Antibiotic prophylaxis in non-cardiac thoracic surgery: cefazolin versus placebo

A total of 127 patients (57 given placebo and 70 given a single preoperative dose of 1 g cefazolin) undergoing thoracic surgery were included in a randomized double-blind trial. The two groups were similar in regard to mean age, sex ratio, in-hospital stay before surgery, underlying disease, risk factors, type of surgery, mean duration of surgical procedure, and mean duration of chest tube drainage. The relative risk of wound infection of the patients from the placebo group was 3.27 (range 1.5-11.5; 95% confidence interval). Cefazolin significantly reduced (p less than 0.01) the wound infection rate--1 case (1.5%) in the cefazolin group versus 8 cases (14%) in the placebo group--but not the incidence of postoperative pleural empyema--5 (7%) versus 8 cases (14%)--or nosocomial pneumonia--3 (4%) versus 5 cases (9%). Cultures were made from 3 out of 9 wound infections and Staphylococcus aureus or S. epidermidis was isolated in all 3. In addition, cultures were made from 6 out of 13 pleural cavity infections and S. aureus (1 case) or other microorganisms (5 cases) were isolated in all 6. Mortality was similar in both groups and all deaths unrelated to the infections. No adverse side effects of the drug were encountered. In conclusion, a single preoperative dose of 1 g cefazolin proved to be effective for reducing the wound infection rate in non-cardiac thoracic surgery.

Proliferation and differentiation of glial fibrillary acidic protein-immunoreactive glial cells in organotypic slice cultures of rat hippocampus

The present paper deals with the proliferation and differentiation of glial cells in organotypic slice cultures of the rat hippocampal formation. Transverse slices of hippocampus of newborn to five-day-old rats were cultivated using the roller tube technique. To study the development of glial cells under these conditions, the slice cultures were processed for immunostaining employing antibodies against the glial fibrillary acidic protein. The proliferation of glial cells was studied in double-labeling experiments employing glial fibrillary acidic protein-immunostaining and the bromodeoxyuridine technique. The three-dimensional glial scaffold in the cultures was analysed in semithin and ultrathin cross-sections through the slice cultures after varying periods following explanation. Our results can be summarized as follows: 1. At all intervals after explanation of the slices there are numerous glial fibrillary acidic protein-positive cells with morphological characteristics of astrocytes. 2. With some modifications, the differentiation of astrocytes and their processes follows similar rules as observed in the hippocampus in vivo. A radial glial scaffold is also formed in the cultures. However, in cultures, a regular pattern of radial fibers is more obvious in the hippocampus proper than in the dentate gyrus. This glial scaffold persists after 20 days in vitro whereas it is known to disappear after the first postnatal week in vivo. 3. Bromodeoxyuridine-positive nuclei of glial cells were found at all time periods after explanation. After short incubation periods, they were most frequent in the "ventricular" zones of the cultures. Following longer incubation periods after bromodeoxyuridine administration, proliferating cells were found throughout the cultures, covering and underlying the cultured tissue. A rim of laterally migrating astrocytes completely surrounds the cultures. Our results demonstrate that glial cells proliferate and differentiate under the present culture conditions. After three weeks of incubation the whole slice culture is surrounded by a glial cover which may play an important role for the survival and differentiation of the cultured hippocampal neurons.

[Severe leptospirosis. Description of a series of 10 cases]

Clinical aspects of 10 consecutive patients hospitalized for acute human leptospirosis, confirmed by serology using the microscopic agglutination test (MAT), between 1975 and 1988 in a 1000 beds Teaching Hospital are retrospectively analyzed. All of them were male, mean age of 55, presenting a suggestive epidemiological data to be at risk for Leptospira infection. Leptospira icterohaemorrhagiae was responsible for 8 cases and Leptospira canicola for 2. 7 patients were treated, after 3-4 days of admittance, with penicillin. 5 patients died. Cause of death was gastrointestinal haemorrhage in 3 and cardiogenic shock in 2. We discuss the clinical, biochemical, pathological and therapeutic aspects of the acute human leptospirosis.

