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Neuregulins (NRG) play important roles in the development, maintenance, and repair of the nervous system, with influences on neuronal migration, synaptogenesis, receptor subunit composition, and the proliferation/survival of oligodendrocytes and Schwann cells. However, the precise detail of how the NRGs signal through ErbB receptors, particularly at central synapses, is incomplete. The receptor kinase domain provides sites for association with adaptor proteins. In addition, evidence from recent reports suggests that ErbB2/4 receptors, through their C-terminal amino acids, can form specific associations with scaffolding proteins. The existence of such assemblies expands the range of signaling cascades available to the NRGs.

Normally, only one isolate of Listeria monocytogenes from a case of listeriosis is subjected to characterization. Here we show that two isolates from different sites of the body were not the same strain. Such a phenomenon may not have any clinical relevance, although it may confuse the epidemiologist trying to match infection source with infection target.

By using pyrosequencing (i.e., sequencing by synthesis) 106 strains of different serovars of Listeria monocytogenes were rapidly grouped into four categories based on nucleotide variations at positions 1575 and 1578 of the inlB gene. Strains of serovars 1/2a and 1/2c constituted one group, and strains of serovars 1/2b and 3b constituted another group, whereas serovar 4b strains were separated into two groups.

Faecal samples from 102 clinically healthy dairy cows, representing 34 farms in the Swedish province of Uppsala, were analysed for the presence of Listeria spp. using an enrichment procedure. Listeria monocytogenes was isolated from six (6%) and L. innocua from 2 (2%) cows. From each of the 6 samples positive for L. monocytogenes, 5 isolates were further characterised by restriction enzyme analysis using the 3 enzymes Apa I, Sma I, and Asc I, followed by pulsed-field gel electrophoresis. Three of the L. monocytogenes positive cows lived at the same farm, and they all harboured the same clonal type. One of these 3 cows also harboured a further clonal type of L. monocytogenes. The fact that one of the cows harboured 2 different clonal types of L. monocytogenes is important from an epidemiological point of view when routes of infection are to be investigated.

Different subtypes of Listeria monocytogenes were isolated from various animal and environmental samples during an episode of increased mortality on a fallow deer (Dama dama) farm. During a 4-wk period, six fallow deer died, including four does, one fawn, and one adult buck. Prior to death, one of the does had exhibited central nervous system signs characteristic of listeriosis. Postmortem examination of the six deer showed no histologic changes typical of listeriosis, although inflammatory changes were present in several organs. Different subtypes of L. monocytogenes were isolated from brain samples from six deer, from fodder and soil from the deer feeding area, and from faces of some healthy animals on the farm. Listeria monocytogenes, which was frequently isolated in the environment of the farm, was considered the probable major cause of mortality in these fallow deer.

Altogether, 100 strains of Listeria monocytogenes serovar 1/2a isolated from humans, animals, food, and the environment were typed by a combination of PCR and restriction enzyme analysis (REA). A PCR product of 2,916 bp, containing the downstream end of the gene inlA (955 bp), the space between inlA and inlB (85 bp), and 1,876 bp of the gene inlB, was cleaved with the enzyme AluI, and the fragments generated were separated by gel electrophoresis. By this method two different cleavage patterns were obtained. Seventy of the 100 strains shared one restriction profile, and the remaining 30 strains shared the second one. No relation was found between the types differentiated by PCR-REA and the origins of the strains.

A polymerase chain reaction (PCR) assay was developed for detection of pathogenic, virulent strains of Yersinia enterocolitica. By using both virulence loci virF and ail as markers for pathogenicity, detection of species with a virulence factor present was possible. DNA preparation in the presence of hexadecyl trimethy ammonium bromide (CTAB) was followed by two 44 cycle amplification reactions, one for each of the markers. As few as 10(2) Y. enterocolitica cells were detected in ground pork in the presence of 10(5)-10(6) bacteria of other species. The described PCR assay provides a sensitive robust assay for the detection of virulent Y. enterocolitica in food.

