Seroprevalence and risk factors of Toxoplasma gondii infection among pregnant women.

INTRODUCTION: Toxoplasma gondii is an obligate intracellular parasite affecting a broad range of warm-blooded animals, including humans. Infection acquired during pregnancy can be transmitted to the fetus and leading to serious problems such as spontaneous abortion, stillbirth, or severe mental and/or physical handicaps in the child. The purpose of this study was to investigate the seroprevalence of Toxoplasma infection and related risk factors in pregnant woman. METHODOLOGY: The study enrolled 1200 serum samples of pregnant women from February-November 2017. Then the samples were tested for the presence of anti-T. gondii antibodies (Ab) using enzyme-linked immunosorbent assay. RESULTS: Out of the 1200 samples, 381 (31.7%) and 41 (3.4%) subjects were positive for IgG and IgM Ab, respectively. Among the evaluated risk factors, the seroprevalence of Toxoplasma infection was not related to the occupation in a significant way. However significant relationship was observed with factors such as; contact with soil, cats, consumption of raw washed vegetables, and washed hands before meals. CONCLUSIONS: According to the results, more than two-thirds of pregnant women are susceptible to Toxoplasma infection, hence training health care programs should be provided to prevent infection.

Yeast ribosome biogenesis factors Puf6 and Nog2 and ribosomal proteins uL2 and eL43 act in concert to facilitate the release of nascent large ribosomal subunits from the nucleolus.

Large ribosomal subunit precursors (pre-LSUs) are primarily synthesized in the nucleolus. At an undetermined step in their assembly, they are released into the nucleoplasm. Structural models of yeast pre-LSUs at various stages of assembly have been collected using cryo-EM. However, which cryo-EM model is closest to the final nucleolar intermediate of the LSU has yet to be determined. To elucidate the mechanisms of the release of pre-LSUs from the nucleolus, we assayed effects of depleting or knocking out two yeast ribosome biogenesis factors (RiBi factors), Puf6 and Nog2, and two ribosomal proteins, uL2 and eL43. These proteins function during or stabilize onto pre-LSUs between the late nucleolar stages to early nucleoplasmic stages of ribosome biogenesis. By characterizing the phenotype of these four mutants, we determined that a particle that is intermediate between the cryo-EM model State NE1 and State NE2 likely represents the final nucleolar assembly intermediate of the LSU. We conclude that the release of the RiBi factors Nip7, Nop2 and Spb1 and the subsequent stabilization of rRNA domains IV and V may be key triggers for the release of pre-LSUs from the nucleolus.

Induction of TLR5, IRAK1, and NF-κB expression by Trichomonas vaginalis in cervical cancer cell (HeLa) and normal human vaginal epithelial cell (HVECs) lines.

INTRODUCTION: Trichomoniasis is the most common non-viral sexually transmitted infection that increases the risk of cervical cancer. Trichomonas vaginalis (T. vaginalis) can regulate the pro-inflammatory cytokine production in the host cells. Toll-like receptors (TLRs) are a family of the pattern recognition receptors (PRRs) of mammalian cells, expressed in various host cells and have an important role in recognizing pathogens, and pro-inflammatory responses. The aim of the present study is to investigate the role of TLR5 in cervical cancer cells (HeLa) and human vaginal epithelial cells (HVECs) exposed to T. vaginalis. METHODOLOGY: First, the cells and parasites were cultured in RPMI and trypticase yeast extract maltose (TYM), respectively. After adaption of parasite and epithelial cells by RPMI-TYM medium co-culture (9:1 vol/vol), HVECs and HeLa cells were stimulated with T. vaginalis trophozoites (24-hour incubation at 37 °C, 5% CO2). Following RNA extraction and cDNA synthesis, the gene expression levels of TLR5, IRAK1, and NF-κB were assessed using real-time PCR. Besides, the protein levels were measured using western blotting. All tests and controls were normalized using ß-actin as a housekeeping control. RESULTS: Real-time PCR results showed an increased gene expression of TLR5, IRAK1, and NF-κB in T. vaginalis exposed HVECs and HeLa cells compared to the control group (p < 0.05). Additionally, western blot analysis showed a statistically significant increase in TLR5, and NF-κB proteins in both groups after exposure to the parasite (p < 0.05). CONCLUSIONS: These findings provide insight into the host-parasite interaction, and the results indicated that T. vaginalis could stimulate TLR5 and activate related pathways.

