Rats with hippocampal lesions can learn a place response, but how long can they retain it?

Previous research has shown that electrolytic hippocampal lesions do not affect the acquisition of a place response if a special training procedure is used. However, 24 days later, the hippocampal rats manifest a profound deficit in the retention of the spatial information (J. M. J. Ramos, 2000). The goal of the present study was, therefore, to investigate how long the hippocampal rats can retain a place response. Results showed that, 3 days after the end of the training, lesioned rats remembered as well as the control rats, but this was no longer true 6 or 12 days after the training. This retention deficit was not observed when the spatial information was acquired by means of a guidance strategy. These results suggest that, when a special training procedure is used, the hippocampus is not necessary for the learning of a place task but is required for the formation of long-term spatial memory.

Hippocampal damage in rats disrupts decrements in the processing of an intramaze landmark in a spatial task

Using a four-arm plus-shaped maze, rats with neurotoxic lesions in the dorsal hippocampus were trained in a spatial reference memory task in which both the extramaze constellation of stimuli and an intramaze landmark (a piece of sandpaper covering the floor of the goal) indicated the location of the goal arm. After reaching criterion, animals were given two transfer tests in order to investigate how much they had learned about the intra and extramaze cues. Results showed that during the intramaze transfer, based exclusively on the intramaze cue, hippocampal rats produced a performance clearly superior to that of the controls. Importantly, the average percentage of correct responses recorded in the hippocampal group during the extra versus the intramaze transfer test was similar. Thus, no decremental processing of the intramaze cue was detected in the lesioned group. In contrast, control rats showed a decremental processing of the intramaze landmark performing worse during the intramaze transfer as compared with the extramaze transfer. These results support the view that the hippocampus regulates decremental changes in the processing of normally irrelevant stimuli, extending this claim into a spatial domain.

The hippocampus and flexible spatial knowledge in rats

Lesions to the hippocampal system in rats result in a profound impairment of place or locale spatial learning although other learning strategies remain unaltered. The main objective of the present study was to investigate whether the spatial knowledge preserved in the hippocampal animals can be expressed flexibly under conditions different from those of the acquisition period. Rats with neurotoxic lesions to the dorsal hippocampus and sham-operated subjects were trained to reach the goal arm in a four-arm plus-shaped maze using a constant starting arm. During the training a transparent plexiglas barrier divided the maze in two equal halves in such a way that the animals could only travel from the starting arm to the goal arm, not having access to the remaining 50% of the maze. After seven days of training, a transfer test was used in which the starting arms were the two arms from which the animals had not started during the training phase. Results indicated that the lesioned rats made significantly more errors than the control subjects. But the most interesting results revealed that the kind of error made by the lesioned animals was congruent with the turn that they had to make during the acquisition phase in order to access the goal arm (reinforced). These results suggest that when the hippocampus is damaged a preserved highly inflexible egocentric strategy is employed to solve the spatial problem.

Retention of spatial information in hippocampally damaged rats overtrained on a cartographic task

Hippocampal rats were overtrained on a cartographic task until they reached a performance equal to that of the control group. Twenty-four days later, during a retraining period, lesioned rats showed a profound retention deficit as compared to controls. However, Expt. 2 shows no retention deficit when a guidance strategy is used to acquire the spatial task. These results suggest that the hippocampus is crucial for long-term retention/consolidation of allocentric spatial information.

Long-term spatial memory in rats with hippocampal lesions

In animal models of human amnesia, using lesion methods, it has been difficult to establish the role played by the hippocampus in the formation of long-term spatial knowledge. For example, lesions sustained after acquisition have generally produced a flat retrograde amnesia for spatial information. These results have not made it possible to dissociate the participation of the hippocampus in retrieval/performance processes from its participation in consolidation/retention. The present study was designed to investigate if electrolytic hippocampal lesions made before training lead to a deficit in the long-term retention of spatial knowledge when the rats show equal performance levels during the acquisition. Results show that lesioned rats learn a place response just as well as the control rats when, during the training, an intramaze cue orients the animal in its navigation towards the goal arm. One day after reaching criterion, lesioned and control rats remember the task perfectly during a transfer test in which the intramaze signal used previously is not present. However, 24 days later, the hippocampal animals manifest a profound deficit in the retention of the spatial information. When the spatial task learned during the acquisition phase requires only the use of a guidance strategy, control and lesioned animals show the same level of performance during the training phase and the same degree of retention during the retraining phase 24 days after criterion. Taken together, these results suggest that the hippocampus plays a crucial role in long-term retention of allocentric spatial information.

