[Disorders of the pulmonary lymphatic system]

The pulmonary lymphatic system plays an important role in lung perfusion homeostasis. Congenital errors of lymphatic vessel development lead to primary pulmonary lymphatic disorders (lymphangiomas, lymphangiectasis, lymphatic dysplasia syndromes). Acquired disorders of the pulmonary lymphatic system occur in a variety of clinical settings (ranging from trauma to cancer) and may lead to serious pulmonary disease. Because of their scarcity and confusing and inconsistent use of terminology, these conditions are often misdiagnosed. Their management is difficult.

P300 and symptom improvement in schizophrenia

RATIONALE

A reduced amplitude of the auditory evoked P300 was interpreted as a trait marker of schizophrenia but reports about correlations between schizophrenic psychopathology and P300 amplitude indicate also a state character.

OBJECTIVES

To shed light upon these trait and state aspects a longitudinal study was performed to investigate the influence of symptom improvement and atypical neuroleptics on the amplitudes of the P300 and their subcomponents.

METHODS

P300 was recorded in 17 schizophrenic patients before and after 4 weeks under either clozapine or olanzapine in a double-blind controlled design. For comparison, 17 age- and sex-matched healthy subjects were investigated. Parietal and frontal P300 subcomponents were investigated separately using dipole source analysis.

RESULTS

Schizophrenic patients had smaller parietal (temporo-basal dipole) but not frontal subcomponent amplitudes (temporo-superior dipole) than controls. For the whole sample subcomponent amplitudes did not change over 4 weeks despite clinical improvement but patients with a pronounced improvement of the PANSS positive score showed a slight enhancement of both subcomponents. This was not significant when the P300 amplitude was measured at a single electrode (Pz). No significant difference between clozapine and olanzapine concerning effects on P300 amplitudes were observed.

CONCLUSIONS

The results indicate that P300 subcomponents are modulated by changes of positive but not by changes of negative symptoms or different neuroleptics. This result was obvious for P300 subcomponents but not for Pz electrode measurement, which may be due to a higher reliability of the dipole source activity. The results can be integrated into a hypothetical model containing two pathophysiological subgroups of schizophrenia.

Protein adsorption and monocyte activation on germanium nanopyramids

Germanium can form defect-free pyramidal islands on Si(1 0 0)-2 x 1 with a height of 15 nm and a width of 60 nm. Using chemical vapor deposition we have prepared substrates with different nanopyramid densities to study the impact on contact angles, protein adsorption and cell behavior. The advancing contact angle of a water droplet of millimeter size significantly raises with nanopyramid density. The dynamic contact angle measurements reveal that the substrate surface is highly hydrophilic. On such a surface the adsorption of hydrophilic proteins, i.e. albumin and globulin, is drastically increased by the presence of nanopyramids. More important, however, the globulin is inactive after adsorption on nanopyramid edges. This observation is supported by the cytokine release of IL-1beta and TNF-alpha of monocyte-like cell line U937. Consequently, the presence of nanopyramidal structures gives rise to less inflammatory reactions.

[Non-thrombotic pulmonary embolisms]

In the absence of intracardiac or intrapulmonary shunts, the pulmonary microvasculature traps all embolized particles greater than 10 microns. In the vast majority of cases these emboli are venous thrombi which lodge in larger pulmonary arteries, resulting in obstructive phenomena rather than primarily being injurious to lung parenchyma. This review deals exclusively with nonthrombotic pulmonary embolism which involves substances that lodge predominantly in the pulmonary microvessels and cause a true endothelial and parenchymal injury, as well as obstructive phenomena. The article focuses on fat embolism, amniotic fluid embolism, gas embolism, septic emboli, and tumour pulmonary embolism.

Extensive sampling improves preoperative bronchoscopic assessment of airway invasion by supracarinal esophageal cancer: a prospective study in 166 patients

BACKGROUND

The utility of fiberoptic bronchoscopy in the preoperative assessment of patients with esophageal cancer has not been thoroughly investigated. More accurate staging could improve the design of clinical trials and avoid inappropriate surgical decisions in individual patients.

