Increasing impact of COVID-19 on young adults: evidence from hospitalisations in Brazil.

OBJECTIVES: Concerns about the increasing impact of severe COVID-19 in younger individuals in Brazil came after a recent synchronised country-wide wave of cases in Brazil. This communication analyses how hospitalisations due to COVID-19 changed in the age groups 18-49 years and ≥70 years. STUDY DESIGN: Longitudinal study based on secondary data. METHODS: Data from SIVEP-Gripe, a public and open-access database of Severe Acute Respiratory Illness records (including COVID-19 notifications), were used in this study. Statistical control charts examined changes in the magnitude and variation of younger (18-49 years) and older (≥70 years) adults who were hospitalised between 15th March 2020 and 19th June 2021. RESULTS: During the few first weeks of the pandemic in Brazil, the number of COVID-19 hospitalisations increased in older adults but decreased in younger adults. Subsequently, hospitalisations reached statistical control zones in epidemiological weeks (EW) 19-48 of 2020 (EW 19-48/2020) and EW 03-05/2021 (18-49 y, mean = 26.1%; ≥70 y, mean = 32.8%). Between EW 49/2020 and EW 02/2021, the number of hospitalisations of younger adults dropped to levels below the lower control limit. In contrast, the number of hospitalisations of older adults surpassed the upper limit of the corresponding statistical control zones. However, from EW 06/2021, numbers of hospitalisations changed from statistical control zones, with hospitalisations of younger adults increasing and reaching 44.9% in EW 24/2021 and hospitalisations of older adults decreasing until EW 19/2021 (14.1%) and reaching 17.3% in EW 24/2021. CONCLUSIONS: An increasing number of COVID-19 hospitalisations were observed in younger adults from EW 06/2021. This could be a result of the successful vaccination programme in older adults, who were initially prioritised, and possibly an increased exposure to highly transmissible variants of COVID-19 in younger adults who had to go to work in the absence of social protection (i.e. government financial support). Potential consequences of COVID-19 hospitalisations in younger adults could include a reduced life expectancy of the population and an increased number of people unable to perform daily activities due to post-COVID-19 conditions.

Decision trees for optimizing the minimum detectable concentration of radioxenon detectors.

We present a novel application of machine learning techniques to optimize the design of a radiation detection system. A decision tree-based algorithm is described which greedily optimizes partitioning of energy depositions based on a minimum detectable concentration metric - appropriate for radiation measurement. We apply this method to the task of optimizing sensitivity to radioxenon decays in the presence of a high rate of radon-progeny backgrounds (i.e., assuming no physical radon removal by traditional gas separation techniques). Assuming other backgrounds are negligible, and considering sensitivity to each xenon isotope separately (neglecting interference between isotopes), we find that, in general, high resolution readout and high spatial segmentation yield little additional capability to discriminate against radon backgrounds compared to simpler detector designs.

The influence of sampling duration on recovery of culturable fungi using the Andersen N6 and RCS bioaerosol samplers.

UNLABELLED: The influence of sampling duration on recovery of culturable fungi was compared using the Andersen N6 and the Reuter Centrifugal Sampler (RCS). Samplers were operated side-by-side, collecting 15 samples each of incrementally increasing duration (1-15 min). From 270 samples collected, 26 fungal genera were recovered. Species of Alternaria, Aspergillus, Cladosporium, Epicoccum, Penicillium and Ulocladium were most frequent. Data adjusted to CFU/m3 were fitted to a Poisson regression model with a logarithmic link function and evaluated for the impact of sampling time on qualitative and quantitative recovery of fungi, both as individual taxa and in aggregate according to xerotolerance. Significant differences between the two samplers were observed for xerotolerant and normotolerant moulds, as well as Aspergillus spp. and Cladosporium spp. With the exception of Cladosporium spp., overall recoveries were higher with the RCS. When the Andersen N6 was used, the recovered levels of Cladosporium spp. and unidentified yeasts were reduced significantly at sampling times over 6 min. Similarly, when the RCS was used, recovery of Aspergillus spp., Penicillium spp., Ulocladium spp., unidentified yeasts, and low water activity fungi declined significantly at sampling times over 6 min. PRACTICAL IMPLICATIONS: Currently, the industry-wide trend for viable air sampling in indoor environmental investigations is to use sampling times between 2 and 4 min in duration. Our results support the routine use of a 6-min sampling time where low spore loads are expected, resulting in improved limits of detection.