[Diagnosis of pneumonia caused by Pneumocystis carinii using induced sputum]

Pneumocystis carinii pneumonia is one of the most common and severe infections in patients with human immunodeficiency virus (HIV) infection. Classically, the diagnosis of this condition is made with aggressive techniques such as fibrobronchoscopy (FBS) with bronchoalveolar lavage (BAL) or pulmonary biopsy. Sputum induction is a relatively recent technique which permits the diagnosis in a rapid, inexpensive way which is not aggressive for the patient. We have carried out 22 sputum inductions during a 4 month period. All patients had HIV infection and clinical, radiological and gasometric features consistent with P. carinii pneumonia. P. carinii cysts were found in the BAL of 6 patients and in 4 (66%) of the sputum samples induced from them. These still preliminary data support the need to generalize this procedure to achieve a greater experience in the different institutions, so as to achieve a higher yield of a technique which has clear advantages over previously used ones.

[Enteritis caused by Isospora belli in patients with the acquired immunodeficiency syndrome. Description of 9 cases]

The features of the nine first cases of Isospora belli enteritis in patients with acquired immunodeficiency syndrome (AIDS) diagnosed in the Hospital Cliníc i Provincial of Barcelona from September 1984 to May 1989 are reported. All patients were male, five were homosexual and four were parenteral drug abusers. The clinical presentation was watery diarrhea without pathological products lasting for more than one month. Five patients had features of dehydration, five had malabsorption, two had fever and one had metabolic acidosis. Enteritis by I. belli was the first opportunistic infection in eight of the nine cases. The number of T4 lymphocytes was lower than 0.4 x 10(9)/l in four of the seven patients in whom it was measured, and the p24 antigen was detected in serum in three out of five. The response to co-trimoxazole, both in the acute phase and as maintenance therapy, was satisfactory; however, two patients had recurrences despite maintenance therapy with co-trimoxazole. In one of them I. belli was clinically resistant to co-trimoxazole therapy and to other drugs, the diarrhea only responding to the administration of a somatostatin analogue (SMS 201-995).

The parvalbumin-containing nonpyramidal neurons in the rat hippocampus

The calcium-binding protein parvalbumin is considered to be involved in the control of intracellular ion homeostasis of highly active inhibitory neurons. A review of the light and electron microscopical features as well as the identified synaptic connections of these neurons is presented. Parvalbumin-containing neurons are mostly located within or in the vicinity of the granule or pyramidal cell layer. They form a subgroup of GABAergic neurons that has a target specificity for the cell body region. Their fine structural characteristics are identical to those known for hippocampal inhibitory neurons. Parvalbumin-containing neurons are involved in several inhibitory pathways: feed-back inhibition, feed-forward inhibition and disinhibition. The functional implications of our own as well as published data are discussed. Special consideration is given to the possible physiological role of parvalbumin in these neurons.

Naturally occurring cell death in the subicular complex and hippocampus in the rat during development

Cell death in the subicular complex and hippocampus occurs from P0 to P7 in the rat. Dead cells first appear in the subcortical and subammonic plates, and predominate in the border region between the main regional subfields. Cell death in the cellular layers predominates in the subicular complex. CA1 and intermediate region between CA1 and CA3. Dead cells are almost absent in the upper plexiform layers and dentate gyrus.

Axo-axonic chandelier cells in the rat fascia dentata: Golgi-electron microscopy and immunocytochemical studies

