Calcitonin gene-related peptide receptor expression in healthy and inflamed human pulp tissue

AIM

To use radioreceptor analysis for comparing calcitonin gene-related peptide (CGRP) receptor expression in human pulp tissue samples collected from teeth having a clinical diagnosis of acute irreversible pulpitis, healthy pulps and teeth with induced inflammation.

METHODOLOGY

Six pulp samples were obtained from teeth having a clinical diagnosis of acute irreversible pulpitis. Another eight pulp samples were obtained from healthy premolars where extraction was indicated for orthodontic purposes. In four of these premolars, inflammation was induced prior to pulp collection. All the samples were processed and labelled with 125I-CGRP. Binding sites were identified by 125I-CGRP and standard CGRP competition assays.

RESULTS

CGRP receptor expression was found in all human pulp tissue samples. Most receptors were found in the group of pulps from teeth having a clinical diagnosis of acute irreversible pulpitis, followed by the group of pulps having induced inflammation. The least number of receptors was expressed in the group of healthy pulps. The Kruskal-Wallis and Mann-Whitney (post-hoc) tests showed statistically significant differences between the groups (P < 0.05).

CONCLUSION

CGRP receptor expression in human pulp tissue is significantly increased during inflammatory phenomena such as acute irreversible pulpitis.

Nonesophageal side-effects after antireflux surgery plus acid-suppression duodenal diversion surgery in patients with long-segment Barrett's esophagus*

During the last years we have employed acid-suppression duodenal diversion procedures (truncal vagotomy-partial gastrectomy plus Roux-en-Y gastrojejunostomy) in addition to antireflux surgery in order to treat all the pathophysiological factors involved in the genesis of Barrett's esophagus. We have observed very good results concerning the clinical and objective control of GERD at the long-term follow up after this procedure. However, it could be associated with other nonesophageal symptoms or side-effects. This study was conducted to evaluate the presence of gastrointestinal symptoms (diarrhea, vomiting, dumping, weight loss and anastomotic ulcers) after this operation. In this prospective study 73 patients were assessed using a careful clinical questionnaire asking regarding these complications at the early (< 6 months) and late (> 6 months) follow-up (average of 32.4 months). In the early postoperative period, diarrhea was present in 64% (19% considered severe 10-90 days after surgery), dumping in 41% and loss of weight in 71% of cases. Diarrhea occurred daily in 47.7% in the early postoperative period, but only in 16% of cases after 1 year. Shortly after surgery, steatorrea was observed in 9% of cases and responded well to medical treatment. Severe diarrhea or dumping was rare (5% of cases). These symptoms improved significantly after 1 year with medical management (45%, 20% and 30%, respectively) and 42% of patients regained their normal body weight. Only two patients presented anastomotic ulcers and were treated satisfactory with proton pump inhibitors. Revisional surgery was indicated in two patients with severe dumping syndrome. Most side-effects identified by this study were mild and diminished 1 year after operation.

Advances in the management of pneumonia in the intensive care unit: review of current thinking

Interventions to prevent pneumonia in the intensive care unit should combine multiple measures targeting the invasive devices, microorganisms and protection of the patient. Microbiological investigation is useful for evaluating the quality of the respiratory sample, and permits early modification of the regimen in light of the microbiological findings. Once pneumonia develops, the appropriateness of the initial antibiotic regimen is a vital determinant of outcome. Three questions should be formulated: (1) is the patient at risk of acquiring methicillin-resistant Staphylococcus aureus, (2) is Acinetobacter baumannii a problem in the institution, and (3) is the patient at risk of acquiring Pseudomonas aeruginosa? Antibiotic therapy should be started immediately and must circumvent any pathogen resistance mechanisms developed after previous antibiotic exposure. Therefore, antibiotic choice should be institution-specific and patient-oriented.

Effects of post-treatment retention interval and context on neophobia and conditioned taste aversion

We have repeatedly observed that a delay between acquisition and test, and the nature of the context in which the delay is spent, modulates latent inhibition (LI) of conditioned taste aversion (CTA; e.g. [Anim. Learn. Behav. 28 (2000) 389; Anim. Learn. Behav. 30 (2002) 112]). The present paper analysed the effects of delayed testing and treatment context after flavor exposure on the recovery of neophobia (Experiment 1) and on extinction after simple conditioning (Experiment 2). Two experiments were conducted with the same factorial design (2x2: 1 day versus 21 days of delay between first and second stage, and home versus experimental cages as place of experimental treatment). There were independent effects of both variables on habituation of neophobia and conditioning strength as measured on extinction trials. The long delay produced a reduction of neophobia (Experiment 1) and an increase in conditioning (Experiment 2). In addition, more of the flavored solution was consumed when the experimental treatment was conducted in the home cage than in the experimental cage (Experiment 1), and there was stronger conditioning when the delay period took place in the experimental cages than in the home cages (Experiment 2). The implications of these results for LI, as well as their relevance for experiments that use the CTA paradigm, are discussed.

