Neuroinvasive Bacillus cereus Infection in Immunocompromised Hosts: Epidemiologic Investigation of 5 Patients With Acute Myeloid Leukemia.

Background: Bacillus cereus is a ubiquitous gram-positive rod-shaped bacterium that can cause sepsis and neuroinvasive disease in patients with acute leukemia or neutropenia. Methods: A single-center retrospective review was conducted to evaluate patients with acute leukemia, positive blood or cerebrospinal fluid test results for B cereus, and abnormal neuroradiographic findings between January 2018 and October 2022. Infection control practices were observed, environmental samples obtained, a dietary case-control study completed, and whole genome sequencing performed on environmental and clinical Bacillus isolates. Results: Five patients with B cereus neuroinvasive disease were identified. All patients had acute myeloid leukemia (AML), were receiving induction chemotherapy, and were neutropenic. Neurologic involvement included subarachnoid or intraparenchymal hemorrhage or brain abscess. All patients were treated with ciprofloxacin and survived with limited or no neurologic sequelae. B cereus was identified in 7 of 61 environmental samples and 1 of 19 dietary protein samples-these were unrelated to clinical isolates via sequencing. No point source was identified. Ciprofloxacin was added to the empiric antimicrobial regimen for patients with AML and prolonged or recurrent neutropenic fevers; no new cases were identified in the ensuing year. Conclusions: B cereus is ubiquitous in the hospital environment, at times leading to clusters with unrelated isolates. Fastidious infection control practices addressing a range of possible exposures are warranted, but their efficacy is unknown and they may not be sufficient to prevent all infections. Thus, including B cereus coverage in empiric regimens for patients with AML and persistent neutropenic fever may limit the morbidity of this pathogen.

Relationship Between Intraocular Pressure and Age: A Population-Based Study in Nepal.

PRCIS: Intraocular pressure (IOP) decreased with age in a population-based study in Nepal, from a mean of 14.1 mm Hg among those 60-64 years old to 13.0 mm Hg among those 80 years old or older. PURPOSE: Few studies have assessed the distribution of IOP from the Indian subcontinent, despite its large population and high burden of glaucoma. The objective of this study was to assess the distribution of IOP measurements from adults living in a lowland region of Nepal. METHODS: In a population-based cross-sectional study, all individuals aged 60 years and older from an area of lowland Nepal were invited for an IOP assessment with a rebound tonometer. RESULTS: Of 160 communities (28,672 people aged ≥60 y) enrolled, 79 (13,808 people aged ≥60 y) were randomly selected for IOP testing. Of those eligible, 10,017 (72.5%) individuals underwent tonometry. Mean IOP decreased monotonically over 5-year age groups, from 14.1 mm Hg (SD: 3.6) among those aged 60-64 years to 13.0 mm Hg (SD: 4.2) among those 80 years or older. The 97.5th percentile IOP measurement was 21.0 mm Hg for all age groups. In adjusted analyses, younger age, self-reported diabetes, and higher population density were each associated with higher IOP, and self-reported cataract surgery was associated with lower IOP. CONCLUSIONS: Mean IOP was lower among older individuals in Nepal, consistent with many studies from East Asia and in contrast to many studies from western populations. These results suggest that ethnic background might be a consideration when diagnosing ocular hypertension.

Investigation of Bacterial Infections Among Patients Treated With Umbilical Cord Blood-Derived Products Marketed as Stem Cell Therapies.

Importance: The number of clinics marketing stem cell products for joint diseases, chronic pain, and most recently, COVID-19, has increased despite warnings from the US Food and Drug Administration that stem cell products for these and other indications have not been proven safe or effective. Objective: To examine bacterial infections in 20 patients who received umbilical cord blood-derived products marketed as stem cell treatment. Design, Setting, and Participants: This case series is a national public health investigation including case-finding, medical record review and abstraction, and laboratory investigation, including sterility testing of products and whole-genome sequencing of patient and product isolates. Participants included patients who developed bacterial infections following administration of umbilical cord blood-derived products marketed as stem cell treatment during August 2017 to September 2018. Data analysis was performed from March 2019 to September 2021. Exposures: Umbilical cord blood-derived products marketed as stem cell treatment. Main Outcomes and Measures: Data were collected on patient infections and exposures. The Centers for Disease Control and Prevention performed sterility testing on undistributed and distributed vials of product marketed as stem cell treatment and performed whole-genome sequencing to compare patient and product bacterial isolates. Results: Culture-confirmed bacterial infections were identified in 20 patients (median [range] age, 63 [2-89] years; 13 male patients [65%]) from 8 US states who sought stem cell treatment for conditions including pain, osteoarthritis, rheumatoid arthritis, and injury; all but 1 required hospitalization. The most frequently isolated bacteria from patients with infections were common enteric species, including Escherichia coli (14 patients) and Enterobacter cloacae (7 patients). Of unopened, undistributed products sampled for testing, 65% (22 of 34 vials) were contaminated with at least 1 of 16 bacterial species, mostly enteric. A patient isolate from Arizona matched isolates obtained from products administered to patients in Florida, and patient isolates from Texas matched undistributed product sent from the company in California. Conclusions and Relevance: Unapproved stem cell products can expose patients to serious risks without proven benefit. Sequencing results suggest a common source of extensive contamination, likely occurring during the processing of cord blood into product. Patients and health care practitioners who are considering the use of unapproved products marketed as stem cell treatment should be aware of their unproven benefits and potential risks, including serious infections.

