Maxillofacial trauma caused by e-scooters: a retrospective review prior to the extension of the UK scheme

The nationwide extension of the electric scooter (e-scooter) scheme, which began in 2020, aimed to alleviate public transport congestion, to reduce pollution and peak-time road traffic. This retrospective study evaluates the range of e-scooter-related maxillofacial trauma before the recent scheme extension and compares the findings with existing literature on this topic. The Queen Elizabeth Hospital Birmingham, United Kingdom (UK) operates as a Level 1 Regional Major Trauma Centre and serves a population of four million. All patient records between September 2021 to September 2022 were analysed to establish the types of e-scooter-related maxillofacial trauma sustained. A Pearson's chi-squared test was used to assess for significant associations between variables recorded. Falls accounted for the majority of injuries (44.3%), and soft tissue lacerations were the most common maxillofacial injury (38%). Statistically significant results were measured in the following variables: gender and intoxication status (p = 0.007), helmet status and injuries sustained in maxillofacial and non-maxillofacial regions (p = 0.043), mechanism of injury and injuries sustained in both the maxillofacial and non-maxillofacial regions (p = 0.045). E-scooters are an emerging concern within the UK. Further studies across the UK are required to assess the frequency of e-scooter-related injuries. Such data may prove useful in determining the government's decision on e-scooter use on UK roads.

Effectiveness of out-patient based acute heart failure care: a pilot randomised controlled trial

OBJECTIVES

Acute heart failure (AHF) hospitalisation is associated with 10% mortality. Outpatient based management (OPM) of AHF appeared effective in observational studies. We conducted a pilot randomised controlled trial (RCT) comparing OPM with standard inpatient care (IPM).

METHODS

We randomised patients with AHF, considered to need IV diuretic treatment for ≥2 days, to IPM or OPM. We recorded all-cause mortality, and the number of days alive and out-of-hospital (DAOH). Quality of life, mental well-being and Hope scores were assessed. Mean NHS cost savings and 95% central range (CR) were calculated from bootstrap analysis. Follow-up: 60 days.

RESULTS

Eleven patients were randomised to IPM and 13 to OPM. There was no statistically significant difference in all-cause mortality during the index episode (1/11 vs 0/13) and up to 60 days follow-up (2/11 vs 2/13) [p = .86]. The OPM group accrued more DAOH {47 [36,51] vs 59 [41,60], p = .13}. Two patients randomised to IPM (vs 6 OPM) were readmitted [p = .31]. Hope scores increased more with OPM within 30 days but dropped to lower levels than IPM by 60 days. More out-patients had increased total well-being scores by 60 days (p = .04). OPM was associated with mean cost savings of £2658 (95% CR 460-4857) per patient.

CONCLUSIONS

Patients with acute HF randomised to OPM accrued more days alive out of hospital (albeit not statistically significantly in this small pilot study). OPM is favoured by patients and carers and is associated with improved mental well-being and cost savings.

A Cervical Thymic Cyst in an Adult Female; A Case Report and Comprehensive Literature Review

Introduction: Cervical thymic cyst accounts for (0.3-1) % of cervical cysts in children and are usually present during the first decade of life with few reported cases in adults. Herein, we present a 34-year-old female with a cervical thymic cyst. We conducted a review of all the previously reported cases as well. Case presentation: The patient complained of an anterolateral neck swelling that was noticed one year ago. It was a soft, fluctuant, mobile, non-tender swelling in the midline and the right side of the lower neck. Neck ultrasonography revealed a large thin-walled cyst, with no internal septa, echoes, or solid parts. Post-contrast MRI of the neck showed a well-defined, oblong-shaped, lobulated cystic lesion just beneath the strap muscle. The cyst extended caudally to the superior border of the anterior mediastinum at the level of the upper border of the manubrium sterni. The patient underwent excision of the swelling under general anesthesia via Kocher's collar neck incision. Connection with the thymus gland was detected behind the manubrium sterni which was separated. Pathological examination showed prominent thymic tissue confirming the diagnosis of a cervical thymic cyst. Conclusion: Adult cervical thymic cyst is very rare with a few cases reported in the literature. Surgical excision in symptomatic patients is the treatment of choice. Paper's main novel aspects: • A rare presentation of a cervical thymic cyst in an adult. • A comprehensive literature review including all the previously reported cases in one table.

Justifying the implementation of intraoperative computed tomography for midface fracture treatment in improving outcomes

Intraoperative CT scanning is the international standard for treating midface fractures as it allows intraoperative assessment of reduction and fixation. To our knowledge, no NHS hospital in the UK has this facility yet due to the financial and logistical burden of its implementation. The aim of this study was to determine if complications including the requirement for a return to theatre (RTT) could have been predicted from the post-fixation CT scan. All treated midface fractures that had presented to a regionalised major trauma centre within two years (01 January 2020 - 31 December 2021) were identified. Those developing complications including RTT were determined. All postoperative CT scans (including those without complication or RTT) were re-analysed with the clinicians blinded to the outcomes to determine the positive predictive value (PPV) and negative predictive value (NPV) of requiring RTT to alter plate position intraoperatively based on CT scan alone. In all, there were eight episodes of unplanned return to theatre, resulting in an overall RTT rate of 8/119 (6.7%). When only analysing patients treated for orbital fractures this RTT rises to 8/40 (20%). Of those eight patients who had a postoperative CT and required RTT, this could have been predicted in 7/8 (87.5%). A total of 16/44 (36.4%) patients that did not have RTT would have additionally been recommended to have the plate position altered based on CT alone. Based upon those that had a CT, the PPV of CT alone being able to predict those requiring RTT was 40.6% and the NPV 96.2%. Our results would suggest intraoperative CT would likely have prevented eight patients requiring RTT in two years and could have improved outcomes in 16 cases. In preventing RTT as well as potentially improving the outcomes of a further 16 cases in maxillofacial surgery, the purchase of an intraoperative CT scanner could yield net savings of £75534-£114990 over two years.

