145 research outputs found
Toward the Total Synthesis of Spirastrellolide A. Part 2: Conquest of the Northern Hemisphere
North and South: The unique biological activity of the natural product spirastrellolide A renders it an attractive lead for anticancer agents. The southern hemisphere (C1āC25) and the northern hemisphere (including the chlorinated [5,6,6]-bis-spiroacetal entity and the lateral C42āC47 chain) are prepared by concise and efficient routes. Consequently, the entire carbon framework of this potent phosphatase inhibitor, which contains 21 chiral centers, is prepared in an optically active form, and an important step toward structure determination by total synthesis is achieved
Toward the Total Synthesis of Spirastrellolide A. Part 1: Strategic Considerations and Preparation of the Southern Domain
North and South: The unique biological activity of the natural product spirastrellolide A renders it an attractive lead for anticancer agents. The southern hemisphere (C1āC25) and the northern hemisphere (including the chlorinated [5,6,6]-bis-spiroacetal entity and the lateral C42āC47 chain) are prepared by concise and efficient routes. Consequently, the entire carbon framework of this potent phosphatase inhibitor, which contains 21 chiral centers, is prepared in an optically active form, and an important step toward structure determination by total synthesis is achieved
Poorly differentiated loco-regionally advanced naso ā and oropharyngeal carcinoma: results of neoadjuvant chemotherapy followed by radiotherapy
Over the years 1986ā1997, at the Centre of Oncology in KrakĆ³w, 82 patients (28 women, 54 men; mean age: 50.8 years) with poorly differentiatied naso- and oropharyngeal carcinoma with metastases to regional nodes (stage III and IV) received neoadjuvant chemotherapy followed by teleradiotherapy. The primary tumour was located in the nasopharynx in 57 patients (69.5%), in the tonsil ā in 24 (29.3%), and in the base of the tongue (one patient). Chemotherapy cycles consisted of cisplatin in a dose of 100 mg/m2 administered intravenously on the first day, and 5-f1uorouracil in a dose of 1000 mg/m2 over days 1 to 5. Forty-seven (57.3%) patients received 3 cycles, 25 (30.5%) patients ā 2 cycles, 8 (9.8%) patients ā 1 cycle. After chemotherapy, patients received conventionally fractionated (200 cGy 5x a week) radiotherapy to the primary tumour (50ā65 Gy) and regional nodes (50ā70 Gy). The therapy was generally well tolerated, however two patients developed fatal late complications. Improvement in therapy results was observed when comparised with a historical group. Five-year overall survival was 52%. The degree of regression (PR + CR), following neoadjuvant chemotherapy, which appeared to depend on the number of chemotherapy cycles, is the main prognostic factor for this group of patients
A hasznĆ”latalapĆŗ biztosĆtĆ”s mĆŗltja, jelene Ć©s jƶvÅje
[Cp*RuCl]<sub>4</sub> (1) has previously been shown to be the precatalyst of choice for stereochemically unorthodox trans-hydrometalations of internal alkynes. Experimental and computational data now prove that the alkyne primarily acts as a four-electron donor ligand to the catalytically active metal fragment [Cp*RuCl] but switches to adopt a two-electron donor character once the reagent R<sub>3</sub>MH (M = Si, Ge, Sn) enters the ligand sphere. In the stereodetermining step the resulting loaded complex evolves via an inner-sphere mechanism into a ruthenacyclopropene which swiftly transforms into the product. In accord with the low computed barriers, spectral and preparative data show that the reaction is not only possible but sometimes even favored at low temperatures. Importantly, such trans-hydrometalations are