Evaluation of brain chloride determinations in the diagnosis of water deprivation/sodium salt intoxication in pigs

In a series of pig brains submitted from field cases where water deprivation/sodium salt intoxication was suspected, histopathological examinations and chloride determinations were performed. A poor correlation was found between brain chloride concentration and neuropathology. The ranges of chloride concentrations found were similar for brains showing the encephalopathy of water deprivation/sodium salt intoxication, brains with other neuropathological diagnoses and brains without significant histopathological lesions. A close correlation was found between brain sodium and chloride in a further similar series, suggesting that determinations of sodium would not be more helpful diagnostically than determinations of chloride. A wide range of brain chloride values was also found in a group of healthy slaughtered pigs but the significance of this was not apparent. Brain chloride determinations have little value in the diagnosis of water deprivation/sodium salt intoxication in pigs, especially when performed in isolation without concurrent neuropathology and an adequate clinical history.

Aggressive management of ventricular arrhythmias. With newer techniques to predict drug efficacy

Although myocardial infarction is perhaps the more dramatic cause of sudden cardiac death, it is cardiac arrhythmias without infarction that account for over half of these deaths. Dr Wells outlines the various means available for monitoring pharmacologic suppression of arrhythmias to provide maximum effectiveness and discusses two other means of control, pacing and surgery.

Reliability of power measurement of toric soft contact lenses

We studied the reliability of lensometer measurements of hydrated toric soft contact lenses in air and compared them to similar measurements of toric hard contact lenses and a spherocylindrical spectacle lens. Twenty measurements were made of each of five soft lenses, three hard lenses, and one spectacle lens. One-half of the measurements used an eyepiece lensometer and one-half a projection lensometer. The reliability of the technique was found to be lower for soft lenses than for hard lenses and highest for the spectacle lens. Reliability was sufficiently high for hydrated toric soft lenses with either type of lensometer to support recommendation of a standard tolerance of +/-0.25 D when applied to the mean of five measurements.

The production of F41 fimbriae by piglet strains of enterotoxigenic Escherichia coli that lack K88, K99 and 987P fimbriae

The enterotoxigenic Escherichia coli strains 1676, 1706, 1751 and KEC96a, which do not produce fimbrial adhesive antigens of the K88, K99 or 987P antigen type reacted both in vitro and in vivo with antiserum to F41 fimbriae in an indirect immunofluorescent antibody technique. Antiserum used to demonstrate material B, an adhesive antigen thought to mediate the adhesive and mannose-resistant (MR) haemagglutinating properties of E. coli strains 1676, 1706 and 1751, reacted in vitro with an F41+ strain. The antiserum also inhibited the MR haemagglutinating activity of F41 antigen and gave an anionic precipitation line in immunoelectrophoresis experiments with an extract containing F41 antigen. The MR haemagglutinating properties of an antigen extract containing material B from E. coli strain 1706 was neutralized by antiserum to F41 fimbriae and by OK antisera to E. coli strains that produce both F41 and K99 fimbriae. These sera also gave an anionic precipitation line with the MR haemagglutinin from E. coli strain 1706 and the MR haemagglutinin gave a line of identity with F41 in gel diffusion experiments with antiserum to F41 fimbriae. OK antisera to K99+ F41- bacteria and OK antisera to K88+ bacteria and 987P+ bacteria did not react with this haemagglutinin. Transmission electron microscopy on the ileum of newborn gnotobiotic piglets infected with E. coli strain 1706 showed irregular, poorly defined filamentous material surrounding some,though not all, bacteria but regular fimbrial structures were not visible.(ABSTRACT TRUNCATED AT 250 WORDS)

Biventricular function in the adult respiratory distress syndrome

We examined biventricular function in patients with the adult respiratory distress syndrome (ARDS) by a combination of invasively determined pressures and flows and concomitant radionuclide angiography. Right (RVEF) and left (LVEF) ventricular ejection fractions were measured; right and left ventricular end-diastolic (EDVI) and end-systolic (ESVI) volume indices were calculated from the respective ejection fraction and measured thermodilution stroke volume. With an increase in the outflow pressure load on the right ventricle, measured as the mean pulmonary artery pressure (PAP), the RVEF fell (Y = 66.25 -1.01X; r2 = .42; p less than .001) and both the RVEDVI (y = 13.39 + 3.66X; r2 = .33; p less than .001) and RVESVI (Y = 23.9 + 3.57X; r2 = .41; p less than .001) increased. Progressive increases in the PAP also seemed associated with a change in left ventricular end-diastolic pressure-volume relationships: without pulmonary artery hypertension (PAP less than 20 mm Hg) the mean LVEDVI was 87.2 +/- 31.3 ml/m2 (mean +/- SD) and the mean PCWP was 5.0 +/- 2.8 mm Hg; with a mean PAP exceeding 30 mm Hg, the LVEDVI remained constant (90.4 +/- 26.9 ml/m2) although the PCWP was greater than previous (18.5 +/- 5.7 mm Hg; p less than .01). Analysis of right ventricular peak-systolic pressure end-systolic volume ratios implied a concurrent depression in right ventricular contractility at high levels of PAP. However, right ventricular "pump" function to maintain an adequate left ventricular preload remained unaltered regardless of the presence of pulmonary artery hypertension.

