Response-guided neoadjuvant sacituzumab govitecan for localized triple-negative breast cancer: results from the NeoSTAR trial.

BACKGROUND: Sacituzumab govitecan (SG), a novel antibody-drug conjugate (ADC) targeting TROP2, is approved for pre-treated metastatic triple-negative breast cancer (mTNBC). We conducted an investigator-initiated clinical trial evaluating neoadjuvant (NA) SG (NCT04230109), and report primary results. PATIENTS AND METHODS: Participants with early-stage TNBC received NA SG for four cycles. The primary objective was to assess pathological complete response (pCR) rate in breast and lymph nodes (ypT0/isN0) to SG. Secondary objectives included overall response rate (ORR), safety, event-free survival (EFS), and predictive biomarkers. A response-guided approach was utilized, and subsequent systemic therapy decisions were at the discretion of the treating physician. RESULTS: From July 2020 to August 2021, 50 participants were enrolled (median age = 48.5 years; 13 clinical stage I disease, 26 stage II, 11 stage III). Forty-nine (98%) completed four cycles of SG. Overall, the pCR rate with SG alone was 30% [n = 15, 95% confidence interval (CI) 18% to 45%]. The ORR per RECIST V1.1 after SG alone was 64% (n = 32/50, 95% CI 77% to 98%). Higher Ki-67 and tumor-infiltrating lymphocytes (TILs) were predictive of pCR to SG (P = 0.007 for Ki-67 and 0.002 for TILs), while baseline TROP2 expression was not (P = 0.440). Common adverse events were nausea (82%), fatigue (76%), alopecia (76%), neutropenia (44%), and rash (48%). With a median follow-up time of 18.9 months (95% CI 16.3-21.9 months), the 2-year EFS for all participants was 95%. Among participants with a pCR with SG (n = 15), the 2-year EFS was 100%. CONCLUSIONS: In the first NA trial with an ADC in localized TNBC, SG demonstrated single-agent efficacy and feasibility of response-guided escalation/de-escalation. Further research on optimal duration of SG as well as NA combination strategies, including immunotherapy, are needed.

A phase II feasibility study of palbociclib in combination with adjuvant endocrine therapy for hormone receptor-positive invasive breast carcinoma.

BACKGROUND: The CDK4/6 inhibitor palbociclib prolongs progression-free survival in hormone receptor-positive/HER2-negative (HR+/HER2-) metastatic breast cancer when combined with endocrine therapy. This phase II trial was designed to determine the feasibility of adjuvant palbociclib and endocrine therapy for early breast cancer. PATIENTS AND METHODS: Eligible patients with HR+/HER2- stage II-III breast cancer received 2 years of palbociclib at 125 mg daily, 3 weeks on/1 week off, with endocrine therapy. The primary end point was discontinuation from palbociclib due to toxicity, non-adherence, or events related to tolerability. A discontinuation rate of 48% or higher would indicate the treatment duration of 2 years was not feasible, and was evaluated under a binomial test using a one-sided α = 0.025. RESULTS: Overall, 162 patients initiated palbociclib; over half had stage III disease (52%) and most received prior chemotherapy (80%). A total of 102 patients (63%) completed 2 years of palbociclib; 50 patients discontinued early for protocol-related reasons (31%, 95% CI 24% to 39%, P = 0.001), and 10 discontinued due to protocol-unrelated reasons. The cumulative incidence of protocol-related discontinuation was 21% (95% CI 14% to 27%) at 12 months from start of treatment. Rates of palbociclib-related toxicity were congruent with the metastatic experience, and there were no cases of febrile neutropenia. Ninety-one patients (56%) required at least one dose reduction. CONCLUSION: Adjuvant palbociclib is feasible in early breast cancer, with a high proportion of patients able to complete 2 years of therapy. The safety profile in the adjuvant setting mirrors that observed in metastatic disease, with approximately half of the patients requiring dose-modification. As extended duration adjuvant palbociclib appears feasible and tolerable for most patients, randomized phase III trials are evaluating clinical benefit in this population. CLINICALTRIALS.GOV REGISTRATION: NCT02040857.

Clozapine directly increases insulin and glucagon secretion from islets: implications for impairment of glucose tolerance.

