[Intra-abdominal vascular injuries after blunt abdominal trauma]

Vascular injuries and hemorrhaging are serious potential complications in the management of patients with blunt abdominal trauma. The treatment depends on the extent and localization and can range from surveillance to endovascular treatment up to open surgery. The keys to success include the focused assessment with sonography for trauma (FAST) management and timely decision making. Abdominal vascular trauma continues to be a difficult problem and open and endovascular techniques continue to evolve in order to address this complex disease process.

Dragon 1 Protocol Manuscript: Training, Accreditation, Implementation and Safety Evaluation of Portal and Hepatic Vein Embolization (PVE/HVE) to Accelerate Future Liver Remnant (FLR) Hypertrophy

STUDY PURPOSE

The DRAGON 1 trial aims to assess training, implementation, safety and feasibility of combined portal- and hepatic-vein embolization (PVE/HVE) to accelerate future liver remnant (FLR) hypertrophy in patients with borderline resectable colorectal cancer liver metastases.

METHODS

The DRAGON 1 trial is a worldwide multicenter prospective single arm trial. The primary endpoint is a composite of the safety of PVE/HVE, 90-day mortality, and one year accrual monitoring of each participating center. Secondary endpoints include: feasibility of resection, the used PVE and HVE techniques, FLR-hypertrophy, liver function (subset of centers), overall survival, and disease-free survival. All complications after the PVE/HVE procedure are documented. Liver volumes will be measured at week 1 and if applicable at week 3 and 6 after PVE/HVE and follow-up visits will be held at 1, 3, 6, and 12 months after the resection.

RESULTS

Not applicable.

CONCLUSION

DRAGON 1 is a prospective trial to assess the safety and feasibility of PVE/HVE. Participating study centers will be trained, and procedures standardized using Work Instructions (WI) to prepare for the DRAGON 2 randomized controlled trial. Outcomes should reveal the accrual potential of centers, safety profile of combined PVE/HVE and the effect of FLR-hypertrophy induction by PVE/HVE in patients with CRLM and a small FLR.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT04272931 (February 17, 2020). Toestingonline.nl: NL71535.068.19 (September 20, 2019).

Thrombotischer Verschluss der extrakorporalen Zirkulation während hepatischer Chemosaturation trotz zielgerechter Antikoagulation

Die perkutane hepatische Chemosaturation ist eine Behandlungsoption bei nichtresektablen primären oder sekundären Lebertumoren. Dabei wird der Bereich der Lebervenenmündung der Vena cava inferior (VCI) mittels 2 Ballons von der Zirkulation isoliert, sodass die systemische Verteilung des über die Leberarterie applizierten Chemotherapeutikums Melphalan verhindert wird. Nach Passage der Leber und venöser Drainage aus der retrohepatischen VCI durchläuft das chemosaturierte Blut 2 parallel geschaltete extrakorporale Filter. Anschließend wird das gereinigte Blut jugulär rückgeführt. Das Verfahren geht oft mit einer ausgeprägten hämodynamischen Instabilität einher, deren Ursache nicht abschließend geklärt ist. Zusätzlich stellt das Gerinnungsmanagement eine Herausforderung dar. Die Autoren berichten von einem Fall, bei dem sich trotz ausreichender „activated clotting time“ (ACT) ein Thrombus im rückführenden Schenkel der extrakorporalen Zirkulation bildete. Gezielte Problemsuche und -lösung waren parallel zur hämodynamischen Stabilisierung und interdisziplinären Zusammenarbeit notwendig, um die Intervention erfolgreich durchzuführen und der Patientin eine sichere Therapie zukommen zu lassen.

Technical background of a novel detector-based approach to dual-energy computed tomography

Dual-energy information in computed tomography can be obtained through different technical approaches. Most available scanner designs acquire examination with two different X-ray spectra. Recently, the first detector-based approach became clinically available. Upfront, physical principles of dual-energy CT are reviewed, including the interaction of photons with matter in terms of the Photoelectric effect and Compton scattering. In addition, available concepts to dual energy computed tomography are described. Afterwards, the spectral detector CT system is described in detail. The design of the of the stacked detector design and its inherent technical advantages and disadvantages are discussed. Further, the principles of image reconstruction, their possibilities and limitations are referred. The increase in reconstructions and data pose some challenges to both, clinical and technological workflow which are hereafter addressed. Finally, the detector-based approach is discussed in light of other, emission-based DECT approaches.

Comparative analysis of CGUARD embolic prevention stent with Casper-RX and Wallstent for the treatment of carotid artery stenosis