Synaptic transmission can be blocked very efficiently by inhibitory synapses on axon initial segments. Inhibitory chandelier cells forming synapses on the axon initial segment of pyramidal neurons have been found in the neocortex and hippocampus proper. Here we describe an axo-axonic local circuit neuron in the rat fascia dentata that establishes synaptic contacts with axon initial segments of numerous dentate granule cells. Examination of a large number of Golgi-impregnated nongranule cells in the fascia dentata of rats revealed a group of neurons with characteristics of chandelier cells. Thus these cells exhibited an extensive axonal plexus within the granular layer that characteristically formed vertical aggregations of axonal varicosities. The cell bodies of these neurons were located in the inner molecular layer or in the outer part of the granular layer. Their dendrites invaded the molecular layer, suggesting an afferent innervation similar to that of the granule cells. Well impregnated putative axo-axonic cells were gold-toned for an electron microscopic analysis. The cell bodies and dendrites of these neurons exhibited characteristic ultrastructural features of nongranule cells, i.e., large amounts of perinuclear cytoplasm, infoldings of the nuclear membrane, and a large number of synaptic contacts on the perikaryon and on the smooth dendritic shafts. The axon originating from the cell body or from a proximal dendrite gave rise to numerous vesicle-filled varicosities that almost exclusively formed symmetric synaptic contacts with axon initial segments. A semiquantitative study of five axonal complexes demonstrated that 92.3% of identified postsynaptic elements were initial segments of granule cell axons. Immunostaining with antibodies against glutamate decarboxylase (GAD) and parvalbumin (PARV) revealed a subpopulation of neurons that very much resembled the Golgi-impregnated axo-axonic cells with regard to cell body location, dendritic arborization, and fine structural characteristics of perikarya and dendrites. GAD and PARV were found to be coexistent in these cells. Moreover, we found GAD- and PARV-immunoreactive terminals in symmetric synaptic contact with axon initial segments of granule cells. The present study has shown a hitherto unknown axo-axonic cell in the rat fascia dentata. On the basis of our immunocytochemical findings, we hypothesize that this cell exerts a strong inhibitory effect on dentate granule cells. This way, signal transmission from the fascia dentata to the hippocampus proper within the "trisynaptic pathway" can efficiently be controlled by a group of highly specialized neurons.

Naturally occurring cell death in the cerebral cortex of the rat and removal of dead cells by transitory phagocytes

Regressive phenomena are common during the development of the nervous tissue. Among them, naturally occurring cell death has been observed in several regions of the nervous system. Cell death in the somatosensory cortex and medial cortical regions (hind limb, frontal cortex 1, frontal cortex 2, retrosplenial agranular, retrosplenial granular [Zilles K. et al. (1980) Anat. Embryol. 159, 335-360]) as well as in the cortical subplate (future subcortical white matter) in the rat mainly occurs during the first 10 days of postnatal life with peak values of 3.1 dead cells per 1000 live neurons at the end of the first week. Cell death progresses from birth to day 7 with a predominance of dead cells in the subplate and in layers II-III. Later, dead cells are more dispersed in the cerebral cortex, but a significant amount is still present in the subcortical white matter. This pattern correlates with the arrival and settlement of cortical afferents at the different cortical levels, as described in other studies, and points to the likelihood that transitory cellular populations are important clues in the modelling of the cerebral cortex during normal development. Transitory populations of macrophages (amoeboid or nascent microglial cells) that appear in great numbers during the same period and in the same regions are involved in the removal of dead cells.

[Infective endocarditis caused by coagulase-negative staphylococci: a review of 19 cases]

The clinical, microbiological and echocardiographical features as well as the response to therapy of 19 cases of infective endocarditis (IE) caused by coagulase-negative staphylococci (CNS) are reported. Six patients had native valve IE, 11 had prosthetic valve endocarditis and 2 were associated with catheters in right cardiac chambers. In the group of native valve IE, 11 patients were heroin abusers and 4 had previous valvular disease. IE was left sided in 3 cases, mixed in 2 and right sided in 1. All CNS were methicillin-sensitive. The echocardiogram detected vegetations in 5 of the 6 cases. One patient required surgery and another died. In the group of prosthetic valve IE, 5 patients had early endocarditis and 6 had late endocarditis. A bioprosthesis was involved in 5 cases, a mechanical prosthesis in another 5, and an annuloplasty annulus in one. The involved prosthesis was aortic in 5 cases and mitral in 6. The echocardiogram detected vegetations in 3 cases (27%) and prosthetic dysfunction in 4. One patient had a relapse, 8 (73%) required valve replacement and 3 died. Although the greatest incidence of IE caused by CNS is found among patients with prosthetic valves, it can also be seen in patients with underlying valvular heart disease, drug abusers and patients with indwelling catheters in right cardiac chambers.

Plasticity in the barrel cortex of the adult mouse: transient increase of GAD-immunoreactivity following sensory stimulation

Sensory experience during perinatal life and adulthood modifies physiological and anatomical characteristics of the central nervous system. So far, this phenomenon has been studied in situations of complete or partial sensory deprivation. We here report that increased sensory stimulation, during four days, of a number of whisker follicles on the face of the adult mouse results in an increased immunoreactivity of glutamic acid decarboxylase (the biosynthetic enzyme of the inhibitory neurotransmitter GABA) in the somatosensory cortex of the adult mouse. Effects were limited to a column of tissue corresponding to the representation of the stimulated follicles and lasted two days beyond stimulation. These findings suggest that sensory stimulation transiently modifies local cortical processing.

