Nitric oxide synthase type II mRNA stability is translation- and transcription-dependent

Nitric oxide synthase (NOS) type II is induced in many cell types in response to cytokines or endotoxin. The duration of type II NOS mRNA expression in astroglial cells and macrophages in vitro is brief, even in the continuous presence of inducers, and their removal dramatically accelerates mRNA decay. Addition of cycloheximide, in the presence or absence of actinomycin D, protected the mRNA from degradation. Whereas type II NOS mRNA was partially stabilized by actinomycin D, manganese superoxide dismutase mRNA was almost completely stabilized. This suggests that type II NOS mRNA stability is regulated via transcription- as well as translation-dependent processes and that the effect of actinomycin D is mRNA specific.

Rates of bone loss in peri- and postmenopausal women: a 4 year, prospective, population-based study

1. Age-related bone loss is well established but reported rates of bone loss in the spine and femur vary widely. The aim of the present study was to investigate changes in bone mineral density in the lumbar spine and proximal femur in healthy postmenopausal women. 2. One hundred and thirty-eight population-based women, aged 45-65 years, recruited from general practice registers in 1990, were assessed at baseline; 108 returned for repeat assessment 4 years later, of whom 31 had taken hormone replacement therapy for 12 months or more of the 4-year study period. Bone densitometry of the lumbar spine and proximal femur was performed by dual-energy X-ray absorptiometry. Serum 25-hydroxyvitamin D and oestradiol were measured by RIA and serum intact parathyroid hormone by radio-immunometric assay. 3. The mean age at follow-up was 62 years (mean of 13.6 years after menopause). Lumbar spine bone mineral density was significantly higher in women who had received hormone replacement therapy for more than 12 months during the study period than in those who had not (P < 0.01). There was no difference between these two groups in the femoral neck or trochanteric bone mineral density. In the lumbar spine, the annual change in bone mass in untreated women was -0.39% (95% confidence intervals -0.60 to -0.09; P < 0.02) whereas there was a small gain in women receiving hormone replacement therapy [+0.36% (-0.12 to 0.84; P not significant)]. The annual change in bone mass in the femoral neck and trochanter was -0.51 and -0.45 respectively in untreated women (P < 0.01 and P < 0.02), and -0.16 and -0.15 in those receiving hormone replacement therapy (P not significant). 4. Our results demonstrate relatively low rates of bone loss in the spine and proximal femur in these healthy, population-based peri- and postmenopausal women. Hormone replacement therapy appeared to be associated with a significant protective effect on spinal, but not femoral, bone mineral density.

The Nottingham Study of Neurotic Disorder: influence of cognitive therapists on outcome

BACKGROUND

In previously published papers from the Nottingham Study of Neurotic Disorder a short treatment package of cognitive-behaviour therapy was no more effective than placebo drug treatment after 10 weeks' assessment in a cohort of 210 patients with neurotic disorders. This paper examines the outcome over two years of the patients treated by cognitive-behaviour therapy separated into two therapist groups, those who were competent in administering treatment and those of uncertain competence.

METHOD

The therapists (mainly community psychiatric nurses) of 70 patients with an original DSM-III diagnosis of either dysthymic, panic or generalised anxiety disorder were separated into two groups on the basis of their perceived competence by their supervisor (DK). Ratings of psychopathology were made at regular intervals over two years by assessors blind to knowledge of treatment or therapist.

RESULTS

The patients treated by competent therapists (n = 30) generally showed greater improvement than those allocated to therapists of uncertain competence (n = 40), mainly with respect to depressive symptoms, and the difference persisted over two years, long after the cognitive-behaviour therapy had been completed.

CONCLUSIONS

Cognitive-behaviour therapy given by competent therapists over a 10 week period is of lasting benefit in neurotic disorder.