Second generation antipsychotics cause derangements in glucose metabolism that are often interpreted as insulin resistance. In previous studies we have shown that this is not classical insulin resistance but the drugs were actually inducing a hyperglycaemic state associated with elevated hepatic glucose output (HGO) and increased levels of glucagon and insulin. However, it remains unclear whether these effects are directly elicited by drug actions in the liver and pancreas, or whether they are indirectly mediated. Here we investigated if clozapine is capable of inducing insulin resistance in the liver or enhancing insulin and glucagon secretion from the pancreas. It was observed that insulin signalling was elevated in livers from animals treated with clozapine indicating there was no insulin resistance in the early steps of insulin signalling. To explore whether the defects arise at later stages of insulin action we used an isolated perfused liver system. In this model, clozapine had no direct effect on insulin's counter regulatory effect on epinephrine-induced HGO. In isolated mouse islets clozapine significantly increased glucose-stimulated insulin secretion while simultaneously blocking glucose-induced reductions in glucagon secretion. We also show that the non-peptidic glucagon receptor like peptide-1 (GLP-1) receptor agonist Boc5 was able to overcome the inhibitory effects of clozapine on glucose metabolism. Taken together these results suggest that clozapine does not have any direct effect on glucose metabolism in the liver but it simultaneously stimulates insulin and glucagon secretion, a situation that would allow for the concurrent presence of high glucose and high insulin levels in treated animals.

D-chiro-inositol attenuates epinephrine-stimulated hepatic glucose output in the isolated perfused liver independently of insulin.

D-chiro-Inositol (DCI) is a cyclic sugar alcohol that evokes both antidiabetic and insulin sensitizing effects. Pharmacological administration of DCI has been shown to lower blood glucose in rat models of diabetes mellitus and enhance insulin sensitivity in humans with polycystic ovary syndrome (PCOS). We hypothesised that the antidiabetic effects of DCI could be due to inhibition of hepatic glucose output (HGO). To test this hypothesis, we perfused isolated rat livers either with buffer, myo-inositol, DCI, or insulin, and investigated their respective effects on the stimulation of HGO by epinephrine. We found that perfusion with 200 µM DCI attenuated epinephrine-stimulated HGO by 35% over 30 min as compared to the buffer control perfusion (p=0.05). By comparison, perfusion with 1 nM insulin attenuated epinephrine-stimulated HGO by 57% (p<0.0001). The glucose-lowering effects by DCI occurred independently of insulin and were specific to the DCI stereoisomer as 200 µM myo-inositol had no effect. These findings suggest that DCI could evoke its antidiabetic effects in vivo by inhibition of HGO. Further identification of the protein targets involved could open up new avenues to regulate hyperglycaemia with wider implications for the treatment of hepatic insulin resistance in PCOS.

Mammary epithelial cells treated concurrently with TGF-alpha and TGF-beta exhibit enhanced proliferation and death.

Transforming growth factor-alpha (TGF-alpha) stimulates while TGF-beta inhibits mammary epithelial cell growth, suggesting that when cells are treated concurrently with the growth factors their combined effects would result in no net growth. However, combined treatments stimulate proliferation and cellular transformation in several cell lines. The objective of this paper was to describe the effect of long-term (6 days) concurrent TGF-alpha and TGF-beta treatment on normal mammary epithelial cell growth pattern, morphology, and gene expression. Growth curve analysis showed that TGF-alpha enhanced while TGF-beta suppressed growth rate until Day 4, when cells entered lag phase. However, cells treated concurrently with both growth factors exhibited a dichotomous pattern of growth marked by growth and death phases (with no intermittent lag phase). These changes in growth patterns were due to a marked induction of cell death from Day 2 (16.5%) to Day 4 (89.5%), resulting in the transition from growth to death phases, even though the combined treated cultures had significantly more (P < 0.05) cells in S phase on Day 4. TGF-beta stimulated epithelial to mesenchyme transdifferentiation (EMT) in the presence of TGF-alpha, as characterized by increased expression of fibronectin and changes in TGF-beta receptor binding. Expression patterns of genes that regulate the cell cycle showed significant interaction between treatment and days, with TGF-beta overriding TGF-alpha-stimulated effects on gene expression. Overall, the combined treatments were marked by enhanced rates of cellular proliferation, death, and trans-differentiation, behaviors reminiscent of breast tumors, and thus this system may serve as a good model to study breast tumorigenesis.

