Post-Chemotherapy Histiocyte-Rich Pseudotumors: Radiologic and Endoscopic Mimics of Residual Lymphoma.

Development of post-chemotherapy histiocyte-rich pseudotumor (PHP) is an underrecognized event following therapy in lymphoma patients and may mimic residual tumor using current therapy monitoring protocols. We report a series of 5 patients with PHP along with a review of the literature. In our series, we describe 3 patients with persistent hypermetabolic masses by positron emission tomography-computed tomography, one with persistent terminal ileal nodules on endoscopy, and one with bone marrow involvement, a site not associated with mass-like disease. Twenty-three patients with long-term follow-up were identified from our series and review of the literature. Forty-four percent of patients received additional therapy, and only 4% of patients died of lymphoma. This study illustrates that PHPs are not identified using current lymphoma therapy monitoring algorithms and may result in overtreatment with risk for additional therapy-related complications. The need for confirmatory tissue biopsy in this setting is recommended.

Two novel porcine teschovirus strains as the causative agents of encephalomyelitis in the Netherlands.

BACKGROUND: Porcine teschovirus (PTV) circulates among wild and domesticated pig populations without causing clinical disease, however neuroinvasive strains have caused high morbidity and mortality in the past. In recent years, several reports appeared with viral agents as a cause for neurologic signs in weanling and growing pigs among which PTV and new strains of PTV were described. CASE PRESENTATION: On two unrelated pig farms in the Netherlands the weanling pig population showed a staggering gate, which developed progressively to paresis or paralysis of the hind legs with a morbidity up to 5%. After necropsy we diagnosed a non-suppurative encephalomyelitis on both farms, which was most consistent with a viral infection. PTV was detected within the central nervous system by qPCR. From both farms PTV full-length genomes were sequenced, which clustered closely with PTV-3 (98%) or PTV-11 (85%). Other common swine viruses were excluded by qPCR and sequencing of the virus. CONCLUSION: Our results show that new neuroinvasive PTV strains still emerge in pigs in the Netherlands. Further research is needed to investigate the impact of PTV and other viral agents causing encephalomyelitis within wild and domestic pig populations supported by the awareness of veterinarians.

High-Resolution Evolutionary Analysis of Within-Host Hepatitis C Virus Infection.

BACKGROUND: Despite recent breakthroughs in treatment of hepatitis C virus (HCV) infection, we have limited understanding of how virus diversity generated within individuals impacts the evolution and spread of HCV variants at the population scale. Addressing this gap is important for identifying the main sources of disease transmission and evaluating the risk of drug-resistance mutations emerging and disseminating in a population. METHODS: We have undertaken a high-resolution analysis of HCV within-host evolution from 4 individuals coinfected with human immunodeficiency virus 1 (HIV-1). We used long-read, deep-sequenced data of full-length HCV envelope glycoprotein, longitudinally sampled from acute to chronic HCV infection to investigate the underlying viral population and evolutionary dynamics. RESULTS: We found statistical support for population structure maintaining the within-host HCV genetic diversity in 3 out of 4 individuals. We also report the first population genetic estimate of the within-host recombination rate for HCV (0.28 × 10-7 recombination/site/year), which is considerably lower than that estimated for HIV-1 and the overall nucleotide substitution rate estimated during HCV infection. CONCLUSIONS: Our findings indicate that population structure and strong genetic linkage shapes within-host HCV evolutionary dynamics. These results will guide the future investigation of potential HCV drug resistance adaptation during infection, and at the population scale.

Novel Highly Pathogenic Avian Influenza A(H5N6) Virus in the Netherlands, December 2017.

A novel highly pathogenic avian influenza A(H5N6) virus affecting wild birds and commercial poultry was detected in the Netherlands in December 2017. Phylogenetic analysis demonstrated that the virus is a reassortant of H5N8 clade 2.3.4.4 viruses and not related to the Asian H5N6 viruses that caused human infections.

Characterization of Hepatitis C Virus (HCV) Envelope Diversification from Acute to Chronic Infection within a Sexually Transmitted HCV Cluster by Using Single-Molecule, Real-Time Sequencing.