Unraveling the influences of sequence and position on yeast uORF activity using massively parallel reporter systems and machine learning.

Upstream open-reading frames (uORFs) are potent cis-acting regulators of mRNA translation and nonsense-mediated decay (NMD). While both AUG- and non-AUG initiated uORFs are ubiquitous in ribosome profiling studies, few uORFs have been experimentally tested. Consequently, the relative influences of sequence, structural, and positional features on uORF activity have not been determined. We quantified thousands of yeast uORFs using massively parallel reporter assays in wildtype and ∆upf1 yeast. While nearly all AUG uORFs were robust repressors, most non-AUG uORFs had relatively weak impacts on expression. Machine learning regression modeling revealed that both uORF sequences and locations within transcript leaders predict their effect on gene expression. Indeed, alternative transcription start sites highly influenced uORF activity. These results define the scope of natural uORF activity, identify features associated with translational repression and NMD, and suggest that the locations of uORFs in transcript leaders are nearly as predictive as uORF sequences.

Severe Hemoperitoneum due to Ovarian Bleeding after Transvaginal Oocyte Retrieval with Surgical Management: A Retrospective Analysis and Comprehensive Review of the Literature.

Background and Objectives: Severe hemoperitoneum of ovarian bleeding origin is a rare but potentially life-threatening complication of transvaginal oocyte retrieval (TVOR) procedure. The study aimed to present a case series of surgically managed patients from our clinic with hemoperitoneum caused by ovarian bleeding after TVOR, as well as to perform a comprehensive literature review in order to summarize and analyze all published cases with this condition and their management. Materials and Methods: The data of 2939 patients, who underwent TVOR procedures for IVF/ICSI (in vitro fertilization, intracytoplasmic sperm injection) in our clinic between 2010 and 2021 were reviewed. Moreover, a systemic literature search was performed. Main outcome measures from the pooled analysis were incidence and risk factors, type of surgery, intraoperative finding and intervention leading to hemostasis. Results: In our Clinic 4 (0.136%), cases of hemoperitoneum due to ovarian bleeding were surgically managed. Moreover, 39 cases from 18 studies reported in the literature were identified. No risk factors besides lean women with PCOS were identified. In the pooled analysis, the bleeding symptoms appeared in 58.1% of patients within eight hours after TVOR and cumulatively in 81.4% cases during the 24 h after TVOR. The average time from TVOR to surgery was 27.19 ± 53.25 h. Hemostasis was mostly established using electrocoagulation, although few cases of ovariectomy were also reported. Embryo transfer at 60% of cases was postponed and embryos cryopreserved. Conclusions: Severe hemoperitoneum due to ovarian bleeding after TVOR is a rare event that should be treated by techniques of minimally invasive surgery whenever possible. Protocols should be developed to enable optimal management strategies for infertility patients. Embryos obtained should be cryopreserved.

Additional principles that govern the release of pre-ribosomes from the nucleolus into the nucleoplasm in yeast.

