CD8 T cell-mediated rejection of intestinal allografts is resistant to inhibition of the CD40/CD154 costimulatory pathway

BACKGROUND: Disruption of the CD40/CD154 pathway inhibits rejection in numerous models. The importance of this pathway on intestinal allograft rejection was examined in this study. METHODS: Intestinal grafts from B6C3F1 mice transplanted into C57BL/6 recipients were assessed histologically for rejection. RESULTS: The monoclonal antibody to CD154, MR1, failed to inhibit rejection in wild-type mice. Similarly, CD154-/- recipient mice rejected intestinal allografts. MR1 did inhibit early rejection in CD8-/- mice, but had no effect in CD4-/- recipients. All MR1-treated CD8-/- recipients eventually developed rejection. No benefit was observed when blockade of the CD40/CD154 pathway by MR1 was combined with blockade of the CD28/B7 pathway by mCTLA4Ig. CONCLUSIONS: These data suggest that CD4+ T cells mediating intestinal allograft rejection may be more dependent upon the CD40/CD154 pathway than CD8+ T cells. This finding highlights the importance of identifying agents that suppress CD8+ T cell-mediated rejection.     

Is it necessary to resect the diseased esophagus in performing reconstruction for corrosive esophageal stricture?

OBJECTIVE: The incidence of carcinoma of the esophagus among patients with chronic esophageal stricture caused by ingestion of corrosive agents is reported to be significantly higher than that of the general population. The question of whether or not a resection of the diseased esophagus should be included in the surgical reconstruction procedure of the undilatable esophageal stricture continues to be a controversial. METHODS: During the 12 year period from 1988 to 1999, a total of 54 consecutive patients with caustic stricture of the esophagus were treated in our department. We retrospectively reviewed these cases and analyzed the incidence of cicatrical carcinoma among the patients and the risk of esophagectomy according to the procedures performed. RESULTS: We found seven cases of esophageal cancer among these patients. There was no significant increase in mortality or morbidity related to esophagectomy. CONCLUSIONS: Considering the high incidence of cicatrical carcinoma from the stricture sites as well as the possible chance of hidden malignancy, we concluded that the simultaneous resection of the esophagus with reconstruction for patients with chronic intractable caustic stricture would give the patients a better probability of being completely cured of the disease.     

Dynamic sagittal imbalance of the spine in degenerative flat back: significance of pelvic tilt in surgical treatment

STUDY DESIGN: A retrospective study of 26 patients with degenerative flat back treated with corrective osteotomy. OBJECTIVE: To analyze dynamic sagittal imbalance and to elucidate the cause of postoperative persistent stooping in degenerative flat back. SUMMARY OF BACKGROUND DATA: Sagittal spinal imbalance in degenerative flat back was more evident on walking, suggesting its dynamic nature. The most puzzling complication in its surgical treatment was postoperative persistent stooping. METHODS: This study analyzed 26 surgically treated patients with preoperative gait analysis. Patients were divided into two groups according to postoperative improvement in stooping: Group 1 with marked improvement in stooping and Group 2 with persistent stooping. Various radiographic and gait parameters were compared between the two groups. RESULTS: Comparison of radiographic parameters, representing the static status of the spine, did not indicate any clue to the mechanism for persistent stooping. However, comparison of gait parameters, representing the dynamic status of the spine, revealed meaningful differences between the two groups. Among various gait parameters compared, pelvic tilt seemed to be the most important clue. Patients in Group 1 showed posterior pelvic tilt, whereas those in Group 2 showed marked anterior pelvic tilt. CONCLUSION: Degenerative flat back could be classified into two types based on pelvic position during walking: one with posterior pelvic tilt and the other with marked anterior pelvic tilt. In the former type, corrective surgery improved the stooping. In the latter, corrective surgery was ineffective, resulting in postoperative persistent stooping.     

Thoracic pedicle screw fixation in spinal deformities: are they really safe?

STUDY DESIGN: A retrospective study. OBJECTIVE: To determine the safety of pedicle screw fixation in thoracic deformity correction. SUMMARY OF BACKGROUND DATA: Pedicle screw fixation enables enhanced correction of spinal deformities. However, the technique is still not widely applied for thoracic deformities for fear of neurologic complications. MATERIALS AND METHODS: A total of 462 patients subjected to thoracic pedicle screw fixation for spinal deformities were analyzed after a minimum follow-up of 2 years. Etiologic diagnoses were idiopathic scoliosis in 330, congenital kyphoscoliosis in 68, kyphosis in 50, and others in 14. They were reviewed using the medical records and preoperative, intraoperative, and postoperative roentgenograms. Computed tomography was performed when screw position was questionable. RESULTS: A total of 4604 thoracic pedicle screws were inserted (10.1 screws/patient). There were 67 screw malpositions (1.5%) in 48 patients (10.4%). The malpositions were inferior in 33, lateral in 18, superior in 12, and medial in 4. Screw-related neurologic complications occurred in four patients (0.8%); these comprised a transient paraparesis and three dural tears. Other complications comprised 11 intraoperative pedicle fractures, 35 screw loosenings, 9 postoperative infections, and 1 pneumothorax. There were no significant screw-related neurologic or visceral complications that adversely affected the long-term result. The deformity correction was 69.9% for idiopathic scoliosis and 60.7% for congenital scoliosis. The sagittal plane deformity correction was 47 degrees for kyphosis. CONCLUSIONS: Thoracic pedicle screw fixation is a reliable method of treating spinal deformities, with an excellent deformity correction and a high margin of safety.     

