Unapparent hypoxanthine-guanine phosphoribosyltransferase deficiency

Complete deficiency of hypoxanthine-guanine phosphoribosyltransferase (HPRT) activity causes Lesch Nyhan disease (LND), characterized by hyperuricemia, severe action dystonia, choreoathetosis, ballismus, cognitive and attention deficit and self-injurious behavior. Partial HPRT deficiency is present in patients with Lesch-Nyhan variant (LNV), who present with HPRT-related gout and a variable degree of neurological involvement. The diagnosis of HPRT deficiency relies on clinical, biochemical, enzymatic and molecular data. Patients with HPRT deficiency present low or undetectable HPRT activity in hemolysates, with increased adenine phosphoribosyltransferase (APRT) activity. We present a 9-year-old boy who experienced an episode of macroscopic hematuria with dysuria and left flank pain. He presented hyperuricemia and hyperuricosuria. HPRT and APRT activities were both normal in hemolysate; however, HPRT activity assayed in intact erythrocytes was 50% of control levels. A new missense point mutation c.424 A>G (T142A) was found in the HPRT1 gene. The apparent Michaelis constant (Km) for 5-phosphoribosyl-pyrophosphate assayed in patient hemolysate was 20-fold of control levels. In conclusion, we report a patient with HPRT deficiency who presented with both normal HPRT and APRT activity in hemolysate, in which the enzyme activity determined in intact erythrocytes was of diagnostic utility.

Anisakis/Ascaris IgE ratio improves specificity for the diagnosis of Anisakis simplex sensitization in travellers and immigrants

Anisakis simplex is a fish parasite responsible for human infection and is able to induce IgE-mediated reactions with several clinical manifestations. Laboratory diagnosis of Anisakis allergy is based on the detection of specific IgE using parasite whole antigen. Unfortunately, these diagnostic tools detect cross-reactivities with other nematodes and micro-organisms leading to low specificity of the diagnostic tests. The aim of this retrospective study was to assess the diagnostic value of specific IgE to Anisakis for diagnosis of A. simplex-sensitization in native Spanish residents (IMM, n=766) and subjects coming from tropical and sub-tropical geographic areas (TRO, n=233). Since Ascaris is the human parasite most closely related to Anisakis, specific IgE to Ascaris was also determined to assess Anisakis cross-reaction with other nematodes and the diagnostic value of Anisakis/Ascaris IgE ratio for Anisakis allergy was examined. IMM and TRO groups showed similar specific IgE to Anisakis levels, while TRO had higher levels of specific IgE to Ascaris than IMM group (p=0.001). ROC curve analysis determined that an Anisakis specific IgE threshold of 0.71 kU/L yielded 93% and 82% specificities in IMM and TRO groups, respectively. A cut-off value ≥4.4 for Anisakis/Ascaris IgE ratio increased specificity to 95% for samples having IgE to Ascaris ≥0.35. In conclusion, the ratio of specific IgE to Anisakis and Ascaris improved remarkably the specificity and this parameter easily obtained from the commercially available system could be useful in the diagnosis of hypersensitivity to A. simplex.

[Imported malaria and HIV infection in Madrid. Clinical and epidemiological features]

INTRODUCTION

Few data are available in Spain data on human immunodeficiency virus (HIV) patients coinfected with malaria. This study has aimed to determine the epidemiological and clinical characteristics of imported malaria in patients coinfected with HIV.

PATIENTS AND METHODS

A case-series retrospective study was performed using the patient's medical records. The study population consisted on patients diagnosed with malaria attended in our center from january 1, 2002 to december 31, 2007.

RESULTS

A total of 484 episodes of malaria, 398 of which were included in this study, were identified. Co-infection with HIV was described in 32 cases. All of them occurred in individuals presumably with some degree of semi-immunity. In the coinfected group, there were 13 cases (40.6%) asymptomatic, whereas this event occurred in 99 cases of patients not coinfected (37.2%) (P=0.707). The greater presence of anemia in co-infected patients (62.5% vs 32.3% in non-coinfected [P=0.001]) stands out.

