[Contrast Media Toxicity and Its Prevention]

Intravenous iodinated contrast media are commonly used in clinical practice, ranging from medical imaging to interventional radiology (IR) procedures and endovascular interventions. Compared with patients with normal renal function, nephropathic patients have an increased risk of acute kidney injury (AKI). Nevertheless, this condition cannot represent a limit to diagnostics or endovascular interventions. Despite the literature of the last five years, conflicting management and approaches for nephropathic patients persist, including the use of contrast agents and treatments replacing renal functions, which are often mistakenly considered as part of preventive strategies. Though the issue has been widely discussed, specialists often cope with uncertainty in handling properly the administration of contrast media and renal counselling requests. Furthermore, there is a general difficulty in distinguishing the Post-Contrast Acute Kidney Injury (PC-AKI) from the Contrast-Associated Acute Kidney Injury (CI-AKI). The present review aims to provide an update on the issue and examine strategies to reduce the acute kidney injury risk after the administration of contrast media. These strategies include the early identification of high-risk individuals, the choice of the contrast media and the proper dosage, the suspension of nephrotoxic drugs, the follow-up of the high-risk individuals, and the early identification of AKI.

[The management of nephropathic patients during the Covid-19 pandemic: the experience of Ragusa]

The public emergency caused by Covid-19 has forced health services to reorganize in order to separate positive patients from negative ones. In nephrology, this reorganization involves several levels of assistance concerning hospitalizations, ambulatory care and haemodialysis. Within the Complex Unit of Nephrology in Ragusa, the distribution of nephro-dialytic resources has involved four different hospitals, hence ensuring haemodialysis services for asymptomatic and pauci-symptomatic Covid-19 patients as well as for patients in Covid-Unit, Sub-Intensive Therapy and Intensive Care Unit. In this complex context, we had to create a common protocol involving all the professionals who provide assistance in our Unit, across the different structures. We also report some encouraging data that seem to indicate the effectiveness of the protocols put in place.

[Osteoporosis and chronic kidney disease: review and new therapeutic strategies]

Osteoporosis affects a segment of the population in which Chronic Kidney Disease is also greatly represented. Nephropathic patients may present peculiar biochemical abnormalities related to Chronic Kidney Disease, defining the Mineral and Bone Disorder. This kind of anomalies, in the worst scenarios, configure the typical histomorphology patterns of Renal Osteodystrophy. Scientific Societies of Endocrinology have established therapy guidelines for patients with osteoporosis only based on the glomerular filtration rate and recommend avoiding the use of some drugs for the more advanced classes of nephropathy. However, there is no clear therapeutic approach for patients with advanced nephropathy and bone abnormalities. In this paper we propose a systematic review of the literature and present our proposal for managing patients with advanced nephropathy, based on eGFR and on presence of Mineral and Bone Disorder.

SERUM AND BAL YKL-40 LEVELS IN DIFFERENT INFLAMMATORY LUNG DISEASES: AN UPDATE

YKL-40 (also called chitinase 3-like-1 or human cartilage glycoprotein 39) is a chitinase-like protein belonging to the family 18 of glycosyl hydrolase (GH18). This protein is involved in the inflammatory process acting as pro-inflammatory cytokine secreted by neutrophils, activated human macrophages, vascular smooth muscle cells and cancer cells. It has been shown that YKL-40 has a role in pathological tissue remodeling and development of fibrosis of several diseases. To date, the biological and pathophysiological function of YKL-40 protein in pulmonary diseases is still unclear. This review focuses on the role of YKL-40 in diagnosis and monitoring of different lung diseases in order to assess whether this protein could be used as biomarker of specific conditions featured by inflammation and fibrosis. A comprehensive review of the literature using PubMed database, with appropriate terms, was undertaken for articles in English published since 1997. The literature search was undertaken in October 2014.

SERUM YKL-40 IN CHILDREN WITH ASTHMA

Asthma is one of the most common chronic diseases in children. To date the diagnosis of asthma is mainly clinical, based on the clinical history, a careful physical examination and lung function tests. However, symptoms are often not specific and lung function tests are not very sensitive. In order to find a solution to this problem new biomarkers of airway inflammation are being developed. YKL-40 is a chitinase-like protein that has a role in the inflammation and tissue remodeling in several human diseases. The aim of this study is to evaluate serum levels of YKL40 in children with intermittent or persistent asthma. We performed a cross-sectional analysis of serum samples from a cohort of patients with asthma and healthy controls. Patients with asthma were stratified according to four levels of asthma severity (mild intermittent, mild persistent, moderate persistent, and severe persistent). The analysis of serum samples was performed with the use of a commercially available enzyme-linked immune-adsorbent assay (ELISA) kit (Quidel). The minimum detection limit of the assay for YKL-40 is 15.6 ng per milliliter (ng/ml). Our data showed that circulating YKL-40 levels are significantly higher in patients with asthma than healthy subjects (36±18.6 vs 14:41±2.88, p= 0.001). Furthermore, we found significantly higher values of YKL-40 in both groups of children with intermittent asthma (p less than 0.001) and persistent asthma (p less than 0.001) than healthy controls. However, no correlation was found with duration and severity of asthmatic disease (r = 0:18, p= 0:33, r = 0.28 P = 0:13, respectively). Our data allow us to suggest that YKL-40 represents a useful biomarker of asthma in children with intermittent or persistent asthma.

