Evaluation of a glaucoma patient

The diagnosis of glaucoma is usually made clinically and requires a comprehensive eye examination, including slit lamp, applanation tonometry, gonioscopy and dilated stereoscopic evaluation of the optic disc and retina. Automated perimetry is obtained if glaucoma is suspected. This establishes the presence of functional damage and provides a baseline for follow-up. Imaging techniques are not essential for the diagnosis but may have a role to play in the follow-up. We recommend a comprehensive eye examination for every clinic patient with the objective of detecting all potentially sight-threatening diseases, including glaucoma.

Maternal methadone therapy increases QTc interval in newborn infants

INTRODUCTION

Prolongation of the QT interval is a risk factor for sudden death. Methadone treatment is a well-recognised cause of QT interval lengthening in adults. The effect of maternal methadone treatment on the QT interval of the newborn infant is not known. This is the first prospective study of corrected QT (QTc) interval in infants born to mothers receiving methadone.

AIM

To compare QTc interval in infants born to mothers receiving methadone therapy with healthy controls.

METHOD

Twenty-six term infants (median gestation 38 weeks, range 37-40) born to mothers on methadone therapy had ECG recordings on days 1, 2, 4 and 7. The QTc interval was calculated using the Bazzett formula. Results for days 1 and 2 were compared with healthy matched control infants born to mothers who were not receiving methadone. Results for days 4 and 7 were compared with published normal values.

RESULTS

In the methadone group, the QTc interval was significantly prolonged on days 1 and 2 of life. On days 4 and 7, this increase was no longer present. None of the infants in either group had any evidence of significant cardiac rhythm disturbance.

CONCLUSION

Maternal methadone therapy can cause transient prolongation of the QTc interval in newborn infants in the first 2 days of life. Newborns exposed to methadone are at risk of cardiac rhythm disturbances. Bradycardia, tachycardia or an irregular heart rate in an infant born to a mother on methadone treatment should prompt investigation with a 12-lead ECG.

An open-label expanded access study of lapatinib and capecitabine in patients with HER2-overexpressing locally advanced or metastatic breast cancer

BACKGROUND

The Lapatinib Expanded Access Program (LEAP) was designed to provide access to lapatinib plus capecitabine for HER2-positive metastatic breast cancer patients who previously received an anthracycline, a taxane, and a trastuzumab and had no other treatment options.

PATIENTS AND METHODS

LEAP opened globally and enrollment continued until lapatinib received regulatory approval in each participating country. Patients were assessed for progression-free survival (PFS) and overall survival (OS) and monitored for serious adverse events (SAEs).

RESULTS

As of 30 September 2008, 4283 patients from 45 countries enrolled in LEAP. The median treatment duration was 24.7 weeks. The most common drug-related SAEs were diarrhea (9.7%), vomiting (4.3%), and nausea (2.4%) and were mainly grade 3 or higher. The incidences of special interest SAEs were decreased left ventricle ejection fraction (0.5%), interstitial lung disease/pneumonitis (0.2%), and serious hepatobiliary events (0.4%). This safety profile is consistent with the overall lapatinib program. The median PFS and OS were 21.1 [95% confidence interval (CI) = 20.1-22.3] and 39.6 (95% CI = 37.7-40.7) weeks, respectively (n = 4006). Subgroup analysis showed longer PFS and OS in patients who had not received prior capecitabine.

CONCLUSIONS

These results demonstrate the safety and efficacy of lapatinib in a broader patient population compared with a clinical trial.

