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Canine parvovirus (CPV) is a common cause of enteritis, immune suppression and systemic inflammation in young dogs. Endothelial markers, such as intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1), and molecules that upregulate their expression, such as high mobility group box 1 protein (HMGB-1), provide insight into the state of the endothelium during inflammation. This study aimed to determine if circulating concentrations of ICAM-1, VCAM-1 and HMGB-1 were altered in CPV enteritis compared to healthy controls, and whether a correlation existed between these molecules and the degree of inflammation. Thirty dogs with naturally occurring CPV enteritis and ten control dogs were included. Physical examinations, complete blood count and C-reactive protein (CRP) measurements were performed on all dogs at presentation. The concentrations of ICAM-1, VCAM-1 and HMGB-1 were measured using commercially available canine-specific enzyme-linked immunosorbent assay (ELISA) kits. In dogs with CPV enteritis, ICAM-1 concentrations were significantly lower (median: 5.9 [IQR: 4.3-8.3]) and CRP higher (134 [IQR: 85-195]) compared to controls (8.0 [IQR: 6.9-10.3]

A new species of tree snake Dipsadoboa montisilva Branch, Conradie & Tolley sp. nov. (Serpentes: Colubridae) is described from the ‘sky islands’ of Mount Mabu and Mount Ribáuè in northern Mozambique. Features of scalation, colour, body form and habitat distinguish the new species from other Dipsadoboa. This is supported by a phylogenetic analysis using one mitochondrial marker (cytochrome b) that shows the new Mozambican species is divergent from other sampled Dipsadoboa, including D. flavida and D. aulica, the only congeners known to occur in Mozambique. Morphologically, the new Dipsadoboa forms part of the D. werneri-shrevei complex from east and southeast Africa, but differs in having higher subcaudal counts, a different temporal pattern and only two supralabials entering the orbit. Phylogenetically, it occurs in a clade with D. shrevei and D. werneri. The status of D. shrevei in East Africa is reassessed, particularly in terms of the poorly-known Dipsadoboa shrevei kageleri from northern Tanzania. It is morphologically well defined from D. shrevei shrevei and utilises a different habitat. Although based on limited genetic data, it appears to be well-defined from typical D. shrevei and is accordingly raised to specific status. The only Tanzanian record for typical D. shrevei from Mtene, Rondo Plateau in southeast Tanzania is well isolated from the species’ range to the west (e.g. Zambia, Angola) and the published scalation features, particularly ventral counts, do not fully accord with D. shrevei. The Rondo Plateau population is treated as Dipsadoboa incerta sedis, and because we return D. shrevei to its binomial status, we can no longer consider D. shrevei as occurring in Tanzania. Biogeographically, the Rondo Plateau population may have a stronger affinity to the new Mozambican species. The discovery of isolated populations of the new species in mid-altitude forest remnants on Mt Mabu and Mt Ribáuè emphasizes the high conservation importance of the Mozambique forest ‘sky islands’ from which numerous other endemic new species have been recently discovered. These species are impacted by ongoing habitat destruction through slash and burn clearing for subsistence agriculture.

The African green and bush snakes of the genus Philothamnus currently comprises 21 species and three subspecies and occurs throughout sub-Saharan Africa. The genus has been the subject of previous taxonomic revisions based on traditional morphological characters and limited genetic assessment, and may not reflect their evolutionary history. Indeed, previous findings based on phylogenetics show discordant results of interspecific relationships and question the monophyly of the genus, although taxon sampling has been limited to date. We investigated phylogenetic affinities within Philothamnus with more inclusive genetic and geographical sampling, with the aim of better understanding their evolutionary history, so that future taxonomic revision of Philothamnus can be better informed. Species relationships were examined within a phylogenetic context and sampling included 133 ingroup samples from 16 taxa. Phylogenies were constructed in Bayesian and likelihood frameworks using three mitochondrial (16S, cyt b and ND4) and two nuclear (c-mos and RAG1) markers. Competing hypotheses relating to the monophyly of the genus were tested with a Shimodaira-Hasegawa test. To examine species boundaries, Bayesian General Mixed Yule-Coalescent Model and multi-rate Poisson Tree Processes analyses were conducted. In addition, a barcoding approach was used to further clarify species-level relationships by comparing frequency distributions between intra- and interspecific sequence divergence. The genus was recovered as monophyletic; however, species-delimitation results suggest that the current taxonomy does not reflect the evolutionary history of this group. For example, Philothamnus s. semivariegatus is paraphyletic, with at least four distinct clades. Philothamnus carinatus consists of two cryptic (sister) lineages from Central and West Africa that are deeply divergent, suggesting a long history of isolation between those regions. Furthermore, the subspecies P. n. natalensis and P. n. occidentalis show strong support for species-level divergence, which reflects their morphological and ecological differences. Accordingly, we elevate P. occidentalisnov. comb. to a full species. A fully informed taxonomic revision of these taxa will require additional morphological and ecological data for corroboration, but it seems that the morphological characters (e.g. scalation, dentition) used to describe these species to date are labile within and between species. This most likely has clouded our understanding of the species boundaries within the genus. Our phylogeny and species-delimitation analyses should provide a sounder framework for taxonomy, but may also prove useful toward understanding the morphological adaptations of these species to their respective habitats.

