Patients undergoing hip hemiarthroplasty who require early return to theatre have early increased mortality and worse functional outcomes at short term follow-up.

BACKGROUND: Re-operation following hip hemiarthroplasty is potentially devastating due to a frail, co-morbid surgical cohort. We aimed to assess the outcomes of patients who required early return to theatre (RTT) within 30 days of index operation in a high-volume hip fracture unit. METHODS: A retrospective review of a prospectively maintained database was undertaken. All hip hemiarthroplasties performed between 1st January 2010 and 31st December 2019 was included. Demographic details, complications including reason for return to theatre, length of stay, discharge destination, functional outcome and mortality were collected and reviewed. RESULTS: 4340 hip hemiarthroplasty procedures were performed, of which 64 patients (1.47%) required early RTT within 30 days of index procedure and 4276 patients did not require early-RTT. The most common reasons for RTT were infection (n = 47) and dislocation (n = 15). There were no cases of peri­prosthetic fracture requiring RTT within 30 days. Patients requiring early RTT had a significantly increased rate of mortality within 120 days; 32.8% (21 of the 64 patients) versus 13.6% (580 out of the 4276) not requiring early RTT (p < 0.001). The median length of acute inpatient admission for patients who required early RTT was significantly longer at 31 days (range 6-185 days) compared to 10 days (range 3-171 days, p < 0.001) for those without early RTT. Early RTT was associated with a poorer functional mobility outcome at 120 days post-operatively, with a significantly greater reduction in Barthel score compared to the non-RTT cohort (p < 0.05). CONCLUSION: Patients requiring early RTT following hip hemiarthroplasty had a significantly increased length of stay, mortality and worse functional outcome compared to patients who did not require early RTT within 30 days.

Red blood cells in type 1 diabetes and multiple sclerosis and technologies to measure their emerging roles.

Autoimmune diseases affect over 40 million people in the United States. The cause of most autoimmune diseases is unknown; therefore, most therapies focus on treating the symptoms. This review will focus on the autoimmune diseases type 1 diabetes (T1D) and multiple sclerosis (MS) and the emerging roles of red blood cells (RBCs) in the mechanisms and treatment of T1D and MS. An understanding of the role of the RBC in human health is increasing, especially with respect to its role in the regulation of vascular caliber and vessel dilation. The RBC is known to participate in the regulation of blood flow through the release of key signaling molecules, such as adenosine triphosphate (ATP) and the potent vasodilator nitric oxide (NO). However, while these RBC-derived molecules are known to be determinants of blood flow in vivo, disruptions in their concentrations in the circulation are often measured in common autoimmune diseases. Chemical and physical properties of the RBC may play a role in autoimmune disease onset, especially T1D and MS, and complications associated with downstream extracellular levels of ATP and NO. Finally, both ATP and NO are highly reactive molecules in the circulation. Coupled with the challenging matrix posed by the bloodstream, the measurement of these two species is difficult, thus prompting an appraisal of recent and novel methods to quantitatively determining these potential early indicators of immune response.

Interferon-ß Decreases the Hypermetabolic State of Red Blood Cells from Patients with Multiple Sclerosis.

Multiple sclerosis (MS) is an inflammatory disease characterized by damage to the myelin sheath surrounding axons in the central nervous system. While the exact mechanism of this destruction is unknown, excess nitric oxide (NO) and adenosine triphosphate (ATP) have been measured in tissues and fluids obtained from people with MS. Here, incubation of interferon-beta (IFN-ß), an MS drug with an unknown mechanism of action, with red blood cells (RBCs) obtained from people with MS provide evidence of a potential hypermetabolic state in the MS RBC that is decreased with IFN-ß intervention. Specifically, binding of all three components of an albumin/C-peptide/Zn2+ complex to MS RBCs was significantly increased in comparison to control RBCs. For example, the binding of C-peptide to MS RBCs was significantly increased (3.4 ± 0.1 nM) compared to control RBCs (1.6 ± 0.2 nM). However, C-peptide binding to MS RBCs was reduced to a value (1.6 ± 0.3 nM) statistically equal to that of control RBCs in the presence of 2 nM IFN-ß. Similar trends were measured for albumin and Zn2+ binding to RBCs when in the presence of IFN-ß. RBC function was also affected by incubation of cells with IFN-ß. Specifically, RBC-derived ATP and measurable membrane GLUT1 were both significantly decreased (56 and 24%, respectively) in the presence of IFN-ß. Collectively, our results suggest that IFN-ß inhibits albumin binding to the RBC, thereby reducing its ability to deliver ligands such as C-peptide and Zn2+ to the cell and normalizing the basal hypermetabolic state.

