Precentral glioma location determines the displacement of cortical hand representation

OBJECTIVE: Low-grade brain tumors may remain asymptomatic in contrast to malignant gliomas. The mechanisms underlying the preservation of cerebral function in such gliomas are not well understood. METHODS: We used positron emission tomography and transcranial magnetic stimulation for presurgical monitoring of motor hand function in six patients with gliomas of the precentral gyrus. All patients were able to perform finger movements of the contralesional hand. RESULTS: Movement-related increases of the regional cerebral blood flow occurred only outside the tumor in surrounding brain tissue. Compared with the contralateral side, these activations were shifted by 20 +/- 13 mm (standard deviation) within the dorsoventral dimension of the precentral gyrus. This shift of cortical hand representation could not be explained by the deformation of the central sulcus as determined from the spatially aligned magnetic resonance images but was closely related to the location of the maximal tumor growth. Dorsal tumor growth resulted in ventral displacement of motor hand representation, leaving the motor cortical output system unaffected, whereas ventral tumor growth leading to dorsal displacement of motor hand representation compromised the motor cortical output, as evident from transcranial magnetic stimulation. In two patients, additional activation of the supplementary motor area was present. CONCLUSION: Our data provide evidence for the reorganization of the human motor cortex to allow for preserved hand function in Grade II astrocytomas.     

Immunolocalization of basic fibroblast growth factor and fibroblast growth factor receptor-1 and receptor-2 in rat cranial sutures

Craniosynostosis is a common disorder with an unknown etiology. Recent genetic mapping studies have demonstrated a strong linkage between several familial craniosynostotic syndromes and mutations in fibroblast growth factor receptor 1 (FGF-R1) and 2 (FGF-R2). The purpose of this experiment was to investigate by immunohistochemistry the protein production of these receptors as well as of their most prevalent ligand, basic fibroblast growth factor (bFGF), before, during, and after sutural fusion in rat cranial sutures. The posterior frontal (normally fuses between postnatal days 12 and 22) and sagittal (remains patent) sutures of embryonic day 20 and neonatal days 6, 12, 17, 22, and 62 (n = 3 per group) were harvested, fixed, and decalcified. Five-micrometer sections were stained with polyclonal antibodies against bFGF, FGF-R1, and FGF-R2, and patterns of immunohistochemical staining were assessed by independent reviewers. Our results indicate that increased bFGF production correlates temporally with suture fusion, with increased staining of the dura underneath the fusing suture prior to fusion followed by increased staining within osteoblasts and sutural cells during fusion. FGF-R1 and, to a lesser extent FGF-R2 immunostaining revealed a different pattern of localization with increased immunostaining within the patent sagittal suture at these time points. These results implicate bFGF in the regulation of sutural fusion and may imply autoregulatory mechanisms in fibroblast growth factor receptor expression.     

Long-term results of the Angelchik prosthesis for gastro-oesophageal reflux

INTRODUCTION: Between 1982 and 1989, 46 patients had insertion of an Angelchik prosthesis for gastro-oesophageal reflux. Eleven patients (24 per cent) subsequently had the prosthesis removed, all but one for intractable dysphagia. METHODS: Thirty-six of the original patients were followed by questionnaire, and 32 of these had a barium marshmallow swallow investigation. RESULTS: A high proportion of patients (20 of 26) with a prosthesis in situ had symptoms of dysphagia. On objective evaluation by marshmallow swallow, the transit time was significantly slower than that of an age-matched control group (P < 0.01), but showed no significant deterioration with time compared with previous postinsertion studies. CONCLUSION: The Angelchik prosthesis causes long-term dysphagia in a high proportion of patients, severe enough in one-quarter to necessitate its removal. Its continued use cannot, therefore, be recommended.     

Predictive value of letters of recommendation vs questionnaires for emergency medicine resident performance

OBJECTIVE: To evaluate the predictive value of standard letters of recommendation (LORs) vs preprinted questionnaires (PPQs) for resident performance at one emergency medicine (EM) residency program. METHODS: A retrospective association of LORs and PPQs with in-training residents performance ratings was done at one EM residency program. The residency application files of EM residents who completed the program were reviewed to locate files that had LORs and PPQs written by the same author. Seventeen resident files contained 32 LOR/PPQ pairs. These LORs and PPQs were submitted in a blinded fashion to 3 outside EM residency directors. Each LOR and PPQ was evaluated for the applicant's suitability for the specialty of EM, medical knowledge, procedural skills, interpersonal skills, motivation, and overall rank. The scores given by the outside reviewers were compared with resident performance ratings determined by 5 EM attending physicians who evaluated the residents along the same 6 dimensional ratings. RESULTS: Statistically, no differences were found between the LORs and PPQs in predicting resident performance. CONCLUSIONS: PPQs may substitute for LORs in the evaluation of resident applicants.     