White sharks (Carcharodon carcharias) are apex predators that play an important role in the structure and stability of marine ecosystems. Despite their ecological importance and protected status, white sharks are still subject to lethal control to reduce the risk of shark bites for recreational water users. The Shark Spotters program, pioneered in Cape Town, South Africa, provides a non-lethal alternative for reducing the risk of human-shark conflict. In this study we assessed the efficacy of the Shark Spotters program in reducing overlap between water users and white sharks at two popular beaches in False Bay, South Africa. We investigated seasonal and diel patterns in water use and shark presence at each beach, and thereafter quantified the impact of different shark warnings from shark spotters on water user abundance. We also assessed the impact of a fatal shark incident on patterns of water use. Our results revealed striking diel and seasonal overlap between white sharks and water users at both beaches. Despite this, there was a low rate of shark-human incidents (0.5/annum) which we attribute partly to the success of the Shark Spotters program. Shark spotters use visual (coloured flags) and auditory (siren) cues to inform water users of risk associated with white shark presence in the surf zone. Our results showed that the highest risk category (denoted by a white flag and accompanying siren) caused a significant reduction in water user abundance; however the secondary risk category (denoted by a red flag with no siren) had no significant effect on water users. A fatal shark incident was shown to negatively impact the number of water users present for at least three months following the incident. Our results indicate that the Shark Spotters program effectively reduces spatial overlap between white sharks and water users when the risk of conflict is highest.

The changes in plasma cortisol levels, immune response parameters and growth of juvenile Atlantic salmon (Salmo salar) were monitored during a 50 days period following a DNP-HSA (di-nitrophenyl human serum albumin) immunisation program. Antibody titers rose significantly after a single immunisation. An increased plasma cortisol concentration was observed in association with injection of both antigen and saline. A single injection had a significant negative effect on growth of fish and fish subjected to 2 injections with a 25 days interval had an even larger growth reduction. The plasma cortisol concentration and the specific antibody response were compared at an individual level but no correlation was found. Total serum protein increased during the experimental period independently of immunisation. In contrast the total serum immunoglobulin 50 days after the first immunisation was clearly connected to antigen exposure. The observations are discussed in relation to immunophysiological changes during immunisation and stress induction.

Strong anti-neoplastic anthracyclines like daunorubicin (DNR) and doxorubicin (DOX) have high efficacy against systemic neoplasm and solid tumours. However, clinically, they cause chronic cardiomyopathy and congestive heart failure. Red palm oil (RPO) supplementation can protect the heart against ischemic injury. We therefore hypothesize that supplementation with RPO during chemotherapy may protect the heart. Control rats received a standard diet, and the experimental group received RPO in addition for 4 weeks. Each group was subsequently injected with either saline or DNR over a 12-day period towards the end of 4 weeks. Hearts were excised and perfused on a working heart system. Functional parameters were measured. Tissue samples were collected for analysis of mRNA and protein levels. DNR + RPO increased aortic output by 25% (p0.05) compared with DNR only. Furthermore, DNR treatment significantly reduced tissue mRNA levels of superoxide dismutase 1 (SOD1) and nitric oxide synthase 1 (NOS1) compared with untreated controls. Protein expression of SOD1 followed the same pattern as mRNA levels. NOS1 protein levels were significantly increased in DNR treated rats when compared with untreated controls. In addition, DNR increased phosphorylation of p38 and Jun N-terminal kinase compared with untreated controls, whereas DNR + RPO completely counteracted this activation. DNR + RPO significantly up regulated the protein extracellular signal-regulated kinase 1 level compared with DNR only. In this model of DNR treatment, RPO is associated with stabilization of important antioxidant enzymes such NOS and SOD, and inhibition of the 'stress' induced mitogen-activated protein kinase pathways. Dietary RPO also maintained function, similar to control, in DNR treated hearts.

