Nelson J. Wade

The Burrow of Tamias striatus

Little is known of the details of the burrowing habits of the eastern chipmunk, Tamias striatus (Linnaeus). In the hope of clarifying certain particulars of the burrow system, studies were begun in the summer of 1952 at Waupaca, Wisconsin, and continued during the summers of 1953 and 1954 at the same site. During the winters of those years observations were made with captive animals in the laboratories of Saint Louis University. The natural burrows described herein were all excavated during July or early August, and artificial “burrow-boxes” were employed throughout the year. The animal whose burrows were studied is very closely related to Tamias striatus griseus Mearns, the largest of the subspecies of the eastern chipmunk. Since Waupaca seems to be an area where there is apparent intergradation between T. s. griseus and T. s. lysteri ( Richardson), it is probably best to avoid subspecific designation (Burt, 1954). The authors are sincerely grateful to Doctor X. J. Musacchia who offered much assistance, and to Messrs. John Baggarly, John Becker, George Brown, and Ronald Zinkle, who generously aided in the excavations. The Wisconsin Conservation Commission kindly approved the research plans. We also thank the Biochemistry Department of Saint Louis University for the use of some of its facilities. As early as 1748 Peter Kalm said that chipmunk burrows “go deep and commonly further inwards divide into many branches.” He referred to “Sciurus striatus” (= Tamias striatus ) which he found in Pennsylvania. Audubon and Bachman (1849) described three holes leading to a chamber, and noted that the hole descends “almost perpendicularly for about three feet.” J. G. Wood (1892) noted the complexity of the burrow, repeated the notion of a nearly perpendicular descent of three feet, and added that the system is always under some shelter. In 1929 Howell very briefly summarized …

Some Effects of Low Choline Diets

The importance of choline in the prevention of “fatty livers” has been previously demonstrated by the investigations of Best 1 and of Channon. 1 The following experiments indicate that the production of a fatty liver on a low choline diet is only one manifestation of a more fundamental deficiency condition. Male rats, 40 g in weight and 24 days of age, were used in groups of ten. The basal diet consisted of fibrin-4, casein-8, dried egg white-3, salt mixture 2 -4, calcium carbonate-1, codliver oil-5, lard-35, agar-2, and sucrose-38. The water soluble vitamins were supplied by a daily supplement of 0.02 mg of thiamin chloride, 0.02 mg of riboflavin, 0.04 mg of nicotinic acid and 0.1 cc each of concentrated extracts of rice polish and hog liver. The rats consumed 4 to 5 g of food per day. The term fatty liver refers in every case to enlarged livers containing from 8 to 12 times the normal weight of chloroform-soluble substances. This newly recognized effect of choline deficiency was brought to light when rats were killed and examined at the end of a 10-day experimental period. At this time 90% of the rats showed markedly hemorrhagic kidneys as well as fatty livers unless choline was added to the diet. Similar results were obtained when the vitamin supplement was omitted, when it was fed separately, when it was mixed with the basal ration and when it was doubled in amount. Although the minimum effective level has not yet been determined, the degeneration of the kidneys was prevented if the rats received 2 mg of added choline daily. This amount had no effect on the liver fat. Ten mg of choline per day were required to prevent the fatty liver.

Cornification of Vaginal Epithelium of Ovariectomized Rat Produced by Smearing

The histological examination of the vaginae of a number of spayed rats showing an unexpected response to the examination of the vagina by the smear method revealed that smearing alone, without the injection of an estrogenic hormone, may produce, under certain conditions, full cornification of the vaginal epithelium. The results of some of our experiments are summarized in Table I. The spayed rats which were neither smeared nor injected presented a thin, smooth vaginal epithelium usually 2 cell layers in thickness with leucocytes migrating into the lumen. When the animals were smeared once, twice, and 3 times daily the typical section from the vagina showed a progressive thickening of the epithelium up to 12 or more layers with the usual desquamation of the surface cells, thus presenting a picture very similar to that obtained after the administration of estrogenic material. 1 , 2 The vaginal smear picture 3 likewise underwent a progressive change when the animals were examined once, twice, and 3 times daily. The usual — smear observed when the animals were examined once daily changed to a ± or occasionally a ± ± on and after the third day if the animals were examined twice daily. When the vaginal smears were made 3 times daily about 25% of the animals showed full + smears on the third or fourth day of treatment.∗ In order to observe whether smearing 3 times daily would change the typical picture observed after the administration of theelin, 3 animals injected daily with one rat unit of theelin and smeared 3 times each day were compared with 3 other animals injected with the same amount of theelin but smeared once daily.