A GABAergic axo-axonic cell in the fascia dentata controls the main excitatory hippocampal pathway

Neuronal discharge is very efficiently blocked by inhibitory synapses on the axon initial segment. Here we describe a novel type of gamma-aminobutyric acid (GABA)-ergic inhibitory neurons in the rat fascia dentata that exclusively forms synaptic contacts with the axon initial segments of numerous dentate granule cells. This way the main excitatory pathway of the hippocampal formation which interconnects the fascia dentata with the hippocampus proper is controlled. We hypothesize that hypofunction of this inhibitory neuron causes overexcitation in the main excitatory pathway which could play a role in epilepsy.

[Chondrocostal and chondrosternal tuberculosis in 2 heroin addicts infected with the human immunodeficiency virus]

We report two cases of osteoarticular tuberculosis in heroin addict patients infected with human immunodeficiency virus. Both patients presented an inflammatory tumor in the anterior chest wall, with subacute onset; one patient had chondrosternal involvement and the other had chondrocostal involvement with a retrosternal pus collection. Diagnosis was established by needle aspiration of the tumor that gave raise to caseum. Ziehl-Neelsen stain was positive and Löwenstein-Jensen culture yielded Mycobacterium tuberculosis in both cases. The course was good after surgical debridement and tuberculous treatment for 6 months. We review the features of osteoarticular tuberculosis in drug addicts and patients infected with human immunodeficiency virus that in our environment mainly affects this population group. As in our geographical area, an increased incidence of both infections does exist and owing to the high prevalence of extrapulmonary and disseminated tuberculosis in those patients, it is expected that in a future time, the number of cases of tuberculosis will increase. Therefore, physicians must entertain a high degree of suspicion with the purpose of establishing an early diagnosis of these atypic presenting forms.

Immunocytochemical detection of 5'-bromodeoxyuridine incorporation in the central nervous system of the mouse

In order to label postmitotic neuroblasts, pregnant mice received a single pulse of 5'-bromodeoxyuridine (BrdU) between embryonic days E11 and E17. Young adult offspring were stained for BrdU using a monoclonal antibody and the peroxidase-antiperoxidase method. The distribution of immunoreactive nuclei was very similar to the [3H]thymidine data reported in the literature. The pattern of labelled nuclei after injection at different embryonic ages followed the spatiotemporal gradients described for cortical and hippocampal neurogenesis. Lightly and heavily labelled nuclei, probably representing subsequent postmitotic generations, were distinguished in BrdU-immunoreacted preparations. These data indicate that BrdU can be used to map neuronal birthdates.

Entorhinal fibers form synaptic contacts on parvalbumin-immunoreactive neurons in the rat fascia dentata

The entorhinal cortex gives rise to a dense projection to the outer two-thirds of the dentate molecular layer. The main target neurons are the granule cells. This study demonstrates that entorhinal fibers labeled by anterograde degeneration also terminate on parvalbumin-containing non-granule cells in the rat fascia dentata. Since the calcium-binding protein parvalbumin was recently found coexistent with gamma-aminobutyric acid in inhibitory hippocampal neurons, the described connection provides evidence for a role of entorhinal fibers in feed-forward inhibition of the granule cells.

Neurogenesis of glutamic acid decarboxylase immunoreactive cells in the hippocampus of the mouse. II: Area dentata