A retrospective study that involves the analysis of laboratory diagnostic data collected during the period 1996-2006 was conducted. A total of 3417 Salmonella isolations involving 183 different serotypes was recorded from 1999-2006, inclusive, at the Onderstepoort Veterinary Institute, Agricultural Research Council, South Africa. The most common serotypes were Salmonella enterica subspecies enterica serovar Typhimurium (917 incidents), Salmonella enterica subspecies enterica serovar Dublin (248 incidents), Salmonella enterica subspecies enterica serovar Enteritidis (232 incidents), Salmonella enterica subspecies enterica serovar Muenchen (164 incidents), Salmonella enterica subspecies enterica serovar Heidelberg (118 incidents) and Salmonella enterica subspecies enterica serovar Chester (113 incidents). The number of recorded Salmonella isolations over the period 1996 to 2006 varies considerably from year to year. The peak of 693 isolations was recorded in 1997, and the lowest, 108 incidents, in 2001. Of the total incidents recorded during the period of survey, 2410 (70.5 %) occurred in poultry and other birds, 641 (18.75 %) occurred in cattle, 255 (7.46) in pigs and 111 (3.24 %) in sheep. Despite the large number of serotypes isolated (183), 52% of incidents were due to only 6 serotypes in decreasing order of prevalence : S. Typhimurium, S. Dublin, S. Enteritidis, S. Muenchen, S. Heidelberg and S. Chester. Serovar Typhimurium was the most common serotype and was detected in all animal species sampled, with, 65 % (598) of the incidents occurring in poultry and 20 % (187) occurring in cattle. Of the total of 248 incidents of S. Dublin serotype, 95.6 % (237) of incidents occurred in cattle and of the 232 isolates of S. Enteritidis, 223 (96 %) originated from poultry. Serovar Choleraesuis was identified in 16 isolates from pigs. The following 4 serotypes were each recorded in more than 50 incidents : S. Hadar (102), S. Schwarzengrund (99), S. Mbandaka (94) and S. Sandiego (73). The trends of annual incidence of Salmonella infection in cattle, sheep, pigs, poultry and other birds during the 11-year period and the distribution of the main serotypes in individual species of animals from 1996-2006 are discussed.

We studied 26 patients with severe falciparum malaria who were admitted to an ICU in Namibia. The pathophysiologic effects on various organ systems are documented and the mortality associated with organ failure is reported. Patients with three or more organ failures showed a high mortality, especially when pulmonary or renal failure occurred. Predicted mortality based on the Acute Physiology and Chronic Health Evaluation II scoring system was 34% compared to an actual mortality of 38%.

This retrospective study was based on 674 cases of colibacillosis in pigs submitted to the diagnostic bacteriology laboratory of the Onderstepoort Veterinary Institute (OVI) over the 20-year period ranging from 1971-1991. During this time, 28,840 cases from various livestock species were received, of which 4162 (14.4%) were from pigs. The 674 porcine cases selected for this study were included if an E. coli infection had been suspected by the referring veterinarian, and typable E. coli strains were then isolated by this laboratory. Enteritis (45.5%) and septicaemia (46.9%) were the most common syndromes, with agalactiae (1.4%) and abortion (1.1 %) representing a far lower prevalence. Oedema-disease signs were described by the submitting veterinarian in only 12 cases. Samples were received from weaners and sucklers in relatively equal numbers until 1981, but subsequently samples from sucklers declined, while those from weaners remained high. There were 69 different somatic and capsulated (OK) antigen groups associated with E. coli infections in pigs. Escherichia coli O149 was the most common isolate (45.8%), while E. coli O141 was the next most common isolate (18.3%). This was followed by O9 (8.9%), O20 (5.2%) and O8 (3.1%). All other serotypes together accounted for less than 20% of the total number of cases, and were isolated fewer than 20 times each. The fimbrial attachment factor, F4 (K88) was found associated with 46.9% of isolates.

