LAMPBLACK 



133 



LEISHMANLA. DONOVANI 



cytosis, especially by monocytes. Mc- 

 Junkin, F. A., Arch. Int. Med., 1918, 

 21, 59-64, advised adding 0.4 gm. of 

 carefully pulverized lampblack to 100 cc. 

 2% gelatin in aq. dest. Inject intra- 

 venously with 5-9 cc. 10% aq. sodium 

 citrate, as in the case of Higgins' Ink. 

 The method has been slightly modified 

 by Simpson, M. J., J. Med. Res. ,1922, 

 43, 77-144; Wislocki, G. B., Am. J. 

 Anat., 1924, 32, 423-445; and Lang, F. J., 

 Arch. Path., 1926, 1, 41-63. 



Lanacyl Blue BB (CI, 210), an acid monoazo 

 d3^e which colors cell walls and paren- 

 chymatous cells light blue but less well 

 than other blue acid dyes (Emig, p. 35). 



Lanacyl Violet B (CI, 207), an acid monoazo 

 dye of light fastness 3. Directions for 

 staining plant tissue and fungous my- 

 celia (Emig, p. 35). 



Langerhans, see Islets of. 



Lard, reactions in tissue to fat stains after 

 various fixations (Black, C. E., J. Lab. 

 & Clin. Med., 1937-38, 23, 1027-1036). 



Large Intestine. The conditions that in- 

 fluence the appearance of sections are 

 easier to guard against than in the Small 

 Intestine because of the absence of villi 

 and greater uniformity of contents. 

 The pronounced influence of degree of 

 distention is described and well illus- 

 trated by Johnson (F. P., Am. J. Anat., 

 1912-13, 14, 235-250). 



Lauth's Violet, see Thionin. 



Lead, histological demonstration. 



1. Mallory and Parker's method (Mal- 

 lory, F. B. and Parker, F. J., Am. J. 

 Path., 1939, 15, 517-522) : Fix tissues in 

 95 or abs. alcohol (not formalin). Stain 

 celloidin sections at 54°C. in: 5-10 gm. 

 hematoxylin dissolved in few drops abs. 

 or 95% alcohol + 10 cc. freshly filtered 

 2% aq. K2HPO4 for 2-3 hrs. Wash 

 changing tap water 10-60 min., dehy- 

 drate in 95% ale, clear in terpineol and 

 mount in terpineol balsam. Lead light 

 to grayish blue, nuclei deep blue. 

 Another method applicable to paraffin 

 sections of Zenker fixed material is to 

 stain in 0.1% methylene blue in 20% 



- ale. 10-20 min. Differentiate 10-20 

 min. in 95% ale, dehydrate, clear and 

 mount. Phloxine is recommended as a 

 contrast stain before the methylene 

 blue. 



2. Chromate method (Frankenberger, 

 Cretin). By simply fixing in Regaud's 

 Fluid lead is precipitated as insoluble 

 yellow lead chromate easily identifiable 

 microscopically. This method is 

 strongly advised by Lison (p. 101). 

 It has been used by True (E., Bull. 

 d'Hist. AppL, 1929, G, 393-399). See 

 Sieber (E., Arch. f. exper. path. u. 

 pharmak., 1936, 181, 273-280) for demon- 

 stration of lead in bones. 



3. Attempts have been made to 

 identify lead after microincineration by 

 exposure to hydrogen sulphide, because 

 lead sulphide is black, but Gordon H. 

 Scott emphasizes difficulty in dis- 

 tinguishing it from other sulphides and 

 from carbon in imperfectly incinerated 

 specimens (McClung, p. 660). 



4. The method of Sieber, E.. Arch. f. 

 e.xper. Path. u. Pharmak., 1939, 181. 

 273 depending on production of acid 

 resistant brown -black lead sulfide when 

 tissue is treated with acidulated H2S 

 solution is said to be satisfactory by 

 Gomori, G., J. Mt. Sinai Hosp., 1944- 

 45, 11, 317-326 when presence of other 

 heavy metals is ruled out. 



Methods for chemical determination 

 of lead in biological materials are 

 important as checks on above. Consult 

 Smith, F. L. 2nd., Rathmell, T. K. and 

 Williams, T. L., Am. J. Clin. Path., 

 1941, 11, Suppl.5, 653-668. 



For a convenient method of giving 

 colloidal lead intravenously to rabbits 

 see Crawford, B. L., Stewart, H.L., 

 Willoughby, C. E. and Smith, F. L., 

 Am. J. Cancer, 1938, 33, 401-422. The 

 authors describe techniques for direct 

 analysis of lead in the tissues. 



Leather Brown, see Bismark Brown Y. 



Leather Yellow, see Phosphine. 



Lebowich's soap-wax technique eliminates 

 use of alcohol, xylol and overnight drying 

 of paraffin sections. Takes only 6-8 hrs. 

 (Moritz, C. E., Stain Techn., 1939, 14, 

 17-20). 



Lecithin, a compound of phosphoric acid, 

 glycerol, choline and 2 fatty acid mole- 

 cules. It is a phosphatide soluble in 

 alcohol, chloroform, ether and benzene, 

 see Lipoids. 



Lee-Brown. Modification of Mallory's ani- 

 line blue connective tissue stain (Lee- 

 Brown, R. K., and Laidley, J. W. S., 

 J. Urol., 1929, 21, 259-274). Mallory 

 (p. 155) states that the following tech- 

 nique is particularly valuable for the 

 kidney. Treat paraffin sections of Zen- 

 ker fixed material with iodine to remove 

 mercury. Wash. 1% aq. phosphomolyb- 

 dic acid, 30 sec. Wash in aq. dest. 1-2 

 min. Stain in: aniline blue, 0.5 gm.; 

 orange G., 2 gm. ; phosphomolybdic acid, 

 2 gm.; aq. dest., 100 cc. for 30 min. at 

 55°C. Wash in aq. dest 2-5 min. 1% 

 aq. phosphomolybdic acid, 30 sec. 95% 

 ale, abs. ale, xylol, balsam. Glomerular 

 basement membrane and collagen, deep 

 blue; nuclei, orange. 



Leishmania Donovani, a search for stains 

 that will color more rapidly than Giemsa 

 revealed Astra violet F. F. Extra, 

 Himmelblau, Magenta Lermont and 

 Navy blue shade, each to be used in 



