Astrocyte cultures from transgenic mice to study the role of metallothionein in cytotoxicity of tert-butyl hydroperoxide

The cell viability, lipid peroxidation (LPO) and hydrogen peroxide (H(2)O(2)) generation were measured in cultured primary astrocytes, from metallothionein (MT)-I isoform overexpressing transgenic (MT-I*), MT-I/MT-II null and control mice after exposure to tert-butylhydroperoxide (tBH). Astrocytes from MT-I* mice have high basal levels of both MT-I mRNA and MT protein, whereas there is only MT-III isoform in astrocytes from MT-I/MT-II null mice. The results showed that (1) cultured astrocytes from MT-I* mice were most resistant to the cytotoxicity of tBH and those from MT-I/MT-II null mice were most sensitive to the cytotoxicity of tBH; (2) LPO after exposure to tBH were increased in all cells, but the levels were the highest in astrocytes from MT-I/MT-II null mice, while those in MT-I* mice were the lowest; (3) the levels of H(2)O(2) in cultured astrocytes from MT-I* mice were the lowest, while those in astrocytes from MT-I/MT-II null mice were the highest. These results support the hypothesis that MT can scavenge free radicals and protect astrocytes from oxidative stress.     

Role of inhaled nitric oxide as a selective pulmonary vasodilator in pediatric cardiac surgical practice

Our aim was to assess the role of inhaled nitric oxide (NO) therapy in post operative cases of congenital heart defects who developed pulmonary arterial hypertensive (PAH) crisis and had no response with conventional management. From February '95 to January '97, inhaled NO therapy was used in 21 children. Age ranged from 2 months to 9 years (mean 5.6 years) and duration of therapy ranged from 1 to 13 days. Of 21 patients, 17 responded well with 5–20 ppm while 4 did not. The preoperative mean pulmonary systolic pressure was 88 mm Hg against mean systemic pressure of 96 mm Hg. Post operatively, their PA pressure reduced to 62 mm Hg, with systemic pressure of 98 mm Hg. After using inhaled NO, PA pressure dropped to 24 mm Hg (mean systolic) (p<0.007), after excluding the non responders. Of 4 non responders, two died due to irreversible pulmonary vascular disease and remaining two died due to residual defects. The study shows that inhaled NO is a selective pulmonary vasodilator, which is useful in postoperative PAH crisis and also reduces the transpulmonary gradient in single ventricle repair cases. It is safe and effective for prolonged use. It is very useful in Indian perspective, when more number of cases with congenital heart defects (CHD) alongwith severe PAH are encountered routinely.     

Regression of pulmonary MALT lymphoma after treatment with rituximab

We describe a patient with extranodal (pulmonary) marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) who was refractory to treatment with cytotoxic chemotherapy. After a single four-week course of rituximab she had significant regression of pulmonary lesions and remains progression free 19 months after finishing her treatment. This case report demonstrates the potential efficacy of rituximab as a single therapeutic agent in patients with pulmonary MALT lymphoma.     

Standardized interpretation of paediatric chest radiographs for the diagnosis of pneumonia in epidemiological studies

BACKGROUND: Although radiological pneumonia is used as an outcome measure in epidemiological studies, there is considerable variability in the interpretation of chest radiographs. A standardized method for identifying radiological pneumonia would facilitate comparison of the results of vaccine trials and epidemiological studies of pneumonia. METHODS: A WHO working group developed definitions for radiological pneumonia. Inter-observer variability in categorizing a set of 222 chest radiographic images was measured by comparing the readings made by 20 radiologists and clinicians with a reference reading. Intra-observer variability was measured by comparing the initial readings of a randomly chosen subset of 100 radiographs with repeat readings made 8-30 days later. FINDINGS: Of the 222 images, 208 were considered interpretable. The reference reading categorized 43% of these images as showing alveolar consolidation or pleural effusion (primary end-point pneumonia); the proportion thus categorized by each of the 20 readers ranged from 8% to 61%. Using the reference reading as the gold standard, 14 of the 20 readers had sensitivity and specificity of > 0.70 in identifying primary end-point pneumonia; 13 out of 20 readers had a kappa index of > 0.6 compared with the reference reading. For the 92 radiographs deemed to be interpretable among the 100 images used for intra-observer variability, 19 out of 20 readers had a kappa index of > 0.6. CONCLUSION: Using standardized definitions and training, it is possible to achieve agreement in identifying radiological pneumonia, thus facilitating the comparison of results of epidemiological studies that use radiological pneumonia as an outcome.     

Correlation between macroscopic changes of arthrosis and the posterior cruciate ligament histology in the osteoarthritic knee

BACKGROUND: There is ongoing debate about the role of the posterior cruciate ligament (PCL) in total knee arthroplasty. Advocates of PCL retention cite better soft tissue balance and improved proprioception, whereas opponents report late flexion instability. The results of knee replacement are similar whether the PCL is retained or sacrificed. The aim of the present study was to examine the PCL for histological changes that would infer its competence and correlate these with changes easily observed by the operating surgeon. METHODS: A prospective study of 50 osteoarthritic knees was performed. RESULTS: Histology of the PCL showed changes secondary to degeneration and trauma. In most of the ligaments examined, arteriosclerosis and fibrosis were present. Half of the PCL examined showed perineural fibrosis, myxoid change and hyalinization. These changes, although very frequent, did not correlate well to the changes observed in either the anterior or PCL, or in the overall severity of osteoarthrosis. CONCLUSIONS: Posterior cruciate ligaments usually show degenerative and chronic traumatic change of varying degrees on histology. The changes are not predictable from inspection of the knee at surgery. The frequency of these changes suggests that many osteoarthritic PCL are of indifferent quality and the surgeon should consider this when choosing the style of knee replacement.     

Blastocyst implantation failure in mice due to "nonreceptive endometrium": endometrial alterations by Hibiscus rosa-sinensis leaf extract

Many plants are known to possess antifertility activity. However, limited attempts have been made to scientifically evaluate these claims. Hibiscus rosa-sinensis flowers have been shown to possess antifertility and abortifacient activity. In this report, antiimplantation activity of water extract of leaves of H. rosa-sinensis was investigated. Pregnant female mice were dosed with extract (100 mg/kg body weight) from days 1 to 6 of pregnancy. No implantation sites were observed in treated animals when they were surgically opened on day 15 of pregnancy. Biochemical and biophysical alterations were observed in the endometrium in treated animals, especially on day 5, at 4:40 a.m., the day of implantation. A sharp increase in superoxide anion radical and a sharp fall in superoxide dismutase (SOD) activity, as seen in the endometrium from control animals, were altered in treated animals. The extract also exhibited antiestrogenic activity, as judged by increase in uterine weight. The physiological alterations induced by water extract of H. rosa-sinensis are discussed.     

Partial hypoxanthine-guanine phosphoribosyltransferase deficiency presenting as acute renal failure

Hyperuricemia and secondary urate nephropathy are uncommon in the paediatric setting outside of tumour lysis syndrome. We describe the case of a 12-year-old boy who presented at 3 years of age with acute renal failure. The cause of this remained unknown until the development of uric acid renal calculi 9 years later. This, and the availability of the previously unknown family history, provided the subsequent diagnosis of partial hypoxanthine-guanine phosphoribosyltransferase (HPRT) deficiency. Detailed family history is important for early detection of this heterogeneous group of disorders. Early treatment may minimise long-term renal morbidity and mortality from renal insufficiency.