Alterations of the immunoglobulin heavy chain locus in progressive B-cell lymphomas

Twenty-two patients with relapsed or progressive B-cell lymphomas (BCL) were analysed for alterations in the rearrangement status in the immunoglobulin heavy (IgH) chain gene in samples obtained on different occasions during the course of the disease. The analysis was performed using Southern blot hybridization of the IgH gene and polymerase chain reaction (PCR) amplification of the VH gene families combined with single-strand conformation polymorphism (SSCP) analysis. Using Southern blot analysis, we found that all 22 lymphomas displayed clonal IgH rearrangements, and changes during tumour progression occurred in 8 cases. These alterations were mainly observed in cases with follicular or transformed lymphomas. More than one malignant (sub)clone, indicated by more than two rearranged bands, was detected in one case at diagnosis and in three cases at relapse. Outgrowth of subclones with divergent rearrangement patterns in different compartments was also observed in 2 out of 8 cases. PCR-SSCP analysis indicated that all 15 cases studied displayed clonal rearrangements and in 6 cases altered rearrangement patterns were detected in later samples. Southern blotting and PCR-SCCP analysis gave equivalent results. No association was found between time to relapse or survival time and alterations in rearrangement pattern. The present study illustrates that the neoplastic cell clones in BCL often display alterations in their IgH locus, but the significance of this feature remains to be clarified.

Comparative analysis of detection systems for evaluation of PCR amplified immunoglobulin heavy-chain gene rearrangements

Four different detection systems were compared for evaluation of polymerase chain reaction (PCR) amplified immunoglobulin heavy-chain gene rearrangements in acute lymphoblastic leukemia (ALL) and non-Hodgkin's lymphoma (NHL) of B-cell lineage. In 63.0% of the fragments detected by ethidium bromide stained agarose gel electrophoresis (Agarose-EtBr) the sensitivity was insufficient to separate the specific clonal population from the background of normal B cells. Using polyacrylamide gel electrophoresis (PAGE), PAGE combined with single-strand conformation polymorphism (PAGE-SSCP) and PhastGel-SSCP (Phast-SSCP) analysis with silver staining, the resolution was improved and the majority of the inconclusive amplicons were elucidated. However, Phast-SSCP displayed a slightly higher detection level compared to PAGE and PAGE-SSCP. According to our findings PAGE-SSCP and Phast-SSCP were superior to agarose-EtBr and PAGE in detecting new emerging clones and clonal evolution.

Immunoglobulin VH gene replacements in a T-cell lymphoblastic lymphoma

We have analysed the rearrangement status of the immunoglobulin heavy (IgH) chain locus during progression of a T-cell lymphoblastic lymphoma displaying multiple IgH rearrangements as demonstrated by variable heavy (VH) gene family specific polymerase chain reaction (PCR) analysis. The tumor was found to undergo diversification at the IgH locus between diagnosis and relapse through a mechanism of VH to VHDJH replacement. In subsets of the tumor at relapse, two separate VH gene segments were found to have replaced the VH gene utilized by a VHDJH rearrangement identified at diagnosis. The observed VH gene replacement events appear to have been mediated by a heptamer sequence homologous to the heptamer of the recombination signal sequence (RSS) located internally in the VH gene segment. These results support the notion that VH replacements contribute to the diversification of immunoglobulin genes.

Outflow resistance of enucleated human eyes at two different perfusion pressures and different extents of trabeculotomy

Aqueous outflow resistance of enucleated human eyes was measured at 7 and 25 mm Hg before and after partial and complete (12 clock hours) internal trabeculotomy. Following complete trabeculotomy, 71% of the resistance was eliminated at 25 mm Hg while only 49% was eliminated at 7 mm Hg. In contrast to published findings in eyes with intact trabecular meshwork where the resistance increased with increasing IOP (1), following complete trabeculotomy, the resistance decreased 2% per mm Hg with increasing IOP. Experiments with trabeculotomy limited to part of the circumference showed that a one hour trabeculotomy produced 41% (25 mm Hg) to 60% (7 mm Hg) of the effect of a twelve hour trabeculotomy. The results indicate that a surprisingly high fraction of aqueous outflow resistance resides in the distal aspects of the outflow system at normal IOP, and that this distal resistance drops as IOP is increased.

A technique for removal of filariasis of the anterior chamber

We describe a useful technique for removing filaria from the anterior chamber. In the case described, an immature female filaria approximately 15 mm in length was removed from the anterior chamber of a 32-year-old man in western Oregon and identified as a species of Dipetalonema. Features of four cases of filarial infection in the anterior chamber from the same geographic area are described. In three out of four cases, the worms were removed alive without difficulty by means of simple irrigation aspiration system.

