Pseudomembranous colitis: spectrum of imaging findings with clinical and pathologic correlation.

Pseudomembranous colitis (PMC) is a potentially life-threatening acute infectious colitis caused by one or more toxins produced by an unopposed proliferation of Clostridium difficile bacteria. PMC is characterized by the presence of elevated, yellow-white plaques forming pseudomembranes on the colonic mucosa. These plaques can be visualized at both pathologic analysis and endoscopy. Plain radiography, contrast enema studies, and computed tomography (CT) are useful in the evaluation of PMC. Plain radiography of the abdomen can demonstrate polypoid mucosal thickening, "thumbprinting" (wide transverse bands associated with haustral fold thickening), or gaseous distention of the colon. A toxic megacolon with distention and occasionally pneumoperitoneum may be seen in the most severe cases of PMC involving perforation. At contrast enema studies, the primary finding in mild cases of PMC is small nodular filling defects representing the mucosal plaques. With more extensive colonic involvement, the plaques are larger and coalesce to form an irregular bowel wall margin. Mural thickening and wide haustral folds caused by intramural edema may also be seen. A contrast enema study is contraindicated in patients with severe PMC due to the danger of perforation. Common CT findings include wall thickening, low-attenuation mural thickening corresponding to mucosal and submucosal edema, the "accordion sign," the "target sign" ("double halo sign"), pericolonic stranding, and ascites. Familiarity with these imaging characteristics may allow early diagnosis and treatment and prevent progression to more serious pathologic conditions.     

Correlation of tensile strength with bursting pressure in the evaluation of intestinal anastomosis

BACKGROUND: Although bursting pressure and tensile strength have long been measured to evaluate anastomotic techniques, it has yet to be clarified whether or not they are correlated, what implications they have, and which should be used as a gold standard. MATERIAL AND METHODS: Using an experimental model to estimate pressure and tension in the same colonic anastomosis, the following variables were measured in 48 rats between days 0 and 14: bursting pressure (BP); minimal tensile strength (MITS) necessary to break a part of the anastomosis, and maximal tensile strength (MATS) needed to disrupt the whole anastomosis. Also, circulatory wall tension (CWT) was derived from BP and the anastomotic circumference (AC), and longitudinal wall tension (LWT) from MITS and AC. These variables were compared using correlation and regression analysis. RESULTS: During the lag phase (days < or = 4) there was poor correlation between pressure-related and tension-related variables whereas highly significant correlations were noted in the subsequent fibroplastic phase (day > or = 5). It was shown by regression lines that positive MITS and MATS were expected when BP was zero. CONCLUSION: Contrary to the previous assumption, no correlation was found between BP and tensile strength in the critical postoperative period. Based on our present and previous studies, measurement of MITS is recommended to evaluate the healing of colonic anastomosis.     

Aesthetic Male Facial Skeletal Surgery

Craniofacial surgery concepts developed originally for reconstruction may also be applied to aesthetic surgery. The facial skeleton is an important component of appearance and may be modified using common craniofacial surgery techniques. Three representative male patients are presented, who each desired an improvement in his appearance. The techniques used were different and combined orthognathic and remodeling procedures. Aesthetic male facial skeletal surgery was beneficial in these selected cases. The results were well received and without complications. Surprisingly, we have found that male skeletal aesthetic patients did not have unrealistic expectations and were pleasant to manage pre- and postoperatively.     

Gamete development inPlasmodium berghei regulated by ionic exchange mechanisms

Ionic regulation in the induction of exflagellation ofPlasmodium berghei was investigated by culturing the parasites in various isotonic media. Of the salts tested, NaHCO₃ exhibited the highest activity in inducing exflagellation, whereas KHCO₃ showed no activity. In the absence of HCO ₃ ^– , media containing monovalent cation (Na⁺, K⁺, Cs⁺, Rd⁺, choline⁺, lysine⁺, arginine⁺) and Cl^– also induced exflagellation, but their activities were lower than that of NaHCO₃. Anions of Br^– or NO ₃ ^– could be substituted with Cl^–, whereas other anions such as I^–, NO ₂ ^– , SO ₄ ^2– , SCN^–, H₂PO ₄ ^– , or HPO ₄ ^2– failed to induce exflagellation, as did tetramethylammonium-Cl, CaCl₂, MgSO₄, MgCl₂ and sucrose as well. These results suggest that the induction of exflagellation requires the presence of Na⁺ and HCO ₃ ^– or monovalent, membrane-permeable cation and Cl^– in the medium. Measurements of the efflux of H[¹⁴C]O ₃ ^– or Cl^– indicated that these anions were released from the cells into the NaCl or the NaHCO₃ medium, respectively, probably by exchange in HCO ₃ ^– /Cl^–. Determination of intracellular ionic concentrations by electron microscopic X-ray microanalysis of cryopreserved specimens revealed that in the NaHCO₃ medium, external Na⁺ (and probably HCO ₃ ^– ) enters the gametocytes by exchange with internal Cl^– (and probably H⁺), whereas in Cl^–-containing media, external unspecified cation and Cl^– influx by exchange, probably with H⁺ and HCO ₃ ^– . It is therefore suggested that two separate ion exchangers, i.e., Na⁺-dependent HCO ₃ ^– (in)/Cl^–(out) and nonspecific monovalent-cation-dependent Cl^–(in)/HCO ₃ ^– (out) exchangers, are involved in the induction of gametogenesis inP. berghei. Furthermore, the presence of both classes of anion in the medium enhanced exflagellation activity and increased Na⁺ uptake more than did the NaCl or NaHCO₃ medium alone. The apparent synergistic enhancement by two contraactive anion exchangers is consistent with a recycling model of pH_i regulation, in which HCO ₃ ^– and Cl^– are exchanged between the cells and the media, resulting in the acceleration of monovalent cation/H⁺ exchange.This work was supported by a Grant-in-Aid (No. 01570212) from the Ministry of Education, Science and Culture, Japan and the Ohyama Health Foundation, Japan (to FK), and in part by the Medical Research Council, United Kingdom (to RES)     

