A new view of things

Ohne Zusammenfassung     

The role of scintigraphy in the diagnosis of mandibular bone changes

Investigating the scintigraphic images of jaws may have a diagnostic value of bone alterations of dental origin. Anterior view of whole body bone scintigraphy revealed hot spot on jaws of 61% (279) of patients. Twenty-six patients (mean age 58.3 year) from all of those who had increased tracer uptake (ITU) in the maxillo-mandibular region were called back for dental examination. 279 out of 459 (61%) patients had ITU in the maxillo-mandibular region. Dental examination revealed the dental origin of ITU in all cases. In case of periapical pathosis tracer uptake showed 28.79% increase compared to the contralateral side. In marginal periodontitis 23.82% ITU was found. In case of loading due to prosthesis 13.06% ITU was observed. The mean DMF-T value was 26.36 +/- 4.52 (D = 4.12, M = 20.8, F = 1.44). The prosthetic index was 0.42 on the mandible. The above mentioned data mean very low oral health conditions of the patients included in this examination. The results show that bone scintigraphy is a valuable procedure in detecting tooth related jaw lesions. Bone scintigraphy provides very useful data on oral health of these patients. Enrolling of these patients into regular dental care is inevitable.     

Cerebellum and speech perception: a functional magnetic resonance imaging study

A variety of data indicate that the cerebellum participates in perceptual tasks requiring the precise representation of temporal information. Access to the word form of a lexical item requires, among other functions, the processing of durational parameters of verbal utterances. Therefore, cerebellar dysfunctions must be expected to impair word recognition. In order to specify the topography of the assumed cerebellar speech perception mechanism, a functional magnetic resonance imaging study was performed using the German lexical items "Boden" ([bodn], Engl. "floor") and "Boten" ([botn], "messengers") as test materials. The contrast in sound structure of these two lexical items can be signaled either by the length of the wordmedial pause (closure time, CLT; an exclusively temporal measure) or by the aspiration noise of wordmedial "d" or "t" (voice onset time, VOT; an intrasegmental cue). A previous study found bilateral cerebellar disorders to compromise word recognition based on CLT whereas the encoding of VOT remained unimpaired. In the present study, two series of "Boden - Boten" utterances were resynthesized, systematically varying either in CLT or VOT. Subjects had to identify both words "Boden" and "Boten" by analysis of either the durational parameter CLT or the VOT aspiration segment. In a subtraction design, CLT categorization as compared to VOT identification (CLT - VOT) yielded a significant hemodynamic response of the right cerebellar hemisphere (neocerebellum Crus I) and the frontal lobe (anterior to Broca's area). The reversed contrast ( VOT - CLT) resulted in a single activation cluster located at the level of the supratemporal plane of the dominant hemisphere. These findings provide first evidence for a distinct contribution of the right cerebellar hemisphere to speech perception in terms of encoding of durational parameters of verbal utterances. Verbal working memory tasks, lexical response selection, and auditory imagery of word strings have been reported to elicit activation clusters of a similar location. Conceivably, representation of the temporal structure of speech sound sequences represents the common denominator of cerebellar participation in cognitive tasks acting on a phonetic code.     

Heart-rate-adapted image reconstruction in multidetector-row cardiac CT: influence of physiological and technical prerequisite on image quality

The purpose of this study was to develop strategies for optimal image reconstruction in multidetector-row cardiac CT and to discuss the results in the context of individual heart rate, cardiac physiology, and technical prerequisite. Sixty-four patients underwent multidetector-row cardiac CT. Depending on the heart rate either a single-segmental reconstruction (SSR) or an adaptive two-segmental reconstruction (ASR) was applied. Image reconstruction was done either antegrade (a) or retrograde (r) in relation to the R-peak. Reconstruction of all data sets was performed at multiple time points within the t-wave/p-wave interval, differing from each other by 50 ms. In addition, each reconstruction was assigned to one of six reconstruction intervals (A–F), each corresponding to a specific event in the cardiac cycle. While no significant time points were found for absolute values, the following interval/reconstruction technique combinations provided significant better image quality: F/r at HR <60 bpm for all coronary segments (p≤0.004) and at HR 60–65 bpm for segments 5–10 (p≤0.001); B/a at HR 60–65 bpm for segments 1–4 and 11–15 (p<0.001) and at HR >65 bpm for all segments (p≤0.002). The results show that in order to achieve optimal image quality, image reconstruction has to be adjusted to each patient's ECG curve and heart rate individually. The moment of reconstruction should be determined as absolute rather than as relative distance from the previous R-peak. Electronic Publication     

The learning curve of laparoscopic cholecystectomy and changes in indications: one institutions's experience with 2,650 cholecystectomies

PURPOSE: In a prospective series of 2,650 consecutive patients undergoing cholecystectomy, we analyzed the learning curve since the introduction of laparoscopic cholecystectomy (LC) in terms of operating time, conversion rate, morbidity, mortality, and consequent changes in indications for either laparoscopic or open cholecystectomy (OC). PATIENTS AND METHODS: Between July 1990 and June 1997, LC was performed in 1,929 patients (73%), 203 of whom (7.5%) had to be converted to OC, while 518 patients (19.5%) had primary OC. Patients having LC were predominantly female, younger, with less comorbidity and less complicated gallstone disease than patients having OC. RESULTS: Barring a learning curve during the first 6 months of LC, operating time remained constant at an average of 71 minutes while operating on ever more complex pathologies. The conversion rate decreased from 9.4% to 6.7% during the 7-year period. A relatively constant team of surgeons with growing experience as well as constantly improving technical equipment allowed the complication rate to remain low. The total morbidity of LC was 2.5% (0.1% bile duct injury), that of conversions 5%, and that of OC 12.5%. The mortality was 0 for LC, 0.5% for conversions, and 1% for OC. CONCLUSION: The indications for primary OC decreased from 50% to 8.5% and the indications for LC could be broadened over the years.     

