Targeted therapy in older patients with solid tumors

The introduction of targeted therapy has ushered in the era of personalized medicine in cancer therapy. The increased understanding of tumor heterogeneity has led to the determination of specific targets that can be exploited in treatment. This review highlights approved drugs in different therapeutic classes, including tyrosine kinase inhibitors, mammalian target of rapamycin inhibitors, drugs targeted to the human epidermal growth factor receptor 2, BRAF-mutation targeted drugs, anti-epidermal growth factor receptor inhibitors, and anti-vascular endothelial growth factor therapy. There have not been elderly patient-specific trials of these therapies. Most of the data are extrapolated from larger trials in which older patients generally were a fraction of the participants. Therapeutic recommendations are made on the basis of this analysis with the recognition that the older clinical trial participants may not be representative of patients seen in daily practice. Patient selection and geriatric evaluation are critical for appropriate drug selection, dosing, and monitoring. With care, these therapies are a major step forward in the safe and effective treatment of older patients with cancer.

Vismodegib in the treatment of advanced BCC

Basal-cell carcinoma (BCC) is the most commonly diagnosed malignancy, comprising over 80 per thousand of non-melanoma skin cancers. Surgical excision is adequate treatment for most BCC's. Options are however limited for the minority of patients presenting with locally advanced inoperable or metastatic BCC. The Hedgehog signalling pathway is a critical driver in the pathogenesis of both sporadic and hereditary BCC. On 31st January 2012, based on a phase II clinical trial the US Food and Drug Administration approved Vismodegib (Erivedge, Roche) a first-in-class, small-molecule oral Hedgehog-inhibitor for the treatment of locally advanced inoperable and metastatic BCC. We present our experience treating the first Irish patient with this agent.

Cross-regulation of Connexin43 and β-catenin influences differentiation of human neural progenitor cells

Connexin43 (Cx43) is the most widely and abundantly expressed gap junction (GJ) protein and it is strongly associated with the regulation of cell cycle progression. Emerging roles for Cx43 in cell adhesion and migration during neural differentiation have also been recently recognized, and this has emphasized the involvement of Cx43 in different physiological process beyond its role as a GJ protein. In this study, we explore the function of Cx43 in the differentiation of human neural progenitor cells (hNPCs) using viral vectors that mediate the overexpression or knockdown of the protein. Results showed that in the absence of this protein fetal cortex-derived hNPCs differentiated toward a neuronal phenotype at expenses of a glial phenotype. Furthermore, the silencing of Cx43 did not affect hNPC proliferation rate or numbers of apoptotic cells. The increase in the number of neurons was not recapitulated when GJ intercellular communications were pharmacologically blocked, and this suggested that Cx43 was influencing hNPCs differentiation with a GJ-independent effect. In addition, Cx43 knockdown significantly increased β-catenin signaling, which has been shown to regulate the transcription of pro-neuronal genes during embryonic neural development. Our results add further support to the hypothesis that Cx43 protein itself regulates key signaling pathways during development and neurogenesis beyond its role as GJ protein.

Abstract P2-11-04: Expression of immune checkpoint related genes are prognostic in untreated breast cancer

Background

The prognostic and predictive relevance of different components of the adaptive immune system in HER2-positive, TN and high proliferation ER+/HER2- subtypes have been shown. In this scenario, the remarkable therapeutic efficacy of new immunomodulatory drugs targeting the immune checkpoints (i.e. CTLA4) provides attractive opportunities. We aimed to investigate the prognostic value of genes related to CD28 and CTLA-4 signaling pathways in early breast cancer patients.

Methods

We assessed the affymetrix gene expression data of 789 untreated, node-negative, early breast cancer patients. Expression of CTLA4, CD28 and the two corresponding natural ligands CD80 (B7-1) and CD86 (B7-2) were evaluated. The sum of these two ligands was combined as a unique marker (CDligs). The prognostic value of the three biomarkers and their interaction were assessed independently in each molecular subtype (ER-/HER2-, HER2+ and high proliferation ER+/HER2- [ER+/HER2- HP]). Multivariate analysis was adjusted for PGR, proliferation and other immune related genes (Tcell, IGG, MHC II, MHC I, Interferon and STAT1) (Gianni L, SABCS 2012). Distant event free survival was the outcome of interest.