The temporal patterns of neurogenesis of cells showing glutamic acid decarboxylase (GAD) immunoreactivity were determined in the area dentata of the mouse. Pregnant C57Bl mice received pulse injections of (3H)thymidine from E11 through E17 (E0 being the day of mating). The distribution of (3H)thymidine-labeled, GAD-positive neurons in the hilus and in the different strata of the fascia dentata (stratum infragranulosum, stratum granulosum, stratum moleculare) were recorded in adult animals. A radial gradient of neurogenesis of GAD-positive cells in the area dentata was not apparent. In the transverse axis, neurogenesis of GAD-positive cells seemed to follow a faint suprapyramidal to infrapyramidal gradient, which was due to differential timing of neurogenesis of GAD-positive cells destined for the stratum infragranulosum of the suprapyramidal and infrapyramidal blades of the fascia dentata. GABAergic neurons in the fascia dentata comprise a limited number of well-defined cell types. All of the different morphologic types of GAD-positive neurons present in the area dentata were generated prenatally. These diverse forms did not have specific times of neurogenesis. These results support the concept that the adult morphology of GAD-positive cells in the area dentata of the mouse do not bear any relationship to their times of origin.

Neurogenesis of glutamic acid decarboxylase immunoreactive cells in the hippocampus of the mouse. I: Regio superior and regio inferior

The neurogenetic gradients of neurons showing glutamic acid decarboxylase (GAD) immunoreactivity were determined in the regio superior and in the regio inferior of the mouse hippocampus. Pregnant C57Bl mice received pulse injections of (3H)thymidine from E11 through E17 (E0 being the day of mating). Distributions of (3H)thymidine-labeled, GAD-positive neurons in the different strata of the hippocampus proper were recorded in adult animals. GAD-positive neurons in this region are generated prenatally. Radial gradients of neurogenesis of GAD-positive cells are characterized by two main features: 1) with the exception of the stratum lacunosum-moleculare and its interface with the stratum radiatum, GAD-positive neurons of the plexiform strata are generated before those destined for the pyramidal layer; 2) within the pyramidal layer, GAD-positive cells are positioned according to an inside-out sequence. In the transverse axis, neurogenesis of GAD-positive cells follows a regio inferior to regio superior gradient. This gradient is due to prolonged neurogenesis of GAD-positive cells for the pyramidal layer in the regio superior. Given the selective laminar disposition of the GABAergic interneurons in the hippocampus, the present authors explored whether or not the diverse types of these interneurons could have specific birth dates and concluded that no relationship exists between birth dates and adult phenotypes of GAD-immunoreactive cells in the mouse hippocampus proper.

[Treatment of atypical pneumonia with josamycin]

In the present study the clinical efficacy and tolerance of josamycin (1 g every 12 hours) was prospectively evaluated for the empirical therapy of patients below 70 years with community acquired pneumonia of atypical presentation (AP), without respiratory failure, radiological cavitation or risk factors of pharyngeal colonization by gram-negative bacilli. During a 28-month period 168 patients adequate for the study were included. The etiological diagnosis was established in 56 cases (33.3%); in 55 by seroconversion (28 Mycoplasma pneumoniae, 22 Legionella pneumophila, 1 Chlamydia psittaci and 4 Coxiella burnetii) and in only one case by positive blood culture (Streptococcus pneumoniae). The mean duration of therapy was 9 days and that of fever 1.4 days. Five patients (3%) had mild transient gastrointestinal complaints. No patient required a change of therapy. Relapses were not observed in the 45 days of follow up. In conclusion, josamycin (1 g/12 h p.o.) is an effective and well tolerated antibiotic for the therapy of pneumonia by M. pneumoniae or L. pneumophila, and it represents a good empirical treatment of AP in patients below 70 years without risk factors of GNB infection, respiratory failure or radiological cavitation.

Diagnostic value of serum antibody and antigen detection in heroin addicts with systemic candidiasis

The diagnostic value of antibody detection by indirect hemagglutination (IHA), indirect immunofluorescence (IFA), and counterimmunoelectrophoresis (CIE) and of Candida albicans mannan antigen detection by latex agglutination was studied in 36 cases of systemic candidiasis in heroin addicts. The IHA and IFA techniques were highly sensitive (97% and 91%, respectively), but their specificity was low (60% and 50%). When a titer of greater than or equal to 1:2,560 was used as a criterion for IHA positivity, the specificity of the test rose to 87%, with sensitivity at 75%. CIE had a high degree of specificity (96%) but a low degree of sensitivity (58%). A good correlation was found between clinical evolution of infection and serologic data. Two of 12 patients who could be followed for 9-16 months had a rise in antibody titer detected either by IFA or by IHA and CIE. These two patients had a persistent chondrocostal tumor and C. albicans endocarditis, respectively. All of the other patients, who were cured, had a decrease in titer detected by IHA and IFA and had negative CIE results at the end of follow-up. Serum mannan antigen was not found in any case. The detection of antibody to C. albicans may be useful for diagnosis and follow-up of such patients.