O-071 In progestin primed double stimulation protocol: Is luteal phase stimulation more effective than follicular phase stimulation in poor responders? A randomized controlled study

Study question

Is follicular phase or luteal phase stimulation more effective in progestin primed double stimulation protocol in poor responders?

Summary answer

The luteal phase stimulation was more effective than follicular phase stimulation in the progestin primed dual stimulation protocol in poor responders.

What is known already

Poor ovarian responders involve 9–24% of patients undergoing in vitro fertilization (IVF), with the management of these patients posing an everyday practical challenge.

Owing to the follicular waves theory, two or three waves of folliculogenesis were detected during the interovulatory interval, two consecutive ovarian stimulation protocols could be initiated in the follicular phase and the subsequent luteal phase. This is an effective way to increase the number of oocytes and embryos obtained over a relative short period of time. Furthermore, there is increasing evidence that progestins can be a reliable method of preventing premature LH surge during ovarian stimulation.

Study design, size, duration

This was a randomized controlled study performed at the Infertility and Assisted Reproduction Unit of ElShatby Maternity Hospital, Alexandria University and Madinah Fertility Centre. The study was conducted on 90 infertile women with poor ovarian response as defined by the Bologna criteria. 7 patients were excluded due to protocol violation, loss to follow-up and patient withdrawal. The study commenced in September 2020 and was finalized in September 2021.

Participants/materials, setting, methods

Group 1

45 patients were given the progestin primed double stimulation protocol. Dydrogesterone was started from the first day of the ovulation induction till the end of luteal phase stimulation. Embryo transfer was scheduled in a subsequent cycle.

Group 2

45 patients were given the flexible GnRh antagonist protocol in 2 cycles. The best blastocyst from either cycle was transferred in the second cycle.

Main results and the role of chance

When comparing the follicular and luteal phases, the M2 oocytes number retrieved in the luteal phase was statistically significantly higher than the follicular phase, with the median number of 4 oocytes against a median number of 2 oocytes (P value 0.001). The fertilization rate was significantly higher in the M2 oocytes of the luteal phase stimulation (P value 0.04). The resultant embryos from the luteal stimulation phase were statistically significantly higher than the follicular phase, with the median number of 3 embryos against a median number of 1 embryo (P value <0.001). However, we found that the days of controlled ovarian hyperstimulation were statistically significant higher in stimulation of the luteal phase with the median of 12 days against the 10 days seen in follicular phase stimulation (P value 0.002). Consequently, the total dosage of gonadotropins was statistically significant higher in the luteal phase with a P value of 0.007.

After Subgroup analysis, Poseidon Group 4 patients demonstrated that a significantly higher number of oocytes were retrieved after the progestin primed double stimulation than after two waves of flexible GnRh antagonist stimulation (median of 12 oocytes against a median of 10 oocytes with P value 0.01).

Limitations, reasons for caution

Firstly, preimplantation genetic testing was not performed to detect euploid embryos which could be vital when comparing both the phases and the protocols. Secondly, despite the importance of the live birth rate as an outcome measure, we did not enroll this measure.

Wider implications of the findings

In the light of our findings, we recommend the usage of progestin primed dual stimulation protocol in poor responder patients. Additionally, we call for multicentric randomized controlled research to verify this protocol as a first-line treatment protocol in poor responder patients.

Trial registration number

ClinicalTrials.gov ID: NCT04537078

O-058 Obstetric outcomes of twin gestation after In-Vitro Fertilization and Embryo Transfer (IVT-ET) treatment in patients who underwent hysteroscopic septoplasty for subseptate uterus

Study question

Is there an associated increased risk of preterm birth (PTB) in patients who underwent hysteroscopic septoplasty for subseptate uterus (SSU) with twin gestation through IVF-ET?

Summary answer

This study suggests an increased risk of PTB in patients, who underwent hysteroscopic septoplasty for SSU, and subsequently conceived twins after IVF-ET treatment.

What is known already

In general, the incidence of PTB is higher after IVF-ET treatment. In addition, Müllerian uterine anomalies, such as unicornuate uterus, are considered risk factors for PTB, even with singleton pregnancy. Furthermore, historical data suggest that some patients with uterine anomaly may have cervical incompetence. Twin gestation is associated with PTB in approximately 50% of cases. It is assumed that the obstetric outcome of twin gestation after successful septoplasty should be no different from those with normal uterine cavity. The impact of previous septoplasty for SSU on the obstetric outcomes of twin gestation after IVF-ET treatment has not been adequately studied.

Study design, size, duration

This retrospective cohort study included 377 fertility patients who received treatment between 2006-2019. The study group included 162 patients who underwent hysteroscopic septoplasty for SSU and subsequently conceived dichorionic-diamniotic (DI-DI) twins after IVF-ET treatment (Group 1). The control group included 215 patients who had normal endometrial cavity on hysteroscopy (#109) or Transvaginal 3D ultrasound scan with saline sonohysterogram (#106) and subsequently conceived DI-DI twins after IVF-ET treatment (Group 2).

Participants/materials, setting, methods

This study was conducted at an infertility clinic affiliated with an academic hospital. Demographic, clinical, and obstetric outcome data were collected for both groups and compared using appropriate statistical methods. PTB, severe PTB, extreme PTB, and peri-viable birth were defined as < 37 weeks, <32 weeks, <28 weeks and between 20 weeks-25 weeks 6 days gestation respectively.

