Hepatoerythropoietic porphyria: neuroimaging findings

CT and MR findings in two patients with hepatoerythropoietic porphyria are presented. CT scans showed atrophy and cortical mineralization at the same level. MR examination performed in one of the two patients showed mainly frontal cortical atrophy and punctate bright signal on T1- and T2-weighted sequences.

Isoniazid preventive therapy in human immunodeficiency virus-infected persons. Long-term effect on development of tuberculosis and survival

BACKGROUND

Although the short-term benefit of isoniazid prophylaxis in patients coinfected with human immunodeficiency virus (HIV) and tuberculosis has been shown, long-term benefits are unknown.

METHODS

Historical cohort study in an acquired immunodeficiency syndrome unit at a tertiary referral hospital. A sample of 121 HIV-infected patients with positive results on a purified protein derivative test were followed up for development of active tuberculosis and survival. Patients who received isoniazid prophylaxis were compared with patients who did not receive prophylaxis.

RESULTS

Of the 121 patients examined, 29 (24%) completed a 9- to 12-month course of isoniazid prophylaxis (median follow-up, 89 months), and 92 (76%) did not receive the drug (median follow-up, 60 months). Active tuberculosis developed in 46 patients (38%). The incidence of tuberculosis was higher among patients with no prophylaxis (9.4 per 100 patient-years) than among patients with isoniazid prophylaxis (1.6 per 100 patient-years) (P = .006). Risk for development of tuberculosis was associated with the absence of isoniazid prophylaxis (relative risk [RR], 6.55; 95% confidence interval [CI], 2.02-21.19). Death during the period of study was more frequent in patients who did not receive isoniazid (50/92 or 54%) than in patients who received isoniazid (7/29 or 24%) (P = .008). Median survival was more than 111 months in patients who received isoniazid compared with 75 months in patients who did not receive isoniazid (P < .001). In a proportional hazards analysis, the development of tuberculosis (RR, 1.88; 95% CI, 1.09-3.27), the absence of isoniazid prophylaxis (RR, 2.68; 95% CI, 1.16-6.17), and a CD4+ cell count lower than 0.20 x 10(9)/L (RR, 3.03; 95% CI, 1.39-6.61) were independently associated with death. Patients who received isoniazid had a longer survival after stratifying for the CD4+ cell count.

CONCLUSIONS

Preventive therapy with isoniazid confers long-term protection against tuberculosis and significantly increases survival in patients dually infected with HIV and Mycobacterium tuberculosis.

Deep infections caused by Scedosporium prolificans. A report on 16 cases in Spain and a review of the literature. Scedosporium Prolificans Spanish Study Group

Scedosporium prolificans, a mold morphologically similar to Scedosporium apiospermum, may cause asymptomatic colonization or localized or disseminated infection following trauma, surgery, and immunosuppression. S. prolificans is normally resistant to available antifungal agents, and prognosis depends largely on the host's immune status, extent of infection, and feasibility of surgical debridement. We report on 16 patients with deep S. prolificans infections, focusing on predisposing factors, clinical characteristics, outcome, postmortem findings, and antifungal susceptibility testing to 6 antifungal agents. Between 1989 and 1994, 16 cases of deep infections by S. prolificans were documented in 6 clinical centers in Spain (15 adults and 1 child: male/female = 0.77). Fifteen patients had underlying hematologic malignancy (14 with neutropenia) and 1 had a prosthetic cardiac valve. Syndromes included disseminated infection in 14 patients (1 with prosthetic valve endocarditis) and fungal pneumonia and meningoencephalitis in 1 patient each. S. prolificans was isolated from 2 specimens in 14 patients and from 1 specimen in 2 patients (blood, n = 12; respiratory tract, n = 4; CNS, n = 4; and skin biopsy, n = 3). Antifungal susceptibility testing by a micromethod with RPMI-2% glucose medium was performed in 8 isolates, all of which were resistant to amphotericin B, flucytosine, ketoconazole, fluconazole, itraconazole, and miconazole. All patients received antifungal therapy (amphotericin B, n = 9; amphotericin B+ flucytosine, n = 1; amphotericin B+ itraconazole, n = 2; liposomal amphotericin B+ itraconazole, n = 1; amphotericin B+ fluconazole, n = 1 and 2 underwent surgical procedures. Two patients survived coinciding with hematologic recovery and 14 (87.5%) patients died in a median time of 4 days after the first positive culture (range, 0-60 d). Necropsy was performed in 10 patients, and disseminated infection was found in 9. In conclusion, S. prolificans is an emerging multiresistant fungal pathogen that may cause asymptomatic colonization, localized infection related to trauma or surgery, and rapidly fatal disseminated infection in immunocompromised hosts, particularly those with neutropenia. This mycosis underscores the urgent need for new antifungal agents.