Relation of Methionine, Cystine and Choline to Renal Lesions Occurring on Low Choline Diets

In a previous report 1 it was demonstrated that a severe pathological state characterized by hemorrhagic degeneration of the kidneys occurs within 10 days in young rats maintained on a low choline diet. This deficiency was prevented by choline. It was suggested that proteins relatively high in methionine and low in cystine possessed a choline-sparing action since the deficiency was produced more readily on diets containing fibrin than on those containing casein. Subsequent work has confirmed the earlier suggestion that choline might prevent the renal lesion resulting from the addition of cystine to a purified diet containing casein. Furthermore, it has been found that the addition of methionine to a diet containing fibrin completely protected the rats. Normal kidneys were found in 40 g rats fed the following diet for 10 days: casein, 15; salt mixture, 4; calcium carbonate, 1; codliver oil, 5; lard, 35; agar, 2; sucrose, 32, and yeast, 6. Hemorrhagic kidneys invariably occurred if 0.3% cystine was added but not if 0.1% choline was added in addition to the cystine. Hemorrhagic kidneys resulted if the protein of the above basal ration consisted of fibrin, 4; casein, 8, and dried egg white, 3. The addition of 0.04% choline or of 1% dl-methionine completely protected the rats. The ratio of the 2 amino acids, methionine and cystine, is not the only factor which determines the choline requirement. This became evident from the fact that hemorrhagic lesions were produced on the 15% casein diet by decreasing the level of choline in the diet through substitution of vitamin concentrates for the codliver oil and yeast and through lowering the fat content to 10%. Furthermore, the effect of a fibrin diet in producing the renal lesions was no longer evident if the fibrin was decreased from 15 to 5%.

Field Observations on Tamias striatus in Wisconsin

Observations and collecting of Tamias striatus (L.) in the area of Waupaca, Wisconsin during the summers of 1952 through 1955 have yielded data relevant to sex ratios and natural history. The paucity of reports involving large numbers of this chipmunk prompt us to present this communication—drawn from field records of more intensive research on the hibernation of this species. Most captured chipmunks appeared closely related to T. s. griseus Mearns. Some resembled T. s. lysteri (Richardson), and others appeared to be intermediates. The ranges of these two subspecies have long been known to be contiguous in this part of central Wisconsin (Howell, 1929). In such mammalian populations we favor the viewpoint of Burt (1954) and others and will not attempt subspecific designation. No Eutamias were found in the area of Waupaca during the present study. At first wooden, sliding-door traps and later “Havahart” live traps were employed. Weights were measured on a “Hansen” diet spring-scale. Field weights were taken before captured animals were fed or watered. In general, captured animals were without food or water for several hours prior to the initial weighing. Subsequent weights were made on animals which had access to Purina Laboratory Chow and water ad lib . Glass drinking bottles served for the measurement of water consumption, and animals were marked by toe clipping. The sites, all within a few miles of Rainbow Lake (Waupaca County), can be differentiated into three areas: 1) Government Island, an uninhabited, tree-covered island; 2) wooded shore areas fairly close to human dwellings; and 3) a large vegetable garden, the “Hacker” site. At Sites 1 and 2 traps were usually placed near burrow entrances and shifted as burrows were apparently trapped out. At Site 3 traps were simply placed in random fashion throughout the garden area. The trap-lines were examined daily …

Survival, Respiration and Morphology of Sarcoma-37 Cells Exposed to Liquid Nitrogen.

Summary 1. The survival of mouse sar-coma-37 cells frozen in liquid air has been quantitatively estimated by determinations of the rate of cellular respiration. The results were checked by morphological examination of the frozen incubated tissue and by in vivo growth. 2. Measurements of the rate of respiration were reliable as an index of survival if the cells were incubated for more than 2 hours at 37°C following freezing, and if they were suspended in a physiological medium compatible with normal survival and recovery of injured cells. 3. Krebs-Ringer-Phosphate medium was unsuitable, but equal parts of partially neutralized horse serum and Krebs-Ringer-Phosphate provided an adequate medium. 4. The respiration and survival of sarcoma-37 cells, pretreated for 2 1/4 to 3 minutes in the ethylene glycol in Krebs-Ringer solution then frozen in liquid air was 50 to 60% of the unfrozen controls. 5. The respiration of untreated frozen sarcoma-37 was not usually significant. Morphological analyses of these tissues indicated fewer than 1% surviving cells in most experiments. 6. No significant difference in survival was observed between the rapidly and slowly frozen tissues. 7. Good correlation was observed between the morphological and respiratory characteristics of the frozen incubated tumor cells.