Stent protected Angioplasty of extracranial carotid artery stenosis using the dual-layered CGUARD stent is a novel treatment option. In this study we evaluate the feasibility and the safety of the CGUARD in symptomatic and asymptomatic patients in comparison to Casper-RX and Wallstent. This is a multi-center study of consecutive patients treated with the CGUARD, Casper-RX and Wallstent at two German high volume neurovascular centers between April 2017 and May 2018. Patient characteristics, neuroimaging data and angiographic outcome were retrospectively analyzed. The primary end points of the study were acute occlusion of the carotid stent and symptomatic intracerebral hemorrhage (sICH). Carotid artery stenting was performed in 76 patients; of those 26 (34%) were treated with the CGUARD, 25 (33%) with Casper-RX, and 25 (33%) with Wallstent. In 58/76 (76%) cases carotid artery stenosis was symptomatic with a median baseline National Institutes of Health Stroke Scale of 4. Angioplasty and stenting as part of a mechanical thrombectomy for acute ischemic stroke was performed in 25/76 (33%) patients. Baseline patient characteristics were similar between the treatment groups, except for a higher portion of scheduled cases in the Casper-RX group. There were no significant differences in the rate of acute in stent occlusions (CGUARD, 2/26 (8%); Casper-RX, 1/25(4%); Wallstent, 1/25 (4%)) and postinterventional sICH (1/26 (4%), 0/25(0%), 0/25 (0%)). Clinical outcome at discharge did not differ between groups. Treatment of carotid artery stenosis using CGUARD is feasible with a good safety profile comparable to that of Casper-RX and Wallstent.

Stenosis of the celiac trunk is associated with anastomotic leak after Ivor-Lewis esophagectomy

Transthoracic esophagectomy with gastric tube formation is the surgical treatment of choice for esophageal cancer. The surgical reconstruction induces changes of gastric microcirculation, which are recognized as potential risk factors of anastomotic leak. This prospective observational study investigates the association of celiac trunk (TC) stenosis with postoperative anastomotic leak. One hundred fifty-four consecutive patients with esophageal cancer scheduled for Ivor-Lewis esophagectomy were included. Preoperative staging computed tomography (CT) was used to identify TC stenosis. Any narrowing of the lumen due to atherosclerotic changes was classified as stenosis. Percentage of stenotic changes was calculated using the North American Symptomatic Carotid Endarterectomy Trial formula. Multivariable analysis was used to identify possible risk factors for leak. The overall incidence of TC stenosis was 40.9%. Anastomotic leak was identified in 15 patients (9.7%). Incidence of anastomotic leak in patients with stenosis was 19.4% compared to 2.3% in patients without stenosis. Incidence of stenosis in patients with leak was 86.7% (13 of 15 patients) and significantly higher than 38.8% (54 of 139 patients) in patients without leak (P < 0.001). There was a significant difference in median degree of TC stenosis (50.0% vs 39.4%; P = 0.032) in patients with and without leak. In the multivariable model, TC stenosis was an independent risk factor for anastomotic leak (odds ratio: 5.98, 95% CI: 1.58-22.61). TC stenosis is associated with postoperative anastomotic leak after Ivor-Lewis esophagectomy. Routine assessment of TC for possible stenosis is recommended to identify patients at risk.

Combined Heart and Kidney Transplantation: A 23-Year Experience

BACKGROUND

We report clinical experience with combined heart and kidney transplantation (HKTx) over a 23-year time period.

METHODS

From June 1992 to August 2015, we performed 83 combined HKTx procedures at our institution. We compared the more recent cohort of 53 HKTx recipients (group 2, March 2009 to August 2015) with the initial 30 previously reported HKTx recipients (group 1, June 1992 to February 2009). Pre-operative patient characteristics, peri-operative factors, and post-operative outcomes including survival were examined.

RESULTS

The baseline characteristics of the two groups were similar, except for a lower incidence of ethanol use and higher pre-operative left-ventricular ejection fraction, cardiac output, and cardiac index in group 2 when compared with group 1 (P = .007, .046, .037, respectively). The pump time was longer in group 2 compared with group 1 (153.30 ± 38.68 vs 129.60 ± 37.60 minutes; P = .007), whereas the graft ischemic time was not significantly different between the groups, with a trend to a longer graft ischemic time in group 2 versus group 1 (195.17 ± 45.06 vs 178.07 ± 52.77 minutes; P = .056, respectively). The lengths of intensive care unit (ICU) and hospital stay were similar between the groups (P = .083 and .39, respectively). In addition, pre-operative and post-operative creatinine levels at peak, discharge, 1 year, and 5 years and the number of people on post-operative dialysis were similar between the groups (P = .37, .75, .54, .87, .56, and P = .139, respectively). Overall survival was not significantly different between groups 2 and 1 for the first 5 years after transplant, with a trend toward higher survival in group 2 (P = .054).

CONCLUSIONS

The most recent cohort of combined heart and kidney transplant recipients had similar ICU and hospital lengths of stay and post-operative creatinine levels at peak, discharge, and 1 and 5 years and a similar number of patients on post-operative dialysis when compared with the initial cohort. Overall survival was not significantly different between the later and earlier groups, with a trend toward higher overall survival at 5 years in the more recent cohort of patients. In selected patients with co-existing heart and kidney failure, combined heart and kidney transplantation is safe to perform and has excellent outcomes.

Supplementation with nutrients modulating insulin-like growth factor-1 negatively correlated with changes in the levels of pro-inflammatory cytokines in community-dwelling elderly people at risk of undernutrition

BACKGROUND

Suboptimal nutrition accompanied by chronic low-grade increases in circulating cytokine levels is more common in elderly people. We explored the improvement in nutritional status, especially in the level of insulin-like growth factor-1 (IGF-1) and its relationship with changes in circulating cytokine levels, after providing extra protein and energy content to community-dwelling older adults at risk of undernutrition.

