Finite element analysis of mechanical stress in a cementless tapered-wedge short stem in the varus position.

BACKGROUND: In recent years, the use of tapered-wedge short stems has increased due to their ability to preserve bones and tendons. Surgical techniques occasionally result in a varus position of the stem, which is particularly pronounced in short stems. Although the varus position is not clinically problematic, there are reports of an increased incidence of stress shielding and cortical hypertrophy. Thus, we evaluated and examined the acceptable range of varus angles using finite element analysis. METHODS: Patients diagnosed with osteoarthritis of the hip joint who had undergone arthroplasty were selected and classified into three types [champagne-flute (type A), intermediate (type B), and stovepipe (type C)]. Finite element analysis was performed using Mechanical Finder. The model was created using a Taperloc microplasty stem with the varus angle increased by 1° from 0° to 5° from the bone axis and classified into seven zones based on Gruen's zone classification under loading conditions in a one-leg standing position. The volume of interest was set, the mean equivalent stress for each zone was calculated. RESULTS: A significant decrease in stress was observed in zone 2, and increased stress was observed in zones 3 and 4, suggesting the emergence of a distal periosteal reaction, similar to the results of previous studies. In zone 2, there was a significant decrease in stress in all groups at a varus angle ≥ 3°. In zone 3, stress increased from ≥ 3° in type B and ≥ 4° in type C. In zone 4, there was a significant increase in stress at varus angles of ≥ 2° in types A and B and at ≥ 3° in type C. CONCLUSION: In zone 2, the varus angle at which stress shielding above Engh classification grade 3 may appear is expected to be ≥ 3°. Distal cortical hypertrophy may appear in zones 3 and 4; the narrower the medullary cavity shape, the smaller the allowable angle of internal recession, and the wider the medullary cavity shape, the wider the allowable range. Long-term follow-up is required in patients with varus angles > 3°.

Developing an Instructional Design-Based Dementia Education Program.

Community building is necessary to help create a dementia-inclusive society. In this study, a one-of-a kind dementia education program based on mutual learning using instructional design was developed alongside community members and stakeholders. The purpose was to implement and evaluate this program and gain insight into dementia education for the community. A total of 118 individuals participated in the program; however, data of 80 participants (Male = 26, Female = 54), who completed a questionnaire before and after the program, were analyzed. The results showed a significant pre-post difference in mean total scores on the Attitudes Toward Dementia Scale (32.1 points pre-program vs. 33.7 points post-program). Nine necessary learning topics were identified. The program could successfully teach participants to take the perspectives of various other people, view dementia as something relevant to themselves, and think about specific ways of responding to people with dementia considering their feelings. This study recommends creating education programs using scenario stories that depict the desire of people with dementia to be a part of the community, using visual depictions to create a shared impression and facilitate mutual learning.

Hypothetical model for on-the-job training through case conferences of public health nurses.

Public health nurses (PHNs) face difficulties supporting vulnerable individuals and families. On-the-job training (OJT) is essential for improving nurses' competencies. However, PHN managers lack the knowledge to systematically implement OJT. The aim of this study was to develop a hypothetical model to systematically promote OJT for PHNs through case conferences (CC). Literature review, based on an integrative approach, has three stages: (1) theoretical framework development, (2) literature review, and (3) modeling. Literature review from five databases (MEDLINE, CINAHL, PsycInfo, Cochrane Central Register of Controlled Trials, Japan Medical Abstract Society) was conducted to identify the OJT process, its outcomes, and the conditions associated with OJT according to the theoretical framework. Based on 18 articles, this model progressed from "OJT process through CC," comprising the CC design, implementation, and evaluation to OJT produced "outcomes through CC." Outcomes included staff perception and behavior changes, improvements in client's condition, and staff turnover reductions. The OJT model involved "conditions for implementing CC as OJT" and "individual and organizational conditions." Future research should incorporate the social, political, and historical contexts of specific practice situations into the hypothetical model to help refine the model to be used in practice.

Association between adrenal function and dialysis vintage in hemodialysis patients.