During eukaryotic ribosome biogenesis, pre-ribosomes travel from the nucleolus, where assembly is initiated, to the nucleoplasm and then are exported to the cytoplasm, where assembly concludes. Although nuclear export of pre-ribosomes has been extensively investigated, the release of pre-ribosomes from the nucleolus is an understudied phenomenon. Initial data indicate that unfolded rRNA interacts in trans with nucleolar components and that, when rRNA folds due to ribosomal protein (RP) binding, the number of trans interactions drops below the threshold necessary for nucleolar retention. To validate and expand on this idea, we performed a bioinformatic analysis of the protein components of the Saccharomyces cerevisiae ribosome assembly pathway. We found that ribosome biogenesis factors (RiBi factors) contain significantly more predicted trans interacting regions than RPs. We also analyzed cryo-EM structures of ribosome assembly intermediates to determine how nucleolar pre-ribosomes differ from post-nucleolar pre-ribosomes, specifically the capacity of RPs, RiBi factors, and rRNA components to interact in trans. We observed a significant decrease in the theoretical trans-interacting capability of pre-ribosomes between nucleolar and post-nucleolar stages of assembly due to the release of RiBi factors from particles and the folding of rRNA. Here, we provide a mechanism for the release of pre-ribosomes from the nucleolus.

Acute hepatitis in a paediatric patient: immune-mediated drug-induced liver injury or albendazole-induced autoimmune hepatitis?

INTRODUCTION: Drug-induced liver injury (DILI) is one of the most common causes of liver damage. A large number of drugs, dietary supplements, and herbal medications can cause hepatotoxicity. In some situations, it is difficult to distinguish between DILI and autoimmune hepatitis, especially when the mechanism is immune-mediated. Albendazole is a drug that has been used for decades for the treatment of parasitic infections in humans. One of the side effects is liver enzyme elevation, but rarely requires the discontinuation of therapy. Previous experience has shown that hypersensitivity is the most common mechanism of albendazole hepatotoxicity. CASE REPORT: Here we presented a paediatric patient in whom albendazole induced severe liver injury. In laboratory analyses, in addition to markedly elevated transaminases and parameters of cholestasis, there was also a significant increase in IgG, so autoimmune hepatitis was considered. Even though the liver histology indicated toxic liver disease, prednisolone was started. Corticosteroid therapy resulted in the complete normalization of liver function, as well as IgG. With the cessation of corticosteroid therapy, transaminases, bilirubin and gamma-glutamyl transferase (GGT) remained within normal levels, but an increase in anti-smooth muscle antibodies (SMA) was noted in immunological analyses after one year of follow-up. CONCLUSIONS: Immune-mediated hepatotoxicity from albendazole is one possible mechanism of liver injury. The use of albendazole in the treatment of parasitic infections, especially in children, requires close monitoring. The question remains as to whether albendazole is a drug that can induce autoimmune hepatitis in the paediatric population.

Predictive Value of Basal Serum Progesterone for Successful IVF in Endometriosis Patients: The Need for a Personalized Approach.

The data regarding the role of progesterone (P4) in reproductive events of endometriosis patients are limited. This prospective study aimed to examine the predictive value of basal P4 serum levels for successful in vitro fertilization (IVF) in patients with primary infertility and endometriosis. The study included 73 patients divided according to endometriosis treatment (surgery vs. control-no treatment). The general data, basal hormonal status, and pregnancy rates were determined for every patient. Clinical pregnancy was achieved in 40.3% of patients, and more often in patients treated for endometriosis before IVF. The regression analysis showed that higher basal P4 serum levels were associated with achieving pregnancy through IVF. When regression was adjusted for the patient and IVF characteristics, higher basal P4 serum levels were associated with pregnancy achievement in both groups of women, along with the basal serum levels of FSH, LH, and AMH; EFI score; and stimulation protocol. The ROC analysis showed that the basal P4 serum level for successful IVF should be ≥0.7ng/mL. The basal P4 serum level cut-off for IVF success in endometriosis patients was determined for the first time. Constructed models for IVF success prediction emphasize the importance of determining the basal P4 serum levels for the personalized treatment of endometriosis-related infertility.

Fatal invasive candidiasis in COVID-19 patient with severe bleeding and extensively drug-resistant Klebsiella enterobacter.

