Polyimide Compounds For Post-Lithium Energy Storage Applications

The exploration of cathode and anode materials that enable reversible storage of mono and multivalent cations has driven extensive research on organic compounds. In this regard, polyimide (PI)-based electrodes have emerged as a promising avenue for the development of post-lithium energy storage systems. This review article provides a comprehensive summary of the syntheses, characterizations, and applications of PI compounds as electrode materials capable of hosting a wide range of cations. Furthermore, the review also delves into the advancements in PI based solid state batteries, PI-based separators, current collectors, and their effectiveness as polymeric binders. By highlighting the key findings in these areas, this review aims at contributing to the understanding and advancement of PI-based structures paving the way for the next generation of energy storage systems.

Detection of early-universe gravitational-wave signatures and fundamental physics

Detection of a gravitational-wave signal of non-astrophysical origin would be a landmark discovery, potentially providing a significant clue to some of our most basic, big-picture scientific questions about the Universe. In this white paper, we survey the leading early-Universe mechanisms that may produce a detectable signal-including inflation, phase transitions, topological defects, as well as primordial black holes-and highlight the connections to fundamental physics. We review the complementarity with collider searches for new physics, and multimessenger probes of the large-scale structure of the Universe.

Outcomes of patients treated with blood transfusion in a contemporary tertiary intensive cardiac care unit

Background

Different trials showed that patients treated with blood transfusion (BT) have unfavorable prognosis regarding outcomes and mortality. Nevertheless, outcomes in patients treated with BT hospitalized in a contemporary tertiary intensive cardiac care unit (ICCU) is limited.

Objective

To determine mortality rate in patients treated with BT in a contemporary tertiary ICCU.

Methods

A prospective single center study to evaluate short- and long-term mortality rate of patients treated with BT between January 2020 and December 2021 in a tertiary ICCU.

Outcomes

During the study period 2132 consecutive patients were admitted with a mean age of 66.9±16 and 650 (30.5%) of them were women. Of the total population, 108 (5%) patients were treated with BT (BT-group) during their hospitalization. Patients were followed-up for 2 years with a median [IQR] follow up time of 82.5 [12.25–240.50] days in BT-group vs. 138.5 [34–325, 75] days in the non-BT (NBT) group. Mean age was 73.81±14 years in BT-group vs. 66.59±16 years in NBT-group, p<0.0001. There was a higher rate of female gender in the BT-group 48.1% vs. 29.5% in the NBT, p<0.0001. Crude mortality rate was 29.6% in BT-group and 9.2% in NBT-group, p<0.0001. Median [IQR] length of stay was 5 [2–6] days in BT-group vs. 3 [2–4] days in the NBT-group. Multivariate Cox analysis for (Female gender, prior trans-catheter aortic valve replacement, prior cardiac intervention, sepsis, history of congestive heart failure, pulmonary hypertension, pacemaker implantation and anemia) showed that BT was independently associated with more than two folds the mortality rate [HR=2.19 95% CI (1.47–3.62)] as compared with the NBT-group, p<0.0001. Receiver operating characteristic curve (ROC) was plotted for multivariable analysis and showed area under curve (AUC) of 0.8, 95% CI [0.760–0.852].

Conclusion

Even in contemporary tertiary ICCU, with advanced technology, equipment and delivery of care, BT remains a strong predictor for short- and long-term mortality.

Funding Acknowledgement

Type of funding sources: None.

Use of artificial intelligence for point-of-care echocardiographic assessment of left ventricular ejection fraction among COVID-19 patients

Background

The association between COVID-19 infection and the cardiovascular system has been well described. Isolation precautions limit the use of formal echocardiography in this setting. Artificial intelligence (AI) utilization using a hand-held device in these patients can be a reliable tool for left ventricular ejection fraction (LVEF) assessment.

Aims

To prospectively investigate the accuracy of AI-base tool for LVEF assessment using a hand-held echocardiogram in patients with COVID-19.

Methods

From April-28 through July-26, 2020, consecutive patients with COVID-19 underwent a real-time LVEF assessment within 48-h of admission using a hand-held echocardiogram evaluation (Vscan Extend) equipped with LVivoEF, an AI-based tool that automatically evaluates LVEF. The examinations were further analyzed off-line by a blinded fellowship-trained echocardiographer for LVEF as a gold standard.

Results

Among 42 patients, 21 (50%) were male (aged 53.3±17.8 years, mean BMI 27.6±5.1 kg/m²). Seven (16.7%) patients couldn't turn on their left side and three (7.1%) couldn't maintain effective communication. The mean length of each echocardiogram study was 6.8±2.2 minutes, battery usage was 13.4±4.9%, and mean operator-to-patient proximity was 64.5±9.3 cm.

A fair to good correlation was demonstrated between the AI and the echocardiographer LVEF assessment (Pearson's correlation of 0.691, p<0.001). An almost perfect agreement was demonstrated between the AI and the echocardiographer for LVEF using a threshold of 45% (kappa=0.806, p<0.001).

The sensitivity of focused echocardiogram for 45% LVEF threshold is 85.7%, specificity is 97.1% with a PPV of 85.7% and NPV of 97.1%.

Conclusions

An AI-based algorithm incorporated into an existing hand-held echocardiogram device can be reliably utilized as a decision support tool for automatic real-time LVEF assessment among COVID-19 patients.

Funding Acknowledgement

Type of funding sources: None.