Recurrent respiratory papillomatosis complicated by aspergillosis: a case report with review of literature.

Pulmonary extension of recurrent invasive papillomatosis often poses a diagnostic challenge to the examining bronchoscopist, pathologist, radiologist and surgeon, in distinguishing it as a benign lesion that is confined to the mucosa and extending along the branches of the tracheobronchial tree from true invasion of a malignant tumor. We document here a case of recurrent invasive respiratory papillomatosis which initially presented as a laryngeal papilloma. After multiple recurrences, the patient presented with bronchopulmonary involvement, complicated by invasive aspergillosis in a non-immunocompromised setting.

Complex recognition site for the group I intron-encoded endonuclease I-SceII.

We have characterized features of the site recognized by a double-stranded DNA endonuclease, I-SceII, encoded by intron 4 alpha of the yeast mitochondrial COX1 gene. We determined the effects of 36 point mutations on the cleavage efficiency of natural and synthetic substrates containing the Saccharomyces capensis I-SceII site. Most mutations of the 18-bp I-SceII recognition site are tolerated by the enzyme, and those mutant sites are cleaved between 42 and 100% as well as the wild-type substrate is. Nine mutants blocked cleavage to less than or equal to 33% of the wild-type, whereas only three point mutations, G-4----C, G-12----T, and G-15----C, block cleavage completely. Competition experiments indicate that these three substrates are not cleaved, at least in part because of a marked reduction in the affinity of the enzyme for those mutant DNAs. About 90% of the DNAs derived from randomization of the nucleotide sequence of the 4-bp staggered I-SceII cleavage site are not cleaved by the enzyme. I-SceII cleaves cloned DNA derived from human chromosome 3 about once every 110 kbp. The I-SceII recognition sites in four randomly chosen human DNA clones have 56 to 78% identity with the 18-bp site in yeast mitochondrial DNA; they are cleaved at least 50% as well as the wild-type mitochondrial substrate despite the presence of some substitutions that individually compromise cleavage of the mitochondrial substrate. Analysis of these data suggests that the effect of a given base substitution in I-SceII cleavage may depend on the sequence at other positions.

The Mauriceville plasmid of Neurospora crassa: characterization of a novel reverse transcriptase that begins cDNA synthesis at the 3' end of template RNA.

The Mauriceville and Varkud plasmids are retroid elements that propagate in the mitochondria of some Neurospora spp. strains. Previous studies of endogenous reactions in ribonucleoprotein particle preparations suggested that the plasmids use a novel mechanism of reverse transcription that involves synthesis of a full-length minus-strand DNA beginning at the 3' end of the plasmid transcript, which has a 3' tRNA-like structure (M. T. R. Kuiper and A. M. Lambowitz, Cell 55:693-704, 1988). In this study, we developed procedures for releasing the Mauriceville plasmid reverse transcriptase from mitochondrial ribonucleoprotein particles and partially purifying it by heparin-Sepharose chromatography. By using these soluble preparations, we show directly that the Mauriceville plasmid reverse transcriptase synthesizes full-length cDNA copies of in vitro transcripts beginning at the 3' end and has a preference for transcripts having the 3' tRNA-like structure. Further, unlike retroviral reverse transcriptases, the Mauriceville plasmid reverse transcriptase begins cDNA synthesis directly opposite the 3'-terminal nucleotide of the template RNA. The ability to initiate cDNA synthesis directly at the 3' end of template RNAs may also be relevant to the mechanisms of reverse transcription used by LINEs, group II introns, and other non-long terminal repeat retroid elements.

An outbreak of extended spectrum beta-lactamase producing Klebsiella pneumoniae in a neonatal intensive care unit.

Klebsiella pneumoniae has long been a prominent cause of nosocomial infections and outbreaks have been observed in the intensive care units and in high risk groups. We present here a brief report on an outbreak of Klebsiella pneumoniae which occurred in a neonatal intensive care unit in our teaching hospital. As neonates are at highest risk for acquisition of Klebsiella pneumoniae producing extended spectrum beta-lactamase, infection control policies and procedures should be strictly followed to prevent such outbreaks.

