Walter Voigt

Automated light- and dark-adapted perimetry for evaluating retinitis pigmentosa.

Visual fields and dark-adapted thresholds, essential measurements of visual function in patients with retinitis pigmentosa (RP), are usually performed manually. The authors have modified a computerized perimeter to perform automated light- and dark-adapted static perimetry across the visual field of RP patients. Results permit assessment of the level of visual disability in the light and dark and also help define subtypes of RP.

Mononuclear Cell Phenotypes and Immunoglobulin Gene Rearrangements in Lacrimal Gland Biopsies from Patients with Sjögren's Syndrome

Immunocytochemical studies of lacrimal gland biopsies obtained from eight patients with Sjögrens syndrome revealed the major component of the mononuclear cell infiltrates to be comprised of B cells and Leu-3+ T-helper cells, which were present well in excess of control glands. Three of seven cases that were tested harbored cells that stained with monoclonal antibodies against different components of Epstein-Barr virus (EBV); one of the biopsies also contained cells that bore cytomegalovirus antigens. Immunoglobulin-gene rearrangements, but not T-cell receptor rearrangements, were demonstrated in one of two Sjögrens lacrimal gland biopsies tested. The authors conclude that the destruction of the tubuloacinar architecture of lacrimal gland tissue in Sjögrens syndrome appears secondary to lymphoproliferation of B cells and T-helper cells, probably derived from primary lymphoid follicles. Productive infection of lacrimal gland tissue with EBV may play a role in the pathogenesis of the syndrome in selective cases.

Ocular-adnexal Lymphoid Tumors: A Clinicopathologic and Molecular Genetic Study of 77 Patients

PURPOSE To determine whether molecular genetic analysis of ocular-adnexal lymphoid tumors, combined with histopathology and tumor location, is helpful in predicting which patients will develop systemic lymphoma. METHODS A combined retrospective and prospective study of 77 patients with ocular-adnexal lymphoid tumors was performed. The tumors were subdivided into conjunctival, orbital, and eyelid lesions, and all were studied using both routine histopathology and molecular genetic analysis. RESULTS Most lesions (70%) were small cell lymphomas of the mucosa-associated lymphoid tissue type, and the majority of tumors (90%) contained monoclonal or oligoclonal populations of lymphocytes discovered on molecular genetic analysis. Additionally, 72% of tumors exhibiting clonality had more than one gene rearrangement. Fifty-three percent of patients developed extraocular lymphoma sometime during the course of their disease. Patients with gene rearrangements on Southern blot hybridization had a 52% incidence of nonocular disease, compared with 63% of those without rearrangements. Patients with conjunctival tumors had a 37.5% incidence of nonocular disease, those with orbital tumors had a 54% incidence, and those with eyelid tumors had a 100% incidence of nonocular lymphoma. Only two patients died as result of systemic lymphoma. CONCLUSIONS Most ocular-adnexal lymphoid tumors are lymphomas of the mucosa-associated lymphoid tissue type. The majority of tumors exhibit gene rearrangements on molecular genetic analysis, and this technique was not helpful in predicting which patients would develop nonocular lymphoma. Tumor location did have predictive value: Conjunctival lesions had the lowest incidence of nonocular lymphoma, and lid lesions had the highest incidence. Even with disseminated disease, most patients have a favorable prognosis with treatment.

Photoreactivation spectrum of the co-inhibited taurochenodeoxycholate 6β-hydroxylase system☆

The 6&hydroxylation of chenodeoxycholic and taurochenodeoxycholic acid by cell free preparations of rat liver has been reported in a previous paper [l] . The enzymic activity was located in the microsomal fraction, and an active extract was prepared by suspension of the microsomes in 1 .O M phosphate buffer, pH 7.6 and subsequent centrifugation at 105,000 X g. The requirements for NADPH and 0, indicated that the 6@hydroxylase is a mixed function oxidase [Z] . Carbon monoxide was found to inhibit the hydroxylase activity of the 1 .O M phosphate extract and the inhibition could be partially reversed by white light. This, along with the spectrophotometric detection of cytochrome P-450 in the extract [I] , following reduction with Na dithionite and exposure to CO, suggested the participation of the P-450 in the 6&hydroxylase system. In a continuation of our study we have determined the photoreactivation spectrum of the COinhibited hydroxylase system. This communication reports the results which support that P450 functions as the oxygen activating enzyme in the G/3-hydroxylase system.

