Hepatic leptin signalling and subdiaphragmatic vagal efferents are not required for leptin-induced increases of plasma IGF binding protein-2 (IGFBP-2) in ob/ob mice

AIMS/HYPOTHESIS

The fat-derived hormone leptin plays a crucial role in the maintenance of normal body weight and energy expenditure as well as in glucose homeostasis. Recently, it was reported that the liver-derived protein, insulin-like growth factor binding protein-2 (IGFBP-2), is responsible for at least some of the glucose-normalising effects of leptin. However, the exact mechanism by which leptin upregulates IGFBP-2 production is unknown. Since it is believed that circulating IGFBP-2 is predominantly derived from the liver and leptin has been shown to have both direct and indirect actions on the liver, we hypothesised that leptin signalling in hepatocytes or via brain-liver vagal efferents may mediate leptin control of IGFBP-2 production.

METHODS

To address our hypothesis, we assessed leptin action on glucose homeostasis and plasma IGFBP-2 levels in both leptin-deficient ob/ob mice with a liver-specific loss of leptin signalling and ob/ob mice with a subdiaphragmatic vagotomy. We also examined whether restoring hepatic leptin signalling in leptin receptor-deficient db/db mice could increase plasma IGFBP-2 levels.

RESULTS

Continuous leptin administration increased plasma IGFBP-2 levels in a dose-dependent manner, in association with reduced plasma glucose and insulin levels. Interestingly, leptin was still able to increase plasma IGFBP-2 levels and improve glucose homeostasis in both ob/ob mouse models to the same extent as their littermate controls. Further, restoration of hepatic leptin signalling in db/db mice did not increase either hepatic or plasma IGFBP-2 levels.

CONCLUSIONS/INTERPRETATION

Taken together, these data indicate that hepatic leptin signalling and subdiaphragmatic vagal inputs are not required for leptin upregulation of plasma IGFBP-2 nor blood glucose lowering in ob/ob mice.

Hearing loss in children with mitochondrial disorders

OBJECTIVE

At least 1-5 children per 1000 suffer from congenital hearing loss, and 50% of these cases can be attributed to genetic causes. It has been estimated that 1% of pre-lingual hearing loss is due to mutations in mitochondrial DNA. Previous literature reports audiometric data for few patients, usually less than 20 per study. The goal of this study was to characterize the hearing loss associated with mitochondrial mutations and determine whether previously characterized patterns of hearing loss in these patients (progressive, sensorineural, high frequency losses) are found in our population as well.

METHODS

An IRB-approved retrospective chart review of the electronic medical records in the Nemours/Alfred I. dupont Hospital for Children system from January 2004 to October 2009 (a five-year period) was undertaken using ICD-9 codes 277.87 (mitochondrial disorder) and 359.89BA (mitochondrial myopathy). These 149 records were then evaluated for audiologic data, resulting in 26 charts with both a mitochondrial disorder and hearing evaluation.

RESULTS

Of 26 patients with known mitochondrial disorders and audiometric documentation, 15 (58%) had hearing loss, and 11 patients had normal hearing (42%). Ten patients had sensorineural hearing loss (38%), two patients had conductive hearing loss (7.7%), one patient had a mixed hearing loss (3.8%), and two patients had an as yet undefined hearing loss (ABR had not yet been performed at the time of this study) (7.7%).

CONCLUSION

In comparison with previous studies, generally including less than 20 patients, this is one of the largest collections of audiometric data on children with mitochondrial disorders. Unlike prior studies describing a progressive, sensorineural loss across all frequencies or mainly affecting high frequencies, the hearing loss in our patients was more variable including low frequency losses, mid-frequency losses, and conductive losses and was often not progressive or even improved. Our overall 38% rate of sensorineural hearing loss correlates well with previous case series; this study clearly justifies the use of routine audiometric screening in children with mitochondrial disorders, including use of ABR and OAEs as ASND can be seen in this population, as well as repeat testing over time to evaluate for progression.

