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Therapeutic time window and dose response of the beneficial effects of ketamine in experimental head injury.

BACKGROUND AND PURPOSE: The aim of this study was to determine the time and dose response of the therapeutic effects of the N-methyl-D-aspartate receptor antagonist ketamine in experimental head injury. METHODS: Sixty-six male Sprague-Dawley rats were divided into eight groups. Groups A, B, and C were surgically prepared but received no trauma. Groups D through H received a nonpenetrating impact to the left cranium. Group A (n = 7) received no treatment. Groups B (n = 4) and C (n = 5) received 60 and 120 mg/kg IP ketamine, respectively. Group D (n = 8) received no treatment. Groups E (n = 8) and F (n = 7) received 120 and 180 mg/kg IP ketamine, respectively, 1 hour after head trauma. Groups G (n = 7) and H (n = 9) were treated with 180 mg/kg IP ketamine 2 and 4 hours after head trauma, respectively. Neurological severity score (NSS, 0 through 25 from no injury to severe injury) was determined at 1, 24, and 48 hours after head trauma. After death at 48 hours, cortical slices were taken adjacent to the lesion on the traumatized hemisphere and from comparable sites in the contralateral hemisphere for determination of tissue specific gravity and water content. Brains were then placed in 4% formaldehyde, and the volume of hemorrhagic necrosis was measured 4 days later. NSS was compared within and between groups using the Kruskal-Wallis test for repeated measurements and Mann-Whitney U test for post hoc testing. Water content, specific gravity, and hemorrhagic necrosis were compared within and between groups using two-way ANOVA followed by Fisher's protected least significant difference procedure. A value of P < .05 was considered statistically significant. RESULTS: Head trauma alone increased NSS, decreased specific gravity, increased water content, and caused cerebral infarction in the injured hemisphere. Ketamine given in two time-dose regimens, 180 mg/kg IP at 2 hours (group G) and 120 mg/kg IP at 1 hour (group F) after trauma, improved NSS from 11.6 +/- 1.7 and 14.4 +/- 0.8 at 1 hour to 4.4 +/- 1.3 and 8.0 +/- 1.4 (mean +/- SEM) at 48 hours, respectively (P < .03). Compared with the untreated group (group D), 180 mg/kg IP ketamine given at 2 and 4 hours after head trauma decreased the volume of hemorrhagic necrosis from 37.1 +/- 9.5 mm3 to 10.1 +/- 3.8 and 15.3 +/- 3.6 mm3, respectively (P < .05). Brain tissue specific gravity and water content at 48 hours were not significantly different between treated and untreated groups. There was no difference in rectal and temporalis muscle temperature between groups. CONCLUSIONS: We conclude that 180 mg/kg IP ketamine was effective in ameliorating neurological dysfunction after head trauma in rats when the administration time was delayed for 1 hour to 2 hours but not after 4 hours. When given at 1 hour after head trauma, ketamine at 120 mg/kg but not 60 mg/kg is effective in reducing neurological damage after head trauma.

Analysis of Variance↗

Influence of soil texture in the recovery of Toxocara canis eggs by a flotation method.

In epidemiological surveys, the evaluation of soil contamination by Toxocara canis eggs requires a quick and easy method for the isolation of parasite eggs from soil samples. The efficiency of flotation methods is influenced by sample size, soil texture, degree of soil contamination, pretreatment, flotation solutions and time of flotation. This investigation was designed to evaluate the influence of soil texture in the recovery of T. canis eggs with the centrifugal flotation technique of Dada (Dada, B.J.O., 1979. A new technique for the recovery of Toxocara eggs from soil. J. Helminthol., 53: 141-144). Four types of soil (clay silt, sandy, silty clay and sand) were artificially contaminated with T. canis eggs (200 eggs per gram). Zinc sulphate (specific gravity 1.20) and sodium dichromate (specific gravity 1.35) were used as flotation solutions. Twenty replicated examinations were performed for each type of soil and flotation solution. There was a statistically significant difference in the results depending on soil type. The highest recovery percentages were observed in soils rich in sand (62.5% for sand and 38.0% for sandy soil). Differences were also observed with different flotation solutions. Sodium dichromate solution was more efficient for recovering T. canis eggs, regardless of the soil texture.

