GB1586582A - Quaternary ammonium solutions for use in blood serum analyses - Google Patents

Description

(54) QUATERNARY AMMONIUM SOLUTIONS FOR USE IN BLOOD SERUM ANALYSES (71) We, WILLIAM VILLEE DORWART, JR.

and WALTER BRUMMUND, JR., both citizens of the United States of America, residing respectively at 124 Maple Avenue, Bala Cynwyd and 4033 Spruce Street, City of Philadelphia, both in the Commenwealth of Pennsylvania, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to a laboratory standard material, and more particularly, to a stable reference standard useful from the assay of animal body fluids, especially blood serum, and to a method of preparation and use thereof.

Various types of apparatus have been developed in recent years for the automatic analysis of human blood serum, which apparatus are capable of making rapid simultaneous analytical determinations on a precise quantitative basis of various components of each of a series of blood serum samples successively introduced into the apparatus. Biochemical determinations may be made, for example, by such apparatus, of the following constituents of the blood serum samples; albumin, alkaline phosphatase, bilirubin, calcium, chloride, chloesterol, carbon dioxide content, creatinine, glucose, lactic dehydrogenase, inorganic phosphorus, potassium, sodium total protein, transaminase, urea nitrogen, uric acid and creatine phosphokinase.

In order to calibrate the apparatus of the type for making these determinations, a reference standard blood serum sample is used whose constituents have precisely predetermined values. It is necessary for such reference standard serums to be capable of being stored for long periods of time without deterioration, and for that reason, it has been the practice to freeze-dry (lyophilize) them. It has also been the prior art practice to reconstitute the reference standard serum before use by means of, for example, a separate aqueous solution containing ammonium bicarbonate to restore the carbon dioxide that has been lost in the blood serum during the lyophilizing process. Examples of reconstituting solutions that have been used in the prior art can be found in U.S. Patents Nos. 3,466,249 and 3,629,142.

Although the composition of this invention has as its primary purpose the reconstitution of lyophilized blood serum to return to the serum a known quantity of carbonate or bicarbonate so that the apparatus can be calibrated for determining the amount of carbon dioxide in the blood, the composition of this invention is useful for various other chemical analyses. As is well known, secondary reference materials serve two important functions in analytical chemistry laboratories. They are used as standards for calibrating instruments, and they are used to check the accuracy and precision of the assay results. These secondary reference materials usually contain multiple substances, so that just one solution can be used for most of the assays done by the laboratory.Moreover, multiple-substance quality control reference materials are essential for use with multiple assay chemistry analysers.

In compounding these materials, there is often difficulty in fixing the concentration of one or more anions at a desired level in the material without having the obligatory cations affect other laboratory assays. One very important example of the problem is that set forth above, namely, fixing the total carbon dioxide content (bicarbonate plus carbonate) in quality control or reference serums used in clinical chemistry laboratories.

Bicarbonate salts which have been used to fix total carbon dioxide content in these serums are the bicarbonates of sodium, potassium, lithium, rubidium, Tris (tris(hydroxymethyl)aminomethane) and ammonia. Hpwever, sodium, potassium and lithium bicarbonates are unsuitable for the purposes described because sodium, potassium and lithium are important analytes, and because lithium is also used as an internal standard in the common flame photometric determination of sodium and potassium. Rubidium bicarbonate (at a concentration of 25 mM) is unsuitable as a total carbon dioxide reference material because it elevates sodium determinations by about 2 mM, possibly through a matrix effect in the flame photometer.

It has been found that the Tris bicarbonate-based reference material disclosed in aforementioned U.S. Patent No. 3,629,142 has a major shortcoming for reference purposes because it depresses the urea result (urease-Berthelot method) by about 15 per cent, and enhances protein results by about 10 per cent. The effect of Tris on the urea results may be' related to interference with the Berthelot reaction by a number of nitrogen-containing compounds, as reported by Gips and Reitsema, "Clin. Chem. Acta.", 33, 257 (1971). Ammonium bicarbonatereconstituted reference materials, which are the most widely used total carbon dioxide reference materials, are useless for most urease-based procedures for determining urea, because of ammonium ion interference. The ammonium ion also severely disturbs specific electrodes employed for determining potassium.