An outbreak of listeriosis in Sweden, consisting of nine cases, was investigated by means of molecular typing of strains from patients and strains isolated from suspected foodstuffs, together with interviews of the patients. Listeria monocytogenes was isolated from six of the patients, and all isolates were of the same clonal type. This clonal type was also isolated from a "gravad" rainbow trout, made by producer Y, found in the refrigerator of one of the patients. Unopened packages obtained from producer Y were also found to contain the same clonal type of L. monocytogenes. Based on the interview results and the bacteriological typing, we suspect that at least six of the nine cases were caused by gravad or cold-smoked rainbow trout made by producer Y. To our knowledge, this is the first rainbow trout-borne outbreak of listeriosis ever reported.

A man died in endocarditis due to listeriosis in the late autumn. He had been looking after two goats during the summer. Listeria monocytogenas was isolated from a rectal swab from one of the goats. The goat faeces isolate and the human blood isolate were of identical serovar. The two isolates, however, were shown to be different by multilocus electrophoretic enzyme analysis and ribotyping, as well as by biotyping. Thus, these results do not support the hypothesis that the man was infected by the goat.

A 70-year-old woman fell seriously ill overnight with meningitis and was admitted to hospital. Cerebrospinal fluid culture yielded Listeria monocytogenes. One of the first problems in solving a human case of listeriosis suspected to be foodborne is to find the foods likely to have been transmitting L. monocytogenes. Two enrichment procedures and a direct plating procedure were used for isolation of the bacteria from different food items collected from the patient's refrigerator, local retail store and producer. Samples of vacuum-packed products of sliced pork brawn, sliced cooked medwurst and berliner wurst of the same brand harboured L. monocytogenes. Serotyping and restriction enzyme analysis (REA) with pulsed-field gel electrophoresis (PFGE) were used to characterize and compare 41 isolates, including the human strain. At least three clones were present in the foods investigated, and one of these was identical to the human clone. This clone was present in samples of medwurst from the patient's refrigerator and the local retail store. This is, to our knowledge, the first proven foodborne case of listeriosis reported in Sweden.

The aim of this study was to develop a polymerase chain reaction (PCR) method for the detection of pathogenic Yersinia enterocolitica and to compare it with an official culture method (NMKL-117). Primers were selected for nested PCR directed at the attachment invasion locus, ail, on the bacterial chromosome, as well as at a sequence on the pathogenic marker plasmid, termed virulence factor, virF. The final results obtained by the two methods were similar. However, while the conventional method yielded contradictory data for some steps the PCR method provided unambiguous results. Considerable advantages, i.e. higher sensitivity and specificity of the PCR method, compared with the conventional method for detecting pathogenic Y. enterocolitica, were demonstrated in this study.

To get a better understanding of the epidemiology of Campylobacter, a chicken farm was studied for 16 weeks with samplings in each flock weekly from input until the flock became colonized with Campylobacter or slaughtered. Samples were taken from fresh droppings and from drinkers during the rearing period, as well as from the environment in empty houses. The spread of Campylobacter during the slaughter process was also surveyed. No Campylobacter was found in samples from newly-hatched or one-week-old chickens or their drinkers. All flocks but one were colonized at two to five weeks of age. All Campylobacter isolates belonged to the same sero- and biotype; C. jejuni Penner 2. The spread of Campylobacter in the flock was rapid and usually all samples were positive once colonization had been proven. C. jejuni was isolated from flies in ante-rooms as well as from air in chicken units in houses with positive chicken flocks. Samples were taken at slaughter when some of the Campylobacter positive flocks from the farm were slaughtered. Campylobacter were isolated from all sampled equipment along the processing line, from the chicken transport crates to the chillers, as well as from the air.

Restriction enzyme analysis (REA) with pulsed-field gel electrophoresis (PFGE) has been used to characterize and compare Listeria monocytogenes strains isolated from foods by two methods, an enrichment procedure and a direct plating procedure. In total 151 isolates from nine foods were investigated. In six of the foods (101 strains investigated) only one clone of L. monocytogenes was found irrespective of the method used. In three foods (50 strains investigated) the direct plating procedure yielded more clones than the enrichment procedure. At the most, five clones were detected in the same food. The results presented here indicate that direct plating from the food reveals more L. monocytogenes clones than revealed by an enrichment procedure.