STUDY OBJECTIVE

To evaluate the utility of bronchoscopy in the preoperative assessment of airway invasion by supracarinal esophageal cancer.

DESIGN

We prospectively analyzed 220 bronchoscopies in 166 consecutive patients with supracarinal esophageal cancer and correlated the findings with operative results and survival.

RESULTS

In 126 bronchoscopies (57.3%), no abnormal findings could be seen in the airways. Compared with histologic and cytologic results, the normal macroscopic appearance of the airways had a negative predictive value of 94.4%, but the positive predictive value of all macroscopic abnormalities for the diagnosis of airway invasion was low, particularly after radiation therapy. Endoluminal tumor mass, protrusion of the posterior tracheal wall, and signs of mucosal invasion were visible in 5.9%, 28.6%, and 4.1% of the bronchoscopies, respectively. However, in only 8.6% of the 220 bronchoscopies, cancer invasion was proved by biopsy or cytology. Bronchoscopy with biopsies and brush and washing cytology examinations was the sole decisive staging procedure, enabling the exclusion from surgery because of airway invasion in 18.1% of otherwise potentially operable patients, with an overall accuracy of 93.3% (95% confidence interval, 86.7 to 97.3%). The results of bronchoscopy were falsely negative in six patients, who all underwent surgery after neoadjuvant therapy.

CONCLUSIONS

Fiberoptic bronchoscopy with systematic multiple biopsies and brush and washing cytology examinations is an accurate procedure in evaluating the possible invasion of supracarinal esophageal cancer into the airways. Macroscopic findings alone are not reliable; errors in sole bronchoscopic inspection would have resulted in operations that would be unlikely to help the patients or would have inappropriately excluded patients from surgery.

The immune system and schizophrenia. An integrative view

Immune alterations in schizophrenia have been described for decades. Modern immunological methods and new insights into the highly developed and functionally differentiated immune system allow an integrative view of both the older and the recent findings of immunological abnormalities in schizophrenia. Both the unspecific and the specific arms of the immune system seem to be involved in the dysfunction of the immune system in schizophrenia. The unspecific, "innate" immune system shows signs of overactivation in unmedicated schizophrenic patients, as indicated by increased monocytes and gamma delta-cells. Increased levels of interleukin-6 (IL-6) and the activation of the IL-6 system in schizophrenia might be the result of the activation of monocytes/macrophages, too. On the other hand, several parameters of the specific cellular immune system are blunted, such as, for example, the decreased T helper-1 (TH-1)-related immune parameters in schizophrenic patients both in vitro and in vivo. It seems that a TH-1-TH-2 imbalance with a shift to the TH-2 system is associated with schizophrenia. During antipsychotic therapy with neuroleptics, the specific TH-1-related immune answer becomes activated, but in addition the B cell system and antibody production increase.

Predictors of tracheobronchial invasion of suprabifurcal oesophageal cancer

BACKGROUND

Factors possibly predicting airway invasion of oesophageal cancer in the absence of frank oesophagotracheal fistulas have not been studied.

OBJECTIVES

To identify possible predictors of airway invasion by oesophageal cancer that are readily accessible in the preoperative setting.

METHODS

We prospectively investigated 148 patients with newly diagnosed oesophageal cancer located at or above the level of the tracheal bifurcation and without any evidence of oesophago-respiratory fistulas or distant metastases. Demographic variables, respiratory parameters, results of bronchoscopy and other staging procedures (oesophagoscopy, swallow oesophagography, endosonography, CT and histology) and findings at surgery were compared between the patients with (n = 30) and without (n = 118) proven airway invasion and entered into a stepwise logistic regression model to evaluate their independent predictive roles.