In contrast to other available next-generation sequencing platforms, PacBio single-molecule, real-time (SMRT) sequencing has the advantage of generating long reads albeit with a relatively higher error rate in unprocessed data. Using this platform, we longitudinally sampled and sequenced the hepatitis C virus (HCV) envelope genome region (1,680 nucleotides [nt]) from individuals belonging to a cluster of sexually transmitted cases. All five subjects were coinfected with HIV-1 and a closely related strain of HCV genotype 4d. In total, 50 samples were analyzed by using SMRT sequencing. By using 7 passes of circular consensus sequencing, the error rate was reduced to 0.37%, and the median number of sequences was 612 per sample. A further reduction of insertions was achieved by alignment against a sample-specific reference sequence. However, in vitro recombination during PCR amplification could not be excluded. Phylogenetic analysis supported close relationships among HCV sequences from the four male subjects and subsequent transmission from one subject to his female partner. Transmission was characterized by a strong genetic bottleneck. Viral genetic diversity was low during acute infection and increased upon progression to chronicity but subsequently fluctuated during chronic infection, caused by the alternate detection of distinct coexisting lineages. SMRT sequencing combines long reads with sufficient depth for many phylogenetic analyses and can therefore provide insights into within-host HCV evolutionary dynamics without the need for haplotype reconstruction using statistical algorithms.IMPORTANCE Next-generation sequencing has revolutionized the study of genetically variable RNA virus populations, but for phylogenetic and evolutionary analyses, longer sequences than those generated by most available platforms, while minimizing the intrinsic error rate, are desired. Here, we demonstrate for the first time that PacBio SMRT sequencing technology can be used to generate full-length HCV envelope sequences at the single-molecule level, providing a data set with large sequencing depth for the characterization of intrahost viral dynamics. The selection of consensus reads derived from at least 7 full circular consensus sequencing rounds significantly reduced the intrinsic high error rate of this method. We used this method to genetically characterize a unique transmission cluster of sexually transmitted HCV infections, providing insight into the distinct evolutionary pathways in each patient over time and identifying the transmission-associated genetic bottleneck as well as fluctuations in viral genetic diversity over time, accompanied by dynamic shifts in viral subpopulations.

Raised in Darkness: A 7-Month-Old With Nystagmus From Severe Visual Deprivation.

Child neglect is the most common form of child maltreatment and accounts for 60% of all cases reported to child protective services. Whereas physical and emotional neglect account for a quarter of the reported cases of child neglect, educational neglect accounts for half of the cases. We describe a 7-month-old infant with several manifestations of physical and emotional neglect including excessive quietness, failure to thrive, global developmental delay, and a gastric lactobezoar. In addition, our patient had a fine, lateral nystagmus likely due to being kept in the dark for long periods. To our knowledge, this is the first reported case of acquired nystagmus due to visual deprivation from child neglect.

Hyperglycemic Hyperosmolar State During Induction Chemotherapy for Acute Lymphoblastic Leukemia.

We present the case of a 16-year-old boy who presented with fatigue, polyuria, and polydipsia while on chemotherapy for his relapsed acute lymphoblastic leukemia (ALL). Blood gas examination confirmed the diagnosis of hyperosmolar hyperglycemic state. The etiology for his hyperglycemia was most likely a result of oral glucocorticoid therapy combined with asparaginase therapy-both are a cornerstone of induction chemotherapy for ALL. The patient was aggressively rehydrated with saline, and medications were administered to correct his hyperkalemia. He was then slowly brought to euglycemia with a continuous infusion of insulin. Although hyperosmolar hyperglycemic state is rare during the treatment of ALL, frontline providers should be aware of this diagnosis because of the significant risk of hypovolemic shock and death if correction of hyperglycemia occurs prior to complete fluid resuscitation.

Atomic structure of the KEOPS complex: an ancient protein kinase-containing molecular machine.

Kae1 is a universally conserved ATPase and part of the essential gene set in bacteria. In archaea and eukaryotes, Kae1 is embedded within the protein kinase-containing KEOPS complex. Mutation of KEOPS subunits in yeast leads to striking telomere and transcription defects, but the exact biochemical function of KEOPS is not known. As a first step to elucidating its function, we solved the atomic structure of archaea-derived KEOPS complexes involving Kae1, Bud32, Pcc1, and Cgi121 subunits. Our studies suggest that Kae1 is regulated at two levels by the primordial protein kinase Bud32, which is itself regulated by Cgi121. Moreover, Pcc1 appears to function as a dimerization module, perhaps suggesting that KEOPS may be a processive molecular machine. Lastly, as Bud32 lacks the conventional substrate-recognition infrastructure of eukaryotic protein kinases including an activation segment, Bud32 may provide a glimpse of the evolutionary history of the protein kinase family.

Resistance-associated polymorphisms in Dutch hepatitis C genotype 1a patients with and without HIV infection.

