The evolution of carbapenem resistance determinants and major epidemiological lineages among carbapenem-resistant Acinetobacter baumannii isolates in Germany, 2010-2019

The aim of this study was to investigate and compare the molecular epidemiology and carbapenem resistance determinants in clinical Acinetobacter baumannii isolates collected during four multicentre surveillance studies conducted by the Paul-Ehrlich-Society for Infection Therapy. Isolates were collected prospectively from hospital in-patients at 17 medical centres in Germany over four periods of three- to six-months starting in October of each of 2010, 2013, 2016 and 2019. Species identification was performed by MALDI-TOF, gyrB multiplex polymerase chain reaction (PCR), and detection of the intrinsic bla_OXA-51-like gene. Minimum inhibitory concentrations were determined by broth microdilution. The prevalence of carbapenemase-encoding genes was investigated by OXA-multiplex PCR and whole-genome sequencing. Molecular epidemiology was examined by rep-PCR and core-genome multi-locus sequence typing. A total of 302 A. baumannii isolates were collected. Resistance to imipenem and/or meropenem was detected in 58 isolates (19.2%) from 14 centres. The proportion of carbapenem-resistant isolates increased from 21.3% in 2010 to 33.3% in 2013, and then decreased to 13.8% in 2016 and 12.3% in 2019. Forty-six of these isolates were associated with the international clonal lineage IC2 and five with IC1. The most prevalent carbapenemase gene detected was bla_OXA-23-like (n=51). Further carbapenem-resistance determinants were bla_OXA-40-like (n=1), bla_OXA-58-like (n=3) and bla_NDM-1 (n=2). In one isolate, ISAba1 was detected upstream of bla_OXA-51-like. In conclusion, IC2 was the most prevalent clonal lineage detected in this study. Interestingly, in Germany, carbapenem resistance seems to have decreased in A. baumannii between 2013 and 2019.

The Performance of a Dithiothreitol-Based Diagnostic System in Diagnosing Periprosthetic Joint Infection Compared to Sonication Fluid Cultures and Tissue Biopsies

PURPOSE

The aim of this study was to evaluate the performance of a commercially available dithiothreitol (DTT) kit for routine use in diagnosing periprosthetic joint infections (PJIs) in comparison to conventional microbiological tissue specimens and sonication procedures in a maximal care hospital.

METHODS

We applied the DTT system in 40 consecutive cases of revision arthroplasty (23 PJIs and 17 aseptic revisions), with an exchange or a removal of components. The hardware components were split between the DTT system and the conventional sonication procedure. At least three tissue biopsies and a joint fluid specimen were sent for microbiological and histopathological analysis. Data was analysed retrospectively to compare between the different methods.

RESULTS

Cultures of the DTT fluid showed a sensitivity of 65% and specificity of 100%, as referenced to conventional microbiological cultures. Sonication had better sensitivity (75%) but lower specificity (85%). The categorical agreement of DTT cultures compared to sonication fluid cultures was 78% (31/40). Neither pathogen type, infection duration nor antibiotic pretreatment influenced the accuracy of the DTT, but a low pH in the DTT seemed to be associated with false-negative results.

CONCLUSION

DTT was inferior in sensitivity when diagnosing PJIs compared to sonication fluid cultures and tissue biopsies. A low pH in the DTT fluid correlated with false-negative results. Nevertheless, the closed system of the DTT kit avoids contamination and false-positive results, and DTT can be an alternative where sonication is not available.

