Glutamate Chemical Exchange Saturation Transfer (GluCEST) MRI to Evaluate the Rapid Antidepressant Effects of Ketamine in the Hippocampus of Rat Depression Model

BACKGROUND

Ketamine is a quick acting antidepressant drug, and an accurate detection method is lacking. Ketamine's effects in a rat depression model have not previously been well explored using glutamate chemical exchange saturation transfer (GluCEST).

PURPOSE

To investigate the GluCEST changes of chronic unpredictable mild stress (CUMS) rats after receiving either ketamine or saline injection.

STUDY TYPE

Randomized animal model trial.

ANIMAL MODEL

12 CUMS and 6 Sprague-Dawley rats. Divided into three groups: ketamine (N = 6), saline (N = 6), and control (N = 6).

FIELD STRENGTH/SEQUENCE

7.0 T/the sequence is GluCEST and 1 H MR spectroscopy (MRS).

ASSESSMENT

The CUMS rats were exposed to different stress factors for 8 weeks. The glutamate concentration in the hippocampus was assessed by the GluCEST,1 H MRS, and the high-performance liquid chromatography (HPLC).

STATISTICAL TESTS

The t-test, Mann-Whitney U test, and Pearson's correlation.

RESULTS

In depression conditions, GluCEST signals were lower in the bilateral hippocampus than in control group. Thirty minutes after ketamine injection, the GluCEST signals in the bilateral hippocampus were higher compared with the saline group (left: 2.99 ± 0.34 [Control] vs. 2.44 ± 0.20 [Saline] vs. 2.85 ± 0.11 [Ketamine]; right: 2.97 ± 0.28 [Control] vs. 2.49 ± 0.25 [Saline] vs. 2.86 ± 0.19 [Ketamine]). In 1 H MRS, significant changes were only observed in the left hippocampus (2.00 ± 0.16 [Control] vs. 1.81 ± 0.09 [Saline] vs. 2.04 ± 0.14 [Ketamine]). Furthermore, HPLC results showed similar trends to those observed in the GluCEST results (left: 2.32 ± 0.22 [Control] vs. 1.96 ± 0.11 [Saline] vs. 2.18 ± 0.11 [Ketamine]; right: 2.35 ± 0.18 [Control] vs. 1.87 ± 0.16 [Saline] vs. 2.09 ± 0.08 [Ketamine]).

DATA CONCLUSION

GluCEST can sensitively evaluate the ketamine's antidepressant effects by detecting the fast increase in glutamate concentration.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY STAGE: 1.

Preclinical multi-physiologic monitoring of immediate-early responses to diverse treatment strategies in breast cancer by optoacoustic imaging

Optoacoustic imaging enables the measurement of tissue oxygen saturation (sO2) and blood perfusion while being utilized for detecting tumor microenvironments. Our aim was to employ multispectral optoacoustic tomography (MSOT) to assess immediate-early changes of hemoglobin level and sO2 within breast tumors during diverse treatments. Mouse breast cancer models were allocated into four groups: control, everolimus (EVE), paclitaxel (PTX), and photodynamic therapy (PDT). Hemoglobin was quantified daily, as well as sO2 and blood perfusion were verified by immunohistochemical (IHC) staining. MSOT showed a temporal window of enhanced oxygenation and improved perfusion in EVE and PTX groups, while sO2 consistently remained below baseline in PDT. The same results were obtained for the IHC. Therefore, MSOT can monitor tumor hypoxia and indirectly reflect blood perfusion in a non-invasive and non-labeled way, which has the potential to monitor breast cancer progression early and enable individualized treatment in clinical practice.

[Long-term outcomes of intravascular ultrasound-guided drug-eluting stents implantation in patients with acute coronary syndrome: ULTIMATE ACS subgroup]

Objective: To explore the long-term effects of intravascular ultrasound (IVUS) guidance on patients with acute coronary syndrome (ACS) undergoing drug-eluting stents (DES) implantation. Methods: Data used in this study derived from ULTIMATE trial, which was a prospective, multicenter, randomized study. A total of 1 448 all-comer patients were enrolled between 2014 August and 2017 May. Primary endpoint of this study was target vessel failure (TVF) at 3 years, including cardiac death, target-vessel-related myocardial infarction, and clinically-driven target vessel revascularization. Results: ACS was present in 1 136 (78.5%) patients, and 3-year clinical follow-up was available in 1 423 patients (98.3%). TVF in the ACS group was 9.6% (109/1 136), which was significantly higher than 4.5% (14/312) in the non-ACS group (log-rank P=0.005). There were 109 TVFs in the ACS patients, with 7.6% (43/569) TVFs in the IVUS group and 11.6% (66/567) TVFs in the angiography group (log-rank P=0.019). Moreover, patients with optimal IVUS guidance were associated with a lower risk of 3-year TVF compared to those with suboptimal IVUS results (5.4% (16/296) vs. 9.9% (27/273),log-rank P=0.041). Conclusions: This ULTIMATE-ACS subgroup analysis showed that ACS patients undergoing DES implantation were associated with a higher risk of 3-year TVF. More importantly, the risk of TVF could be significantly decreased through IVUS guidance in patients with ACS, especially in those who had an IVUS-defined optimal procedure.

