Fast diffusion kurtosis imaging of fibrotic mouse kidneys

Diffusion kurtosis imaging (DKI) is sensitive to tissue microstructure and may therefore be useful in the diagnosis and monitoring of disease in brain and body organs. Generally, diffusion magnetic resonance imaging (dMRI) in the body is challenging because of the heterogeneous body composition, which can cause image artefacts as a result of chemical shifts and susceptibility differences. In addition, the abdomen possesses physiological factors (e.g. breathing, heartbeat, blood flow) which may severely reduce image quality, especially when echo planar imaging is employed, as is typical in dMRI. Collectively, these challenging measurement conditions impede the use and exploration of DKI in the body. This impediment is further exacerbated by the traditionally large amount of data required for DKI and the low signal-to-noise ratio at the b-values needed to effectively probe the kurtosis regime. Recently introduced fast DKI techniques reduce the challenge of DKI in the body by decreasing the data requirement substantially, so that, for example, triggering and breath-hold techniques may be applied for the entire DKI acquisition without causing unfeasible scan times. One common pathological condition for which body DKI may be of immediate clinical value is kidney fibrosis, which causes progressive changes in organ microstructure. With its sensitivity to microstructure, DKI is an obvious candidate for a non-invasive evaluation method. We present preclinical evidence indicating that the rapidly obtainable tensor-derived mean kurtosis ( W̅) distinguishes moderately fibrotic kidneys from healthy controls. The presence and degree of fibrosis are confirmed by histology, which also indicates fibrosis as the main driver behind the DKI differences observed between groups. We therefore conclude that fast kurtosis is a likely candidate for an MRI-based method for the detection and monitoring of renal fibrosis. We provide protocol recommendations for fast renal DKI in humans based on a b-value optimisation performed using data acquired at 3 T in normal human kidney.

High-resolution, high-throughput imaging with a multibeam scanning electron microscope

Electron–electron interactions and detector bandwidth limit the maximal imaging speed of single-beam scanning electron microscopes. We use multiple electron beams in a single column and detect secondary electrons in parallel to increase the imaging speed by close to two orders of magnitude and demonstrate imaging for a variety of samples ranging from biological brain tissue to semiconductor wafers.

Remote Ischemic Perconditioning in Thrombolysed Stroke Patients: Randomized Study of Activating Endogenous Neuroprotection – Design and MRI Measurements

Background

Intravenous administration of alteplase is the only approved treatment for acute ischemic stroke. Despite the effectiveness of this treatment, 50% of patients suffer chronic neurological disability, which may in part be caused by ischemia-reperfusion injury. Remote ischemic perconditioning, performed as a transient ischemic stimulus by blood-pressure cuff inflation to an extremity, has proven effective in attenuating ischemia-reperfusion injury in animal models of stroke. Remote ischemic perconditioning increases myocardial salvage in patients undergoing acute revascularization for acute myocardial infarction. To clarify whether a similar benefit can be obtained in patients undergoing thrombolysis for acute stroke, we included patients from June 2009 to January 2011.

Aim and design

The aims of the study are: to estimate the effect of remote ischemic perconditioning as adjunctive therapy to intravenous alteplase of acute ischemic stroke within the 4½-h time window and to investigate the feasibility of remote ischemic perconditioning performed during transport to hospital in patients displaying symptoms of acute stroke. Patients are randomized to remote ischemic perconditioning in a single-blinded fashion during transportation to hospital. Only patients with magnetic resonance imaging-proven ischemic stroke, who subsequently are treated with intravenous alteplase, and in selected cases additional endovascular treatment, are finally included in the study.

Study outcomes

Primary end-point is penumbral salvage. Penumbra is defined as hypoperfused yet viable tissue identified as the mismatch between perfusion-weighted imaging and diffusion-weighted imaging lesion on magnetic resonance imaging scans. Primary outcome is a mismatch volume not progressing to infarction on one-month follow-up T2 fluid attenuated inversion recovery. Secondary end-points include: infarct growth (expansion of the diffusion-weighted imaging lesion) from baseline to the 24-h and one-month follow-up examination. Infarct growth inside and outside the acute perfusion-weighted imaging–diffusion-weighted imaging mismatch zone is quantified by use of coregistration. Clinical outcome after three-months. The influence of physical activity (Physical Activity Scale for the Elderly score) on effect of remote ischemic perconditioning. Feasibility of remote ischemic perconditioning in acute stroke patients.

