Crystallographic studies on the ribosome, a large macromolecular assembly exhibiting severe nonisomorphism, extreme beam sensitivity and no internal symmetry.

Crystals, diffracting best to around 3 A, have been grown from intact large and small ribosomal subunits. The bright synchrotron radiation necessary for the collection of the higher-resolution X-ray diffraction data introduces significant decay even at cryo temperatures. Nevertheless, owing to the reasonable isomorphism of the recently improved crystals of the small ribosomal subunits, reliable phases have been extracted at medium resolution (5-6 A) and an interpretable five-derivative MIR map has been constructed. For the crystals of the large subunits, however, the situation is more complicated because at higher resolution (2.7-7 A) they suffer from substantial radiation sensitivity, a low level of isomorphism, instability of the longest unit-cell axis and nonisotropic mosaicity. The 8 A MIR map, constructed to gain insight into this unusual system, may provide feasible reasoning for the odd combination of the properties of these crystals as well as hints for future improvement. Parallel efforts, in which electron-microscopy-reconstructed images are being exploited for molecular-replacement studies, are also discussed.

Cost-effective health information systems: user-driven internal development at the University of Iowa.

GOALS: The Information Network For Online Retrieval & Medical Management (INFORMM), health information system (HIS) for the University of Iowa Hospitals and Clinics (UIHC), was analyzed with regard to development of a Computer-Based Patient Record (CBPR) in a cost-effective manner. The analysis: i) profiles INFORMM system functionality; ii) displays INFORMM use and satisfaction among physicians, nurses, and other hospital employees; iii) characterizes dynamics affecting INFORMM growth; and iv) evaluates the cost of a system of internal-development of software. DATA SOURCES: INFORMM utilization for 1989, 1994, and 1995; service requests from users for the years 1985, 1990, and 1994; 1994 MECON-PEERx data; gap analysis user survey conducted by an independent consulting firm. MAIN RESULTS: 1) Physician use has been dominated by a single function: retrieval of laboratory results. 2) Nurse use of the system was more diverse. A recent surge of nurse and physician use resulted from the introduction of online documentation of nursing care. 3) Overall use has been predominantly by non-clinician users, no one function dominating their pattern of use. 4) User service requests were predominantly from the non-clinician group of users. Requests from non-physician groups have been coordinated by a limited number of representatives of those groups, unlike requests from physicians. 5) The UIHC HIS ranked high in user satisfaction. 6) The overall cost of the UIHC HIS system is relatively low as a percentage of the gross operating budget or as a ratio to the volume of patient activities in this medical center. CONCLUSIONS: Internal development of INFORMM has been a cost-effective solution to the information demands of nursing staff and other users. INFORMM system composition reflects the quantity and organization of user requests. Satisfying the needs of physicians requires a change in the manner in which physician needs are assessed.

[Infratentorial and craniospinal osseous anomalies--incidence and clinical significance]. / Knöcherne infratentorielle und kraniospinale Anomalien--Häufigkeit und klinische Bedeutung.

A comprehensive summary is given about the clinical importance of bony dysplasias of occipitocervical region. An informative case history from among the authors cases, in which the extent of the bony craniospinal malformation was 0.38%, is used to show that such disorders are often not recognized at first.

[Intracranial teratoma of excessive clinical latency--case report]. / Intrakranielles Teratom übermässiger klinischer Latenz--Kasuistischer Beitrag.

The contribution deals with an intracranial teratoma that seems unusual with regard to the discrepancy between the volume of the tumour and the duration, 56 years, of its clinical latency.

[Artificial stenosis of the left vertebral artery in the rabbit]. / Die artifizielle Stenosierung der A. vertebralis sinistra beim Kaninchen.

Animal experiments were carried out to clarify if a unilateral stenosis of the vertebral artery leads to a typical symptomatology and if a surgical therapy may be promising. The left vertebral artery was stenosed in 12 rabbits. The result was checked for 3 weeks electro-encephalographically and doppler-sonographycally. Conclusions after this long-term experiment: 1) A unilateral stenosis of the vertebral artery leads to a brain stem symptomatology. 2) This symptomatology shows determined development in dependence of the time. 3) Correlates of the brain stem lesion by vertebral stenosis were discovered electroencephalographically they were increased by specific activation methods. 4) The expected success produced the operative removal of the artificial stenosis of the vertebral artery. 5) The blood flow of the vessels which are of interest could be controlled by means of the ultrasound doppler-sonography during the whole experiment.