INTRODUCTION: Adrenal insufficiency in hemodialysis patients is commonly encountered in clinical practice. However, its association with end-stage renal disease is unclear. We investigated the relationship between adrenal function and relevant clinical parameters, focusing on dialysis vintage. METHODS: Altogether, 100 maintenance hemodialysis patients were enrolled (age: 69.8 ± 11.8 years, dialysis vintage: 9.4 ± 9.2 years). Basal serum cortisol levels were measured and their associations with relevant clinical parameters were investigated. Subsequently, hormone stimulation tests were performed to assess adrenal function. RESULTS: Basal serum cortisol significantly decreased with an increase in dialysis vintage (< 10 years, 11.9 ± 3.7 µg/dL; 10-19 years, 10.9 ± 2.9 µg/dL; ≥ 20 years, 9.7 ± 3.8 µg/dL). Basal cortisol was negatively correlated with dry weight, ß2-microglobulin, creatinine, and lymphocyte count and positively correlated with brachial-ankle pulse wave velocity. Significant negative correlations were observed between basal cortisol and dialysis vintage after adjusting for confounding variables in the multivariate analysis. Standard adrenocorticotropic hormone (ACTH) and corticotropin-releasing hormone (CRH) stimulation tests were performed in 17 patients. Seven patients were diagnosed with adrenal insufficiency and all of them had a long dialysis vintage (≥ 10 years). According to the rapid ACTH test, cortisol responses were significantly decreased in patients with long dialysis vintage compared to those with short dialysis vintage (< 10 years). Similar findings were observed in ten patients without adrenal insufficiency. The CRH loading test showed similar tendencies, although the differences were not statistically significant. CONCLUSIONS: Adrenal function decreased with an increase in dialysis vintage. Long-term dialysis patients might be susceptible to adrenal insufficiency.

Acoustic characteristics of broaching procedure for post-operative stem subsidence in cementless total hip arthroplasty.

PURPOSE: Avoiding stem subsidence is crucial for achieving better outcome for cementless total hip arthroplasty (THA). The aim of this study was to develop a prediction model for the incidence of post-operative stem subsidence using full quantitative acoustic parameters in hammering sound during the broaching procedure and to assess the accuracy of this prediction model. METHODS: The acoustic parameters of the hammering sounds during a broaching procedure for 55 hips in 49 patients who underwent THAs with cementless taper-wedged stem were analysed. The stem subsidence was assessed at one month post-operatively, and the relationship between the acoustic parameters and the value of stem subsidence was investigated. RESULTS: The average stem subsidence was 2.15 ± 2.91 mm. The subsidence 3 mm or more was observed in eleven hips (20%), and 5 mm or more was observed in seven hips (12.7%). Basic patient's characteristics, preoperative femoral morphology and immediate post-operative canal fill ratio and stem alignment were not significantly related to the volume of stem subsidence. Nine acoustic parameters were significantly correlated with the value of subsidence. The prediction model for post-operative subsidence using only acoustic parameters during broaching procedure was established, and this model showed a positive prediction value of 100% and a negative prediction value of 90.6% for post-operative stem subsidence at 5 mm or more. CONCLUSION: Post-operative stem subsidence can be predicted by using acoustic parameters of the hammering sound during the broaching procedure. Our results suggest that we are at the start of a new era in which novel and innovative smart technologies can be used to assist in orthopaedic surgery.

Primary Membranous Nephropathy With Enhanced Staining of Exostosin 1/Exostosin 2 in the Glomeruli: A Report of 2 Cases.

Technological advances have allowed the discovery of 6 subtypes of membranous nephropathy based on target antigens: M-type phospholipase A2 receptor (PLA2R), thrombospondin type 1 domain-containing 7A (THSD7A), neural epidermal growth factor-like 1 protein, semaphorin 3B, exostosin 1 (EXT1), and EXT2. EXT1/EXT2 are thought to be associated with secondary (autoimmune) membranous nephropathy. Although it has been reported that PLA2R- and THSD7A-associated membranous nephropathy have rarely been detected concomitantly, there have been no previous reports demonstrating PLA2R- or THSD7A-associated membranous nephropathy with enhanced glomerular staining of EXT1/EXT2. We describe 2 cases of primary membranous nephropathy with enhanced glomerular staining of EXT1/EXT2. Patient 1 was diagnosed with PLA2R-associated primary membranous nephropathy, and patient 2 was diagnosed with THSD7A-associated primary membranous nephropathy. Both patients achieved clinical remission in response to immunosuppressive therapy. Neither patient demonstrated signs of autoimmune diseases, and antinuclear antibodies were absent in their sera. Based on these 2 cases, enhanced staining of EXT1/EXT2 in glomeruli, although rare, can be detected in primary membranous nephropathy without autoimmune diseases.