The premixed cholesterol reagent (acetic acid, sulphuric acid, ferric chloride and phosphoric acid) employed in a spectrophotometric method for serum cholesterol determinations was applied to frozen sections of various rat and rabbit tissues. The histochemical reaction was compared with the results obtained by the classical Schultz reaction. The same bluish-green color was observed after treatment of formalin-fixed and fresh cryostat sections incubated in 2.5% iron alum at 37 C for 3 days. The premixed cholesterol reagent is stable for years at room temperature if stored in a brown bottle and is thus readily available for routine use.

An experimental model of haemorrhagic hypotension was standardized using rabbits to investigate the shock lung syndrome over a period of 120 minutes. Acute hypovolaemia was induced by withdrawal of blood under anaesthesia to a mean arterial pressure of 30 +/- 5 mmHg within 10 minutes. The mean leucocyte counts and the release of lysosomal enzymes (acid phosphatase and beta-glucuronidase) in the blood and in lung tissue, as well as the metabolic capacities of lung tissue in terms of protein and lipid biosynthesis, were investigated at set intervals after 30, 60, 90 and 120 minutes. The results indicate a progressive decline in leucocyte numbers over 120 minutes to about 40% of the original. An immediate granulocytopenia was observed with a relative lymphocytosis within 30 minutes. The beta-glucuronidase and acid phosphatase contents of the plasma increased with time; beta-glucuronidase activity increased progressively as leucocytes disappeared from the circulation. Concomitantly, the capacity of the lung tissue to synthesize protein and lipids was retarded with time, becoming significantly lower than baseline values after 60 minutes of hypovolaemia. The decline in leucocyte numbers in the circulation correlated well with the increase in beta-glucuronidase activity and the retarded metabolic capacity of the lung tissue.

In this study the effects of paraquat on the aerobic metabolism and viability of isolated rabbit alveolar macrophages and lung fibroblasts were investigated, and compared with the effects of other known metabolic inhibitors, i.e. sodium fluoride (NaF) and potassium cyanide (KCN). The manometrically and polarographically determined endogenous oxygen consumption of lavaged alveolar macrophages compared very well (180,9 +/- 35,8 and 169,3 +/- 26,8 nmol per 10(6) viable cells per hour respectively). Exogenous glucose (10 mM) and autologous serum (1:3 v/v) added to the medium had no significant effect on the basal respiration rate. The mean cell protein content, determined by the micro-Kjeldahl and Lowry techniques, amounted to 242,6 +/- 37,6 microgram/10(6) macrophages. Paraquat (2 mM), like NaF (20mM) and KCN (5 mM), decreased the viability of the macrophages far less than it did the oxygen utilization of the viable cells, and resulted in an 80% inhibition of oxygen uptake. In contrast, paraquat (1 mM) induced a marked stimulation (230%) of the cyanide-insensitive respiration of alveolar macrophages. The concentrations of paraquat (nmol/10(3) cells) which reduce macrophage metabolism to almost zero were virtually non-toxic to fibroblasts, as measured by their oxygen consumption.