Comparison between two different modes of non-invasive ventilatory support in preterm newborn infants with respiratory distress syndrome mild to moderate: preliminary data

Despite of improved survival of premature infants, the incidence of long term pulmonary complications, mostly associated with ventilation-induced lung injury, remains high. Non invasive ventilation (NIV) is able to reduce the adverse effects of mechanical ventilation. Although nasal continuous positive airway pressure (NCPAP) is an effective mode of NIV, traumatic nasal complications and intolerance of the nasal interface are common. Recently high flow nasal cannula (HFNC) is emerging as a better tolerated form of NIV, allowing better access to the baby's face, which may improve nursing, feeding and bonding. HFNC may be effective in the treatment of some neonatal respiratory conditions while being more user-friendly for care-givers than conventional NCPAP. Limited evidence is available to support the specific role, efficacy and safety of HFNC in newborns and to demonstrate efficacy compared with NCPAP; some studies suggest a potential role for HFNC in respiratory care of the neonate as a distinct non invasive ventilatory support. We present the preliminary data of a randomized clinical trial; the aim of this study was to assess efficacy and safety of HFNC compared to NCPAP in preterm newborns with mild to moderate respiratory distress syndrome (RDS).

High prevalence of chitotriosidase deficiency in Peruvian Amerindians exposed to chitin-bearing food and enteroparasites

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Catalytic deficiency of chitotriosidase has a very high frequency in Amerindians highly exposed to chitin from enteroparasites and diet.

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Mutation frequencies are similar to those found in East Asian populations, and is probably conserved for a founder effect.

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Such condition precludes the use of CHIT1 as a disease biomarker in South American populations with strong ethnic ancestry.

The human genome encodes a gene for an enzymatically active chitinase (CHIT1) located in a single copy on Chromosome 1, which is highly expressed by activated macrophages and in other cells of the innate immune response. Several dysfunctional mutations are known in CHIT1, including a 24-bp duplication in Exon 10 causing catalytic deficiency. This duplication is a common variant conserved in many human populations, except in West and South Africans. Thus it has been proposed that human migration out of Africa and the consequent reduction of exposure to chitin from environmental factors may have enabled the conservation of dysfunctional mutations in human chitinases. Our data obtained from 85 indigenous Amerindians from Peru, representative of populations characterized by high prevalence of chitin-bearing enteroparasites and intense entomophagy, reveal a very high frequency of the 24-bp duplication (47.06%), and of other single nucleotide polymorphisms which are known to partially affect enzymatic activity (G102S: 42.7% and A442G/V: 25.5%). Our finding is in line with a founder effect, but appears to confute our previous hypothesis of a protective role against parasite infection and sustains the discussion on the redundancy of chitinolytic function.

[Therapy with high-flow nasal prongs in preterm infants]

Despite of improved survival of premature infants, the incidence of long-term pulmonary complications, mostly associated with ventilation-induced lung injury, remains high. Non invasive ventilation (NIV) is able to reduce the adverse effects of mechanical ventilation. Although nasal continuous positive airway pressure (NCPAP) is an effective mode of NIV, traumatic nasal complications and intolerance of the nasal interface are common. Recently high flow nasal cannula (HFNC) is emerging as an efficient, better tolerated form of NIV, allowing better access to the baby's face, which may improve nursing, feeding and bonding. The aim of this review is to discuss the available evidence of effectiveness and safety of HFNC in preterm newborns with respiratory distress syndrome (RDS). It is known that distending pressure generated by HFNC increases with increasing flow rate and decreasing infant size and varies according to the amount of leaks by nose and mouth. The effects of HFNC on lung mechanics, its clinical efficacy and safety are still insufficiently investigated. In conclusion, there is a growing evidence of the feasibility of HFNC as an alternative mode of NIV. However, further larger randomized trials are required, before being able to recommend HFNC in the treatment of moderate respiratory distress of preterm infants.

Efficacy of interferon-based therapy in the treatment of thalassaemic patients with chronic hepatitis C: a meta-analysis

OBJECTIVE

To identify the interferon-alpha (IFNalpha) treatment protocol most suitable for patients with thalassaemia major who have chronic hepatitis C.

DESIGN AND SETTING

This was a meta-analysis of studies in the international literature between 1990 and 1999.

METHODS

Studies were identified from a search of Medline and Embase, and analysed by the Mantel-Haenszel-Peto statistical method.

RESULTS

We identified 6 nonrandomised trials, 2 of which were controlled, that treated a total of 201 patients. Most studies used the lowest dose level (3 MIU/m(2)), all used a thrice-weekly regimen, and most used IFNalpha-2b, although the use of natural IFNalpha did not induce production of anti-interferon antibodies. The best sustained response and remission rates tended to be achieved with higher doses and longer cycles of IFNalpha.

CONCLUSIONS

The best interferon-based therapy to treat polytransfused thalassaemic patients with chronic hepatitis C is represented by the use of natural IFNalpha or IFNalpha-2b, initially at high dosages (5 to 10 MIU/m(2) 3 times weekly) for 6 months, followed by lower dosages (3 MIU/m(2) 3 times weekly) for a further 6 to 9 months.