CONCLUSIONS

In present study, the clinical presentation forms were similar, regardless of the presence or absence of HIV infection. Although the study population does not reflect all possible scenarios of malaria and HIV coinfection, our results indicate the reality of patients attended in the Autonomous Community of Madrid.

[Imported malaria in adults. Clinical, epidemiological and analytical features]

INTRODUCTION

Up to now, the epidemiological and clinical features of imported malaria in Spain have been described in small series from general hospitals. Almost all diagnosis had been made based on symptomatic patients. The aim of this study has been to determine the epidemiological, clinical and laboratorial characteristics of imported malaria in a Reference Unit for Tropical Diseases.

PATIENTS AND METHODS

We performed a cross-sectional, observational and retrospective study. The series consisted of patients diagnosed of malaria who had been attended at the Hospital Carlos III from January 1, 2002 to December 31, 2007.

RESULTS

We identified 484 episodes of malaria, of which 398 cases were included in the analysis. Almost 50% of the patients were natives of endemic areas, while the rest were native-travelers or travelers. Most cases (88-98% according to the group) had not taken malaria chemoprophylaxis correctly when indicated. At the time of diagnosis, 30.4% of patients were asymptomatic and 28.1% of asymptomatic patients had anemia, 19.8% thrombocytopenia, 14% leukopenia, 5% hypocholesterolemia, 5% renal failure and 4.1% hypoglycemia. Low parasitemia was present in 97.5% of asymptomatic individuals compared to 80.5% of the symptomatic patients (P<0.001).

DISCUSSION

Absence of chemoprophylaxis (or poor compliance) is the main reason for malaria in individuals traveling to endemic areas. Malaria must be ruled out in individuals coming from tropical countries with compatible symptoms, and it also should be suspected in certain groups of asymptomatic individuals with abnormal laboratorial parameters.

Utility of real-time PCR for the detection of Paracoccidioides brasiliensis DNA in the diagnosis of imported paracoccidioidomycosis

An increase in immigration from endemic regions has resulted in a number of cases of paracoccidioidomycosis (PCM) being imported into Spain. A molecular diagnostic technique based on real-time PCR was developed for the detection of Paracoccidioides brasiliensis DNA in both culture and patients' clinical samples. A Molecular Beacon probe was used, labelled with FAM and directed at the ITS1 region of ribosomic DNA. The detection limit of the technique developed was 1 fg of fungal DNA per microl of sample. This procedure proved to be very reproducible and specific. The technique was tested with cultures of 12 clinical strains and on samples from two patients with proven PCM. Real-time PCR was positive for all the culture strains, as well as those from both patients. By samples, the technique was positive in sputum and tissue biopsies but less useful on blood samples. Samples were analyzed several months after patient treatment, detecting a small amount of fungal DNA in one respiratory sample. This technique of real-time PCR is a sensitive method for rapid diagnosis of paracoccidioidomycosis and could serve to monitor patients after treatment has begun.

The role of a positive trigger event in actioning authentic leadership development

Authenticity can best be understood in context, and context implies action (Payne, 1996). For the purpose of this study, leadership in general, and authentic leadership in particular, were explored in terms of the actions of former mayor of New York City, Rudolph Giuliani, who displayed authentic leadership in action during the tragic aftermath of the World Trade Centre attacks. Authentic leadership development tends to be triggered by a negative event (as in the case of 9/11 for Giuliani, for example). Since there is limited knowledge of how a positive event may trigger authentic leadership development, the aim of this study was to explore the potential of Appreciative Inquiry (AI) - an affirmative mode of action research - as a positive trigger event for authentic leadership development. The results indicated that this positive approach to change could indeed be implemented for this purpose.