Erratum: Multifunctional Nanosnowflakes for T1-T2 Double-Contrast Enhanced MRI and PAI Guided Oxygen Self-Supplementing Effective Anti-Tumor Therapy [Corrigendum]

[This corrects the article DOI: 10.2147/IJN.S379526.].

Multifunctional Nanosnowflakes for T1-T2 Double-Contrast Enhanced MRI and PAI Guided Oxygen Self-Supplementing Effective Anti-Tumor Therapy

Introduction

Accurate tumor diagnosis is essential to achieve the ideal therapeutic effect. However, it is difficult to accurately diagnose cancer using a single imaging method because of the technical limitations. Multimodal imaging plays an increasingly important role in tumor treatment. Photodynamic therapy (PDT) has received widespread attention in tumor treatment due to its high specificity and controllable photocytotoxicity. Nevertheless, PDT is susceptible to tumor microenvironment (TME) hypoxia, which greatly reduces the therapeutic effect of tumor treatment.

Methods

In this study, a novel multifunctional nano-snowflake probe (USPIO@MnO2@Ce6, UMC) for oxygen-enhanced photodynamic therapy was developed. We have fabricated the honeycomb-like MnO2 to co-load chlorin e6 (Ce6, a photosensitizer) and ultrasmall superparamagnetic iron oxide (USPIO, T1-T2 double contrast agent). Under the high H2O2 level of tumor cells, UMC efficiently degraded and triggered the exposure of photosensitizers to the generated oxygen, accelerating the production of reactive oxygen species (ROS) during PDT. Moreover, the resulting USPIO and Mn2+ allow for MR T1-T2 imaging and transformable PAI for multimodal imaging-guided tumor therapy.

Results

TEM and UV-vis spectroscopy results showed that nano-snowflake probe (UMC) was successfully synthesized, and the degradation of UMC was due to the pH/ H2O2 responsive properties. In vitro results indicated good uptake of UMC in 4T-1 cells, with maximal accumulation at 4 h. In vitro and in vivo experimental results showed their imaging capability for both T1-T2 MR and PA imaging, providing the potential for multimodal imaging-guided tumor therapy. Compared to the free Ce6, UMC exhibited enhanced treatment efficiency due to the production of O2 with the assistance of 660 nm laser irradiation. In vivo experiments confirmed that UMC achieved oxygenated PDT under MR/PA imaging guidance in tumor-bearing mice and significantly inhibited tumor growth in tumor-bearing mice, exhibiting good biocompatibility and minimal side effects.

Conclusion

The multimodal imaging contrast agent (UMC) not only can be used for MR and PA imaging but also has oxygen-enhanced PDT capabilities. These results suggest that UMC may have a good potential for further clinical application in the future.

Testing telediagnostic thyroid ultrasound in Peru: a new horizon in expanding access to imaging in rural and underserved areas

PURPOSE

Thyroid ultrasound is a key tool in the evaluation of the thyroid, but billions of people around the world lack access to ultrasound imaging. In this study, we tested an asynchronous telediagnostic ultrasound system operated by individuals without prior ultrasound training which may be used to effectively evaluate the thyroid and improve access to imaging worldwide.

METHODS

The telediagnostic system in this study utilizes volume sweep imaging (VSI), an imaging technique in which the operator scans the target region with simple sweeps of the ultrasound probe based on external body landmarks. Sweeps are recorded and saved as video clips for later interpretation by an expert. Two operators without prior ultrasound experience underwent 8 h of training on the thyroid VSI protocol and the operation of the telemedicine platform. After training, the operators scanned patients at a health center in Lima. Telediagnostic examinations were sent to the United States for remote interpretation. Standard of care thyroid ultrasound was performed by an experienced radiologist at the time of VSI examination to serve as a reference standard.

RESULTS

Novice operators scanned 121 subjects with the thyroid VSI protocol. Of these exams, 88% were rated of excellent image quality showing complete or near complete thyroid visualization. There was 98.3% agreement on thyroid nodule presence between VSI teleultrasound and standard of care ultrasound (Cohen's kappa 0.91, P < 0.0001). VSI measured the thyroid size, on average, within 5 mm compared to standard of care. Readers of VSI were also able to effectively characterize thyroid nodules, and there was no significant difference in measurement of thyroid nodule size (P = 0.74) between VSI and standard of care.