Altogether 150 samples of vacuum-packed fish were examined for the presence of Listeria species. Listeria monocytogenes were isolated from 12 of 58 'gravad' fish samples, 3 of 26 cold-smoked and one of 66 hot-smoked fish samples. Ten of these 16 positive samples harboured more than 100 L. monocytogenes cfu/g. The highest level (132,000) was found in a sample of hot-smoked rainbow trout (Oncorhynchus mykiss). Serogroup 1/2 was most frequently found, followed by 4 and 3. One sample of gravad rainbow trout harboured more than one serogroup of L. monocytogenes. L. innocua and L. seeligeri were isolated from 12 and 1 samples, respectively.

Altogether, 133 strains of Listeria monocytogenes serovar 4b were investigated. A segment of 2,916 bp containing parts of the two genes inlA and inlB in L. monocytogenes was amplified by the PCR technique. The PCR product obtained was cleaved with the restriction enzyme AluI, and the fragments generated were separated by gel electrophoresis, leading to two distinct groups: PCR-restriction enzyme analysis groups I and II, containing 37 and 96 strains, respectively. The PCR-restriction enzyme analysis method described in this paper could be a useful tool for the subtyping of L. monocytogenes serovar 4b strains.

Samples of 333 retail cheeses produced in or imported into Sweden were examined for the presence of Listeria monocytogenes. Listeria monocytogenes was isolated from 6% of the cheese samples. Cheeses made from raw milk were more frequently contaminated with L. monocytogenes (42%) than cheeses made from heat-treated milk (2%). The incidence of the organism in whole cheeses and pre-cut wedges was similar (6%). L. monocytogenes was only found in imported cheeses (18 from France, and one from Germany and Italy, respectively). The numbers of L. monocytogenes varied from < 1 x 10(2) to 1 x 10(5) cfu/g. All L. monocytogenes strains belonged to serogroup 1/2, except isolates from two samples that belonged to serogroup 4.

The ability of one human and two chicken strains of Campylobacter jejuni to colonise and survive in three different strains of laboratory mice (NMRI, CBA and C57-Black) was studied. Mice were inoculated orally with Campylobacter jejuni and faeces samples were cultured at regular intervals during the following months. The length of colonisation of mice differed between mouse strains but also between Campylobacter strains. The mouse strain C57-Black was not colonised with C. jejuni to the same degree as the other mouse strains. It is concluded that mice can become colonised for prolonged periods and that they may act as reservoirs of Campylobacter for other species.

Altogether 323 pooled samples of neck skins from 1615 broilers from 2 processing plants (A and B) were examined for the presence of Listeria species. The broilers were sampled pre-chilling-after leaving the final rinser but before entering the chiller with chlorinated water-and post-chilling-immediately upon leaving the chiller. Free available chlorine in the chilling water varied from 2 to 15 ppm in plant A and was about 10 ppm in plant B. Listeria monocytogenes was only isolated from broilers in plant A sampled post-chilling (58% of 62 samples). L. innocua was isolated from 19% and 39% of broilers sampled pre-chilling in plants A and B, respectively. Post-chilling, L. innocua was isolated from 3% and 6% of samples from plants A and B, respectively.

Altogether 496 samples of meat, lymph nodes, process water and swabs from different places in the abattoir were examined for the presence of Listeria spp. L. monocytogenes was isolated from 31 (6%) and other Listeria spp. from 65 (13%) samples L. monocytogenes was isolated from 2 of 10 beef meat samples, 4 of 50 pig meat samples and 1 of 21 lymph nodes of pigs. No Listeria bacteria were isolated from lymph nodes of cattle. The highest percentage of Listeria was recovered from the unclean sections (cattle 22% and pigs 27%) and the highest frequency was observed during the winter months.

