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Organic crop production, whether for export or local consumption, is increasing to avoid the residual effects of synthetic herbicides in foods, soil, and water, toxicity to other nontarget organisms, and herbicide-resistant weed populations. Organic farmers consistently ranked weed management as one of their most important production problems. Therefore, a 2-year study was conducted under 15-year-old mandarin trees to compare the effects of rice straw mulch, cattail mulch, black plastic mulch, hand hoeing, cultivation, glyphosate, and unweeded control treatments on weed control, fruit yield, and fruit quality. The greatest control (94%-100%) of weeds occurred with the plastic mulch (200 or 150 µm) and three mulch layers of rice straw or cattail. Covering soil with cattail or rice straw mulch (two layers) gave 85% to 98% control of weeds. Uncontrolled weeds in the weedy control caused significant reduction in yield and fruit quality and decreased the yield/tree by 62% compared with hand hoe treatment. Plastic mulches of 200 and 150 p.m, cattail (Cyprus articulatus L.) mulch (two or three layers) and two mulch layers of rice (Oryza sativa L.) straw treatments significantly increased the fruit yield/tree by 24%, 18%, 20%, 11%, and 12% more than cultivation treatment, respectively, without significant differences among these superior treatments. Soil mulching with three layers of rice straw, cultivation, glyphosate, and 80-µm plastic mulch treatments caused a significant reduction in weed density and weed biomass, but gave lower yield than superior treatments. Total soluble solids of fruits was unaffected by any of the weed management strategies, whereas values of total acidity and vitamin C were significantly lower in the unwedded control than most weeded treatments. These results demonstrate that two layers of cattail or rice straw mulch could be used effectively for controlling weeds in citrus groves. Their effectiveness in controlling weeds may increase their use in agriculture systems with a concomitant decrease in the need for synthetic herbicides. Further studies are needed to evaluate their side effects on beneficial organisms, diseases, and insects. [ABSTRACT FROM AUTHOR]

Background: The impact of clinical factors and social determinants of health on treatment patterns and health care costs among patients with HCC is unknown., Methods: Using 100% Medicare Fee-For-Service claims and a commercial multipayor claims database, we identified patients diagnosed with HCC from January 1, 2017, to December 31, 2020. Surveillance receipt was defined 12 months prior to HCC diagnosis, whereas treatment and health care costs were assessed post-HCC diagnosis. Multinomial logistic regression was used to assess the association between demographics, social determinants of health, and surveillance or HCC treatment. Multivariable generalized linear regression was used to identify factors associated with total health care costs., Results: Of the 32,239 patients with HCC (mean age 68 y, 67% male, 73% White), 70% received surveillance and only half (51%) received any treatment. Curative treatment receipt was higher among those with prior surveillance (24% with CT/MRI and 18% with ultrasound vs. 9% with no surveillance). Curative treatment was independently associated with HCC surveillance and inversely associated with Black race, lower education level, and diagnosis in the year 2020 (COVID-19 year). Higher health care costs were independently associated with Black race, low English proficiency, living alone, and diagnosis in 2018-2020, and inversely associated with CT/MRI-based surveillance., Conclusions: Race and social determinants of health were independently associated with curative treatment receipt and health care costs. Increasing access to high-quality HCC surveillance may improve treatment receipt and reduce health disparities among patients with HCC., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Association for the Study of Liver Diseases.)

