Coal Tar Hydrocarbons Research Articles

Induction of Uterine Cancer with Inactivated Herpes Simplex Virus, Types 1 and 2

A series of studies were performed to evaluate the oncogenic potential of inactivated herpes simplex viruses types 1 (HSV-1) and 2 (HSV-2) in the mouse cervix. HSV-1 or HSV-2 prepared in HEp-2 cell cultures and inactivated by exposure to formalin or ultraviolet light was applied to the mouse cervix for periods ranging from 20 to 90 weeks. Control mice were exposed for the same period to control fluids. Vaginal cytologic preparations from all animals were examined weekly to detect epithelial abnormalities. Animals were sacrificed and histopathological studies were carried out when cellular changes seen on vaginal smears resembled those indicative of premalignant or malignant changes as previously established in a similar model system using coal tar hydrocarbons. Other animals were exposed for periods up to 90 weeks, or until there was cellular evidence of invasive cancer. Cytologic and histologic materials were coded and evaluated without knowledge of whether they were from virus-exposed or control animals. Premalignant and malignant cervical lesions similar to those that occur in women were encountered in 78 to 90% of the virus-exposed animals. All controls were normal. Invasive cancer was detected in 24 to 60% of the animals and dysplasia was found in 18 to 66%. The yield of invasive cancer was twice as great after exposure to ultraviolet-inactivated HSV-2 as compared with formalin-inactivated virus. Various histologic grades of carcinoma of the cervix and endometrium were found. No primary lesions were found in the vagina or ovaries.

Induction of uterine cancer with inactivated herpes simplex virus, types 1 and 2.

A series of studies were performed to evaluate the oncogenic potential of inactivated herpes simplex viruses types 1 (HSV-1) and 2 (HSV-2) in the mouse cervix. HSV-1 or HSV-2 prepared in HEp-2 cell cultures and inactivated by exposure to formalin or ultraviolet light was applied to the mouse cervix for periods ranging from 20 to 90 weeks. Control mice were exposed for the same period to control fluids. Vaginal cytologic preparations from all animals were examined weekly to detect epithelial abnormalities. Animals were sacrificed and histopathological studies were carried out when cellular changes seen on vaginal smears resembled those indicative of premalignant or malignant changes as previously established in a similar model system using coal tar hydrocarbons. Other animals were exposed for periods up to 90 weeks, or until there was cellular evidence of invasive cancer. Cytologic and histologic materials were coded and evaluated without knowledge of whether they were from virus-exposed or control animals. Premalignant and malignant cervical lesions similar to those that occur in women were encountered in 78 to 90% of the virus-exposed animals. All controls were normal. Invasive cancer was detected in 24 to 60% of the animals and dysplasia was found in 18 to 66%. The yield of invasive cancer was twice as great after exposure to ultraviolet-inactivated HSV-2 as compared with formalin-inactivated virus. Various histologic grades of carcinoma of the cervix and endometrium were found. No primary lesions were found in the vagina or ovaries.

Experimental studies of carcinogenesis of the uterine cervix in mice

In conclusion, the histogenesis of cervical carcinomas induced in mice by coaltar hydrocarbons or inactivated herpes simplex virus, types 1 and 2, has been described. The lesions antedating the development of squamous cell carcinoma were similar to lesions encountered in patients with the same keratinizing type of carcinoma of the ectocervix. A theory for the development of the three grades of human cervical squamous cell carcinoma has been presented based on experimental and clinical data which demonstrate that each of the three grades of cancer consists of cells which resemble those of the tissue of origin and of the antecedent noninvasive lesion.

