Analysis of the virus-induced inhibition of photosynthesis in malmsey grapevines.

• Virus infections decrease photosynthesis in plants, but the mechanistic basis is poorly understood. This was analysed in Banyalbufar malmsey, a grapevine (Vitis vinifera) variety of Mallorca (Spain). • The aim of this study was to analyse the mechanisms by which virus infection affect photosynthesis. Gas exchange (limitation analysis), chlorophyll fluorescence and Rubisco activity were compared in potted virus-infected and virus-free potted plants, and in field-grown young lowly infected and older highly infected plants. • Virus infection resulted in decreased photosynthesis (c. 50%). Stomatal limitation was unaffected in virus-infected plants, demonstrating that stomatal closure was not causing photosynthesis decreases. Chlorophyll fluorescence and limitation analysis suggested that the inhibition of primary light reactions was only a minor effect of virus infection. By contrast, mesophyll conductance to CO2 and Rubisco activity substantially decreased in virus-infected plants, corresponding to increases in the limitations to photosynthesis imposed by mesophyll conductance and carboxylation. • It is concluded that decreases in carboxylation and, possibly, in mesophyll conductance are the primary mechanisms by which virus infection impairs photosynthesis in Banyalbufar malmsey.

Stage I and stage II infiltrating ductal carcinoma of the breast analyzed for chromosome 8 copy number using fluorescent in situ hybridization.

We previously reported the results of 30 informative samples (from a total of 34 specimens gathered) of archival breast cancer tissue, including infiltrating ductal carcinoma (NOS), ductal carcinoma in situ, lobular carcinoma, papillary carcinoma and benign lesions of the breast. The study was conducted using fluorescent in situ hybridization (FISH) and a chromosome 8 alpha-satellite probe. Subsequently, a total of 34 cases of infiltrating ductal carcinoma of the breast (NOS, 17 cases stage I and 17 cases stage II) were studied, again using interphase cytogenetics. The aim of the present study is to confirm and extend the results of our initial study of stage I and stage II disease. Towards this end, 36 additional specimens of formalin-fixed paraffin-embedded breast cancer tissue have been analyzed cytogenetically under blinded conditions for the frequency of abnormal chromosome 8 copy numbers using FISH and the previously described protocol optimized for our laboratory. Of these, 18 were stage I and 18 were stage II. The frequency of trisomy 8 among stage I tumors was found to be 28% (5 out of 18). The frequency of trisomy 8 among stage II tumors was found to be 61% (11 out of 18). These results, while less striking, are consistent with those reported in our initial study of stage I and stage II disease, where the frequencies of trisomy 8 among stage I and stage II tumors were 24% (4 out of 17) and 82% (14 out of 17). These results not only establish that chromosome 8 trisomy is a recurrent finding in breast cancer, but also confirm that a higher frequency of trisomy 8 was observed with a higher clinical stage (stage II) than with a lower stage (stage I). It will be of interest to extend the findings in stage I and stage II breast cancer to other stages as well.

Single fraction per day versus two fractions per day versus radiochemotherapy in the treatment of head and neck cancer.

From January 1978 to January 1988, 859 patients with T3-T4, NO-3, MO were randomly allocated to receive either: Group A--60Co 60, 60 Gy in 30 fractions; Group B--60Co, 70.4 Gy in 64 fractions; Group C--60Co, 60 Gy in 30 fractions plus chemotherapy (5 Fu, 250 mg/m2/IV every 2 days). Chemotherapy and radiotherapy were combined simultaneously. The average age was 56 years; the male/female ratio was 802/57. Median performance status (ECOG scale) was 1 (range 0-2). The TNM distribution as UICC criteria was T3 529 patients; T4 330 patients; No 217 patients; N1 52 patients; N2 319 patients; and N3 271 patients. The primary sites were nasopharynx 92, oral cavity 252, hypopharynx 119, larynx 310, and others (sinuses and unknown primary)86. Complete response was achieved in 188/277 patients in Group A (67.8%), 254/282 patients in Group B (90%), and 289/300 in Group C (96.3%). All patients were followed and statistical analysis shows a significant improvement in median duration of response, as well as survival for Groups B and C compared with Group A. No significant differences were seen between Group B and C. The acute toxicity was mucositis, skin toxicity, bone marrow depression. A mean temporary weight loss of 4.9 Kg was observed with a range of 2.3-10.5 Kg.