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1.
Rheumatology (Oxford) ; 63(4): 953-961, 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-37632777

RESUMEN

OBJECTIVES: There is little data on renal relapse in childhood-onset LN (cLN). We investigate the incidence, predictive factors and outcomes related to renal relapse. METHODS: We conducted a retrospective cohort study of all cLN diagnosed at ≤18 years between 2001-2021 to investigate the incidence and outcomes related to renal relapse. RESULTS: Ninety-five Chinese cLN patients (91% proliferative LN) were included. Induction immunosuppression was prednisolone and CYC [n = 36 (38%)] or MMF [n = 33 (35%)]. Maintenance immunosuppression was prednisolone and MMF [n = 53 (54%)] or AZA [n = 29 (31%)]. The rates of complete remission/partial remission (CR/PR) at 12 months were 78.9%/7.4%. Seventy renal relapses occurred in 39 patients over a follow-up of 10.2 years (s.d. 5.9) (0.07 episode/patient-year). Relapse-free survival was 94.7, 86.0, 80.1, 71.2, 68.3, 50.3 and 44.5% at 1, 2, 3, 4, 5, 10 and 20 years, respectively. Multivariate analysis showed that LN diagnosis <13.1 years [adjusted hazard ratio (HRadj) 2.59 995% CI 1.27, 5.29), P = 0.01], AZA maintenance [HRadj 2.20 (95% CI 1.01, 4.79), P = 0.05], PR [HRadj 3.9 (95% CI 1.03, 9.19), P = 0.01] and non-remission [HRadj 3.08 (95% CI 1.35, 11.3), P = 0.04] at 12 months were predictive of renal relapse. Renal relapse was significantly associated with advanced chronic kidney disease (stages 3-5) and end-stage kidney disease (17.9% vs 1.8%, P < 0.01). Furthermore, patients with renal relapse showed an increased incidence of infections (30.8% vs 10.7%, P = 0.02), osteopenia (38.5% vs 17.9%, P = 0.04) and hypertension (30.8% vs 7.1%, P < 0.01). CONCLUSION: Renal relapse is common among cLN, especially among young patients, and is associated with an increased incidence of morbidity and mortality. Attaining CR and the use of MMF appear to decrease the incidence of renal relapse.


Asunto(s)
Nefritis Lúpica , Niño , Humanos , Adolescente , Nefritis Lúpica/tratamiento farmacológico , Nefritis Lúpica/epidemiología , Nefritis Lúpica/diagnóstico , Inmunosupresores/uso terapéutico , Azatioprina/uso terapéutico , Estudios Retrospectivos , Ácido Micofenólico , Resultado del Tratamiento , Prednisolona/uso terapéutico , Recurrencia , Ciclofosfamida , Inducción de Remisión
2.
Am J Med Genet A ; 194(8): e63616, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38551204

RESUMEN

Multicentric carpotarsal osteolysis syndrome (MCTO) is a rare skeletal disorder characterized by progressive osteolysis involving the carpal and tarsal bones, and often associated with nephropathy. It is caused by heterozygous mutation in the MAF bZIP transcription factor B (MAFB) gene. Heterogeneous clinical manifestation and wide spectrum of disease severity have been observed in patients with MCTO. Here, we report a case of a male patient who presented with kidney failure in childhood with progressive disabling skeletal deformity. He was diagnosed with MCTO at 31-years-old, where a de novo pathogenic heterozygous variant in NM_005461.5:c.212C>A: p.(Pro71His) of the MAFB gene was identified. While there has been little data on the long-term prognosis and life expectancy of this disease, this case report sheds light on the debilitating disease course with multiple significant morbidities of a patient with MCTO throughout his lifetime of 33 years.


