Hypothesized life cycle of the snow algae Chlainomonas sp. (Chlamydomonadales, Chlorophyta) from the Cascade Mountains, USA.

Chlainomonas (Chlamydomonadales, Chlorophyta) is one of the four genera of snow algae known to produce annual pink or red blooms in alpine snow. No Chlainomonas species have been successfully cultured in the laboratory, but diverse cell types have been observed from many field-collected samples, from multiple species. The diversity of morphologies suggests these algae have complex life cycles with changes in ploidy. Over 7 years (2017-2023), we observed seasonal blooms dominated by a Chlainomonas species from late spring through the summer months on a snow-on-lake habitat in an alpine basin in the North Cascade Mountains of Washington, USA. The Bagley Lake Chlainomonas is distinct from previously reported species based on morphology and sequence data. We observed a similar collection of cell types observed in other Chlainomonas species, with the addition of swarming biflagellate cells that emerged from sporangia. We present a life cycle hypothesis for this species that links cell morphologies observed in the field to seasonally available habitat. The progression of cell types suggests cells are undergoing both meiosis and fertilization in the life cycle. Since the life cycle is the most fundamental biological feature of an organism, with direct consequences for evolutionary processes, it is critical to understand how snow algal life cycles will influence their responses to changes in their habitat driven by climate warming. For microbial taxa that live in extreme environments and are difficult to culture, temporal field studies, such as we report here, may be key to creating testable hypotheses for life cycles.

Complications following single-stage bilateral total knee arthroplasty and unilateral procedures: experience of a high-volume community hospital.

INTRODUCTION: The safety of single-stage bilateral total knee arthroplasty (SSBTKA) compared to unilateral total knee arthroplasty (TKA) remains controversial. The present study compares the 90-day postoperative complications encountered following SSBTKA and unilateral TKA in an unselected cohort of patients performed at a high-volume community hospital. MATERIALS AND METHODS: The perioperative electronic medical records of an unselected consecutive cohort of 1032 patients (1345 knees) having undergone unilateral or SSBTKA were reviewed. Ninety-day postoperative complications or need for additional procedures were compared between unilateral and SSBTKA groups. RESULTS: A total of 719 and 313 patients underwent unilateral and SSBTKA, respectively. There were no significant differences in age or BMI between groups. Patients undergoing SSBTKA were more likely to be male (p = 0.019), have longer lengths of stay (p < 0.001) and were less likely to discharge directly home (13.1%) compared to unilateral patients (80.9%) (p < 0.001). Patients undergoing SSBTKA were more likely to require a transfusion (14.7%) compared to unilateral patients (2.2%) (p < 0.001). Interestingly, mortality rate following unilateral TKA (1.7%) was significantly higher than SSBTKA (0.0%) (p = 0.013). There were no significant differences regarding other complications or need for additional procedures within 90 days following surgery. CONCLUSION: SSBTKA did not result in greater complications when compared to unilateral TKA in this particular cohort. As expected, transfusion rates will likely be higher and there will be a greater need for acute inpatient care following surgery for SSBTKA patients.

Patchy and Pink: Dynamics of a Chlainomonas sp. (Chlamydomonadales, chlorophyta) algal bloom on Bagley Lake, North Cascades, WA.

Snow algal blooms frequently occur throughout alpine and polar environments during spring and summer months; however, our understanding of bloom dynamics is limited. We tracked a recurrent bloom of Chlainomonas sp. on Upper Bagley Lake in the North Cascade Mountains, USA, to assess the spatiotemporal dynamics in bloom color intensity, community photophysiology, and community composition over eight weeks. We found that the algae biomass had a dynamic patchy distribution over space and time, which was decoupled from changes in community composition and life-cycle progress averaged across the bloom. The proportional representation of Chlainomonas sp. remained consistent throughout the study while the overall community composition shows a progression through the bloom. We found that community photophysiology, measured by the maximum quantum yield of PSII (Fv/Fm), decreased on average throughout the bloom. These findings suggest that the Chlainomonas sp. community on Bagley Lake is not simply an algal bloom with rapid increase in biomass followed by a population crash, as is often seen in aquatic systems, though there is a physiological trajectory and sensitivity to environmental stress. These results contribute to our understanding of the biology of Chlainomonas sp. and its response to environmental stress, specifically an extreme warming event.