METHODS

Sixty nondiabetic subjects, aged ≥65 years and living independently in a community for elderly people, with a serum pre-albumin level ≤30 mg dL^-1 and a body mass index <25 kg m^-2 , were recruited. The subjects were followed for a 2-week pre-intervention period, during which they maintained routine dietary habits. This was followed by an intervention period, during which they received oral nutritional supplementation for 2 weeks.

RESULTS

Following 2 weeks of intervention, there were significant increases in total lymphocyte count (TLC) and insulin-like growth factor (IGF)-1, pre-albumin and transferrin compared to baseline. Body weight and mid-arm circumference significantly increased without alteration of tricep skinfold thickness at the end of the intervention. There was a significant reduction in interleukin (IL)-6 levels and a trend toward a decrease in the tumor necrosis factor (TNF)-α levels. At baseline, age was negatively correlated with IGF-1 levels and positively correlated with IL-6 and TNF-α levels. The change (▵, from baseline) in IGF-1 level was positively correlated with age and negatively correlated with ▵IL-6 and ▵TNF-α.

CONCLUSIONS

A 2-week intervention with oral nutritional supplementation improved nutritional status and decreased circulating cytokine levels. Specifically, ▵IGF-1 was negatively correlated with changes in pro-inflammatory cytokine levels in community-dwelling elderly people at risk of undernutrition. (Clinicaltrials.gov: NCT02656186).

Bile duct carcinoma recurrence in the papillary region in a long-term survivor of hilar cholangiocarcinoma: a case report

Background

Because of its high rate of early recurrence and its poor prognosis, long-term survival after cholangiocarcinoma is rare; therefore, only limited information on patients surviving more than 5 years after surgical therapy is available.

Case presentation

We report the case of a 57-year-old white man who developed a distal bile duct carcinoma 9 years after curative surgical therapy of intrahepatic cholangiocarcinoma. He had undergone a right lobe hemihepatectomy 11 years ago. Nine years later, he was diagnosed with a distal bile duct carcinoma and a duodenopancreatectomy was performed. On histologic examination both carcinomas revealed a tubular and papillary growth pattern with cancer-free resection margins and for both carcinomas there were no signs of lymphatic infiltration or metastatic spreading. Targeted next-generation sequencing showed an identical activating mutation pattern in both carcinomas.

Conclusions

Late recurrence of cholangiocarcinoma, even anatomically distant to the primary, in long-time survivors is possible and could be caused by a distinct tumor biology. A better understanding of the individual tumor biology could help hepatologists as well as hepatobiliary and pancreatic surgeons in their daily treatment of these patients.

Modification to the accelerator of the NBI-1B ion source for improving the injection efficiency

Minimizing power loss of a neutral beam imposes modification of the accelerator of the ion source for further improvement of the beam optics. The beam optics can be improved by focusing beamlets. The injection efficiencies by the steering of ion beamlets are investigated numerically to find the optimum modification of the accelerator design of the NBI-1B ion source. The beam power loss was reduced by aperture displacement of three edge beamlets arrays considering power loadings on the beamline components. Successful testing and operation of the ion source at 60 keV/84% of injection efficiency led to the possibility of enhancing the system capability to a 2.4 MW power level at 100 keV/1.9 μP.

Trends in U.S. hospitalizations and inpatient deaths from pneumonia and influenza, 1996-2011

BACKGROUND

To reduce excess morbidity and mortality of pneumonia and influenza (PI), the Advisory Committee on Immunization Practices has recommended the use of 7-valent pneumococcal conjugate vaccine (PCV7), and incrementally expanded the target group for annual influenza vaccination of healthy persons, to ultimately include all persons ≥6 months of age without contraindications as of the 2010-2011 influenza season. We aimed to capture broader epidemiologic changes by looking at PI collectively.

METHODS

Using interrupted time series, we evaluated the changes in the rates of PI hospitalization and inpatient death across three periods defined according to the changes in vaccination policy. We assessed linear trends adjusting for seasonality, sex, and age group, allowing for differential impact across age groups. PI hospitalizations were defined as a principal diagnosis of PI, or a principal diagnosis of sepsis or respiratory failure, accompanied by a secondary diagnosis of PI.

RESULTS

Overall annual rates of PI hospitalizations and inpatient deaths declined by 95 per 100,000 (95% CI: 45-145) and by 4.4 per 100,000 (95% CI: 0.9-7.8), respectively. This translates to 295,000 fewer PI hospitalizations and 13,600 fewer PI inpatient deaths than expected based on the average rates from 1996 through 1999. PI hospitalizations dropped the most among seniors aged 65+ by 487 per 100,000, followed by children aged <2, by 228 per 100,000. PI inpatient deaths declined most among seniors aged 65+, by 25.3 per 100,000.

CONCLUSIONS

In this nationally representative study, PI hospitalizations and inpatient deaths decreased in U.S. between 1996 and 2011. There is a temporal association with the introduction and widespread use of pneumococcal conjugate vaccines, and the expansion of the target group for annual influenza vaccination to include all persons ≥6 months of age, while it is difficult to attribute these changes directly to specific vaccines used in this era.

