, 95% confidence interval 7.5 to 11.4) and < 37 weeks (odds ratio 2.8, 95% confidence interval 2.4 to 3.1) compared with term. Hemorrhage (3.5% overall) was increased among subjects with manual placenta removal (odds ratio 10.4, 95% confidence interval 9.1 to 11.9); hemorrhage was also increased among gestations < or = 26 weeks (odds ratio 3.0, 95% confidence interval 2.3 to 4.0) and < 37 weeks (odds ratio 1.2, 95% confidence interval 1.01 to 1.3) compared with term. The frequency of hemorrhage peaked by 40 minutes regardless of gestational age. Life-table analysis predicted 90% of placentas would spontaneously deliver by 180 minutes for gestations at 20 weeks, 21 minutes at 30 weeks, and 14 minutes at 40 weeks; the predicted frequency of retained placentas was 42% higher than the recorded incidence.

CONCLUSIONS

The duration of the third stage decreases and the frequencies of hemorrhage and manual removal decrease with increasing gestational age. Hemorrhage was associated with manual placental removal. Life-table analysis indicated that manual removal of placentas shortened the duration of the third stage of labor, especially among preterm deliveries. A prospective trial is needed to determine whether manual placental removal can reduce hemorrhage among prolonged third stages.

Hyperinsulinemia and insulin resistance are associated with preeclampsia in African-Americans

There is evidence that hyperinsulinemia and insulin resistance play a role in the development of hypertension. Accordingly, in our ongoing longitudinal study of pregnancy-induced hypertension, we have measured fasting levels of insulin and glucose at 18 to 25 weeks gestation in 140 nulliparous African-American women followed prospectively to delivery. To test the hypothesis that hyperinsulinemia may be related to the development of preeclampsia, discriminant analysis of mean arterial pressure (MAP), fasting plasma insulin levels, insulin to glucose ratios, and left lateral forearm vascular resistance were examined as predictors of preeclampsia. Statistical analysis controlled for two factors known to be related to insulin levels, gestational age and pregestational body mass index. Gestational hypertensives were not different with regard to blood pressure and metabolic factors from normals and thus were placed in the control group. Women who subsequently developed preeclampsia had mean (+/- SE) fasting plasma insulin levels of 51.0 +/- 12.0 microU/mL at 20 weeks and controls had values of 29.0 +/- 2.8. Only MAP [F(4,135) = 8.8, P < .01] and insulin [F(1,135) = 6.5, P < .05] were related to the development of preeclampsia [F(4,135) = 4.39, R2 = 11.5%]. The finding that elevated second-trimester insulin levels characterize the subsequent development of preeclampsia with control for increased MAP supports the hypothesis that hyperinsulinemia and associated insulin resistance may contribute to the pathogenesis of preeclampsia.

Effect of alcohol on platelet-activating factor acetylhydrolase activity in pregnant and nonpregnant mice

Platelet-activating factor (PAF) induces platelet aggregation and hypotension. It has been implicated in embryonic implantation, fetal lung maturation, and parturition. Alcohol abuse is associated with platelet dysfunction, chronic hypertension, and alcohol-related birth defects. We hypothesized that alcohol may cause, in part, these effects by increasing the activity of PAF-acetylhydrolase (PAF-AH), thereby decreasing PAF concentration. Pregnant mice were given 3.5 g/kg of alcohol orally twice daily from gestation days 7-17. PAF-AH was measured on gestation days 5, 14, and 19 in pregnant females. Nonpregnant females were treated and sampled at parallel time intervals. Pair-fed and untreated control groups were also used. The maternal plasma PAF-AH decreased with gestational age in the untreated controls. Alcohol significantly increased PAF-AH levels in both the pregnant and nonpregnant animals. PAF deficiency might contribute to the tocolytic action of alcohol, as well as some alcohol-related pregnancy complications.

Hemostasis and diagnosis of preeclampsia

The diagnosis of preeclampsia, with all of its consequences, is at times difficult to establish, especially when the patient has underlying chronic hypertension and is not known from prior prenatal care visits. Many screening tests have been proposed. These should be sensitive, relatively specific, easy to perform, of low cost, and have a reasonable interval from prediction to disease onset. Laboratory assays would obviously be useful. We evaluated hemostasis tests for the diagnosis of preeclampsia, and compared fibronectin, antithrombin III and alpha 2-antiplasmin in 48 preeclamptics and 86 control nulliparas. Receive operator characteristic (ROC) curve analysis suggested that fibronectin is the most effective of these tests. A similar analysis comparing the results of previous studies using serum iron, angiotensin infusion, urinary calcium/creatinine ratio, the rollover test and uric acid suggested a possible role for fibronectin in the diagnosis of preeclampsia. While not ideal, there seems to be, at present, no other, easy to perform laboratory test that outperforms fibronectin in predicting preeclampsia.

Birth weight-length ratios, ponderal indexes, placental weights, and birth weight-placenta ratios in a large population

BACKGROUND

Birth weight (BW)/length ratios, ponderal indexes, placental weights, and BW/placental weight ratios have been correlated with perinatal morbidity and mortality.

METHODS

Cross-sectional survey of live-born, structurally normal, singleton neonates delivered at a tertiary care center in Detroit, Mich, from 1984 through 1991. Subjects were included if dating based on menstrual dates and ultrasonographic estimations agreed with Ballard examination to within 2 weeks.

RESULTS

Of 33,138 neonates, 26,983 (81.4%) were black. While all indexes significantly increased with advancing gestational age, only placental weights (without prior draining of blood, blotting the placenta dry, or trimming the membranes or cord) and BW/length ratios significantly increased beyond 40 weeks' gestation. Multivariate analysis of variance revealed that placental weights, BW/placenta ratios, and BW/length ratios were significantly related to gender and ethnicity, but ponderal index was not. Placental weights were larger, and BW/placenta ratios were smaller than studies that trimmed the placentas before weighing.

CONCLUSIONS

All indexes were gestational age dependent, but ponderal index and BW/placenta ratios do not increase beyond 40 weeks' gestation. Except for ponderal index, interpretation of these indexes should be specific for ethnicity, gender, and manner of placental preparation.

Platelet activating factor-acetylhydrolase activity following chorionic villus sampling and amniocentesis

OBJECTIVE

Platelet activating factor (PAF) is essential for embryonic development and is a potent vasodilator. It increases vascular permeability and stimulates prostaglandin E2 (PGE2) production. Platelet activating factor-acetylhydrolase (PAF-AH), the enzyme that degrades PAF, is synthesized by decidual macrophages. The aim of this study was to test the hypothesis that chorionic villus sampling (CVS) and/or amniocentesis might cause an increase in maternal PAF-AH activity.

METHODS

Maternal plasma PAF-AH activity was evaluated before and after genetic amniocentesis (N = 13) and transcervical CVS (N = 29). A control group (N = 9) was evaluated to study the effects of venipuncture.

RESULTS

Chorionic villus sampling caused a significant elevation in PAF-AH activity (P < .0005). No changes were noted in PAF-AH activity in the amniocentesis or the control group.

CONCLUSIONS

Chorionic villus sampling causes subclinical release of PAF-AH, possibly from the decidual macrophages. Increased PAF-AH activity might result in decreased PAF levels, which might lead to vasoconstriction in the placental circulation due to lack of the vasodilator effects of PAF and possibly PGE2. This mechanism might explain the increased risk for fetal limb reduction noted with CVS performed at very early gestational ages.