Orbital volume measurement in the management of pure blowout fractures of the orbital floor

With the recent advent of accurate orbital volume assessment by computed tomography, a retrospective analysis was made of 31 patients with 'pure' blowout fracture of the orbital floor, managed either surgically or conservatively, to determine whether orbital volume measurement could provide an additional parameter of use in the management of such fractures. There was a significant difference in orbital volume discrepancy between patients managed surgically or conservatively suggesting that this investigation may be of use in decision making on surgical intervention in patients with orbital blowout fractures.     

Epithelioid sarcoma: a clinicopathologic review of 55 cases

OBJECTIVE: To identify any clinical and pathologic features of treatment modalities that are predictive of outcome in patients with epithelioid sarcoma, a rare slow-growing soft tissue tumor most commonly occurring in the distal extremities of young adults. DESIGN: We reviewed the institutional files for cases of epithelioid sarcoma for the period 1956 to 1991 and analyzed the effect of various factors on survival. MATERIAL AND METHODS: Fifty-five cases of epithelioid sarcoma were found, and the relevant clinical, pathologic, treatment, follow-up, and outcome features were assessed. RESULTS: All tumors were treated initially by operative resection. The recurrence rate progressively decreased with increasing aggressiveness of the initial operation; however, no difference was noted in metastatic rate. Overall, the recurrence rate was 38% and the metastatic rate was 47%. At the end of a mean follow-up of 102 months, 69% of patients had no evidence of disease, 27% had died of the disease, and 4% were alive with disease. Increasing tumor size, necrosis of more than 30%, and vascular invasion correlated significantly with a worse prognosis. CONCLUSION: Epithelioid sarcoma should be considered a malignant neoplasm with a significant potential for aggressive behavior, and close follow-up of affected patients should be maintained for many years. Initial treatment should be aggressive in an attempt to prevent recurrence.     

The role of squamous cell carcinoma antigen in the management of laryngeal and hypopharyngeal cancer

BACKGROUND: The efficacy of squamous cell carcinoma antigen (SCC-Ag) in laryngeal cancer to predict those patients who will relapse after primary treatment (surgery or radiotherapy) and its utility to detect relapses early and thereby increase salvage rates and cure were assessed. METHODS: Sixty healthy donors and 168 patients with laryngeal cancer were included in this prospective trial. Squamous cell carcinoma antigen was measured at diagnosis in all patients, 24 hours and 1 week after surgery in 113 patients and every 10 Gy of administered dose and 2 weeks after treatment in 49 patients primarily referred to radiotherapy. The marker was determined every 3-6 months during follow-up. All patients who relapsed had SCC-Ag studies before and after salvage treatment. RESULTS: The selected cut-off value was 1.5 ngr/ml (mean value in control group, 0.65 + 2 standard deviation [0.38]). Seventy-eight percent of patients with cancer had elevated SCC-Ag values at diagnosis. Squamous cell carcinoma antigen was statistically related to TNM categories (T, P < 0.04; N, P < 0.05; Stage, P < 0.01). Seventy-five percent of those patients with previously elevated pretreatment values normalized after treatment. Incomplete surgical resection (P < 0.0001) or persistence of the disease after radiotherapy (P < 0.01) were related to high posttreatment values. Squamous cell carcinoma antigen was elevated in 88% of the patients who relapsed. In 55% of the recurrences, SCC-Ag was elevated 3 months before pathologic confirmation of relapse. Salvage by surgery or radiotherapy was effective in 70% of the patients. Squamous cell carcinoma antigen posttreatment values were the most important factor in predicting disease free survival (DFS) (P < 0.0001) and overall survival (P < 0.03). CONCLUSIONS: Squamous cell carcinoma antigen is an excellent marker of residual disease after primary treatment that can lead to the addition of other therapeutic procedures (surgery and postoperative radiotherapy). The absence of posttreatment SCC-Ag is the best predictor of DFS, its presence detects recurrence in early stages, permitting salvage of an increased proportion of patients primarily referred for palliative treatment.     

Genetic fusions of subunit c in the F0 sector of H+-transporting ATP synthase. Functional dimers and trimers and determination of stoichiometry by cross-linking analysis

The multicopy c subunit of the H+-transporting ATP synthase of Escherichia coli folds through the transmembrane F0 sector as a hairpin of two hydrophobic alpha-helices with the proton-translocating aspartyl-61 side chain centered in the second transmembrane helix. The number of subunits c in the F0 complex, which is thought to determine the H+-pumping/ATP stoichiometry, was previously not determined with exactness but thought to range from 9-12. The studies described here indicate that the exact number is 12. Based upon the precedent of the subunit c in vacuolar-type ATPases, which are composed of four transmembrane helices and seem to have evolved by gene duplication of an F0-type progenitor gene, we constructed genetically fused dimers and trimers of E. coli subunit c. Both the dimeric and trimeric forms proved to be functional. These results indicate that the total number of subunit c in F0 should be a multiple of 2 and 3. Based upon a previous study in which the oligomeric organization of c subunits in F0 was determined by cross-linking of Cys-substituted subunits (Jones, P. C. , Jiang, W., and Fillingame, R. H. (1998) J. Biol. Chem. 273, 17178-17185), we introduced Cys into the first and last transmembrane helices of subunit c monomers, dimers, and trimers and attempted to generate cross-linked products by oxidation with Cu(II)-(1,10-phenanthroline)2. Double Cys substitutions at two sets of positions gave rise to extensive cross-linked multimers. Multimers of the monomer that extended up to the position of c12 were correlated and calibrated with distinct cross-linked species of the appropriate doubly Cys-substituted dimers (i.e. c2, c4, . c12) and doubly Cys-substituted trimers (i.e. c3, c6, c9, c12). The results show that there are 12 copies of subunit c per F0 in E. coli, the exact number having both mechanistic and structural significance.     