Radiation Dose Reduction in Computed Tomography-Guided Lung Interventions using an Iterative Reconstruction Technique

PURPOSE

To compare the radiation doses and image qualities of computed tomography (CT)-guided interventions using a standard-dose CT (SDCT) protocol with filtered back projection and a low-dose CT (LDCT) protocol with both filtered back projection and iterative reconstruction.

MATERIALS AND METHODS

Image quality and radiation doses (dose-length product and CT dose index) were retrospectively reviewed for 130 patients who underwent CT-guided lung interventions. SDCT at 120 kVp and automatic mA modulation and LDCT at 100 kVp and a fixed exposure were each performed for 65 patients. Image quality was objectively evaluated as the contrast-to-noise ratio and subjectively by two radiologists for noise impression, sharpness, artifacts and diagnostic acceptability on a four-point scale.

RESULTS

The groups did not significantly differ in terms of diagnostic acceptability and complication rate. LDCT yielded a median 68.6% reduction in the radiation dose relative to SDCT. In the LDCT group, iterative reconstruction was superior to filtered back projection in terms of noise reduction and subjective image quality. The groups did not differ in terms of beam hardening artifacts.

CONCLUSION

LDCT was feasible for all procedures and yielded a more than two-thirds reduction in radiation exposure while maintaining overall diagnostic acceptability, safety and precision. The iterative reconstruction algorithm is preferable according to the objective and subjective image quality analyses.

KEY POINTS

Implementation of a low-dose computed tomography (LDCT) protocol for lung interventions is feasible and safe. LDCT protocols yield a significant reduction (more than 2/3) in radiation exposure. Iterative reconstruction algorithms considerably improve the image quality in LDCT protocols.

Development progresses of radio frequency ion source for neutral beam injector in fusion devices

A large-area RF (radio frequency)-driven ion source is being developed in Germany for the heating and current drive of an ITER device. Negative hydrogen ion sources are the major components of neutral beam injection systems in future large-scale fusion experiments such as ITER and DEMO. RF ion sources for the production of positive hydrogen (deuterium) ions have been successfully developed for the neutral beam heating systems at IPP (Max-Planck-Institute for Plasma Physics) in Germany. The first long-pulse ion source has been developed successfully with a magnetic bucket plasma generator including a filament heating structure for the first NBI system of the KSTAR tokamak. There is a development plan for an RF ion source at KAERI to extract the positive ions, which can be applied for the KSTAR NBI system and to extract the negative ions for future fusion devices such as the Fusion Neutron Source and Korea-DEMO. The characteristics of RF-driven plasmas and the uniformity of the plasma parameters in the test-RF ion source were investigated initially using an electrostatic probe.

Improvement of a plasma uniformity of the 2nd ion source of KSTAR neutral beam injector

The 2nd ion source of KSTAR (Korea Superconducting Tokamak Advanced Research) NBI (Neutral Beam Injector) had been developed and operated since last year. A calorimetric analysis revealed that the heat load of the back plate of the ion source is relatively higher than that of the 1st ion source of KSTAR NBI. The spatial plasma uniformity of the ion source is not good. Therefore, we intended to identify factors affecting the uniformity of a plasma density and improve it. We estimated the effects of a direction of filament current and a magnetic field configuration of the plasma generator on the plasma uniformity. We also verified that the operation conditions of an ion source could change a uniformity of the plasma density of an ion source.

First neutral beam injection experiments on KSTAR tokamak

The first neutral beam (NB) injection system of the Korea Superconducting Tokamak Advanced Research (KSTAR) tokamak was partially completed in 2010 with only 1∕3 of its full design capability, and NB heating experiments were carried out during the 2010 KSTAR operation campaign. The ion source is composed of a JAEA bucket plasma generator and a KAERI large multi-aperture accelerator assembly, which is designed to deliver a 1.5 MW, NB power of deuterium at 95 keV. Before the beam injection experiments, discharge, and beam extraction characteristics of the ion source were investigated. The ion source has good beam optics in a broad range of beam perveance. The optimum perveance is 1.1-1.3 μP, and the minimum beam divergence angle measured by the Doppler shift spectroscopy is 0.8°. The ion species ratio is D(+):D(2)(+):D(3)(+) = 75:20:5 at beam current density of 85 mA/cm(2). The arc efficiency is more than 1.0 A∕kW. In the 2010 KSTAR campaign, a deuterium NB power of 0.7-1.5 MW was successfully injected into the KSTAR plasma with a beam energy of 70-90 keV. L-H transitions were observed within a wide range of beam powers relative to a threshold value. The edge pedestal formation in the T(i) and T(e) profiles was verified through CES and electron cyclotron emission diagnostics. In every deuterium NB injection, a burst of D-D neutrons was recorded, and increases in the ion temperature and plasma stored energy were found.