International Conference for the Development of Consensus on the Diagnosis and Treatment of Ventilator-associated Pneumonia

Ventilator-associated pneumonia (VAP) is an important health problem that still generates great controversy. A consensus conference attended by 12 researchers from Europe and Latin America was held to discuss strategies for the diagnosis and treatment of VAP. Commonly asked questions concerning VAP management were selected for discussion by the participating researchers. Possible answers to the questions were presented to the researchers, who then recorded their preferences anonymously. This was followed by open discussion when the results were known. In general, peers thought that early microbiological examinations are warranted and contribute to improving the use of antibiotherapy. Nevertheless, no consensus was reached regarding choices of antimicrobial agents or the optimal duration of therapy. Piperacillin/tazobactam was the preferred choice for empiric therapy, followed by a cephalosporin with antipseudomonal activity and a carbapenem. All the peers agreed that the pathogens causing VAP and multiresistance patterns in their ICUs were substantially different from those reported in studies in the United States. Pathogens and multiresistance patterns also varied from researcher to researcher inside the group. Consensus was reached on the importance of local epidemiology surveillance programs and on the need for customized empiric antimicrobial choices to respond to local patterns of pathogens and susceptibilities.

Use of the Medication Event Monitoring System to estimate medication compliance in patients with schizophrenia

OBJECTIVE

To determine the feasibility of using the Medication Event Monitoring System (MEMS) to estimate medication compliance in patients with schizophrenia or schizoaffective disorder.

SUBJECTS AND SETTING

Fourteen of 35 consecutive patients admitted to a psychiatric inpatient hospital with schizophrenia or schizoaffective disorder who met eligibility requirements and gave informed consent.

INTERVENTION

After random assignment to either risperidone or typical antipsychotic treatment, medication upon discharge from hospital was dispensed in a bottle with a MEMS cap which recorded the number of bottle openings and the date and time of each opening. The first 6 patients were asked to return monthly for data downloading. The next 8 were asked to return weekly during the first month and every 2 weeks thereafter; they were also paid $5 for returning each bottle.

OUTCOME MEASURES

MEMS data collected over a 6-month period and hospital readmission data.

RESULTS

Patient medication compliance data were collected from 10 (71%) of 14 patients during the first month, from 7 (58%) of 12 (2 patients dropped out) during the second and from 5 (45%) of 11 (a third patient dropped out) during months 3-6. Mean compliance rates were 63% for the first month and ranged from 56% to 45% over the next 5. First-month compliance rates were significantly lower for those who were subsequently readmitted to hospital (n = 7) than for those who were not (p < 0.01).

CONCLUSIONS

Electronic monitoring devices can be used to estimate compliance with medication regimens in patients with severe schizophrenic disorders, but there are methodological improvements that can be made to increase data recovery and compliance, and these are discussed.

Perceived needs and service use of Spanish speaking monolingual patients followed at a Hispanic clinic

This study compared Spanish speaking monolingual patients at a Hispanic Clinic, with Hispanics and non-Hispanics at a conventional mental health center. A questionnaire in English and Spanish surveyed sociodemographic characteristics and subjectively reported health needs. The monolingual Hispanic Clinic patients perceived a significantly greater need for help with health and benefits, and better access to physical health care providers. Hispanics seen at the Hispanic Clinic report more difficulties managing medications than the other groups suggesting that this problem is not adequately addressed by receiving services in a culturally sensitive clinic, possibly due to the persistent effect of language barriers and low level of education. Additional interventions may be needed to address this problem.

Effect of adrenomedullin receptor and calcitonin gene-related peptide receptor antagonists on centrally mediated adrenomedullin renal action

To determine pharmacological specificity of intracerebroventricular (IVT) administration of adrenomedullin (AM) on water and sodium excretion, studies were performed in rats pretreated with AM (22-52), a putative AM-receptor antagonist or CGRP(8-37), a ligand that preferentially antagonizes the CGRP(1)-receptor subtype. In addition, the effects of IVT injection of calcitonin-gene-related peptide (CGRP) on urinary water and electrolyte excretion was assessed. Intracerebroventricular administration of rat adrenomedullin to conscious hydrated rats resulted in a significant increase in urinary volume and sodium excretion during the 6-h period of urine collection and was most effective at 3 and 6 h. Although less effective than AM, central administration of CGRP induced diuresis and natriuresis. Pretreatment with AM (22-52) or CGRP(8-37) significantly suppressed the diuretic and natriuretic effect of IVT-AM. These data suggest that both CGRP(1) and AM receptors are involved in the centrally mediated diuretic and natriuretic action of the AM. Our results provide evidence supporting the hypothesis that endogenous AM plays a role in the central nervous control of fluid and electrolyte homeostasis.

[Portal vein thrombosis associated with a myeloproliferative disorder, prothrombin G20210A mutation, antiphospholipid syndrome, with repermeation during anticoagulant therapy]

Portal vein thrombosis, except in hepatocellular carcinoma and severe cirrhosis, is due to one or several prothrombotic disorders with or without a local precipitating factor. We report a case of a portal and splenic vein thrombosis, without cavernoma and varices which occurred in a 72-year-old man with abdominal pain and weakness. Three prothrombotic states including latent myeloproliferative disorder, antiphospholipid syndrome, and factor II G202101 mutation, were observed. Anticoagulant treatment resulted in complete repermeation of the portal and splenic veins without a hemorrhagic event. This illustrates that several prothrombotic states may occur in a single patient with portal vein thrombosis. Early anticoagulant therapy, in recent portal vein thrombosis, can result in repermeation.

Transmandibular, circumglossal, retropharyngeal approach for chordomas of the clivus and upper cervical spine

Extensive clival tumors that involve both the midline and lateral skull base compartments, or those that extend inferiorly to the anterior cervical spine, are difficult to expose in a wide fashion using any of the transmaxillary, transoral, or transcervical routes. In the transmandibular, circumglossal, retropharyngeal (TCR) approach wide access of this region can be obtained, thus allowing for a more complete resection of tumor and infiltrated bone. It also provides for an improved ability to perform dural reconstruction, should it be necessary. Over the past 4 years four patients with extensive clival chordomas underwent resection via the TCR approach. Gross-total resection was achieved in two patients, a greater than 98% resection in one patient, and a greater than 95% resection in the fourth patient. The surgical technique, all approach-related complications and morbidity, and patient outcome are discussed. If an expanded exposure of the clivus is necessary, the TCR approach is a good choice as well as a useful surgical technique to have available.