A C-peptide complex with albumin and Zn2+ increases measurable GLUT1 levels in membranes of human red blood cells.

People with type 1 diabetes (T1D) require exogenous administration of insulin, which stimulates the translocation of the GLUT4 glucose transporter to cell membranes. However, most bloodstream cells contain GLUT1 and are not directly affected by insulin. Here, we report that C-peptide, the 31-amino acid peptide secreted in equal amounts with insulin in vivo, is part of a 3-component complex that affects red blood cell (RBC) membranes. Multiple techniques were used to demonstrate saturable and specific C-peptide binding to RBCs when delivered as part of a complex with albumin. Importantly, when the complex also included Zn2+, a significant increase in cell membrane GLUT1 was measured, thus providing a cellular effect similar to insulin, but on a transporter on which insulin has no effect.

Psychometric Properties of the Athens Insomnia Scale in Occupational Computer Users.

Background: Various studies have shown that insomnia is associated with computer use. The Athens Insomnia Scale (AIS) is an 8-item tool that has been widely used for screening insomnia. No studies have investigated the psychometric validity of AIS in occupational computer users. Objective: the current research aimed to test the psychometric properties of the AIS among occupational computer users. Materials and Methods: a sample of four hundred and twenty-four occupational computer users (age: 20-65 years and body mass index: 21.6 ± 3.5 kg/m2) completed an AIS and a socio-demographic questionnaire in this cross-sectional study. Results: a confirmatory factor analysis demonstrated that the three-factor model had an adequate fit (the goodness of fit index (0.95), incremental fit index (0.90) and χ2/df (2.61)). Evidence was found for configural, scalar and metric invariance of the 3-factor model across gender groups. A moderate level of internal consistency was implied by a Cronbach's alpha of 0.66. Conclusion: the findings of the present research support the validity of AIS for screening insomnia, as demonstrated by the scale's psychometric properties; its internal consistency, internal homogeneity, item discrimination, and factorial validity.

Psychometric properties of the Epworth sleepiness scale in Ethiopian university students.

BACKGROUND: Daytime sleepiness is highly prevalent across the globe. The Epworth sleepiness scale (ESS) is the most widely used tool for screening daytime sleepiness. The psychometric properties of the ESS have not been comprehensively examined in African populations. MATERIAL AND METHODS: A cross-sectional design with simple random sampling was used in the present study. The study recruited 600 students from Mizan-Tepi University, Ethiopia, of which 329 (age = 18-28 years and body mass index = 21.19 ± 3.17 kg/m2) completed the study. ESS, a semi-structured socio-demographics questionnaire and a clinical interview to diagnose insomnia according to the International Classification of Sleep Disorders were employed. RESULTS: All except one item of the ESS showed a floor effect, while only one item score showed ceiling effect. However, no ceiling/floor effect was observed in the ESS total score. The Cronbach's alpha (0.75) and composite reliability (0.75), indicated good internal consistency, while a moderate item-total score correlation (r = 0.55-0.67) implied favorable internal homogeneity. The known-group validity was established by significantly higher scores for all the ESS item scores and the ESS total scores among those with symptoms of insomnia than among non-symptomatic students. Fit indices along with the consideration of inter-factor correlation coefficient, measures of item retention favored the unidimensional structure of the ESS. CONCLUSION: The ESS has excellent psychometric validity for screening daytime sleepiness in Ethiopian university students.

ROC study and SUV threshold using quantitative multi-modal SPECT for bone imaging.

