Intrastromal keratorhexis with the Nd:YAG laser--a possible method of refractive surgery?

A new method of refractive corneal surgery is presented. With the q-switched Nd:YAG-laser Visulas (Zeiss-Oberkochen) we succeed in altering the optical power of the cornea of rabbits, pigs and humans. The number of applied laser spots and the distribution pattern influence the way and the amount of change of refraction. The method, clinical and histological features, complications and prospects of the Nd: YAG laser keratorhexis are described.     

Lifetime toxicity/carcinogenicity studies of FD & C Blue No. 1 (brilliant blue FCF) in rats and mice

FD & C Blue No. 1 was fed to Charles River CD rats and CD-1 mice as a dietary admixture in lifetime toxicity/carcinogenicity studies. The rat study was conducted with an in utero phase in which the compound was administered to the F0 generation rats (60/sex/group) at dietary concentrations of 0.0%, 0.0%, 0.1%, 1.0% or 2.0%. After randomly selecting the F1 animals, the lifetime phase was initiated at the same levels with 70 rats/sex/group, including two control groups. The maximum exposure times were 116 and 111 wk for males and females, respectively. The no-observed-adverse-effect levels are dietary concentrations of 2.0% for males (1072 mg/kg body weight/day), and 1.0% for females (631 mg/kg/day) based on a 15.0% decrease in terminal body weight and decreased survival in the high-dose females compared with the combined control groups. Charles River CD-1 mice (60/sex/group) were fed FD & C Blue No. 1 as a dietary admixture at levels of 0.0%, 0.0%, 0.5%, 1.5% or 5.0% in a lifetime toxicity/carcinogenicity study. The maximum exposure time was 104 wk for both males and females. No consistent, significant compound-related adverse effects were noted. The no-observed-adverse-effect level established in this study is a dietary concentration of 5.0% (7354 mg/kg/day and 8966 mg/kg/day for male and female mice, respectively.     

Tyramine-Induced cardiac arrhythmias

Five out of 12 physically healthy patients with depression undergoing a tyramine pressor test developed cardiac arrhythmias. These arrhythmias occurred in drug-free patients in three out of 12 infusions following as little as 0.03 mg/kg of tyramine and after moclobemide, a reversible inhibitor of monoamine oxidase-A, in four out of 14 tyramine infusions with as little as 0.04 mg/kg of tyramine. The arrhythmias seen were independent of patient's age and occurred both before and after 30 mmHg elevations in systolic blood pressure. Electrocardiographic abnormalities and arrhythmias seen were a loss of p waves, sinus tachycardia, frequent atrial ectopic beats, atrial premature beats, Wenckebach phenomenon, junctional rhythm, ventricular ectopics, varying QRS configurations, and ventricular bigeminy. Tyramine, both oral and intravenous, caused similar reproducible changes in dogs, though not in rats, mice or guinea pigs. Practical implications are that tyramine pressor testing in humans should be performed cautiously and only with adequate cardiac monitoring and resuscitation facilities at hand. These findings suggest that a normal dietary component can induce serious cardiac arrhythmias, and that a low-tyramine diet may be of value for patients who are susceptible to cardiac arrhythmias.     

Hand infections in the diabetic and the diabetic renal transplant recipient

We present a series of 41 diabetic patients with severe tissue destruction and deformity secondary to hand infections. Thirty (73%) of the patients showed propagation of the infection to bone, tendons, or deep palmar spaces, and 26 of 41 (63%) required amputations. Sixty-three percent of the cultures were mixed; pure Staphylococcus aureus accounted for only 12%. Diabetics who were renal transplant recipients were at increased risk, with a 100% amputation rate and an average hospitalization of 41 days. Recommendations for management of diabetic hand infections are given to reduce the mortality and morbidity in these patients.     

Prospective comparison of plain abdominal radiography with conventional and digital renal tomography in assessing renal extracorporeal shock wave lithotripsy patients

Most publications citing the effectiveness of renal extracorporeal shock wave lithotripsy have used plain abdominal radiography to assess residual calculi after treatment. We compared radiologist sensitivity and specificity in the detection of calculi on plain abdominal radiographs versus conventional film-screen and digital renal tomograms in extracorporeal shock wave lithotripsy patients. Of the patients 50 were imaged before and within 24 hours after lithotripsy. Six radiologists evaluated the resultant 300 studies for the presence and location of calculi. The mean sensitivity for digital tomograms was 83% for pre-lithotripsy and post-lithotripsy studies, which was significantly higher than for plain abdominal radiography and conventional tomography after lithotripsy. However, there were significantly more false positive stone diagnoses associated with digital tomogram interpretation. Signal detection analysis verified the over-all superiority of digital tomography for post-extracorporeal shock wave lithotripsy imaging. Calculus detection by conventional and digital tomography is superior to detection by plain abdominal radiography. However, because we did not perform delayed imaging, it is not possible to say what impact digital tomography might have on the management of extracorporeal shock wave lithotripsy patients.     