Influence of the shape of the experimental room on spatial learning in rats

Rats and other mammals can orient themselves in their habitat and locate various goals using different learning strategies. When a cartographic or local strategy is used, the animals construct and store in their long-term memories a complex representation of the extramaze space. However, exactly what constitutes the behaviorally key components of the extramaze space is still little known. The purpose of this study was to investigate whether the shape of the environment that surrounds the animal is an informative factor when a cartographic strategy is used. Two experiments were performed in which the rats were trained to find food in the goal arm of a four-arm, plus-shaped maze. Experiment 1 shows that lesions to the hippocampus impair the acquisition of this task, which suggests that in fact, a cartographic strategy is necessary to solve it. In Experiment 2, in which only one group of neurologically intact rats was used, we directly manipulated the shape of the space around the maze. The results showed that once the animals have learned the task, the hiding of all the extramaze single landmarks while keeping intact the general shape of the experimental room does not affect performance. Only when the shape of the surrounding space was modified did the performance deteriorate significantly. These results are discussed in relation to the different components of the extramaze environment and the contribution of each of them to the spatial learning.

[Isolated left anterior artery disease: angiographic features and clinical evolution of patients submitted to surgical myocardial revascularization or angioplasty]

The option for revascularization and the choice of intervention in isolated left anterior descending artery disease may be controversial. We decided to study retrospectively a group of revascularized patients (PTCA or surgery), with previous isolated LAD disease, to evaluate the angiographic features of LAD lesion, its contribution to the persistence of symptoms after revascularization and also to compare the occurrence of cardiac events in the two subgroups (PTCA and surgery). We studied 87 patients (mean age 57 +/- 10 years) submitted to myocardial revascularization (68 PTCA; 19 surgery), whose clinical evolution was followed for a mean period of 49 +/- 10 months (cardiac events: death, myocardial infarction, angina, heart failure, PTCA, surgery). We evaluated in cineangiography angiographic features of LAD lesions (degree of stenosis, lesion length and diameter, ectasia, luminal irregularity, ulcerated plaque, eccentricity, thrombus, calcification, type of lesion). On comparing angiographic features, we noted coronary lesions were longer in operated patients (p < 0.05) and a tendency for more complex lesions in this group (p = 0.08). After revascularization, 65% of PTCA patients and 26% of operated patients maintained angina (p < 0.01). The frequency of events was significantly higher in patients submitted to PTCA (84%) due to the greater occurrence of angina (65%). Sixteen percent PTCA were redilated and 6% operated whereas 11% of the surgical group were reoperated, without statistical difference regarding reintervention between the two groups. In the PTCA group, the greater frequency of angina and the necessity of a new PTCA could reflect restenosis. The disappearance of angina in operated patients may reflect probable patency of coronary bypass.

Retrograde amnesia for spatial information: a dissociation between intra and extramaze cues following hippocampus lesions in rats

Several recent studies have shown a flat retrograde amnesia for spatial information following lesions to the hippocampus in rats and mice. However, the results of the present investigation demonstrate that in rats that presurgically learned a spatial reference memory task based on extramaze cues, a temporally graded retrograde amnesia is evident following lesions to the hippocampus (1, 16, 32 or 64 days after learning) if two conditions are met. First, that a wide range of retention intervals is used, and second, that independent groups of rats are tested, not a single group that learns different spatial discrimination tasks at different times (expt 1). The results of expt 2 show that the hippocampus does not serve as a consolidating mechanism when the spatial task learned presurgically is based on intramaze cues. Taken together, these results indicate that the hippocampus is critical for the storage and/or retrieval of spatial reference information that was learned up to 1 month before hippocampus damage; however, in the absence of the hippocampus, efficient retention can still occur provided that the spatial knowledge was learned in a simple associative manner.

