Efficacy of immune checkpoint inhibitors in alveolar soft-part sarcoma: results from a retrospective worldwide registry

BACKGROUND

Conventional cytotoxic drugs are not effective in alveolar soft-part sarcoma (ASPS). Immune checkpoint (programmed cell death protein 1/programmed death-ligand 1) inhibitors (ICIs) are promising drugs in ASPS. A worldwide registry explored the efficacy of ICI in ASPS.

MATERIALS AND METHODS

Data from adult patients diagnosed with ASPS and treated with ICI for advanced disease in expert sarcoma centers from Europe, Australia and North America were retrospectively collected, including demographics and data related to treatments and outcome.

RESULTS

Seventy-six ASPS patients, with a median age at diagnosis of 25 years (range 3-61 years), were registered. All patients received ICI for metastatic disease. Immunotherapy regimens consisted of monotherapy in 38 patients (50%) and combination in 38 (50%) (23 with a tyrosine kinase inhibitor). Among the 68 assessable patients, there were 3 complete responses and 34 partial responses, translating into an overall response rate of 54.4%. After a median follow-up of 36 months [95% confidence interval (CI) 32-40 months] since the start of immunotherapy, 45 (59%) patients have progressed on ICI, with a median progression-free survival (PFS) of 16.3 months (95% CI 8-25 months). Receiving ICI in first line (P = 0.042) and achieving an objective response (P = 0.043) correlated with a better PFS. Median estimated overall survival (OS) from ICI initiation has not been reached. The 12-month and 24-month OS rates were 94% and 81%, respectively.

CONCLUSIONS

This registry constitutes the largest available series of ASPS treated with ICI. Our results suggest that the ICI treatment provides long-lasting disease control and prolonged OS in patients with advanced ASPS, an ultra-rare entity with limited active therapeutic options.

Systemic treatment in advanced phyllodes tumor of the breast: a multi-institutional European retrospective case-series analyses

BACKGROUND

We aimed at investigating outcome of systemic treatments in advanced breast PT.

METHODS

All cases of advanced breast PT treated with systemic treatments from 1999 to 2019, in one of the referral sarcoma centers involved in the study, were retrospectively reviewed.

RESULTS

56 female patients were identified. Median age was 52 (range of 25-76) years. Patients received a median number of 2 systemic treatments (range of 1-4). Best responses according to RECIST were 1 (3.7%) CR, 11 (40.7%) PR, 6 (22.2%) SD, 9 (33.3%) PD with anthracyclines plus ifosfamide (AI); 2 (16.7%) PR, 4 (33.3%) SD, 6 (50.0%) PD with anthracycline alone; 3 (18.8%) PR, 4 (25.0%) SD, 9 (56.3%) PD with high-dose ifosfamide given as a continuous infusion (HD-IFX); 3 (20.0%) SD, 12 (80.0%) PD with a gemcitabine-based regimen (with 2 patients not evaluable); 1 (8.3%) PR, 2 (16.7%) SD, 9 (75.0%) PD with trabectedin (with 1 patient not evaluable); 1 (16.7%) PR, 1 (16.7%) SD, 4 (66.7%) PD with tyrosine-kinase inhibitors (TKI). The median PFS were 5.7 (IQR 2.5-9.1) months with AI; 3.2 (IQR 2.2-5.0) months with anthracycline alone; 3.4 (IQR 1.4-6.7) months with HD-IFX; 2.1 (IQR 1.4-5.2) months with gemcitabine-based chemotherapy; 1.8 (IQR 0.7-6.6) months with trabectedin; 3.4 (IQR 3.1-3.8) months with TKI. With a median follow-up of 35.3 (IQR 17.6-66.9) months, OS from the start of first-line systemic treatment was 15.2 (IQR 7.6-39.6) months.

CONCLUSION

In this series of advanced PT (to our knowledge, the largest reported so far), AI was associated with a high rate of responses, however, with a median PFS of 5.7 months. Other systemic treatments were poorly active.