Asunto(s)
Factor de Transcripción MafB , Osteólisis , Humanos , Masculino , Osteólisis/genética , Osteólisis/patología , Factor de Transcripción MafB/genética , Adulto , Mutación/genética , Huesos Tarsianos/patología , Huesos Tarsianos/anomalías , Huesos del Carpo/anomalías , Huesos del Carpo/patología , Heterocigoto , Fenotipo
3.
J Surg Res ; 295: 340-349, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38061239

RESUMEN

INTRODUCTION: To gain an understanding of the changing faces of leadership in surgery, we examined trends in the demographics, additional degrees pursued, and scientific publication characteristics of the past presidents of three major surgery organizations. METHODS: We queried the BoardCertifiedDocs and Web of Science databases for the demographics, as well as the quantity and quality of publications, of the past presidents of the Association for Academic Surgery, Society of University Surgeons, and American College of Surgeons from 1970 to 2020. Data were analyzed by decade to identify any trends. RESULTS: We identified a total of 140 presidents from the organizations. The proportion of female presidents significantly increased from the 1990s to the 2010s (10% versus 33%, P < 0.05). The percentage of non-White presidents increased from the 1970s to the 2010s (3.33% versus 21.2%, P = 0.024). The percentage of presidents with additional degrees also increased from the 1970s to the 2010s (10.0% versus 48.8%, P = 0.039). During this same time period, the most common area of expertise of presidents shifted from cardiothoracic surgery to surgical oncology. The ratio of presidents' postinduction to preinduction publications was significantly increased among all three organizations in the 2010s compared to the 1970s (P < 0.05). Co-cluster analysis revealed a research topic change from the 1970s to the 2010s. CONCLUSIONS: The faces of surgical leadership have changed in terms of gender equality, racial diversity, surgical subspecialty, and additional degrees held. Such a transformation mirrors evolving diversity, equity, and inclusion initiatives, and it further highlights the adaptability of surgical leadership to the ever-changing landscape of surgery.


Asunto(s)
Especialidades Quirúrgicas , Cirujanos , Humanos , Femenino , Sociedades Médicas , Liderazgo , Publicaciones
4.
Pediatr Nephrol ; 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38597973

RESUMEN

Acquired cystic kidney disease (ACKD) can occur in patients with chronic kidney disease and kidney failure, and its incidence increases with the duration of dialysis. In adults, ACKD is less common in the pre-dialysis group (~ 7%), but its incidence can be as high as 80% for those who are on dialysis for more than ten years. There is, however, very little information about the prevalence of ACKD in children. We report a case of malignant transformation of ACKD following a kidney transplant, highlighting the importance of surveillance of the native kidneys in paediatric patients who have been in long-term kidney replacement therapy.

5.
Pediatr Nephrol ; 38(7): 2171-2178, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-36449100

RESUMEN

BACKGROUND: Remote patient monitoring (RPM) for automated peritoneal dialysis (APD) may improve clinical outcomes. Paediatric data, however, remain extremely scarce. METHODS: We conducted a prospective observational study of children (0-18 years) receiving APD with cloud-based RPM over two 24-week periods (pre- and post-RPM). Primary outcomes were unplanned hospitalizations and fluid management. Children receiving APD without RPM (non-RPM) were included as control. RESULTS: Seven patients (6 females) receiving APD were enrolled in the RPM programme at 11.3 years (IQR 2.6-17.1). Main indications for RPM included history of fluid overload (n = 3) and non-adherence (n = 2). Ten children were included in the non-RPM group (6 females; 16.9 years, IQR 12.8-17.6). Four patients (57.1%, 95% CI 22.5-100%) experienced fewer unplanned hospitalizations and 5 patients (71.4%, 95% CI 34.1-100%) had shorter hospital stays during the post-RPM period. The hospitalization rates and length of stay were reduced by 45% and 42%, respectively. The higher hospitalization rates among the RPM group, compared to the non-RPM group, were no longer observed following implementation of RPM. There was a significant increase in ultrafiltration (565.6 ± 248.7 vs. 501.7 ± 286.6 ml/day, p = 0.03) and reduction in systolic blood pressure (114.1 ± 12.6 vs. 119.9 ± 11.19 mmHg, p = 0.02) during the post-RPM period. All patients demonstrated satisfactory adherence. Although quality of life (PedsQL 3.0 ESRD module) was not different pre- and post-RPM, all patients agreed in the questionnaires that the use of RPM improved their quality of life and sense of security. CONCLUSIONS: In conclusion, RPM in children receiving APD is associated with fewer and shorter unplanned hospitalizations, improved fluid management and favourable adherence to PD. A higher resolution version of the Graphical abstract is available as Supplementary information.