CONCLUSION

Thyroid VSI telediagnostic ultrasound demonstrated both excellent visualization of the thyroid gland and agreement with standard of care thyroid ultrasound for nodules and thyroid size evaluation. This system could be deployed for evaluation of palpable thyroid abnormalities, nodule follow-up, and epidemiological studies to promote global health and improve the availability of diagnostic imaging in underserved communities.

Radiographic and CT appearance of cavitary pulmonary lesions in a lamb

BACKGROUND

Pulmonary abscesses may be cavitary lesions on thoracic radiographs and computed tomography (CT).

CASE REPORT

A 26-day-old, cross-breed lamb presented for respiratory distress despite procaine penicillin treatment. Thoracic radiographs revealed several pulmonary ovoid thin-walled gas and soft tissue opacity structures. CT showed that these gas-filled structures enclosed mildly contrast enhancing soft tissue attenuating material and surrounded the lobar bronchus to the right middle and caudal lung lobes. Imaging revealed pulmonary cavitary lesions, and chronic pulmonary abscesses was confirmed with histopathology on samples obtained from a right caudal lung lobectomy.

CONCLUSION

To the authors' knowledge, this is the first radiographic and CT report of cavitary pulmonary lesions in a lamb. The pulmonary abscesses in this case were suspected to be due aspiration pneumonia occurring during bottle feeding, along with the high possibility of failure of passive transfer from its orphan history.

[Long-term outcomes of intravascular ultrasound-guided drug-eluting stent implantation in patients with chronic kidney disease: ULTIMATE CKD subgroup analysis]

Objective: To explore the long-term effect of intravascular ultrasound (IVUS) guidance on patients with chronic kidney disease (CKD) undergoing drug-eluting stent (DES) implantation. Methods: Data used in this study derived from ULTIMATE trial, which was a prospective, multicenter, randomized study. From August 2014 to May 2017, 1 448 patients with coronary heart disease undergoing DES implantation were selected from 8 domestic centers and randomly divided into two groups in the ratio of 1∶1 (IVUS or coronary angiography guided stent implantation). A total of 1 443 patients with the baseline serum creatine available were enrolled. The patients were divided into CKD group and non CKD group. CKD was defined as the estimated glomerular filtration rate (eGFR) derived from Cockcroft Gault (CG) formula< 60 ml·min^-1·1.73 m^-2 for at least 3 months. Primary endpoint of this study was target vessel failure (TVF) at 3 years, including cardiac death, target vessel myocardial infarction, and clinically-driven target vessel revascularization. Kaplan Meier method was used for survival analysis, and log rank test was used to compare the occurrence of end-point events in each group. Cox proportional hazards model was used to calculate HR and 95%CI, and interaction was tested. Multivariate Cox regression was used to analyze the independent influencing factors of TVF. Results: A total of 1 443 patients with coronary heart disease were enrolled in this study, including 349 (24.2%) patients in CKD group and 1 094 patients in non CKD group. In CKD group, IVUS was used to guide stent implantation in 180 cases and angiography was used in 169 cases; in non CKD group, IVUS was used to guide stent implantation in 543 cases and angiography was used in 551 cases. Three-year clinical follow-up was available in 1 418 patients (98.3%). The incidence of TVF in CKD group was 12.0% (42/349), which was higher than that in non CKD group (7.4% (81/1 094) (P = 0.01). The difference was mainly due to the higher cardiac mortality in CKD group (4.6% (16/349) vs. 1.5% (16/1094), P<0.001). In CKD group, the incidence of TVF in patients who underwent IVUS guided stent implantation was lower than that in angiography guided stent implantation (8.3% (15/180) vs. 16.0% (27/169), P = 0.03). There was no significant difference in the incidence of TVF between IVUS guided stent implantation and angiography guided stent implantation in non CKD group (5.9% (32/543) vs. 8.9% (49/551), P = 0.06), and there was no interaction (P = 0.47). Multivariate Cox regression analysis showed that IVUS guidance (HR = 0.56, 95%CI 0.39-0.81, P = 0.002), CKD (HR = 1.83, 95%CI 1.17-2.87, P = 0.010) and stent length (every 10 mm increase) (HR = 1.11, 95%CI 1.04-1.19, P = 0.002) were independent risk factors for TVF within 3 years after DES implantation. Conclusions: CKD patients undergoing DES implantation are associated with a higher risk of 3-year TVF. More importantly, the risk of TVF could be significantly decreased through IVUS guidance in comparison with angiography guidance in patients with CKD.