Nephron-sparing surgery for renal cell carcinoma with venous involvement

A nephron-sparing operation recently has been shown to provide extended survival free of disease in selected patients with localized renal cell carcinoma, particularly for tumors of lower stage. To define better the role of conservative surgical treatment in more locally advanced renal cell carcinoma we reviewed 9 patients with venous tumor involvement in solitary functioning kidneys who underwent a nephron-sparing operation. Complete tumor resection with adequate preservation of renal function was accomplished in all cases. Of the 9 patients 5 had no evidence of disease 7 to 93 months (mean 33.2 months) postoperatively. The remaining 4 patients died of metastatic renal cell carcinoma 17 to 47 months (mean 35.5 months) postoperatively, 2 of whom had concomitant local recurrences in the renal remnant. Based on previously reported results of total nephrectomy for renal cell carcinoma with venous involvement and the morbidity associated with renal replacement therapy, we believe that a nephron-sparing operation is a viable option in the management of these patients.     

Unrelated donor marrow transplantation between 1977 and 1987 at four centers in the United Kingdom

Retrospectively we analyzed the histocompatibility data and clinical results of bone marrow transplantation in 51 patients who received marrow from unrelated donors (UD) from 1977 to 1987 at one of four UK BMT centers. We compared the results with those obtained in 51 transplants carried out at the same centers using HLA-identical (ID) sibling donors. Of the UD/recipient pairs 32 (63%) were serologically identical for HLA A, B, and DR antigens, and 37% showed varying degrees of mismatch. UD-BMT primary diagnoses were: severe aplastic anemia or Fanconi's anemia (n = 17), acute leukemia (n = 11), chronic myeloid leukemia (n = 21), and other conditions (n = 2). T cell depletion of the graft was associated with a significant improvement in survival in both UD and ID-BMT. Graft failure was more common in recipients of UD than of ID transplants (13 [25%] vs. 5 [10%] P = 0.05) but there was no significant difference in the frequency of acute or chronic graft-versus-host disease. Actuarial survival was superior for recipients of ID transplants (UD vs. ID: 49% vs. 78%, respectively, at 3 months; 32% vs. 63% at one year). Reduced survival for recipients of UD-BMT was confirmed in case control regression analysis (relative risk 3.0, P = 0.01). Nevertheless in patients whose only alternative is a partially mismatched family donor we think that UD-BMT is justified.     

The synthetic prostaglandin E1 analogue rioprostil reduces the nephrotoxic potential of cyclosporine A

Acute CyA nephrotoxicity involves alteration in the proximal tubule and leads to glomerular lesions. Administration of a vasodilatator agent such as the prostaglandin E1 analogue Rioprostil (Bayer AG, BAY 06893) might prevent preglomerular vasoconstriction and hence reduce cyclosporin nephrotoxicity. As an increased excretion of urinary enzymes as a consequence of CyA-nephrotoxicity is well known we investigated in 40 male Wistar rats the excretion of three urinary enzymes: the brush border enzyme gamma-glutamyltransferase (GGT), the leucine aminopeptidase (LAP), and the lysosomal enzyme N-acetyl-beta-glucosaminidase (NAG). Additionally we determined s-creatinine and CyA plasma level. The kidneys were studied histologically at the end of the study. Wistar rats receiving 20 or 50 mg CyA/kg/d showed a marked deterioration in renal function and an increase of all urinary enzymes determined. In the rats receiving 20 mg CyA/kg/d and Rioprostil (150 micrograms/d) renal function and the enzymes determined remained in the normal range. There was no change in the enzyme excretion and only a minor improvement of renal function in rats receiving 50 mg CyA/kg/d and Rioprostil. Histological findings showed prevention of CyA nephrotoxicity in the 20 mg/kg/d group and diminished renal damage in the 50 mg/kg/d group.