Development of a poly(2-hydroxyethyl methacrylate) orbital implant allowing direct muscle attachment and tissue ingrowth.

PURPOSE: To develop a poly(2-hydroxyethyl methacrylate) orbital implant that allows tissue ingrowth and direct muscle attachment to minimize the risk of extrusion and to enhance cosmesis. METHODS: Assessment of clinical outcomes and histologic findings after implantation of 18 prototype prostheses into rabbits. The implants were not wrapped with other tissues or materials. RESULTS: One case of infection was observed but there were no extrusions, with up to 21 months follow-up. Biocolonization was confirmed histologically. Good movement was observed when a cosmetic shell was fitted. CONCLUSIONS: The prototype prosthesis appears promising, with particular advantages being the direct attachment of extraocular muscles, good cosmesis and movement, and a low complication rate in this pilot study.     

Hepatic toxicity and persistence of ser/thr protein phosphatase inhibition by microcystin in the little skate Raja erinacea

Microcystin-induced ser/thr protein phosphatase (PP) inhibition and toxicity were examined in the little skate (Raja erinacea), an evolutionarily primitive marine vertebrate. As in mammals, PP inhibition and toxicity were exclusively hepatocellular, but were much more persistent in the skate. A dose of 63 microg/kg given iv to adult male skates resulted in the near complete inhibition of hepatic PP activity at 24 h. PP activity was still 95% inhibited 7 days after dosing in skates given 125 microg/kg microcystin. Mortality occurred at doses of 500 microg/kg or more. Hepatic lesions were only seen in animals with fully inhibited PP activity in liver. The histological changes seen at 125 microg/kg were mild periportal inflammatory changes increasing in severity together with hepatocyte necrosis at higher doses of microcystin. Microcystin persisted and could be detected in plasma up to 7 days after dosing. This finding shows that, in the skate, as in mammals, the liver is the only organ capable of uptake of microcystin, since there was no significant inhibition of PP activity in the rectal gland and small decreases in PP activity of the kidney that were not time or dose dependent. In vitro microcystin caused dose-dependent inhibition of PP activity in isolated skate hepatocytes, while it was without effect in cultured rectal glands. Uptake of microcystin and the accompanying inhibition of PP activity in skate hepatocytes was prevented by the addition of a series of organic dyes and bile acids. The spectrum of inhibitors of microcystin uptake in skate is similar to that seen in the rat, indicating common features of the carrier(s) in these diverse species.     

Treatment of stage D2 hormone refractory carcinoma of the prostate with 5-fluorouracil and Roferon-A: a Southwest Oncology Group study

Based upon prior data suggesting that alpha-interferon possesses chemomodulatory activity, the Southwest Oncology Group conducted a study in which patients with hormone refractory, metastatic (stage D2) adenocarcinoma of the prostate were treated with 5-fluorouracil (5-FU) and Roferon-A. All patients had bidimensionally measurable disease. Treatment consisted of 5-FU 750 mg/m2/day by continuous i.v. infusion for 5 days with Roferon-A 9 million units subcutaneously ono days 1, 3 and 5. Roferon-A was continued three times weekly throughout treatment. Following a one week hiatus from 5-FU (week 2), 5-FU was continued at a dose of 750 mg/m2 i.v. bolus weekly. Nineteen patients were evaluable for toxicity. The most common toxicities were gastrointestinal and mucosal, hematologic and a flu-like syndrome. There were no deaths related to treatment. Among the 14 patients evaluable for response, the response rate was 0% (95% confidence interval, 0-18%). Thirteen of the 19 evaluable patients have died with a median survival of 9 months. The combination of 5-FU and Roferon-A does not have sufficient activity against advanced, hormone refractory prostate cancer to warrant further investigation.     

Prognostic significance of DNA ploidy in Ta/Tl bladder cancer: A southwest oncology group study

While 80% of transitional cell carcinomas (TCC) present as Ta Tl lesions, they account for only 15% of deaths caused by TCC. We have evaluated the ability of DNA ploidy analysis to predict outcome in 228 patients with Ta Tl TCC. All patients were judged to be at increased risk for tumor recurrence due to having two occurrences of Stage TI tumor within 56 weeks, or three or more tumors presenting simultaneously within 16 weeks of registration. Concurrent carcinoma in situ was acceptable. All patients were treated with either bacillus Calmette Guerin (BCG) immunotherapy or mitomycin-C (MMC) intravesical chemotherapy. Patients with nondiploid tumors had higher hazard rates for both tumor progression and death (p = 0.007 and p = 0.016, respectively); however, the prognostic information of DNA ploidy was not additive to tumor grade.     

