Effect of type of grain and feed processing on gastrointestinal retention times in horses.

Gastrointestinal retention time may affect digestive processes in the horse. To evaluate the effect of processing of grains on mean retention time in different segments of the gastrointestinal tract, 4 Norwegian Cold-blooded trotters (cecally cannulated, approximately 500 kg of BW) were used. Barley, maize, and wheat were all ground, pelleted, extruded, and micronized to create a total of 12 processed grains. After an adaptation period of 5 d, each horse was given 0.2 kg of Yb-mordanted grain together with their morning meal, which consisted of 2 kg of hay and 1 kg of one of the grains. Fecal samples were collected 5, 6, 7, 8, 9, 10, 11, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 48, and 52 h after administration of the marker dose. The samples were analyzed for Yb, and values were used for a 2-compartment nonlinear passage model to calculate the retention times in different segments of the gastrointestinal tract for each type of grain and each processing method. Among grains, maize had a longer retention time in the time-dependent compartment (believed to be cecum) than barley and wheat (P < 0.05) and hence a decreased passage rate out of this compartment (P < 0.05). For the feed processing treatment, ground grains had a longer compartmental retention time than those grains processed with the high temperature (extruded and micronized; P < 0.05), but the total mean retention time was not affected by treatments. In conclusion, feed processing affected passage rates and compartmental retention times, but did not affect the overall retention time in the gastrointestinal tract of the horse.

Models for estimating digesta passage kinetics in the gastrointestinal tract of the horse.

Fecal samples were collected to evaluate mathematical models to describe the kinetics of digesta passage in the segments of the equine gastrointestinal tract and to compare the passage kinetics of hay and oats. Four Norwegian Cold-blooded trotters (cecally cannulated, approximately 500 kg of BW) were fed Cr-mordanted hay and Yb-marked oats with their morning meal. The meal consisted of 2 kg of hay and 1 kg of oats processed as ground, pelleted, extruded, or micronized. Each horse was fed each type of oats on different days of collection, after a 5-d adaptation period, in a 4 x 4 Latin square design. Fecal samples were collected 5, 6, 7, 8, 9, 10, 11, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 48, and 52 h after administration of the marker dose. The samples were analyzed for Cr and Yb, and values were plotted using 1- and 2-compartment nonlinear passage models and an algebraic model. The 1-compartment G4 model and the 2-compartment G4G1 model showed an equally good fit to the observed excretion curves, based on low mean square error and SE. The excretion curves for hay (Cr) and oats (Yb) showed a striking similarity, and there seemed to be no difference in retention time between hay and oats in the horse. The mixing compartments in the horse are believed to be the cecum or both the cecum and the right ventral and dorsal segments of the colon, but further research in this area is needed to make a final conclusion.

The significance of malignancies incidental to microcalcifications in breast spot localization biopsy specimens.

BACKGROUND: Incidental breast cancer is occasionally found in spot localization biopsy specimens adjacent to mirocalcifications in benign breast disease. Because this phenomenon could prove problematic for percutaneous sampling of microcalcifications without excisional biopsy, we studied surgical specimens from patients with cancers incidental to microcalcifications and compared them with specimens with microcalcifications within the malignancy. METHODS: The pathology database at the Mount Sinai Medical Center from January 1993 to July 1998 was reviewed to identify breast cancer patients who underwent spot localization biopsy for microcalcifications. Patients presenting with microcalcifications within malignancy (determinate) were compared with patients with mirocalcifications in benign breast tissue adjacent to malignancy (incidental). RESULTS: Thirty-two (13%) of the 241 specimens had microcalcifications in benign tissue adjacent to malignancy and 209 (87%) had microcalcifications within the malignancy. Fifty-six percent of the incidental cases and 65% of the controls had ductal carcinoma in situ. Infiltrating lobular carcinoma accounted for 25% of the incidental cancers and 2% of the determinate cancers (P <0.001). Fifty-seven percent of the infiltrating carcinomas incidental to mammographic findings were infiltrating lobular carcinoma compared with 7% of the nonincidental infiltrating carcinomas. None of the incidental invasive carcinomas were poorly differentiated (P = 0.002). There were no significant differences with regard to age, tumor size, stage, differentiation, estrogen and progesterone receptors, type of surgery and final margin status. In none of the patients with incidental malignancies did local or distant recurrences develop. CONCLUSIONS: Incidental carcinomas were found in 13% of spot localization biopsy specimens obtained for suspicious mammographic microcalcifications and have a favorable prognosis. Infiltrating lobular carcinomas are more commonly found with incidental microcalcifications than with determinate microcalcifications, and incidental invasive carcinomas are less likely to be poorly differentiated. The majority of malignancies, both determinate and incidental to microcalcifications, are due to ductal carcinoma in situ. Incidental malignancies commonly occur adjacent to fibrocystic changes and their other pathologic characteristics are not significantly different from nonincidental carcinomas. Despite the absence of radiographic findings, these patients can be successfully treated with breast conservation.

