Prehospital Ultrasound Diagnosis of Massive Pulmonary Embolism by Non-Physicians: A Case Series.

Massive pulmonary embolism (hemodynamically unstable, defined as systolic BP <90 mmHg) has significant morbidity and mortality. Point of care ultrasound (POCUS) has allowed clinicians to detect evidence of massive pulmonary embolism much earlier in the patient's clinical course, especially when patient instability precludes computerized tomography confirmation. POCUS detection of massive pulmonary embolism has traditionally been performed by physicians. This case series demonstrates four cases of massive pulmonary embolism diagnosed with POCUS performed by non-physician prehospital personnel.

Directed Palladium-Catalyzed Acetoxylation of Indolines. Total Synthesis of N-Benzoylcylindrocarine.

We describe a palladium-catalyzed C7-acetoxylation of indolines with a range of amide directing groups. While a variety of substituents are tolerated on the indoline-core and the N1-acyl group, the acetoxylation is most sensitive to the C2- and C6-indoline substituents. The practicality of this indoline C7-acetoxylation is demonstrated using a cinnamamide substrate on a mmol scale. Several N1-acyl groups, including those present in natural alkaloids, guide C7-acetoxylation of indoline substrates over a competitive C5-oxidation. The application of this chemistry allowed for the first synthesis of N-benzoylcylindrocarine by late-stage C17-acetoxylation of N-benzoylfendleridine.

Enantioselective Synthesis of (-)-Vallesine: Late-Stage C17-Oxidation via Complex Indole Boronation.

The first enantioselective total synthesis of (-)-vallesine via a strategy that features a late-stage regioselective C17-oxidation followed by a highly stereoselective transannular cyclization is reported. The versatility of this approach is highlighted by the divergent synthesis of the archetypal alkaloid of this family, (+)-aspidospermidine, and an A-ring-oxygenated derivative, (+)-deacetylaspidospermine, the precursor to (-)-vallesine, from a common intermediate.

Enantioselective Total Synthesis of (-)-Deoxoapodine.

The first enantioselective total synthesis of (-)-deoxoapodine is described. Our synthesis of this hexacyclic aspidosperma alkaloid includes an efficient molybdenum-catalyzed enantioselective ring-closing metathesis reaction for the desymmetrization of an advanced intermediate that introduces the C5-quaternary stereocenter. After C21-oxygenation, the pentacyclic core was accessed by electrophilic C19-amide activation and transannular spirocyclization. A biogenetically inspired dehydrative C6-etherification reaction proved highly effective to secure the F-ring and the fourth contiguous stereocenter of (-)-deoxoapodine with complete stereochemical control.

Concise Total Syntheses of (+)-Haplocidine and (+)-Haplocine via Late-Stage Oxidation of (+)-Fendleridine Derivatives.

We report the first total syntheses of (+)-haplocidine and its N1-amide congener (+)-haplocine. Our concise synthesis of these alkaloids required the development of a late-stage and highly selective C-H oxidation of complex aspidosperma alkaloid derivatives. A versatile, amide-directed ortho-acetoxylation of indoline amides enabled our implementation of a unified strategy for late-stage diversification of hexacyclic C19-hemiaminal ether structures via oxidation of the corresponding pentacyclic C19-iminium ions. An electrophilic amide activation of a readily available C21-oxygenated lactam, followed by transannular cyclization and in situ trapping of a transiently formed C19-iminium ion, expediently provided access to hexacyclic C19-hemiaminal ether alkaloids (+)-fendleridine, (+)-acetylaspidoalbidine, and (+)-propionylaspidoalbidine. A highly effective enzymatic resolution of a non-ß-branched primary alcohol (E = 22) allowed rapid preparation of both enantiomeric forms of a C21-oxygenated precursor for synthesis of these aspidosperma alkaloids. Our synthetic strategy provides succinct access to hexacyclic aspidosperma derivatives, including the antiproliferative alkaloid (+)-haplocidine.

Direct Observation of Intermediates Involved in the Interruption of the Bischler-Napieralski Reaction.