Baseline Urinary Angiotensinogen Excretion Predicts Deterioration of the Kidney Function in Patients with Chronic Kidney Disease.

Objective The intrarenal renin-angiotensin system (RAS) is activated in patients with chronic kidney disease (CKD), and urinary angiotensinogen (AGT) levels, a surrogate marker of the intrarenal RAS activation, are associated with blood pressure (BP) and urinary albumin excretion. In addition, it has been shown that changes in urinary AGT levels correlate with annual changes in the estimated glomerular filtration rate (eGFR) in patients with type 2 diabetes and that elevated levels of urinary AGT in type 2 diabetic patients with albuminuria are a high-risk factor for worsening renal and cardiovascular complications. However, whether or not baseline urinary AGT levels predict deterioration of the kidney function in all patients with CKD is unclear. Methods We recruited 62 patients with CKD whose eGFR was >15 mL/min/1.73 m2. We performed 24-hour ambulatory BP monitoring at 30-min intervals and daily urinary collection to examine the urinary AGT levels and albumin excretion and measured the levels of plasma angiotensin II (Ang II), a surrogate marker of circulating RAS. In addition, annual changes in the eGFR were followed up for 3.4±1.5 years. Results Annual changes in the eGFR were significantly and negatively associated with urinary AGT levels (r=-0.31, p=0.015) as well as the age, systolic BP, and urinary albumin levels. In contrast, annual changes in the eGFR were not correlated with plasma Ang II levels. Furthermore, when dividing patients into quartiles according to urinary AGT levels, patients with the highest urinary AGT levels showed a progressive decline in the eGFR. Conclusion These results suggest that elevated baseline urinary AGT levels can predict renal dysfunction in patients with CKD.

Circadian rhythm of the intrarenal renin-angiotensin system is caused by glomerular filtration of liver-derived angiotensinogen depending on glomerular capillary pressure in adriamycin nephropathy rats.

Circadian fluctuation disorder of the intrarenal renin-angiotensin system (RAS) causes that of blood pressure (BP) and renal damage. In renal damage with an impaired glomerular filtration barrier, liver-derived angiotensinogen (AGT) filtered through damaged glomeruli regulates intrarenal RAS activity. Furthermore, glomerular permeability is more strongly affected by glomerular hypertension than by systemic hypertension. Thus, we aimed to clarify whether the circadian rhythm of intrarenal RAS activity is influenced by AGT filtered through damaged glomeruli due to glomerular capillary pressure. Rats with adriamycin nephropathy and an impaired glomerular filtration barrier were compared with control rats. In adriamycin nephropathy rats, olmesartan medoxomil (an angiotensin II type 1 receptor blocker) or hydralazine (a vasodilator) was administered, and the levels of intrarenal RAS components in the active and rest phases were evaluated. Moreover, the diameter ratio of afferent to efferent arterioles (A/E ratio), an indicator of glomerular capillary pressure, and the glomerular sieving coefficient (GSC) based on multiphoton microscopy in vivo imaging, which reflects glomerular permeability, were determined. Mild renal dysfunction was induced, and the systemic BP increased, resulting in increased A/E ratios in the adriamycin nephropathy rats compared with the control rats. Fluctuations in intrarenal RAS activity occurred in parallel with circadian fluctuations in glomerular capillary pressure, which disappeared with olmesartan treatment and were maintained with hydralazine treatment. Furthermore, the GSCs for AGT also showed similar changes. In conclusion, intrarenal RAS activity is influenced by the filtration of liver-derived AGT from damaged glomeruli due to circadian fluctuation disorder of the glomerular capillary pressure.