INTRODUCTION: Multi-organ dysfunction caused by thromboembolic complications may complicate the course of SARS-CoV-2 infection. Most patients require anticoagulant therapy which predisposes them to the development of hemorrhagic syndrome. In critically ill COVID-19 patients secondary infections due to opportunistic pathogens are associated with a high mortality rate. CASE REPORT: Herein, we present a COVID-19 patient with severe hemorrhage at unusual sites complicated with invasive candidiasis and an extensively drug-resistant (XDR) strain of Klebsiella enterobacter. CONCLUSIONS: Clinicians should be aware of the possibility for invasive fungal infections in severely ill patients with SARS-CoV-2 infection due to pre-existing conditions, risk factors, and COVID-19 associated pathological mechanisms. Management of invasive candidiasis is challenging because of the high prevalence of comorbidities, risk of toxicities, and drug interactions.

Ribosomal protein eL39 is important for maturation of the nascent polypeptide exit tunnel and proper protein folding during translation.

During translation, nascent polypeptide chains travel from the peptidyl transferase center through the nascent polypeptide exit tunnel (NPET) to emerge from 60S subunits. The NPET includes portions of five of the six 25S/5.8S rRNA domains and ribosomal proteins uL4, uL22, and eL39. Internal loops of uL4 and uL22 form the constriction sites of the NPET and are important for both assembly and function of ribosomes. Here, we investigated the roles of eL39 in tunnel construction, 60S biogenesis, and protein synthesis. We show that eL39 is important for proper protein folding during translation. Consistent with a delay in processing of 27S and 7S pre-rRNAs, eL39 functions in pre-60S assembly during middle nucleolar stages. Our biochemical assays suggest the presence of eL39 in particles at these stages, although it is not visualized in them by cryo-electron microscopy. This indicates that eL39 takes part in assembly even when it is not fully accommodated into the body of pre-60S particles. eL39 is also important for later steps of assembly, rotation of the 5S ribonucleoprotein complex, likely through long range rRNA interactions. Finally, our data strongly suggest the presence of alternative pathways of ribosome assembly, previously observed in the biogenesis of bacterial ribosomal subunits.

Reproductive outcomes of IVF after comprehensive endometriosis treatment: a prospective cohort study.

OBJECTIVES: To evaluate the impact of pharmacological and surgical endometriosis treatment on IVF reproductive outcomes in patients with primary infertility. MATERIAL AND METHODS: The study, conducted over a five year period, included 73 patients with endometriosis associated primary infertility subjected to 77 cycles. Group I included patients treated for endometriosis before the IVF (subgroups A: surgical and pharmacological treatment and B: only surgical treatment). Group II included patients immediately subjected to IVF. Assessed outcomes were pregnancy rate (PR) per started cycle, fertilization rate (FR), implantation rate (IR) and live birth rate (LBR). RESULTS: Group IA included 25 patients, Group IB 21 and Group II 27 patients. FR and IR showed no significant differences between groups. PR was significantly higher in the Group I than Group II (49% vs 25%, p = 0.030). PR per started cycle was the highest in the Group IA and the lowest in the Group II (p = 0.040). LBR was significantly higher in whole Group I (p = 0.043) and subgroup IA (p = 0.020) than Group II. Group IA and IB did not differ regarding examined outcomes. Regression analysis showed that endometriosis pretreatment method can impact both achieving pregnancy (p = 0.036) and having a live born child (p = 0.008) after IVF. The combined surgical and pharmacological endometriosis treatment, shorter infertility duration, lower EFI score, using long protocol with FSH+HMG gonadotropins increase the probability of successful IVF. CONCLUSIONS: A combined surgical and pharmacological endometriosis treatment had a positive impact on IVF reproductive outcomes, both on pregnancy and on live birth rates.

Coupling of 5S RNP rotation with maturation of functional centers during large ribosomal subunit assembly.

