Suppression of mitochondrial mRNA levels and mitochondrial function in cells responding to the anticellular action of interferon

A lambda cDNA library prepared from polyadenylated RNA isolated from Daudi cells was differentially screened to isolate cDNAs that recognize mRNA whose levels are reduced following interferon (IFN) treatment. Southern blot and DNA sequence analysis of 20 cDNA clones that were isolated revealed that they represented mitochondrially encoded mRNAs for the following proteins: cytochrome c oxidase subunits II and III, ATPase 6, cytochrome b, and subunit 1 of the NADH dehydrogenase. Northern blot analysis employing these cDNAs and oligonucleotides generated to the remaining mitochondrially encoded mRNAs demonstrated that IFN-alpha treatment of Daudi cells mediates a time-dependent suppression of the level of all of the mitochondrially encoded mRNAs. Study of this IFN-mediated effect reveals that: (i) the suppression of the level of these mRNAs is dependent on protein synthesis, (ii) it can be observed to occur prior to any detectable effect on thymidine incorporation, (iii) the degree of suppression correlates with the sensitivity of the cells to the anticellular action of IFN, and (iv) the suppression of the level of these RNAs appears to result from an effect on the level of transcription rather than on the stability of these mRNAs. A study of the level of cellular respiration in IFN-treated Daudi cells reveals a clear suppression 3 h following IFN treatment.

Halothane, enflurane, and isoflurane stimulate calcium leakage from rabbit sarcoplasmic reticulum

The sarcoplasmic reticulum (SR) controls uptake and release of Ca2+ in muscle. Little information is available regarding the effect of volatile anesthetics on Ca2+ release from SR isolated from normal skeletal muscle, even though an abnormality of Ca2+ handling is implicated in malignant hyperthermia. In this study we used a Ca2+ electrode to monitor continuously the release of Ca2+ from SR and the effect of volatile anesthetics on this process. We found that halothane, enflurane, and isoflurane at 0.6, 0.7, and 0.8 vol%, respectively, each increased the velocity of Ca2+ leakage by at least 150% when compared to control. Ruthenium red, a blocker of the SR Ca(2+)-release channel, was shown to have no effect on the velocity of Ca2+ leakage. Halothane and isoflurane both shortened the time at which Ca2+ leakage began (T) in a dose-dependent fashion. Halothane at 4.8 vol% decreased T from 293 +/- 21 s to 149 +/- 20 s. Isoflurane (4.8 vol%) decreased T to 203 +/- 16 s, and enflurane at 5 vol% had little effect, decreasing T to 259 +/- 19 s. We noted a marked stimulation in the ATPase activity of the SR by all three volatile anesthetics. Halothane at 0.63 vol%, isoflurane at 0.42 vol%, and enflurane at 0.62 vol% each increased ATPase activity by at least 300%. We conclude that the stimulation of the velocity of Ca2+ leakage by the volatile anesthetics is related to the more rapid depletion of ATP, but that the shortening of the onset of Ca2+ leakage is a independent phenomenon with a markedly different dose dependence.(ABSTRACT TRUNCATED AT 250 WORDS)

A longitudinal study of lung function in jute processing workers

A 5-y follow-up study of pulmonary function was conducted in 1982 and in 1987 for 50 current and retired jute-processing workers who had been employed for more than 10 y in a jute mill in China. Control subjects, who had no history of dust or gas exposure, were selected from a paper-packing plant in the same city. Forced expiratory maneuvers were conducted in the same manner in both 1982 and 1987. The jute workers' pulmonary functions, i.e., forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1.0), and forced expiratory flow (FEF25-75%), were more compromised than were pulmonary functions in the controls for the same 5-y period; however, only the increased incidence of abnormal FEV1.0s in jute workers was statistically significant. Male jute workers had significantly higher annual decrements of FVC, FEV1.0, and FEF25-75% than did control workers. Regression analysis indicated that in 1987, predicted values of FEV1.0 and FEF25-75% for the jute workers were related to years of employment. Our results suggest that long-term exposure to jute dust could produce chronic loss of lung function.