Zinc mediates resuscitation of lactic acid-injured Escherichia coli by relieving oxidative stress

AIMS

Lactic acid is a natural antimicrobial in food industry, and also exists in fermented food. It was reported that sublethally injured Escherichia coli could survive in acidic conditions. When conditions become advantageous, injured E. coli can restore physiological function, which is a potential threat in food industry. Recovery is a necessary step for discriminating injured bacteria, but the resuscitation mechanism of injured bacteria is still unknown.

METHODS AND RESULTS

In our study, sublethal lactic acid treatment (pH 4·2, 60 min) posed oxidative stress on E. coli by decrease of superoxide dismutase (SOD) activity and overproduction of reactive oxygen species (ROS). Zinc with low concentration (1·0 mmol l^-1 ) significantly increased the recovery ratio of injured E.coli induced by lactic acid. The recovery ratios of injured cell in minimal A medium (minA) with 1·0 mmol l^-1 zinc reached to that with 3·0 mmol l^-1 catalase (CAT). Conversely, the addition of zinc chelator N, N, N', N'-tetrakis (2-pyridylmethyl) decreased the recovery ratio. Zinc accelerated resuscitation of injured E. coli by improving SOD activity, and decreasing ROS production. Deletion of sodC encoding Cu/ZnSOD, katE/katG encoding CAT or regulating gene rpoS significantly decreased the recovery ratio. Among all of the mutants in this study, ΔrpoS and ΔsodC showed the lowest recovery ratio, which means they played significant roles in the process of resuscitation.

CONCLUSION

We provided direct evidence that zinc mediated resuscitation of lactic acid-injured E. coli by relieving oxidative stress. Zinc can be used as a low-cost and effective agent to improve recovery ratio and detection efficiency of injured bacteria.

SIGNIFICANCE AND IMPACT OF THE STUDY

Antibacterial agents are a challenge for bacteria, but bacteria can survive as a sublethally injured state under stresses. Using injured E. coli induced by lactic acid as a model organism, we validated the significant role of zinc on resuscitation of injured cells.

Development of loop-mediated isothermal amplification assays for genotyping of Type III Secretion System in Pseudomonas aeruginosa

Pseudomonas aeruginosa is a well-known environmental bacterium capable of causing a variety of life-threatening human infections, with a Type III Secretion System (T3SS) as the most significant virulence determinant. P. aeruginosa strains exhibit unique T3SS virulence genotypes defined by the presence of either exoS or exoU. In this study, loop-mediated isothermal amplification (LAMP) assays for rapid detection of exoS and exoU in P. aeruginosa have been developed and evaluated. Set of four primers were designed for LAMP-based amplification of exoS and exoU respectively. The LAMP reactions were performed at 63°C for 40 min, with detection limits of 100 fg purified DNA. In 107 river water isolates, exoS and exoU were detected in 10 (9%) and 89 (83%) isolates, respectively, and in 38 soil isolates, they were detected in 7 (18%) and 31 (82%) cases respectively. In conclusion, the LAMP assays are rapid, simple and cost-effective tools for detection of the exoU- and exoS-types of P. aeruginosa strains.

SIGNIFICANCE AND IMPACT OF THE STUDY

This method can be used for the rapid, sensitive and low-cost detection of genes (exoS and exoU) encoding proteins that are part of Type III Secretion System of Pseudomonas aeruginosa. It can serve as an efficient method in outbreak situations or in routine surveillance studies to judge virulence potential and to investigate pathogenesis of P. aeruginosa.

Feasibility of a novel abluminal groove-filled biodegradable polymer sirolimus-eluting stent in patients with complex anatomical and clinical scenarios

AIM

We aimed to investigate the feasibility, initial safety and efficacy of coronary intervention using FIREHAWK®, a novel abluminal groove-filled biodegradable polymer sirolimus-eluting stent (SES), in patients with complex anatomical and clinical scenarios.

METHODS

A total of 57 patients (79 lesions) with complex anatomical and clinical scenarios implanted with the FIREHAWK® SES between March and November 2014 were studied. The primary endpoint was target lesion failure (TLF), a composite endpoint of cardiac death, target vessel-myocardial infarction (TV-MI), and ischemia-driven target lesion revascularization (iTLR). Optical coherence tomography and intravascular ultrasound was performed according to the discretion of operators.

RESULTS

28.1% of patients presented acute myocardial infarction and all patients had at least one of the following anatomical and locational complexity: multi-vessel disease (64.9%), left main disease (24.6%), chronic total occlusion (17.5%), bifurcation (56.1%), and heavily calcified lesions (10.5%). One patients experienced coronary perforation during the procedure and resolved without any additional treatment. Device success was 100%, clinical success was 100%. There was 1 (1.8%) TLF occurred at follow-up of 150 ± 65 days. One patients had non-iTLR. Out of 2 non-Q-wave MI, 1 patient experienced TV-MI, but no death and stent thrombosis were reported. OCT and IVUS imaging showed a high rate of covered struts and low neointimal hyperplasia at follow-up.