Asunto(s)
Fallo Renal Crónico , Diálisis Peritoneal , Femenino , Humanos , Niño , Estudios Prospectivos , Nube Computacional , Calidad de Vida , Monitoreo Fisiológico , Percepción , Fallo Renal Crónico/terapia
6.
Pediatr Nephrol ; 38(11): 3823-3833, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37219640

RESUMEN

BACKGROUND: In onco-nephrology, data on acute kidney injury (AKI) among children with haematological malignancies are scarce. METHODS: A retrospective cohort study of all patients in Hong Kong diagnosed with haematological malignancies from 2019 to 2021 before 18 years of age, was conducted to investigate the epidemiology, risk factors and clinical outcomes of AKI during the first year of treatment. AKI was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. RESULTS: We included 130 children with haematological malignancy at median age of 9.4 years (IQR, 3.9-14.1). Of these patients, 55.4% were acute lymphoblastic leukemia (ALL), 26.9% were lymphoma and 17.7% were acute myeloid leukemia (AML). Thirty-five patients (26.9%) developed 41 AKI episodes during the first year of diagnosis, corresponding to 32 episodes per 100-patient-year. A total of 56.1% and 29.2% of the AKI episodes occurred during induction and consolidation chemotherapy respectively. Septic shock (n = 12, 29.2%) was the leading cause of AKI; 21 episodes (51.2%) were stage 3 AKI; 12 episodes (29.3%) were stage 2 AKI; and 6 patients required continuous kidney replacement therapies. Tumor lysis syndrome and impaired baseline kidney function were significantly associated with AKI on multivariate analysis (P = 0.01). History of AKI was associated with chemotherapy postponement (37.1% vs. 16.8%, P = 0.01), worse 12-month patient survival (77.1% vs. 94.7%, log rank P = 0.002) and lower disease remission rate at 12-month (68.6% vs. 88.4%, P = 0.007), compared to patients without AKI. CONCLUSION: AKI is a common complication during treatment of haematological malignancies which is associated with worse treatment outcomes. A regular and dedicated surveillance program for at-risk patients should be studied in children with haematological malignancies for prevention and early detection of AKI. A higher resolution version of the Graphical abstract is available as Supplementary information.


Asunto(s)
Lesión Renal Aguda , Neoplasias Hematológicas , Humanos , Niño , Preescolar , Adolescente , Estudios Retrospectivos , Lesión Renal Aguda/epidemiología , Lesión Renal Aguda/etiología , Lesión Renal Aguda/terapia , Riñón , Resultado del Tratamiento , Factores de Riesgo , Neoplasias Hematológicas/complicaciones , Neoplasias Hematológicas/epidemiología , Neoplasias Hematológicas/terapia
7.
Pediatr Nephrol ; 38(12): 4001-4011, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37358717