Feed associated haemorrhagic disorder in pigs accompanied by pancreatic lesions

The introduction of a new batch of feed to 400 pigs aged five to eight weeks resulted in 38 deaths and further morbidity associated with multiple haemorrhages. Signs abated within two days of withdrawal of the feed. Widespread haemorrhages were present in many tissues including the pancreas. Additional pancreatic lesions comprised focal necrosis, atrophy and fibrosis of exocrine tissue. The condition was reproduced experimentally in pigs and vitamin K protected mice against the injurious effects of the feed. The cause was not determined but it is speculated that more than one toxic factor and an imbalance of nutritional factors may have been present in the diet.

The short-term effects of increasing plasma colloid osmotic pressure in patients with noncardiac pulmonary edema

We infused hyperoncotic albumin (25 or 50 gm of a 50% solution) into patients with noncardiac pulmonary edema (adult respiratory distress syndrome [ARDS]) to evaluate its effect on the transmicrovascular flux from blood to pulmonary edema fluid of two radiotracers--111In-DTPA (mol wt 504) and 125I-human serum albumin (HSA) (mol wt 69,000). Two groups of patients were studied--one with a modest increase in permeability of the pulmonary alveolocapillary membrane to 125I-HSA (group 1) and another with a large increase in permeability to 125I-HSA (group 2). We used furosemide, when necessary, to minimize the effect of albumin infusion to increase the pulmonary microvascular hydrostatic pressure (Pmv), measured clinically as the pulmonary capillary wedge pressure (PCWP). Therapy significantly increased the mean colloid osmotic pressure (COP) in both groups, but not the mean PCWP or calculated Pmv. Albumin had no significant effect on the mean pulmonary transmicrovascular flux of the radiotracers in either group, despite the increase in COP. In individual patients, a change in the Pmv in response to albumin infusion was directly correlated with the change in flux of 111In-DTPA [group 1: delta In-DTPA (%) = 8.66 + 1.4 delta Pmv (%) r = 0.51, P less than 0.02; group 2: delta In-DTPA (%) = -3.43 + 1.6 delta Pmv (%) r = 0.67, P less than 0.01]. A change in the transmicrovascular flux of I-HSA also correlated with a change in the intravascular Starling forces in both groups. We conclude that albumin infusion in patients with ARDS will not augment the pulmonary transmicrovascular flux of low or high molecular-weight solutes when the effect of albumin to increase the Pmv is minimized; nor, however, does an increase in plasma COP significantly reduce the flux of such solutes.

Clinical correlates of the spectrum of lung microvascular injury in human noncardiac edema

We measured the clearance from blood to pulmonary edema fluid of a small molecular weight hydrophilic radiotracer, Indium-111-DTPA (In-DTPA) and a larger molecular weight radiotracer, Iodine-125-HSA (I-HSA), in patients with pulmonary edema on either a cardiac or noncardiac (permeability) basis. In previous investigations, we had noted an apparent relationship between the magnitude of clearance of I-HSA across the alveolocapillary membrane and the severity of noncardiac pulmonary edema. In this study, we were able to distinguish at least 2 distinct groups of patients with noncardiac pulmonary edema. Patients with the greatest damage to the alveolo-capillary exchanging membrane, defined by the flux of I-HSA from blood to edema fluid, were significantly differentiated from those with a lesser microvascular injury on the basis of higher mean heart rate (HR), temperature, cardiac index (CI), pulmonary artery pressures, right ventricular stroke work index (RVSWI), and a lower mean total white blood cell count (WBC), among others. Therefore, noncardiac pulmonary edema is characterized by a spectrum of permeability injury to the pulmonary microvasculature which seems to parallel other measurable indices of the severity of the systemic response to the illness.

Evaluation of autofluorescence as an aid to diagnosis of cerebrocortical necrosis

A series of brains from sheep, cattle, goats and pigs was examined histopathologically and illuminated by ultraviolet light to test the specificity of autofluorescence in the diagnosis of cerebrocortical necrosis. Fluorescence was seen in only four cases of porcine encephalopathy. In the ruminant brains it occurred in seven out of eight cases of cerebral oedema of lambs; otherwise it was confined to cases of cerebrocortical necrosis, although a few false negative cases were encountered. Ovine cerebral oedema is a disease of unweaned lambs which is unlikely to be confused with cerebrocortical necrosis. Thus bright cerebrocortical autofluorescence in a naturally occurring disease of cattle, sheep and goats is a likely indicator of cerebrocortical necrosis; however, a small proportion of cases will escape detection by this method.