Results

A significant moderately positive correlation was observed between each biomarker. Expression of CTLA4 and CDligs was higher in ER-/HER2- and HER2+ compared to luminal subtypes.

High expression of CTLA4 and CD28 were associated with lower risk of relapse in HER2+ (p = 0.008 and p = 0.03, respectively) and ER+/HER2-HP (p = 0.03 and p = 0.008, respectively). High expression of CDligs was also associated with lower risk of distant event in HER2+ group only (p = 0.01). No interactions were observed between CD28 and CTLA4 in any subtype. In both TN and ER+/HER2- HP subtypes, a significant interaction between CDligs and CTLA4 (interaction term p = 0.009 and p = 0.025, respectively), CDligs and CD28 (interaction term p = 0.028 and p = 0.008, respectively) and CDligs and Tcell metagene (interaction term p = 0.006 and p = 0.019, respectively) was observed. For instance, in high-CTLA4 group (above median cut point), higher expression of CDligs was associated with significantly lower risk of distant relapse in TN [HR 0.41 (0.21-0.82); p = 0.012], HER2+ [HR 0.25 (0.08-0.72); p = 0.011) and ER+/HER2- HP [HR 0.40 (0.29-0.85); p = 0.01] subtypes. Instead, in the low-CTLA4 group, CDligs was not associated with distant relapse in any subtype [TN, HR 1.80 (0.28-3.96) p = 0.141; HER2+, HR 0.69 (0.24-1.99) p = 0.495; ER+/HER2- HP, HR 1.28 (0.70-2.35) p = 0.425].

These interactions retain statistical significance in multivariate analysis including PGR, proliferation scores and other immune metagenes.

Conclusions

Genes related to the CD28/CTLA4 immune checkpoint are associated with risk of distant relapse independently of other biomarkers and immune related metagenes. A significant interaction between expression of ligands (CD80/CD86) and the two corresponding receptors CD28 and CTLA4 was found in TN and ER+/HER2- HP subtypes. These data confirm the complex interactions involved in the adaptive immune system regulation which may not be fully appreciated without consideration of biomarker interactions. They also provide additional evidence for exploring the use of immunomodulatory drugs in breast cancer.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-11-04.

Abstract P2-10-10: Clinical implications of molecular heterogeneity in highly proliferative, ER-positive, HER2-negative breast cancer

Objectives: Different clinical behaviors are observed in tamoxifen-treated and untreated ER-positive, HER2-negative highly-proliferative breast cancer (BC) that demonstrate either high (highERS) or low (lowERS) expression of estrogen-related genes (Bianchini SABCS 2011). LowERS tumors are intrinsically endocrine resistant and at significant risk of relapse in the first 5 yrs after diagnosis. We studied lowERS and highERS BC in pts treated with neoadjuvant chemotherapy (NAC) and examined prognostic and predictive markers in the highest risk group of lowERS BC.

Methods: We examined affymetrix gene expression data from 193 ER+/HER2−, high proliferation BC from pts treated with taxane-anthracycline-based NAC followed by endrocrine therapy. Previously defined cut-offs for markers of proliferation (MKS), and estrogen-related genes were applied (Bianchini SABCS 2011). Within the lowERS group, we examined pts treated with no systemic adjuvant therapy (n = 137; 50 events); adjuvant tamoxifen-only (n = 141; 36 events); and NAC (n = 127, 27 RCB0/I). We performed gene enrichment analysis for 2617 gene sets with known biological function (by 5000 random permutations). Primary endpoints were distant event free survival (DEFS) with follow-up censored at 5-yrs and pathological response (pathR) using the residual cancer burden (RCB) (Symmans JCO 2007).

Results: The median follow-up of the NAC series was 3.1yrs. The DEFS at 4yrs was 0.94 [0.87–1.00] and 0.70 [0.60–0.81] in the high and low ERS groups, respectively (p = 0.004) (despite the higher rate of pathR (RCB0/I) to NAC in the low ERS group (9.5% and 21.9%; p = 0.04)). The pathR was prognostic in the lowERS group [HR 9.1 (CI 1.23–67.4); p = 0.009] but not in highERS (p = 0.485). In contrast, a different outcome was observed in BC with RCBII-III, were the 4-yrs DEFS was 0.93 [0.86–1.00] and 0.61 [0.49–0.76] in high and low ERS group, respectively (p = 0.0007). In the lowERS group there was substantial overlap in biological functions associated with prognosis in both tamoxifen-treated and untreated pts. At a conservative threshold of p < 0.0005, 38 gene sets were significant (31 good-prognosis involved in adaptive immune function, inflammation and chemotaxis and 7 poor prognosis gene sets involved in regulation of nuclear division and cell polarity). Only proliferation-related gene sets were predictive of RCB0/I. MKS as a continuous variable was predictive of pathR beyond clinical variables [OR 5.43 (2.04–16.1); p = 0.001].