Chronic salicylate poisoning and severe malaria

BACKGROUND Salicylates continue to be marketed and to be used in developing countries as over-the-counter (OTC) antipyretics in children, whereas in developed countries they are no longer used in children because of safety concerns. The presenting signs of salicylate poisoning, especially chronic (repeated administration of therapeutic or excessive doses for longer than 12 h), can include metabolic acidosis, hypoglycaemia, lethargy, and coma and fits. These signs are also common in severe malaria in African children. Admission of two probable cases of chronic salicylate poisoning prompted us to look for other cases among children presenting to our hospital in Kenya, apparently with severe malaria. METHODS All children admitted to Kilifi District Hospital between July and September, 1994, who had a positive blood film for Plasmodium falciparum, and one or more of coma, prostration, or respiratory distress were eligible. As well as routine tests for malaria and routine biochemistry, salicylate concentrations were measured. Management of children (aged 6 months to 10 years) in the community was assessed by a cross-sectional survey of 463 households and by interviews with mothers 2 days after they had bought OTC drugs for a child with fever. FINDINGS Data were available for 143 of 154 children with initial primary diagnoses of severe malaria. 129 (90 percent) had detectable (>l mg/dL) salicylate. Six of these had salicylate concentrations of 20 mg/dL or higher. All six had neurological impairment and metabolic acidosis and four were, or became, hypoglycaemic. OTC drugs were the first-line treatment in 188 (74 percent) of 254 fever episodes during the 2 weeks before the cross-sectional survey. Of 250 mothers who bought drugs for a febrile child, 236 (94 percent) bought a preparation containing salicylates and 50 (21 percent) gave a dose higher than the manufacturer's recommended maximum. INTERPRETATION These cases suggest that in some children salicylate poisoning may cause or contribute to the development of metabolic acidosis and hypoglycaemia, complications of severe malaria associated with high mortality.

Alterations in CNS gene expression in a rodent model of moderate traumatic brain injury complicated by acute alcohol intoxication

The combined effects of acute alcoholic intoxication and moderate traumatic brain injury (TBI) on zif/268, glial fibrillary acidic protein (GFAP), and preproenkephalin (PPE) mRNA expression were examined. Adult male Wistar rats received ip injections of a 5% alcohol solution (2.4 g/kg in a final volume of 20 ml isotonic saline) 10 min prior to fixed-head, mechanical injury. Using Northern analysis, a transient three- to fourfold induction of zif/268 mRNA levels was observed 45 min after injury in both TBI and alcohol-treated rats. This induction occurred in regions close to the impact site, namely, the olfactory bulb (OB) and frontal cortex (FTCTX) but not in the more distal piriform/amygdala cortex (P/A). No PPE mRNA changes were observed at 45 min for any experimental group. By 6 h, zif/268 transcript levels returned to or fell below basal levels in the OB and FTCTX while GFAP mRNA levels began to increase in TBI rats. At 24 h, GFAP mRNA levels were greatly increased in all three brain regions of TBI rats. However, alcohol inhibited the temporal induction of GFAP mRNA in the FTCTX and P/A triggered by TBI at 6 and 24 h. These results suggest that although acute alcohol intoxication prior to TBI does not influence gene expression patterns immediately after injury, it may minimize the transcriptional activation of astrocytes particularly in more distant brain regions that were influenced by the impact in nonintoxicated rats.

Expression of nitric oxide synthase type II in the spinal cord under conditions producing thermal hyperalgesia

There is evidence supporting spinal cord nitric oxide (NO) production in the mechanisms underlying hyperalgesia, presumed to arise from the activity of neuronal nitric oxide synthase type I (NOS I). Intrathecal administration of interleukin-1 beta and interferon-gamma to rats results in a thermal hyperalgesia which peaks at 2 h post-injection but which is undetectable 8 h post-injection. Expression of mRNA for nitric oxide synthase type II (NOS II) was detected by reverse transcription-polymerase chain reaction followed by Southern hybridization utilizing specific oligonucleotides in spinal cord tissue from animals 4 h and 8 h after cytokine injection, but not at longer time points. NOS II protein was detected in soluble fractions of spinal cords from animals 4 h and 8 h after cytokine injection. In situ hybridization for NOS II mRNA revealed positive cells bilaterally in the spinal cord 4 h after cytokine injection in a perivascular distribution and scattered throughout the gray and white matter. Immunohistochemistry for NOS II showed a similar distribution which could only be partially accounted for by macrophages/microglia. These results provide evidence for induction of NOS II expression under conditions producing thermal hyperalgesia and suggest a possible role in this behavior for the production of NO by a variety of cell types in the CNS.

