Technical note: Understanding the effect of COVID-19 on particle pollution using a low-cost sensor network.

The 2020 coronavirus pandemic and the following quarantine measures have led to significant changes in daily life worldwide. Preliminary research indicates that air quality has improved in many urban areas as a result of these measures. This study takes a neighborhood-scale approach to quantifying this change in pollution. Using data from a network of citizen-hosted, low-cost particulate matter (PM) sensors, called Air Quality & yoU (AQ&U), we obtained high-spatial resolution measurements compared to the relatively sparse state monitoring stations. We compared monthly average estimated PM2.5 concentrations from February 11 to May 11, 2019 at 71 unique locations in Salt Lake County, UT, USA with the same (71) sensors' measurements during the same timeframe in 2020. A paired t-test showed significant reductions (71.1% and 21.3%) in estimated monthly PM2.5 concentrations from 2019 to 2020 for the periods from March 11-April 10 and April 11-May 10, respectively. The March time period corresponded to the most stringent COVID-19 related restrictions in this region. Significant decreases in PM2.5 were also reported by state monitoring sites during March (p < 0.001 compared to the previous 5-year average). While we observed decreases in PM2.5 concentrations across the valley in 2020, it is important to note that the PM2.5 concentrations did not improve equally in all locations. We observed the greatest reductions at lower elevation, more urbanized areas, likely because of the already low levels of PM2.5 at the higher elevation, more residential areas, which were generally below 2 µg/m3 in both 2019 and 2020. Although many of measurements during March and April were near or below the estimated detection limit of the low-cost PM sensors and the federal equivalent measurements, every low-cost sensor (51) showed a reduction in PM2.5 concentration in March of 2020 compared to 2019. These results suggest that the air quality improvement seen after March 11, 2020 is due to quarantine measures reducing traffic and decreasing pollutant emissions in the region.

Bladder trigone sparing radiotherapy in prostate cancer treatment.

INTRODUCTION: Evidence suggests the bladder trigone to be a potential organ at risk (OAR) in predicting acute and late genitourinary (GU) side effects when treating prostate cancer with radiotherapy. METHODS: A search of MEDLINE, Cinahl, EMBASE, PubMed, the Cochrane Database of Systematic Reviews and OpenGrey was conducted and no current or underway systematic reviews or scoping reviews on the topic were identified. A systematic literature review was carried out assessing the quality of this evidence. All evidence that prospectively or retrospectively reviewed radiotherapy or modelled radiotherapy dose to the bladder trigone were included. The search was conducted on the 8th July 2021 with 32 studies included in this review. This was repeated 10th June 2023 and two additional studies were identified. Any evidence published since this date have not been included and are a limitation of this review. RESULTS: MRI imaging is recommended to assist in delineating the trigone which has been shown to have a high amount of inter-observer variability and the use of specific training may reduce this. Across all radiotherapy treatment modalities, trigone dose contributed to GU acute and late toxicity symptoms. Trigone motion is relative to prostate motion but further research is required to confirm if the prostate can be used as a reliable surrogate for trigone position. The dose tolerance given for specific trigone related toxicities is debated within the literature, and on analysis the authors of this review suggest bladder trigone dose limits: Dmean < 45.8 Gy, V61.0Gy < 40%, V59.8Gy < 25%, V42.5Gy-V41.0Gy < 91% and V47.4Gy-V43.2Gy < 91% with α/ß of 3 Gy to reduce acute and late GU toxicities. CONCLUSION: There is evidence to support further research into bladder trigone sparing radiotherapy to improve patient outcomes. IMPLICATION FOR PRACTICE: Using the bladder trigone as an organ at risk is possible and the authors are currently seeking funding for a feasibility trial to further investigate this.

Relapse or worsening of nephrotic syndrome in idiopathic membranous nephropathy can occur even though the glomerular immune deposits have been eradicated.