Conclusions: Among ER+/HER2−, high proliferation BC the highERS group showed a low pathR rate with excellent prognosis even if there was residual disease. The lowERS group showed a higher rate of pathR which was significantly prognostic for good outcome. Lack of pathR in this group predicted for very poor prognosis despite subsequent adjuvant endocrine treatment. The clinical behaviour and aggressiveness of this subgroup is similar to triple negative tumors. The prognostic relevance of immune function provides a rationale for testing immunotherapeutic strategies in this subgroup.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-10-10.

Clusterin secreted by astrocytes enhances neuronal differentiation from human neural precursor cells

Neuronal differentiation from expanded human ventral mesencephalic neural precursor cells (NPCs) is very limited. Astrocytes are known to secrete neurotrophic factors, and so in order to enhance neuronal survival from NPCs, we tested the effect of regional astrocyte-conditioned medium (ACM) from the rat cortex, hippocampus and midbrain on this process. Human NPC's were expanded in FGF-2 before differentiation for 1 or 4 weeks in ACM. The results show that ACM from the hippocampus and midbrain increase the number of neurons from expanded human NPCs, an effect that was not observed with cortical ACM. In addition, both hippocampal and midbrain ACM increased the number and length of phosphorylated neurofilaments. MALDI-TOF analysis used to determine differences in media revealed that although all three regional ACMs had cystatin C, α-2 macroglobulin, extracellular matrix glycoprotein and vimentin, only hippocampal and midbrain ACM also contained clusterin, which when immunodepleted from midbrain ACM eliminated the observed effects on neuronal differentiation. Furthermore, clusterin is a highly glycosylated protein that has no effect on cell proliferation but decreases apoptotic nuclei and causes a sustained increase in phosphorylated extracellular signal-regulated kinase, implicating its role in cell survival and differentiation. These findings further reveal differential effects of regional astrocytes on NPC behavior and identify clusterin as an important mediator of NPC-derived neuronal survival and differentiation.

Coping with uncertainty: T1a,bN0M0 HER2-positive breast cancer, do we have a treatment threshold?

BACKGROUND

Recent retrospective studies have suggested that patients with T1a,bN0M0 human epidermal growth factor receptor 2 (HER2)-positive breast cancer are at a higher risk for recurrence and might benefit from adjuvant trastuzumab. The absolute benefits associated with treating this subgroup are uncertain.

DESIGN

We reviewed recent studies examining the prognostic value of HER2 in patients with node-negative T1a,b HER2-positive breast cancer. We calculated the number needed to treat (NNT) using baseline risk estimates for untreated T1a,bN0M0 breast cancer and the number needed to harm (NNH) using the incidence of cardiac events in each of the adjuvant trastuzumab clinical trials.

RESULTS

Several studies were identified, each with limitations inherent to retrospective database analyses: small cohort sizes, lack of systematic HER2 testing in older specimens, variations in the use of adjuvant therapy and definitions of study end points, and lack of information relating to comorbidities. The 5-year disease-free survival in the pre-trastuzumab era ranged from 77% to 95%. Comparisons between small HER2 -positive and small HER2 -negative cancers showed numerically worse outcome for the HER2-positive cohort in some but not all studies. In many instances, the NNH was larger (26-250) than the NNT (13-35); however, in a subset of patients, the NNH was lower (6) than the NNT (13-35).

CONCLUSIONS

Better prediction tools to estimate more precisely the risk for death due to comorbid illness versus breast cancer are needed. In some patients, the risks of therapy could outweigh the benefits. Treatment selection for T1a,bN0 HER2-positive cancers remains in the transition area between evidence- and subjective judgment-based medicine.