Efficient Decontamination of HD by an Electrophilic Iodine/Carboxylate Composite as an Active Sorbent

The development of new and efficient decontamination methods has become more relevant in recent years, especially with regard to solid-based decontamination and detoxification systems. The majority of powders used today are dealing with the physical adsorption of chemical warfare agents (CWAs) and their removal from sites without actively destroying them. In this work, we have designed and developed an active solid composite matrix combining organic carboxylate salts and N-iodosuccinimide (NIS) for HD decontamination via oxidation. All the reactions and mechanistic studies for the sorption and degradation of CWAs were conducted using direct polarization and cross polarization solid-state magic-angle spinning nuclear magnetic resonance techniques. Performance toward the sorption and detoxification of HD was tested, exhibiting oxidation within minutes in a mild and selective manner to the nontoxic sulfoxide derivative followed by visible formation of iodine. The results indicate that carboxylate moieties in the matrix are important for stabilizing the positively charged sulfonium ion intermediate and for supplying oxygen for hydrolysis in a water-deficient environment. The NaOBz/NIS composite was shown to be the most efficient in sorbing and converting the water-insoluble agent HD to its nontoxic, water-soluble sulfoxide, which could then be removed from the site with mere water, resulting in less environmental damage and quick remediation.

Association between cardiac pathology and outcomes of patients with COVID-19 using a hand-held ultrasound

Background

The association between COVID-19 infection and the cardiovascular system has been well described. Strict precautions limit the use of formal echocardiography in this setting. Information on the importance of the utilization of a hand-held point-of-care cardiac ultrasound (POCCUS) for cardiac evaluation in these patients is scarce.

Objective

To investigate the utilization of hand-held echocardiography in COVID-19 hospitalized patients and the association between cardiac pathologies and outcomes.

Methods

Consecutive patients diagnosed with COVID-19 underwent POCCUS evaluation using a hand-held ultrasound within 24 hours of admission at our institute, throughout March-May 2020. According to the POCCUS results, the patients were divided into two groups: 'Normal' and 'Abnormal' (including left or right ventricular dysfunction or enlargement, or moderate/severe valvular regurgitation/stenosis).

Results

Among 102 patients, 26 (25.5%) had an abnormal POCCUS study. They were older, with more co-morbidities, cardiovascular disease history, chronic medical therapy, and more severe presenting symptoms, as compared to the group with a normal echocardiography exam. Individual and composite endpoints (advanced ventilatory support, acute decompensated heart failure, shock, or death) are presented in Table 1. Multivariate logistic regression analysis adjusting for pertinent variables revealed that abnormal echocardiography at presentation was independently associated with the composite endpoint OR=4.63 (95% CI 1.51–14.15, p=0.007).

Conclusions

Abnormal echocardiography results in COVID-19 infection settings are associated with a higher burden of medical comorbidities and independently predict major adverse endpoints. Hand-held POCCUS at presentation can be utilized as an important tool for risk stratification for hospitalized COVID-19 patients.

Funding Acknowledgement

Type of funding sources: Private hospital(s). Main funding source(s): SZMC Scientific

The prevalence and characteristics of patients with ST-elevation myocardial infarction during the first two months of the COVID-19 pandemics

Background

ST-Segment elevation MI (STEMI) is one of the leading cause of mortality in the western world. The coronavirus disease-2019 (COVID-19) pandemic might have implications of the treatment of STEMI patients. Our aim was to evaluate the treatment of STEMI patients during 2 months of the COVID-19 pandemic as compared with the year before.

Methods

Data of 90 STEMI patients treated at the Shaare Zedek Medical Center intensive coronary care unit (ICCU) Between March-April 2019 and March-April 2020 were collected. Patients were divided into 2 groups: The pre COVID-19 group and the COVID-19 era group. Data regarding complications upon arrival and during hospitalization, door to balloon time and echocardiographic exams.

Results

Fifty one (56%) patients were admitted with STEMI in the pre COVID-19 group and only 39 (44%) in the COVID-19 era group. Of them 13.7% vs. 20.5% were female, p=0.392 with a mean age of 62.1 (±13.5) vs. 63.4 (±11) years old, p=0.635 in the pre vs. post COVID-19 era group, respectively. Interestingly, more Jewish vs. non-Jewish were admitted with STEMI in the COVID-19 era group. There were no differences regarding baseline characteristics, catheterization access, culprit vessel and percutaneous coronary intervention rate. Door to balloon time was also similar in both pre and post COVID-19 era groups 35.4 (±32) vs. 30.5 (±29.1) minutes (p=0.896). Moreover, there was no difference regarding infarct size. Complications including acute renal failure, cardiogenic shock, and the use of intra-aortic balloon pump were similar in both groups. 30-day mortality rate was low and similar in both pre and post COVID-19 era groups (5.9% vs. 2.6%, respectively, p=0.426).

Conclusions

During the beginning of COVID-19 era there was a reduction in STEMI admission rate, while no significant difference was found regarding baseline characteristics, door to balloon time, infarct size and mortality rate

Funding Acknowledgement

Type of funding sources: None.

Heavy Thermal Dark Matter from a New Collision Mechanism

We propose a new thermal freeze-out mechanism that results in dark matter masses exceeding the unitarity bound by many orders of magnitude, without violating perturbative unitarity or modifying the standard cosmology. The process determining the relic abundance is χζ^{†}→ζζ, where χ is the dark matter candidate. For m_{ζ}<m_{χ}<3m_{ζ}, χ is cosmologically long-lived and scatters against the exponentially more abundant ζ. Therefore, such a process allows for exponentially heavier dark matter for the same interaction strength as a particle undergoing ordinary 2→2 freeze-out, or equivalently, exponentially weaker interactions for the same mass. We demonstrate this mechanism in a leptophilic dark matter model, which allows for dark matter masses up to 10^{9}  GeV.

