Partial Complexation

Our ability to separate free metal cations by CE is Umited because many of the metal ions have similar electrophoretic mobilities. An excellent way to enhance the separation of metal ions is to add a relatively weak complexing ligand (L ) such as tartrate, lactate or a-hydroxyiso-butyric acid (HIBA) to the BGE. Now part of each metal ion will remain as the free ion (M, for example) and part will be converted to a complexed form (ML , ML2, ML3, for example). The total mobility (iU) will be the sum of the products of the mole fractions of each species (a) multiplied by their respective mobiUties. 

Lactate has the same a-hydroxycarboxylate complexing group as tartrate and HIBA, but it is a smaller molecule and forms somewhat weaker complexes than tartrate with most metal ions. Shi and Fritz [13] found that a lactate system gave excellent separations for divalent metal ions and for trivalent lanthanides. A brief optimization was first carried out to establish the best concentrations of lactate and UV probe ion and the best pH. Excellent separations were obtained for all thirteen lanthanides, alkali metal ions, magnesium and the alkaUne earths, and several divalent transition metal ions. All of these except copper(ll) eluted before the lanthanides. An excellent separation of 27 metal ions was obtained in a single run that required only 6 min (Eigure 11.13). 

Lactic acid makes possible the separation of metal ions with almost identical mobilities by complexing the individual metal ions to varying degrees. However, NH andK cations also have virtually identical mobilities and are not complexed by lactic acid. Potassium ions can be separated by CZE if a suitable crown ether is incorporated into the electrolyte [15-18]. The K ion is selectivity complexed and its mobility is reduced just enough to permit a good separation. 

Incorporation of 18-crown-6 into the electrolyte containing lactic acid affects the migration of several metal ions other than and NHj. The crown ether increases the migration time of Sr by 15%, Pb by 18% and Ba by 35%, apparently by complexation to form a bulkier, less mobile species. 

---

Measurements were performed employing a Perkin Elmer X2, 5 or 12 UV-Vis spectrophotometer at 25 O.r- C. Equilibrium constants were determined by measuring the extinction coefficient at a suitable wavelength of the partially complexed dienophile (y,.hs) as a function of the concentration of... 

The solubility of most metals is much higher when they exist as organometallic complexes.4445 Naturally occurring chemicals that can partially complex with metal compounds and increase the solubility of the metal include aliphatic acids, aromatic acids, alcohols, aldehydes, ketones, amines, aromatic hydrocarbons, esters, ethers, and phenols. Several complexation processes, including chelation and hydration, can occur in the deep-well environment. 

Phenotype determined by cortical region activated (e.g. if motor cortex representing left thumb is activated, then left thumb jerking results). Consciousness is preserved Impaired consciousness lasting seconds to minutes, often associated with automatisms such as lip smacking Simple or partial complex seizure evolves into a tonic-clonic seizure with loss of consciousness. There are sustained muscular contractions (tonic) followed by periods of relaxation (clonic) lasting 1-2 min... 

Defects of complex II. These have not been fully characterized in the few reported patients, and the diagnosis has often been based solely on a decrease of succinate-cytochrome c reductase activity (Fig. 42-3). However, partial complex II deficiency was documented in muscle and cultured fibroblasts from two sisters with clinical and neuroradiological evidence of Leigh s syndrome, and molecular genetic analysis showed that both patients were homozygous for a point mutation in the flavoprotein subunit of the complex [17]. This was the first documentation of a molecular defect in the nuclear genome associated with a respiratory chain disorder. 

For G2-OH, there is an absorption shoulder at 605 nm and a band centered at 810 nm, which indicates only partial complexation of Cu +. For G4-OH, the band... 

Zeolite X and A with Gd(III) complexed by 8-hydroxyquinoline (8-HQ) was prepared either by the introduction of Gd(III)(8-HQ)2Cl complex into the zeolite synthesis gel or by stirring the Gd(III)-exchanged zeolite X in an ethanolic solution of 8-HQ (85). In vitro MRI studies showed signal enhancement (Ti shortening). However, the data cannot be compared with the previous results obtained with Gd(III)-loaded, but uncomplexed zeolites (because of partial complexation of Gd(III), different methods for determining the relaxivity enhancement, etc.)... 