In Sweden, many Listeria monocytogenes strains belonging to serovar 4b and isolated during the last five years from different sources share the same phagovar--2389:2425:3274:2671:47:108:340. The object of the present study was to investigate if 31 L. monocytogenes serovar 4b strains belonging to this particular phagovar could be differentiated by use of a simple restriction endonuclease analysis (REA). Among the enzymes tested, Xho I was found to be the most useful, since this enzyme could divide the 31 strains into five groups. The profiles of all human clinical isolates were indistinguishable from each other, which indicates that these strains may represent a single clone. The food isolates and the strains of human origin did not share the same profile. This further characterization may be of epidemiological importance as this phagovar of L. monocytogenes has been associated with at least two outbreaks of human listeriosis in Europe.

This article presents an industrial case study, examining the application of a novel adaptive biomass estimator to an industrial microfungi production process. It is our intention that this contribution should focus upon the implementation issues of the algorithm, in preference to a rigorous theoretical development. The novel algorithm adopted is developed from Adaptive Inferential Estimation studies of Guilandoust and co-workers. The technique utilizes input-output process measurements obtained at different frequencies, thereby providing more frequent estimates of biomass concentration than are otherwise available from off-line laboratory analyses. The algorithm is particularly suited to the biotechnology industry, as it is capable of utilizing irregular assay measurements with varying delays.Although this article demonstrates the encouraging industrial implications of the adaptive algorithm, like all adaptive techniques currently developed, it is restricted by the inability to perform robust on-line system identification. The ultimate selection of a "suboptimal" "fixed parameter" algorithm for on-line implementation, is therefore directly attributable to these inadequacies. Aspects of data acquisition, data pretreatment, and data quality are critical for real process applications, and while some practical approaches are adopted here, many important implementation problems remain unresolved., ((c) 1993 John Wiley & Sons, Inc.)

The method most often used in Sweden for isolation of Listeria monocytogenes from animal autopsy material is a cold enrichment method. This method is very slow. The International Dairy Federation (IDF) has recently presented a method for detection of L. monocytogenes in milk and milk products that is complete in one week. During a two year period 69 specimens from dead animals with suspected listeriosis were examined for L. monocytogenes in parallel analyses with both the cold enrichment method and the IDF method. Samples derived from different autopsy material representing a variety of animals. L. monocytogenes was isolated in 27.5% of the samples with the IDF method but only in 4.3% with the cold enrichment method. It is concluded that the IDF method was more sensitive than the cold enrichment method.

Three soft cheeses were exposed to quantitative analysis for listeria and found to contain a large number of listeria. Thirty-five of the listeria strains isolated from the three cheeses were characterized by use of biochemical tests, serotyping, phagetyping and DNA restriction enzyme analysis. Seven isolates were identified as Listeria innocua and 28 as Listeria monocytogenes. Two to four different clones of L. monocytogenes could be identified from each cheese. In contrast, only one clone could be detected among the L. innocua isolates. From an epidemiological point of view the findings of different clones of L. monocytogenes in the same cheese emphasize the need for typing several listeria isolates from one and the same food sample. It is concluded that the best overview of the population of the listeria strains is obtained after direct plating of the sample followed by enumeration, isolation and extensive typing.

Listeria monocytogenes was isolated from the brain of a goat, which was euthanized due to listeriosis. A few weeks later a similar subtype of L. monocytogenes was isolated from an on-farm manufactured fresh cheese which did not contain any milk from the goat which had suffered from listeriosis. A similar subtype was also found on 1 of the shelves in the refrigerator where cheeses were stored. Prior to the onset of listeriosis, 1 fresh cheese had been made of milk from the actual goat, which may have excreted L. monocytogenes in her milk. Thus, the cheese made of this milk may have contaminated the shelves in the refrigerator which then has served as a Listeria reservoir for new cheeses during several weeks.

This paper discusses the concept of generic model-based software sensors with particular reference to bioprocess application. The industrial need for software sensing is considered and two industrial bioprocess systems are used in order to highlight the operability problems which warrant their development. Alternative philosophies for formulation are considered and the relative merits of the methodologies discussed. In particular, two different procedures are presented--an adaptive linear model based method, and a method based upon artificial neural networks. The performances of these alternative approaches are studied by their application to two industrial demonstrator processes. The results serve to highlight the operability improvements that can be gained through software sensor development.

