[Neuroimaging of hypoglycemia]

INTRODUCTION

Sustained hypoglycemia causes serious cerebral damage. The cortex, hippocampus and basal ganglia are particularly vulnerable to this. Exceptionally, there have been communications regarding neuroimaging visualization of cerebral lesions attributable to hypoglycemia only. We present the case of a woman who suffered hypoglycemic coma with permanent neurological damage. Lesions were seen on magnetic resonance (MR) and cranial computerized tomography (CT).

CLINICAL CASE

A 22 year old woman with no vascular risk factors was admitted to hospital in hypoglycemic coma, after attempting suicide with oral antidiabetic drugs. The duration of the coma was unknown. On admission the glycaemia was 28 mg/dl. Cranial CT scan was normal during the first 24 hours. Cerebral MR scan one week late showed hyperintense lesions in T2, basal ganglia and left hippocampus. The cranial CT scan one year later showed diffuse atrophy, with bilateral lesions of low attenuation in the basal ganglia and dilatation of the ventricular system.

CONCLUSIONS

It is unusual to see lesions secondary to hypoglycemia on neuroimaging investigations. The etiopathogenic mechanism is still unknown and it has generally been described in diabetic patients. In our case these lesions can only be attributed to hypoglycemia. MR is more sensitive than cranial CT scan for the detection of these lesions during the acute phase.

[Endocarditis caused by Staphylococcus lugdunensis. Hospital incidence]

BACKGROUND

Staphylococcus lugdenensis is a coagulase negative staphylococcus (CNS) associated with a wide spectrum of infections among which infectious endocarditis may be found and in which it is an aggressive pathogen.

METHODS

Since 1993 a systematic search for S. lugdenensis in all the staphylococci isolated in blood cultures and the possibility of endocarditis en all of these was determined. A review of all the cases of endocarditis in the literature was performed.

RESULTS

Three cases of endocarditis by S. lugdenensis on the native valve were detected from January 1993 to June 1997. None of the patients presented previous heart disease or risk factors. In all the cases, at least three blood cultures were positive for S. lugdenensis and vegetations were observed by echocardiogram. Despite correct antibiotic treatment, disappearance of fever, negativization of control blood cultures and in the third case, valve replacement, two patients presented heart failure and all died. On review of the literature 31 cases of endocarditis were found with valve replacement and mortality being 55%. It should be indicated that 85% of the patients who survived required surgery.

CONCLUSIONS

Endocarditis by S. lugdenensis is a severe infection frequently requiring valve replacement and is associated with a high mortality. Therefore, adequate early identification of the microorganism is necessary distinguishing it from the remaining CNS.

Clinicoepidemiologic characteristics, prognostic factors, and survival analysis of patients coinfected with human immunodeficiency virus and Leishmania in an area of Madrid, Spain

From 1987 to 1995, a retrospective case study was conducted at the Ramon y Cajal Hospital in Madrid, Spain, a public teaching hospital with 1,100 beds, to determine the clinicoepidemiologic characteristics, survival, and prognostic factors of patients with visceral leishmaniasis (VL) and human immunodeficiency virus (HIV) infection. The prevalence of VL in HIV+ patients compared with HIV- patients was studied. Epidemiologic, clinical, and parasitologic characteristics, as well as the effects of treatment, prognosis, and survival in 54 HIV+ patients (90 episodes) with VL were defined. Comparative survival studies among patients with and without acquired immunodeficiency syndrome (AIDS)-defining criteria and multivariate analysis of survival risk factors were performed. The prevalence of VL in patients with AIDS was much higher than in immunocompetent individuals. In spite of a good initial response to treatment for VL, 60.6% of the patients had relapsed by the end of one year. Mortality from the first episode was 18.5%, and 24% died in the first month after diagnosis of any VL episode. The mean survival of the 29 patients who died was 10.27 months. Survival in patients with and without AIDS at the time of the first episode of VL was compared at 30 months: 53.7% versus 20.5% (P = 0.00149). We found no significant difference (P = 0.24) in the survival of HIV+ patients who had died of VL without AIDS at the time of the first episode of VL compared with those of a control group of 413 dead patients with AIDS without VL. A diagnosis of AIDS at the time of the first episode of VL and thrombocytopenia were the only risk factors found related to survival. We conclude that in AIDS patients, VL is a recurrent disease that is highly prevalent and whose clinical course is modified by HIV.