Phase I study of lapatinib, a dual-tyrosine kinase inhibitor, and pemetrexed in the second-line treatment of advanced or metastatic non-small cell lung cancer

e19027

Background: Lapatinib is an oral, reversible small-molecule inhibitor of epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2). EGFR overexpression is very common in non-small-cell lung cancer (NSCLC), ranging from 30% to 83%, whereas HER2 overexpression occurs in about 20%. Pemetrexed is currently given as second-line therapy and achieves a 9% response rate. The rationale for EGFR/HER2 inhibition in combination with pemetrexed is to demonstrate clinical synergy as previously shown with gemcitabine, another fluoropyrimidine pathway inhibitor. Methods: Eligible patients included those with stage IIIB or IV NSCLC and European Cooperative Oncology Group performance status of 0–2 following 1 previous chemotherapy treatment. Patients were treated in 3 escalating dose levels (DLs) of pemetrexed (given intravenously every 21 days) and daily lapatinib (DL 0: 400 mg/1,250 mg; DL 1: 500 mg/1,250 mg; DL 2: 500 mg/1,500 mg, respectively). A standard phase 1, 3+3 trial design was used. The primary objective was to determine the optimal treatment regimen. Results: Eighteen patients were treated (DL 0: n=4, DL 1: n=8; DL 2: n=6). The most common adverse events (any grade) were diarrhea (61%), rash (44%), fatigue (28%), nausea (28%), anemia (28%), anorexia (22%), vomiting (22%), dyspnea (17%), and neutropenia (17%). Grade 3/4 adverse events were lymphocytopenia (n=5) and neutropenia (n=5). Other related grade 3 events were diarrhea (n=2), nausea (n=1), decreased ejection fraction (n=1), and increased alkaline phosphatase (n=1). The optimal treatment regimen was determined as lapatinib 1250 mg given with 500 mg pemetrexed after occurrence of 3 dose-limiting toxicities during the first cycle in DL 2 (grade 3 diarrhea, grade 4 lymphocytopenia, and grade 3 mucositis). No further dose-limiting toxicities were observed in DL 0 or DL 1. Preliminary evidence of clinical activity was encouraging, with 3 patients showing partial response. Conclusions: The combination of lapatinib with pemetrexed is well tolerated; encouraging activity has been demonstrated in pretreated NSCLC patients and warrants further studies.

[Table: see text]

An emergency physician activated protocol, 'Code STEMI' reduces door-to-balloon time and length of stay of patients presenting with ST-segment elevation myocardial infarction

INTRODUCTION

National consensus guidelines recommend that ST-segment elevation myocardial infarction (STEMI) patients achieve a door-to-balloon time of < 90 min. We sought to determine if emergency physician initiated simultaneous activation of the cardiac catheterisation laboratory team and the on-call interventional cardiologist has any impact on reducing door-to-balloon-times at our hospital.

METHODS

A total of 72 consecutive STEMI patients were evaluated from January 2007 to December 2007. The emergency physician activated Code STEMI required concurrent activation of cardiac catheterisation personnel and the on-call interventional cardiologist by the emergency physician. These patients were compared with our staff cardiologist activated primary angioplasty protocol from January 2006 to December 2006 for 51 consecutive STEMI patients. The primary outcome was to measure median door-to-balloon time between both groups. Secondary end-points included the individual components of door-to-balloon times (i.e. door-to-ECG time), peak troponin-I level within 24 h, length of stay and all-cause in-hospital mortality.

RESULTS

Median door-to-balloon time decreased overall (112 vs. 74 min, p < 0.001). Of the three components of door-to-balloon time analysed, the ECG to cardiac catheterization laboratory time exhibited the largest area of improvement with 16 min absolute reduction in median door-to-balloon time. Median peak troponin levels (50 vs. 25 ng/ml, p < 0.001), and hospital length of stay (4 vs. 3 days, p < 0.01) decreased. We did not see any statistically significant difference in all-cause in-hospital mortality (p = 0.6).

CONCLUSIONS

Emergency physician activation of the Code STEMI significantly reduces door-to-balloon time to within national standards of care, and length of stay in STEMI patients.

