43 research outputs found
Systematic review of factors influencing patient and practitioner delay in diagnosis of upper gastrointestinal cancer
As knowledge on the causation of cancers advances and new treatments are developed, early recognition and accurate diagnosis becomes increasingly important. This review focused on identifying factors influencing patient and primary care practitioner delay for upper gastrointestinal cancer. A systematic methodology was applied, including extensive searches of the literature published from 1970 to 2003, systematic data extraction, quality assessment and narrative data synthesis. Included studies were those evaluating factors associated with the time interval between a patient first noticing a cancer symptom and presenting to primary care, between a patient first presenting to primary care and being referred to secondary care, or describing an intervention designed to reduce those intervals. Twenty-five studies were included in the review. Studies reporting delay intervals demonstrated that the patient phase of delay was greater than the practitioner phase, whilst patient-related research suggests that recognition of symptom seriousness is more important than recognition of the presence of the symptom. The main factors related to practitioner delay were misdiagnosis, application and interpretation of tests, and the confounding effect of existing disease. Greater understanding of patient factors is required, along with evaluation of interventions to ensure appropriate diagnosis, examination and investigation
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Hematoporphyrin phototherapy of cancer.
Hematoporphyrin phototherapy of cancer is a new modality for cancer diagnosis and treatment that is currently undergoing clinical trials worldwide. A variety of tumors have been studied, e.g., breast (mostly recurrent skin), lung, bladder, eye, head and neck, gynecological and brain. The most success to date has been with lung and the gynecological tract. Cell and animal studies are being conducted to elucidate the basic photobiological mechanisms involved, as well as the histopathological events associated with tumor destruction. Although major questions remain to be resolved, hematoporphyrin phototherapy is an exciting new therapeutic modality for the treatment of cancer, especially in sites where the unique features of lasers and fiber optics are advantageous
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Hematoporphyrin phototherapy of cancer.
Hematoporphyrin phototherapy of cancer is a new modality for cancer diagnosis and treatment that is currently undergoing clinical trials worldwide. A variety of tumors have been studied, e.g., breast (mostly recurrent skin), lung, bladder, eye, head and neck, gynecological and brain. The most success to date has been with lung and the gynecological tract. Cell and animal studies are being conducted to elucidate the basic photobiological mechanisms involved, as well as the histopathological events associated with tumor destruction. Although major questions remain to be resolved, hematoporphyrin phototherapy is an exciting new therapeutic modality for the treatment of cancer, especially in sites where the unique features of lasers and fiber optics are advantageous
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Soluble suppressor factors elaborated in experimental malignant ascites.
Soluble suppressor factors in the sera of cancer patients inhibit lectin-stimulated lymphocyte proliferation. These factors, derived from human material, preclude easy corroboration by other investigators. To gain a general understanding of soluble suppressor factors and to avoid the necessary restrictions of human experimentation, an animal model was devised. Sprague-Dawley rats were injected ip with the Walker 256 carcinoma. The resultant ascites proved to be a stable, reproducible source of soluble suppressor factors. Ascites inhibited phytohemagglutinin (PHA)-induced blastogenesis of normal splenocytes by 98%. The possibility of a toxic effect was eliminated by vital staining of splenocytes and by examination in a specific lymphotoxin assay. Suppressor activity persisted after heating at 100 degrees C for 40 min. Extraction by lipid solvents revealed that the bulk of suppressor activity resides in the lipid phase. The active fraction of heat-treated ascites passed through an Amicon PM-10 filter. Thin-layer chromatography revealed the presence of prostaglandins E2 and F2 alpha. Tissue culture supernatants from short-term cultures derived from tumor-bearing animals revealed suppressor activity from thymus, spleen, and liver cultures (97, 91, and 71%, respectively). No suppressor activity was detected in cultures of cancer cells. This study has demonstrated in this animal model that prostaglandins play a major role in suppression of lectin-induced blastogenesis. All suppressor factors appear to be host derived. An understanding of the mechanism of release of these suppressor substances may open new avenues in the immunotherapy of cancer
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Heterogeneity of soluble suppressor factors in rat malignant ascites.
A study was undertaken to enumerate and partially characterize soluble factors generated by tumor-bearing animals capable of suppressing PHA-induced splenocyte proliferation. Sprague-Dawley rats were induced to form malignant ascites by the intraperitoneal injection of the Walker 256 carcinoma. Intact ascites suppressed splenocyte proliferation by 96%. Molecular sieving of the ascites by means of ultrafiltration (10-kilodalton particle cutoff) revealed suppressor activity to reside in both the ultrafiltrate and retentate. Further enumeration of suppressor factors was achieved by preparative polyacrylamide gel electrophoresis of the ascites ultrafiltrate and retentate. Five discrete bands of suppressor activity were resolved in the ultrafiltrate, three of which were heat-labile. Three discrete bands of suppressor activity were resolved in the retentate, none of which were heat-labile. This study underscores the complexity and heterogeneity of soluble factors elaborated in a cancer-bearing animal
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Heterogeneity of soluble suppressor factors in rat malignant ascites.
A study was undertaken to enumerate and partially characterize soluble factors generated by tumor-bearing animals capable of suppressing PHA-induced splenocyte proliferation. Sprague-Dawley rats were induced to form malignant ascites by the intraperitoneal injection of the Walker 256 carcinoma. Intact ascites suppressed splenocyte proliferation by 96%. Molecular sieving of the ascites by means of ultrafiltration (10-kilodalton particle cutoff) revealed suppressor activity to reside in both the ultrafiltrate and retentate. Further enumeration of suppressor factors was achieved by preparative polyacrylamide gel electrophoresis of the ascites ultrafiltrate and retentate. Five discrete bands of suppressor activity were resolved in the ultrafiltrate, three of which were heat-labile. Three discrete bands of suppressor activity were resolved in the retentate, none of which were heat-labile. This study underscores the complexity and heterogeneity of soluble factors elaborated in a cancer-bearing animal