Workforce strategies during the first wave of the COVID-19 pandemic: a retrospective online survey at intensive care units in Germany

BACKGROUND

As the COVID-19 pandemic swept across the globe at the beginning of 2020, healthcare systems were forced to rapidly adapt and expand to meet the sudden surge in demand for intensive care services. This study is the first systematic analysis of the strategies employed by German hospitals to recruit personnel and expand bed capacities during the first wave of the pandemic, and to evaluate the effectiveness of those recruitment measures.

METHODS

152 German hospitals with intensive care capacities were selected and invited to participate in an online-based retrospective survey. Factors like the geographic distribution, individual COVID burden and level of care were considered for inclusion in the sample. The data were analyzed descriptively.

RESULTS

A total of 41 hospitals participated in the survey. The additional demand for intensive care beds was met primarily by activating intensive care beds that were previously considered as non-operational in existing intensive care units (81% of respondents) and by upgrading recovery rooms (73%). The physician staffing requirements were met at approximately 75%, while the nursing staffing requirements were only met by about 45%. Staffing needs were met through reallocations/transfers (85%), staff recruitment from parental leave or retirement (49%), increased hours worked by internal staff (49%), new staff hiring (44%) and increased use of temporary staff (32%). Staff reallocations/transfers to critical care within a hospital were rated as the most effective measure. In this context, specialized personnel mostly from anesthesiology departments were appointed to intensive care medicine.

CONCLUSIONS

Despite multiple recruitment efforts, the pandemic has exacerbated the nursing staff shortage. The reallocation of existing staff within hospitals was a key element in covering the staffing needs. However, additional measures and efforts are required in order to ensure that critically ill patients can be cared for without compromise. The results of this study may have important implications for healthcare providers and policymakers, offering an evidence-based foundation for responding to future public health emergencies with agility, efficiency, and success.

Current Status of Measurement Accuracy for Total Hemoglobin Concentration in the Clinical Context

OBJECTIVE

The main objective of this investigation is to provide data about the accuracy of total hemoglobin concentration measurements with respect to clinical settings, and to devices within the categories of point-of-care and reference systems. In particular, tolerance of hemoglobin concentrations below 9 g/dL that have become common in clinical practice today determines the need to demonstrate the limits of measurement accuracy in patient care.

METHODS

Samples extracted from six units of heparinized human blood with total hemoglobin concentrations ranging from 3 to 18 g/dL were assigned to the test devices in a random order. The pool of test devices comprised blood gas analyzers, an automatic hematology analyzer, a laboratory reference method, and the point-of-care system HemoCue. To reduce the pre-analytic error, each sample was measured three times. Due to the characteristics of the tested devices and methods, we selected the mean values of the data from all these devices, measured at the corresponding total hemoglobin concentrations, as the reference.

MAIN RESULTS

The measurement results of the test devices overlap within strict limits (R² = 0.999). Only the detailed analysis provides information about minor but systematic deviations. In the group of clinically relevant devices, which are involved in patient blood management decisions, the relative differences were within the limit of +/- 5 % for values down to 3 g/dL.

CONCLUSIONS

A clinically relevant change of +/- 0.5 g/dL of total hemoglobin concentration can be detected with all selected devices and methods. Compliance with more stringent definitions-these are the relative differences of 5 % in relation to the corresponding reference values and the clinically adapted thresholds in the format of a tolerance level analysis-was achieved by the clinical devices assessed here.

Time to treatment initiation: An analysis of sarcoma patients treated at Multidisciplinary-Team/Sarcoma-Board (MDT/SB's) over a four-year period

Objective

It is hypothesized that in the treatment of patients with soft tissue sarcomas (STS) the interval from establishing the diagnosis until initiation of treatment is relevant for the overall survival. Therefore, time to treatment initiation (TTI) was defined as a quality indicator for monitoring the treatment standard. The primary objective of this study was to find out how long (in days) it takes from establishing the sarcoma diagnosis through biopsy until initiation of treatment in patients suffering from STS. Secondary objectives were defined as the comparison between the different dignities, the different institutions and how the Swiss Sarcoma Network (SSN) cohort compares to the international standard.