Treatment of chronic hepatitis C with interferon-alpha. Clinical histological and virological implications

OBJECTIVE

to identify pretreatment predictive factors of long-term biochemical and virological response to interferon-alpha in chronic hepatitis C and to determine the effects of a second course of interferon-alpha in patients who responded but relapsed after interferon withdrawal.

DESIGN

retrospective analysis.

SETTING

outpatient liver clinic of a tertiary hospital in Spain.

PATIENTS

112 patients with chronic hepatitis C were treated with recombinant interferon-alpha (3 MU three times a week for 6 months). Twenty-four patients who responded but relapsed after interferon withdrawal were treated with a second course of interferon (3 MU three times a week for 12 months).

RESULTS

seventy-two patients were non-responders (64%), 11 patients had a sustained response (10%) and 29 patients responded but relapsed after interferon withdrawal (26%). Five (25%) of the 24 patients who relapsed and were treated with a second course of interferon experienced a sustained response (mean follow-up: 10 months). By multivariate analysis, four pretreatment variables were found to be predictive of a complete response: age < 40 years (p = 0.0004), history of IVDA (p = 0.001), low serum levels (p = 0.013), and genotype 3 (p = 0.01). Two variables were found to be predictive of a sustained response: short duration of HCV infection (p = 0.09) and genotype 3 (p = 0.01). Sustained responders appeared to have lower HCV-RNA levels than those with complete response who relapsed and non-responders. HCV viremia levels were not associated with the severity of liver histology, duration of disease or the source of hepatitis.

CONCLUSIONS

in the present study a low sustained response rate was observed using a standard interferon-alpha regimen (3 MU three times a week for 6 months). The sustained response rate increased slightly with a second course of interferon-alpha (3 MU three times a week for 12 months) in patients with a complete response who relapsed after interferon withdrawal. Sustained response is related to viral genotype and duration of HCV infection.

Group A streptococcal bacteremia. A 10-year prospective study

In this paper we present a prospective evaluation of 100 patients with Group A Streptococcal (GAS) bacteremia evaluated in our hospital over a 10-year period. Sixty-two patients were intravenous drug users (IVDU); all but 1 of these had an obvious cutaneous portal of entry related to the injection of illicit drugs. Twenty-seven patients had infectious metastasis, and the presence of septic pulmonary embolism was associated with suppurative phlebitis. Four of these patients had endocarditis. In the non-IVDU group, 24 patients had an underlying disease, and 12 were immunosuppressed. In 14 cases the infection was of hospital acquisition; in 35% infection was related to medical manipulations. Comparing the IVDU and non-IVDU groups, GAS bacteremia in IVDU patients is associated with a more benign outcome, a longer time of evolution before diagnosis, and a lower frequency of septic shock and mortality than in non-IVDU patients. Although in the univariate analysis GAS bacteremia was associated with several variables, in the multivariate analysis only the presence of shock and nosocomial acquisition of the infection were independently associated with a fatal outcome. Fifty-two patients were infected with human immunodeficiency virus (HIV); 5 of these were in the non-IVDU group. During the last 5 years of study, GAS bacteremia in our hospital was 39 times more frequent in HIV-infected patients than in patients without HIV. Nine patients presented clinical criteria corresponding to Streptococcal toxic shock syndrome (STSS), although its incidence was lower in the IVDU group. In the non-IVDU group, STSS was more frequent in patients with a necrotizing portal of entry, an age between 20 and 40 years, women, and when the origin of the infection was the skin or soft tissue. Six patients with STSS died, and death was associated with the presence of necrotizing lesions and lower counts of white cells, platelets, or hemoglobin.