Diagnosis and management of tropomyosin receptor kinase (TRK) fusion sarcomas: expert recommendations from the World Sarcoma Network

Sarcomas are a heterogeneous group of malignancies with mesenchymal lineage differentiation. The discovery of neurotrophic tyrosine receptor kinase (NTRK) gene fusions as tissue-agnostic oncogenic drivers has led to new personalized therapies for a subset of patients with sarcoma in the form of tropomyosin receptor kinase (TRK) inhibitors. NTRK gene rearrangements and fusion transcripts can be detected with different molecular pathology techniques, while TRK protein expression can be demonstrated with immunohistochemistry. The rarity and diagnostic complexity of NTRK gene fusions raise a number of questions and challenges for clinicians. To address these challenges, the World Sarcoma Network convened two meetings of expert adult oncologists and pathologists and subsequently developed this article to provide practical guidance on the management of patients with sarcoma harboring NTRK gene fusions. We propose a diagnostic strategy that considers disease stage and histologic and molecular subtypes to facilitate routine testing for TRK expression and subsequent testing for NTRK gene fusions.

Synthesis and structural studies on (E)-3-(2,6-difluorophenyl)-1-(4-fluorophenyl)prop-2-en-1-one: a promising nonlinear optical material

A new fluorinated chalcone (E)-3-(2,6-difluorophenyl)-1-(4-fluorophenyl)prop-2-en-1-one was synthesized in 90% yield and crystallized by a slow evaporation technique. Its full structural characterization and purity were determined by scanning electron microscopy, infrared spectroscopy, gas chromatography-mass spectrometry, 1H, 13C and 19F nuclear magnetic resonance, thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), Raman microspectroscopy, UV-Vis absorption spectroscopy, single crystal X-ray diffraction (XRD) and Hirshfeld surface (HS) analysis. The fluorinated chalcone crystallized in centrosymmetric space group P21/c stabilized by the C-H⋯O and C-H⋯F interactions and the π⋯π contact. The crystalline environment was simulated through the supermolecule approach where a bulk with 378 000 atoms was built. The electric parameters were calculated at the DFT/CAM-B3LYP/6-311++G(d,p) level as function of the electric field frequency. The macroscopic parameters such as linear refractive index and third-order nonlinear susceptibility (χ (3)) were calculated, and the results were compared with experimental data obtained from the literature. The χ (3)-value for the chalcone crystal is 369.294 × 10-22 m2 V-2, higher than those obtained from a few similar types of molecule, showing that the chalcone crystal can be considered as a nonlinear optical material. Also, molecular theoretical calculations such as infrared spectrum assignments, frontier molecular orbital analysis and MEP were implemented, revealing that the most positive region is around the hydrogen atoms of the aromatic rings, and electrophilic attack occurs on the carbonyl group.

[ECMO support in a child with cardiogenic shock due to Kingella Kingae endocarditis]

INTRODUCTION

Endocarditis is a rare disease in children, especially in those without previous heart disease, and Kingella Kingae (KK) is rarely identified as the cause. Extracorporeal membrane oxyge nation (ECMO) is a support for both heart and respiratory failure.

OBJECTIVE

To report the first case of infectious endocarditis (IE) due to KK which required ECMO support secondary to refractory cardiogenic shock.

CLINICAL CASE

19-months-old previously healthy female patient, with a 2-day his tory of fever, and diagnosed with hand-foot-and-mouth disease. The patient developed refractory cardiogenic shock, multiorgan failure, acute respiratory distress syndrome, and deep hemodynamic compromise that required veno-arterial ECMO support. The echography showed an image compa tible with mitral valve vegetation, confirming IE with transthoracic echocardiography. Blood culture was positive for KK. She had an ischemic stroke and required two heart surgeries, the first one for the mass resection and the second one for mitral valve repair, which had a posterior ring pseudoa neurysm. The patient had a favorable evolution and was discharged 73 days after admission. At one year of follow-up, she had no cardiological symptoms, but a mild right brachial-crural hemiparesis persisted.

CONCLUSION

This is the first reported case of IE due to KK that required extracorporeal life support. KK endocarditis is an uncommon pathology that can cause multiorgan failure, which can be successfully supported with ECMO.

Therapeutic Drug Monitoring of Vancomycin in Pediatric Patients With Extracorporeal Membrane Oxygenation Support

OBJECTIVES

Determine pharmacokinetic (PK) parameters and optimal dosage of vancomycin for children on extracorporeal membrane oxygenation (ECMO).

METHODS

Retrospective PK study of vancomycin in pediatric patients on ECMO who received IV vancomycin 40 to 60 mg/kg/day every 6 hours. Patients were analyzed according to the presence of acute kidney injury (AKI) and requirement of renal replacement therapy (RRT).