Analysis of Variance↗

Efficiency of the salt flotation technique in the recovery of Ascaris lumbricoides eggs from the soil.

The efficacy of the salt flotation technique using saturated solutions of sodium nitrate (specific gravity 1.30) and zinc sulphate (specific gravity 1.16) for separating Ascaris lumbricoides eggs from clay, loamy and sandy soils has been investigated. Ten samples of each of the egg concentrations of 100, 500, 2500, 5000 and 10,000 eggs/25 g of soil were used for each soil type. Using T-test and ANOVA, the number of eggs recovered from sand was significantly higher than from loam and the number from loam significantly higher than from clay. With sodium nitrate, the maximum egg recovery rate was 25.04% from sandy soil at a concentration of 500 eggs/25 g soil while with zinc sulphate it was 13.88% also from sandy soil and concentration of 500 eggs/25 g soil. While the number of eggs recovered increased with soil egg concentration, the percentage of eggs recovered is inversely proportional to egg concentration. The number of eggs recovered with sodium nitrate was significantly higher than with zinc sulphate solution in the three soil types.

Animals↗

CD44 and CD69 represent different types of cell-surface activation markers for human eosinophils.

Eosinophils (EOS) purified from peripheral blood or late-phase bronchoalveolar lavage (BAL) were analyzed with 473 monoclonal antibodies (mAbs) from the Fifth International Workshop on Human Leukocyte Antigens in an attempt to identify markers of EOS activation. Two strategies were used: (1) to look for surface markers absent on fresh EOS but present after in vivo activation (e. g., in late-phase BAL fluid [BALF]) or after in vitro culture for up to 72 h with cytokines (<= 10 ng/ml of interleukin-3 [IL-3], IL-5, or granulocyte-macrophage colony-stimulating factor [GM-CSF]); and (2) to look for markers constitutively expressed on fresh EOS that were increased after activation in vivo or after culture in vitro. With indirect immunofluorescence and flow cytometry, the first approach revealed that among approximately 350 mAbs tested, only those recognizing CD69 became bound to late-phase BALF EOS or cytokine-cultured EOS, but not to fresh EOS. Using the second approach, we observed statistically significant concentration- and time-dependent increases in CD44 expression in EOS cultured with IL-3, IL-5, or GM-CSF (approximately 2-fold increase in fluorescence intensity, P < 0.05), but not with interferon-gamma (IFN-gamma) (up to 100 ng/ml), whereas levels of 15 other constitutively expressed markers were unchanged. Despite increased expression, neither fresh nor cytokine-cultured EOS adhered to immobilized hyaluronate, a ligand for CD44. Additionally, simultaneous comparison of hypodense (specific gravity < 1.085 g/liter) and normodense (specific gravity > 1.085 g/liter) EOS from allergic donors consistently revealed higher levels of CD44 expression (approximately 3- to 8-fold) but not CD69 expression on hypodense EOS. We conclude that CD69 and CD44 represent different types of activation markers for human EOS. These findings may be useful in assessing the state of EOS activation in vitro and in vivo.

Antibodies, Monoclonal↗

Genetic correlation and heritabilities for purebred and crossbred performance in poultry egg production traits.