Can a community hospital successfully transition to outpatient total knee arthroplasty in unselected patients?

BACKGROUND: The removal of total knee arthroplasty (TKA) from the Inpatient-Only list in 2018 created pressure on community hospitals to develop rapid discharge protocols (RAP) to increase outpatient discharge. The purpose of this study, therefore, was to compare the efficacy, safety and barriers in achieving outpatient discharge between the standard discharge protocol and newly developed RAP in unselected, unilateral TKA patients. METHODS: This retrospective chart review included 288 standard protocol patients and the first 289 RAP patients following unilateral TKA in a community hospital. The RAP focused on patient discharge expectations and post-operative patient management, with no change in post-operative nausea or pain management. Non-parametric tests were performed to compare demographics, perioperative variables and 90-readmission/complication rates between standard and RAP groups, as well as between inpatient and outpatient discharged RAP patients. Multivariate, stepwise logistic regression was performed to evaluate patient demographics and discharge status, presented as odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Demographics were similar between groups, however, outpatient discharge significantly increased from 22.2% to 85.8% for standard discharge and RAP, respectively (p < 0.001), with no significant difference in post-operative complications. For RAP patients, age (OR:1.062, CI:1.014-1.111; p = 0.011) and female gender (OR:2.224, CI:1.042-4.832; p = 0.039) increased the risk of inpatient and 85.1% of RAP outpatients were discharged home. CONCLUSIONS: While RAP was successful, 15% of patients required inpatient care and 15% of patients achieving outpatient discharged were not discharged to their home environment, emphasizing the difficulties of achieving true outpatient status in 100% of patients from a community hospital.

The austral biflagellate Chloromonas rubroleosa (Chlorophyceae) is the closest relative of the unusual quadriflagellate genus Chlainomonas, both found in snow.

The quadriflagellate genus Chlainomonas frequently dominates red snow globally. It is unusual in several respects, with two separated pairs of flagella, apparent cell division via extrusion of cytoplasmic threads, and being nested phylogenetically within the biflagellate genus Chloromonas. Here, we showed that the austral species Chloromonas (Cr.) rubroleosa, originally described from Antarctic red snow, is a close biflagellate relative of Chlainomonas, challenging the monophyly of Chlainomonas as currently conceived. Sequences of the 18S rRNA gene robustly linked Cr. rubroleosa with near-identical environmental sequences from Antarctic red snow and Chlainomonas from North America, Japan, and Europe. Furthermore, the 18S rRNA and rbcL gene sequences of Cr. rubroleosa were almost identical to New Zealand and North American collections of Chlainomonas. Cr. rubroleosa and New Zealand Chlainomonas are separated by only a single-base substitution across the ITS1-5.8S-ITS2 rRNA loci (and according to ITS2, the North American collection is the next closest relative). This again raises the possibility that Chlainomonas is a life-cycle stage of vegetatively biflagellate organisms, although this remains confounded by the scarcity of biflagellates in field populations, the apparent cell division by quadriflagellates, and the absence of Chlainomonas-type cells in cultures of Cr. rubroleosa. The latter species is broadly similar to Chlainomonas, being poor at swimming, with similar pigment, chloroplast arrangement and ultrastructure, and is relatively large. Increased size is a feature of the wider clade of "Group D" snow algae. A synthesis of field and laboratory investigations may be needed to unravel the life cycle and correct the systematics of this group.

Population-Based Estimates of Associations Between Child Maltreatment Types: A Meta-Analysis.