CONCLUSION

The study showed the feasibility, initial safety and efficacy of coronary intervention using FIREHAWK® SES for treating patients with complex anatomical and clinical scenarios. The performance of the FIREHAWK® SES in complex patients justifies the conduct of a large, randomized trial.

Diverse bacterial groups are associated with corrosive lesions at a Granite Mountain Record Vault (GMRV)

AIMS

This study applied culture-dependent and molecular approaches to examine the bacterial communities at corrosion sites at Granite Mountain Record Vault (GMRV) in Utah, USA, with the goal of understanding the role of microbes in these unexpected corrosion events.

METHODS AND RESULTS

Samples from corroded steel chunks, rock particles and waters around the corrosion pits were collected for bacterial isolation and molecular analyses. Bacteria cultivated from these sites were identified as members of Alphaproteobacteria, Gammaproteobacteria, Firmicutes and Actinobacteria. In addition, molecular genetic characterization of the communities via nested-polymerase chain reaction-denaturing gradient gel electrophoresis (DGGE) indicated the presence of a broad spectrum of bacterial groups, including Alphaproteobacteria, Betaproteobacteria, Deltaproteobacteria, Actinobacteria, Firmicutes and Bacteroidetes. However, neither cultivation nor molecular approaches identified sulfate-reducing bacteria (SRB), the bacteria commonly implicated as causative organisms were found associated with corrosive lesions in a process referred to as microbially influenced corrosion (MIC). The high diversity of bacterial groups at the corrosion sites in comparison with that seen in the source waters suggested to us a role for the microbes in corrosion, perhaps being an expression of a redox-active group of microbes transferring electrons, harvesting energy and producing biomass.

CONCLUSIONS

The corrosion sites contained highly diverse microbial communities, consistent with the involvement of microbial activities along the redox gradient at corrosion interface. We hypothesize an electron transport model for MIC, involving diverse bacterial groups such as acid-producing bacteria (APB), SRB, sulfur-oxidizing bacteria (SOB), metal-reducing bacteria (MRB) and metal-oxidizing bacteria (MOB).

SIGNIFICANCE AND IMPACT OF THE STUDY

The characterization of micro-organisms that influence metal-concrete corrosion at GMRV has significant implications for corrosion control in high-altitude freshwater environments. MIC provides a potential opportunity to further our understandings of extracellular electron transfer and interspecies communications.

Scientific rationale for the surgical and prosthodontic protocol for immediately loaded root form implants in the completely edentulous patient

This paper discusses a modified surgical and prosthodontic protocol to place implants in the completely edentulous patient. Methods for presurgical, prosthodontic workup, impression transfer technique, provisionalization, and attachment placement are also discussed.

The effect of surfactant on birthweight-specific neonatal mortality rate, New York City

PURPOSE

Surfactant has been shown to cause decreased neonatal mortality rate (NMR) in randomized studies of preterm infants. It is not clear whether the introduction of surfactant caused a decrease in neonatal mortality in a community. This study explores the hypothesis that the introduction of surfactant in 1990 to 1991 explains a decrease in neonatal mortality in New York City (NYC) among infants with birthweight of 500 to 1499 g.

METHODS

For each of the 20 hospitals in New York City that began using surfactant in 1990 or 1991, we compared the NMR in the 2 years before the introduction of surfactant with the NMR in the 2 years after its introduction. Poisson regression models were fit to the death rates, adjusting for birthweight and other determinants of neonatal mortality.

RESULTS

NMR in the 20 hospitals decreased by 13.7% (from 231.3 to 199.6 neonatal deaths per 1000 live births). This decrease remained significant after adjusting for birthweight and other risk factors. Infants with birthweight 1000 to 1249 grams benefited most from the introduction of surfactant; their NMR decreased by 19.6%. After adjusting for birthweight, those born before the introduction of surfactant were 1.18 times as likely to die in the first 27 days as those born after the introduction of surfactant (95% CI 1.04, 1.33).

CONCLUSION

It appears that surfactant had a significant impact on NMR in NYC among very low birthweight babies.