Effective program against mother-to-child transmission of HIV at Saint Camille Medical Centre in Burkina Faso

The present research was aimed to prevent mother-to-child transmission of HIV; to use RT-PCR in order to detect, 6 months after birth, infected children; and to test the antiretroviral resistance of both children and mothers in order to offer them a suitable therapy. At the Saint Camille Medical Centre, 3,127 pregnant women (aged 15-44 years) accepted to be enrolled in the mother-to-child transmission prevention protocol that envisages: (i) Voluntary Counselling and Testing for all the pregnant women; (ii) Antiretroviral therapy for HIV positive pregnant women and for their newborns; (iii) either powdered milk feeding or short breast-feeding and RT-PCR test for their children; (iv) finally, pol gene sequencing and antiretroviral resistance identifications among HIV positive mothers and children. Among the patients, 227/3,127 HIV seropositive women were found: 221/227 HIV-1, 4/227 HIV-2, and 2/227 mixed HIV infections. The RT-PCR test allowed the detection of 3/213 (1.4%) HIV infected children: 0/109 (0%) from mothers under ARV therapy and 3/104 (2.8%) from mothers treated with Nevirapine. All children had recombinant HIV-1 strain (CRF06_CPX) with: minor PR mutations (M36I, K20I) and RT mutations (R211K). Among them, two twins had Non-Nucleoside Reverse Transcriptase Inhibitor mutation (Y18CY). Both mothers acquired a major PR mutation (V8IV), investigated 6 months after a single-dose of Nevirapine. Prevention by single-dose of Nevirapine reduced significantly mother-to-child transmission of HIV, but caused many mutations and resistance to antiretroviral drugs. Based on present study the antiretroviral therapy protocol, together with the artificial-feeding, might represent the ideal strategy to avoid transmission of HIV from mother-to-child.

A fine functional homology between chitinases from host and parasite is relevant for malaria transmissibility

High levels of plasma chitotriosidase are a marker of macrophage activation in several pathologies and, in particular, in human malaria. Plasmodium falciparum, during its maturative cycle in the midgut of the Anopheles mosquito, secretes a chitinase to disrupt the peritrophic membrane, a necessary step in the migration of the parasite from the midgut to the salivary glands of malaria's vector. The cooperation between human chitotriosidase (Chit) and the chitinase from P. falciparum in attacking the peritrophic membranes in the Anopheles midgut has been recently demonstrated by in vivo experiments. The present study confirms, by computational methods, this functional homology. A simple sequence analysis method, potentially useful to assess fine textual closeness in families of homologous proteins, is reported here and applied to a set of chitinases from mammals and plasmodia. This analysis confirms the clustering and the phylogenetic relationships obtained with well-known alignment methods, but also shows that the sequences of chitinases from malaria hosts and malaria parasites are correlated. This correlation, a sign of functional homology, is discussed as a condition for the spreading of different forms of malaria. From this perspective, one can get insight into the origins of malaria and its genetic or pharmacological control.

Intrathecal chitotriosidase and the outcome of multiple sclerosis

Activated macrophages are major effectors at all stages of lesion formation in multiple sclerosis (MS) brain. Here, we report that the macrophage enzyme chitotriosidase (Chit) is significantly elevated both in plasma and cerebrospinal fluid (CSF) of patients with MS as compared to healthy controls and other neurological patients (P<0.001). Furthermore, the Chit activity in blood significantly associates with the MS clinical course (higher in secondary progressive relative to relapsing-remitting, P=0.01) and the clinical severity as measured by Kurtkze's Expanded Disability Status Scale (P<0.001). Also, we found that Chit activity is compartmentalized in the central nervous system of early MS patients and that its CSF/plasma quotient, in the presence of a preserved albumin quotient, correlates with the extent of future clinical deterioration (r=0.91; P<0.001). These findings confirm that innate immunity, here represented by Chit, is clinically relevant in MS and allows, if confirmed, reconsidering novel MS therapeutic strategies specifically aimed at this branch of the immune response.

High levels of human chitotriosidase hinder the formation of peritrophic membrane in anopheline vectors

In the Anopheles midgut, Plasmodium falciparum produces a specific chitinase able to penetrate the blood meal surrounding the chitin-containing peritrophic membrane (PM). High levels of an analogous chitinase, chitotriosidase (CHIT), may be found in human blood, being the markers of macrophage activation. To verify the hypothesis that CHIT present in malaria patient blood could help parasite to overcome PM, we carried out a bioassay by feeding Anopheles stephensi females on an artificial apparatus that contained human blood from four different sources and with different chitinase concentrations: (1) healthy donors, as negative controls; (2) patients with malaria; (3) patients with Gaucher disease; and (4) whole blood enriched with commercial P. falciparum chitinase, as positive controls. After 16, 20 and 24 h of bloodfeeding, mosquitoes were dissected to extract the midgut and assess the effect of the different chitinases on membrane structure. Optical microscopy showed that formation of PM was clearly complete after 16 h in the posterior midgut from Anopheles already fed with healthy donor bloods. By contrast, PM formation was visible after 16 h in the posterior midgut of mosquitoes fed with malaria and Gaucher patient bloods but appeared clearly damaged at 20 and 24 h. At the same time, the PM formation was almost completely inhibited in the midgut of Anopheles fed with P. falciparum chitinase-enriched bloods. These alterations were clearly confirmed by transmission electronic microscopy. In the present paper, we demonstrate that human CHIT from different sources is active on anophelines' PM.

Immunomodulation of fucosyl-lactose and lacto-N-fucopentaose on mononuclear cells from multiple sclerosis and healthy subjects

The 1,2-fucosyl-oligosaccharides, and among these the 2'-fucosyl-lactose (2'-FL) and lacto-N-fucopentaose (LNFP)-I, are quantitatively the most represented oligosaccharides of human milk. They are also seen to represent an important immune device to prevent nursing infants from severe infectious diarrhoea. Recent evidences show that the appearance of 2'-FL and LNFP-I in human colostrums is synchronised with the macrophage inhibition and that LNFP-III induces a Th2 response from the mouse peripheral immune system. Since mannosyl-fucosyl receptors are described on the macrophage surface, all these evidences allow us to investigate on the possible immune function of human 2'-FL and LNFP-I in vitro on LPS-activated mononuclear cells (MNC) from 12 patients with multiple sclerosis (MS) and 20 matched health controls (HC). We found that 2'-FL and LNFP-I significantly decrease, to a different extent, the MNC proliferation from both HC and MS patients, in a linear and dose-dependent manner. 2'-FL and LNFP-I also reduce the production of IL-12 and IFN-γ, particularly in MS patients as compared to HC (p=0.01 and p<0.001, respectively), while increasing that of IL-10. The overall immunomodulatory effect of 2'-FL and LNFP I here presented may represent a future therapeutic option for the abnormal immune response found in some monocyte-mediated diseases.