BACKGROUND: Relapse or worsening of nephrotic syndrome (NS) in idiopathic membranous nephropathy (IMN) is generally assumed to be due to recurrent disease. Here we document that often that may not be the case. SUBJECTS AND METHODS: This is a prospective study of 7 consecutive IMN patients whose renal status improved, then worsened after completing a course of immunosuppressive therapy. Each underwent detailed testing and repeat kidney biopsy. RESULTS: In 4 patients (group A), the biopsy showed recurrent IMN (fresh subepithelial deposits). Immunosuppressive therapy was begun. In the other 3 patients (group B), the biopsy showed that the deposits had been eradicated. However, the glomerular basement membrane (GBM) was thickened and vacuolated. Immunosuppressive therapy was withheld. Groups A and B were comparable except that group B had very high intakes of salt and protein, based on 24-hour urine testing. Reducing their high salt intake sharply lowered proteinuria to the subnephrotic range and serum creatinine stabilized. CONCLUSION: This work is the first to demonstrate that relapse/worsening of NS can occur in IMN even though the GBM deposits have been eradicated. High salt and protein intake in combination with thickened and vacuolated GBM appears to be the mechanism.

Persistent pollutants exceed toxic thresholds in a freshwater top predator decades after legislative control.

Declining emissions of persistent organic pollutants (POPs), subject to international control under the Stockholm convention, are not consistently reflected in biotic samples. To assess spatial and temporal variation in organochlorine pesticides and PCBs in UK freshwaters, we analysed tissues of a sentinel predator, the Eurasian otter, Lutra lutra between 1992 and 2009. Past declines in otter populations have been linked to POPs and it is unclear whether otter recovery is hampered in any areas by their persistence. PCBs, DDT (and derivatives), dieldrin and HCB were detected in over 80% of 755 otter livers sampled. Concentrations of ∑PCB, ∑DDT and dieldrin in otter livers declined across the UK, but there was no significant time trend for ∑PCB-TEQ (WHO toxic equivalency, Van den Berg et al., 2006) or HCB. In general, higher concentrations were found in the midlands and eastern regions, and lowest concentrations in western regions. Concentrations of PCBs and HCB in otters increased near the coast, potentially reflecting higher pollutant levels in estuarine systems. Decades after legislative controls, concentrations of these legacy pollutants still pose a risk to otters and other freshwater predators, with spatially widespread exceedance of thresholds above which reproduction or survival has been reduced in related species.

A multicenter study of the effect of dietary supplementation with fish oil omega-3 fatty acids on carprofen dosage in dogs with osteoarthritis.

OBJECTIVE: To determine the effects of feeding a diet supplemented with fish oil omega-3 fatty acids on carprofen dosage in dogs with osteoarthritis. DESIGN: Randomized, controlled, multisite clinical trial. ANIMALS: 131 client-owned dogs with stable chronic osteoarthritis examined at 33 privately owned veterinary hospitals in the United States. PROCEDURES: In all dogs, the dosage of carprofen was standardized over a 3-week period to approximately 4.4 mg/kg/d (2 mg/lb/d), PO. Dogs were then randomly assigned to receive a food supplemented with fish oil omega-3 fatty acids or a control food with low omega-3 fatty acid content, and 3, 6, 9, and 12 weeks later, investigators made decisions regarding increasing or decreasing the carprofen dosage on the basis of investigator assessments of 5 clinical signs and owner assessments of 15 signs. RESULTS: Linear regression analysis indicated that over the 12-week study period, carprofen dosage decreased significantly faster among dogs fed the supplemented diet than among dogs fed the control diet. The distribution of changes in carprofen dosage for dogs in the control group was significantly different from the distribution of changes in carprofen dosage for dogs in the test group. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that in dogs with chronic osteoarthritis receiving carprofen because of signs of pain, feeding a diet supplemented with fish oil omega-3 fatty acids may allow for a reduction in carprofen dosage.

Multicenter veterinary practice assessment of the effects of omega-3 fatty acids on osteoarthritis in dogs.