Safety and tolerability of lapatinib in combination with taxanes (T) in patients with breast cancer (BC)

1027

Background: Lapatinib (L) is an oral, dual ErbB1/B2 tyrosine kinase inhibitor. T are mainstay of BC treatment. The side-effects seen with T in combination with gefitinib and erlotinib include neutropenia, diarrhea and rash. Based on preclinical synergy, early clinical studies with L and paclitaxel (P) or docetaxel (D) were studied. Methods: We summarize pharmacokinetics (PK) and preliminary safety data from 192 patients. Results: PK analysis for EGF10009 (q3w), show systemic exposure was increased for both L (21%) and P (23%) at doses of 1500mg daily and 175mg/m2/q3w, respectively. PK analysis in EGF10021 , (L 1250 mg & D 75 mg/m2 with prophylactic pegfilgrastim) indicated no significant effect on systemic exposure of either agent. Toxicities across all studies include i.e., for all patients = grade 3, neutropenia (7.3%), diarrhea (18.2%), rash (3.6%). The rate of adverse events for neutropenia and rash were similar to each agent alone, however diarrhea was more common. The frequency and severity of diarrhea was increased in studies EGF10009 and EGF102580 where no proactive treatment of diarrhea was introduced, whereas in EGF105764, with proactive treatment, currently no =grade 3 diarrhea has been reported. The data show that the combination of L and P has clinical activity (>70% RR reported in EGF102580). Conclusions: T plus L combinations have a predictable and manageable safety profile and clinical activity of P plus L combination was observed. Proactive diarrhea management is essential for these combinations. Based on the PK data, no dose adjustments are required, and any dose adjustments should be toxicity-based. Ongoing clinical studies investigating the combinations of L with T, and combinations of L with T plus trastuzumab will be reported in the future.

[Table: see text]

No significant financial relationships to disclose.

Self-expanding versus balloon-mounted stents for vessel recanalization following embolic occlusion in the canine model: technical feasibility study

BACKGROUND AND PURPOSE

Despite advances in mechanical thrombolysis for acute stroke, recanalization rates remain approximately 50%-60%. Technologic improvements allowed safe intracranial delivery of stents. To study the feasibility of stent-assisted recanalization for acute stroke, we deployed self-expanding or balloon-mounted stents in 2- to 3.5-mm canine vessels acutely occluded with clot emboli.

METHODS

Six mongrel dogs were placed under general anesthesia. A guiding catheter was placed in the distal vertebral artery or an external carotid artery branch. A 7 x 3 mm (length x diameter) soft or hard clot was injected into the catheter and allowed to embolize distally; 20 vessels were successfully occluded. After systemic heparin anticoagulation, recanalization with a self-expanding stent was attempted in 11 vessels (5 occluded with soft clot; 6, with hard clot). Balloon-mounted stents were placed in an attempt to revascularize 9 vessels (4 occluded with soft clot; 5, with hard clot). Vessel recanalization was assessed as the primary end point. Side-branch occlusion and stent-induced vasospasm were also assessed.

RESULTS

Thrombolysis in Myocardial Infarction/Thrombolysis in Cerebral Infarction flow for 11 vessels treated with self-expanding stents versus 9 treated with balloon-mounted stents was as follows: grade 3, 91% of vessels versus 78% of vessels; grade 2, 0% versus 11%; grade 1, 9% versus 0%; grade 0, 0% versus 11%. Lower rates of spasm and side-branch occlusion were noticed with self-expanding stents. Grade 2/3 flow was achieved in 18/20 vessels (90%).

CONCLUSIONS

Excellent recanalization was demonstrated with both stents. Recanalization in self-expanding stents was achieved without pre- or post-balloon dilation. Stents may prove to be a useful adjunct for intra-arterial acute stroke treatment.