The protein composition and structure of assembling 60S ribosomal subunits undergo numerous changes as pre-ribosomes transition from the nucleolus to the nucleoplasm. This includes stable anchoring of the Rpf2 subcomplex containing 5S rRNA, rpL5, rpL11, Rpf2 and Rrs1, which initially docks onto the flexible domain V of rRNA at earlier stages of assembly. In this work, we tested the function of the C-terminal domain (CTD) of Rpf2 during these anchoring steps, by truncating this extension and assaying effects on middle stages of subunit maturation. The rpf2Δ255-344 mutation affects proper folding of rRNA helices H68-70 during anchoring of the Rpf2 subcomplex. In addition, several assembly factors (AFs) are absent from pre-ribosomes or in altered conformations. Consequently, major remodeling events fail to occur: rotation of the 5S RNP, maturation of the peptidyl transferase center (PTC) and the nascent polypeptide exit tunnel (NPET), and export of assembling subunits to the cytoplasm.

Lyme Endocarditis as an Emerging Infectious Disease: A Review of the Literature.

Lyme endocarditis is extremely rare manifestation of Lyme disease. The clinical manifestations of Lyme endocarditis are non-specific and can be very challenging diagnosis to make when it is the only manifestation of the disease. Until now, only a few cases where reported. Physicians should keep in mind the possibility of borrelial etiology of endocarditis in endemic areas. Appropriate valve tissue sample should be sent for histopathology, culture, and PCR especially in case of endocarditis of unknown origin PCR on heart valve samples is recommended. With more frequent PCR, Borrelia spp. may be increasingly found as a cause of infective endocarditis. Prompt diagnosis and treatment of Lyme carditis may prevent surgical treatment and pacemaker implantations. Due to climate change and global warming Lyme disease is a growing problem. Rising number of Lyme disease cases we can expect and rising number of Lyme endocarditis.

Risk factors associated with poor clinical outcome in pyogenic spinal infections: 5-years' intensive care experience.

INTRODUCTION: Management of pyogenic spinal infections (PSI) after the development of neurological deficit has not been specifically addressed in the literature. We aimed to describe real-life clinical outcomes of PSI in patients admitted to an intensive care unit with neurological deficit and identify factors associated with good prognosis. METHODOLOGY: Consecutive patients admitted to ICU with a possible diagnosis of spinal infection over five years' period were included. Descriptive statistics were performed to examine the demographics and clinical parameters. RESULTS: The majority (71%) of patients were male. The mean age was 57.4 years (27-79), and 71% were > 50 years old. At least one underlying risk factor was identified in 68% of the patients; the most common comorbidity was diabetes mellitus (DM). All patients have presented with fever accompanied by a neurological deficit (86%) and back pain (79%). A complete recovery was achieved in 25% of patients. However, the majority of patients had adverse outcomes with 21.4% mortality, and 43% remaining neurological sequelae. Increased age with a cut-off of 65 years and pre-existing DM were identified as being associated with poor outcome. CONCLUSION: Mortality among patients admitted to ICU with PSI was significantly higher than reported in the literature. The residual neurological deficit was common, one-third of patients had remaining neurological sequelae, and only one-fourth had complete recovery. Increased age and background DM were the most important determinants of poor clinical outcome. The impact of DM appears to be much more important than currently recognised in this population.

An exceptional case report of disseminated cryptococcosis in a hitherto immunocompetent patient.

Cryptococcosis is an opportunistic fungal infection causes significant disease predominantly in immunocompromised patients. Here we present an excepcional case of disseminated cryptococcosis with pulmonary and cerebral involvement in an immunocompetent patient with no apparent predisposing factors at the time of hospital admission. We described a case of an apparently immunocompetent 66-years old man admitted to hospital with a one-month history of cough, fever and vertigo. During hospitalization, thorax imaging was suggestive of lung metastasis, therefore, he went through several investigations. During hospitalization, he developed neurological symptoms and subsequently underwent a lumbar puncture. Cerebrospinal fluid (CSF) culture was positive for Cryptococcus spp. isolated on Sabouraud's dextrose agar and bird seed agar. In addition, the direct microscopy examination was positive for the India ink test, as well as with the latex agglutination test for cryptococcal polysaccharide antigen (CrAg) in CSF, while serum CrAg was negative. Despite the absence of classic immunocompromising features, he was treated with amphotericin B and fluconazole due to suspected disseminated cryptococcal infection. Later, he was diagnosed with prostatic adenocarcinoma. Upon successful completion of treatment for disseminated cryptococcosis, the patient underwent radical prostate ablation surgery as a treatment forprostatic adenocarcinoma. This exceptional case emphasizes the high degree of suspicion of atypical infections, and in these cases, it is particularly important to consider fungal infections in hitherto healthy patients with no apparent predisposing factors. Although Cryptococcus spp. is predominantly reported in patients with hematological malignancies, cryptococcosis investigation should also be considered as part of the initial workup of patients with a new diagnosis of a solid tumour prior to chemotherapy or radiotherapy.