Idiopathic esophagopathies resembling gastroesophageal reflux disease in dogs

ObjectivePathologic gastroesophageal reflux (GER) has been demonstrated experimentally in dogs, and it is suspected to occur naturally in dogs, yet its clinical significance is unknown. The aim of the study was to demonstrate clinical indicators of pathologic GER in dogs with idiopathic esophagopathies. Materials and methods: Dogs with clinical signs suggestive for esophageal disease (regurgitation, ptyalism, or dysphagia) and where extraesophageal and specific esophageal diseases had been ruled out, were retrospectively diagnosed with idiopathic esophagopathies. History, physical examination findings, clinicopathologic, radiographic, and endoscopic data, and treatment results were obtained from medical records, reviewed and evaluated. Results: Out of 67 dogs with anamnestic esophageal signs, 12 (17.4%) dogs were identified as having idiopathic esophagopathies and were included in the study. Median age was 3.0 years (range 1.0–11.0), and median bodyweight was 28.2 kg (range 8.2–44.0). The most frequent anamnestic esophageal signs were ptyalism (10/12 dogs), regurgitation (8/12 dogs), signs of discomfort, pain (8/12 dogs), and cough (5/12 dogs). The most common radiographic abnormality was segmental esophageal dilation (8/12 dogs). Esophagoscopy revealed single mucosal surface defects at the gastroesophageal junction in 3/12 dogs. In dogs with altered esophageal motility, cytological and microbiological examinations of bronchial aspirates showed goblet cell hyperplasia (8/8 dogs), neutrophilic infiltration (5/8 dogs) and culturable bacteria (4/8 dogs), respectively. All dogs were treated with omeprazole (median 0.7 mg/kg once per day, range 0.5-1.2). Reported median treatment duration until remission of the main clinical signs was 20.0 days (range 8.0–54.0 days). This endpoint was reached in 11/12 dogs. Conclusion and clinical relevance: Results suggest that in some dogs with esophageal clinical signs, and where no primary disease could be identified, clinical indicators of pathologic GER such as pain, mucosal lesions and motility disturbances of the esophagus, respiratory complications, and response to therapy can be observed.

Evaluation of the quality of endoscopically obtained esophageal biopsies in the dog

Objective: An important premise for obtaining diagnostically relevant histology specimens is an appropriate biopsy technique. Goal of this study was to determine if biopsies of adequate quality can be obtained from the canine esophagus at the gastro-esophageal junction (GEJ) during routine upper gastrointestinal endoscopy. Material and methods: Over the course of one year, 58 dogs undergoing upper gastrointestinal endoscopy because of the presence of esophageal (n = 22) or gastrointestinal (n = 36) clinical signs were prospectively included. Five biopsies were repeatedly collected from the same dorsal and ventral locations of the GEJ, fixated individually in 4% neutral buffered formaldehyde, and evaluated histopathologically after standard preparation and haematoxylin and eosin staining. The presence of esophageal squamous epithelium with a basal cell layer and lamina propria mucosae in conjunction with foveolar columnar epithelium and cardiac glands, and the absence of fundic glands in one specimen, respectively, was judged as an adequately sampled biopsy. Results: Adequately sampled biopsies were reported in 45 out of 58 dogs, with 31 samples originating from the dorsal GEJ, 36 samples originating from the ventral GEJ, and with 22 samples originating from both sites, respectively. The incidence of adequately sampled biopsies increased significantly over time (r = 0,22; p < 0,05), with these biopsies being reported significantly more often during the last 6 months compared to the first 6 months of the study (p = 0,03). Histopathological evaluation of the esophageal squamous epithelium showed fibrosis, inflammation, elongation of the stromal papillae, and increased thickness of the basal cell layers in 14 out of 58 dogs. Stromal papillae of the ventral esophageal epithelium were significantly elongated in dogs with esophageal clinical signs compared to dogs with gastrointestinal clinical signs (p = 0,03). Conclusion and clinical relevance: After an initial learning phase adequate esophageal biopsies from the GEJ can be obtained in canine patients undergoing upper gastrointestinal endoscopy, and histological lesions can be found in these biopsies.

Assessment of the histological quality of endoscopic biopsies obtained from the canine gastro-esophageal junction

Objective: In the dog biopsy samples from the gastro-esophageal junction (GEJ) are rarely obtained during routine gastroscopy. The aim of this pilot study was to assess the histological quality of endoscopic biopsies sampled from the canine esophagus and cardia. It was hypothesised that it is possible to sample adequate specimens from these sites.

Materials and methods: For this purpose 10 dogs with an indication for gastroscopy were enrolled in a prospective study. Biopsy samples were obtained with standard biopsy forceps for single use exactly from the GEJ thus containing preferably columnar epithelium from the cardia and squamous epithelium from the esophagus, respectively. In every dog the specimens were examined for size, layers and site, respectively. Study endpoint was reached when specimens originated from cardia and esophagus, showing at least epithelium and lamina propria mucosae, and a diameter > 2 mm on the slide, respectively.

