Pegivirus Detection in Cerebrospinal Fluid from Patients with Central Nervous System Infections of Unknown Etiology in Brazil by Viral Metagenomics

Metagenomic next-generation sequencing (mNGS) methodology serves as an excellent supplement in cases where diagnosis is challenging to establish through conventional laboratory tests, and its usage is increasingly prevalent. Examining the causes of infectious diseases in the central nervous system (CNS) is vital for understanding their spread, managing outbreaks, and effective patient care. In a study conducted in the state of São Paulo, Brazil, cerebrospinal fluid (CSF) samples from 500 patients with CNS diseases of indeterminate etiology, collected between 2017 and 2021, were analyzed. Employing a mNGS approach, we obtained the complete coding sequence of Pegivirus hominis (HPgV) genotype 2 in a sample from a patient with encephalitis (named IAL-425/BRA/SP/2019); no other pathogen was detected. Subsequently, to determine the extent of this virus's presence, both polymerase chain reaction (PCR) and/or real-time PCR assays were utilized on the entire collection. The presence of the virus was identified in 4.0% of the samples analyzed. This research constitutes the first report of HPgV detection in CSF samples in South America. Analysis of the IAL-425 genome (9107 nt) revealed a 90% nucleotide identity with HPgV strains from various countries. Evolutionary analyses suggest that HPgV is both endemic and extensively distributed. The direct involvement of HPgV in CNS infections in these patients remains uncertain.

Effect of kinin B2 receptor ablation on skeletal muscle development and myostatin gene expression

Bradykinin (BK) is an active peptide that binds to the kinin B(2) receptor and induces biological events during the development and adult life. In this study we aimed to investigate the effect of kinin B(2) receptor ablation in the postnatal skeletal muscle development and body composition in adult life. For studies of skeletal muscle development, control (C57Bl6 - WT) and B(2) receptor knockout mice (B(2)(-/-)) were sacrificed at 15, 30 and 90days after birth, the gastrocnemius skeletal muscle was weighed and myostatin gene expression evaluated by real time PCR. For energy balance determination, data from control and B(2)(-/-) at 90 and 120days were collected by calorimetric method. Body composition at 120days was determined by chloroform-methanol (total body fat) and Lowry-modified method (total body protein). The results show that B(2)(-/-) have significantly increased total body weight at 15, 30 and 90days of life, when compared to WT. The weight of the gastrocnemius skeletal muscle was also significantly increased at 30 and 90days of life. Body composition analyses revealed that B(2)(-/-) mice exhibit more total corporal protein and less total corporal fat. Energy balance revealed that B(2)(-/-) have increased metabolizable energy intake and energy expenditure when compared to control mice, resulting in a lower energy gain. Interestingly, myostatin mRNA expression was significantly decreased in 15 and 30days old B(2)(-/-) mice and after icatibant treatment of WT adult mice for 5days. In conclusion, together our results show that kinin B(2) receptor deletion increases lean mass, reduces fat mass and improves metabolism efficiency in mice. The mechanism involved in this phenotype could be related to the reduction of myostatin gene expression during postnatal life.

[The Maffucci syndrome with axial bone lesions. A rare cause of low back pain]

The authors describe the case of a twenty-nine-year-old female with the diagnosis of Maffucci's syndrome, since the age of five, with lower back and lower limb pain. The diagnosis was made of bone axial lesions, which are seldom found in this syndrome. Sarcomatous transformation was found in one of them.

[Adhesive lumbar arachnoiditis]

Spinal arachnoiditis, an inflammatory process involving all three meningeal layers as well as the nerve roots, is a cause of persistent symptoms in 6% to 16% of postoperative patients. Although spinal surgery is the most common antecedent associated with arachnoiditis, multiple causes have been reported, including infection, intrathecal steroids or anesthetic agents, trauma, subarachnoid hemorrhage and ionic myelographic contrast material--both oil soluble and water soluble. In the past, oil-based intrathecal contrast agents (Pantopaque) were associated with arachnoiditis especially when this material was introduced into the thecal sac and mixed with blood. Arachnoiditis is apparently rarely idiopathic. The pathogenesis of spinal arachnoiditis is similar to the repair process of serous membranes, such as the peritoneum, with a negligible inflammatory cellular exudate and a prominent fibrinous exudate. Chronic adhesive arachnoiditis of the lower spine is a myelographic diagnosis. The myelographic findings of arachnoiditis were divided into two types by Jorgensen et al. In type 1, "the empty thecal sac" appearance, there is homogeneous filling of the thecal sac with either absence of or defects involving nerve root sleeve filling. In type 2 arachnoiditis, there are localized or diffuse filling defects within the contrast column. MRI has demonstrated a sensitivity of 92% and a specificity of 100% in the diagnosis of arachnoiditis. The appearance of arachnoiditis on MRI can be assigned to three main groups. The MRI findings in group I are a conglomeration of adherent roots positioned centrally in the thecal sac. Patients in group II show roots peripherally adherent to the meninges--the so called empty sac. MRI findings in group III are a soft tissue mass within the subarachnoid space. It corresponds to the type 2 categorization defined by Jorgensen et al, where as the MRI imaging types I and II correspond to the myelographic type 1.