Determination of hormonal response in uterine cancer cell lines by the ATP bioluminescence assay and flow cytometry

Although progesterone receptor status has been shown to correlate with response to hormonal therapy, not all progesterone receptor-positive patients respond to this treatment and additional biologic assays are needed to help better predict clinical response to hormonal therapy. This study explored the potential of the ATP bioluminescence assay and flow cytometry as biological assays of hormonal response. Five uterine cancer cell lines were used: AE7, ECC-1, HEC1A, AN3, and SKUT1B. Cells were exposed to Provera or tamoxifen at 0.1, 0.2, 0.5, 1, 2, and 5X (X equal to peak plasma concentrations: 1.0 micrograms/ml Provera and 0.1 micrograms/ml tamoxifen). For correlation, estrogen and progesterone receptors were determined by the standard dextran-coated charcoal method. Only AE7 and ECC-1 were positive for progesterone receptors (501 fmol/mg AE7, 194 fmol/mg ECC-1) and the rest were negative (less than 8 fmol/mg). Tamoxifen exerted no inhibition to the above cell lines. Meanwhile, Provera exerted dose-response inhibition on both AE7 and ECC-1 cell lines. The effects of accumulation of G0-G1 phase and reduction of S, G2 cells (P less than 0.05), but not on the HEC1A cell line (P = 0.4). These changes confirmed the antiproliferative property of Provera. Further studies are needed to establish the role of the ATP bioluminescence assay and flow cytometry as biological assays of hormonal response.

Studies of immunoglobulin and T cell receptor gene rearrangement in cutaneous B and T cell lymphomas

We report two patients with cutaneous B and T cell lymphomas, respectively, in which DNA rearrangement studies were instrumental in establishing a diagnosis. In each case clinical, histopathologic, and immunologic criteria were not sufficient to establish a definitive tissue classification. The use of DNA gene rearrangement studies in the analysis of cutaneous lymphomas is discussed.

Transformation of dehydroepiandrosterone into dihydrotestosterone by isolated cells from rat preputial gland.

After the rat preputial gland was treated with collagenase and trypsin, five bands of cells were isolated by centrifugation in Ficoll gradients. Homogenates of the heavier cells (Bands IV and V) which contained less lipids, were more active than the homogenates of the lighter cells (Bands I, II and III) in transforming [1,2-3H]-dehydroepiandrosterone ([1,2-3H]-DHA) into [3H]-androstenedione and [3H]-testosterone and the latter into [3H]-dihydrotestosterone (DHT). In the presence of NAD, NADH and NADPH-generating system, [1,2-3H]-DHA was transformed into [3H]-DHT in 50-60% yield by homogenates of cells in Bands IV and V. DHT levels in the preputial gland were measured by radioimmunoassay. The levels in female rats reduced by 77% from 3.14 +/- 0.27 to 0.72 +/- 0.10 pg/mg tissue after adrenalectomy, and by 45% to 1.71 +/- 0.10 pg/mg tissue after ovariectomy. In male rats, the level reduced by 15% from 4.58 +/- 0.55 to 3.88 +/- 0.62 pg/mg tissue after adrenalectomy and by 40% to 2.74 +/- 0.21 pg/mg tissue after orchidectomy. These results demonstrated the transformation of DHA into DHT in the preputial gland of the rat, and that the adrenal is an important source of precursor steroid (DHA) for DHT formation in the preputial gland.

P-450 Level and Taurochenodeoxycholate 6β-Hydroxylase System of Rat Liver Microsomes

Summary The level of cytochrome P-450 and the activity of taurochenodeoxycholate 6β-hydroxylase of rat liver microsomes were determined after the administration of phenobarbital, cholestyramine, thyroxine and chenodeoxycholate. Treatment with phenobarbital caused increases in both the 6β-hydroxylase activity and P-450 level, while the other compounds caused decreases in both. Quantitatively there was a lack of parallelism between the hydroxylase activity and the level of P-450, indicating that P-450 is not a rate-limiting factor in the 6β-hydroxylase system. An extract of the microsomes was prepared in 1.0 M phosphate (pH 7.6) as previously described. The extract was active in 6β-hydroxylation, with an apparent Michaelis-Menten constant towards taurochenodeoxycholate of 1.2 × 10-4M, and a maximum rate of hydroxylation of approximately 1 nmole/min/mg protein. The ratio of P-450 to protein of the extract was 2 to 2.5 times greater than that in the microsomes.

Value of 8S/4S fractionation of estrogen receptors (ER) for prediction of response to hormonal manipulation in metastatic breast cancer

SummaryUsing sucrose gradient centrifugation, human breast cancer estrogen receptors appear in two molecular forms sedimenting at either 8S or 4S fractions. The sum of these two fractions has been valuable clinically in helping to predict response to hormonal therapies. It has been suggested that the 4S receptor may not be of predictive value and that the practice of using only dextran-coated charcoal methodology might thus overestimate the number of patients whose tumors might be hormonally dependent. The present study correlates clinical response to hormonal manipulations with 8S and 4S receptors as determined by sucrose density gradient centrifugation. Patients with only 4S positive receptors had a 56% response rate to hormonal manipulation compared with a 52% response rate in patients with positive 8S alone or with both 8S and 4S receptors. Although patient numbers are small in this and the other three published series addressing this question, our data do not confirm two previously published studies suggesting clinical importance of 8S/4S fractionation.