Recombination by resolvase is inhibited by lac repressor simultaneously binding operators between res sites.

The Tn3 resolvase requires that the two recombination (res) sites be aligned as direct repeats on the same molecule for efficient recombination to occur. To test whether resolvase must contact the DNA between res sites as predicted by tracking models, we have determined the sensitivity of recombination to protein diffusion blockades. Recombination between two res sites is unaffected either by lac repressor or bacteriophage T7 RNA polymerase being bound between them. Yet recombination is inhibited by lac repressor if the res site is bounded by a lac operator on both sides. We demonstrate that lac repressor will bind to more than one DNA site under the conditions used to assay recombination. This result suggests that lac repressor can inhibit resolvase by forming a DNA loop that isolates a res site topologically. These results do not support a tracking model for resolvase but suggest that the structure and topology of the DNA substrate is important in the formation of a synapse between res sites.

Analysis of the CYT-18 protein binding site at the junction of stacked helices in a group I intron RNA by quantitative binding assays and in vitro selection.

The Neurospora crassa mitochondrial tyrosyl-tRNA synthetase (CYT-18 protein) functions in splicing group I introns by promoting the formation of the catalytically active structure of the intron RNA. Previous studies showed that CYT-18 binds with high affinity to the P4-P6 domain of the catalytic core and that there is some additional contribution to binding from the P3-P9 domain. Here, quantitative binding assays with deletion derivatives of the N. crassa mitochondrial large rRNA intron showed that at least 70% of the binding energy can be accounted for by the interaction of CYT-18 with the P4-P6 domain. Within this domain, P4 and P6 are required for high affinity CYT-18 binding, while the distal elements P5 and P6a may contribute indirectly by stabilizing the correct structure of the binding site in P4 and P6. CYT-18 binds to a small RNA corresponding to the isolated P4-P6 domain, but not to a permuted version of this RNA in which P4-P6 is a continuous rather than a stacked helix. Iterative in vitro selection experiments with the isolated P4-P6 domain showed a requirement for base-pairing to maintain helices P4, P6 and P6a, but indicate that P5 is subject to fewer constraints. The most strongly conserved nucleotides in the selections were clustered around the junction of the P4-P6 stacked helix, with ten nucleotides (J3/4-2,3, P4 bp -1 and 3, and P6 bp -1 and 2) found invariant in the context of the wild-type RNA structure. In vitro mutagenesis confirmed that replacement of the wild-type nucleotides at J3/4-2 and 3 or P4 bp-3 markedly decreased CYT-18 binding, reflecting either base specific contacts or indirect readout of RNA structure by the protein. Our results suggest that a major function of CYT-18 is to promote assembly of the P4-P6 domain by stabilizing the correct geometry at the junction of the P4-P6 stacked helix. The relatively large number of conserved nucleotides at the binding site suggests that the interaction of CYT-18 with group I introns is unlikely to have arisen by chance and could reflect either an evolutionary relationship between group I introns and tRNAs or interaction with a common stacked-helical structural motif that evolved separately in these RNAs.

Pseudoaneurysm of the popliteal artery. Surgical management of 3 cases.

Pseudoaneurysm of the popliteal artery is much less common than true aneurysm in this location. We report 3 cases of popliteal artery pseudoaneurysms, each of differing etiopathology, one presenting 3 months after trauma, one following aortic valve replacement for aortic regurgitation with suspected endocarditis, with no organism detected, and the 3rd of infective etiology. The clinical presentation and surgical management are discussed with a review of the literature.

Failure of systemic thrombolytic and heparin therapy in the treatment of neonatal aortic thrombosis.

An unsuccessful attempt was made to lyse a large aortic thrombus in a newborn using systemic high-dose streptokinase and urokinase therapy and subsequently the use of heparin failed to prevent the propagation of thrombus. The patient was a seven-day old premature, sick neonate in whom an aortic thrombosis developed following umbilical artery catheterization. Surgical thrombectomy could not be performed in this patient, and local thrombolytic therapy was not technically feasible. Systemic thrombolytic therapy failed to induce any noteable clinical or laboratory response, and the use of heparin failed to prevent thrombus extension. Experience with the use of fibrinolytic agents in neonates is limited. Local therapy has been variably effective, and systemic therapy has not been adequately investigated. The thrombotic phenomenon in neonates and the role of umbilical vessel catheterization as a cause are discussed in reference to this patient and suggestions are made regarding the management of similar cases.