Effects of divalproex versus lithium on length of hospital stay among patients with bipolar disorder

The medical records of all inpatients with bipolar disorder at the Connecticut Mental Health Center in 1997 were examined to compare length of stay for patients who began monotherapy with divalproex (27 treatment starts) and lithium (20 treatment starts). No statistically significant difference was found in length of stay (11. 5+/-6.9 and 10.3+/-5.2 days for patients on divalproex and lithium, respectively) or other length-of-stay variables. Demographic variables, diagnostic variables, and dosages of neuroleptics and benzodiazepines used adjunctively were similar as well. Dosages and blood levels for divalproex and lithium were consistent with practice guidelines. Prospective randomized studies are needed to compare the cost-effectiveness of divalproex and of lithium in the treatment of bipolar disorder.

Isolation and partial characterization of three DNA polymerases from Trypanosoma cruzi

Three distinct DNA polymerase fractions (A, B and C), were isolated from Trypanosoma cruzi epimastigote forms. Fraction A is a low molecular mass enzyme corresponding to beta-like DNA polymerase of T. cruzi. Fraction B co-purified along several purification steps with fraction A, but in the last step it was clearly separated by a phosphocellulose chromatography. Fraction C was separated from fractions A and B by binding to DEAE-cellulose column, since the other two fractions were eluted in the flowthrough. This enzyme has an apparent native molecular mass of 100 kDa and showed a high preference for poly(dC)-oligo(dG) among different template-primers tested as substrate. Western-blot and biochemical analysis strongly suggest that the three DNA polymerase fractions correspond to different molecular entities. These results are in agreement with the idea that fraction C is a new DNA polymerase of T. cruzi, not described before.

Prognostic factors for survival in malignant melanoma of the eyelid skin

PURPOSE

This study aimed to determine the prognostic factors for survival and disease-free interval for malignant melanoma of the eyelid skin.

METHODS

This was a retrospective, nonrandomized, clinical review. Twenty-four patients with eyelid skin melanoma were identified through a search of the tumor registry at M. D. Anderson Cancer Center. Patients were treated between 1953 and 1994. The follow-up ranged from 3 to 18 years (mean = 9.6 years). Primary treatment in all cases entailed wide local excision of the tumor. Patients in whom regional lymph node metastasis developed underwent parotidectomy or neck dissection, with or without adjuvant chemotherapy or external beam radiation. Descriptive statistics were used to characterize the patients. Survival analysis in terms of disease-free survival and recurrence-free survival was performed using age, sex, location of tumor (upper lid, lower lid, or both), histologic type of melanoma, Breslow thickness, and Clark's level as independent variables for survival.

RESULTS

Age, sex, location, and the histologic type of tumor were not significant prognostic indicators for survival in this cohort. Clark's level > or = IV by itself was a statistically significant predictor of decreased survival. In addition, tumors with either Clark's level > or = IV or Breslow thickness > or = 1.5 mm were associated with increased mortality.

CONCLUSION

Clark's level > or = IV or Breslow thickness > or = 1.5 mm are poor prognostic indicators for malignant melanomas of the eyelid skin. Clinicians should have a high level of suspicion for occult regional lymph node metastasis when treating patients with these tumor features.

Diuretic and natriuretic action of adrenomedullin administered intracerebroventricularly in conscious rats

Intracerebroventricular administration of rat adrenomedullin (AM) to conscious hydrated or salt-loaded rats, resulted in a significant increase in urinary volume. The diuretic effect of adrenomedullin occurred during the 6-h period of urine collection and was most effective during the 3 and 6 h. Most remarkably, AM given IVT induced a dose-related increase in urinary sodium excretion at all periods of urine collection. In addition, AM induced significant kaliuresis. Our results strongly suggest that AM may play a significant role in the central regulation of fluid and electrolyte homeostasis, and that its diuretic and natriuretic effect may be, at least in part, centrally mediated.

Effects of ageing and exogenous melatonin on pituitary responsiveness to GnRH in rats

The effect of age and melatonin on the activity of the neuroendocrine reproductive system was studied in young cyclic (3-5 months-old), and old acyclic (23-25 month-old) female rats. Pituitary responsiveness to a bolus of GnRH (50 ng per 100 g body weight) was assessed at both reproductive stages in control and melatonin-treated (150 micrograms melatonin per 100 g body weight each day for 1 month) groups. After this experiment, female rats were treated for another month to study the influence of ageing and melatonin on the reproductive axis. Plasma LH, FSH, prolactin, oestradiol and progesterone were measured. A positive LH response to GnRH was observed in both control groups (cyclic and acyclic). However, a response of greater magnitude was observed in old acyclic rats. Melatonin treatment reduced this increased response in acyclic rats and produced a pituitary responsiveness similar to that of young cyclic rats. FSH secretion was independent of GnRH administration in all groups, indicating desynchronization between LH and FSH secretion in response to GnRH in young animals and during senescence. No effect on prolactin was observed. Significantly higher LH (3009.11 +/- 1275.08 pg ml(-1); P < 0.05) and FSH concentrations (5879.28 +/- 1631.68 pg ml(-1); P < 0.01) were seen in acyclic control rats. After melatonin treatment, LH (811.11 +/- 89.71 pg ml(-1)) and FSH concentrations (2070 +/- 301.62 pg ml(-1)) decreased to amounts similar to those observed in young cyclic rats. However, plasma concentrations of oestradiol and progesterone were not reduced. In conclusion, the results of the present study indicate that, during ageing, the effect of melatonin is exerted primarily at the hypothalamo-pituitary axis rather than on the ovary. Melatonin restored the basal concentrations of pituitary hormones and pituitary responsiveness to similar values to those observed in young rats.

