PARENCHYMATOUS 

 DEGENERATION 



262 



PEPTIDASE 



Eight legs in adult, 6 in larva, head and ab- 

 domen coalesced, ectoparasites, may burrow 

 under skin or live in hair follicles (ticks, mites, 

 etc.) Acarina 



Four claws about mouth, larvae encysted in various 

 tissues, adulta occasionally in nasal passages 

 (tongue worms) Linguatulidae 



Numeroiis legs, occasionally in nasal passages and 

 intestine (thousand leggera) Myriapoda 



See Tapeworm Progloltids, Trema- 

 todes, Taenia, Ticks, Insects, Enda- 

 moeba, Trichinella, Glychrogel. 



Parenchymatous Degeneration, see Cloudy 

 Swelling. 



Parhemoglobin, a kind of hemoglobin which 

 crystallizes in same fashion but is in- 

 soluble in alcohol (Mallory, p. 135). 



Paris Blue, see Spirit Blue. 



Paris Violet, see Methyl Violet. 



Parlodion, a derivative of pyroxylin (see 

 Celloidin). 



Paschen's Method for elementary bodies as 

 given by Seiffert, G., Virus Diseases in 

 Man, Animal and Plant. New York: 

 Philosophical Library, Inc., 1944, 332 

 pp. Dry very thin smears in air. 

 Place slides perpendicular in aq. dest. 

 Ringer or physiological saline, 3-10 

 min., longer for older specimens. Then 

 dry and place in abs. ale. 1-24 hours, or 

 in methyl alcohol, 10 min. Dry, cover 

 with filtered Loeffler caustic (HoUborn) 

 and heat. Rinse in aq. dest. and color 

 with well filtered Carbol Fuchsin. 

 Rinse in aq. dest. (To destain if neces- 

 sary dip in abs. ale, then rinse in aq. 

 dest.), blot dry. 



Pasteurella, capsules of. A modification of 

 Hiss's method advocated by Jasmin, 

 A. M., J. Bact., 1945, 50, 361-363. 

 Transfer amount of surface culture ad- 

 hering to a fine, straight platinum wire 

 to loopful physiological saline 4-0.5-1% 

 phenol and 10% blood serum. Spread 

 thin film on clean polished slide; fix 

 dried film by quickly dipping in methyl 

 alcohol. Drain and flame to remove 

 excess alcohol. Finally color i to 1 min. 

 in any regular bacterial stain, wash in 

 water and dry. Capsules appear as 

 clear areas about strongly stained bac- 

 teria in lightly colored background. 



Patent Blue A (CI, 714)— Brilliant Acid 

 Blue A — an acid dye of light fastness 4, 

 stains parenchyma blue green with poor 

 definition (Emig, p. 52). 



Pectinols are enzyme preparations of 4 

 grades supplied by Rohm and Haas Co. 

 of Philadelphia. Their primary action 

 is on pectins. McKay, H. H. and 

 Clarke, A. E., Stain Techn., 1946, 21, 

 111-114 recommend their use to demon- 

 strate chromosomes of root tip smears 

 after colchicine and before staining 

 with carmine. 



Pectins, macromolecular properties, test for 

 (Hueper, W. C, Arch. Path., 1942, 33. 

 267-290). See Ruthenium Red. 



Pencil Red Cells are oval or elongated 

 erythrocytes in the condition of ovalo- 

 cytosis 4 or 5 times as long as they are 

 broad. 



Pentose Nucleic Acid is present in cyto- 

 plasm, nucleoli and possibl}^ in the 

 chromatin of cells. With proper con- 

 trols the substance may be identified 

 in cells by use of ultraviolet micro- 

 spectrophotometry or by Pyronin- 

 methyl Green and ribonuclease. It is 

 found in high concentration in cell, 

 actively producing protein (Stowells 

 R. E., Cancer, 1948, 2, 121-131) and is 

 generally associated with basophilia 

 (Caspersson, T. and Schultz, J., Nature, 

 1939,143,602-603). 



Pepsin, microchemical determination : 



1. Freeze gastric mucous membrane 

 of freshly killed pig. Keep at — 10°C. 

 Cut cylinders of tissue (2.5 mm. in diam- 

 eter) with sharp cylindrical borer ver- 

 tical to surface. Mount cylinders with 

 muscle down on a piece of cardiac mu- 

 cosa or on stiffened gelatin. Freeze 

 with COj. Cut sections at 25 microns. 

 Make enzyme determinations on section 

 and correlate with structure in adjacent 

 sections and with known distribution of 

 cell types at different distances from 

 lumen. This shows that chief cells are 

 the source of the pepsin (Holter, H. and 

 Linderstr0m-Lang, K., C. rend. Trav. 

 Lab. Carlsberg, 1935, 20 (11) 1-32). 



2. Make extract of tissue, mix with 

 buffers at suitable pH, apply to gelatin 

 surface of Eastman lantern slide plate, 

 incubate, wash gelatin surface, fix in 

 20% formalin, stain with acid fuchsin 

 or Delafield's hematoxylin and observe 

 sites of proteolytic activity evidenced 

 by clear spots. Test is positive for 0.0001 

 -0.0002 gm. stomach of young ambly- 

 stoma weighed wet. Details of this in- 

 genious technique, also applicable with 

 slight modification for trypsin, are given 

 by Dorris (F., J. Exp. Zool., 1935, 

 70, 491-527). See also Peptidase, Pep- 

 sin and Dipeptidase. 



Pepsinogen, antecedent of pepsin in body 

 chief cells of stomach. For staining 

 reaction and discharge by vagal stimu- 

 lation, see Bowie, D. J. and Vineberg, 

 A. M., Quart. J. Exper. Physiol., 1935, 

 25, 247-257. 



Peptidase can be localized in centrifuged 

 marine eggs by direct enzymatic analysis 

 of fragments containing different cyto- 

 plasmic components using a procedure 

 essentially the same as that advocated 

 by Linderstr0m-Lang and his associates. 

 It occurs in the hyaline ground sub- 

 stance and is not bound to the granular 