distinguished by excellent levels of regioselectivity when unsymmetrical alkynes are used that carry an āOH or āNHR group in vicinity of the triple bond. A nascent hydrogen bridge between the protic substituent and the polarized [RuāCl] unit imposes directionality onto the ligand sphere of the relevant intermediates, which ultimately accounts for the selective delivery of the R<sub>3</sub>Mā group to the acetylene C-atom proximal to the steering substituent. The interligand hydrogen bonding also allows site-selectivity to be harnessed in reactions of polyunsaturated compounds, since propargylic substrates bind more tightly than ordinary alkynes; even the electronically coupled triple bonds of conjugated 1,3-diynes can be faithfully discriminated as long as one of them is propargylic. Finally, properly positioned protic sites lead to a substantially increased substrate scope in that they render even 1,3-enynes, arylalkynes, and electron-rich alkynylated heterocycles amenable to trans-hydrometalation which are otherwise catalyst poisons
75. Validity of accelerated hyperfractionated conformal radiation therapy and monitoring of treatment results in patients with advanced NSCLC. Assessment of tolerance and early failure
AimThe assessment of the early failure and toxicity of treatment for the advanced NSCLC using the accelerated hyperfractional conformal irradiationMaterial13 patients (12 men, 1woman, aged 50 ā 74), in good performance status/70ā90 points of Karnofsky scale/were treated.Patients have been irradiated with 15 MV or 6 MV photon two times a day with 6 hours break using 1.25 Gy fraction to total dose 50 Gy. PTV ranged from 599 to 1104 cm3 (mean 858 cm3).MethodsThe mean tumor dimension before and 6 weeks after finishing treatment with the use of CT have been assessed.Results3 early failure have been observed, all outside of PTV. The 2/3 of that recurrence have been recognized by CT. These patients have been ordered to chemotherapy. The mean tumor dimension was equal to 2,38 cm 6 weeks after finishing of treatment. This means 44% regression of the mean tumor dimension. No side effects and deteriorations of performance status have been observed.All patients have finished the treatment, all are in follow up, alive.ConclusionsThe accelerated hyperfractioned regimen can be carried out in outpatients service if PTV is smaller than 1000 cm3.Observed early recurrence two months of follow up are connected with a progression of a tumor outside of irradiated volume
20 Typ z przewagÄ limfocytĆ³w ziarnicy zÅoÅliwej: Czy wymaga odmiennego leczenia?
WstÄpTyp z przewagÄ
limfocytĆ³w ziarnicy zÅoÅliwej (LP-HD) jest wyrĆ³Å¼niany jako odrÄbna postaÄ histokliniczna. Ponadto wykazuje siÄ duże morfologiczne podobieÅstwo do chÅoniaka nieziarniczego z limfocytĆ³w B, ktĆ³ry w rozpoznaniach LP-HD LP-HD może stanowiÄ do 10%. Celem pracy jest ocena przebiegu klinicznego i wyniki leczenia chorych na LP-HD.MateriaÅW Krakowskim Centrum Onkologii w latach 1987ā1996 leczono 53 chorych z rozpoznaniem LP-HD, 14 kobiet i 39 mÄżczyzn (M:K ā 2,8:1). Wiek chorych wahaÅ siÄ od 14 do 73 lat, mediana 39 lat. W stopniu zaawansowania I+II byÅo 31 chorych (58,5%), III+IV 22 chorych (41,5%). Objawy B stwierdzono u 13/53 chorych (24,5%), X 10/53 chorych (18,8%), E u 2/53 chorych (3,8%). U 2/31 chorych (6,5%) proces byÅ zlokalizowany w ukÅadzie chÅonnym przedprzeponowym. W grupie I+II, 1 chory byÅ leczony wyÅÄ
cznie chemicznie (CHT), 22 chorych leczono wyÅÄ
cznie CHT, 3 chorych RT i 10 chorych CHT+RT. Czas obserwacji waha siÄ od 16 do 132 miesiÄcy (mediana 66 miesiÄcy).WynikiW caÅej grupie uzyskano 78% 5 ā letnich i 71% 10 ā letnich przeżyÄ, w grupie I+II odpowiednio 90% i 78%. W grupie III+IV 5 i 10 ā letnie przeżycia wyniosÅy 62%. CaÅkowitÄ