Summary

This phase 3 trial is the first study in patients with acute ischemic stroke to evaluate the effect size of remote ischemic perconditioning as a pretreatment to intravenous alteplase, measured as penumbral salvage on multimodal magnetic resonance imaging and clinical outcome after three-months follow-up.

Angular tunneling ionization probability of fixed-in-space H2 molecules in intense laser pulses

We propose a new approach to obtain molecular frame photoelectron angular distributions from molecules ionized by intense laser pulses. With our method we study the angular tunnel ionization probability of H2 at a wavelength of 800 nm over an intensity range of 2-4.5 x 10(14) W/cm2. We find an anisotropy that is stronger than predicted by any existing model. To explain the observed anisotropy and its strong intensity dependence we develop an analytical model in the framework of the strong-field approximation. It expresses molecular ionization as a product of atomic ionization rate and a Fourier transform of the highest occupied molecular orbital filtered by the strong-field ionization process.

Laser-induced electron tunneling and diffraction

Molecular structure is usually determined by measuring the diffraction pattern the molecule impresses on x-rays or electrons. We used a laser field to extract electrons from the molecule itself, accelerate them, and in some cases force them to recollide with and diffract from the parent ion, all within a fraction of a laser period. Here, we show that the momentum distribution of the extracted electron carries the fingerprint of the highest occupied molecular orbital, whereas the elastically scattered electrons reveal the position of the nuclear components of the molecule. Thus, in one comprehensive technology, the photoelectrons give detailed information about the electronic orbital and the position of the nuclei.

High-order harmonic transient grating spectroscopy in a molecular jet

We study high-order harmonic generation in excited media using a four-wave-mixing-like configuration. We analyze the spatial profile of high harmonics emitted by a grating of rotationally excited molecules as a function of the pump-probe delay. We demonstrate a dramatic improvement in the contrast of the diffracted signal relative to the total high harmonic signal. This allows us to observe subtle effects in the rotational wave packet excitation such as the pump-intensity dependence of the wave packet dynamics. High harmonic transient grating spectroscopy can be extended to all forms of molecular excitation and to weak resonant excitation.

Binary and recoil collisions in strong field double ionization of helium

We have investigated the correlated momentum distribution of both electrons from nonsequential double ionization of helium in a 800 nm, 4.5 x 10(14 W/cm2 laser field. Using very high resolution coincidence techniques, we find a so-far unobserved fingerlike structure in the correlated electron momentum distribution. The structure can be interpreted as a signature of the microscopic dynamics in the recollision process. We identify features corresponding to the binary and recoil lobe in field-free (e,2e) collisions. This interpretation is supported by analyzing ab initio solutions of a fully correlated three-dimensional helium model.

High harmonic generation and the role of atomic orbital wave functions

High harmonic spectra were recorded from different rare-gas atoms under identical experimental conditions. It is shown that although each atom's spectrum is different, the differences are due almost entirely to the orbital influence in the recombination step. The amplitude of the continuum electron wave packet versus kinetic energy is derived from these data and is shown to be largely independent of the atom, in agreement with models of tunnel ionization. We compare the measurements with calculations in both the length gauge and the velocity gauge and show that the two gauges imply a different de Broglie wavelength.

Attosecond strobing of two-surface population dynamics in dissociating H2+

Using H2+ and D2+, we observe two-surface population dynamics by measuring the kinetic energy of the correlated ions that are created when H2+ (D2+) ionize in short (40-140 fs) and intense (10(14) W/cm2) infrared laser pulses. Experimentally, we find a modulation of the kinetic energy spectrum of the correlated fragments. The spectral progression arises from a hitherto unexpected spatial modulation on the excited state population, revealed by Coulomb explosion. By solving the two-level time-dependent Schrödinger equation, we show that an interference between the net-two-photon and the one-photon transition creates localized electrons which subsequently ionize.