Characterization of drug-resistance mutations in HIV-1 isolates from non-HAART and HAART treated patients in Burkina Faso

Non-B HIV subtypes have been estimated to account for 88% of HIV infections in the world. These subtypes are particularly relevant in view of the availability of antiretroviral (ARV) drugs, since subtype-specific mutations are associated with drug-resistance in developing countries. Therefore, the pol gene sequences in HIV-1 isolates were examined from the three distinct groups of 39 infected patients from Ouagadougou in Burkina Faso: 17 patients who had not received any antiretroviral therapy (ART); 16 patients received ART, and 6 HIV-infected children, from infected mothers, received a single Nevirapine dose prophylaxis during birth. HIV-1 pol sequencing was successful for 29 samples. As expected, all patients presented the common (non-B subtype) M36I polymorphism and 26/29 (90%) the K20I mutation. Phylogenetic studies showed high predominance of recombinant HIV-1 strains: CRF06_cpx 16/29 (55.17%), CRF02_AG 9/29 (31.03%), A1 2/29 (6.89%), G 1/29 (3.44%), and CRF09_cpx 1/29 (3.44%). Two twins showed, 6 months after birth, a NNRTI-mutation (Y181C/Y). During the same period, the twin mother presented a different NNRTI-mutation (V106I), thus suggesting that the different blood drug concentration may determine a different drug-resistance pathway. Among 17 non-highly active antiretroviral therapy (HAART) patients, 3/17 (17.64%) presented virus with reverse transcriptase (RT) mutations [V118I: 1/17 patients (5.88%), V179E: 2/17 patients (11.76%)]. 10/17 (58.82%) presented virus with minor protease (PR) mutations [L63P: 5/17 patients (29.41%), V77I: 3/17 patients (17.64%), L10I: 2/17 patients (11.76%)]. 4/17 patients did not show any PR and RT mutations (23.52%). Among six HAART-treated patients, 6/6 and 3/6 had M36I and L63LP protease minor subtypes, respectively; and only two (33.33%) presented virus with K103N mutation. The low prevalence of drug-resistant associated mutations in Burkina Faso is encouraging. However, further studies with a larger cohort with a high non-B subtype prevalence are necessary to optimize ART in developing countries.

Interferon-gamma, tumor necrosis factor-alpha, and lipopolysaccharide promote chitotriosidase gene expression in human macrophages

Human chitotriosidase (Chit), a chitinolytic enzyme, is a member of the chitinase family. In human plasma, Chit activity has been proposed as a biochemical marker of macrophage activation in several lysosomal diseases. Recently we found that Chit activity is higher in patients affected by Plasmodium falciparum malaria infection, suggesting that Chit may reflect induction of an immunological response. To assess this hypothesis, we evaluated the CHIT1 mRNA levels in human monocytes/macrophages (HMMs) following treatment with interferon-gamma (IFNgamma), tumor necrosis factor-alpha (TNFalpha), and lipopolysaccharide (LPS). Stimulation of macrophages with INF-gamma, TNF-alpha, and LPS resulted in an increase in Chit activity as well as the levels of CHIT1 mRNA as measured by quantitative real-time PCR. The data presented in this article show that Chit plays a role in the response to the activation of INF-gamma-, TNF-alpha-, and LPS-driven macrophages, suggesting that the production of Chit by macrophages could have biological relevance in the immune-response.

Hyperhomocysteinemia in acute Plasmodium falciparum malaria: an effect of host-parasite interaction

BACKGROUND

Plasmodium falciparum utilises the polyamine pathway, essential in proliferation and differentiation, and imposes an oxidative stress on host cell, enhancing the loss of glutathione.

METHODS

Standard hematological parameters were determined in 40 black African subjects with acute P. falciparum malaria, 30 aged 5-24 months, 5 aged 4-10 years and 5 aged 19-35 years. Plasma homocysteine, cysteine, glutathione and cysteinylglycine levels were measured by HPLC method. Twenty-eight healthy black children (15 aged 6-24 months and 13 aged 3-10 years) and 20 healthy black adults (aged 20-40 years) were also included as controls.

RESULTS

Plasma homocysteine levels were higher in all subjects with P. falciparum malaria and correlated positively with the disease severity and number of parasites, but negatively with Hb levels and patient ages. Cysteine level was found higher in all patients and markedly higher in 4-10 year old patients. Cysteinylglycine level was found lower particularly in 19-35 year old patients. Glutathione level was significantly lower in all patients.

CONCLUSIONS

The elevated level of homocysteine during acute P. falciparum infection suggests an imbalance in the folate cycle, which could be a consequence of the reduced availability of NADPH and Vit B12, caused by increased oxidative stress. This may suggest a selection for the C677T MTHFR allele, driven by P. falciparum in sub-Saharan regions. Hence Hcy level could be useful as a predictive parameter of severity, as well as of treatment efficacy.