[Methods for evaluating diagnostic tests in Enfermedades Infecciosas y Microbiología Clínica]

BACKGROUND

In the field of infectious diseases and clinical microbiology, the evaluation of diagnostic tests (DT) is an important research area. The specific difficulties of this type of research has motivated that have not caught the severity methodological of others areas of clinical research. This article try to asses and characterize the methodology of articles about DT published in Enfermedades Infecciosas y Microbiología Clínica (EIMC) journal.

METHODS

Forty-five articles was selected in the EIMC journal during the 1990-1996 period, because of determinate the sensitivity and specificity of different DT. Methodological standards, extensively accepted was used.

RESULTS

In all of articles, except one (98%) the gold standard was specified yours use, however in 4 studies (9%) include the DT in the gold standard (incorporation bias). The correct description of DT was reported in 75% of cases, but only in 11% cases the reproducibility of test was evaluated. The description of source of reference population, standard of inclusion and spectrum of composition was described in 58, 33 and 40% of articles, respectively. In 33% of studies presented workup bias, only 6% commented blind-analysis of results, and 11% presented indeterminate test results. Half of the studies reported test indexes for clinical subgroups, only one article (2%) provided numerical precision for test indexes, and only 7% reported receiver operating characteristics curves.

CONCLUSIONS

The methodological quality of DT research in the EIMC journal may improve in different aspects of design and presentation of results.

[A review of infectious endocarditis due to Candida]

OBJECTIVE

As fungal endocarditis is a serious disease, frequently requiring cardiac surgery, a review was made of the experience of our Departments in this pathology.

DESIGN

A retrospective analysis of clinical, echocardiographic and surgical data.

SETTING

Patients studied in a tertiary care Hospital with cardiac surgery available.

PATIENTS

Between 1984 and 1994 there were ten cases of candida endocarditis in nine patients, four male and five female, mean age--45 +/- 12 years (31-65).

INTERVENTIONS

The following parameters were analysed: clinical (predisposing factors, clinical evolution, complications, therapy and mortality), echocardiographic (presence of vegetations, abscesses, valvular regurgitations). Patients studied in other Centres and referred to our Department only for examination (echocardiograms) were excluded from this analysis.

RESULTS

Eight cases in seven patients were prosthetic valve endocarditis and two native valve endocarditis. No patient was drug addicted. Seven cases of prosthetic valve endocarditis developed less than one year after surgery and another had a gynecological fungal infection as the cause of the endocarditis. Four patients had had previous endocarditis. There were four embolic events and three developed heart failure. There were three perivalvular infections, six valvular regurgitations and only one case with huge vegetations on echocardiography. Nine patients were treated with amphotericin B, in five fluocytosin was added and in four ketoconazol, which was replaced by flukonazol in one patient. Therapy was continued for at least eight weeks. Six patients were operated during the acute stage and one died. One patient was operated on late after the infection. Three patients died during the active stage. In a follow up of 5.2 +/- 4.8 years (8 months to 8 years) there was one fatal candida endocarditis relapse, one fatal candida sepsis, one non cardiac death, one patient developed a periprosthetic leak and one had recurrent systemic embolization. Abscesses/pseudoaneurysms were found in five out of seven patients submitted to surgery.

CONCLUSION

Candida infective endocarditis has a bad prognosis, specially in those patients not operated early; it develops in patients with predisposing factors, which in our series were a previous infective endocarditis (four patients) and/or a prosthetic valve implantation less than one year before; it has important morbidity with multiple embolic events, perivalvular involvement, valvular regurgitation and heart failure.