Hyperlipidemia in liver transplant recipients: prevalence and risk factors

Hyperlipidemia is common in transplant patients. Although a causal relationship to the use of cyclosporine is accepted, additional risk factors are as yet unidentified. Eighty-five liver transplant recipients treated with standard triple immunosuppression with a survival of at least 6 months were evaluated. Pretransplantation and posttransplantation variables were analyzed as predictive factors of posttransplantation hyperlipidemia. Serum cholesterol and triglyceride levels were considered elevated if they were > 250 mg/dL and > 150 mg/dL, respectively. Before and after transplantation, hyperlipidemia occurred in 8% (95% confidence interval [CI], 3% to 16%) and 66% (95% CI, 55% to 76%), respectively. After transplantation, 47% (95% CI, 36% to 58%) of the patients had isolated high triglyceride levels, 12% (95% CI, 6% to 21%) had both elevated cholesterol and triglyceride levels, and 7% (95% CI, 3% to 15%) had isolated elevated cholesterol levels. Hypertriglyceridemia occurred early after transplantation (67% by first month) and persisted nearly unchanged throughout the first year. In contrast, cholesterol levels increased with time (5%, 13%, and 27% at 1, 3, and 6 months, respectively). In univariate analysis, factors predictive of hypercholesterolemia included female sex, pretransplantation cholestatic liver disease, pretransplantation cholesterol levels > 141 mg/dL, and > 3 methylprednisolone "boluses." In multivariate analysis, only a pretransplantation cholesterol level of > 141 mg/dL (odds ratio [OR], 5.5; 95% CI, 1.4 to 21) was an independent risk factor. Risk factors associated with hypertriglyceridemia included pretransplantation hepatocellular liver disease (OR, 6.8; 95% CI, 1.2 to 40) and posttransplantation renal dysfunction (OR, 5.4; 95% CI, 1.9 to 15.4). Hyperlipidemia is a frequent finding in liver transplant recipients, and hypertriglyceridemia is the most common abnormality. Hypertriglyceridemia can be predicted on the basis of pretransplant hepatocellular disease and posttransplant renal dysfunction. Pretransplant serum cholesterol level is an independent risk factor for posttransplant hypercholesterolemia.

Molecular biology of S-layers

In this chapter we report on the molecular biology of crystalline surface layers of different bacterial groups. The limited information indicates that there are many variations on a common theme. Sequence variety, antigenic diversity, gene expression, rearrangements, influence of environmental factors and applied aspects are addressed. There is considerable variety in the S-layer composition, which was elucidated by sequence analysis of the corresponding genes. In Corynebacterium glutamicum one major cell wall protein is responsible for the formation of a highly ordered, hexagonal array. In contrast, two abundant surface proteins from the S-layer of Bacillus anthracis. Each protein possesses three S-layer homology motifs and one protein could be a virulence factor. The antigenic diversity and ABC transporters are important features, which have been studied in methanogenic archaea. The expression of the S-layer components is controlled by three genes in the case of Thermus thermophilus. One has repressor activity on the S-layer gene promoter, the second codes for the S-layer protein. The rearrangement by reciprocal recombination was investigated in Campylobacter fetus. 7-8 S-layer proteins with a high degree of homology at the 5' and 3' ends were found. Environmental changes influence the surface properties of Bacillus stearothermophilus. Depending on oxygen supply, this species produces different S-layer proteins. Finally, the molecular bases for some applications are discussed. Recombinant S-layer fusion proteins have been designed for biotechnology.

Analysis of the predictive value of clinical data in patients with suspected colonic disease

OBJECTIVE

To develop guidelines for predicting colonic disease on the basis of clinical parameters.

EXPERIMENTAL DESIGN

A prospective study of the clinical data prior to colonoscopy. On the basis of the endoscopic findings, the patients were divided into three diagnostic groups: absence of significant disease, significant benign disease and malignant disease. The patient population was divided randomly into two subgroups. The clinical data from one of them was used to build a database which, using Bayes' theorem, was compared with the variables from the other subgroup to predict the diagnosis for each patient.

PATIENTS

A total of 336 patients (170 males and 166 females; mean age: 58 years; range: 15 to 87 years) were evaluated.