Effects of ageing and exogenous melatonin on pituitary responsiveness to GnRH in rats

The effect of age and melatonin on the activity of the neuroendocrine reproductive system was studied in young cyclic (3-5 months-old), and old acyclic (23-25 month-old) female rats. Pituitary responsiveness to a bolus of GnRH (50 ng per 100 g body weight) was assessed at both reproductive stages in control and melatonin-treated (150 micrograms melatonin per 100 g body weight each day for 1 month) groups. After this experiment, female rats were treated for another month to study the influence of ageing and melatonin on the reproductive axis. Plasma LH, FSH, prolactin, oestradiol and progesterone were measured. A positive LH response to GnRH was observed in both control groups (cyclic and acyclic). However, a response of greater magnitude was observed in old acyclic rats. Melatonin treatment reduced this increased response in acyclic rats and produced a pituitary responsiveness similar to that of young cyclic rats. FSH secretion was independent of GnRH administration in all groups, indicating desynchronization between LH and FSH secretion in response to GnRH in young animals and during senescence. No effect on prolactin was observed. Significantly higher LH (3009.11 +/- 1275.08 pg ml(-1); P < 0.05) and FSH concentrations (5879.28 +/- 1631.68 pg ml(-1); P < 0.01) were seen in acyclic control rats. After melatonin treatment, LH (811.11 +/- 89.71 pg ml(-1)) and FSH concentrations (2070 +/- 301.62 pg ml(-1)) decreased to amounts similar to those observed in young cyclic rats. However, plasma concentrations of oestradiol and progesterone were not reduced. In conclusion, the results of the present study indicate that, during ageing, the effect of melatonin is exerted primarily at the hypothalamo-pituitary axis rather than on the ovary. Melatonin restored the basal concentrations of pituitary hormones and pituitary responsiveness to similar values to those observed in young rats.

Characteristics of participants and nonparticipants in medication trials for treatment of schizophrenia

OBJECTIVE

The study compared the characteristics of patients who participated in efficacy trials of medications for treatment of schizophrenia with those of the other patients in the clinical population from which the trial participants had been selected.

METHODS

Study participants from ten trials of treatment efficacy conducted at a community mental health center in the early and mid-1990s were compared with nonparticipants using data on demographic and diagnostic characteristics and service utilization from the center's administrative database. Six of the trials selected patients with schizophrenia and no concurrent substance use disorder, and four selected patients with dual diagnoses of schizophrenia and a substance use disorder.

RESULTS

Compared with nonparticipants, participants in both types of trial were about six to eight years younger, were two to four times less likely to have ever married, and used more services. Participants in trials that selected patients with no substance use disorder were more likely to be high school graduates and were four times more likely to work full time, compared with nonparticipants. Participants in trials that selected patients with dual diagnoses were likely to be minorities and less likely to have medical comorbidities, compared with nonparticipants.

CONCLUSIONS

Participants in treatment efficacy trials differed substantially from nonparticipants. Some characteristics of the trial participants, including reduced likelihood of ever having been married and male gender, have been associated with poorer treatment outcomes in earlier studies. Other characteristics, such as younger age and greater likelihood of having graduated from high school and of working full time, have been associated with better outcomes.

Risk factors for developing pneumonia within 48 hours of intubation

Two hundred fifty intubated patients were followed during the first 48 h after intubation in order to identify potential risk factors for developing pneumonia within this period. Thirty-two developed pneumonia during this time. Univariate analysis established that large volume aspiration, presence of sedation, intubation caused by respiratory/cardiac arrest or decrease in the level of consciousness, emergency procedure, cardiopulmonary resuscitation (CPR), and Glasgow coma score < 9 were significantly associated with pneumonia. In contrast, prior infection and prior antimicrobial use were associated with a protective effect. Presence of subglottic secretion drainage and 15 other variables had no significant effect. Multivariate analysis selected CPR (odds ratio [OR] = 5.13, 95% confidence intervals [CI] = 2.14, 12.26) and continuous sedation (OR = 4.40, 95% CI = 1.83, 10.59) as significant risk factors for pneumonia, while antibiotic use (OR = 0.29, 95% CI = 0.12, 0.69) showed a protective effect. Our findings emphasize that risk factors for pneumonia change during the intubation period, and preventing pneumonia requires a combined approach.

Cryopreserved arterial homografts: preliminary results in infrageniculate arterial reconstructions

The aim of this report is to present our preliminary experience using cryopreserved arterial homografts in below-knee revascularization. We carried out a retrospective study at the Public Health Hospital of the Servicio Galego da Saude (SERGAS) from October 1995 to March 1997 in which cryopreserved arterial homografts were used for revascularization of 17 lower limbs in 16 patients. The clinical indications were limb-threatening ischemia in 15 lower extremities (7 with rest pain and 8 with ischemic ulcers or gangrene), and large aneurysms of femoropopliteal arteries in 2. In addition, 75% of the patients had undergone previous surgical procedures for revascularization on the involved extremity. No patient had a suitable greater saphenous vein in the ipsilateral extremity and all patients required a below-knee arterial reconstruction procedure. There was just one runoff vessel in 11 of 17 extremities (65%). A histological exam was performed in four patients who died (1 case) or had homograft-related complications (3 cases). The results of this study indicated that cryopreserved arterial homografts could be a promising alternative when below-knee revascularization is required in patients lacking suitable greater saphenous vein, especially in those with limited life expectancy, but despite early acceptable results, many aspects must be clarified. Close follow-up is mandatory.