The effect of corticosteroid therapy on the broncho-alveolar cell response, the changes in activity of some lysosomal enzymes and the protein and lipid biosynthesis rates in lung tissue of normal rabbits and of rabbits after induction of an acute inflammation by the intravenous injection of complete Freund's adjuvant (CFA) 0,2 ml/kg body weight was investigated. Three intramuscular injections of methylprednisolone acetate (Depo-Medrol) 1,2 mg/kg over a period of 8 days reduced the mean total broncho-alveolar free cell yields significantly. The percentages of lymphocytes and granulocytes were decreased. The increase in the macrophage percentage was associated with a significant increase in the acid phosphatase activity of the broncho-alveolar cells. The beta-glucuronidase activity, on the other hand, was lowered in alveolar cells and even significantly suppressed in lung tissue. Protein and lipid biosynthesis was significantly retarded in lung tissue 8 days after the start of therapy. Administration of a single dose of CFA 0,2 ml/kg evoked an acute lung inflammation and a significant increase in total alveolar free cell yields. The macrophage percentage was reduced and the lymphocyte numbers doubled, whereas the granulocyte percentage increased more than sevenfold. The change in the percentage distribution of granulocytes may be associated with the marked increase in beta-glucuronidase activity of the cells as well as of the lung tissue. In the inflammatory phase, protein biosynthesis was significantly increased but lipid synthesis was not affected. Corticosteroid therapy in animals treated with adjuvant reversed all the effects of CFA. It has very pronounced anti-inflammatory action and a catabolic effect on protein and lipid metabolism.

The beneficial effects of adenosine triphosphate (ATP)-MgCl2 administered as a bolus following fluid infusion or in combination with the infusion fluid were investigated in rabbits subjected to severe but reversible haemorrhagic shock. ATP-MgCl2 treatment led to a significant improvement of the metabolic functions of lung and liver tissue. Kidney tissue showed the same tendency, but the improvement did not reach significant levels. The release of lysosomal enzymes in vivo was retarded after treatment but not stopped. The mean arterial pressure was kept at a relatively constant level when ATP-MgCl2 was infused slowly. Administration as a bolus resulted in an immediate dramatic drop in pressure, followed by recovery and then a gradual decrease to levels which appeared to be incompatible with survival.

The effects of paraquat on the aerobic metabolism of rabbit lung slices were investigated. The oxygen consumption of lung slices was examined at different oxygen tensions and in the presence or absence of glucose as substrate in a Krebs-Ringer phosphate medium. In an air phase, the oxygen consumption of control lung tissue with glucose in the medium was practically the same as the oxygen consumption without glucose over a 3-hour period. In a 100% oxygen phase, glucose induced a marked increase in oxygen uptake, which persisted for about 2 hours. Thereafter, a decrease occurred in oxygen consumption which was notably faster than that of lung tissue without added glucose. With 10 mM glucose in the medium, paraquat (10(-5)M and 10(-3)M) immediately stimulated the oxygen consumption of lung slices. Although the initial increase in aerobic metabolism seemed to be glucose-dependent, the secondary inhibitory effect of paraquat appeared to be of the same magnitude in the presence or absence of glucose. Both the initial stimulation as well as the secondary inhibition were much more pronounced in a 100% oxygen atmosphere than in an air phase. These results indicate that the rabbit lung is sensitive to paraquat toxicity in vitro, and confirm that oxygen and paraquat supplement each other's toxicity in the lung.

Subcellular fractions (mitochondria, microsomes and cytosol) were prepared from the lungs of rabbits and rats to investigate the effects of paraquat (Aldrich Laboratories) on the activity of some cytosol and mitochondrial dehydrogenases and on the microsomal respiration and reduced pyridine nucleotide oxidation rate. The normal basal oxygen consumption of rabbit lung microsomes was 1,9 +/- 0,3 nmol O2/mg microsomal protein/min, and the oxidation rates of reduced nicotinamide-adenine dinucleotide phosphate (NADPH) and reduced nicotinamide-adenine dinucleotide (NADH) were 4,29 +/- 0,53 and 4,0 +/- 0,55 nmol/mg microsomal protein/min respectively. One molecule of oxygen can therefore oxidize two molecules of NADPH or NADH, and the generated hydrogen peroxide is probably immediately broken down by the catalase activity of the normal lung microsomal preparation. When Aldrich paraquat (1,0 mM) was added to microsomes metabolizing NADPH (0,5-0,75 mM), both the rate of oxygen consumption and the generation of nicotinamide-adenine dinucleotide phosphate (NADP) were significantly (P less than 0,001) stimulated over the first 5 minutes, and thereafter returned to within basal limits. When microsomes were preincubated with 1,0 mM paraquat before NADPH was added, the oxygen consumption was substantially lower (10,01 +/- 1,01 nmol oxygen/mg microsomal protein/min), while the NADPH oxidation rate was almost similar to the basal rate in the absence of paraquat. This resulted in a striking dissociation in the H/O ratio under these circumstances. The addition of potassium cyanide (KCN) (5.0 mM) prior to paraquat pre-incubation and followed by the addition of NADPH restored the stimulatory effect of paraquat on microsomal respiration and on NADPH oxidation rate.(ABSTRACT TRUNCATED AT 250 WORDS)