RESULTS

Data from 40 children, with a median age of 2.7 years of age (1 month to 14 years) were evaluated. Thirty-two patients (80%) received vancomycin. Vancomycin therapeutic drug monitoring was performed in 29 patients. The subgroup without AKI or RRT were 15. With initial doses, vancomycin trough levels were within therapeutic range in 53% of patients. After dose change, 93% of patients achieved therapeutic levels. The adjusted dose was 40 (34-60) mg/kg/day every 6 hours. Estimated PK parameters were clearance (CL) 1.67 (1-1.67) mL/kg/min; volume of distribution (Vd) 0.73 (0.7-0.9) L/kg; and half-life (t½) 6.2 (4.9-8.06) hours. In the AKI subgroup, 11 patients, the initial median dose was 40 (30-45) mg/kg/day every 8 (6-12) hours. Trough concentrations of vancomycin were within therapeutic range in 27% of patients. After dose modifications, 63% of patients achieved target trough concentration. The final adjusted dose was 20 mg/kg/day (15-30) every 12 (12-24) hours. Estimated PK parameters were Vd 1.16 (0.68-1.6) L/kg; CL 0.83 (0.38-1) mL/kg/min; and a t½ of 23.6 (16.2-31) hours.

CONCLUSIONS

In patients without AKI or RRT, Vd of vancomycin was similar and CL was lower compared to pediatric critically ill patients without ECMO. Treatment could be started at 40 mg/kg/day every 6 hours. In patients with AKI, the use of lower doses should be used.

GEIS-21: a multicentric phase II study of intensive chemotherapy including gemcitabine and docetaxel for the treatment of Ewing sarcoma of children and adults: a report from the Spanish sarcoma group (GEIS)

BACKGROUND

First Spanish trial of Ewing sarcoma (ES) including adults and children with the aim to test the efficacy of Gemcitabine and Docetaxel (G/D) in newly diagnosed high-risk (HR) patients.

METHODS

This was a prospective, multicentric, non-randomised, open study for patients ⩽40 years with newly diagnosed ES. HR patients (metastatic, axial-pelvic primaries or bone marrow micrometastasis) received 2 window cycles of G/D. Patients with an objective response (OR) to G/D received 12 monthly cycles of G/D after completion of mP6. The primary end point was the OR rate to the G/D window phase and the event-free survival (EFS) and overall survival (OS) for all patients. The study is registered at ClinicalTrials.gov (identifier: NCT00006734).

RESULTS

Forty-three patients were enroled, median age 17 years (range, 3-40). After a median follow-up of 43.4 months, the 5-year OS rate is 55.0% (95% CI, 41-74%) with an EFS of 50.0% (95% CI, 36-68%). The 5-year OS and EFS rates for standard risk (SR) patients was 76.0% (95% CI, 57-100%) and 71.0% (CI, 54-94%); for HR 36.0% (CI, 20-65%) and 29.0% (CI, 15-56%). Twelve of 17 (70.6%) high-risk (HR) patients showed an OR (7 PR and 5 SD) to G/D window therapy. The 5-year OS rate for patients ⩽18 years of age was 74.0% (CI, 56-97%) and 31.0% for >18 years (95% CI, 15-66%), P<0.001. Grade 4 adverse events during mP6 occurred in 28/39 of patients (72%) and did not correlate with age. Multivariate survival analyses with <18 vs ⩾18 and risk groups significant differences, P<0.00001. Using a Cox model for OS, both age and risk group were statistically significant (P=0.0011 and P=0.0065, respectively).

CONCLUSIONS

Age at diagnosis is an independent prognostic factor superior to the presence of metastases with 18 years as the strongest cut-off. The mP6 regimen provided survival curves that plateau at 3 years and G/D produced significant responses in HR-ES that is worth further exploring.

SEOM Clinical Guideline of management of soft-tissue sarcoma (2016)

Soft-tissue sarcomas are uncommon and heterogeneous tumors of mesenchymal origin. A soft-tissue mass that is increasing in size, greater than 5 cm, or located under deep fascia are criteria for suspicion of sarcoma. Diagnosis, treatment, and management should preferably be performed by a multidisciplinary team in reference centers. MRI and lung CT scan are mandatory for local and distant assessment. A biopsy indicating histological type and grade is needed previous to the treatment. Wide surgical resection with tumor-free tissue margin is the primary treatment for localized disease. Radiotherapy is indicated in large, deep, high-grade tumors, or after marginal resection not likely of being improved with reexcision. Neoadjuvant and adjuvant chemotherapy improve survival in selected cases, usually in high-grade sarcomas of the extremities. In the case of metastatic disease, patients with exclusive lung metastasis could be considered for surgery. First-line treatment with anthracyclines (or in combination with ifosfamide) is the treatment of choice. New drugs have shown activity in second-line therapy and in specific histological subtypes.