An open randomized trial of artemether versus quinine in the treatment of cerebral malaria in African children

We have compared the efficacy of artemether versus quinine as treatment for cerebral malaria in children in an open randomized clinical trial in Kenya. Children admitted to hospital with coma and Plasmodium falciparum parasitaemia were treated with either intramuscular artemether (3.2 mg/kg loading dose followed by 1.6 mg/kg daily) or intravenous quinine (20 mg/kg loading dose followed by 10 mg/kg every 8 h). Both drugs were well tolerated and no significant adverse effect was observed. Parasite clearance times (50% and 90%) were shorter in patients treated with artemether (median times [h], with interquartile ranges in brackets, were: 50%, 7.3 [4.2-12.4] vs. 15.5 [9-22]; 90%, 16.9 [13.2-25] vs. 28.5 [22-35]; P < 0.0001). The total mortality in 160 children with cerebral malaria was 16.25%, with no overall significant difference between the 2 treatment groups. In a subgroup of children with respiratory distress, mortality was higher in those treated with artemether (43.7% vs. 11.1%, P < 0.05). The frequency of neurological sequelae and clinical recovery times were similar in both treatment groups. We conclude that there would currently be no advantage in replacing quinine with artemether for the treatment of cerebral malaria in African children.

Improved survival for children with B-cell acute lymphoblastic leukemia and stage IV small noncleaved-cell lymphoma: a pediatric oncology group study

PURPOSE

In an effort to improve outcome for children with advanced B-cell malignancies, a treatment plan based on a published regimen that consists of four courses of fractionated cyclophosphamide (cyclo) given with doxorubicin (doxo) and vincristine (VCR) was intensified by alternating with sequential high-dose methotrexate (MTX) and cytarabine (Ara-C), given in conjunction with intrathecal (IT) MTX and Ara-C.

PATIENTS AND METHODS

From October 1986 to October 1992, 133 eligible patients were enrolled: 74 with B-cell (surface immunoglobulin-positive [Slg+] acute lymphoblastic leukemia (B-ALL) and 59 with stage IV small noncleaved-cell lymphoma (SNCCL). The median age was 8 years; there were 103 males and 30 females. Abdominal tumor masses were prominent in 63 cases (33 B-ALL and 30 stage IV SNCCL).

RESULTS

Complete remission (CR) was achieved in 66 B-ALL and 57 stage IV patients (93% overall). At 4 years, the estimated event-free survival (EFS) rate is 65% +/- 8% for patients with B-ALL and 79% +/- 9% for those with stage IV SNCCL. Among patients with CNS involvement, 23 of 36 remain in CR (4-year EFS rate, 64% +/- 13%). Relapses occurred early; only 3 patients relapsed after completion of therapy. Thirteen relapses occurred in the marrow, three in the CNS, and six in other sites. Of 11 CNS-positive patients who relapsed, only two recurred primarily in the CNS.

CONCLUSION

The results of this study indicate that with intensified chemotherapy an increasing potential for cure exists for patients with B-ALL and stage IV SNCCL.

Effect of hypoxia and reoxygenation on regional activity of nitric oxide synthase in brain of newborn piglets

The activity of nitric oxide synthase (NOS) was measured in homogenates from cortex, striatum, hippocampus, cerebellum, pons, thalamus and midbrain of the brain of newborn piglets and the effects of hypoxia and posthypoxic period on this activity was evaluated. The control activities were 19.7, 31.5, 26.8, 16.7, 33.6, 19.3 and 39.4 pmol/mg protein per min, respectively. A 1 h period of hypoxia (an FiO2 of 7%) resulted in statistically significant decreases in the activity of NOS in every region of the brain except for the cortex, where the activity was not significantly altered compared to control. By 2 h of reoxygenation following such a hypoxic episode, the NOS activities increased to above control levels in all regions of the brain, but this increase was statistically significant compared to control only in thalamus. Since hypoxia induced the greatest decrease in NOS activity in the cerebellum, the kinetic constants of the enzyme were measured in homogenates from this region of brain. The decreased activity following the hypoxic episode was associated with an approximately four-fold increase in the apparent affinity (KM) for arginine with no significant change in the maximal rate of reaction (Vmax). The decrease in NOS activity subsequent to a hypoxic episode may contribute to the disturbances in cellular metabolism in the immature brain induced by episodes of hypoxia-reoxygenation.