The first mechanistic investigation of electrophilic amide activation of α,α-disubstituted tertiary lactams and the direct observation of key intermediates by in situ FTIR, (1)H, (13)C, and (19)F NMR in our interrupted Bischler-Napieralski-based synthetic strategy to the aspidosperma alkaloids, including a complex tetracyclic diiminium ion, is discussed. The reactivity of a wide range of pyridines with trifluoromethanesulfonic anhydride was systematically examined, and characteristic IR absorption bands for the corresponding N-trifluoromethanesulfonylated pyridinium trifluoromethanesulfonates were assigned. The reversible formation of diiminium ether intermediates was studied, providing insight into divergent mechanistic pathways as a function of the steric environment of the amide substrate and stoichiometry of reagents. Importantly, when considering base additives during electrophilic amide activation, more hindered α-quaternary tertiary lactams require the use of non-nucleophilic pyridine additives in order to avoid deactivation via a competing desulfonylation reaction. The isolation and full characterization of a tetracyclic iminium trifluoromethanesulfonate provided additional correlation between in situ characterization of sensitive intermediates and isolable compounds involved in this synthetic transformation.

Prolonged survival after hepatic artery embolization in patients with midgut carcinoid syndrome.

BACKGROUND: Hepatic artery embolization (HAE) is a palliative treatment for patients with liver metastases from neuroendocrine tumours. HAE reduces hormonal symptoms, but its impact on survival has been questioned. METHODS: Biochemical responses and survival in consecutive patients with disseminated liver metastases from midgut carcinoid tumours were studied after HAE. Repeat HAE was performed in selected patients with radiological and biochemical signs of progression. RESULTS: Of 107 patients who had HAE, the median survival from the first procedure was 56 (range 1-204) months. Prolonged survival showed a strong correlation with reduction of urinary 5-hydroxyindoleacetic acid (P = 0.003) and plasma chromogranin A (P = 0.001) levels. The biochemical response to repeat HAE was similar to that for the first procedure (P = 0.002). The complication rate was low (7.5 per cent), as was the mortality rate (1.9 per cent) within 1 month of HAE. CONCLUSION: HAE is safe, provides good control of hormonal symptoms, and prolongs survival in biochemically responsive patients. It is a valuable palliative option for patients with midgut carcinoid syndrome due to liver metastases and can be repeated in patients with a favourable response to the first procedure.

Successful receptor-mediated radiation therapy of xenografted human midgut carcinoid tumour.

Somatostatin receptor (sstr)-mediated radiation therapy is a new therapeutic modality for neuroendocrine (NE) tumours. High expression of sstr in NE tumours leads to tumour-specific uptake of radiolabelled somatostatin analogues and high absorbed doses. In this study, we present the first optimised radiation therapy via sstr using [(177)Lu-DOTA(0)-Tyr(3)]-octreotate given to nude mice xenografted with the human midgut carcinoid GOT1. The tumours in 22 out of 23 animals given therapeutic amounts showed dose-dependent, rapid complete remission. The diagnostic amount (0.5 MBq [(177)Lu-DOTA(0)-Tyr(3)]-octreotate) did not influence tumour growth and was rapidly excreted. In contrast, the therapeutic amount (30 MBq [(177)Lu-DOTA(0)-Tyr(3)]-octreotate) induced rapid tumour regression and entrapment of (177)Lu so that the activity concentration of (177)Lu remained high, 7 and 13 days after injection. The entrapment phenomenon increased the absorbed dose to tumours from 1.6 to 4.0 Gy MBq(-1) and the tumours in animals treated with 30 MBq received 120 Gy. Therapeutic amounts of [(177)Lu-DOTA(0)-Tyr(3)]-octreotate rapidly induced apoptosis and gradual development of fibrosis in grafted tumours. In conclusion, human midgut carcinoid xenografts can be cured by receptor-mediated radiation therapy by optimising the uptake of radioligand and taking advantage of the favourable change in biokinetics induced by entrapment of radionuclide in the tumours.

