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1.
A comparison is made between in vitro and human and rat in vivo methods for estimating food iron availability. Complex meals formulated to replicate meals used by Cook and Monsen (Am J Clin Nutr 1976;29:859) in human iron availability trials were used in the comparison. The meals were prepared by substituting pork, fish, cheese, egg, liver, or chicken for beef in two basic test meals and were evaluated for iron availability using in vitro and rat in vivo methods. When the criterion for comparison was the ability to show statistically significant differences between iron availability in the various meals, there was substantial agreement between the in vitro and human in vivo methods. There was less agreement between the human in vivo and the rat in vivo and between the in vivo and the rat in vivo and between the in vitro and the rat in vivo methods. Correlation analysis indicated significant agreement between in vitro and human in vivo methods. Correlation between the rat in vivo and human in vivo methods were also significant but correlations between the in vitro and rat in vivo methods were less significant and, in some cases, not significant. The comparison supports the contention that the in vitro method allows a rapid, inexpensive, and accurate estimation of nonheme iron availability in complex meals.  相似文献   

2.
To detect cytomegalovirus-associated interstitial pneumonia (CMV-IP) in recipients of BMT in its earliest stage, five CMV methods were assessed for their usefulness using bronchoalveolar lavage fluid as the test specimen. Of the 43 cases enrolled in the study, PCR was positive in 12 cases, shell vial in eight, culture in eight and cytology in three. There were no positive cases in in situ hybridization. Based on this result, the 43 cases were classified into four groups: Group 1, three cases: positive in PCR, shell vial and cytology; Group 2, five cases: positive in PCR and shell vial; Group 3, four cases: positive only in PCR; and Group 4, 31 cases: negative in all CMV tests. Cases in Group 1 were judged as having the highest risk of overt CMV-IP. They were successfully treated with a combination of ganciclovir and immunoglobulin. Group 2 was diagnosed as having active CMV infection and ganciclovir monotherapy was effective for these patients. Groups 3 and 4 were not given anti-CMV therapy, but they were free from CMV-related manifestations throughout the study. The sensitivity and specificity of each survey method for the detection of Groups 1 and 2 were 1.0 and 0.89 in PCR, 1.0 and 1.0 in shell vial, 0.88 and 1.0 in culture, and 0.38 and 1.0 in cytology. Similarly, the positive and negative predictive values were 0.67 and 1.0 in PCR, 1.0 and 1.0 in shell vial, 1.0 and 0.97 in culture, and 1.0 and 0.88 in cytology. Thus, CMV survey on bronchoalveolar fluid was thought to be useful in detecting post BMT CMV-IP in its earliest stage.  相似文献   

3.
Concentrations of metals (Zn, Cu, Se, Cd), metallotionein (MT) and ceruloplasmin (Cp), and the activity of N-acetyl-beta-D-glucosaminidase (NAG) and gamma-glutamyltransferase (gammaGT) in pregnant women who smoke and in passive smokers as well as in their newborns were measured. In smoking women a many-fold increase in cotinine concentrations in maternal and infant urine, amniotic fluid, placenta and milk was found as compared to passive smokers. Smoking lowered serum Se concentration in mothers and infants, increased serum ceruloplasmin in mothers and decreased serum Cu concentration in infants. Serum Zn level in infants was higher than in mothers, and smoking furthered its increase. Statistically significant increase in concentrations of Cd in placenta, amniotic fluid and milk, of Cu in placentae and amniotic fluid and of Zn in placenta and milk was revealed. Higher concentrations of metals were accompanied by an elevated MT level in placenta and amniotic fluid. In smoking women a significant increase in NAG activity in urine, amniotic fluid and milk, increase in gammaGT activity in urine and amniotic fluid and decrease in gammaGT activity in milk and placenta were observed. There was high, positive correlation between MT/NAG and MT/gammaGT in amniotic fluid of passive and active smokers, while similar correlation in milk was indicated only in the group of active smokers. The biochemical parameters analysed proved their usefulness in the evaluation of effects of exposure to cigarette smoke on pregnant woman and her fetus.  相似文献   