Attosecond temporal gating with elliptically polarized light

Temporal gating allows high accuracy time-resolved measurements of a broad range of ultrafast processes. By manipulating the interaction between an atom and an intense laser field, we extend gating into the nonlinear medium in which attosecond optical and electron pulses are generated. Our gate is an amplitude gate induced by ellipticity of the fundamental pulse. The gate modulates the spectrum of the high harmonic emission and we use the measured modulation to characterize the sub-laser-cycle dynamics of the recollision electron wave packet.

Generation of 11 fs pulses by using hollow-core gas-filled fibers at a 100 kHz repetition rate

Using self-phase modulation in a hollow-core fiber filled with xenon, we were able to produce 2.3 microJ laser pulses with a duration of 10.9 fs at a repetition rate of up to 100 kHz. We started with 45 fs, 4.4 microJ, 800 nm pulses generated by a Coherent RegA Ti:sapphire regenerative amplifier system, then spectrally broadened the 30 nm bandwidth to more than 100 nm. Dispersion compensation was achieved with two pairs of chirped mirrors. This is believed to be the first time this type of compression was achieved at a repetition rate as high as 100 kHz. This brings the advantages of few-cycle laser pulses to experiments that require high-repetition-rate, low-energy laser systems, for example, coincidence experiments.

Controlling attosecond double ionization dynamics via molecular alignment

We investigate the dynamics of double ionization in aligned nitrogen molecules. An ultrashort, weak laser pulse creates an aligned ensemble of molecules that is ionized with a subsequent, strong probe pulse. We find that the two electrons involved in nonsequential double ionization more likely exit the molecule in the same direction if it is parallel to the probe laser polarization, indicating that they are ejected within a few hundred attoseconds of each other. Double ionization is less probable and takes longer for perpendicular molecules.

Controlling high harmonic generation with molecular wave packets

We show that, by controlling the alignment of molecules, we can influence the high harmonic generation process. We observed strong intensity modulation and spectral shaping of high harmonics produced with a rotational wave packet in a low-density gas of N2 or O2. In N2, where the highest occupied molecular orbital (HOMO) has sigma(g) symmetry, the maximum signal occurs when the molecules are aligned along the laser polarization while the minimum occurs when it is perpendicular. In O2, where the HOMO has pi(g) symmetry, the harmonics are enhanced when the molecules are aligned around 45 degrees to the laser polarization. The symmetry of the molecular orbital can be read by harmonics. Molecular wave packets offer a means of shaping attosecond pulses.

Tomographic imaging of molecular orbitals

Single-electron wavefunctions, or orbitals, are the mathematical constructs used to describe the multi-electron wavefunction of molecules. Because the highest-lying orbitals are responsible for chemical properties, they are of particular interest. To observe these orbitals change as bonds are formed and broken is to observe the essence of chemistry. Yet single orbitals are difficult to observe experimentally, and until now, this has been impossible on the timescale of chemical reactions. Here we demonstrate that the full three-dimensional structure of a single orbital can be imaged by a seemingly unlikely technique, using high harmonics generated from intense femtosecond laser pulses focused on aligned molecules. Applying this approach to a series of molecular alignments, we accomplish a tomographic reconstruction of the highest occupied molecular orbital of N2. The method also allows us to follow the attosecond dynamics of an electron wave packet.