Rapid and efficient purification of native histidine-tagged protein expressed by recombinant vaccinia virus

Vaccinia virus has been used as a vector to express foreign genes for the production of functional and posttranslationally modified proteins. A procedure is described here that allows the rapid native purification of vaccinia-expressed proteins fused to an amino-terminal tag of six histidines. Extracts from cells infected with recombinant vaccinia virus are loaded onto Ni2+.nitrilotriacetic acid (Ni2+.NTA)-agarose and histidine-tagged proteins are selectively eluted with imidazole-containing buffers. In the case of the human serum response factor (SRF), a transcription factor involved in the regulation of the c-fos protooncogene, the vaccinia-expressed histidine-tagged SRF (SRF-6His) could be purified solely by this step to greater than 95% purity. SRF-6His was shown to resemble authentic SRF by functional criteria: it was transported to the nucleus, bound specifically the c-fos serum response element, interacted with the p62TCF protein to form a ternary complex, and stimulated in vitro transcription from the serum response element. Thus, the combination of vaccinia virus expression and affinity purification by Ni2+.NTA chromatography promises to be useful for the production of proteins in a functional and posttranslationally modified form.

Necrotising fasciitis in leukaemic children

This is a report of necrotising subcutaneous infection in the perineum of three young girls with acute lymphoblastic leukaemia (ALL). This occurred during induction therapy when they were granulocytopenic. Pseudomonas aeroginosa was isolated from both blood and affected sites. With aggressive chemotherapy and extensive surgical debridement, two patients were salvaged but one perished from the septicaemia. Necrotizing Fasciitis is an uncommon progressive infection of the subcutaneous tissue. It occurs more frequently in adults following surgery or trauma and rarely arises spontaneously. In the paediatric literature, reports are few and mainly in healthy children occurring post-operatively. There was only one case of this occurring in a boy with Aplastic anaemia. Early recognition and aggressive therapy helps to improve the morbidity and mortality of this devastating condition.

Danazol for treatment of refractory autoimmune hemolytic anaemia

Autoimmune hemolytic anemia (AHA) is uncommon in childhood. A female child presented with severe and chronic clinical course. She was refractory to steroid and the response to splenectomy was poor. She showed excellent remission of hematological condition with Danazol. Danazol may be the drug of choice for refractory autoimmune hemolytic anemia.

Acute gastroenteritis in children--aetiology and comparison of two modes of treatment

287 patients with Acute Gastroenteritis were studied. Rotavirus accounted for 29.7% and bacterial aetiology for 9.3% of the cases. In the early infant age group (0-6 months), bacterial aetiology (28.8%) was commoner than Rotavirus aetiology (7.7%). In the older age groups, Rotavirus was more common than bacteria as a cause for Gastroenteritis.

Wilms' tumour with acquired von Willebrand's disease

A young infant with Wilms' tumour was found to have acquired von Willebrand's syndrome but no bleeding symptoms. Neither parent of the infant had evidence of von Willebrand's syndrome. Postoperatively, after removal of the tumour, factor VIII complex levels returned to normal. The mechanism of the acquired von Willebrand's syndrome was unclear. No evidence was found of an inhibitor of factor VIII complex or entrapment of factor VIII in the tumour.

Infections in children with acute lymphoblastic leukaemia

Infective and febrile episodes were studied in 28 patients with childhood acute lymphoblastic leukaemia. Most of the infections were referrable to the respiratory tract. Organisms commonly cultured were Gram positive bacteria. The incidence of febrile episodes were generally low but was higher during induction and remission.

Interaction of bilirubin with human serum albumin and cationic detergents

Bilirubin shows a red-shift in the visual spectra on binding to albumin. In bilirubin-cationic detergent systems a similar spectral change was observed. These comparisons allow one to deduce that the environment of the binding site in albumin is most likely apolar than when bilirubin is solubilized by the cationic detergents.