BACKGROUND: We investigated the clinical performance of a quantitative multi-modal SPECT/CT reconstruction platform for yielding radioactivity concentrations of bone imaging with 99mTc-methylene diphosphonate (MDP) or 99mTc-dicarboxypropane diphosphonate (DPD). The novel reconstruction incorporates CT-derived tissue information while preserving the delineation of tissue boundaries. We assessed image-based reader concordance and confidence, and determined lesion classification and SUV thresholds from ROC analysis. METHODS: Seventy-two cancer patients were scanned at three US and two German clinical sites, each contributing two experienced board-certified nuclear medicine physicians as readers. We compared four variants of the reconstructed data resulting from the Flash3D (F3D) and the xSPECT Bone™ (xB) iterative reconstruction methods and presented images to the readers with and without a fused CT, resulting in four combinations. We used an all-or-none approach for inclusion, compiling results only when a reader completed all reads in a subset. After the final read, we conducted a "surrogate truth" reading, presenting all data to each reader. For any remaining discordant lesions, we conducted a consensus read. We next undertook ROC analysis to determine SUV thresholds for differentiating benign and lesional uptake. RESULTS: On a five-point rating scale of image quality, xB was deemed better by almost two points in resolution and one point better in overall acceptance compared to F3D. The absolute agreement of the rendered decision between the nine readers was significantly higher with CT information either inside the reconstruction (xB, xBCT) or simply through image fusion (F3DCT): 0.70 (xBCT), 0.67 (F3DCT), 0.64 (xB), and 0.46 (F3D). The confidence level to characterize the lesion was significantly higher (3.03x w/o CT, 1.32x w/CT) for xB than for F3D. There was high correlation between xB and F3D scores for lesion detection and classification, but lesion detection confidence was 41% higher w/o CT, and 21% higher w/CT for xB compared to F3D. Without CT, xB had 6.6% higher sensitivity, 7.1% higher specificity, and 6.9% greater AUC compared to F3D, and similarly with CT-fusion. The overall SUV-criterion (SUVc) of xB (12) exceeded that for xSPECT Quant™ (xQ; 9), an approach not using the tissue delineation of xB. SUV critical numbers depended on lesion volume and location. For non-joint lesions > 6 ml, the AUC for xQ and xB was 94%, with SUVc > 9.28 (xQ) or > 9.68 (xB); for non-joint lesions ≤ 6 ml, AUCs were 81% (xQ) and 88% (xB), and SUVc > 8.2 (xQ) or > 9.1 (xB). For joint lesions, the AUC was 80% (xQ) and 83% (xB), with SUVc > 8.61 (xQ) or > 13.4 (xB). CONCLUSION: The incorporation of high-resolution CT-based tissue delineation in SPECT reconstruction (xSPECT Bone) provides better resolution and detects smaller lesions (6 ml), and the CT component facilitates lesion characterization. Our approach increases confidence, concordance, and accuracy for readers with a wide range of experience. The xB method retained high reading accuracy, despite the unfamiliar image presentation, having greatest impact for smaller lesions, and better localization of foci relative to bone anatomy. The quantitative assessment yielded an SUV-threshold for sensitively distinguishing benign and malignant lesions. Ongoing efforts shall establish clinically usable protocols and SUV thresholds for decision-making based on quantitative SPECT.

Technologies for Measuring Pharmacokinetic Profiles.

The creation of a pharmacokinetic (PK) curve, which follows the plasma concentration of an administered drug as a function of time, is a critical aspect of the drug development process and includes such information as the drug's bioavailability, clearance, and elimination half-life. Prior to a drug of interest gaining clearance for use in human clinical trials, research is performed during the preclinical stages to establish drug safety and dosing metrics from data obtained from the PK studies. Both in vivo animal models and in vitro platforms have limitations in predicting human reaction to a drug due to differences in species and associated simplifications, respectively. As a result, in silico experiments using computer simulation have been implemented to accurately predict PK parameters in human studies. This review assesses these three approaches (in vitro, in vivo, and in silico) when establishing PK parameters and evaluates the potential for in silico studies to be the future gold standard of PK preclinical studies.

Principles of Valgus Intertrochanteric Osteotomy (VITO) after Femoral Neck Nonunion.

Nonunion is a relatively rare, yet challenging problem after fracture of the femoral neck. Risk factors include verticality of the fracture line and presence of comminution of the posteromedial calcar, as well as quality of reduction. Treatment options consist of valgus intertrochanteric osteotomy versus arthroplasty. Treatment should be tailored to the individual patient, taking into account patient age and activity demands. This review outlines the principles and technical considerations for valgus osteotomy of the proximal femur in the setting of femoral neck nonunion.

C-Peptide replacement therapy in type 1 diabetes: are we in the trough of disillusionment?