Investigation of a healthcare-associated Candida tropicalis candidiasis cluster in a haematology unit and a systematic review of nosocomial outbreaks.

BACKGROUND: Non-albicans Candida spp. are an emerging cause of hospital-acquired bloodstream infections, associated with high mortality due to the challenges in diagnosis and delayed treatment. OBJECTIVES: We aimed to investigate a cluster of healthcare-associated invasive candidiasis caused by C tropicalis and review the literature of healthcare-associated outbreaks or clusters caused by C tropicalis. METHODS: An investigation was performed to determine clinical presentation, treatment outcomes and the factors contributing to C tropicalis candidemia occurrence. We searched the Medline database via PubMed and Ovid using the keywords of "Candida tropicalis" combined with "outbreak" or "clustering" or "clusters," and we limited the search to studies conducted from January 1989 to January 2019. RESULTS: We report two related cases of C tropicalis candidemia among patients with AML following a period of neutropenia, who had erythematous skin rash as a first manifesting sign of candidiasis. C tropicalis was isolated from blood and skin cultures of both patients, which were identical by pulsed-field gel electrophoresis typing. Our systematic review of outbreaks caused by C tropicalis suggests that (a) most reported outbreaks have occurred in neonatal and adult ICUs; (b) patients who receive total parenteral therapy, antibiotics and those who have indwelling catheters and recent surgery are at high risk of infection; and (c) environmental and healthcare personnel surveillance suggest that cross-contamination is a major risk factor. CONCLUSION: Control of nosocomial outbreaks caused by C tropicalis should include better infection control measures, education of healthcare professionals especially working in adult and neonatal intensive care and haematology units.

Management of Orbital Complications of Acute Rhinosinusitis in Pediatric Patients: A 15-Year Single-Center Experience.

BACKGROUND: The major clinical dilemma managing acute rhinosinusitis (ARS) in pediatric population is distinguishing uncomplicated rhinosinusitis from a complicated bacterial ARS and orbital complications, the latter requiring antimicrobials and surgical intervention. However, factors associated with severe orbital complications and the optimum management strategy remains controversial. The objectives of this study were to characterize the clinical outcomes of children with orbital complications of ARS and to identify risk factors associated with disease severity. METHODS: This retrospective cohort analysis evaluated the clinical outcomes of 61 children admitted for orbital complications between January 1, 2002 and December 31, 2017. Descriptive statistics were performed to examine the demographics and clinical findings. We compared groups using Mann-Whitney U test for continuous variables and χ for categorical variables. RESULTS: Although two-thirds of children had received prehospital antibiotics, half of the cohort presented with post-septal orbital complications. While 83% of isolates obtained from the same patients were susceptible to the prehospital antibiotics given, the majority of those who received prehospital antibiotics nevertheless required surgical intervention. We observed significant association between the age of presentation and disease severity. Children >5 years of age presented with more severe orbital complications despite prehospital antibiotics and were more likely to require surgical intervention (P < 0.001). CONCLUSIONS: In this study, stage II/III orbital complications at presentation and older age were the most important determinants of medical treatment failure. Early referral to eye, nose and throat (ENT) should be considered for children >5 years with ARS due to worse orbital complications despite prehospital antibiotics.