Genetic correlations between purebred and crossbred performance and purebred and crossbred heritabilities were estimated for egg production traits of laying chickens using a multivariate sire model accounting for additive relationships between sires. Two sire lines, denoted lines 1 and 2, were crossed to one dam line to produce crossbred progeny. Records for egg weight, egg specific gravity, and egg number were collected on purebred and crossbred hens. In total, 99 sires in line 1 and 292 sires in line 2 were used in the analysis, each sire producing on average 45 purebred and 105 crossbred daughters. Estimates of purebred heritability in lines 1 and 2 were in range of .54 to .74 for egg number traits, .52 to .91 for egg weight traits, and .41 to .83 for egg specific gravity traits. Estimates of crossbred heritability were .04 to .51 for egg numbers, .23 to .45 for egg weight, and .13 to .31 for egg specific gravity. The sire component in crossbreds differed up to 78% from the sire component in purebreds depending on traits. The estimate of genetic correlation (rpc) between purebred and crossbred performance was .56 to .73 for egg number, .69 to .99 for egg weight, and .72 to .82 for egg specific gravity. Although crossbred parameters were strongly affected by environmental factors, the results tend to agree with the theory that traits with a larger dominance variation and a larger difference between sire components in purebreds and crossbreds show a lower rpc.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

A comparison of hyper- and isobaric solutions of bupivacaine for subarachnoid block.

The comparative efficacy of two solutions of bupivacaine, 0.5% plain (isobaric-specific gravity 1.010), and 0.4% bupivacaine (hyperbaric-specific gravity 1.027) in 4% dextrose, for spinal anaesthesia was studied in 67 patients. Both solutions were clinically satisfactory (94% completely successful neural blockade). Hyperbaric bupivacaine blocks a greater number of spinal segments (p less than 0.01), causes a more rapid fall in blood pressure (p less than 0.05), and is more predictable in effect with regard to the number of segments blocked and to the lateralisation of the block. The duration of perioperative analgesia with the hyperbaric preparation is, however, shorter-3.8 hours as opposed to 5.8 hours (p less than 0.01)--but this was likely to be due to the smaller total dosage of bupivacaine used in the hyperbaric group. It is concluded that either solution may be used satisfactorily in clinical practice. The isobaric solution, however, despite its ready availability, is less satisfactory than the hyperbaric because its effect with regard to the extent of blockade is less predictable.

Adult↗

Hydration status in college football players during consecutive days of twice-a-day preseason practices.

BACKGROUND: Football players lose 3.5 to 5 kg of body weight during preseason practices because of heavy sweating. This fluid may be difficult to replace when practices occur 2 times per day on consecutive days. HYPOTHESIS: Football players are hypohydrated during twice-a-day preseason training in a hot, humid environment. STUDY DESIGN: Descriptive laboratory study. METHODS: In 10 college football players, body weight was measured, and blood and urine samples were obtained before and after practices on days 2 through 8 of preseason training. Baseline samples were obtained when subjects were euhydrated. Blood samples were used to calculate plasma volume changes. Urine samples were analyzed for specific gravity, sodium, and potassium. Sweat rate was calculated. Core temperature was monitored during half- and full-padded practices. RESULTS: Mean wet bulb temperatures were 23.3 degrees C during morning practices and 23.7 degrees C during afternoon practices. Plasma volume was below baseline on day 2 and expanded by day 6. Urine specific gravity was higher than baseline for 12 of 20 measurements over the 8 days. It was 1.0175 +/- 0.006 at baseline but subsequently ranged from 1.0214 +/- 0.007 to 1.0321 +/- 0.004. Mean daily urine sodium dropped from baseline to day 2 (194 +/- 43 vs 43 +/- 38 mmol x L-1), remaining lower on days 3, 4, and 6 (40 +/- 39, 39 +/- 39, and 68 +/- 40 mmol x L-1, respectively). Urine potassium was lower on days 6 and 8 compared with baseline and day 3. Body weight was below baseline before and after both daily practices. Core temperature was higher in full pads; sweat rate and body weight loss were not different between half and full pads. CONCLUSION: Body weight, plasma volume, urine specific gravity, and urine sodium indicate that football players become dehydrated by day 2 of preseason training. Urine sodium increased to near baseline by day 8; urine specific gravity was elevated. CLINICAL RELEVANCE: Football players struggle to maintain euhydration during preseason twice-a-day sessions.

Adult↗

Dextrose affects gravitational spread of epidural anesthesia.