Schwannomas, benign tumors with a senescent phenotype

BACKGROUND

Schwannomas are benign nerve sheath tumors that only very rarely undergo malignant changes. Oncogenic-induced senescence is a defense mechanism against such malignant transformation. Different molecular pathways are involved in this process, such as RAS-RAF-MAPK. Based on the fact that the RAS-RAF-MAPK pathway is known to be activated in peripheral nerve sheath tumors, this study analyzes senescence markers in Schwannomas to demonstrate the possible role of senescence in their genesis.

METHODS

A retrospective immunohistochemical study was done in 39 schwannoma and 18 malignant peripheral nerve sheath tumors (MPNST). Staining for p16INK4a, Ki67, p53 and CyclinD1 was performed in all the cases. Additionally, β-galactosidase staining was done in those cases in which frozen tissue was available (n=8).

RESULTS

Higher levels of p16INK4a (p=0.0001) and lower levels of Ki67 (p=0.0001) were found in Schwannomas. Beta-galactosidase activity was positive in 5/5 Schwannomas and negative in 3/3 MPNST.

CONCLUSIONS

Our results support the senescence nature of Schwannomas and the absence of a senescence phenotype in MPNST.

[Viral respiratory co-infections in pediatric patients admitted for acute respiratory infection and their impact on clinical severity]

INTRODUCTION

Respiratory viruses are the leading cause of acute respiratory tract infection (ARI) in children. It has been reported that viral respiratory co-infection could be associated with severe clinical course.

OBJECTIVES

To describe the frequency of viral co-infection in children admitted for AlRI and evaluate whether this co-infection was associated with more severe clinical course.

PATIENTS AND METHODS

Prospective, descriptive study in pediatric patients who were hospitalized for ARI, with molecular detection of at least 1 respiratory virus in nasopharyngeal sample studied by PCR-Microarray for 17 respiratory viruses.

RESULTS

110 out of 147 patients with detection of > 1 respiratory virus were included. Viral co-infection was detected in 41/110 (37%). 22/110 children (20%) were classified as moderate to severe clinical course and 88/110 (80%) were classified as mild clinical course. In the group of moderate to severe clinical course, viral respiratory co-infection was detected in 6/22 (27.3%), compared to 35/88 (39.8 %) in the mild clinical course group. No statistically significant difference was found regarding the presence of co-infection between groups (p = 0.33).

CONCLUSIONS

We detected high rates of viral co-infection in children with ARI. It was not possible to demonstrate that viral co-infections were related with severe clinical course in hospitalized children.

Chilean experience in liver transplantation for acute liver failure in children

BACKGROUND

Acute liver failure (ALF) in children is a life-threatening condition, associated with high mortality, and in almost one third of the cases, with no other therapeutic option than orthotopic liver transplant (OLT). The aim of this study was to present our experience with OLT for ALF in pediatric patients in Chile. Patients fulfilling the criteria for ALF who were transplanted in our centers were prospectively included in an excel Microsoft database. We analyzed demographics, etiology, surgical techniques, complications, and long-term results.

PATIENTS AND METHODS

Between 1994 and 2009, we transplanted 52 pediatric patients with ALF. The most frequent known etiology was acute hepatitis A in 9 cases (18%), but in 26 cases (50%) it was impossible to determine the etiology. Thirty- one patients were males (63%). The overall mean age was 7.5 years and the mean weight, 28.1 kg. Thirty-five (67%) received a cadaveric graft. Among them in 18 cases (34%) the liver had to be reduced but 17 (33%) received whole livers. There were 17 (33%) recipients of living-related livers. Twenty-two patients needed reoperation, including 13 due to surgical complications (59%) and 9 (41%) as planned interventions. Ten patients were retransplanted.

RESULTS

Actuarial survival of patients at 1 year was 80% and at 5 and 10 years, 72%. Graft survival at 1 year was 79%, at 5 years 69%, and at 10 years 50%.

CONCLUSION

We have reported a series of pediatric liver transplant patients due to ALF whose results were comparable to other reported series. Living donor transplantation for ALF should be considered and offers a low morbidity rate without mortality.