Main results and the role of chance

There was no significant difference in mean age, BMI and infertility duration or in the incidence of smoking, primary infertility, tubal factors and unexplained infertility between the two groups. There was significantly lower mean baseline FSH levels (p < 0.01), lower incidence of male infertility (p < 0.001) and higher incidence of ovulatory disorders (p < 0.001) and endometriosis (p < 0.05) in Group 1 compared to Group 2. As expected, there was past history of lower parity rate (p < 0.01) and higher miscarriage rate (p < 0.001) in Group 1 compared to Group 2 prior to septum division. There was significantly higher incidence of PTB (72.8% vs 56.3%, p < 0.01), severe PTB (20.3% vs 8.2%, p < 0.01), extreme PTB (8.3% vs 3.9%, p < 0.05), and peri-viable birth (6.3% vs 1.9%, p < 0.05) in Group 1 compared to Group 2. There was no significant difference in cesarean section rate (82.8% vs 87.5%, p = 0.349) between Group1 and Group 2 respectively. There was significantly lower gestational age at birth in weeks (34.0 + 4.0 vs 35.6 + 3.0, p < 0.001), birth weight of the first newborn (2180.5 + 717.9 vs 2436.4 + 606.6, p < 0.001), and the second newborn (2235.2 + 674.2 vs 2398.0 + 537.9, p < 0.05) in grams in Group 1 compared to Group 2.

Limitations, reasons for caution

Our study has limitations being retrospective in nature. Data on cervical length measurements via ultrasound, if performed, was not available. However, recall bias was prevented by retrieving data from that submitted to the Society of Assisted Reproductive Technology. Additionally, procedural variation was reduced as this was a single-center study.

Wider implications of the findings

Our study suggests that twin gestation after IVF-ET in patients who underwent successful hysteroscopic septoplasty for SSU may increase the likelihood of PTB. Such patients may require increased surveillance with ultrasound cervical length and signs for preterm labor. Future research should focus on measures to reduce PTB in such patients.

Trial registration number

Not Applicable

Retropharyngeal lymph node metastasis in oral cancer. Systematic review and survival analysis

INTRODUCTION

Metastasis to retropharyngeal lymph nodes (RPLN) from oral squamous cell carcinoma is rare and associated with poor outcomes. The poor prognosis of RPLN is multifactorial and includes the clinicopathological aggressiveness of the primary disease and the late presentation. The aim of this systematic review is to assess the evidence on RPLN in patients diagnosed with oral squamous cell carcinoma (OSCC), the quality of the diagnostic modalities and the available treatment options. We aimed to analyse the overall survival of these patients diagnosed with RPLN.

METHODS

A systematic review was undertaken according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement guidelines. The initial literature search generated 289 articles. A total of 11 papers satisfied our criteria. Eight papers provided enough data to perform survival analysis and 3 papers compared the diagnostic modalities used in the detection of RPLN.

RESULTS

A total of 73 OSCC patients diagnosed with RPLN metastasis were identified. The most common primary tumour subsites included the tongue (20), buccal mucosa (15) and gingiva (11). The cumulative 5-year OS rate was 17.8% while the 2-year overall survival was 35.9%.

CONCLUSION

The presence of nodal metastasis is an independent prognostic factor in head and neck cancer. In this study, RPLN metastasis had a poorer prognosis (5 years overall survival is 17.8%) when compared to the survival rate of oral cancer without RPLN metastasis (5 years overall survival is 40%). There was no statistically significant difference between the overall survival in primary RPLN metastasis and recurrent RPLN disease.

1412 De Garengeot's Hernia Complicated by Perforated Appendicitis and Groin Abscess: Report of A Rare Surgical Emergency

Introduction

De Garengeot's hernia is a rare subtype of femoral hernia which contains the vermiform appendix. Acute appendicitis in a femoral hernia is even more unusual, accounting for 0.08% - 0.13% of all cases of femoral hernias.

Case presentation

A 91-year-old woman was referred with a painful, cellulitic right groin mass. A computed tomography scan demonstrated a right-sided femoral hernia containing a loop of bowel and a collection in the right groin containing fluid and gas. The patient had early dementia but no other major medical co-morbidities. At surgery, she was found to have perforated appendicitis in a right femoral hernia. Most of the appendix and sac had fully disintegrated, forming a large abscess cavity beneath the skin in the right groin which extended down to the upper labia majora. The appendix tip was lying deep within the abscess cavity. A modified McEvedy approach was used to access the peritoneal cavity for the appendicectomy and sutured repair of the femoral neck. The groin abscess cavity was drained and managed with a negative pressure (VAC) dressing.

Discussion

De Garengeot's hernia is often difficult to diagnose pre-operatively and reporting of cross-sectional imaging may not always be reliable. Currently, there is no gold standard method for repairing these hernias. However, the modified McEvedy approach is well-described and is the preferred technique for emergent femoral hernia presentations. It provides sufficient access to manage both appendicitis and the femoral hernia. Adjuncts such as negative pressures dressings may be used to manage concomitant abscess cavities.

823 The ‘Blue Blood' Chicken Thigh Model: Microsurgery Simulation Teaching for Surgical Trainees

Introduction

The simulation of microsurgery via various models helps surgical trainees to further their instrument handling and techniques. This model allows trainees to strengthen hand-microscope-eye coordination; a crucial ability required when handling critical vessels and tissues. The ‘Blue Blood’ Chicken Thigh Model imitates delicate vessels enabling the enhancement of dexterity.

Aim

To raise awareness amongst trainees in how the model may be used as a simulation tool for learning. To outline the arrangement of the ‘Blue Blood’ chicken thigh model allowing the practice of exceptionally fine suturing such as end-end anastomosis and end-side anastomosis. To improve trainee confidence in instrument handling and technique.