Chloroprocaine, 0.5 per cent, with physiologic saline solution, has a specific gravity of 1.007 and a osmolarity of 283 mOsm/l, which increase to a specific gravity of 1.025 and an osmolarity of 542 mOsm/l when chloroprocaine is prepared in dextrose, 5 per cent. Chloroprocaine, 2.7 per cent, shows similar increases in specific gravity and osmolarity with dextrose 5 per cent. The highest sensory anesthesia level attained in pregnant patients following epidural injection of 10 ml of each of these solutions was determined. Chloroprocaine in dextrose, 5 per cent, produced a significant lowering of the highest sensory anesthesia level attained, compared with solutions to which dextrose was not added.

Anesthesia, Epidural↗

Brain ion and amino acid contents during edema development in hepatic encephalopathy.

Brain edema in hepatic encephalopathy has been associated with circulating ammonia that is metabolized to glutamine. We measured alterations in blood chemistry and brain regional specific gravity and ion and amino acid contents in models of simple hyperammonemia and liver failure induced by daily administrations of ammonium acetate (AAc) or thioacetamide (TAA), respectively. Serum and brain ammonia increased to similar levels (200 and 170% of control, respectively) in both experimental groups. Serum transaminase activities increased 10-fold in animals injected with TAA but were unchanged in animals given AAc injections. In both experimental groups glutamine was elevated in cerebral white matter, cerebral gray matter, and basal ganglia, whereas brain tissue specific gravity decreased in all brain regions, indicating edema formation. In the AAc group, we observed a decrease in glutamate and taurine contents concomitant with the development of brain edema. In these animals, cerebral gray matter specific gravity and taurine contents returned to control levels 24 h after the third AAc injection. TAA-injected animals demonstrated similar decreases in brain tissue specific gravity, whereas glutamine, glutamate, and taurine contents were all elevated. During hepatic encephalopathy, ammonia-induced changes in brain amino acid content may contribute to brain edema development.

Acetates↗

Calcium metabolism in broiler breeder hens. 2. The influence of the time of feeding on calcium status of the digestive system and eggshell quality in broiler breeders.

Experiments were conducted to determine the influence of time of dietary calcium intake on eggshell quality in broiler breeder hens. In Experiment 1, 60 hens were randomly divided among three treatment groups. The control group received 155 g feed (3.1% calcium) per day at 0800 hr whereas the morning- (a.m.) and evening-fed (p.m.) treatments received a .42% calcium diet (155 g/bird) and were intubated with 4.2 g calcium at 0800 or 1600 hr, respectively. Egg weight, shell weight, and specific gravity were determined at 3-day intervals for 15 days. In Experiment 2, 150 breeder hens were randomly divided among two treatment groups. They were fed 122 g per hen during a 2.5-hr feeding time at 0700 to 0930 or 1530 to 1800 hr. Eggs were collected for egg weight, shell weight, and specific gravity determinations. At the end of the 5th week, 10 hens from each treatment group were sacrificed at various times throughout a 24-hr period and the contents of each segment of the GI tract and feces were analyzed for moisture, dry matter, and calcium. In Experiment 3, two commercial broiler-breeder houses with 5,000 hens each were used. They were fed 132 g/hen per day at 0530 hr daily with water provided ad lib. The feeding time of one house was moved forward by 2 or 2.5 hr per day until the feeding time was 1600 hr. Eggs were collected for 2 weeks following pretreatment data and values determined for specific gravity. Eggs were also candled at 7 days incubation to determine embryonic mortality and fertility. Hens intubated at 0800 hr with their daily supply of calcium did not maintain shell quality equivalent to controls (Experiment 1). However, hens intubated at 1600 hr had no difficulty maintaining shell quality. Hens fed at 1530 hr had significantly better shell quality during all weeks tested compared to hens fed at 0700 hr (Experiment 2). The p.m.-fed hens had 66.9% more calcium available at 1800 hr (2.07 vs. 1.24 g) compared to a.m.-fed hens. Hens fed at 1600 hr in the commercial houses (Experiment 3) had significantly better eggshell quality (specific gravity) than hens fed at 0530 hr. There was no significant difference in percent embryonic mortality or percent fertility when eggs were candled after 7 days of incubation. It was concluded that p.m.-fed hens had significantly more calcium available during the stages of eggshell calcification. The result was significantly better eggshell quality.