A g.l.c. simulated distillation technique to study changes in the composition of coke‐oven road tars in service

AbstractA simulated distillation technique has been developed making use of gas‐liquid chromatography (g.l.c.) for the quantification of oils present in road tars derived from coke‐oven crude tars. The tar‐oil constituents are grouped into boiling temperature ranges which coincide with those of fractions or cuts used in a standard (conventional) distillation test. The g.l.c. method caters for the wide range in boiling temperatures of tar‐oil constituents and for the fact that only about half of the tar substance injected is eluted from the column. In the analyses of tars recovered from road surfaces a means has been found to compensate for the presence of detritus in the tar. This method has several important advantages over the standard distillation procedure. Its accuracy and precision are superior and it can be used to determine constituents boiling as high as 400°C (673 K). (Due to the thermal sensitivity of coal tar hydrocarbons, the temperature in the standard distillation test may not exceed 340°C.) The g.l.c. method is more rapid and the small amount of tar required facilitates the analyses of tars weathered in road surfaces. In addition, repeat analyses can be carried out without inconvenience and the handling of the tar material is reduced. The g.l.c. method provides a powerful research tool for the study of the weathering of road tars. This paper gives the results of some weathering investigations. These show that even constituents with high boiling points (in the range 370–400°C) may be partially lost from tars in the first year of service. Oil losses are most rapid in the first year, but all constituents with boiling points below 300°C may be lost after prolonged service. From data provided by this method and measurements of the change in viscosity of tars on weathering, it has been possible to conclude that, in the case of coke‐oven tars, evaporation is the major weathering mechanism in the South African Highveld climate. There is a good correlation between oil losses and the hardening of tars, particularly in the early life of a spray‐and‐chip surfacing. Such studies have led to the development of improved road tar binders with economic benefit to the South African road industry.

Solvent Extraction of Tar Acids from Coal Tar Hydrocarbons

Solvent Extraction of Tar Acids from Coal Tar Hydrocarbons

Possible Future Sources of Aromatic Hydrocarbons

THE growth of the plastics industry has engendered continually increasing demands for two coal-tar hydrocarbons, benzene and naphthalene, and this has been previously discussed by the writer ( 1 , 2 ). The source of these hydrocarbons, the high-temperature carbonization of coal, has not expanded at a proportionate rate, and during 1948 we experienced a condition of severe shortage and increasing prices. Although a substantial number of new by-product ovens are being installed to compensate for wartime depreciation and to provide for increased steel production, it seems that such increase will be decidedly inadequate from the long-term standpoint of aromatics. Even if all the coke-oven tar is distilled to recover its naphthalene content, the writer believes it will prove insufficient for the needs of a prosperous chemical industry. There appear to be only two basic avenues of relief—imports from other countries, or production from petroleum, either per se or incidental to other operations. Imports can, at ...

Transparency of Rubber and Its Solutions

Abstract When rubber is dissolved in benzene or a mixture of coal-tar hydrocarbons, a clear bright solution is usually obtained. On the other hand, when dissolved in a petroleum solvent, the solution is opalescent. In the latter case it is necessary to postulate the presence of small particles having a different refractive index from that of the solvent. As rubber gives a substantially clear solution in benzene, it follows that the foreign particles are invisible and must, therefore, possess the same refractive index as this solvent or one very close to it.

Synthetic Resins from Coal-Tar Hydrocarbons

Synthetic Resins from Coal-Tar Hydrocarbons

Volatile Solvents and Thinners used in the Paint and Varnish Industries

IN less than 140 pages of text the author has attempted the task of compiling “for reference and comparison detailed information as to the nature, preparation and properties of every solvent of industrial importance in the paint and allied industries.” His sixty-odd substances are broadly classified under the heading of petroleum and coal-tar hydrocarbons, hydrocarbon chlorides, terpenes, alcohols, ketones, ethers, esters, and in addition, carbon disulphide. His claim that his list of individual solvents includes every one of the type indicated is scarcely correct, especially in the United States, where the lacquer trade has made enormous strides in recent years. There is a final short chapter on the general significance of the tests for solvents, with some theoretical considerations involved in their use. Volatile Solvents and Thinners used in the Paint and Varnish Industries. By Noel Heaton. (Oil and Colour Chemistry Monographs.) Pp. 158. (London: Ernest Benn, Ltd., 1925.) 15s. net.