Methods

This is a retrospective analysis of prospectively collected data from the SSN. All patients being presented to the MDT/SB within a four-year period from 2018 to 2022 were included in this study. TTI and secondary objectives were determined using non-parametric summary statistics and presented as median and interquartile range. Ethic approval was granted for this study.

Results

In total 383 patients were recorded in the respective time period in the SSN. In this study 278 patients with a malignant or intermediate STS according to WHO2020 were included. There were 66% (n=185) with a malignant and 44% (n=93) with an intermediate STS. The median TTI was 23 (8-52) days. In the malignant group, the median TTI was 21 (5-43) days and in the intermediate group 32 (11-59) days. In the different institutions the median TTI's were 10 (-6-30), 28 (12-78), 24 (10-58), 24 (10-53) and 12 (-12-54) days.

Conclusion

In the SSN cohort the overall median TTI was 23 days. In the literature, a TTI delay of more than 42 days led to a slightly reduced overall survival. Compared to the international standard, we conclude that within the SSN network, patients face an adequate waiting time until treatment initiation with no potential restrictions to overall survival.

Measurement of Blood Pressure by Ultrasound-The Applicability of Devices, Algorithms and a View in Local Hemodynamics

OBJECTIVE

Due to ongoing technical progress, the ultrasonic measurement of blood pressure (BP) as an alternative to oscillometric measurement (NIBP) or the continuous non-invasive arterial pressure method (CNAP) moves further into focus. The US method offers several advantages over NIBP and CNAP, such as deep tissue penetration and the utilization of different arterial locations.

APPROACH

Ten healthy subjects (six female, aged 30.9 ± 4.6 years) volunteered in our investigation. In the ultrasonic BP measurement, we differentiated between the directly measured (pulsatile diastolic and systolic vessel diameter) and indirectly calculated variables at three different artery locations on both arms, with two different ultrasound devices in the transversal and longitudinal directions of the transducer. Simultaneously, NIBP monitoring served as reference BP, while CNAP monitored the steady state condition of the arm under investigation. The Moens-Korteweg algorithm (MKE) and the algorithm of the working group of San Diego (SanD) were selected for the indirectly calculated ultrasonic BP data.

MAIN RESULTS

With US, we were able to measure the BP at each selected arterial position. Due to the investigation setup, we found small but significant interactions of the main effects. Bland and Altman analysis revealed that US-BP measurement was similar to NIBP, with superior accuracy when compared to the established CNAP method. In addition, US-BP measurement showed that the measurement accuracy of both arms can be regarded as identical. In a detailed comparison of the selected arterial vascular sections, systematic discrepancies between the right and left arm could be observed.

CONCLUSION

In our pilot study, we measured BP effectively and accurately by US using two different devices. Our findings suggest that ultrasonic BP measurement is an adequate alternative for live and continuous hemodynamic monitoring.

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Efficacy and safety of an oral device to reduce food intake and promote weight loss

Objective

Minimal risk weight loss tools are needed. This study's objective was to confirm Food and Drug Administration submissions of the SmartByte™ System's safety and efficacy.

Methods

This 16-week, prospective, single-arm, four-centre, observational study assessed the oral device in combination with a video-delivered lifestyle programme in adults aged 18-49 years with body mass index 27 to <35 kg m-2.

Results

Seventy-six subjects received the device and video lifestyle instruction. The prespecified per protocol (PP) population (N = 40) required sensor-verified use of the device ≥7 times per week for 14 of 16 weeks, overall device usage rate of ≥33% and study completion. At week 16, 12 (30%) achieved ≥5% weight loss, 16 (40%) achieved ≥4% and 21 (52.5%) achieved ≥3%. Week 16 mean loss for the PP population was 2.93%, and among 36 participants who did not meet PP criteria, it was 1.45%. Among 76 intent-to-treat subjects, two subjects reported three mild to moderate device-related adverse events, resolving spontaneously (one hard palate abrasion and two tongue lacerations).