Phase I study of bi-weekly pemetrexed (P) plus cisplatin (C) in patients with advanced cancer

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Background: Cisplatin and pemetrexed have demonstrated clinical activity in several malignant tumors including mesothelioma and non small cell lung cancer. There is preclinical evidence of synergism between both agents as well as clinical non-overlapping toxicities, thus providing the rationale for their evaluation in combination. Our aim was to develop a well-tolerated combination of bi-weekly CP able to deliver higher dose intensity than the every 3-week standard. Methods: Escalating doses of P from a starting dose level of 300 mg/m2, with a fixed-dose of C 50 mg/m2, both biweekly on 28-day cycles, were administered to patients with refractory advanced solid malignancies and calculated creatinine clearance = 45 mL/min. Results: Twenty one patients (5 female/16 male); median age 61 (39–76); ECOG 0 (16), 1 (5); lung cancer (9); soft-tissue sarcoma (3); unknown primary, bladder, breast, rectum, esophagus, melanoma, mesothelioma, prostate, and tonsil (1, each) have received a total of 48 courses (median 2, range 0–5), at P dose levels of 300 mg/m2 [8 pts, Dose level 1 (DL1)], 400 mg/m2 (7 pts, DL2), and 500 mg/m2 (6 pts, DL3), with full doses of C. Four patients were non-evaluable (2 at DL1, 1 at DL2 and 1 at DL3) because of early PD (2) and non-drug related serious adverse event (2 pt). Dose Limiting Toxicities (DLT) were G4 neutropenia (1 pt) at 300 mg/m2; and prolonged G 1/2 thrombocytopenia (1 pt) at 500 mg/m2. There were also 2 pts with non-DLT G4 neutropenia at DL3. The rest of toxicities were mild to moderate being the most frequent asthenia, nausea, anorexia, stomatatis, and sensory neuropathy. DL3 was considered the Maximum Tolerated Dose (MTD) and the previous level with P at 400 mg/m2 was declared the recommended phase II dose. Three additional patients were treated at DL2 for dose confirmation. A PR has been observed in 2 pts with NSCLC, 1 pt with breast, and 1 with esophagus cancer. Conclusions: Biweekly administration of pemetrexed (400 mg/m2) plus cisplatin (50 mg/m2) is clinically well tolerated and can be used safely. The regimen delivers higher dose intensity of P and equal of C as the standard. This regimen is currently being studied in a phase 2 trial in patients with locally advanced, non resectable or metastatic urothelial cancer.

No significant financial relationships to disclose.

Activated charcoal laryngitis in an intubated patient

Activated charcoal is useful in the management of poisonings, but it is not harmless. We report the case of a patient who developed obstructive laryngitis secondary to aspiration of activated charcoal with a protected airway.

CASE

A 2-year-old girl presented acute mental alteration secondary to presumed poisoning. Mechanical ventilation was initiated, and a single dose of activated charcoal was administered. She had an episode of vomiting during the respiratory weaning. Black-tinted tracheal secretions were suctioned through the tube immediately. Pulmonary auscultation and radiologic examination were normal. When she was extubed, she developed obstructive laryngitis. Fiberbronchoscopy was performed and showed edema and a significant amount of charcoal particles on the epiglottis, arytenoids, and arytenoepiglottic folds. Charcoal particles were removed by bronchoscopy successfully. Later evolution was normal, and no symptoms were present when she was discharged at home.

COMMENTS

Obstructive laryngitis is a new major complication of activated charcoals use in upper airway. It is remarkable that this complication occurred in a protected airway. Charcoal is not an innocuous agent. This case shows that nasogastric administration of activated charcoals presents a significant degree of risk.

Chronic otitis externa/media with total ear canal ablation and bulla curettage in a North American bison (Bison bison)

An adult female North American bison (Bison bison) with a chronic otitis externa/media of the right ear was examined because of a 4-mo history of intermittent anorexia, apparent painful behavior, and auricular discharge from the right ear. Computerized tomography (CT) demonstrated osteolysis of the tympanic, petrous, and squamous aspects of the temporal bone with soft tissue replacement and sclerosis of the right bulla. A total ear canal ablation with bulla curettage was performed, and cefazolin-impregnated polymethacrylate beads were left within the right bulla and the remnant temporal bone. Six months after the surgery, the bison had no clinical signs of otitis media.