A unique drug treatment program for pregnant and postpartum substance-using women in New York City: results of a pilot project, 1990-1995

In the 1980s, there was virtually no drug treatment for pregnant women in New York City, especially women who used crack cocaine. The purpose of the Parent and Child Enrichment (PACE) demonstration project was to assess the effectiveness of the one-stop shopping model of drug treatment for this population. Among PACE clients, 88% were primarily users of crack cocaine. The mean total length of stay was 100.0 days (median 55.5 days). Client retention 42 days after intake was 54.3%. This paper describes the essential components of this program model. "Long-stay" and "short-stay" clients were compared using urine toxicology tests and activity logs. In addition, the birth outcomes of clients were compared to two similar populations. A strong positive correlation was found between total length of stay and low rate of positive urine drug tests (UDTs). Infants of PACE long-stay clients had greater mean birth weight, less low birth weight, and less intrauterine growth retardation than the infants of the comparison groups. Fetal exposure to cocaine was decreased dramatically among women who were enrolled for 42 or more days during their pregnancy. This model of drug treatment for pregnant and postpartum women seems to improve mothers' lives, fetal drug exposure, and birth outcome significantly.

[X-ray diffraction spectrum of heroin]

In this paper, practical measured X-ray diffraction spectra of heroin and opium are given and the parameters of each diffraction peak of the heroin are listed. The heroin belongs to orthorhombic crystal system; the basic vectors of the primitive cell are: a = 8.003, b = 14.373, c = 16.092 x 10(-10) m. As compared with the standard spectra of pure heroin and sucrose, the main doped additive checked by us, is sugar affirmatively.

The relationship between neurally mediated hypotension and the chronic fatigue syndrome

OBJECTIVE

To compare the clinical symptoms and response evoked by upright tilt-table testing in healthy individuals and in a sample of those satisfying strict criteria for chronic fatigue syndrome.

DESIGN

Case-comparison study with mean (SD) follow-up of 24 (5) weeks.

SETTING

Tertiary care hospital.

PATIENTS AND OTHER PARTICIPANTS

A sample of 23 patients with chronic fatigue syndrome (five men and 18 women; mean age, 34 years), each of whom fulfilled the strict diagnostic criteria of the Centers for Disease Control and Prevention, was recruited from regional chronic fatigue support groups and from the investigators' clinical practices. There were 14 healthy controls (four men and 10 women; mean age, 36 years).

INTERVENTIONS

Each subject completed a symptom questionnaire and underwent a three-stage upright tilt-table test (stage 1, 45 minutes at 70 degrees tilt; stage 2, 15 minutes at 70 degrees tilt with 1 to 2 micrograms/min of isoproterenol; and stage 3, 10 minutes at 70 degrees with 3 to 4 micrograms/min of isoproterenol). Patients were offered therapy with fludrocortisone, beta-adrenergic blocking agents, and disopyramide, alone or in combination, directed at neurally mediated hypotension.

MAIN OUTCOME MEASURES

Response to upright tilt and scores on symptom questionnaires prior to and during follow-up.

RESULTS

An abnormal response to upright tilt was observed in 22 of 23 patients with chronic fatigue syndrome vs four of 14 controls (P < .001). Seventy percent of chronic fatigue syndrome patients, but no controls, had an abnormal response during stage 1 (P < .001). Nine patients reported complete or nearly complete resolution of chronic fatigue syndrome symptoms after therapy directed at neurally mediated hypotension.

CONCLUSIONS

We conclude that chronic fatigue syndrome is associated with neurally mediated hypotension and that its symptoms may be improved in a subset of patients by therapy directed at this abnormal cardiovascular reflex.

Value of standardized gestational age charts for fetuses of first-generation Oriental immigrants to Canada

OBJECTIVE

to ascertain if standard gestational age charts can be used to accurately predict the gestational age of fetuses of first-generation Oriental immigrants to Canada.

PATIENTS AND METHODS

Over a 3-year period, all patients presenting for obstetric ultrasound examinations were invited to participate in the study. The authors recorded biparietal diameter, head circumference, femur length and abdominal circumference for 139 fetuses in the second and third trimesters. A study performed in the first trimester was used as the baseline for gestational age. The data for 126 of the fetuses were complete, and these data were used for the analysis.

RESULTS

For 77 of the fetuses, both parents were Oriental, and for 49, one or both parents were not Oriental; the latter constituted the control group. A total of 1008 individual measurements were obtained, and of these, all but 14 fell within two standard deviations of the norm, according to standard gestational age charts. Of the abnormal measurements, seven were obtained from five fetuses with Oriental parents, and seven were obtained from six fetuses in the control group. The difference between the two groups in the proportion of measurements falling either above or below two standard deviations from the norm was not statistically significant (Fisher's exact test, p = 0.41694).

CONCLUSION

The authors conclude that standard gestational age charts can be used to determine gestational age in first-generation Oriental immigrants to Canada.