Recent Progress on the Synthesis of CF2H-Containing Derivatives

Recent years have witnessed a growing interest in the development of novel synthetic methods and new reagents for the synthesis of difluoromethylated compounds. Dozens of studies have been published on this topic each year over the past few years. These studies are focused on direct and indirect difluoromethylation of various organic functionalities via nucleophilic-, electrophilic-, radical-, carbene- or metal-mediated mechanisms. The present short review covers the very recent studies, published between mid-2017 and early 2019, on the synthesis of compounds containing a CF2H group. A brief summary of the physicochemical properties and medicinal applications of difluoromethylated compounds is also included.

1 Introduction

2 Nucleophilic Difluoromethylation

2.1 Metal-Mediated Nucleophilic Difluoromethylation

2.2 Non-Metal Difluoromethyl Nucleophiles

3 Radical Difluoromethylation

3.1 Metal-Induced Radical Difluoromethylation

3.2 Non-Metal-Induced Radical Difluoromethylation

3.3 Electrochemically Induced Radical Difluoromethylation

4 Carbene-Based Difluoromethylation

4.1 Metal-Induced Carbene Difluoromethylation

4.2 Non-Metal-Induced Difluoromethyl Carbenes

5 Cross-Coupling Difluoromethylation

5.1 Palladium-Catalyzed Difluoromethylation

5.2 Nickel-Catalyzed Difluoromethylation

5.3 Copper-Mediated Difluoromethylation

5.4 Iron-Catalyzed Difluoromethylation

5.5 Gold-Mediated Difluoromethylation

6 Electrophilic Difluoromethylation

7 Other Examples

7.1 A Difluoromethyl-Borane Complex

7.2 A Tellurium Difluoromethyl Derivative

8 Summary

Mononuclear complexes of a tridentate redox-active ligand with sulfonamido groups: structure, properties, and reactivity

The design of molecular complexes of earth-abundant first-row transition metals that can catalyze multi-electron C-H bond activation processes is of interest for achieving efficient, low-cost syntheses of target molecules. To overcome the propensity of these metals to perform single-electron processes, redox-active ligands have been utilized to provide additional electron equivalents. Herein, we report the synthesis of a novel redox active ligand, [ibaps]3-, which binds to transition metals such as FeII and CoII in a meridional fashion through the three anionic nitrogen atoms and provides additional coordination sites for other ligands. In this study, the neutral bidentate ligand 2,2'-bipyridine (bpy) was used to complete the coordination spheres of the metal ions and form NEt4[MII(ibaps)bpy] (M = Fe (1) or Co (1-Co)) salts. The FeII salt exhibited rich electrochemical properties and could be chemically oxidized by 1 and 2 equiv. of ferrocenium to form singly and doubly oxidized species, respectively. The reactivity of 1 towards intramolecular C-H bond amination of aryl azides at benzylic and aliphatic carbon centers was explored, and moderate to good yields of the resulting indoline products were obtained.

Synchrotron radiation Mössbauer spectra of a rotating absorber with implications for testing velocity and acceleration time dilation

Many Mössbauer spectroscopy (MS) experiments have used a rotating absorber in order to measure the second-order transverse Doppler (TD) shift, and to test the validity of the Einstein time dilation theory. From these experiments, one may also test the clock hypothesis (CH) and the time dilation caused by acceleration. In such experiments the absorption curves must be obtained, since it cannot be assumed that there is no broadening of the curve during the rotation. For technical reasons, it is very complicated to keep the balance of a fast rotating disk if there are moving parts on it. Thus, the Mössbauer source on a transducer should be outside the disk. Friedman and Nowik have already predicted that the X-ray beam finite size dramatically affects the MS absorption line and causes its broadening. We provide here explicit formulas to evaluate this broadening for a synchrotron Mössbauer source (SMS) beam. The broadening is linearly proportional to the rotation frequency and to the SMS beam width at the rotation axis. In addition, it is shown that the TD shift and the MS line broadening are affected by an additional factor assigned as the alignment shift which is proportional to the frequency of rotation and to the distance between the X-ray beam center and the rotation axis. This new shift helps to align the disk's axis of rotation to the X-ray beam's center. To minimize the broadening, one must focus the X-ray on the axis of the rotating disk and/or to add a slit positioned at the center, to block the rays distant from the rotation axis of the disk. Our experiment, using the (57)Fe SMS, currently available at the Nuclear Resonance beamline (ID18) at the ESRF, with a rotating stainless steel foil, confirmed our predictions. With a slit installed at the rotation axis (reducing the effective beam width from 15.6 µm to 5.4 µm), one can measure a statistically meaningful absorption spectrum up to 300 Hz, while, without a slit, such spectra could be obtained up to 100 Hz only. Thus, both the broadening and the alignment shift are very significant and must be taken into consideration in any rotating absorber experiment. Here a method is offered to measure accurately the TD shift and to test the CH.

The cucurbit pathogenic bacterium Acidovorax citrulli requires a polar flagellum for full virulence before and after host-tissue penetration

Acidovorax citrulli causes seedling blight and bacterial fruit blotch of cucurbits. Previous reports demonstrated the contribution of type IV pili (T4P) to A. citrulli virulence and to systemic infection of melon seedlings. Microfluidic flow-chamber assays demonstrated the involvement of T4P in surface adhesion and biofilm formation, whereas polar flagella did not appear to contribute to either of these features. On the other hand, a transposon mutant impaired in the biosynthesis of polar flagella was identified in screens for reduced virulence of an A. citrulli mutant library. Further characterization of polar flagellum mutants confirmed that A. citrulli requires a polar flagellum for full virulence on melon plants. Foliage and stem inoculation experiments revealed that polar flagella contribute to A. citrulli virulence and growth in planta at both pre- and post-host-tissue penetration. Interestingly, light microscope observations revealed that almost all A. citrulli wild-type cells extracted from the xylem sap of stem-inoculated melon seedlings remained motile, supporting the importance of this organelle in virulence and colonization of the host vascular system. We also report a negative effect of polar flagellum impairment on T4P-mediated twitching motility of A. citrulli and discuss a possible co-regulation of these two motility machineries in this bacterium.