Comparison of alamar blue and MTT assays for high through-put screening

The performance of alamar blue and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) cell viability assays in a high through-put format were compared. A total of 117 drugs chosen for their wide range of therapeutic areas were screened at 10 microM using both assays in human hepatoma cell line HepG2. Except for terfenadine and astemizole, which performed consistently in both assays, the alamar blue assay was slightly more sensitive than the MTT assay for most compounds. The MTT assay was less sensitive detecting an effect for daunorubicin and trifluoperazine. Seven drugs, astemizole, daunorubicin, ellipticine, fluphenazine, terfenadine, thioridazine and trifluoperazine, had percent viability results of 55% or less in the alamar blue assay at the single point screen. These were re-tested in both assays for reconfirmation of cytotoxicity and determination of the EC50 values. Except for daunorubicin, the EC50 values were comparable in both assays. Based on these results and the Z'-factor assessment of assay quality, both assays provided useful information to identify in vitro cytotoxic drugs at early stages of drug candidate selection. However, careful interpretation of data is warranted due to the possibility of false positive or negative results caused by inducers and/or inhibitors of metabolic enzymes that are responsible for transformation of cell toxicity end points, as we demonstrated using dicumarol.

Five year risk of progression of primary angle closure suspects to primary angle closure: a population based study

AIM

To report progression of primary angle closure suspects (PACS) to primary angle closure (PAC) at the 5 year follow up of a population based sample.

METHODS

82 of 118 PACS who could be contacted and 110 randomly selected normals from a population based survey in 1995 were invited for a follow up examination in 2000. Progression to PAC was based on the development of raised IOP or synechiae in a PACS.

RESULTS

50 of the 82 PACS contacted were examined. 11 (22%; 95% CI 9.8 to 34.2) developed PAC (seven synechial and four appositional); all were bilateral PACS. Two of 50 people previously diagnosed as PACS were reclassified as normal. One person among the 110 normals progressed to PAC. The relative risk of progression among PACS was 24 (95% CI 3.2 to 182.4). There was no significant difference in axial length, anterior chamber depth, or lens thickness between those who progressed and those who did not. None of the patients developed optic disc or field damage attributable to angle closure. One angle closure suspect was diagnosed to have normotensive glaucoma.

CONCLUSION

In this population based study of PACS the 5 year incidence of PAC was 22%; none developed functional damage. Bilateral PACS was a clinical risk factor for progression.

The implication of compromised renal function at presentation in myeloma: similar outcome in patients who receive high-dose therapy: a single-center study of 251 previously untreated patients

The purpose of the study was to determine the role of sequential therapy (ST) in new patients with myeloma presenting with renal dysfunction (RD): serum creatinine >140 micromol/L (1.6 mg/dL). Between April 1985 and June 1998, 251 patients, 59 (23%) with RD were entered into a ST program comprised of infusional chemotherapy (IC) with VAMP/C-VAMP (vincristine, doxorubicin, and methylprednisolone with/without cyclophosphamide) followed by autologous transplantation and interferon maintenance. The median overall survival (OS) of 251 patients from the start of IC was 4.2 yr with the RD group faring significantly poorer (median 2.5 yr) than those with no renal dysfunction (NRD; median 4.6 yr; p = 0.0025). Mortality during the first 100 d of IC was significantly higher in patients with RD (11/59; p = 0.01) compared to patients with NRD. In patients consolidated with high-dose therapy, the OS and event-free survival (EFS) were not significantly different between the two groups. Cox analysis of the variables at presentation failed to show RD as a factor influencing outcome, but it showed that patients with beta-2-microglobulin (beta2M) > or = 3.7 (p < 0.0001), age > or = 52.5 yr (p = 0.002), performance status (PS) > or = 2 (p = 0.005) and patients with light-chain myeloma (p = 0.03) had a significantly shorter OS, beta2M > or = 3.7, PS > or = 2, and light-chain myeloma were predictive of shorter EFS. The study shows that with modern intensive schedules of treatment, renal disease at presentation in isolation does not compromise outcome.

Frequency doubling perimetry in glaucoma

PURPOSE

To evaluate the validity of frequency doubling perimetry (FDP) in the detection of glaucomatous field defects.