Resistance to HIV-1 infection. Multicenter AIDS Cohort Study

Men from the Multicenter AIDS Cohort Study were classified as "susceptible" and "resistant" to HIV infection. Resistant men were still HIV antibody negative in 1993 and were estimated to have had > 45 different anal intercourse partners (median, 92; range, 46-504) in the 2.5 years before visit 2 (1985). Susceptible men were seroconverters who were estimated to have had < 13 different anal partners (median, 4; range, 0-12). Leukocyte groups were compared between the two groups of men. Values were excluded for 12 months before the first antibody-positive visit in the susceptible men. White blood cells, polymorphonuclear neutrophils, total lymphocyte count, CD8+ percentage and number, and CD3+ and CD4+ number were higher in the resistant men. Logistic regression analyses were used to develop 50 bivariate models. Higher levels of neutrophils and CD8+ cells were included in four of the six best-fitting bivariate models, suggesting that each is associated with resistance to HIV-1 infection. These results support the hypothesis that CD8+ cells may modulate the outcome of HIV-1 exposure.

Atrial septostomy: stationary angioplasty balloon technique--experimental work and preliminary clinical applications

A new approach to creating an interatrial communication using a stationary fixed-diameter angioplasty balloon is presented. Stationary balloon septostomy was used to create an atrial communication in 19 young swine using a transseptal technique through a closed atrial septum, and in 18 newborn lambs through a patent foramen ovale. In animals with an intact septum, there was persistent patency of the atrial communication using balloons larger than 12 mm in diameter. The average diameter of the atrial communication was 96% of the expanded diameter of the angioplasty balloon. For newborn lambs with a patent foramen, a smooth oval atrial communication was noted by 4 weeks, and there was persistent patency of the opening using balloons larger than 15 mm in diameter. The average diameter of the opening was 81% of the diameter of the angioplasty balloon used. The new procedure was used successfully in five patients. All five showed resolution of the clinical symptomology. In conclusion, stationary angioplasty balloon atrial septostomy has been effective in producing interatrial communications, which remained patent for 4-14 weeks, in animals with intact septum, as well as in those with a patent foramen ovale.

Balloon angioplasty for the treatment of native coarctation: results of Valvuloplasty and Angioplasty of Congenital Anomalies Registry

Data on dilation of 141 native coarctation procedures in 140 patients between 3 days and 29 years of age were submitted to the Valvuloplasty and Angioplasty of Congenital Anomalies (VACA) Registry. Fifteen patients were less than 4 weeks old, 15 between 1 month and 12 months old and 110 patients over 1 year old. The immediate results confirmed that native coarctations could be effectively dilated in both infants and older children. The data do not support any conclusions concerning balloon size relative to results or complications. There were 24 complications (17%) reported with 1 death after 3 days and after intervening surgery in an infant with associated persistent ductus arteriosus. There were 2 early and 6 late "aneurysms" reported after the coarctation dilations with insufficient immediate and no long-term information about the significance of these. The VACA Registry data suggest that dilation of native coarctations can be performed effectively and relatively safely but do not answer whether this procedure should be performed.

Balloon dilation of miscellaneous lesions: results of Valvuloplasty and Angioplasty of Congenital Anomalies Registry

Data on 111 lesions, in addition to pulmonary valve, aortic valve, branch pulmonary stenosis, native coarctation and recoarctation, were submitted to the Valvuloplasty and Angioplasty of Congenital Anomalies Registry. Because there was a very heterogenous group of lesions both in types of lesions and techniques of dilation, only minimal data can be offered concerning the efficacy of the dilation of any or all of these lesions. The registry data do, however, demonstrate the safety of these dilations compared to alternative surgical therapy.

Balloon angioplasty for aortic recoarctation: results of Valvuloplasty and Angioplasty of Congenital Anomalies Registry

Balloon angioplasty was performed in 200 patients with recoarctation of the aorta in a multicenter prospective study. The average age at the time of the procedure was 7.0 years (range 1 month to 26 years). Systolic pressure (mean +/- standard deviation) in the ascending aorta decreased from 134.5 +/- 23.4 to 127.4 +/- 22.0 mm Hg. The descending aortic systolic pressure rose from 92.7 +/- 18.2 to 114.1 +/- 21.6 mm Hg. Peak systolic pressure differences decreased from 41.9 +/- 19.6 to 13.3 +/- 12.1 mm Hg. The diameter of the recurrent coarctation site increased from 5.2 +/- 2.9 to 8.9 +/- 3.4 mm. After angioplasty residual pressure differences of less than or equal to 20 mm Hg were found in 79.4% of the patients. Five patients died of complications related to the procedure (2.5%). Two deaths were directly related to the technical aspects of the procedure and 3 patients died because of the severity of the underlying disease. One additional patient had a cerebrovascular accident. Femoral artery complications occurred in 17 patients (8.5%) and 8 patients required surgical thrombectomy. Balloon angioplasty offers a satisfactory alternative to surgery for recurrent coarctation; both results and complications compare favorably with surgical therapy.