Animals↗

Detection of brain atrophy following traumatic brain injury using gravimetric techniques.

We hypothesized, that with atrophy, the correlation between water content and specific gravity of brain solids would break down signifying the onset of the atrophic process. The correlation between tissue water content, specific gravity of solids and ventricular size was studied in an impact acceleration model of closed head injury of the rat. Adult Sprague Dawley rats weighing 350 to 375 grams (n = 63) were separated into two groups: Group 1: Sham (n = 21), Group II: Trauma (n = 42). Water content was assessed using both gravimetric method and drying-weighing method at 1 hour, on days 1, 3, 7, 14, 28, and 42 in the trauma group as well as in the control group. Ventricular size was measured in cm2 on the MRI computer console in the coronal section at the coronal suture at the same time points. In the trauma group we found a significant increase (p < 0.01) in water content during the first week except on day 3 and there was a good correlation between the results of water content using both methods (p < 0.001). However, this relationship was poorly correlated after day 14 (p = 0.25). Although the ventricular size was the smallest at 1 hour post trauma, it significantly increased over the next 3 days (p < 0.001). On day 7 and 14 ventricular size decreased to normal size, yet gradually increased and then reached a significantly larger size on 42 days post trauma again (p < 0.01). We may consider, that brain edema following CHI begins immediately following trauma and resolves within 2 weeks. After 14 days degenerative change occurs in the cortex, as detected by specific gravity measurements which signifies the onset of the atrophic process and subsequent post traumatic ventricular dilatation.

Animals↗

Response of commercial Leghorns to sodium aluminosilicate when fed different levels and sources of available phosphorus.

Two experiments were conducted to elucidate possible explanations for the adverse interaction of sodium aluminosilicate (ZA) and low phosphorus on egg production. In Experiment 1, hens were fed available phosphorus at two levels (.40 and .31%) and from three sources (dicalcium phosphate, defluorinated phosphate, and meat and bone meal). Two levels (0 and .75%) of ZA were concomitantly fed with these treatments. In Experiment 2, hens were fed two levels (.30 and .20%) and two sources (dicalcium phosphate and defluorinated phosphate) of phosphorus with and without ZA (0 and .75%). In both experiments, egg production, egg specific gravity, feed consumption, and egg weight were measured. In Experiment 2, plasma sodium, potassium, chloride, total and free calcium, and phosphorus were also monitored. Results of both Experiments indicated that ZA significantly increased egg specific gravity; whereas, phosphorus level and source had no effect on egg specific gravity. Egg production was influenced by ZA level, phosphorus source, and phosphorus level with significant phosphorus source by phosphorus level interactions. In Experiment 1, ZA reduced egg production at the higher phosphorus level when dicalcium phosphate or defluorinated phosphate was used but not at the lower phosphorus level. Egg production was not influenced by ZA when meat and bone meal was the source of phosphorus. In Experiment 2, ZA reduced egg production more at the lowest level of phosphorus and more when the phosphorus source was defluorinated phosphate than when it was dicalcium phosphate but the interaction was not significant. Sodium aluminosilicate had no influence on egg weight, but it did reduce feed consumption.(ABSTRACT TRUNCATED AT 250 WORDS)

Aluminum Silicates↗

Floating gallstones in bile without added contrast material.

Floating gallstones can occur without the administration of contrast material to increase the specific gravity of bile. This was observed in three patients in 17 months. After a long fast, a large stone was noticed to float because of the high specific gravity of inspissated bile. This stone sank after the patient resumed food intake. In another patient, some stones floated while others sank due to their difference in specific gravity. Sonographic demonstration of a floating stone, however, requires certain strict criteria.

