Cyclospora species as a cause of diarrhoea in humans

Within the past 10 years, the coccidian parasite Cyclospora cayetanensis has been clearly recognised as a cause of protracted diarrhoea in humans. Heavy infection results in inflammation and epithelial injury in the duodenum and jejunum. Of the multiple symptoms, diarrhoea may neither be the presenting nor predominant one. Following an incubation period of 12 hours to 11 days, the abrupt onset of watery diarrhoea occurring in a relapsing cyclic pattern is characteristic, lasting from six to eight weeks in immunocompetent patients, but three months in the immunocompromised. Of worldwide distribution, it is endemic in certain regions where it can be associated with rainy seasons. Outbreaks or isolated cases may also occur in developed countries. Contaminated water can transmit the oocysts, and usual control procedures for potable water supplies fail to detect the parasite, which resists chlorination. Diagnosis depends upon laboratory investigations, usually faecal microscopy. For reliable detection of characteristic oocysts in the faeces, special procedures may be necessary. Trimethoprim-sulphamethoxazole is established as the treatment of choice and leads to rapid relief of symptoms, although relapse in immunocompromised patients may require secondary prophylaxis.     

Pseudomonas putrefaciens as a cause of infection in humans.

Pseudomonas putrefaciens, a strongly H2S-producing pseudomonad, was isolated from 10 human infections over a two-year period. In one patient the organism was repeatedly isolated from a phlegmone developing in the depth of a varicose leg ulcer. This is the first report on the occurrence of Ps. putrefaciens in humans outside the USA and the first to provide the detailed account of a clinical observation where the opportunistic pathogenic role of this unfamiliar organism has been sufficiently documented. Data are presented on the bacteriological properties and on the antibiotic sensitivity of Ps. putrefaciens.     

Pseudomonas putrefaciens as a cause of bacteremia in humans.

Pseudomonas putrefaciens has been presented as an opportunistic pathogen in a few isolations from humans. This is the first documented report of a local infection of P. putrefaciens complicated by invasion of the blood stream. The organism was twice isolated from the blood culture and once from the wound exudate of a 73-year-old woman hospitalized for extensive ulcerations on the legs. Parenteral ampicillin and gentamicin together with local antiseptic treatment led to an uneventful recovery.     

Pseudomonas putrefaciens as a cause of septicemia in humans.

Septicemia due to Pseudomonas putrefaciens was found in an elderly man with chronic leg ulcers. This organism is rarely cultured from human material and has been reported to cause skin and ear infections in only a few patients. Its potential for invasiveness is documented in this case for the fourth time.     

Stimulation of sympathetic innervation in the upper gastrointestinal tract as a treatment for obesity

Sympathetic activity and obesity have a reciprocal relationship. Firstly, hypothalamic obesity is associated with decreased sympathetic activity. Caffeine and ephedrine increase sympathetic activity and induce weight loss, of which 25% is due to increased metabolic rate and 75% is due to a reciprocally decreased food intake. Secondly, hormones and drugs that affect body weight have an inverse relationship between food intake and metabolic rate. Neuropeptide Y decreases sympathetic activity and increases food intake and body weight. Thirdly, a gastric pacemaker Transcend^® and vagotomy increase the ratio of sympathetic to parasympathetic activation, decrease food intake, and block gut satiety hormones. Weight loss with the pacemaker or vagotomy is variable. Significant weight reduction is seen only in a small group of those treated. This suggests that activation of the sympathetic arm of the autonomic nervous system may be most important for weight loss. Systemic sympathetic activation causes weight loss in obese patients, but side effects limited its use. We hypothesize that selective local electrical sympathetic stimulation of the upper gastrointestinal tract may induce weight loss and offer a safer, yet effective, obesity treatment. Celiac ganglia delivers sympathetic innervation to the upper gastrointestinal tract. Voltage regulated electrical simulation of the rat celiac ganglia increased metabolic rate in a dose-dependent manner. Stimulation of 6, 3, or 1.5 V increased metabolic rate 15.6%, 6.2%, and 5%, respectively in a single rat. These responses support our hypothesis that selective sympathetic stimulation of the upper GI tract may treat obesity while avoiding side effects of systemic sympathetic activation.     

Noxious compounds in exhaled air, a potential cause for ocular manifestations of H. pylori gastrointestinal infection

Helicobacter pylori infection is one of the most common chronic bacterial infections worldwide. In the past few years, a variety of extradigestive disorders have been associated with H. pylori infection. This infection has also been linked to some ophthalmic disorders, including glaucoma, central serous chorioretinopathy, uveitis and blepharitis. Several possible theories to explain pathogenetic mechanism underlying the observed associations have been provided. H. pylori infection causes elaboration of some noxious compounds, including ammonia, hydrogen nitrate and hydrogen cyanide, in exhaled breath of infected individuals. Herein we hypothesize that chronic exposure of ocular surface to these compounds may explain some ophthalmic and also respiratory manifestations of the chronic gastrointestinal infection.     