Results: 72 biopsy specimens (median 7, range 5–10) obtained from the GEJ were examined in 10 dogs. Specimens from the esophagus containing squamous epithelium with lamina propria mucosae were found in 5 of 10 (50.0%) dogs. Specimens from the cardia containing columnar epithelium with lamina propria mucosae were found in 10 of 10 (100.0%) dogs. Four of 10 (40.0%), and 10 of 10 (100.0%) dogs showed at least one specimen > 2 mm on the slide originating from the esophagus, and from the cardia, respectively. Histological quality was found to be adequate in 4 of 10 (40.0%) dogs, showing specimens of adequate size, originating from both esophagus and cardia, and containing at least epithelium and lamina propria mucosae.

Conclusion and clinical relevance: The pilot study provides evidence that during routine gastroscopy it is possible to sample endoscopic biopsies from the cardia and with limitations from the esophagus showing a quality adequate for histological examination of the epithelium and the lamina propria mucosae.

[Determination of hyperregeneratory esophagopathy in dogs with clinical signs attributable to esophageal disease]

OBJECTIVE

It was hypothesized that typical characteristics of hyperregeneratory esophagopathy (HRE) in humans such as basal cell hyperplasia and elongation of stromal papillae are also histologically detectable in canine esophageal epithelium, and that these changes are associated with clinical signs and endoscopic findings suggesting gastroesophageal reflux (GER).

MATERIAL AND METHODS

Sixty-five adult dogs with clinical signs attributable to esophageal disease underwent esophagoscopy and biopsy. Clinical signs suggesting GER (regurgitation, ptyalism, painful discomfort) were prospectively evaluated through a questionnaire. Endoscopic mucosal alterations suggesting GER such as minimal endoscopic changes and obvious mucosal defects were assessed via video endoscopy. Biopsy specimens obtained from the esophageal squamous epithelium were evaluated histologically. The squamous epithelium's substructures of esophageal biopsies were quantitatively assessed through microscopic morphometry.

RESULTS

Esophageal squamous epithelium was considered normal in 48 dogs, and HRE was detected histologically in 17 dogs; both pathognomonic changes (basal cell hyperplasia, elongation of stromal papillae) were consistently present. Morphometrically assessed stromal papillary length and basal cell layer thickness was significantly (each, p < 0.0001) higher in the 17 dogs with HRE than in the 48 dogs without HRE, respectively. Overall, clinical signs suggesting GER were significantly (p = 0.02) more frequently encountered and regurgitation was significantly (p = 0.009) more common in the 17 dogs with HRE than in the 48 dogs without HRE. Similarly, endoscopic changes were significantly (p = 0.002) more frequently observed and minimal endoscopic changes suggesting GER were significantly (p = 0.004) more common in 17 dogs with HRE than in the 48 dogs without HRE.

CONCLUSION AND CLINICAL RELEVANCE

Typical characteristics of hyperregeneratory esophagopathy in humans are also histologically detectable in canine esophageal epithelium. Histological changes are associated with clinical signs and endoscopic findings suggesting GER.

Idiopathic esophagopathies resembling gastroesophageal reflux disease in dogs

OBJECTIVE

Pathologic gastroesophageal reflux (GER) has been demonstrated experimentally in dogs, and it is suspected to occur naturally in dogs, yet its clinical significance is unknown. The aim of the study was to demonstrate clinical indicators of pathologic GER in dogs with idiopathic esophagopathies.

MATERIALS AND METHODS

Dogs with clinical signs suggestive for esophageal disease (regurgitation, ptyalism, or dysphagia) and where extraesophageal and specific esophageal diseases had been ruled out, were retrospectively diagnosed with idiopathic esophagopathies. History, physical examination findings, clinicopathologic, radiographic, and endoscopic data, and treatment results were obtained from medical records, reviewed and evaluated.