4.
Age adjusted mortality in Belgium (B) and The Netherlands (NL) was calculated from 5 yearly age-specific death rates between the ages 45-74 and 75-85+ years. Mortality was available in Belgium from 1954 to 1991 or 1994 (depending on the cause of death) and from 1950 to 1993 in The Netherlands. In the 45-74 years age class all-cause mortality decreased in B between 1955 and 1992 with 33% in men and 48% in women. In NL this was 11% and 40%, respectively. In the age class 75-85+ it was 21% and 37% in B, and 4% and 36% in NL, respectively. Since 1980 to the last available year there was a marked decrease in mortality in the age class 75-85+ years in men and women from B and no change in NL. Wallonia always had the highest mortality, followed by B, Flanders and NL. However, recently the observed mortality in Flanders was the lowest. Mortality trends, in both age classes and sexes, were obtained between 1980 to the last available year for 11 causes of death in men and 13 in women. Among 48 possible comparisons, 38 (79%) were in favor of B, 9 in favor of NL and 1 ex aequo. Life expectancy in 1992 was compared in the 15 EU countries. For both sexes together B ranked 8th, NL 3rd. The difference in life expectancy between the two countries was 3 year in 1967 and 1 year in 1992. Flanders ranked 5th (0.3 year lower than NL) and Wallonia 14th (2.2 years lower) when substituted for B in the EU. Portugal had the best and Denmark had the worst results between 1967 and 1992). Changes in life style-fat, salt, fruit and vegetable intake and smoking habits -which occurred since 1960 in B, its regions and in NI are consistent with the changes in mortality and life expectancy. Curative medicine and medical technology cannot explain the observed differences and trends.  相似文献   

5.
6.
Tubal pathology with tubal blockage due to the pelvic inflammatory diseases is one of the most frequent causes of infertility in a woman [1]. The two most important diagnostic procedures which are used for evaluation of tubal patency are hysterosalpingography and laparoscopic hydrotubation [4]. SUBJECT: The aim of the study was the comparison of hysterosalpingographic and laparoscopic findings and determination of accuracy of these two procedures in the diagnosis of tubal patency. MATERIAL AND METHODS: We studied and compared the results of hysterosalpingography and laparoscopy in 102 infertile women who were operated on at the Narodni Front Hospital of Gynaecology and Obstetrics in Belgrade during 1993 and 1994. Of 102 operated women 47 women were with primary infertility and 55 with secondary infertility. The patients were from 20 to 41 years of age, the average 28 +/- 2.4 years. RESULTS: Of one hundred and two operated women tubal blockage was found in 94 (92.1%) patients. Unilateral hydrosalpinx was found by hysterosalpingography in 16 (15.7%) subjects and bilateral hydrosalpinx in 30 (29.4%) women. Unilateral hydrosalpinx was found by laparoscopy in 17 (16.1%) patients and bilateral hydrosalpinx in 32 (31.4%) subjects. The concordant findings by hysterosalpingography and laparoscopy in the diagnostics of unilateral hydrosalpinx were found in 76.5% of cases, and in bilateral hydrosalpinx in 70.4%. This difference was not statistically significant. Unilateral tubal blockage was identified by laparoscopy in 26 (25.5%) patients and bilateral in 27 (26.5%) subjects. The concordant findings by hysterosalpingography and laparoscopy in unilateral tubal blockage were found in 61.5% of cases, and in bilateral tubal blockage in 70.4% of women. The total concordant findings by hysterosalpingography and laparoscopy in tubal blockage were found in 65.7 of cases, and concordant findings after hysterosalpingography and surgery were noted in 61.7% cases. The findings by laparoscopy and surgery were in harmony in 86.3% patients. Ovarian abnormalities were found by laparoscopy and surgery in 22 (21.6%) women. Pelvic adhesions were found by laparoscopy in 42 women of 49 patients in whom pelvic adhesions were found during the operation. Uterine congenital anomalies were found by laparoscopy in 3 (2.9%), women and by hysterosalpingography in 6 (5.9%) patients. DISCUSSION: Of 102 operated women tubal blockage was found in 94 (92.2%) women. Unilateral tubal blockage was found in 38 (40.4%) patients, and bilateral tubal blockage in 56 (59.6%) subjects. Hysterosalpingographic and laparoscopic hydrotubation findings in the diagnosis of tubal patency were concordant in 65% of cases, hysterosalpingographic and operative findings in 61.7% of patients, and laparoscopic and operative findings in 86.3% of subjects. Although concordant findings of 65.7% were noted in this study, which were similar to findings of other authors, the percentage of 62.5% [4], and 76% was observed [5]. During the operation pelvic adhesions were found in 49 patients, and laparoscopic in 42 women only. Ovarian abnormalities were found by laparoscopy in 22 (21.6%) patients, while uterine fibroid was found in 10 (9.8%) subjects. Uterine congenital anomalies were found by hysterosalpingography in 6 (5.9%) cases and by laparoscopy only in 3 (2.9%) patients. The advantage of visual hysterosalpingography seems to be in identification of some congenital uterine anomalies. However, the advantage of laparoscopy is identified by the possibility of visualisation of some other pelvic abnormalities which may be the cause of infertility. CONCLUSION: There are some hysterosalpingographic and laparoscopic advantages and disadvantages in the diagnosis of infertility in women. Only by using both procedures accurate results can be achieved in the tubes, the uterus and the ovary, that can be a cause of infertility in women.  相似文献   