Increasing urinary cotinine concentrations at elevated temperatures: the role of conjugated metabolites

The presence of cotinine, a nicotine metabolite, in urine above a specified cutoff concentration is commonly used to distinguish smokers from nonsmokers, as in smoking cessation studies. A stability study of cotinine in urine was carried out after questions arose concerning analyte stability at elevated storage and shipment temperatures. Aliquots from a smokers urine pool were stored at 5, 25, 40, 50 and 60 degrees C for 30 days. Another set of aliquots, obtained by diluting the smokers pool 1:1 with nonsmokers urine, were stored under the same conditions. Free cotinine levels, determined by a stability-indicating gas chromatographic/mass spectrometric (GC/MS) assay, increased over the 30-day period at higher storage temperatures. Cotinine concentrations in the aliquots stored at 60 degrees C, for example, nearly doubled over 30 days (1301 to 2476 ng/ml), with similar proportional increases observed in the aliquots diluted with nonsmokers urine. Since cotinine can be excreted to a large degree as cotinine-N-glucuronide, this conjugated metabolite was determined by an indirect method. As the storage temperature increased, the free/conjugated cotinine ratio dramatically increased, pointing to cotinine-N-glucuronide as the source of the additional free cotinine at the higher storage temperatures. The results of this study are of much practical importance, since urine samples with free cotinine concentrations just below a cutoff value may become positive for smoking status if suitably low temperatures cannot be maintained during sample handling and shipment.

Focal infections due to non-typhi Salmonella in patients with AIDS: report of 10 cases and review

Bacteremia due to non-typhi Salmonella is frequent in human immunodeficiency virus (HIV)-infected patients; however, focal complications rarely have been reported. Ten of 38 HIV-infected patients (26.3%) with salmonellosis documented over a period of 9 years had focal suppurative complications; only 19 (3.9%) of 490 adults without HIV infection who were seen during the same period had focal complications (P = .001). Infections of the urinary tract, lungs, and soft tissue, followed by arthritis, endocarditis, and meningitis were most frequently seen. Although salmonellosis occasionally heralded HIV infection, most patients were severely immunocompromised and had CD4 cell counts of <100/mm3. The mortality rate was 50%, equivalent to that observed among patients with other immunosuppressive disorders (52.6%). Major emphasis must be put on intensive therapy for salmonella bacteremia and prevention of its complications.

[Serologic diagnosis of severe non-bacterial pneumonia and acquired in the community]

BACKGROUND

The aim of this study was to evaluate the profitability of the serology, especially against Streptococcus pneumoniae and Chlamydia sp., in the community pneumonia with hospital admission.

METHOD

Descriptive and retrospective study. One hundred fifty-five pair of sera of 129 patients adults and 26 patients with less of 15 years with pneumonia were analysed. Antibody against respiratory virus, Coxiella burnetii, Mycoplasma pneumoniae, Legionella pneumophila, Chlamydia sp. and S. pneumoniae were investigated.

RESULTS

The serology diagnosis was obtained in 58 patients (37.4%) (42 [32.6%] adults and 16 [61.5%] children; p = 0.006). The pneumonia most frequently detected was caused by M. pneumoniae (21 cases; 13.5%), followed by Chlamydia spp. (13, 8.4%), S. pneumoniae (8, 5.2%) and mixed infection in other 7 cases. Detection of antibodies against pneumococcus and Chlamydia sp. improved as a whole in 8.4% (from 29% to 37.4%), a 10.9% (from 22.5 to 32.6%) in adults and none case in children. Moreover, a major proportion of mixed infection and by syncytial respiratory virus in children (19.5 and 11.5%, respectively) versus adults (1.6 and 0%, respectively; p < 0.1) was observed.

CONCLUSION

With the detection of antibodies against Chlamydia spp. by indirect immunofluorescence and capsular polysaccharide pneumococcal by enzyme-immunoanalysis increased the etiologic diagnosis of the community pneumonia.

[Bacteremia caused by Alcaligenes (Achromobacter) xylosoxidans. Description of 3 cases and review of the literature]

BACKGROUND

Alcaligenes (Achromobacter) xylosoxidans occasionally cause infections, mainly in immunocompromised hosts.

METHODS

Three cases of bacteremia due to A. xylosoxidans observed at the Fundación Jiménez Díaz between 1985-1994 were described. Moreover, 38 single cases of bacteremia due to A. xylosoxidans and 21 episodes associated with outbreak were reviewed by using computerized bibliography data base MEDLINE (1970-december 1994).