Method

A Microsurgery course was set up for maxillofacial surgical trainees within the West Midlands Deanery in November 2019. Detailed steps of dissecting the femoral vessels and preparing the ‘Blue Blood’ Chicken Thigh Model were presented. Microsurgical tools were then used to practise end-end and end-side anastomosis.

Results

The feedback received from the trainees was positive and it is hoped this will become an annual session for all trainees. Many trainees felt this was a resourceful tool to help them practise - even at home.

Conclusions

It is important for trainees to be able to display precise hand-eye movements especially when concerned with anastomosis techniques. This model will allow trainees to be able to simulate such an environment outside of theatre where they can spend time to hone skills and become comfortable with handling finer tissues and instruments.

Sonographic evaluation of diaphragmatic thickness and excursion as a predictor for successful extubation in mechanically ventilated preterm infants

Sonographic assessment of diaphragmatic thickness and excursion has been found to be an accurate tool in predicting successful extubation of adult patients from invasive mechanical ventilation. We aimed to evaluate the accuracy of sonographic assessment of diaphragmatic thickness and excursion in predicting successful extubation of preterm infants from invasive conventional mechanical ventilation. Preterm infants less than 32 weeks gestation who required invasive conventional mechanical ventilation were evaluated by diaphragmatic sonography within 1 h of their planned extubation. Infants were classified into successful or failed extubation groups based on their ability to stay off invasive mechanical ventilation for 72 h after extubation. Inspiratory and expiratory thickness plus excursion of the right and left hemidiaphragm as well as diaphragmatic thickening fraction (DTF) measures were compared between groups. We included 43 eligible infants, of whom 34 infants succeeded and 9 infants failed extubation. Infants in the successful extubation group had a significantly higher expiratory thickness of the right and left hemidiaphragm, excursion of the right and left hemidiaphragm, inspiratory thickness of the left hemidiaphragm, and DTF of the left hemidiaphragm compared with infants who failed extubation. The receiver-operating characteristic curves showed that excursion of the right and left hemidiaphragm has the highest significant accuracy in predicting successful extubation of preterm infants among all diaphragmatic parameters (AUC is 0.98 and 0.96, respectively; p value < 0.001 for both).Conclusion: We conclude that diaphragmatic excursion is a useful indicator for successful extubation of preterm infants from mechanical ventilation. What is Known: • Invasive mechanical ventilation induces ventilator induced diaphragmatic dysfunction (VIDD) particularly when used for long time. • Assessment of diaphragmatic dimensions and functional activity has been a valuable tool in predicting successful extubation of adult patients from invasive mechanical ventilation. What is New: • Sonographic assessment of diaphragmatic dimensions can be used to predict successful extubation of preterm infants from mechanical ventilation. • Sonographic assessment of diaphragmatic excursion shows the highest sensitivity and specificity in predicting successful extubation of preterm infants.

One-year outcomes of percutaneous coronary intervention in native coronary arteries versus bypass grafts in patients with prior coronary artery bypass graft surgery

Background

Patients with prior coronary artery bypass graft (CABG) surgery often require percutaneous coronary intervention (PCI). Data are still limited in regards to the outcomes of native versus graft PCI after CABG.

Methods

We performed a retrospective study in a tertiary reference cardiac centre of consecutive patients who underwent PCI after CABG. The data were collected for patients who underwent either native or graft PCI from January 2008 to December 2018. Major adverse cardiac events (MACE) included death or myocardial infarction (MI) or revascularization. All outcomes were assessed at 1-year after each index procedure.

Results

A total of 445 PCI were performed in 410 patients (209 had native PCI and 201 had graft PCI). The groups of patients with native vessel PCI and graft PCI were statistically comparable regarding their baseline characteristics. In multivariable Cox regression graft PCI relative to native PCI was an independent risk factor for MACE (hazard ratio [HR] 1.818, 95% confidence interval [CI] 1.148–2.878).

Conclusion

Compared with native coronary PCI, bypass graft PCI was significantly associated with higher incidence of MACE at 1-year and this was mainly driven by MI and revascularization.

MACE outcomes

Funding Acknowledgement

Type of funding source: None

Neurological involvement and MRI brain findings in an adult with hemolytic uremic syndrome: A case report

Hemolytic uremic syndrome is a frequent complication of shiga toxin producing Escherichia coli in pediatric population. It rarely affects adults with extremely rare neurological manifestation. We present a case of hemolytic uremic syndrome in a 64-year-old male who presented with a bloody diarrhea 30 minutes after eating an expired meat sandwich. Shiga-toxin producing Escherichia coli O157:H7 was confirmed as the causative agent. The patient developed neurological manifestations with persistent encephalopathy that ultimately leads to his death after 22 days of hospitalization. Magnetic resonance imaging findings was significant for signal changes in the thalami, tectum, insulae, and central pons, impressive of hemolytic uremic syndrome.

Sonographic Evaluation of Diaphragmatic Excursion and Thickness in Healthy Infants and Children

OBJECTIVES

M-mode sonography is a noninvasive method for detection of diaphragmatic excursion and thickness. A few studies have assessed diaphragmatic kinetics in children with diaphragmatic paresis and paralysis, but to our knowledge, no data about normal values in pediatrics are available. The aims of this study were to determine reference values for diaphragmatic excursion and thickness, as evaluated by sonography in healthy infants and children, and identify correlations between them and anthropometric measurements, age, and sex.

METHODS

A total of 400 healthy participants aged between 1 month and 16 years, divided into 4 equal groups (group 1, 1 month-2 years; group 2, 2-6 years; group 3, 6-12 years); and group 4, 12-16 years) were studied. M-mode sonography was used to measure the excursion and thickness of the right and left hemidiaphragms (using the liver and spleen as acoustic windows, respectively).