Cold-induced increment in rat adrenal gland type II deiodinase is corticosterone dependent

In this study we analyzed whether corticosterone synthesis is involved in the regulation of adrenal gland type II deiodinase (AG-D2) activity during acute cold exposure. Two well-known inhibitors of steroidogenesis, aminoglutethimide (AGT) and metyrapone (MTP), were administered to male Wistar rats maintained either at room temperature or acutely exposed to cold (1 h at 4 degrees C). AG-D2 activity was measured by the radioiodide release method, and corticosterone circulating levels were measured by competitive protein binding assay. Results show that resting corticosterone levels and AG-D2 activity were lower in both AGT- and MTP-treated rats. Furthermore, the phasic increase normally exhibited by AG-D2 activity in response to acute cold stress was blunted in AGT- and MTP-treated animals. Therefore, we conclude that corticosterone synthesis is necessary in preserving the physiologic response of AG-D2 activity to cold exposure.

Kinetic characterization of outer-ring deiodinase activity (ORD) in the liver, gill and retina of the killifish Fundulus heteroclitus

Conversion of T4 to T3 is the first step in TH action and deiodinases are the major determinants of TH tissue availability and disposal. We here report the kinetic characterization of the outer-ring deiodinating (ORD) enzymes in the liver, gill and retina of sea water-adapted killifish, by using both rT3 and T4 as substrates. In liver, by using rT3, we detected a high Km (84 nM) and a low Km (1.3 nM) component with kinetic characteristics similar to mammalian deiodinases DI and DII. In contrast, T4-ORD only generated a low Km (0.5 nM) component. As judged by its Vmax (920 fmol 125I/mg per h) this DII enzyme is very abundant, approximately five and 20 times higher than that found in trout liver and hypothyroid rat, respectively. Kinetic analysis in killifish gill showed only one enzymatic component, with a high rT3 Km (430 nM) and a relatively low Vmax (4.3 pmol 125I/mg per h). Our results in killifish retina show the expression of a T4-low Km (0.6 nM) deiodinase with high cofactor requirements akin to the mammalian DII. The Vmax value for this enzyme is 182 fmol 125I/mg per h, five times lower than the one found in killifish liver, but comparable to that in hypothyroid rat pituitary. The biochemical similarities between fish and mammalian deiodinases could reflect their high conservation during vertebrate evolution and thus their importance in the regulation of thyroid hormone action.

[Neck hydatidosis. Thyroid and submaxillary gland involvement in 2 cases]

Neck located hydatid cysts are of rare occurrence. We report two patients with such condition. A 66 years old male with a slowly progressive painless 4 cm nodule located in the right thyroid. It did not concentrate 131I and a fine needle aspiration cytology was informed as an acute thyroiditis. A 5 years old boy presented with a 5 cm painless right submaxillary cyst. Ultrasound examination showed that it was unilocular, and fine needle aspiration biopsy disclosed unspecific findings. In both cases surgical findings and the pathological study showed hydatid cysts. Both patients had normal chest x ray and abdominal ultrasound examinations. They had an uneventful postoperative evolution. Echinococcosis must be considered in the differential diagnosis of cervical cysts in endemic area.

Mammary type I deiodinase is dependent on the suckling stimulus: differential role of norepinephrine and prolactin

Mammary deiodinase type I (M-D1) is present only during lactation and exhibits a clear direct correlation with lactation intensity (size of litters). The present work shows that M-D1 is suckling dependent and that intervals between suckling periods no longer than 12 h are essential to maintain this activity. Moreover, we find that with only 15 min of resuckling in 12-h nonsuckled mothers, the 50% decrease in both M-D1 messenger RNA and enzymatic activity could be restored to control values. This restorative effect by suckling may involve pre- and posttranscriptional mechanisms in which norepinephrine and PRL play important roles. Norepinephrine elicits a potent stimulatory effect on M-D1 messenger RNA and enzyme activities, whereas PRL only increases M-D 1 activity and may modulate the enzyme response to norepinephrine. Oxytocin and GH had no effect. These data suggest that the adrenergic nervous system and PRL could directly participate in mammary energetic expenditure, regulating the local T3 supply.

Frequency of spontaneous congenital defects in rhesus and cynomolgus macaques

This paper summarizes the spontaneous incidence of congenital defects in the rhesus and cynomolgus macaque colonies (Macaca mulatta and M. fascicularis) at the California Regional Primate Research Center. The computerized database used in this analysis included fetuses, term infants, juveniles, and adults that underwent a necropsy procedure over a 14-year period (1983-1996). The calculated malformation rates were 0.9% (40/4,390) and 0.3% (3/965) for the rhesus and cynomolgus monkey, respectively. Most of the observed malformations in both species affected the musculoskeletal and the cardiovascular systems, while a smaller number of defects were observed in the gastrointestinal, urogenital, endocrine, and central nervous systems. Inbreeding did not contribute to the spontaneous malformation incidence and there was no predilection for sex (male vs. female) or housing (indoors vs. outdoors) among the malformed cases. This spontaneous malformation database in our macaque colony aids in the interpretation of defects that occur in an experimental study as well as in the ongoing assessment of a healthy nonhuman primate breeding colony.