A new PCR-based approach for the specific amplification of DNA from different Schistosoma species applicable to human urine samples

Currently available methods for the diagnosis of human schistosomiasis often lack enough sensitivity and specificity. Recently, several authors have developed more specific and sensitive diagnostic methods, mainly based on the polymerase chain reaction (PCR) technique. Nevertheless, these have been only applied for the diagnosis of 1 out of 4 Schistosoma species affecting man (S. mansoni). Additionally, application of specific PCR has been exclusively used for blood or faecal patients' samples. Here, we develop a new, high sensitive PCR approach that allows the genus- and species-specific amplification of the main 4 Schistosoma species causing disease in man plus S. bovis. We further successfully apply this technique for the detection of parasite DNA in easy-to-handle urine samples from patients with schistosomiasis. With these samples, we have found 94.4% sensitivity and 99.9% specificity when applying a genus-specific (Schistosoma spp.) primer pair, and 100% sensitivity and 98.9% specificity in a species-specific (S. mansoni) PCR.

Abnormal depolarizing patterns in three patients with filarial infection

Several authors have described a particular potential of automated depolarization analysis in detecting malaria infection as part of the routine full blood count (FBC) performed by the Cell-Dyn 4000 analyzer. In these cases, abnormal depolarizing patterns are due to the presence of leukocyte-associated malaria hemozoin, a pigment which depolarizes the laser light. In this report we describe samples from three individual patients who did not have malaria infection but showed abnormal depolarizing events. Further investigation determined that these samples were from patients infected by the nematode Mansonella perstans. The observed depolarizing pattern consisted of a normal depolarizing eosinophil population and in addition an abnormal depolarizing population that showed a close "linear" relationship between "granularity" (90 degrees depolarization) and "lobularity" (90 degrees polarization). This atypical population was smaller than normal leukocytes and thus clearly different from the patterns associated with malaria infection. Abnormal depolarization patterns of M. perstans clearly do not reflect leukocyte-associated malaria hemozoin. It is possible however that the erythrocyte-lysing agent used to facilitate leukocyte analysis by the instrument may have caused microfilaria fragmentation and thus the distinctive "straight-line" features of the abnormal scatter plots

Epidemiology and clinical features of vivax malaria imported to Europe: sentinel surveillance data from TropNetEurop

BACKGROUND

Plasmodium vivax is the second most common species among malaria patients diagnosed in Europe, but epidemiological and clinical data on imported P. vivax malaria are limited. The TropNetEurop surveillance network has monitored the importation of vivax malaria into Europe since 1999.

OBJECTIVES

To present epidemiological and clinical data on imported P. vivax malaria collected at European level.

MATERIAL AND METHODS

Data of primary cases of P. vivax malaria reported between January 1999 and September 2003 were analysed, focusing on disease frequency, patient characteristics, place of infection, course of disease, treatment and differences between network-member countries.

RESULTS

Within the surveillance period 4,801 cases of imported malaria were reported. 618 (12.9%) were attributed to P. vivax. European travellers and immigrants were the largest patient groups, but their proportion varied among the reporting countries. The main regions of infection in descending order were the Indian subcontinent, Indonesia, South America and Western and Eastern Africa, as a group accounting for more than 60% of the cases. Regular use of malaria chemoprophylaxis was reported by 118 patients. With 86 (inter-quartile range 41-158) versus 31 days (inter-quartile range 4-133) the median symptom onset was significantly delayed in patients with chemoprophylaxis (p < 0.0001). Common complaints were fever, headache, fatigue, and musculo-skeletal symptoms. All patients survived and severe clinical complications were rare. Hospitalization was provided for 60% and primaquine treatment administered to 83.8% of the patients, but frequencies varied strongly among reporting countries.

CONCLUSIONS

TropNetEurop data can contribute to the harmonization of European treatment policies.

Imported schistosomiasis in Europe: sentinel surveillance data from TropNetEurop

BACKGROUND

Schistosomiasis is a major parasitic disease, increasingly imported into temperate climates by immigrants from and travelers to endemic areas.