Cluster-randomised trial of community-based screening for eye disease in adults in Nepal: the Village-Integrated Eye Worker Trial II (VIEW II) trial protocol.

INTRODUCTION: The majority of blindness worldwide could be prevented or reversed with early diagnosis and treatment, yet identifying at-risk and prevalent cases of eye disease and linking them with care remain important obstacles to addressing this burden. Leading causes of blindness like glaucoma, diabetic retinopathy and age-related macular degeneration have detectable early asymptomatic phases and can cause irreversible vision loss. Mass screening for such diseases could reduce visual impairment at the population level. METHODS AND ANALYSIS: This protocol describes a parallel-group cluster-randomised trial designed to determine whether community-based screening for glaucoma, diabetic retinopathy and age-related macular degeneration reduces population-level visual impairment in Nepal. A door-to-door population census is conducted in all study communities. All adults aged ≥60 years have visual acuity tested at the census visit, and those meeting referral criteria are referred to a local eye care facility for further diagnosis and management. Communities are subsequently randomised to a community-based screening programme or to no additional intervention. The intervention consists of a single round of screening including intraocular pressure and optical coherence tomography assessment of all adults ≥60 years old with enhanced linkage to care for participants meeting referral criteria. Four years after implementation of the intervention, masked outcome assessors conduct a repeat census to collect data on the primary outcome, visual acuity. Individuals with incident visual impairment receive a comprehensive ophthalmological examination to determine the cause of visual impairment. Outcomes are compared by treatment arm according to the originally assigned intervention. ETHICS AND DISSEMINATION: The trial has received ethical approval from the University of California San Francisco Institutional Review Board, Nepal Netra Jyoti Sangh and the Nepal Health Research Council. Results of this trial will be disseminated through publication in peer-reviewed journals and presentation at local and international meetings. TRIAL REGISTRATION NUMBER: NCT03752840.

Iron deficiency during pregnancy and lactation modifies the fatty acid composition of the brain of neonatal rats.

Iron deficiency is common in pregnant and lactating women and is associated with reduced cognitive development of the offspring. Since iron affects lipid metabolism, the availability of fatty acids, particularly the polyunsaturated fatty acids required for early neural development, was investigated in the offspring of female rats fed iron-deficient diets during gestation and lactation. Subsequent to the dams giving birth, one group of iron-deficient dams was recuperated by feeding an iron-replete diet. Dams and neonates were killed on postnatal days 1, 3 and 10, and the fatty acid composition of brain and stomach contents was assessed by gas chromatography. Changes in the fatty acid profile on day 3 became more pronounced on day 10 with a decrease in the proportion of saturated fatty acids and a compensatory increase in monounsaturated fatty acids. Long-chain polyunsaturated fatty acids in the n-6 family were reduced, but there was no change in the n-3 family. The fatty acid profiles of neonatal brain and stomach contents were similar, suggesting that the change in milk composition may be related to the changes in the neonatal brain. When the dams were fed an iron-sufficient diet at birth, the effects of iron deficiency on the fatty acid composition of lipids in both dam's milk and neonates' brains were reduced. This study showed an interaction between maternal iron status and fatty acid composition of the offspring's brain and suggests that these effects can be reduced by iron repletion of the dam's diet at birth.

The effect of amino acid deprivation on the transfer of iron through Caco-2 cell monolayers.