Phase II trial of capecitabine and docetaxel as second line therapy for locally advanced and metastatic pancreatic cancer

15029

Background: Docetaxel and Capecitabine in combination are synergistic in preclinical models. The role of second line chemotherapy in pancreatic cancer is palliative and the role under investigation. Methods: Capecitabine 800 mg/m2 PO bid on days 1–14 in combination with docetaxel 30 mg/m2 IV on days 1 and 8 of each 21-day cycle were given to patients with advanced and metastatic pancreatic cancer previously treated with Gemcitabine. A 3-stage sequential design phase II trial was used with early stopping rules for efficacy at 13 and 26 enrolled patients Results: Twenty-four patients are evaluable for toxicity and evaluable for response. Thirteen are females and 11 male patients. Median age was 65 years. ECOG PS was as follows: PS 0: 2 patients; PS 1: 15 patients; PS 2: 5 patients. Three patients achieved a PR, with a RR of 12.5%. Stable disease for 2 or more cycles was observed in 70.8% of patients (n=17). 45 % (n=11) of patients had a 50% or more decrease in CA 19–9 levels. Treatment was well tolerated with no toxic deaths. Grade III and IV toxicities consisted of fatigue in 4 pts (17%); hand-foot syndrome in 4 patients (17%); diarrhea, anemia and mucositis in 2 patients (9%) and peripheral neuropathy in one patient (4%) Conclusions: The combination of capecitabine and docetaxel is active and well tolerated in pancreatic cancer previously treated with gemcitabine based-therapy. Enrollment continues.

[Table: see text]

A phase II trial of capecitabine and docetaxel in patients with previously treated pancreatic cancer

14111

Background: There is no accepted standard treatment for patients with advanced pancreatic cancer who progress after gemcitabine-based therapy. Capecitabine and docetaxel have single-agent activity in pancreatic cancer and have documented synergy in both pre-clinical models and in the treatment of other solid tumors. Methods: A phase II trial with a 3-stage sequential design was planned to assess the efficacy (primary end-point: response rate) and toxicity of capecitabine 800 mg/m2 PO bid on days 1–14 in combination with docetaxel 30 mg/m2 IV on days 1 and 8 of each 21-day cycle in patients with advanced pancreatic cancer who failed first-line gemcitabine-based chemotherapy. If no responses are observed after 13 patients or less than 3 responses are seen after 26 patients, accrual will stop and the combination deemed ineffective. Results: Eight patients have been enrolled (5 women, 3 men). Median age was 67 years. ECOG PS was as follows: PS 1, three patients; PS 2, five patients. All patients had adequate organ function. A total of 26 cycles have been administered (median: 2 cycles, range 1 to 8). Four patients had stable disease (median duration 9 weeks, range 6 to 24), and 3 had progressed at the time of first evaluation (2 cycles). One patient has not yet completed 2 cycles and is therefore not assessable for radiologic response. Out of 7 patients with an elevated CA 19–9, four had a decrease of 50% or greater while on chemotherapy. Grade 1 or 2 toxicity was seen in 3 patients (diarrhea, 1 patient; fatigue, 2 patients). Grade 3 or 4 toxicity was as follows: fatigue, 2 patients; dehydration, 1 patient; neuropathy, 1 patient. There were no treatment related deaths. Enrollment continues. Efficacy data fulfilling the first stage sequential design should be available at the time of the meeting. Median survival for all patients is currently 13 weeks (range 7–23 weeks) Conclusions: Capecitabine in combination with docetaxel is a well-tolerated regimen in the treatment of patients with pancreatic cancer who have failed prior gemcitabine-based therapy. Four out of 8 patients have had stable disease. Four of 7 patients have had a decrease of 50% or greater in CA 19.9 levels. Enrollment continues. Median survival of 13 weeks underscores the poor prognosis of this patient population.

