Prediction of gas chromatographic retention indices of a diverse set of toxicologically relevant compounds.

For a set of 846 organic compounds, relevant in forensic analytical chemistry, with highly diverse chemical structures, the gas chromatographic Kovats retention indices have been quantitatively modeled by using a large set of molecular descriptors generated by software Dragon. Best and very similar performances for prediction have been obtained by a partial least squares regression (PLS) model using all considered 529 descriptors, and a multiple linear regression (MLR) model using only 15 descriptors obtained by a stepwise feature selection. The standard deviations of the prediction errors (SEP), were estimated in four experiments with differently distributed training and prediction sets. For the best models SEP is about 80 retention index units, corresponding to 2.1-7.2% of the covered retention index interval of 1110-3870. The molecular properties known to be relevant for GC retention data, such as molecular size, branching and polar functional groups are well covered by the selected 15 descriptors. The developed models support the identification of substances in forensic analytical work by GC-MS in cases the retention data for candidate structures are not available.

Systematic toxicological analysis: computer-assisted identification of poisons in biological materials.

A new software was developed to improve the chances for identification of a "general unknown" in complex biological materials. To achieve this goal, the total ion current chromatogram was simplified by filtering the acquired mass spectra via an automated subtraction procedure, which removed mass spectra originating from the sample matrix, as well as interfering substances from the extraction procedure. It could be shown that this tool emphasizes mass spectra of exceptional compounds, and therefore provides the forensic toxicologist with further evidence-even in cases where mass spectral data of the unknown compound are not available in "standard" spectral libraries.

Resolution of three nonproliferative immature splenic B cell subsets reveals multiple selection points during peripheral B cell maturation.

Although immature/transitional peripheral B cells may remain susceptible to selection pressures before full maturation, the nature and timing of these selection events remain unclear. We show that correlated expression of surface (s) IgM (sIgM), CD23, and AA4 defines three nonproliferative subpopulations of immature/transitional peripheral B cells. We designate these populations transitional (T) 1 (AA4(+)CD23(-)sIgM(high)), T2 (AA4(+)CD23(+)sIgM(high)), and T3 (AA4(+)CD23(+)sIgM(low)). Cells within all three subsets are functionally immature as judged by their failure to proliferate following sIgM cross-linking in vitro, and their rapid rate of turnover in vivo as assessed by 5-bromo-2'-deoxyuridine labeling. These labeling studies also reveal measurable cell loss at both the T1-T2 and T2-T3 transitions, suggesting the existence of multiple selection points within the peripheral immature B cell pool. Furthermore, we find that Btk-deficient (xid) mice exhibit an incomplete developmental block at the T2-T3 transition within the immature B cell pool. This contrasts markedly with lyn(-/-) mice, which exhibit depressed numbers but normal ratios of each immature peripheral B cell subset and severely reduced numbers of mature B cells. Together, these data provide evidence for multiple selection points among immature peripheral B cells, suggesting that the B cell repertoire is shaped by multiple unique selection events that occur within the immature/transitional peripheral B cell pool.

A common pathway for dendritic cell and early B cell development.

B cells and dendritic cells (DCs) each develop from poorly described progenitor cells in the bone marrow (BM). Although a subset of DCs has been proposed to arise from lymphoid progenitors, a common developmental pathway for B cells and BM-derived DCs has not been clearly identified. To address this possibility, we performed a comprehensive analysis of DC differentiative potential among lymphoid and B lymphoid progenitor populations in adult mouse BM. We found that both the common lymphoid progenitors (CLPs), shown here and elsewhere to give rise exclusively to lymphocytes, and a down-stream early B-lineage precursor population devoid of T and NK cell precursor potential each give rise to DCs when exposed to the appropriate cytokines. This result contrasts with more mature B-lineage precursors, all of which failed to give rise to detectable numbers of DCs. Significantly, both CLP and early B-lineage-derived DCs acquired several surface markers associated with functional DCs, and CLP-derived DCs readily induced proliferation of allogeneic CD4(+) T cells. Surprisingly, however, DC differentiation from both lymphoid-restricted progenitors was accompanied by up-regulation of CD11b expression, a cell surface molecule normally restricted to myeloid lineage cells including putative myeloid DCs. Together, these data demonstrate that loss of DC developmental potential is the final step in B-lineage commitment and thus reveals a previously unrecognized link between early B cell and DC ontogeny.

[Encephalopathy following poisoning with an anticholinergic agent]. / Enzephalopathie nach Intoxikation mit einem Anticholinergikum.

A 55-year-old chemical laboratory technician developed mydriasis and ocular hypertension, which lasted for 6 weeks, after synthesizing several kilograms of a scopolamine-related test agent with anticholinergic action and then decanting a powdery intermediary substance, the dust of which he may have inhaled. Six weeks later he suddenly had symptoms of an acute intoxication while synthesizing a scopolamine-related substance. The anticholinergic delirium regressed completely within one day requiring no treatment. But subsequently he developed symptoms of a toxic encephalopathy. This only partially regressed over the following 3 years. Its probable cause is thought to have been either the manifestation of an already existing organic cerebral psychiatric syndrome or an as yet unknown effect of the test substance.