Development of a plasma generator for a long pulse ion source for neutral beam injectors

A plasma generator for a long pulse H(+)/D(+) ion source has been developed. The plasma generator was designed to produce 65 A H(+)/D(+) beams at an energy of 120 keV from an ion extraction area of 12 cm in width and 45 cm in length. Configuration of the plasma generator is a multi-cusp bucket type with SmCo permanent magnets. Dimension of a plasma chamber is 25 cm in width, 59 cm in length, and 32.5 cm in depth. The plasma generator was designed and fabricated at Japan Atomic Energy Agency. Source plasma generation and beam extraction tests for hydrogen coupling with an accelerator of the KSTAR ion source have been performed at the KSTAR neutral beam test stand under the agreement of Japan-Korea collaborative experiment. Spatial uniformity of the source plasma at the extraction region was measured using Langmuir probes and ±7% of the deviation from an averaged ion saturation current density was obtained. A long pulse test of the plasma generation up to 200 s with an arc discharge power of 70 kW has been successfully demonstrated. The arc discharge power satisfies the requirement of the beam production for the KSTAR NBI. A 70 keV, 41 A, 5 s hydrogen ion beam has been extracted with a high arc efficiency of 0.9 -1.1 A/kW at a beam extraction experiment. A deuteron yield of 77% was measured even at a low beam current density of 73 mA/cm(2).

An ion optics study for KSTAR neutral beam injector development

Ion optics of three accelerator geometries was studied in terms of an analytic linear optics analysis, a numerical simulation using the IGUN program, an optical multichannel measurement of Doppler-shifted H(alpha) lines, and a water-flow calorimetry on the beam absorbing target. In general, there was a reasonable agreement observed between the four analysis methods and thus the theoretical analyses can be utilized with confidence for design iteration.

Extraction and characterization of metallic wear debris from total joint arthroplasty

Wear debris generated from total joint arthroplasty may elicit a granulomatous and inflammatory response and has also been implicated in the development of osteolysis. Technical difficulty in retrieval and isolation of wear material from tissues has hindered the study of their physicochemical properties. The purpose of this study was to retrieve and analyze metallic wear debris from periprosthetic tissue obtained during revision arthroplasty. Tissue from six osteoarthritic patients was obtained during revision arthroplasty. The tissue was minced and then heated in a sodium dodecyl sulfate solution. Undigested tissue was incubated sequentially with papain and pepsin solutions. Metallic wear debris retrieved from the digestion procedure was analyzed by scanning electron microscopy. Wear fragments were seen as irregularly shaped flakes, splinters and polyhedral structures ranging from 1 to 100 microns in size. These structures appeared to be free from non-metallic surface-adherent material. Energy dispersion spectroscopy verified the presence of cobalt, chrome and molybdenum which comprised the implant alloy. Fatigue lines were observed on the surface suggesting brittle wear. Our technique for isolating metallic fragments facilitates the retrieval and preparation of wear debris for analysis of physicochemical properties and how wear debris interacts with cellular elements in surrounding tissue.

Corneoscleral rim cultures: lack of utility and implications for clinical decision-making and infection prevention in the care of patients undergoing corneal transplantation

PURPOSE

To assess the utility of donor corneoscleral rim cultures.

METHODS

A retrospective review of the culture results of 774 corneoscleral rims that remained after trephination of corneas for transplantation into patients at our academic medical center between January 1992 and November 1997.

RESULTS

Forty-one (5.3%) corneoscleral rim cultures yielded microorganisms, mostly coagulase-negative staphylococci. Two patients developed endophthalmitis (one with Staphylococcus aureus and one with Pseudomonas aeruginosa) within 3 months after transplantation; each had a negative corneoscleral rim culture and neither patient's infection was temporally related to the transplant procedure.

CONCLUSIONS

Preoperative donor corneoscleral rim cultures are unreliable predictors of endophthalmitis complicating corneal transplantation and, therefore, are not useful in the clinical management of patients having corneal transplants. Moreover, the discrepancy between the results of corneoscleral rim cultures and subsequent endophthalmitis renders them invalid as a quality assurance procedure. Instead, for patients with suspected endophthalmitis after corneal transplantation, we recommend that corneal surgeons select antimicrobial therapy based on current guidelines and the results of directed sampling. Furthermore, eye banks should prospectively track recipients who develop clinical endophthalmitis, immediately notify the corneal surgeon who transplanted the matched cornea of that used for the index case, and, in selected situations, attempt to identify a possible source of contamination.

Cardiotoxicity with modern local anaesthetics: is there a safer choice?

The recognition that long-acting local anaesthetics, particularly bupivacaine the de facto standard long-acting local anaesthetic, were disproportionately more cardiotoxic than their shorter-acting counterparts stimulated the development of the bupivacaine congeners, ropivacaine and levobupivacaine. These agents, like all local anaesthetics, can produce cardiotoxic sequelae by direct and indirect mechanisms that derive from their mode of local anaesthetic actions, i.e. inhibition of voltage-gated ion channels. While all local anaesthetics can cause direct negative inotropic effects, ropivacaine and levobupivacaine are less cardiotoxic than bupivacaine judging by the larger doses tolerated in laboratory animal preparations before the onset of serious cardiotoxicity (particularly electro-mechanical dissociation or malignant ventricular arrhythmias). Additionally, they are less toxic to the CNS than bupivacaine judging by the larger doses tolerated before the onset of seizures. This may be clinically important because CNS effects may be involved in the production of serious cardiotoxicity. Preclinical studies in humans are a 'blunt instrument' in their ability to distinguish significant differences between these drugs because of the relatively small doses that can be used. Nevertheless, available evidence from human studies corroborates the preclinical laboratory animal studies. Because clinically significant differences between these drugs are more quantitative than qualitative, i.e. toleration of a larger dose before manifestation of toxicity, we have concluded that these newer agents have a lower risk of causing serious cardiotoxicity than bupivacaine. Thus, compared with bupivacaine, the newer agents may be seen as 'safer', but they must not be regarded as 'safe'.

