Coherent manipulation of electron spins in the {Cu3} spin triangle complex impregnated in nanoporous silicon.

We report on coherent manipulation of electron spins in an antiferromagnetically coupled spin triangle {Cu3-X} (X=As, Sb) impregnated in freestanding nanoporous silicon (NS) by using 240 GHz microwave pulses. Rabi oscillations are observed and the spin coherence time is found to be T(2)=1066 ns at 1.5 K. This demonstrates that the {Cu3-X}:NS hybrid material provides a promising scheme for implementing spin-based quantum gates. By measuring the spin relaxation times of samples with different symmetries and environments we give evidence that a spin chirality is the main decoherence source of spin triangle molecules.

Opportunities with combined modality therapy for selective organ preservation in muscle-invasive bladder cancer.

Combined-modality therapy for organ preservation represents an appropriate alternative to radical surgery in the management of several malignant diseases. The standard therapy for muscle-invasive bladder cancer in the United States has been radical cystectomy. Although the sequelae of radical surgery have been ameliorated somewhat by techniques for the construction of orthotopic bladders, the ideal therapy should both cure the patient of cancer and maintain a functioning natural bladder. Years of experience in Europe and Canada with bladder preservation using radiation therapy are documented. Advances in transurethral surgery technique and in the combination of radiation and chemotherapy have led to safe and effective regimens for patients with bladder cancer. Several recent trials with combined-modality therapy have established this treatment as a viable alternative to radical cystectomy in selected patients.

Preliminary results in invasive bladder cancer with transurethral resection, neoadjuvant chemotherapy and combined pelvic irradiation plus cisplatin chemotherapy.

Preliminary data are presented of a clinically feasible pilot study to select a significant subgroup of patients among those with muscle-invading bladder tumors for local cure and bladder preservation, while also to offer all patients the possibility of preventing the development of distant metastases. Transurethral debulking surgical resection was combined with neoadjuvant methotrexate, cisplatin and vinblastine chemotherapy plus 2 additional courses of cisplatin and 4,000 cGy. If tumor was found on cystoscopic re-evaluation by biopsy and for cytology after cisplatin and partial irradiation (4,000 cGy.) immediate cystectomy was advised. If tumor was not found consolidation by a radiotherapy boost to a total of 6,480 cGy. plus 1 additional course of cisplatin was given. Of 53 consecutive patients the planned treatment was completed in 42 (79%). With a median followup of 26 months (range 15 to 42 months), 72% of all entered patients were alive, 70% have not required cystectomy and 74% have not had distant metastases. Among the 42 patients who completed the planned protocol chemotherapy dose reductions were required in 39% for stomatitis, bone marrow depression and/or renal dysfunction. There were 2 serious complications but no treatment-related sepsis, deaths or significant renal dysfunction. Eight patients underwent immediate radical cystectomy because of positive biopsy and/or cytology results after 4,000 cGy., while 34 completed full chemotherapy and radiotherapy without any significant bladder or bowel injury. Of 42 patients 22 (52%) have maintained the bladder without any recurrence, and of those selected for full chemotherapy and radiotherapy this number increased to 65%. To date 12 patients have persistent or recurrent bladder tumors: 5 (15%) had invasive tumors treated by cystectomy and 7 (21%) had carcinoma in situ treated by intravesical therapy. The true success of this or other selective bladder-preserving treatments will require 3 to 5 years of followup to be confident that such treatment has sterilized the bladder of cancer. This feasibility study has been clinically practical, modestly well tolerated and encouraging for the significant proportion of patients with a sustained complete response and for the 70% over-all survival rate at 2 years. To evaluate critically the efficacy of methotrexate, cisplatin and vinblastine chemotherapy in the prevention of occult distant micrometastases and in increasing the rate of successful bladder preservation, in May 1988 we began a randomized phase 3 trial with and without neoadjuvant methotrexate, cisplatin and vinblastine chemotherapy.

The treated histories of patients with Ta grade 1 transitional-cell carcinoma of the bladder.

One hundred sixty patients with grade 1 transitional-cell carcinoma of the bladder were evaluated and treated at the Massachusetts General Hospital, Boston. The mean follow-up period was 57 months. There were 92 new patients and 68 patients who had a history of transitional-cell carcinoma. Fifty-three patients (33%) never had another transitional-cell carcinoma. Sixty-eight (43%) of the remaining 107 patients had recurrent Ta grade 1 transitional-cell carcinoma. In 32 patients (20%) disease progressed in grade, in seven patients (4%) invasive transitional-cell carcinoma developed, five patients underwent cystectomy, and one patient died of transitional-cell carcinoma. High-risk factors included positive results of cytologic studies after therapy and three or more recurrences. Multiple therapies were used, but it is impossible to determine if anything other than transurethral resection altered the course in these patients. The data suggest that patients with low-risk factors and Ta grade 1 tumors might be followed up with a quarterly cytologic examination and cystoscopy once or twice a year, unless a change in symptoms occurs.

Validation of the tumor, nodes and metastasis classification of renal cell carcinoma.

A retrospective analysis of 252 patients with renal cell carcinoma was performed with the tumor, nodes and metastasis system of cancer staging. Each patient received a clinical and a pathological classification. Patient survival was calculated for each pT stage. All patients with stage pT1 disease (100 per cent) were alive at 5 years, as were 91 per cent of those with stage pT2 tumors. Higher T stages showed poorer survival; 58 per cent of the patients with stage pT3 and only 25 per cent with stage pT4 tumors were alive at 5 years. Invasion into the inferior vena cava (pT3c) had an adverse effect on survival, which was statistically significant compared to patients in the pT3a and pT3b subgroups. The type of surgical procedure performed had no influence on ultimate survival, nor did the use of adjuvant radiation therapy. The tumor, nodes and metastasis system clearly documents that the survival of patients with renal cell carcinoma depends on the local extent of the primary tumor, determined at the time of surgical exploration.