[Clinical aspects of mitochondrial diseases]

Mitochondrial disorders are multisystemic diseases with very heterogeneous clinical manifestations. A same genetic mutation can result in distinctive clinical phenotypes and, on the other hand, distinct mutations can result in the same clinical phenotype. This article review the manifestations of the diverse clinical syndromes, their relationship with the molecular defects, and the diagnostic protocol in the investigation of a suspected mitochondrial disorder.

Acrosome reaction inactivation in sea urchin sperm

Acrosome reaction inactivation (ARI) is a process that renders sperm irreversibly refractory to the egg jelly (the natural inducer of the acrosome reaction, AR). This process triggered by the egg jelly, is associated with an increase in [Ca2+]i. However, we show here that a rise in [Ca2+]i alone is not sufficient to induce ARI, since artificially increasing [Ca2+]i with either an ionophore or rising external pH, does not trigger ARI. Contrary to the AR which strictly requires Ca2+, ARI can be triggered almost equally well by Sr2+. On the other hand, Mn2+ inhibits ARI and, as we showed earlier, does not affect AR. These observations indicate that the mechanisms involved in ARI differ from those leading to AR. In addition, we report here that high external pH (a non-physiological inducer of AR) triggers the AR in previously inactivated sperm by opening the same Ca2+ channels activated by the egg jelly. Considering that the opening of Ca2+ channels is one of the earliest responses triggered by the egg jelly and that ARI requires the egg jelly receptor to be activated, we have concluded that ARI involves the uncoupling between the egg jelly receptor and Ca2+ channels. Furthermore, intracellular pH (pHi) determinations, in the presence or absence of ionomycin to substitute for the uncoupled Ca2+ channels, indicate that pHi regulation is also impaired in inactivated sperm. In conclusion, ARI is a manifestation of the uncoupling of the egg jelly receptor from the different ion transport systems required for the acrosome reaction.

Thyroid abscess due to Rhodococcus equi in a patient infected with the human immunodeficiency virus

A case of thyroid abscess due to Rhodococcus equi in an HIV-positive patient with previous pulmonary abscess is reported. Rhodococcus equi is a gram-positive rod that can cause infections in both immunocompetent and immunocompromised patients, though it occurs more frequently in patients with dysfunctional cellular immune systems. Several cases of Rhodococcus equi infection in persons infected with HIV have been reported. In these patients Rhodococcus equi usually invades the lungs, producing pneumonia. These infections often relapse, accompanied by intermittent bacteremia, despite conventional treatment. Extrapulmonary abscesses can occur.

Nosocomial transmission of Mycobacterium bovis resistant to 11 drugs in people with advanced HIV-1 infection

BACKGROUND

Since 1990, several nosocomial outbreaks of multidrug-resistant (MDR) tuberculosis have occurred, none of which have involved Mycobacterium bovis. We describe an epidemic of nosocomial and primary MDR M bovis tuberculosis from December, 1993, to February, 1995, among HIV-1-infected patients in a district of Madrid.

METHODS

We undertook genetic characterisation of the M bovis strain and investigated its presence in a tuberculosis epidemic in a Madrid hospital in a case-controlled study. We assessed 19 cases diagnosed with MDR tuberculosis due to M bovis during the study period. For the control group, we randomly selected 33 patients with HIV-1 infection and isolation of a strain of M tuberculosis susceptible to isoniazid, rifampicin, or both, who were treated in Ramón y Cajal Hospital. Infection-control policies and practices were implemented.

FINDINGS

We detected 19 cases in HIV-1-infected patients of primary MDR tuberculosis produced by M bovis resistant to 11 antituberculosis drugs. We found phenotypic and genotypic similarities in the strains of M bovis. In the case group, the index case and two other cases had had previous contact with another hospital that had had an MDR tuberculosis outbreak. All patients died after a mean of 44 days (range 2-116), despite multidrug treatment with first-line and second-line antituberculosis drugs. The cases with M bovis MDR tuberculosis were significantly more likely than controls to have been admitted to a hospital ward at the same time as patients already infected with MDR tuberculosis during the 10 months before their diagnosis (adjusted odds ratio 94.6 [95% CI 9.4-956.3], p < 0.0001). Advanced HIV-1 immunosuppression was associated with the development of MDR tuberculosis. Implementation of control measures stopped the epidemic.

INTERPRETATION

An M bovis primary MDR tuberculosis epidemic that cannot be treated effectively and with high mortality has emerged in Europe and has been transmitted between hospitals.