RESULTS

Reference values for diaphragmatic excursion and thickness were determined in different age groups of healthy infants and children. There were no significant differences with respect to sex. Significant positive correlations were found between excursion of the right hemidiaphragm and body weight in all age groups (r = 0.52, 0.25, 0.27. and 0.20; P < .001, .013, .011, and .047 for groups 1-4, respectively). We plotted percentile curves for right diaphragmatic excursion against body weight.

CONCLUSIONS

This study provides reference values for diaphragmatic excursion and thickness in healthy infants and children. Percentile curves for right diaphragmatic excursion plotted against body weight were plotted.

Primary focal segmental glomerulosclerosis in Egyptian children: a 10-year single-centre experience

Primary focal segmental glomerulosclerosis (FSGS) in children accounts for 7-20% of all cases of idiopathic nephrotic syndrome (NS). To evaluate the clinical course of children with primary FSGS, the records of 72 patients with biopsy-proven FSGS admitted between 1995 and 2008 were retrospectively analysed. Forty-eight patients were male (66.7%). The mean age at presentation was 76.5 +/- 54 (range 12-192) months. The mean duration of follow-up was 76.3 +/- 42 (range 9-156) months. Seventeen patients (23.6%) presented with gross haematuria at initial presentation, 15 (20.8%) presented with hypertension and 10 patients (14%) presented with chronic renal insufficiency (CRI). The initial response to oral prednisolone was steroid resistance in 63 patients (87.5%) and steroid dependence in 4 patients (5%), while 5 patients (6.9%) were biopsied from the start because of atypical presentation. According to pathological classification, there were the tip variant (2%), collapsing variant (6%), perihilar variant (7%) and NOS (not otherwise specified; 85%). At the last clinical visit, 12 patients (16.7%) were in complete remission and 11 (15.3%) had progressed to CRI. Renal survival rates at 5 and 10 years were 93% and 68%, respectively. In conclusion, in this study we had a low percentage of FSGS, and fewer patients presenting with gross haematuria and hypertension compared with previous reports. In addition, the short-term overall renal survival seems to be better in our cohort.

Adiabatically induced coherent Josephson oscillations of ultracold atoms in an asymmetric two-dimensional magnetic lattice

We propose a new method to create an asymmetric two-dimensional magnetic lattice which exhibits magnetic band gap structure similar to semiconductor devices. The quantum device is assumed to host bound states of collective excitations formed in a magnetically trapped quantum degenerate gas of ultracold atoms such as a Bose-Einstein condensate (BEC) or a degenerate Fermi gas. A theoretical framework is established to describe possible realization of the exciton-Mott to discharging Josephson states oscillations in which the adiabatically controlled oscillations induce ac and dc Josephson atomic currents where this effect can be used to transfer n Josephson qubits across the asymmetric two-dimensional magnetic lattice. We consider second-quantized Hamiltonians to describe the Mott insulator state and the coherence of multiple tunneling between adjacent magnetic lattice sites where we derive the self consistent non-linear Schrödinger equation with a proper field operator to describe the exciton Mott quantum phase transition via the induced Josephson atomic current across the n magnetic bands.

Metabolic effects of diets differing in glycaemic index depend on age and endogenous glucose-dependent insulinotrophic polypeptide in mice

AIMS/HYPOTHESIS

High- vs low-glycaemic index (GI) diets unfavourably affect body fat mass and metabolic markers in rodents. Different effects of these diets could be age-dependent, as well as mediated, in part, by carbohydrate-induced stimulation of glucose-dependent insulinotrophic polypeptide (GIP) signalling.

METHODS

Young-adult (16 weeks) and aged (44 weeks) male wild-type (C57BL/6J) and GIP-receptor knockout (Gipr ( -/- )) mice were exposed to otherwise identical high-carbohydrate diets differing only in GI (20-26 weeks of intervention, n = 8-10 per group). Diet-induced changes in body fat distribution, liver fat, locomotor activity, markers of insulin sensitivity and substrate oxidation were investigated, as well as changes in the gene expression of anorexigenic and orexigenic hypothalamic factors related to food intake.

RESULTS

Body weight significantly increased in young-adult high- vs low-GI fed mice (two-way ANOVA, p < 0.001), regardless of the Gipr genotype. The high-GI diet in young-adult mice also led to significantly increased fat mass and changes in metabolic markers that indicate reduced insulin sensitivity. Even though body fat mass also slightly increased in high- vs low-GI fed aged wild-type mice (p < 0.05), there were no significant changes in body weight and estimated insulin sensitivity in these animals. However, aged Gipr ( -/- ) vs wild-type mice on high-GI diet showed significantly lower cumulative net energy intake, increased locomotor activity and improved markers of insulin sensitivity.

CONCLUSIONS/INTERPRETATION

The metabolic benefits of a low-GI diet appear to be more pronounced in younger animals, regardless of the Gipr genotype. Inactivation of GIP signalling in aged animals on a high-GI diet, however, could be beneficial.

Immunofluorometric assay of pepsinogen C and preliminary clinical applications

We developed mouse monoclonal antibodies (Abs) against pepsinogen C with highly purified antigen isolated from gastric mucosa. The Abs were used to construct a two-site sandwich-type assay for pepsinogen C with time-resolved fluorometry as a detection technique. The assay has a detection limit of 0.1 microgram/L and is precise (within-run and day-to-day CVs < 11%). We used this assay to measure pepsinogen C in seminal plasma, breast cyst fluid, amniotic fluid, male and female serum, serum from patients with prostate cancer, urine, breast tumor cytosolic extracts, breast milk, and cerebrospinal fluid. Highest pepsinogen C concentrations were in seminal plasma, followed by breast cyst fluid and amniotic fluid. We found no correlation between prostate-specific antigen concentrations and concentrations of pepsinogen C in serum of prostate cancer patients, and concluded that this marker is not useful for either diagnosing or monitoring prostatic carcinoma. The availability of a highly sensitive, reliable, and convenient method for quantifying pepsinogen C will allow investigations into the possible diagnostic value of this analyte in various clinical conditions, including benign breast diseases, breast cancer, fertility, and pregnancy.