Thus, the presently available total carbon dioxide reference materials are unsuitable as reference materials for several other important analytical chemistry assays. A laboratory performing total carbon dioxide measurements in addition to the assays which are interfered with by the above-mentoned total carbon dioxide reference materials must prepare two different lyophilized serum references, that is, one reconstituted with water and the other reconstituted with a bicarbonate solution. This duplication is burdensome, especially if a single multipie-channei instrument is performing the above tests, since twice the usual number of standards and/or quality controls are required.

We have found that duplication is eliminated and that expenses are reduced when the reference materials of this invention are used as a total carbon dioxide reference, because the reference materials of the invention affect the level of no analyte of clinical chemical interest, save total carbon dioxide. An additional advantage of the invention is the direct comparability of data for different laboratories participating in a regional quality control program (in which the participating laboratories all use the same lyophilized serum pool), even if some of the laboratories use water-reconstituted instead of bicarbonate-reconstituted serum controls.

This invention comprises the use of a solution of a quaternary ammonium salt described below, for use in fixing the concentration of carbon dioxide in analytical chemistry reference materials, and which, when used for this purpose, causes no other interference in chemical assays.

According to the invention we provide an aqueous solution, suitable for use in the assay of animal body fluids, especially of blood serum, of a water-soluble carbonate and/or bicarbonate of a tetra-substituted quaternary ammonium compound, wherein pairs of substituent groups on the same molecule may be linked to form a heterocyclic ring, and pairs of substituent groups on different molecules may be linked to form a polymer, having a maximum content of contaminating ions as follows: : sodium 2 millimoles per mole of quaternary ammonium compound potassium 0.25 millimoles per mole of quaternary ammonium compound calcium 0.5 milligrams per 100 millilitres solution ammonium 0.5 micrograms per 100 millilitres solution chloride 3 millimoles per mole of quaternary ammonium compound iron 3 micrograms per 100 millilitres solution which compound does not have significant pH buffering capacity.

The preferred maximum contents of said ions are: sodium 1 millimole potassium 0.1 millimole calcium 0.2 milligrams ammonium 0.2 micrograms chloride 2 millimoles iron 2 micrograms.

Desirably, the concentration of the carbonate or bicarbonate is sufficient to give, in the solution, a carbon dioxide concentration of 10 to 40 milliequivalents per litre.

The substituents cause minimal interference in chemical analyses, and should not render the compounds so insoluble that particles thereof would disrupt optical measurement of the reference material. Most importantly, no substituents should introduce significant buffering capacity into the compounds.

Pairs of the substituent groups may be joined to form heterocycles containing the quaternary ammonium nitrogen atom, for example, a l-alkylpyridine or a 1,1dialkylpiperidine. Other examples of substituent groups are saturated or unsaturated heterocycles in which the quaternary ammonium nitrogen atom is not part of the heterocyclic substituent, such as furan or tetrahydrothiophen radicals, aromatic groups such as phenyl, cycloalkenyl groups, cycloalkyl groups, such as cyclohexyl and cyclopropyl, and branch chain or normal alkyl or alkenyl groups including methyl, ethyl, propyl, butyl, pentyl, octyl, hexenyl, isobutyl and neohexyl (2,2-dimethyl butyl). Further, any of the foregoing groups can be additionally substituted with or contain oxygen, covalent halogen, or thioether, ketone, ester, nitro or hydroxyl groups.However, it is preferred to employ the compounds containing branch chain or normal alkyl or alkenyl groups as these are the most chemically inert substituent groups, with the most preferred being methyl. Each of the four substituent groups can be the same as or different from one or more of the remaining groups.

Two or several molecules of the quaternary ammonium compound may be linked at their substituents to form a polymer.