Idiopathic extension contracture of the cervical spine: a report of two cases.

Two cases of a previously undescribed condition are reported. Both patients had an extension contracture of the cervical spine, secondary to a tight ligamentum nuchae. This condition has not been described in patients without an underlying disease process.

Multiple pterygium syndrome. An overview.

The longitudinal course of two sisters with multiple pterygium syndrome is reported. The findings in these siblings are compared with those of 27 children described in the medical literature. The longitudinal course of short stature, scoliosis, talipes equinovarus, pterygia, hearing loss, and pubertal and intellectual development in this syndrome is described. Recommendations are made for a multidisciplinary approach to individuals with multiple pterygium syndrome, which includes the services of a primary care physician, orthopedist, physical therapist, and plastic surgeon.

Improving depression severity assessment--II. Content, concurrent and external validity of three observer depression scales.

The Hamilton Depression Scale (HAMD), the Montgomery-Asberg Depression Rating Scale (MADRS) and the Bech-Rafaelsen Melancholia Scale (BRMS) were compared with respect to content, concurrent and external validity in sample of 130 patients with a major depressive episode. The three scales did equally well in concurrent and external validity. The HAMD showed some deficiencies in content validity. The consequences for depression severity assessment are discussed.

Guidelines for the use of digital tourniquets based on physiological pressure measurements.

A potential complication of a digital tourniquet is neurovascular damage due to excessive tissue pressure. A technique for measuring digital tourniquet pressures was developed in our laboratory and was tested on fresh cadaver hands in order to establish guidelines for proper application of tourniquets. A saphenous vein from a fresh cadaver was laid subcutaneously along the neurovascular bundle of the test finger. Digital tourniquets consisting of Penrose drains or rolled surgical gloves were then applied in a standardized fashion. Saline solution was injected through the saphenous vein in a quasi-static fashion using a Harvard pump, and the pressure within the vein was monitored with a pressure transducer. When the pressure within the vein reached the closing pressure generated by the tourniquet, the pressure stabilized due to leakage of fluid beyond the tourniquet. Digital tourniquets applied in customary fashion by selected physicians and surgeons produced a wide range of closing pressures that did not exceed 360 millimeters of mercury. Rolled surgical gloves produced closing pressures ranging from 113 to 363 millimeters of mercury, depending on the relationship between the size of the glove and that of the hand. Penrose drains produced closing pressures of more than 800 millimeters of mercury, depending on the amount of stretch applied.

Treatment of renal artery embolism.

Renal artery embolectomy was performed on four patients. There was no operative mortality. Four of the five affected kidneys were salvaged. The most common initial symptom was flank pain. The literature from 1970 to 1982 was reviewed to determine the current operative mortality (11%) and frequency of kidney salvage (67% to 90%) with surgery or anticoagulation. Newer treatment modalities, including intraarterially injected low-dose streptokinase and percutaneous transluminal angioplasty, have also proved useful. The addition of these newer methods, combined with the fact that kidneys can frequently be salvaged after prolonged periods of acute renal artery occlusion, led to the development of a clinical algorithm for treatment. With this algorithm, surgical embolectomy was reserved for patients with total renal parenchymal compromise caused by emboli, whose conditions failed to respond to less invasive treatment modes.

[Occupational rehabilitation of psychiatric patients--psychological diagnosis and counseling]. / Berufliche Rehabilitation psychiatrischer Patienten - psychologische Diagnostik und Beratung.

Rehabilitative measures should not set in only after a patient's discharge from hospital but already during his in-patient stay. This applies in particular relative to the occupational integration or reintegration of psychiatric patients, all the more so since rehabilitation always includes a certain measure of prevention. The author presents the system of occupational rehabilitation consulting hours practised at the Psychiatric Clinic of the University of Mainz for some 15 years now, in which some 800 patients have so far been counselled; further, the work of the clinical psychologist in the framework of this rehabilitative measure is described. The psychological evaluation methods used are presented in detail, emphasizing their importance for occupational rehabilitation. Social contacts being essential also in the working world, the relevant personality questionnaires and projective methods used are set forth, illustrating their relationship to the patient counselled.

[Development of a HAWIE (Hamburg Wechsler Intelligence Test for Adults) short form for examination and assessment]. / Entwicklung einer HAWIE-Kurzform für Untersuchung und Begutachtung.