RESUMEN

BACKGROUND: Long-term data pertaining to rituximab as add-on therapy in childhood-onset lupus nephritis (cLN) is scarce. METHODS: A retrospective cohort study was conducted on all patients with proliferative cLN, diagnosed ≤ 18 years and between 2005 and 2021, who received rituximab for LN episodes that were life/organ threatening and/or treatment resistant to standard immunosuppression. RESULTS: Fourteen patients with cLN (female, n = 10) were included, with median follow-up period of 6.9 years. LN episodes (class III, n = 1; class IV, n = 11; class IV + V, n = 2) requiring rituximab occurred at 15.6 years (IQR 12.8-17.3), urine protein:creatinine ratio was 8.2 mg/mg (IQR 3.4-10.1) and eGFR was 28 mL/min/1.73 m2 (IQR 24-69) prior to rituximab treatment. Ten and four patients received rituximab at 1500 mg/m2 and 750 mg/m2, which were given at 46.5 days (IQR 19-69) after commencement of standard therapies. Treatment with rituximab resulted in improvements in proteinuria (ps < 0.001), eGFR (ps < 0.01) and serological parameters, including haemoglobin levels, complement 3 levels and anti-dsDNA antibodies, compared with baseline. Rates of complete/partial remission at 6-, 12- and 24-month post-rituximab were 28.6/42.8%, 64.2/21.4% and 69.2/15.3%. All three patients who required acute kidney replacement therapy became dialysis-free after rituximab. Relapse rate following rituximab was 0.11 episodes/patient-year. There was no lethal complication or severe infusion reaction. Hypogammaglobulinaemia was the most frequent complication (45%) but was mostly asymptomatic. Neutropenia and infections were observed in 20% and 25% of treatments. Upon last follow-up, three (21%) and two (14%) patients developed chronic kidney disease (stage 2, n = 2; stage 4; n = 1) and kidney failure, respectively. CONCLUSION: Add-on rituximab is an effective and safe rescue therapy for cLN patients with life-/organ-threatening manifestations or treatment-resistance. A higher resolution version of the Graphical abstract is available as Supplementary information.


Asunto(s)
Lupus Eritematoso Sistémico , Nefritis Lúpica , Humanos , Femenino , Rituximab/efectos adversos , Nefritis Lúpica/tratamiento farmacológico , Estudios Retrospectivos , Resultado del Tratamiento , Diálisis Renal , Inmunosupresores/efectos adversos
8.
J Am Soc Nephrol ; 33(6): 1193-1207, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35354600

RESUMEN

BACKGROUND: Long-term outcomes after multiple courses of rituximab among children with frequently relapsing, steroid-dependent nephrotic syndrome (FRSDNS) are unknown. METHODS: A retrospective cohort study at 16 pediatric nephrology centers from ten countries in Asia, Europe, and North America included children with FRSDNS who received two or more courses of rituximab. Primary outcomes were relapse-free survival and adverse events. RESULTS: A total of 346 children (age, 9.8 years; IQR, 6.6-13.5 years; 73% boys) received 1149 courses of rituximab. A total of 145, 83, 50, 28, 22, and 18 children received two, three, four, five, six, and seven or more courses, respectively. Median (IQR) follow-up was 5.9 (4.3-7.7) years. Relapse-free survival differed by treatment courses (clustered log-rank test P<0.001). Compared with the first course (10.0 months; 95% CI, 9.0 to 10.7 months), relapse-free period and relapse risk progressively improved after subsequent courses (12.0-16.0 months; HRadj, 0.03-0.13; 95% CI, 0.01 to 0.18; P<0.001). The duration of B-cell depletion remained similar with repeated treatments (6.1 months; 95% CI, 6.0 to 6.3 months). Adverse events were mostly mild; the most common adverse events were hypogammaglobulinemia (50.9%), infection (4.5%), and neutropenia (3.7%). Side effects did not increase with more treatment courses nor a higher cumulative dose. Only 78 of the 353 episodes of hypogammaglobulinemia were clinically significant. Younger age at presentation (2.8 versus 3.3 years; P=0.05), age at first rituximab treatment (8.0 versus 10.0 years; P=0.01), and history of steroid resistance (28% versus 18%; P=0.01) were associated with significant hypogammaglobulinemia. All 53 infective episodes resolved, except for one patient with hepatitis B infection and another with EBV infection. There were 42 episodes of neutropenia, associated with history of steroid resistance (30% versus 20%; P=0.04). Upon last follow-up, 332 children (96%) had normal kidney function. CONCLUSIONS: Children receiving repeated courses of rituximab for FRSDNS experience an improving clinical response. Side effects appear acceptable, but significant complications can occur. These findings support repeated rituximab use in FRSDNS.