Using the tetrasubstituted ammonium bicarbonate or carbonate salts the total carbon dioxide level in a serum or other biological fluid control may be conveniently adjusted to any desired level, without interfering with other chemistry procedures. Assays in which no interferences were found include the following assays: sodium, potassium, chloride, glucose, blood urea nitrogen, creatinine, calcium, phosphorus, total protein, alkaline phosphatase, total bilirubin, iron, total iron binding capacity, cholesterol, triglycerides, uric acid, alanine aminotransferase, lactate dehydrogenase, hydroxybutyrate dehydrogenase, gamma-glutamyltransferase, lactic acid dehydrogenase, acid phosphatase, alkaline phosphatase, thyroid hormone uptake, total thyroid hormone and amylase. The bicarbonate materials add no color, so that they do not affect colorimetric determinations.They do not cause precipitation of any of the other components of the control material which could result in the plugging of instruments. In addition, the pH of the control solution can be adjusted by varying the ratio of bicarbonate to carbonate in the tetrasubstituted ammonium salt. An important feature of the present invention is that the tetrasubstituted ammonium ion has no buffering capacity, and as a result, only minimal amounts of such ions are required in fixing the carbon dioxide content of the reference material, regardless of the pH. Tris, on the other hand, is a buffer at pH 8, and therefore Tris bicarbonate solutions contain more Tris than bicarbonate, since some of the Tris is uncharged. Further, the presence of buffering capacity will interfere with titrimetric methods for determining CO2.

The quaternary ammonium salts used in this invention are all soluble in water.

Additionally, when used with blood serum, they are also soluble in the serum. They are also soluble in the chemical mixtures used in the clinical tests. Naturally, the quaternary ammonium salts should not interfere in any clinical assay.

The compositions containing the quaternary ammonium salts should be sterile.

Sterility can be obtained by well known methods which will not affect the quaternary ammonium salts, for example, filtration of a solution of a quaternary ammonium salt through a filter which will retain particles of the size of microoganisms.

Among the cations which can be used in forming the amines used in this invention are the following: trimethyl hydroxyethylammonium dimethyl chloromethyl phenylammonium tetraethylammonium tetramethylammonium tetrapropylammonium tetrabutylammonium N,N-dimethyl-N-ethyl-p-nitrophenylammonium N,N-dimethyl-N-fluoromethyl-N-phenylammonium N-cyclohexyl-N,N-dimethyl-N-isobutylammonium N-ethyl-N-methylpiperidinium N,N-dimethyl-N-ethyl-N-vinyl-ammonium N,N-diethyl-N-(2-methoxyethyl).N-n-butylammonium N-n-octyl-N,N,N-trimethylammonium N,N,N,N' ,N' ,N'-hexamethylethylene diammonium and N-(2-hydroxyethyl)trimethylammonium.

To prepare a solution according to the present invention, an aqueous solution of an analytically pure tetra-substituted quaternary ammonium halide may be passed through a basic ion exchange resin in the hydroxide form, and the resultant solution of the corresponding hydroxide compound is treated with carbon dioxide gas until the corresponding carbonate and/or bicarbonate salt is formed, which can be determined by the change in pH of the solution. The solution may then be diluted with distilled water.

The tetrasubstituted ammonium carbonate salts used in this invention are known compounds. However, these salts have not been previously used in the analytical chemistry procedures described in this specification. Thus Patent Specification No. 379,260 discloses the preparation of solutions in water of pure choline carbonate, i.e. (p-hydroxyethyl) trimethylammonium carbonate, of tetraethanol ammonium bicarbonate and of oxypropyl pyridinium bicarbonate; carbonates of other quaternary ammonium salts can be produced likewise.

However, that specification is not concerned with serum assay and gives no suggestion of keeping the content of contaminating ions to any minimum level.

The salts and their methods of production are also disclosed in Czechoslovakian Patent No. 157,000, U.S. Patent No. 3,190,919, an article by Mahajan and Rao, "Proton Magnetic Resonance and Internal Motions in some Tetramethyl Ammonium Compounds", J. Phys. C: Solid State Phys., Vol. 7, London (1974), and the Ph.D. Thesis of E. Teeter entitled "Reduction of Carbon Dioxide on Mercury Cathodes", the University of Oregon, Eugene, Oregon, U.S.A., June 1954.

In using the solution of this invention lyophilized animal body fluid such as blood serum is reconstituted with sufficient of the ammonium carbonate or bicarbonate solution to provide preferably from 10 to about 40 meq/l of carbon dioxide iri the reconstituted fluid.

A reference sample of the invention may be prepared by mixing a solution according to the invention of the tetrasubstituted ammonium salt of the desired final concentration with previously lyophilized animal body fluid, e.g. blood serum.