Plasticity in the barrel cortex of the adult mouse: effects of peripheral deprivation on GAD-immunoreactivity

The whisker-to-barrel pathway of the adult mouse was used in a study on the effects of peripheral sensory deprivation on GAD-immunoreactivity in the somatosensory cortex. At varying periods of time after removal of a set of vibrissal follicles, mice were processed for immunohistochemistry using an antibody against GAD. In sections tangential to the cortical surface we observed, in the barrels whose follicles were removed, decreased immunoreactivity as early as three days after surgery. The decrease was due to a lesser numerical density of stained puncta and to less intense staining of those remaining. GAD-positive somata were also less intensely stained, whereas their number did not seem to be changed. The changes, apparent at 3 days after the surgery, were restricted to the barrels corresponding to the removed follicles and were maximal at 2-4 weeks. At longer survival times (until 7 months) the immunoreactivity returned to normal, coincident with the regeneration of peripheral nerve fibres in the absence of their follicles. We conclude that GAD-immunoreactivity in the barrel cortex swiftly reacts to modifications of neuronal activity evoked in the periphery.

Ceftriaxone monotherapy for severe bacteremic infections. Spanish Ceftriaxone Study Group

We tested the efficacy of a single daily dose of ceftriaxone (active ingredient of Rocephin) for the treatment of severe bacteremic infections in 125 non-neutropenic adult patients. A single daily dose of ceftriaxone ranging from 1 to 4 g was given. Surgical procedures were performed if needed. Seventy-six (60.8%) were males and bacteremia was nosocomially acquired in 45 (36%). Microbiologically proven bacteremia was demonstrated in all patients. The most common microorganisms isolated were Escherichia coli (46 episodes), Streptococcus pneumoniae (17 episodes), Klebsiella pneumoniae, and Haemophilus influenzae, Serratia marcescens, Salmonella sp., and Staphylococcus aureus (9, 7, 6, 6, respectively). The urinary tract was the source of the bacteremia in 45 cases (36%), and the lower respiratory tract in 33 (26.4%). Mean duration of treatment was 10.8 days (range 3-21 days). One hundred and six patients (84.8%) recovered completely, 11 (8.8%) improved, but needed an alternative antibiotic treatment. An alternative treatment was also given to a patient whose condition had initially deteriorated. Seven patients (5.6%) died. Death was directly related to the infection in 2 cases. Three patients (2.4%) developed a superinfection, and 5 (4%) a severe (1 case) or mild (4 cases) adverse effect. In summary, a single daily dose of ceftriaxone proved to be useful for the treatment of selected severe bacteremic infections.

Characteristics of tuberculosis in HIV-infected patients: a case-control study

To test the hypothesis that HIV infection can modify the clinical characteristics of tuberculosis, 65 consecutive cases of tuberculosis in HIV-seropositive patients diagnosed in Barcelona (Spain) were compared with 65 HIV-seronegative controls matched for age and sex. Thirty of the 65 cases were accepted as AIDS cases (August 1987 Centers for Disease Control criteria) only because of the tuberculosis. Among the cases 54 (83%) were parenteral drug addicts and 88% were males. The tuberculosis was pulmonary or pleural in 62 controls (96%) but in only 25 cases (39%; P less than 0.0001). Lymph nodes were involved in 25 cases (39%) and in none of the controls (P less than 0.0001). Disseminated forms of tuberculosis were present in seven cases (11%) and in no controls (P less than 0.007). Bone, joints and central nervous system involvement were also significantly (P less than 0.05) more frequent in cases. The treatment (isoniazid and rifampin for 6 months plus ethambutol and pyrazinamide during the first 2 months) was always effective. One relapse was detected after a median follow-up of 55 months in cases and none in controls after a median follow-up of 43 months. Twenty-five cases (39%) and 14 controls (22%) developed mild or severe side effects related to the treatment (P less than 0.004). In conclusion, most of the HIV-infected patients with tuberculosis were drug addicts with extrapulmonary or disseminated forms. A short course of treatment (6 or 9 months) may be enough but side effects were frequent.