Effect of high-fat meals and fatty acid saturation on postprandial levels of the hormones ghrelin and leptin in healthy men.

OBJECTIVE: Ghrelin and leptin play a role in control of food intake and adiposity but mechanisms regulating these hormones in man are poorly defined and evidence that dietary fats may have adverse effects is inconclusive. We investigated whether high-fat meals, which differed in saturated fatty acid (SFA) content acutely modified these hormones. DESIGN: Randomised, double-blind, crossover trial. A high-fat (HF) test meal (59 +/- 4 g fat; 71% of energy as fat) was given for breakfast on two occasions. Meals comprised either high (approximately 70:30) or low (approximately 55:45) saturated:unsaturated fatty acid (SFA:USFA) ratio. Fasting and postprandial measurements of serum total ghrelin (RIA), leptin (enzyme-linked immunosorbent assay (ELISA)) and insulin (RIA) were made over 6 h. Postprandial measurements were also made at 10 and 24 h following a fat-exclusion lunch, snack and dinner. SUBJECTS: A total of 18 lean, healthy men. RESULTS: There was no significant effect of the fatty meal (time, P > 0.05), nor a differential effect of SFA:USFA ratio (treatment*time, P > 0.05) on ghrelin over 6h. Leptin decreased in response to both HF treatments (time, P < 0.001) but increased SFA content did not further inhibit hormone secretion (treatment*time, P > 0.05). There was no significant correlation between ghrelin or leptin and circulating insulin (P>0.05). CONCLUSION: We conclude that HF diets may adversely effect serum leptin, although the circadian decrease may account in part for this response. Increasing dietary SFAs had no deleterious effects on leptin or total ghrelin.

Exogenous TGF-beta1 promotes stromal development in the heifer mammary gland.

The objectives of this study were to determine the local effects of transforming growth factor-beta1 (TGF-beta1) on mammary epithelial and stromal cell proliferation and expression of the TGF-beta1 responsive genes c-myc and fibronectin. A single slow-release plastic pellet containing 5 microg of TGF-beta1 and 20 mg of BSA was implanted in the parenchyma of the right rear quarter of the mammary gland of 9-mo-old prepubertal heifers. A control pellet containing 20 mg of BSA was implanted in the left rear quarter of each heifer. All heifers were treated with bromodeoxyuridine (BrdU) at 4, 12.5, and 22 h after the pellets were implanted to label proliferating cells. Two hours after the last BrdU injection, the animals were euthanatized, and their mammary glands were recovered. Proliferation of mammary stromal cells was significantly higher in TGF-beta1-treated quarters than in BSA-treated, control quarters (3.5 vs. 1.8% BrdU-positive cells). This result coincided with a lack of significant effect of TGF-beta1 on proliferation of mammary epithelial cells and apoptosis. By quantitative reverse transcriptase-polymerase chain reaction, we found that c-myc gene expression was unchanged after TGF-beta1 treatment, but fibronectin gene expression was increased 3-fold in TGF-beta1-treated quarters compared with BSA-treated, control quarters. Thus, we concluded that TGF-beta1 selectively acts on the stromal compartment of the bovine mammary gland by increasing cell proliferation and gene expression of the extracellular matrix protein fibronectin.

Effect of moderate changes in dietary fatty acid profile on postprandial lipaemia, haemostatic and related CVD risk factors in healthy men.

OBJECTIVE: To investigate the effect of moderate changes in dietary fatty acid profile on postprandial risk factors for cardiovascular disease (CVD). DESIGN: Double-blind, randomised, crossover, intervention trial. SETTING: : University of Auckland Human Nutrition Unit, New Zealand. SUBJECTS: A total of 18 lean healthy men. INTERVENTION: A dairy butter fat modified to reduce the saturated:unsaturated fatty acid ratio and a conventional high saturated butter fat were given on two separate occasions as a high-fat test meal (59+/-4 g fat; 71 en% fat) at breakfast. A fat exclusion lunch, dinner and snacks were also given. Blood samples were collected at 0 (baseline), 1, 3, 6, 10 and 24 h. RESULTS: Maximum peak in total triacylglycerol (TAG) occurred 3 h postprandially and was highest on modified treatment (diet, P<0.05) due predominantly to increased TAG within the chylomicron-rich fraction. Transient peaks in total-, LDL- and HDL-cholesterol occurred postprandially, but did not differ between dietary treatments (P>0.05). There were no differential effects of diet on postprandial free fatty acids, apo A, apo B, glucose, insulin, amylin or haemostatic clotting factors (P>0.05). CONCLUSIONS: In a group of healthy young men, replacement of 16% of total saturated fatty acids by mono- and polyunsaturated fats within a dairy lipid did not induce postprandial changes in CVD risk that may be considered beneficial for health. SPONSORSHIP: Fonterra, Wellington; New Zealand.