RESULTS

From 41 patients with bacteremia (including our 3 cases) reviewed, 27 were immunosuppressed hosts (twenty had neoplasia disease). The most common clinical presentation was primary bacteremia (11 cases, 27%) and pneumonia (10, 24%), followed by catheter-associated bacteremia (8, 20%), meningitis (4), bacteremia from abdominal cavity (4), endocarditis (3) and pyelonephritis (1). The mortality rate was higher (39%), specially in patients whom were a intensive care unit acquisition (87%), and illness with endocarditis (100%). No patient with catheter-related bacteremia died. All of 21 outbreak episodes of bacteremia had a autolimited form and low mortality (4.8%).

CONCLUSION

A. xylosoxidans is a microorganism with demonstrated capacity of cause bacteremia, mainly in immunocompromised hosts, with high mortality rates. Sometimes, it causes outbreaks of bacteremia with low mortality.

Clinical spectrum of urinary tract infections due on nontyphoidal Salmonella species

We performed a retrospective analysis of 28 cases of bacteriuria due to nontyphoidal Salmonella (NTS). Twenty-one patients (75%) had symptoms of urinary tract infection (16, cystitis; 3, pyelonephritis; and 2, renal abscess), and 7 remained asymptomatic. In 24 cases NTS was the sole pathogen isolated from urine. Salmonella enteritidis (a Salmonella subgroup 1 serotype) was the serotype most frequently isolated (16 cases), followed by Salmonella enteritidis serotype typhimurium (5 cases). Sixteen patients (57%) were severely immunocompromised, and 14 (52%) had urologic abnormalities. Recurrence of bacteriuria occurred in four patients. It is suggested that in cases of urinary salmonellosis one must consider the existence of an occult urologic problem or severe immunosuppression.

[Epidemiological profile of non-typhi salmonellosis in a hospital in urban Madrid (1980-1994)]

BACKGROUND

The aim of this study was to describe the epidemiologic profile of non-typhoid salmonellosis at a general hospital in the metropolitan area of Madrid.

METHODS

A descriptive and retrospective study of non-typhoid salmonellosis diagnosed at Microbiology Department of Fundación Jiménez Díaz from May 1980 to December 1994 was done.

RESULTS

Non-typhoid Salmonella (NTS) was identified in 1796 specimens of 1463 patients, 520 (35.5%) were under 15 years and 943 (64.5%) were over 14 years. The infection was intestinal in 1288 (88%) cases, bacteremic in 129 (8.8%) and focal in 46 (3.1%). The extraintestinal infection was most frequent in patients over 14 years (15.5% versus 5.6%; p < 0.001). From 1987, 34 adults patients with human immunodeficiency virus (HIV) infection developed salmonellosis. The infection was due to Salmonella serogroup B (29.4%) and the extraintestinal manifestations (58.8%) were most frequent in HIV-infected patients than in the control-group (p = 0.004 and p < 0.001, respectively). Salmonella serogroup D was identified in 1041 (71.2%) episodes, and serogroup B in 259 (17.7%). Salmonella serogroup B and C were more resistant to one or more antibiotics than Salmonella serogroup D (p = 0.001). Resistance of NTS (principally Salmonella serogroup B) for one or more antibiotics (particularly ampicillin and chloramphenicol) increased significantly during the period of study (p < 0.001).

CONCLUSIONS

The HIV-infected patients had a predisposition to develop extraintestinal Salmonella infections. Resistance of NTS for antibiotics, especially Salmonella serogroup B, has significantly increased during the last years.