Although it is accepted that experiences of child maltreatment are multidimensional and often include several correlated but distinct experiences, many clinical and research decisions regarding exposure and treatment do not consider their potential overlap or potential independence. The purpose of this meta-analysis-using a single retrospective self-report measure, the Childhood Trauma Questionnaire (CTQ), in population-representative samples-was to investigate the magnitude and specificity of associations between forms of child maltreatment. A systematic review of studies available on PubMed, PsycINFO, and Google Scholar was conducted, resulting in the inclusion of nine journal articles, 11 independent samples, and 25,415 participants. Data were converted from Pearson correlations to Z statistics and pooled using a random effects model. All maltreatment types were positively and significantly associated. Effect sizes varied from medium to large, with (1) physical abuse and emotional abuse (Z = 0.72, 95% CI [.48, .96]), (2) physical neglect and emotional neglect (Z = 0.62, 95% CI [.43, .81]), and (3) emotional abuse and emotional neglect (Z = 0.54, 95% CI [.35, .72]) demonstrating the strongest associations. These analyses provide evidence of the associations between types of child maltreatment, indicate the likelihood of shared risk, and point to characteristics that may link different types of maltreatment. These findings have important clinical implications as they may help guide comprehensive screening for associated maltreatment types as well as intervention and prevention efforts. Limitations include the relatively few studies included and those associated with the CTQ-a retrospective, self-report measure that does not account for the concurrence of experiences.

Perioperative Complications in Patients over 70 Years of Age following Simultaneous Bilateral Total Knee Arthroplasty.

Single-stage bilateral total knee arthroplasty (ssBTKA) can be used for patients presenting with bilateral arthritis and may result in fewer systemic and wound complications compared with two, independent procedures. However, the safety of ssBTKA in the elderly remains controversial. Therefore, the purpose of this study was to compare early complications and transfusion rates following ssBTKA in patients ≤ 70 years old or > 70 years old. This retrospective chart review of 313 consecutive patients undergoing ssBTKA included 174 patients ≤ 70 years old and 139 patients > 70 years old. Perioperative variables and postoperative complications were compared with univariate analyses between age groups. Multivariate analyses were performed to determine risk factors for developing perioperative complications and transfusions. Compared with patients ≤ 70, patients > 70 had significantly lower body mass index (p < 0.001) and were more commonly female (p = 0.024). Although wound (p > 0.12) and systemic complications (p > 0.54) were similar, 23% of patients > 70 required transfusion compared with only 8% of patients ≤ 70 (p < 0.001). Patients with preoperative anemia (p < 0.001), age > 70 (p = 0.002), or diabetes mellitus (p = 0.007) were at 5.7, 3.3, and 2.9 times greater risk for requiring a transfusion, respectively. Patients > 70 undergoing ssBTKA have a similar complication profile to patients ≤ 70 years old, suggesting age should not be an absolute exclusion criterion for ssBTKA. However, the risk of transfusion was significantly higher in those > 70, despite lower tourniquet times. Treatment of preoperative anemia may decrease the risk of transfusion and could provide adequate safety for patients > 70 to undergo ssBTKA by an experienced surgeon.

Similar infection rates in a new wound closure method following knee arthroplasty.

Surgical site infections, defined as acute wound infections requiring surgical intervention within 90 days post-surgery, were retrospectively compared between a novel, zipper-like closure method (ZM) and staples in 682 patients (904 knees) and 772 patients (971 knees), respectively. The incidence of deep infections was 0.6% for staples and 0.2% for ZM (p = 0.169) and superficial infections was 0.1% for staples and 0.0% for ZM (p = 0.518). With no difference in wound complications, the ZM may be preferred since the two-week post-operative clinic visit required for wound check and staple removal was eliminated, thereby, decreasing clinic volume.

Can obese patients undergo simultaneous bilateral total knee arthroplasty without an increased risk of perioperative complications?