Type 1 diabetes is associated with such complications as blindness, kidney failure, and nerve damage. Replacing C-peptide, a hormone normally co-secreted with insulin, has been shown to reduce diabetes-related complications. Interestingly, after nearly 30 years of positive research results, C-peptide is still not being co-administered with insulin to diabetic patients. The following review discusses the potential of C-peptide as an auxilliary replacement therapy and why it's not currently being used as a therapeutic.

Dimensionality of the Pittsburgh Sleep Quality Index in the collegiate young adults.

PURPOSE: To explore and validate the factor structure of the Pittsburgh Sleep Quality Index (PSQI) in the collegiate young adults. METHODS: Six hundred university students were initially contacted and invited to participate in a survey of their sleep experience and history. Of this preliminary sample 418 of the students (age = 20.92 ± 1.81 years, BMI = 23.30 ± 2.57 kg/m(2)) fulfilled the screening criteria and ultimately completed the Pittsburgh Sleep Quality Index (PSQI), a self-report survey of respondents' sleep habits and sleep quality. The students were enrolled in various undergraduate and postgraduate programs at Jamia Millia Islamia, New Delhi, India. Exploratory factor analysis (EFA) investigated the latent factor structure of the scale. Confirmatory factor analysis evaluated both of the models found by EFA. RESULTS: The Kaiser's criteria, the Scree test, and the cumulative variance rule revealed that a 2-factor model accounted for most of the variability in the data. However, a follow up Parallel Analysis found a 1-factor model. The high correlation coefficient (r = 0.91) between the two factors of the 2-factor model and almost similar values of the fit indices supports the inference that the PSQI is a unidimensional scale. CONCLUSIONS: The findings validate the 1-factor model of the PSQI in the collegiate young adults.

Contralateral ulnar neuropathy following total hip replacement and intraoperative positioning.

Peripheral neuropathy is a rare but important complication of total hip arthroplasty (THA) and has previously been reported in the ipsilateral arm and associated with inflammatory arthritis. The results of 7004 primary hip arthroplasties performed between January 1993 and February 2009 were retrospectively reviewed to identify patients who reported ulnar neuropathy symptoms, with ten patients identified at mean follow-up of 57 months (range = 3-195 months). Eight patients experienced unilateral ulnar nerve symptoms in the contralateral upper limb post-surgery, one patient experienced symptoms in the ipsilateral upper limb and one patient experienced symptoms in both upper limbs. The incidence of post-THA ulnar neuropathy was 0.14%. All patients had a pre-operative diagnosis of osteoarthritis and none had diabetes, a previous history of neuropathy or inflammatory arthritis. All operations were primary arthroplasties and were performed under the care of a single surgeon in a single centre. Two of the ten patients (20%) had a general anaesthetic. The pattern of symptoms reported, i.e. mainly unilateral affecting the contralateral side with variable resolution, contrasts with previous studies and suggests that intraoperative patient positioning may be an important factor influencing ulnar neuropathy following THA. Attention to support and positioning of the contralateral arm may help reduce the incidence of this complication.

The relationship between breastfeeding and postpartum weight change--a systematic review and critical evaluation.

Pregnancy and the postpartum period is a time of increased vulnerability for retention of excess body fat in women. Breastfeeding (BF) has been shown to have many health benefits for both mother and baby; however, its role in postpartum weight management is unclear. Our aim was to systematically review and critically appraise the literature published to date in relation to the impact of BF on postpartum weight change, weight retention and maternal body composition. Electronic literature searches were carried out using MEDLINE, EMBASE, PubMed, Web of Science, BIOSIS, CINAHL and British Nursing Index. The search covered publications up to 12 June 2012 and included observational studies (prospective and retrospective) carried out in BF mothers (either exclusively or as a subgroup), who were ≤ 2 years postpartum and with a body mass index (BMI) >18.5 kg m(-2), with an outcome measure of change in weight (including weight retention) and/or body composition. Thirty-seven prospective studies and eight retrospective studies were identified that met the selection criteria; studies were stratified according to study design and outcome measure. Overall, studies were heterogeneous, particularly in relation to sample size, measurement time points and in the classification of BF and postpartum weight change. The majority of studies reported little or no association between BF and weight change (n=27, 63%) or change in body composition (n=16, 89%), although this seemed to depend on the measurement time points and BF intensity. However, of the five studies that were considered to be of high methodological quality, four studies demonstrated a positive association between BF and weight change. This systematic review highlights the difficulties of examining the association between BF and weight management in observational research. Although the available evidence challenges the widely held belief that BF promotes weight loss, more robust studies are needed to reliably assess the impact of BF on postpartum weight management.