Gas-particle concentration and characterization of sources of PAHs in the atmosphere of a suburban area in Athens, Greece

Atmospheric polycyclic aromatic hydrocarbons (PAH) were determined in two places in a suburban area of Athens greater area (AGA) during June and November 2003. Fourteen PAHs were quantified in the collected samples. The total concentration in the gas phase ranged between 6.89 and 124ngm(-3), while in the particulate phase between 0.44 and 13.2ngm(-3). Maximum concentrations of the total PAHs (gas and particulate phase) were observed during the cold period with an average of 40.7ngm(-3). PAHs were correlated with NO, NO(2) and O(3), wind speed, wind direction and temperature. Positive correlation was observed between PAHs and NO, NO(2), while negative correlation was detected between PAHs and O(3). The most abundant members were phenanthrene, anthracene, fluorene, fluoranthene and pyrene. Potential sources of PAHs in aerosols were investigated using molecular diagnostic ratios, which reflect sources such as diesel and gasoline engines, although other sources such as coal combustion and liquefied petroleum gas also contributed.

[Prognosis of surgery in epimacular membranes after retinal break or rhegmatogenous retinal detachment]

INTRODUCTION

The prognosis of the formation of epiretinal membranes after retinal break or rhegmatogenous retinal detachment, treated or not treated, does not seem as favorable as that of the idiopathic membranes, but has not yet been extensively studied. Our goal was to analyze the functional result and the retinal complications of the treatment of these membranes.

METHODS

The retrospective study deals with a consecutive series of 28 patients operated on for epimacular membranes, with a minimum follow-up of 3 months. The outcome measures were the postoperative visual acuity at 3-6 months compared with the preoperative visual acuity, taking into account the condition of the crystalline lens as well as the incidence of membrane recurrence and new or recurrent retinal detachment.

RESULTS

A 2-line or more visual improvement was achieved in 57% of the cases (16/28), i.e., 36% of eyes with progressive cataract (4/11), 50% of primary pseudophakic eyes (3/6), and 80% of eyes with unchanged lens (8/10). There was no recurrent epimacular membrane formation, with a mean follow-up of 8.7 months. A new or recurrent retinal detachment was observed in 25% of the cases (7/28).

DISCUSSION AND CONCLUSION

These results, compared with those achieved in the treatment of idiopathic membranes, as the literature reports, confirm the fair surgical prognosis of epimacular membrane formation after retinal break or rhegmatogenous retinal detachment.

Basal and post-methionine serum homocysteine and lipoprotein abnormalities in patients with chronic liver disease

BACKGROUND

Lipoprotein abnormalities are commonly found in chronic liver diseases (CLDs), particularly hypercholesterolemia in primary biliary cirrhosis (PBC). However, affected patients may not be at increased risk of coronary heart disease. Cirrhotic patients display impaired methionine clearance, and an increased level of homocysteine, a methionine metabolite, is an independent risk factor for coronary heart disease. Thus, we hypothesized that the low risk of coronary heart disease in patients with CLD may be related to low serum levels of homocysteine. The aim of this study was to test this hypothesis after methionine load and to describe the serum lipoprotein profile in patients with PBC and in patients with hepatocellular liver disease.

METHODS

Fifteen female patients (mean age, 58.2 +/- 11.7 years) with PBC, 15 female patients (mean age, 54.5 +/- 9.6 years) with other causes of CLD, and 15 healthy sex- and age-matched controls were given L-methionine (50 mg/kg of ideal body weight). Basal fasting serum homocysteine level and 2, 4, and 6 hours of post-methionine load were determined using high-performance liquid chromatography with a fluorometric detector. Levels of fasting serum cholesterol, triglycerides, high-density lipoprotein (HDL), low-density lipoprotein (LDL), lipoprotein (a) (Lp(a)), and apoprotein B were also determined.

RESULTS

Results showed that mean basal and post-methionine load (6 hours) serum homocysteine levels were statistically significantly higher in the patients with PBC and with CLD than in the control group (P=0.04) and that levels of serum cholesterol, LDL, HDL, and apoprotein B were significantly higher in the PBC patients than in the other two groups (P < or = 0.05). There was no correlation between any of these parameters and the severity of liver disease. Serum HDL was significantly lower in the CLD group (P < or = 0.05) and correlated with severity of liver disease. There was no significant difference in serum cholesterol, LDL, or apoprotein B between the CLD group and the controls. Serum triglyceride and Lp(a) levels were similar for all three groups.

CONCLUSIONS

In contrast to previous reports, the site of the methionine metabolic impairment was found to be below the homocysteine synthesis level. For most patients with CLD, factors other than serum homocysteine or Lp(a) are responsible for the reduction in the risk of coronary heart disease. Further studies with larger samples are needed.

Failure of total hip arthroplasty with Boneloc bone cement

Early failure of Boneloc cemented total hip arthroplasty is well documented. However, information regarding the long term prognosis is scanty. The aim of this study was therefore to assess the long term failure rate of total hip replacement with Boneloc bone cement. Between January 1991 and March 1992, Boneloc bone cement (Polymers Recontructive A/S, Farum, Denmark) was used in 42 consecutive total hip replacements in 42 patients. The average age of the patients was 75 years. There were 25 women and 17 men. The diagnosis at operation was osteoarthritis in all cases. A cemented Muller Taperloc femoral stem was used with a cemented Muller acetabular cup (Biomet, Warsaw, USA). The follow-up time was 9 years. All patients underwent radiographic control the first postoperative year and annually after 1995. To date 21 patients have been revised for aseptic loosening at a mean of 5 years (range: one year to 8 years). Three other patients have definite radiographic evidence of loosening. The overall failure rate is therefore 24/42 = 57%. Our results confirm the previously reported poor results of Boneloc bone cement for hip arthroplasty and support the recommendation of indefinite follow-up for surviving prostheses. New prosthesis designs and new cements should have documentation, including laboratory tests and randomized clinical studies with radiostereometric evaluation. However, the ethical responsibility rests heavily on the shoulders of the clinician to make a correct analysis of the need for a new product before he begins to use it.