Chronotherapy with a Renin-angiotensin System Inhibitor Ameliorates Renal Damage by Suppressing Intrarenal Renin-angiotensin System Activation.

Objective The intrarenal renin-angiotensin system (RAS) is activated in chronic kidney disease (CKD) patients and is not suppressed at night in CKD patients showing nocturnal hypertension, contributing to renal damage. Furthermore, changes in RAS inhibitor administration from morning to evening, namely chronotherapy, ameliorates renal damage at night. We attempted to clarify whether or not chronotherapy ameliorates renal damage by suppressing the intrarenal RAS activity. Methods We recruited 34 CKD patients with RAS inhibitors in the morning. We conducted ambulatory blood pressure (BP) monitoring and urine collection and evaluated urinary albumin (Alb) and angiotensinogen (AGT), which are surrogate markers for intrarenal RAS activity during the day and at night, respectively. The same experiments were conducted after changing the administration time. The ratio of values associated with morning versus evening dosing was defined as the morning to evening (M/E) ratio. Results The M/E ratio of urinary Alb had a significant and positive relationship with that of urinary AGT during the day and at night in all CKD patients. However, no significant relationships were found between the M/E ratios of urinary Alb and AGT using multiple linear regression analyses. Conversely, there was a significant and positive relationship between the M/E ratios of urinary Alb and AGT at night but not during the day in CKD patients whose estimated glomerular filtration rate was <45 mL/min/1.73 m2 and whose night-to-day ratio of systolic BP was >0.90, even after adjustment. Conclusion This study indicated that chronotherapy with RAS inhibitors improved the renal damage via intrarenal RAS suppression, especially in CKD patients with an impaired renal function and nocturnal hypertension.

Case report: increased single-nephron estimated glomerular filtration rate in an adult patient with low birth weight.

BACKGROUND: Low birth weight (LBW) is associated with end-stage kidney disease and hypertension and is considered to be a surrogate marker of low nephron number. Low nephron number is hypothesized to contribute to glomerular hyperfiltration that may cause kidney injury; however, this is not yet proven. Until now, the hyperfiltration in LBW patients has not been shown directly yet. CASE PRESENTATION: A 23-years-old female was referred with the persistent proteinuria and decreased renal function (estimated glomerular filtration rate by cystatin C (eGFRcys); 41.86 ml/min). She was a premature baby with low birth weight (704 g, 24 gestational weeks). Renal biopsy demonstrated focal segmental glomerulosclerosis (FSGS) of the perihilar variant with expanded glomerular diameter. We calculated the single-nephron estimated glomerular filtration rate (SN-eGFR) that was higher than that of the same age group in the healthy living kidney donors and speculated that glomerular hyperfiltration is a pathophysiological cause of FSGS. CONCLUSION: This is the first case of SN-eGFR measurement in a patient with LBW. The increased SN-eGFR in this case provides an important insight into the pathophysiological mechanisms of LBW for its progression to kidney disease.

The Urinary Angiotensinogen to Urinary Albumin Ratio Reflects Whether the Renin-angiotensin System in the Kidney Is Activated due to Filtration of Plasma Angiotensinogen through the Damaged Glomeruli or the Production of Angiotensinogen in the Proximal Tubules.

Objective Urinary angiotensinogen (AGT) is a surrogate marker for intrarenal renin-angiotensin system (RAS) activity that plays an important role in the development of renal damage. Urinary AGT levels are determined by the filtration of plasma AGT through the damaged glomeruli and production of AGT in the proximal tubules. However, the relative merits of the filtration and production of urinary AGT levels in chronic kidney diseases (CKD) have not been clarified. Therefore, we investigated them in CKD patients. Methods We recruited 41 biopsy-proven patients diagnosed with IgA nephropathy (IgAN) in 31, membranous nephropathy (MN) in 5, and tubulointerstitial nephritis (TIN) in 5. The patients taking RAS blockers were excluded. Results The urinary albumin levels in MN patients were significantly higher and those in TIN patients significantly lower than in IgAN patients, and the urinary AGT levels in the MN and TIN patients were significantly higher than those in IgAN patients. Conversely, the urinary AGT-to-urinary albumin (urinary AGT/Alb) ratios were the same for IgAN and MN patients, and those of TIN patients were significantly higher than those of IgAN and MN patients. A multiple linear regression analysis revealed that the urinary AGT/Alb ratios had a significant positive association with IgAN and TIN after adjustments (ß=0.75, and p<0.01). Conclusion These data suggest that the origins of urinary AGT may differ according to the etiology of renal damage [i.e. glomerular damage (such as IgAN and MN) or tubulointerstitial damage (such as TIN)], and a higher urinary AGT/Alb ratio, as in TIN, may reflect AGT production in the kidney.