Chorioamnionitis and early lung inflammation in infants in whom bronchopulmonary dysplasia develops

OBJECTIVE

The development of bronchopulmonary dysplasia (BPD) often has been attributed to injury from mechanical ventilation and supplemental oxygen. Early lung inflammation in infants with BPD has been thought to be secondary to these factors. The purpose of this study was to evaluate whether preexisting (prenatal) inflammation may be a primary causative factor in the development of BPD.

METHODS

Intubated newborns of less than 2,000 g birth weight were prospectively enrolled. The presence or absence of chorioamnionitis was documented. Lung inflammation was evaluated on days 1, 2, and 4 of intubation by assaying concentrations of interleukin 1 beta (IL-1 beta), thromboxane B2, leukotriene B4, and prostaglandin E2 in tracheal lavages. Infants in whom BPD developed were compared with those in whom it did not using these measures.

RESULTS

Fifty-three infants were enrolled; 41 survived. Thirty-eight had respiratory distress syndrome; 15 were intubated for other diagnoses. Infants prenatally exposed to chorioamnionitis were less likely to present with respiratory distress syndrome; however, chorioamnionitis was significantly associated with both the presence of IL-1 beta from the first day of intubation and the development of BPD. Tracheal lavage concentrations of IL-1 beta were higher in infants in whom BPD developed. Thromboxane B2 concentrations were similar on day 1 but were higher on days 2 and 4 in infants in whom BPD developed.

CONCLUSIONS

In this study, intubated infants weighing less than 2,000 g at birth in whom BPD developed had increased exposure to inflammation prenatally (chorioamnionitis) and evidence of increased lung inflammation from the first postnatal day. We speculate that chorioamnionitis may accelerate lung maturation but that it also causes lung inflammation and subsequent lung injury in intubated infants, fostering the development of BPD.

A multicenter inspection of the swirling phenomenon in platelet concentrates prepared in routine practice. Biomedical Excellence for Safer Transfusion (BEST) Working Party of the International Society of Blood Transfusion

BACKGROUND

In a previous multicenter study, the absence of the swirling phenomenon correlated well with platelet disc-to-sphere transformation, a morphology feature associated in the past with poor platelet viability.

STUDY DESIGN AND METHODS

In 13 centers, 5366 platelet concentrates (PCs) were prepared and stored under routine conditions and evaluated for the presence of swirling. PCs found not to have swirling were evaluated for pH and platelet and white cell counts in parallel with an equal number of PCs with swirling that were studied as controls.

RESULTS

In 13 participating centers, swirling was reported to be absent after 3 and 5 days of storage in 0 to 3.8 percent and in 0 to 18 percent of PCs, respectively. In 94 percent of units with swirling, pH was 6.7 to 7.5; this is a range of values associated with adequate in vivo survival. In 69 percent of PCs without swirling, pH was lower than 6.4 or higher than 7.6; these values are associated with reduced platelet viability. Three-quarters of the cases in which the absence of swirling was associated with pH values between 6.7 and 7.5 were reported from 2 out of the 13 participating centers.

CONCLUSION

In PCs prepared and stored under routine conditions, the presence of swirling correlated well with pH values associated with adequate platelet in vivo viability. In about 20 percent of PCs without swirling, this was not due to a low or high pH value, and it would be useful to investigate whether this lack of swirling is associated with poor platelet viability. These data support the possibility that the evaluation of swirling by visual inspection might replace invasive and more cumbersome assays currently used for routine PC quality control.