METHODS

Group I consisted of 85 eyes of 85 patients with established field defects in automated perimetry, classified by severity of defect. Group II consisted of 48 eyes of 48 control subjects. Both groups underwent Swedish Interactive Testing Algorithm (SITA) standard tests as well as FDP screening strategies (C20-1 and C20-5 and full threshold test). Sensitivity and specificity measures for the FDP tests were calculated using one new and two previously published algorithms.

RESULTS

A described scoring system provided the best sensitivity (85.9%) and specificity (95.1%). For moderate and severe cases, the sensitivity improved to 91%. Quantification of the defect did not improve detection.

CONCLUSIONS

FDP is a valid screening test for glaucoma. The scoring system described by Patel et al. provided the best results.

Stain removal efficacy of two new fluoride dentifrices containing essential oils

PURPOSE

To assess in vitro the stain removal efficacy of two new antiplaque/antigingivitis dentifrices utilizing a modification of a previously validated Stookey method.

MATERIALS AND METHODS

The modifications to the original Stookey method are the following: (1) study design; three 5 x 5 Latin Squares were employed to minimize bias stemming from position or test run in the study. (2) statistical success criteria; a test formulation was judged to be effective if the lower one-sided 95% confidence limit was "equal to or higher than" 50 since a minimum PCR (pellicle cleaning ratio) score of 50 is needed for a dentifrice to show clinical efficacy. The two test dentifrice formulations contained a fluoride source, a silica abrasive system, and four essential oils. The ADA reference abrasive material (calcium pyrophosphate) and placebo toothpaste were included as positive and negative controls, respectively.

RESULTS

Compared to the negative control, the positive control exhibited a statistically higher PCR score; therefore, the validity of this modified Stookey method was confirmed. Additionally, the lower limits of the one-sided 95% confidence interval for the two dentifrice formulations were above the threshold PCR of 50; therefore, this modified Stookey method should predict that both essential oil-containing dentifrices possess acceptable stain removal power.

Anticalculus effect of two zinc citrate/essential oil-containing dentifrices

PURPOSE

To assess the feasibility of incorporating zinc citrate, a known anticalculus ingredient, into a dentifrice formulation containing a fixed combination of essential oils, a known antiplaque/antigingivitis agent.

MATERIALS AND METHODS

This randomized, parallel, double-blind study evaluated the potential of two essential oil dentifrice formulations containing different levels of zinc citrate (1.0% and 2.0% ZCT) to reduce supragingival calculus formation compared to a marketed control dentifrice, Crest Regular. Following a 3-month pre-test phase, subjects received a dental prophylaxis, were stratified into three balanced groups on the basis of Volpe-Manhold calculus scores and brushed twice daily with their assigned dentifrice for 3 months.

RESULTS

One hundred ninety-six evaluable subjects completed all phases of the study. ANCOVA revealed that the 1.0% ZCT and 2.0% ZCT essential oil dentifrice formulations provided significant reductions in calculus formation of 26.4% and 29.0% (P< 0.001), respectively, compared to the control dentifrice, Crest Regular. The magnitude of calculus reductions is similar to those levels obtained by other zinc salt formulations.

Essential oils in an antiplaque and antigingivitis dentifrice: a 6-month study

PURPOSE

To determine if a dentifrice formulated with the fixed combination of essential oils possessed antiplaque and antigingivitis properties.

MATERIALS AND METHODS

This study was a blinded, randomized, controlled clinical trial. The 6-month study had clinical examinations at baseline, 3 and 6 months. The examinations consisted of three indices; a plaque index, the Modified Gingival Index and a bleeding index.

RESULTS

At 6 months, the essential oil-containing dentifrice group had statistically significantly (P < 0.001) lower whole-mouth and interproximal mean plaque index scores exhibiting mean reductions of 18.3% and 18.1% relative to the vehicle control. At 6 months, the essential oil-containing dentifrice group had statistically significantly (P < 0.001) lower whole-mouth and interproximal mean gingival index scores compared to the vehicle control with reductions of 16.2% and 15.5%, respectively. Finally, for the gingival bleeding index, the essential oil-containing dentifrice group had statistically significantly (P < 0.001) lower whole-mouth and interproximal mean bleeding index scores and reductions of 40.5% and 46.9% at 6 months compared to the vehicle control.