Conclusion

The System, a minimal risk tool, can help individuals achieve meaningful weight loss, when used with a lifestyle video. More frequent device use was associated with more weight loss, on average, and greater chance of achieving ≥4% or ≥5% weight loss.

Knotted fields and explicit fibrations for lemniscate knots

We give an explicit construction of complex maps whose nodal lines have the form of lemniscate knots. We review the properties of lemniscate knots, defined as closures of braids where all strands follow the same transverse (1, ℓ) Lissajous figure, and are therefore a subfamily of spiral knots generalizing the torus knots. We then prove that such maps exist and are in fact fibrations with appropriate choices of parameters. We describe how this may be useful in physics for creating knotted fields, in quantum mechanics, optics and generalizing to rational maps with application to the Skyrme-Faddeev model. We also prove how this construction extends to maps with weakly isolated singularities.

Efficacy and safety of once-daily insulin degludec/insulin aspart compared with once-daily insulin glargine in participants with Type 2 diabetes: a randomized, treat-to-target study

AIMS

To investigate, in a 26-week, open-label, randomized, treat-to-target trial, the efficacy and safety of insulin degludec/insulin aspart (IDegAsp) once daily vs insulin glargine (IGlar) once daily in adults with Type 2 diabetes, inadequately controlled on basal insulin.

METHODS

Participants were randomized (1:1) to IDegAsp once daily or IGlar once daily in combination with existing oral antidiabetic drugs. IDegAsp once daily was administered with the main evening meal or the largest meal of the day (agreed at baseline); dosing time was maintained throughout the trial. Participants titrated their insulin dose weekly to a mean pre-breakfast self-measured plasma glucose target [3.9-4.9 mmol/l (70-89 mg/dl)].

RESULTS

IDegAsp once daily was non-inferior to IGlar once daily in reducing HbA_1c after 26 weeks [mean estimated treatment difference IDegAsp once daily - IGlar once daily: -0.03% (95% CI -0.20, 0.14)]. The evening meal glucose increment was significantly lower with IDegAsp once daily vs IGlar once daily [estimated treatment difference IDegAsp once daily - IGlar once daily: -1.32 mmol/l (95% CI -1.93, -0.72); P < 0.05]. The overall confirmed hypoglycaemia rate was higher with IDegAsp once daily (estimated rate ratio 1.43; 95% CI 1.07, 1.92; P < 0.05). The rate of nocturnal hypoglycaemia did not significantly differ between the IDegAsp and IGlar groups [estimated rate ratio 0.80 (95% CI 0.49, 1.30); not significant].

CONCLUSIONS

In participants with Type 2 diabetes inadequately controlled on basal insulin, IDegAsp once daily improved glycaemic control and was non-inferior to IGlar once daily. IDegAsp led to higher rates of overall hypoglycaemia than IGlar, with no significant difference in rates of nocturnal hypoglycaemia.

Long-term efficacy and safety of canagliflozin over 104 weeks in patients aged 55-80 years with type 2 diabetes

AIMS

The long-term efficacy and safety of canagliflozin, a sodium glucose co-transporter 2 inhibitor, was evaluated over 104 weeks in patients aged 55-80 years with type 2 diabetes mellitus (T2DM) inadequately controlled on a stable antihyperglycaemic agent regimen.

METHODS

In this randomized, double-blind, phase III study, patients received canagliflozin 100 or 300 mg or placebo once daily during a 26-week core period (N = 714) and a 78-week extension period (n = 624). Efficacy endpoints at week 104 included change from baseline in glycated haemoglobin (HbA1c), fasting plasma glucose (FPG) and systolic blood pressure, and percent change from baseline in body weight and fasting plasma lipids. Safety was assessed by adverse event (AE) reports.