METHOD

To generate valid data on imported infectious diseases to Europe and to recognize trends over time, the European Network on Imported Infectious Diseases Surveillance (TropNetEurop) was founded in 1999. Three hundred and thirty-three reports of schistosomiasis were analyzed for epidemiologic and clinical features.

RESULTS

Male patients accounted for 64% of all cases. The average age of all patients was 29.5 years. The majority of patients were of European origin (53%). Europeans traveled predominantly for tourism (52%). Main reasons for travel for people from endemic areas were immigration and refuge (51%) and visits to relatives and friends (28%). The majority of infections were acquired in Africa; 92 infections were clearly attributable to Schistosoma haematobium, 130 to Schistosoma mansoni, and 4 to Schistosoma intercalatum. Praziquantel was the only treatment used. No deaths were recorded.

CONCLUSION

TropNetEurop sentinel provides valuable epidemiologic and clinical data on imported schistosomiasis to Europe.

Age as a risk factor for severe manifestations and fatal outcome of falciparum malaria in European patients: observations from TropNetEurop and SIMPID Surveillance Data

Previous studies have indicated that age is a risk factor for severe falciparum malaria in nonimmune patients. The objectives of this study were to reevaluate previous findings with a larger sample and to find out how strongly clinical outcomes for elderly patients differ from those for younger patients. Results of adjusted analyses indicated that the risks of death due to falciparum malaria, of experiencing cerebral or severe disease in general, and of hospitalization increased significantly with each decade of life. The case-fatality rate was almost 6 times greater among elderly patients than among younger patients, and cerebral complications occurred 3 times more often among elderly patients. Antimalarial chemoprophylaxis was significantly associated with a lower case-fatality rate and a lower frequency of cerebral complications. Women were more susceptible to cerebral complications than were men. Our study provides evidence that falciparum malaria is more serious in older patients and demonstrates that clinical surveillance networks are capable of providing quality data for investigation of rare events or diseases.

Epidemiology and clinical features of imported dengue fever in Europe: sentinel surveillance data from TropNetEurop

Travelers have the potential both to acquire and to spread dengue virus infection. The incidence of dengue fever (DF) among European travelers certainly is underestimated, because few centers use standardized diagnostic procedures for febrile patients. In addition, DF is currently not reported in most European public health systems. Surveillance has commenced within the framework of a European Network on Imported Infectious Disease Surveillance (TropNetEurop) to gain information on the quantity and severity of cases of dengue imported into Europe. Descriptions of 294 patients with DF were analyzed for epidemiological information and clinical features. By far the most infections were imported from Asia, which suggests a high risk of DF for travelers to that region. Dengue hemorrhagic fever occurred in 7 patients (2.4%) all of whom recovered. Data reported by member sites of the TropNetEurop can contribute to understanding the epidemiology and clinical characteristics of imported DF.

Two cases of imported gnathostomiasis in Spanish women

Reported here are two new cases of imported cutaneous gnathostomiasis that occurred in two Spanish women. The first patient acquired the helminth infection while travelling in Southeast Asia and the second in Mexico. Although the highest prevalence of gnathostomiasis infection is in Southeast Asia, the disease is now an emerging public health problem in some countries of Latin America. The cases reported here demonstrate the increasing frequency with which human gnathostomiasis is being diagnosed in nonendemic countries as a result of more extensive international travel and migration.

Imported Falciparum malaria in Europe: sentinel surveillance data from the European network on surveillance of imported infectious diseases

Malaria continues to have a high morbidity rate associated among European travelers. Thorough recording of epidemiological and clinical aspects of imported malaria has been helpful in the detection of new outbreaks and areas of developing drug resistance. Sentinel surveillance of data collected prospectively since 1999 has begun within TropNetEurop, a European network focusing on imported infectious diseases. TropNetEurop appears to cover approximately 10% of all patients with malaria seen in Europe. Reports of 1659 immigrants and European patients with Plasmodium falciparum malaria were analyzed for epidemiological information and data on clinical features. Regional data were quite diverse, reflecting local patterns of immigration and international travel. By far, the most infections were imported from West Africa. Europeans had more clinical complications; consequently, all deaths occurred in this group. Compared with European standards, the mortality rate was low (0.6% in Europeans). Data from TropNetEurop member sites can contribute to our understanding of the epidemiological and clinical findings regarding imported falciparum malaria.