UNLABELLED:  Background and aim. Resistance-associated variants (RAVs) on the NS3 region of the hepatitis C virus (HCV) may be relevant for antiviral therapy, but data in human immunodeficiency virus (HIV) coinfected patients are scarce. We assessed frequencies of NS3 RAVs in patients infected with HCV genotype 1a with or without HIV coinfection. MATERIAL AND METHODS: HCV NS3 amino acids 1-181 were sequenced by the Sanger method and analyzed for RAVs. RAVs and their distribution between HCV genotype 1a clade I and II viruses were compared between HIV-infected versus HIV-uninfected patients. RESULTS: 148 samples were available (n = 68 HIV and n = 80 non-HIV). Relative frequency of clade I and clade II was significantly different between HIV (85% and 15%) and non-HIV groups (49% and 51%). Overall, HIV infected patients exhibited significantly lower prevalence of RAVs than HIV-uninfected patients (62% vs. 79%, p = 0.03). However, Q80K prevalence was significantly higher in HIV-infected subjects (50% vs. 24%, p = 0.001), whereas prevalence of S122D/G/N/S (2% vs. 16%, p = 0.002) and N174G/N/S (10% vs. 55%, p < 0.0001) polymorphisms were significantly lower. Q80K was found exclusively in clade I viruses. S122 (3% vs. 22%, p=0.001) and N174 (13% vs. 75%, p<0.0001) polymorphisms had significantly lower prevalence in clade I than clade II viruses. CONCLUSIONS: In the Netherlands, prevalence of clade I viruses and Q80K was significantly higher in HCV genotype 1a infected patients with HIV coinfection than in those without HIV coinfection. Prevalence of N174 and S122 polymorphisms was significantly higher in clade II than clade I viruses.

Theoretical and experimental assessment of degenerate primer tagging in ultra-deep applications of next-generation sequencing.

Primer IDs (pIDs) are random oligonucleotide tags used in next-generation sequencing to identify sequences that originate from the same template. These tags are produced by degenerate primers during the reverse transcription of RNA molecules into cDNA. The use of pIDs helps to track the number of RNA molecules carried through amplification and sequencing, and allows resolution of inconsistencies between reads sharing a pID. Three potential issues complicate the above applications. First, multiple cDNAs may share a pID by chance; we found that while preventing any cDNAs from sharing a pID may be unfeasible, it is still practical to limit the number of these collisions. Secondly, a pID must be observed in at least three sequences to allow error correction; as such, pIDs observed only one or two times must be rejected. If the sequencing product contains copies from a high number of RT templates but produces few reads, our findings indicate that rejecting such pIDs will discard a great deal of data. Thirdly, the use of pIDs could influence amplification and sequencing. We examined the effects of several intrinsic and extrinsic factors on sequencing reads at both the individual and ensemble level.

Myocarditis in drug rash with eosinophilia and systemic symptoms.

Drug rash with eosinophilia and systemic symptoms is a drug hypersensitivity reaction. Hepatitis and nephritis are the most common visceral manifestations. Myocarditis is important to recognise, given the high mortality rate. We describe a child with drug rash with eosinophilia and systemic symptoms and discuss the role of N-terminal pro-hormone of basic natriuretic peptide in early recognition of associated myocarditis.

Bitter bottle gourd (Lagenaria siceraria) toxicity.

BACKGROUND: Bottle gourd (Lagenaria siceraria) is an edible plant in the Cucurbitaceae family. When extremely bitter, ingestion of bottle gourd can cause rapid onset diarrhea, vomiting, gastrointestinal bleeding, and hypotension due to release of a substance named cucurbitacin. OBJECTIVE: Our aim was to increase physician awareness of cucurbitacin poisoning in order to facilitate accurate diagnosis and appropriate management. CASE REPORT: Five adult patients presented with nausea, vomiting, and diarrhea within 5 to 25 min of ingesting cooked bitter bottle gourd. One patient developed severe diarrhea, hematemesis, and hypotension requiring hospitalization. All patients improved within a few days with intravenous fluids and proton pump inhibitors. To our knowledge, this is the first reported group of patients with toxicity due to ingestion of bottle gourd in the United States (US). CONCLUSIONS: Physicians should be suspicious of cucurbitacin toxicity in patients who present with symptoms within minutes of ingestion of a plant in the Cucurbitaceae family. Patients should be asked if the plant tasted unusually bitter. The most common symptoms include diarrhea and hematemesis. More than half of patients develop hypotension. There is no known antidote for bottle gourd poisoning; treatment is supportive. Proton pump inhibitors should be given to patients with gastrointestinal mucosal injury.

Visual diagnosis: 10-year-old girl with fever and altered mental status.

Necrotizing soft tissue infections are rare but deadly infections. Diagnosis is made clinically with a high index of suspicion. Definitive treatment includes emergency surgical debridement, broad-spectrum antibiotics, and supportive care in the intensive care unit. The initial antibiotic regimen should be broad and cover gram-negative, anaerobic, and gram-positive organisms. Increased mortality is associated with delay in operative intervention.

A 67-Year-Old Woman With Fluctuating Hypertension and Hypotension After Elective Surgery.

CASE PRESENTATION: A 67-year-old woman with hypertension, type 2 diabetes mellitus, and hypothyroidism presented for an elective blepharoplasty. She underwent monitored anesthesia care with propofol and dexmedetomidine. No inhaled gases or neuromuscular blockade were administered during the procedure.