OBJECTIVE: To assess the effect of food containing high concentrations of fish oil omega-3 fatty acids and a low omega-6-omega-3 fatty acid ratio on clinical signs of osteoarthritis in dogs. DESIGN: Randomized, double-blinded, controlled clinical trial. ANIMALS: 127 client-owned dogs with osteoarthritis in 1 or more joints from 18 privately owned veterinary clinics. PROCEDURES: Dogs were randomly assigned to be fed for 6 months with a typical commercial food or a test food containing a 31-fold increase in total omega-3 fatty acid content and a 34-fold decrease in omega-6-omega-3 ratio, compared with the control food. Dog owners completed a questionnaire about their dog's arthritic condition, and investigators performed a physical examination and collected samples for a CBC and serum biochemical analyses (including measurement of fatty acids concentration) at the onset of the study and at 6, 12, and 24 weeks afterward. RESULTS: Dogs fed the test food had a significantly higher serum concentration of total omega-3 fatty acids and a significantly lower serum concentration of arachidonic acid at 6, 12, and 24 weeks. According to owners, dogs fed the test food had a significantly improved ability to rise from a resting position and play at 6 weeks and improved ability to walk at 12 and 24 weeks, compared with control dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Ingestion of the test food raised blood concentrations of omega-3 fatty acids and appeared to improve the arthritic condition in pet dogs with osteoarthritis.

Evaluation of the effects of dietary supplementation with fish oil omega-3 fatty acids on weight bearing in dogs with osteoarthritis.

OBJECTIVE: To evaluate the effects of a food supplemented with fish oil omega-3 fatty acids on weight bearing in dogs with osteoarthritis. DESIGN: Randomized, double-blinded, controlled clinical trial. ANIMALS: 38 client-owned dogs with osteoarthritis examined at 2 university veterinary clinics. PROCEDURES: Dogs were randomly assigned to receive a typical commercial food (n = 16) or a test food (22) containing 3.5% fish oil omega-3 fatty acids. On day 0 (before the trial began) and days 45 and 90 after the trial began, investigators conducted orthopedic evaluations and force-plate analyses of the most severely affected limb of each dog, and owners completed questionnaires to characterize their dogs' arthritis signs. RESULTS: The change in mean peak vertical force between days 90 and 0 was significant for the test-food group (5.6%) but not for the control-food group (0.4%). Improvement in peak vertical force values was evident in 82% of the dogs in the test-food group, compared with 38% of the dogs in the control-food group. In addition, according to investigators' subjective evaluations, dogs fed the test food had significant improvements in lameness and weight bearing on day 90, compared with measurements obtained on day 0. CONCLUSIONS AND CLINICAL RELEVANCE: At least in the short term, dietary supplementation with fish oil omega-3 fatty acids resulted in an improvement in weight bearing in dogs with osteoarthritis.

Distribution of Eurasian otter biliary parasites, Pseudamphistomum truncatum and Metorchis albidus (Family Opisthorchiidae), in England and Wales.

Gall bladders from 273 otter carcasses, collected throughout England and Wales, were screened to assess the status of gall bladder parasites in the Eurasian otter, Lutra lutra. The digenean Pseudamphistomum truncatum had previously been found in UK otters collected between 2000 and 2007. The parasite was established in Somerset and Dorset but its distribution elsewhere in the UK was largely unknown. In the current study, P. truncatum was also found to be abundant in south Wales, with occasional cases elsewhere, but appears to be absent from the north of England. Overall, 11.7% of otters were infected with 1-238 P. truncatum. A second digenean, Metorchis albidus, previously unreported in British otters, was found in the biliary system of 6.6% of otters. M. albidus appears well established in Suffolk, Norfolk and north Essex but was recorded elsewhere rarely. Both parasites are associated with pathological damage to the otter gall bladder. The recent discovery of these two non-native parasites provides a unique opportunity to assess their impact on native British fauna.

TACI-Ig prevents the development of airway hyperresponsiveness in a murine model of asthma.