Limited level of accuracy provided by available rapid diagnosis tests for malaria enhances the need for PCR-based reference laboratories

The rise of imported malaria cases and the high fatality rate in Europe make the search for new and easy diagnostic methods necessary. Rapid diagnosis tests (RDTs) are, in part, developed to cover the lack of diagnosis experience. Unfortunately, our data suggest that the accuracy of RDTs is insufficient and could increase the number of incorrect malaria diagnoses.

[Three cases of imported dermatomycosis by Scytalidium dimidiatum]

Scytalidium dimidiatum dermatomycosis are usually reported in tropical and subtropical countries. Some cases in Spain have been diagnosed due to the increasing number of immigrants from these areas. We herein describe three new cases of S. dimidiatum infections detected in Madrid. Two patients were from Guinea Ecuatorial and the third from Angola. We also report the first case of S. dimidiatum infection in a HIV patient in Spain. Clinical and epidemiological characteristics of S. dimidiatum infections reported in Spain are discussed.

The use of PCR in the diagnosis of hyper-reactive malarial splenomegaly (HMS)

Between August 1997 and September 1998, 14 cases of hyper-reactive malarial splenomegaly (HMS) were diagnosed in the Instituto de Salud Carlos III in Madrid, Spain. These cases, from Equatorial Guinea and Cameroon, were identified using the diagnostic criteria established by Y. M. Fakunle in 1981: gross splenomegaly; high levels of anti-malarial antibodies; IgM in serum at least two standard deviations above the local mean; and clinical and immunological response to antimalarial treatment. Although malarial parasites were only detected in the Giemsa-stained blood films of four of the cases, these four and four others were found to have the DNA of such parasites in their blood when tested using a method based on a semi-nested, multiplex PCR. These result indicate that malarial parasitaemias may be more prevalent in HMS than is usually recognized.

Usefulness of seminested multiplex PCR in surveillance of imported malaria in Spain

The use of a new PCR-based method for the diagnosis of malaria in the Spanish Malaria Reference Laboratory has promoted an increase in confirmed cases of malaria. From August 1997 to July 1998, a total of 192 whole-blood samples and 71 serum samples from 168 patients were received from the hospitals of the Spanish National Health System. Most of the patients came from west-central African countries (85%). This molecular method showed more sensitivity and specificity than microscopy, detecting 12.4% more positive samples than microscopy and 13% of mixed infections undetectable by Giemsa stain. Plasmodium falciparum was the main species detected, with 68% of the total positive malaria cases, followed by Plasmodium malariae (29%), Plasmodium vivax (14%), and Plasmodium ovale (7%), including mixed infections in all cases. This report consists of the first wide, centralized survey of malaria surveillance in Spain. The reference laboratory conducted the analysis of all imported cases in order to detect trends in acquisition. The use of a seminested multiplex PCR permitted confirmation of the origins of the infections and the Plasmodium species involved and confirmation of the effectiveness of drug treatments. This PCR also allowed the detection of the presence in Spain of primaquine-tolerant P. vivax strains from west-central Africa, as well as the detection of a P. falciparum infection induced by transfusion.