Presence of platelet-activating factor in rhesus (Macaca mulatta) spermatozoa

Platelet-activating factor [1-O-alkyl-2-acetyl-sn-glycero-phosphocholine; PAF] is a unique signaling phospholipid which has been implicated in a number of biological activities (e.g., reproduction). PAF has been detected in the spermatozoa from a number of laboratory and domestic species, including, but not limited to, rabbit, bovine, and the mouse. The concentration of PAF is inversely related to human (Homo sapien) spermatozoal quality. Additionally, PAF levels are significantly higher in Bolivian squirrel monkey (Saimiri sciureus) spermatozoa obtained during the breeding season than spermatozoa obtained during the nonbreeding season. There are no reports on the presence of PAF in rhesus (Macaca mulatta) spermatozoa. Therefore, the primary objective of this study was to detect the presence of PAF in rhesus spermatozoa. A second objective was to determine if PAF spermatozoa levels differ between animals housed individually (single-caged) versus free-ranging (open corrals). Semen were collected from mature rhesus via electro-ejaculation. Spermatozoa were washed free of ejaculatory plug and quick frozen in PBS. Endogenous lipids were extracted from thawed spermatozoa and ejaculatory plugs then assayed for the presence of PAF by [125I]-radioimmunoassay. PAF was not detected in any ejaculatory plugs. PAF levels were significantly higher (P < 0.01) in spermatozoa obtained from free-ranging males (mean: 1.16 pmol/10(6) spermatozoa) than males housed individually in single cage units (mean: 0.53 pmol/10(6) spermatozoa). PAF was present in rhesus spermatozoa. Additionally, PAF levels were higher in spermatozoa obtained from corral-housed animals. Additional studies are warranted to elucidate the role of PAF in spermatozoa function.

Improvement in oxygenation by prone position and nitric oxide in patients with acute respiratory distress syndrome

OBJECTIVE

Inhaled nitric oxide (NO) and prone position improve arterial oxygenation in patients with the acute respiratory distress syndrome. This study was undertaken to assess the combined effects of NO and prone position in these patients.

DESIGN

Prospective clinical study.

SETTING

General intensive care service in a community teaching hospital.

PATIENTS

14 mechanically ventilated adult patients with the acute respiratory distress syndrome (mean lung injury score 3.23+/-0.27).

MEASUREMENTS AND RESULTS

We measured hemodynamic and oxygenation parameters in the supine position and 2 h later in the prone position, before and during inhalation of 10 ppm NO. A positive response in oxygenation was defined as a > or =20% increment in the arterial oxygen tension/fractional inspired oxygen ratio (PaO2/FIO2). In the prone position PaO2/FIO2 increased significantly (from 110+/-55 to 161+/-89 mm Hg, p<0.01) and venous admixture decreased (from 38+/-12 to 30+/-7%, p<0.01) compared to the supine position. Ten of the 14 patients were responders in the prone position. In the supine position, inhalation of NO improved oxygenation to a lesser extent, increasing PaO2/FIO2 to 134+/-64 mm Hg (p<0.01) and decreasing venous admixture to 35+/-12%, (p<0.01). Five of the 14 patients responded to NO inhalation supine and 8 of 14 responded prone (p = 0.22). The combination of NO therapy and prone positioning was additive in increasing PaO2/FIO2 (197+/-92 mm Hg) and decreasing venous admixture (27+/-8%) (p<0.01). This combination also showed a positive oxygenation response on compared to the supine value without NO in 13 of the 14 patients (93 %). NO-induced changes in PaO2/FIO2 were correlated to changes in pulmonary vascular resistance only in the prone position.

CONCLUSIONS

In patients with the acute respiratory distress syndrome, the combination of NO and prone position is a valuable adjunct to mechanical ventilation.

Managing data for a randomised controlled clinical trial: experience from the WHO Antenatal Care Trial. WHO Antenatal Care Trial Research Group

The World Health Organisation, in collaboration with four developing countries, is conducting a randomised controlled clinical trial to evaluate a new programme of antenatal care. In a city or region in Argentina, Cuba, Saudi Arabia and Thailand, 53 clinical units were randomly allocated to provide either the new programme or the programme currently in use. This paper describes the organisation of the data management system used to collect the data. Each woman participating in the trial is uniquely identified, and information such as her name, address and expected delivery date is recorded in the trial 'subject number list'. If the clinic belongs to the intervention group, information about the woman's eligibility is recorded on the classification form. Details of the outcome of the pregnancy are indicated on two additional case report forms: the antenatal hospital admission form and the summary form. When forms are completed by the investigators, they are submitted to the country data coordinating centre (CDCC). The CDCCs are responsible for the processing of the country study forms. This includes verification of the batch of forms, data capture into computer files, data verification, data validation, production of query sheets for data problems, maintenance and updating of study master files. All operations on data such as additions or modifications are performed using transaction processing. At monthly intervals, recruitment reports and transaction files are sent to the trial coordinating centre in Geneva. All transaction files are processed to accumulate data on the trial's consolidated master files. A monthly report including number of women recruited in the trial, adverse events reported by the countries, recruitment charts by clinic and analyses on eligible women in the intervention group is prepared and submitted to the data safety and monitoring committee. A workshop was organised in 1995, before the start of the trial, to introduce the data management system to the four participating countries. Annual site visits were made to each CDCC to monitor progress. Additional visits were made when major or critical problems could not be solved by the CDCC. At the closure of data collection, a visit is made to review and assess all data management procedures including form filling, maintenance of registers, computer files, query sheets, data modifications. In addition, final cleaning of the data is performed, and an analysis file is produced for inclusion in the centralised trial analyses and in the country-specific analyses. Based on the experience gained in this trial, the decentralised data management model can be advocated only if CDCCs that will be involved in the trial are already in place with competent and experienced staff. Uniformity of the data management system and of standard operating procedures across countries is also a crucial issue for the effective management of the data collection phase.

