Heptavalent

Pneumococcal vaccine. The heptavalent pneumococcal conjugate vaccine (PCV) is recommended for all children age 2-23 months. It is also recommended for certain children age 24-59 months. Pneumococcal polysaccharide vaccine (PPV) is recommended in addition to PCV for certain high-risk groups. See MMWR. 2000 49(RR-9) 1-35. 

Technetium is usually supplied in the form of heptavalent pertechnetate. Consequently, the syntheses of technetium complexes is necessarily accompanied by the reduction of pertechnetate. When concentrated hydrochloric acid is employed as a reductant, tetrachlorooxotechnetate(V) complexes can easily be obtained. A further reduction procedure is required to obtain hexachlorotech-netate(IV). Using these complexes, a number of technetium complexes have been synthesized by ligand substitution. The importance of preparative substitution reactions also increases in the light of the design and preparation of radiopharmaceuticals labelled with 99mTc and 188Re. 

Koide et al. [537] have described a graphite furnace atomic absorption method for the determination of rhenium at picomolar levels in seawater and parts-per-billion levels in marine sediments, based upon the isolation of heptavalent rhenium species upon anion exchange resins. All steps are followed with 186-rhenium as a yield tracer. A crucial part of the procedure is the separation of rhenium from molybdenum, which significantly interferes with the graphite furnace detection when the Mo Re ratio is 2 or greater. The separation is accomplished through an extraction of tetraphenylarsonium perrhenate into chloroform, in which the molybdenum remains in the aqueous phase. 

Ballestra et al. [32] described a radiochemical measurement for determination of "technetium in rain, river, and seawater, which involved reduction to technetium (IV), followed by iron hydroxide precipitation and oxidation to the heptavalent state. Technetium (VII) was extracted with xylene and electrode-posited in sodium hydroxide solution. The radiochemical yield was determined by gamma counting on an anticoincidence shield GM-gas flow counter. The radiochemical yield of 50 to 150 litre water samples was 20-60%. 

Virtually all serotypes of S. pneumoniae exhibiting intermediate or complete resistance to penicillin are found in the current 23 serotype pneumococcal vaccine. A heptavalent conjugate vaccine is available for use in infants between 2 months and 9 years of age. Current recommendations are for all healthy infants younger than 2 years of age to be immunized with the heptavalent vaccine at 2, 4, 6, and 12 to 15 months. 

Because children younger than 2 years of age do not respond adequately to the pneumococcal polysaccharide vaccine, a heptavalent pneumococcal conjugate vaccine was created that can be administered at 2, 4, and 6 months of age and between 12 and 15 months of age. 

Structure (3.226c), for example, depicts a central heptavalent Cl atom (Fa = 7), exceeding the normal valence octet by six electrons (These excess electrons are assumed to be accommodated in chlorine 3d orbitals, whereas d-orbital participation is prevented in first-row compounds.) Hypervalent structures such as (3.226a)-(3.226c) are claimed to be justified by the electroneutrality principle, which stipulates that second-row central atoms have zero formal charge (whereas first-row oxyanion Lewis structures commonly violate this principle).148... 

Drugs Available Yes. IND Heptavalent Anti-toxin A-F (equine despeciated) also, Tri-valent Equine anti-toxin A, B, and E. 

Drugs There is an antitoxin stored at the CDC. To arrange to use this antitoxin, call your state health department (or CDC at 404-639-2206 or 404-639-3753 workdays, or call weekends or evenings at 404-639-2888). This chemotherapy (antitoxin) available from CDC is a licensed trivalent equine antitoxin for serotypes A, B, and E. There is no reversal of botulism disease with this drug, but the antitoxin does usually prevent further nerve damage. The U.S. Department of Defense (DOD) has a heptavalent equine despeciated antitoxin for serotypes A - G (IND). DOD also has pentavalent toxoid (vaccine) for serotypes A - E (IND). The currently recommended schedule is for use at zero, two, and twelve weeks with a one year booster. This vaccine is supposed to induce solidly protective antitoxin levels in greater that 90 percent of those vaccinated after one year. Contact USAMRIID, (U.S. Army Medical Research Institute of Infectious Diseases), Fort Detrick, Maryland. Tel. 301-619-2833. 