This study reports the antibacterial and antibiofilm activities of Magnesium ferrite nanoparticles (MgFe 2 O 4 ) against gram-positive and gram-negative bacteria. The photocatalytic degradation of Carbol Fuchsin (CF) dye (a class of dyestuffs that are resistant to biodegradation) under the influence of UV-light irradiation is also studied. The crystalline magnesium ferrite (MgFe 2 O 4 ) nanoparticles were synthesized using the co-precipitation method. The morphology of the resulting nanocomposite was examined using scanning electron microscopy (SEM), while transmission electron microscopy (TEM) was employed for further characterization of particle morphology and size. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were utilized to analyze the crystalline structure, chemical composition, and surface area, respectively. Optical properties were evaluated using UV-Vis spectroscopy. The UV-assisted photocatalytic performance of MgFe 2 O 4 nanoparticles was assessed by studying the decolorization of Carbol fuchsin (CF) azo dye. The crystallite size of the MgFe 2 O 4 nanoparticles at the (311) plane, the most prominent peak, was determined to be 28.5 nm. The photocatalytic degradation of 10 ppm CF using 15 mg of MgFe 2 O 4 nanoparticles resulted in a significant 96% reduction after 135 min at ambient temperature (25 °C) and a pH value of 9. Additionally, MgFe 2 O 4 nanoparticles exhibited potent antibacterial activity against E. coli and S. aureus in a dose dependent manner with maximum utilized concentration of 30 µg/ml. Specifically, MgFe 2 O 4 nanoparticles demonstrated substantial antibacterial activity via disk diffusion and microbroth dilution tests with zones of inhibition and minimum inhibitory concentrations (MIC) for E. coli (26.0 mm, 1.25 µg/ml) and S. aureus (23.0 mm, 2.5 µg/ml), respectively. Moreover, 10.0 µg/ml of MgFe 2 O 4 nanoparticles elicited marked percent reduction in biofilm formation by E. coli (89%) followed by S. aureus (78.5%) after treatment. In conclusion, MgFe 2 O 4 nanoparticles demonstrated efficient dye removal capabilities along with significant antimicrobial and antibiofilm activity against gram-positive and gram-negative bacterial strains suggesting their potential as promising antimicrobial and detoxifying agents., (© 2024. The Author(s).)

The Revised Cardiac Risk Index (RCRI) and the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) preoperative risk assessment tools are the most widely used methods for quantifying the risk of major negative perioperative cardiac outcomes that a patient may face during and after noncardiac surgery. However, these tools were created to include as wide a range of surgical factors as possible; thus, some predictive accuracy is sacrificed when it comes to certain surgical subpopulations. In this review, we explore the various surgical oncology patient populations for whom these assessment tools can be reliably applied and for whom they demonstrate poor reliability.

To assess epidemiology, clinical presentation, treatment and overall survival of adult patients with renal sarcomas, the 2004-2016 SEER and NCDB databases were queried for adult patients diagnosed with renal sarcoma, calculating average annual age-adjusted incidence rates (AAIR) and average annual percentage change (AAPC) as well as overall survival (OS). In n = 1279 included renal sarcoma patients, AAIR remained constant over the study period (average 0.53 cases/1million; AAPC = 0.7, p = 0.6). Leiomyosarcoma (AAIR 0.14 cases/1 million) and malignant rhabdoid tumors (0.06 cases/1 million) were most common. Sarcoma histiotypes demonstrated considerable heterogeneity regarding demographic and cancer-related variables. Patients presented with advanced local extent (T3 33.3%; T4 14.2%) or distant metastases (29.1%) and commonly underwent surgical resection (81.6%). Longer OS was independently associated with younger age, female sex, lower comorbidity index, low T stage, negative surgical margins, absence of tumor necrosis or distant metastases and leiomyosarcoma histiotype (multivariable p < 0.05 each). Treatment efficacy varied according to sarcoma histiotype (interaction p < 0.001). Accounting for 0.25% of renal malignancies, renal sarcomas include 43 histiotypes with distinct epidemiology, clinical presentation, outcomes and sensitivity to systemic therapy, thereby reflecting soft-tissue sarcoma behavior. Renal sarcoma treatment patterns follow recommendations by renal cancer guidelines with surgical resection as the cornerstone of therapy., (© 2024. The Author(s).)