7.
In the present study, we characterized surfactant protein (SP)-A messenger RNA (mRNA) in mid-trimester human fetal trachea and bronchi. SP-A protein was localized by immunocytochemistry to scattered epithelial cells in the airway surface epithelium and in submucosal glands of the fetal trachea and bronchi. SP-A mRNA (2.2 kb) was detected by Northern blot analysis in human fetal trachea, as well as in primary and more distal bronchi. The levels of detectable SP-A mRNA were highest in the upper airways and were decreased in smaller bronchi in comparison. SP-A mRNA was barely detectable in the distal fetal lung tissue. In contrast, SP-A mRNA was abundant in cultured explants of distal human fetal lung tissue. SP-A1 and SP-A2 mRNA were detected by primer extension analysis in adult human lung tissue and in cultured human fetal lung explants. Only SP-A2 mRNA was detected in RNA isolated from human fetal trachea and bronchi. SP-A mRNA was localized by in situ hybridization in the fetal trachea and bronchi in scattered cells in the surface epithelium and, most prominently, in submucosal glands. Our results suggest that SP-A2, and not SP-A1, is produced in the human fetal tracheal and bronchial epithelium and in submucosal glands.  相似文献   

8.
Changes in copper concentration in the arterial wall are important because of cross-linkage formation in collagen and elastin. The breakdown of the elastic layer is characteristic for aneurysm and is affected by the abnormalities in copper metabolism. This study was undertaken to evaluate Ca, Mg, Zn and Cu concentrations and their relationships in the arterial wall, serum and calcified plaque in atherosclerosis obliterans (AO) and abdominal aortic aneurysm (AA). Samples of the aorta wall were obtained at the endarterectomy in AO and the vascular reconstruction in AA. Elements were determined by means of atomic absorption spectrometry. Serum concentrations of Zn and Cu were higher and that of Ca lower in AO as compared to AA and the controls. Arterial concentrations of Zn, Cu and Mg were higher in AO as compared to AA. The ratios of element concentrations in serum (Ca/Mg, Ca/Zn and Mg/Cu) were higher in serum in AA than in AO. Positive correlations were calculated for Ca and Mg (r > or = 0.74), Ca and Zn (r > or = 0.73), Mg and Zn (r > or = 0.90) in the arterial wall in AO and AA. Low but significant correlation was calculated for Cu concentrations between serum and the arterial wall in AA (r = 0.43). Concentrations of Ca, Mg, Zn and Cu were higher in plaque than in the surrounding tissue. The results indicate differences in arterial and serum concentrations of Ca, Mg, Zn and Cu between AO and AA and the accumulation of these elements in the plaque rather than in the surrounding vascular tissue.  相似文献   