Kinetic characterisation of skin inner-ring deiodinative pathway and its correlation with circulating levels of reverse tri-iodothyronine in developing rainbow trout

The present study has demonstrated the presence of circulating reverse tri-iodothyronine (rT3) levels and its main generating pathway in rainbow trout. A specific rT3, RIA using thyronine-stripped sera in the standard curve was standardised, allowing precise and accurate quantification of radioimmunoassayable rT3. We also demonstrated that trout skin is an important source of rT3 production. T3 or thyroxine trout skin inner-ring deiodination (IRD) activity was assessed by using rT3 RIA and/or paper chromatography. The kinetic characterisation of this deiodinative pathway disclosed a typical deiodinase type III (DIII) enzyme, except for its conspicuous thermodependency which attained its maximal catalytic efficiency at 15 degrees C. This finding suggested the expression of enzymatic variants, which is a common functional array in teleosts. Both circulating rT3 and DIII activity were present in juvenile and adult individuals and were inversely correlated with age, weight and length. In conclusion, this study demonstrated that (1) skin IRD activity and its product rT3 are present throughout the development of rainbow trout, and (2) trout skin DIII activity attains its higher catalytic efficiency in the physiological range of temperature for this species, thus suggesting the expression of enzymatic variants.

Mitogenic effects of thyroxine and TRH on thyrotrophs and somatotrophs of the anterior pituitary gland in thyroidectomized rats

The question of whether thyroxine (T4) and TRH have a mitogenic effect on pituitary thyrotrophs and somatotrophs in thyroidectomized rats was investigated. Mitoses were counted in hematoxylin-eosin-stained or periodic acid-Schiff-hematoxylin-stained pituitary slides or immunostained for TSH or GH using male rats thyroidectomized for 5 months. Ten days before they were killed groups of rats were injected with different doses of T4 (0.5, 3 or 10 micrograms i.m. every second day for 10 days), TRH alone (100 ng s.c. three times a day for 10 days), or T4 plus TRH (same doses as above). Mitoses (stopped with colchicine) were counted in 1 mm2 areas at a magnification of x1000. In thyroidectomized rats, mitoses were not significantly increased and treatment with TRH or 0.5 microgram T4 alone in thyroidectomized rats did not affect mitotic counts. In thyroidectomized rats treated with higher doses of T4, mitoses were increased in a dose-dependent fashion. Simultaneous administration of TRH and T4 had a significant synergistic effect on pituitary mitoses in a T4 dose-dependent manner. The treatments also had differential effects on the relative percentages of cellular types in mitosis. Thus, 60% somatotrophs and 12.5% thyrotrophs were found in the euthyroid group. In thyroidectomized and thyroidectomized plus TRH groups, no somatotrophs in mitosis were seen, while thyrotrophs were 28.5% and 33.3% respectively. In thyroidectomized rats treated with low doses of T4, somatotrophs and thyrotrophs in mitosis increased to 38.4% and 80% respectively and, with simultaneous administration of a low dose of T4 plus TRH, although less effective than T4 alone, mitosis increased in somatotrophs and thyrotrophs to 11.1% and 54.5% respectively. A high dose of T4 alone did not increase the mitotic figures in somatotrophs (38.8%), while it diminished the percentage of thyrotrophs to 25%. The administration of high doses of T4 plus TRH had an opposite effect on the mitotic figures of somatotrophs and thyrotrophs and thus the percentage of somatotrophs increased to 50% while thyrotrophs decreased to 5.5%. Ten days of treatment with T4 were insufficient to reverse the histology to euthyroidism. It can be concluded that in long-standing hypothyroidism: (1) thyroid hormone replacement elicits a dose-dependent and differential proliferative response on pituitary thyrotrophs and somatotrophs, (2) TRH is devoid of mitogenic effects when administered alone and (3) the proliferative response of somatotrophs to T4 is enhanced by its co-administration with TRH, suggesting a permissive and/or synergistic effect of the thyroid hormone and TRH.

