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Biomedical subjects

D Nadal

Publications and source records attributed to D Nadal.

At least 73 records · Page 4Linked to original sources

Severe tick-borne encephalitis following passive immunization.

UNLABELLED: We report on a 5-year-old girl with an unusually severe course of tick-borne encephalitis following passive immunization with specific hyperimmune globulin after a tick bite in an endemic area. Serial investigations of the CSF revealed intrathecal production of specific antibodies paralleled by increasing numbers of B-cells after initial T-cell pleocytosis. Focal central lesions were evident on MRI. CONCLUSION: The severity of the presented case questions the benefit of passive immunization and rather justifies consideration of vaccine recommendation to residents and travellers to areas endemic for tick-borne encephalitis virus.

Child, Preschool↗

Vertical human immunodeficiency virus-1 infection: involvement of the central nervous system and treatment.

UNLABELLED: Involvement of the central nervous system (CNS) contributes substantially to morbidity and mortality of vertical infection with the human immunodeficiency virus (HIV)-1. The clinical spectrum ranges from minor developmental disabilities to severe and progressive encephalopathy. Progression of the disease varies considerably. Both direct viral and indirect host-related pathogenic mechanisms have been proposed. The diagnosis depends on neurological and neurodevelopmental assessments. So far, HIV-1-specific antiviral treatment has shown limited effects on neurological manifestations in symptomatic children. Thus, efforts are needed to improve prevention and treatment of CNS involvement. It is still unclear whether early use of antiretroviral agents is of benefit. CONCLUSION: Since experience of treatment of HIV-1 infections in adults cannot easily be translated to children, paediatric clinical trials are needed to answer questions specific to the unique characteristics of children.

AIDS Dementia Complex↗

Sternal wound infection after heart operations in pediatric patients associated with nasal carriage of Staphylococcus aureus.

A cluster of six pediatric cases of deep-seated Staphylococcus aureus infection after heart operations prompted us to perform molecular typing of the S. aureus isolates by pulsed-field gel electrophoresis. This revealed the presence of genotypically distinct isolates in four of the six patients. Isolates of two patients were genotypically identical. All patients carried S. aureus in the anterior nares. In each patient, the banding pattern of deoxyribonucleic acid in these isolates was indistinguishable from that in strains isolated from blood or wound cultures. Molecular typing with pulsed-field gel electrophoresis ruled out nosocomial transmission of S. aureus between four patients; at the same time, it provided evidence for an association between nasal colonization and postoperative wound infection. Epidemiologic investigation of potential links between two patients with identical isolates did not provide any evidence for nosocomial transmission of S. aureus between these patients. Because nasal colonization with S. aureus may be a risk factor for surgical wound infection in pediatric patients undergoing heart operations, preoperative decolonization appears to be warranted.

Anti-Bacterial Agents↗

Late intrauterine Cytomegalovirus infection: clinical and neuroimaging findings.

Fetal Cytomegalovirus (CMV) infection in early pregnancy usually results in severe neurological handicap and sensorineural hearing loss with typical neuroradiological findings of calcification, migrational anomalies, disturbed myelination, and cerebellar hypoplasia. Infections acquired in late pregnancy have less prominent signs, such as microcephaly, hearing deficits, and minor neurological handicap. We report 7 children who presented with a similar clinical complex of signs: microcephaly, sensorineural hearing impairment, behavior problems with hyperactivity, reduced apprehension for pain in 5 of the 7, ataxia in 3, and hypotonia with clumsiness in 3 others. All manifested mild to severe developmental problems. Cranial CT revealed calcification in 4 of 6 patients. MRI in all 7 children showed patchy to confluent nonprogressive dysmyelination. Only 2 children had acute neonatal signs of congenital CMV infection. We assume that these children acquired CMV infection in the third trimester of gestation, leading to microcephaly, hearing loss, and neurological and developmental problems with typical neuroradiological signs.

Child↗

Cerebral tuberculosis presenting as complex febrile convulsions.