Uptake of meta-iodobenzylguanidine in neuroendocrine tumours is mediated by vesicular monoamine transporters.

The radio-iodinated noradrenaline analogue meta-iodobenzylguanidine (MIBG) can be used for scintigraphy and radiation therapy of neuroendocrine (NE). The aim of the present study was to study the importance of vesicular monoamine transporters (VMATs) for the uptake of (123)I-MIBG in NE tumours. In nude mice, bearing the human transplantable midgut carcinoid GOT1, all organs and xenografted tumours accumulated (123)I after i.v. injection of (123)I-MIBG. A high concentration of (123)I was maintained in GOT1 tumours and adrenals, which expressed VMATs, but rapidly decreased in all other tissues. In the VMAT-expressing NE tumour cell lines GOT1 and BON and in VMAT-expressing primary NE tumour cell cultures (carcinoids, n=4 and pheochromocytomas, n=4), reserpine significantly reduced the uptake of (123)I-MIBG. The membrane pump inhibitor clomipramine had no effect on the uptake of (123)I-MIBG in GOT1 and BON cells, but inhibited the uptake in one out of four primary carcinoid cell cultures and three out of four primary pheochromocytoma cell cultures. In conclusion, VMATs and secretory granules are of importance for the uptake and retention of (123)I-MIBG in NE tumours. Information about the type and degree of expression of VMATs in NE tumours may be helpful in future to select patients suitable for radiation therapy with radio-iodinated MIBG.

Randomized clinical trial of the effect of interferon alpha on survival in patients with disseminated midgut carcinoid tumours.

BACKGROUND: Midgut carcinoid tumours often present with widespread disease making curative surgery impossible. Medical treatment therefore plays a major role in the treatment of these patients. METHODS: In this prospective randomized study, the effect of interferon (IFN) alpha on survival and risk of tumour progression was evaluated in 68 patients with midgut carcinoid tumours metastatic to the liver. All patients had undergone primary surgical treatment and hepatic arterial embolization of liver metastases before randomization. Patients were randomized to treatment with either octreotide alone (n = 35) or octreotide in combination with IFN-alpha (n = 33). RESULTS: Forty-one of the 68 patients died during a follow-up period of 33-120 months, equivalent to a 5-year survival rate of 46.5 per cent. There was no significant difference in survival between patients treated with octreotide alone (5-year survival rate 36.6 per cent) and those given octreotide in combination with IFN-alpha (56.8 per cent). However, patients treated with IFN-alpha had a significantly reduced risk of tumour progression during follow-up (P = 0.008). CONCLUSION: Addition of IFN-alpha to octreotide may retard tumour growth in patients with midgut carcinoid tumours.

NESP55, a novel chromogranin-like peptide, is expressed in endocrine tumours of the pancreas and adrenal medulla but not in ileal carcinoids.

Neuroendocrine secretory protein 55, NESP55, is an acidic protein belonging to the chromogranin family. The distribution of NESP55 in human tumours is not known. The aim of the present study was to study the expression of NESP55 in human gastrointestinal, pancreatic and adrenal tumours. A total of 118 human endocrine and nonendocrine tumours were examined by immunocytochemistry, and compared to the expression of chromogranin A (CgA) in the same tumours. Pancreatic endocrine tumours (14 out of 25), pheochromocytomas (19 out of 19), and neuroblastomas (seven out of 14) expressed NESP55, with the same strong labelling pattern in both benign and malignant tumours. Expression of NESP55 in pancreatic endocrine tumours and pheochromocytomas was confirmed by Western and Northern blot analysis. Immunocytochemical analysis demonstrated no labelling in ileal carcinoids (zero out of 15), and adrenocortical adenomas (zero out of 15). The majority of gastrointestinal and pancreatic carcinomas were negative for NESP55, with focal staining observed in two out of 30 tumours. In contrast, CgA was present in all neuroendocrine tumours examined (25 out of 25 pancreatic endocrine tumours, 19 out of 19 pheochromocytomas, 14 out of 14 neuroblastomas and 15 out of 15 ileal carcinoids). Thus, the expression of NESP55 in endocrine tumours of the gastrointestinal tract, pancreas and adrenals differs from that of CgA. Neuroendocrine secretory protein 55 is found in a subset of neuroendocrine tumours showing differentiation towards adrenal chromaffin cells and pancreatic islets cells.