A MRI-compatible stereotaxic localizer box enables high-precision stereotaxic procedures in pigs

We present a nonmagnetic Plexiglas stereotaxic localizer box that can be fitted directly to the pig skull by aluminum screws, allowing stereotaxic MRI or ventriculography and subsequent high-precision stereotaxic procedures. The localizer box was used to target the subthalamic nucleus (STN) bilaterally in five female Göttingen minipigs. Stereotaxic markers were inserted in the pig skull, the head fixated in the localizer box by aluminum screws inserted bilaterally in the zygoma bone with the hard palate locked on a horizontal palate holder. MRI was obtained on a 3T-MR-imager revealing the relation between the inserted markers and the estimated STN-position, and thus the target coordinates. After the MRI, a stereotaxic frame with attached micromanipulator was locked on to the localizer box converting it into a stereotaxic device. The stereotaxic markers were exposed and used as starting point for the stereotaxic procedure, whereby a microelectrode for electrolytic lesioning was inserted in the STN. Postmortem histological analysis revealed 70% correct STN-targeting. The average distance from the lesion center to the STN center was 1.2 mm with a S.D. of 1.1 mm. The most displaced lesion being 3.6 mm from the STN center. We conclude that the described localizer box secure firm head fixation, allowing stereotaxic MRI and subsequent conversion into a stereotaxic device for high-precision stereotaxic procedures.

Fully differential rates for femtosecond multiphoton double ionization of neon

We have investigated the full three-dimensional momentum correlation between the electrons emitted from strong field double ionization of neon when the recollision energy of the first electron is on the order of the ionization potential. The momentum correlation in the direction perpendicular to the laser field depends on the time difference of the two electrons leaving the ion. Our results are consistent with double ionization proceeding through transient double excited states that field ionize.

[Secondary lung surgery following contralateral pneumonectomy. Anaesthesiological considerations]

Although there have been an increasing number of reports on secondary lung surgery following contralateral pneumonectomy in recent years, little information is available about the anaesthesiological management of these patients. We therefore report on a 58-year-old patient who had already undergone a left-sided pneumonectomy and now required a right-sided thoracotomy to remove a recurrent tumour in the right upper lobe. The patient received a total intravenous anaesthesia (propofol, fentanyl) combined with atracurium for muscle relaxation. Following the orotracheal intubation with a Woodbridge tube, the patient was ventilated with the high frequency jet ventilation technique. The jet stream was administered via a catheter placed in the tube. The arterial O(2) saturation during ventilation was always 100%, and arterial CO(2) partial pressure was also normal. No complications occurred during tumour resection from the right upper lobe, and the patient was transferred to the ICU with stable pulmonary and haemodynamic conditions. After 2 h of ventilation, the patient was extubated with a completely expanded lung. The postoperative recovery was uneventful. This case report shows that,presupposing a sufficient pulmonary capacity, secondary lung surgery in previously pneumonectomised patients is feasible without complications given an appropriate anaesthesiological management.

Programmable amplitude- and phase-modulated femtosecond laser pulses in the mid-infrared

We present a scheme to produce programmable phase- and amplitude-modulated femtosecond laser pulses in the mid-infrared regime of 3-10mum by difference frequency mixing. The 80-fs signal output of an optical parametric amplifier is shaped with a liquid-crystal mask and mixed in an AgGaS(2) crystal with a temporally stretched idler pulse. Without changing the mechanical alignment, we produce programmable amplitude modulations and chirped pulses at lambda=3mum with energy as high has thas 1muJ . This scheme, further, allows the generation of controllable pulse sequences. The results are in good agreement with theoretical simulations.

Optical parametric amplification of a shaped white-light continuum

Phase-locked two-color sub-40-fs double pulses in the visible are produced by noncollinear parametric amplification of white light tailored in a pulse shaper with a liquid-crystal mask. The carrier phase between the pulses is conserved during the amplification process and can be adjusted, as can the temporal separation and the center of wavelengths of the pulses.