Complex febrile convulsions were the initial clinical manifestation of miliary tuberculosis in a 4-year-old immigrant girl. The cerebral lesions were visible only after contrast-enhanced cranial computed tomography (CT) while native CT scan as well as cell count and glucose concentration in the cerebrospinal fluid were normal. Mycobacterium tuberculosis was cultured from gastric aspirate and liver biopsy tissue. Treatment with isoniazid and rifampin for 12 months, pyrazinamide for 9 months, and ethambutol for the initial 6 weeks resulted in resolution of the cerebral lesions but a retinal scar after granuloma formation in the right eye caused reduced visus. This case demonstrates the importance of thorough search for tuberculosis even in the absence of overt clinical pulmonary signs especially in high-risk individuals such as immigrants.

Antitubercular Agents↗

Regression of AIDS-related Kaposi's sarcoma during therapy with thalidomide.

A 14-year-old girl with HIV infection and subcutaneous Kaposi's sarcoma (KS) received thalidomide therapy for oral ulcers, resulting in regression of KS lesions, disappearance of KS-associated herpesvirus (KSHV) DNA from blood, and reduced viral load in tumor tissue. Administration of grauntocyte colony-stimulating factor resulted in clinical exacerbation of KS and reappearance of KSHV DNA in blood.

Adolescent↗

Molecular polymorphism distribution in phenotypically distinct populations of wine yeast strains.

Electrophoretic karyotyping and mitochondrial DNA restriction analysis were used to analyze natural yeast populations from fermenting musts in El Penedès, Spain. Both analyses revealed a considerable degree of polymorphism, indicating heterogeneous natural populations. By specifically designed genetic selection protocols, strains showing potentially interesting phenotypes, such as high tolerance to ethanol and temperature or the ability to grow and to ferment in wine-water-sugar mixtures, were isolated from these natural populations. Genetic analysis showed a strong correlation between the selected phenotypes and mitochondrial DNA polymorphisms. Karyotype analysis revealed several genetically similar yeast lineages in the natural yeast microflora, which we interpret as genetically isolated subpopulations of yeast strains with distinct genetic traits, which may correspond to specific microenvironments. Thus, molecular polymorphism analysis may be useful not only to study the geographical distribution of natural yeast strains but also to identify strains with specific phenotypic properties.

DNA, Fungal↗

T-cell death by apoptosis in vertically human immunodeficiency virus-infected children coincides with expansion of CD8+/interleukin-2 receptor-/HLA-DR+ T cells: sign of a possible role for herpes viruses as cofactors?

One mechanism proposed to play a role in T-cell depletion in human immunodeficiency virus (HIV) infection is apoptosis (activation-induced cell death). We assessed whether apoptosis is related to activation of T cells in vivo and its possible triggers. DNA was extracted from peripheral blood mononuclear cells (PBMC) taken from 16 vertically HIV-infected children and 9 HIV-negative children born to HIV-positive mothers (controls) and tested by agarose gel electrophoresis for the presence of DNA fragments specific for apoptosis. Signs of apoptosis were found on in vitro culture of PBMC from 12 of 16 HIV-infected children, but not in PBMC from the nine controls. Eleven of the 12 HIV-infected children with apoptosis showed an elevated (> 15%) proportion of CD3+/HLA-DR+ cells. This was due to an increased proportion of CD8+/HLA-DR+ cells, as shown in 7 of 7 further tested patients. In none of the probands an increased (> 5%) proportion of IL-2 receptor expressing CD3+ cells was found. T cells undergoing apoptosis were preferentially of the CD8+ phenotype. Expansion of circulating CD8+/interleukin-2 receptor (IL-2R)-/HLA-DR+ T cells is known to occur during active infection with herpes viruses. To investigate the possible role of herpes viral coinfections for apoptosis in HIV infection, we focused on Epstein-Barr virus (EBV) as an example for a herpes virus usually acquired during childhood. In 10 of 12 patients with apoptosis, we found increased levels of EBV genome in PBMC and/or tissues, indicating active EBV replication. By contrast, no increased burden of EBV was found in the four HIV-infected patients without apoptosis or in the controls. Our data indicate that in children the occurrence of apoptosis in HIV infection is closely related to activation of CD8+ T cells. Furthermore, primoinfection with or reactivation of herpes viruses, such as EBV, may substantially contribute to such T-cell activation and the ensuing apoptosis. Additional studies are warranted to evaluate the contribution of herpes virus-triggered apoptosis to the T-cell loss leading to the acquired immunodeficiency syndrome.