RESULTS

Out of 67 dogs with anamnestic esophageal signs, 12 (17.4%) dogs were identified as having idiopathic esophagopathies and were included in the study. Median age was 3.0 years (range 1.0-11.0), and median bodyweight was 28.2 kg (range 8.2-44.0). The most frequent anamnestic esophageal signs were ptyalism (10/12 dogs), regurgitation (8/12 dogs), signs of discomfort, pain (8/12 dogs), and cough (5/12 dogs). The most common radiographic abnormality was segmental esophageal dilation (8/12 dogs). Esophagoscopy revealed single mucosal surface defects at the gastroesophageal junction in 3/12 dogs. In dogs with altered esophageal motility, cytological and microbiological examinations of bronchial aspirates showed goblet cell hyperplasia (8/8 dogs), neutrophilic infiltration (5/8 dogs) and culturable bacteria (4/8 dogs), respectively. All dogs were treated with omeprazole (median 0.7 mg/kg once per day, range 0.5-1.2). Reported median treatment duration until remission of the main clinical signs was 20.0 days (range 8.0-54.0 days). This endpoint was reached in 11/12 dogs.

CONCLUSION AND CLINICAL RELEVANCE

Results suggest that in some dogs with esophageal clinical signs, and where no primary disease could be identified, clinical indicators of pathologic GER such as pain, mucosal lesions and motility disturbances of the esophagus, respiratory complications, and response to therapy can be observed.

Evaluation of the quality of endoscopically obtained esophageal biopsies in the dog

OBJECTIVE

An important premise for obtaining diagnostically relevant histology specimens is an appropriate biopsy technique. Goal of this study was to determine if biopsies of adequate quality can be obtained from the canine esophagus at the gastro-esophageal junction (GEJ) during routine upper gastrointestinal endoscopy.

MATERIAL AND METHODS

Over the course of one year, 58 dogs undergoing upper gastrointestinal endoscopy because of the presence of esophageal (n = 22) or gastrointestinal (n = 36) clinical signs were prospectively included. Five biopsies were repeatedly collected from the same dorsal and ventral locations of the GEJ, fixated individually in 4% neutral buffered formaldehyde, and evaluated histopathologically after standard preparation and haematoxylin and eosin staining. The presence of esophageal squamous epithelium with a basal cell layer and lamina propria mucosae in conjunction with foveolar columnar epithelium and cardiac glands, and the absence of fundic glands in one specimen, respectively, was judged as an adequately sampled biopsy.

RESULTS

Adequately sampled biopsies were reported in 45 out of 58 dogs, with 31 samples originating from the dorsal GEJ, 36 samples originating from the ventral GEJ, and with 22 samples originating from both sites, respectively. The incidence of adequately sampled biopsies increased significantly over time (r = 0,22; p < 0,05), with these biopsies being reported significantly more often during the last 6 months compared to the first 6 months of the study (p = 0,03). Histopathological evaluation of the esophageal squamous epithelium showed fibrosis, inflammation, elongation of the stromal papillae, and increased thickness of the basal cell layers in 14 out of 58 dogs. Stromal papillae of the ventral esophageal epithelium were significantly elongated in dogs with esophageal clinical signs compared to dogs with gastrointestinal clinical signs (p = 0,03).

CONCLUSION AND CLINICAL RELEVANCE

After an initial learning phase adequate esophageal biopsies from the GEJ can be obtained in canine patients undergoing upper gastrointestinal endoscopy, and histological lesions can be found in these biopsies.

Assessment of the histological quality of endoscopic biopsies obtained from the canine gastro-esophageal junction

OBJECTIVE

In the dog biopsy samples from the gastro-esophageal junction (GEJ) are rarely obtained during routine gastroscopy. The aim of this pilot study was to assess the histological quality of endoscopic biopsies sampled from the canine esophagus and cardia. It was hypothesised that it is possible to sample adequate specimens from these sites.

MATERIALS AND METHODS

For this purpose 10 dogs with an indication for gastroscopy were enrolled in a prospective study. Biopsy samples were obtained with standard biopsy forceps for single use exactly from the GEJ thus containing preferably columnar epithelium from the cardia and squamous epithelium from the esophagus, respectively. In every dog the specimens were examined for size, layers and site, respectively. Study endpoint was reached when specimens originated from cardia and esophagus, showing at least epithelium and lamina propria mucosae, and a diameter >2mm on the slide, respectively.

RESULTS

72 biopsy specimens (median 7, range 5-10) obtained from the GEJ were examined in 10 dogs. Specimens from the esophagus containing squamous epithelium with lamina propria mucosae were found in 5 of 10 (50.0%) dogs. Specimens from the cardia containing columnar epithelium with lamina propria mucosae were found in 10 of 10 (100.0%) dogs. Four of 10 (40.0%), and 10 of 10 (100.0%) dogs showed at least one specimen >2mm on the slide originating from the esophagus, and from the cardia, respectively. Histological quality was found to be adequate in 4 of 10 (40.0%) dogs, showing specimens of adequate size, originating from both esophagus and cardia, and containing at least epithelium and lamina propria mucosae.