Prolactin induces chitotriosidase gene expression in human monocyte-derived macrophages

Human chitotriosidase (Chit), a chitinolytic enzyme, is a member of the chitinase family. In human's plasma Chit activity have been proposed as a biochemical marker of macrophage activation in several lysosomal diseases. Recently we found that Chit activity is higher in patients affected by Plasmodium falciparum malaria infection suggesting that chitotriosidase may induce an immunological response. The pituitary hormone prolactin (PRL) is a multifunctional polypeptide also produced by immune cells and represents a key component of the neuroendocrine-immune loop. The presence of PRL receptors in macrophage suggests that PRL is involved in regulating functions in these cells. Our objective in this study was to investigate the effect of PRL in human monocyte-derived macrophages (HMMs) on Chit production. Administration of PRL in HMMs was found to increase both expression and activity of Chit in a time and dose dependent manner as quantified, respectively, by real time PCR and Chit activity assay. PRL-treated monocyte-derived macrophages showed also an enhanced release of superoxide anion (O2-) release. Our observations confirm that PRL regulates HMMs activation and suggest, for the first time, that it influences immune function also through the induction of Chit activity.

Reduction of mother-to-child transmission of HIV at Saint Camille Medical Centre in Burkina Faso

One thousand three hundred and twenty-eight pregnant women with less than 32 weeks of amenorrhea received voluntary counseling and testing at Saint Camille Medical Center from May 1, 2002 to December 30, 2004. Following informed consent and pre-test counseling, HIV screening was performed in 1,202 women. According to the prevention protocol, HIV-positive women received a single dose of Nevirapine (200 mg) during their labor, while their newborn received a single dose of Nevirapine (2 mg/kg) within 72 hr from birth. HIV seroprevalence (11.2%) was higher than in the overall population. One hundred and ninety-three children were born at the end of December 2004; 53 children (27.5%) followed a short breastfeeding protocol for 4 months, while 140 (72.5%) were fed artificially. All the children underwent RT-PCR test for HIV 5-6 months after their birth: 173 (89.6%) were HIV negative whilst 20 children (10.4%) were HIV positive. Out of the 20 positive children 5/53 (9.4%) had received breast milk for 4 months, while the remaining 15/140 (10.7%) had been fed artificially (P = 0.814). Artificially fed babies (3/140 (2.1%)) and 1/53 (1.9%) of those breast fed for 4 months deceased according to mortality rate of HIV-positive children. This shows that there is no statistically significant difference (P = 0.648) between the mortality of artificially fed (3/140 or 2.1%) and breast-fed (1/53 or 1.9%) children. Artificially fed children (20/140 (14.3%)) and 5/53 (9.4%) of breast-fed children died within 6-10 months. This figure indicates that there is no significant difference between the mortality rate of artificially and that of breast-fed children (P = 0.427). Although the HIV prevention program reduced significantly the vertical transmission of HIV at Saint Camille Medical Center, the mortality of artificially fed children was still high due to gastrointestinal diseases. The HIV diagnosis by RT-PCR technique was of great help in the early identification of HIV-infected children.

The evolutionary conservation of the human chitotriosidase gene in rodents and primates

Chitinases have been identified in a variety of organisms ranging from prokaryotes to eukaryotes, known to specifically degrade chitin, an abundant polymer of N-acetylglucosamine. Recently a human chitinolytic enzyme called CHIT1 was discovered. CHIT1 is expressed by activated macrophages and hydrolyzes artificial chitotrioside substrates, but its specific function in humans is unknown, since it is generally believed that man completely lacks endogenous chitin and endogenous substrates for chitinases. An intriguing question is whether the chitotriosidase activity is just an evolutionary remnant or it has a physiological function in man. To test these hypotheses we utilized a "phylogenomic" approach performing accurate sequence analyses of this gene, coding for CHIT1, in rodents and primates. Inspecting the sequences available in public databases, we determined that this gene is conserved in rodents (mouse and rat) and primates (chimpanzee, gorilla, orangutan, gibbon, baboon, a common marmoset and black macaque). Moreover we found that a 24-base pair duplication that determines an enzymatically inactive human protein is not present in primates, suggesting that this polymorphism was created during human evolution. These results indicate that chitotriosidase is conserved across the evolutionary scale. Such conservation of the CHIT1 gene argues in favour of an important biological role.

Helicobacter pylori infection in Burkina Faso: an enigma within an enigma

BACKGROUND

In Burkina Faso, in contrast with high rates of Helicobacter pylori infection from an early age, the prevalence of H. pylori-associated diseases (ulcer and gastric cancer) is low.

AIMS

To look for the prevalence of H. pylori in healthy natives of Burkina Faso, both children and adults.

METHODS

We studied the prevalence of H. pylori infection in 258 healthy natives of Burkina Faso (70 children aged 6 months-15 years and 188 adults aged 16-65 years), using a serological screening (IgA and IgG H. pylori antibodies). All the studied subjects underwent a questionnaire regarding their life-style, socio-economic status, dietary habits and hygienic sanitary conditions. Data concerning the questionnaire were compared between H. pylori positive and negative subjects.

RESULTS

The rates of H. pylori positivity in children were significantly higher than in adults, and in adults the positivity for H. pylori infection decreased with increasing age. The comparison of the questionnaire's data between H. pylori seropositive and seronegative subjects showed that poor socio-economic status and hygienic sanitary conditions were similar in the two groups. Instead, a higher prevalence of H. pylori positivity was observed in subjects belonging to families living in close contact with sheep, because of their labour and agro-pastoral tradition (shepherds and sedentary farmers).