9.
BACKGROUND: This study examined the results of surgical treatment of leiomyosarcoma of the esophagus. METHODS: Between January 1920 and December 1996, 17 patients (9 men and 8 women) with leiomyosarcoma of the esophagus were treated surgically at the Mayo Clinic. Median age was 58 years and ranged from 26 to 76 years. Symptoms included dysphagia in 11 patients (64.7%) and odynophagia in 6 (35.3%). The tumor was located in the middle third of the esophagus in 10 patients (58.8%) and in the cervical esophagus in 7 (41.2%). Procedures performed included esophagogastrectomy in 9 patients (Ivor Lewis in 5, left thoracoabdominal in 3, and transhiatal in 1), enucleation in 3, transgastric excision in 1, and exploration without resection in 4. RESULTS: The procedure was considered curative in 11 patients (64.7%). There was one operative death (mortality, 5.9%). Complications occurred in 3 patients (17.6%) and included anastomotic leak in 2 and bleeding requiring reoperation in 1. Growth pattern was infiltrating in 7, polypoid in 5, and intramural in 5. Histologically, the tumor was grade 1 in 6 patients, grade 2 in 2, grade 3 in 7, and grade 4 in 2. The tumor was postsurgically classified as stage I in 2 patients, stage IIA in 7, stage IIB in 1, stage IIIA in 5, stage IV in 1, and unknown in 1. Six patients (35.3%) received adjuvant treatment. Follow-up was complete in 16 patients (94.1%) and ranged from 1 to 182 months (median, 48 months). Five- and 10-year actuarial survivals were 47.0% and 31.0%, respectively. Seven patients (41.2%) are currently alive (median survival, 72 months); all underwent curative resection. Factors affecting survival included completeness of resection, growth pattern, postsurgical stage, tumor grade, and tumor location (p < 0.05). CONCLUSIONS: We conclude that leiomyosarcoma of the esophagus is rare. Complete resection provides long-term survival.  相似文献   

10.
BACKGROUND: Some doubts exist as to whether the increase in the prevalence of asthma is real or an artefact. The 10 year trend of asthma up to 1993 in England and Scotland was therefore assessed. METHODS: Information on asthma and bronchitis attacks, occasional wheeze, and persistent wheeze in the last 12 months, was obtained using a self administered questionnaire completed by the parents. Exactly the same questions were asked in 14 study areas in Scotland and 22 study areas in England in 1982 or 1983 and in 1992 or 1993 in 5-11 year old children. RESULTS: The numbers of children with data for all respiratory illness were 5556 (85.2%) and 5801 (87.1%) in England and 3748 (90.4%) and 3738 (90.4%) in Scotland in 1982 and 1992, respectively. There was a significant increase in asthma attacks (approximately three times more in 1992 than in 1982) and occasional wheeze (30-60% more in 1992 than in 1982) in both sexes in England and Scotland. Persistent wheeze also increased in both countries, but the increase was significant only in England (30-40% more in 1992 than in 1982). CONCLUSIONS: The study coincides with others that suggest that the increased prevalence of asthma may be due, in part, to changes in diagnostic behaviour. However, the continuing increase of persistent wheeze in the total sample suggests that part of the increase is real. There was no difference in the increase of persistent wheeze between Scotland and England, but the trend was only significant in England.  相似文献   