RESULTS

At week 104, canagliflozin 100 and 300 mg were associated with reductions in HbA1c versus placebo (-0.32 and -0.43% vs 0.17%, respectively; overall mean baseline, 7.7%) and more patients achieved HbA1c <7.0% with canagliflozin 100 and 300 mg than with placebo (35.8 and 41.9% vs 20.3%, respectively). Reductions in FPG, body weight and systolic blood pressure, and increases in high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were seen with canagliflozin compared with placebo. The overall incidence rates of AEs over 104 weeks were 88.0, 89.8 and 86.1% with canagliflozin 100 and 300 mg and placebo, respectively; serious AE rates were low across treatment groups. The incidence rates of urinary tract infections, genital mycotic infections and osmotic diuresis- and volume depletion-related AEs were higher with canagliflozin than with placebo.

CONCLUSION

Canagliflozin improved glycaemic control, reduced body weight and systolic blood pressure, and was generally well tolerated in patients aged 55-80 years with T2DM over 104 weeks.

Uncommon case of brain metastasis in a patient with a history of heavy smoking

Primary sarcomas of the aorta are extremely uncommon. Depending on histomorphology and immunohistochemical pattern, intimal sarcomas can show angiosarcomatous differentiation. Here, we describe the case of a 60-year-old woman with a primary intimal sarcoma of the aortic arch and signs of cerebral metastatic disease as the initial manifestation. After the patient experienced the onset of severe headaches, ataxia, and left-sided weakness, magnetic resonance imaging showed several brain lesions. Histologic assessment of a brain biopsy specimen revealed a malignant tumour composed of large pleomorphic cells that were positive for pancytokeratin and CD10. Radiation to the brain did not significantly improve the patient's symptoms, and cranial computed tomography (ct) imaging revealed several metastases, indicating lack of response. Because of the patient's smoking history, the presence of central nervous system and skeletal metastases on combined positron-emission tomography and ct imaging, and the focal pan-cytokeratin positivity of the tumour, carcinoma of the lung was favoured as the primary tumour. Despite chemotherapy with cisplatin and etoposide, the patient's neurologic symptoms and general condition deteriorated rapidly, and she died within a few days. At autopsy, an undifferentiated intimal sarcoma of the aortic arch was diagnosed. The primary tumour in the aorta consisted of large pleomorphic cells. Immunohistochemical analysis of the aortic tumour and brain metastases demonstrated diffuse positivity for vimentin and p53 and focal S-100 staining. In summary, we report a challenging case of advanced intimal sarcoma of the aortic arch with brain and bone metastases at initial presentation. Our report demonstrates the difficulties in diagnosing and treating this disease, and the need for multicentre studies to accrue more patients for investigations of optimal therapy.

Hypoglycaemia risk with insulin degludec compared with insulin glargine in type 2 and type 1 diabetes: a pre-planned meta-analysis of phase 3 trials

AIM

Hypoglycaemia and the fear of hypoglycaemia are barriers to achieving normoglycaemia with insulin. Insulin degludec (IDeg) has an ultra-long and stable glucose-lowering effect, with low day-to-day variability. This pre-planned meta-analysis aimed to demonstrate the superiority of IDeg over insulin glargine (IGlar) in terms of fewer hypoglycaemic episodes at equivalent HbA1c in type 2 and type 1 diabetes mellitus (T2DM/T1DM).

METHODS

Pooled patient-level data for self-reported hypoglycaemia from all seven (five in T2DM and two in T1DM) randomized, controlled, phase 3a, treat-to-target trials in the IDeg clinical development programme comparing IDeg once-daily (OD) vs. IGlar OD were analysed.

RESULTS

Four thousand three hundred and thirty subjects (2899 IDeg OD vs. 1431 IGlar OD) were analysed. Among insulin-naïve T2DM subjects, significantly lower rates of overall confirmed, nocturnal confirmed and severe hypoglycaemic episodes were reported with IDeg vs. IGlar: estimated rate ratio (RR):0.83[0.70;0.98](95%) (CI) , RR:0.64[0.48;0.86](95%) (CI) and RR:0.14[0.03;0.70](95%) (CI) . In the overall T2DM population, significantly lower rates of overall confirmed and nocturnal confirmed episodes were reported with IDeg vs. IGlar [RR:0.83[0.74;0.94](95%) (CI) and RR:0.68[0.57;0.82](95%) (CI) ). In the T1DM population, the rate of nocturnal confirmed episodes was significantly lower with IDeg vs. IGlar during maintenance treatment (RR:0.75[0.60;0.94](95%) (CI) ). Reduction in hypoglycaemia with IDeg vs. IGlar was more pronounced during maintenance treatment in all populations.