CONCLUSION

H. pylori infection in Burkina Faso is acquired early in life and is related not only to some yet well-known risk factors (poor socio-economic and hygienic status), but also to a close contact with sheep. The gradually decreasing H. pylori seropositivity in adult population of Burkina Faso represents an unexplained enigma, which needs further studies.

A 24-bp duplication in exon 10 of human chitotriosidase gene from the sub-Saharan to the Mediterranean area: role of parasitic diseases and environmental conditions

Human chitotriosidase (Chit) is a member of the chitinase family and it is synthesized by activated macrophages. Recently, a genetic polymorphism was found to be responsible for the common deficiency in Chit activity, frequently encountered in different populations. We analyzed the Chit gene in some ethnic groups from the Mediterranean and African areas, to evaluate whether the Chit gene polymorphism correlates with the changes in environmental features and the disappearance of parasitic diseases. We found a heterozygote frequency for the duplication of 24 bp in exon 10 of 44% in Sicily and 32.71% in Sardinia, whereas those homozygous Chit deficient were 5.45 and 3.73%, respectively. In contrast, in Benin and Burkina Faso, both mesoendemic regions for Plasmodium falciparum malaria and other infections due to intestinal parasites, a low incidence of Chit mutation was found (heterozygous 0 and 2%, respectively) and no subject was homozygous for Chit deficiency. Our results provide evidence of the fact that the low frequency or the absence of mutant Chit gene may represent a protective factor in the population still living in disadvantaged environmental conditions. The present study suggests that the disappearance of parasitic diseases and the improved environmental conditions may have ensued the occurrence of a high percentage of 24-bp mutation in Sicily, in Sardinia and in other Mediterranean countries, whereas in the sub-Saharan regions (Benin and Burkina Faso), the widespread parasitic diseases and the poor social status have contributed to maintenance of the wild-type Chit gene.

Antibiotic resistance in Burkina Faso

Burkina Faso is one of the Subsaharan African nations. No national services for monitoring of antibiotic resistance are available, so the number of reports of resistance patterns among hospital pathogens are inconsistent. In order to evaluate antibiotic resistance, a total of 1998 valuable microrganisms were analysed during 2000 at the Medical Centre St. Camille of Ouagadougou, Burkina Faso's capital. They were isolated as follows: 1012 from urine-culture, 503 from tonsil swabs, 398 from pus, 53 from sputum and 32 from blood-cultures. Escherichia coli was the most isolated microrganism from urine (44%); Enterococcus faecalis from tonsil swabs (96.4%), Staphylococcus aureus from pus (17%) and K. pneumoniae (70%) from sputum. In general, resistance to the old antibiotics, such as aminopenicillins and cotrimoxazole was shown. The most active antibiotic was norfloxacin, a rarely used antibiotic in this country. In conclusion, our study shows that it is necessary to create antibiotic-resistance surveillance centers in the developing countries to adopt an accurate therapy to avoid exporting of antibiotic resistance to the developed countries linked to increased emigration.

Modulation of immune response in Plasmodium falciparum malaria: role of IL-12, IL-18 and TGF-beta

The interaction between pro- and anti-inflammatory cytokines such as interleukin 12 (IL-12), interleukin 18 (IL-18) and transforming growth factor beta (TGF-beta) plays an important role in malaria pathogenesis and outcome, modulating the immunoresponse in Plasmodium falciparum malaria. In our previous studies, we analyzed the plasmatic levels of IL-12, IL-18 and TGF-beta in 105 African children with different degrees of malaria and we correlated the production of these cytokines with the severity of the disease. The aim of the present study was to analyze with a mathematical model, taking into account all the relationships between these cytokines and the parameter variations involved in malaria pathogenesis that influence the results of each type of treatment or therapeutic protocol on patients at different stages of the disease. A mathematical correlation was demonstrated between the levels of pro-inflammatory and anti-inflammatory cytokines, and from this it was possible to build curves of reference in which each patient was positioned based on IL-12 level. Our data, obtained in patients with mild and severe diseases, demonstrate that the levels of IL-12 represent a reliable parameter to predict the progression of the disease, which may be complemented or modulated by administration of IL-18 and TGF-beta. Our findings provide future implications for an immune therapy against the P. falciparum malaria infection, especially in the early phase of the disease showing that a more aggressive outcome may be due to the lack of a balanced immune response.

Incremental prognostic value of technetium-99m-tetrofosmin exercise myocardial perfusion imaging for predicting outcomes in patients with suspected or known coronary artery disease

Technetium-99m (Tc-99m)-tetrofosmin is a radio isotope that has been shown to be an accurate alternative to thallium-201 for detecting coronary artery disease. However, its prognostic value is less well determined. To this end, 459 consecutive patients (mean age 58 +/- 10 years) with suspected or known coronary artery disease underwent exercise single-photon emission tomography Tc-99m-tetrofosmin scintigraphy. Follow-up, defined as the time from scanning until a soft event (revascularization procedures), a hard event (myocardial infarction and cardiac death), or patient response, lasted up to 78 months (median 38). An ischemic scintigraphic perfusion score, which takes into account both the extent and severity of reversible perfusion defects, was calculated to estimate the severity of perfusion abnormalities. Patients with normal scans were at low risk of events (yearly hard event rate 0.5% and soft event rate 0.9%). The rate of outcomes increased significantly with abnormal scans (yearly hard event rate 4.9% and soft event rate 10.3%). Statistical analysis using the Kaplan-Meyer survival curves showed a significant difference in event-free survival between patients with normal and abnormal scans. With use of Cox proportional-hazards analysis, after adjusting for prescan information, nuclear data provided incremental prognostic value for hard events (clinical and exercise data vs nuclear data; chi-square = 15.5 vs 33.4, p <0.001). Exercise single-photon emission tomographic scintigraphy using Tc-99m-tetrofosmin provides significant independent information on the subsequent risk of hard and soft events. The annual event rate for hard and soft events is <1% for patients with a normal scan. Furthermore, this tracer yields incremental prognostic information in addition to that provided by clinical and exercise data for hard events.