Thyroid function in haemodialysed patients of Gassim, Saudi Arabia: TRH stimulation

To study the hypophysical-pituitary-thyroid axis in Saudi patients on (RDT), 200 units of TRH were given intravenously predialysis to each of 21 such subjects. As expected (TSH) rose promptly within 30 minutes followed by a gentle decline at 60 minutes. A more gentle rise was also noted in T3 which continued for the 60 minutes of observation. Rather unexpectedly, T4 level was noted to show a reciprocal decline. To our knowledge, this pattern has not been defined in literature. In 12 patients (GH) was noted to rise promptly within 30 minutes followed by a gentle decline at 60 minutes. (LH) and (FSH) did not follow any definite pattern as observed for T3 and T4. Since the oral preparation of TRH is now available, can (TRH) be effectively used to treat renal dwarfism?

Blockade by intravenous losartan of AT1 angiotensin II receptors in rat brain, kidney and adrenals demonstrated by in vitro autoradiography

1. The in vivo inhibition of angiotensin II (AII) receptor binding in the rat brain, kidney and adrenal was investigated after intravenous administration of the AT1-selective AII receptor antagonist losartan. 2. Male Sprague-Dawley rats were administered intravenously either vehicle, or losartan at doses of 1, 3 or 10 mg/kg. Plasma samples were collected and tissues removed at 1, 2, 8 or 24 h after administration of the antagonist. The effects of losartan on AII receptor binding were assessed by quantitative in vitro autoradiography. 3. Losartan significantly increased plasma renin activity (PRA) by six-fold and nine-fold at doses of 1 and 10 mg/kg, respectively (P < 0.05). Plasma losartan concentrations rose from 0.83 micrograms/mL at 1 mg/kg to 46.5 micrograms/mL at 10 mg/kg 1 h after administration of the drug. Plasma renin activity returned to control, whilst losartan was undetectable 24 h after injection of the antagonist. 4. In the brain, losartan produced a dose-dependent inhibition of AII receptor binding to the brain structures which express exclusively, or predominantly, AT1 receptors both outside and within the blood brain barrier. By contrast, losartan did not affect binding to the nuclei which contain exclusively, or predominantly, AT2 receptors. 5. In the kidney, losartan blocked AII receptor binding to all anatomical sites in a dose-dependent manner. The inhibition peaked at 1 h and persisted beyond 24 h despite the fact that PRA had returned to control, and losartan was not detectable in the circulation. In the adrenal gland, where AT1 and AT2 receptors occur in both the cortex and medulla, losartan caused partial inhibition at both regions. 6. These results indicate that losartan, administered intravenously at these doses, and/or its active metabolites, partially penetrate the blood brain barrier to selectively inhibit central AT1 receptors, and exert selective and prolonged blockade at AT1 receptors in peripheral target tissues.

Selective inhibition of pressor and haemodynamic effects of NG-nitro-L-arginine by halothane

We investigated the characteristics of inhibition by halothane of the pressor responses to NG-substituted L-arginine derivatives, nitric oxide (NO) synthase inhibitors. Intravenous (i.v.) bolus injections of NG-nitro-L-arginine (L-NNA, 1-32 mg/kg), NG-nitro-L-arginine methyl ester (L-NAME, 0.4-12.8 mg/kg), norepinephrine (NE, 0.25-8 micrograms/kg) and angiotensin II (AII, 0.02-0.64 micrograms/kg) each caused dose-dependent pressor responses in conscious rats. Halothane attenuated responses to the highest dose of NE and AII by approximately 18% but completely abolished responses to L-NNA and L-NAME. The haemodynamic effects of L-NNA were further examined by the microsphere technique in two groups of conscious rats and two groups of halothane-anaesthetized rats. An i.v. bolus injection of L-NNA (16 mg/kg) in conscious rats increased mean arterial pressure (MAP) and total peripheral resistance (TPR) and reduced heart rate (HR) and cardiac output (CO). These changes were associated with reduced conductance in all vascular beds, with the greatest reduction in the lungs and the least in the liver. In halothane-anaesthetized rats, L-NNA caused significant but markedly less change in MAP, HR, TPR, and CO as compared with those in conscious rats. The vasoconstrictor effects of L-NNA were attenuated by halothane in all beds except liver and spleen, with the greatest inhibition in heart. Our results suggest that NO plays a role in maintenance of peripheral vascular resistance and that halothane selectively and "noncompetitively" inhibits the vasoconstrictor effects of NO synthase inhibitors.

Role of tyrosine kinase and phosphotyrosine phosphatase in growth of the intestinal crypt cell (IEC-6) line

The roles of gastrin and sodium vanadate in proliferation were examined in cultured IEC-6 cells that are mitotically active and derived originally from jejunal crypts of the rat intestine. Incubation of the cells in the presence of gastrin at a concentration of 250 ng/ml or of sodium vanadate at a concentration of 0.2 mM leads to a 60% increase in cell growth in 24 hr. The stimulated growth in both cases was inhibited by genistein, a tyrosine kinase inhibitor. Incubation in the presence of gastrin and sodium vanadate together produced a small, albeit significant, potentiation of growth of the cells. Gastrin as well as sodium vanadate also promoted the phosphorylation on tyrosine of a similar group of proteins with molecular masses of 42, 45, 52, 60, 78, and 120 kDa. The phosphorylations were rapidly occurring as early as 5 min and lasted for only 15 min. Several proteins were detected in normal IEC-6 cells, including GTPase activating protein, raf1 kinase, phospholipase C gamma-1, and phosphoinositide 3-kinase. The results suggest that gastrin and sodium vanadate induce growth of IEC-6 cells by stimulation of tyrosine kinase and/or inhibition of tyrosine phosphatase. The gastrin and sodium vanadate effects also involve the phosphorylation of a number of proteins, the identities of which are not known at present but may include some of the kinases that are frequently associated with cell growth, such as mitogen-activated protein kinase, raf1 kinase, phosphoinositide 3-kinase, and others.