Methods of measuring susceptibility of anaerobic bacteria to trovafloxacin, including quality control parameters

Three methods approved by the National Committee for Clinical Laboratory Standards for testing the susceptibility of anaerobic bacteria were used to evaluate the fluoroquinolone, trovafloxacin. The methods gave essentially comparable results with 126 anaerobes and with three quality control strains. A collaborative study defined the quality control range for trovafloxacin MICs. Trovafloxacin had good in vitro activity against the more common anaerobes (MIC 90 < = or 2.0 micrograms/ml).     

Acute arthritis of cats associated with feline calicivirus infection

Twelve specific pathogen-free cats were infected either by intra-articular inoculation or by contact exposure to one of two strains of feline calicivirus (FCV), either F65, a field strain originating from an outbreak of lameness in a group of cats, or a vaccine strain. Following either route of exposure, both strains induced signs typical of FCV infection including oral and nasal ulceration, conjunctivitis and ocular discharge. These signs were of equal severity for both virus strains, but overall, following either route of infection, F65 induced more severe disease than the vaccine strain, with marked pyrexia, lethargy and lameness. Vaccine virus only induced a relatively mild lameness following intra-articular inoculation. Gross pathological and histopathological lesions were seen in some of the joints, but again changes were more severe in the F65-exposed cats. Virus was isolated from both normal and affected joints from both groups of F65-exposed cats, and from a joint from each cat inoculated intra-articularly with vaccine virus. Mild transient lameness was also seen in one of two control cats inoculated intra-articularly, but no pathological changes were seen or virus isolated from joints. A cDNA probe used in RNA dot blot hybridisation experiments was found to be specific and more sensitive than virus isolation in detecting FCV in selected tissues. This may be useful in future studies on the pathogenesis of FCV disease and in studies on viral persistence in FCV carriers.     

Synthesis and characterization of cyclic pseudopeptide libraries containing thiomethylene and thiomethylene-sulfoxide amide bond surrogates

Resistance-modifying agents (RMAs) such as Verapamil have been proved to be effective in reversing multi-drug resistance (MDR) in many in vitro assays. In this study we have investigated the efficacy of Dex-Verapamil, the R-isomer of Verapamil, as a chemosensitizer in a murine leukemia cell line (P388) and in its resistant counterpart (P388/Dx) expressing a typical MDR phenotype. We have examined in vivo the effect of the co-administration of Dex-Verapamil and Doxorubicin in mice transplanted with P388 or P388/Dx cells. Mice treated with the combination of Doxorubicin plus RMA had a significant increase in survival rate as compared to controls; however, the effect was modest. On the contrary, in vitro Dex-Verapamil can enhance Doxorubicin cytotoxicity in P388/Dx cells with a much greater effect depending on the treatment scheme used, by increasing the intracellular content of drug. Taken together our data indicate that Dex-Verapamil can indeed increase the sensitivity to Doxorubicin in resistant cells, but the limited efficacy shown in vivo demonstrates that this phenomenon is strongly dependent on the treatment scheme used and on the maintenance of constantly elevated serum levels.     

The preferential mobilisation of C20 and C22 polyunsaturated fatty acids from the adipose tissue of the chick embryo: potential implications regarding the provision of essential fatty acids for neural development

The effects of 10 day clenbuterol administration on cardiac and skeletal muscle capillarities were studied, particularly in terms of the distribution of arteriolar and venular capillaries and their capillary density, in young (10-week-old) and middle-aged (37-week-old) male Wistar rats. Rats of the treated groups were fed a diet containing 2 mg kg-1 clenbuterol hydrochloride. In both young and middle aged rats, clenbuterol treatment increased the body wt and the weights of the heart and hindlimb muscles. The mean fibre cross-sectional area was significantly increased after the treatment in the left ventricle, soleus, plantaris and both deep and superficial portions of gastrocnemius (P < 0.01). In the left ventricle, the total capillary density and the density of venular capillaries were decreased after the treatment in both young (9 and 13%, respectively) and middle-aged rats (10 and 11%, respectively). A decrease in total capillary density was also observed in all skeletal muscles examined. In both young and middle-aged rats, the capillary-to-fibre (C:F) ratio and the proportion of each capillary did not change after the treatment in both the left ventricle and skeletal muscles. Clenbuterol significantly decreased the activity of succinate dehydrogenase in all skeletal muscles examined (P < 0.01). These results suggest that clenbuterol increased the diffusion distance for oxygen in the left ventricle and skeletal muscles. These changes may reduce the oxygen supply to tissues and increase muscle fatigability.     

Effect of atherogenic diet on chicken plasma lipids and lipoproteins

Adult male White Leghorn chickens were used in an experimental model system to study atherogenesis, and the effects of an atherogenic diet on plasma lipoprotein composition including carotenoids were determined. This model also included treatment with diazepam, a drug known to reduce formation of atherogenic plaques. After 6 wk consumption of a high-cholesterol, high-triglyceride diet, chickens had mean total plasma cholesterol, triglyceride, and carotenoid concentrations that were significantly increased over those from chicks that consumed the standard diet. Diazepam treatment had no significant effect on whole plasma concentrations of these lipids. Total body weight gain was unaffected by diet, but liver weight expressed as percentage of body weight was significantly increased in chickens that consumed the atherogenic diet. High density lipoprotein (HDL) and low density lipoprotein (LDL) fractions were isolated from plasma samples by ultracentrifugation. The atherogenic diet increased the carotenoid, cholesterol, and protein content of the LDL fractions but not the HDL fractions.