[Table: see text]

Phase I study of docetaxel plus ifosfamide in patients with advanced cancer

The aim of this study was to determine the maximum tolerated dose of a fixed dose of docetaxel when combined with continuous infusion ifosfamide, with and without G-CSF support, in the treatment of advanced cancer, and to evaluate anti-tumour activity of this combination. Thirty-one patients with advanced malignancies were treated with docetaxel 75 mg/m(2) intravenously on days 1, and ifosfamide at increasing dose levels from 1500 mg/m(2)/day to 2750 mg/m(2)/day as a continuous infusion from day 1-3, every 3 weeks. A total of 107 cycles of treatment were administered. Without G-CSF support dose-limiting toxicity of grade 4 neutropenia greater than 5 days duration occurred at dose level 1. With the addition of G-CSF the maximum tolerated dose was docetaxel 75 mg/m(2) on day 1 and ifosfamide 2750 mg/m(2)/day on days 1-3. Dose limiting toxicity (DLT) included ifosfamide-induced encephalopathy, febrile neutropenia and grade three mucositis. Three complete responses and 3 partial responses were seen. This combination of docetaxel and infusional ifosfamide is feasible and effective. The recommended dose for future phase II studies is docetaxel 75 mg/m(2) on day 1 and ifosfamide 2500 mg/m(2)/day continuous infusion on days 1-3.

New approaches to HIV surveillance: means and ends. Summary report of conference held at Yale University, 21-22 May 1998, by the Law, Policy and Ethics Core, Center for Interdisciplinary Research on AIDS, Yale University

A system of HIV surveillance based on AIDS case reporting is no longer adequate to monitor the epidemic of HIV/AIDS in the U.S. We are now faced with the challenge of designing an effective system of HIV surveillance. The "New Approaches to HIV Surveillance: Means and Ends" conference emphasized that there are several alternatives, each with strengths and limitations. The CDC has recommended that all states adopt a system of HIV surveillance based on case reporting. Although it has not specified that such systems need be name-based, CDC appears to reward states that adopt name-reporting systems. The rationale for this stance should be reviewed and made explicit. Name reporting may be superior in some respects to a system of case reports based on unique identifiers (UIs), especially in its greater ability to link surveillance activities to follow up at the individual level. Neither a name-reporting nor a UI approach to case reporting would provide HIV incidence data. The only currently envisioned means of providing incidence data is statistical estimation based on "snapshot estimates" of HIV incidence in sample cohorts. Calibration of this new instrument for HIV incidence estimation against existing data or through field trials is of critical importance.

What do we need from surveillance? And how do we get it?

The Yale-hosted conference, "New Approaches to HIV Surveillance: Means and Ends," is now over two years old; it is time for the public health and AIDS community to move beyond the debate on name reporting and focus on rethinking what we need from surveillance and how we might best get it. Rethinking the role and methods of surveillance is critical for HIV; but it will also show the way for public health in general.

Benign and solid tumors of the liver: relationship to sex, age, size of tumors, and outcome

From 1983 through 1997, our center diagnosed 130 cases of benign neoplasms: 27 with focal nodular hyperplasia (FNH), 25 with hepatic adenoma, 71 with cavernous hemangioma, and seven with mixed tumors of different diagnoses. Most often these lesions were seen in females [female-to-male ratio (f/m): 5.5/1]. Hepatic adenomas and mixed tumors were seen exclusively in females and FNH predominantly in females (f/m: 26/1). Hemangiomas, however, were not uncommon in men (f/m: 52/19) relative to the other tumors (P < 0.001). Furthermore patients with hemangioma were older (mean age: 49 years) whereas patients with hepatic adenoma, FNH, and mixed tumors were often younger (mean age: 33, 35, and 44 years respectively; P < 0.004). Oral contraceptive steroid use was related by 21 of 25 patients (84%) with hepatic adenoma, 22 of 26 (85%) females with FNH, five of seven (71%) females with mixed tumors, and 10 of 52 (19%) patients with hemangioma. Ninety-five of the 130 patients (73%) had one or more symptoms. There was no statistically significant correlation between symptoms and the size of the lesion, the final diagnosis, and whether there were solitary or multiple masses. Three of 25 (12%) with hepatic adenoma presented with rupture, and one of 27 (4%) with FNH had such a consequence. None of the hemangiomas presented with rupture or progressed to such a state. One patient with hepatic adenoma (4%) had a focus of malignancy. Surgical removal of benign tumors was performed in 82 of 130 patients (63%), and there was one operative mortality (1.2%) in a patient who had a caudate lobe FNH. The types of surgical procedures included segmentectomy (62%), lobectomy (34%), and trisegmentectomy (4%). In two of 84 patients who had undergone laparotomy resection was not technically possible. Resection is recommended in all cases of hepatic adenoma because of fear of rupture or associated focus of malignancy. FNH was not observed to undergo a malignant transformation and will rarely rupture. Surgery is only recommended for symptomatic hemangioma, and size of the lesion is not a criterion for excision.

