Radiotherapy in the treatment of Hodgkin's disease.

Eighty-seven untreated patients with localised Hodgkin''s disease seen from 1969 to 1975 were treated by megavoltage radiotherapy. All were followed for at least 33 months. Thirty-three patients were staged clinically and 54 underwent more extensive investigation by lapaortomy and splenectomy. The projected five-year disease-free survival figures for patients staged surgically were 100% for the 17 with stage IA disease, 70% for the 19 with stage IIA disease, and 73% for the 15 with stage IIIA disease. These results were consistently better than those obtained in clinically staged patients. Five patients died, one of them without evidence of Hodgkin''s disease. As irradiation seems to produce excellent disease-free survival in most patients who are staged accurately at diagnosis, caution should be exercised in the routine use of adjuvant chemotherapy until the full risks of such treatment are clear. Combined modality therapy may be appropriate for patients with unfavourable features at presentation.     

Evidence for a repeating cross-beta sheet structure in the adenovirus fibre

The amino acid sequence of the adenovirus fibre protein reveals an approximately repeating motif of 15 residues. A diagonal comparison matrix established that these repeats extended from residue 43 to residue 400 of the 581 residue sequence. Assignment of secondary structure combined with model building showed that each 15-residue segment contained two short beta-strands and two beta-bends, one of which incorporated an extra residue in a beta-bulge of the Gx type. The 44 strands together gave a long (210 A) narrow, amphipathic beta-sheet, which could be stabilised by dimer formation to give the shaft of the fibre. The knob could arise from a dimer of the C-terminal 180 residue segment, predicted to be an 8-10 stranded beta-sandwich. This model is consistent with the electron micrographs of the fibre and it was supported by measurements of c.d. and of electron diffraction from microcrystals. The latter gave a pair of wide angle arcs, corresponding to a repeat of 4.7 A, oriented appropriately for a cross-beta structure. The relation of this structure to globular structures is discussed and a folding pathway is proposed. In its general features the structure resembles that proposed for the tail fibre of bacteriophage T4.     

Electrophoresis of small proteins in highly concentrated and crosslinked polyacrylamide gradient gels

A high concentration (40%) of acrylamide plus N,N′-methylenebisacrylamide combined with a high level of crosslinking (12.5%) yielded clear gels capable of restricting the passage of small proteins. This gel composition was chosen in preference to other combinations, in particular those producing opaque gels which have larger pore sizes and which provide a reduced sieving effect. Gradient gels were prepared in which the gel concentration rose from 3 to 40% and the degree of crosslinking increased from 4 to 12.5%. Such gels were suitable for fractionating crude, unreduced, and uncharacterized extracts containing proteins ranging in molecular size from 10,000 to several million daltons under conditions where all proteins are retained on the gel even after prolonged electrophoresis. The gels yielded zones which were of improved sharpness and resolution compared with gels of lower concentration and degree of crosslinking, and can be used to provide an estimate of molecular size. Examples of the use of HX gradient gels included both anodic and cathodic electrophoresis at pH 8.3 and 3.1, respectively, of serum and cereal-grain proteins and a partial enzymic hydrolysate of serum albumin.     

The geminal dimethyl analogue of Flurbiprofen as a novel Abeta42 inhibitor and potential Alzheimer's disease modifying agent

The subtle modification of a selection of Abeta42 inhibiting non-steroidal anti-inflammatory drugs (NSAIDs), through synthesis of the geminal dimethyl analogues, was anticipated to ablate their cyclooxygenase activity whilst maintaining Abeta42 inhibition. Methylflurbiprofen 6 exhibited similar in vitro Abeta42 inhibition to its parent NSAID Flurbiprofen and was further evaluated in the Tg2576 mouse model of Alzheimer's disease and an animal model of gastro-intestinal (GI) impairment, but proved unviable for further clinical development.     

Serglycin proteoglycan expression and synthesis in embryonic stem cells

The serglycin proteoglycan is expressed in most hematopoietic cells and is packaged into secretory vesicles for constitutive or regulated secretion. We have now shown serglycin mRNA expression in undifferentiated murine embryonic stem (ES) cells and in embryoid bodies, and synthesis and secretion in undifferentiated ES cells. Serglycin was localized to ES cell cytoplasm by immunostaining. Serglycin mRNA is expressed in tal-1((-/-)) ES cells and embryoid bodies; tal-1((-/-)) mice cannot produce hematopoietic cells. Thus, ES serglycin expression is probably not associated with hematopoiesis. Serglycin expression was increased by treatment of ES cells with retinoic acid (RA) and dibutyryl cAMP (dbcAMP). The serglycin core protein obtained from control ES culture medium after chondroitinase digestion appears as a doublet. Only the lower Mr band is present in serglycin secreted from RA-treated and the higher Mr band in RA+dbcAMP-treated cells, suggesting that core protein structure is affected by differentiation.     

Combination chemotherapy for acute lymphoblastic leukaemia in adults.

Fifty-one adults with acute lymphoblastic leukaemia were entered into a trial of intense initial chemotherapy and early "prophylaxis" of the central nervous system (CNS). Initial treatment with OPAL (Oncovin (vincristine), prednisolone, adriamycin (doxorubicin), and L-asparaginase (colaspase)) followed by craniospinal or cranial irradiation and intrathecal methotrexate produced remission in 36 patients (71%). Seventeen of these patients relapsed three to 18 months after the start of remission; the remainder had been in remission for 12 to 52 months by the end of the study. The predicted median duration of complete remission was 18.5 months. None of the four patients who initially had clinical evidence of CNS disease, three of whom also had leukaemic cells identical to those found in Burkitt''s lymphoma, achieved remission. Those patients who initially had hepatomegaly or splenomegaly had a shorter remission than those without. The predicted median survival was 27 months in those who achieved complete remission, one month in those who did not, and 21 months overall. The addition of colaspase and doxorubicin to vincristine and prednisolone and the use of early CNS treatment clearly improved the remission rate among adults with acute lymphoblastic leukaemia, though the presence and length of remission was affected by the extent of disease at presentation. Burkitt-like leukaemia, which had a poor prognosis, is probably a separate disease and may benefit from a different therapeutic approach.