Influence of menopausal status and use of hormone replacement therapy on radiation dose from mammography in routine breast screening

Menopausal status and hormone replacement therapy (HRT) cause alterations in breast structure which can affect mammographic image quality. Here we present the results of a study to discover the effect of menopausal status and HRT use on breast dose. Women attending routine screening completed questionnaires which included questions regarding menopausal status and HRT use. Details of the radiographic technique factors were recorded, from which the mean glandular dose (MGD) per film for each woman was calculated. MGD values were analysed with regard to the woman's menopausal status and HRT use. The data from 516 women were analysed. Among the women who had never used HRT, women who had not undergone the menopause had a mean MGD of 2.94 mGy per film, whereas post-menopausal women had a lower mean MGD of 2.52 mGy per film: a difference which was found to be highly significant (p = 0.0045). Post-menopausal women who had never used HRT and those who had previously used HRT, but had ceased using it, had identical mean MGDs (2.54 mGy per film), whereas current HRT users had a significantly greater mean MGD (2.89 mGy per film, p = 0.003). Women currently using HRT receive a statistically significantly larger radiation dose from routine breast screening than other women. However, this effect is small and only occurs during the period of HRT use. Women who have ceased using HRT show no difference in MGD compared with women who have never taken HRT.

The use of a closed expandable prosthesis for pediatric sarcomas

PURPOSE

The purpose of this paper is to review our experience with a non-invasive expandable prosthesis for skeletally immature patients following limb-salvage for malignant tumors about the knee.

MATERIALS & METHODS

Between 1998 and 2002, Repiphysis prostheses (Wright Medical Technology, Memphis, Tenn.) were implanted in 18 patients. 16 patients had at least 12 months follow-up. There were 10 males and 8 females. The diagnosis was Stage IIB osteosarcoma in all patients. Sites included femur 14, and 4 proximal tibias. The average age was 10.7 years (range 8-16); the average age for males was 12 years and females, 9 years. Fifteen of the prostheses were implanted at the time of surgical resection and the remainder was conversions of previous surgery.

RESULTS

Follow-up averaged 24.8 months (range 12-47). Fourteen patients have undergone a total of 58 lengthening procedures. Average expansion 38 mm per patient (range, 10-76 mm). An average of 8.5 mm per lengthening procedure. There was only one failure to lengthen. ISOLS functional scores averaged 83.5%. For those with a current functional prosthesis, the ISOLS score averaged 94%. Three patients have reached maximal expansion and converted to a conventional prosthesis. There were complications in 7 patients: 2 expandable component fractures, 1 femoral component fracture, 2 stem fractures, 1 stem loosening and 1 deep infection. Of the two expandable component fractures, 1 patient reached full expansion and was converted to an endoprosthesis. The femoral component fracture and 2 stem fractures were revised to a new prosthesis 13 months post-op and are functioning well. The 1 loose stem was revised to an APC.

CONCLUSIONS

The Repiphysis prosthesis utilizes energy stored in a spring that is held compressed by a locking mechanism. Controlled release of the locking mechanism via an external electromagnetic field allows for lengthening of the device. In our early experience, the functional results were excellent similar to conventional modular devices. Complications should be anticipated but are salvageable. This device allows limb salvage in pediatric patients when amputation would be otherwise chosen.

Effects of polyvinyl alcohol administered in the diet to rats on fertility, early embryonic development, growth and development

PVA was administered in the diet to male and female Sprague-Dawley rats (26/sex/group) at doses of 0, 2000, 3500 and 5000 mg/kg/day for two generations. The study design assessed gonadal function, estrous cycle, mating behavior, conception, gestation, parturition, lactation, weaning, and growth and development of F(1) and F(2) offspring. Parental rats were treated for 70 days prior to mating, throughout mating, gestation and lactation until sacrifice. Clinical observations, body weights and feed consumption were recorded routinely. Dietary concentrations were adjusted for each sex on a weekly basis except during gestation and lactation, to provide the intended mg/kg/day PVA levels. Pups were weighed routinely and weaned at 21 days of age prior to selection for the next generation. Unformed stool was noted predominately at the 3500 and 5000 mg/kg/day levels in P(0) and F(1) parental animals. This finding was attributed to the high levels of PVA being fed and subsequently excreted in the stool. Slight decreases in the mean body weights of P(0) males were noted at 2000 and 5000 mg/kg/day. Feed consumption was elevated at the 3500 and 5000 mg/kg/day doses in both generations but not during either lactation period. These increases generally were observed in a dose-related manner (g/kg/day), as a result of the large amount of PVA being consumed to maintain the caloric intake necessary for normal growth. There were no effects of PVA on P(0), F(1) male or female reproductive performance or pup survival, growth, organ weights, and macroscopic or microscopic observations at doses of 2000, 3500 and 5000 mg/kg/day. Therefore the no-observed-effect level (NOAEL) is 5000 mg/kg/day for both parental and offspring in this reproductive study.