Metabolic effects of growth hormone treatment: an early predictor of growth response?

Fourteen children receiving one year of recombinant human growth hormone (rhGH) treatment underwent measurement of serial changes in body composition (measured by skinfold thickness, bioelectrical impedance, and H2(18)O dilution), resting energy expenditure (REE, estimated by ventilated hood indirect calorimetry), and total free living daily energy expenditure (TEE, measured by the doubly labelled water technique). Mean height velocity increased from 4.9 to 8.6 cm/year after six months of treatment. Fat free mass (FFM) increased more during the first six weeks (24.4 g/day) than from six to 26 weeks of treatment (6.8 g/day); fat mass decreased by 7.2 g/day and 1.1 g/day respectively. The six week increase in REE (kJ/day) was maintained after six months of treatment, though expressed per kilogram FFM (kJ/kgFFM/day), returned to pretreatment values by three months. Height velocity increases at six months correlated with six week changes in fat mass measured by skinfold thickness and REE, though use of this relationship to predict growth response in individuals is limited by the wide 95% prediction intervals. No significant changes in growth, body composition, or energy expenditure were observed between six and 12 months of treatment, in either patients who had initially responded well to treatment or those who were poor initial responders to treatment and who had their dose of rhGH doubled after six months.     

Enhanced adhesion of Pasteurella multocida to cultured turkey peripheral blood monocytes

Capsular hyaluronic acid (HA) mediates adhesion of serogroup A strains of Pasteurella multocida to elicited turkey air sac macrophages (TASM). In contrast, freshly isolated turkey peripheral blood monocytes (TPBM) do not bind serogroup A strains. Following culture of TPBM for 6 days in chamber slides, adhesion of the bacteria to TPBM increased gradually. Incubation in chamber slides coated with entactin-collagen IV-laminin (ECL) attachment matrix or exposure to phorbol myristate acetate (PMA) further enhanced the adhesion of P. multocida to TPBM. Addition of HA, but not Arg-Gly-Asp peptide, to TPBM culture inhibited bacterial adherence similarly to the inhibition previously reported for TASM. Exposure of TPBM to monoclonal antibody directed against HA-binding cell surface proteoglycan (CD44) decreased binding of P. multocida. Collectively, these findings indicate that P. multocida adhesion to TPBM is mediated by capsular HA and can be increased by culture on ECL attachment matrix or PMA exposure. Additionally, the findings suggest that the capsular mucopolysaccharide of serogroup A strains of P. multocida recognizes an isoform of CD44 expressed on cultured TPBM.     

Neonatal stroke: Clinical characteristics and cerebral blood flow velocity measurements

The clinical courses of 8 term infants with focal cerebral infarction or neonatal stroke were studied to determine whether such infants can be identified by current markers of perinatal distress, and whether changes in cerebral blood flow velocity (CBFV) occur during the acute phase of the disease. CBFV was measured from the middle cerebral artery (MCA) and anterior cerebral artery (ACA) utilizing duplex Doppler. Seven of the 8 patients required no resuscitation in the delivery room; 1 infant required brief bag and mask ventilation. No infant had evidence of severe fetal acidemia (i.e., cord pH <7). All 8 infants were initially admitted to the newborn nursery. Infants were identified on the basis of abnormal clinical findings observed during the first 48 hours: seizures (n = 6) and hypotonia and apnea (n = 2). Serum electrolytes, calcium, magnesium, and glucose levels were normal, and the sepsis evaluation including a spinal tap was sterile in all patients. Neuroimaging revealed nonhemorrhagic left focal MCA infarction (n = 6) and right focal MCA infarction (n = 2). Duplex Doppler demonstrated transient ipsilateral decreases in CBFV as compared to the contralateral unaffected side at clinical presentation in 4 infants. In 2 of these infants the decrease in CBFV involved both the MCA and ACA, and in 2 infants, only the MCA vessels. These side-to-side differences were not present at subsequent CBFV measurements. The data indicate that infants who develop neonatal stroke cannot be distinguished from infants who do not develop the lesion by current markers of perinatal distress. Because neonatal stroke frequently occurs as an unanticipated event, prevention may not be possible.     

Paraesophageal hiatal hernia--risks and surgical indications

During a 25-year period, 40 patients with paraoesophageal hiatus hernia were operated on by narrowing of the hiatus and gastropexy. The main symptoms were: epigastric pain (40%), reflux symptoms (25%), cardiac symptoms (20%), dysphagia (20%) and dyspnea (8%). Six patients were free of symptoms. Anaemia was present in 33%, gastric ulcer in 15%. Six patients (18%) had to be operated on as emergencies because of gastric ulcer complications in 4 (3 perforations, 1 severe bleeding) and incarceration in 2 patients. Considering the important risk of acute complications in paraoesophageal hernia an elective gastropexy seems generally advisible--also in patients with few or no symptoms, provided there are no contraindications.