Lipid-lowering effects of a modified butter-fat: a controlled intervention trial in healthy men.

OBJECTIVE: To investigate the lipid-lowering potential of a butter-fat modified through manipulations in bovine feeding to increase the unsaturated:saturated fatty acid ratio. DESIGN: Double-blind, randomised, cross-over intervention trial. SETTING: University of Auckland Human Nutrition Unit, New Zealand. SUBJECTS: Twenty healthy, male subjects. INTERVENTION: A residential trial in which all foods and beverages were provided during two intervention periods, comprising 3 weeks of high unsaturated 'modified' vs. 3 weeks of saturated 'control' butter feeding separated by a 4 week washout. Diets were of typical composition of 39 percentage energy (en%) fat (20 en% butter-fat), 48 en% CHO, 13 en% protein. RESULTS: There was a significant decrease in both total (P<0.05, -7.9%) and LDL-cholesterol (P<0.01, -9.5%) during modified butter feeding. There was no significant effect of treatment on a range of other risk factors including HDL-cholesterol, triglyceride, apolipoprotein A or B, nonesterified fatty acids (NEFA), haemostatic clotting factor VII and fibrinogen or glucose (P>0.05). Subjects were maintained in energy balance and there was no significant change in body weight during intervention. Butter-fat composition alone differed between treatments. CONCLUSIONS: A significant improvement in cardiovascular risk can be achieved by moderate changes in dietary fatty acid profile, achieved through a common and well accepted food source, butter-fat.

Systemic administration of adrenomedullin(27-52) increases bone volume and strength in male mice.

Adrenomedullin is a 52-amino acid peptide first described in a human phaeochromocytoma but since been found to be present in many tissues, including the vascular system and bone. Because of its structural similarity to amylin and calcitonin gene-related peptide, both of which have actions on bone cells, we have previously assessed the effects of adrenomedullin on the skeleton, and found that it increases osteoblast proliferation in vitro and bone formation following local injection in vivo. The present study carries this work forward by assessing the effects on bone of the systemic administration of a fragment of this peptide lacking the structural requirements for vasodilator activity. Two groups of 20 adult male mice received 20 injections of human adrenomedullin(27-52) 8.1 microg or vehicle over a 4-week period and bone histomorphometry and strength were assessed. In the tibia, adrenomedullin(27-52) produced increases in the indices of osteoblast activity, osteoid perimeter and osteoblast perimeter (P<0.05 for both using Student's t-test). Osteoclast perimeter was not affected. There was a 21% increase in cortical width and a 45% increase in trabecular bone volume in animals treated with adrenomedullin(27-52) (P<0.002 for both). Assessment of bone strength by three-point bending of the humerus showed both the maximal force and the displacement to the point of failure were increased in the animals treated with adrenomedullin(27-52) (P<0.03 for both). There was also a significant increase in the thickness of the epiphyseal growth plate. No adverse effects of the treatment were noted. It is concluded that adrenomedullin(27-52) acts as an anabolic agent on bone. These findings may be relevant to the normal regulation of bone mass and to the design of agents for the treatment of osteoporosis.

Trifluoroacetate, a contaminant in purified proteins, inhibits proliferation of osteoblasts and chondrocytes.