Effect of chipping on emergence of the redbay ambrosia beetle (Coleoptera: Curculionidae: Scolytinae) and recovery of the laurel wilt pathogen from infested wood chips.

Significant mortality ofredbay trees (Persea borbonia (L.) Spreng.) in the southeastern United States has been caused by Raffaelea lauricola, T.C. Harr., Fraedrich, & Aghayeva (Harrington et al. 2008), a fungal symbiont of the exotic redbay ambrosia beetle, Xyleborus glabratus, Eichhoff (Fraedrich et al. 2008). This pathogen causes laurel wilt, which is an irreversible disease that can kill mature trees within a few weeks in summer. R. lauricola has been shown to be lethal to most native species of Lauraceae and cultivated avocado (Persea americana Mill.) in the southeastern United States. In this study, we examined the survival of X. glabratus and R. lauricola in wood chips made from infested trees by using a standard tree chipper over a 10-wk period. After 2 wk, 14 X. glabratus were recovered from wood chips, whereas 339 X. glabratus emerged from nonchipped bolts. R. lauricola was not found 2 d postchipping from wood chips, indicating that the pathogen is not likely to survive for long inside wood chips. In contrast, R. lauricola persisted in dead, standing redbay trees for 14 mo. With large volumes of wood, the potential for infested logs to be moved between states or across U.S. borders is significant. Results demonstrated that chipping wood from laurel wilt-killed trees can significantly reduce the number of X. glabratus and limit the persistence of R. lauricola, which is important for sanitation strategies aimed at limiting the spread of this disease.

The impact of body mass index on maternal and neonatal outcomes: a retrospective study in a UK obstetric population, 2004-2011.

OBJECTIVE: To assess the prevalence of overweight and obesity, and the impact of body mass index (BMI) on maternal and neonatal outcomes, in a UK obstetric population. DESIGN: Retrospective study. SETTING: A tertiary referral unit in Northern Ireland. POPULATION: A total of 30 298 singleton pregnancies over an 8-year period, 2004-2011. METHODS: Women were categorised according to World Health Organization classification: underweight (BMI < 18.50 kg/m(2)); normal weight (BMI 18.50-24.99 kg/m(2); reference group); overweight (BMI 25.00-29.99 kg/m(2)); obese class I (BMI 30.00-34.99 kg/m(2)); obese class II (BMI 35-39.99 kg/m(2)); and obese class III (BMI ≥ 40 kg/m(2)). Maternal and neonatal outcomes were examined using logistic regression, adjusted for confounding variables. MAIN OUTCOME MEASURES: Maternal and neonatal outcomes. RESULTS: Compared with women of normal weight, women who were overweight or obese class I were at significantly increased risk of hypertensive disorders of pregnancy (OR 1.9, 99% CI 1.7-2.3; OR 3.5, 99% CI 2.9-4.2); gestational diabetes mellitus (OR 1.7, 99% CI 1.3-2.3; OR 3.7, 99% CI 2.8-5.0); induction of labour (OR 1.2, 99% CI 1.1-1.3; OR 1.3, 99% CI 1.2-1.5); caesarean section (OR 1.4, 99% CI 1.3-1.5; OR 1.8, 99% CI 1.6-2.0); postpartum haemorrhage (OR 1.4, 99% CI 1.3-1.5; OR 1.8, 1.6-2.0); and macrosomia (OR 1.5, 99% CI 1.3-1.6; OR 1.9, 99% CI 1.6-2.2), with the risks increasing for obese classes II and III. Women in obese class III were at increased risk of preterm delivery (OR 1.6, 99% CI 1.1-2.5), stillbirth (OR 3.0, 99% CI 1.0-9.3), postnatal stay > 5 days (OR 2.1, 99% CI 1.5-3.1), and infant requiring admission to a neonatal unit (OR 1.6, 99% CI 1.0-2.6). CONCLUSIONS: By categorising women into overweight and obesity subclassifications (classes I -III), this study clearly demonstrates an increasing risk of adverse outcomes across BMI categories, with women who are overweight also at significant risk.

Modifiable factors delaying early discharge following primary joint arthroplasty.