Primary closure of deep sternal wound infection following open heart surgery: a safe operation?

BACKGROUND

Deep median sternotomy wound infection is a significant source of morbidity and mortality after cardiac operations. Management of an infected median sternotomy incision is a subject of controversy. The aim of this study was to assess our experience with primary closure without any irrigation system for infected deep median sternotomy wound.

METHODS

Between January 1994 and December 1997, 4,227 consecutive open heart procedures via a median sternotomy under cardiopulmonary bypass were performed in our department. A total of 27 (0.64%) consecutive patients with deep sternotomy wound infection were identified. The mean age of the patients was 45 years. Six were female and 21 were male.

RESULTS

The incidence of deep sternal wound infection was therefore 0.64%. The mean duration between the primary operation and the onset of deep sternal wound infection was 2.5 weeks. Staphylococcus aureus and Staphylococcus epidermidis were the most common pathogen causing postoperative mediastinal infection. Out of the 27 cases, 17 were successfully treated, 8 (30%) died and 2 had a persistent fistula. The mean follow-up time was 18 months (range 4 to 52 months). The mortality in the pediatric group was 4/8 (50%) and 4/19 (21%) in the adult group. The mortality for mediastinitis presenting before one week or after 4 weeks after operation was 63%. In contrast, the mortality for mediastinitis presenting after one week but before 4 weeks after operation was 17%.

CONCLUSIONS

Mediastinitis after cardiac surgical procedures remains a devastating complication. Primary closure without irrigation-suction system should only be considered in selected patients.

Storage of viruses on filter paper for genetic analysis

The purpose of this study was to develop a method to store viruses on filter paper without the need for special conditions for future use of the genetic material. Two non-enveloped viruses were used as models. Infectious bursal disease virus (IBDV), a double-stranded RNA virus that infects chickens, belongs to the Birnaviridae family. Hemorrhagic enteritis virus (HEV), with double-stranded DNA, belongs to the Adenoviridae family. Three different solutions were found suitable for loading the virus. The viruses were stored at room temperature or at 37 degrees C for periods of 5-30 days. Direct reverse transcription-polymerase chain reaction (RT-PCR) (without previous extraction of the RNA) was carried out on filter paper loaded with IBDV, and fragments of the expected size were detected. HEV DNA was extracted from filter paper loaded with purified virus or crude tissue. PCR fragments were found to be of similar intensity to those of control virus that was kept in a tube at -20 degrees C. This method permits the storage and transport of viruses from the field or from clinics to a regional laboratory or any laboratory elsewhere, without the need for prior treatment or special environmental conditions.

Dynamic hip screw versus 3 parallel screws in the treatment of garden 1 + 2 and garden 3 + 4 cervical hip fractures

OBJECTIVE

The main objective of this study was to evaluate the failure rate following operations of undisplaced and displaced cervical hip fractures with a dynamic hip screw compared with 3 parallel screws.

DESIGN

The study was retrospective. The minimum follow-up time was 1 year. The data tta collested between January 1990 and December 1993.

SETTING

University Hospitals.

PATIENTS

A total of 456 patients (352 women and 104 men) with cervical hip fractures were included. The mean age was 80 years (range 51-100 years).

INTERVENTION

This was internal fixation of the fractured hip with a dynamic hip screw or 3 parallel screws.

MAIN OUTCOME MEASURES

Failure was defined as nonunion, fixation failure or avascular necrosis and reoperation was found indicated. The 3 months mortality rate, the wound infection rate, the delay between admission and time of surgery and the blood transfusion requirement were also recorded.

RESULTS

A total of 456 cervical hip fractures were operated with a dynamic hip screw or 3 parallel screws. The failure rate for fractures treated with a dynamic hip screw was 14/98 = 14% for Garden 1 + 2 fractures and 43/108 = 40% for Garden 3 + 4 fractures. The failure rate for fractures treated with 3 parallel screws was similar: 23/154 = 15% for Garden 1 + 2 fractures and 38/196 = 40% for Garden 3 + 4 fractures. The average follow-up time was 2.5 years.

CONCLUSION

Operation of cervical hip fracture with a dynamic hip screw or 3 parallel screw seem to give similar results.

True and anastomotic femoral artery aneurysms: is the risk of rupture and thrombosis related to the size of the aneurysms?

OBJECTIVE

the management of asymptomatic femoral aneurysms remains controversial. The purpose of this study was to investigate the relation between the diameter of true and anastomotic aneurysms and the risk of rupture.

DESIGN

retrospective study.

MATERIAL AND METHODS

we reviewed the case records of 17 patients who underwent 17 arterial reconstructive procedures for true femoral aneurysms. In addition, the case records of 76 patients who underwent 90 arterial reconstructive procedures for femoral anastomotic aneurysms were identified and reviewed.

RESULTS

the rupture rate for aneurysms less than 5 cm in diameter was 1.6% (one out of 64) compared with 16% (seven out of 43) for those larger than 5 cm. The thrombosis rate for aneurysms less than 5 cm in diameter was 17% compared with 5% for those larger than 5 cm.