Subchronic toxicity study in rats and genotoxicity tests with polyvinyl alcohol

The potential systemic and neurotoxicity of polyvinyl alcohol (PVA) was assessed when fed in the diet to male and female Sprague-Dawley rats for 90 days at doses of 2000, 3500 and 5000 mg/kg/day. Control rats received untreated standard laboratory diet. Assessments included clinical observations, ophthalmology, body weight and food consumption, hematology, coagulation, clinical chemistry, urinalyses, motor activity and functional observational battery evaluations and gross and microscopic pathology. The only test-article-related finding observed during the study was unformed stool with brown/black anogenital staining in rats fed 3500 and 5000 mg/kg/day. This finding was attributed to the high levels of test article being consumed and subsequently excreted in the stool. It was not accompanied by macroscopic or microscopic changes in these rats. No test-article-related changes were seen in mortality, ophthalmology, body weight and food consumption data, hematology, clinical chemistry, urinalysis data, functional observational assessments, motor activity, organ weight data and macroscopic and microscopic examinations. Doses of 2000, 3500 and 5000 mg/kg/day of PVA administered as a dietary admixture to male and female Sprague-Dawley rats for up to 90 days did not result in any adverse, toxicological effects. The no-observed-adverse-effect level (NOAEL) was determined to be 5000 mg/kg/day. PVA showed no evidence of mutagenic activity in the Ames test, mouse lymphoma assay and the mouse micronucleus test. (A critical evaluation of the available information on PVA will appear in a review to be published in Food and Chemical Toxicology 2003, 41, 319-326)

Molecular analysis of paternity

The unit covers Variable Numbers of Tandem Repeats (VNTR) based paternity analysis as well as the newer methods relying on PCR to analyze sequence-specific polymorphisms and microsatellite regions. The discussion of data analysis and probability calculations has been expanded to address a number of special circumstances, such as the lack of sample from an alleged father, motherless cases, and more.

Dietary monounsaturated fatty acids and haemostasis

Diets high in monounsaturated fatty acids (MUFA) are increasingly being recommended as a highly-effective cholesterol-lowering strategy in populations at risk of CHD. However, the need for a re-appraisal of the benefits of diets rich in MUFA became apparent as a result of recent studies showing that meals high in olive oil cause greater postprandial activation of blood coagulation factor VII than meals rich in saturated fatty acids. The present review evaluates the evidence for the effects of MUFA-rich diets on fasting and postprandial measurements of haemostasis, and describes data from a recently-completed long-term controlled dietary intervention study. The data show that a background diet high in MUFA has no adverse effect on fasting haemostatic variables and decreases the postprandial activation of factor VII in response to a standard fat-containing meal. Since the same study also showed a significant reduction in the ex vivo activation of platelets in subjects on the high-MUFA diet, the overall findings suggest that there is no reason for concern regarding adverse haemostatic consequences of high-MUFA diets.

Degradation and glycemic effects of His(7)-glucitol glucagon-like peptide-1(7-36)amide in obese diabetic ob/ob mice