Classifying extraintestinal non-typhoid Salmonella infections

Non-typhoid Salmonella infection in man has been divided into five clinical groups: gastroenteritis, enteric fever, bacteraemia, chronic carrier state and localized infection. This classification has neither pathogenic nor prognostic significance. We retrospectively reviewed the charts of 183 patients with extraintestinal salmonellosis who presented to our institution during a period of 32 years. Patients were classified into four groups: primary bacteraemia (PB), enteritis-associated bacteraemia (secondary bacteraemia) (SB), digestive focal infection (DI) and non-digestive focal infection (NDI). Sex, age, acquisition, underlying disease and outcome were compared between patients with bacteraemia and diseases with focal infection. The differences found between PB and SB were: community acquisition (66% in PB and 85% in SB, p = 0.06) severe immunosuppression (53% in PB and 15% in SB, p < 0.001) and mortality (37% in PB and 3% in SB, p < 0.001). The differences found between NDI and DI were: age over 60 years (45% in NDI and 18% in DI, p < 0.05), severe immunosuppression (51% in NDI and 12% DI, p < 0.001) and associated bacteraemia (38% in NDI and 6% in DI, p < 0.001). This classification of extraintestinal salmonellosis may have pathogenic and prognostic implications, and could help us to understand the clinical significance of this disease.

Changes in susceptibility of Salmonella enteritidis, Salmonella typhimurium, and Salmonella virchow to six antimicrobial agents in a Spanish hospital, 1980-1994

To determine changes in the susceptibility patterns of Salmonella enteritidis, Salmonella typhimurium, and Salmonella virchow over time, resistance to ampicillin, chloramphenicol, tetracycline, gentamicin, trimethoprim/sulfamethoxazole, and nalidixic acid was studied by the disk diffusion method in 1,024, 191, and 61 clinical isolates of these organisms, respectively. All isolates were recovered from 1980 to 1994 at a hospital in Madrid, Spain. Salmonella enteritidis isolates were less resistant (10.9%) than Salmonella typhimurium (43.5%) and Salmonella virchow (36.1%; p < 0.001). The incidence of resistance of Salmonella enteritidis to ampicillin increased from 2.7% during the period 1980-1982 to 15.6% during 1992-1994 (p < 0.001). The resistance of Salmonella typhimurium to ampicillin, chloramphenicol, and tetracycline increased from 15.2%, 7.6%, and 21.2% respectively in 1980-1982 to 73.3%, 46.7%, and 73.3% in 1992-1994 (p < 0.001). These marked increases in antimicrobial resistance suggest the need for public health interventions, several of which are discussed.

[Soft-tissue infection caused by Aeromonas hydrophila]

BACKGROUND

Two cases of soft tissue infection by Aeromonas hydrophila are presented with review of the literature.

PATIENTS AND METHODS

Two cases of soft tissue infection by Aeromonas hydrophila diagnosed from 1992-1993 are reported.

RESULTS

Most soft tissue infection produced by Aeromonas organisms are caused by Aeromonas hydrophila. These infections predominantly affect the lower limbs of middle-aged males with previous history of injury favoring infection. The most common clinical presentation is cellulitis with a good prognosis if bacteremia is not produced. Antibiotics, such as mainly third generation cephalosporins, imipenem, aztreonam, cotrimoxazole, tetracycline, chloramphenicol, quinolones and aminoglucosides (except streptomycin) are usually very active in vitro against these organisms. Surgery is often necessary to cure the process.

CONCLUSIONS

Cellulitis by Aeromonas hydrophila is a very infrequent entity in Spain and is usually associated to previous injury and probable contamination by environmental bacteria.

[Osteoarticular infections by Salmonella non-typhi]

BACKGROUND

The aim of this study was to know the clinical characteristics of osteoarticular infection by Salmonella non typhi (SNT) in Spain.

PATIENTS AND METHODS

The medical records of 14 patients with osteoarticular infection by SNT from January 1970 to December 1992 were reviewed.

RESULTS

Over the above mentioned 23 years, 1334 patients had been diagnosed with one or more SNT isolations, with 14 (1%) having osteoarticular infection. Seven patients had septic arthritis, 3 osteomyelitis and 4 mixed infection (arthritis and osteomyelitis). Thirteen patients (93%) presented with underlying systemic disease (immunosuppression 12 cases [86%] and hemoglobinopathy 1 case [7%]) and 5 (36%) had predisposing osteoarticular disease. The most commonly affected joint was the knee (9.58%). Involvement was monoarticular in 8 episodes (73%). Out of the 7 cases with osteomyelitis, 4 (57%) were secondary to an articular foci and 3 (43%) were of hematogenic origin. The femur (4 cases, 44%) and the tibia (4 cases, 44%) were the most frequent localizations. On nine occasions (64%) the cultures remained positive 7 days after initiation of antibiotic treatment. Only one patient died as a consequence of the articular infection.