Stress X-rays and the low back pain patient.

This study was undertaken to determine if demographic, historical and/or clinical information would be helpful in predicting the presence of abnormal motion depicted on a stress radiograph (flexion, extension and lateral bending views). A total of 72 patients were divided into "normals" and "abnormals" based on the presence of abnormal sequential intersegmental vertebral motion as demonstrated on the stress radiographs. Demographically and historically, the "normal" and "abnormal" groups were essentially the same. Clinical data also failed to show any statistically significant differences between the two groups. Other radiographic findings (scoliosis, degenerative disease, and foraminal encroachment) did not show any significant differences. The value of demographic, historical and/or clinical information as input into the formulation of a protocol for stress radiography is questioned. Suggestions for further research are given.

[Correspondence of functional and structural findings in tubulo-interstitial disorders in chronic glomerulonephritis]. / Zur Ubereinstimmung funktioneller und struktureller Befunde der tubulo-interstitiellen Störung bei chronischer Glomerulonephritis.

In 237 patients with chronic glomerulonephritis and according to the serum creatinine level of functional compensation tubular and tubulointerstitial renal functions, respectively, were investigated and compared with the light-microscopic findings of the renal interstice. A distinct structural tubulointerstitial lesion (tiK) was found in 30%. The diagnostic predictivity for the recognition and the exclusion of the tiK was tested for single or paired data of the renal function. As a result it is possible with a suitable combination of parameters in on an average more than 80% of the cases to establish or to exclude function-diagnostically a tubulointerstitial structural lesion even in still inconspicuous creatinine values. From the clinical point of view thus the information value of functional diagnostic investigations of the renal water treatment is confirmed (concentration power, dilution ability, water diuresis), in which case the differentiated test of the renal acidification may supplement the informations about the tiK-situation.

Myocardial free-wall rupture after acute infarction: survival aided by percutaneous intraaortic balloon counterpulsation.

After his first acute myocardial infarction, a 69-year-old male suffered the usually lethal complication of ventricular free-wall rupture. Early suspicion of possible rupture and immediate percutaneous insertion of an intraaortic balloon pump assist device afforded sufficient hemodynamic stability to proceed with cardiac catheterization. The diagnosis of ventricular free-wall rupture was confirmed and the extent of coronary artery disease defined. The patient underwent repair of the free-wall rupture and coronary artery bypass grafting and has returned to full activity.

Biohydrogenation of unsaturated fatty acids. Hydrogenation by cell-free preparations of Butyrivibrio fibrisolvens.

Hydrogenation of cis-9,trans-11-octadecadienoic acid to yield trans-11-octadecenoic acid by cell-free preparations of Butyrivibrio fibrisolvens has been obtained under strictly anaerobic conditions. Reduced methyl viologen, NADH, and an endogenous electron donor each can serve as a reductant. Inhibition studies and gel filtration patterns reveal the presence of at least two hydrogenation systems, one of which is coupled through a flavin, possibly FMN. Although the enzymes comprising the biohydrogenation pathway, the fatty acid reductases and linoleic acid isomerase, are part of the bacterial membrane, they do not appear to be constituted as a multienzyme complex.

Beta-Ketoacyl-acyl carrier protein synthetase. Characterization of the acyl-enzyme intermediate.

