Environmental trade-offs of pig production systems under varied operational efficiencies.

Production of pork, the most consumed meat globally, is estimated to emit 668 m tonnes CO2-eq of greenhouse gases each year. Amongst various production systems that comprise the pig industry, grain-based intensive production is widely regarded as the largest polluter of the environment, and thus it is imperative to develop alternative systems that can provide the right balance between sustainability and food security. Using an original dataset from the Republic of Ireland, this paper examines the life-cycle environmental impacts of representative pig farms operating under varying production efficiencies. For the baseline farm with an average production efficiency, global warming potential (GWP), acidification potential (AP) and eutrophication potential (EP) per kg carcass weight departing the slaughterhouse were estimated to be 3.5 kg CO2-eq, 43.8 g SO2-eq and 32.1 g PO4-eq, respectively. For herds with a higher production efficiency, a 9% improvement in feed conversion ratio was met by 6%, 15% and 12% decreases in GWP, EP, AP, respectively. Scenario and sensitivity analyses also revealed that (a) a switch to high-protein diets results in lower GWP and higher AP and EP, and (b) reducing transportation distances by sourcing domestically produced wheat and barley does not lower environmental impacts in any notable manner. To improve cross-study comparability of these findings, results based on an auxiliary functional unit, kg liveweight departing the farm gate, are also reported.

Immunoperoxidase techniques: the deleterious effect of sodium azide on the activity of peroxidase conjugates.

The effect of including sodium azide as a bacteriostatic agent in solutions used to dilute antibodies conjugated with the enzyme horseradish peroxidase was examined. An enzyme-linked immunosorbent assay (ELISA) and an immunohistochemical method were used and both techniques demonstrated an inhibitory effect of sodium azide on the activity of the peroxidase conjugates. It is concluded that the use of sodium azide in solutions used to dilute peroxidase conjugates is to be avoided.

Biological markers in lung cancer: an immunocytochemical approach.

In oat cell (small cell) carcinoma and, to some extent, in other histological types of lung cancer, improved forms of treatment have resulted in prolongation of survival and even cure. Progress is hampered by the lack of reliable biochemical markers such as those which have completely changed the management and outlook in testicular and gestational carcinoma. Carcinoembryonic antigen (CEA) has been of some value. Raised circulating levels of calcitonin and of adrenocorticotropic hormone (ACTH) are found in many patients with lung cancer but have not proved as useful for monitoring disease progression. It is probable that since lung tumors form a heterogeneous population, production of markers varies with histological type. Our approach has been to affinity purify those polyclonal antisera to potential lung tumor markers which are not yet available as monoclonal hybridoma antibodies and to examine 10 representative resection specimens of each of the four common carcinoma types--squamous, adeno-, large cell, and small cell using an indirect immunoperoxidase localization technique on formalin-fixed paraffin-embedded sections. Substances localized included CEA, epithelial membrane antigen, calcitonin, alpha and beta subunits of human chorionic gonadotropin, and human placental lactogen.

Epithelial markers in primary skin cancer: an immunoperoxidase study of the distribution of epithelial membrane antigen (EMA) and carcinoembryonic antigen (CEA) in 65 primary skin carcinomas.

Sixty-five primary malignant skin tumours have been stained for carcinoembryonic antigen (CEA) and epithelial membrane antigen (EMA) using rabbit polyclonal affinity-purified antibodies and an indirect immunoperoxidase technique. The tumours consisted of 15 invasive squamous carcinomas, 23 basal cell carcinomas, 16 malignant eccrine poromas (porocarcinomas), and 11 sebaceous carcinomas. The basal cell carcinomas were negative for CEA and EMA except where there was keratotic or sebaceous differentiation. All the sebaceous and squamous carcinomas and 15/16 porocarcinomas contained EMA. 12/15 squamous carcinomas were positive for CEA. The malignant poromas were negative for CEA except on the ulcerated surface of two. In tumours classified as sebaceous carcinomas there was positive staining for CEA in some cells, cyst contents and/or keratotic foci. These findings have implications for the use of immunoperoxidase localization of epithelial markers in the differential diagnosis of primary and metastatic skin cancer.

Human chorionic gonadotropin and human placental lactogen in extragonadal tumors. An immunoperoxidase study of ten non-germ cell neoplasms.

The immunoperoxidase localization of the alpha and beta subunits of human chorionic gonadotropin (hCG) and of human placental lactogen (hPL) was studied in ten extragonadal nontrophoblastic tumors associated with raised serum levels of one or more of these placental proteins. Three of the tumors were bronchial carcinomas, one was a gastric carcinoma, two were malignant carcinoids (one bronchial and one gastric), two were pancreatic islet cell carcinomas, and two were metastatic carcinomas with an unknown primary site. The maximum alpha subunit serum level was 33,000 ng/ml (gastric carcinoid), the maximum hCG/hCG-beta level was 705,000 ng/ml, and the maximum hPL level was 50 ng/ml (both in the gastric carcinoma). An indirect immunoperoxidase technique and rabbit polyclonal affinity-purified antibodies and peroxidase conjugates were used on formalin-fixed, paraffin-embedded sections. Five blocks (eight cases) or six blocks (two cases) from various sites were obtained from each patient at surgery and/or autopsy. Positive stains for hCG/hCG-beta were seen in six of seven tumors (25/37 blocks) with raised levels, for the alpha subunit in nine of nine tumors (30/47 blocks), and for hPL in two of five tumors (4/26 blocks). Only a relatively minor number of the cells were positive, and within the same case, there was considerable site-to-site variation in the number of positive cells. Large bizarre cells contained hCG/hCG-beta as well as the alpha subunit, if it was demonstrated in the same tumor as the beta subunit. Otherwise, the alpha subunit was found in small unremarkable cells. Giant cells that were smaller than those positive for hCG/hCG-beta contained in hPL. In some serial sections, hCG-alpha, hCG/hCG-beta, and hPL were segregated in different cell populations, supporting the concepts of their separate genetic control.

Intercellular canaliculi in eccrine sweat glands: an immunoperoxidase study.

Using an indirect immunoperoxidase technique, both epithelial membrane antigen and carcinoembryonic antigen were identified within the ducts and secretory coils of the eccrine sweat gland. Antibodies to epithelial membrane antigen stained the intercellular canaliculi of the secretory coils, as did those antisera to CEA which showed activity against normal cross-reacting antigen (CEX, NCA). Those without such activity showed minimal or no staining of intercellular canaliculi. There is a difference in antigenic expression between the acinar cells and their intercellular canaliculi, and the cells of eccrine ducts.