CONCLUSIONS

Osteoarticular infection by Salmonella non typhi should take the existence of immune disorders into account.

[Bacteremia caused by group A and B beta-hemolytic Streptococcus in adults]

In order to know the epidemiological, clinical and evolutive characteristics of bacteriemia caused by beta-hemolytic streptococci groups A and B, a retrospective investigation was undertaken of 48 bacteremic episodes observed in adult patients for 10 years (1985-1994). Twenty-two episodes were caused by Group A beta-hemolytic streptococci (GAS) and 26 by Group B beta-hemolytic streptococci (GBS). Patients with GAS bacteremia (GASB) had a lower mean age than patients with GBS bacteremia (GBSB) (p = 0.03). Infection with immunodeficiency virus was more common in patients with GASB than in patients with GBSBA (27 and 4%, respectively; p = 0.04); in contrast, diabetes mellitus was more common in patients with GBSB than in patients with GASB (27 and 5%, respectively) (p = 0.04). Nine (41%) patients with GBSB were i.v. drug abusers; nevertheless, none of the subjects with GBSB were i.v. drug abusers (p < 0.001). The proportion of bacteremia without demonstrable source due to GBS (41%) was significantly higher than that due to GAS (9%) (p = 0.02). Five (23%) patients with GASB and other five (20%) patients with GBSB had fatal outcomes, but only in two (9%) and three (12%) cases, respectively, was death directly attributed to bacteremia. In conclusion, bacteremias caused by GAS and GBS have different epidemiological characteristics but similar prognosis.

[Extrapulmonary tuberculosis. Experience at a general hospital (1980-1993)]

In order to know extrapulmonary tuberculosis in our environment the results of all samples submitted for culture of mycobacteria to the Microbiology Department, Fundación Jiménez Díaz, from 1980 to 1993 were analyzed. During this period 290 cases of extrapulmonary cases were diagnosed, 101 from 1980 to 1985 and 189 from 1986 to 1993. The most common site of infection before 1985 was in genitourinary tract (42.6%); in contrast, from 1986 onwards the more common sites of infection were pleural (22.8%), genitourinary tract and lymphatic glands (22.2% in both sites). When EPT was compared in the two periods of time the observations made were a relative decrease of genitourinary infections (p = 0.00004) and increase in disseminated (p = 0.015) and pleural tuberculosis (p = 0.011) from 1986 compared with previous years. From 1986 a greater proportion of disseminated form was observed (p < 0.0001) in positive-HIV patients and of genitourinary (p = 0.011) and pleural (p = 0.076) forms in negative HIV-patients. In conclusion, extrapulmonary tuberculosis has increased in our environment during the period 1980-1993, and this increase is not attributable only to positive-HIV patients. The distribution of clinical forms of this disease was different in the two studied periods and among positive and negative HIV patients.

Surgical wound infections due to Propionibacterium acnes: a study of 10 cases

Ten cases of surgical wound infection in which Propionibacterium acnes was probably the aetiologic agent were reviewed; in five the organism was isolated in pure culture. Six patients underwent a neurosurgical procedure. The average time for development of infection was 17.5 days (range 1-30 days). All patients were cured by surgical drainage and, in nine cases, with appropriate antimicrobial therapy. In conclusion, P. acnes must be considered as a cause of surgical wound infections especially after neurosurgery.

Role of laparoscopy in colorectal surgery. A prospective evaluation of 200 cases

PURPOSE

The aim of this study was to prospectively evaluate the role of laparoscopic-assisted surgery in patients presenting for routine colorectal surgical procedures.

METHODS

Two hundred consecutive patients were assessed for the possible use of laparoscopic surgery. The decision regarding suitability of the patient for the procedure was made by the operator. For the purpose of analysis, patients were assigned to open, converted, and laparoscopic groups.