Beta-Ketoacyl-acyl carrier protein (ACP) synthetase catalyzes the condensation reaction of fatty acid synthesis in Escherichia coli. The homogeneous enzyme reacts with hexanoyl-CoA to form hexanoyl-enzyme which was isolated and characterized. Hexanoyl-enzyme contains 2 mol of hexanoate/mol of enzyme (molecular weight 66,000); it is liable at alkaline pH, and it reacts with neutral hydroxylamine to form hexanoyl hydroxamic acid. Hexanoate was cleaved from the enzyme when hexanoyl-enzyme was subjected to performic acid oxidation. These properties indicate that hexanoyl-enzyme is a thioester. Studies of the circular dichroism spectra of fully acylated and nonacylated forms of the enzyme indicated that the secondary structure of the enzyme is relatively unperturbed by the presence of the hexanoyl groups. An alpha helical content of 65% was estimated for the enzyme from the circular dichroism spectrum. Hexanoyl-enzyme is active in both partial reactions that comprise the beta-ketoacyl-ACP synthetase reaction; it reacts with ACP to form hexanoyl-ACP and with malonyl-ACP to form beta-ketooctanoyl-ACP. Although the hexanoate of hexanoyl-enzyme is transferred very rapidly to ACP, the physiological acceptor in this reaction, it is also transferred very slowly to CoA, dithiothreitol, and 2-mercaptoethanol, indicating that the enzyme can react nonspecifically with a number of unrelated mercaptans.

Multiple forms of beta-ketoacyl-acyl carrier protein synthetase in Escherichia coli.

Two forms of beta-ketoacyl-acyl carrier protein (ACP) synthetase (designated I and II) have been identified in extracts of Escherichia coli. Synthetase I corresponds to the condensing enzyme that was studied earlier (GREENSPAN, M.D., ALBERTS, A.W., and VAGELOS, P.R. (1969) J. Biol. Chem. 244, 6477-6485); synthetase II represents a new form of the enzyme. Synthetase II was isolated as a homogeneous protein. It differs from synthetase I in having a higher molecular weight (76,999 versus 66,000), a lower pH optimum (5.5 to 6.1 versus 7.2), and a greater resistance to denaturation by heat. Synthetase II is similar to synthetase I in that both are inactivated by iodoacetamide, and prior incubation of the enzymes with fatty acyl thioesters prevents the inhibitory effect of iodoacetamide. Both also react with a fatty acyl thioester to form an acyl-enzyme intermediate, and the latter reacts with malonyl-ACP to form a beta-ketoacyl thioester. Specificity studies indicated that synthetase II, like synthetase I, has similar affinities with saturated and cis unsaturated fatty acyl thioesters of ACP that are intermediates in the synthesis of saturated and unsaturated fatty acids, respectively. The two synthetases differ only with respect to reactivity with palmitoleyl thioesters: synthetase II has a lower Km and higher Vmax than synthetase I with palmitoleyl-ACP. This finding suggests that synthetase II functions specifically in the elongation of palmitoleyl-ACP to form cis-vaccenyl-ACP. An investigation of synthetases I and II in two classes of unsaturated fatty acid auxotrophs revealed that synthetase I is absent in one class, fabB. Addition of wild type synthetase I to fabB fatty acid synthetase, which synthesizes only saturated fatty acids, permitted this fatty acid synthetase to synthesize unsaturated fatty acids. These experiments indicate that synthetase I plays a critical role in the synthesis of unsaturated fatty acids.

National health planning in the United States: prospects and portents.

The National Health Planning and Resources Development Act of 1974 in the United States demonstrates a growing determination in Congress to motivate the system of health services toward greater efficiency in utilization of resources. The Act was designed to overcome some of the weaknesses in earlier planning legislation. More complete coverage and more functional local jurisdictions for planning should result. The Act provides better financial support, and more effective incentives and inducements to assure adherence to plans. Concern is expressed about aspects of the legislation which the authors feel may deserve consideration. The principle of delegating responsibility to voluntary agencies for disbursement of public funds is questioned, and the authors suggest that local public health authorities apply for designation as planning agencies. Reservation is expressed about the adequacy of regional organization as provided by the Act to accomplish its purposes, and the authors recommend demonstrations of regional administrative agencies to implement plans developed by Health Systems Agencies. Failure to incorporate the provision of the House planning bill to set up a national health policy council in the Act is considered unfortunate. Persistence in pursuing the course outlined in the Act is urged.