2D 1H and 13C NMR evidence for stereoselective formation of a new bond C-N, C-S or C-C in the reaction of ivalin acetate with substituted pyrimidines

Several pyrimidine derivatives of ivalin acetate were synthesized as potential anti HIV agents. High stereoselective Michael addition to ivaline acetate was observed and a new C-C, C-N or C-S bond was formed. 2D NMR 1H and 13C as well as X-ray crystallographic studies were performed on the compounds herein described to establish the structure and stereochemistry.

Hepatitis G virus co-infection in liver transplantation recipients with chronic hepatitis C and nonviral chronic liver disease

Hepatitis G virus (HGV) is a newly described RNA virus that is parenterally transmitted and has been found frequently in patients with chronic hepatitis C infection. To determine the impact of hepatitis G virus co-infection on morbidity and mortality following liver transplantation, we measured HGV RNA by polymerase chain reaction in pre and posttransplantation sera from a cohort of patients transplanted for chronic hepatitis C and a control group of patients transplanted for nonviral causes who were negative for hepatitis C virus (HCV) RNA in serum. The overall prevalence rate of HGV RNA in transplanted patients with chronic hepatitis C was 20.7%. HGV infection was present before transplantation in 13% while it appeared to have been acquired at the time of transplantation in 7.4%. Mean serum alanine aminotransferase activity, hepatic histological activity, and patient and graft survival were similar between HGV-positive and HGV-negative patients. The prevalence rate of HGV RNA in transplanted controls was 64% (P < .01) with a significantly higher rate of acquisition of HGV infection following transplantation (53%, P < .001) when compared with patients with chronic hepatitis C. Mean serum alanine aminotransferase activity was significantly lower in the control patients with HGV infection alone following transplantation than in patients co-infected with hepatitis C (37 +/- 9 vs. 70 +/- 33 U/L, P < .01). Thus, HGV is frequently found in transplantation patients co-infected with hepatitis C although it appears to have minimal clinical impact. In patients transplanted for nonviral causes of end-stage liver disease, a high rate of hepatitis G acquisition at the time of transplantation may occur but does not appear to predispose to chronic hepatitis.

Molecular characterization of PadA, a phenylacetaldehyde dehydrogenase from Escherichia coli

The padA gene encoding the phenylacetaldehyde dehydrogenase involved in the catabolism of 2-phenylethylamine in Escherichia coli has been cloned, sequenced, and located at 31.0 min on the chromosome. The deduced PadA polypeptide contains 499 amino acid residues with a predicted molecular mass of 53.7 kDa, and its primary structure reveals significant similarity with that of members of the aldehyde dehydrogenase superfamily. By engineering optimal transcription and translation elements, a high expression of the padA gene has been achieved. The active PadA enzyme is a homodimer that prefers NAD+ over NADP+ as coenzyme. The enzyme efficiently oxidizes only phenylacetaldehyde-like aromatic aldehydes, and has a weak esterase activity with p-nitrophenol. The padA gene constitutes a new catabolic tool for designing DNA cassettes to expand the abilities of microorganisms to degrade toxic aromatic compounds.

Hemodynamic and gas exchange responses to inhalation of nitric oxide in patients with the acute respiratory distress syndrome and in hypoxemic patients with chronic obstructive pulmonary disease

OBJECTIVE

Inhalation of nitric oxide (NO) can improve oxygenation and decrease mean pulmonary artery pressure (MPAP) in patients with the acute respiratory distress syndrome (ARDS). It is not known whether inhaled NO exerts a similar effect in hypoxemic patients with chronic obstructive pulmonary disease (COPD).

DESIGN

Prospective clinical study.

SETTING

General intensive care unit in Sabadell, Spain.

PATIENTS

Nine mechanically ventilated COPD patients (mean age 72 +/- 2 years; forced expiratory volume in 1 s 0.91 +/- 0.11 l) and nine ARDS patients (mean age 57 +/- 6 years; mean lung injury score 2.8 +/- 0.1).