Diffusion of hydrogen sulfide and methyl mercaptan onto microporous alkaline activated carbon

Activated carbon kinetic studies show that both H2S and CH3SH yielded pore diffusion coefficients from 10(-6) to 10(-8) cm2/s. Results indicated that pore structures could influence effective diffusivity. Under the same adsorbate concentration, CH3SH exhibited a greater effective pore diffusion coefficient than H2S. This may be attributed to the fact that CH3SH has both polar (-SH) and non-polar (-CH3) functional groups and dissolves into water easier, thus providing more attraction for the activated carbon surface. In addition, the saturation vapor pressure of CH3SH is lower than that of H2S. Therefore, CH3SH is easier to adsorb onto activated carbon than H2S.

Tolerability of large-dose intravenous levobupivacaine in sheep

In preclinical pharmacological studies of levobupivacaine (S-bupivacaine), we determined its tolerability, cardiovascular actions, and pharmacokinetics, and we estimated its margin of safety compared with bupivacaine in conscious sheep. Levobupivacaine HCl. H(2)O was infused IV for 3 min into 10 previously instrumented ewes (approximately 50 kg). On subsequent days, the doses were increased by 50 mg from 200 or 250 mg until fatality occurred. All doses produced convulsions, QRS widening, and cardiac arrhythmias. With incremental doses, 4 of 4 animals survived 200 mg, 7 of 10 survived 250 mg, 3 of 7 survived 300 mg, but 0 of 3 survived 350 mg. Death resulted from sudden onset ventricular fibrillation (n = 3, within 2-3 min), electromechanical dissociation-pump failure (n = 5, within 4-5 min), or ventricular tachycardia-induced cardiac insufficiency (n = 2, >10 min). The estimated fatal dose (mean +/- SD) was 277 +/- 51 mg for levobupivacaine (compared with 156 +/- 31 mg found previously for bupivacaine). Pharmacokinetic analysis indicated initial and total distribution volumes = 4.5 (+/-1.6) and 97 (+/-22) L, total clearance = 1.7 (+/-0.4) L/min, and slow half life = 70 (+/-29) min; these values did not differ from those found previously with smaller doses. Heart and brain tissue levobupivacaine concentrations were approximately 3 times those in arterial blood. The doses of levobupivacaine survived were larger than found previously for bupivacaine, indicating its greater margin of safety.

IMPLICATIONS

Levobupivacaine produced fatal cardiac toxicity at doses significantly greater than those found in previous studies with bupivacaine. As the two drugs have similar potency for producing clinical nerve blocks, the data imply that levobupivacaine should provide a safer alternative to bupivacaine in practice.

BLIMP-1: trigger for differentiation of myeloid lineage

B lymphocyte-induced maturation protein-1 (BLIMP-1 or PRDI-BF1) is induced when bone marrow-derived progenitors differentiate in response to macrophage-colony stimulating factor (M-CSF) and is present in peripheral blood monocytes and granulocytes. BLIMP-1 is also induced during differentiation of U937 and HL-60 cells into macrophages or granulocytes. Induction of BLIMP-1 mRNA during macrophage differentiation of U937 and HL-60 shows a biphasic pattern. Overexpression of BLIMP-1 is sufficient to initiate macrophage differentiation of U937 cells whereas blocking endogenous BLIMP-1 inhibits differentiation. One target of BLIMP-1-dependent transcriptional repression in U937 cells is c-myc, providing an explanation for cessation of cell division. Thus BLIMP-1 is a key regulator of terminal differentiation in two separate hematopoietic lineages: myeloid cells and B lymphocytes.

Changes in cardiovascular responsiveness to dopexamine and beta 1- and beta 2-adrenoceptor function after the chronic treatment of beta-adrenoceptor antagonists and agonists in anaesthetized dogs

1. The studies were designed to investigate the changes in responsiveness to beta-adrenoceptor agonists induced by chronic administration of beta-adrenoceptor antagonists and agonists. 2. Dose-response curves for dopexamine, isoprenaline, noradrenaline and impromidine on heart rate, blood pressure and myocardial contractility (dP/dt:integrated isometric tension) were obtained in untreated dogs and compared to those measured in dogs which had been pretreated with propranolol (8 mg kg-1 day-1), atenolol (6 mg kg-1 day-1), isoprenaline (0.5 microgram kg-1 min-1) or noradrenaline (0.5 microgram kg-1 min-1) for 14 days. 3. Propranolol pretreatment significantly enhanced the inotropic and chronotropic responses to isoprenaline. There were noticeable, but non-significant increases in inotropic sensitivity to noradrenaline and dopexamine, especially at higher dose levels. In the atenolol treatment group, there were significant increases in inotropic responses to dopexamine and isoprenaline and in depressor responses to isoprenaline. 4. Thus, chronic administration of propranolol increased responses mediated by both beta 1- and beta 2-adrenoceptors, whereas, atenolol selectively enhanced the inotropic responsiveness to dopexamine, which is mediated mainly by beta 2-adrenoceptors. 5. Isoprenaline pretreatment caused a significant decrease in inotropic sensitivity to dopexamine, isoprenaline and noradrenaline and a significant reduction in chronotropic responses to dopexamine. The tendency to reduced depressor responses to isoprenaline and dopexamine failed to reach significance. Pretreatment with noradrenaline decreased only the inotropic response to noradrenaline. 6. Thus, chronic isoprenaline treatment reduced the responsiveness of both beta 1- and beta 2-adrenoceptors, while chronic noradrenaline infusion only reduced beta 1-adrenoceptor-mediated responses. 7. There was no significant change in any of the dose-response curves to impromidine after any beta-adrenoceptor antagonist or agonist treatment. This indicates that there was no non-specific alteration in responsiveness and that the observed changes were likely to be associated with specific alterations in beta-adrenoceptor number or function.