Glucagon-like peptide-1(7-36)amide (tGLP-1) has attracted considerable potential as a possible therapeutic agent for type 2 diabetes. However, tGLP-1 is rapidly inactivated in vivo by the exopeptidase dipeptidyl peptidase IV (DPP IV), thereby terminating its insulin releasing activity. The present study has examined the ability of a novel analogue, His(7)-glucitol tGLP-1 to resist plasma degradation and enhance the insulin-releasing and antihyperglycemic activity of the peptide in 20-25-week-old obese diabetic ob/ob mice. Degradation of native tGLP-1 by incubation at 37 degrees C with obese mouse plasma was clearly evident after 3 h (35% intact). After 6 h, more than 87% of tGLP-1 was converted to GLP-1(9-36)amide and two further N-terminal fragments, GLP-1(7-28) and GLP-1(9-28). In contrast, His(7)-glucitol tGLP-1 was completely resistant to N-terminal degradation. The formation of GLP-1(9-36)amide from native tGLP-1 was almost totally abolished by addition of diprotin A, a specific inhibitor of DPP IV. Effects of tGLP-1 and His(7)-glucitol tGLP-1 were examined in overnight fasted obese mice following i.p. injection of either peptide (30 nmol/kg) together with glucose (18 mmol/kg) or in association with feeding. Plasma glucose was significantly lower and insulin response greater following administration of His(7)-glucitol tGLP-1 as compared to glucose alone. Native tGLP-1 lacked antidiabetic effects under the conditions employed, and neither peptide influenced the glucose-lowering action of exogenous insulin (50 units/kg). Twice daily s.c. injection of ob/ob mice with His(7)-glucitol tGLP-1 (10 nmol/kg) for 7 days reduced fasting hyperglycemia and greatly augmented the plasma insulin response to the peptides given in association with feeding. These data demonstrate that His(7)-glucitol tGLP-1 displays resistance to plasma DPP IV degradation and exhibits antihyperglycemic activity and substantially enhanced insulin-releasing action in a commonly used animal model of type 2 diabetes.

The use of a surgical grade calcium sulfate as a bone graft substitute: results of a multicenter trial

In a prospective, nonrandomized, multicenter study, 109 patients with bone defects were treated with a surgical grade calcium sulfate preparation as a bone graft substitute. The calcium sulfate pellets were used in place of morselized cancellous bone graft for the treatment of patients with bone defects who usually would require grafting secondary to trauma, periprosthetic bone loss, tumor, or fusion. The calcium sulfate was used alone or mixed with other materials such as bone marrow aspirate, demineralized bone matrix, or autograft. The defects that were treated were contained and were not necessary for the stability of the bony structure. Radiographic and clinical data were collected at predetermined intervals for 12 months. At 6 months postoperatively, radiographic results for all patients showed that 99% of the calcium sulfate had been resorbed and 88% of the defect was filled with trabeculated bone. There were 13 complications; however, only four (3.6%) were attributable to the product. The results of a subgroup of 46 patients with benign bone lesions treated in the same manner are identical to the results of the overall study population. Surgical grade calcium sulfate pellets are considered a convenient, safe, and readily available bone graft substitute that yield consistent successful results.

Factitious hearing loss and otorrhea in an adolescent boy

Asialo, or beta(2), transferrin occurs in cerebrospinal fluid and a few other body fluids, e.g., perilymph and aqueous humor. It is used clinically as a marker protein to detect CSF otorrhea and rhinorrhea. Asialo-transferrin is separated from sialylated serum transferrin glycoforms by electrophoresis and detected by Western blotting. Potential pitfalls in interpreting Western blots occur when other transferrin isoforms approximate the migratory behavior of asialo-transferrin. In the present report an adolescent boy was seen by an otolaryngologist for otorrhea and acute hearing loss. The otorrhea fluid, subsequently identified as saliva, contained a transferrin isoform with electrophoretic mobility similar to that of asialo-transferrin.

Improved glycaemic control in obese diabetic ob/ob mice using N-terminally modified gastric inhibitory polypeptide

Gastric inhibitory polypeptide (GIP) is an important insulin-releasing hormone of the enteroinsular axis which is rapidly inactivated by the exopeptidase dipeptidyl peptidase (DPP) IV. The present study has examined the ability of Tyr(1)-glucitol GIP to be protected from plasma degradation and to enhance insulin-releasing and antihyperglycaemic activity in 20- to 25-week-old obese diabetic ob/ob mice. Degradation of GIP by incubation at 37 degrees C with obese mouse plasma was clearly evident after 3 h (35% degraded). After 6 h, more than 61% of GIP was converted to GIP(3-42) whereas N-terminally modified Tyr(1)-glucitol GIP was resistant to degradation in plasma (>99% intact after 6 h). The formation of GIP(3-42) was almost completely abolished by inhibition of plasma DPP IV with diprotin A. Effects of GIP and Tyr(1)-glucitol GIP were examined in overnight-fasted obese mice following i.p. injection of either peptide (20 nmol/kg) together with glucose (18 mmol/kg) or in association with feeding. Most prominent effects were observed in the former group where plasma glucose values at 60 min together with the area under the curve (AUC) for glucose were significantly lower following GIP (AUC, 874+/-72 mmol/l.min; P<0.01) or Tyr(1)-glucitol GIP (770+/-134 mmol/l.min; P<0.001) as compared with administration of glucose alone (1344+/-136 mmol/l.min). This was associated with a significantly greater and more protracted insulin response following Tyr(1)-glucitol GIP than GIP (AUC, 491+/-118 vs 180+/-33 ng/ml.min; P<0.05). Administration of Tyr(1)-glucitol GIP also enhanced the glucose-lowering ability of 50 units/kg insulin (218.4+/-30.2 vs insulin alone 133.9+/-16.2 mmol/l.min; P<0.05). These data demonstrate that Tyr(1)-glucitol GIP displays resistance to plasma DPP IV degradation in a commonly used animal model of type 2 diabetes, resulting in enhanced antihyperglycaemic activity and insulin-releasing action in vivo.