Self medication and health habits in the management of upper gastrointestinal symptoms

Upper gastrointestinal symptoms are a common complaint among the general population but only a small proportion of sufferers seek medical advice. The aim of this study was to examine what kind of perceptions persons using self medication have about the causes of their gastrointestinal symptoms, whether they have made any health-related lifestyle changes, and whether visits to a physician are related to lifestyle changes. A pharmacy-based survey was done in 10 pharmacies in the Helsinki area in 1995. The questionnaire was completed by 292 customers. The response rate was 53%. Respondents in a population-based health interview survey (n = 10,410) were used as a comparison group for poor health-behavior (consumption of tobacco, alcohol, coffee). The most common perceived causes of gastrointestinal symptoms were poor diet, coffee, and stress. Ignorance about possible causes of symptoms was especially common among less educated respondents and among those persons who had never visited a physician due to their symptoms. Respondents were significantly more often smokers and they had attempted to reduce their coffee and alcohol consumption more often than the general population. Those who had visited a physician during past year, less often had poor health-behavior and they had better knowledge about the possible causes of their symptoms. They had also made lifestyle changes more often, but after adjustment for background characteristics, physician visits were positively correlated only with coffee reduction. Counseling about healthy lifestyles, especially about smoking, should be increased in physician consultations and in pharmacies for all patients and customers having gastrointestinal problems.     

Startle reflex facilitation as a function of classical eyeblink conditioning in humans

I investigated whether classical eyeblink conditioning increases the activating effect of the conditional stimulus (CS) on the relevant alpha motoneuron pool in the facial nucleus. The activating effect was measured by the reflex modification method, where startle reflexes, sharing the facial nerve motor pathway with conditional and unconditional eyeblink reflexes, were elicited in the presence of reinforced and nonreinforced CSs (CS+ and CS?). To reduce influences of conditional arousal on startle, a weak airpuff to the eye was used as unconditional stimulus and relatively short stimulus onset asynchronies (SOAs) of 300 and 600 ms were used in three startle tests presented while conditioning was in progress. Two groups (N= 72) received 100% or 0% reinforcement (Groups 100 and 0) of a tone CS+. The CS? was not reinforced. Three startle tests, consisting of acoustic startle probes presented alone and after CS+ and CS? onset, were conducted early, middle, and late in conditioning. Results showed increased startle reflex facilitation after CS+ onset in the late startle test in Group 100, indicating that startle increased as a function of classical conditioning. Although reflex facilitation at the 300-ms SOA in Group 100 is consistent with the hypothesis that CS presentations activated motoneurons in the facial nucleus, the present study cannot itself definitively support this hypothesis. Reflex facilitation at the 600-ms SOA in Group 100 could be influenced by conditional arousal.     

Adjustment of the vestibulo-ocular reflex gain as a function of perceived target distance in humans

The human vestibulo-ocular reflex (VOR) was investigated during active head movements in yaw while subjects were asked to view targets located at 20, 30, 40, 60, 90, and 120 cm distance aligned with eye level. Binocular video cameras were used to study conjugate eye movements and binocular convergence. Perceived target distance was determined during head oscillation by having the subjects move a cursor to the remembered position of the previously seen targets. The changes in VOR gain with viewing distance were found to be more closely related to perceived target distance than to actual target distance or fixation distance. This result suggests that the adjustment of VOR gain with viewing distance is under stronger cognitive control than would be expected of a simple motor reflex.     

Bartonella species as a potential cause of epistaxis in dogs

Infection with a Bartonella species was implicated in three cases of epistaxis in dogs, based upon isolation, serology, or PCR amplification. These cases, in conjunction with previously published reports, support a potential role for Bartonella spp. as a cause of epistaxis in dogs and potentially in other animals, including humans.     

Aeromonas spp as a potential cause of diarrhoea in children.