BACKGROUND: Increased levels of serum IgE are associated with greater asthma prevalence and disease severity. IgE depletion using an anti-IgE monoclonal antibody has met with success in the treatment of moderate-to-severe and severe persistent allergic asthma. OBJECTIVE: To test whether B cell-targeted therapy is a more effective treatment for airway hyperresponsiveness (AHR) in a murine model compared with IgE-depletion. METHODS: We delivered soluble mTACI-Ig, a receptor for the B cell survival factors BLyS (B Lymphocyte Stimulator) and APRIL (A PRoliferation-Inducing Ligand), or anti-IgE to allergen-sensitized mice before airway challenge with allergen. RESULTS: mTACI-Ig treatment reduced circulating mature B cell levels in the blood, while anti-IgE treatment had no effect on B cell counts. Both mTACI-Ig and anti-IgE decreased the levels of total and allergen-specific IgE in the serum. Histopathologic analysis of lungs showed a reduction in disease severity scores for both treatment groups, but results were more pronounced in mTACI-Ig-treated mice. Neutrophil and eosinophil numbers in the bronchoalveolar lavage (BAL) were significantly reduced following mTACI-Ig treatment, but not after anti-IgE delivery. BLyS and APRIL blockade also resulted in a significant decrease in IL-4 and eotaxin mRNA and IL-4 and KC protein levels in total lung homogenates and BAL fluid, respectively. Finally, mTACI-Ig treatment was more effective than anti-IgE treatment in reducing AHR to inhaled antigen. CONCLUSIONS: Our data demonstrate that delivery of mTACI-Ig is a more effective treatment than anti-IgE mAb in a murine model of AHR.

The relationship between two different mechanical cost functions and muscle oxygen consumption.

Inverse-dynamic models often use cost functions to solve the load-sharing problem. Although it is often assumed that energy is minimised, most cost functions are based on mechanically related measures like muscle force or stress. The aim of this study was to analyse the relationships of two cost functions with experimentally determined data on muscle energy consumption. Four subjects performed isometric contractions generating combinations of elbow flexion/extension and pro/supination moments. Muscle oxygen consumption (VO2) of the m. biceps breve, m. biceps longum, m. brachioradialis and m. triceps laterale was measured with near infrared spectroscopy. Both cost functions were implemented into an existing inverse-dynamic shoulder and elbow model and the individual cost values per muscle were calculated, normalised and subsequently compared to experimental VO2 values. The minimum stress cost function led to a good correspondence between VO2 and cost for the m. triceps laterale but for the flexor muscles cost was significantly lower. A newly proposed energy-related cost function showed, however, a far better correspondence. The inclusion of a linear term and muscle mass in the new criterion led model results to correspond better to experimental results. The energy-related cost function appeared to be a better measure for muscle energy consumption than the stress cost function and led to more realistic predictions of muscle activation.

Glenohumeral joint loading in tetraplegia during weight relief lifting: a simulation study.

BACKGROUND: The incidence of shoulder complaints in wheelchair users is high and the etiology is poorly understood. The goal of this study was to examine the effect of lesion level and isolated triceps muscle paresis on the internal load on the shoulder by simulation. METHODS: Kinematic and kinetic profiles from four able-bodied subjects and four subjects with tetraplegia were used as input for an inverse dynamics biomechanical model. The model was modified to simulate lesion level and triceps muscle paresis. FINDINGS: The simulations resulted in a significantly higher (+56%) glenohumeral contact force (P=0.037) for tetraplegic profiles than for able-bodied profiles. The model modifications to simulate lesion level only had a minor effect (+7%) on the calculated glenohumeral contact force. More simulations were successful at lower triceps force levels for tetraplegic profiles compared to able-bodied profiles (P=0.012). The muscle forces at the simulated T1 lesion were not significantly higher in tetraplegic profiles compared to able-bodied profiles. INTERPRETATION: The glenohumeral contact force for the tetraplegic profiles is mainly higher due to different task performance. Model modifications only have a minor effect on the calculated glenohumeral contact force. For able-bodied profiles the triceps force seems to be an important factor. The high internal load at the shoulder recommends new techniques of weight relief lifting and proper training of the arm-shoulder muscles in rehabilitation.

A kinematical analysis of the shoulder after arthroplasty during a hair combing task.