CONCLUSION AND CLINICAL RELEVANCE

The pilot study provides evidence that during routine gastroscopy it is possible to sample endoscopic biopsies from the cardia and with limitations from the esophagus showing a quality adequate for histological examination of the epithelium and the lamina propria mucosae.

Antimalarial peroxide dyads from natural artemisinin and hydroxyalkylated 1,2,4-trioxanes

Three synthetic approaches to highly antimalarial peroxide dyads that are composed of the natural artemisinin part (either as dihydroartemisinin or artesunic acid components) and synthetic 1,2,4-trioxanes linked by ether or ester bridges are described. Photooxygenation is the key step to introduce the trioxane group initially or at the end of the reaction sequence, respectively. Dihydroartemisinin or artesunate coupling to hydroxyethyltrioxanes are the two processes that use intact peroxide units from the beginning, whereas the dihydroartemisinin-coupling to an allylic alcohol is a postphotooxygenation route, where the second trioxane ring is installed in the last step of the procedure.

Radiotherapy in three suspect cases of feline thymoma

Radiation therapy for three cases of suspect feline thymoma is described. The thymoma was controlled for 4 years in case no. 1. Case no. 2 responded well to radiation therapy but was euthanized after 2 months because of a nasal adenocarcinoma. Case no. 3 continues to do well more than 8 months after radiotherapy. Difficulties in diagnosing feline thymomas are discussed, and biological behavior as well as different treatment modalities of feline and human thymomas are compared.

Ultrasonographic examination of the adrenal gland and evaluation of the hypophyseal-adrenal axis in 20 cats

The adrenal glands of 20 healthy, non-sedated cats were examined ultrasonographically; visualisation and assessment was possible in all cases. In comparison with the surrounding tissue, the adrenal glands were hypoechoic and two distinct zones could be differentiated in six of the cats. The length and width of the adrenal glands varied from 0.45 to 1.37 cm and 0.29 to 0.53 cm, respectively, and both dimensions could be reliably reproduced. The adrenal glands did not differ between male and female cats, and, in comparison to dogs, those of cats are more easily visualised ultrasonographically. The basal cortisol value ranged from 2.0 to 79 micrograms/litre. Values 30 and 60 minutes after administration of ACTH (0.125 mg/cat intramuscularly) varied from 36 to 126 micrograms/litre. The basal value of aldosterone ranged from 4 to 618 pg/ml. Values 30 and 60 minutes after administration of ACTH varied from 100 to 832 pg/ml. In all cats, suppression of the cortisol value below the level of detection (< 2.0 micrograms/litre) occurred four and eight hours after the administration of dexamethasone (0.1 mg/kg intravenously).

[Effects of mitotane therapy in dogs with pituitary dependent Cushing syndrome on the adrenal gland size--an ultrasonographic study]

The effect of mitotane therapy on adrenal gland size was evaluated in 13 dogs with pituitary dependent hyperadrenocorticism. Ultrasonographic measurements were obtained before and during mitotane therapy. During therapy both adrenal glands were shorter and thinner (median during therapy: left adrenal gland 19.4 mm long, 5.4 mm thick, right adrenal gland 18.1 mm long, 6.1 mm thick) than before mitotane therapy (median before therapy: left adrenal gland 23.6 mm long, 8.3 mm thick, right adrenal gland 21.6 mm long, 8.1 mm thick). Statistical evaluation showed a significant reduction in size. But ultrasonographic measurement of adrenal gland size is not useful in the evaluation of adrenal reserve during mitotane therapy. Inadequate adrenal reserve was not identified and adrenal size measurement by ultrasonography was not helpful to differentiate adequate and inadequate control of adrenal cortisol secretion during mitotane therapy.