Coping mechanisms in patients presenting for in-vitro-fertilization

OBJECTIVES

The purpose of this study was to assess the coping mechanisms in patients presenting for in-vitro fertilization (IVF).

METHODS

We evaluated thirty consecutive couples presenting for in-vitro-fertilization. All couples were interviewed individually at first, and then together, using a semi-structured interview technique. Psychiatric diagnoses were made using the Diagnostic and Statistical Manual-IV (DSM-IV) criteria. Coping mechanisms used by the individuals were assessed using the Mechanisms of Coping Scale (MOCS). Other instruments used were Hamilton Depression Rating Scale (HAM-D-17), Hamilton Anxiety Rating Scale (HAM-A), Brief Psychiatric Rating Scale (BPRS), Self-Rating Symptom Scale (SRSS), and Eysenck Personality Inventory (EPI).

RESULTS

The mean age of the sixty patients was 32.3 +/- 5.2 years. Fatalism was the commonest factor on the mechanisms of coping scale. Analysis of variance (ANOVA) across all factors of the MOCS for demographic factors showed that men used problem-solving mechanisms significantly more often than women (F = 3.0, df = 1, 58, p < 0.05). ANOVA across coping factors on stressors with post-hoc tests of significance revealed that individuals facing social stress used fatalism significantly more often than other coping mechanisms, while those facing career stress used problem-solving significantly more often than other coping mechanisms (F = 5.6, df = 1, 58, p < 0.05 and F = 3.04, df = 1, 58, p < 0.01 respectively). ANOVA across coping factors on HAM-D-17 scores revealed that individuals who used fatalism had significantly higher HAM-D-17 scores compared to those who did not (F = 4.4, df = 1, 58, p < 0.05). ANOVA across coping factors on HAM-A scores revealed that individuals who used escape-avoidance had significantly lower HAM-A scores than those who did not (F = 4.3, df = 1, 58, p < 0.05). ANOVA across coping factors on SRSS scores revealed that individuals who used passivity or fatalistic coping mechanisms had significantly higher scores on SRSS than who did not (F = 4.6, df = 1, 58, p < 0.05 and F = 3.5, df = 1, 58, p < 0.05).

CONCLUSIONS

Differential patterns of coping were found among the sixty individuals presenting for IVF and were associated with a variety of factors including gender, education, stressors, and levels of depression, anxiety, and overall psychopathology. Efforts to recognize and recruit the coping mechanisms of infertile individuals are likely to enhance their ability to participate effectively in treatment.

Topical morphine in a canine model: a pilot study

OBJECTIVE

To determine if topical morphine can enter the synovial cavity and the effect of ultrasound on this process.

DESIGN

A randomized control trial to investigate which body fluids morphine enters after topical application.

SETTING

A university animal laboratory.

SUBJECTS

Ten mongrel dogs raised by the Comparative Medicine Department. All animals were certified to be free of disease, all had received standard scheduled immunizations, and none had been used for any other research.

INTERVENTION

Topical morphine and ultrasound or topical morphine and sham ultrasound was applied to the knees of the dogs. Samples were obtained afterward from synovial fluid, serum, and urine, and were analyzed for the presence of morphine.

MAIN OUTCOME MEASURES

Blood samples were collected every 60 minutes for 240 minutes, urine samples were collected at 120 minutes and 240 minutes, and synovial joint fluid was collected at 120 minutes and 240 minutes. The process of collection and analysis was the same for dogs treated with topical morphine and ultrasound and those treated with topical morphine and sham ultrasound. Fisher's exact test was used to test for an association between the use of ultrasound and the presence of morphine in the synovial fluid, serum, or urine. Two-sample t tests were used to test for group differences in mean body weight.