RESULTS

Univariate analysis indicated that the incidence of airway invasion increased with the presence of suspect CT findings, the presence of respiratory symptoms, tumour length, T stage on endoscopic ultrasonography, and histopathologic grading of the primary cancer. A multivariate logistic regression model indicated that suspect CT findings (odds ratio, 4.4; 95% confidence interval 1.7-11.1, p = 0.002) and maximal tumour length >8 cm (odds ratio, 3.7; 95% confidence interval 1.4-9.6, p = 0.007) were associated independently with airway invasion. The accuracy of predicting airway invasion was 82.5% with both variables combined.

CONCLUSIONS

The high incidence of airway involvement by oesophageal cancer and the difficulty to predict it accurately with clinical data or other staging procedures justifies the routine use of bronchoscopy in all patients with the tumour located at or above the level of the tracheal bifurcation. A particular effort to objectively prove or exclude airway invasion should be made in patients with tumours longer than 8 cm and/or with CT findings suggesting airway invasion.

The Th2-hypothesis of schizophrenia: a strategy to identify a subgroup of schizophrenia caused by immune mechanisms

Immunologic findings in schizophrenia have been described for decades, but it was not possible to identify a pathogen until now. Most of these studies report immune abnormalities in a group of the investigated patients, but a distinct subgroup of schizophrenia with immune-related pathology has still not been characterized. In this paper we have integrated the most important immunologic data in schizophrenia research and hypothesize a shift to Th2-like immune reactivity in a subgroup of schizophrenic patients. Besides the immunological abnormalities, this subgroup is further characterized by more pronounced negative symptoms and poor therapy outcome. There is evidence that this subgroup might be caused by a prenatal viral infection.

Increased titers of antibodies against streptococcal M12 and M19 proteins in patients with Tourette's syndrome

It has been suggested that a post-streptococcal autoimmune process may be involved in the pathogenesis of a subgroup of children with tics and obsessive-compulsive symptoms (PANDAS). Elevated antibody titers against streptococcal antigens have also been described in adult patients suffering from Tourette's syndrome (TS). In order to characterise further streptococcal antigens, we focussed on M proteins. M proteins are a major virulence factor of group A streptococci and known to evoke an immunologic cross-reaction with diverse epitopes of human tissue including brain tissue. Therefore, antibodies against M proteins may play a role in the pathophysiology of at least a subgroup of TS patients. Antibodies against M proteins were studied in 25 adult patients suffering from TS and 25 healthy controls after careful medical examination. The antibody titers against the peptides M1, M4, M6, M12 and M19 were estimated by ELISA. Our results show increased titers of antibodies against the streptococcal M12 and M19 proteins in TS patients as compared with controls, while antibody titers against M1, M4 and M6 did not differ between the TS and control groups. Elevated serum titers of antibodies against M12 and M19 proteins support the view that a streptococcus-induced autoimmune process may be involved in TS. The finding of a possible autoimmune origin of TS has implications for both pathophysiology and future therapeutic strategies.

Dipole localization of P300 and normal aging

At present, our understanding of how normal aging affects in vivo brain function is rudimentary. Therefore, the aim of the present study was to investigate age effects on auditory P300 topography. A recently developed dipole source model for P300 distinguishes overlapping P300 subcomponents and enhances reliability as well as validity of the measurement. 67 healthy subjects were examined using the P300 dipole model in addition to the scalp data measurement. The results show that P300 subcomponents reflect functionally different processes concerning age changes of P300 activities. Temporo-parietal P300 is smaller in older subjects, whereas frontal P300 is not attenuated. Age affected both P300 subcomponents' latencies. Therefore, the functionally different alteration of P300 subcomponents might be the reason for P300 topography changes with the P300 maximum more frontally in older age.

[Diagnosis of pulmonary embolism]

Accurate diagnosis of pulmonary embolism is essential to minimize morbidity and mortality caused by failure to treat when necessary or by inappropriate treatment. Because clinical symptoms and signs are nonspecific, it is impossible to prove the diagnosis solely on clinical grounds. The diagnosis requires high level of suspicion, estimation of the pretest clinical likelihood of embolism, and judicious use of objective investigations (scintigraphy, computed tomography, or angiography) to confirm or refute the suspicion. The choice of tests depends on the availability of these tests, the hemodynamic state of the patient, and the presence of other cardiopulmonary diseases. Despite the availability of most accurate tests, pulmonary embolism will continue to be missed if not first considered by the physician.