Salmonella lung involvement in patients with HIV infection

STUDY OBJECTIVE

To determine the frequency, clinical features, and outcome of lung involvement in HIV-infected patients having nontyphoid strains of Salmonella bacteremia.

DESIGN

A retrospective clinical study.

PATIENTS AND SETTING

We studied the records of all HIV-infected patients with Salmonella bacteremia diagnosed at a university tertiary hospital from January 1987 to December 1995.

RESULTS

Lung involvement was found in 18 (35.3%) of 51 HIV-infected individuals with Salmonella bacteremia. Six of 18 (33.3%) were diagnosed as having definite Salmonella pulmonary infection by isolation of Salmonella from respiratory specimens, while probable Salmonella lung disease was considered in two patients who developed lung abscesses without the identification of any pathogen. Predisposing factors for focal disease, such as prior lung disease or Salmonella serotype, were equally prevalent regardless of the presence of Salmonella pulmonary involvement. Cavitary infiltrates or abscess formation were seen in five of the eight patients. With the exception of one patient coinfected with Nocardia asteroides who died 1 month later, all patients were cured with antibiotic treatment. Superinfection with other pulmonary pathogens (10 cases, 56%) was more frequent than Salmonella pneumonia; the most frequent alternative diagnosis was Pneumocystis carinii pneumonia (5 cases, 28%), pyogenic bacterial infection (17%), and tuberculosis (11%).

CONCLUSIONS

In HIV-infected patients with Salmonella bacteremia, lung involvement is frequent, although there were no significant factors to explain this association. Cavitary disease was the most common radiologic pattern, and focal lung disease due to Salmonella does not seem to be associated with a worse prognosis. Coinfection and superinfection with other respiratory pathogens are more common than isolated Salmonella lung disease, and therefore, additional diagnostic procedures must be considered in the evaluation of these patients.

Effects of trifluoromethyl ketones and related compounds on the EAG and behavioural responses to pheromones in male moths

Trifluoromethyl ketones (TFMKs) and analogues affect pheromone detection and behaviour in male moths. 3-Octylthio-1,1,1-trifluoropropan-2-one (OTFP), one of the most effective antiesterase agents, decreased the EAG amplitude and increased the repolarization time in Spodoptera littoralis. It also modified EAG responses of Mamestra brassicae and Heliothis zea to their pheromones and analogues, containing an acetate, an alcohol or an aldehyde function. In addition, OTFP also reduced the amplitude of the EAG response to linalool, a monoterpenic alcohol, but not its kinetics. The responses of male S. littoralis to the pheromone in the wind tunnel were significantly reduced after pre-exposure to vapours of OTFP. Comparison of the activity of other TFMKs and analogues with that of OTFP revealed a good agreement on EAG and behaviour. The effects of TFMKs on the EAG kinetics are discussed considering the hypothesis of an inhibition of the pheromone deactivation in the antenna.

Acute polyradiculopathies in HIV-infected patients

We studied 17 consecutive cases of acute polyradiculopathy (PR) diagnosed in HIV-infected patients to investigate the possible causes of this syndrome in our milieu. Sixteen patients presented with lumbosacral PR and one patient had predominantly cervical PR. Electrophysiological study showed a predominantly motor axonal neuropathy in all patients examined. Six patients had a laboratory-confirmed aetiology for the PR: cytomegalovirus (CMV) was isolated from cerebrospinal fluid (CSF) in three cases, meningeal lymphomatosis was diagnosed by CSF cytology in two cases, and one patient had cryptococcal meningitis. Another patient was thought to have acute axonal polyradiculoneuritis associated with HIV infection. CMV and Mycobacterium tuberculosis were the probable agents in four and three patients, respectively. Finally, in three patients a cause could not be foscarnet were effective in the treatment of definite or probable CMV PR. The present study confirms that acute lumbosacral PR in HIV-infected patients must be considered a syndrome with different causes. CMV and M. tuberculosis infections were the most frequent causative agents in our series (41% and 18% of the cases, respectively). Early empirical therapy is often necessary as definite diagnosis may be delayed or never achieved. Our experience suggests that, at least in our milieu, anti-tuberculous drugs should be considered in some cases together with ganciclovir or foscarnet in the empirical therapy for PR in HIV-infected patients.