Differential expression of vesicular monoamine transporter (VMAT) 1 and 2 in gastrointestinal endocrine tumours.

Neuroendocrine tumours are characterized by their capacity to produce hormones, which are stored in vesicles and secretory granules. Demonstration of granule/vesicle proteins in tumours is taken as evidence of neuroendocrine differentiation. Vesicular monoamine transporters (VMAT1 and VMAT2) mediate the transport of amines into vesicles of neurons and endocrine cells. The expression of VMAT1 and VMAT2 and the usefulness of VMAT1 and VMAT2 in the histopathological diagnosis of gastrointestinal endocrine tumours have not been fully explored. This study therefore investigated the expression of VMAT1 and VMAT2 in 211 human gastrointestinal tumours by immunocytochemistry and western blotting. VMAT1 and/or VMAT2 were demonstrated in the majority of amine-producing endocrine tumours of gastric, ileal, and appendiceal origin. Serotonin-producing endocrine tumours (ileal and appendiceal carcinoids) expressed predominantly VMAT1, while histamine-producing endocrine tumours (gastric carcinoids) expressed VMAT2 almost exclusively. In peptide-producing endocrine tumours such as rectal carcinoids and endocrine pancreatic tumours, only a small number of immunopositive tumour cells were observed. No labelling was found in non-endocrine tumours, including gastric, colorectal and pancreatic adenocarcinomas and gastrointestinal stromal tumours. In conclusion, VMAT1 and VMAT2 are differentially expressed by gastrointestinal endocrine tumours, with a pattern specific for each tumour type, reflecting their neuroendocrine differentiation and origin. VMAT1 and VMAT2 may therefore become valuable markers in the classification of neuroendocrine tumours and may also indicate patients suitable for radioisotope treatment operating via these transporter systems.

Dosimetric comparison of radionuclides for therapy of somatostatin receptor-expressing tumors.

PURPOSE: Therapy of tumors expressing somatostatin receptors, sstr, has recently been clinically tested using somatostatin analogues labeled with (111)In and (90)Y. Several other radionuclides, i.e., (131)I, (161)Tb, (64)Cu, (188)Re, (177)Lu, and (67)Ga, have also been proposed for this type of therapy. The aim of this work was to investigate the usefulness of the above-mentioned radionuclides bound to somatostatin analogues for tumor therapy. METHODS: Biokinetic data of (111)In-labeled octreotide in mice and man were used, primarily from our studies but sometimes from the literature. Dosimetric calculations were performed with the assumption that biokinetics were similar for all radionuclides bound to somatostatin analogues. The cumulated tumor:normal-tissue activity concentration, TNC was calculated for the various physical half-lives of the radionuclides. Using mathematical models, the tumor:normal-tissue mean absorbed dose rate ratio, TN D and tumor:normal-tissue mean absorbed dose ratio, TND, were calculated for various tumor sizes in mice and humans. RESULTS: TNC of radionuclide-labeled octreotide increased with physical half-life for most organs, both in mice and in humans. TN D showed that radionuclides emitting electrons with too high energy are not suitable for therapy of small tumors. Furthermore, radionuclides with a higher frequency of photon emissions relative to electron emissions will yield lower TN D and are thus less suitable for therapy than radionuclides with a lower frequency of photon emissions. The TND was highest for (161)Tb in both mice and humans. CONCLUSIONS: The results demonstrate that long-lived radionuclides, which emit electrons with rather low energy and which have low frequency of photon emissions, should be the preferred therapy for disseminated small sstr-expressing tumors.

Biokinetics of 111In-DTPA-D-Phe(1)-octreotide in nude mice transplanted with a human carcinoid tumor.