CONCLUSIONS

The limitations of this study include the open-label design and exclusion of subjects with recurrent severe hypoglycaemia. This meta-analysis confirms that similar improvements in HbA1c can be achieved with fewer hypoglycaemic episodes, particularly nocturnal episodes, with IDeg vs. IGlar across a broad spectrum of patients with diabetes.

[Role of cytology in hematopathological diagnostics]

The role of cytology has so far been underrecognized in the diagnostic process of hematopathological questions. This article presents an algorithm which allows a stepwise work-up of cytology specimens obtained by minimally invasive ultrasound-guided fine needle aspiration in patients with unexplained lymph node swelling. Moreover, it is shown how the selective separation of cytology specimens allows the application of immunophenotypic analysis including flow cytometry and immunohistochemistry as well as molecular analyses, such as fluorescence in situ hybridization (FISH) and polymerase chain reaction (PCR) strategies. With the integrative procedure presented, cytology offers an excellent cost-effective tool for the diagnostic approach of patients with suspected hematopathological malignancies allowing a high diagnostic accuracy, ideal for initial diagnosis or follow-up.

The economic and clinical benefits of adequate insulin initiation and intensification in people with type 2 diabetes mellitus

AIM

To study the clinical and economic benefits associated with adequate and early initiation and intensification of insulin in people with type 2 diabetes mellitus (T2DM).

METHODS

A systematic review was performed using published articles from January 2000 to August 2010 that linked intervention, disease, study design and outcomes. Studies were further classified as initiation and intensification based on predefined criteria. Individual studies in systematic reviews and meta-analysis were searched and included if relevant.

RESULTS

A total of 2690 articles were screened with 76 (40 initiation and 36 intensification) studies included. Most initiation studies had mean baseline HbA1c values of >8.5%. The endpoint HbA1c values were reduced with insulin treatment in these studies, with endpoint values ranging from 6.6 to 9.8%. Similar results were seen with the intensification studies (endpoint HbA1c: 6.4-9.6%). Addition of insulin to oral antidiabetics (OADs) resulted in better glycaemic control in most studies. Blood glucose levels reduced substantially with OADs + insulin compared with OADs alone. Quality of life outcomes and treatment satisfaction were reported in six studies and not significantly different for insulin vs. OADs. Hypoglycaemic events were manageable with insulin initiation. However, all insulin types were associated with weight gain although the comparison with OADs elicited varying results.

CONCLUSIONS

Proactive management with early insulin initiation and intensification should be considered in people with T2DM in inadequate glycaemic control. The economic benefits with early initiation and intensification have to be fully explored.

Liraglutide, a once-daily human glucagon-like peptide 1 analogue, provides sustained improvements in glycaemic control and weight for 2 years as monotherapy compared with glimepiride in patients with type 2 diabetes

AIMS

Most treatments for type 2 diabetes fail over time, necessitating combination therapy. We investigated the safety, tolerability and efficacy of liraglutide monotherapy compared with glimepiride monotherapy over 2 years.

METHODS

Participants were randomized to receive once-daily liraglutide 1.2 mg, liraglutide 1.8 mg or glimepiride 8 mg. Participants completing the 1-year randomized, double-blind, double-dummy period could continue open-label treatment for an additional year. Safety data were evaluated for the full population exposed to treatment, and efficacy data were evaluated for the full intention-to-treat (ITT) and 2-year completer populations. Outcome measures included change in glycosylated haemoglobin (HbA1c), fasting plasma glucose (FPG), body weight and frequency of nausea and hypoglycaemia.