Iron (Fe) metabolism is modified by many nutritional factors. Amino acids (AA) play a central role in various biological processes, such as protein synthesis and energy supply. However, the influence of AA status on iron metabolism has not been investigated. Here, we test whether AA alters iron metabolism in an intestinal cell model. Both Fe uptake and transfer across the cell monolayer were significantly increased by non-essential AA deficiency (both p<0.001) while only Fe transfer was increased by essential AA deficiency (p<0.0001). Both essential and non-essential AA deficiency decreased DMT1 (±IRE) exon1A mRNA expression (respectively p=0.0007 and p=0.006) and increased expression of ferritin heavy chain. DMT1+IRE (also expressing exon1A or 1B) mRNA levels were decreased by essential AA deficiency (p=0.012). The mRNA levels of total DMT1 were also decreased by essential, but not non-essential, AA deficiency (p=0.006). Hepcidin levels were increased significantly by non-essential amino acid deprivation (p=0.047). Protein levels of ferroportin and/or ferritin heavy chain were not altered by AA deficiency, suggesting that they had no effect on Fe efflux or storage in the cell, though iron content of ferritin could be increased. Our data demonstrate, for the first time, that AA status affects iron transport and the expression of genes related to iron metabolism in Caco-2 cells, although the changes observed are not sufficient to explain the alteration in iron transport. We hypothesise that the effect on Fe transfer is mediated through an increased movement across the cell layer, rather than transfer across the cell membranes.

The effect of iron deficiency on the temporal changes in the expression of genes associated with fat metabolism in the pregnant rat.

Iron is essential for the oxidative metabolism of lipids. Lipid metabolism changes during gestation to meet the requirements of the growing fetus and to prepare for lactation. The temporal effects of iron deficiency during gestation were studied in female rats fed complete or iron-deficient diets. Plasma triglycerides were elevated in the iron-deficient group throughout gestation. There were time-dependent changes in the triglyceride content of the maternal liver, falling at the midpoint of gestation and then increasing on d21.5. Compared to the control, triglycerides in the maternal liver were not different in the iron-deficient group prior to pregnancy and on d12.5, but were markedly reduced by d21.5. The abundance of mRNAs in the maternal liver suggests that lipogenesis is unchanged and beta-oxidation is reduced on d21.5 by iron deficiency. On d21.5 of gestation, the expression of placental lipase was unchanged by iron deficiency, however, the abundance of mRNAs for SREBP-1c, FABP4 were reduced, suggesting that there were changes in fatty acid handling. In the fetal liver, iron deficiency produced a marked decrease in the abundance of the L-CPT-1 mRNA, suggesting that beta-oxidation is reduced. This study shows that the major effect of iron deficiency on maternal lipid metabolism occurs late in gestation and that perturbed lipid metabolism may be a common feature of models of fetal programming.

Pregnancy and maternal iron deficiency stimulate hepatic CRBPII expression in rats.

Iron deficiency impairs vitamin A (VA) metabolism in the rat but the mechanisms involved are unknown and the effect during development has not been investigated. We investigated the effect of pregnancy and maternal iron deficiency on VA metabolism in the mother and fetus. 54 rats were fed either a control or iron deficient diet for 2weeks prior to mating and throughout pregnancy. Another 15 female rats followed the same diet and were used as non-pregnant controls. Maternal liver, placenta and fetal liver were collected at d21 for total VA, retinol and retinyl ester (RE) measurement and VA metabolic gene expression analysis. Iron deficiency increased maternal hepatic RE (P<.05) and total VA (P<.0001), fetal liver RE (P<.05), and decreased placenta total VA (P<.05). Pregnancy increased Cellular Retinol Binding Protein (CRBP)-II gene expression by 7 fold (P=.001), decreased VA levels (P=.0004) and VA metabolic gene expression (P<.0001) in the liver. Iron deficiency increased hepatic CRBPII expression by a further 2 fold (P=.044) and RBP4 by~20% (P=.005), increased RBPR2 and decreased CRBPII, LRAT, and TTR in fetal liver, while it had no effect on VA metabolic gene expression in the placenta. Hepatic CRBPII expression is increased by pregnancy and further increased by iron deficiency, which may play an important role in VA metabolism and homeostasis. Maternal iron deficiency also alters VA metabolism in the fetus, which is likely to have consequences for development.

Identification of zyklopen, a new member of the vertebrate multicopper ferroxidase family, and characterization in rodents and human cells.

We previously detected a membrane-bound, copper-containing oxidase that may be involved in iron efflux in BeWo cells, a human placental cell line. We have now identified a gene encoding a predicted multicopper ferroxidase (MCF) with a putative C-terminal membrane-spanning sequence and high sequence identity to hephaestin (Heph) and ceruloplasmin (Cp), the other known vertebrate MCF. Molecular modeling revealed conservation of all type I, II, and III copper-binding sites as well as a putative iron-binding site. Protein expression was observed in multiple diverse mouse tissues, including placenta and mammary gland, and the expression pattern was distinct from that of Cp and Heph. The protein possessed ferroxidase activity, and protein levels decreased in cellular copper deficiency. Knockdown with small interfering RNA in BeWo cells indicates that this gene represents the previously detected oxidase. We propose calling this new member of the MCF family "zyklopen."