Glucoregulation after canine islet transplantation:Contribution of insulin secretory capacity, insulin action, and the entero-insular axis

The physiological glucoregulatory mechanisms after islet transplantation have been incompletely investigated, We studied the insulin secretory capacity (ISC) by intravenous arginine stimulation during 35-mM glucose clamps, insulin action during hyperinsulinemic euglycemic clamps, and mixed-meal stimulation at 6-9 mo after intrasplenic islet autotransplantation in 8 dogs, as compared with 30 controls, The enteroinsular axis in the recipients was examined by infusion of porcine glucose-dependent insulinotropic polypeptide (GIP) and human glucagon-like peptide-1 (GLP-1) (7-36 amide) under 8.5-mM glycemic clamp conditions in order to mimic the postprandial glycemia after transplantation. The grafts comprised 25% of the native islet mass, and the ISC likewise averaged 25% of the control value, The postprandial insulin response, in contrast, had increased to 140% after transplantation-albeit with a concomitant glucose excursion to approximately 8.5 mM, Insulin action declined on average by 45% posttransplant. The ISC correlated both with the postprandial glucose excursion and insulin action in the grafted dogs, Insulin action did not correlate with the postprandial glucose excursion, Infusion of GIP had no effect, but GLP-1 nearly doubled glucose-stimulated insulin, Thus, a hyperglycemia-enhanced insulinotropic effect of GLP-1, and perhaps other gut hormones, may account for the difference in the insulin response to the intravenous and oral challenges, Because the ISC reflects the engrafted islet mass and appears to be the primary determinant of glucose tolerance, transplantation of higher islet doses should allow prolonged near-normal glucoregulation-at least, in the autotransplant setting. (C) 1997 Elsevier Science Inc

Small-molecule modulators of Hedgehog signaling: identification and characterization of Smoothened agonists and antagonists

BACKGROUND: The Hedgehog (Hh) signaling pathway is vital to animal development as it mediates the differentiation of multiple cell types during embryogenesis. In adults, Hh signaling can be activated to facilitate tissue maintenance and repair. Moreover, stimulation of the Hh pathway has shown therapeutic efficacy in models of neuropathy. The underlying mechanisms of Hh signal transduction remain obscure, however: little is known about the communication between the pathway suppressor Patched (Ptc), a multipass transmembrane protein that directly binds Hh, and the pathway activator Smoothened (Smo), a protein that is related to G-protein-coupled receptors and is capable of constitutive activation in the absence of Ptc. RESULTS: We have identified and characterized a synthetic non-peptidyl small molecule, Hh-Ag, that acts as an agonist of the Hh pathway. This Hh agonist promotes cell-type-specific proliferation and concentration-dependent differentiation in vitro, while in utero it rescues aspects of the Hh-signaling defect in Sonic hedgehog-null, but not Smo-null, mouse embryos. Biochemical studies with Hh-Ag, the Hh-signaling antagonist cyclopamine, and a novel Hh-signaling inhibitor Cur61414, reveal that the action of all these compounds is independent of Hh-protein ligand and of the Hh receptor Ptc, as each binds directly to Smo. CONCLUSIONS: Smo can have its activity modulated directly by synthetic small molecules. These studies raise the possibility that Hh signaling may be regulated by endogenous small molecules in vivo and provide potent compounds with which to test the therapeutic value of activating the Hh-signaling pathway in the treatment of traumatic and chronic degenerative conditions

Cloning and characterization of the cDNA encoding human adenylosuccinate synthetase

Adenylosuccinate synthetase (AS) catalyzes the first committed step in the conversion of IMP to AMP. A cDNA was isolated from a human liver library which encodes a protein of 455 amino acids (Mr of 49.925). Alignments of human, mouse, Dictyostelium discoideum and E. coli AS sequences identify a number of invariant residues which are likely to be important for structure and/or catalysis. The human AS sequence was also 19% identical to the human urea cycle enzyme, arginosuccinate synthetase (ASS), which catalyses a chemically similar reaction. Both human liver and HcLa AS mRNA showed signals of 2.3 and 2.8 kb. An unmodified N-terminus is required for function of the human AS enzyme in E. coli mutants lacking the bacterial enzyme. The human cDNA provides a means to assess the possible role of AS abnormalities in unclassified, idiopathic cases of gout.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30040/1/0000408.pd

Physical function and physical activity in older breast cancer survivors: 5-year follow-up from the Climb Every Mountain study