State-related changes in upper airway caliber and surrounding soft-tissue structures in normal subjects

State-dependent changes in upper airway caliber were studied with magnetic resonance imaging (MRI) techniques. We hypothesized that changes in airway caliber during sleep in normal subjects would result from positional and dimensional changes in upper airway soft-tissue structures, including the lateral pharyngeal walls, tongue, and soft palate. We used MRI to study 15 normal subjects during wakefulness and sleep. Sleep was facilitated by one night of sleep deprivation prior to MRI. During sleep, the volume of the retropalatal (RP) airway was reduced by 19% (p = 0.03). The volume of the retroglossal (RG) airway was not significantly reduced during sleep, suggesting that the RP region may be more likely to collapse. The mean minimal cross-sectional airway area was reduced by 228% (p = 0.004) in the RP and by 22% (p = 0.02) in the RG region during sleep as compared with values in anatomically matched axial images during wakefulness. Airway anteroposterior (AP) and lateral dimensions were also significantly reduced in the RP region. Airway narrowing in the RP region was associated with a 7% increase in thickness of the lateral pharyngeal walls (p = 0.04). In nine subjects, sagittal data showed significant posterior displacement of the soft palate during sleep as compared with wakefulness. Multiple linear regression analyses indicated that reduction in the RP airway area during sleep resulted from posterior movement of the soft palate, thickening of the lateral pharyngeal walls, and an increase in tongue oblique distance. We conclude that the lateral pharyngeal walls play an important role in upper airway narrowing during sleep in normal subjects.     

Interinstitutional comparison of frozen section consultations. A college of American Pathologists Q-Probes study of 90,538 cases in 461 institutions

OBJECTIVE: To assess concordant, discordant, and deferred diagnosis rates from frozen sections; to determine reasons for discordance; to identify pathologic processes associated with discordant diagnoses; to determine false-positive or false-negative rates for neoplasms; and to identify anatomic sites associated with discordant frozen section diagnoses. DESIGN: Q-Probes study of the College of American Pathologists. PARTICIPANTS: Four hundred sixty-one institutions participating in the Q-Probes program from November 1, 1990, through March 31, 1991. MAIN OUTCOME MEASURES: Concordant and discordant diagnosis rates. RESULTS: The frozen section concordance rate for diagnoses from the aggregate group was 98.58% and the discordance rate was 1.42%, when uncorrected for deferred diagnoses. During the study period, participating institutions accessioned 1,693,331 surgical pathology cases; 90,538 of these cases were evaluated by frozen section consultation, resulting in the examination of 121,668 specimens and 148,506 frozen section blocks. The majority of the frozen section discordances occurred because of misinterpretation of the original frozen section (31.8%), presence of diagnostic tissue in permanent sections of the frozen block when the frozen section was negative (30.0%), and presence of diagnostic tissue in the portion of the specimen not sampled by the frozen section (31.4%). Of the discordant diagnoses, 67.8% had false-negative diagnoses for neoplasm. The pathology processes and anatomic sites represented in discordant diagnoses are also evaluated. CONCLUSIONS: High diagnostic accuracy of frozen section consultations was demonstrated. Frozen sections are used to evaluate a variety of pathologic processes and anatomic sites.     

Differential response of glomerular epithelial and mesangial cells after subtotal nephrectomy

