Overexpression of parathyroid hormone-related protein inhibits pancreatic beta-cell death in vivo and in vitro

Pancreatic beta-cell survival is critical in the setting of diabetes as well as in islet transplantation. Transgenic mice overexpressing parathyroid hormone-related protein (PTHrP) targeted to beta-cells using the rat insulin II promoter (RIP) display hyperinsulinemia, hypoglycemia, and islet hyperplasia, without a concomitant increase in beta-cell proliferation rate or enlargement of individual beta-cell size. Thus, the mechanism for increased beta-cell mass is unknown. In this study, we demonstrated that beta-cells of transgenic mice are resistant to the cytotoxic effects of streptozotocin (STZ) in vivo, as documented by a sixfold reduction in the rate of STZ-induced beta-cell death in RIP-PTHrP mice relative to their normal siblings. The reduced cell death in transgenic mice is due neither to their increased islet mass nor to a decrease in their sensing of STZ, but rather results from PTHrP-induced resistance to beta-cell death. This is also demonstrated in vitro by markedly reduced cell death rates observed in beta-cells of transgenic mice compared with normal mice when cultured in the absence of serum and glucose or in the presence of STZ. Finally, we demonstrated that NH(2)-terminal PTHrP inhibits beta-cell death. These findings support the concept that PTHrP overexpression increases islet mass in transgenic mice through inhibition of beta-cell death.     

PATHOLOGICAL CASE OF THE MONTH: SUDDEN DEATH IN A CHILD AS A RESULT OF PANCREATITIS DURING VALPROIC ACID THERAPY

Valproic acid is a widely used drug in the treatment of epilepsy and, compared to other anticonvulsant drugs, is considered safe. The most common side effects of valproic acid ingestion or therapy are transient nausea, vomiting, abdominal cramps, and diarrhea. Most of these complaints are mild. However, more serious adverse reactions can occur such as hepatotoxicity and pancreatitis. It has been proposed that, whenever possible, valproic acid not be used in the younger child, the child with a severe seizure disorder or other neurological disorders, mental retardation, developmental delay, organic brain disease, congenital abnormalities, or the child who is taking multiple anticonvulsant drugs, as these factors may increase the likelihood of hepatotoxicity and/or pancreatitis. In the present report, we describe a fatal case of acute hemorrhagic pancreatitis in a four and a half-year-old Hispanic female child who was receiving valproic acid in combination with another anticonvulsant drug for control of focal seizures. The patient also received the macrolide antibiotic azithromycin. For pediatricians and forensic pathologists valproic acid-induced pancreatitis can be a challenging diagnosis which must not be mistaken for abdominal trauma. We discuss the workup of the patient and differential diagnosis.     

The aqueous humour antioxidative capacity in different types and color of the age-related cataract

BACKGROUND/AIM: Oxidative stress results from increased oxidative processes, decreased antioxidative protection, or both processes simultaneously. Photooxidative stress, as a form of oxidative stress, induced by the energy of solar radiation, today is considered as crucial in the age-related cataractogenesis. Other known and unknown, endogenous and egsogenous factors that contribute to the oxidative stress intensity, can influnce the cataract type and brunescence. Thus the oxidative stress intensity and its form might determine the cataract type and brunescence, and also make the efforts in cataract prevention more complex. Hence, the objective of the present paper was to investigate the current amount of antioxidative capacity in aqueous humour during the cataract genesis of different types and pigmentation of cataract. METHODS: Transversal review of 80 samples of humour aqueous obtained during extracapsular cataract extraction. Aqueouses were analyzed by tiobarbituric acid (TBA) method for the total antioxidant activity estimation, expressed as %iMDA, and by using 0.1 ml of aqueous. RESULTS: The mixed type of cataract showed the statistically significantly lower values of the intensities of antioxidative protection in aqueous humour compared to cortical and nuclear cataracts (p < 0.001, respectively). Between pure nuclear and cortical cataracts we found the small differences of the investigated parameter, but they pointed to the decreased level of antioxidative protection, i.e. the increased intensity of the aqueous humour oxidative stress in the cortical cataract type. A significant correlation betweer the cortical cataract maturation and the %iMDA (p < 0.05) was found. CONCLUSIONS: The role of the oxidative stress, here expressed as the antioxidative capacity of aqueous humour, could not be the same for all the cataract types. The lower level of antioxidative protection of aqueous in brunescent and mixed cataracts may point to the higher intensity of oxidative stress in those cataract types. The correlation betweer the cortical cataract maturity and %iMDA points to the significant decrease of the aqueous antioxidative protection in the cataract progression.     

