The "pre-anterior belly" of the temporalis muscle: a preliminary study of a newly described muscle.

Gross anatomical structures of the human body have been known and taught to students for centuries. However, at times, anomalies or even previously undescribed structures are discovered and subsequently reported. This preliminary report discusses the discovery of either a previously undescribed belly of the temporalis muscle, a previously undescribed muscle of mastication, or simply an anomaly of the temporalis. The somatosensory innervation of this structure was identified and will be presented. Preliminary measurements of this structure will also be provided. Finally, clinical implications of these findings, which may aid in the diagnosis and treatment of temporal and facial pain, will be discussed.

The extracranial facial nerve: high resolution three-dimensional Fourier transform MR imaging.

PURPOSE: To investigate the use of high-resolution three-dimensional Fourier transform gradient-echo MR in evaluation of the extracranial facial nerve. METHODS: Nine normal subjects and one clinical patient were scanned. Several imaging parameters, including echo time, field-of-view, and the use of Gd-DTPA, were manipulated to determine the optimal technique. Adequate results were obtained in less than 7 minutes acquisition time using a T1-weighted (50/5.3) gradient-echo technique, with a 30 degree flip angle, a 12-cm field of view, 128 x 256 matrix, and 28 or 60 1.0-mm-thick contiguous sections. RESULTS: Gd-DTPA administration was not found useful in identifying the normal extracranial facial nerve. The proximal extracranial facial nerve was seen as a branching low signal intensity tubular structure on 10 to 20 contiguous images in all five volunteers in which this optimal technique was employed. Postprocessing of the images to produce curved oblique planar reconstructed images was useful to display long segments of the facial nerve on a single image. CONCLUSION: Our experience with high resolution three-dimensional Fourier transform MR imaging indicates that it can consistently demonstrate the intraparotid facial nerve on multiple contiguous images.

Effects of capsaicin (C) and dihydrocapsaicin (DC) on serum ethanol (ET) concentration of ET treated CF-1 mice.

In this study adult male CF-1 mice were treated on a daily basis as follows: Group A - controls, Group B - ethanol (ET) treated (1.25 g ET/kg body weight (b.wt.], Group C - ET plus 4 mg Capsaicin (C)/kg b.wt., and Group D - ET plus 4 mg dihydrocapsaicin (DC)/kg b.wt. At the end of the sixth week experimental period the animals were anesthetized, exsanguinated and hepatectomized. Our study suggests that ET administered at the rate of 1.25 g ET/kg b.wt. reaches a mean serum value of 43 + 14 mg/dL within 15 minutes. In addition, chronic ET ingestion significantly decreases mean hepatic glycogen content and mean serum triglyceride concentration of the animals. Conjoint administration of ET plus C decreases significantly mean body weight and mean ET and the triglyceride concentration of the serum. Prolonged ET ingestion plus DC administration decreases mean wet liver weight and lowers significantly the mean serum ET, cholesterol and triglyceride concentrations of CF-1 mice.

Dihydrocapsaicin (DC) protects against serum hyperlipidemia in guinea pigs fed a cholesterol-enriched diet.

Juvenile guinea pigs were maintained either on a standard diet (cholesterol-free) or a 0.5% cholesterol-enriched vitamin C deficient diet for six weeks. Half of the animals of each dietary group were treated with dihydrocapsaicin (DC) at the rate of 8 mg per animal per day. DC administration significantly altered food consumption, body weight, and dry weight of feces of animals maintained on the standard diet. In addition, the mean serum triglyceride concentration of these animals was significantly decreased with DC treatment. Food consumption, body weight and (wet) fecal weight of animals maintained on the 0.5% cholesterol-enriched diet were significantly lower than the corresponding values in control animals even though the liver was much larger in proportion to the total body weight. The mean serum cholesterol concentration of the animals fed a cholesterol-enriched diet was significantly elevated. However, in animals also receiving DC, the cholesterol and triglyceride levels were comparable to controls fed a regular diet. The gross and microscopic fatty infiltration of the liver observed in the cholesterol-fed animal were minimized in those animals fed cholesterol and DC.

Effects of pure capsaicinoids (capsaicin and dihydrocapsaicin) on plasma lipid and lipoprotein concentrations of turkey poults.