Treatment—Since C. botulinum toxin blocks the actions of nerves that activate muscles necessary for breathing, an antitoxin can be injected up to about 24 hours (based on monkey studies) after exposure to a lethal toxin dose and still prevent death. The two types of available antitoxins prepared from horse sera are trivalent (includes types A, B, E) and heptavalent (types A, B, C, D, E, F, and G) preparations. It should be noted that patients face a theoretical risk of developing serum sickness from such antitoxins. 

Trivalent and heptavalent antitoxins are available A vaccine allows development of antibodies to the most common forms of Clostridium botulinum (Types A, B, C, D, and E)... 

Lyalikova NN, Khizhnyak TV. 1996. Reduction of heptavalent technetium by acidophilic bacteria of the genus Thiobacillus. Microbiology 65 468-73. 

Technetium compounds of the oxidation states 0 to -1-7 have hitherto been isolated, pertechnetates being the most stable. Also, compounds of quadrivalent technetium are fairly stable. Oxidation states lower than -1-4 can easily be oxidized to the quadrivalent or heptavalent state, whereas penta- and hexavalent technetium readily disproportionate into the hepta- and quadrivalent states. 

With all solvents studied including cyclohexanol, methyl ethyl ketone and cyclohexanone, heptavalent technetium is extracted most effectively from sodium sulfate and weakest from sodium nitrate or sodium perchlorate solutions. The data in Fig. 5 appear to be consistent with those on the solubilities of various sodium salts in pure tri-H-butyl phosphate. For example, the solubility of Na SO in TBP is extremely small compared with NaClO. ... 

Satisfactory separation of pertechnetate from perrhenate can be achieved by reducing Tc (VII) with hydrochloric acid and co-precipitating technetium with Fe(OH)j Technetium can then be oxidized to the heptavalent state by oxidizing the precipitate in cone, nitric acid and precipitating Fe(OH)j with ammonia. 

Only one reaction was reported in which FClOg was oxidized from the penta- to the heptavalent state (49, 52, 69). The powerful oxidizer PtFg was required to obtain the following reaction ... 

Botulism A (Clostridium bofulinum toxin) Bacteria— food (particularly improperly canned foods), wound, and infantile 1-5 days No Standa d Descending muscle paralysis, ptosis (drooping upper eyelids), blurred vision/ diplopia Fatal about 4-6 days nonfatal several months Aggressive resp support, supportive care trivalent and heptavalent antitoxin... 

Rhenium has a 5d56. electron configuration and all oxidation states from 0 to 7+ are known, although the heptavalent is the most stable state. 

He demonstrated that the antibodies raised against the antigens of seven selected serotypes of the organism afforded crossprotection, when used in combination as a heptavalent vaccine, against a wide range of strains of the organism. 

Feng, X., Song, C. 2001. The extraction and stripping behavior of heptavalent technetium with trialkyl phosphine oxide. Solvent Extr. Ion Exch. 19 (1) 51-60. 

The first two types, (a) and (b), called iodanes, are conventionally considered as derivatives of trivalent iodine I(+3). The next two, (c) and (d), periodanes, represent the most typical structural types of pentavalent iodine I(+5). The structural types (e) and (f) are typical of heptavalent iodine I(+7). 

Gouin et al. described a heptavalent a-Man-based glycocluster (Fig. 16.9a) as a strong inhibitor to block the hemagglutination of type 1 fimbrial adhesins of E. coli... 

Some elements, like hydrogen, oxygen, or the alkali metals, seem always to have the same valency in all of their compounds. Other elements however show different valencies thus, for example, chlorine can be mono-, tri-, penta- or heptavalent in its compounds. It is true that compounds of the same element with different valencies show different physical and chemical characteristics. 

Tc is a more complex isotope that is normally found in a quadrivalent state, but tends to oxidize to its heptavalent state as pertechnetate, which is easily leachable. As seen from Fig. 17.2, its oxidation potential in acidic and neutral environments is small hence. 

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