RESULTS

For patients completing 2 years of therapy, HbA1c reductions were -0.6% with glimepiride versus -0.9% with liraglutide 1.2 mg (difference: -0.37, 95% CI: -0.71 to -0.02; p = 0.0376) and -1.1% with liraglutide 1.8 mg (difference: -0.55, 95% CI: -0.88 to -0.21; p = 0.0016). In the ITT population, HbA1c reductions were -0.3% with glimepiride versus -0.6% with liraglutide 1.2 mg (difference: -0.31, 95% CI: -0.54 to -0.08; p = 0.0076) and -0.9% with liraglutide 1.8 mg (difference: -0.60, 95% CI: -0.83 to -0.38; p < 0.0001). For both ITT and completer populations, liraglutide was more effective in reducing HbA1c, FPG and weight. Over 2 years, rates of minor hypoglycaemia [self-treated plasma glucose <3.1 mmol/l (<56 mg/dl)] were significantly lower with liraglutide 1.2 mg and 1.8 mg compared with glimepiride (p < 0.0001).

CONCLUSION

Liraglutide monotherapy for 2 years provides significant and sustained improvements in glycaemic control and body weight compared with glimepiride monotherapy, at a lower risk of hypoglycaemia.

Quartz crystal microbalance based on torsional piezoelectric resonators

A quartz crystal microbalance (QCM) is described, which is based on a torsional resonator, rather than a conventional thickness-shear resonator. Typical applications are measurements of film thickness in the coating industry and monitoring of biofouling. The torsional QCM is about a factor of 100 less sensitive than the conventional QCM. On the other hand, it can probe film thicknesses in the range of hundreds of microns, which is impossible with the conventional QCM due to viscoelastic artifacts. Data acquisition and data analysis proceed in analogy to the conventional QCM. An indicator of the material's softness can be extracted from the bandwidth of the resonance. Within the small-load approximation, the frequency shift is independent of whether the sample is applied to the face or to the side of the cylinder. Details of the geometry matter if the viscoelastic properties of the sample are of interest.

Should human chondrocytes fly? The impact of electromagnetic irradiation on chondrocyte viability and implications for their use in tissue engineering

A significant logistic factor as to the successful clinical application of the autologous tissue engineering concept is efficient transportation: the donor cells need to be delivered to tissue processing facilities which in most cases requires air transportation. This study was designed to evaluate how human chondrocytes react to X-ray exposure. Primary cell cultures were established, cultured, incubated and exposed to different doses and time periods of radiation. Subsequently, quantitative cell proliferation assays were done and qualitative evaluation of cellular protein production were performed. Our results show that after irradiation of chondrocytes with different doses, no significant differences in terms of cellular viability occurred compared with the control group. These results were obtained when chondrocytes were exposed to luggage transillumination doses as well as exposure to clinically used radiation doses. Any damage affecting cell growth or quality was not observed in our study. However, information about damage of cellular DNA remains incomplete.

Duodenal motility is not affected during duodenotomy in pigs

The effects of surgical procedures on intestinal motility are still under debate. In order to quantify the effects of duodenotomy on duodenal motility, the present study used the electric impedance technique (IMP). Ten pigs (32-40 kg) were instrumented under general anaesthesia with a central venous catheter (CVC) and a percutaneous enterogastrostomy (PEG). Duodenal phases I-III and the duration of the migrating motor complex (MMC) were measured by an IMP catheter, which was introduced non-invasively into the proximal duodenum via the PEG by endoscopy, or through surgical placement in an invasive manner via duodenotomy. There were no significant differences in the length of interdigestive phases I-III between the groups. In tendency, pigs after laparotomy and duodenotomy demonstrated slightly prolonged median duration of phase I (P = 0.1) and phase III (P = 0.7), while phase II (P = 0.1) and the MMC cycle length (P = 0.6) seemed to be shortened as compared to pigs of the PEG group. In conclusion, simple laparotomy with duodenotomy did not affect the proximal duodenal motility activity measured by the impedance technique.