CONCLUSIONS

this study seems to show that the risk of rupture of femoral artery aneurysms is related to the diameter of the aneurysms. However, the rise in the risk of rupture with increasing size seems less dramatic than for abdominal aortic aneurysm (AAA).

Pneumococcal arthritis in the wrist and ankle. A case report and short review of the literature

In this paper we report a 48-year-old man with septic arthritis of the wrist and ankle due to Streptococcus pneumoniae. No known predisposing factor was found. Only about 300 cases of pneumococcal arthritis have been reported in the literature since 1888 and less than 10% of these affect the wrist. The management of bacterial arthritis is reviewed.

False iliac artery aneurysm following renal transplantation

We report a very rare case of a false iliac artery aneurysm following renal transplantation. The patient was a 51-year-old women who presented with a painful 10 x 10 cm pulsating mass in her left iliac fossa. The patient had received a second cadaveric renal transplantation 5 years previously. The graft never functioned and transplant nephrectomy was performed 2 weeks later. A CT-scanning showed a 10 x 10 cm large aneurysm arising from the left external iliac artery. At operation a large false aneurysm was identified arising from the original transplant anastomotic site. Due to the extent of the aneurysms, a Gortex graft was inserted between the external iliac artery and the common femoral artery. The patient made an uneventful post-operative recovery.

Thoracic disc herniation. Unilateral transpedicular approach in 35 consecutive patients

BACKGROUND

Thoracic disc herniation is uncommon and surgery for thoracic disc herniation represents less than 1-2% of operations for disc disease. However, there is no consensus on the best approach and reports are based on small series.

METHODS

A consecutive series of 35 thoracic disc herniations (25 in women and 10 in men) were treated between 1991 and 1996 using the transpedicular approach and followed in a prospective study. All patients had a preoperative MRI examination. The mean age was 51 years. The T6-7 and T7-8 level were the most frequent localization. The interval between onset of symptoms and operation ranged from 6 weeks to 4 years with a mean of 18 months. Presenting symptoms on admission was radiculopathy in 12 patients and myelopathy in 23 patients. Severe urinary symptoms were found in 2 patients, moderate symptoms in 9 patients, mild symptoms in 3 patients and 21 patient had no urinary symptoms.

RESULTS

One patient was paraplegic immediately after surgery and she made no further improvement. A good result was found in 15 patients, a fair result was found in a further 11 patients but in 8 patients the outcome was unchanged with no effect of a reoperation in two cases. No clinical or radiographic features of instability were found. The postoperative course was uneventful, except in one patient with a wound abscess leading to discitis.

CONCLUSIONS

The transpedicular approach can be an effective and safe method of surgical decompression in carefully selected patients.

Undiagnosed phaeochromocytoma following infrainguinal bypass surgery

We present a rare case of undiagnosed phaeochromocytoma following infrainguinal bypass surgery. The patient, a 59-year-old lady, had a one year history of hypertension following a first femoro-tibial bypass and presented as a cardiorespiratory emergency in the admission room following her contralateral femoro-tibial bypass. The patient recovered after some days in intensive care despite a delayed diagnosis.

Contributions of hypoxia and respiratory disturbance index to sympathetic activation and blood pressure in obstructive sleep apnea syndrome

Hypertension is a common finding among obstructive sleep apnea (OSA) patients, and is thought to be caused by sympathetic hyperactivity. The present study compares the contributions of the respiratory disturbance index (RDI) as a reflection of sleep fragmentation, and the magnitude of oxygen desaturation, to sympathetic activation as indexed by urinary norepinephrine concentrations, as well as to morning and evening blood pressure in sleep apnea syndrome patients. Data (polysomnography, blood pressure [BP], and urine catecholamines) of 38 consecutive OSA patients (age, 46+/-14.5 years) were analyzed. Stepwise logistic regression analysis revealed that minimal oxygen saturation level (SaO2min) was a significant predictor of both morning and evening norepinephrine levels, and that 37% of morning systolic BP variance could be accounted for by a combination of age and norepinephrine, while 20% of the diastolic BP variance was accounted for by SaO2min alone. In contrast, RDI entered the prediction equation only when minimal oxygen saturation was rejected first. Our results indicate that the degree of nocturnal hypoxia is more closely associated with the level of sympathetic activation and with daytime level of blood pressure than with sleep fragmentation.

Isolated iliac artery aneurysms

OBJECTIVE

To assess our experience with isolated iliac artery aneurysms and to assess the blood transfusion requirement in patients undergoing surgery for iliac artery aneurysms.

MATERIAL AND METHODS

The case records of 12 patients who underwent 12 arterial reconstructive procedures for isolated iliac aneurysms from January 1989 to December 1995 were identified from our prospective vascular database and reviewed. Only patients with aneurysms limited to the common, external, or internal iliac arteries were included.

RESULTS

Eleven patients had symptoms and rupture occurred in five patients. Aneurysmorrhaphy with graft interposition was the most common procedure. There was no perioperative mortality. The median transfusion requirement was 11 units per operation (range 1-30 units). The median intraoperative blood loss was 4700 ml (range < 500-13,000 ml).

CONCLUSIONS

Isolated iliac aneurysm is a dangerous condition. A low perioperative mortality is possible only if large volumes of blood are available.

Two-level thoracic disc herniation

We report a rare case of two-level thoracic disc herniation that occurred in a 48-year-old woman. She was referred with a 10-month history of pain on the right side of the thorax. On examination, she had hypoesthesia and hypalgesia in the right T6-T8 dermatomes. An MRI scan revealed a large herniated disc at the T7/8 level and a smaller herniated disc at the T6/7 level. At surgery, the unilateral transpedicular approach was used, and a large prolapse was removed at the T7/8 level. The T6/7 level was decompressed. The patient made an uneventful recovery. Six months after surgery her pain had disappeared, but she still had hypoesthesia in the right T6-T8 dermatomes.

