Potassium depletion downregulates chloride-absorbing transporters in rat kidney.

Potassium depletion (KD) causes renal chloride wasting, suggesting defect(s) in Cl- reabsorption in renal tubules. To determine whether alterations in expression of the major Cl- transporter genes might contribute to the chloride wasting, we analyzed their expression in renal cortex and medulla of animals placed on KD diet. Feeding KD diet to rats resulted in significant hypokalemia at 14 d but not at 6 d. Northern hybridization revealed that mRNA levels for the apical Na-K-2Cl cotransporter in the medulla decreased by 56 and 51% at 6 and 14 d of KD diet, respectively. Functional studies in tubular suspensions from medullary thick ascending limb demonstrated that the Na-K-2Cl cotransporter activity decreased by approximately 45 and approximately 37% at 6 and 14 d of KD diet, respectively. mRNA levels for the thiazide-sensitive Na-Cl cotransporter decreased by 57 and 64% at 6 and 14 d of KD diet. Decreased expression of the apical Na-Cl and the Na-K-2Cl cotransporters became evident at 48 and 72 h of KD, respectively. Urinary chloride excretion increased at 48 h and further increased at 72 h of KD, correlating with suppression of the Na-Cl and the Na-K-2Cl transporters. Our results indicate that increased urinary chloride loss in KD results from suppression of the chloride-absorbing transporters. Downregulation of chloride transporters in KD is an early event and can lead to hypochloremia and subsequently hypovolemia and decreased glomerular filtration rate.     

Evaluation of the gastric antiulcerogenic effects of Portulaca oleracea L. extracts in mice

Portulaca oleracea is commonly used in Iranian folk medicine. The aqueous and ethanolic extracts were studied in mice for their ability to inhibit gastric lesions induced by HCl or absolute ethanol. In addition, their effects on gastric acid secretion were measured. Both extracts showed a dose-dependent reduction in severity of ulcers. The highest dose of extracts exerted similar activity to sucralfate. The oral and intraperitoneal administration of extracts reduced the gastric acidity in pylorus-ligated mice. These results suggest that Portulaca oleracea has gastroprotective action and validates its use in folk medicine for gastrointestinal diseases.     

Acute renal failure leads to dysregulation of lung salt and water channels

BACKGROUND: Renal ischemia/reperfusion (I/R) injury and the acute respiratory distress syndrome (ARDS) frequently coexist in the intensive care setting, and this combination is associated with a high mortality. Recent experimental data demonstrate that renal I/R injury leads to an increase in pulmonary vascular permeability, similar to that observed in ARDS. However, the effects of renal I/R injury on alveolar fluid clearance-of potential importance in the setting of increased permeability-are unknown. We investigated the effects of renal I/R injury on pulmonary epithelial sodium channel (ENaC), Na,K-ATPase and aquaporin expression as a first step in addressing this question. METHODS: Sprague Dawley rats were subjected to four protocols: (1) surgery for bilateral I/R injury, (2) sham surgery, (3) surgery for unilateral I/R injury, or (4) bilateral nephrectomy. Lung tissue was examined for Na channel, Na,K-ATPase, aquaporin-1, and aquaporin-5 expression. Northern and Western blots were performed. RESULTS: Renal I/R injury and bilateral nephrectomy both led to marked down-regulation of pulmonary ENaC, Na,K-ATPase and aquaporin-5 but not aquaporin-1 compared to sham surgery. These changes were not influenced by the animals' volume status. In contrast, unilateral I/R with an intact contralateral kidney did not lead to down-regulation of channel down-regulation. CONCLUSIONS: Ischemic acute renal failure leads to down regulation of pulmonary ENaC, Na,K-ATPase and aquaporin-5, but not aquaporin-1. Since bilateral nephrectomy but not single kidney I/R injury also leads to lung changes, these changes are likely mediated by systemic effects of acute renal failure (ARF), such as "uremic toxins," rather than reperfusion products. These changes may modulate lung dysfunction, susceptibility to lung injury, or both.     

Mouse Na+: HCO3- cotransporter isoform NBC-3 (kNBC-3): cloning, expression, and renal distribution

BACKGROUND: Na+:HCO3- cotransporters mediate the transport of HCO3- into or out of the cell. We recently reported the partial cloning and characterization of a new human Na+:HCO3- cotransporter (referred to as NBC-3 or kNBC-3). The purpose of the present studies was to clone the mouse kNBC-3 and to examine its properties and expression in the kidney. METHODS: Using primers from human kNBC-3 cDNA and 5' and 3' rapid amplification cDNA end polymerase chain reaction (RACE PCR), the mouse kNBC-3 full-length cDNA was cloned from inner medullary collecting duct (mIMCD-3) cells. The tissue distribution and functional properties of NBC-3 was determined using established methods. RESULTS: The coding region of the mouse kNBC-3 has 1089 amino acids and shows 73 and 56% identity to human NBC-2 and NBC-1, respectively. The renal distribution of kNBC-3 demonstrated a unique expression pattern: Whereas kNBC-1 is predominantly expressed in the cortex and is absent in the inner medulla, kNBC-3 shows an intense expression level in the inner medulla and is absent in the cortex. Expression studies in oocytes indicated that NBC-3 mediates Na-dependent HCO3- cotransport. Electrophysiological experiments demonstrated that unlike kNBC-1, which is electrogenic, kNBC-3 is electroneutral. CONCLUSIONS: Based on its distribution and electroneutrality, we propose that kNBC-3 mediates the transport of HCO3- into the cells.     