The kidney is a comparatively hostile microenvironment characterized by highsodium concentrations; however, lymphocytes infiltrate and survive therein in autoimmune diseases such as lupus. The effects of sodium-lymphocyte interactions on tissue injury in autoimmune diseases and the mechanisms used by infiltrating lymphocytes to survive the highsodium environment of the kidney are not known. Here, we show that kidney-infiltrating B cells in lupus adapt to elevated sodium concentrations and that expression of sodium potassium adenosine triphosphatase (Na + -K + -ATPase) correlates with the ability of infiltrating cells to survive. Pharmacological inhibition of Na + -K + -ATPase and genetic knockout of Na + -K + -ATPase γ subunit resulted in reduced B cell infiltration into kidneys and amelioration of proteinuria. B cells in human lupus nephritis biopsies also had high expression of Na + -K + -ATPase. Our study reveals that kidney-infiltrating B cells in lupus initiate a tissue adaption program in response to sodium stress and identifies Na + -K + -ATPase as an organ-specific therapeutic target.

Preoperative nutritional status is an important and modifiable risk factor of a patient's recovery and outcome after radical cystectomy. There are multiple malnutrition screening tools and treatment options. In this review, we discuss the best indicators of this condition and how to optimize nutrition status prior to radical cystectomy.

Studies comparing the histomorphologic features and phenotypic heterogeneity between primary and its corresponding metastatic hepatocellular carcinoma (HCC) are lacking. The aim of this study was to assess and compare the histomorphologic features and heterogeneity between primary and metastatic HCC. A total of 39 cases with both primary and metastatic tissues were identified from pathology archives (2000-2019). The common sites of metastasis included lung (28.21%), abdominal cavity (25.64%), lymph nodes (20.51%), bone (17.95%), soft tissue (15.38%), and adrenal gland (10.26%). Both the primary and metastatic tumors showed heterogeneity in intratumoral histologic patterns (87.18% and 76.92%, respectively). The most common histologic pattern was solid in both primary (61.54%) and metastases (56.41%), followed by macrotrabecular in primary (17.95%) and metastases (10.26%). Among HCC-subtypes, macrotrabecular-massive HCC was the most common subtype in both primary and metastases (28.21% each). Primary tumors in noncirrhotic livers were more likely to have larger size and microvascular invasion than those in cirrhotic livers. The histomorphology (histologic pattern, subtype, and grade) between the primary and metastases was discordant in about 50% cases (48.72%, 48.72%, and 51.28%, respectively). Our findings exhibit significant intratumoral heterogeneity and histomorphologic discordance between primary and metastatic HCCs. The solid and macrotrabecular histologic patterns and the macrotrabecular-massive subtype were the most common histomorphologic features seen in primary tumors associated with metastasis. Further studies to identify and explore different pathways that promote HCC metastasis and to compare the differences between primary and metastatic tumors on a larger cohort are needed to better understand the pathogenesis of metastasis., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Importance: Atrial fibrillation is the most clinically significant arrhythmia in humans when viewed both from a global and also a national perspective. In the United States, approximately 2.7-6.1 million people are estimated to have atrial fibrillation. With the aging of the population, this prevalence is on an increasing trend and remains an obstacle to cardiovascular health despite significant advancements specific to cardiovascular disease management., Observation: In this specific group of patients, healthcare utilization is a concern from the public health perspective. Unfortunately, misconceptions dominate clinical decision making; for instance, the avoidance of safe and effective anticoagulation strategies in patients at the highest risk for embolic strokes continues to be widespread in clinical practice and is often based on a skewed assessment of risk versus benefit. Also, when there are contraindications to standard interventions for atrial fibrillation, a clear and nuanced understanding of second- and third-line interventions with proven benefit is often lacking., Conclusions and Relevance: An individualized approach should be followed by physicians when managing atrial fibrillation in the elderly patient, taking into consideration the risk of complications, particularly the embolic stroke and the availability of treatment options for stroke prevention whether through pharmacological anticoagulation or left atrial appendage occluding devices. The following review sets out to clarify these issues., Competing Interests: Authors declare no conflict of interests for this article., (© 2021 The Authors. Journal of Arrhythmia published by John Wiley & Sons Australia, Ltd on behalf of Japanese Heart Rhythm Society.)