Bioassayed demineralized bone matrix and calcium sulfate: use in bone-grafting procedures

BACKGROUND AND AIMS

A combination product of bioassayed, demineralized bone matrix (AlloGro, AlloSource, Denver CO) and calcium sulfate pellets (OsteoSet, Wright Medical Technology, Arlington TN) was utilized in a prospective clinical study in 50 patients in need of bone-grafting procedures. It was proposed that the osteoinductive activity of the demineralized bone matrix combined with the osteoconduction and rapid dissolution of the calcium sulfate pellets would complement each other in promoting bone formation.

MATERIALS AND METHODS

The patients were evaluated clinically and radiographically at regular intervals post-operatively by an independent clinician. A total 10-point healing score was used to determine healing characteristics and progress. Fifty patients (24 males and 26 females) were treated for benign bone lesions (35), nonunion (11), osteomyelitis (3), and acute fracture (1). The average age was 33 years (range, 3-64 years). Lesions were located in the femur (16), tibia (15), humerus (7), and other sites (12).

RESULTS

The average length of follow-up was 14 months (range, 6-32 months). Forty-nine of 50 patients healed their lesions (98%), requiring an average time to heal of 11.8 weeks (range, 3-48 weeks). There were no graft-related complications.

CONCLUSIONS

The results of this preliminary clinical study suggest that a combination of bioassayed demineralized bone matrix and calcium sulfate is very effective in treating benign lesions of bone, as well as nonhealing fractures, which is comparable to grafting with autograft. Future studies have been undertaken utilizing this combination in all acute operative settings and fracture management situations.

Current income profile for academic pediatric emergency medicine faculty

STUDY OBJECTIVES

To survey academic pediatric emergency medicine (PEM) programs for information on financial compensation and patient care activities of PEM faculty and compare the results to the financial data published by the AAEM, AAAP, and MGMA.

METHODS

A survey was mailed to program directors requesting information on medical school affiliation, ED census, recruitment, patient care activity and annual income for each academic rank. The survey also included questions on CME benefits, and income adjustment mechanisms/bonus plans for PEM faculty. The survey income data were stratified by program size and geographic region and then compared to income data from the AAMC, AAAP, and MGMA.

RESULTS

Of 47 eligible programs, 37 (78.7%) responded,and four were excluded. Mean number of clinical hours per week for academic faculty and clinical faculty were 27.9 +/- 3.5 and 32.4 +/- 3.9, respectively, (P = 0.000). Clinical appointments in academic departments were offered by 82% of the programs. Mean annual income for all academic ranks was $121,503 +/- $15,795, and is nearly $37,000 less than the annual income for academic adult emergency medicine (AEM) faculty. Compared to medium and large programs, small programs are offering higher salaries to recent fellowship graduates (P = 0.004). When income data were stratified by program size or geographic region, no significant difference in average annual income was observed. Bonus or incentive plans were available only in 45.5% of the programs.

CONCLUSION

Direct patient care responsibility of PEM academic faculty has not changed significantly in the past 13 years, despite the availability of clinical appointments within most of the surveyed programs. Our data indicate that the annual income for PEM faculty in academic institutions is significantly less than AEM faculty. No significant difference was observed between programs at the assistant, associate, or full professor level when stratified by size or geographic region. Bonus/incentive plans for exceptional patient care or scholarly activity were available in less than half of the surveyed programs.