Plasma chitotriosidase activity in beta-thalassemia major: a comparative study between Sicilian and Sardinian patients

BACKGROUND

Chitotriosidase is a functional chitinase secreted by activated macrophages, which is extremely increased in plasma of patients with Gaucher disease (beta-glucocerebrosidase deficiency). Recently, we found that chitotriosidase plasma levels were increased to a variable extent in Sicilian patients with beta-thalassemia major. The aim of this study is to elucidate the possible mechanisms underlying chitotriosidase overproduction in beta-thalassemia major.

METHODS

Plasma chitotriosidase was measured in 134 patients with beta-thalassemia major (64 from Sardinia and 70 from Sicily), which are treated chronically by blood transfusions leading to systemic iron overload. They all have peripheral anemia and enormous enlargement of the reticulo-endothelial system.

RESULTS

Plasma chitotriosidase activity was found most frequently elevated among Sardinian (48.4%) than Sicilian (17.1%) patients. In either group, the highest levels of plasma chitotriosidase were observed in patients with the highest degree of iron overload, suggesting that this factor could trigger chitotriosidase overproduction.

CONCLUSIONS

The higher rate of subjects with increased plasma chitotriosidase values among Sardinian than Sicilian could be related to distinct molecular basis of beta-thalassemia and environmental features.

Accuracy of exercise testing in the assessment of the severity of myocardial ischemia as determined by means of technetium-99m tetrofosmin SPECT scintigraphy

BACKGROUND

The separation of patients with suspected or known coronary artery disease into low- and high-risk subgroups by means of noninvasive testing is highly relevant in the selection of patients who require further diagnostic or therapeutic investigation. We evaluated whether exercise electrocardiographic variables during exercise testing might be a means of predicting the severity of myocardial ischemia as assessed with myocardial scintigraphy.

METHODS AND RESULTS

We retrospectively reviewed 816 consecutive patients (mean age, 57+/-10 years) who underwent exercise technetium-99m tetrofosmin single photon emission computed tomography (SPECT) for the assessment of suspected or known coronary artery disease. Eight independent significant predictors of the extent and severity of reversible perfusion defects (ischemic perfusion score), which when integrated in a diagnostic algorithm satisfactorily discriminated patients with no reversible perfusion defects (sensitivity, 75%; specificity, 80%) and patients with severe impaired myocardial perfusion (> or =11 ischemic perfusion score; sensitivity, 77%; specificity, 82%), were identified by means of stepwise discriminant analysis. However, patients with mildly to moderately impaired myocardial perfusion (> or =21 but <11 ischemic perfusion score) were poorly discriminated (sensitivity, 50%; specificity, 78%). The set of variables that were significant (P<.0001) for prediction included sex, myocardial infarction, exercise angina, the maximal amount of ST segment depression, rate-pressure product threshold criteria, slope of ST segment depression, ST/heart rate index, and peak exercise heart rate.

CONCLUSIONS

The results of the use of clinical and electrocardiographic exercise variables satisfactorily agrees with the results from scintigraphy only for patients with no reversible perfusion defects and with severely impaired myocardial perfusion. However, it fails as an approach with universal applicability.

Thromboembolic events in beta thalassemia major: an Italian multicenter study

Thromboembolic (TE) events have been frequently reported in beta-thalassemic patients in association with known risk factors such as diabetes, complex cardiopulmonary abnormalities, hypothyroidism, liver function anomalies, and postsplenectomy thrombocytosis. In a recent survey involving 9 Italian thalassemic centers, we identified 32 patients with TE episodes in a total of 735 subjects, of whom 683 had thalassemia major and 52 thalassemia intermedia, corresponding to 3.95 and 9.61%, respectively. There was a great variation in localization: the main one (16/32) was CNS, with a clinical picture of headache, seizures and hemiparesis. Other localizations were the pulmonary (3 patients), mesenteric (1 patient) and portal (2 patients) sites. There were 6 cases of deep venous thrombosis (2 in the upper limbs, 4 in the lower ones). Intracardiac thrombosis was found in 2 subjects and clinical and laboratory signs of DIC were observed in 2 others during pregnancy. Since our patients with TE events present a statistically significantly higher incidence of associated dysfunction (cardiomyopathy, diabetes, liver function anomalies, hypothyroidism) than those without TE events (50 vs. 13.8%), we suggest close monitoring of those patients who are at higher risk of developing TE events because of the presence of one or more of these predisposing factors.

Effectiveness of forced rehydration and early re-feeding in the treatment of acute diarrhoea in a tropical area

BACKGROUND

The administration of oral re-hydration solution (ORS) via continuous infusion through a nasogastric (NG) tube and early refeeding facilitates delivery in hospitalised children and the return back home.

METHODS

DESIGN

the observation was made during a one-year stage in the Camillian Medical Centre (CMC) of Ouagadougou in Burkina Faso. 4,131 infants and children under 5 years old, affected by acute diarrhoea and severe dehydration (loss of weight > 10%) were studied. Those children having difficulties for oral re-hydration were hydrated by continuous infusion through naso-gastric (NG) tube; the NG tube was put in by the nurses and connected to a 500 ml bottle, in which a mixture of glucose and electrolytes was dissolved according to the formula (glucose 20 g + NaCl 3.5 g + NaHCO3 2.5 g KCl 1.5 g in 1 litre of water). The infusion rate was 20-30 drops/minute. No sedative or anti-emetic drug was given, unless in the presence of uncontrolled vomiting. At the end of infusion, flour of millet (60%), soy bean (20%), peanut butter (10%), sugar (10%) and salt (1%) was administered and continued at home or in the nearby areas available for the night.