Multi-vessel disease including the brachiocephalic artery remains a relatively rare finding in atherosclerotic disease when compared to stenosis of other major vasculature. Its management presents many difficulties. Endovascular intervention is a highly preferred choice of therapy in these patients although it is dependent on operator experience. We present a case of left common carotid and brachiocephalic arterial stenosis in a patient who presented with neurological alterations that was treated with endovascular stenting. Technical difficulty was encountered during intervention but was successful., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2021, Salih et al.)

Objective: The aim of this study was to translate the Palliative Performance Scale (PPSv2) into Arabic and to test the reliability and validity of the PPS Arabic translation (PPS-Arabic)., Method: The PPSv2 was translated into Modern Standard Arabic using a forward-backward method. Inter-rater and intra-rater reliabilities were tested in a pilot study that included 20 patients. The validation study included 150 cancer patients. Patients were divided according to their treatment plan into three groups (in-remission, palliative chemotherapy, and best supportive care) to perform hypothesis-testing construct validity. Validity was further evaluated by correlating PPS-Arabic with the Karnofsky Performance Scale (KPS), the Eastern Cooperative Oncology Group (ECOG) scale, and Physical Functioning (PF2) and Role Functioning (RF2) scales of the European Organization for Research and Treatment of Cancer quality of life questionnaire (EORTC QLQ-C30)., Results: The intraclass correlation coefficients for the intra-rater and inter-rater reliability were 0.935 (95% CI: 0.88-0.965; p < 0.001) and 0.965 (95% CI: 0.934-0.981; p < 0.001), respectively. The PPS-Arabic internal consistency Cronbach's alpha was 0.986. The average PPS-Arabic score differed significantly (p < 0.001) between the three groups of patients being 89 for in-remission, 58 for palliative chemotherapy, and 38 for best supportive care. The PPS-Arabic score correlated significantly (p < 0.001) with the KPS, ECOG performance scale, and the EORTC QLQ-C30 PF2 and RF2 scales., Conclusion: The PPS-Arabic is a reliable and valid tool for the assessment of performance status of cancer patients.

An anomalous origin of the right coronary artery (RCA) from the left anterior descending artery (LAD), also known as a single coronary artery, is an extremely rare finding in clinical practice. It is usually a benign anomaly; however, symptoms are highly dependent on the course that the anomalous RCA takes after branching off of the LAD. We present a case of a patient who had decompensated heart failure and was detected to have a single coronary artery. The patient was treated with guideline-directed medical therapy with notable improvement in clinical status in the following days. Enhanced awareness of congenital cardiac anomalies may help guide management., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2020, Salih et al.)

Deep vein thrombosis (DVT) is a common disorder affecting 1 to 2 per 1000 Americans annually, resulting in significant morbidity and mortality. Anticoagulation is the mainstay management strategy for DVT. However, this could prove insufficient in cases where a mechanical obstruction is responsible for the DVT. We are presenting an interesting case of iatrogenic DVT incurred after Prolene suturing of lacerated iliac vein and the management employed for this challenging case with a successful and significant improvement in the clinical outcome., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Bronchial artery embolization (BAE) is a well-established intervention for hemoptysis that requires airway management by a trained anesthesiologist. The use of fluoroscopic guidance for positioning a double-lumen endotracheal tube (DLT) has been described in previous studies. The case presented illustrates a combined fluoroscopic- and bronchoscopic-guided approach for positioning a DLT in a patient with active pulmonary hemorrhage causing obstruction of views on bronchoscopy. This combined technique proved valuable in a situation marked by high clinical urgency.