Seroprevalence of Ehrlichia canis and of canine granulocytic Ehrlichia infection in dogs in Switzerland

Serum samples from 996 dogs in Switzerland were examined for antibodies to Ehrlichia canis and to the agent causing canine granulocytic ehrlichiosis (CGE). Ehrlichiosis, borreliosis, and systemic illness not associated with ticks were suspected in 75, 122, and 157 of these dogs, respectively. The remainder of the serum samples were obtained from clinically healthy dogs which resided north (n = 235) or south (n = 407) of the Alps. The serum samples were tested by an indirect immunofluorescence technique for antibodies to the two agents incriminated, E. canis and Ehrlichia phagocytophila, a surrogate marker of the agent of CGE. Twenty-two of 996 (2.2%) serum samples had antibodies to E. canis and were distributed as follows: 20 of 75 (26.7%) samples from dogs suspected of having ehrlichiosis, 1 of 122 (0.8%) from dogs suspected of having borreliosis, and 1 of 407 (0.2%) from healthy dogs which resided south of the Alps. Of the 75 (7.5%) serum samples that had antibodies to E. phagocytophila, significantly more samples were from ill dogs than from healthy dogs. Among the sera from healthy dogs, antibodies to E. phagocytophila were significantly more prevalent in the north. Because seropositive dogs had a history of travel outside Switzerland and because Rhipicephalus sanguineus is found exclusively south of the Alps, it was presumed that, in contrast to the agent of CGE, E. canis is not indigenous to Switzerland.

[Indirect blood pressure measurement in cats with diabetes mellitus, chronic nephropathy and hypertrophic cardiomyopathy]

In the present study blood pressure was measured in cats comparing two indirect methods (oscillometric versus Doppler-sonographic) over a wide pressure range. It was shown, that at the lower pressures Doppler and oscillometric measurements were basically equivalent. However for higher pressures oscillometric measurements were consistently lower than Doppler measurements. This difference became greater as blood pressure increased. The determination of blood pressure by the Doppler-sonographic method was always possible, whereas the measurement by the oscillometric method was often not possible, especially at higher blood pressure levels. In a second step, the frequency of hypertension was determined in cats with diabetes mellitus, chronic renal failure and hypertrophic cardiomyopathy. Eight cats with diabetes mellitus had oszillometric blood pressure values of 101-155 mmHg systolic, 42-105 mmHg diastolic and 65-125 mmHg mean arterial pressure determined at the front leg and 110-167 mmHg systolic, 44-98 mmHg diastolic, and 61-125 mean arterial pressure determined at the tail. The Doppler-sonographic values were 120-180 mmHg. Only the oscillometric measurement (at the tail) of the systolic pressure was significantly higher than that of normal cats. In 11 cats with chronic renal failure the following values were determined by the oszillometric method: at the front leg 137-182 mmHg systolic, 74-138 mmHg diastolic, 100-162 mmHg mean arterial pressure and at the tail 134-189 mmHg systolic, 53-109 mmHg diastolic, 80-135 mmHg mean arterial pressure. With the Doppler-sonographic technique the blood pressure was between 120 and 280 mmHg. All blood pressure measurements were significantly higher than those of healthy cats, except the oscillometric measurements of diastolic blood pressure. In 12 cats with hypertrophic cardiomyopathy systolic pressure was 108-179 mmHg, diastolic pressure was 64-135 mmHg, and mean arterial pressure was 89-154 mmHg at the front leg using the oscillometric method. At the tail results were as follows: 121-201 mmHg systolic, 61-141 mmHg diastolic, and 85-160 mmHg mean arterial pressure. By the Doppler-sonographic technique determined blood pressure was 110-260 mmHg. All oscillometric measurements except the diastolic pressure determined at the front leg were significantly higher than in normal cats. Four cats with chronic renal failure and five cats with hypertrophic cardiomyopathy showed retinal hemorrhages and/or detachments. Eight of this nine cats had blood pressure measurements above the normal range. We conclude that hypertension can be detected in cats with several diseases. In most cases reliable measurements can only be obtained by Doppler-sonographic methods.