Zonisamide has only recently been approved for use in the United States, although it has been available in Japan for several years. It is effective in partial complex and generalized tonic-clonic seizures and also appears to be beneficial in certain myoclonic seizures. It has a long half-life (about 60 hours) and requires about 2 weeks to achieve steady-state levels. It causes cerebellovestibular side effects similar to those of most other AEDs sharing its mechanism of action. In addition, it appears to cause an increased incidence of kidney stones. 

Clorazepate dipotassium is approved in the United States as an adjunct in the treatment of partial complex seizures. It appears to be useful, especially in patients with high seizure frequencies and psychic disturbances. 

Unlabeled Uses Partial complex (psychomotor) seizures... 

Hexacyanoferrates were immobilized on Au covered with SAM of 3,3 -thiodipropionic acid [86]. It has been found from voltammetric studies that the surface coverage of hexacyanoferrate is close to one monolayer and such an electrode exhibits very good surface redox behavior. Cheng et al. [87] have described the formation of an extremely thin multilayer film of polybasic lanthanide heteropolytungstate-molybdate complex and cationic polymer of quaternary poly(4-vinylpyridine), partially complexed with osmium bis(2,2 -bipyridine) on a gold electrode precoated with a cysteamine SAM. Consequently, adsorption of inorganic species might also be related to the properties of SAMs. This problem will be discussed in detail in a separate section later. 

Gilhg P, Sackellares S, Greenberg HS Right hemisphere partial complex seizures mania, hallucinations, and speech disturbances during ictal events. Epilepsia 29 26-29, 1988... 

However, by taking into account that in the case of model compounds 1 1 ether-AlR8 complexes have been obtained, while in the case of the polymers only a partial complexation dependent on stereoregularity has... 

Partial complexation with alkali metal cation... 

Carbamazepine (Tegretol) is closely related to the tricyclic antidepressants. In neurological medicine, its principal uses are as an anticonvulsant for partial complex seizures and in the management of tic... 

The treatment of intermittent explosive disorder, kleptomania, pyroma-nia, pathological gambling, trichotillomania, and impulse control disorder not otherwise specified is beyond the scope of this text, and we only briefly discuss some key aspects of impulse control disorders, about which the therapist should seek consultation with the psychiatrist. In particular, one must consider whether the person with intermittent problems of impulse control is manifesting a partial complex seizure (rare), or whether the person who habitually or rhythmically pulls his or her hair has a partial complex seizure instead of trichotillomania (unusual). 

Doses of vigabatrin up to 10 g have been taken without serious effects. Toxic manifestations include vertigo, tremor, sedation, coma, myoclonic jerks, and psychosis. Gastric lavage within 1-2 hours is recommended after doses in excess of 12 g in adults and 2 g in children (SEDA-22,85). The development of discontinuous partial complex status epilepticus in a patient with partial epilepsy who had taken a 20 g overdose 6 days earher was considered to be a possible effect of withdrawal (SEDA-22, 85). 

Hyperthyroidism Meniere s disease (early stages) Parathyroid disease Partial-complex seizures Postconcussion syndrome Premenstrual syndrome Pulmonary embolism Mitral valve prolapse ... 

These findings have important implications for the treatment of bipolar affective disorder. Some agents used to treat partial-complex seizures such as carbamazepine and various valproate formulations have been found to be effective in bipolar affective disorder (Bowden 1995). One such agent, divalproex, is now the most commonly prescribed antimanic agent. These agents may be more effective in subtypes of mania that are not lithium responsive. As noted earlier, African Americans are more often prescribed antipsychotics. Poor tolerance of lithium maybe a factor. Improving access to alternatives to lithium may reduce the need for antipsychotics in some African Americans with mania. 

---