regresjÄ po I rzucie leczenia uzyskano u 100% chorych w grupie I+II 4/5 wznĆ³w (80%) stwierdzono w ukÅadzie chÅonnym przedprzeponowym. Czas wystÄ
pienia wznowy wahaÅ siÄ od 14 do 712 miesiÄcy (mediana 41 miesiÄcy). U jednego chorego stwierdzono transformacjÄ typu LP w LD.U 3/53 chorych (5,6%) stwierdzono w kontroli chÅoniaka nieziarniczego (MALT żoÅÄ
dka, nieokreÅlony chÅoniak o wysokim stopniu zÅoÅliwoÅci, chÅoniak z limfocytĆ³w T) w okresie od 13 do 35 miesiÄcy (mediana 28 miesiÄcy). W grupie III+IV przeżycie 5 ā letnie wyniosÅo 69% u chorych leczonych CHT i 32% leczonych wyÅÄ
cznie RT (p = 0,3).Wnioski1.Wyniki leczenia chorych na LP-HD w naszym materiale nie odbiegajÄ
od wynikĆ³w leczenia chorych na klasycznÄ
postaÄ ziarnicy. Ograniczenie zakresu RT w grupie I+II i CHT w grupie III+IV może mieÄ wpÅy na pogorszenie wynikĆ³w leczenia.2.Mimo odrÄbnoÅci morfologicznych typ LP-HD powinien byÄ leczony jak klasyczna postaÄ ziarnicy zÅoÅliwej
Quantum power correction to the Newton law
We have found the graviton contribution to the one-loop quantum correction to
the Newton law. This correction results in interaction decreasing with distance
as 1/r^3 and is dominated numerically by the graviton contribution. The
previous calculations of this contribution to the discussed effect are
demonstrated to be incorrect.Comment: 10 pages, 5 figures; numerical error corrected, few references adde
6. The technique of total body irradiation applied in the St. LeszczyÅski Memorial Hospital in Katowice
At the St. LeszczyÅski Memorial Hospital in Katowice a modification of TBI technique was prepared. For this a special two variant of body frame ā one for treatment planning and an another one for treatment delivery ā was made. The total dose of 12 ā 15 Gy (in lung not more than 9 Gy) was delivered in six fraction of 15 MV photons, produced in Primus linear accelerator, for 3 consecutive days. Patient was treated by a combination of fields: lateral ā set at SSD of 330 cm and AP/PA ā set at 135 cm. The dose-rate measured at 10 cm in a water phantom for lateral fields was 4,3 cGy/min., and for AP/PA fields 23,6 cGy/min. Lung shields were made from wood alloy and their shape was carried out from computerized tomograph scans (CT). For each patient a set of computerized tomograph scans was prepared. Patient during the CT was laying in supine position in the body frame made of 1 cm thick plexi plates. On the walls of that body frame a special marks of tin material were inserted. These marks allow to reproduce both ā the same patient position during the irradiation and also in the treatment planning system HELAX. Position of shields before AP/PA fraction was determined by means of HELAX, and then shields were fastened to plexi trays inserted in the head of Primus. Lung was also shielded during one lateral fraction and the shape of the shield was carried out on a simulator. The volume between the patient and walls of the body frame was fulfilled by bolus (bags with rice) to get a homogenous dose distribution. The electron boost to the thorax wall (shielded for 15 MV photons) was delivered with a 6 or 9 MeV electron beam.The percentage deviation of dose, for all 9 irradiated patients, calculated at ten anatomical points representative of the body anatomy, was in the limit ā0,4% to +13% (excluded in lung) from the dose delivered to PC (reference point: 1/2 AP and 1/2 lateral dimension at 1/2 of patient length in irradiation position). The in vivo measurements carried out by means of MOSFET detectors confirmed that accuracy
Molecular Dissection of the [epsilon] Subunit of the Chloroplast ATP Synthase of Spinach
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