the present invention is predicated on the discovery that polyamines of the above formulae , when administered to human or non - human mammals , suppress the intracellular biosynthesis of spermidine by depleting the cell of the enzymes ornithine decarboxylase ( odc ) and s - adenosylmethionine decarboxylase ( adometdc ), thereby depleting the supply of intracellular spermidine available to initiate synthesis of eif5a . as a result , depending on the dosage of polyamine administered , the amount of intracellular eif5a produced may be severely limited or eliminated . in the polyamines of formula ( iv ), the bridging groups a , b and c may be the same or different and are preferably alkyl , branched alkyl , cycloalkyl , arylalkyl or a heterocyclic bridging group wherein at least one of said n 1 , n 2 , n 3 or n 4 atoms is incorporated in the ring as a hetero atom . suitable polyamines for use in the compositions and methods of the present invention having the formulae ( i ), ( ii ), ( iii ) and ( iv ) above , as well as derivatives and salts thereof ( v ), are those described in u . s . pat . nos . 5 , 091 , 576 ; 5 , 393 , 757 ; and 5 , 510 , 390 , the entire contents and disclosures of each of which are incorporated herein by reference . methods for the preparation of the polyamines are also disclosed therein . hydroxy - substituted polyamines suitable for use in the methods and compositions of the invention and methods for their production are described in u . s . patent application ser . no . 08 / 595 , 877 filed feb . 6 , 1996 , now u . s . pat . no . 5 , 962 , 533 the entire contents and disclosures of which are incorporated herein by reference . it will be understood that those skilled in the art , given the disclosure herein of the invention , will be able to determine , without the exercise of undue experimentation , the dosage of polyamine necessary to reduce the intracellular production of eif5a to a desired level in any particular application while not severely disrupting intracellular polyamine homeostasis . generally , dosages in the range of from about 5 to about 200 mg / m 2 will be sufficient . it will be appreciated that while the agents described above form acid addition salts and carboxy acid salts , the biological activity thereof will reside in the agent itself . these salts may be used in human medicine and presented as pharmaceutical formulations in the manner and in the amounts ( calculated as the base ) described herein , and it is then preferable that the acid moiety be pharmacologically and pharmaceutically acceptable to the recipient . examples of such suitable acids include ( a ) mineral acids , i . e ., hydrochloric , hydrobromic , phosphoric , metaphosphoric and sulfuric acids ; ( b ) organic acids , i . e ., tartaric , acetic , citric , malic , lactic , fumaric , benzoic , glycolic , gluconic , gulonic , succinic and aryl - sulfonic acids , e . g ., p - toluenesulfonic acid . the pharmaceutical compositions of the invention preferably contain a pharmaceutically acceptable carrier or excipient suitable for rendering the compound or mixture administrable orally as a tablet , capsule or pill , or parenterally , intravenously , intradermally , intramuscularly or subcutaneously , or transdermally . the active ingredients may be admixed or compounded with any conventional , pharmaceutically acceptable carrier or excipient . it will be understood by those skilled in the art that any mode of administration , vehicle or carrier conventionally employed and which is inert with respect to the active agent may be utilized for preparing and administering the pharmaceutical compositions of the present invention . illustrative of such methods , vehicles and carriers are those described , for example , in remington &# 39 ; s pharmaceutical sciences , 4th ed . ( 1970 ), the disclosure of which is incorporated herein by reference . those skilled in the art , having been exposed to the principles of the invention , will experience no difficulty in determining suitable and appropriate vehicles , excipients and carriers or in compounding the active ingredients therewith to form the pharmaceutical compositions of the invention . the therapeutically effective amount of active agent to be included in the pharmaceutical composition of the invention depends , in each case , upon several factors , e . g ., the type , size and condition of the patient to be treated , the intended mode of administration , the capacity of the patient to incorporate the intended dosage form , etc . generally , an amount of active agent is included in each dosage form to provide from about 0 . 1 to about 250 mg / kg , and preferably from about 0 . 