Spinal angiolipomas revisited: two case reports

Approximately 60 cases of spinal angiolipomas have been described in the medical literature. Extradural tumours predominate. Lesions with a bony component, the infiltrating subgroup, were reported in 10 patients. Intradural angiolipomas were found three times. Several excellent review articles are available, but a systematic comparison of the characteristics of the two major varieties, infiltrating and non-infiltrating spinal extradural angiolipomas, has not so far been made. The authors operated on two patients with spinal angiolipomas and found one of them the infiltrating and the other the non-infiltrating type. Then, they proceeded to a review of all publish cases of infiltrating angiolipomas. With a knowledge of recently reported data on the subject the authors compared essential clinical features of both varieties of tumours. They share identical clinical characteristics. Differences found in age, sex or location were not statistically significant. Mode of onset and signs and symptoms present on admission were essentially similar. As could be anticipated, removal was more often complete in non-infiltrating tumours, but outcome was good or fair in more than 85% of cases in both groups. Involvement of bone by spinal angiolipomas does not imply a worsening in the prognosis.

[Sinus pericranii and developmental venous anomalies: a frequent association]

The authors describe 2 cases of congenital sinus pericranii associated with intracranial venous anomalies. After a review of the literature concerning this association they consider the possible etiopathogenic mechanisms and treatment implications.

Profile of alveolar gases during periodic and regular breathing in preterm infants

To determine the changes in alveolar PCO2 (PACO2) and PO2 (PAO2) during periodic and regular breathing epochs in the same infants, we studied 11 preterm infants during quiet sleep (birth weight 1,630 +/- 94 g; gestational age 31 +/- 1 weeks; postnatal age 32 +/- 3 days). A total of 94 breathing/apneic cycles were analyzed and compared with regular periods. During periodic and regular breathing epochs, there were negative correlations of PAO2 on PACO2. Short (< or = 5 s) and long (> 5 s) apneas for individual infants occurred along the regression line for that infant. There was not a single overall critical PACO2 below which apnea occurred, but for individual infants the PACO2 and the PAO2 of the breath preceding apnea varied within a limited range. Apneas occurred in clusters of PACO2 and PAO2 along the average regression line of PAO2 on PACO2. Analysis of the data showed that apnea occurred at the lowest PACO2 and highest PAO2 levels if allowance was made for circulation time. During apnea, 'the best fit' for the increase in PACO2 and the decrease in PAO2 was linear, rather than logarithmic. The findings suggest the following. (1) There is not a single overall critical level of PACO2 for apnea to occur, but in a given infant this level varies within a limited range. This indicates that these infants are likely breathing near the apnea threshold. (2) Short and long apneas appear to occur randomly along the regression of PAO2 on PACO2 for a particular infant. (3) The changes in alveolar gases are linear during apnea.(ABSTRACT TRUNCATED AT 250 WORDS)

[Prefrontal syndrome as a manifestation of intracranial dural arterio-venous malformation]

The authors present a clinical case of an intracranial dural arteriovenous malformation with clinical manifestations of a prefrontal syndrome, documented with its respective diagnostic tests, including imaging studies. A number of considerations are being enlarged upon, concerning possible pathophysiological mechanisms.

Epidemiology of cystic fibrosis in Latin America: preliminary communication

We conducted a retrospective study of 743 patients with cystic fibrosis (CF), covering the 1979-89 period in 4 Latin American (LA) institutions to evaluate the clinical features of the disease. The review, although dealing only with patients referred to, or diagnosed at these institutions may be considered to comprise the majority of patients living in these areas. Diagnosis was confirmed by the sweat test in all cases. There was a slight predominance of males, (61.0%) mainly in the Brazilian group. The mean age at diagnosis was over 3 years. This was similar to the mean age at admission. Almost half of the patients were still alive at follow-up, but their mean age was low (6.4 years in Brazil, 7.4 in Chile, 9.6 in Mexico, and 11.3 in Argentina). Mean age at death ranged from 3.1 years (Chile) to 8.7 years (Argentina). The highest proportion of living patients was in Chile (71.4%) and the lowest in Argentina (33.8%). Survival curve comprised 15 years after diagnosis for the Argentinian group, compared to 6 years for the remaining groups. Fifty percent of the patients lived 6-7 years after diagnosis in Argentina, 4-5 years in Mexico and Chile, and 3 years in Brazil. Among Argentine patients 39.2% survived to 10 years of age, and 18% to 15 years. These findings suggest that CF is not rare in LA but extensive epidemiological studies are needed to obtain accurate figures on the magnitude of the problem.

[Development of the embolization technique for cerebral and spinal marrow arteriovenous malformations, and its clinical basis]

The authors revised 4 cases of large AVM's--3 cerebral and 1 medullary--illustrating the evolution of their technique of endovascular occlusion. These embolizations always preceding the surgery have their interest discussed in terms of the clinical grounds, the easiest access to the nidus and the possibilities of preventing some of the surgical risks.