BACKGROUND: After shoulder arthroplasty, post-operative Range of Motion is usually compromised. It is, however, unclear to what extent limitations in Range of Motion are related to functional outcome in terms of Activities of Daily Living. METHODS: The upper extremity motions of 13 patients (16 shoulders) and a control group (N = 24) during four Range of Motion tasks and Activities of Daily Living were measured using a six degree-of-freedom electromagnetic tracking device. Based on the results for the Activities of Daily Living task 'hair combing', the patient groups was divided into a group that could perform this task ('Able', N = 8, 10 shoulders) and a group that could not perform the task ('Unable', N = 6, six shoulders). RESULTS: Both patient groups showed considerable limitation in glenohumeral Range of Motion, when compared to controls, but between patient groups only axial rotation Range of Motion was different: the 'Able' group has a larger external rotational Range of Motion, but less internal rotation. During 'combing hair' the Able group appeared to successfully perform the task through a larger clavicular retraction. INTERPRETATION: The ability to perform, or not perform a task appeared to be related to a compensatory movement implementation by means of clavicular retraction. It is concluded that the functional outcome after arthroplasty is limited due to a lack of glenohumeral Range of Motion but that it is possible to compensate for this restriction.

Requirements for upper extremity motions during activities of daily living.

BACKGROUND: Functioning of the upper extremity after implantation of an endoprosthesis remains limited despite the achieved pain relief. Upper extremity kinematics can give insight into function after shoulder arthroplasty. Data on ranges of motion related to the performance of a selection of activities of daily living can aid the clinician in evaluating the outcome of the shoulder and elbow arthroplasties. METHODS: Cross-sectional descriptive study of range of motion and activities of daily living kinematics, conducted on non-impaired subjects. The shoulder and elbow motions of 24 healthy female subjects are measured with an electromagnetic tracking device while performing 8 range of motion tasks and five activities of daily living. The angles of shoulder and elbow are calculated during these tasks. RESULTS: A data set with upper extremity joint angles has been obtained. Large glenohumeral rotations are found for the tasks that require high elevation angles. Large axial rotations of the humerus are found for two of the activities of daily living tasks: the perineal care task and the hair-combing task. Large elbow flexions were seen in the following tasks: combing hair, washing the axilla and eating with a spoon. INTERPRETATION: This study shows a suitable method to describe range of motion and activities of daily living and can serve as a starting point for developing a database on how activities of daily living are performed in a larger population and which joint angles are required to perform these tasks. Results can be used to identify restrictions in upper extremity functioning in patients with shoulder impairments.

Spatial and seasonal factors are key determinants in the aggregation of helminths in their definitive hosts: Pseudamphistomum truncatum in otters (Lutra lutra).

Parasites are typically aggregated within their host populations. The most heavily infected hosts are frequently cited as targets for optimal disease control. Yet a heavily infected individual is not necessarily highly infective and does not automatically contribute a higher proportion of infective parasitic stages than a host with fewer parasites. Here, Pseudamphistomum truncatum (Opisthorchiida) parasitic infection within the definitive otter host (Lutra lutra) is used as a model system. The hypothesis tested is that variation in parasite abundance, aggregation and egg production (fecundity, as a proxy of host infectivity) can be explained by abiotic (season and region) or biotic (host age, sex and body condition) factors. Parasite abundance was affected most strongly by the biotic factors of age and body condition, such that adults and otters with a higher condition index had heavier infections than sub-adults or those with a lower condition index, whilst there were no significant differences in parasite abundance among the seasons, regions (ecological regions defined by river catchment boundaries) or host sexes. Conversely, parasite aggregation was affected most strongly by the abiotic factors of season and region, which were supported by four different measures of parasite aggregation (the corrected moment estimate k, Taylor's Power Law, the Index of Discrepancy D, and Boulinier's J). Pseudamphistomum truncatum was highly aggregated within otters, with aggregation stronger in the Midlands (England) and Wales than in the southwestern region of the United Kingdom. Overall, more parasites were found in fewer hosts during the summer, which coincides with the summer peak in parasite fecundity. Combined, these data suggest that (i) few otters carry the majority of P. truncatum parasites and that there are more infective stages (eggs) produced during summer; and (ii) abiotic factors are most influential when describing parasite aggregation whilst biotic factors have a greater role in defining parasite abundance. Together, parasite abundance, aggregation and fecundity can help predict which hosts make the largest contribution to the spread of infectious diseases.

Combination antibiotic therapy in pediatrics.