11.
The phenotype of autosomal dominant polycystic kidney disease (ADPKD) is characterized by basement membrane abnormalities, hyperproliferation, and alterations in epithelial cell polarity. Since proteinases have been implicated in matrix degradation and growth factor activation, lysosomal enzymes were compared in normal and ADPKD tissues and cell cultures. Acidic proteolytic activity (azocasein) was reduced in ADPKD, and specific enzymatic assays detected disease-dependent decreases in the specific activities of beta-galactosidase, beta-hexosaminidase, and cathepsins, B, L, and H. Cathepsin D-specific activities were unchanged. Lucifer yellow fluorescence in ADPKD cells was consistent with an alteration in heterogeneity of lysosomal enzyme content in ADPKD rather than a decrease in total lysosomal number. Western analysis, metabolic labeling, and immunoprecipitation analysis confirmed decreases in the expression and synthesis of the major normal molecular immunoreactive species of beta-galactosidase and cathepsins B and H in ADPKD tissue and cells but no changes in cathepsin D. In addition, ADPKD-specific high-molecular-weight species of cathepsin H were seen and abnormal forms of cathepsin B and beta-galactosidase were common in ADPKD, suggesting abnormal molecular processing and posttranslational modifications. In addition, immunolocalization studies showed abnormal apical plasma-membrane localization of cathepsins B and H in ADPKD cyst epithelial cells, consistent with a protein sorting defect in ADPKD. Increased extracellular secretion of lysosomal enzymes was also measured in ADPKD cultured cells and in filter-grown epithelia shown to be predominantly directed to the basal compartment. These results demonstrate that lysosomal enzyme alterations in ADPKD may play a role in aberrant processing of the basement membrane. Alterations in the polarized secretion of lysosomal enzymes by ADPKD epithelia in vitro were also detected. Whereas all normal epithelia cells secreted lysosomal enzymes predominantly to the apical medium compartments, basally directed secretion was increased in all ADPKD epithelia and attained an overall reversal of polarity for cathepsins B + L. It is concluded that alterations in lysosomal enzyme function in ADPKD are the result of alterations in synthesis, molecular processing, and polarized secretion of specific enzymes and may have impact on proliferative and basement membrane abnormalities in this genetic disease. These results are consistent with a fundamental defect in protein processing sorting, and trafficking in ADPKD.  相似文献   

12.
Sham-operated and parathyroidectomized (PTX) rats were divided into two pair-fed groups, one on a normal mineral intake (0.5% Ca, 0.3% P), the other on a regimen low in phosphorus (0.5% Ca, 0.03% P). P depletion led to a drop in plasma P and urine P, a rise in plasma Ca and a marked rise in urine Ca, a drop in serum magnesium and a rise in urine Mg. The changes were more pronounced in the PTX animals, but final values were the same in both groups. Parallel bone-seeking isotope (85Sr, 177Lu, 237Np) studies in nonablated animals revealed an increase in the urinary nuclide output and in the urine/tibia ratio in P-deficient animals. Normal and primary bone osteocytes decreased and enlarged osteocytes increased as a result of P deficiency; osteoclasts and osteoblasts also increased. Bone composition showed a drop in ash content and a rise in water, with a light decrease in both Ca and P, and a corresponding rise in hydroxyproline and nitrogen in the P-deficient animals. The results are interpreted to mean that P-deficiency in the young growing rat leads to an increase in bone resorption which occurs also in the absence of parathyroid hormone (PTH). The fact that final values were similar in the control and PTX P-deficient animals suggests that steady-state regulation can also occur without PTH. Because P-deficiency leads to rapid hypercalcemia and rapid marked hypercalciuria, there may exist a mechanism for phosphate regulation which would then supersede Ca homeostasis. The change in serum and urine Mg levels may reflect a decrease in tubular Ca and Mg reabsorption associated with P-deficiency.  相似文献   

13.
Nonocular malignant melanoma is a rare but lethal disease increasing in incidence and mortality in western countries with improved survival if diagnosed and treated early. This study reports its epidemiology from cancer registry data in six different parts of India; its anatomic distribution and trends in Bombay from 1964 to 1984. Age-adjusted incidence in Bombay patients shows no increase from 1964 to 1984 unlike in white caucasians. Males exceed females in patients 45 years or older unlike whites, but are equalled or exceeded by females in those less than 45 years. The sole of foot and internal mucous membranes are its major anatomic sites in Indians as in negroid blacks. This cancer in Indians resembles that in blacks and nonwhites in affecting less pigmented epithelia and skin. Susceptible melanosomes and ultraviolet light exposure may both be involved in its aetiopathogenesis.  相似文献   