1 to about 100 mg / kg . while it is possible for the agents to be administered as the raw substances , it is preferable , in view of their potency , to present them as a pharmaceutical formulation . the formulations of the present invention for human use comprise the agent , together with one or more acceptable carriers therefor and optionally other therapeutic ingredients . the carrier ( s ) must be “ acceptable ” in the sense of being compatible with the other ingredients of the formulation and not deleterious to the recipient thereof . desirably , the formulations should not include oxidizing agents and other substances with which the agents are known to be incompatible . the formulations may conveniently be presented in unit dosage form and may be prepared by any of the methods well known in the art of pharmacy . all methods include the step of bringing into association the agent with the carrier which constitutes one or more accessory ingredients . in general , the formulations are prepared by uniformly and intimately bringing into association the agent with the carrier ( s ) and then , if necessary , dividing the product into unit dosages thereof . formulations suitable for parenteral administration conveniently comprise sterile aqueous preparations of the agents which are preferably isotonic with the blood of the recipient . suitable such carrier solutions include phosphate buffered saline , saline , water , lactated ringers or dextrose ( 5 % in water ). such formulations may be conveniently prepared by admixing the agent with water to produce a solution or suspension which is filled into a sterile container and sealed against bacterial contamination . preferably , sterile materials are used under aseptic manufacturing conditions to avoid the need for terminal sterilization . such formulations may optionally contain one or more additional ingredients among which may be mentioned preservatives , such as methyl hydroxybenzoate , chlorocresol , metacresol , phenol and benzalkonium chloride . such materials are of special value when the formulations are presented in multidose containers . buffers may also be included to provide a suitable ph value for the formulation . suitable such materials include sodium phosphate and acetate . sodium chloride or glycerin may be used to render a formulation isotonic with the blood . if desired , the formulation may be filled into the containers under an inert atmosphere such as nitrogen or may contain an anti - oxidant , and are conveniently presented in unit dose or multi - dose form , for example , in a sealed ampoule . the cem - ss cell line derived from a human t4 - lymphoblastoid line was chosen as a test model because it is cd4 positive and is susceptible to infection with hiv . the cells were treated with a 1 μm dose of diethylhomospermine that resulted in only a mild inhibition of cell growth , i . e ., a concentration estimated to result in only 25 % growth inhibition ( ic 75 ). the results over 72 - hour , 96 - hour and 144 - hour treatment programs are set forth graphically in fig1 which shows the decrease in the levels of spermidine ( spd ) and spermine ( spm ) in the cell line as a result of treatment with diethylhomospermine ( dehspm ). the results of the 96 - hour treatment on the levels of hypusine in the cell line are set forth in fig2 ( control ) and fig3 . the reduced level of hypusine reflects the decreased production of eif5a in the cells as a result of treatment with diethylhomospermine . fig4 shows the effect on the levels of hypusine in the cell line after 72 , 96 and 144 hours of treatment with diethylhomospermine . several human patients were selected for a five ( 5 ) day protocol of treatment with diethylnorspermine . polyamine levels [ spermidine ( spd ), diethylnorspermine ( denspm ) and hypusine ( hpu )] were measured on day one and used as pretreatment controls . each patient then received the drug for five days and a second sample was taken . in several cases , samples were taken in the middle of the dosing schedule . the dose is contained in the first column of the following table under “ patient .” for example , “ 1 - 094 ” means this patient received a dose of 94 mg / m 2 once per day for five days ; “ 1 - 118 ” means this patient received a dose of 118 mg / m 2 once per day for five days , etc . the polyamine levels were again determined on day five . the results are set forth in the following table . # monday = first day of a five - day course of treatment ending on subsequent friday ; thus , monday = pre - treatment “ control .” ideally , “ fraction of control ” compares friday [ hypusine ] with a “ control ” [ hypusine ] from the previous monday . * represents a comparison of a friday [ hypusine ] with a different monday sample from the same patient . ** represents a comparison of friday sample to the wednesday sample of the same week . as can be seen from the results set forth in the foregoing table , the levels of spermidine were lowered in each patient &# 39 ; s cell line , resulting in a decreased production of eif5a as demonstrated by the reduced levels of hypusine in each case . the results for hypusine levels in patient 1 - 094 are graphically depicted in fig5 [ hypusine level on day monday ( control )] and fig6 [ hypusine level on day friday ( after treatment )].
a method and pharmaceutical composition for inhibiting or preventing the intracellular biosynthesis of eif5a by the administration to a human or non - human mammal in need thereof an amount of a polyamine analogue or salt thereof sufficient to deplete the supply of intracellular spermidine required for eif5a biosynthesis .