Adhesion in vitro and in vivo associated with an adhesive antigen (F41) produced by a K99 mutant of the reference strain Escherichia coli B41

A K99-negative mutant of the K99 reference strain Escherichia coli B41 (O101:K99) was isolated (strain B41M). It did not react with OK antiserum to a K12 K99+ recombinant or with OK antiserum to K99-positive organisms from the O8, O20, or O64 serogroups, but it did react with OK antiserum to K99-positive organisms from the O101 and O9 serogroups. The mutant hemagglutinated sheep erythrocytes and attached in vitro to calf enterocytes when cultured at 37 degrees C but not when grown at 18 degrees C. Attachment was mannose resistant but susceptible to heating and formaldehyde. These properties were associated with the presence of fimbriae. The isolated hemagglutinin migrated to the anode in immunoelectrophoresis experiments, competitively inhibited attachment of strain B41M to calf enterocytes, and could be demonstrated adhering to these cells in vitro by indirect immunofluorescent staining. The anionic hemagglutinin is referred to provisionally as F41. Germfree piglets infected with strain B41M developed diarrhea within 16 h. Scanning electron microscopy showed groups of bacteria adherent to the microvilli of villous enterocytes. Indirect immunofluorescent staining demonstrated the presence of F41 antigen in vivo.

A comparison of estrogen use by women with endometrial cancer, gynecologic disorders, and other illnesses

Exogenous estrogen use was determined by interview in 206 endometrial cancer patients, 191 women with nonmalignant gynecologic disorders, and 199 women with other illnesses. Separate comparisons of these patients with gynecologic and other illness control subjects provided estimates of the risk of endometrial cancer among estrogen users, adjusted for the effects of confounding variables, of 1.5 (95% confidence limits 0.9 and 2.7) and 4.8 (2.7 and 8.4), respectively. In both comparisons, risk increased with increasing duration of use; regardless of duration of use, risks were higher among users of estrogen within 12 months of diagnosis than among past users. The effects of bias, including surveillance bias, on the results were considered and it was concluded that the true risk was not less than the case/gynecologic control estimate and was likely to approach the case/other control estimate.

Inherited renal cysts in pigs: results of breeding experiments

A landrace boar with a previous history of siring progeny with cystic kidneys was bred to five unrelated large white sows. Thirty-eight of 61 progeny (62 per cent) were affected with renal cysts. This incidence does not differ significantly from that expected with autosomal dominant inheritance. Three of the dams and the boar were found at post mortem examination to have renal cysts. The number of cysts may be determined by polygenic inheritance. Study of the pathology of the cysts in one-day-old, 25- to 32-day-old and 370-day-old progeny indicated a complex pathogenesis including probable recruitment to the cyst population throughout the period studied. The syndrome studied did not resemble previously described polycystic syndromes of the pig nor was it closely comparable to any of the well described polycystic syndromes and renal cystic disorders of man.

A progressive, familial myopathy of the pietrain pig: the clinical syndrome

A familial progressive muscular weakness is described in a herd of pietrain pigs. The onset of disease was at two to three weeks of age taking the form of a muscular tremor when the piglets were standing. An impaired gait followed and by 12 weeks of age the pigs had become permanently recumbent. The observed incidence of the syndrome and the breeding data available were consistent with an autosomal recessive inheritance of the condition.

Renal cysts in pigs: prevalence and pathology in slaughtered pigs from a single herd

An abattoir investigation into kidney condemnations due to renal cysts in pork pigs from one producer showed a prevalence of 47.5 per cent. Affected pigs were the progeny of a landrace boar. Similar cysts found in a small sample of day-old piglets sired by the same boar indicated a congenital origin. A marked variation in size and frequency of cysts in the kidneys of slaughtered pigs was seen, some resembling the severity of polycystic kidneys. Histologically cysts appeared to be of tubular origin. The prevalence of affected pigs in slaughter groups from the single herd could be genetically determined. If this were so the data would be consistent with autosomal dominant inheritance. A breeding experiment to examine this hypothesis is in progress.

Back muscle necrosis of pigs

The clinical signs and pathological features of back muscle necrosis (BMN) in four pigs from three English pig herds were similar to those recorded in pigs from mainland Europe. The observations made support the view that BMN is a special manifestation of the porcine stress syndrome. Diagnosis of acute BMN can be made clinically supported by the analysis of plasma creatine phosphokinase activity and can be confirmed post mortem by macroscopic and microscopic observation on the back muscles.

Solanum malacoxylon toxicity to pigs

Newly weaned pigs were given Solanum malacoxylon at dose rates of 0.2 and 1.0 g per kg body-weight per week for eight weeks. The Solanum malacoxylon was given either as an aqueous extract (SM) or as an aqueous extract incubated with fresh rumen liquor (SMLR). Tubulonephrosis, dose related in severity, was evident in all treated pigs and focal calcification in kidney and lung occurred in pigs receiving the higher dose rate. There was a marked hypercalcaemia and hypophosphataemia over the trial period; the latter feature was in contrast with the hyperphosphataemia produced in sheep. Incubation of SM with rumen liquor enhanced hypophosphataemia at both dose levels in the pig but its effect on serum calcium was equivocal.