Background A decline in physical activity and the ability to perform activities of daily living (ADL) and instrumental activities of daily living (IADL) could interfere with independent living and quality of life in older patients, but may be prevented with tailored interventions. The aim of the current study was to assess changes in physical activity and ADL/IADL in the first 5 years after breast cancer diagnosis in a real-world cohort of older patients and to identify factors associated with physical decline. Methods Patients aged >= 70 years with in situ or stages I-III breast cancer were included in the prospective Climb Every Mountain cohort study. Linear mixed models were used to assess physical activity (according to Metabolic Equivalent of Task (MET) hours per week) and ADL/IADL (according to the Groningen Activity Restriction Scale (GARS)) over time. Secondly, the association with geriatric characteristics, treatment, quality of life, depression, apathy, and loneliness was analyzed. Results A total of 239 patients were included. Physical activity and ADL/IADL changed in the first 5 years after diagnosis (mean change from baseline -11.6 and +4.2, respectively). Geriatric characteristics at baseline were strongly associated with longitudinal change in physical activity and ADL/IADL, whereas breast cancer treatment was not. A better quality of life was associated with better physical activity and preservation of ADL/IADL, while depression and loneliness were negatively associated with these outcomes. Discussion Geriatric characteristics, loneliness, and depressive symptoms were associated with physical decline in older patients with breast cancer, while breast cancer treatment was not.A decline in physical activity and the ability to perform activities of daily living may interfere with quality of life in older patients. This article assessed changes in physical activity and activities of daily living in the first 5 years after breast cancer diagnosis in a real-world cohort of older patients and identified factors associated with physical decline

Association between endocrine therapy and cognitive decline in older women with early breast cancer: findings from the prospective CLIMB study

Introduction: Studies investigating the long-term effects of breast cancer treatment on cognition in older women with breast cancer are lacking, even though preserving cognition is highly valued by the older population. Specifically, concerns have been raised regarding the detrimental effects of endocrine therapy (ET) on cognition. Therefore, we investigated cogni-tive functioning over time and predictors for cognitive decline in older women treated for early breast cancer.Methods: We prospectively enrolled Dutch women aged >70 years with stage I-III breast can-cer in the observational CLIMB study. The Mini-Mental State Examination (MMSE) was performed before ET initiation and after 9, 15 and 27 months. Longitudinal MMSE scores were analysed and stratified for ET. Linear mixed models were used to identify possible pre-dictors of cognitive decline.Results: Among the 273 participants, the mean age was 76 years (standard deviation 5), and 48% received ET. The mean baseline MMSE score was 28.2 (standard deviation 1.9). Cogni-tion did not decline to clinically meaningful differences, irrespective of ET. MMSE scores of women with pre-treatment cognitive impairments slightly improved over time (significant interaction terms) in the entire cohort and in women receiving ET. High age, low educational level and impaired mobility were independently associated with declining MMSE scores over time, although the declines were not clinically meaningful.Conclusion: Cognition of older women with early breast cancer did not decline in the first two years after treatment initiation, irrespective of ET. Our findings suggest that the fear of declining cognition does not justify the de-escalation of breast cancer treatment in older women. 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

Differences in treatment and survival of older patients with operable breast cancer between the United Kingdom and the Netherlands – A comparison of two national prospective longitudinal multi-centre cohort studies

Background Previous studies have shown that survival outcomes for older patients with breast cancer vary substantially across Europe, with worse survival reported in the United Kingdom. It has been hypothesised that these differences in survival outcomes could be related to treatment variation. Objectives We aimed to compare patient and tumour characteristics, treatment selection and survival outcomes between two large prospective cohorts of older patients with operable breast cancer from the United Kingdom (UK) and The Netherlands. Methods Women diagnosed with operable breast cancer aged ≥70 years were included. A baseline comprehensive geriatric assessment was performed in both cohorts, with data collected on age, comorbidities, cognition, nutritional and functional status. Baseline tumour characteristics and treatment type were collected. Univariable and multivariable Cox regression models were used to compare overall survival between the cohorts. Results 3262 patients from the UK Age Gap cohort and 618 patients from the Dutch Climb cohort were included, with median ages of 77.0 (IQR: 72.0–81.0) and 75.0 (IQR: 72.0–81.0) years, respectively. The cohorts were generally comparable, with slight differences in rates of comorbidity and frailty. Median follow-up for overall survival was 4.1 years (IQR 2.9–5.4) in Age Gap and 4.3 years (IQR 2.9–5.5) in Climb. In Age Gap, both the rates of primary endocrine therapy and adjuvant hormonal therapy after surgery were approximately twice those in Climb (16.6% versus 7.3%, p < 0.001 for primary endocrine therapy, and 62.2% versus 38.8%, p < 0.001 for adjuvant hormonal therapy). There was no evidence of a difference in overall survival between the cohorts (adjusted HR 0.94, 95% CI 0.74–1.17, p = 0.568). Conclusions In contrast to previous studies, this comparison of two large national prospective longitudinal multi-centre cohort studies demonstrated comparable survival outcomes between older patients with breast cancer treated in the UK and The Netherlands, despite differences in treatment allocation