Induction of histamine release in parasitized individuals by somatic and cuticular antigens from Onchocerca volvulus

The host immune response in onchocerciasis is believed to contribute to the clinical manifestations of infection. Mazzotti and chronic inflammatory reactions might be mediated by mechanisms involving specific IgE and reactivity of mast cells and basophils to the parasite antigens. In this report, we show that Onchocerca volvulus antigens are capable of inducing histamine release. Three types of extracts were prepared from the parasite: soluble total, surface, and cuticular collagen. Soluble extracts released histamine in all individuals with onchocerciasis at significantly higher levels (P < 0.05) than those found in endemic controls, but similar levels to those found in patients with mansonellosis. However, cuticular collagen induced significantly (P < 0.01) higher histamine release in patients with onchocerciasis than in those with mansonellosis. No reactivity against human type IV collagen was observed. Implications derived from the presence of sensitized basophils in the pathogenesis of onchocerciasis are discussed.

HLA class I and class II allele distribution in the Bubi population from the island of Bioko (Equatorial Guinea)

We determined the HLA frequency distribution in a sample of 100 Bubi individuals born on the island of Bioko (Equatorial Guinea). HLA-A, -B and -C typing was performed by serology and PCR-SSP. DRB1/3/4/5, DQB1 and DQA1 alleles were determined by PCR-SSOP. The HLA allele distribution of this population group resembles those found in other Bantu-speaking groups; however, the higher frequency of A30, A32, B44, DRB1*1301 in the Bubi with respect to other Bantu groups and the absence of DR4 deserve special mention. The cloning and sequencing of class I and II genes in this population allowed the description of five new allelic variants: B*4407, Cw*0706, Cw*1801, Cw*1802 and DQB1*0612 and five confirmatory sequences: B*3910, B*5703, B*8101, Cw*1203 and Cw*1701. The following new HLA-C,B haplotypes have been found in Bubi: Cw*08-B*57, Cw*18-B*57, Cw*0302-B*53, Cw*07-B*53 and Cw*1601-B*63. The most frequent seven-locus haplotype is: A*30-Cw*17-B*42-DRB1*1102-DRB3*0202-DQA1*05-DQB1 *0301. In terms of genetic distance, the Bubi are closer to other Bantu groups than to West African populations.

The novel HLA-Cw*1802 allele is associated with B*5703 in the Bubi population from Equatorial Guinea

The HLA-Cw*1801 specificity, a Cw7/Cw4 hybrid allele, has recently been described in association with B*8101 (formerly B"DT"). In this study, the new Cw*1802 variant, differing from Cw*1801 at exon 5, is found associated with B*5703 in Bubi individuals from Equatorial Guinea. Confirmatory complete coding regions of B*5703 and B*3910 are also reported.

[Eosinophilic gastroenteritis caused by bee pollen sensitization]

A 34-year-old Spanish woman with a lifelong history of seasonal rhinoconjunctivitis and honey intolerance (pyrosis and abdominal pain) developed, 3 weeks after starting ingestion of bee pollen, astenia, anorexia, abdominal pain, diarrhoea, peripheral blood hypereosinophilia and elevated serum total IgE levels. A duodenal biopsy showed eosinophilic infiltration of the mucosal layer. Other causes of hypereosinophilia were not found. Repeated parasitological stool studies, as well as a duodenal aspirate showed negative results. Symptoms, hypereosinophilia and elevated IgE levels resolved after bee pollen ingestion was stopped. This is a typical case of eosinophilic gastroenteritis by ingestion of bee pollen in a woman with intolerance to honey bee, because the patient fulfilled the usual diagnostic criteria: gastrointestinal symptoms were present, eosinophilic infiltration of the digestive tract was demonstrated by biopsy, no eosinophilic infiltration of other organs was found and the presence of parasites was excluded. Honey intolerance and/or bee pollen administration should be considered as a cause of eosinophilic gastroenteritis.