AIMS: Recent NHS reforms have incentivised reduction in length of stay, with the UK department of health expecting health trusts to reduce bed days and ultimately reduce overall costs. The aim of this study was to identify avoidable causes for protracted hospital admission following total hip arthroplasty (THA) or total knee arthroplasty (TKA) within a fast-track unit. METHODS: During a 6-month period, 535 consecutive patients underwent primary THA or TKA under the care of a single surgeon. All patients with a post-operative stay of greater than 72 h were identified, and reasons for delayed discharge were determined. RESULTS: The majority of arthroplasty patients were discharged within 3 days post-operatively. Twenty-one per cent of THA patients and 25 % of TKA patients remained as inpatients for greater than 72 h. For the THA population, this equates to 43 % of bed days used by 21 % of patients, and for the TKA population, 44 % of bed days were used by 25 % of patients. The major factor within both groups for delayed discharge was attributed to inadequate social support. CONCLUSIONS: Delayed discharge can never be totally prevented. This unit aims to develop improvement in social work provision, with a greater focus on pre-admission discharge planning to reduce the number of delayed discharges and ultimately reduce the cost burden of joint replacement surgery. It is not conducive with the ethos of fast-track arthroplasty to only identify social circumstances upon admission.

Sleep and circadian rhythm dysregulation in schizophrenia.

Sleep-onset and maintenance insomnia is a common symptom in schizophrenic patients regardless of either their medication status (drug-naive or previously treated) or the phase of the clinical course (acute or chronic). Regarding sleep architecture, the majority of studies indicate that non-rapid eye movement (NREM), N3 sleep and REM sleep onset latency are reduced in schizophrenia, whereas REM sleep duration tends to remain unchanged. Many of these sleep disturbances in schizophrenia appear to be caused by abnormalities of the circadian system as indicated by misalignments of the endogenous circadian cycle and the sleep-wake cycle. Circadian disruption, sleep onset insomnia and difficulties in maintaining sleep in schizophrenic patients could be partly related to a presumed hyperactivity of the dopaminergic system and dysfunction of the GABAergic system, both associated with core features of schizophrenia and with signaling in sleep and wake promoting brain regions. Since multiple neurotransmitter systems within the CNS can be implicated in sleep disturbances in schizophrenia, the characterization of the neurotransmitter systems involved remains a challenging dilemma.

Melatonin antioxidative defense: therapeutical implications for aging and neurodegenerative processes.

The pineal product melatonin has remarkable antioxidant properties. It is secreted during darkness and plays a key role in various physiological responses including regulation of circadian rhythms, sleep homeostasis, retinal neuromodulation, and vasomotor responses. It scavenges hydroxyl, carbonate, and various organic radicals as well as a number of reactive nitrogen species. Melatonin also enhances the antioxidant potential of the cell by stimulating the synthesis of antioxidant enzymes including superoxide dismutase, glutathione peroxidase, and glutathione reductase, and by augmenting glutathione levels. Melatonin preserves mitochondrial homeostasis, reduces free radical generation and protects mitochondrial ATP synthesis by stimulating Complexes I and IV activities. The decline in melatonin production in aged individuals has been suggested as one of the primary contributing factors for the development of age-associated neurodegenerative diseases. The efficacy of melatonin in preventing oxidative damage in either cultured neuronal cells or in the brains of animals treated with various neurotoxic agents, suggests that melatonin has a potential therapeutic value as a neuroprotective drug in treatment of Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), Huntington's disease (HD), stroke, and brain trauma. Therapeutic trials with melatonin indicate that it has a potential therapeutic value as a neuroprotective drug in treatment of AD, ALS, and HD. In the case of other neurological conditions, like PD, the evidence is less compelling. Melatonin's efficacy in combating free radical damage in the brain suggests that it can be a valuable therapeutic agent in the treatment of cerebral edema following traumatic brain injury or stroke. Clinical trials employing melatonin doses in the range of 50-100 mg/day are warranted before its relative merits as a neuroprotective agent is definitively established.

Control of cascading in multiple-order Raman lasers.

In this work we explore a method for controlling Raman cascade within an intracavity Raman laser, with a view to maximizing output power at desired visible wavelengths. Sum-frequency generation is used to suppress unwanted Stokes orders, and prevent their build up. Using this method to control the Raman cascade, we demonstrate increases in output power of 40% at 532 nm, 42% at 559 nm, and 67% at 586 nm.