Our original goal was to explore the nature of the grouping-by-movement phenomenon reported by Driver and Baylis (1989). In their studies, distractors that moved in common with a centrally located target had a larger influence on focused-attention performance than did more proximate but stationary distractors. These results seemed particularly important since they suggested, contrary to the predictions of space-based models of attention, that attention could be allocated to noncontiguous regions of the visual field. Their results also suggested mandatory processing of stimuli with common motion. Unfortunately, we were unable to replicate this grouping-by-movement effect. In the conditions of Experiment 1 in which we replicated Driver and Baylis's methodology, stationary distractors produced a larger response-compatibility effect than did the more distant distractors that moved in common with the target. In Experiment 2, we redundantly coded the centrally located target and the far distractors with common movement and color. However, the results were identical to those obtained in Experiment 1. The stationary near distractors that appeared in a different color from the target and the far distractors produced the largest response-compatibility effect. In a final experiment, we attempted to compensate for the reduced acuity of the moving distractors by adjusting their size by a cortical magnification factor. However, even with this manipulation, we found a larger response-compatibility effect for the stationary near distractors than for the moving distant distractors. Our results suggest that subjects are capable of selectively processing a target item that moves in common with distractors.

Cheeses were made of heat-treated goat milk inoculated with large numbers of a histamine-producing strain of Streptococcus faecium or a non-histamine-producing strain of S. faecalis. Every second week during ripening (91 days) the cheeses were sampled for histamine analyses and bacteriological analyses. The numbers of enterococci remained high throughout the whole period of investigation and the maximum amount of histamine detected was 8.2 micrograms/g in one of the cheeses. The enterococci seem to have no relevance from a histamine intoxication point of view in cheeses of this kind.

The bacteriological quality of 198 ripened soft or semi-soft goat cheeses obtained from dairy farms and the retail trade was investigated. The cheeses were examined for total counts of aerobic bacteria, coliform bacteria (37 and 44 degrees C respectively), enterococci, coagulase positive staphylococci, Bacillus cereus and Clostridium perfringens. Cheeses obtained from dairy-farms were also determined for pH value. In terms of all tests performed, cheeses made of heat-treated milk with starter culture had the best prospects for fulfilling the criteria for 'fit for consumption'. Cheeses made of raw milk without starter culture made up the most unsatisfactory group from a food-hygiene point of view. Bacteriological guidelines for on-farm manufactured goat cheese are suggested.

Because of reports of fluroxene toxicity in man, the effect of phenobarbital treatment on the toxicity and metabolism of fluroxene was studied in 9 rhesus monkeys. Six monkeys that were exposed to a mean calculated alveolar fluroxene concentration of 5.8% for 4-hr periods up to a total of 16 hr showed no evidence of toxicity. Two animals were sacrificed after a single 4-hr exposure to obtain control measures of fluroxene metabolites in tissues. Four monkeys that had previously survived received exposures to fluroxene and 3 monkeys that had no exposure to fluroxene died during fluroxene anesthesia after treatment with phenobarbital (mean time, 3 hr). Toxicity was manifested by arterial hypotension, pulmonary edema, and arterial hypoxemia. Phenobarbital treatment enhanced production of fluroxene metabolites, including the highly toxic trifluoroethanol. Concentrations of trifluoroethanol in mixed-expired gas, blood, and urine, and of total nonvolatile fluorine in blood, urine, and tissues of animals treated with phenobarbital were 2 to 10 times as in control animals. The results suggest that the rhesus monkey is a valuable model for the study of fluroxene pharmacology and that inclusion of an enzyme-inducing challenge in the evaluation of potential toxicity of other anesthetics seems warranted.