HIV: challenging the health care delivery system

HIV offers a lens through which the underlying problems of the US health care system can be examined. New treatments offer the potential of prolonged quality of life for people living with HIV if they have adequate access to health care. However, increasing numbers of new cases of HIV occur among individuals with poor access to health care. Restrictions on eligibility for Medicaid (and state-by-state variability) contribute to uneven access to the most important safety net source of HIV care financing, while relatively modest discretionary programs attempt to fill in the gap with an ever-increasing caseload. Many poor people with HIV are going without care, even though aggregate public spending on HIV-related care will total $7.7 billion in fiscal year 2000, an amount sufficient to cover the care costs of one half of those living with HIV. But inefficiencies and inequities in the system (both structural and geographic) require assessment of the steps that can be taken to create a more rational model of care financing for people living with HIV that could become a model for all chronic diseases.

Identification of ATM mutations using extended RT-PCR and restriction endonuclease fingerprinting, and elucidation of the repertoire of A-T mutations in Israel

Ataxia-telangiectasia (A-T) is an autosomal recessive disorder characterized by neurodegeneration, immunodeficiency, cancer predisposition, and radiation sensitivity. The responsible gene, ATM, has an extensive genomic structure and encodes a large transcript with a 9.2 kb open reading frame (ORF). A-T mutations are extremely variable and most of them are private. We streamlined a high throughput protocol for the search for ATM mutations. The entire ATM ORF is amplified in a single RT-PCR step requiring a minimal amount of RNA. The product can serve for numerous nested PCRs in which overlapping portions of the ORF are further amplified and subjected to restriction endonuclease fingerprinting (REF) analysis. Splicing errors are readily detectable during the initial amplification of each portion. Using this protocol, we identified 5 novel A-T mutations and completed the elucidation of the molecular basis of A-T in the Israeli population.

Extent of resection in the management of duodenal adenocarcinoma

BACKGROUND

It has been postulated that segmental duodenal resection (SR) is not an adequate operation for patients with adenocarcinoma of the duodenum and that pancreaticoduodenectomy (PD) is the procedure of choice, regardless of the tumor site. However, data from previous studies do not clearly support this position.

METHODS

We reviewed the records of 63 patients treated for duodenal adenocarcinoma from 1979 through 1998. Perioperative outcome, patient survival, and extent of lymphadenectomy were compared in patients who underwent PD and SR.

RESULTS

The overall morbidity for PD and SR was 27% and 18%, respectively (not significant [NS]). Patients who underwent SR had a 5-year survival of 60% versus 30% for patients who underwent PD (NS). Lymph node status was a prognostic factor for survival (P = 0.014). The mean number of lymph nodes in the specimens was 9.9 +/- 2.1 for PD and 8.3 +/- 4.4 for SR (NS).

CONCLUSIONS

Segmental duodenal resection for patients with duodenal adenocarcinoma is associated with acceptable postoperative morbidity and long-term survival. The procedure is especially well suited for distal duodenal tumors. Clearance of lymph nodes and outcome are comparable to PD.