MEASUREMENTS AND RESULTS

We measured hemodynamic and gas exchange parameters before NO inhalation (basal 1), during inhalation of 10 ppm NO (NO-10), and 20 min after NO was discontinued (in basal 2) in the ARDS group. In the COPD group, these parameters were measured before NO inhalation (basal 1), during different doses of inhaled NO (10, 20, and 30 ppm), and 20 min after NO was discontinued (basal 2). A positive response to NO was defined as a 20% increment in basal arterial partial pressure of oxygen (PaO2). MPAP and pulmonary vascular resistance (PVR) decreased significantly, while other hemodynamic parameters remained unchanged after NO-10 in both groups. Basal oxygenation was higher in the COPD group (PaO2/FIO2 (fractional inspired oxygen) 190 +/- 18 mmHg) than in the ARDS group (PaO2/FIO2 98 +/- 12 mmHg), (p < 0.01). After NO-10, PaO2/FIO2 increased (to 141 +/- 17 mmHg, p < 0.01) and Qva/Qt decreased (39 +/- 3 to 34 +/- 3%, p < 0.01) in the ARDS group. There were no changes in PaO2/FIO2 and Qva/Qt when the NO concentration was increased to 30 ppm in the COPD group. In both groups, a correlation was found between basal MPAP and basal PVR, and between the NO-induced decrease in MPAP and in PVR. The NO-induced increase in PaO2/FIO2 was not correlated with basal PaO2/FIO2. In the ARDS group, six of the nine patients (66%) responded to NO and in the COPD group, two of nine (22%) (p = 0.05).

CONCLUSIONS

NO inhalation had similar effects on hemodynamics but not on gas exchange in ARDS and COPD patients, and this response probably depends on the underlying disease.

Use of colicin e3 for biological containment of microorganisms

The genetic determinant of the lethal antibiotic colicin E3 was cloned under the control of a tightly regulated promoter in the absence of the gene for its cognate inhibitor. Combination of this killing cassette with a stringent regulatory element provided a substrate-dependent conditional suicide system that was exploited for the biological containment of a Pseudomonas putida strain. The lethality of a single gene copy and the distinct and universal cellular target of the antibiotic suggest colicin E3 as an ideal candidate for combination with other lethal functions to design highly efficient containment systems for microorganisms.

Free-living energy expenditure assessed by two different methods in rural Gambian men

OBJECTIVE

To assess total free-living energy expenditure (EE) in Gambian farmers with two independent methods, and to determine the most realistic free-living EE and physical activity in order to establish energy requirements for rural populations in developing countries.

DESIGN

In this cross-sectional study two methods were applied at the same time.

SETTING

Three rural villages and Dunn Nutrition Centre Keneba, MRC, The Gambia.

SUBJECTS

Eight healthy, male subjects were recruited from three rural Gambian villages in the sub-Sahelian area (age: 25 +/- 4y; weight: 61.2 +/- 10.1 kg; height: 169.5 +/- 6.5 cm, body mass index: 21.2 +/- 2.5 kg/m2).

INTERVENTION

We assessed free-living EE with two inconspicuous and independent methods: the first one used doubly labeled water (DLW) (2H2 18O) over a period of 12 days, whereas the second one was based on continuous heart rate (HR) measurements on two to three days using individual regression lines (HR vs EE) established by indirect calorimetry in a respiration chamber. Isotopic dilution of deuterium (2H2O) was also used to assess total body water and hence fat-free mass (FFM).

RESULTS

EE assessed by DLW was found to be 3880 +/- 994 kcal/day (16.2 +/- 4.2 MJ/day). Expressed per unit body weight the EE averaged 64.2 +/- 9.3 kcal/kg/d (269 +/- 38 kJ/kg/d). These results were consistent with the EE results assessed by HR: 3847 +/- 605 kcal/d (16.1 +/- 2.5 MJ/d) or 63.4 +/- 8.2 kcal/kg/d (265 +/- 34kJ/kg/d). Physical activity index, expressed as a multiple of basal metabolic rate (BMR), averaged 2.40 +/- 0.41 (DLW) or 2.40 +/- 0.28 (HR).

CONCLUSIONS

These findings suggest an extremely high level of physical activity in Gambian men during intense agricultural work (wet season). This contrasts with the relative food shortage, previously reported during the harvesting period. We conclude that the assessment of EE during the agricultural season in non-industrialized countries needs further investigations in order to obtain information on the energy requirement of these populations. For this purpose the use of the DLW and HR methods have been shown to be useful and complementary.

The two-step lysis system of pneumococcal bacteriophage EJ-1 is functional in gram-negative bacteria: triggering of the major pneumococcal autolysin in Escherichia coli

The holin function Ejh of the pneumococcal bacteriophage EJ-1 has been characterized. It shows structural features similar to, and functionally complemented, the prototype member of the holin family. In Escherichia coli and Pseudomonas putida the Ejh product caused cellular death, and changes in cell morphology could be accounted for by lesions in the cytoplasmic membrane. Expression of ejh resulted in the inhibition of growth in a variety of phylogenetically distant bacterial genera, suggesting a broad spectrum of action. Concomitant expression of the ejh and ejl (encodes a lysin) genes led to lysis of E. coli and P. putida cells. Remarkably, the Ejl lysin was able to attack murein from bacteria lacking choline in their sacculi, which suggests that pneumococcal lysins have a broader substrate specificity than previously assumed. Furthermore, the Ejh holin was able to trigger activity of the major pneumococcal autolysin cloned and expressed in E. coli, and this raised new questions about the regulation of this model autolysin. A new function for holins in systems where the phage lysin is supposed to be associated with the membrane is proposed.