Using HL7 and the World Wide Web for unifying patient data from remote databases

W3-EMRS is an architecture designed to access clinical data from remote heterogeneous electronic medical record system (EMRS) databases. We describe the technologies used in an experimental implementation of W3-EMRS that concurrently collects data from several sources and presents them in an integrated set of views. After describing some of the organizational constraints, the architectural decision, implementation methodology, and operation of the completed project are discussed.

Uniform approach to risk classification and treatment assignment for children with acute lymphoblastic leukemia

PURPOSE

To define more uniform criteria for risk-based treatment assignment for children with acute lymphoblastic leukemia (ALL), the Cancer Therapy Evaluation Program (CTEP) of the National Cancer Institute (NCI) sponsored a workshop in September 1993. Participants included representatives from the Childrens Cancer Group (CCG), Pediatric Oncology Group (POG), Dana-Farber Cancer Institute (DFCI), St Jude Children's Research Hospital (SJCRH), and the CTEP.

METHODS

Workshop participants presented and reviewed data from ALL clinical trials, using weighted averages to combine outcome data from different groups.

RESULTS

For patients with B-precursor (ie, non-T, non-B) ALL, the standard-risk category (4-year event-free survival [EFS] rate, approximately 80%) will include patients 1 to 9 years of age with a WBC count at diagnosis less than 50,000/microL. The remaining patients will be classified as having high-risk ALL (4-year EFS rate, approximately 65%). For patients with T-cell ALL, different treatment strategies have yielded different conclusions concerning the prognostic significance of T-cell immunophenotype. Therefore, some groups/institutions will classify patients with T-cell ALL as high risk, while others will assign risk for patients with T-cell ALL based on the uniform age/WBC count criteria. Workshop participants agreed that the risk category of a patient may be modified by prognostic factors in addition to age and WBC count criteria, and that a common set of prognostic factors should be uniformly obtained, including DNA index (DI), cytogenetics, early response to treatment (eg, day-14 bone marrow), immunophenotype, and CNS status.

CONCLUSIONS

The more uniform approach to risk-based treatment assignment and to collection of specific prognostic factors should increase the efficiency of future ALL clinical research.

Sharing electronic medical records across multiple heterogeneous and competing institutions

Most early reports of implemented World-Wide Web (W3) medical record systems describe single institution architectures. We describe W3-EMRS, a multi-institutional architecture, and its implementation. Thorny problems in data sharing underlined by the W3-EMRS project are reviewed.

Extravasation rates and complications of intraosseous needles during gravity and pressure infusion

OBJECTIVE

To compare the extravasation rates and insertion complications under gravity and 300 mm Hg (40 kPa) pressure infusion of threaded (SurFast and Sussmane-Raszynski intraosseous needles, Cook Critical Care, Bloomington, IN); and nonthreaded needles (16-gauge disposable intraosseous needle with 45 degrees trocar Cook Critical Care, Bloomington, IN; Jamshidi bone marrow needle; Baxter Health Care Corp, Valencia, CA).

DESIGN

A prospective, randomized study.

SETTING

An animal laboratory at a university center.

SUBJECTS

Five healthy mix breed piglets, weighing 15 to 15.5 kg.

INTERVENTIONS

Piglets were anesthetized and ventilated. Tibial, femoral, and humeral osseous sites were exposed by dissection of overlying tissue. All bleeding points were cauterized and oozing was prevented by sealing with cyanoacrylate. Intraosseous access devices then were inserted one at a time in random order and rated for difficulty of insertion. Normal saline solution was infused under gravity or 300 mm Hg (40 kPa) pressure. Extravasation rates then were calculated from the increase in weight of a gauze sponge wrapped tightly at the base of the needle during infusion.

MEASUREMENTS AND MAIN RESULTS

No significant (p > .05) differences in extravasation rates were noted among the different types of needles, either under gravity or pressure infusions. The Sussmane-Raszynski needle was significantly more difficult to insert than the others (rated difficult to insert and control in 16 of 34 attempts). Inadvertent penetration of both cortices occurred with nonthreaded needles only (three of 66 attempts). The SurFast needle provided greatest penetration control and was most resistant to accidental dislodgement.