The effects of capsaicin and dihydrocapsaicin on blood lipid and lipoprotein concentrations were determined in two groups of turkeys. The first group was maintained on a cholesterol-free diet, while the second received a diet supplemented with 0.2% cholesterol. Daily administration of capsaicinoids occurred at a dose of 4 mg per animal. Neither drug had an effect on serum triglyceride concentrations in the animals receiving the cholesterol-free diet. However, total cholesterol, LDL-cholesterol and HDL-cholesterol concentrations were increased significantly, while VLDL cholesterol concentrations were decreased significantly by both drugs relative to controls. In the cholesterol-fed group triglycerides, total cholesterol and LDL-cholesterol decreased significantly with dihydrocapsaicin treatment. Both compounds reduced VLDL-cholesterol and increased HDL-cholesterol in the cholesterol-fed animals. Dihydrocapsaicin had a greater efficacy in producing beneficial anti-hyperlipidemic effects in the cholesterol-fed animals.

Effects of growth and maturation on biliary structures of guinea pigs.

The biliary system and major duodenal papilla of male guinea pigs were examined in vivo using intravital microscopy. Study of the photomicrographs and videotape recordings indicated that biliary organs changed with age and growth of the guinea pigs. Physiological data including the frequency of sphincteric contractions were recorded and efforts were made to correlate these data with changes in structure thought to be due to maturation. The volume of smooth muscle in the bile duct sphincter (measured using histological sections) increased with age as did surface area of the mucosa. The bile duct was separate from the pancreatic duct in each of 28 guinea pigs. Study of the guinea pig extrahepatic biliary system (EBS) allowed the isolated examination of effects of maturation on bile duct capacity. The anatomical reason for this is that the ampulla of the bile duct emptied into the duodenum (independently of the pancreatic duct) at the major duodenal papilla. The duct of the pancreas entered the duodenum distally (caudally) to the major duodenal papilla on the minor duodenal papilla. The separation of biliary and pancreatic ducts simplified the making of casts of the EBS. It is important to consider this feature in selection of a model for studies of bile duct function in living animals. Three anatomical techniques were selected to focus from differing perspectives on growth-related changes that occurred among the EBS of neonatal, juvenile and adult animals. These techniques were: The capacity (volume) of bile contained within the EBS was determined using plastic casts of the system.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of lithium carbonate administration on growth in the domestic fowl.

Lithium carbonate is routinely used for the treatment of aggressive behavior disorders in adolescents. The current study was undertaken in order to determine the effect of lithium carbonate administration on growth in a domestic fowl model. The results showed that lithium treatment at a therapeutic level (0.2-2.0 mEq/L) did not significantly alter plasma pH levels, food intake, fecal output or body weight gain. Bivariate and multivariate analysis of tibial dimensions revealed that lithium treatment primarily caused increased growth of proximal epiphyseal height. Allometric analyses indicated that lithium administration increased the growth differential between proximal and distal epiphyses. Two possible mechanisms by which lithium carbonate administration may cause accelerated osseous growth are given.

Capsaicin lowers plasma cholesterol and triglycerides of lagomorphs.

The present study determines the effect on plasma total cholesterol, triglycerides, and HDL-C values when capsaicin (8-methyl-N-vanillyl-6-nonenamide) is administered at the dose of 8mg/animal/day to young female rabbits maintained on a 0.5% cholesterol diet over a five week experimental period. Our data indicate that mammals of the order Lagomorpha fed cholesterol rich diets and supplemented with capsaicin show decreased plasma total cholesterol, triglycerides, and total cholesterol to HDL-C ratio as compared to cholesterol level of controls. The mechanism of this effect is probably due to decreased intestinal absorption of the lipids.

Effects of oestrogen upon tensile properties of healing fractured avian bone.

The present work considers some of the effects of oestrogen treatment on the biomechanical properties of long bones during the process of osteosynthesis. The influence of the steroid was assessed by determining the tensile strength properties of treated and untreated healing fractured ossa radii. The ultimate tensile strength and modulus of elasticity were determined at one and two week post-fracture induction. In general, oestrogen treatment decelerated healing process of long bones. This was indicated by a significantly reduced ultimate tensile callus strength of oestrogen-treated birds over a two week period post-fracture induction. The same group also exhibited a significant increase in callus cross-sectional area while the elastic moduli of their bones were not significantly different at either one or two weeks post-fracture induction.

The architecture of the avian retina following exposure to chronic 2 G.

Rhode Island REd female chicks at 2 weeks posthatch were subjected, for 7 d, to either earth gravity of 1 G or a 2-G hypergravity environment by chronic whole-body centrifugation. Animals were sacrificed at 3 weeks posthatch and the eyes were enucleated, fixed in 10% BNF, doubly embedded, sectioned at 7-8 micrometer and routinely processed with H & E for histological examination. Compared to normogravity controls, animal exposure for 1 week to the chronic effects of 2-G resulted in a significantly decreased mean width of the photoreceptor, inner nuclear, and inner plexiform retinal layers. The outer nuclear, outer plexiform, and ganglion cell layers of the retina appeared minimally affected by the hypergravity state since the mean width of these layers showed no noticeable differences from earth gravity control animals. The present anatomic findings suggest a reduction in the detection of motion or rapid changes in illumination by the avian retina when the animal is exposed to a 2-G environment.