The complete primary structure of Cw*1701 reveals a highly divergent HLA class I molecule

Genotyping of the HLA-C locus by PCR-SSP has previously shown 100% association of B41 and B42 with a new allelic variant. Partial sequencing studies (exons 2-4) demonstrated that this PCR-SSP variant corresponded to the new allele Cw*1701. In this study we have characterized the whole coding region of Cw*1701 from a Bubi individual of Equatorial Guinea. Our results partially confirm the previously reported sequence and reveal that Cw*1701 has many new polymorphisms at several exons, including a 18-bp insertion in exon 5. Cw*1701 is thus a most unusual HLA-C molecule defining a third allelic lineage of this locus.

Differences in intracellular CA2+ stores of submandibular cells of adult and newborn rats

The intracellular Ca2+ stores of submandibular acinar cells of adult and newborn rats were compared by measuring changes in cytosolic Ca2+ ([Ca2+]i) with the Ca2+-sensitive fluorescent probe, fura-2, in intact cells and 45Ca2+ release in permeabilized cells. In cells of adult rats, acetylcholine (ACh) and thapsigargin (TG) elicited, respectively, a 105% and 125% net increase in [Ca2+]i in Ca2+-free medium. In cells of newborn animals, the ACh-induced [Ca2+]i increase (218%) was larger; but the TG-induced increase was significantly smaller (77%), suggesting that the TG-sensitive Ca2+ pump of the store is less developed, abundant, or responsive in these cells. After ACh or TG, ionomycin elicited a further Ca2+ release. Ionomycin by itself completely discharged the ACh- and TG-sensitive store in cells of mature glands but not in cells of immature glands, suggesting a further difference in the distribution of the agonist and ionomycin sensitivities in the two types of cells. After exposure to ACh + ionomycin or TG + ionomycin, collapsing the intracellular pH gradient with monensin caused a third and large Ca2+ release (262% and 289%, respectively) in cells of adult rats, but a significantly smaller release (96%, P < 0.001, and 57%, P < 0.001, respectively) in cells of newborn rats, suggesting that a third, IP3-insensitive acidic store is significantly smaller in cells of immature glands. In permeabilized and 45Ca2+-loaded cells, inositol-1,4,5-trisphosphate (IP3, 5 microM) induced an identical 45Ca2+ release (34% and 33%, respectively) in both types of cells, but TG induced a significant smaller 45Ca2+ release in cells of immature glands (15%) than in cells of mature glands (33%). Monensin discharged <10% of loaded 45Ca2+ in both types of cells, indicating that the radiotracer was not loaded into the monensin-sensitive store. These results suggest that in cells of immature glands: (1) the TG-sensitive Ca2+ pump of the IP3-sensitive store is not well developed; (ii) the IP3-sensitive store is not completely discharged by ionomycin; and (iii) an acidic store likely to be associated with secretory granules is also underdeveloped and of a smaller size than in cells of mature glands.

Evidence for a Ca2+ pool associated with secretory granules in rat submandibular acinar cells

Intracellular Ca2+ stores in rat submandibular acinar cells were characterized using the Ca(2+)-sensitive fluorescent indicator fura 2 and the radiotracer 45Ca2+. Acetylcholine induced a rapid Ca2+ release from a store sensitive to inositol 1,4,5-trisphosphate (IP3) and to thapsigargin (TG). After this store was presumably depleted, ionomycin caused a further increase in cytosolic free Ca2+ concentration ([Ca2+]i), suggesting the presence of an IP3-insensitive Ca2+ release from a store that is more extensive and heterogeneous than the IP3-sensitive one and includes a small mitochondrial component. After both of these stores had been discharged, exposure to monensin caused an additional release of Ca2+ from a third store. This store appears to be associated with secretory granules, since Ca2+ release was significantly reduced when degranulation was induced by isoprenaline. This third store appears to be insensitive to IP3, discharges Ca2+ when the pH gradient across the limiting membrane is collapsed with monensin and only in the presence of both ionomycin and monensin. Ca2+ release from this store is not by Na+/Ca2+ exchange, since simply altering [Na+]i did not cause significant Ca2+ release. In permeabilized cells, IP3 and TG released approx. 35% of 45Ca2+, and ionomycin released an additional 57%, whereas monensin only caused a small additional release, suggesting that only IP3- and ionomycin-sensitive stores are loaded with 45Ca2+ under these conditions. The absence of significant isotope uptake into the ionomycin+monensin-sensitive store may result from a low rate of tracer accumulation or from the lack of Ca2+ pumps in the store. The pattern of response was similar in the presence and absence of mitochondrial inhibitors, indicating that the store is not located in mitochondria. In summary, these results suggest that a substantial IP3-insensitive Ca2+ store is present in secretory granules in rat submandibular acinar cells.