The long time biokinetics of the radiolabeled somatostatin analogues 111In-DTPA-D-Phe(1)-octreotide was studied in nude mice transplanted with the human carcinoid tumor, GOT1. The results were compared with those from the patient with the original tumor. This patient has been diagnosed and later treated with 111In-DTPA-D-Phe(1)-octreotide. The animals received about 2 MBq 111In-DTPA-D-Phe(1)-octreotide (0.1 microg) by injection into a tail vein. The animals were killed 0.5 h-14 d after injection of the radiopharmaceutical. Tumor tissue and normal tissues were collected and weighed and measured for 111In activity. The 111In uptake in the tumor was higher than in all normal tissues except the kidneys. The tumor-to-normal-tissue activity concentration, TNC, increased with time for all normal tissues studied. These data were similar to those observed for the original tumor in the patient. The similar biokinetics for 111In-DTPA-D-Phe(1)-octreotide in the tumor-bearing mice and the patient makes this animal model suitable as a model for evaluation of therapy of somatostatin receptor (sstr) expressing tumors with radiolabeled somatostatin analogues. Furthermore, the increase with time of TNC both in mice and the patient indicates that long-lived radionuclides are preferred for therapy with radiolabeled somatostatin analogues.

A transplantable human carcinoid as model for somatostatin receptor-mediated and amine transporter-mediated radionuclide uptake.

A human midgut carcinoid tumor was successfully transplanted into nude mice and propagated for five consecutive generations (30 months) with well-preserved phenotype. Tumor cells in nude mice expressed identical neuroendocrine markers as the original tumor, including somatostatin receptors (somatostatin receptors 1 to 5) and vesicular monoamine transporters (VMAT1 and VMAT2). Because of the expression of somatostatin receptors and VMAT1 and VMAT2 the grafted tumors could be visualized scintigraphically using the somatostatin analogue 111In-octreotide and the catecholamine analogue 123I-metaiodobenzylguanidine. The biokinetics of the somatostatin analogue 111In-octreotide in the tumors was studied and showed a high retention 7 days after administration. Cell cultures were re-established from transplanted tumors. Immunocytochemical and ultrastructural studies confirmed the neuroendocrine differentiation. The human origin of transplanted tumor cells was confirmed by cytogenetic and fluorescence it situ hybridization analyses. Spontaneous secretion of serotonin and its metabolite, 5-hydroxyindole acetic acid, from tumor cells was demonstrated. The tumor cells increased their [Ca2+]i in response to beta-adrenoceptor stimulation (isoproterenol) and K+-depolarization. All somatostatin receptor subtypes could be demonstrated in cultured cells. This human transplantable carcinoid tumor, designated GOT1, grafted to nude mice, will give unique possibilities for studies of somatostatin receptor- and VMAT-mediated radionuclide uptake as well as for studies of secretory mechanisms.

Multicolor spectral karyotype analysis of a transplantable human ileal carcinoid.

In this report we present the results of a combined cytogenetic and multicolor spectral karyotype (SKY) analysis of a transplantable human ileal carcinoid (GOT1). By using SKY it was possible to identify the origin and organization of all clonal marker chromosomes and to identify cryptic translocations not detectable by conventional chromosome banding. The stemline karyotype of low passage GOT1 cells was interpreted as 43,XX, der(1)del(1)(?), inv(2)(p25q13), del(3)(p21), del(5)(q13q31), del(6)(q13), -9, -13, -15, del(16) (q22). Analysis of the GOT1 cells after about 2.5 years of propagation in nude mice allowed us to follow the in vivo progression of this tumor. Relatively few additional rearrangements had occurred during this period, indicating that the GOT1 cells are genetically stable. Most of the abnormalities detected result in loss of whole or parts of chromosomes, suggesting that loss of multiple chromosomal regions, presumably containing tumor suppressor genes, might be important genetic events in ileal carcinoids.

111In-DTPA-D-Phe1-octreotide binding and somatostatin receptor subtypes in thyroid tumors.