Simultaneous bilateral total knee arthroplasty (simBTKA) remains controversial, especially in obese patients. Therefore, this retrospective study compared six month perioperative complications in 313 simBTKA patients. Comparison groups included 139 non-obese patients (BMI < 30), 61 obese patients (BMI = 30-35) and 48 severely obese patients (BMI > 35). Increased BMI was associated with longer tourniquet and surgical times (p < 0.001). However, no differences were found for transfusion (p = 0.288), deep infection (p = 0.971), pulmonary embolism (p = 0.454), or deep vein thrombosis (p = 0.670). Increased BMI was, therefore, not associated with greater post-operative complications and should not necessarily contraindicate simBTKA.

Disruption of a ∼23-24 nucleotide small RNA pathway elevates DNA damage responses in Tetrahymena thermophila.

Endogenous RNA interference (RNAi) pathways regulate a wide range of cellular processes in diverse eukaryotes, yet in the ciliated eukaryote, Tetrahymena thermophila, the cellular purpose of RNAi pathways that generate ∼23-24 nucleotide (nt) small (s)RNAs has remained unknown. Here, we investigated the phenotypic and gene expression impacts on vegetatively growing cells when genes involved in ∼23-24 nt sRNA biogenesis are disrupted. We observed slower proliferation and increased expression of genes involved in DNA metabolism and chromosome organization and maintenance in sRNA biogenesis mutants RSP1Δ, RDN2Δ, and RDF2Δ. In addition, RSP1Δ and RDN2Δ cells frequently exhibited enlarged chromatin extrusion bodies, which are nonnuclear, DNA-containing structures that may be akin to mammalian micronuclei. Expression of homologous recombination factor Rad51 was specifically elevated in RSP1Δ and RDN2Δ strains, with Rad51 and double-stranded DNA break marker γ-H2A.X localized to discrete macronuclear foci. In addition, an increase in Rad51 and γ-H2A.X foci was also found in knockouts of TWI8, a macronucleus-localized PIWI protein. Together, our findings suggest that an evolutionarily conserved role for RNAi pathways in maintaining genome integrity may be extended even to the early branching eukaryotic lineage that gave rise to Tetrahymena thermophila.

Barriers to achieving same day discharge following unilateral unicompartmental knee arthroplasty.

BACKGROUND: Evidence suggests that only a minority of unselected patients are able to achieve same day (SD) discharge following unilateral unicompartmental knee arthroplasty (UKA). However, many hospitals continue to classify UKA as an outpatient procedure, creating financial pressure to limit prolonged hospitalizations. To understand and address challenges that decrease patients' likelihood of achieving SD discharge, this study aimed to identify barriers commonly contributing to SD discharge failures with following a rapid discharge protocol (RDP). METHODS: Retrospectively collected data from 158 unselected patients having undergone unilateral UKA between 2018 and 2019 were reviewed. All patients were treated using an established RPD with intended SD discharge. RESULTS: Successful SD discharge was achieved by 84.2% of patient. Overall, those failing to achieve SD discharge were older (p < 0.001), more commonly female (p = 0.037), have multiple functional deficits (p < 0.05) and experience post-operative nausea (p < 0.001). Increased age, the use of an assisted device, and post-operative nausea accounted for 44.8% of the variability for patient not achieving SD discharge. The model was able to classify 95.7% of SD discharge and 38.1% of unsuccessful SD discharge patients, for an overall success rate of 85.1%. CONCLUSIONS: The use of a well-developed, interdisciplinary RDP for unilateral UKA results in high SD discharge success in a community hospital setting. However, with 15.8% of patients still not able to achieve SD discharge, a more efficient RDP may include prioritizing patient scheduling, with lower priority given to older individuals requiring an assisted device, and changes to preventative and symptomatic treatment options for post-operative nausea.

Effect of Cytochrome P450 (CYP) 2D6 Genetic Polymorphism on the Inhibitory Action of Antidepressants on CYP2D6-Mediated Dopamine Formation from p-Tyramine.