RESULTS

Ninety-five of 200 patients were considered appropriate for laparoscopic surgery, 62 (65.3 percent) being successfully completed. These completed operations included right colectomy (24/30), sigmoid colectomy (22/36), appendectomy (9/10), anterior resection (3/8), abdominoperineal resection (3/5), and left colectomy (1/2). Complications attributable to laparoscopy were infrequent (6.3 percent) and were not responsible for any deaths. Patients in the laparoscopic group required less analgesia, tolerated oral intake earlier, and were discharged from the hospital earlier than those who were converted or who had open procedures.

CONCLUSIONS

Laparoscopic-assisted surgery is safe, effective, and applicable to many of the standard colorectal procedures. Observed benefits include less postoperative pain and shorter hospital stay.

[Abnormal origin of left coronary artery from pulmonary artery]

OBJECTIVE

To assess the frequency and severity of the anomalous origin of the left coronary artery (ALCA) from the pulmonary artery (PA).

DESIGN OF THE STUDY

Prospective study of case series between March 1991 and December 1994.

SETTING

Referral-based Paediatric Cardiology Department of a Tertiary Care Center.

PATIENTS AND METHODS

Five consecutive patients (pts) with anomalous origin of the LCA from the PA; there were three infants aged 4 months and two children one 8 year and one 9 year old. There were three girls and two boys. All pts had clinical and 2D-echo and Doppler investigation prior to cardiac catheterization (CC). Indication for CC was based in the association of symptoms and signs of myocarditis or dilated cardiomyopathy of acute or subacute onset and electrocardiographic (ECG) signs of ischemia in infants. In older patients (pts) diagnosis was suspected mainly from ECG. During CC in all pts, aortograms and when necessary selective coronary angiograms were performed. Surgical correction was performed in all children. In two pts stress exercise ECG and stress Thallium studies before and after surgery were performed.

RESULTS

two pts had "adult" an three had "infantile" type of ALCA from the PA. CC was performed and diagnosis was confirmed at surgery in all cases. In one child, correct diagnosis was made by ECO prior to CC and in one case LCA to PA fistula was suspected on Colour-Doppler study. No complications were attributed to CC. Several types of surgery were performed: reimplantation of the ALCA from the PA to the aorta (three pts); tunnel connection of the aorta to the ALCA via the PA (one pt) and left internal mammary to LCA anastomosis (one pt). Two infants died intraoperatively due to extensive myocardial infarction and poor left ventricular function. All the three survivors are asymptomatic after a mean follow up of 34 months. Two oldest pts are currently in New York Heart Association functional class I with normal ECG and improved myocardial perfusion on Thallium scan despite almost total occlusion of LCA at the site of implantation in the aorta as diagnosed on coronary angiogram.

CONCLUSIONS

ALCA from PA is associated with major morbidity and mortality. Diagnosis should be suspected in pts with unexplained myocardial ischemia on ECG and even more if it is associated to clinical signs of dilated cardiomyopathy or myocarditis. Careful assessment on ECO and pulsed Doppler and colour flow mapping should make the diagnosis in most cases. Although surgery can be performed based only on ECO diagnosis, we strongly advise for angiography in all cases as in our experience there are false negative diagnosis by ECO. Preoperative Thallium studies can be useful for the selection of the type of surgery as pts with very little viable myocardium will not survive the establishment of a direct systemic to coronary blood flow and may be candidates for heart transplantation.

Isolation of Propionibacterium acnes from central nervous system infections

Propionibacterium acnes is a common skin colonizer and its involvement in central nervous system (CNS) infections may be related with previous neurosurgical procedures. P. acnes was isolated in pure or mixed cultures from ten patients with CNS infections during a 5-year period. The clinical presentation, treatment and outcome were retrospectively reviewed. Nine out of 11 patients had CNS infections after a neurosurgical procedure. The clinical presentation was: brain abscess (five patients), subdural or epidural empyema (four patients) and shunt meningitis (one patient). Three patients had also secondary meningitis. All patients received antibiotic therapy and all abscesses and empyemas were drained. The patient with shunt meningitis cured without catheter removal. Only one patient with a brain abscess by P. acnes died, but several months thereafter and as a consequence of a Gram-negative superinfection. P. acnes is a pathogen for the CNS and infections must be surgically managed under adequate antibiotic treatment.