Autoradiography of antidepressant binding sites in the human brain: localization using [3H]imipramine and [3H]paroxetine

[3H]Imipramine and [3H]paroxetine were used to label sites associated with serotonin uptake mechanisms in post-mortem brain tissue from control subjects. The anatomical localization of these sites was examined by autoradiography and densities measured by microdensitometry. We found [3H]imipramine binding to increase with age in the cortex and amygdala, but to be independent of gender and post-mortem delay. Preliminary results indicate that the binding of both [3H]imipramine and [3H]paroxetine is diminished in the brain of patients treated with imipramine. The distribution of [3H]imipramine and [3H]paroxetine high-affinity binding sites was very similar, and correlated well with the distribution of serotonergic presynaptic markers in the brain. The highest densities of binding sites were found in the raphé nuclei and the midline thalamic nuclei. Other structures presenting high levels of binding were the substantia nigra, nucleus interpeduncularis, locus coeruleus, nucleus nervi hypoglossi, nucleus nervi facialis, mammillary bodies and other parts of the hypothalamus. In contrast, regions such as the neocortex, hippocampus, amygdala and cerebellum showed low densities of [3H]imipramine and [3H]paroxetine binding sites. This distribution seems to indicate that the ascending serotonergic pathways are the main site of action of antidepressants.

Vertebral arch tuberculosis in two human immunodeficiency virus-seropositive heroin addicts

We studied two cases of disseminated tuberculosis with vertebral arch involvement in drug addicts seropositive for human immunodeficiency virus. The first patient developed a paraplegia while he was recovering from a meningeal tuberculosis. On the abdominal plain roentgenogram, the right transverse process of L-2 was absent, and a computed tomographic scan revealed destruction of the right vertebral arch together with a collection in the paravertebral area. The second patient had miliary tuberculosis and complained of lumbar pain. The radiologic findings were similar to those in the first case, but at the L-4 level.

Pseudomonas aeruginosa bacteremia: univariate and multivariate analyses of factors influencing the prognosis in 133 episodes

One hundred thirty-three consecutive episodes of Pseudomonas aeruginosa bacteremia were prospectively followed in a university hospital over a 36-month period. The attack rate was 1.8 episodes per 1,000 discharges, and 85% of the episodes were hospital acquired. P. aeruginosa bacteremia represented 13.6% and 25.6% of the episodes of nosocomial bacteremia and gram-negative nosocomial bacteremia, respectively. The crude mortality rate was 50%. A stepwise logistic regression analysis defined four variables as independently influencing the outcome: development of septic shock (P = .00002), a granulocyte count less than 500/mm3 (P = .0008), inappropriate antibiotic therapy (P = .001), and the development of septic metastasis (P = .003). Among them, only the antibiotic treatment is easily amenable to medical intervention in order to improve the prognosis. Consequently, major efforts should focus on prevention and on the development of other therapeutic measures apart from antibiotic treatment.

Nosocomial bacteremia in a large Spanish teaching hospital: analysis of factors influencing prognosis

Five hundred forty-three episodes of nosocomial bacteremia were prospectively followed in a large Spanish university hospital. The commonest isolates were Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida species. The most frequent sources of infection were intravenous lines, urinary tract, and lower respiratory tract. Overall mortality was 18%. A step-forward logistic regression analysis defined eight variables independently influencing the outcome: shock, underlying rapidly fatal disease, high-risk source of bacteremia (intraabdominal, lower respiratory tract, or not identified), age more than 70 years, hospitalization in intensive care or medical units, inappropriate antibiotic treatment, infection due to a high-risk microorganism (P. aeruginosa, Serratia marcescens, Klebsiella, Bacteroides, or Candida), and development of septic metastasis. The identification of those factors independently influencing the outcome and their possible modification may represent a further step in the control of nosocomial bacteremia by improving its prognosis.