Effects of anaesthetic agents on pressor response to beta-blockers in the rat

It has been shown that paradoxical pressor response to a beta-adrenoceptor antagonist occurs in conscious rats pretreated with an alpha-adrenoceptor antagonist. This study examines the influence of anaesthetic agents on mean arterial pressure (MAP) response to a beta-blocker. Cumulative dose-response curves of propranolol (non-selective), ICI 118,551 (beta 2-selective) and atenolol (beta 1-selective) were constructed in phentolamine-treated rats anaesthetized with urethane, pentobarbitone or halothane. I.v. injections of all three beta-blockers caused dose-dependent increases in MAP in urethane-anaesthetized rats. In halothane-anaesthetized rats, propranolol and atenolol did not alter MAP while ICI 118,551 caused a small dose-dependent increase in MAP. In the presence of pentobarbitone, none of the beta-blockers raised MAP. In the second series of experiments, a single i.v. bolus dose of propranolol was given in phentolamine-treated rats anaesthetized with pentobarbitone, amobarbitone, ketamine or chloralose. Propranolol did not affect MAP in rats anaesthetized with pentobarbitone, amobarbitone and chloralose but it partially reversed the hypotensive effect of phentolamine in ketamine-anaesthetized rats. In the third series, propranolol or atenolol was i.v. injected in pentobarbitone-anaesthetized rats treated with both phentolamine and adrenaline. Both propranolol and atenolol raised MAP. Our results show that anaesthetic agents differentially affect the MAP response to a beta-blocker.

Calcitonin gene-related peptide is a venous dilator in conscious rats

The effect of calcitonin gene-related peptide (CGRP) on body venous tone is not known. This study examines the dose-response effects of rat alpha CGRP on mean circulatory filling pressure (MCFP), an index of body venous tone, in conscious rats. Dose-response curves of CGRP were constructed in three groups of rats, namely, (I) intact, (III) rats pretreated with the ganglionic blocker hexamethonium and (V) rats pretreated with noradrenaline to raise mean arterial pressure (MAP) and MCFP. Three additional groups, (II), (IV) and (VI), served as time controls and were treated similarly to (I), (III) and (V), respectively, except that they were given saline (0.9% NaCl) in place of CGRP. The infusion of CGRP in intact rats dose dependently decreased MAP, increased heart rate (HR) and slightly reduced MCFP. In ganglionic-blocked rats, CGRP caused similar depressor responses but less tachycardia than in intact rats, however, it also slightly reduced MCFP. In rats given noradrenaline, CGRP dose dependently decreased MAP, MCFP and increased HR. The results show that CGRP has venodilator activities; its venous effect is best revealed at elevated venous tone.

Competitive antagonism of pressor responses to angiotensin II and angiotensin III by the angiotensin II-1 receptor ligand losartan

Losartan (DuP 753) and PD123177 are nonpeptide angiotensin (ANG) receptor ligands for subtypes of ANG II receptors ANG II-1 and ANG II-2, respectively. We examined the effects of losartan and PD123177 on dose - mean arterial pressure (MAP) response curves for ANG II and ANG III in eight groups (n = 6 each) of conscious rats. Saline (0.9% NaCl), losartan (1 x 10(-6) and 9 x 10(-6) mol/kg), and PD123177 (2 x 10(-5) mol/kg) were i.v. bolus injected 15 min before the construction of ANG II dose - response curves in groups I, II, III, and IV, respectively. Groups V-VIII were treated similarly to I-IV except that ANG III was given in place of ANG II. Losartan dose dependently shifted the dose-response curves of ANG II and ANG III to the right with similar dissociation constants (-log KI of 6.6 +/- 0.7 and 6.6 +/- 0.1 mol/kg, respectively) and no change in the maxima. PD123177 affected neither maximum MAP nor ED50 values for ANG II or ANG III. Our results show that losartan but not PD123177 is a competitive antagonist of the MAP effects of ANG II and ANG III.

Mechanism of the vasodilator action of calcitonin gene-related peptide in conscious rats

1. The aim of this study was to investigate whether the hypotensive effect of rat alpha-calcitonin gene-related peptide (alpha CGRP) in conscious rats is mediated by endothelium-derived nitric oxide (NO) or the opening of adenosine 5'-triphosphate (ATP)-sensitive potassium (KATP) channels. 2. Dose-mean arterial pressure (MAP)-response curves of alpha CGRP were examined in the presence of vehicle, phenylephrine, KATP channel antagonist glibenclamide or NO synthase inhibitors, NG-nitro-L-arginine methyl ester (L-NAME) and NG-nitro-D-arginine methyl ester (D-NAME). Dose-MAP-response curves for sodium nitroprusside were also constructed in the presence and absence of L-NAME and D-NAME. 3. alpha CGRP and nitroprusside produced dose-dependent reductions in MAP which were potentiated by phenylephrine. Both L-NAME and D-NAME attenuated the depressor response to alpha CGRP but not nitroprusside. 4. Dose-MAP-response curves for pinacidil, a KATP-channel activator, were also examined in the presence of glibenclamide or vehicle. Glibenclamide attenuated pinacidil- but not alpha CGRP-induced reductions in MAP. 5. It is concluded that the hypotensive effects of alpha CGRP are partially mediated via endothelium-derived NO but not via the opening of KATP channels.