Evaluation of balloon angioplasty of coarctation restenosis by magnetic resonance imaging

Eight patients treated by balloon angioplasty for coarctation restenosis have been followed for 4 to 54 months (mean 40) by physical examination using Doppler pressures and by magnetic resonance imaging in a superconducting magnet operating at 0.6 tesla. Image analysis was performed by inspection and by measurement of the aorta, with particular attention to the angioplasty site and its relation to the ascending aorta at the same axial level. Similar measurements were made from immediate postangioplasty angiograms. Residual pressure gradients were 0 to 12 mm (mean 2), reflecting persistent absence of a gradient in 1 patient and further gradient reduction in 7. Images showed no aneurysm formation, mild residual or recurrent stenosis in 4 patients, minimal focal periaortic soft tissue thickening in 1 patient and an interval increase in the ratio of ballooned segment diameter to ascending aortic diameter in the 7 patients in whom it could be measured. Thus, intermediate-term results of balloon dilatation of coarctation restenosis are excellent and magnetic resonance imaging is well suited to the serial studies required in these patients.

Interventional procedures in congenital heart disease

Balloon septostomy changed the natural history of transposition of the great arteries. Relatively little more occurred in catheter treatment of congenital heart disease until the development of the balloon catheter for transluminal angioplasty. Modification of these catheters led to successful treatment of valvular pulmonic stenosis, peripheral pulmonic stenosis, and coarctation restenosis. Possible future applications of balloon valvuloplasty include valvar aortic stenosis, stenotic shunts, and palliative operations. Pulmonary arteriovenous malformations are well managed by detachable balloon techniques, and balloons and coils are used for occluding large systemic collaterals. Interventional techniques have made a significant impact on the treatment of congenital heart disease, and it is anticipated that as technology improves further advances will occur.

Reducing distress in pediatric cardiac catheterization

To examine the efficacy of rehearsal in reducing distress in 3- to 6-year-old children undergoing diagnostic cardiac catheterization, 40 children were assigned randomly to the rehearsal preparation procedure or to usual preparation. The rehearsal program involved the use of behavioral rehearsal in the catheterization laboratory, manuals to explain the procedure to the parents, and coloring books to provide parents and children with a vicarious experience of catheterization. Rehearsed patients cried, yelled for mother, complained of pain less, and showed lower rates of motor activity than did control patients. Rehearsed patients also showed less overt regressive, aggressive, and anxiety behaviors at home following the catheterization than did controls. Parents in the rehearsed group showed less anxiety following the catheterization, and negative reactions in children correlated significantly with parental anxiety. Participants' reactions were uniformly more positive in the rehearsed than in the control patients.

Prostaglandin E1 as an adjunct to emergency cardiac operation in neonates

Prostaglandin E1 (PGE1) has been used prior to operation in 28 neonates (0 to 30 days) with congenital heart disease (CHD). The patients were divided into two groups. Group I consisted of 19 neonates with CHD resulting in marked cyanosis. Thirteen patients had pulmonary atresia, three had tetralogy of Fallot, and three had complex defects with pulmonary stenosis. All patients were markedly hypoxemic. The average oxygen saturation was 41%. PGE1 infusion, 0.1 mcg/kg/min, was successful in 17 of 19 patients, as it resulted in an increase in oxygen saturation from 41% to 79%, average increase 38%. Two patients did not respond to PGE1 infusion. One was 30 days of age and the other had no patient ductus arteriosus. All of the patients underwent a palliative shunt procedure. There were three hospital deaths in this group. No patient died of hypoxemia. Group II consisted of nine patients whose CHD was predominantly that of aortic obstructive disease with clinical manifestations of cardiac failure, hypoperfusion, and acidemia. Six of these patients had complicated coarctation of the aorta. Three patients had interruption of the aortic arch. The pH of these patients averaged 7.19. PGE1 infusion resulted in improvement of the pH to average of 7.37, improvement of congestive heart failure, and reappearance of femoral pulses. One patient failed to respond. All patients in Group II underwent operation. There were three hospital deaths in this group. No patient died intraoperatively. PGE1 infusion is a valuable aid to surgical treatment of desperately ill neonates with both cyanotic and acyanotic forms of CHD.

Large-scale purification of two forms of active lac operator from plasmids

A practical procedure is described for obtaining milligram quantities of a small (29 nucleotide) Eco RI restriction fragment of DNA containing the Escherichia coli lac operator. A yield of 10--15 mg of operator is obtained from 1 kg of wet cell paste. The resultant operator is shown to be homogeneous and competitively active in filter assays. Two separable but interconvertible forms of lac operator exist in solution, probably linear duplex and hairpin isomers. Only the presumed linear form is active in binding lac repressor by competition assay, but the two isomers are interconvertible by heating to 80 degrees C. The methods described here should be generally applicable for purifying other restriction fragments from plasmids.