The prophylactic and therapeutic effects of hydrocortisone (50 mg/kg) in severe haemorrhagic shock were evaluated by metabolic, biochemical and haematological investigations in a rabbit model. It was found that administration of hydrocortisone prior to severe haemorrhage had no beneficial effect on any of the values measured. Owing to haemoconcentration and marked mobilization of leucocytes it would appear that in pretreated animals the magnitude of the hypoxia was increased and led to greater tissue damage and higher levels of lysosomal enzymes than in rabbits which had not received pretreatment with hydrocortisone. On the other hand, hydrocortisone therapy combined with volume replacement 1 hour after the haemorrhagic insult had several beneficial effects. The metabolic capacity of liver and kidney tissues was improved, the lysosomal concentration remained within normal limits, and the mean blood pressure and pulse pressure were maintained better than in controls. However, it would appear that this beneficial effect is only exerted on tissue still in a reversible state of shock. There is therefore no beneficial effect on lung tissue metabolism, the lungs being more sensitive to hypoxic damage than either liver or kidney tissue. Administration of hydrocortisone results in the immediate release of endotoxins into the circulation. This might be due to its vasodilatory action on the microcirculation of the intestinal viscera.

The in vitro effects of paraquat on the aerobic metabolism of lung and liver homogenates, as well as on the oxygen consumption of isolated rat and rabbit lung mitochondria, were investigated. It was found that the endogenous oxygen uptake of a 40% lung homogenate was similar to that of a 10% liver homogenate, and that succinate (20 mM) was well oxidized by both homogenates. About 14% of the basal respiration rate was due to cyanide-insensitive oxidative systems in lung and liver homogenates. Paraquat (1 mM and higher concentrations) induced an acute and highly significant increase in the cyanide-insensitive oxygen utilization. We were able to recover about 5% of the protein in the supernatant (1,000 g) of the original homogenate as mitochondrial protein. Only results obtained from mitochondrial preparations with a respiratory control ratio between 2,7 and 3,3 were used in the final analyses, and the normal state 3 respiration values of rabbit and rat lung mitochondria were 45,2 +/- 5,3 and 38,7 +/- 2,9 nmol oxygen per mg protein per minute respectively. Paraquat in concentrations up to 0.5 mM had no significant effect, but higher concentrations up to 1 mM induced a highly significant inhibition of mitochondrial oxygen consumption. When slices were pre-incubated with 1 mM and with 0,01 mM paraquat in the incubation medium, the oxygen consumption of the mitochondria isolated after 2 hours and 4 hours respectively, was significantly reduced.

The effectts of variable periods of ischaemia on the isolated lungs of rats and rabbits, stored for up to 6 hours at 4 degrees C, 21 degrees C and 37 degrees C under standardized conditions, were investigated in vitro in terms of oxygen consumption, the rate of 1-14C-leucine incorporation into soluble proteins, and 1-14C-palmitate incorporation into total phospholipids and lipid fractions. The endogenous oxygen uptake of rat lung slices in an air phase, from tissues stored at 4 degrees C and 21 degrees C under ischaemic conditions for 6 hours and at 37 degrees C for 4 hours, was significantly different from the control values. The oxygen uptake of lungs from animals anaesthetized with pentobarbitone prior to exsanguination and stored for only 2 hours at 37 degrees C differed significantly from control values. Judged by the rate of incorporation of radiolabelled leucine into soluble proteins and that of palmitate into total lipids and phospholipids of lungs after storage for increasing periods at 4 degrees C and 37 degrees C, significant differences were already found after 1 1/2 hours. From this observation it would appear that these parameters are very sensitive indicators for assessing irreversible lung damage due to ischaemia.