RESULTS

All samples (synovial fluid, serum, and urine) were negative at time zero. All of the subsequent serum samples were negative for morphine. Two or three of the dogs in each group of five (ultrasound or sham ultrasound) had positive urine and synovial fluid samples at 120 and 240 minutes. Ultrasound did not affect the results. Body weight of the dogs influenced the results, with lighter animals having a significantly larger percentage (p=.03) of synovial fluid samples positive for morphine.

CONCLUSION

Ultrasound did not affect the absorption of topical morphine in this canine model. Body weight may have influenced the results. Dogs that tested positive for morphine in synovial fluid had a lower mean body weight than dogs that did not test positive (p=.03).

Metabolic and orexigenic effects of intracerebroventricular neuropeptide Y are attenuated by food deprivation

Administration of neuropeptide Y (NPY) into the hypothalamus or cerebral ventricles has been shown to increase food intake, the secretion of hormones such as insulin, glucagon and corticosterone and to alter the metabolism of carbohydrate and lipids. It has been suggested that metabolic effects of hypothalamic NPY may contribute to fat accretion in some types of obesity and to the metabolic and behavioural adaptation to food deprivation. However, it is currently unknown if different nutritional states alter the responses to hypothalamic NPY. Consequently, we have compared the effects of NPY injected into the third ventricle (ICV) in the fed and overnight-fasted state on ingestive behaviour, on insulin, glucagon and corticosterone secretion before, and following, an IV glucose bolus (IVGTT) and on blood glucose following an intra-arterial insulin bolus (ITT). Studies were performed on conscious, unrestrained adult female rats. In the fed state, 2 and 6 micrograms ICV NPY produced a potent orexigenic and dypsogenic effect. In the fasted state, the 2 micrograms dose had a dypsogenic effect, while only the 6 micrograms dose had a significant orexigenic effect. In the fed but not fasted state, 3 micrograms ICV NPY increased plasma glucagon and corticosterone levels and attenuated the decline in blood glucose during the ITT. By contrast, in both fed and fasted groups, 3 micrograms ICV NPY potentiated the insulin secretory responses during the IVGTT. We conclude that, apart from stimulating insulin secretion, the acute metabolic and orexigenic responses to ICV NPY in this study were substantially reduced or abolished by overnight fasting. Therefore, behavioural and metabolic responses to endogenous hypothalamic NPY may also be more significant in the fed than the fasted state.

Effect of chemical sympathectomy on serum levels of thyroid hormones and the biochemical profile of domestic pigeons

Recent studies have stressed the importance of the cholinergic system on avian metabolism. However, the role of the sympathetic nervous system (SNS) remains unclear. The present study was, therefore, aimed to probe the mechanisms for modulation of avian metabolism by the sympathetic nervous system after inhibition of the adrenergic responses. Activities of serum thyroid hormones (tri-iodothyronine, T3, and thyroxine, T4), body weight, hepatic weight, as well as total lipid and water content in the liver and body temperature were some of the parameters examined after chemical sympathectomy with 6-hydroxydopamine (6-OHDA) and reserpine treatment in 24-h starved pigeons. In addition, glucose was administered to the pigeons to identify the regulatory role played by glucose after disruption of the SNS. A reduction in body weight of the pigeons and an enhancement in the lipogenic machinery along with a corresponding increase in water content were some of the obvious effects in 6-OHDA+reserpine treated, as well as glucose-loaded sympathectomized birds. The cloacal temperature (Tc) and both the thyroid hormones showed a drastic decrease while the T3/T4 ratio was augmented as a result of sympathectomy. However, serum T3 and T4 levels were restored to control values when glucose load was given, indicating that glucose might be reversing some of the detrimental effects of 6-OHDA treatment by activating intrinsic autoregulatory mechanisms of thyroid gland, thereby reviving the levels of thyroid hormones. Thus, the influence of SNS appears to be crucial in the maintenance of serum thyroid hormones and body temperature, as well as metabolic activities of hepatic cells.