Phase I and subsequent phase II study of filgrastim (r-met-HuG-CSF) and dose intensified cyclophosphamide plus epirubicin in patients with non-Hodgkin's lymphoma and advanced solid tumors

BACKGROUND

To define a maximum tolerated dose (MTD) for the combination of epirubicin and cyclophosphamide with filgrastim (r-met-HuG-CSF) in patients with advanced solid tumors and non-Hodgkin's lymphoma (NHL).

PATIENTS AND METHODS

Thirty-five patients with advanced solid tumors were enrolled in stages I and II. Twenty-one patients were treated in stage I in sequential cohorts of at least three patients at increasing dosage levels of cyclophosphamide and epirubicin, for up to six cycles every 21 days. At the completion of stage I, a MTD for epirubicin was established. Fourteen patients were treated in stage II, in cohorts of three or more. The epirubicin dose remained constant at the MTD dosage from stage I. Cyclophosphamide was further dose-escalated to establish its MTD. Twenty-one patients with previously untreated non-Hodgkin's lymphoma were treated in stage III with the MTD established in the prior stages.

RESULTS

The MTD in stage I was epirubicin 150 mg/m2 and cyclophosphamide 1500 mg/m2 with cumulative neutropenia as the dose-limiting toxicity (DLT). Cumulative thrombocytopenia prevented further dose-escalation of cyclophosphamide in stage II. The stage III regimen consisted of six, 21-day cycles of epirubicin 150 mg/m2, cyclophosphamide 1500 mg/m2, vincristine 2 mg, and prednisolone 100 mg for five days with filgrastim support. Nineteen of twenty-one patients (90%) completed six cycles of treatment, eight (38%) without dose reduction. Common toxicity criteria (CTC) grade 4 neutropenia (neutrophil nadir < 0.5 x 10(9)/l) was documented in 85 of 118 cycles (72%). Neutropenic fever was documented in 17 of 21 patients (81%) on at least one occasion. Severe thrombocytopenia (< 25 x 10(9)/l) was seen in fourteen of 118 cycles (12%) and increased with cycle number. There was no significant non-hematological toxicity.

CONCLUSION

Significant dose-escalation of epirubicin and cyclophosphamide was possible with filgrastim support. The MTD achieved was approximately double that of standard-dose therapy. This study forms the basis of an ongoing randomized study evaluating dose-intensification in intermediate grade NHL.

Initial paclitaxel improves outcome compared with CMFP combination chemotherapy as front-line therapy in untreated metastatic breast cancer

PURPOSE

To determine the place of single-agent paclitaxel compared with nonanthracycline combination chemotherapy as front-line therapy in metastatic breast cancer.

PATIENTS AND METHODS

Patients with previously untreated metastatic breast cancer were randomized to receive either paclitaxel 200 mg/m(2) intravenously (IV) over 3 hours for eight cycles (24 weeks) or standard cyclophosphamide 100 mg/m(2)/d orally on days 1 to 14, methotrexate 40 mg/m(2) IV on days 1 and 8, fluorouracil 600 mg/m(2) IV on days 1 and 8, and prednisone 40 mg/m(2)/d orally on days 1 to 14 (CMFP) for six cycles (24 weeks) with epirubicin recommended as second-line therapy.

RESULTS

A total of 209 eligible patients were randomized with a median survival duration of 17.3 months for paclitaxel and 13.9 months for CMFP. Multivariate analysis showed that patients who received paclitaxel survived significantly longer than those who received CMFP (P =.025). Paclitaxel produced significantly less severe leukopenia, thrombocytopenia, mucositis, documented infections (all P <.001), nausea or vomiting (P =.003), and fever without documented infection (P =.007), and less hospitalization for febrile neutropenia than did CMFP (P =.001). Alopecia, peripheral neuropathy, and myalgia or arthralgia were more severe with paclitaxel (all P <.0001). Overall, quality of life was similar for both treatments (P > = .07).

CONCLUSION

Initial paclitaxel was associated with significantly less myelosuppression and fewer infections, with longer survival and similar quality of life and control of metastatic breast cancer compared with CMFP.