UNLABELLED: The purpose of this study was to evaluate the potential for therapy of thyroid tumors using the radiolabeled somatostatin (SS) analog octreotide. METHODS: Concentrations of 111In activity in human thyroid tumors and normal thyroid tissue and blood samples were determined 1-15 d after intravenous injection of 111In-diethylenetriaminepentaacetic acid-Phe1-octreotide. The results were compared with SS receptor (sstr subtype profile (by Northern blot analysis) and the relative expression of the second subtype, sstr2 (by ribonuclease protection assay, RPA). The true tumor volumes in lymph node metastases from 1 patient were estimated. In total, tissues from 68 patients were included in the study. RESULTS: The highest tumor-to-blood ratio (T/B) for medullary thyroid carcinoma (MTC) was 360; for follicular adenoma (FA), 190; for Hurthle cell adenoma (HCA), 140; and for Hurthle cell carcinoma (HCC) and papillary carcinoma (PC), 70. The corresponding value was 7-18 for normal thyroid tissue, with higher values for colloid goiter (8-48) and thyroiditis (7-120). A high T/B was related to a large fraction of tumor cells in lymph node metastases. T/Bs were higher for the tumor samples with expression of sstr2 at Northern blot analysis than for those without. All thyroid tumor types regularly expressed sstr1, sstr3, sstr4, and sstr5. sstr2 was expressed in most MTC tumors but was not detected in FA or PC and was irregularly expressed in HCA and HCC. However, RPA analysis detected sstr2 in all tumors studied. CONCLUSION: Despite the lack of sstr2 at Northern blot analysis in most of the thyroid tumors studied, high T/Bs were in general found when compared with corresponding values for normal thyroid tissue. The sometimes extremely high ratios are promising and indicate a possibility of using radiolabeled octreotide for radiation therapy of sstr-positive tumors in the future.

Expression of cholecystokinin-B/gastrin receptors in medullary thyroid cancer.

OBJECTIVE: To characterise the cholecystokinin (CCK) receptor subtypes in medullary thyroid cancer by measuring the expression of CCK-A and CCK-B/gastrin receptor mRNA. DESIGN: Open study. SETTING: Teaching hospital, Sweden. SUBJECTS: 6 patients with medullary thyroid cancer. INTERVENTION: Pentagastrin stimulation test and measurement of calcitonin concentration. Biopsy specimens were analysed using reverse transcription polymerase chain reaction (RT-PCR). MAIN OUTCOME MEASURE: Presence of CCK-A and CCK-B/gastrin receptors. RESULTS: All 6 patients with medullary thyroid cancer had positive pentagastrin tests preoperatively. CCK-B/gastrin receptors but not CCK-A receptors were detected by RT-PCR in all six biopsy specimens. By contrast, no CCK receptors were found in normal thyroid tissues or in other thyroid tumours (follicular adenoma, papillary carcinoma, or anaplastic carcinoma). CONCLUSION: The presence of CCK-B/gastrin receptors in medullary thyroid tumours may have important clinical implications.

Expression of somatostatin receptors in oncocytic (Hürthle cell) neoplasia of the thyroid.

Ten consecutive patients with Hürthle cell lesions of the thyroid (nodule/adenoma/carcinoma) were studied by (111)In-DTPA-D-Phe1-octreotide scintigraphy. Octreotide scintigraphy localized the primary Hürthle cell tumour in eight patients as distinct areas of increased uptake of radionuclide. Two patients with Hürthle cell carcinoma, previously thyroidectomized, had their metastases visualized by octreotide scintigraphy. Northern analyses showed expression of multiple somatostain receptor subtypes. Visualization of the Hürthle cell tumour may be due to a higher expression of somatostatin receptors in the lesions than in surrounding normal thyroid tissue. The tissue/blood (111)In concentration ratios for tumour samples from five patients showed clearly higher values than observed for normal connective tissue, muscle or lymph nodes. A relatively high uptake of (111)In was also observed in goiter tissue, which may lead to misinterpretations. The main indication for octreotide scintigraphy in patients with Hürthle cell carcinoma is suspicion of metastatic disease.