Epidemiological features and clinical manifestations in 469 adult patients with brucellosis in Babol, Northern Iran

The epidemiological features and clinical manifestations of adult cases of brucellosis admitted to the Department of Infectious Diseases, Babol Medical University, Iran from 1997 to 2002 were investigated. Of 469 cases, 267 (56.9%) were males. The mean age of cases was 36.9 +/- 15 years. Most (60.8%) were from rural areas. Two thirds of cases (306, 66.3%) presented during spring or summer. Fresh cheese (22.4%), animal husbandry (11.3%), laboratory worker (8.1%) and veterinary profession (1.5%) were the main risk factors. Forty-five families (9.6%) had two cases. Sweating, fever, and arthralgia were the most frequent clinical symptoms. Complications were documented in 105 males (39.5%) and 41 females (20.3%, P=0.0001). Peripheral arthritis was seen in 24 (9%) males and 19 (9.4%) females, with knees and hips being the most common sites of infection. Sacroiliitis and spondylitis were seen in 28 (6%) and 32 (6.8%) cases respectively with spondylitis more common in males (P=0.023). Epididymo-orchitis was seen in 29 (10.9%) males. There were three cases each of endocarditis (0.6%) and neurological complications (0.6%). Most patients with brucellosis did not have any of the known risk factors for brucellosis. Thus consumption of unsafe dairy products could be the main route of infection. The disease manifested with a diversity of clinical manifestations and complications. Complications were more frequent in males than females.     

Caring for Dying Patients: Attitude of Nursing Students and Effects of Education

Background:

Education about caring for dying patients could be effective in changing nursing students’ attitude toward caring for dying patients.

Aim:

The aim of the present study was to examine the nursing students’ attitude toward caring for dying patients and effects of education on their attitude.

Materials and Methods:

The present study enjoys a quasi-experimental method with using one-group pre-test/post-test design conducted in Bam in southeast of Iran. The attitude of nursing students was measured using Frommelt Attitude Toward Care of the Dying (FATCOD) scale before and after an educational intervention. Data were analyzed using non-parametric tests in Statistical Package for the Social Sciences (SPSS) 18 software.

Results:

Of 32 students, 30 participated in this study (response rate of 94%). Only 20% of the students reported previous experience of dying patients in their clinical courses. Students showed moderately negative to neutral attitudes toward caring for dying patients. Education has improved students’ attitude significantly (mean score of FATCOD before study were 3.5 ± 0.43 and after intervention were 4.7 ± 0.33) (P < 0.001).

Conclusion:

Educational programs about death and caring for dying patients should be added to undergraduate nursing curricula. Further research recommended examining nursing students’ knowledge about caring for dying patients and the effect of education on their knowledge.     

Using bipedicled myocutaneous Tripier flap to correct ectropion after excision of lower eyelid basal cell carcinoma

Many techniques have been described for correcting ectropion, but when the ectropion follows skin cancer excision, only a technique that replaces missing skin should be used. The bipedicled Tripier flap tends to give some excess bulk at each end but gives an excellent correction of ectropion. The aim of this study was to apply musculocutaneous bipedicled Tripier flap from upper lid for correction of ectropion due to previous excision of lower-lid malignancies and evaluate its outcome. This was a prospective case-series study. In this study, 15 patients (6 women, 9 men), ranging from 35 to 72 years old (mean, 51 years) underwent operation with Tripier flap for reconstruction of ectropion because of basal cell carcinoma (BCC) resection. In patients with ectropion, Tripier flap with or without ear or nasal septal cartilage was used for reconstruction of deformities 3 months after lower-lid reconstruction with local flaps. All patients were satisfied, and ectropion was corrected in all cases. There were no complications such as dry eye or corneal abrasion after operation. Also, we had not any case of ischemic flap. We suggest that Tripier flap is one of the best methods for reconstruction of lower-lid retraction or ectropion. This is a desirable method, functionally and aesthetically.     

A simple quantitative affinity capturing assay of poliovirus antigens and subviral particles by single-domain antibodies using magnetic beads

Recently, single-domain recombinant antibody fragments (VHHs or nanobodies) against poliovirus type 1 were isolated. To examine the antigenicity of poliovirus using these recombinant VHHs, an alternative technique mimicking protein A immunoprecipitation had to be developed that was designed specifically for VHHs. The current study validated an affinity capturing assay that is based on the magnetic separation of unbound antigen and antigen-VHH complexes. The technique is simple, fast, reliable, quantitative and inexpensive and was employed to assess the reactivity of 15 VHHs for native infectious poliovirus (N antigen), heat-denatured virus (H antigen) and 14S subviral particles. Three distinct subsets of VHHs were tentatively distinguished based on their specificity for the antigens: one that binds only to 14S precursors, another that binds to the H antigen and a third that binds to the N antigen. Some VHHs of the latter two subsets bound 14S subviral particles with equal affinity but others had at least 100-fold less affinity for the precursors. All neutralizing VHHs were demonstrated to recognize N antigen and all N-specific VHHs were shown to be neutralizing. This study corroborates the findings that VHHs mainly target conformational epitopes and that they target additional epitopes as compared to classical antibodies. The described technique may be useful for epitope mapping and tracking conformational changes of proteins.