Asunto(s)
Agammaglobulinemia , Nefrosis Lipoidea , Síndrome Nefrótico , Neutropenia , Agammaglobulinemia/inducido químicamente , Agammaglobulinemia/tratamiento farmacológico , Niño , Femenino , Humanos , Inmunosupresores/uso terapéutico , Masculino , Nefrosis Lipoidea/tratamiento farmacológico , Síndrome Nefrótico/tratamiento farmacológico , Neutropenia/inducido químicamente , Neutropenia/tratamiento farmacológico , Recurrencia , Estudios Retrospectivos , Rituximab/efectos adversos , Esteroides/uso terapéutico , Resultado del Tratamiento
9.
Pediatr Blood Cancer ; 69(5): e29592, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35129877

RESUMEN

We report a case series of 14 children with intracranial germ cell tumor and concomitant central diabetes insipidus, who developed hyponatremia secondary to renal salt-wasting syndrome (RSWS) following the administration of carboplatin. Clinicians prescribing platinum-based chemotherapy for this group of patients should be alert to the risk of RSWS. Regular monitoring should be performed as hyponatremia can be asymptomatic until it is severe.


Asunto(s)
Neoplasias Encefálicas , Diabetes Insípida Neurogénica , Diabetes Mellitus , Hiponatremia , Neoplasias de Células Germinales y Embrionarias , Síndrome Debilitante , Neoplasias Encefálicas/complicaciones , Carboplatino/efectos adversos , Niño , Diabetes Insípida Neurogénica/complicaciones , Femenino , Humanos , Hiponatremia/inducido químicamente , Hiponatremia/complicaciones , Masculino , Neoplasias de Células Germinales y Embrionarias/complicaciones , Neoplasias de Células Germinales y Embrionarias/tratamiento farmacológico , Síndrome , Síndrome Debilitante/complicaciones
10.
Pediatr Transplant ; 26(7): e14366, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35860972

RESUMEN

BACKGROUND: Transplant-associated thrombotic microangiopathy (TA-TMA) is an under-recognized yet potentially devastating complication of hematopoietic stem cell transplantation (HSCT) which had increased awareness in recent years. This report summarizes the demographics and outcomes of pediatric TA-TMA in Hong Kong. METHODS: All patients aged below 18 years who underwent HSCT in the Hong Kong Children's Hospital and were diagnosed to have TA-TMA during the 2-year period from April 1, 2019 to March 31, 2021 were included. RESULTS: A total of 73 transplants (51 allogeneic and 22 autologous) in 63 patients had been performed. Six patients (four males and two females) developed TA-TMA at a median duration of 2.5 months post-HSCT. The incidence rate was 9.52%. Of the six TA-TMA patients, five underwent allogenic one underwent autologous HSCT, respectively. Three of them were histologically proven. All four patients with cyclosporine had stopped the drug once TA-TMA was suspected. Median six doses of eculizumab were administered to five out of six patients. Three patients died (two due to fungal infection and one due to acute-on-chronic renal failure) within 3 months upon diagnosis of TA-TMA. Among three survivors, two stabilized with mild stage 2 chronic kidney disease (CKD) while the other suffered from stage 5 end-stage CKD requiring lifelong dialysis. CONCLUSION: In conclusion, recognition and diagnosis of TA-TMA are challenging. Early recognition and prompt administration of complement blockage with eculizumab may be beneficial in selected cases. Further prospective research studies are recommended to improve the management and outcomes of TA-TMA.


Asunto(s)
Ciclosporinas , Trasplante de Células Madre Hematopoyéticas , Insuficiencia Renal Crónica , Microangiopatías Trombóticas , Anciano , Niño , Femenino , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Hong Kong/epidemiología , Humanos , Masculino , Insuficiencia Renal Crónica/etiología , Microangiopatías Trombóticas/diagnóstico , Microangiopatías Trombóticas/epidemiología , Microangiopatías Trombóticas/etiología
11.
Nephrology (Carlton) ; 27(2): 171-180, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34837272