[Neurosurgical treatment variants of rheumatogenic dislocation of the occipito-cervical transition]. / Neurochirurgische Behandlungsvarianten der rheumatogenen Subluxation des okzipito-zervikalen Ubergangs.

Part of the rheumatogenic suboccipital subluxations are associated with mainly progressive neurological deficiencies involving the danger of a brain-stem irrigation with a sudden lethal outcome. On the basis of the author's casuistics (three cases), the problem of a surgical treatment is discussed.

[Sacrococcygeal chordomas--peculiarities of their morphology, clinical aspects, diagnosis and therapy]. / Sakrokokzygeale Chordome--Besonderheiten ihrer Morphe, Klinik, Diagnose und Therapie.

Sacro-coccygeal chordomas are discussed with respect to particularities of their morphology, clinical aspects, diagnosis and therapy, including two cases treated by the authors. The consideration of almost always ignored or misinterpreted initial lumboischialgia is pointed out. Because of the primary benign growth of these tumours, early diagnosis and immediate radical surgical treatment would possibly increase the survival chance of their carriers or even--so far only a speculation--lead to permanent curing.

[Diagnosis and surgical indications in brachial plexus injuries]. / Diagnostik und Operationsindikation bei Plexus-brachialis-Verletzungen.

The application of microsurgery is suited to enlarge the indication to operative interventions in lesions of the brachial plexus and to improve the results of their neurosurgical treatment. On the basis of a follow-up study of an adequate clinical material consisting of 16 patients during the last 4 years the results of the treatment report and postulates are formulated concerning the pre-examinations, the indication and the neurosurgical approach.

[Problem of the early recognition of spinal cord tumors]. / Zur Problematik der Früherkennung der Rückenmarkstumoren.

Two thirds of a group of patients with 40 space-restricting processes in the region of the spinal canal were submitted to an operation in the stage of an incomplete transverse syndrome. A striking fact was that these patients had tumours of different histological classifications which were localised in the thoracic and thoraco-lumbal transitional region Tumours in the cervical and cervico-thoracic transitional region were mainly operated on in their early stages. They had a considerably shorter period of anamnesis from the beginning of the clinical symptoms up to the operation. A cause of the different periods of anamnesis with different localisations is discussed.

[The treatment of carotico-cavernous fistulas, past and present (author's transl)]. / Historisches und Aktuelles in der Behandlung von Karotis interna- Sinus cavernosus-Fisteln.

Even at the present time, the surgical treatment of carotico-cavernous fistulas still presents problems. The author gives a brief review of the diagnosis, incidence and pathology and a detailed survey of the earlier methods of treatment, as well as those used at present, particular attention being drawn to the intravascular invasive procedures. It appears appropriate to rationalize the methods used today, namely ligation, embolization and coagulation. The author describes the use of his own successful method, in which injection of a tissue adhesive with an acrylate base (FIMOMED) through a double lumen microcatheter remains the method of choice.

[Diagnosis of brain abscesses by angiography and nuclear medicine methods]. / Diagnostik von Hirnabszessen mit Angiographie und nuklear-medizinischen Methoden.

In most cases, abscesses are formed otogenically or rhinogenically. The clinical symptoms may be uncharacteristic. The diagnosis is made by employing nuclear-medical and angiographic procedures. In 40 patients suspected of having a cerebral abscess, transfemoral cerebral angiography and in 14 cases gammaencephalography or cerebral scintigraphy was carried out. Angiographically, cerebral abscesses mostly appear as avascular growths while nuclear-medical or localised increase in the activity concentration suggests a pathological finding. The symptoms are uncharacteristic and can only be attributed to an abscess process in connection with clinical and paraclinical findings.

[Surgical treatment of occlusive intracranial cerebrovascular disorders (author's transl)]. / Die chirurgische Behandlung intrakranieller Gefässverschlüsse.

Management of intracranial cerebral circulatory disorders represents a relatively new interesting and delicate field in neuro--and vascular surgery. Today, we know the reconstructive and constructive microsurgical approach to brain vessels in man. Most surgeons practise the constructive procedure. The authors criteria for selection of patients are presented. The aim of surgical therapy is to increase the blood flow because retrograde blood supply by the collateral system is anatomically or functionally insufficient.