In another embodiment, the invention provides a method of preparing a reference sample by adding a predetermined amount of a carbonate or bicarbonate of a tetrasubstituted quaternary ammonium compound as defined above to animal body fluid such as blood serum prior to lyophilization of the serum. To prepare a reference blood serum sample of the invention by the latter method, the tetrasubstituted ammonium salt is added to pooled blood serum in sufficient amounts that the content of any contaminating ions is kept below the aforesaid levels. The lyophilised sample can be reconstituted with distilled water, preferably to provide a desired total CO2 level in the reconstituted serum.

The following Examples illustrate the solution, serum and method of the invention.

EXAMPLE 1 The preparation of a solution of tetramethylammonium bicarbonate (TM A- HCO3) was carried out by the following steps.

An aqueous solution of tetramethylammonium bromide which was analytically pure (therefore any contaminating metal ions were present at levels below the aforesaid maxima) of the desired concentration (for example, 0.15 M) was converted to tetramethylammonium hydroxide by passage through a chromatographic column containing a strongly basic exchange resin in the hydroxide form (step 1).

Conversion of the tetramethylammonium hydroxide to TMA-HCO2 was accomplished, in step 2, by bubbling a stream of CO2 gas into the stirred solution until a pH of 8 was obtained. (The pH of the solution can be changed by changing the amount of CO2 added to the solution). The reactions are shown in the following equations: step 1 step 2

O. 1 5M(CH3)4NtHCO3- The TMA-HCO3 solution was diluted with pure water to give the desired total carbon dioxide content (for example 30 mM). This TMA-HCO3 solution was then used to reconstitute previously lyophilized human blood serum controls.

These TMA-CHO3-reconstituted controls were then analyzed by known analytical chemistry procedures. Many such control serums so reconstituted were analyzed in parallel with controls reconstituted with only distilled water. No significant differences between these two types of controls was found for any of these assays, which included those for the substances mentioned above.

EXAMPLE 2 In order to show the efficacy of a quaternary ammonium bicarbonate used in this invention in adding carbon dioxide to a blood serum reference material, two samples from the same lot of lyophilized blood serum were taken. Each sample consisted of powdered human blood serum which had been lyophilized from 10 ml of blood serum. 10 ml of distilled water were added to the first sample (a), and the bottle containing the same was agitated so that the serum would completely dissolve. The content of this sample was then analyzed with a conventional apparatus for analyzing blood serum.

The second sample (b) of lyophilized blood serum was reconstituted by adding 10 ml of 22 mM aqueous solution of analytically pure tetramethylammonium bicarbonate. Here again, the mixture was slightly agitated so that the serum would be completely dissolved in the solution of tetramethylammonium bicarbonate. The second sample was then analyzed using the same apparatus as used for the first sample.

The following chart gives the results of the tests for the constituents tested, and also shows the normal range for the constituents.

(b) Value in Serum Recon stituted with (a) Value in soln of Serum Recon- Tetramethyl Blood stituted with Ammonium Constituents Water Bicarbonate Normal Range Sodium 150meq/1 150meq/1 138-146 Potassium 6.4 meq/l 6.4 meq/l 3.5-5.3 Chloride 107 meq/l 107 meq/l 97-108 Carbon Dioxide 3 meq/l 25 meq/l 24-32 Glucose 172mg/dl 171 mg/dl 60105 Urea Nitrogen 44 mg/dl 44 mg/dl 10-20 Creatinine 4.9 mg/dl 4.9 mg/dl 0.7-1.4 Calcium ll.9mg/dl 12.0 mg/dl 8.5-10.5 Phosphorus 7.3 mg/dl 7.3 mg/dl 2." 4.4 Total Protein 6.5 mg/dl 6.4 mg/dl 5.8-8.5 Alkaline Phosphatase 107 IU/I 109 IU/I 12 "0 Bilirubin 3.6 mg/dl 3.6 mg/dl 0.2-1.2 Iron 198 g/dl 196 ,ug/dl 70-200 Iron Binding Capacity 386yg/dl 412,ug/dl 250-400 Cholesterol 153 mg/dl 150 mg/dl up to 260 (age-dependent) Triglycerides 0.9 meq/l 0.88 meq/l up to 2.15 (age-dependent) Uric Acid 9.1 mg/dl 9.0mg/dl 3-8 Aspartate Transaminase 63 lU/I 61 lU/I Alanine Transaminase 165 IU/I 166 IU/I 9-25 Lactate Dehydrogenase 737 lU/I 738 IU/I 140--270 Creatine Kinase 260 lU/I 274 IU/1 1" 90 Hydroxybutyrate Dehydrogenase 587 lU/I 591 lU/I 110--230 Gamma Glutamyl Transpeptidase 26 lU/I 26 lU/I 4--40 Amylase 430 U 434 U 40-180 Abbreviations: IU/I=international units per liter meq/l=milliequivalents/liter mg/dl=milligrams/deciliter Mg/dl=micrograms/deciliter gm/dl=grams/deciliter It is seen from a review of the foregoing test results that, with the exception of the carbon dioxide, the addition of the tetramethylammonium bicarbonate did not affect or interfere with the measurement of any of the other constituents of the blood serum or contribute any of the other constituents to the serum to change the concentration of the constituent in the serum.Insofar as the carbon dioxide is concerned, it can be seen from the foregoing analysis that the concentration of carbon dioxide had fallen to 3 meq/l in the blood serum during lyophilization. This is from a normal range of 24 to 32 meq/l. However, by mixing the lyophilized blood serum with the solution of tetramethylammonium bicarbonate, the concentration of carbon dioxide had risen to 25 meq/l, which is within the normal range. Subsequent tests gave similar results.