[Clinical characteristics of pulmonary embolism]

Pulmonary embolism is nearly always a complication of deep venous thrombosis. The evaluation of risk factors for venous thromboembolism not only aids diagnosis but also guides decisions about the intensity of prophylactic measures. As both the extent and chronicity of pulmonary vascular obstruction vary widely, pulmonary embolism can produce widely differing clinical pictures. From the clinical, pathophysiological and therapeutical point of view, it is convenient to classify pulmonary embolism into four types: acute minor embolism (dyspnoea with or without pleuritic pain or haemoptysis), acute massive embolism (hemodynamic instability), subacute massive embolism (mimicking heart failure or indolent pneumonia), and chronic thromboembolic pulmonary hypertension (slowly progressing dyspnoea). This classification is of importance not only for the rational diagnosis and differential diagnosis, but also for the institution of adequate therapy. Because the disease has many nonspecific manifestations but no pathognomonic symptoms or signs, it is impossible to prove the diagnosis of pulmonary embolism alone on the basis of clinical presentation.

Influence of simultaneous neoadjuvant radiotherapy and chemotherapy on bronchoscopic findings and lung function in patients with locally advanced proximal esophageal cancer

To assess the bronchoscopic and lung function changes induced by preoperative radiochemotherapy (30 Gy radiation and 5-fluorouracil) in patients with proximal esophageal cancer, we prospectively compared the findings in 77 consecutive patients before and after the therapy. All patients completed the radiochemotherapy protocol; toxicity was minimal. Sixty-four patients underwent surgery, 48 had total gross removal of disease, and six had a complete histologic response. Of the 13 patients who developed apparent direct macroscopic signs of tumor invasion into the airways during therapy, histologic proof of cancer was obtained in only one of the abnormalities. Bronchoscopy was falsely negative in six patients in whom airway invasion of the cancer was found at surgery. Neoadjuvant therapy led to no systematic changes in the appearance of the uninvolved tracheal mucosa; microscopically, an increase in postinflammatory changes, hyperplasia, and metaplasia was found. There was no significant change in the values of lung function parameters after the therapy. No patient developed symptoms suggestive of radiation-induced lung changes, although in one of them, subtle radiologic features consistent with radiation pneumonitis were found. No patient died of postoperative pulmonary complications. The interpretation of bronchoscopy in the assessment of airway invasion of esophageal cancer after radiochemotherapy is more difficult than at baseline staging; the positive predictive value of macroscopic abnormalities without microscopic proof of cancer is low, and even with extensive sampling for histology and cytology, the procedure was falsely negative in 9.4%. Neoadjuvant therapy did not induce radiation pneumonitis or changes in lung function that could be of concern at the following operation.

Origin of surface conductivity in diamond

Hydrogen-terminated diamond exhibits a high surface conductivity (SC) that is commonly attributed to the direct action of hydrogen-related acceptors. We give experimental evidence that hydrogen is only a necessary requirement for SC; exposure to air is also essential. We propose a mechanism in which a redox reaction in an adsorbed water layer provides the electron sink for the subsurface hole accumulation layer. The model explains the experimental findings including the fact that hydrogenated diamond is unique among all semiconductors in this respect.

