Carcinoma of the hepaticopancreatic ampullar region: role of US

Hepaticopancreatic ampullar tumors are so called because they are located at the confluence of the bile duct, pancreatic duct, and duodenum. Jaundice is an early sign of the disease and often leads to early diagnosis and favorable prognosis compared with other tumors that occur in this area. Of eight patients who underwent ultrasound (US) in the past 5 years, six (75%) were found to have tumor. The sizes of the tumors ranged from 1.6 to 2 cm. An intraluminal, polypoid mass in the distal part of the common bile duct was seen in four patients. In the other two patients, a sharply delineated mass gave rise to abrupt termination of the distal duct. Improved US resolution, more experience with this modality, and accurate diagnosis of these tumors with US will contribute to improved detection and prompt treatment.     

Effects of neonatal spinal cord serotonin depletion on opiate-induced analgesia in tests of thermal and mechanical pain

There is considerable evidence that serotonin (5-HT) is involved in the analgesic actions of various opiates. However, it is less clear which opioid receptor types interact with these descending systems and whether the various monoaminergic pathways are specific for different types of nociceptive signals. In the present study we lesioned the spinal cord serotonin pathways by neonatal spinal injections of 5,7-dihydroxytryptamine (5,7-DHT) and tested the analgesic effects of morphine and ketocyclazocine one and two weeks later using both mechanical and thermal noxious stimuli. The treatment depleted spinal cord serotonin by more than 90% while not affecting norepinephrine levels. The effects of morphine were greatly attenuated in the depleted animals when the thermal noxious stimulus was applied. The analgesic actions of morphine were only slightly affected when the mechanical stimulus was applied. The effects of ketocyclazocine were not reduced by the treatment. The results further buttress the conclusion that at least part of morphine's analgesic effects are mediated by descending serotonin systems and that these systems are primarily effective against a thermal stimulus. The data suggest that non-5-HT brainstem system(s) are involved in morphine-induced analgesia to a mechanical noxious stimulus.     

Repetitive, negligible force reaching in rats induces pathological overloading of upper extremity bones.

Work-related repetitive motion disorders are costly. Immunohistochemical changes in bones resulting from repetitive reaching and grasping in 17 rats were examined. After 3-6 weeks, numbers of ED1+ macrophages and osteoclasts increased at periosteal surfaces of sites of muscle and interosseous membrane attachment and metaphyses of reach and nonreach forelimbs. These findings indicate pathological overloading leading to inflammation and subsequent bone resorption. INTRODUCTION: Sixty-five percent of all occupational illnesses in U.S. private industry are attributed to musculoskeletal disorders arising from the performance of repeated motion, yet the precise mechanisms of tissue pathophysiology have yet to be determined for work-related musculoskeletal disorders. This study investigates changes in upper extremity bone tissues resulting from performance of a voluntary highly repetitive, negligible force reaching and grasping task in rats. MATERIALS AND METHODS: Seventeen rats reached an average of 8.3 times/minute for 45-mg food pellets for 2 h/day, 3 days/week for up to 12 weeks. Seven rats served as normal or trained controls. Radius, ulna, humerus, and scapula were collected bilaterally as follows: radius and ulna at 0, 3, 4, 5, 6, and 12 weeks and humerus and scapula at 0, 4, and 6 weeks. Bones were examined for ED1-immunoreactive mononuclear cells and osteoclasts. Double-labeling immunohistochemistry was performed for ED1 (monocyte/macrophage lineage cell marker) and TRACP (osteoclast marker) to confirm that ED1+ multinucleated cells were osteoclasts. Differences in the number of ED1+ cells over time were analyzed by ANOVA. RESULTS: Between 3 and 6 weeks of task performance, the number of ED1+ mononuclear cells and osteoclasts increased significantly at the periosteal surfaces of the distal radius and ulna of the reach and nonreach limbs compared with control rats. These cells also increased at periosteal surfaces of humerus and scapula of both forelimbs by 4-6 weeks. These cellular increases were greatest at muscle attachments and metaphyseal regions, but they were also present at some interosseous membrane attachments. The number of ED1+ cells decreased to control levels in radius and ulna by 12 weeks. CONCLUSIONS: Increases in ED1+ mononuclear cells and osteoclasts indicate that highly repetitive, negligible force reaching causes pathological overloading of bone leading to inflammation and osteolysis of periosteal bone tissues.     