[Unilateral high-frequency jet ventilation supporting one-lung ventilation during thoracic surgical procedures]

We report two cases where surgery on the right lung had to be performed for resection of a malignoma. In both cases, function of the left lung was severely restricted. In the first patient, the volume on this side was reduced by around 50% as the result of a recently performed upper lobe resection. In the second patient, perfusion of the left lung accounted for only 18% of the total lung perfusion. On the basis of these changes we considered conventional one-lung ventilation impracticable and performed surgery using differential lung ventilation. The dependent (left) lung was ventilated by intermittent positive pressure ventilation (IPPV), where the tidal volume in the first patient had to be reduced to 200 ml because of high airway pressures. Ventilation of the non-dependent (right) side was performed simultaneously in both patients by means of high frequency jet ventilation (HFJV). Under this procedure arterial O2 saturation ranged from 96 to 100%, and arterial CO2 partial pressure was 45 mmHg. Surgery was not hindered by ventilation, the postoperative progress was also without complications. The case reports show that with the help of the ventilation regime described (operated side: HFJV, non-operated side: IPPV) lung surgery can be successfully performed on patients who are unsuitable for conventional one-lung ventilation for functional reasons.

Role of bronchoalveolar lavage in immunocompromised patients with pneumonia treated with a broad spectrum antibiotic and antifungal regimen

BACKGROUND

In a retrospective study the value of bronchoalveolar lavage (BAL) in the diagnosis of pneumonia was investigated in 95 immunocompromised patients suffering from haematological disorders and receiving a regimen of broad spectrum antibiotics and antifungal agents (BSAR).

METHODS

With the exception of four afebrile patients, all had fever, raised C reactive protein (CRP) levels, and new infiltrates visible on chest radiography. All patients underwent BAL to identify the organism causing the pneumonia and surveillance cultures were performed regularly for pathogens at different sites. Following classification of the isolates, patients with positive cultures were subdivided into two groups, pathogenic or contaminated. We investigated whether relevant pathogens were cultured only from the BAL fluid and whether they were susceptible to BSAR.

RESULTS

Although 77 of the 95 patients were thrombocytopenic, bleeding during BAL occurred in only 15% of all patients. Ten days after the procedure the fever improved in 88% of patients, radiographic findings improved in 71%, and CRP levels improved in 75% of patients; 22% of patients died within 28 days. Pathologically relevant isolates were found in 65% of all patients. Respiratory pathogens were detected only in the BAL fluid of 29 of the 95 patients (35% Gram positive species, 40% Gram negative species, 11% Mycobacterium, 11% fungi, and 3% cytomegalovirus). In 16 of these 29 patients (55%) the pathogens cultured only from the BAL fluid were resistant to treatment. Pathogens detected only in the BAL fluid were not susceptible to a standard broad spectrum antibiotic and antifungal regimen including teicoplanin, ceftriaxon, tobramycin, and amphotericin B in 12 of the 29 patients (41%).

CONCLUSIONS

Our data suggest that 12 patients were treated with broad spectrum antimicrobial agents which were not directed at the appropriate organism on in vitro sensitivity tests without BAL. BAL is a relatively safe procedure in the diagnosis of pneumonia, supplying important information in immunocompromised patients as well as in immunocompromised patients receiving BSAR.

[One-lung respiration in a nasally intubated patient using a single-lumen endobronchial tube]

We report the case of a 57-year-old patient who underwent a right-sided thoracotomy. The preoperative examination of the patient already revealed a clear diminution of the mouth opening (Mallampati class 4). Ventilation per mask following the induction of anaesthesia was unproblematic. As oral intubation with a double-lumen tube seemed to be impossible because of the difficult anatomic conditions, nasal intubation was carried out. For this we used a left-sided single-lumen endobronchial tube of Rüsch (size 8.0). The tube was inserted into the left mainstem bronchus using a fiberoptic bronchoscope. Intraoperatively we were able to ventilate exclusively the dependent left lung by inflating the bronchial cuff. The operation itself was performed on the collapsed right lung. At the end of the operation the right lung could be ventilated once again by deflating the bronchial cuff (tracheal cuff inflated). This example demonstrates that one-lung ventilation is possible even under difficult intubation conditions.

Atracurium during thoracic surgery: impaired efficiency in septic processes

OBJECTIVE

The aim of the study was to examine whether the neuromuscular blocking potency of atracurium changes in patients with a septic intrathoracic process.

DESIGN

Prospective clinical study.

SETTING

Community hospital.