AIMS: To determine the prevalence of Aeromonas spp in the faeces of children and the association with symptoms of gastroenteritis. METHODS: Faecal specimens (n = 1026) were cultured for Aeromonas spp using three selective media and an enrichment broth at both 30 degrees C and 37 degrees C. The isolation of Aeromonas spp was correlated with symptoms of gastroenteritis, previous antibiotic use, and environmental temperature. RESULTS: Aeromonas spp (n = 28) from 26 (2.5%) patients were recovered. Bile salt, Irgasan, and brilliant green agar was the most efficient selective culture medium. Eleven of the patients had symptoms of gastroenteritis, usually mild diarrhoea of two to three days' duration, in the absence of other recognised enteropathogens. A caviae was a particularly frequent isolate (nine out of 11 cases) in symptomatic individuals. Only one out of seven Aeromonas spp recovered by enrichment culture alone was possibly associated with symptoms of gastroenteritis. There was a close correlation between the environmental temperature and isolation of Aeromonas spp. CONCLUSIONS: Aeromonas spp and particularly A caviae may cause gastroenteritis in children, most often during warmer months of the year. Culture for these potential enteropathogens could be confined to summer and autumn months. Bile salt, Irgasan, and brilliant green selective agar, but not alkaline peptone water enrichment, is an efficient culture medium for recovering possibly clinically important isolates.     

The existence of hypoglossal root ganglion cells in adult humans: potential clinical implications

INTRODUCTION: Ganglion cells of the hypoglossal nerve (HN) have been confirmed in certain animals but have been thought not to be present in man. To investigate for the presence of these structures in adult humans and if present, to verify their functionality, the present study was performed. MATERIALS AND METHODS: We harvested adult cadaveric HN and observed for ganglion cells. Histological and immunohistochemical analyses were performed on all specimens. RESULTS: Ganglion cells were found in 33% of specimens. Using immunohistochemistry, we found that these ganglia were sympathetic in nature. Based on our findings, ganglion cells do exist in the human HN although they are located sporadically and are found inconstantly. CONCLUSIONS: Such information may be valuable in elucidating other functions of the HN and may aid in the histological diagnosis of this nerve. Additionally, pathology involving HN such as paragangliomas, are supported by our findings of the presence of autonomic ganglion cells in some HN specimens.     

Hafnia alvei, a probable cause of diarrhea in humans.

Hafnia alvei, a member of the family Enterobacteriaceae, was the only species of bacteria cultured from the stool of a 9-month-old child who was admitted with a 3-day history of watery diarrhea. The isolated strain of H. alvei failed to produce heat-labile or heat-stable enterotoxins or Shiga-like toxin I or II and did not invade HeLa cells, nor did it cause keratoconjunctivitis (determined by the Sereny test) in a guinea pig's eye. The strain, however, induced diarrhea in 8 of 12 adult rabbits with removable intestinal ties (removable intestinal tie-adult rabbit diarrhea [RITARD] assay) and in 1 of 2 orally fed animals. No diarrhea could be induced with Escherichia coli K-12 in eight RITARD assay rabbits and three orally fed rabbits, respectively. Microscopic examination of affected animals revealed moderate inflammatory cellular infiltration of the intestinal mucosa, in which bacterial attachment to the surface epithelium and loss of the microvillus border were evident in the ileum and colon. Electron microscopy demonstrated cellular modifications of the apical surface, with cupping or pedestal formation and increased terminal web density at sites of bacterial "attachment-effacement," a well-known characteristic and mechanism of diarrhea of enteropathogenic E. coli. Identical lesions were also induced by H. alvei in rabbit ileal loops, which ruled out naturally occurring rabbit enteropathogenic E. coli strains, which are known to produce similar lesions. It is concluded that at least some strains of H. alvei have the potential to cause diarrhea and that attachment-effacement is a virulence characteristic shared by bacteria other than E. coli.     

Pseudomonas aeruginosa as a potential cause of antibiotic-associated diarrhea.

Although Pseudomonas aeruginosa is not generally considered as a cause of antibiotic-associated diarrhea, several cases of diarrhea caused by P. aeruginosa have been reported. We experienced seven cases of nosocomial diarrhea presumably caused by P. aeruginosa, which was the predominant organism isolated from stool cultures. Clostridium difficile toxin was also positive in one patient. No other potential or recognized enteropathogens were identified from stools. All patients had underlying diseases and had been receiving antibiotics before the diarrheal onset. All of the seven P. aeruginosa isolates were resistant to previously given antibiotics. Diarrhea stopped three days after withdrawal of probable offending antibiotics without specific treatment in two patients. The other five patients having continuous diarrhea despite withdrawal of probable offending antibiotics, were successfully treated with antipseudomonal agents. The median duration of diarrhea after the initiation of treatment was 6.3 days. These data suggest that P. aeruginosa can be a potential cause of antibiotic-associated diarrhea. Further investigations are warranted to evaluate the possible etiologic role of P. aeruginosa in antibiotic-associated diarrhea.