Peptides purified by HPLC are often in the form of a trifluoroacetate (TFA) salt, because trifluoroacetic acid is used as a solvent in reversed-phase HPLC separation. However, the potential effects of this contaminant in culture systems have not been addressed previously. TFA (10(-8) to 10(-7) M) reduced cell numbers and thymidine incorporation into fetal rat osteoblast cultures after 24 h. Similar effects were found in cultures of articular chondrocytes and neonatal mouse calvariae, indicating that the effect is not specific to one cell type or to one species of origin. When the activities of the TFA and hydrochloride salts of amylin, amylin-(1-8), and calcitonin were compared in osteoblasts, cell proliferation was consistently less with the TFA salts of these peptides, resulting in failure to detect a proliferative effect or wrongly attributing an antiproliferative effect. This finding is likely to be relevant to all studies of purified peptides in concentrations above 10(-9) M in whatever cell or tissue type. Such peptides should be converted to a hydrochloride or biologically equivalent salt before assessment of their biological effects is undertaken.

Dissociation of the effects of amylin on osteoblast proliferation and bone resorption.

This study assesses the structure-activity relationships of the actions of amylin on bone. In fetal rat osteoblasts, only intact amylin and amylin-(1-8) stimulated cell proliferation (half-maximal concentrations 2.0 x 10(-11) and 2.4 x 10(-10) M, respectively). Amylin-(8-37), COOH terminally deamidated amylin, reduced amylin, and reduced amylin-(1-8) (reduction results in cleavage of the disulfide bond) were without agonist effect but acted as antagonists to the effects of both amylin and amylin-(1-8). Calcitonin gene-related peptide-(8-37) also antagonized the effects of amylin and amylin-(1-8) on osteoblasts but was substantially less potent in this regard than amylin-(8-37). In contrast, inhibition of bone resorption in neonatal mouse calvariae only occurred with the intact amylin molecule and was not antagonized by any of these peptides. The rate of catabolism of the peptides in calvarial cultures was not accelerated in comparison with that of intact amylin. This dissociation of the actions of amylin suggests that it acts through two separate receptors, one on the osteoclast (possibly the calcitonin receptor) and a second on the osteoblast.

Recognition and treatment of depressive disorders by internal medicine attendings and housestaff.

Depression is underdiagnosed and undertreated by nonpsychiatric practitioners. Research suggests improvement is needed in the recognition and treatment of depressive disorders by primary care physicians. This study was undertaken to better understand internists' ability to recognize depressive disorders, choice of appropriate medications, dosage, and treatment patterns. Questionnaires were distributed to 45 internal medicine attendings, 45 internal medicine housestaff, and 32 adult psychiatry residents. Each questionnaire contained four vignettes: major depressive disorder (MDD), MDD with melancholic features, MDD with atypical features, and MDD with psychotic features. Eleven questions per case covered diagnoses, management, and treatment. Data analysis with intragroup comparisons on 20 internal medicine attendings, 33 internal medicine housestaff, and 32 psychiatry residents suggested that many internal medicine attendings and housestaff had difficulty in recognizing major depression and its subtypes. Although the findings indicated that internists would initiate pharmacological treatment, they frequently made incorrect or questionable pharmacological choices. Psychiatric referral or consultation was often endorsed. Our findings among internists are consistent with previous research examining other primary care physicians suggesting that depression is underdiagnosed and undertreated.

Diabetic home blood glucose monitoring using a direct reading glucose sensitive test strip.

The aim of this study was to assess the performance of the BM Test Glycemie 20-800. Twelve diabetic patients were studied using the BM Test Glycemie 20-800, compared with one of the commonly available reflectance meters. The correlation coefficient for the BM 20-800 strip versus reference blood glucose result was significantly better than the reflectance meter (p = 0.01). In a separate study, laboratory staff tested both methods and achieved results which were similar to those of the patients using the BM Test Glycemie 20-800, but better than those of the patients using the reflectance meters. The BM Test Glycemie 20-800 is a cheap, reliable and acceptable method for the measurement of blood glucose levels.

Scherzer's formula and the correction of spiral distortion in the electron microscope.

Scherzer's general expression of 1937 for the spiral distortion coefficient of electron lenses is used to calculate the spiral distortion of the rectangular-field model for the axial flux density distribution in magnetic projector lenses. The results show why it is difficult to correct the spiral distortion produced by conventional lenses. On the other hand, corresponding calculations for single-polepiece projector lenses indicate that the employment of such lenses could lead to a significant improvement of the projector stage of the electron microscope, especially that of the high voltage electron microscope.