Effects of propofol and fentanyl on duodenal motility activity in pigs

To investigate the effects of propofol and fentanyl on the postprandial duodenal motility the intraluminal impedance technique was used. Six pigs were instrumented with a central venous catheter, a percutaneous enterogastrostomy (PEG), and an impedance catheter, which was introduced via the PEG into the duodenum through endoscopy. Over the following 3 d, duodenal motility was measured for 8-hour periods. Measurements were taken on each subject under 3 different sets of conditions: in the conscious unrestrained pig, during propofol sedation, and during sedation with propofol-fentanyl. Both, after morning feeding and during gastric nutrition via the PEG, duodenal feeding patterns and duodenal phase II of the migrating motor cycle were shortened during propofol and propofol-fentanyl sedation. In contrast, the duration of phase I was prolonged by propofol and propofol-fentanyl. In conclusion, either propofol or propofolfentanyl sedation shortens duodenal feeding patterns, as well as phase II of the migrating motor cycle.

Solitary fibrous tumor of the orbit--two cases and a review of the literature

Solitary fibrous tumors of the orbit (SFT) are mesenchymal lesions that can develop either as malignant or benign neoplasias. We describe the histological features leading to the diagnosis in two females and review the current literature. Diagnosis of SFT only can be performed by histological examination, since clinical signs and radiological features are not specific enough. Even a malignant or benign course cannot be predicted, since clinical and radiological features do not correlate with histological signs of malignancy and vice versa. Radical resection is the treatment of choice, since no other treatment option has been proven to be efficient.

Combined resection and adjuvant therapy improves prognosis of sarcomas of the pulmonary trunk

BACKGROUND

Diagnosis of pulmonary artery sarcoma is difficult and frequently delayed owing to the insidious, non-specific nature of the symptoms. We present our experience with surgery for this rare disease.

METHODS

Between 1995 and 1998, four patients underwent surgery for pulmonary trunk sarcomas. They presented with similar symptoms and were initially treated for thromboembolic disease of the lung. Preoperative diagnosis was established using computer tomography and echocardiography. Postoperatively, two patients received radiotherapy and one combined radio-/chemotherapy.

RESULTS

One patient underwent thrombendarteriectomy of the trunk with adjuvant radiotherapy and remains tumor-free after three years and one showed complete regression of metastases after chemotherapy and remains well after more than one year. The other two patients died within two months of surgery, one due to a tumor mass in the inferior caval vein and the other because of cerebral metastases.

CONCLUSIONS

According to the literature, mean survival rate is 1.5 months without resection and 10 months with resection, with survival up to four years following combined resection and adjuvant therapy. Our findings are in agreement with this.

A novel brain receptor is expressed in a distinct population of olfactory sensory neurons

Three novel G-protein-coupled receptor genes related to the previously described RA1c gene have been isolated from the mouse genome. Expression of these genes has been detected in distinct areas of the brain and also in the olfactory epithelium of the nose. Developmental studies revealed a differential onset of expression: in the brain at embryonic stage 17, in the olfactory system at stage E12. In order to determine which cell type in the olfactory epithelium expresses this unique receptor type, a transgenic approach was employed which allowed a coexpression of histological markers together with the receptor and thus visualization of the appropriate cell population. It was found that the receptor-expressing cells were located very close to the basal membrane of the epithelium; however, the cells extended a dendritic process to the epithelial surface and their axons projected into the main olfactory bulb where they converged onto two or three glomeruli in the dorsal and posterior region of the bulb. Thus, these data provide evidence that this unique type of receptor is expressed in mature olfactory neurons and suggests that it may be involved in the detection of special odour molecules.