Comparison of gas chromatography/mass spectrometry and immunoassay techniques on concentrations of atrazine in storm runoff

Gas chromatography/mass spectrometry (GC/MS) and enzyme-linked immunosorbent assay (ELISA) techniques were used to measure concentrations of dissolved atrazine in 149 surface-water samples. Samples were collected during May 1992–September 1993 near the mouth of the White River (Indiana) and in two small tributaries of the river. GC/MS was performed on a Hewlett-Packard 5971 A with electron impact ionization and selected ion monitoring of filtered water samples extracted by C-18 solid phase extraction; ELISA was performed with a magnetic-particle-based assay with photometric analysis. ELISA results compared reasonably well to GC/MS measurements at concentrations below the Maximum Contaminant Level for drinking water set by the U.S. Environmental Protection Agency (3.0 g/L), but a systematic negative bias was observed at higher concentrations. When higher concentration samples were diluted into the linear range of calibration, the relation improved. A slight positive bias was seen in all of the ELISA data compared to the GC/MS results, and the bias could be partially explained by correcting the ELISA data for cross reactivity with other triazine herbicides. The highest concentrations of atrazine were found during the first major runoff event after the atrazine was applied. Concentrations decreased throughout the rest of the sampling period even though large runoff events occurred during this time, indicating that most atrazine loading to surface waters in the study area occurs within a few weeks after application.

---

     

Jejunoileal arteriovenous malformation: localization for resection by segmental bowel staining techniques.

Arteriovenous malformations, submucosal vascular lakes, of the jejunum and ileum which cause chronic gastrointestinal bleeding and anemia are easily identified before operation by selective arteriography but difficult at operation owing to lack of physical signs. This report is concerned with a patient who had such a lesion located in the proximal jejunum. The involved segment was easily identified at operation by injection of Indigo Carmine solution during operation into the involved jejunal artery subselectively catheterized immediately prior to operation. The duration of jejunal staining before resection was 45 minutes in this case and varied from 35 to 55 minutes in five other patients who had right colectomy for carcinoma, providing the opportunity to inject accurately in a conveniently located radiology suite before operation. Safe, convenient, longer periods of staining which could be performed at the time of original diagnosis were demonstrated in dog experiments using "biologic" colloidal carbon in which the bowel segment was well stained at the time of sacrifice five days after injection. There were no gross or microscopic signs of injury to bowel.     

Behavioral studies of stimulus deprivation amblyopia in monkeys

Contrast sensitivity and increment-threshold functions were studied for three rhesus monkeys with stimulus deprivation amblyopia. The monkeys' right eyelids were sutured closed before the age of 1 month for periods of two weeks, 19 months and 23 months. Contrast sensitivity measurements for all three monkeys showed greatly reduced visual function in the deprived eye with a high spatial frequency cut-off 6 octaves lower in the deprived than the nondeprived eyes. The increment-threshold data collected for the two long-term lid-sutured monkeys showed both photopic and scotopic abnormalities in the deprived eyes. For example, with complete dark adaptation although the spectral sensitivity data for both the deprived and nondeprived eyes were well fit by the scotopic luminosity function, the sensitivity for the deprived eye was approximately 4 log units lower than the nondeprived eye. In addition, the spectral sensitivity data for the deprived eyes showed scotopic luminosity functions for achromatic adapting field luminances of 188, 750 and 3000 td whereas the nondeprived eye showed normal photopic function for all light adapted conditions. Even when the spectral sensitivity measurements were made in the presence of intense blue backgrounds, the data obtained for the deprived eyes were best described as showing scotopic function over the short wavelengths and photopic function only at the longer wavelengths. The increment-threshold functions for achromatic stimuli showed normal rod-cone interactions in the nondeprived eyes, but the functions were monotonic for the deprived eyes over a 9 log unit range of background luminances. Therefore, the results of these experiments show that stimulus deprivation causes profound defects for visual resolution, rod saturation and the rate of change of sensitivity with light adaptation.     

Evaluation of serum beta 2-microglobulin as a prognostic indicator in myelomatosis

Serum beta 2-microglobulin (beta 2-m) is frequently increased in patients with myelomatosis. The possibility that it could provide a biochemical indicator of prognosis was tested in a group of 129 patients from 3 centres, all serum analyses being carried out in one laboratory by radioimmunoassay. A strong association between the pretreatment serum beta 2-m level and survival was demonstrated, the data for the 2 main subgroups being very similar. In further detailed analyses of 64 patients, serum beta 2-m proved to be a stronger indicator of prognosis than current "standard" clinical and laboratory data, including stage determined by the method of Durie and Salmon and the combination of haemoglobin level and blood urea. The association between serum beta 2-m and survival remained close after treatment as indicated by the findings at one year. The serum beta 2-m in myeloma reflects the tumour mass and also reduced glomerular filtration when renal failure supervenes. It is concluded that the serum beta 2-m is a powerful prognostic indicator in myelomatosis and of considerable value in the investigation of patients with the disease.     

Liquid versus nonliquid heparinization of blood samples

Recent studies demonstrate that liquid heparinization of blood samples causes errors in PCO2 that range from 6% to 40%. Various nonliquid forms of heparin are available as alternatives.