Oxydation of oleic acid to (E)-10-hydroperoxy-8-octadecenoic and (E)-10-hydroxy-8-octadecenoic acids by Pseudomonas sp. 42A2

Biotransformation of oleic acid with Pseudomonas sp. 42A2 has been found to produce(E)-10-hydroxy-8-octadecenoic acid (2a), (E)-10-hydroperoxy-8-octadecenoic acid (3a), and (E)-7,10-dihydroxy-8-octadecenoic acid (4a). Structures of the metabolites were fully characterized by infrared and 1H and 13C NMR spectra of the acids, by fast atom bombardment (FAB) and electron impact (EI) and chemical ionization (CI) mass spectrometry of the corresponding methyl esters. This is the first time that the two former compounds of trans stereochemistry have been described to have originated from a Pseudomonas sp. cell culture. Time course of products accumulation showed that biotransformation started with bacterial growth, the amount of products 2a (5.58 g/l) and 4a (2.63 g/l) being optimum after 24 h of incubation while hydroperoxide 3a (1.15 g/l) reached its maximum after 16 h of the biotransformation process. Experiments conducted to ascertain whether the conversion enzyme(s) was cell-bound or extracellular, showed that the enzyme(s) is cell bound, located in the periplasmic space and has lipoxygenase activity.

Genetic characterization of multidrug-resistant Mycobacterium bovis strains from a hospital outbreak involving human immunodeficiency virus-positive patients

Nineteen multidrug-resistant (MDR) Mycobacterium complex strains isolated in a nosocomial outbreak were characterized at the molecular level. The strains were microbiologically characterized as Mycobacterium bovis. The mpt40 sequence was not present in chromosomal DNA from these strains, supporting the fact that they were M. bovis. All of the isolates were resistant to isoniazid, rifampin, pyrazinamide, ethambutol, streptomycin, para-aminosalicylic acid, clarithromycin, cycloserine, ethionamide, ofloxacin, capreomycin, and amikacin. By performing the standardized IS6110 fingerprinting by restriction fragment length polymorphism (RFLP) analysis, we were able to differentiate two groups (groups A and B) containing two (16 isolates) and three (3 isolates) IS6110 copies, respectively. These strains were typed by spoligotyping, developed to distinguish M. bovis strains and also to distinguish them from M. tuberculosis strains (J. Kamerbeek et al., J. Clin. Microbiol. 35:907-914, 1997). All the strains were confirmed to be M. bovis. In addition, spoligotyping showed a difference in only 1 of 43 spacers between RFLP groups A and B. The rpo beta region of several strains representative of each identified group was cloned and sequenced, and identical mutations (Ser-531 to Leu) responsible for the rifampin resistance phenotype were found. To our knowledge, this is the first characterization at the molecular level of an MDR M. bovis strain responsible for a nosocomial outbreak.

Selection of Candida glabrata strains with reduced susceptibility to azoles in four liver transplant patients with invasive candidiasis

The cases of four liver transplant recipients who developed invasive candidiasis (2 cholangitis, 1 perihepatic abscess, 1 candidemia) due to azole-resistant, Candida glabrata are reported. Three patients were receiving azolic compounds (2 itraconazole, 1 fluconazole) when the infection was diagnosed. All four patients received fluconazole as intestinal decontamination during the first three weeks post transplantation. The infections occurred two months after transplantation in all patients, and in one patient Candida infection was the direct cause of death. Infection of the biliary tree was the origin of candidiasis in three patients; the fourth patient developed neutropenic-related candidemia. Fluconazole MICs exceeded 16 micrograms/ml in all cases; itraconazole MICs were 16, 2, 1, and 2 micrograms/ml, respectively. The potential role of Candida species other than albicans in these patients after administration of azole agents is discussed.

[Neurological manifestations in patients with sera positive for Borrelia burgdorferi]

Eight years of case histories of patients with positive serum tests for Borrelia burgdorferi (Bb) are reviewed with the aims of analyzing the neurological manifestations involved and of assessing the value of serology in the diagnosis of neuroborreliosis (NB) in our clinical setting. Of the 105 cases with neurological manifestations that could be examined, 25 patients (24%) with other infections, neoplasms or other diseases had false positive serologies. Forty-one patients (39%) met the criteria for NB diagnosis: 26 had lymphocytic meningitis, 13 had polyradiculitis and 20 had cranial neuropathy. Spinal fluid cultures were positive in 43% of the patients on whom the test was performed, and all patients in this group who were treated with antibiotics improved. The other 39 patients (37%) had only neurological manifestations, which were not typical of NB (peripheral neuropathy, stroke, demyelinating disease, dementia or myelopathy), but for which no other etiology could be demonstrated. Spinal fluid serology was positive in 16% of those cases studied and none of those treated only with antibiotics improved. Among patients with both neurological manifestations and Bb positive serology, there were many false positives and cases with signs that were of dubious relation to infection by Bb; therefore, the prevalence of cases consistent with NB is low [corrected].