RESULTS

When the endoscopic findings were grouped on the basis of their clinical importance, 211 patients (63%) belonged to the group without significant disease, 60 patients (18%) had significant benign disease and 65 (19%) presented a neoplastic disease. Of the 21 variables selected for use in the database, 6 showed statistically significant differences in terms of the absence or presence of malignant disease: age, absence of previous similar episodes, weight loss, rectal bleeding, lack of improvement and the presence of a mass on digital rectal examination. The predictive model differentiated patients with neoplasm from those without malignant disease, but was not capable of identifying differences among the latter. The model was useful for assessing the risk of malignant disease for each patient.

CONCLUSIONS

The predictive model obtained is a useful tool for establishing the diagnosis and the priority in the performance of colonoscopy.

Surface proteins and a novel transcription factor regulate the expression of the S-layer gene in Thermus thermophilus HB8

We have identified proteins that control the expression of slpA, the gene encoding the crystalline surface layer of Thermus thermophilus HB8. We cloned three genes from T. thermophilus that specifically repressed the expression of the slpA promoter in Escherichia coli. The proteins encoded by two of them (Rep6 and Rep29) bound in vitro to the slpA promoter, while that from the third (Rep54) bound specifically to the 5'-untranslated region (5'UTR) of the slpA mRNA. Rep6 protein was identified as a C-fragment from a Thermus cytoplasmic basic protein of 28 kDa, whose coding gene, slrA (for S-layer regulator), was characterized. Surprisingly, Rep29 was identified as a C-fragment of SlpM, an S-layer-like protein that is overexpressed in slpA mutants. Insertional inactivation of slrA and slpM demonstrated their in vivo function in the control of slpA transcription: SlrA acts as a repressor, and SlpM as an activator. Even more surprising was the identification of Rep54, the 5'UTR mRNA-binding protein, as a C-terminal fragment of the SlpA protein. This result, in addition to further in vivo evidence presented here, supports the existence of a translational autoregulation in slpA expression. The physiological meaning of overlapping transcriptional and translational controls of S-layer expression, and its relationships with other systems, are discussed.

Simulation by a diagnostic CT for the early vocal cord carcinoma

The CT-based simulation with a 3D planning system permits the optimization of radiotherapy treatments. The goal is to obtain an increase in the local control and survival with a reduction of the treatment related toxicity. In our hospital, we do not have a CT simulator and our 3D planning system is not yet working, therefore, we have developed a system to simulate radiotherapy treatments using a diagnostic CT. We began by simulating an early vocal cord carcinoma. The rules of this simulation are presented using a clinical case as an example.

Characterization of L-glutamine:D-fructose-6-phosphate amidotransferase from an extreme thermophile Thermus thermophilus HB8

Glucosamine-6-phosphate synthase from the extremophile Thermus thermophilus (GlmSth) was purified to homogeneity from an Escherichia coli overproducer. The homodimeric enzyme exhibits an optimum activity at 70 degrees C with a half-life of 90 min at 80 degrees C. Dissociation experiments in guanidinium chloride and urea are consistent with the absence of catalytic activity of the monomer. Differential scanning microcalorimetry analysis of GlmSth revealed an irreversible denaturation process with a delta(H)cal = 257 kcal x mol(-1) and Tm = 82.6 degrees C. Antigenic cross-reaction with GlmSth was observed with the E. coli enzyme using monoclonal antibodies (mAbs) specific for linear epitopes of the glutamine binding domain. However, no cross-reactivity was observed with an mAb specific for a native conformation of the E. coli enzyme. The inhibition constants of 6-diazo-5-oxo-L-norleucine and methoxyfumaroyl-L-2,3-diaminopropionic acid, potent glutamine site-directed affinity labels of the E. coli enzyme, were reduced by 2 to 3 orders of magnitude when tested on GlmSth, whereas the properties of 2-amino-2-deoxyglucitol-6P, a potent competitive inhibitor of the fructose-6P site, remained unaffected. These data, combined with its unexpected resistance to limited proteolysis, are consistent with an increase in the structural constraint of the thermophile enzyme vs its mesophilic counterpart.