Hypergravity and estrogen effects on avian anterior pituitary growth hormone and prolactin levels.

Developing female chicks with fractured right radii were maintained for 14 d at either earth gravity (1 G) or a hypergravity state (2 G). The birds at 1 G were divided into groups which received daily injections of 1) saline, 2) 200 micrograms estrone, and 3) 400 micrograms estrone for 14 d. The 2-G birds were divided into three similarly treated groups. All 2-G birds showed significantly lower body weights than did 1-G birds. Anterior pituitary (AP) glands were excise; and analyzed for growth hormone and prolactin content by analytical electrophoresis. The 1-G chicks receiving either dose of daily estrogen showed increased AP growth hormone levels, whereas hypergravity alone did not affect growth hormone content. Chicks exposed to daily estrogen and hypergravity displayed reduced growth hormone levels. AP prolactin levels were slightly increased by the lower daily estrogen dose in 1-G birds, but markedly reduced in birds exposed only to hypergravity. Doubly-treated chicks displayed normal prolactin levels. Reduced growth in 2-G birds might be due, in part, to reduced AP levels of prolactin and/or growth hormone.

Effects of fracture trauma, estrone treatment, and 2-G environment on the epiphyseal cartilage zones of developing avian radii.

Female birds subjected to closed fracture of the right radius at 2 weeks post-hatching were allowed to heal for 14 d at either earth gravity (1 G) or a 2-G hypergravity state, with saline-injected controls and 0.2- and 0.4-mg estrone (estrogen) treated groups. Animals were sacrificed following the last injection and radii were routinely processed histologically for micrometer measurements of the mid-coronal height and width of the cartilage zones of the proximal and distal epiphyses. Proximal epiphyses of estrone-treated, normo-gravity chicks showed a decreased growth in height of the articular, proliferating, and hypertrophic cartilage zones and an increased interstitial growth of the hypertrophic and calcified layers of estrone-treated, 2-G animals. Growth in height of the cartilage layers of the distal epiphyses of fractured radii was primarily stimulated when estrone-treated chicks were also exposed to the 2-G state. Appositional growth of all cartilage layers of the proximal and distal epiphyses of normo-gravity birds was increased by 0.2 mg estrone. In addition, growth in the width of all cartilage layers of the distal epiphyses of 2-G animals was increased with the administration of 0.4 mg estrone.

Remodeling of the avian fracture callus by estrone treatment and exposure to a 2 g environment.

Rhode Island Red female chicks were subjected to complete closed fracture of the right radius at two weeks post hatching. The animals were allowed to heal for 2 weeks at either earth gravity (1 g) or a 2 g environment with saline injected controls and estrone injected experimentals. Total fractured bone weight was decreased by exposure to the 2 g environment regardless of whether the animal received saline or estrone treatment. The mean weight of fracture callus was significantly decreased when the hypergravity exposed animals received low hormonal levels of 0.2 mg estrone. The average mid-cross sectional diameter of fracture callus was significantly decreased when the centrifuged chicks received saline or 0.2 mg estrone and it was increased with the administration of high hormonal levels of 0.4 mg to the 2 g animal. The mean thickness of the subperiosteal trabeculae of the bridging callus was decreased by exposure to hypergravity either with or without estrone treatment.

The effect of ethanol on cerebral glycogen levels in the chick embryo.

Ethanol (10 to 50 micro-liters/egg) was injected into the albumen of the 13 day chick embryo. The control solution and ethanol carrier was bacteriostatic saline (0.1 ml). The KOH-alcohol-Anthrone colorimetric method was used for glycogen determination. Ethanol at 20 or 30 mul/egg lowered the mean cerebral glycogen (p less than 0.05). Higher dosages elevated cerebral glycogen over the same time period (p less than 0.05). The glycogen-depleting effect of 20 mul/egg and the glycogen increasing effect of 40 mul/egg were maintained through 168 hours of ethanol exposure (20 days incubation).

Responses of articular and epiphyseal cartilage zones of developing avian radii to estrone treatment and a 2-G environment.