AM218, a new polyanionic polysaccharide, induces radioprotection in mice when administered shortly before irradiation

We have shown that the polyanionic polysaccharide AM218 improves the survival rate of the potentially lethally irradiated mice. This radioprotective effect was highly dependent on the administration schedule, the most efficient protocol being that in which the drug was given shortly before irradiation. The haematopoietic implications in the pharmacological action of AM218 were confirmed by the improved recovery in the three peripheral blood lineages observed in the AM218-treated mice. However, because of a marked increase observed in the number of white blood cells during the period of highest mortality of the control irradiated mice, effects on the neutrophil lineage may account for the effects mediated by AM218 in the irradiated mice. Both in vitro and in vivo treatment with AM218 before irradiation improved the survival rate of CFU-GM progenitors, while no effects were observed on the CFU-S pool. This led us to postulate that the improved survival rate of the committed progenitors, at least the granulocyte-macrophage progenitors, accounts for the radioprotective capacity of AM218.

Plasma lipids, erythrocyte membrane lipids and blood pressure of hypertensive women after ingestion of dietary oleic acid from two different sources

OBJECTIVE

To study the effect of a diet rich in mono-unsaturated fatty acids (MUFA), from high-oleic sunflower oil (HOSO) and olive oil, on plasma lipids, erythrocyte membrane lipids (including fatty acid composition) and blood pressure of hypertensive (normocholesterolaemic or hypercholesterolaemic) women.

METHODS

There were 16 participants who were hypertensive women aged 56.2 +/- 5.4 years. The participants ate a diet enriched with HOSO or olive oil for two 4-week periods with a 4-week washout period before starting the second type of MUFA diet. At entry and during study of each diet, plasma lipids and apolipoproteins were measured by conventional enzymatic methods. Erythrocyte membrane lipid and fatty acid compositions were analysed by means of the latroscan thin-layer chromatography/flame ionization detection technique and by gas chromatography, respectively. Blood pressure was also measured. The statistical analysis was conducted by using Student's two-tailed paired t-test.

RESULTS

In both groups of hypertensive patients, there was a significant increase in plasma high-density lipoprotein (HDL) cholesterol concentration after the HOSO or olive oil diets, with regard to baseline. Additionally, a significant decrease in plasma HDL2 cholesterol concentration and an increase in plasma HDL3 cholesterol concentration were evident. The membrane free-cholesterol concentration increased significantly and the phospholipid concentration decreased significantly in erythrocytes after the olive oil diet, though both MUFA diets produced a significant decrease in the concentration of membrane esterified cholesterol. Therefore, the molar ratio of cholesterol to phospholipids was raised significantly in the erythrocyte membrane of hypertensive women after the dietary olive oil, but not after the HOSO diet. In the hypertensive and normo-cholesterolaemic group the HOSO diet significantly increased the content in the erythrocyte membrane of oleic, eicosenoic, arachidonic and docosapentaenoic acids, whereas the olive oil diet increased the content of palmitoleic acid and long-chain polyunsaturated fatty acids of the n-3 family besides, compared with baseline. A significant decrease in linoleic acid was also evident. In the hypertensive and hypercholesterolaemic group, the HOSO diet resulted in significant increases in palmitoleic, oleic, eicosenoic and behenic acids, whereas the olive oil diet enhanced the content of arachidonic, docosapentaenoic and docosahexaenoic acids besides, with respect to baseline. In addition, there was a significant decrease in stearic acid, but only after dietary olive oil was there a decrease in linoleic acid. The most important differences between the two MUFA diets were the increase in n-3 fatty acids and the decrease in the n-6; n-3 fatty acids ratio after dietary olive oil in the erythrocyte membranes of hypertensive patients. Interestingly, a significant reduction in systolic and diastolic blood pressures was only evident after the ingestion of olive oil.

CONCLUSION

These data suggest that the beneficial effects of dietary olive oil on the plasma lipids and lipoprotein profile, lipid and fatty acid composition of erythrocyte membrane, and blood pressure in women with untreated essential hypertension are not found equally for the HOSO-rich diet, despite both vegetable oils providing a similar concentration of MUFA.