14.
Transplasma membrane redox plays a significant role in cellular activation and growth. Six isoenzymes could be prepared from purified rat brain synaptic plasma membrane. Polyclonal antibodies have been prepared against six transplasma membrane oxydoreductases (PMO-I to PMO-VI) and the tissue distribution of the various iso-enzymes have been investigated in adult rat brains by means of immunohistochemistry. PMO-I is densely observed in layers I, IV and V of the parietal cortex, in CA1 of the hippocampus (except for the molecular layer), in the caudate putamen, in the dorsal, granular and ventral parts of the auditory nuclei, in some loci of the vestibular nuclei as well as in the deep cerebellar nucleus and in the granular layer of the cerebellar cortex. PMO-II is mainly located in the polymorphic layer of the dentate gyrus and in the deep cerebellar nucleus and in the granular layer of the cerebellar cortex. PMO-III is abundant in the piriform cortex, in the pyramidal layers of both CA1 and CA2, in the diagonal band of the basal ganglia, in the supraoptic nucleus and in various loci of the magnetocellular paraventricular nucleus of the hippothalamus as well as in the vestibular nuclei from the brain stem. In addition PMO-III is also densely present in motor nuclei (oculomotor, facial, hypoglossal and ambiguus nuclei), in the reticular formation and in the deep cerebellar nucleus as well as in the Purkinje layer of the cerebellar cortex. PMO-IV has a similar location but is less abundant in the vestibular nuclei of the sensory brain stem and in the motor nucleus. PMO-V in contrast is poorly present in most brain areas compared to the other iso-enzymes, apart of the Purkinje layer of the cerebellar cortex. Finally PMO-VI is mainly present in the oriens layer and in the stratum radiatum of the hippocampus formation, in the supraoptic and lateral magnocellular nucleus of the hypothalamus, in the mesencephalic trigeminal nucleus, in the ventral auditory nucleus and in the facial nucleus of the brain stem as well as in red nucleus of the reticular formation and in the Purkinje layer of the cerebellar cortex. These data show that the iso-enzymes are located in specific brain nuclei. The significance of the results in respect to the yet very poorly defined function of PMO's is discussed.  相似文献   

15.
The repeated administration of methamphetamine (METH) can result in long-lasting decreases in dopamine (DA) levels, tyrosine hydroxylase activity and DA uptake sites in the striatum. However, whether these changes lead to functional alterations in the dynamics of DA release and uptake has not been extensively examined. The present study used in vivo electrochemistry and microdialysis to examine potassium- and amphetamine-evoked release of DA in the striatum and nucleus accumbens (NAc) of METH-treated rats. Male Fischer-344 rats were administered METH (5 mg/kg s.c.) or saline four times in 1 day, at 2-hr intervals. One week later the animals were anesthetized with urethane and prepared for in vivo electrochemical recordings. The METH treatment resulted in dramatic decreases in potassium-evoked release of DA and in the rate of DA clearance in the striatum, whereas the NAc was not significantly affected. In vivo microdialysis studies demonstrated significant decreases in basal DA levels and in potassium- and amphetamine-evoked overflow of DA in the striatum of METH-treated animals. Basal and evoked DA levels in the NAc were not altered. Post-mortem levels of tissue DA were decreased by 41 to 67% in the striatum and 25 to 31% in the NAc. These results indicate that the striatum is more sensitive than the NAc to the neurotoxic effects of METH, both in measures of functional dynamics of DA signaling and in tissue levels of DA. It remains to be determined whether these functional changes in DA release and uptake are permanent or tend to recover over time.  相似文献   