PURPOSE: The inhibitory effects of antidepressants, such as imipramine, desipramine, and fluvoxamine, on dopamine formation from p-tyramine catalyzed by cytochrome P450 (CYP) 2D6.2 (Arg296Cys, Ser486Thr) and CYP2D6.10 (Pro34Ser, Ser486Thr), were compared with those on dopamine formation catalyzed by CYP2D6.1 (wild type), to investigate the effect of a CYP2D6 polymorphism on neuroactive amine metabolism in the brain. METHODS: Inhibition constants (Ki) of the antidepressants toward dopamine formation catalyzed by CYP2D6.1, CYP2D6.2, and CYP2D6.10, which were expressed in recombinant Escherichia coli, were compared. RESULTS: Imipramine and desipramine competitively or non-competitively inhibited dopamine formation mediated by CYP2D6.1, CYP2D6.2, and CYP2D6.10 with Ki values of 3.9-4.9, 5.9-9.6, and 26.7-37.5 µM, respectively. The maximal velocity (Vmax) values for dopamine formation by all CYP2D6 variants gradually increased with increasing fluvoxamine concentrations up to 40-100 µM, indicating that fluvoxamine stimulated dopamine formation. CONCLUSIONS: These results suggest that the inhibition/stimulation of CYP2D6-mediated dopamine formation by these antidepressants would be affected by CYP2D6 polymorphism in the brain. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

Determination of N-ethylglycine in urine of cancer patients with metastatic bone disease by HPLC using 4-(5,6-dimethoxy-2-phthalimidinyl)-2-methoxyphenylsulfonyl chloride as a fluorescent labeling reagent.

A simple and highly sensitive HPLC for the determination of N-ethylglycine in urine was developed. The labeling reaction of N-ethylglycine with 4-(5,6-dimethoxy-2-phthalimidinyl)-2-methoxyphenylsulfonyl chloride was carried out at 70 degrees C for 15 min at pH 9.0. The fluorescent derivative was separated on a reversed-phase column and detected at excitation and emission wavelengths of 320 and 400 nm, respectively. The detection limit of N-ethylglycine was 15 fmol (S/N = 3). The recovery of N-ethylglycine added to urine was 101.9%. The concentration of N-ethylglycine in urine of cancer patients with metastatic bone disease was 11.3 +/- 22.0 nmol/mg creatinine, and that of normal subject was 0.4 +/- 0.4 nmol/mg creatinine.

Identification of N-ethylglycine in urine of cancer patients with metastatic bone disease.

BACKGROUND: Previously, a HPLC method for the determination of N-terminal prolyl dipeptides, proline and hydroxyproline in urine with fluorescence detection after pre-column derivatization with 4-(5,6-dimethoxy-2-phthalimidinyl)-2-methoxyphenylsulfonyl chloride (DMS-Cl) [Inoue H, Iguchi H, Kono A, Tsuruta Y. Highly sensitive determination of N-terminal prolyl dipeptides, proline and hydroxyproline in urine by high-performance liquid chromatography using a new fluorescent labelling reagent, 4-(5,6-dimethoxy-2-phthalimidinyl)-2-methoxyphenylsulfonyl chloride. J Chromatogr 1999;724:221-230] was developed to study the relation between those analytes and bone diseases. When the urinary analytes were measured, a large peak due to an unknown substance was recognized in the chromatograms of cancer patients with metastatic bone disease, although it was scarcely present in normal subjects. In this study, we identified the unknown substance. METHODS: The fluorescent fraction based on the unknown substance was collected using HPLC and the structure of the fluorescence product was analyzed with MS, (1)H NMR and (13)C NMR. RESULTS: The fluorescence product based on the unknown substance was established to be a DMS-derivative of N-ethylglycine. CONCLUSIONS: Excretion of N-ethylglycine in the urine of cancer patients with metastatic bone disease is recognized, although N-ethylglycine is scarcely excreted in the urine of normal subjects.