Blood-gas partition coefficients of N2O, enflurane, halothane, methoxyflurane, and isoflurane were measured on blood samples from 12 healthy male volunteers before and after eating. The solubility values determined while volunteers fasted substantiate previously reported blood-gas partition coefficients for enflurane, isoflurane, and halothane. Solubility values for methoxyflurane and N2O were slightly greater and smaller, respectively, than accepted values. The uptake and excretion of N2O, enflurane, halothane, and methoxyflurane also were measured in 6 of these subjects in the fasted and postprandial states. Subjects breathed a constant, inspired mixture containing trace concentrations of all 4 gases. Eating increased blood solubility by 17 to 24 percent for all agents except N2O. Accordingly, the rates of rise of the end-tidal enflurane, halothane, and methoxyflurane concentrations were 7 to 8 percent below control, and the rates of anesthetic uptake increased 20 to 23 percent. Simulation studies showed that the increased ventilation induced by eating opposed and, therfore, minimized the impact of increased blood solubility and cardiac output on the rate of end-tidal anesthetic rise. Changes in blood solubility did not correlate with levels of plasma triglycerides and cholesterol.

A previously healthy 27 year-old male plumber presented with six days of fever, nausea, vomiting, malaise and headache. The subsequent development of cough, dyspnoea and pleuritic pain coincided with the simultaneous development of progressive bilateral cavitary pneumonia with pleural effusion. Leucocytosis, thrombocytopenia, hyponatraemia, hypoalbuminaemia, hypophosphataemia and hypoxaemia were the main laboratory abnormalities. Clinical suspicion of Legionnaires' disease was confirmed by the presence of serum antibody to Legionella pneumophila (titre 1:512) by an indirect fluorescent antibody test. Treatment with erythromycin and rifampicin resulted in clinical recovery with minimal residual bilateral pleural effusion six months after presentation. This patient is the first to acquire Legionnaires' disease in Singapore.

Three adult monkeys were anesthetized with ketamine and ventilated with fluorocarbon liquid [perfluoro bis (1, 4-isopropoxy) butane (Caroxin-D)] at 1 atmosphere on two separate occasions. During five runs, liquid ventilation was continued for 60 minutes. The sixth run was continued for ten minutes. Arterial blood gas levels during and after liquid ventilation were adequate for survival. Three years after the first period of liquid ventilation, the animals were killed. Approximately 0.001 mg of fluorocarbon per gram of tissue was present in the kidney, liver, brain, spleen, muscle, and heart. Fat contained approximately seven to nine times this amount, and the lung and pulmonary lymph nodes contained approximately 1,000 times this amount. In no case was it clinically evident that the monkeys had undergone periods of liquid ventilation. We conclude that primates can be ventilated successfully with liquid fluorocarbon on at least two separate occasions and can return to breathing air without obvious deleterious effects, but fluorocarbon is retained in small amounts for at least three years.

Solubility coefficients for seven inhalation anesthetic agnets were determined in maternal and fetal blood at 37 C. Halothane, isoflurane, diethyl ether, and nitrous oxide were significantly more soluble in maternal than in fetal blood, while methoxyflurane, fluroxene, and cyclopropane were significantly less soluble. Reasons for these differences cannot be accounted for by differences in the type or amount of hemoglobin present.

Heat stroke is the most serious entity amongst the heat disorders. Whilst potentially fatal, it is preventable and salvageable. A retrospective study involving 27 patients admitted for exertional heat stroke to the Medical Unit, Toa Payoh Hospital, Singapore from January, 1984 to January, 1987 was carried out. These patients presented with a rectal temperature of greater than 40 degrees C and central nervous system disturbances. All were males and, except for three, were local born. All except two were below thirty years old. The patients were treated with a standard regime of IV fluids and sponging in the ICU. 19 patients (70.4%) presented in coma whilst abnormal behaviour, e.g. aggression and mental confusion was seen in the remainder. Fits were seen in only 5 patients (18.5%). Metabolic acidosis was seen in 93.3%. Hypokalaemia was present in 3 patients (11.1%). Of the enzymes, creatinine phosphokinase was elevated in all except 1 patient (mean: 4868.8, range: 146-28850). There were no deaths recorded in this series. Complications include reversible DIVC (3 instances), oliguric renal failure (4 instances) and residual neurological deficit (2 instances). 9 patients (39.1%) took more than 4 hours for the rectal temperature to attain 37.5 degrees C. All the above complications except for 1 instance of DIVC occurred in this group with delayed cooling. Heat stroke is a serious condition with serious complications and require prompt treatment.