Tick-borne encephalitis in Serbia: A case series.

INTRODUCTION: In the Europe, the number of tick-borne encephalitis (TBE) has been increased in the last decade, and the number of endemic areas has been also increased and is still growing. In the present case series, we present clinical and socio-epidemiological data of patients with TBE hospitalized in the period of TBE virus epidemic in Serbia. METHODOLOGY: A case series was conducted in Serbia in 2017. Patients with confirmed TBE were included in the study. Biochemical and serological analysis of blood and CSF, as well as radiological imaging (CT and MRI) were done. RESULTS: In total, 10 patients with TBE were included in the study. M:F ratio was 1.5:1, while average age was 45.1 years. Half of the patients had severe clinical picture. Endocranial CT scan and MRI did not reveal any abnormality, except in the patient with the most severe CNS infection (meningoencephalomyelitis). Mean value of sedimentation and CRP was slightly elevated (29.6 mm/1hours and 20.1 mg/L, respectively) in 80% of the patients, although elevation was almost negligible. The average number of leucocytes in the cerebrospinal fluid (CSF) was 171×106/L, the mean value of the CSF protein was 1.1g/L. There were no fatal outcomes. CONCLUSION: Since other CNS infections have similar clinical picture and CSF finding as TBE, serological analysis for TBE should be included in routine diagnostic practice.

A rare case of pacemaker lead endocarditis successfully treated with open heart surgery.

BACKGROUND: Cardiac device-related endocarditis has emerged as a serious complication in the era of advanced medical technology. Pacemaker related infections are rare and life-threatening with incidence from 0.06% to 7% and high mortality rate (30-35%). Diagnosis is hard, frequently delayed and could be even missed due to poor clinical findings. The average delay in diagnosis is 5.5 month. We report a case of the late-onset of pacemaker lead endocarditis caused by S. epidermidis successfully treated with open heart surgery. CASE REPORT: Patient with persistent high fever for 11 month and suspicion for infective endocarditis was admitted in Cardiovascular Institute. No clinical signs of endocarditis were observed. TTE revealed large vegetation 30 × 17 mm attached to the atrial electrodes with high embolic potential. This finding was verified by transesophageal echocardiography (TEE), although CT scan did not reveal vegetation. Blood cultures were negative. A sternotomy with cardiopulmonary bypass was performed and electrodes were extracted with large vegetation. Intraoperative finding revealed large thrombus with vegetation around pacemaker leads. Cultures of the electrodes and vegetation revealed Staphylococcus epidermidis. Surgery was followed up with antibiotic treatment for 6 weeks. He has been followed up for the next 2 years, and without complications. CONCLUSION: The absence of criteria for endocarditis and negative blood cultures should not keep the physician from ruling out lead endocarditis. This complication carries high risk of mortality if left untreated.

Hierarchical recruitment of ribosomal proteins and assembly factors remodels nucleolar pre-60S ribosomes.

Ribosome biogenesis involves numerous preribosomal RNA (pre-rRNA) processing events to remove internal and external transcribed spacer sequences, ultimately yielding three mature rRNAs. Removal of the internal transcribed spacer 2 spacer RNA is the final step in large subunit pre-rRNA processing and begins with endonucleolytic cleavage at the C2 site of 27SB pre-rRNA. C2 cleavage requires the hierarchical recruitment of 11 ribosomal proteins and 14 ribosome assembly factors. However, the function of these proteins in C2 cleavage remained unclear. In this study, we have performed a detailed analysis of the effects of depleting proteins required for C2 cleavage and interpreted these results using cryo-electron microscopy structures of assembling 60S subunits. This work revealed that these proteins are required for remodeling of several neighborhoods, including two major functional centers of the 60S subunit, suggesting that these remodeling events form a checkpoint leading to C2 cleavage. Interestingly, when C2 cleavage is directly blocked by depleting or inactivating the C2 endonuclease, assembly progresses through all other subsequent steps.