PARTICIPANTS

Thirty patients who underwent thoracic surgery for resection of a pulmonary carcinoma were examined. Fifteen patients showed typical signs of a concomitant bacterial superinfection (infection group), 15 age-matched patients without infection served as the control (no-infection) group.

INTERVENTIONS

Relaxation was induced with atracurium, 0.6 mg/kg intravenously for intubation, followed by a continuous infusion to maintain a 90% neuromuscular blockade. Relaxometry was performed electromyographically using the Datex Relaxograph by stimulating the ulnar nerve next to the wrist.

MEASUREMENTS AND MAIN RESULTS

The onset time was significantly longer (5.3 +/- 2.9 v 3.3 +/- 1.2 minutes; p < 0.05), and the recovery phase (DUR 10%) was significantly shorter (23.5 +/- 8.6 v 36.9 +/- 7.3 minutes; p < 0.001) in the infection group compared with the controls. The infusion rate within the first hour of continuous application was 77.4% higher in the infection group than in the control group (11.0 +/- 2.9 v 6.2 +/- 1.0 microg/kg/min; p < 0.001).

CONCLUSION

The study showed that septic intrathoracic processes cause a clear reduction of the neuromuscular blocking potency of atracurium. To guarantee adequate muscle relaxation in such cases, precise neuromuscular monitoring is highly advisable.

[Reduced neuromuscular blocking potency of atracurium in patients with purulent intrathoracic diseases]

OBJECTIVE

Based on personal observations the neuromuscular blocking potency of atracurium was supposed to be diminished in purulent intrathoracic diseases. This hypothesis was tested in a prospective clinical trial.

METHODS

52 adult patients undergoing general anaesthesia (methohexitone, sufentanil, flunitrazepam, N2O, enflurane) for elective thoracic surgery were investigated. After the intubation dose of 0.6 mg/kg atracurium was applied continuously to maintain a 90% suppression of the evoked compound electromyogram. According to the intraoperatively established diagnosis patients were allocated to three categories: 1) non-malignant tumor as the control group (n = 15), 2) lung cancer (n = 22), 3) purulent intrathoracic process without tumor (n = 15). The groups were compared regarding onset time, DUR 10% and maintenance dose of atracurium.

RESULTS

Patients with lung cancer did not differ significantly from the controls regarding efficiency of atracurium. In contrast, patients with a purulent intrathoracic process showed a significantly longer onset time (6.3 +/- 2.5 vs. 2.9 +/- 0.8 min, p < 0.001), and a significantly shorter DUR 10% (23 +/- 6 vs. 36 +/- 10 min, p < 0.001) compared to the control group. Mean infusion rate of atracurium to maintain a 90% suppression of the evoked compound electromyogram was significantly higher in patients with a purulent process compared to the controls (10.5 +/- 3.2 vs. 6.0 +/- 1.2 micrograms/kg.min, p < 0.001).

CONCLUSION

Our results support the hypothesis that patients with a purulent intrathoracic disease show a clear reduction in neuromuscular blocking potency of atracurium.

[Postoperative resistance against atracurium]

Supported by two case reports we show that resistance to atracurium can develop postoperatively. Both patients had septic complications after elective thoracic surgery. A 39-year-old patient developed a bronchial fistula and a superinfection of the remaining thoracic cavity after pneumonectomy. At the time of rethoracotomy the neuromuscular blocking potency of atracurium had changed drastically: onset time was lengthened (7 vs. 3.5 min), recovery period (DUR 10%) was reduced (14 vs. 28 min) and the maintenance dose had to be tripled (14.3 vs. 5.0 micrograms/kg per minute). Following superior lobe resection in a 56-year-old patient, middle lobe gangrene occurred which had to be removed. In contrast to the first anaesthesia the intubation dose of atracurium had to be increased significantly (70 vs. 40 mg), and even with this amount the neuromuscular blocking effect was not complete. Furthermore to accomplish a convenient state of relaxation the maintenance dose had to be raised considerably (11.8-16.5 vs. 5.5 micrograms/kg per minute). These reports show that even within a short period of time resistance to atracurium can develop and we must suppose that the severe inflammatory reaction caused these changes.