The adrenals of rabbits on a cholesterol-rich diet for 35 days show histopathological changes, a marked increase in weight and a lowering in the ascorbate content. A focal increase in the neutral lipid and cholesterol content was noted mostly in the inner cortical zones; and a characteristic acid phosphatase-positive pattern in areas of infiltrating cells, and an alkaline phosphatase-positive reaction in heterophils in the infiltrated areas. Electron microscopy confirmed that the zona glomerulosa cells were relatively normal in hypercholesterolaemic rabbits, while necrosis and fibrosis were very obvious in the inner two zones. The cellular infiltrate was shown to consist of large, granular mononuclear cells, heterophils, eosinophils, stromal phagocytes, lymphocytes and plasma cells. The possibility that the reaction was of an immunological nature is considered. The morphology of the adrenals of rabbits which were on a cholesterol-rich diet for 35 days and on a normal diet for 6 weeks afterwards, was indistinguishable from that of those rabbits killed after 35 days on a cholesterol-rich diet.

Paraquat is a potent and widely used herbicide which acts as a specific pulmonary toxin and causes lung fibrosis in man and animals. Some controversy still exists concerning the details of the morphogenesis of the pulmonary lesions. The lungs of rats exposed to intravenous injections of paraquat and sacrificed 6-24 days later were examined by light and electron microscopy. Autoradiography was used to detect possible paraquat accumulation in the lung 5 hours after a single intravenous injection. The findings on microscopy suggested an acute phase of damage to alveolar lining epithelium followed by epithelial regeneration. The most pronounced light and electron microscopic findings were: signs of disruption of the alveolar wall; type II alveolar epithelial hyperplasia; mobilization of mononuclear cells, and migration and accumulation of fibroblast-like cells in the intra-alveolar and interstitial spaces. After three equally spaced intravenous injections of paraquat signs of interstitial connective tissue proliferation could be seen. Autoradiography showed low-grade radioactivity over the alveolar wall, indicating possible active uptake of paraquat by alveolar epithelium; this coincides with in vitro evidence of an active transport mechanism for paraquat by alveolar epithelial cells.

Relation between macrophage migration inhibition and immunity to Brucella abortus in guinea-pigs. Onderstepoort Journal of Veterinary Research 43 (4), 175-184 (1976). A soluble protein antigen was prepared from Brucella melitensis Rev I with which macrophage migration inhibition (MMI) assays were successfully done using guinea-pig peritoneal exudate cells. By comparing the MMI, agglutinin response and immunity of groups and of individual guinea-pigs which had been immunized with either B. melitensis Rev I live vaccine or B. melitensis Rev I inactivated antigen, an association between the MMI and resistance to infection was demonstrated.

Changes in catabolic and biosynthetic parameters measured in vitro were used as criteria to assess the degree of damage in tissues after an animal was exposed to severe haemorrhagic shock for periods of 1 and 2 hours (blood loss 36,8%, blood pressure 30 +/- 5 mmHg). The biosynthetic capacity of lung tissue, as determined by the incorporation of 1-14C-palmitate into total lung lipids, declined significantly with time. This reduction correlates well (r =0,99) with the rate of decline in 14CO2 production from 1-14C- and 6-14C-glucose oxidation as well as with the decline in the rate of oxygen uptake. Any one of these parameters could therefore be used as an index of the degree of tissue damage due to haemorrhagic shock. Comparing the rates of decline in 14CO2 production from 1-14C-glucose by lung, liver and kidney tissue from the same animal after haemorrhagic insult for 1 hour, lung tissue appeared to be the most sensitive to hypoxia and kidney the least so. However, 2 hours after severe haemorrhage, i.e. near the terminal phase, the rate of 14CO2 production from 6-14C-glucose by liver tissue decreased dramatically by more than 53% of the control value. Apart from kidney and lung dysfunction, irreparable liver damage probably plays a major role in the fatal course of severe haemorrhage.