Bile↗

Various irrigation fluids affect postoperative brain edema and cellular damage during experimental neurosurgery in rats.

BACKGROUND: This study was conducted to investigate how various irrigation fluids used during neurosurgical procedures affect the degree of postoperative brain edema and cellular damage during experimental neurosurgery in rats. METHODS: The cerebral cortex was exposed and incised crosswise with a surgical knife under irrigation with an artificial CSF, lactated Ringer's solution, or normal saline. Four hours after injury, irrigation was stopped and brain tissue samples were obtained from injured and uninjured sites. Specific gravity, cerebrovascular permeability, and TTC staining of the samples were evaluated. Incision and irrigation of the brain were not performed on the control group. RESULTS: At the injured site, specific gravities of the samples in the normal saline group and the lactated Ringer's solution group were significantly lower than the specific gravity in the artificial CSF group. The EB concentration was significantly higher in the lactated Ringer's solution group and relatively high in the normal saline group as compared with the artificial CSF group. TTC staining did not differ significantly between the artificial CSF group and the control group. It was significantly lower in the lactated Ringer's solution group and the normal saline group than in the control group and the artificial CSF group. CONCLUSIONS: As compared with normal saline and lactated Ringer's solution, artificial CSF reduced postoperative brain edema, cerebrovascular permeability, and cellular damage in sites injured by experimental neurosurgery in rats.

Animals↗

Conversion of biovolume measurements of soil organisms, grown under various moisture tensions, to biomass and their nutrient content.

Direct microscopic measurements of biomass in soil require conversion factors for calculation of the mass of microorganisms from the measured volumes. These factors were determined for two bacteria, five fungi, and a yeast isolated from soil. Moisture stress conditions occurring in nature were simulated by growth in two media using shake cultures, on agar plates, and on membranes held at 34, 330, and 1,390 kPa of suction. The observed conversion factors, i.e., the ratio between dry weight and wet volume, generally increased with increasing moisture stress. The ratios for fungi ranged from 0.11 to 0.41 g/cm with an average of 0.33 g/cm. Correction of earlier data assuming 80% water and a wet-weight specific gravity of 1.1 would require a conversion factor of 1.44. The dry-weight specific gravity of bacteria and yeasts ranged from 0.38 to 1.4 g/cm with an average of 0.8 g/cm. These high values can only occur at 10% ash if no more than 50% of the cell is water, and a specific conversion factor to correct past data for bacterial biomass has not yet been suggested. The high conversion factors for bacteria and yeast could not be explained by shrinkage of cells due to heat fixing, but shrinkage during preparation could not be completely discounted. Moisture stress affected the C, N, and P content of the various organisms, with the ash contents increasing with increasing moisture stress. Although further work is necessary to obtain accurate conversion factors between biovolume and biomass, especially for bacteria, this study clearly indicates that existing data on the specific gravity and the water and nutrient content of microorganisms grown in shake cultures cannot be applied when quantifying the soil microbial biomass.

Journal Article↗

Relative density of urine: methods and clinical significance.