Homograft aortic root replacement to correct infective endocarditis requiring seven open cardiac procedures.

Infective endocarditis, presumably from a septic dental focus, affecting the aortic valve was seen as acute aortic regurgitation in a 20-year-old woman. Seven open cardiac procedures for replacement of the aortic valve and left ventricular outflow tract were performed over the subsequent 6 years. Aortic root replacement using a fresh antibiotic-sterilized homograft was performed as the last definitive operative procedure. This article is presented to highlight (1) the use of homograft aortic root replacement for extensive involvement of aortic valve and left ventricular outflow tract in cases of infective endocarditis and (2) the feasibility of multiple sternal reentries when indicated.

Cerebrospinal fluid lactate dehydrogenase in neonatal intracranial hemorrhage.

Cerebrospinal fluid (CSF) lactate dehydrogenase (LDH) was measured in 54 neonates with intracranial hemorrhage and compared with 82 control, 27 traumatic lumbar puncture, seven meningitis, and 30 asphyxiated newborns. Hospital data, neonatal outcomes, and long-term neurodevelopmental follow-up results were reviewed. CSF LDH was not significantly affected by traumatic lumbar puncture but was elevated in proportion to the severity of CNS hemorrhage as scored by computerized tomography. LDH was also significantly associated with subsequent seizures and hydrocephalus and abnormal long-term developmental outcome.

Coronary artery surgery in Asian patients.

We studied retrospectively, 412 consecutive Asian patients undergoing coronary artery bypass grafting between January 1st, 1982 and June 30th, 1987. The mean age was 55 +/- 9 years at operation with a 70.5% male predominance. Patients of Chinese origin accounted for 60.9%, Indonesian for 26.4%, Indian 9.9% and Malaysian 2.6%. Chronic stable angina was the most consistent presenting symptom in 71% and 49% had at least one myocardial infarction in the past. Fifty percent were hypertensive and 26% diabetic. Left main stem coronary artery obstruction was evident in 21.6% and the coronary arteries diffusely diseased in 53%. An average of 3.8 +/- 0.4 grafts were performed per patient using reversed saphenous vein, and endarterectomies were necessitated in 27.1%. The small calibre of coronary arteries in Asian patients was reflected by 54% of grafted vessels having a luminal diameter of 1.5 mm. The early mortality rate and the peri-operative myocardial infarction rate was 1.2% in each instance. A mean follow-up of 30 months revealed a late mortality of 1.9% and 76% of patients were in NYHA Functional Class I. This study suggests that despite a high incidence of hypertension, diabetes and diffuse coronary artery disease Asian patients tolerate coronary artery bypass graft surgery well and obtain significant benefit from it.

Myocardial revascularisation in patients over seventy five years.

A consecutive series of 73 patients aged 75 years and above underwent coronary artery bypass graft surgery during a 6 year period. Pre-operatively unstable angina (61.6%) and congestive heart failure (10.9%) were significant presenting features. Triple vessel disease accounted for 61.6% of cases while 26% had left main coronary obstruction. The mean number of grafts per patient was 3.2 +/- 0.9. Combined procedures such as valve replacement were done in 16.2% of patients. The hospital mortality rate was 2.7% and there was not a single recordable case of peri-operative myocardial infarction. Significant complications post-operatively were atrial arrhythmias (43.8%), segmental pulmonary atelectasis (43.8%) and renal problems (15%). Of the sixty patients followed up at an average of 27.7 months, 58 were in NYHA Functional Class I. Good patient selection and careful monitoring leads to encouraging results with coronary artery bypass grafting in the elderly.

The Bentall procedure: a surgical option in Ehlers-Danlos syndrome.