Lipolytic effects of beta1, beta2 and beta3-adrenergic agonists in isolated human fat cells from omental and retroperitoneal adipose tissues

The presence of beta1- and beta2-adrenoceptors has been clearly established in human fat cells. There is some controversy about the presence and function of beta3-adrenoceptors. It is well established that there are marked regional variations in catecholamine-induced lipolysis. In this work the possibility that a beta3-adrenoceptor plays a significant role in the control of lipid mobilization is studied and also its importance in comparison to beta1- and beta2-adrenoceptors in isolated human fat cells, is evaluated, by measuring the in vitro lipolysis induced by dobutamine, salbutamol, metaproterenol, BRL 37344 and CGP 12177A. Human adipocytes from omental and retroperitoneal fat deposits exhibited an "atypical" beta-adrenergic response but, given the small lipolytic effect initiated by BRL 37344 and CGP 12177A, they are probably poorly equipped in functional beta3-adrenoceptors.

Looking forward: using a sociocultural perspective to reframe the study of learning disabilities. VODD group

The purpose of this series has been to invite educators involved with individuals with learning disabilities to look through other lenses and listen to other voices. In this article, the authors use a sociocultural perspective of teaching and learning, based on cultural-historical and activity theory, to synthesize the articles of this series and to project where inquiry in the field of learning disabilities might be headed. A model is used to organize the discussion and help illuminate the sociocultural nature of the pathways of ideas, expectations, and activities that either foster or hinder students' school experiences. This final article invites readers to refocus and reframe their conversations about learning disabilities based on the "new visions" that have been presented in this series.

Clinical pathways: improving patient education and influencing readmission rates

Clinical pathways have long been used as a mechanism for implementing a managed care delivery system. They have been effective in highlighting lengths of stay, outcome variances, and systems problems. Clinical pathways play an important part in enhancing quality improvement activities, especially in accordance with the standards of the Joint Commission on Accreditation of Healthcare Organizations. This article addresses benefits of clinical pathways in general, and benefits at the authors' facility in particular, specifically, a clinical pathway's effectiveness in influencing readmissions of patients with atrial fibrillation.

Appearance of resistance to beta-lactam antibiotics during therapy for Streptococcus pneumoniae meningitis

A young boy had meningitis caused by Streptococcus pneumoniae that was relatively resistant to penicillin and susceptible to cefotaxime. After 10 days of therapy with penicillin and cefotaxime, fever recurred and a second lumbar puncture revealed a pneumococcus that was resistant to all beta-lactam antibiotics. We now add vancomycin to empiric third-generation cephalosporin therapy for meningitis in children when gram-positive cocci are seen on the cerebrospinal fluid smear.

Potentiation of insulin stimulation of phosphatidylinositol 3-kinase by thiazolidinedione-derived antidiabetic agents in Chinese hamster ovary cells expressing human insulin receptors and L6 myotubes

Thiazolidinedione derivatives are insulin-sensitizing agents with proven antidiabetic activities in vivo. To explore the mechanism of action of this class of compounds, the effects of pioglitazone, CP-86,325, and AD-5075 on elements of the insulin signal transduction pathways were studied in Chinese hamster ovary cells overexpressing human insulin receptor (CHO.T) and L6 myotubes. In CHO.T cells, the binding of insulin to its receptor and the insulin-stimulated tyrosine kinase activity of the receptor were not altered by pioglitazone or CP-86,325. In contrast, treatment of CHO.T cells with the compounds resulted in significant increases in insulin-stimulated phosphatidylinositol (PI) 3-kinase activity. This insulin-enhancing effect was also observed in L6 myotubes treated with CP-86,325. The augmentations in kinase activity observed in CHO.T cells correlated with increases in the amount of PI 3-kinase (p85 subunit) in anti-phosphotyrosine immunoprecipitates of cell lysates. No gross changes in the tyrosine phosphorylation state of the insulin receptor substrate-1 were detected in insulin-stimulated CHO.T cells following treatment with the compounds. Furthermore, the compounds did not enhance insulin stimulation of mitogen-activated protein kinase or DNA synthesis in CHO.T cells. Thus, thiazolidinedione-derived antidiabetic agents may act as insulin sensitizers by augmenting insulin stimulation of PI 3-kinase activity in a rather specific manner.

Carboxy-terminal deletion analysis of the major pneumococcal autolysin

Autolysins are endogenous enzymes that specifically degrade the covalent bonds of the cell walls and eventually can induce bacterial lysis. One of the best-characterized autolysins, the major pneumococcal LytA amidase, has evolved by the fusion of two domains, the N-terminal catalytic domain and the C-terminal domain responsible for the binding to cell walls. The precise biochemical role played by the six repeat units that form the C-terminal domain of the LytA amidase has been investigated by producing serial deletions. Biochemical analyses of the truncated mutants revealed that the LytA amidase must contain at least four units to efficiently recognize the choline residues of pneumococcal cell walls. The loss of an additional unit dramatically reduces its hydrolytic activity as well as the binding affinity, suggesting that the catalytic efficiency of this enzyme can be considerably improved by keeping the protein attached to the cell wall substrate. Truncated proteins lacking one or two repeat units were more sensitive to the inhibition by free choline than the wild-type enzyme, whereas the N-terminal catalytic domain was insensitive to this inhibition. In addition, the truncated proteins were inhibited by deoxycholate (DOC), and the expression of a LytA amidase lacking the last 11 amino acids in Streptococcus pneumoniae M31, a strain having a deletion in the lytA gene, conferred to the cells an atypical phenotype (Lyt+ DOC-) (cells autolysed at the end of the stationary phase but were not sensitive to lysis induced by DOC), which has been previously observed in some clinical isolates of pneumococci. Our results are in agreement with the existence of several choline-binding sites and suggest that the stepwise acquisition of the repeat units and the tail could be considered an evolutionary advantage for the enzyme, since the presence of these motifs increases its hydrolytic activity.