Perioperative cefamandole prophylaxis against infections

Seven hundred and seventeen patients were included in a prospective randomized double-blind trial comparing the efficacy of five doses of cefamandole (group I, 335 patients) with that of a single preoperative dose (group II, 382 patients) for prophylaxis against sepsis in patients who had an operation using either a Moore prosthesis, Ender or Küntscher nails, a bone plate, or another internal-fixation device. Patients who had an open fracture or total joint replacement were not included in the study. The two groups were similar in terms of mean age, sex ratio, duration of preoperative hospital stay, underlying risk factors, and type of surgical procedure. A wound infection developed in none of the seventy-four patients in group I and in five (6.6 per cent) of the seventy-six in group II (p = 0.03) who required a Moore prosthesis. A wound infection developed in three patients (1 per cent) in group I and in fifteen (5 per cent) in group II (p = 0.006) who required an internal fixation device other than a Moore prosthesis. Staphylococcus aureus, Staphylococcus epidermidis, and gram-negative bacilli were the most common infecting organisms. The rate of mortality was similar in both groups, while the percentage of postoperative urinary-tract infections was lower in group I (p = 0.04). No adverse side effects of the drug were encountered.

Univariate and multivariate analyses of risk factors predisposing to auditory toxicity in patients receiving aminoglycosides

Risk factors predisposing to auditory toxicity of aminoglycosides were analyzed from records of 187 patients enrolled in three prospective randomized trials comparing the toxicity of netilmicin, tobramycin, and amikacin. Patients were eligible if they received three or more days of therapy and at least two serial audiograms were available. The overall auditory toxicity rate was 9.6% (18 of 187). Auditory toxicity was detected in 4.4, 10.8, and 23.5% of patients given netilmicin, tobramycin, and amikacin, respectively (P = 0.05). In the univariate analysis, patients who developed auditory toxicity were significantly older (P = 0.01) and had a significantly higher (P = 0.04) percentage of trough levels of netilmicin or tobramycin above 2 mg/liter or amikacin above 5 mg/liter. In the final logistic regression model, only age was retained as independently influencing the development of auditory toxicity (P less than 0.00001). Conversely, factors that did not add significantly to the prediction of auditory toxicity were aminoglycoside serum levels, total aminoglycoside dose, duration of therapy, sex, peak temperature, presence of bacteremia, shock, liver cirrhosis, dehydration, previous otic pathology or renal failure, and development of renal toxicity. At least in certain populations, age is the most important predisposing factor for the development of auditory toxicity in patients receiving aminoglycosides.

Nutritionally variant Streptococcus pyogenes from a periorbital abscess

A nutritionally variant Streptococcus pyogenes strain was isolated from a periorbital abscess. The organism was identified with the use of three rapid biochemical test kits, and the group A antigen was detected by conventional serology as well as direct antigen detection tests.

Asynchronism in the neurogenesis of GABAergic and non-GABAergic neurons in the mouse hippocampus

The time course of the neurogenesis of cells showing glutamic acid decarboxylase (GAD) immunoreactivity has been analyzed in the dorsal hippocampus and area dentata of the mouse. The quantitative data indicate that gamma-aminobutyric acid (GABA)ergic cells are generated prenatally, and that their peaks of neurogenesis occur before the peaks of neurogenesis of non-GABAergic cells. Additionally, GABAergic cells in the hippocampus proper follow a 'sandwich' sequence of positioning.

Morphological aspects of the ectopic granule-like cellular populations in the albino rat hippocampal formation: a Golgi study

Rat hippocampal formation was examined by the Golgi impregnation method. Three different ectopic granule-like populations of cells were differentiated: (1) Ectopic granule-like cells of the regio inferior, located in the stratum radiatum; one or two dendrites arose from the cell body and ran towards either the molecular layer of the fascia dentata or the stratum lacunosum-moleculare of the hippocampus, where they branched into secondary and tertiary dendrites. (2) Ectopic granule-like cells of the hilar region; this cell population showed bipolar and monopolar types of dendritic tree. Unipolar cells had dendrites oriented towards the granular layer where they branched profusely. Dendritic arborisation of bipolar cells was confined to the hilus. (3) Ectopic granule-like cells of the molecular layer; they showed several structural appearances depending on their location within the layer. Axonal tracts of ectopic granule-like cells gave rise to numerous collaterals; the main branch ran to the CA4 and CA3 hippocampal subregions. Several 'en passant' and mossy-like boutons were shown along this path.