| 1. |
- Ahlman, Håkan, 1947, et al.
(författare)
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Somatostatin receptors on neuroendocrine tumors--a way to intraoperative diagnosis and localization.
- 1994
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Ingår i: The Yale journal of biology and medicine. - 0044-0086. ; 67:3-4, s. 215-21
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Tidskriftsartikel (refereegranskat)abstract
- Intraoperative radionuclide detection using 111In-DTPA-D-Phe1-octreotide was evaluated in five patients with midgut carcinoids and in three patients with recurrent medullary thyroid carcinoma. Three different time intervals (24, 48 and 120 hr) from injection of the radiopharmaceutical to surgery were used. At surgery, suspect tumors were measured by probe in situ and ex vivo after excision. All tissue specimens and blood samples withdrawn during surgery were measured for 111In activity, and tissue/blood activity concentration ratios were calculated. In situ measurements were valuable especially in neck surgery, where the probe was helpful not only in localization of tumors but also in the control of tumor clearance. Ex vivo measurements were helpful in diagnosing tumor tissue. All five patients with midgut carcinoids were somatostatin receptor-positive, while only three out of seven patients with medullary thyroid carcinoma were receptor-positive. The tissue/blood activity concentration ratios and probe measurement ratios were in general higher in patients with midgut carcinoid than in patients with medullary thyroid carcinoma. Of particular interest were the high tissue/blood concentration ratios in all receptor-positive patients at all time intervals studied. This fact suggests a potential role for radiolabelled octreotide in radiotherapy of these tumor types.
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| 2. |
- Ahlman, Håkan, 1947, et al.
(författare)
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The relevance of somatostatin receptors in thyroid neoplasia.
- 1997
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Ingår i: The Yale journal of biology and medicine. - 0044-0086. ; 70:5-6, s. 523-33
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- 111In-octreotide scintigraphy in patients with persistent medullary thyroid carcinoma (MTC) visualized tumors in about half of the surgically explored sites. Tumor visualization correlated with rapid tumor growth and large tumor volume as judged from calcitonin levels. The 111In concentration ratio between tumor (T) and blood (B) in surgically excised lymph node metastases of MTC showed a large variation, with low values for microscopic and high values for macroscopic metastases in individual patients. Three cases of MTC, Hürthle cell adenoma and papillary thyroid cancer are reported with preoperative scintigraphy, T/B ratios and Northern analyses of the surgical biopsies. Visualization of tumors was possible in the absence of sstr2 (the high affinity receptor for octreotide) with the exception of microscopic tumor growth. T/B values in the patient with Hürthle cell adenoma were similar to those found in the contralateral thyroid lobe with goitre. The relatively high uptake of 111In in benign thyroid conditions probably limits the use of octreotide scintigraphy in the diagnosis of primary tumors. The technique has certain advantages over radioiodine scintigraphy after the surgical treatment of thyroid tumors: no need for withdrawal of thyroxin substitution; a possibility to diagnose metastases of tumors that do not concentrate radioiodine (MTC, Hürthle cell cancer); and complementary information about metastatic sites of non-medullary thyroid cancer (papillary and follicular tumors).
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| 3. |
- Chen, DA, et al.
(författare)
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ECL cell morphology
- 1998
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Ingår i: The Yale journal of biology and medicine. - 0044-0086. ; 71:3-4, s. 217-231
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Tidskriftsartikel (refereegranskat)
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| 4. |
- Gustavsson, Erik, 1982-, et al.
(författare)
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The Ethical Relevance of "Alternatives" in Health Care Priority Setting - The Case of Preexposure Prophylaxis (PrEP) of HIV
- 2022
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Ingår i: The Yale Journal of Biology and Medicine. - : Yale Journal of Biology and Medicine, Inc.. - 0044-0086 .- 1551-4056. ; 95:3, s. 359-365
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Tidskriftsartikel (refereegranskat)abstract
- Preexposure prophylaxis for HIV is a drug that reduces the risk for an HIV-negative person to acquire HIV if taken prior to sex. It has been suggested that it is important for resource allocation decisions that there are alternatives (such as abstinence, masturbation, etc.) for individuals potentially benefitted by this prophylaxis. In this paper we explore this idea from an ethical perspective in relation to three notions often discussed in priority setting ethics, namely responsibility, outcomes, and severity of disease. While the relevance of alternatives may be explained in terms by responsibility-sensitive priority setting, such a view comes with several challenges. We then discuss two other ways in which this intuition could be better explained: (a) in terms of total outcome of health, and (b) in terms of severity of the condition.
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| 5. |
- Kölby, Lars, 1963, et al.