EXAMPLE 3 1.0 ml of 0.4 M analytically pure tetraethyl ammonium bicarbonate was added to 10.0 ml of pooled liquid human blood serum. This mixture was then lyophilized by a known lyophilization process. The lyophilized serum could be reconstituted prior to use by dissolving it in 10.0 ml of distilled water, whereupon it could be analyzed by known procedures.

WHAT WE CLAIM IS: 1. An aqueous solution, suitable for use in the assay, of animal body fluid, of a water-soluble carbonate and/or bicarbonate of a tetra-substituted quaternary ammonium compound, wherein pairs of substituent groups on the same molecule

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (17)

**WARNING** start of CLMS field may overlap end of DESC **. The following chart gives the results of the tests for the constituents tested, and also shows the normal range for the constituents. (b) Value in Serum Recon stituted with (a) Value in soln of Serum Recon- Tetramethyl Blood stituted with Ammonium Constituents Water Bicarbonate Normal Range Sodium 150meq/1 150meq/1 138-146 Potassium 6.4 meq/l 6.4 meq/l 3.5-5.3 Chloride 107 meq/l 107 meq/l 97-108 Carbon Dioxide 3 meq/l 25 meq/l 24-32 Glucose 172mg/dl 171 mg/dl 60105 Urea Nitrogen 44 mg/dl 44 mg/dl 10-20 Creatinine 4.9 mg/dl 4.9 mg/dl 0.7-1.4 Calcium ll.9mg/dl 12.0 mg/dl 8.5-10.5 Phosphorus 7.3 mg/dl 7.3 mg/dl 2." 4.4 Total Protein 6.5 mg/dl 6.4 mg/dl 5.8-8.5 Alkaline Phosphatase 107 IU/I 109 IU/I 12 "0 Bilirubin 3.6 mg/dl 3.6 mg/dl 0.2-1.2 Iron 198 g/dl 196 ,ug/dl 70-200 Iron Binding Capacity 386yg/dl 412,ug/dl 250-400 Cholesterol 153 mg/dl 150 mg/dl up to 260 (age-dependent) Triglycerides 0.9 meq/l 0.88 meq/l up to 2.15 (age-dependent) Uric Acid 9.1 mg/dl 9.0mg/dl 3-8 Aspartate Transaminase 63 lU/I 61 lU/I Alanine Transaminase 165 IU/I 166 IU/I 9-25 Lactate Dehydrogenase 737 lU/I 738 IU/I 140--270 Creatine Kinase 260 lU/I 274 IU/1 1" 90 Hydroxybutyrate Dehydrogenase 587 lU/I 591 lU/I 110--230 Gamma Glutamyl Transpeptidase 26 lU/I 26 lU/I 4--40 Amylase 430 U 434 U 40-180 Abbreviations: IU/I=international units per liter meq/l=milliequivalents/liter mg/dl=milligrams/deciliter Mg/dl=micrograms/deciliter gm/dl=grams/deciliter It is seen from a review of the foregoing test results that, with the exception of the carbon dioxide, the addition of the tetramethylammonium bicarbonate did not affect or interfere with the measurement of any of the other constituents of the blood serum or contribute any of the other constituents to the serum to change the concentration of the constituent in the serum.Insofar as the carbon dioxide is concerned, it can be seen from the foregoing analysis that the concentration of carbon dioxide had fallen to 3 meq/l in the blood serum during lyophilization. This is from a normal range of 24 to 32 meq/l. However, by mixing the lyophilized blood serum with the solution of tetramethylammonium bicarbonate, the concentration of carbon dioxide had risen to 25 meq/l, which is within the normal range. Subsequent tests gave similar results. EXAMPLE 3 1.0 ml of 0.4 M analytically pure tetraethyl ammonium bicarbonate was added to 10.0 ml of pooled liquid human blood serum. This mixture was then lyophilized by a known lyophilization process. The lyophilized serum could be reconstituted prior to use by dissolving it in 10.0 ml of distilled water, whereupon it could be analyzed by known procedures. WHAT WE CLAIM IS:

1. An aqueous solution, suitable for use in the assay, of animal body fluid, of a water-soluble carbonate and/or bicarbonate of a tetra-substituted quaternary ammonium compound, wherein pairs of substituent groups on the same molecule

may be linked to form a heterocyclic ring or pairs of substituent groups on different molecules may be linked to form a polymer having a maximum content of contaminating ions as follows: sodium 2 millimoles per mole of quaternary ammonium compound potassium 0.25 millimoles per mole of quaternary ammonium compound calcium 0.5 milligrams per 100 millilitres solution ammonium 0.5 micrograms per 100 millilitres solution chloride, 3 millimoles per mole of quaternary ammonium compound iron, 3 micrograms per 100 millilitres solution which compound does not have significant pH buffering capacity.

2. A solution as claimed in Claim 1, wherein said maximum contents of ions are: sodium 1 millimole potassium 0. I millimole calcium 0.2 milligrams ammonium 0.2 micrograms chloride 2 millimoles iron 2 micrograms.

3. A solution as claimed in Claim 1 or 2, wherein the concentration of the carbonate or bicarbonate is sufficient to give, in the solution, a carbon dioxide concentration of 10 to 40 milliequivalents per litre.

4. A solution as claimed in Claim 1, 2 or 3, wherein the substituents on the tetra-substituted quaternary ammonium compound are selected from alkyl, alkenyl, cycloalkyl, cycloalkenyl and heterocyclic groups.

5. A solution as claimed in Claim 4, wherein at least one of the substituents is a methyl group.

6. A solution as claimed in any preceding claim, wherein some of the substituents are linked to form a l-alkylpyridine or l,l-dialkyl piperidine group.

7. A solution as claimed in Claim 1, 2 or 3, wherein the quaternary ammonium cation of said compound is any of the cations listed hereinbefore.

8. A solution as claimed in any preceding claim, which has been rendered sterile, so as to be free of microorganisms.

9. An aqueous solution as claimed in Claim 1, substantially as hereinbefore described with reference to Example 1.

10. A mixture of a solution as claimed in any preceding claim, and an animal body fluid in fresh or lyophilized form, the mixture being useful in the assay of said fluid.

11. A mixture as claimed in Claim 10, wherein the body fluid is blood serum.

12. A method of making a clinical assay sample, which consists of mixing a solution as claimed in any of Claims I to 9 with an animal body fluid in fresh or lyophilized form.

13. A method as claimed in Claim 12, substantially as hereinbefore described with reference to Example 1 or 2.

14. A method of making a clinical assay sample, which comprises mixing a carbonate and/or bicarbonate of a quaternary ammonium compound as claimed in Claim 1, 4, 5, 6 or 7 with a fresh animal body fluid in an amount such that the content of contaminating ions introduced into the mixture by said compound is within the maxima stated in Claim 1 or 2, and lyophilizing the resultant mixture.

15. A method as claimed in Claim 14, wherein the lyophilized sample is reconstituted with distilled water to give a sample ready for assay.

16. A method as claimed in Claim 14 or 15, substantially as hereinbefore described with reference to Example 3.

17. A clinical assay sample derived from an animal body fluid when made by a method as claimed in any of Claims 14 to 16.