Cellular and humoral immune system in schizophrenia: a conceptual re-evaluation

Immune alterations in schizophrenia have been described for decades. However, modern immunological methods and new insights into the highly developed and functionally differentiated immune system allow an integrative view of both the older and also more recent findings of immunological abnormalities in schizophrenia. The conceptual advances in immunology require the re-evaluation of elder immunological findings in schizophrenia. In this overview, recent advances in immunological research regarding the differentiation between T-Helper-1 and T-Helper-2 cells and between the so-called specific and unspecific arms of the immune system are discussed. The unspecific "innate" immune system shows signs of an over-activation in unmedicated schizophrenic patients, as increased monocytes and gamma delta-cells point to. Increased levels of Interleukin-6 (IL-6) and the activation of the IL-6 system in schizophrenia might be the result of the activation of monocytes/macrophages, too. In contrast, several parameters of the specific cellular immune system are blunted, e.g. the decreased T-helper-1 (TH-1) related immune parameters in schizophrenic patients, both in vitro and in vivo. It seems that a TH-1-TH-2 imbalance with a shift to the TH-2 system is associated with schizophrenia. During therapy with antipsychotics, the specific TH-1 related immune answer becomes activated, but the B-cell system and the antibody production become activated too.

Digitized analysis of abnormal hand-motor performance in schizophrenic patients

Many studies have shown a high prevalence of discrete neuromotor disturbances in schizophrenic patients. It was hypothesized that these disturbances are lateralized and reflect a neurodevelopmental disorder underlying schizophrenia. A new method for assessing subtle motor dysfunction and hemispheric asymmetries is the registration of hand movements with a digitizing tablet. Using this method, we studied hand-motor dysfunction and its lateralization in schizophrenics, as compared with healthy controls. All subjects (27 schizophrenic patients, 13 of them without neuroleptic medication, the others under neuroleptics; 31 healthy controls) drew super-imposed concentric circles. We computed kinematic parameters reflecting velocity and automatization to quantify neurological soft signs (NSS). The patients had significant impairments of regularity of repetitive hand movements, as compared with the healthy controls (F> or =5.35; p< or =0.024(*)). Comparing differences of left- and right-hand performance between patients and controls, we found longer stroke duration (F=(15,98); p=0.000***) and decreased automatization (F=18,14; p=0.000***), especially on the left side in schizophrenic patients. Measuring hand movements with a digitizing tablet is a sensitive method for assessing subtle motor dysfunction in schizophrenic patients, not reflected in the scores of clinical scales. Our findings show NSS in schizophrenic patients, independently of neuroleptics. Further, the hypothesis of lateralization of cerebral structures generating NSS towards the right hemisphere in schizophrenia is supported.

Bronchoscopy in the preoperative staging of oesophageal cancer below the tracheal bifurcation: a prospective study

Oesophageal cancer located above the level of the tracheal bifurcation is frequently complicated by its spread into the airways and by the simultaneous occurrence of malignant bronchial tumours. Although bronchoscopy is an essential procedure in identifying malignant tumoral invasion of the airways and detection of primary airway tumours in patients with suprabifurcal oesophageal cancer, its role in patients with infrabifurcal oesophageal cancer is not clear. This study aimed to assess the value of fibreoptic bronchoscopy in the preoperative staging of oesophageal cancer located below the level of the tracheal bifurcation. In a prospective protocol, bronchoscopic findings were correlated with the results of other staging procedures, operative results and survival in 51 patients with oesophageal cancer located below the level of the tracheal bifurcation. One unsuspected primary bronchial cancer in a patient with squamous cell oesophageal cancer and one case of lower lobe invasion of an oesophageal adenocarcinoma were found. By excluding from surgery these two patients in whom curative resection was not possible bronchoscopy was the sole decisive staging investigation in 6.5% of potentially operable and 3.9% of all patients. Suspect macroscopic abnormalities were shown in 15.7% of the patients at bronchoscopy. Taking bronchoscopic biopsy as the gold standard the positive predictive value for all macroscopic abnormalities was only 25% (95% confidence interval (CI) 3.2-65.1%). The overall accuracy of bronchoscopy with biopsy and brush and washing cytology in proving or excluding airway invasion in otherwise potentially operable patients was 100% (95% CI 89.4-100%). Bronchoscopy is useful in the preoperative staging of oesophageal carcinoma located below the level of the tracheal bifurcation, particularly if the oesophageal cancer is of the squamous cell type.