Blood transfusion and postoperative wound infection in intracapsular femoral neck fractures

The relationship between blood transfusion and postoperative wound infection was studied in 695 operations for cervical hip fractures. A total of 156 (22%) patients were transfused with a total of 392 units of blood. A total of 31 (4.5%) patients developed a postoperative superficial or deep wound infection. Cultures identified Staphylococcus aureus as the cause in 71% and E. coli in 9.7% of the infections. A total of 11 out of 156 (7.05%) transfused patients developed a wound infection. In contrast only 20 out of 539 (3.71%) non-transfused patients developed a wound infection (p < 0.05).

Thoracic disk herniation in an 82-year-old patient. Treatment with the transpedicular approach

A rare case of thoracic disk herniation in an 82-year-old female is reported. The patient was referred with a 2-month history of weakness and paresthesia of her left leg. On examination she had a severe paresis of the left leg and mild paresis of the right leg. Myelography and magnetic resonance imaging showed a T10-T11 disk herniation. The unilateral transpedicular approach was used and a large prolapse was surgically removed. The patient made an uneventful recovery and her neurologic function recovered to almost normal.

Is preoperative tibial traction responsible for peroneal nerve palsy in patients with a fractured hip?

A study of 456 cervical hip fractures treated with internal fixation was performed to evaluate the incidence of paralysis of the peroneal nerve following hip-fracture treatment. There were no cases of peroneal nerve paralysis in a group of 206 patient treated with a dynamic hip screw without preoperative traction. There were 2 cases of peroneal nerve paralysis in a group of 250 patients treated with 3 parallel screws with preoperative skeletal traction via a tibia pin. This difference was not significant according to Fischer's test (two-tailed P value = 0.5036). We conclude that the incidence of paralysis of the peroneal nerve following hip-fracture treatment is low although preoperative skeletal traction with the injured leg positioned in a Böhler-Braun splint may contribute to this complication.

Anastomotic femoral aneurysms: is an increase in interval between primary operation and aneurysms formation related to change in incidence?

OBJECTIVE

Anastomotic pseudoaneurysms continue to be a late complication of vascular surgery, particulary following prosthetic graft procedures. The purpose of this study was to investigate if a previously reported increase in interval between the original operation and the development of pseudoaneurysm was related to a change in incidence.

DESIGN

Retrospective study.

METHODS

We reviewed the records of 76 patients who presented with 90 femoral pseudo-aneurysms and underwent reconstructive procedures from January 1989 to June 1994. The median age was 69 years (range: 39-83). In the same time period all femoral artery anastomosis operations were recorded.

RESULTS

The incidence of femoral pseudo-aneurysms in Copenhagen was approximately 4.3%.

CONCLUSIONS

A previously reported increase in interval between primary operation and aneurysms formation was not related to a change in incidence during the same time period.

An unnecessary femoral amputation?

Non-traumatic gas gangrene is extremely rare. It is commonly associated with perforation of an occult gastro-intestinal cancer. The patient's course is usually fulminant. We report a case of subcutaneous emphysema and myonecrosis of the lower extremity due to a perforated carcinoma of the large bowel. The diagnosis of colonic cancer was suspected but treatment was regrettably delayed leading to the perforation and subsequent lower extremity gas gangrene. The patient survived following a femoral amputation.

Percutaneous recanalization of iliac artery occlusions with the Strecker stent

Within a 3-year period a total of 16 iliac artery occlusions in 16 patients were treated with percutaneous angioplasty and stenting with the Strecker stent without adjunctive thrombolytic therapy. The length of the occlusions varied from 0.5 to 8 cm (mean 4.1 cm). The average stent diameter was 7.6 mm and the average length was 6.1 cm. Reocclusion occurred in 3 patients (two after one month and one after 11 months). One case of dissection and two cases of distal embolization to the external iliac artery were diagnosed during the procedure by an angiogram and were successfully treated by stenting. Two cases of small groin hematoma were treated conservatively.

Experimental induction and termination of acute psychological stress in human volunteers: effects on immunological, neuroendocrine, cardiovascular, and psychological parameters

The present research investigated the effects of controlled experimental manipulations of stress on biological and psychological reactions. Fifty young adult male volunteers were exposed to a 12-min period of stress induced by the threat of an unavoidable, painful electric shock. A 12-min period without this threat preceded or followed the stress period. Blood was drawn during the 4th and the 12th minute of each period. Anticipatory threat led to significant elevations in the proportions and cytotoxic activity of natural killer (NK) lymphocytes, plasma epinephrine levels, pulse rate, and reported level of tension, and to a reduction in the CD4/CD8 ratios. The no-threat period induced a return to baseline values for epinephrine, pulse rate, and tension, and lower than baseline levels for cytotoxic activity of NK lymphocytes, within a similarly short time span. The findings underline the rapidity with which physiological changes may transpire in the course of a brief and acute period of psychological stress, and the rapidity of their reversal upon relief from the stressor.

Dysplasia epiphysealis hemimelica (Trevor's disease) of the distal radius

The authors report a rare case of dysplasia epiphysealis hemimelica (DEH) or Trevor's disease of the radius in an Eskimo from Greenland. DEH is indistinguishable microscopically from osteochondroma, however its epiphyseal site of origin differentiates it from the osteochondroma, which characteristically originates in the metaphysis.

Delayed appearance of hip fractures in citizens of Bergen born in the countryside compared to cityborn

Of a total of 1735 consecutive patients admitted to Engen Hospital in Bergen, 299 had sustained a hip fracture. A distinction was made according to sex, and according to whether the patients were born in the city of Bergen or in the surrounding rural areas. At the time of fracture, the countryborn had lived on average 51 years in Bergen. A delay in fracture appearance of approximately 3 years in the countryborn relative to the cityborn was found.