RESUMEN

AIM: To evaluate the demographics and long-term patient outcomes of children with end-stage kidney disease in Hong Kong. METHODS: We conducted a cohort study at the Paediatric Nephrology Centre, the designated site providing kidney replacement therapy (KRT) for children in Hong Kong. The clinical characteristics and outcomes of all children who initiated chronic KRT before 19 years, between 2001 and 2020, were analysed. RESULTS: One hundred forty-seven children (50% male) received KRT at a mean age of 11.4 ± 5.7 years. The incidence of ESKD was 6.28 per million age-related population (pmarp). The leading cause of ESKD was congenital anomalies (33%). Ten children (7%) had pre-emptive kidney transplants, 104 (71%) and 33 (22%) patients received automated peritoneal dialysis and haemodialysis as initial KRT. The incidence of ESKD increased over time, and were 4.38, 5.07, 6.15 and 9.17 pmarp during 2001-2005, 2006-2010, 2011-2015 and 2016-2020, respectively (p = .005). Ninty-seven patients (66%) received kidney transplants and the median time to receive a kidney graft was 3.7 years (95% CI 3.1-4.3). Only 10 patients had pre-emptive kidney transplants. The mortality rate was 9.1 deaths per 1000-patient-years (95%CI 4.6-16.2). The survival probabilities at 1-, 5-, 10- and 15-year were 100%, 94.8% (95%CI 90.7-98.9%), 89.7% (95% CI 83.4%-95.9%), 87.1% (95% CI 79.3%-94.9%), respectively. Standardised mortality ratio was 54.5. 72% of deaths were due to infections. Young infants and those without kidney transplants were associated with worse survival (p < .01). Multivariate analysis demonstrated that dialysis was the only factor associated with significantly increased risk of death (HRadj 12.9, 95% CI 2.7-63.2, p = .002). CONCLUSION: We observed an increasing incidence of paediatric ESKD in Hong Kong with considerable waiting time to kidney transplant. Mortality risk is comparable to other developed countries and is highest among dialysis population. Efforts should be made to facilitate early access to paediatric kidney transplantation in Hong Kong.


Asunto(s)
Fallo Renal Crónico/terapia , Terapia de Reemplazo Renal , Adolescente , Niño , Estudios de Cohortes , Demografía , Femenino , Hong Kong , Humanos , Masculino , Factores de Tiempo , Resultado del Tratamiento
12.
Pediatr Nephrol ; 36(7): 1751-1764, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33057769

RESUMEN

Renin-angiotensin-aldosterone inhibitors (RAASi) are the mainstay therapy in both adult and paediatric chronic kidney disease (CKD). RAASi slow down the progression of kidney failure by optimization of blood pressure and reduction of proteinuria. Despite recommendations from published guidelines in adults, the evidence related to the use of RAASi is surprisingly scarce in children. Moreover, their role in advanced CKD remains controversial. Without much guidance from the literature, paediatric nephrologists may discontinue RAASi in patients with advanced CKD due to apparent worsening of kidney function, hyperkalaemia and hypotension. Current data suggest that this strategy may in fact lead to a more rapid decline in kidney function. The optimal approach in this clinical scenario is still not well defined and there are varying practices worldwide. We will in this review describe the existing evidence on the use of RAASi in CKD with particular focus on paediatric data. We will also address the use of RAASi in advanced CKD and discuss the potential benefits and harms. At the end, we will suggest a practical approach for the use of RAASi in children with CKD based on current state of knowledge.


Asunto(s)
Antagonistas de Receptores de Angiotensina , Inhibidores de la Enzima Convertidora de Angiotensina , Hiperpotasemia , Insuficiencia Renal Crónica , Aldosterona , Antagonistas de Receptores de Angiotensina/efectos adversos , Antagonistas de Receptores de Angiotensina/uso terapéutico , Inhibidores de la Enzima Convertidora de Angiotensina/efectos adversos , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Antihipertensivos/farmacología , Niño , Progresión de la Enfermedad , Humanos , Antagonistas de Receptores de Mineralocorticoides , Insuficiencia Renal Crónica/tratamiento farmacológico , Renina , Sistema Renina-Angiotensina/efectos de los fármacos
13.
J Pediatr Hematol Oncol ; 43(3): e445-e447, 2021 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-32287097

RESUMEN

We herein report an unusual case of lupus with bleeding diathesis in a Chinese adolescent boy. In the presence of lupus anticoagulant and hypoprothrombinemia, the diagnosis of lupus anticoagulant-hypoprothrombinemia syndrome was made. He responded promptly to immunosuppressive agents and achieved disease remission.