To date, no case studies specifically describing a curved kyphoplasty needle becoming lodged in the vertebral body with the inability to be withdrawn have been reported. We describe a case involving a single level balloon kyphoplasty with a curved coaxial needle during which the cement delivery device could not be removed after cavity filling. In this case, a board-certified interventional pain management specialist was performing balloon kyphoplasty for an L2 osteoporotic vertebral compression fracture. The tools utilized in this procedure included flexible curved instruments designed to traverse the vertebral body and achieve uniform cement distribution through a unipedicular approach. Cannulation and cavity formation were completed without issue. Upon conclusion of cement filling, the curved cement delivery device was unable to be removed. After several attempts to remove the needle and consultation with both the device company and local spine surgeons, it was agreed that the device should be cut at the level of entry into the pedicle and left as a retained foreign object. The involved area was surgically exposed, the retained instrument was cut flush to the pedicle, and the free portion was removed without further complication. The patient followed up in clinic several months later without evidence of neurologic complications. Considerations when using a curved kyphoplasty device and a method of resolution when faced with the inability to remove such an instrument are discussed., Competing Interests: The authors have declared that no competing interests exist.

The use of the laryngeal mask airways is well established in routine and emergency airway management. Due to its traditional use as a supraglottic airway, it is often overlooked in patients with abnormal airway anatomy such as tracheostomies and laryngeal stomas. We present the unique method of using the laryngeal mask airways externally to facilitate preoxygenation and ventilation in a patient with a laryngeal stoma.

High dose rate interstitial brachytherapy is a commonly performed procedure for carcinoma of the lower lip. Placement of the brachytherapy catheters can be painful and may require monitored anesthesia care or general anesthesia. We present the use of bilateral mental nerve blocks with minimal sedation to facilitate placement of brachytherapy catheters.

Spontaneous otorrhagia following laparoscopic pelvic surgery is a complication that is rarely reported and incompletely understood. Few case reports have described this phenomenon, though its true incidence is unknown. It has been hypothesized that a combination of extreme patient positioning and abdominal insufflation is the contributing factor. There does not appear to be any untoward consequences and patients can be managed conservatively. We present two cases of spontaneous otorrhagia associated with laparoscopic pelvic surgery, which occurred over a 1-week period at our institution.

Acute heart failure (AHF) patients rarely present complaining of 'acute heart failure.' Rather, they initially present to the emergency department (ED) with a myriad of chief complaints, symptoms, and physical exam findings. Such heterogeneity prompts an initially broad differential diagnosis; securing the correct diagnosis can be challenging. Although AHF may be the ultimate diagnosis, the precipitant of decompensation must also be sought and addressed. For those AHF patients who present in respiratory or circulatory failure requiring immediate stabilization, treatment begins even while the diagnosis is uncertain. The initial diagnostic workup consists of a thorough history and exam (with a particular focus on the cause of decompensation), an EKG, chest X-ray, laboratory testing, and point-of-care ultrasonography performed by a qualified clinician or technologist. We recommend initial treatment be guided by presenting phenotype. Hypertensive patients, particularly those in severe distress and markedly elevated blood pressure, should be treated aggressively with vasodilators, most commonly nitroglycerin. Normotensive patients generally require significant diuresis with intravenous loop diuretics. A small minority of patients present with hypotension or circulatory collapse. These patients are the most difficult to manage and require careful assessment of intra- and extra-vascular volume status. After stabilization, diagnosis, and management, most ED patients with AHF in the United States (US) are admitted. While this is understandable, it may be unnecessary. Ongoing research to improve diagnosis, initial treatment, risk stratification, and disposition may help ease the tremendous public health burden of AHF., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Intrathecal ziconotide is used for the treatment of chronic pain and is delivered by an implanted drug delivery device. Anesthesiologists should be familiar with the perioperative management of the pump as well as the potential adverse events related to continued ziconotide infusion during general anesthesia. A case is presented demonstrating the perioperative management of an intrathecal drug delivery device infusing ziconotide in a patient presenting for radical cystectomy with pelvic lymphadenectomy and ileal conduit diversion.