The latest innovations in the operation of en-bloc resection on the frontal skull base

We have organized skull base surgery teams with otolaryngologists, neurosurgeons and plastic surgeons since 1993 and managed frontal skull base malignancies by a combined transbasal and transfacial approach. However, in the maneuvers, several problems are yet to be solved in minimizing tumor recurrence and postoperative complications. We have recently developed a microscopic en-bloc resection method assisted by an endoscope, and VFOT flap (vascularized frontal outer table flap) for the reconstruction on the frontal skull base. The VFOT flap can be elevated simultaneously with bifrontal craniotomy. The pedicled calvarian bone is split, and the frontal outer table with the pericranium is placed on the frontal base defect caused by the tumor resections. Those procedures seem to be useful for skull base surgery, and easy to perform for neurosurgeons.     

Subjective and functional results after total gastrectomy: prospective study for longterm comparison of reconstruction procedures

Background: Many reconstruction procedures have been developed in efforts to resolve patients' complaints after total gastrectomy. However, there have been few reports of longterm comparisons between reconstruction procedures, especially with regard to the prevention of duodenal food passage. This study was undertaken to compare the longterm subjective and functional results among Roux-en-Y esophagojejunostomy (R-Y), R-Y with pouch (P-Y), and jejunal interposition with pouch (P-I) after total gastrectomy. Methods: Consecutive patients requiring curative total gastrectomy were enrolled in this prospective study by the envelope method. Results: Hospital stay was longer following a P-I than an R-Y or a P-Y. Over 50% of R-Y patients complained of heartburn, and 20% of R-Y patients showed dumping syndrome throughout the postoperative period, with this rate being significantly different from rates in the other two groups. P-Y patients complained of early satiety in the late postoperative period, while P-I patients complained of early satiety in the early postoperative period. The nutritional index in P-I patients was higher than those in patients with the other two procedures. Gastrointestinal and hepatobiliary dual scintigraphy (GHDS) showed that the rate of bile reflux with an R-Y was relatively high after surgery. Food reflux with a P-Y was increased (9.4% to 11.1%), but with a P-I food reflux was decreased at 3 years after surgery (13.3% to 9.9%). Patients with a P-Y had a faster recovery of body, weight in the early postoperative period; however, at 5 years after operation, body weight recovery with a P-I was greatest. Conclusion: Reconstruction should be performed with pouch formation after total gastrectomy with curative intent. Received: March 7, 2002 / Accepted: September 26, 2002 Acknowledgments This study was partly supported by the University of Tsukuba Research Project. Offprint requests to: S. Adachi     

Seasonal changes in calcium homeostasis affect the incidence of postoperative tetany in patients with Graves' disease

BACKGROUND: We have found that postoperative tetany occurs in patients with Graves' disease who have secondary hyperparathyroidism caused by a deficiency in calcium and vitamin D concomitant with transient hypoparathyroidism after surgery. There are seasonal variations in serum 25-hydroxyvitamin D (25[OH]D) concentrations. The purpose of this study was to investigate the effects of seasonal changes in calcium homeostasis on the incidence of postoperative tetany in patients with Graves' disease who undergo subtotal thyroidectomy. PATIENTS AND METHODS: A prospective study was carried out to investigate sequential changes in serum levels of intact parathyroid hormone (iPTH), calcium and other electrolytes, 25(OH)D, and 1,25-dihydroxyvitamin D (1,25[OH]2D) in female patients with Graves' disease who underwent subtotal thyroidectomy during the summer (n = 89) and during the winter (n = 89). RESULTS: The serum levels of calcium, magnesium, and 25(OH)D were significantly higher, but iPTH levels and 1,25(OH)2D levels were lower in summer than in winter. The percentage of vitamin D deficiency (25(OH)D < 25 nmol/L) was 23% in summer and 62% in winter (P < .001). iPTH was below the detection limit on the first postoperative day in 15 patients (13.8%) in summer and in 13 patients (11.4%) in winter. In summery, tetany developed in only 4 of 15 patients and in one patient whose iPTH level was below normal (incidence of tetany, 5.6%). In winter, however, tetany developed in 6 of 13 patients and in 4 patients whose iPTH level was below normal (incidence of tetany, 11.2%). CONCLUSIONS: Patients with Graves' disease are more susceptible to calcium and vitamin D deficiency during the winter than during the summer, resulting in the tendency toward a higher incidence of postoperative tetany in winter.     

Longitudinal elongation of primary afferent axons in the dorsal funiculus of the chick embryo spinal cord

The longitudinal elongation of primary afferent axons (PAAs) in the dorsal funiculus of chick embryo spinal cord was examined using a lipophilic tracer, DiI and immunohistochemistry. The earliest developing PAAs in the brachial segments invaded the spinal cord around embryonic day (E) 3.5. Thereafter, they elongated both rostrally and caudally in the presumptive dorsal funiculus, with frequent contacts between pre-existing axons and later arriving growth cones. By E4, the PAAs had elongated 3 segments both rostrally and caudally. In the course of their longitudinal elongation, the PAAs shifted their trajectory dorsally within the dorsal funiculus. By E6-6.5, the PAAs had extended as far as 10 segments rostrally and 6 segments caudally in the dorsal funiculus, and collaterals began to enter the dorsal horn. By E9, the PAAs extended up to 13 segments rostrally and 7 segments caudally, and collaterals reached the ventral spinal cord. During their longitudinal course, the PAAs shifted their trajectory medially within the dorsal funiculus.