Physiology of aging leukocytes. I. Phagocytosis and transformation.

Summary Sequential changes in the human leukocytes ability to phagocytize latex particles and lymphocyte transformation were correlated with concomitant biochemical modifications during a 30° incubation period. There were no pH adjustments nor nutritional additives during the period of sequential testing of aging blood cells. Locomotion and phagocytosis of neutrophils continued unimpaired for 22-23 hr or until “starvation” conditions prevailed. Attachment of inert polystyrene latex particles to the plasma membrane did not trigger ingestion. Streaming cytoplasm associated with cellular motility seemed to be the main vehicle for interiorization of particles. Small lymphocytes have a potential for transformation into large mononucelar cells after incubating 1-2 hr. There was a gradual decline in their reactivity after 2-5 hr which may have been due to an inhibitory effect of the granulocytes present in the incubating blood. Not all lymphocytes responded uniformly to the stimulation of surface contact. Their behavior was variable and they did not show the same effects of aging. By examining the progression of changes during the aging and “death” of the cell, the cytological adjustments and alterations associated with this basic pathologic process were defined within the limits of the methodology used, but the exact time when the cell was irreversibly altered, “dead,” must await further study.

Hibernation in Mesocricetus auratus

As a check on laboratory conditions designed primarily for a study of the hibernation of Tamias striatus , hamsters were exposed to cold. Although the hibernation of hamsters has been discussed by Lyman (Jour. Exp. Zool., 109: 55, 1948; Jour. Mamm., 35: 545, 1954), Chatfield and Lyman (Amer. Jour. Physiol., 163: 566, 1950), Kayser (Annee Biol., 29: 109, 1953) and others, the present complementary observations merit brief mention. Fourteen six-month-old Mesocricetus auratus Waterhouse, half of them males, were placed in a cold room at 3°±.5°C. Eight of these were of the white variety and were refrigerated on December 22, 1955. Three white hamsters of the same age were maintained in a constant-temperature warm room at about 20°c. as controls. Six of the …

Effect of Tungstic Acid Extract of Normal Human Urine Upon Ovary of Rodents

This is a histological report on the study of the ovaries of 20 rats and 24 mice which had been injected by Drs. Katzman and Doisy with their tungstic acid extract of normal human urine. All of the animals were injected on the twenty-first day of life and upon the 2 following days with 1 cc. of extract in the case of the mice and 2 cc. in the case of the rats. The mice were killed on the twenty-fourth or twenty-fifth day of life and the rats on the twenty-eighth or twenty-ninth day. Six rats and 8 mice were injected with the extract from the urine of adult males, 4 rats and 6 mice with the extract from the urine of normal females, 2 rats and 2 mice with the urine extract of pre-pubertal boys, one rat with the urine extract from a 16-year-old boy, one rat and 2 mice with the urine extract of an elderly female past the menopause, 6 rats and 6 mice with the urine extract from female castrates receiving theelin therapy. The common qualitative effects are: inhibition of follicular growth in most cases, marked conversion of granulosa and theca of small follicles into interstitial gland substance, cystic degeneration of many of the larger follicles, luteinization of some large follicles with the formation of pseudo-corpora suggesting those of ovulation, luteinization of granulosa and theca of many follicles, extensive atretic degeneration of follicles and congestion of vessels. There is a wide quantitative variation in the degree of response produced by the extracts. The rats gave greater response than the mice but the latter were killed sooner after treatment. The extracts from the urine of female castrates receiving theelin therapy produced the greatest degree of change in the ovaries of the animals treated.

Effects of Chronic Injection of Rats with Extract of Pituitaries of the Same Species

Summary We have confirmed our previous findings that rats receiving chronic treatment with active principles of the anterior lobes of the same species fail to become refractory. Under the conditions of the experiment an aqueous extract of acetone-desiccated hypophyses obtained by extraction with dilute sodium bicarbonate produced effects similar to those of implants of fresh anterior lobes.