[Treatment of mitral valve insufficiency in dogs with the ACE inhibitor enalapril. A clinical progress study]

The efficacy and safety of the angiotensin converting enzyme inhibitor enalapril in dogs with naturally acquired class III or class IV heart failure was evaluated in this study. Eighteen small-breed dogs with insufficiency of their mitral valves, but without other diseases were included in this study over a period of six months. When necessary due to massive pulmonary edema or high serum potassium concentrations, furosemide was added to the therapy with enalapril. No other drugs, including digitalis, were used in this study. The treatment was followed by anamnesis, clinical examinations, electrocardiography, radiography, echocardiography and laboratory diagnosis. Examinations were performed before treatment and after one week, after six weeks and after six months of treatment. 72% of the dogs improved in NYHA classification until the end of the study (p < 0.05). The incidence of seizures due to syncopes or severe respiratory distress decreased during this study (p < 0.01). For 28% of the dogs this treatment was not successful. In the electrocardiographic, radiographic and laboratory examinations statistically significant changes could not be recorded. The decrease in heart rate did not reach statistical significance. The echocardiographic investigation evaluated a significant decrease in fractional shortening and in the diastolic diameter of the left ventricular wall (p < 0.05 respectively p < 0.01), but no significant change in the diastolic or systolic diameter of the interventricular septum. The average oral dose of enalapril was 0.38 mg/kg body weight b.i.d., the average dose of furosemide was 0.37 mg/kg body weight b.i.d. in the first week of the study and was raised to 0.74 mg/kg body weight b.i.d. until the end of the study. Side effects like diarrhea, vomiting or reduced appetite did not increase during the course of the study. However one dog was excluded from the study because of repeated vomiting after six weeks of treatment. This study shows the beneficial clinical and hemodynamic effects and the security of the therapy with enalapril for dogs with heart failure due to mitral insufficiency.

Leishmania major Hsp100 is required chiefly in the mammalian stage of the parasite

In Leishmania major a 100-kDa heat shock protein, Hsp100, is abundant in the intracellular amastigote stage which persists in the mammalian host. A replacement of both clpB alleles which encode Hsp100 does not affect promastigote viability under standard culture conditions but impairs thermotolerance in vitro. In experimental infections of BALB/c inbred mice, the lack of Hsp100 in the gene replacement mutants results in a markedly delayed lesion development compared with that in infections with wild-type L. major. Overexpression of exogenous clpB gene copies can partly restore virulence to the gene replacement mutants. Genetic-selection experiments also reveal a strong pressure for Hsp100 expression in the mammalian stage. This requirement for Hsp100 was also observed in in vitro infection experiments with mouse peritoneal macrophages. These experiments indicated a role for Hsp100 during the development from the promastigote to the amastigote stage. Our results suggest an important role for this parasite heat shock protein during the initial stages of a mammalian infection.

Immune responses to filarial infection in laboratory mice

Models of filarial infection in laboratory inbred mice are valuable tools for assessing the relevance of anti-filarial immune responses in protection against these parasites. However, laboratory mice are not permissive for those filarial species which are known to infect humans. Therefore, immunity to the different stages of these filariae, i.e. infective third stage larvae (L3), adults and microfilariae, has been analyzed separately, as a surrogate approach. Although much information has been gathered by analysis of immunity and intervention in particular immune responses in these experimental systems, interference of different stage-specific responses as well as modulation of filarial maturation by the immune system cannot be assessed. A newly established infection model of filariasis, namely infection of laboratory mice with Litomosoides sigmodontis, accommodates the full developmental cycle of the parasite and may overcome this deficiency. Although the disadvantage of this latter model is that it deals with a filaria which is not pathogenic to man, it is the only model in which immunity can be analyzed during maturation of infective larvae into adult worms, the period considered most important for vaccination studies.

[Sonographic demonstration of an aortic thrombosis in the dog]

A case of aortic thrombosis in a Golden Retriever is reported. The main clinical signs were paresis of the left hind limb, weak femoralis pulses and cool distal limbs. The diagnosis was made by ultrasonography. An echogenic, intraluminal mass was detected in the iliac bifurcation.

[Cystocentesis in dogs and cats]

The technique of cystocentesis in dogs and cats was studied. The indications and contraindications of this method are discussed, using illustrations.

[The diagnostic significance of the protein-creatinine ratio in urine for the differentiation of feline nephropathies]

The normal U-P/C-range in cats was established with urine samples of 19 cats. The upper limiting value was fixed at 0.33 (mean +/- 2s). U-P/C is a reliable parameter for diagnosing proteinuria in the uremic cat. However, only very high U-P/C-values allow a conclusion on the type of nephropathy, whereas with moderately increased U-P/C values, do not allow any distinction between feline nephropathies.