Asunto(s)
Hipoprotrombinemias/sangre , Inhibidor de Coagulación del Lupus/sangre , Coagulación Sanguínea , Factores de Coagulación Sanguínea/análisis , Niño , Hemorragia/sangre , Humanos , Hipoprotrombinemias/diagnóstico , Masculino
14.
Biochemistry ; 59(35): 3271-3283, 2020 09 08.
Artículo en Inglés | MEDLINE | ID: mdl-32786410

RESUMEN

Most terpene synthase reactions follow Markovnikov rules for formation of high-energy carbenium ion intermediates. However, there are notable exceptions. For example, pentalenene synthase (PS) undergoes an initial anti-Markovnikov cyclization reaction followed by a 1,2-hydride shift to form an intermediate humulyl cation with positive charge on the secondary carbon C9 atom of the farnesyl diphosphate substrate. The mechanism by which these enzymes stabilize and guide the regioselectivity of secondary carbocations has not heretofore been elucidated. In an effort to better understand these reactions, we grew crystals of apo-PS, soaked them with the nonreactive substrate analogue 12,13-difluorofarnesyl diphosphate, and determined the X-ray structure of the resulting complex at 2.2 Å resolution. The most striking feature of the active site structure is that C9 is perfectly positioned to make a C-H···π interaction with the side chain benzene ring of residue F76; this would enhance hyperconjugation to stabilize a developing cation at C10 and thus support the anti-Markovnikov regioselectivity of the cyclization. The benzene ring is also positioned to catalyze the migration of H to C10 and stabilize a C9 carbocation. On the opposite face of C9, further cation stabilization is possible via interactions with the main chain carbonyl of I177 and the neighboring intramolecular C6═C7 bond. Mutagenesis experiments also support a role for residue 76 in these interactions, but most interesting is the F76W mutant, whose crystal structure clearly shows C9 and C10 centered above the fused benzene and pyrrole rings of the indole side chain, respectively, such that a carbocation at either position could be stabilized in this complex, and two anti-Markovnikov products, pentalenene and humulene, are formed. Finally, we show that there is a rough correlation (although not absolute) of an aromatic side chain (F or Y) at position 76 in related terpene synthases from Streptomyces that catalyze similar anti-Markovnikov addition reactions.


Asunto(s)
Liasas Intramoleculares/química , Liasas Intramoleculares/metabolismo , Streptomyces/enzimología , Transferasas Alquil y Aril/química , Transferasas Alquil y Aril/metabolismo , Catálisis , Dominio Catalítico , Cristalografía por Rayos X , Ciclización , Ciclopentanos/química , Ciclopentanos/metabolismo , Modelos Moleculares , Conformación Proteica
15.
Kidney Int ; 97(2): 393-401, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31874801

RESUMEN

Rituximab is an effective treatment for steroid-dependent/ frequently-relapsing nephrotic syndrome (SDFRNS) in children. However, the optimal rituximab regimen remains unknown. To help determine this we conducted an international, multicenter retrospective study at 11 tertiary pediatric nephrology centers in Asia, Europe and North America of children 1-18 years of age with complicated SDFRNS receiving rituximab between 2005-2016 for 18 or more months follow-up. The effect of rituximab prescribed at three dosing levels: low (375mg/m2), medium (750mg/m2) and high (1125-1500mg/m2), with or without maintenance immunosuppression (defined as concurrent use of corticosteroids, mycophenolate motile or calcineurin inhibition at first relapse or for at least six months following the rituximab treatment) was examined. Among the 511 children (median age 11.5 year, 67% boys), 191, 208 and 112 received low, medium and high dose rituximab, respectively. Within this total cohort of 511 children, 283 (55%) received maintenance immunosuppression. Renal biopsies were performed in 317 children indicating the predominant histology was minimal change disease (74%). Without maintenance immunosuppression, low-dose rituximab had a shorter relapse-free period and a higher relapse risk (8.5 months) than medium (12.7 months; adjusted hazard ratio, 0.62) and high dose (14.3 months; adjusted hazard ratio, 0.50; all significant). With maintenance immunosuppression, the relapse-free survival in low-dose rituximab (14 months) was similar to medium (10.9 months; adjusted hazard ratio, 1.23) and high dose (12.0 months; adjusted hazard ratio, 0.92; all non-significant). Most adverse events were mild. Thus, children receiving low-dose rituximab without maintenance immunosuppression had the shortest relapse-free survival. Hence, both rituximab dose and maintenance immunosuppression have important effects on the treatment outcomes.