[Adjuvant treatment of colonic cancers]

In the last decade, adjuvant chemotherapy has led to significant improvement in survival for large bowel cancer patients. The association of 5-FU plus levamisole was the first described and demonstrated its efficacy in stage Dukes C (T1,2,3,4 N1 M0) completely-resected adenocarcinoma. Recently, chemotherapy with 5-FU and folinic acid was recommended on the basis of randomized trials. Advances in adjuvant chemotherapy may result in increasing 5-FU doses as described in metastatic colorectal carcinomas, and in use of new drugs such as oxaliplatin or raltitrexed, whose activity has been well-studied in Dukes D (M1) carcinomas. Immunotherapy, intraperitoneal and intraportal infusion of chemotherapy are promising approaches but still in evaluation. The main difficulty for the future is to define the best therapeutic regimen in order to reach the highest improvement in survival.

Isolation and characterization of metallic wear debris from a dynamic intervertebral disc prosthesis

A dynamic intervertebral disc prosthesis (DIDP) has been developed. It consists of a CoCrMo body and uses Ti6Al4V springs to replicate the mechanical function of the lumbar joint. Wear studies have been performed previously on the DIDP using two specialized simulators to test the wear properties of the moving parts of the disc prosthesis. A pin-in-slot simulator generates wear that would occur in the hinge-pin assembly of the prosthesis. A spring-in-pocket simulator approximates the conditions under which the springs would wear against the body of the prosthesis. The spring-pocket interface is responsible for the production of approximately 90% of the total wear occurring in the prosthesis, and is therefore the main focus of this study. Bovine serum with a preservative has been used as a lubricant in both simulators. The spring-in-pocket simulator compares the effects of two different manufacturing techniques of CoCrMo (HIPing and forging) on their wear characteristics against Ti6Al4V springs. Debris from the spring-in-pocket simulator has been isolated from the serum lubricant and characterized using scanning electron microscopy techniques. The morphology of the Ti6Al4V fragments is rough and irregularly shaped. The size of these fragments ranges from < 1 microns to > 30 microns. The forged CoCrMo alloy debris has an irregular polyhedral shape, with sizes in the same range as the spring fragments. The morphology of the HIPed CoCrMo debris is spherical with a size range < 5 microns to > 30 microns. Length and width measurements of micron-size particles were made with the particle measurements feature of the scanning electron microscope. Micron-size particles were found in all stations. This article provides a unique way to isolate and analyze debris from serum lubricants used in simulators.

Small cell carcinoma of the uterine cervix with neurosecretory granules associated with pregnancy. A case report

An extremely rare case is reported of small cell carcinoma of the cervix with a fulminating course complicating pregnancy. The primary lesion was first noted in the 27-year old patient at 36 weeks of gestation. Cesarean section followed by radical hysterectomy with bilateral pelvic lymph node dissection was performed. Brain and breast metastases occurred two months after primary surgery, while adjuvant radiotherapy to the pelvis was ongoing. The patient died suddenly of massive tumor emboli in the brain. The microscopic and ultrastructural findings, immunohistochemical studies and flow cytometric analysis are presented.

Cardiovascular actions of dopexamine in anaesthetized and conscious dogs

1. Arterial blood pressure, heart rate and cardiac contractility were measured in pentobarbitone-anaesthetized mongrel dogs and in conscious, instrumented dogs. 2. In anaesthetized dogs (n = 5), dose-response curves were obtained by intravenous infusion of increasing doses of dopexamine (5-20 micrograms kg-1 min-1). Infusions were administered three times to each animal to determine whether the responses were reproducible. Dopexamine increased heart rate and myocardial contractility and decreased blood pressure. The dose-response curves for dopexamine did not differ significantly over time. 3. In a second group of dogs (n = 6), dose-response curves (5-20 mg kg-1 min-1) were obtained as above and repeated after the administration of amitriptyline (2 mg kg-1, i.v.). Amitriptyline caused a non-significant reduction in the inotropic and chronotropic responses to dopexamine. 4. Control dose-response curves for dopexamine (5-50 micrograms kg-1 min-1) were similarly obtained in a third group of dogs (n = 6), and repeated after bilateral vagotomy and sympathetic denervation of the heart. In these animals, a third dose-response curve for dopexamine was obtained after the administration of ICI 118551 (0.2 mg kg-1, followed by 0.2 mg kg-1 h-1). The chronotropic response to dopexamine was significantly reduced after cardiac denervation. There was a small, non-significant reduction in the inotropic and depressor responses after denervation. Administration of ICI 115881 significantly reduced both the inotropic and chronotropic response to dopexamine and caused a non-significant reduction in the depressor response. 5. The effect of raclopride (0.2 mumol kg-1, p.o.) was investigated by comparison of the dose-response curves for dopexamine in a control group of dogs (n = 6) to those obtained in dogs which had been pretreated with raclopride (n = 5). Raclopride had no significant effect on the cardiovascular responses to dopexamine. 6. In conscious, instrumented dogs (n = 5), pretreated with raclopride, dose-related positive inotropic and chronotropic and depressor responses to dopexamine infusions were recorded. The chronotropic responses in conscious animals were significantly greater than those in the anaesthetized animals.7. The results of this study indicate that both the positive inotropic and chronotropic actions of dopamine are due to a combination of direct, Beta2-adrenoceptor-mediated effects and the baroreceptor reflex response to the depressor action of the drug.