16.
The arrangement and numbers of intralaryngeal ganglia and associated neurons in humans and four mammals (dogs, rabbits, guinea pigs and rats) were investigated morphologically and compared with the results obtained in the cat which have been reported previously. Intralaryngeal ganglia were mostly distributed in branches of the internal branch of superior laryngeal nerve in all species, dorsal and/or dorsolateral to the posterior cricoarytenoid muscle in humans, dogs and cats and around the inferior laryngeal nerve in humans, dogs, cats, guinea pigs and rats. The total number of laryngeal ganglionic neurons was 2,000 to 2,400 in humans, 300-450 in dogs, 600-800 in cats, 250-320 in rats, and 100-150 in rabbits and guinea pigs. More than 80 percent of ganglionic neurons were present in the supraglottis in all species, except the rat, in which about 60 percent were in the subglottis. Each ganglion in all species existed within the nerve bundle, and was chiefly encapsulated with fibrous tissue, many ganglionic cells, glial cells, Schwann cells, vessels and connective tissue. The present morphological study of intralaryngeal ganglia in humans and four mammals suggests that the laryngeal ganglionic neurons have the same arrangement as in cats.  相似文献   

17.
18.
Infection with the abomasal nematode, Ostertagia ostertagi, is an important cause of impaired productivity in young cattle in temperate parts of the world. Such losses have been associated with marked changes in feed intake, gastrointestinal function, protein, energy and mineral metabolism, and in body composition. The reduction in feed intake is an important factor in the pathogenesis of infection and may account for a large part of the difference in weight gain between ad libitum fed control and infected calves. Despite the obvious importance of inappetance, only recently has an association been made between reduced intake, altered gut motility and elevated levels of certain gastrointestinal hormones, such as gastrin. It has been suggested that the elevated gastrin levels accompanying abomasal parasitism may impair reticulo-ruminal motility and slow down abomasal emptying, leading to a stasis of ingesta and a reduction in feed intake. The rise in blood gastrin levels may also be partly responsible for the marked hyperplasia of the fundic mucosa seen in abomasal infections. Pronounced changes in protein metabolism have also been associated with Ostertagia infection. Radioisotopic studies have demonstrated increased losses of albumin into the gastrointestinal tract which are accompanied by an increase in the rate of synthesis in the liver. Dietary protein breakdown in the abomasum is also likely to be impaired, although there is evidence of a compensatory increase in protein digestion in the lower gut of parasitised calves. Increased losses of albumin are not always accompanied by increases in faecal nitrogen, suggesting that albumin is broken down and recycled as ammonia. Radioisotopic studies in animals with intestinal nematode infections have demonstrated a marked reduction in muscle protein synthesis and an increase in protein synthesis in gastrointestinal tissue. Such changes in the balance of protein synthesis are likely to be brought about by alterations in the balance of certain metabolic hormones. Marked changes in energy metabolism also accompany Ostertagia infection. Parasitised calves exhibit a marked increase in non-esterified fatty acid levels, resulting from the mobilisation of adipose tissue, and a reduction in digestive efficiency of energy, probably associated with the increase in cycling of protein through the gastrointestinal tract and the compensatory increases in protein synthesis. Mineral metabolism may also be affected although relatively little work has been conducted in cattle. Changes in body composition reflect a reduction in deposition of muscle protein and fat, and an increase in bone content and water retention.  相似文献   

19.
The electrocapacitance plethysmograph was utilized to measure peripheral blood flow and venous distensibility in 17 newborn infants and 20 adults. Measurements were made in the upper and lower extremities in each subject under identical environmental conditions. Blood flow in the forearm and calf were found to be significantly higher in infants than adults. In infants there were no significant differences in the blood flow between the upper and lower extremities. In contrast, in the adults, the blood flow was significantly higher in the upper than in the lower extremities. Similarly, venous distensibility was observed to be higher in infants than in adults. While no significant differences were observed in the venous distensibility between the upper and lower extremities in infants, the venous distensibility was found to be higher in the forearm than in the leg in adults.  相似文献   

20.
O. Chanute, C.E.     
Octave Chanute was one of the leading civil engineers in the United States in the period between 1850 and 1890. His work on eastern and western railroads was unsurpassed. He began his bridge building career in 1856 and designed his last major bridge in 1888. Starting in 1890, he began his study in the work that others conducted in the area of manned flight and designed and tested many of his own gliders. He later assisted the Wright Brothers in their experiments in Dayton and at Kitty Hawk.  相似文献   

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