Effects of neuropeptide Y on mean circulatory filling pressure in intact and ganglionic-blocked conscious rats

The dose-response effects of neuropeptide Y (NPY) and the vehicle, 0.9% NaCl, on mean arterial pressure (MAP), heart rate (HR) and mean circulatory filling pressure (MCFP), an index of body venous tone, were examined in conscious, intact and hexamethonium-treated rats. Saline infusions in intact and hexamethonium-treated rats did not significantly affect MAP, HR and MCFP. The i.v. infusion of NPY in intact rats dose dependently increased MAP, decreased HR, but did not alter MCFP. In the presence of hexamethonium, the pressor effect of NPY was enhanced, the lack of MCFP effect remained and the bradycardic effect was markedly attenuated. Our results suggest that NPY has moderate effects on MAP, but negligible effects on body venous tone.

Differential venous effects of isoprenaline in conscious rats

The role beta-adrenoceptors in the control of venous tone is not clear. This study examines the dose-response effects of isoprenaline, a non-selective beta-adrenoceptor agonist, on mean circulatory filling pressure (MCFP), an index of body venous tone, in conscious and unrestrained rats. Dose-response curves of isoprenaline were constructed in three groups of rats, namely, I, intact; III, pretreated with the ganglionic blocker hexamethonium; and V, pretreated with noradrenaline. Three additional groups, Groups II, IV and VI, served as time controls and were treated similar to I, III and V, respectively, except that they were given normal saline in place of isoprenaline. The infusion of isoprenaline in intact rats dose dependently decreased mean arterial pressure (MAP) and increased heart rate (HR) and MCFP while in the ganglionic-blocked rat, it caused similar effects on MAP and HR but had no significant effects on MCFP. In rats given noradrenaline, isoprenaline again decreased MAP and increased HR and, in contrast to the other two groups, it decreased MCFP. The results show that isoprenaline has variable venous effects depending on existing venous tone. It causes reflex-mediated venoconstriction under normal conditions due to its hypotensive effects and direct venodilatation when venous tone is elevated by the infusion of noradrenaline.

Effects of beta 1- and beta 2-adrenoceptor stimulation on hemodynamics in the anesthetized rat

The role of beta 1-adrenoceptors in mediation of vasodilatation is not clear. The microsphere technique was used to compare the effects of mixed beta-, beta 1-, and beta 2-stimulation on blood flow and conductance changes in five groups of pentobarbital-anesthetized rats: I, vehicle; II, mixed beta-stimulation; III, beta 1-stimulation; IV, beta 2-stimulation; and V, mixed beta-blockade. Isoproterenol (32 ng/kg/min) was infused into rats either without (group II) or with ICI 118,551 (beta 2-blocker, 30 micrograms/kg, group III), atenolol (beta 1-blocker, 100 micrograms/kg, group IV), or both blockers (group V), respectively. At the doses selected, ICI 118,551 shifted the dose-vasodepressor response curve of salbutamol (beta 2-agonist) to the right but had no effect on the dose-chronotropic response curve of dobutamine (beta 1-agonist), whereas atenolol shifted the dose-chronotropic response curve of dobutamine to the right and had no effect on the dose-vasodepressor response curve of salbutamol. The results show that isoproterenol increased heart rate (HR) and arterial conductances in the coronary and skeletal muscle beds but had no effects in other beds. Combined with ICI 118,551, isoproterenol caused similar increases in HR and coronary arterial conductance but markedly less increase in skeletal muscle conductance. Atenolol abolished the increase in HR by isoproterenol but did not affect the increases in coronary and muscular arterial conductances. With both blockers, isoproterenol produced no increase in coronary and skeletal muscle conductance. Therefore, both beta 1- and beta 2-adrenoceptors play a role in coronary and skeletal muscle vasodilatation.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemodynamic changes that accompany the pressor response to propranolol in urethane anesthetized rats subjected to alpha-blockade

It has been shown that a paradoxical pressor response to a beta-blocker occurs in rats given an alpha-blocker. The dual-isotope microsphere technique was used to investigate the hemodynamic changes that accompany the pressor response to propranolol in phentolamine-treated, urethane-anesthetized rats. Rats were divided into four groups (n = 8 per group): group I received 10 min of saline infusion; group II received intravenous infusion of phentolamine (300 micrograms/kg/min) for 10 min; group III received intravenous injection of propranolol (100 micrograms/kg) after 20 min of phentolamine infusion, and group IV received intravenous injection of saline after 20 min of phentolamine infusion. In groups I and IV, saline did not cause any significant hemodynamic changes. In group II, phentolamine decreased the mean arterial pressure (MAP) and total peripheral resistance (TPR) by 34 +/- 3 mm Hg and 0.28 +/- 0.07 mm Hg/min/ml, respectively. Arterial conductances in the skeletal muscle and skin were increased to 157 and 165% of control values, respectively. Cardiac output and conductances in other tissues and organs were not significantly affected. In rats given phentolamine (group III), propranolol raised MAP (+40 +/- 2 mm Hg) by increasing TPR (+0.41 +/- 0.03 mm Hg/min/ml). Vascular conductances in the skeletal muscle, skin and kidneys were decreased to 38, 57 and 69% of control values, respectively. Conductances in other tissues and organs were not significantly affected. Our results show that propranolol raised MAP by increasing flow resistance, primarily via the reversal of the vasodilator effects of phentolamine in the muscle and skin.