Comprehensive strategy to prevent nosocomial spread of methicillin-resistant Staphylococcus aureus in a highly endemic setting

BACKGROUND: The effectiveness and feasibility of a comprehensive strategy to reduce nosocomial transmission of methicillin-resistant Staphylococcus aureus (MRSA) in a highly endemic setting have not yet been proved. Limited benefits and the high cost of such programs are the main concerns. METHODS: We prospectively evaluated the effect of an aggressive infection control program on transmission of MRSA in the University Clinic of Respiratory and Allergic Diseases. All patients with MRSA carriage during 5 years (January 1, 1998, through December 31, 2002) were included and categorized into imported or hospital-acquired cases. RESULTS: Methicillin-resistant S aureus was recovered from 223 hospitalized patients; 142 cases were imported and 81 were acquired at our institution. After introduction of the comprehensive infection control program in 1999, the annual incidence of MRSA carriage per 1000 admissions increased from 4.5 in 1998 to 8.0 in 1999 (P = .02), and remained stable thereafter. In this period, the proportion of MRSA cases acquired in our institution decreased from 50.0% in 1999 to 6.1% in 2002 (P<.001), whereas the proportion of MRSA cases transferred from other hospitals (P<.001) and nursing homes (P = .03) increased. All 19 MRSA carriers with 3 sets of follow-up cultures were successfully decolonized. CONCLUSIONS: With a comprehensive infection control program, it was possible to reduce nosocomial transmission of MRSA in a highly endemic setting. With good hand hygiene using alcohol handrub, early detection, isolation, and a decolonization strategy, containment of MRSA was achievable, despite a high rate of transferred patients with MRSA.     

Effects of cholinesterase inhibitor metrifonate on naive rats and rats with a model of hypoxia-induced impaired memory

Cholinesterase inhibitors are currently used in the therapy of different kind of dementia to improve brain memory functions. The acetylcholinesterase inhibitor metrifonate was studied in naive rats and in rats with a model of sodium nitrite-induced hypoxia. One active avoidance test and in two passive avoidance tests were used. In the active avoidance test metrifonate increased the number of avoidances during the learning session only. In both passive avoidance tests, metrifonate prolonged latency differently during the learning session and in short-term or in long-term memory retention. Hypoxic rats showed lower numbers of avoidances in learning and memory retention sessions. Metrifonate increased the number of avoidances during the learning session for hypoxic rats. In the step-through passive avoidance test, metrifonate increased the latency of reactions in the learning session and in long-term memory retention tests. In the step-down passive avoidance test, the groups with hypoxia and metrifonate did not change the latency of reaction in the learning and long-term memory retention sessions, but increased the latency of reactions in the short-term memory retention test. Morphological data showed a significant impaired neuronal structure in a CA1 zone of the hippocampus in hypoxic rats and a tendency to preserving in rats treated with metrifonate. Our results suggest that metrifonate improves cognitive functions in naive and in hypoxic rats.     