Micromotion of conventionally cemented all-polyethylene tibial components in total knee replacements. A roentgen stereophotogrammetric analysis of migration and inducible displacement

Micromotion of the tibial component in 27 knee arthroplasties for gonarthrosis, three of which were regarded as failures for reasons other than mechanical loosening, was studied using high-resolution roentgen stereophotogrammetric analysis (RSA). Migration over time was found in all cases, ranging from 0.2 to 2.1 mm. The majority of the cases showed migration during the first year only, while a minority migrated continuously during the period studied. The latter group showed more migration even after 1 year. All cases showed inducible displacement in response to external forces, ranging from 0.2 to 1.0 mm. The micromotion correlated with the age of the patient but not with other demographic parameters. Alignment or component position did not correlate with the micromotion. All cases but one had developed a radiolucent zone, and it was concluded that the micromotion occurred in the soft tissue interface between bone and cement. Such micromotion is a normal finding in cemented tibial components in knee arthroplasty.

Tibial component fixation in knee arthroplasty

Using roentgen stereophotogrammetric analysis (RSA), the integrity of the bond between the tibial component and the tibia was studied in seven knees, implanted with a cemented Kinematic total knee prosthesis for gonarthrosis. Migration ranging from 0.3 to 1.9 mm over a two-year period occurred in all seven cases. Displacement, induced by external forces, ranging from 0.2 to 1.0 mm was observed in five cases. Measurable migration and inducible displacement may be the rule rather than an exception in total knee arthroplasty (TKA). Accordingly, absolute rigid fixation would not be necessary for successful function of a TKA.

A one-year multicenter clinical trial of pilocarpine gel

In a one-year clinical trial of pilocarpine gel, a form designed for once-a-day administration, in 83 patients with glaucoma, average intraocular pressures during gel therapy were equal to or slightly lower than previous values during pilocarpine eyedrop therapy (morning values, 18.7 mm Hg vs 19.7 mm Hg; afternoon values, 20.9 mm Hg vs 20.2 mm Hg). Monitoring of diurnal intraocular pressure showed that 33 of 77 patients (43%) using the gel and 25 of 77 (33%) using eyedrops had afternoon values more than 2 mm Hg higher than their morning values. This difference was not statistically significant. Fifteen of 76 patients (20%) who used the gel for more than eight weeks developed a diffuse superficial corneal haze with gel treatment. The haze persisted 12 months after the gel was discontinued. Although the haze produced no symptoms, its long-term consequences are unknown.

Early carcinoma of the prostate: comparison of stages A and B

Stage A--occult, latent, preoperatively undiagnosed, incidentally found, stage I or T0--carcinoma of the prostate has been considered to be an earlier stage than stage B--II, T1 or T2, palpable nodule. In a comparative study of 118 patients with stage A lesions and 115 patients with stage B lesions we have found more focal lesions in A than in B. The A lesions were also less highly malignant than the B. However, the survival of patients with A lesions was a little less than those with B lesions. Age differences and more extensive growth before a detection may account for the differences. Patients with diffuse lesions and those with the more highly malignant lesions had a shorter survival than those with focal lesions and with a lower grade of malignancy in stages A and B. All available preoperative diagnostic data and a through histopathological examination of the surgical specimen are necessary to accurately stage prostatic carcinoma. Other well recognized diagnostic tests, such as the lymphangiogram, acid phosphatase value bone scan and so forth, are also necessary to accurately assess the extent of the disease.

Hemodynamic changes during ventricular pacing in patients with complete heart block and aortic and mitral valvular heart disease

Increasing the heart rate to near normal in patients with complete heart block (CHB) and slow ventricular rates may lead to greater improvement in ventricular function than when the heart rate is increased from normal to more rapid heart rates. Improvement in ventricular function is usually manifested by a decrease in left ventricular end-diastolic pressure (LVEDP) and volume and by an increase in contractility. In patients with both CHB and valvular heart disease improvement in ventricular function during pacing may be modified by the nature of the valvular disease. Hemodynamic data from six patients with both valvular heart disease and CHB were compared with those from ten patients with CHB and normal cardiac valves. Hemodynamic studies were performed at slow or idioventricular rates and again after increasing the heart rate to more nearly normal levels by ventricular pacing. When obstruction to left ventricular inflow (mitral stenosis) co-existed with CHB, increasing the heart rate resulted in a reduction of an elevated LVEDP to normal. This resulted in only a small increase in left atrial pressure in spite of a striking increase in the mean left atrial-ventricular gradient. When obstruction to left ventricular outflow prevailed (aortic stenosis), improvement in cardiac function was manifested mainly by a decrease in LVEDP and was accompanied by a decrease in left ventricular stroke work. When a large regurgitant volume (aortic insufficiency) was added to a ventricle which has enlarged subsequent to CHB, there was striking elevation in ventricular filling pressures which returned to more nearly normal levels when the heart rate was increased. This was accompanied by a reduction in regurgitant stroke volume in the patient in whom it was measured. Thus, an increase in heart rate may be especially beneficial to those patients with CHB who also have valvular lesions which contribute to an increase in LVEDP and end-diastolic volume. Careful hemodynamic evaluation is helpful in determining appropriate therapy in these patients.