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941.
942.
The chicken, which has no endogenous lactase, was assessed as a possible model for studies on lactose intolerance. The ability of yoghurt to reverse changes induced by lactose was examined. In the caecum lactose had little effect on the viable counts of three groups of organisms which utilize lactose and no effect on the water content. It suppressed body weight, induced gas formation in the caecum and slightly lowered caecum pH. None of these effects was reversed by yoghurt.The β-glucuronidase activity of the caecal contents was slightly reduced by lactose and markedly reduced in chickens receiving lactose and yoghurt. The additional effect of yoghurt also occurred with yoghurt which had been heated to kill the bacteria and inactivate the lactase. The suppression of β-glucuronidase activity was also achieved by supplements of yoghurt alone.  相似文献   
943.
Tick-borne diseases in the United States   总被引:1,自引:0,他引:1  
  相似文献   
944.
We tested the influence of in vivo volume resuscitation on intrinsic contractile properties of left ventricular (LV) preparations of endotoxemic guinea pigs. Escherichia coli endotoxin (LPS)-injected animals were divided into nonresuscitated and resuscitated groups. Volume resuscitation improved cardiac output and stroke volume, increased arterial pH and body temperature, and decreased mortality. In isovolumetric LV preparations isolated 4 h after LPS injection, LV systolic pressures (in mmHg) preparations isolated 4 h after LPS injection, LV systolic pressures (in mmHg) of LPS with (42 +/- 3) and without (42 +/- 2) fluid resuscitation were consistently less than control values (70 +/- 3). LV end-diastolic pressure-volume (compliance) decreased in LPS-nonresuscitated hearts, while LV compliance of LPS-resuscitated hearts was similar to control. Thus, intravascular volume expansion selectively improved LV diastolic compliance of LPS hearts without affecting LV systolic function. These findings suggest that LV systolic and diastolic dysfunctions associated with endotoxemia and Gram-negative sepsis may involve separate pathogenic mechanisms.  相似文献   
945.
INTRODUCTION: Hereditary nonpolyposis colorectal cancer (HNPCC) is an autosomal dominant condition characterized by early age of onset colorectal cancer, right-sided predominance, excess of synchronous and metachronous colonic neoplasms, and extracolonic cancers. The purpose of this study is to report clinical characteristics of HNPCC families in our registry. METHODS: This is a retrospective review of medical records of patients with a significant history of colorectal cancer and interviews with their families. RESULTS: Three hundred one people with cancer in 40 HNPCC families were identified. In 284 of 301 (94 percent) people, 363 cancers were identified. Colorectal cancer only was identified in 182 people (64 percent) and, in conjunction with extracolonic tumors, in another 31 people (11 percent). Extracolonic cancer alone was noted in 71 people (25 percent). Median age at diagnosis of colorectal cancer was 48 (range, 17-92) years. In patients with documented pathology, right-sided tumors predominated (55 percent), synchronous and metachronous tumors were noted in 53 percent, and synchronous of metachronous adenomas were documented in 51 percent of people. Generational anticipation was also noted. CONCLUSION: This study demonstrates and confirms characteristics that have been described in HNPCC. Namely, early age of onset of colorectal cancer, right-sided predominance, multiple synchronous and metachronous neoplasms, increased extracolonic cancers, and generational anticipation.  相似文献   
946.
Citrate, when activated by a water-soluble carbodiimide, covalently modifies hemoglobin. At pH values near neutrality, complete modification of the N-terminal valine residues of alpha- and beta-globin chains can be accomplished with a high degree of specificity. These groups react at a much more rapid rate than a slower reacting set of functional groups. Modification of hemoglobin with citrate alters the oxygen affinity of the protein. Although the p50 is not changed, the cooperative nature of oxygen binding is greatly decreased. Hemoglobin S modified with citrate is more soluble than unmodified hemoglobin S. The time taken for deoxygenated hemoglobin S to come out of solution in concentrated phosphate solutions is increased by citrate modification.  相似文献   
947.
948.
949.
Occupational respiratory diseases have been reported following exposure to metal working fluids. We report a spectrum of respiratory illnesses occurring in an outbreak in 30 workers of an automobile parts engine manufacturing plant. Workers presented with respiratory complaints and, after clinical and laboratory evaluations, were classified as those having hypersensitivity pneumonitis, occupational asthma, or industrial bronchitis, or those without occupational lung disease. Hypersensitivity pneumonitis affected seven workers, with six exhibiting serum precipitins to Acinetobacter Iwoffii. Occupational asthma and industrial bronchitis affected 12 and six workers, respectively. Oil-mist exposures were below current recommendations. Gram-negative bacteria, but no fungi, Thermophiles, or Legionella, were identified. Although specific agents responsible for each individual case could not be identified, probably both specific sensitizing agents and non-specific irritants from metal working fluids, additives, or contaminants contributed to this spectrum of occupational respiratory illness.  相似文献   
950.
Adiabatic reactive rheometry involves the simultaneous measurement of viscosity and temperature changes during adiabatic polymerization. Using the adiabatic reactor method to relate temperature to fractional conversion results in a useful rheokinetic tool ideally suited for fastreacting reaction injection molding (RIM) systems for which the mold-filling step is nearly adiabatic. In this work, a small laboratory RIM machine is used to mix the reactants and deliver them to a constant stress rheometer retrofitted with a wide-gap Couette geometry and two thermocouples. Measurements on two polyurethane systems are reported. A simple cross-linking system is used to verify the adiabatic rheokinetic method through comparison to a known gel conversion. Subsequent measurements on a phase-separating RIM system show that increases in catalyst level, hard segment content, and initial reactant temperature result in a decreased gel time and an increased gel conversion. The viscosity rise profiles aid our understanding of the onset and development of phase separation. They are also essential for mold-filling models and establishing moldability criteria for these RIM systems.  相似文献   
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