Recent studies in both human and experimental chronic renal disease suggest that there is a linkage between glomerular hypertrophy and glomerulosclerosis. To further define these relationships, we studied the changes in glomerular hypertrophy, procollagen alpha 1(IV) mRNA levels and glomerulosclerosis in rats undergoing 1 2/3 nephrectomy (Nx) or sham nephrectomy (SNx). Glomerular hypertrophy, measured biochemically by RNA/DNA and protein/DNA ratios, was significantly increased in Nx compared to SNx two days after subtotal renal ablation (RNA/DNA: Nx = 133 +/- 8%, SNx = 100 +/- 3% of the mean control value, P < 0.01; protein/DNA: Nx = 164 +/- 22%, SNx = 100 +/- 10%, P < 0.05) and remained elevated after 7 and 15 days (RNA/DNA: seven days Nx = 155 +/- 3%, SNx = 100 +/- 13%, P < 0.01; 15 days Nx = 303 +/- 21%, SNx = 100 +/- 24%, P < 0.001; protein/DNA: seven days Nx = 228 +/- 57%, SNx = 100 +/- 18%, P < 0.05; 15 days Nx = 341 +/- 23%, SNx = 100 +/- 18%, P < 0.01). Light microscopic measures of glomerular tuft volume (GTV) were too insensitive to detect glomerular enlargement until 15 days postoperatively, but GTV measured ultrastructurally demonstrated a 20% increment in Nx compared to SNx as early as two days postoperatively (P < 0.01). The latter increment in GTV was due exclusively to glomerular visceral epithelial cell (GVEC) expansion. Glomerular procollagen alpha 1(IV) mRNA levels were significantly elevated only 15 days after nephrectomy (Nx = 265 +/- 58% of the mean control value, SNx = 100 +/- 12%, P < 0.05; corrected for beta-actin mRNA levels). As this time, exuberant mesangial expansion measured ultrastructurally contributed to a 1.6 +/- 0.1-fold increase in GTV (P < 10(-5)), and to a relative decrement in the GVEC contribution to glomerular cells plus matrix (P < 0.01). Segmental sclerosis was observed only 15 days postoperatively in Nx (Nx = 1.3 +/- 0.4% of glomeruli evaluated, SNx = 0.0%, P < 0.05), and there was a strong correlation between the prevalence of segmental sclerosis and the procollagen alpha 1(IV) mRNA levels in Nx at 15 days (r = 0.93, P < 0.01). There was no significant correlation between the RNA/DNA and protein/DNA ratios and procollagen alpha 1(IV) mRNA levels. Thus, glomerular regions responded differentially to subtotal nephrectomy. Early epithelial cell expansion was followed by later mesangial expansion. Glomerular procollagen alpha 1(IV) mRNA levels were elevated only during the second (mesangial) phase of glomerular hypertrophy, when it correlated with glomerulosclerosis, but not during the initial (epithelial) phase, a pattern consistent with a mesangial origin of the procollagen alpha 1(IV) mRNA.     

The intake of proteins and essential amino acids in top-competing women athletes]

PURPOSE: The literature on diagnostic peritoneal lavage in the assessment of blunt abdominal trauma reflects an ongoing controversy. Therefore we conducted a prospective evaluation of the diagnostic management of blunt abdominal trauma used at our clinic, in which this procedure plays a substantial role. During the years 1993 and 1994 a total of 75 patients could be included in the study. The study population consisted of all patients with a diagnosis of blunt abdominal trauma. In addition, all trauma patients who were unresponsive on admission to the emergency receiving unit underwent the same program of diagnostic work-up. This group included polytraumatized patients, patients with craniocerebral injuries and all those who had been intubated prior to admission. Patients with stable vital signs were evaluated first by sonography of the abdomen, whereas those showing signs of hypovolemic shock received a diagnostic peritoneal lavage as the first evaluation of abdominal trauma. In order to assess the relative value of the two diagnostic methods, all patients who had had ultrasound as their first examination subsequently also underwent peritoneal lavage. RESULTS: 37 patients (49%) had lavage evidence of intraperitoneal bleeding. Of these 22 (29% of the total) subsequently underwent emergency laparotomy with lesions requiring surgical treatment found in 21 (95%). Only in one patient (1.3% of the study population) laparotomy failed to reveal a lesion requiring surgical correction. The accuracy of peritoneal lavage findings as an indication for laparotomy was 99%, compared to 82% for ultrasonography used as a initial diagnostic procedure. Diagnostic peritoneal lavage is quick, safe and almost independent of the experience of the investigating physician. It can be performed during other diagnostic procedures and can be repeated at will. If beyond macroscopical evaluation the lavage fluid is assessed chemically, even duodenal and pancreatic lesions as well as injuries to other hollow viscera can be suspected. With a sensitivity of 100% and a specificity of 98%, diagnostic peritoneal lavage is an extremely reliable diagnostic tool. It should be used as the initial diagnostic procedure in all hypovolemic and/or unresponsive patients suspected of having suffered blunt abdominal trauma. In conscious patients with stable vital signs, ultrasonography can be used for initial diagnosis. It should, however, be complemented by subsequent peritoneal lavage whenever the clinical course gives rise to suspicion.