[Benign metastatic leiomyoma of the lung]

The authors report on the case of a woman of 41 years of age presenting with asymptomatic multiple circular foci in the lung that were primarily suspected of being malignomas. Diagnosis of benign metastasising leiomyomas was confirmed for bilateral multiple circular foci suspected of lung metastasising originating from an unknown tumour of the lung. This diagnosis was achieved by open biopsy. The seemingly contradictory diagnosis of a benign but metastasising tumour is characteristic of a rare disease pattern that, however, is well documented in the literature. The course of the disease is compared with the data given in the literature.

[Life expectancy and disability following pleural empyema]

The pleural empyema, e.g. postpneumonial or postoperative, has, in an acute state of being, to be treated before all by an aimed intensive puncture, irrigation, and drainage therapy. Removing the cause of the empyema you can expect a cure as a rule, but in certain cases an operative intervention is still necessary. The chronic empyema often needs a decortication for an operative correction. The trials of medical treatment being often conservative and the chronic intoxication most often cause a strong impairment of the general condition. A lot of other organic affections or damages reduce the chances of cure and increase lethality. The chronic empyema not available for an operative correction has, as a whole, a bad long-term prognosis with a high morbidality and lethality. The qualities of living of these patients are often reduced a lot.

[Differential diagnostic and therapeutic measures after aspiration of foreign bodies]

While aspiration is extremely rare, it must be considered as a possibility. Its prompt consideration is already half of the diagnosis, and the patient is protected from avoidable complications. The patient should be admitted to a hospital or department where routine bronchoscopic examinations are carried out and where personnel and equipment are available for immediate foreign body extraction.

[Aspiration accidents in dental practice]

Lack of symptoms does not necessarily mean that a small foreign body has been swallowed. Symptoms may not be present after aspiration of a foreign body which lodges in the bronchial tract. In any case, the event must be clarified roentgenologically. The patient should be removed from the practice. Ominous symptoms, on the other hand, indicate that a large foreign body has lodged in the trachea or behind the larynx. The patient should be immediately escorded to the hospital in a sitting position. The administration of a sedative is indicated in some cases.

[Primary spindle cell sarcoma of the pulmonary artery]

It is reported on a patient with a primary, mainly spindle-cell sarcoma of the left pulmonary artery. It is a case of a centrally located tumor, which caused a subtotal occlusion of the truncus pulmonalis and a complete occlusion of the left pulmonary artery. The diagnostical and therapeutical methods with their results and possible complications are discussed. The indication for an operation is demonstrated. In the pertinent literature hitherto 35 cases of this disease are reported.

[Traumatic rupture of the diaphragm (author's transl)]

Traumatic rupture of the diaphragm is diagnosed during the acute stage in only 50% of the cases. The reasons for this failure are that in many of these cases clinical symptoms of damage to abdominal organs or of injuries to the limbs predominate. Traumatic rupture of the diaphragm is usually the result of an indirect trauma. Clinical signs of extensive prolapse of viscera into the thoracic cavity are: dyspnoea, tachycardia, cyanosis or intestinal sounds heard over the thorax during auscultation. Once the diagnosis has been established surgical repair should follow. During the acute stage laparotomy is preferable; thoracotomy is indicated during the chronic stage. Post-operative symptoms are: dyspnoea during exercise, pain in the affected half of the chest and roentgeno-kymographically demonstrable restrictions of movement in the ruptured side of the diaphragm.

[Treatment of postoperative sternal osteomyelitis (author's transl)]

Report on 5 cases of postoperative sternal osteomyelitis after cardiac valve replacement. In 3 cases evaluation of Pseudomonas aeruginosa in probes taken of sternal wounds. Treatment of the osteomyelitis with continuous irrigation and suction supported by excochleation of the fistulae and application of pure spongiosa chips to the bone defect of the sternum. Uncomplicated postoperative course in 4 patients. In 1 patient postoperative time too short for a final decision.