Endoprosthetic reconstruction for malignant upper extremity tumors

Between December 1980 and December 1992, 59 patients underwent 60 reconstructions with endoprostheses after resection of malignant tumors in the upper extremity. There were 32 male patients and 27 female patients, with a mean age of 33 years (range, 3-83 years). The type of reconstruction was based on the location of the primary tumor site. The histologic diagnoses included osteosarcoma, chondrosarcoma, Ewing's sarcoma, malignant fibrous histiocytoma, soft tissue sarcoma, and fibrosarcoma of bone. Most of the patients had Stage IIB disease (N = 38), as established by the Musculoskeletal Tumor Society classification. An additional six patients had metastatic tumors to the upper extremity. Twenty-seven of 59 patients died of disease progression. Two patients died of other causes (chronic leukemia, human immunodeficiency virus infection). The 30 survivors had a mean followup of 90 months (range, 60-170 months). The Musculoskeletal Tumor Society functional analysis for the patients with a minimum 2-year followup (N = 41) averaged 74%. Sixteen of the 59 (27%) patients had local complications. Problems related to mechanical failure and infection were managed successfully with second operation. Amputation was rare, occurring in three of 60 (5%) patients and was related only to local recurrence. Endoprosthetic reconstructions of the upper extremity after tumor resections have proven to be successful.

Evaluation of single-cell sources of docosahexaenoic acid and arachidonic acid: 3-month rat oral safety study with an in utero phase

Owing to the presence of the polyunsaturated fatty acids (PUFA) docosahexaenoic acid (DHA) and arachidonic acid (ARA) in human milk and their important biological function, several authorities recommend that they be added to infant formulas. This study assessed the safety of an algal oil rich in DHA and a fungal oil rich in ARA, blended to provide a DHA to ARA ratio similar to human milk. The oil blend was incorporated into diets and fed to rats such that they received 3, 11 and 22 times the anticipated infant exposure to DHA and ARA. Low-fat and high-fat control groups received canola oil. Rats received experimental diets over a premating interval and throughout mating, gestation and lactation. Pups born during this period (F1) consumed treatment diets from weaning for 3 months. Physical observations, ophthalmoscopic examinations, body weight, food intake, clinical chemistry, neurobehavioural evaluations and postmortem histopathology of selected tissues were performed. No statistically significant, dose-dependent adverse effects were seen in reproductive performance or fertility, nor in the neonates from birth to weaning. Mid- and high-dose treated F1 animals exhibited increased white cell count, neutrophil count and blood urea nitrogen; increased liver and spleen weights (absolute and relative to body weight) also were observed. There were no corresponding microscopic findings. The clinical pathology and organ weight differences at these treatment levels represent physiological or metabolic responses to the test substance rather than adverse responses. These single-cell oils produced no adverse effects in rats when administered in utero and for 90 days at dietary levels resulting in exposures up to 22 or 66 times higher than those expected in infant formulas when extrapolated on the basis of diet composition (g/100 Cal) or intake (g/kg body weight), respectively.

Glycated cholecystokinin-8 has an enhanced satiating activity and is protected against enzymatic degradation

Monoglycated cholecystokinin octapeptide (CCK-8) (glucitol-Asp1 adduct) modified at the NH2-terminus was prepared under hyperglycemic conditions, purified by high-performance liquid chromatography, and characterized by mass spectrometry (Mr 1228.4 Da) and peptide sequencing. CCK-8 (100 nmol/kg, i.p.) significantly (P < 0.001) reduced voluntary food intake of fasted mice for up to 30 min after its administration, compared with saline-administered controls. Glycated CCK-8 reduced food intake at 30-120 min (P < 0.01 to P < 0.001) and significantly reduced feeding compared with CCK-8 from 60 to 120 min (P < 0.01). In vitro plasma degradation studies indicated that glycated CCK-8 was resistant to the normal rapid enzymatic conversion to CCK fragments. This study demonstrated that CCK-8 is a potent short-term inhibitor of food intake, and that structural modification of this peptide by amino-terminal glycation leads to enhanced satiating activity, partially due to increased resistance to serum aminopeptidase degradation.

Vasopressin use in cardiopulmonary resuscitation

While these preliminary results in humans seem promising, no large trials have been conducted to compare vasopressin and epinephrine in CPR. At this time, standard guidelines using epinephrine are still preferred.