Apoptosis↗

[Pneumocystis carinii pneumonia in infants with vertically acquired HIV infection in Switzerland].

OBJECTIVE: Review of incidence, clinical picture, therapy, and outcome of Pneumocystis carinii pneumonia (PCP) in infants with vertically-acquired HIV infection in Switzerland. METHODS: Inquiry among members of the Swiss Pediatrics AIDS Group, review of the data base of the Swiss Neonatal HIV Study and retrospective analysis of the charts from infants with PCP. RESULTS: Since 1986 PCP has been diagnosed in 10 out of 107 infants with vertically-acquired HIV infection. PCP occurred in 7 infants at the age of 3-6 months and in 3 at the age of 9-11 months. 4 infants showed symptoms related to HIV infection before developing PCP. Before the development of PCP, infection with HIV had been ascertained in 6 infants. In 2 the diagnosis was still unclear and in the 2 remaining the risk of HIV infection was not known. None of the infants was on primary prophylaxis against PCP. Signs and symptoms of PCP included cough and tachypnea (100%) as well as high fever up to 40 degrees C (90%). Transcutaneous oxygen saturation was 70-95%. Chest X-rays revealed interstitial infiltrates in 6 infants, localized infiltrates in 2 and interstitial as well as localized infiltrates in 2. The CD4+ cell count was, with one exception, < 1500/microliters, i.e. below the normal value for age. Side effects of high dose cotrimoxazole were noted in 6 patients. 5 infants required intubation and mechanical ventilation. 4 infants died due to PCP, including 3 of those who required intubation and mechanical ventilation. CONCLUSIONS: PCP in infants with vertically-acquired HIV infection preferentially occurs at the age of 3 to 6 months and is often lethal, especially in patients requiring intubation. Evaluation for HIV infection should be done as early as possible in order to introduce primary PCP prophylaxis in infants at risk for this opportunistic infection.

AIDS-Related Opportunistic Infections↗

In vitro immunization: generation of neutralizing monoclonal antibodies to human interleukin-10.

The potential of the in vitro immunization technique to evoke an immune response against an immunomodulatory protein was evaluated using, as antigen, human interleukin-10 (IL-10), a novel cytokine with pleiotropic effects on human and murine lymphocytes and macrophages. After pre-priming the support cells for 48 h and subsequent 3-day stimulation of splenocytes from a non-immune BALB/c mouse with recombinant human IL-10 (rhIL-10; 2 micrograms/ml), significant stimulation of splenocytes was observed. 7 days after fusion with the non-secreting myeloma line X63/Ag8.653, IL-10-specific antibodies were detected by ELISA and dot blot in more than 70% of the hybridoma supernatants. After limiting dilution of the hybridoma cells showing IL-10-neutralizing activity in a bioassay using murine MC/9 mast cells, the isotype of the monoclonal antibodies (mAbs) obtained was 20% IgM, 16% IgG and 6% IgA. All other antibodies elicited IgM as well as IgG isotypes. The neutralizing activity of the specific mAbs tested was dose-dependent. Our results show that in vitro immunization can be employed successfully to generate functional mAbs to immunomodulatory proteins, even if these exhibit cross-species activity.

Animals↗

Serology to Bartonella (Rochalimaea) henselae may replace traditional diagnostic criteria for cat-scratch disease.

Bartonella (Rochalimaea) henselae has been identified as causative agent of cat-scratch disease (CSD). Employing an indirect fluorescence antibody test we found that 20 (100%) out of 20 children with suspected CSD had serum titres to B. henselae of > or = 512. By contrast, in all but one of the controls (n = 332) including subjects exposed to the same cats, patients with diseases other than CSD, and blood donors the antibody titres were < or = 256 (P < 0.001). However, significant regional differences in seroprevalence were noted. CONCLUSION. Serology to B. henselae may supplant traditional criteria for the diagnosis of CSD and prevent patients from unnecessary surgery.

Adolescent↗