CONCLUSIONS

Under ideal conditions, needle type does not influence extravasation rates. However, difficulty with insertion and penetration of both cortices occur commonly and may lead to extravasation during stressful emergency situations or when performed by unskilled personnel.

Platelet storage for transfusion in synthetic media: further optimization of ingredients and definition of their roles

Currently, most platelet concentrates (PC) are stored for transfusion at 20 degrees C to 24 degrees C in autologous plasma. There are potential advantages in replacing some of this plasma with a synthetic medium. In this study, our major goals were to define the optimal ingredients and their concentrations in such a medium and to gain insight into the mechanism by which each ingredient confers benefit. In addition, we wished to validate a new polyvinyl chloride container plasticized with di-n-decyl phthalate (DnDP) for PC storage. PC derived from donations of whole blood were stored for 7 days in autologous plasma or a basic synthetic medium (BSM) containing 15 mmol/L glucose, 21 mmol/L citrate, and physiologic concentrations of salts other than bicarbonate within either the DnDP container or a licensed polyolefin container, PL-732. Metabolic events were characterized and a panel of in vitro tests were used to monitor platelet quality as systematic changes in the BSM were made. Platelet quality was as least as good, if not better, after storage in DnDP in comparison to PL-732. pH consistently decreased to less than 6.0 because of inadequate buffering of lactic acid in BSM alone. However, pH and the in vitro tests were well maintained by either the serial addition of bicarbonate (BSM + B) or the addition of at least 15 mmol/L acetate and 10 mmol/L phosphate (BSM + AP). The benefits of BSM + AP were traced to a decrease in lactic acid production by 33% and 19% relative to plasma and BSM + B, respectively, and the vigorous oxidation of acetate (0.66 +/- 0.09 mmol/d/10(12 platelets). The rates of lactate production and acetate consumption were similar and the pH during storage correlated with difference between the two rates, suggesting that acetate oxidation has an alkalinizing effect equivalent on a molar basis to the acidifying effect of production of lactate and a hydrogen ion. When pyruvate replaced acetate, it was also metabolized vigorously (0.52 +/- 0.06 mmol/d/10(12) platelets). Its presence suppressed lactic acid production by 44% relative to BSM + B and allowed maintenance of pH and platelet quality similar to what is achieved with acetate. The results strongly suggest that the benefit from acetate (or pyruvate) is derived from its oxidation and the use of a hydrogen ion during that oxidation. For reasons that are not yet clear, the omission of phosphate resulted in pH decrease to less than 6.0 in 3 of 9 PC even with acetate present.(ABSTRACT TRUNCATED AT 400 WORDS)

Functional redundancy of promoter elements ensures efficient transcription of the human 7SK gene in vivo

Deletion and mutation studies of the human 7SK gene transfected into HeLa cells have identified three functional regions of the promoter corresponding to the TATA box at -25, the proximal sequence element (PSE) between -49 and -65 and the distal sequence element (DSE) between -243 and -210. These elements show sequence homology to equivalent regions in other snRNA genes and are functionally analogous. Unlike the DSEs of many snRNA genes however, the 7SK DSE does not contain a consensus binding site for the transcription factor Oct-1 but rather, contains two non-consensus Oct-1 binding sites that can function independently of one another to enhance transcription. Unusually, the 7SK PSE can retain function even after extensive mutation and removal of the conserved TGACC of the PSE has little effect in the context of the whole promoter. However, the same mutation abolishes transcription in the absence of the DSE suggesting that protein/protein interactions between DSE and PSE binding factors can compensate for a mutant PSE. Mutation of the 7SK TATA box allows snRNA type transcription by RNA polymerase II to occur and this is enhanced by the DSE, indicating that both the DSE and the PSE can also function with pol II. In addition, mutation of the TATA box does not abolish pol III dependent transcription, suggesting that other sequence elements may also play a role in the determination of polymerase specificity. Although the human 7SK gene is transcribed efficiently in Xenopus oocytes, analysis of the 7SK wild-type gene and mutants in Xenopus oocytes gives significantly different results from the analysis in HeLa cells indicating that the recognition of functional elements is not the same in the two systems.