Background: We hypothesized that nicotinamide adenosine diphosphate oxidase 2 (Nox2) plays an important role in cyclosporine A (CsA)-induced chronic hypoxia., Methods: We tested this hypothesis in Fisher 344 rats, C57BL/6 J wild type and Nox2-/- mice, and in liver transplant recipients with chronic CsA nephrotoxicity. We used noninvasive molecular imaging (blood oxygen level-dependent magnetic resonance imaging and dynamic contrast-enhanced magnetic resonance imaging) and molecular diagnostic tools to assess intrarenal oxygenation and perfusion, and the molecular phenotype of CsA nephrotoxicity., Results: We observed that chemical and genetic inhibition of Nox2 in rats and mice resulted in the prevention of CsA-induced hypoxia independent of regional perfusion (blood oxygen level-dependent magnetic resonance imaging and dynamic contrast-enhanced magnetic resonance imaging, pimonidazole, HIF-1α). Nicotinamide adenosine diphosphate oxidase 2 knockout was also associated with decreased oxidative stress (Nox2, HIF-1α, hydrogen peroxide, hydroxynonenal), and fibrogenesis (α-smooth muscle actin, picrosirius red, trichrome, vimentin). The molecular signature of chronic CsA nephrotoxicity using transcriptomic analyses demonstrated significant changes in 40 genes involved in injury repair, metabolism, and oxidative stress in Nox2-/- mice. Immunohistochemical analyses of kidney biopsies from liver transplant recipients with chronic CsA nephrotoxicity showed significantly greater Nox2, α-smooth muscle actin and picrosirius levels compared with controls., Conclusions: These studies suggest that Nox2 is a modulator of CsA-induced hypoxia upstream of HIF-1α and define the molecular characteristics that could be used for the diagnosis and monitoring of chronic calcineurin inhibitor nephrotoxicity.

Morphological changes that occur during kidney injury involve actin skeleton remodeling. Here we tested whether heat-shock protein 27 (HSP27), a small stress response protein involved in cytoskeletal remodeling, protects the kidney from tubulointerstitial fibrosis in obstructive nephropathy. Tubular cell HSP27 immunostaining was significantly increased in human kidneys with ureteropelvic junction obstruction, supporting the clinical relevance of our studies. To develop an animal model for mechanistic studies, we generated transgenic mice that specifically overexpress human HSP27 in renal tubules, under the kidney androgen-regulated protein promoter, and determined the effects of HSP27 overexpression on epithelial-to-mesenchymal transition and tubulointerstitial fibrosis following unilateral ureteral obstruction. This was associated with decreased fibrogenesis as evidenced by significant declines in phosphorylated p38MAPK, collagen III, α-smooth muscle actin, 4-hydroxynonenal, and reduced trichrome staining following obstruction. Notably, E-cadherin and β-catenin remained at the cell membrane of tubular cells in transgenic mice with an obstructed ureter. Monocyte/macrophage infiltration, however, was not significantly affected in these transgenic mice. Thus, tubular HSP27 inhibits fibrogenesis in obstructive nephropathy. Further studies are needed to determine pathways regulating the interactions between HSP27 and the E-cadherin-β-catenin complex.