Characterization of L-leucine transport system in brush border membranes from human and rabbit small intestine

The branched-chain amino acids (BCAAs) leucine, isoleucine, and valine are beneficial to catabolic patients by improving hepatic protein synthesis and nitrogen economy, yet their transport from the intestinal lumen is not well-defined. The leucine transport system in human and rabbit small intestine was characterized using a brush border membrane vesicle (BBMV) model. Sodium and pH dependence and transport activity along the longitudinal axis of the small bowel were determined. Transport kinetics and inhibition profiles were defined. Although previous studies in other tissues show leucine transport to be mostly a Na+-independent process, our studies show that leucine transport is a predominantly Na+-dependent process occurring mainly via a single saturable pH-independent transporter resembling system B0 in the intestine. This system B0 transporter demonstrates stereoisomeric specificity. There is also a minor Na+-independent transport component (<6% in rabbits). Leucine uptake in both rabbits and humans is significantly greater than the uptake of other clinically relevant nutrients such as glutamine. In the rabbit, ileal leucine transport is significantly greater than jejunal uptake. While the affinities of the human and rabbit transporters are similar, the rabbit transporter has greater carrier capacity (maximal transport velocity [Vmax]). These findings suggest that the transport of leucine in the gut mucosa is significantly different from the transport in other tissues.

Patient-reported experience with Velosulin human insulin in continuous subcutaneous insulin infusion

A multicenter, retrospective survey of 339 patients with insulin-dependent diabetes mellitus was done to evaluate patient experience with Velosulin Human insulin, a regular insulin in a phosphate buffer, used in continuous subcutaneous insulin infusion. Patients had used this insulin exclusively for 3 months preceding the survey. Responses were elicited through interviews conducted by physicians or nurses. Patients were queried as to the occurrence of specific complications associated with pump therapy that occurred while using Velosulin Human insulin, including hypoglycemia, diabetic ketoacidosis, unexplained hyperglycemia, tubing obstruction, and infection or abscess at the infusion site. Most patients reported that they did not experience any of these complications during the preceding 3 months. The most frequently cited complication was hyperglycemia unexplained by dosage, exercise, or dietary changes, reported by 110 (32%) patients. The second most frequently reported complication was tubing obstruction, reported by 99 (29%) patients. The reported frequencies of the other complications were: severe hypoglycemia, 45 (13%) patients; diabetic ketoacidosis, 28 (8%) patients; and infection or abscess at the infusion site, 26 (8%) patients. The low morbidity reported by the patients in this survey probably was due in large part to careful patient selection, a high level of motivation on the part of the patients, and experience and education on the part of the health care team, as well as to the use of buffered regular human insulin.

[Ectopic ossification as a cause of vague abdominal pain following heart surgery: a case report]

Vague abdominal pain after cardiac surgery was caused by ectopic ossification in the distal part of sternotomy. The rarity of this complication (one case seen in recent years, operation volume: 1200 cases/year) prompted us to review the literature, where only 6 cases are described. Diagnostic problems and therapy are discussed.

Characteristics and regulation of hepatic glutamine transport

Glutamine is an important amino acid because of its key role in the transfer of both carbon and nitrogen between tissues in the body. Specific tissues are usually associated with either net synthesis or net utilization of glutamine, but the liver plays a central role in glutamine homeostasis, in that it can shift to function in either capacity. This capability, along with the localization of urea biosynthesis in the periportal hepatocytes, focuses attention on the transport mechanisms in hepatocytes for uptake and release of glutamine. Active transport of glutamine by hepatocytes is mediated by a Na(+)-dependent activity termed system N, which exhibits a rather narrow substrate specificity mediating uptake of histidine and asparagine as well as of glutamine. This secondary active transport system allows for the net accumulation of glutamine against a concentration gradient and maintenance of intracellular concentrations of glutamine between 4 and 8 mM in the face of a plasma concentration of 0.6 mM. Utilization of the Na+ electrochemical gradient as a driving force ensures that the system N carrier catalyzes a unidirectional transport event favoring the cytoplasm. It is obvious from the glutamine gradient across the plasma membrane that efflux of this amino acid is typically slower than accumulation; measurement of saturable, Na(+)-independent glutamine transport by system L substantiates this proposal. However, it is clear that under certain metabolic conditions the liver represents a source of glutamine for other tissues in the body and net efflux must occur. The system N transport activity in hepatocytes is regulated by hormones such as insulin, glucagon, and glucocorticoids, as demonstrated both in vivo and in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)