Studies on delayed ettringite formation in heat-cured mortars: II. Characteristics of cement that may be susceptible to DEF

Expansions of mortar bars, stored over (but not in) water after simulated steam curing to 85 °C, were related to certain cement compositional parameters. The relationship is expressed in the form of a “delayed ettringite formation (DEF) index.” The DEF index is computed as the joint product of the SO₃/Al₂O₃ molar ratio of the cement, the sum of its SO₃ and Bogue C₃A percentages divided by 10 and the square root of the alkali content expressed as equivalent % Na₂O. The mortars studied were made with 18 different cements, prepared from a set of six representative clinkers by incorporating Terra Alba gypsum to total SO₃ contents that were 1% below optimum, at optimum and 1% above optimum (as defined in ASTM C 563). Measurements of expansion were recorded at intervals for up to 1400 days. Severe cracking and prominent DEF-induced expansions were observed in mortar bars derived from four of the six ‘oversulfated’ cements and lesser expansions from three of the six cements prepared at optimum SO₃ contents. No expansion was found for cements of DEF index below a threshold value; above this value expansions were approximately proportional to the difference between DEF index and its threshold value. The relationship confirms the significance of all three compositional parameters making up the index, e.g., the SO₃/Al₂O₃ molar ratio, the joint contents of SO₃ and C₃A, and the alkali content, in influencing the extent of DEF-induced expansion. In these measurements, the apparent pessimum effect for SO₃ content previously reported by others was not found, although SO₃ contents examined spanned the supposed pessimum value of 4%. Rather, expansion increased with increasing SO₃ content for mortars made with all clinkers exhibiting expansion.     

Nonsurgical repigmentation therapies in vitiligo. Meta-analysis of the literature

OBJECTIVE: To assess the effectiveness and safety of nonsurgical repigmentation therapies in localized and generalized vitiligo by means of a meta-analysis. DATA SOURCES: Computerized searches of bibliographic databases, a complementary manual literature search, and contacts with researchers and pharmaceutical firms. STUDY SELECTION: Predefined selection criteria were applied to both randomized and nonrandomized controlled trials. DATA EXTRACTION: Two investigators independently assessed the articles for inclusion. When there was a disagreement, a third investigator was consulted. DATA SYNTHESIS: Sixty-three studies were found on therapies for localized vitiligo. Of these, 10 of 11 randomized controlled trials and 29 of 110 patient series were included. One hundred seventeen studies on therapies for generalized vitiligo were found. Of these, 10 of 22 randomized controlled trials and 46 of 231 patient series were included. Among randomized controlled trials on localized vitiligo, the pooled odds ratio vs placebo was significant for topical class 3 corticosteroids (14.32; 95% confidence interval [CI], 2.45-83.72). In the patient series, topical class 3 and class 4 corticosteroids carried the highest mean success rates (56% [95% CI, 50%-62%] and 55% [95% CI, 49%-61%], respectively). Side effects were reported mostly with topical psoralen and intralesional and class 4 corticosteroids. In the randomized controlled trials on generalized vitiligo, the odds ratio vs placebo was significant for oral methoxsalen plus sunlight (23.37; 95% CI, 1.33-409.93), oral psoralen plus sunlight (19.87; 95% CI, 2.37-166.32), and oral trioxsalen plus sunlight (3.75; 95% CI, 1.24-11.29). In the series, the highest mean success rates were achieved with narrowband UV-B (63%; 95% CI, 50%-76%), broadband UV-B (57%; 95% CI, 29%-82%), and oral methoxsalen plus UV-A therapy (51%; 95% CI, 46%-56%). Oral methoxsalen plus UV-A was associated with the highest rates of side effects. No side effects were reported with UV-B therapy. CONCLUSIONS: Class 3 corticosteroids and UV-B therapy are the most effective and safest therapies for localized and for generalized vitiligo, respectively.     

Medical reference databases used by Army primary care physicians in field environments

A cross-sectional survey of U.S. Army primary care physicians was done to answer two questions: (1) which medical reference materials are Army primary care physicians currently using when deployed to a field environment? and (2) what would they like to have for medical reference in a field environment? Of 740 surveys delivered to their intended recipients, 445 (60%) were returned. Currently, 96% of primary care physicians use books, 37% use journals, and 11% use computer software in their medical reference database. Of those now using books, 72% were satisfied with them, compared with 61% of those using journals and 45% of those using software. The most common book used was the Merck Manual. The most important characteristics desired in a field medical database were broad coverage, ease of use, and light weight. The majority of respondents believe that a good medial reference database is important but that current medical databases limit the quality of the medicine they practice in the field.     