Differences in treatment and survival of older patients with operable breast cancer between the United Kingdom and the Netherlands – a comparison of two national prospective longitudinal multi-centre cohort studies

Background Previous studies have shown that survival outcomes for older patients with breast cancer vary substantially across Europe, with worse survival reported in the United Kingdom. It has been hypothesised that these differences in survival outcomes could be related to treatment variation. Objectives We aimed to compare patient and tumour characteristics, treatment selection and survival outcomes between two large prospective cohorts of older patients with operable breast cancer from the United Kingdom (UK) and The Netherlands. Methods Women diagnosed with operable breast cancer aged ≥70 years were included. A baseline comprehensive geriatric assessment was performed in both cohorts, with data collected on age, comorbidities, cognition, nutritional and functional status. Baseline tumour characteristics and treatment type were collected. Univariable and multivariable Cox regression models were used to compare overall survival between the cohorts. Results 3262 patients from the UK Age Gap cohort and 618 patients from the Dutch Climb cohort were included, with median ages of 77.0 (IQR: 72.0–81.0) and 75.0 (IQR: 72.0–81.0) years, respectively. The cohorts were generally comparable, with slight differences in rates of comorbidity and frailty. Median follow-up for overall survival was 4.1 years (IQR 2.9–5.4) in Age Gap and 4.3 years (IQR 2.9–5.5) in Climb. In Age Gap, both the rates of primary endocrine therapy and adjuvant hormonal therapy after surgery were approximately twice those in Climb (16.6% versus 7.3%, p < 0.001 for primary endocrine therapy, and 62.2% versus 38.8%, p < 0.001 for adjuvant hormonal therapy). There was no evidence of a difference in overall survival between the cohorts (adjusted HR 0.94, 95% CI 0.74–1.17, p = 0.568). Conclusions In contrast to previous studies, this comparison of two large national prospective longitudinal multi-centre cohort studies demonstrated comparable survival outcomes between older patients with breast cancer treated in the UK and The Netherlands, despite differences in treatment allocation

Screening for distant metastases in patients with ipsilateral breast tumor recurrence: the impact of different imaging modalities on distant recurrence-free interval

Purpose In patients with ipsilateral breast tumor recurrence (IBTR), the detection of distant disease determines whether the intention of the treatment is curative or palliative. Therefore, adequate preoperative staging is imperative for optimal treatment planning. The aim of this study is to evaluate the impact of conventional imaging techniques, including chest X-ray and/or CT thorax-(abdomen), liver ultrasonography(US), and skeletal scintigraphy, on the distant recurrence-free interval (DRFI) in patients with IBTR, and to compare conventional imaging with 18F-FDG PET-CT or no imaging at all. Methods This study was exclusively based on the information available at time of diagnoses of IBTR. To adjust for differences in baseline characteristics between the three imaging groups, a propensity score (PS) weighted method was used. Results Of the 495 patients included in the study, 229 (46.3%) were staged with conventional imaging, 89 patients (19.8%) were staged with 18F-FDG PET-CT, and in 168 of the patients (33.9%) no imaging was used (N=168). After a follow-up of approximately 5 years, 14.5% of all patients developed a distant recurrence as frst event after IBTR. After adjusting for the PS weights, the Cox regression analyses showed that the diferent staging methods had no signifcant impact on the DRFI. Conclusions This study showed a wide variation in the use of imaging modalities for staging IBTR patients in the Netherlands. After using PS weighting, no statistically signifcant impact of the diferent imaging modalities on DRFI was shown. Based on these results, it is not possible to recommend staging for distant metastases using 18F-FDG PET-CT over conventional imaging technique