Detection of the carrier state of X-linked retinoschisis

We determined the extent of suppressive rod-cone interaction in 11 obligate carriers and eight potential carriers of X-linked retinoschisis from eight families. Despite otherwise normal ophthalmoscopic and functional testing, all of the obligate heterozygous carriers demonstrated a complete absence of normal rod-cone interaction. Of the potential heterozygous carriers, three had normal rod-cone interactions, two had no detectable interaction, and two yielded technically unsatisfactory results. This lack of rod-cone interactions allows heterozygous individuals to be identified clinically and has implications concerning the origin of this inherited disorder.     

Acceleration of hemopoietic recovery after autologous bone marrow transplantation by low doses of peripheral blood stem cells.

Twenty patients with advanced malignant disease submitted to autologous bone marrow transplantation with marrow either unpurged (10 patients) or purged in vitro with mafosfamide (10 patients) after ablative chemotherapy, received simultaneously autologous peripheral blood stem cells (PBSC) collected during one to three 3 h cytapheresis procedures. The kinetics of the hematological recovery of these patients were compared to those of a group of patients suffering from similar diseases and grafted in the same institution with either unpurged marrow only (14 patients) or purged in vitro with mafosfamide (six patients). The median times to reach 10(9)/l leukocytes, 0.5 x 10(9)/l polymorphs, and 50 x 10(9)/l platelets were reduced by 10, 10, and 13 days, respectively, in patients transfused with both autologous bone marrow and peripheral blood stem cells as compared to those receiving bone marrow only. A reduction in the numbers of days spent in hospital post-transplantation (p less than 0.01), of days of fever greater than 38 degrees C (p = NS), and of platelet (p = 0.07) and of red blood cell transfusions (p less than 0.01) were also observed in the group of patients grafted with bone marrow and PBSC.     

Some aspects of structural disturbances in the DNP complex when damaged by N-nitroso-N-methylurea

The effect of solubilization of deoxyribonucleoproteins (DNP) in a medium of near-physiological ionic strength after treatment with the mutagen N-nitroso-N-methylurea (NMU) is highly dependent on the NMU concentration. To convert DNP into a soluble state, the critical number of groups in the DNA and protein must evidently be modified. On the basis of data obtained by the circular dichroism method and by viscosimetry it is concluded that after treatment with NMU the DNP complex becomes soluble in solvents with near-physiological ionic strength largely as a result of labilization and dissociation of the DNA-protein bonds.Laboratory of Biophysics, Institute of Medical Genetics, Academy of Medical Sciences of the USSR. Sector of Kinetics of Chemical and Biological Processes, Institute of Chemical Physics, Academy of Sciences of the USSR. Laboratory of Physical Methods of Investigation, D. I. Ivanovskii Institute of Virology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR S. S Debov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 6, pp. 674–677, June, 1976.     

Genetic heterogeneity of Usher syndrome type II.

Usher syndrome is an autosomal recessive disorder characterised by retinitis pigmentosa and congenital sensorineural hearing loss. A gene for Usher syndrome type II (USH2) has been localised to chromosome 1q32-q41. DNA from a family with four of seven sibs affected with clinical characteristics of Usher syndrome type II was genotyped using markers spanning the 1q32-1q41 region. These included D1S70 and D1S81, which are believed to flank USH2. Genotypic results and subsequent linkage analysis indicated non-linkage of this family to these markers. The A test analysis for heterogeneity with this family and 32 other Usher type II families was statistically significant at p < 0.05. Further clinical evaluation of this family was done in light of the linkage results to determine if any phenotypic characteristics would allow for clinical identification of the unlinked type. No clear phenotypic differences were observed; however, this unlinked family may represent a previously unreported subtype of Usher type II characterised by a milder form of retinitis pigmentosa and mild vestibular abnormalities. Heterogeneity of Usher syndrome type II complicates efforts to isolate and clone Usher syndrome genes using linkage analysis and limits the use of DNA markers in early detection of Usher type II.     

Expansion by folinic acid of the peripheral blood progenitor pool after chemotherapy: its use in autografting in acute leukaemia

We have tested folinic acid (FA) for ability to increase peripheral blood stem cells (PBSC) after chemotherapeutic aplasia in acute leukaemia. Five adult patients (four AML, one ALL) entered the study, each patient underwent two series of three leukapheresis, the first following induction chemotherapy and the second following the first course of consolidation. The first leukapheresis of each series was done when the white blood cell count reached 10⁹/1 with subsequent leukapheresis every other day. Folinic acid (Lederle Laboratories, France) was administered at a dose of 50 mg (i.v.) per day, 15 days from initiation of chemotherapy and continuing through the third leukapheresis of the series (days 25–30). PBSC were collected on a Haemonetics V50 cell separator.
In these five cases we observed an increased yield of both colony-forming units, granulocyte macrophage (CFU-GM) and burst forming units-erythroid (BFU-E) expressed per ml of cytapheresis product: CFU-GM × 18, BFU-E × 3 and if expressed per 10⁴/kg of body weight: CFU-GM × 30, BFU-E×3 (CFU-GM P <0·05, BFU-E<0·01). Long-term blood culture (LTSC) from FA stimulated leukapheresis, in an attempt to quantitate the most primitive stem cells, demonstrated that this expansion of the PBSC was sustained in time. We found by means of LTSC that FA did not stimulate CFU-L from patients with AML (two cases tested).
Finally two AML patients were grafted with FA-PBSC after Cytotoxan and total body irradiation (TBI). Haematopoietic reconstitution was rapid complete and sustained in time in both patients.
This indication for folinic acid should be further studied with or as an alternative to haematopoietic growth factors.     

Chronic cavitary histoplasmosis. Failure of oral treatment with ketoconazole

Ketoconazole appears to be a safe drug in the treatment of chronic cavitary histoplasmosis. Primary failure and relapse have been described, requiring amphotericin B, even after long therapy with ketoconazole. Four typical cases are presented. We caution about such potential failures and stress the importance of close observation of patients begun on therapy with ketoconazole for chronic cavitary histoplasmosis.     

Long-term cryopreservation of human stem cells.

Successful engraftment of autologous bone marrow depends on preserving the viability of stem cells during cryopreservation. While several techniques for effective bone marrow and peripheral blood stem cell collection and processing have been reported, little is known about the effect of the duration of cryopreservation on stem cell viability in humans. We reviewed, retrospectively, the engraftment data of 33 patients with leukemia treated at Brigham and Women's Hospital, Boston and the European Bone Marrow Transplant Group from 1981-1989 who received stem cells cryopreserved for greater than or equal to 2 years. Data on cryopreservation methods are available in 18 of 33 patients. In all cases, stem cells were frozen in liquid nitrogen with a programmed freezer and stored at or below -140 degrees C. The median duration of cryopreservation was 2.8 years (range 2-11 years). Thirty of 32 (94%) evaluable patients achieved granulocyte counts greater than 500 x 10(6)/l (median 23 days; range 10-119 days); 26 of 32 (74%) evaluable patients achieved platelets greater than 50 x 10(9)/l (median 30 days; range 19-128 days) while 22/32 (69%) patients achieved platelets greater than 100 x 10(9)/l (median 45 days; range 20-328 days). This report demonstrates that human stem cells cryopreserved for up to 11 years are capable of engrafting. Stem cells may be stored for prolonged periods and used for transplantation in patients harvested prior to pelvic irradiation or alkylating agent therapy.