Female chicks at 2 weeks post-hatch were maintained for 2 weeks at earth gravity or 2 G with daily injections of 0.2 or 0.4 mg estrone. Animals were sacrificed following the last injection and radii were fixed in 10% NBF, decalcified in 3% Nitric acid, doubly embedded, sectioned at 4 to 5 micrometer, and routinely processed for histological measurements of the midcoronal height and width of the cartilage zones of the proximal and distal epiphyses. Estrone treatment increased the growth in height and width of the cartilage layers of the proximal epiphyses and inhibited the growth in height of the distal epiphyseal cartilage of earth gravity chicks. Animal exposure to 2 G without estrone treatment resulted in increased width of the cartilage layers of the proximal epiphyses and inhibition of both height and width growth of the cartilage layers of the distal epiphyses. Growth in height, but not width, of the cartilage layers of both proximal and distal epiphyses was inhibited by combined estrone treatment and animal exposure to the 2 G environment.

Effects of increased earth gravity and estrone treatment on intact and healing avian radii.

Estrone, 0.4 mg administered daily for 7 days to developing chicks at 2 weeks post hatching, increased total mass and accelerated the rate of growth of the diaphyseal and proximal epiphyseal diameters of intact radii. Fractured radii of animals subjected to the same hormonal treatment displayed decreased bone weight but increased rate of growth of the proximal epiphyseal diameters and longer but thinner and lighter calluses. Two-week-old chicks, which had received no estrone, when exposed to a week-long 2g environment showed decreased intact bone weight and, with the exception of length of fracture callus, a reduction of all measured parameters of fractured bones. Estrone treatments of 0.4 mg administered daily to hypergravity-exposed animals over a week-long period resulted in greater length of fracture callus and increased rate of growth of the proximal epiphyseal diameter of both intact and fractured bones. The same treatments decreased weight and linear growth of fractured bones and width and weight of the fracture callus.

The glycogen-depleting effect of aqueous estrone on the cerebral hemispheres of the chick embryo.

Aqueous estrone (10 to 50 pigrams/egg) was injected into the albumen of the 13 day chick embryo. The control solution and estrone carrier was 0.1 ml bacteriostatic saline. The KOH-alcohol-Anthrone colorimetric method was used to determine glycogen. 20 or more pigrams estrone/egg lowered the mean cerebral glycogen significantly (P less than 0.01) after 24 hours duration in a non-dosage-dependent manner. The glycolytic effect was demonstrated by the 20.0 pigram dosage after 120 hours duration.

Simplified hypophysectomy technique for young birds.

The present work introduces a modified oral approach to the pituitary gland of the immature bird with improved localization and visualization of the organ in situ. The hypophysectomy procedure is based on simplified instrumentation readily available or constructed with materials present in most, if not all, laboratories. The technique has the added advantage of minimal exsanguination, virtually no operative trauma, and allows for a rapid post operative animal recovery.

Hypergravity effects on normal and avulsed developing avian radii.

Rhode Island Red female chicks were subjected to complete closed fracture of the right radius at 2 weeks post-hatching. The animals were allowed to heal for 1 week at either earth gravity or 2 G hypergravity state with control and estrogen-injected groups. Intact and fractured radial length, weight, average epiphysial-diaphysial diameters, and length, width, and weight of healing fracture callus were measured. Daily 2000 IU estrogen administration for 7 d increased intact radial length. Estrogen augments the effects of the 2-G state by inhibiting growth and depleting the mass of both intact and fractured radii and by decreasing the average distal epiphysial diameter of fractured bones. Animals exposed to the hypergravity state without hormonal treatment showed decreased fractured radial length, weight, and smaller proximal epiphysial diameters. The measurable parameters of the fracture callus (width, length, and weight) were depressed by the hypergravity state regardless of whether the animal was untreated or supplemented with estrogen.

Accumulative effects of 2 weeks' exposure to a 2-G hypergravity state and estrogen treatment upon intact and fractured radii of young female birds.

Female birds were subjected to closed fractured of the right radius at 2 weeks post-hatching and allowed to heal for 14 d. The animals were maintained at either earth gravity or a 2-G hypergravity state with control and 2000 and 4000 IU Estrone-(estrogen) injected groups. Intact and fractured radii were measured for length, weight, average epiphysial-diaphysial diameters, and length, width and weight of fracture callus. Animals receiving 2000 IU estrogen treatment showed decreased intact and fractured bone weight, as well as smaller diaphysial diameters. Fractured, but not intact, bone length was decreased by the two estrogen levels without affecting the callus parameters. Bone weight and average epiphysial diameters of both intact and fractured radii were decreased by the hypergravity state. Intact bone diaphysis and fractured bone length were similarly affected. Large, 4000 IU, estrogen levels potentiated the hypergravity state and reduced distal epiphysial diameter of intact radii.