The Ehlers-Danlos syndrome (EDs) is one of the most frequently encountered inherited disorders of connective tissue. The arterial-ecchymotic type IV is notorious for large vessel involvement associated with spontaneous catastrophic bleeding. Most of these patients who require cardiovascular surgical procedures have a poor prognosis. Our experience of two patients, with aneurysmal dilatation of the ascending aorta is presented. The first patient presented with an aortic dissection extending from the ascending aorta to the common iliac arteries. The second patient presented with asymptomatic but progressive aneurysmal dilatation of the aortic root. Both patients underwent the Bentall procedure using a 25 mm St. Jude composite valved conduit. Despite increased vascular friability, both of these patients tolerated the operative procedure without complication and are doing well on early follow-up. This experience suggests that the Bentall procedure may be used to decrease the risks of dissection and rupture of the ascending aorta in patients with Ehlers-Danlos syndrome.

Surgical management of left ventricular myxoma with embolization to the right coronary artery.

We report a rare case of left ventricular myxoma with embolization to the right coronary artery, presenting as an acute myocardial infarction. The tumor was excised from the left ventricle, and the tumor embolus was removed from the right coronary artery. Saphenous vein bypass grafting was also performed successfully.

Surgical experience with congenital heart disease in Down's syndrome.

Children with Down's syndrome and congenital heart defects have multiple problems. The role of cardiac surgery in the management of these patients was investigated by reviewing the clinical data, hospital course and follow-up of 21 patients (9 males and 12 females, age range 1 month to 14 years) with Down's syndrome and congenital heart defects operated in our institute. Twelve (57%) of these were infants and nine (43%), older children. Five were in congestive cardiac failure, four were hypothyroid. The heart lesions ranked in incidence as follows: atrioventricular septal defect 7 (33.3%), tetralogy of Fallot 3 (14.3%), tetralogy of Fallot & atrioventricular septal defect both 2 (9.5%), double outlet right ventricle with pulmonary stenosis 1 (4.8%), patent ductus arteriosus 2 (9.5%), patent ductus arteriosus plus coarctation 1 (4.8%), ventricular septal defect 2 (9.5%), atrial septal defect plus ventricular septal defect 1 (4.8%), atrial septal defect plus patent ductus arteriosus plus right pulmonary artery stenosis 1 (4.8%) and transposition of great arteries with multiple ventricular septal defect 1 (4.8%). Four (19%) patients had palliative procedures while the rest (81%) underwent primary repair. All survived the operation. The post-operative period was complicated in 6 (28.5%), with respiratory infections in 3, pulmonary hypertensive crisis in 2 and complete heart block in 1. The early mortality was 0, while there were 2 (9.5%) late deaths. The number of hospitalisations was markedly reduced according to the parents. Follow-up showed near normal pulmonary artery pressure in 50 percent children with large shunts and a good developmental spurt was seen in 60 percent. From a purely surgical viewpoint, the prognosis for children with Down's syndrome and congenital heart disease is good.

The Baby Doe rule: still a threat.

Current federal policy, as reflected in the final Baby Doe rule, will have a chilling effect on the ability of doctors to care appropriately for severely disabled infants. The policy threatens to prolong life unjustifiably for such infants. It will force physicians to violate a duty to do no harm without compensating benefit. And it raises serious problems for the just distribution of health care.

KIE: The authors argue that the Department of Health and Human Services' final rule, "Child Abuse and Neglect Prevention and Treatment Program," (April 1985) will prevent physicians from providing appropriate care for severely handicapped infants. The regulations stipulate that treatment must be provided unless the infant is permanently and irreversibly comatose and treatment would only prolong dying. Appropriate nutrition, hydration, and medication must be provided to all infants. Moskop and Saldanha fear that physicians will respond to the rule by aggressive overtreatment that will prolong suffering without any compensating benefit. They contend that the high cost of extended intensive care under restrictive public spending policies raises serious questions about the general distribution of health care.

Recent advances in the MOBJ algorithm for training artificial neural networks.

This paper presents a new scheme for training MLPs which employs a relaxation method for multi-objective optimization. The algorithm works by obtaining a reduced set of solutions, from which the one with the best generalization is selected. This approach allows balancing between the training error and norm of network weight vectors, which are the two objective functions of the multi-objective optimization problem. The method is applied to classification and regression problems and compared with Weight Decay (WD), Support Vector Machines (SVMs) and standard Backpropagation (BP). It is shown that the systematic procedure for training proposed results on good generalization neural models, and outperforms traditional methods.