RESULTS

After 4-5 hrs of infusion 3,717 children (90%) showed a significant gain of weight, although the weight prior to the acute event preceding hospitalisation was never reached during their stay at the CMC. Only 413 children (10%) required a longer period of forced infusion: at the end of the day, however, they were fed with this flour.

CONCLUSIONS

A simple strategy, based on a NG infusion plus an oral administration of flour has proven safe and effective in encompassing those difficulties encountered in the treatment and prevention of dehydration in developing countries where the therapy, in children affected by diarrhoea, still represents a major daily occupation.

The prevalence of coeliac disease in infertility

An increased incidence of reproductive problems, including infertility, miscarriage, low birth weight newborns, and shorter duration of breast-feeding, are known to exist in women with coeliac disease; some of these conditions are improved by a gluten-free diet. We have tried to ascertain the prevalence of coeliac disease in 99 couples who were being evaluated for infertility, compared with the known prevalence of silent disease in the population of Northern Sardinia, in which it is endemic. Of all women, four tested positive for at least two out of three markers: immunoglobulin A (IgA) antigliadin, immunoglobulin (IgG) antigliadin, and anti-endomysium antibodies, and underwent a jejunal biopsy; three had histological evidence of coeliac disease. One male partner was positive for two markers, and had a diagnostic jejunal biopsy. The prevalence of coeliac disease in infertile women seems higher (three out of 99, 3. 03%) in the study group than in the general population (17 out of 1607, 1.06%), and particularly in the subgroup with unexplained infertility (two out of 25, 8%, P < 0.03). Screening for coeliac disease should be part of the diagnostic work-up of infertile women, particularly when no apparent cause can be ascertained after standard evaluation.

[Early relapse of herpes simplex encephalitis. Clinical and therapeutic implications]

A case of Herpes simplex virus encephalitis (HSVE) is reported in a 5 year old boy, who relapsed twice during the acute phase of the disease. The second relapse was completely cured by increasing the daily treatment with acyclovir to a dosage of 60 mg/kg intravenously for two weeks and 30 mg/kg by mouth for a further week. The full disappearance of the symptoms and the regression of cerebral lesions could be correlated to a prompt diagnosis and to the dosage of acyclovir employed, higher than that suggested for diseases caused that was by other members of the Herpes virus family.

Jagged-1 mutation analysis in Italian Alagille syndrome patients

Alagille syndrome (AGS) is an autosomal dominant disorder with developmental abnormalities affecting the liver, heart, eyes, vertebrae, and craniofacial region. The Jagged-1 (JAG1) gene, which encodes a ligand of Notch, has recently been found mutated in AGS. In this study, mutation analysis of the JAG1 gene performed on 20 Italian AGS patients led to the identification of 15 different JAG1 mutations, including a large deletion of the 20p12 region, six frameshift, three nonsense, three splice-site, and two missense mutations. The two novel missense mutations were clustered in the 5' region, while the remaining mutations were scattered throughout the gene. The spectrum of mutations in Italian patients was similar to that previously reported. We also studied in detail a complex splice site mutation, 3332dupl8bp, which was shown to lead to an abnormal JAG1 mRNA, resulting in a premature stop codon. With the exception of the missense mutations, the majority of the JAG1 mutations are therefore likely to produce truncated proteins. Since the phenotype of the patient with a complete deletion of the JAG1 gene is indistinguishable from that of patients with intragenic mutations, our study further supports the hypothesis that haploinsufficiency is the most common mechanism involved in AGS pathogenesis. Furthermore, our data confirmed the absence of a correlation between the genotype of the JAG1 gene and the AGS phenotype.

Clinical and neuroradiological follow-up in mucopolysaccharidosis type III (Sanfilippo syndrome)

Mucopolysaccharidosis type III (Sanfilippo syndrome) is an autosomal recessive disorder characterised by progressive nervous system involvement with mental retardation, behavioural problems and seizures. Three patients, of 20 months to 12 years of age, were followed up for 3 years both clinically and by using brain magnetic resonance imaging (MRI). Our results suggest that in MPS III patients MRI findings, including atrophy and abnormal or delayed myelination, may precede the onset of overt neurological symptoms. The increasing neurological morbidity is accompanied by different degrees of progressive atrophic changes, mainly affecting the cerebral cortex and the corpus callosum. However, it appears that, across subjects, the rate of MRI changes is unrelated to the severity of the clinical phenotype. On this basis it could be argued that in MPS III the worsening of the neurological symptoms might not necessarily reflect only the progressive cerebral abnormalities detectable by MRI.

Bone marrow hypoplasia associated with acute viral hepatitis in four children

Four cases of children, aged 2 to 11 years, with acute viral hepatitis and bone marrow hypoplasia are reported. Three patients presented only jaundice and hepatomegaly; one also had liver failure. All the four patients underwent bone marrow aspiration which showed bone marrow aplasia. In two of the four patients a liver biopsy revealed patchy necrosis with inflammatory mononuclear cell infiltrate. Half of the patients received a bone marrow transplantation; the remaining patients were treated by intravenous infusion of immunoglobulins, growth factors and steroids. The main epidemiological and etiological features of such association are also reported.