The physical properties and chemical composition of urine are highly variable and are determined in large measure by the quantity and the type of food consumed. The specific gravity is the ratio of the density to that of water, and it is dependent on the number and weight of solute particles and on the temperature of the sample. The weight of solute particles is constituted mainly of urea (73%), chloride (5.4%), sodium (5.1%), potassium (2.4%), phosphate (2.0%), uric acid (1.7%), and sulfate (1.3%). Nevertheless, urine osmolality depends only on the number of solute particles. The renal production of maximally concentrated urine and formation of dilute urine may be reduced to two basic elements: (1) generation and maintenance of a renal medullary solute concentration hypertonic to plasma and (2) a mechanism for osmotic equilibration between the inner medulla and the collecting duct fluid. The interaction of the renal medullary countercurrent system, circulating levels of antidiuretic hormone, and thirst regulates water metabolism. Renin, aldosterone, prostaglandins, and kinins also play a role. Clinical estimation of the concentrating and diluting capacity can be performed by relatively simple provocative tests. However, urinary specific gravity after taking no fluids for 12 h overnight should be 1.025 or more, so that the second urine in the morning is a useful sample for screening purposes. Many preservation procedures affect specific gravity measurements. The concentration of solids (or water) in urine can be measured by weighing, hydrometer, refractometry, surface tension, osmolality, a reagent strip, or oscillations of a capillary tube. These measurements are interrelated, not identical. Urinary density measurement is useful to assess the disorders of water balance and to discriminate between prerenal azotemia and acute tubular necrosis. The water balance regulates the serum sodium concentration, therefore disorders are revealed by hypo- and hypernatremia. The disturbances are due to renal and nonrenal diseases, mainly liver, cardiovascular, intestinal, endocrine, and iatrogenic. Fluid management is an important topic of intensive care medicine. Moreover, the usefulness of specific gravity measurement of urine lies in interpreting other findings of urinalysis, both chemical and microscopical.

Biophysical Phenomena↗

Studies on the cell-mediated immune response of tonsillar lymphocytes with regard to the clinical course and patient's age.

There was no statistically significant difference in the intensity of the cell-mediated immune response of tonsillar T cells among different pathological conditions of the tonsils nor among different age groups. The tonsillar cell population of the adult was smaller than that of the child. Tonsillar cells were separated into 3 fractions with different specific gravities. In tonsillar cells from adults, fraction III consisting mainly of small lymphocytes with a high specific gravity occupied a larger portion than in those from children. Fraction I consisting of cells with a low specific gravity had a greater number of cells in the swollen tonsils of children than in the tonsils of adults. However, the absolute numbers of the cells in fraction III in adults and in children were nearly the same. The proportion of T cells in fraction III was higher than in fraction I. Hence, the proportion of T cells in adults' tonsils is higher than in children's tonsils. The cells composing fraction I include some cells that have undergone blastoid transformation in response to various stimuli and some lymphoid cells that are ontogenetically immature T cells, besides mature T cells. The cells composing fraction III include fully mature T cells and the total cell population of fraction III does not differ significantly with age. It seems likely that the child's tonsil contains a larger number of cells under antigenic stimulation or in preparation for immune response than does the adult's tonsil.

Adult↗

Phosphorus phase feeding and uterine and isthmus mucosal enzymes and minerals in relation to soft-shelled and shell-less egg production.

The relationships among phosphorus phase feeding, egg shell quality, and the activities and concentrations of several enzymes and minerals in the uterine and isthmus mucosae of hens at the time of oviposition were investigated. During the first 8 months of production (Phase 1), layer diets contained .3, .5, or .7% available phosphorus. Between 9 and 12 months of production (Phase 2), dietary available phosphorus was either increased or decreased by .2% phosphorus, or was left unchanged. No significant differences due to Phase 1 diets were demonstrated for hard-shelled (HS), soft-shelled (SS), or shell-less (SL) egg production, livability, egg weight, or specific gravity. Phase 2 diets had no significant effect on SS or SL egg production, livability, or egg specific gravity; however, decreasing dietary phosphorus reduced egg weight. Levels as high as .9% had no effect on specific gravity or HS egg production, while .1% dietary phosphorus was detrimental to HS egg production and feed consumption. No significant differences due to dietary available phosphorus or egg type (SS vs. HS) were demonstrated for uterine or isthmus mucosal enzyme activities or mineral contents, with one exception. Higher inorganic phosphorus concentrations were found in the uterus of HS egg layers when compared to levels in the uterus of SS egg layers and the isthmus of HS and SS egg layers. Acid phosphatase and carbonic anhydrase activities, and total calcium levels were significantly higher in the isthmus than the uterus, while alkaline phosphatase and pyrophosphatase activities, and inorganic phosphorus levels were significantly higher in the uterus than the isthmus.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid Phosphatase↗