Combinations of beta-lactam and aminoglycoside antibiotics are frequently used in the treatment of pediatric infections. At our institution, amikacin has been the sole aminoglycoside utilized for the past five years. Such regimens are used empirically in specific patient populations to treat the pathogens most likely to be responsible for a symptom complex, e.g., sepsis in the immunocompromised host, pneumonitis in patients with cystic fibrosis, neonatal infections such as sepsis or meningitis, and infections in patients with intestinal perforations. Beta-lactam and aminoglycoside combinations are employed as definitive therapy when synergistic interactions can be predicted, such as in systemic Pseudomonas infections, viridans streptococcal endocarditis, or enterococcal infections. In all of these circumstances, we have utilized amikacin extensively as the sole aminoglycoside, with highly satisfactory results. In vitro antibiotic synergy studies, including those employing aminoglycosides such as amikacin, may be used to predict in vivo antibiotic interactions. However, definitions of in vitro synergy vary with the laboratory method used to evaluate synergy. Furthermore, recent data from our laboratory suggest that the absence of demonstrated in vitro synergy between amikacin and imipenem may not correlate with improved survival of neutropenic rats with gram-negative sepsis that are treated with both agents. Thus, in vitro studies of synergy may underestimate the frequency of improved outcomes with combination antibiotics, especially with amikacin and imipenem. There are potential risks associated with the use of multiple, broad-spectrum antibiotics, including fungal or bacterial superinfection and increased drug toxicity. Although the former is common in pediatric patients, aminoglycoside (amikacin) toxicity has rarely been a problem. Combination antibiotic regimens that include an aminoglycoside such as amikacin continue to have an important role in pediatrics and should be used empirically or definitively for the specific indications discussed.

Haemophilus influenzae type b conjugate vaccine (meningococcal protein conjugate): immunogenicity and safety at various doses.

The Haemophilus influenzae vaccine consisting of purified type b capsular polysaccharide (polyribosylribitol-phosphate [PRP]) was shown in Finland to be protective, with 90% efficacy in children older than 18 to 23 months of age. However, a wide range of estimates of vaccine efficacy has been reported in the United States after its licensure in 1985. These estimates range from -55% to +89%. In addition, the PRP vaccine was not effective in children younger than 18 months of age, in whom 70% to 80% of meningitis cases occur. A further development was the introduction of H influenzae type b polysaccharide-protein conjugate vaccines such as the PRP-D. These conjugate vaccines were found to be more immunogenic than PRP vaccine in children of all ages. Two doses of PRP-D in infants 7 months of age and older induced antibody levels equal to or greater than levels in infants 24 months of age who received the PRP vaccine alone. Recently, Eskola et al reported that repeat vaccinations with PRP-D at 3, 4, 6, and 14 months of age was 83% protective (95% confidence interval, 26% to 96%). Yet PRP-D vaccine elicits only low serum antibody levels in infants younger than 7 months of age. Because of the discrepancy in efficacy results for the PRP vaccine in the United States and Finland and the lack of data about the protective efficacy of PRP-D vaccine in infants in the United States, the PRP-D vaccine is currently recommended only for children 18 months of age or older.(ABSTRACT TRUNCATED AT 250 WORDS)

Serologic response to standard inactivated influenza vaccine in human immunodeficiency virus-infected children.

We compared the serologic response of 46 human immunodeficiency virus (HIV)-infected children and adolescents and 61 age-matched controls to standard trivalent inactivated influenza vaccine (A/Taiwan (H1N1), A/Shanghai (H3N2), B/Yamagata). Children were immunized according to the package insert recommendations before the 1990 to 1991 influenza season. Serum antibody titers to influenza A were determined before and 1 month after each vaccination and compared for study and control subjects. Serologic responses of HIV-infected participants were correlated with absolute CD4 counts and stage of HIV disease. Regardless of age or HIV status, all groups responded with significant increases in antibody to the influenza A strains (range, 2.1-fold to 11.8-fold), with the exception that antibody to H3N2 rose only 1.5-fold (P = 0.058) among HIV-positive subjects > or = 9 years old. Pre- and postimmunization antibody titers were significantly higher for controls than for HIV-positive subjects. There was no correlation between serologic responses and CD4 counts among HIV-infected subjects, but those with Centers for Disease Control and Prevention-defined acquired immunodeficiency syndrome responded significantly less well to vaccine. We conclude that HIV-infected children and adolescents produce significant antibody rises after inactivated influenza A vaccination but that their absolute antibody concentrations are lower than those seen in age-matched controls.