Small cell carcinoma with neurosecretory granules arising in an ovarian dermoid cyst

A rare small cell carcinoma with neurosecretory granules arising in an ovarian dermoid cyst with 7 years survival after conservative surgery and adjuvant chemotherapy with cisplatin, adriamycin, and cyclophosphamide is described. Light microscopy showed the typical uniformly small cells with hyperchromic nuclei and scanty basophilic cytoplasm within the mature cystic teratoma. Although none of the immunohistochemical stains were reactive, electron microscopy demonstrated the membrane-bound neurosecretory granules in some tumor cells. The related literature is reviewed and the issues concerning treatment options in this unusual malignancy are discussed.

The photochemistry of iodo, methyl and thiomethyl substituted aryl azides in toluene solution and frozen polycrystals

The photolysis of para-methyl and para-thiomethylphenylazide at 77 K produces the corresponding triplet nitrenes which can be detected by electron paramagnetic resonance (EPR) spectroscopy. Photolysis of these azides in frozen toluene at 77 K leads to insertion of the nitrene into a benzylic C-H bond of the matrix in modest yields. Photolysis of iodinated aryl azides under these conditions does not produce triplet nitrenes that can be detected by EPR spectroscopy. In contrast to the para-methyl and para-thiomethyl substituted phenyl nitrenes, photo-induced coupling of iodo-substituted phenyl nitrenes to toluene proceeds in very poor yield.

The cytokine CSF-1 (M-CSF) expressed by endometrial carcinomas in vivo and in vitro, may also be a circulating tumor marker of neoplastic disease activity in endometrial carcinoma patients

Endometrial epithelial cell expression of CSF-1 and FMS antigens was studied in vivo and in vitro in 24 human endometrial carcinoma and 11 benign endometrial biopsy specimens. Twenty-one of 24 adenocarcinomas and 4 of 11 benign lesions stained positively (by IHC) with rabbit anti-human CSF-1 antibodies, while all 24 carcinomas and 3 out of 11 benign lesions (all secretory endometrial specimens) showed significant IHC staining (1+ or greater) of epithelial elements and tissue macrophages with a mouse anti-FMS (CSF-1 receptor) monoclonal antibody. CSF-1 levels in plasma from endometrial carcinoma patients (85 samples, 24 patients) were also found to be markedly elevated (some greater than 100 ng/ml) in patients with active or recurrent disease. In vitro, several endometrial carcinoma cell lines were shown to express FMS complementary transcripts and FMS antigen which were very similar if not identical to those expressed in choriocarcinoma cell line positive controls. Autocrine and paracrine effects mediated by tumor or stromally produced CSF-1 and a tumor epithelial cell CSF-1 receptor may therefore contribute to the biological behavior of endometrial neoplasms in vivo and in vitro.

Measurement of stable isotopic enrichment of underivatized acetate by gas chromatography/mass spectrometry: application to in vivo estimation of acetate production

In order to assess endogenous and colonic production of acetate, we have developed an assay for determining the isotopic enrichment of plasma acetate using gas chromatography/mass spectrometry (GC/MS). Acidified, deproteinized plasma (200 microliters) was extracted into ethyl ether, and the ether phase was then injected into a gas chromatograph/mass spectrometer fitted with a 30 m x 0.252 mm i.d. capillary column (temperature program 50-245 degrees C at 10 degrees C min-1). Using electron impact GC/MS and selected ion monitoring, peak areas of ions with m/z 60 and 61 (M + 1) were determined. Triplicate extractions of enriched plasma samples (mol.% excess 1.38-1.5%) resulted in a coefficient of variation of 1.6-5.9%. Unenriched plasma samples were found to have an enrichment close to theoretical natural abundance, and analysis of our (1-13C)acetate tracer (99 at.% excess) revealed an ion at m/z 61 and no ion at m/z 60. To verify accuracy, we conducted an in vivo isotope dilution study. In a 1-month-old piglet, fasted for 24 h, changing the rate of a 4 h infusion (mmol h-1) of (1-13C)acetate from 0.141 to 0.282 doubled the isotope enrichment (2.08 x) of the second plateau. The rate of appearance of acetate was 26.0 mumols kg-1 min-1, which is comparable to that reported in fasting sheep.