Molecular cloning of two new HLA-C alleles: Cw*1801 and Cw*0706

Nucleotide sequence analysis of the HLA-C alleles of the GB92 cell line, heterozygous for B*8101 and B*4407, revealed the existence of two new allelic variants: Cw*1801 and Cw*0706. The former allele, initially detected as a PCR-SSP variant, displays a hybrid aspect, sharing sequence motifs with Cw*07 at exons 1 and 2, and with Cw*04 at distal exons. In serological assays, Cw*1801 is only recognized by some cross-reactive sera. Cw*0706 shows a primary structure closely related to previously known Cw7 alleles, but carries new sequence motifs at its 3'-end. Preliminary data indicate that Cw*1801 is associated to B*8101 and that Cw*0706, B*4407 could account for a part of the Cw7, B44 haplotypes observed in African populations.

Complete coding region of the new HLA-DQB1*0612 allele, obtained by RT-PCR

A novel HLA-DQB1 allele was detected by oligotyping in the Bubi population of Equatorial Guinea. In order to characterize the new allelic variant, a RT-PCR method which permitted the cloning of its complete coding region was designed. With this method, we have determined the nucleotide sequence of the new DQB1*0612 allele, related to *0604 and *0609 but differing from them at polymorphic codon 70. A proposal for the improvement of the sequencing strategies of HLA class II alleles is made.

Visceral leishmaniasis in Angola due to Leishmania (Leishmania) infantum

A 26-year-old man from Angola with no history of travel outside the country presented with typical symptoms of visceral leishmaniasis. The parasite was isolated and biochemically characterized using both kinetoplast DNA and nuclear DNA probes and showed a strong homology with Leishmania (Leishmania) donovani sensu lato (s.l.). When the nuclear DNA of the isolate was hybridized with a specific Leishmania (L.) infantum probe, the pattern obtained showed a clear signal with this species. To establish its identity more specifically, this isolate was typed using a 15-system isoenzyme panel and thick-starch gel electrophoresis, and was identified as L. (L.) infantum zymodeme 1 (MAD-1), the most widespread zymodeme in Mediterranean countries. One case of visceral leishmaniasis has been reported in Angola, but this case is the first report of L. (L.) infantum in Africa south of the equator.

[Histamine liberation and specific IgE against Dermatophagoides pteronyssinus in parasitized patients]

We studied 98 patients with different parasitosis, without clinical symptoms of mite sensitization, most of them coming from Guinea. Histamine release to Dermatophagoides pteronyssinus was performed using whole blood. Specific IgE to the same antigen was measured by EAST, as well as by an immunodot with the same antigen extract employed for the histamine release test. Finally, the EAST positive sera were studied by immunoblotting. The presence of specific IgE by EAST could be proved in 31 patients, but these antibodies were nor detected by dot, blot and histamine release. On the other hand, only two patients showed a positive histamine release test to D. pteronyssinus and in these two cases the EAST to mites was negative. There was no relation between total IgE levels and specific IgE to mites. The presence of mite-specific IgE showed a significative association to the parasite Trichuris trichiura (odds ratio 3.09). This fact suggest that the specific IgE values found in this population can reflect some cross-reaction between parasites and allergens. It is the author's opinion that the same study should be performed in european patients in order to test the relationship between mite-specific antibodies and the presence of parasites, specially of Trichuris trichiura.