Cytarabine therapy for progressive multifocal leukoencephalopathy in patients with AIDS

To evaluate the efficacy and safety of intravenous cytarabine in the treatment of AIDS-associated progressive multifocal leukoencephalopathy (PML), we reviewed the charts of all human immunodeficiency virus-infected patients with PML who were seen during a 28-month period at our institution. Patients with biopsy-proven PML were offered therapy with intravenous cytarabine (2 mg/[kg.d] for 5 days every 4 weeks). The diagnosis of PML was histologically confirmed for 13 patients. The median CD4 cell count was 91 x 10(6)/L. A median of three courses of cytarabine was administered to eight patients. Two patients developed mild drug-related toxicities. Clinical and/or radiological signs of improvement were observed for three patients treated with cytarabine; no signs of improvement were noted for the untreated patients. Median survival time after the diagnosis of PML was 102 days (range, 46-220 days) for patients who received cytarabine and 60 days (range, 28-72 days) for untreated patients matched for Karnofsky scores (P = .06, logrank test). Although cytarabine is well tolerated by patients with AIDS and PML, only modest short-term clinical improvement in the conditions of patients treated with the drug has been observed, with no significant impact on survival.

Individual prediction of response to pneumatic dilation in patients with achalasia

During nine years, 157 consecutive patients with achalasia have been dilated in our unit. First, the long-term effect of dilation on clinical status was evaluated. The probability of being in clinical remission eight years after first dilation was 51%. The pressure of the LES measured after dilation was highly predictive of the long-term clinical evolution. Second, a predictive model of the individual response to pneumatic dilation was developed and simplified. Therapy was effective in 80% of the patients, after one to four dilations. Younger age was the only factor significantly associated with ineffective therapy. Depending on the prognosis of the outcome calculated with the predictive model, patients were classified in groups of risk that showed a different rate of ineffective, therapy. In the simplified model, age < or = 20 years, male gender, esophageal body diameter < or = 3 cm, esophageal body basal pressure > 15 mm Hg, and pressure of the lower esophageal sphincter > 30 mm Hg were predictors of a poor response to dilation. We conclude that pneumatic dilation is an effective therapy for achalasia. A predictive model was useful to classify the patients in groups with a different risk for ineffective dilation. A simplification of this model could be used to predict the response to dilation.

Comparison of a spectrophotometric microdilution method with RPMI-2% glucose with the National Committee for Clinical Laboratory Standards reference macrodilution method M27-P for in vitro susceptibility testing of amphotericin B, flucytosine, and fluconazole against Candida albicans

The National Committee for Clinical Laboratory Standards has proposed a reference broth macrodilution method for in vitro antifungal susceptibility testing of yeasts (the M27-P method). This method is cumbersome and time-consuming and includes MIC endpoint determination by visual and subjective inspection of growth inhibition after 48 h of incubation. An alternative microdilution procedure was compared with the M27-P method for determination of the amphotericin B, flucytosine, and fluconazole susceptibilities of 8 American Type Culture Collection strains (6 of them were quality control or reference strains) and 50 clinical isolates of candida albicans. This microdilution method uses as culture medium RPMI 1640 supplemented with 18 g of glucose per liter (RPMI-2% glucose). Preparation of drugs, basal medium, and inocula was done by following the recommendations of the National Committee for Clinical Laboratory Standards. The MIC endpoint was calculated objectively from the turbidimetric data read at 24 h. Increased growth of C. albicans in RPMI-2% glucose and its spectrophotometric reading allowed for the rapid (24 h) and objective calculation of MIC endpoints compared with previous microdilution methods with standard RPMI 1640. Nevertheless, good agreement was shown between the M27-P method and this microdilution test. The MICs obtained for the quality control or reference strains by the microdilution method were in the ranges published for those strains. For clinical isolates, the percentages of agreement were 100% for amphotericin B and fluconazole and 98.1% for flucytosine. These data suggest that this microdilution method may serve as a less subjective and more rapid alternative to the M27-P method for antifungal susceptibility testing of yeasts.