Photodynamic therapy with phthalocyanine sensitisation: quantitative studies in a transplantable rat fibrosarcoma

Photodynamic therapy (PDT) is a promising approach to the local destruction of malignant tumours, but little work has been done to determine which factors control the extent of tissue necrosis produced. Using a new photosensitiser, a sulphonated aluminium phthalocyanine (AlSPc) and light from an argon ion pumped dye laser at 675 nm, we quantified the effects of interstitial PDT in a transplantable fibrosarcoma in rats. At 100mW laser power, thermal effects were comparable to those of PDT, so subsequent studies were carried out at 50 mW, where thermal effects were minimal. The depth of PDT necrosis increased with the logarithm of the applied energy. Tissue concentration of AlSPc was measured by alkali extraction and at all times after sensitisation, correlated well with the necrosis produced with a given light dose. Peak tumour concentration of AlSPc occurred 24-48 h after sensitisation compared with a peak at 3 h in muscle. The peak ratio tumour:muscle was 2:1 at 24 h. Apart from a different time interval to reach the peak sensitiser concentration, the extent of tumour damage varied with the light and sensitiser parameters in a similar way to that found in normal liver, although the optical penetration depth was greater in the tumour (2.5 mm vs. 1.8 mm). At doses of AlSPc below 1 mg kg-1 the diameter of necrosis increased with the logarithm of the dose of sensitiser, and doubling the dose from 0.25 to 0.5 mg kg-1 increased the depth of necrosis by 50%. However, at higher doses, the changes were smaller and increasing the dose from 2.5 to 5 mg kg-1 only increased the necrosis by 10% for the same light dose. In all dose ranges, a given percentage increase in the tissue concentration of AlSPc gave a much smaller percentage increase in the extent of necrosis for the same light dose, suggesting that selectivity of necrosis between tumour and normal tissue is likely to be much less than the selectivity of retention of the photosensitiser. From these results, the extent of PDT necrosis in this fibrosarcoma is as predictable as it is in normal liver if the light dose, tissue concentration of AlSPc and optical penetration depth of the tissue are known. Further studies are now required on different tumour models to establish how tumours respond compared with adjacent normal tissue when the tumour is growing in its organ of origin rather than the non-physiological situation using a transplantable tumour as in this study.     

Laparoscopic cholecystectomy in Leicester: an audit of 555 patients.

Laparoscopic techniques have revolutionised the surgical approach to cholecystectomy, even though there have been no published randomised controlled trials to demonstrate the safety of this approach. We present an audit of 555 patients offered laparoscopic cholecystectomy. In all, 54 patients (9.7%) were converted to an open procedure. Peroperative cholangiography (POC) was attempted in 190 cases (34.2%) and achieved in 141 (25.4%). Major complications occurred in 26 cases (4.7%) including 5 (0.9%) deaths, two of whom had major pre-existing morbidity. There was one common bile duct (CBD) injury (0.18%). There were 30 patients (5.4%) found to have CBD stones, 27 of which were cleared at ERCP, and three converted to open exploration. Cholecystectomy by any route is a major operation and we conclude that careful case selection remains imperative. However, morbidity is favourable compared with open cholecystectomy, and comparable with other reports using the laparoscopic technique. Our experience of CBD injury (0.18%) is also acceptable compared with the risk of injury during open cholecystectomy. There were 312 patients (56.2%) who did not undergo perioperative CBD imaging with ERCP or POC and three of these developed early symptomatic retained stones. This group requires further follow-up.