Cloning and expression of a 5'-iodothyronine deiodinase from the liver of Fundulus heteroclitus

Recent molecular cloning studies in mammals and amphibians have demonstrated that the types I, II, and III deiodinases constitute a family of selenoproteins of critical importance in metabolizing T4 to active (i.e. T3) and inactive (i.e. rT3) metabolites. In several tissues of teleost fish, various deiodinase processes have been described, but the structural and functional characteristics of these enzymes and their relationship to the deiodinases present in higher vertebrates remains uncertain. Using a complementary DNA library derived from the liver of the teleost Fundulus heteroclitus, we have identified a complementary DNA that codes for a deiodinase with functional characteristics virtually identical to those of the mammalian and amphibian type II deiodinase. Sequence analysis demonstrates a high degree of homology at both the nucleotide and predicted amino acid levels between the Fundulus clone and these previously characterized type II enzymes, including the presence of an in-frame TGA codon that codes for selenocysteine. These findings demonstrate that the deiodinase family of selenoproteins has been highly conserved during vertebrate evolution and underscores their importance in the regulation of thyroid hormone action.

Needs assessment for an urban native HIV and AIDS prevention program

At the request of Native community-based organizations in Montreal, a needs assessment for an HIV and AIDS education and prevention program for urban Natives was initiated. A five-session focus group concerning HIV and AIDS was attended by nine Native persons over a 2-month period. Data was collected using the guidelines of the HIV/AIDS Rapid Anthropological Assessment Procedures (AIDS RAP) developed by the Social and Behavioural Research Unit of the World Health Organization's Global Programme on AIDS. We followed these up with in-depth semistructured interviews with five different members of the Montreal Native community. The data were reviewed by a steering committee to ensure validity. Findings highlight the potential explosive route of transmission of HIV along networks of sexual interaction between persons in urban areas and then to rural partners. Maintaining control over the AIDS program planning within the community permits issues such as traditional values and healing practices to be discussed and taken into account.

Autonomic mediation of glucagon secretion during insulin-induced hypoglycemia in rhesus monkeys

Autonomic activation mediates the majority of the increase of glucagon secretion during insulin-induced hypoglycemia in several species including dogs, mice, and rats. However, the role of the autonomic nervous system to increase glucagon during hypoglycemia in humans remains controversial, and investigations in nonhuman primates have not been previously conducted. The autonomic contribution to glucagon secretion during hypoglycemia in a nonhuman primate was examined by two independent pharmacological approaches. Glucagon responses to clamped insulin-induced hypoglycemia were compared in conscious rhesus monkeys in the presence or absence of ganglionic blockade with trimethaphan, or during combined muscarinic and adrenergic receptor blockade with atropine, propranolol, and tolazoline. Insulin-induced hypoglycemia (plasma glucose = 1.9 +/- 0.1 mmol/l) activated parasympathetic nerves to the pancreas as assessed by increased plasma pancreatic polypeptide (PP) levels (delta = 135.0 +/- 36.8 pmol/l, P < 0.01), produced sympathoadrenal activation as assessed by elevations of plasma epinephrine (EPI) (delta = 22.3 +/- 2.95 nmol/l, P < 0.0005) and norepinephrine (NE) (delta = 3.72 +/- 0.77 mmol/l, P < 0.0025) and increased plasma immunoreactive glucagon (IRG) (delta = 920 +/- 294 ng/l, P < 0.025). Nicotinic ganglionic blockade with trimethaphan prevented parasympathetic (deltaPP = 16.5 +/- 16.3 pmol/l, P < 0.01 vs. control) and sympathoadrenal (deltaEPI = 1.52 +/- 0.98 nmol/l; deltaNE = -0.62 +/- 0.24 mmol/l, both P < 0.0025 vs. control) activation during hypoglycemia and inhibited the IRG response by 70% (delta = 278 +/- 67 ng/l, P < 0.025 vs. control). Combined muscarinic and adrenergic receptor blockade reduced parasympathetic activation (deltaPP = 48.3 +/- 16.3 pmol/l, P < 0.01 vs. control) and inhibited the IRG response by a similar degree to ganglionic blockade (deltaIRG = 284 +/- 60 ng/l, P < 0.025 vs. control). These results demonstrate by two independent pharmacological approaches that autonomic activation makes a substantial contribution to increased glucagon secretion during hypoglycemia of approximately 2.0 mmol/l in a species of nonhuman primate.