Monoclonal immunoglobulin G1 κ-type atypical antiglomerular basement membrane disease accompanied by necrotizing glomerulonephritis
.

INTRODUCTION: Patients without detectable serum antiglomerular basement membrane (GBM) antibodies but with GBM staining for immunoglobulins (Ig), absence of a crescentic phenotype, mild renal insufficiency, and absence of pulmonary hemorrhage have atypical anti-GBM diseases. We report the case of a 64-year-old man with slowly progressive glomerulonephritis. CASE HISTORY: A 64-year-old Peruvian man presented with persistent microscopic hematuria, proteinuria of 2.1 g/g creatinine (Cr), serum Cr 1.00 mg/dL, and C-reactive protein 0.80 mg/dL. Renal biopsy revealed necrotizing glomerulonephritis with 39% cellular crescent formation and diffuse segmental endocapillary proliferation. He had linear staining of monoclonal IgG1-κ in the capillary walls but no detectable serum anti-GBM antibodies. Because renal dysfunction was slowly progressing, steroid monotherapy was initiated, and serum Cr level decreased from 1.48 to 1.13 mg/dL. However, serum Cr increased again to 1.35 mg/dL owing to active glomerular damage with crescent formation and endocapillary proliferation, confirmed by the second renal biopsy at 9 months after therapy. Renal function improved after cyclophosphamide therapy. CONCLUSION: We described an atypical variant of anti-GBM disease due to monoclonal IgG1-κ. Unlike usual atypical anti-GBM disease cases, we observed crescent formation in our patient. Further investigations are needed to identify the cause of nondetectable serum anti-GBM antibodies and to describe the causal relationships between clinicopathological features and the pattern of IgG subclass and light chain in atypical anti-GBM disease.

GATA2 and PU.1 Collaborate To Activate the Expression of the Mouse Ms4a2 Gene, Encoding FcεRIß, through Distinct Mechanisms.

GATA factors GATA1 and GATA2 and ETS factor PU.1 are known to function antagonistically during hematopoietic development. In mouse mast cells, however, these factors are coexpressed and activate the expression of the Ms4a2 gene encoding the ß chain of the high-affinity IgE receptor (FcεRI). The present study showed that these factors cooperatively regulate Ms4a2 gene expression through distinct mechanisms. Although GATA2 and PU.1 contributed almost equally to Ms4a2 gene expression, gene ablation experiments revealed that simultaneous knockdown of both factors showed neither a synergistic nor an additive effect. A chromatin immunoprecipitation analysis showed that they shared DNA binding to the +10.4-kbp region downstream of the Ms4a2 gene with chromatin looping factor LDB1, whereas the proximal -60-bp region was exclusively bound by GATA2 in a mast cell-specific manner. Ablation of PU.1 significantly reduced the level of GATA2 binding to both the +10.4-kbp and -60-bp regions. Surprisingly, the deletion of the +10.4-kbp region by genome editing completely abolished the Ms4a2 gene expression as well as the cell surface expression of FcεRI. These results suggest that PU.1 and LDB1 play central roles in the formation of active chromatin structure whereas GATA2 directly activates the Ms4a2 promoter.

Simultaneous Occurrence of Sarcoidosis and Anti-neutrophil Cytoplasmic Antibody-associated Vasculitis in a Patient with Lung Cancer.