Quantification of proteinuria in children using the urinary protein-osmolality ratio

A prospective study was conducted to determine the correlation of early morning urinary protein/osmolality ratio (mg/l/mosmol/kg) with 24-h urinary protein excretion (mg/m²/day). Study patients consisted of 53 children (aged 1 month to 15 years). Early morning urine samples and 24-h urine samples were collected and analyzed. In group 1 (children without proteinuria), early morning urinary protein/creatinine ratio (Uprot/Ucr, mg/mg) was 0.061±0.011 and the protein/osmolality ratio (Uprot/Uosm, mg/l/mosmol/kg) was 0.073±0.014. Twenty-four hour urinary protein excretion in group 1 had no significant correlation with Uprot/Ucr or Uprot/Uosm. In group II (children with proteinuria), Uprot/Ucr was 5.78±1.10 and Uprot/Uosm was 4.42±1.34. Twenty- four hour urinary protein excretion in group 2 was 1483.6±303.7 mg/m²/day and its correlation with both Uprot/Uosm and Uprot/Ucr was highly significant (r= 0.87, P<0.001 and r=0.88, P<0.001, respectively). The accepted nephrotic level of proteinuria of 40 mg/m²/h coincides with a Uprot/Uosm ratio of 1.9. In conclusion, early morning urinary Uprot/Uosm is a simple and potentially useful test for 24-h urinary protein excretion, and possibly could be used safely for the assessment of the degree of proteinuria in children. Received: 13 April 1999 / Revised: 23 February 2000 / Accepted: 15 August 2000     

Should laparoscopy be the standard approach used for pelvic lymph node dissection?

Involvement of the pelvic lymph nodes in patients with prostate cancer worsens the overall prognosis of this common disease entity. Prior radiographic staging tech-niques, including fine-needle aspiration, are limited by a poor sensitivity and are not reliable. The gold standard for the evaluation of pelvic lymph nodes in men with prostate cancer involves performing a lymphadenectomy. Historically, this procedure was performed using an open surgical technique. Unfortunately, this invasive procedure is associated with significant morbidity. In response, modern surgical technology has provided newer, less invasive techniques, including laparoscopic pelvic lymphadenectomy (LPLND). Improved detection of localized prostate cancer through the institution of screening protocols and early detection programs has decreased the number of patients presenting with lymph node involvement. Various clinical indicators, including prostate-specific antigen, grade, and stage, have been used to improve the selection of “high-risk” patients that are appropriate candidates for pelvic lymph node dissection. The technique of LPLND is a valid option in the armamentarium for staging of prostate cancer. The laparoscopic approach provides the same staging accuracy as the open surgical technique and is superior with respect to morbidity. LPLND is limited to patients who present with a high risk of advanced prostate cancer. In addition, the urologist must accept the additional training, financial expense, and “learning curve” associated with this technique.     

The prevalence of chronic prostatitis-like symptoms in young men: a community-based survey

We surveyed the prevalence of chronic prostatitis-like symptoms in young men using the National Institutes of Health (NIH) Chronic Prostatitis Symptom Index (CPSI) and determined the clinical validity of the NIH-CPSI among men in the community. Of 29,017 men aged 20 years dwelling in the community, 8,705 men were randomly selected at a 30.0% sampling fraction and a total of 6,940 men (a response rate 79.7%) completed a self-administered questionnaire. Six percent reported having pain or discomfort in more than one area . About 5% did not feel that the bladder emptied fully after urinating more than 1 time in 5 and 10.5% had to urinate again within 2 h more than 1 time in 5. As the scores for pain or discomfort increased, those for urinary symptoms and impact on quality of life increased (P < 0.001; Armitage test). As the scores for urinary symptoms increased, those for pain or discomfort and impact on quality of life also increased (P < 0.001; Armitage test). The community-based prevalence of chronic prostatitis-like symptoms were found to be high in young men as well as in older men. Our findings indicate that men with pain or urinary symptoms experience a negative impact on their quality of life and the NIH-CPSI provides a valid measure for the general population. Received: 19 September 2000 / Accepted: 23 November 2000     

The cytotoxic effect of methotrexate loaded bone cement on osteosarcoma cell lines

We mixed various amounts of methotrexate with bone cement and measured the absorbance daily for 4 weeks. The cytotoxic effects on SaOS2 and MG63 osteosarcoma cells were examined by the MTT assay, and analysed according to the methotrexate concentration and the elapsed time. The amount of eluted methotrexate was greatest during the first day, and then decreased rapidly reaching a plateau in the third week. The number of viable tumour cells decreased significantly after 72 h, and they were hardly seen after 1 week.