(författare)
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Histamine metabolism of gastric carcinoids in Mastomys natalensis.
- 1998
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Ingår i: The Yale journal of biology and medicine. - 0044-0086. ; 71:3-4, s. 207-15
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Tidskriftsartikel (refereegranskat)abstract
- Pharmacological inhibition of gastric acid secretion and subsequent hypergastrinemia in Mastomys natalensis is an experimental model well suited for the study of gastric carcinoid formation. The genetic susceptibility of Mastomys to develop such tumors is a feature reminiscent of the situation in patients with the MEN-1 Zollinger Ellison syndrome, in whom tumor-induced hypergastrinemia, promotes the development of gastric carcinoids. Chronic hypergastrinemia, induced by the irreversible H2-receptor antagonist loxtidine will cause carcinoid formation in Mastomys already after four to six months. As in humans, gastric carcinoids in Mastomys are mainly composed of enterochromaffinlike (ECL) cells and have low malignant potential. Administration of exogenous gastrin to normal young animals increases the expression of histidine decarboxylase (HDC) mRNA in the oxyntic mucosa within 30 minutes. Endogenous hypergastrinemia, induced by short-time loxtidine treatment (three to 29 days) enhances the expression of HDC mRNA, histamine contents and ECL cell numbers in the oxyntic mucosa. Long-term loxtidine treatment (seven to 21 months) results in sustained hypergastrinemia and tumor formation. Tumor-bearing animals exhibited an increase in HDC mRNA and histamine content in the oxyntic mucosa as well as increased urinary excretion of the main histamine metabolite, tele-methylimidazole acetic acid (MeImAA). Subsequent to cessation of loxtidine treatment for two weeks, all parameters of histamine metabolism were normalized in tumor-bearing animals. These results indicate that gastric carcinoids developing during hypergastrinemia are well-differentiated neoplasms whose histamine synthesis and metabolism is regulated by plasma gastrin.
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| 6. |
- Leuzy, Antoine, et al.
(författare)
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In vivo Detection of Alzheimer's Disease.
- 2018
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Ingår i: The Yale journal of biology and medicine. - 1551-4056 .- 0044-0086. ; 91:3, s. 291-300
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Forskningsöversikt (refereegranskat)abstract
- Recent revisions to the diagnostic criteria for Alzheimer's disease (AD) incorporated conceptual advances in the field. Specifically, AD is now recognized to encompass a continuum, spanning from preclinical (accruing brain pathology in the absence of symptoms) through symptomatic predementia (prodromal AD, mild cognitive impairment) and dementia phases. The role of biological markers (biomarkers) of both the underlying molecular pathologies and related neurodegenerative changes has also been acknowledged. In this abridged review, we provide an overview of fluid (cerebrospinal fluid and blood) and molecular imaging-based biomarkers used within the field and discuss the potential role of computer driven artificial intelligence approaches for both the early and accurate identification of AD and as a tool for population enrichment in clinical trials testing candidate disease modifying therapies.
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| 7. |
- Nilsson, Ola, 1957, et al.
(författare)
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Praomys (Mastomys) natalensis: a model for gastric carcinoid formation.
- 1992
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Ingår i: The Yale journal of biology and medicine. - 0044-0086. ; 65:6
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Tidskriftsartikel (refereegranskat)abstract
- The gastric carcinoid tumors of Praomys (Mastomys) natalensis have been reviewed with respect to histogenesis, development, biochemistry, and morphological properties. Multicentric gastric carcinoids frequently develop in the oxyntic mucosa of aging Mastomys. The development of these tumors can be significantly enhanced by drug-induced hypergastrinemia, e.g., histamine2-receptor blockade. Spontaneous and drug-induced gastric carcinoids are endocrine in nature, as evidenced by their argyrophilic staining properties and chromogranin A content. They are also rich in histidine decarboxylase activity and produce large amounts of histamine, although other hormones, such as peptide YY and enteroglucagon, have also been demonstrated in these tumors. Ultrastructurally, gastric carcinoids are composed of tumor cells with typical secretory granules resembling those of enterochromaffin-like (ECL) cells. A close examination of the gastric carcinoids in Mastomys reveals striking similarities with gastric carcinoids developing in humans suffering from chronic atrophic gastritis type A or from the Zollinger-Ellison syndrome in combination with multiple endocrine neoplasia type 1 (MEN-1). Both these conditions are associated with hypergastrinemia and a higher risk for developing multi-centric gastric carcinoids of ECL-cell origin. The Mastomys tumor model therefore appears to be a significant experimental model in which induction and formation of gastric carcinoid tumors can be studied.
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