Characterization of nonrandom chromosomal gains and losses in multiple myeloma by comparative genomic hybridization

Clonal chromosomal changes in multiple myeloma (MM) and related disorders are not well defined, mainly due to the low in vivo and in vitro mitotic index of plasma cells. This difficulty can be overcome by using comparative genomic hybridization (CGH), a DNA-based technique that gives information about chromosomal copy number changes in tumors. We have performed CGH on 25 cases of MM, 4 cases of monoclonal gammopathy of uncertain significance, and 1 case of Waldenstrom's macroglobulinemia. G-banding analysis of the same group of patients demonstrated clonal chromosomal changes in only 13 (43%), whereas by CGH, the number of cases with clonal chromosomal gains and losses increased to 21 (70%). The most common recurrent changes detected by CGH were gain of chromosome 19 or 19p and complete or partial deletions of chromosome 13. +19, an anomaly that has so far not been detected as primary or recurrent change by G-banding analysis of these tumors, was noted in 2 cases as a unique change. Other recurrent changes included gains of 9q, 11q, 12q, 15q, 17q, and 22q and losses of 6q and 16q. We have been able to narrow the commonly deleted regions on 6q and 13q to bands 6q21 and 13q14-21. Gain of 11q and deletion of 13q, which have previously been associated with poor outcome, can thus be detected by CGH, allowing the use of this technique for prognostic evaluation of patients, without relying on the success of conventional cytogenetic analysis.     

Comparative study of preemptive and postincisional lumbar epidural morphine in pulmonary resection. Preliminary report

OBJECTIVES: To evaluate the efficacy and incidence of side effects of two types of lumbar epidural analgesia with morphine, preemptive or postincisional, combined with total intravenous anesthesia in chest surgery. PATIENTS AND METHODS: This double-blind prospective study enrolled 20 patients (ASA I-IV) undergoing lobectomy or pneumonectomy. Anesthetic induction and maintenance was provided with propofol, atracurium and alfentanil. Lumbar epidural analgesia (L2-L3) with morphine was provided for group A patients with 2 to 4 mg upon excision of tissue and for group B with 2 to 4 mg during anesthetic induction. The following variables were recorded: arterial blood gas concentrations, heart rate, SpO2, EtCO2, postanesthetic recovery, arterial gases, side effects and pain on a visual analogue scale. Top-up analgesia was provided by intravenous metamizole and/or epidural morphine. For statistical analysis we used ANOVA, chi-square tests and Student-Newman-Keuls tests. RESULTS: The need for propofol and alfentanil during anesthesia, and for morphine and metamizole after surgery were statistically greater in group A. Pain 18 hours after surgery was also greater in group A. No significant differences between groups for other variables was observed. CONCLUSIONS: Preemptive analgesia with lumbar epidural morphine in addition to the general anesthesia described here seems to provide higher-quality analgesia with few side effects, reducing the need for propofol and alfentanil during surgery and for postoperative morphine and metamizole.     

Hippocampectomy disrupts auditory trace fear conditioning and contextual fear conditioning in the rat

The hippocampus is believed to be an important structure for learning tasks that require temporal processing of information. The trace classical conditioning paradigm requires temporal processing because the conditioned stimulus (CS) and the unconditioned stimulus (US) are temporally separated by an empty trace interval. The present study sought to determine whether the hippocampus was necessary for rats to perform a classical trace fear conditioning task in which each of 10 trials consisted of an auditory tone CS (1 5-s duration) followed by an empty 30-s trace interval and then a fear-producing floor-shock US (0.5-s duration). Several weeks prior to training, animals were anesthetized and given aspiration lesions of the neocortex (NEO; n = 6), hippocampus and overlying neocortex (HIPP; n = 7), or no lesions at all (control; n = 6). Approximately 24 h after trace conditioning, NEO and control animals showed a significant decrease in movement to a CS-alone presentation that was indicative of a conditioned fear response. Animals in the HIPP group did not show conditioned fear responses to the CS alone, nor did a pseudoconditioning group (n = 7) that was trained with unpaired CSs and USs. Furthermore, all groups except the HIPP group showed conditioned fear responses to the original context in which they received shock USs. One week later, HIPP, NEO, and control animals received delay fear-conditioning trials with no trace interval separating the CS and US. Six of seven HIPP animals could perform the delay version, but none could perform the trace version. This result suggests that the trace fear task is a reliable and useful model for examining the neural mechanisms of hippocampally dependent learning.     

The clinical pharmacology of amoxicillin and clavulanic acid

Recent clinical reports have shown that intrathecal administration of thyrotropin-releasing hormone (TRH) can induce 2 to 3 day remissions of major depression more reliably than i.v. administration. Although clinically impractical, these remissions are rapid, occur within hours, and they survive at least one night's sleep. TRH and related peptides have regulatory effects in the limbic forebrain. Electroconvulsive shock (ECS) in rats induces synthesis of TRH in multiple subcortical limbic and frontal cortical regions, which are known in humans to be involved in both depression and in sleep. The increases in TRH and related peptides are regionally specific. The quantitative TRH increases in individual limbic regions have been correlated with the amount of forced-swimming done by the individual animal after ECS. Intraperitoneal TRH also gives a positive response in this test, as do all effective antidepressants. This article provides a heuristic framework for interdisciplinary neuroscientific study of the interrelated fields of depression and sleep, with a focus on TRH. Preclinical data suggest that glutamatergic, subcortical limbic circuits contain TRH and related peptides as inhibitory cotransmitters that may normally restrain glutamatergic hyperactivity. It is suggested that, in depression, pathologically overdriven glutamatergic circuits escape inhibitory regulation by TRH. This escape is especially pronounced during rapid eye movement (REM) sleep, and these phenomena may explain the prolonged latency of antidepressant treatment.