Varicella-zoster virus infections in children infected with human immunodeficiency virus.

Primary varicella-zoster (VZ) infection in eight children with perinatally acquired human immunodeficiency virus infection tended to be severe, prolonged, complicated by bacterial infections and in one case fatal. Depletion of CD4-lymphocytes was associated with chronic and recurrent VZ infection. In some patients convalescent VZ antibody titers were low and did not correlate with recurrence of VZ lesions. Administration of acyclovir appeared to be beneficial in suppressing VZ in human immunodeficiency virus-infected children with primary or recurrent VZ infection.

The spectrum of mucosa-associated lymphoid tissue lesions in pediatric patients infected with HIV: A clinicopathologic study of six cases.

Mucosa-associated lymphoid tissue (MALT) lesions in nonimmunocompromised individuals include reactive lymphoid proliferations and both low- and high-grade lymphoid neoplasms. These lesions occur at extranodal mucosal sites, such as the gastrointestinal tract, bronchus, salivary gland, and other locations. The spectrum of MALT lesions in children with HIV infection had not been previously described. In this study, six cases that demonstrated the spectrum of MALT lesions in pediatric patients, aged 28 months to 23 years, who had HIV infection were described. Half the patients acquired the infection perinatally, and half acquired it by transfusion. Mucosal sites of involvement included the salivary gland (4 patients), bronchiolar mucosa (2 patients), and oropharyngeal mucosa (1 patient). One patient had lesions in lung and oropharynx sequentially; all others had involvement of solitary sites. The histologic diagnoses included myoepithelial sialadenitis (MESA), MESA with low-grade MALT lymphoma, typical low-grade MALT lymphoma, diffuse large cell lymphoma (DLCL), and atypical pulmonary lymphoid hyperplasia and lymphoid interstitial pneumonitis complex. The two cases of high-grade DLCL were confined to mucosal sites (tonsil and parotid); in one of these patients, a previous biopsy specimen showed a MALT lesion with low-grade features. In two cases, quantitation of the Epstein-Barr virus (EBV) genome by the polymerase chain reaction showed a very high copy number in peripheral blood mononuclear cells but a low copy number in the MALT lesion, which suggested that MALT lesions may not be directly associated with EBV infection. Two patients who had high-grade tumors (DLCL) were successfully treated with chemotherapy and radiation therapy. The remaining patients, all of whom had low-grade MALT lesions, received either corticosteroids or alpha-interferon or no specific therapy; in all patients, the lesions followed an indolent clinical course. Clinicians and pathologists should be alert to the possibility that MALT lesions, including MALT lymphomas, may be present in children who have AIDS.

Benign and malignant smooth muscle tumors containing Epstein-Barr virus in children with AIDS.

Smooth muscle tumors (leiomyosarcomas) are the second most prevalent malignancy of children with the acquired immunodeficiency syndrome (AIDS). We have investigated the tumors, plasma, and peripheral white blood cells of eight children with AIDS with smooth muscle tumors for evidence of tumor association with human immunodeficiency virus (HIV) and Epstein-Barr virus (EBV). Very low levels of HIV were found in the tumors of the AIDS patients, probably resulting from blood-borne carriage of virus. These smooth muscle tumors had very high quantities of EBV in all the tumor cells by in situ hybridization, with an average of 4.5 EBV genomes per cell by quantitative polymerase chain reaction amplification. Increased amounts of EBV were found in the peripheral blood cells of two AIDS patients before the time of tumor diagnosis. EBV clonality studies demonstrated different monoclonal EBV infection of two separate colonic tumors from one patient, and dual or mixed monoclonal EBV infection in another patient. The muscle cells of leiomyomas and leiomyosarcomas of patients with AIDS demonstrated prominent staining with antibodies to the EBV receptor. The uniform distribution and striking amount of EBV in the tumor cells demonstrates that EBV is capable of infecting smooth muscle cells and that these cells support EBV replication. Clonal EBV proliferation suggests that EBV infection occurs at an early stage of tumor development. These findings indicate that EBV has a causal role in the oncogenesis of leiomyosarcomas of patients with AIDS.