Signaling status of IgG B cell receptor (IgG BCR) is indicative for an activated state of circulating B cells in multiple myeloma

Circulating post-switch B cells have been proposed as proliferative and disseminating progenitors in multiple myeloma. It is unclear whether the class-switched antigen receptor expressed at the surface of these cells plays a role in their expansion. In this work, the signaling status of IgG B cell receptor (BCR) isolated from the lysates of peripheral blood lymphocytes of 32 patients with IgG multiple myeloma, at the time of diagnosis, was investigated by examining whether phosphorylation of BCR Igalpha and Igbeta signal transducer factors (co-receptors) or other signaling molecules was abnormal in these cells when compared with healthy controls. In IgG BCR of normal controls, weak phosphorylation of 56 and 61 kDa Src kinase-related proteins and unphosphorylated co-receptors were found. In myeloma, p56 and p61 kDa proteins, co-receptors, and other IgG BCR-associated proteins from the signal cascade were phosphorylated. Myeloma patients can be classified into subgroups by IgG BCR phosphorylation profiles which characteristically coordinated with the level of IgG paraprotein in serum and the stage of disease. There was a correlative trend between the extent of phosphorylation reduction and advanced stage of disease. Reduced phosphorylation was more pronounced with advanced stages of multiple myeloma.     

FoxP3 demethylation is increased in human colorectal cancer and rat cholangiocarcinoma tissue

Objectives

FoxP3 expression is a marker for Tregs which are known to be involved in tumor immunity. We aimed to evaluate FoxP3 promoter demethylation in human colorectal cancer (CRC) and rat intrahepatic cholangiocarcinoma (ICC).

Design and methods

Bisulfite-treated genomic DNA templates of shock frozen paired samples were studied from 13 anonymous CRC patients and from 10 male rats (n = 6 ICC induced by thioacetamide and n = 4 age-matched controls). Real-time PCR was carried out using a LightCycler 480 system. Human FoxP3 and CD3 promoter demethylations were estimated using previously described assays; and rat FoxP3 promoter demethylation using a newly developed assay.

Results

A significant 3.5-fold increase of the demethylation in FoxP3 promoter region was found in human CRC and rat ICC (P < 0.05). The average frequency of cells with FoxP3 demethylation in patients suffering from CRC was 0.26% in normal tissue and 0.92% in tumor tissue (n = 11 paired samples). Although, no significant difference was found between the mean frequency of CD3 demethylation in normal tissue (4.80%, n = 6) and in tumor tissue (4.14%, n = 6) from CRC patients, the ratio of demethylated CD3/FoxP3 promoter areas was significantly lower in tumor specimens (P < 0.05). Using our novel assay, we found a significant increase in mean frequencies of cells with FoxP3 demethylation in rats with ICC (7.42%, n = 6) in comparison to controls (2.14%, n = 4).

Conclusion

FoxP3 seems to be an interesting biomarker for immune response to epithelial tumors. Functional consequences from the increase of Tregs remain to be demonstrated. Further studies with outcome data are necessary.     

Comparison of clinical test and questionnaires for the evaluation of upper limb prosthetic use in children

Purpose:?The aim of the present study was to find out if there was a correlation between an observational clinical test and a questionnaire for the evaluation of upper limb prosthetic use in children and to determine which one was better and easier to use in clinical practice.

Method:?Twenty children who were patients of the children's prosthetic clinic at the Rehabilitation Institute in Ljubljana, Slovenia, and had a functional prosthesis were included in the study. The age appropriate subtest of the University of New Brunswick Test of Prosthetic Function (the UNB test) was assessed by an occupational therapist. Parents completed either the Child Amputee Prosthetics Project-Functional Status Inventory for Preschool children (CAPP-FSIP) or the Child Amputee Prosthetics Project-Functional Status Inventory (CAPP-FSI), depending on which was appropriate for the child's age. Information was limited to the upper extremity items.

Results:?We found a significant correlation between UNB spontaneity and skill score (r?=?0.956, p?=?0.000) and also between the parental CAPP score and UNB test (UNB spontaneity—CAPP activities r?=?0.634, p?=?0.003; UNB spontaneity—CAPP prosthetic use r?=?0.542, p?=?0.014, UNB skill—CAPP activities r?=?0.559, p?=?0.010, UNB skill—CAPP prosthetic use r?=?0.597, p?=?0.005).

Conclusions:?We concluded that both instruments can be used for assessing upper limb prosthetic use in children but neither is an optimal choice.