As the use of the HAWIE complete form within the framework of conducting a forensic examination and producing an expert report seemed too extravagant to us, by means of using statistical procedures, we developed a short form consisting of the four sub-tests General Information (AW), Digit Span (ZN), Similarities (GF), and Block Design (MT), which correlated to the power of the long form (rxy = 0.905). 300 HAWIE reports by Ss, which were examined for forensic expert report purposes, served as our basis. Our new test form is to be recommended because of its great time saving factor (about 60%), especially when the question at issue within the framework of a forensic expert report is ability to feel guilt, credibility and fitness for questioning, and the general intellectual performance is to be globally determined. Advantages of our short form are economy, specific representativity and high multiple validity; it provides an ideal measuring instrument for investigators and experts.

Patterns of failure following surgery alone for colorectal carcinoma.

Two hundred fifty-one patients with colorectal carcinoma were studied following complete primary resection to determine patterns of failure. Seventy-two patients (29%) subsequently developed failures: Local failure (LF) occurred as the only failure in 49% of the failure group and as some component in 81%; distant metastases (DM) occurred in 19% and 47%, respectively. The groups at highest risk for local failure were those with extension of tumor through the bowel wall whether the nodes were involved or not. Furthermore, those with gross extension of disease through the wall developed a significantly higher incidence of distant metastases compared to those with microscopic extension through the wall (P less than 0.005). The absolute 5-year survival rate for those with tumor through the wall vs within the wall was 40% and 79%, respectively. Adjuvant therapy was discussed in view of the ability to identify subgroups of patients at highest risk for local vs distant failures.

Evaluation of adjuvant postoperative radiotherapy for lung cancer.

One hundred eighteen patients with lung cancer were retrospectively analyzed to determine whether postoperative radiotherapy (RT) improves survival. Patterns of treatment failure and three year NED (no evidence of disease) survival rates were assessed according to extent of tumor spread, histology, and treatment method. Patients with hilar or mediastinal node metastases were at higher risk of local failure compared to those with negative nodes. Postoperative RT reduced local recurrence and improved 3 year survival among patients with positive nodes. However, postoperative RT did not improve survival among those with negative nodes. Our data indicated that patients with positive hilar or mediastinal nodes may require postoperative RT to improve survival.

Carcinoma of the lung: evaluation of histological grade and factors influencing prognosis.

The results in 96 patients with lung cancer who underwent lobectomy or pneumonectomy were analyzed. In reviewing the case histories of these patients, it became apparent that those with poorly differentiated tumor (grade 3) have an increased likelihood of positive lymph node metastases compared with those with well-differentiated (grade 1) or moderately differentiated (grade 2) tumor. Poor differentiation of the tumor, vascular invasion, and lymph node metastases appear to represent poor prognostic indices in patients undergoing operation. Compared with patients with grade 1 and grade 2 tumors, patients with a grade 3 adenocarcinoma had more local recurrences, while those with grade 3 squamous cell carcinoma had more distant metastases. The findings suggest that histological grading is an important adjunct to the clinical evaluation of and planning of treatment for patients with lung cancer.

The role of vascular laboratory criteria in the selection of patients for lower extremity amputation.

We evaluated clinical and vascular laboratory data on 126 patients with below-knee or forefoot amputation. Vascular laboratory examination included Doppler systolic blood pressure and arterial wave form analysis using the segmental plethysmograph. Fifty-four patients had below-knee amputation. A calf systolic pressure greater than 70 torr was associated with 97% (33/34) success (p less than 0.005), an ankle systolic pressure greater than 30 torr yielded 91% (39/43) success (p less than 0.025), and an ankle systolic pressure greater than zero yielded an 87% success (p less than 0.005). In the absence of each of the above criteria, the predictive value of a negative test was only 32%, 40%, and 52%, respectively. The presence of a popliteal pulse was associated with 97% success (p less than 0.025); however, 88% of those with an absent popliteal pulse also achieved successful healing of below-the-knee amputations. Prior vascular reconstructive surgery was detrimental to healing of below-knee amputations. with 33% failure rate (p less than 0.025). For the 72 forefoot amputations, an ankle systolic pressure greater than 70 torr yielded a 65% success (p less than 0.025). The sensitivity of an ankle systolic pressure greater than 70 torr was 80% (32/40) and an ankle systolic greater than 35 yielded a sensitivity of 95% (38/40). The specificity was low for both of these reference values. Clinical and vascular laboratory criteria can identify patients who will have a successful below-knee amputation; however, because of the high false negative rate, patients should not be denied below-knee amputation solely on the basis of Doppler systolic pressure. Vascular laboratory criteria for predicting healing of forefoot amputations are also limited by the high rate of false positive and false negative results.

Avulsion of the innominate artery from the aortic arch associated with a posterior tracheal tear.

The management of a patient with avulsion of the innominate artery from the aortic arch associated with a longitudinal tear on the posterior aspect of the trachea is discussed. It is obviously important to make both diagnoses preoperatively to determine priorities in the surgical management. If the airway injury can be managed by tracheal intubation, then it is recommended that the vascular injury be repaired first. If there is a persistent air leak with respiratory distress, then it is necessary to repair the tracheal injury before performing the vascular procedure. In some patients it may be appropriate to treat the tracheal injury nonoperatively.