In this comparative study we describe the influence of paraquat on the rate of L-2,3-3H-proline incorporation into the acid-extractable proteins and into newly synthesized protropocollagen molecules from the lungs of rats and rabbits. Exposure to paraquat took two forms: (a) addition of paraquat in vitro to lung tissue taken from rats and rabbits, and (b) intraperitoneal injection of paraquat prior to death. Paraquat (0,5 - 1,0 mM) added in vitro significantly slowed the rates of 3H-proline incorporation into the acid-extractable proteins and into newly synthesized protropocollagen in both rat and rabbit lung tissue. Paraquat administered intraperitoneally (27 mg/kg) to rabbits did not markedly influence the rate of 3H-proline incorporation into acid-extractable proteins and collagen assessed in vitro 24, 48 and 96 hours after injection. Paraquat injected intraperitoneally into rats induced no significant difference in synthesis rates of acid-soluble proteins up to 48 hours after injection. During the same period, the collagen synthesis rate of rat lung tissue was reduced. At 96 hours an increase was found when the rate of synthesis was expressed as cpm/mg DNA and as cpm/microgram hydroxyproline.

Ten groups of rats were injected intraperitoneally with one of the following suspensions; (i) standard reference crocidolite; (ii) acid-treated crocidolite (iii) crocidolite plus iron oxide; (iv) crocidolite plus silica; (v) iron oxide; (vi) silica; (vii) long fibre crocidolite; (viii) short fibre crocidolite; (ix) long fibre glass and (x) short fibre glass. Two rats from each group were killed at 45, 90, 150, 240 and 330 days respectively, and the pathology induced by the different suspensions was studied histologically at each time interval. No evidence in support of the chemical induction theory or mechanical irritation theory in the pathogenesis of peritoneal mesotheliomas could be found, although all the suspensions except iron oxide caused a reactive mesothelium.

Resistance to 20 antibiotics of 128 Salmonella and 97 Escherichia coli isolates from various registrable farm feeds was determined. A high frequency of comparatively low levels of resistance was found in both the Salmonella and E. coli isolates. This, together with an elevated frequency of multiple resistance, indicates that problems related to an effective transfer in bacterial populations of resistance to certain antibiotics are a distinct possibility. The addition of antibiotics, such as penicillin and tetracyclines, to animal feeds can create conditions for rapid selection amongst bacteria resistant to antibiotics. The numbers of resistant bacteria in the animal environment may be increased and may lead to the development of veterinary and human health problems from the possible transfer of antimicrobial resistance from animal pathogens to human pathogens or spreading in the human population of animal pathogens resistant to antibiotics. There is a need for caution in the use of antibiotics, particularly in animal feeds. Extended survey of, and epidemiological research on, farm feeds, manufacturing mills and animal production units are emphasized.

In this study, we measured the effects of different concentrations of paraquat (0,01 mM and 1,0 mM) on the 1-14CO2 and 6-14CO2 production of rabbit lung slices and isolated alveolar macrophages, in 20% and 95% oxygen phases respectively. A 95% oxygen phase induced an increase in the 6-14C-glucose oxidation of contorol lung slices over a 3-hour period, while the increased activity of the pentose pathway over the first 2 hours started to decline during the third hour of incubation. Paraquat (1,0 mM) in 20% oxygen caused a consistent increase in the 6-14CO2 production by lung slices, but in a 95% oxygen phase gradually inhibited the 6-14C-glucose oxidation over a period of 3 hours. The pentose phosphate pathway was highly significantly stimulated by 1,0 mM paraquat in 20% and 95% oxygen over 3 hours. When isolated alveolar macrophages (viability 95%) were incubated in a 20% and a 95% oxygen phase respectively, both the 6-14C-glucose and 1-14C-glucose oxidation rates were significantly inhibited by 1,0 mM paraquat after 1 hour. Our results confirmed the initial increase in glycolytic metabolism induced by paraquat, but also inhibited by paraquat when lung slices were incubated in a 95% oxygen phase. The fact that the glucose metabolism in alveolar macrophages is more sensitive to paraquat exposure than that of cells in lung slices may be related to the genesis of the intra-aveolar pulmonary lesions described in the literature.

A rabbit model of hemorrhagic shock is used in assessing the use of naloxone as an adjunct in the treatment of hemorrhagic shock. In vitro oxidation rates of labelled glucose are used as parameters of early tissue damage. Naloxone, given as an adjunct to volume replacement, significantly improves the in vitro capabilities of lung and liver tissues, but has no effect on kidney cortex. Changes in MABP are not affected by naloxone in this rabbit model, and serum lysosomal enzyme activity is not significantly improved. It is proposed that naloxone exerts some of its beneficial effect at the cellular level.