A conserved motif in S-layer proteins is involved in peptidoglycan binding in Thermus thermophilus

There is experimental evidence to suggest that the 100-kDa S-layer protein from Thermus thermophilus HB8 binds to the peptidoglycan cell wall. This property could be related to the presence of a region (SLH) of homology with other S-layer proteins and extracellular enzymes (A. Lupas, H. Engelhardt, J. Peters, U. Santarius, S. Volker, and W. Baumeister, J. Bacteriol. 176:1224-1233, 1994). By using specific monoclonal antibodies, we show that similar regions are present in different members of the Deinococcus-Thermus phylogenetic group. To analyze the role that the SLH domain plays in vivo and in vitro in T. thermophilus, we have obtained a mutant form (slpA.X) of the S-layer gene (slpA) in which the SLH domain was deleted. The slpA.X gene was inserted into the chromosome of the thermophile by gene replacement, resulting in a mutant which expressed a major membrane protein with the size expected from the construction (90 kDa). This protein was identified as the product of slpA.X by its differential reaction with monoclonal antibodies. Mutants expressing the SlpA.X protein grow as groups of cells, surrounded by a common external envelope of trigonal symmetry that contains the SlpA.X protein as a main component, thus showing the inability of the SLH-defective protein to attach to the underlying material in vivo. In addition, averaged images of SlpA.X-rich fractions showed a regular arrangement, identical to that built up by the wild-type (SlpA) protein in the absence of peptidoglycan. Finally, we demonstrate by Western blotting (immunoblotting) the direct role of the SLH domain in the binding of the S-layer of T. thermophilus HB8 to the peptidoglycan layer.

[Isolated hepatic transplant in patient with cystic fibrosis]

Cystic fibrosis (CF) is a recessive autosomic disease with multiorgan, although predominantly pancreatic and pulmonary, involvement. Liver involvement is infrequent in children under the age of 5 years, but increases progressively with time. It is characterized by the development of focal biliary cirrhosis with eventual appearance of portal hypertension. During the last few years the more effective control of the pulmonary complications, which are the main cause of mortality, has led to an increase in the survival of these patients and thus the number of patients with CF and liver involvement is greater every day. In these cases, the prognosis is bad and most patients die in 4 to 5 years. Isolated liver transplantation is a recently proposed alternative for patients who have developed liver cirrhosis but who maintain acceptable pulmonary function. The case of a 14-years-old patient in whom liver transplantation was performed with good results after 8 months of follow-up is presented. Improvement in the nutritive state and pulmonary function was observed.

The "target sign": is it a specific sign of CNS tuberculoma?

In brain lesions, the target sign has been defined as a central nidus of calcification or central enhancement surrounded by a ring of enhancement. It has been considered a pathognomonic finding of central nervous system (CNS) tuberculoma. The purpose of this report is to demonstrate that the target sign related to central enhancement is a nonspecific finding and may lead to erroneous diagnosis of CNS tuberculoma.

[Familial prevalence in chronic intestinal inflammatory disease. Differences among groups of patients with and without a familial history]

OBJECTIVE

To assess the prevalence of familial occurrence in patients with inflammatory bowel disease and to evaluate the differences among groups of patients with and without familial history.

PATIENTS AND METHODS

Complete information about sex, age of onset of inflammatory bowel disease, initial location, extracolonic manifestations and perianal disease (in Crohn's disease) was obtained from 187 patients, 99 with Crohn's disease, and 88 with ulcerative colitis.

RESULTS

In 9 patients (9%) with Crohn's disease and 11 (12.5%) with ulcerative colitis, at least one first-degree relative also had inflammatory bowel disease. Three relatives of patients with Crohn's disease had ulcerative colitis and no relative of patients with ulcerative colitis had Crohn's disease. As compared with the group of patients with ulcerative colitis and no familial history, patients with familial history had more frequently distal location and extra-colonic manifestations. No differences were observed among patients with Crohn's disease and familial or non familial history.

CONCLUSIONS

Prevalence of inflammatory bowel disease in relatives of patients with Crohn's disease or ulcerative colitis is increased. In ulcerative colitis, it is possible to segregate two different groups according to familial history.

Genetic dissimilarity of two fluconazole-resistant Candida albicans strains causing meningitis and oral candidiasis in the same AIDS patient

We describe a patient with AIDS who simultaneously developed Candida meningitis with three positive cerebrospinal fluid cultures and oral candidiasis. This patient also had a history or recurrent episodes of oral candidiasis treated with fluconazole. The patient did not respond to this therapy but was cured with amphotericin B and flucytosine. In vitro susceptibility tests revealed that each infection was caused by fluconazole-resistant Candida albicans isolates. Strain delineation by karyotyping, NotI restriction pattern analysis, hybridization with the specific probe 27A, and PCR fingerprinting with the phage M13 core sequence clearly demonstrated that meningitis and oral thrush were caused by two genetically different isolates.