Mammillary

Warze, /. wart nipple, teat mastoid pin, knob, boss, excrescence, tubercle, warzen-ahnlich, -artig, a. wart-like, mammillary, (Biol.) papillary. -fSnnig, a. wartshaped, wart-like, mammillary, (Biol.) papillary. 

Two-compartment mammillary model for intravenous administration using Laplace transform... 

Fig. 39.12. (a) Two-compartment mammillary model for single intravenous injection of a doseD. The buffer compartment exchanges with plasma with transfer constants and k p. (b) Time courses of the... 

Usually, the buffer compartment is not accessible and, consequently, the absolute amount of X cannot be determined experimentally. For this reason, we will only focus our discussion on the plasma concentration Cp. It is important to know, however, that the time course of the contents in the two compartments is the sum of two exponentials, which have the same positive hybrid transfer constants a and p. The coefficients A and B, however, depend on the particular compartment. This statement can be generalized to mammillary systems with a large number of compartments that exchange with a central compartment. The solutions for each of n compartments in a mammillary model are sums of n exponential functions, having the same n positive hybrid transfer constants, but with n different coefficients for each particular compartment. (We will return to this property of linear compartmental systems during the discussion of multi-compartment models in Section 39.1.7.)... 

By way of illustration, we apply the y-method to the two-compartment mammillary model for intravenous administration which we have already seen in Section 39.1.6. The matrix K of transfer constants for this case is defined by means of ... 

Pharmacokinetics emerged as a discipline in the 1960s with its foundation in compartmental modeling, although earlier origins of pharmacokinetics can be traced [1], Mammillary compartmental models provided the framework for phar-... 

It has been shown that linear mammillary compartment models can readily be represented by products of input and disposition functions in the Laplace domain [20], Solutions for the drug concentration or amount in any compartment are obtained by taking the inverse of the Laplace function. This approach avoids the use of differential equations and their potentially tedious solution. The La-... 

LZ Benet. General treatment of linear mammillary models with elimination from any compartment as used in pharmacokinetics. J Pharm Sci 6 536-541, 1972. 

The ventral subgroup, situated at the ventral surface of the brain, rostral and caudal to the mammillary bodies, is the largest subgroup, containing approximately 2500 neurons (Kohler et a ., 1985). The ventral subgroup has fewer parvicellular neurons than the medial subgroup. 

The histaminergic neurons have several well-developed primary and secondary dendrites that overlap with each other. Furthermore, long dendrites from histaminergic neurons located close to the mammillary recess or to the basal surface of the mammillary body appear to penetrate into the ependymal layer and make contact with cerebrospinal fluid. Thus, it is likely that neuroactive substances such as cytokines, present in the cerebrospinal fluid, may influence the discharge activity of TMN neurons (Wada et al., 1991). Unlike the dopaminergic neurons, which are known to release dopamine from their dendrites, there is no evidence that these histaminergic dendrites store and/or release HA. 

Hypothalamus medial and lateral preoptic areas anterior, lateral, and posterior hypothalamic areas dorsomedial and ventromedial nuclei tuberomammillary nucleus medial and lateral preoptic areas, lateral hypothalamic area, dorsomedial nucleus, complex of mammillary bodies... 

FIGURE 14-2 The histaminergic system of the rat brain. (A) Frontal sections through the posterior hypothalamus showing the location of histaminergic neurons. Arc, arcuate nucleus DM, dorsomedial nucleus LM, lateral mammillary nucleus MM, medial mammillary nucleus MR, mammillary recess PM, premammillary nucleus 3V, third ventricle VMH, ventromedial hypothalamic nucleus. (Modified with permission from reference [5].)... 

A number of substances are colocalized with histamine and its biosynthetic enzyme in hypothalamic tubero-mammillary neurons [15]. These include glutamate... 

Two classical methods used in the analysis of pharmacokinetic data are the fitting of sums of exponential functions (2- and 3-compartment mammillary models) to plasma and/or tissue data, and less frequently, the fitting of arbitrary polynomial functions to the data (noncompartmental analysis). 

Analysis of data using simple mammillary, compartmental models allows the estimation of all of the basic parameters mentioned here, if data for individual tissues are analyzed with one or two compartment models, and combined with results from... 

The mineral mimkite (p. 15), 3Pb3(As04)2.PbCl2, may be prepared artificially by fusing a mixture of its component salts.2 It occurs in yellow to brown crystal aggregates or mammillary crusts. The crystals are hexagonal pyramids, a c =0-73147, isomorphous with pyromor-phite and the apatites.3 It is widely distributed and has been found in Cornwall, Cumberland and Leadhills (Lanark). 

Traditionally, linear pharmacokinetic analysis has used the n-compartment mammillary model to define drug disposition as a sum of exponentials, with the number of compartments being elucidated by the number of exponential terms. More recently, noncompartmental analysis has eliminated the need for defining the rate constants for these exponential terms (except for the terminal rate constant, Xz, in instances when extrapolation is necessary), allowing the determination of clearance (CL) and volume of distribution at steady-state (Vss) based on geometrically estimated Area Under the Curves (AUCs) and Area Under the Moment Curves (AUMCs). Numerous papers and texts have discussed the values and limitations of each method of analysis, with most concluding the choice of method resides in the richness of the data set. 

Wagner [1] has shown, with IV bolus dosing, that the Vss for a n-compartment open mammillary model with first-order elimination from the central compartment is ... 

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