Asunto(s)
Síndrome Nefrótico , Asia , Niño , Europa (Continente) , Femenino , Humanos , Terapia de Inmunosupresión , Inmunosupresores/efectos adversos , Masculino , Síndrome Nefrótico/tratamiento farmacológico , América del Norte , Recurrencia , Estudios Retrospectivos , Rituximab/efectos adversos , Esteroides , Resultado del Tratamiento
16.
Lupus ; 29(13): 1811-1814, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32791932

RESUMEN

We report, to the best of our knowledge, the first case of neuropsychiatric systemic lupus erythematosus with clinical presentation of bilateral upward gaze palsy and intraoral numbness. Magnetic resonance imaging of the brain was able to identify the pathogenic lesion at the left side of midbrain, involving the vertical gaze center and sensory pathways for innervating the buccal and hard palate mucosa. A course of aggressive immunosuppressive treatment resulted in prompt resolution of gaze palsy and the midbrain lesion.


Asunto(s)
Hipoestesia/etiología , Lupus Eritematoso Sistémico/complicaciones , Mesencéfalo/patología , Parálisis Supranuclear Progresiva/etiología , Movimientos Oculares , Femenino , Humanos , Imagen por Resonancia Magnética , Parálisis Supranuclear Progresiva/fisiopatología , Adulto Joven
17.
Pediatr Nephrol ; 35(6): 1051-1060, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32016625

RESUMEN

BACKGROUND: We tested the hypothesis that myocardial stiffness is altered in paediatric patients with end-stage kidney disease (ESKD) and explored its association with clinical parameters of chronic kidney disease (CKD). METHODS: Thirty-five patients with ESKD (16 males) aged 17.5 ± 3 years old, 18/35 of whom were receiving dialysis and 17 post kidney transplant, were studied. Left ventricular (LV) myocardial stiffness was determined by measurement of diastolic wall strain (DWS) and stiffness index (SI), while LV diastolic function was interrogated by pulsed-wave and tissue Doppler echocardiography. RESULTS: Compared with available literature data, both dialysis and transplanted patients had significantly lower DWS and greater SI, reduced transmitral early (E) to late diastolic velocity ratio and septal and lateral mitral annular early (e') diastolic velocities, and greater septal and lateral E/e' ratios (all p < 0.05). Multivariate analysis revealed that z score of diastolic blood pressure (ß = 0.43, p = 0.004) and the duration of renal replacement therapy (ß = 0.55, p < 0.001) were significant determinants of LV SI. Subgroup analysis in post-transplant patients showed z score of diastolic blood pressure (ß = 0.54, p = 0.025) remained as a significant determinant of LV SI. CONCLUSION: Increased LV myocardial stiffness is evident in paediatric dialysis and transplanted patients with ESKD, and is associated with blood pressure and duration of renal replacement therapy.


Asunto(s)
Ventrículos Cardíacos/fisiopatología , Fallo Renal Crónico/fisiopatología , Disfunción Ventricular Izquierda/etiología , Adolescente , Adulto , Ecocardiografía Doppler , Femenino , Humanos , Fallo Renal Crónico/complicaciones , Fallo Renal Crónico/terapia , Trasplante de Riñón , Masculino , Diálisis Renal , Estudios Retrospectivos , Adulto Joven
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