Blood transfusion requirement in surgery for femoral artery aneurysms

BACKGROUND

Audit of blood usage in various surgical specialities have shown that over-ordering of blood is widespread, causing unnecessary pressure on the transfusion facilities and giving growing concern over the expense of cross-matching blood. The aim of this study was to assess the blood transfusion requirement in patients undergoing surgery for femoral artery aneurysms.

METHODS

The blood transfusion requirements of 120 patients undergoing surgery for femoral artery aneurysms were studied. All patients underwent routine pre-operative and postoperative haemoglobin measurement. Operative blood loss was also assessed.

RESULTS

The transfusion requirements were correlated with the type of aneurysms, the existence of preoperative anaemia and intraoperative blood loss. A total of 62 (52%) patients were transfused with a total of 144 units. Out of 90 patients with anastomotic femoral aneurysms, 42 patients were transfused with a total of 89 units. The average measured intraoperative blood loss was 635 ml. Out of 17 patients with atherosclerotic femoral aneurysms, 13 patients were transfused with a total of 34 units. The average measured intraoperative blood loss was 1107 ml. Out of 13 patients with traumatic or mycotic femoral aneurysms, 7 patients were transfused with a total of 21 units. The average measured intraoperative blood loss was 536 ml.

CONCLUSIONS

Patients with a preoperative haemoglobin < 7 mmol/l should be cross-matched 3-4 units. When the preoperative haemoglobin is between 7 and 9 mmol/l, patients should be cross-matched 1-2 units, whereas it should be safe to group and antibody screen patients with a preoperative haemoglobin > 10 mmol/l.

Mycoplasma in urine and blood following catheterisation of patients undergoing vascular surgery

OBJECTIVES

The purpose of this investigation was to determine if mycoplasmas enter the bloodstream after urinary tract catheterisation in patients undergoing vascular surgery in order to evaluate the efficiency of the routine prophylactic antibiotic treatment.

DESIGN

Prospective study.

MATERIALS AND METHODS

A total of 100 patients (63 men and 37 women) undergoing elective vascular surgery had urine and blood cultures performed for mycoplasmas. Blood cultures were taken preoperatively after urinary tract catheterisation and the urine was collected during catheterisation. The median age of the patients was 67 years (range 42-87).

RESULTS

A total of 12 (12%), 5 men and 7 women, had a positive urine culture for mycoplasmas (One patient had Mycoplasma hominis and 11 had Ureaplasma urealyticum isolated). Their median age was 60 years (range 42-76). No blood cultures were positive for Mycoplasma.

CONCLUSIONS

Mycoplasmas do not enter the blood-stream after catheterization in sufficient amounts and sufficiently often to be detected by blood-cultures in this small patient sample. The number of vascular patients harbouring mycoplasmas in the urine was low and we found no indication for changes in the prophylactic antibiotic treatment based on these findings.

Arteriosclerotic femoral artery aneurysms. A short review

True arteriosclerotic aneurysms of the femoral artery are rare but they are dangerous lesions that may thrombose, embolise or rupture. They are often bilateral and frequently the patient has other aneurysms in the abdominal aortic or popliteal artery. True femoral aneurysms were originally classified by Cutler and Darling in 1973 as type 1 and type 2 according to their relationship to the common femoral bifurcation. Case reports of isolated superficial and profunda femoral artery aneurysms have been published, but these are exceedingly rare although isolated aneurysms of the profunda femoris artery may be more common in Denmark. True femoral artery aneurysms are attributed to weakening of the arterial wall due to atherosclerosis. True femoral artery aneurysms are relatively rare and are found in elderly smoking men. Aortic aneurysms are approximately 10 times more common. Distal embolization occurs in 0-26% of cases. Acute thrombosis occurs in around 15% of cases. Rupture is uncommon and varies between 10% and 14%. Aneurysmal dilatation of the profunda femoris artery is uncommon and occurs in only 1% to 2.6% of all femoral artery aneurysms. Individualized operative approaches are based on aneurysmal involvement of the superficial femoral or profunda femoris arteries, as well as the presence or absence of coexisting extremity occlusive disease. Aneurysm excision and interposition or bypass graft reconstruction are favored over direct end-to-end reanastomosis.

Preoperative ultrasound mapping of the saphenous vein: prognostic value on early post operative results, a prospective study

A prospective series of 92 patients had their greater saphenous vein assessed with duplex ultrasound scanning prior to planned infrainguinal bypass procedures. Sixteen (17%) bypass procedures thrombosed within the first week postoperatively. A naturally occurring optimal vein diameter was discovered: 3.5-4.2 mm at mid-thigh level and 0-1.5 mm less at mid-calf level. It was significantly correlated with higher one week patency: thrombosis occurred in 11% in veins with this optimal diameter combination and in 19% in all other combination (P < 0.05). These results confirm and expand a retrospective study.

The incidence of Achilles tendon rupture in Copenhagen

The incidence of Achilles tendon rupture in Copenhagen during an 18 year period, from 1978 to 1995 was studied. A total of 209 patients sustained 213 Achilles tendon ruptures (55 in women and 158 in men). The median age was 41 years. The overall incidence was 13.4/100000 inhabitants/year.

Surgical infections with Mycoplasma: a brief review

Mycoplasma hominis and Ureaplasma urealyticum are common inhabitants of the human genital tract. Evidence for an aetiological role in pyelonephritis, pelvic inflammatory disease, post-abortion and post-partum fever has been presented. There are sporadic reports of Mycoplasma causing serious extragenital infection such as septicemia, septic arthritis, neonatal meningitis and encephalitis. We review 38 cases of surgical infections with Mycoplasma.