Neurotrophins, retinoids and their receptors are present in the sensory epithelia of the inner ear during development. We show that these factors modulate the proliferation of hair cells and their K+-currents when the embryonic day 3 (ED 3) presumptive inner ear (i.e. otocyst) is maintained in organ culture. All trans-retinoic acid (RA) increases hair cell differentiation and enhances the acquisition of outward currents, including a delayed rectifier and a fast activating, transient type, voltage-gated potassium current. In contrast, brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) decrease ionic current activity, and the addition of RA with the neurotrophins enhances this inhibitory response in an age-dependent manner. We measured the total number of cells per explant over time to determine precisely when and how these factors inhibit explant growth. We found that high concentrations of BDNF and NT-3 administered together, and low concentrations of both neurotrophins combined and administered with RA suppress otocyst cell numbers after 24 h in vitro. This suppressive response is induced by RA and NT-3, not by RA and BDNF. The suppressive or inhibitory influence of NT-3 and RA is the result of NT-3 binding to the low affinity receptor, p75NTR, not the result of RA increasing mRNA levels for the high affinity receptor, trkC. However, trk may act with p75NTR, as disruption of trk signalling alleviates the inhibitory response induced by NT-3 and RA. Our data suggest that various combinations and/or concentration gradients of these factors can differentially regulate inner ear development and hair cell excitability.

5-Aminolevulinate synthase is the first enzyme of the heme biosynthetic pathway in animals and some bacteria. Lysine-313 of the mouse erythroid aminolevulinate synthase was recently identified to be linked covalently to the pyridoxal 5'-phosphate cofactor (Ferreira GC, Neame PJ, Dailey HA, 1993, Protein Sci 2:1959-1965). Here we report on the effect of replacement of aminolevulinate synthase lysine-313 by alanine, histidine, and glycine, using site-directed mutagenesis. Mutant enzymes were purified to homogeneity, and the purification yields were similar to those of the wild-type enzyme. Although their absorption spectra indicate that the mutant enzymes bind pyridoxal 5'-phosphate, they bind noncovalently. However, addition of glycine to the mutant enzymes led to the formation of external aldimines. The formation of an external aldimine between the pyridoxal 5'-phosphate cofactor and the glycine substrate is the first step in the mechanism of the aminolevulinate synthase-catalyzed reaction. In contrast, lysine-313 is an essential catalytic residue, because the K313-directed mutant enzymes have no measurable activity. In summary, site-directed mutagenesis of the aminolevulinate synthase active-site lysine-313, to alanine (K313A), histidine (K313H), or glycine (K313G) yields enzymes that bind the pyridoxal 5'-phosphate cofactor and the glycine substrate to produce external aldimines, but which are inactive. This suggests that lysine-313 has a functional role in catalysis.

We have previously reported that a monoclonal antibody-based antigen detection assay (AD12) is sensitive and specific for Bancroftian filariasis in Egypt. The purpose of the present study was to demonstrate the use of this assay in a sentinel population as a means of efficiently screening for filariasis endemicity. Antigen testing was performed with finger-prick blood collected during the day from 743 schoolchildren (ages 11-16 years). The school draws students from 5 villages in Qalubia Governorate, 35 km north-east of Cairo, Egypt. The prevalence of filarial antigenaemia in the school was 17.2%. Antigenaemia rates in children from the 5 villages were 29, 20, 18, 17, and 10% (non-uniformity significant by chi 2 analysis, P = 0.02). These data agree with Ministry of Health rankings of relative endemicity for these villages based on prior night blood surveys. The village with the highest antigen prevalence in children was surveyed one year before the present study. Prevalence rates of antigenaemia and microfilaraemia at that time for a different sample of children aged 11-16 years were 33% and 22%, respectively. We conclude that antigen detection in schoolchildren of this age group is an efficient means of assessing filariasis endemicity in Egypt.

A study of 325,000 residents of 314 villages in six governorates of the Nile delta area of Egypt revealed that the prevalence of lymphatic filariasis increased from < 1% in 1965 to > 20% in 1991, especially in the governorates of Qalyubiya, Monufiya, Dakhaliya, and Giza. The distribution of the communites with endemic filariasis is focal. Clusters of villages with high prevalences are surrounded by others in which the disease is absent, although their environmental, social, and agricultural features appear similar. The article analyses why the significant decline in filariasis between 1945 and 1965 in Egypt has been followed by a resurgence of the disease.