A 71-year-old woman with abnormal pulmonary shadows and multiple enlarged thoracic lymph nodes was diagnosed with stage IIB lung adenocarcinoma, pulmonary sarcoidosis, and sarcoidosis-associated lymphadenopathy after biopsies from multiple organ sites. She also had rapidly progressive renal dysfunction, microhematuria, and high myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA) concentrations. A renal biopsy revealed granulomatous tubulointerstitial nephritis and necrotizing glomerulonephritis with crescent formation. She was diagnosed with nephritis caused by both sarcoidosis and ANCA-associated vasculitis. Oral prednisolone was administered to treat her nephritis, resulting in improvement in both her renal dysfunction and her sarcoidosis-associated lymphadenopathy.

Increased heart rate is associated with intrarenal renin-angiotensin system activation in chronic kidney disease patients.

BACKGROUND: A higher heart rate is one of the risk factors for heart failure and cardiovascular disease. Activation of the intrarenal renin-angiotensin system (RAS) plays an important role in the development of hypertension and renal damage. However, the association between heart rate and intrarenal RAS activation is unclear. METHODS: We investigated the relationship between heart rate and urinary angiotensinogen (U-AGT) excretion, a surrogate marker for intrarenal RAS activity, in ten subjects without chronic kidney disease (CKD) and 72 CKD patients who were not taking medications that influence heart rate and RAS blockers (age 50.0 ± 17.4 years, 27 men and 45 women, serum creatinine (sCr) 1.85 ± 2.71 mg/dL, blood pressure 120.5 ± 15.8/72.9 ± 10.1 mmHg, heart rate 67.3 ± 8.9 /min, urinary protein excretion 1.27 ± 2.63 g/day, and U-AGT excretion 747.4 ± 2714.6 µg/day). RESULTS: As heart rate is influenced by behavior and emotion, we divided it into daytime and nighttime. Heart rate had a significant positive association with sCr levels during daytime and nighttime in CKD patients but not in non-CKD subjects. Moreover, although heart rate was not associated with U-AGT excretion levels in non-CKD subjects, it was associated with U-AGT excretion levels during daytime (r = 0.23 and p = 0.047) and nighttime (r = 0.45 and p < 0.01) in CKD patients. Multiple linear regression analysis revealed that heart rate had a significant positive association with the U-AGT excretion levels during nighttime, but not daytime, after adjustments for age, sex, body mass index, and sCr (ß = 0.31 and p = 0.034). CONCLUSION: Heart rate is associated with U-AGT excretion levels, especially during the nighttime, in CKD patients.

Salt Loading Aggravates the Relationship between Melatonin and Proteinuria in Patients with Chronic Kidney Disease.

Objective Salt loading induces renal damage independently of blood pressure (BP) elevation via reactive oxygen species and sympathetic activity. Melatonin, a hormone that regulates the circadian rhythm, has multiple functions, including anti-oxidant effects and the inhibition of sympathetic activity. We have shown that impaired melatonin secretion is associated with renal damage in chronic kidney disease (CKD) patients. However, the associations between salt loading, melatonin secretion, and urinary albumin and protein have not been clarified. Methods We recruited 32 CKD patients, conducted 24-hour ambulatory BP monitoring and collected daytime and nighttime urine while the patients were consuming a standard salt (10 g/day) or low salt (6 g/day) diet. The excretion levels of albumin, protein and 6-sulfatoxymelatonin (aMT6s), a metabolite of melatonin, in daytime and nighttime urine were investigated in patients consuming standard salt and low salt diets. Results The urinary aMT6s levels in daytime and nighttime of the patients consuming standard salt and low salt diets did not differ to a statistically significant extent. However, the urinary aMT6s levels in patients consuming a standard salt diet-but not patients consuming a low salt diet-were significantly and negatively correlated with the daytime and nighttime urinary albumin and protein levels. Contrarily, no significant correlations were found between the urinary aMT6s levels and the BP levels, renal function, and plasma angiotensin II levels in patients consuming either a standard salt or low salt diet. A multiple regression analysis adjusted for age, sex, and body mass index revealed that the urinary albumin and protein levels were significantly and negatively associated with the urinary aMT6s levels in patients consuming a standard salt diet, but not in patients consuming a low salt diet. Conclusion Salt loading aggravates the relationship between melatonin secretion and albuminuria or proteinuria.