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Biomedical subjects

M J Koruda

Publications and source records attributed to M J Koruda.

33 records · Page 2Linked to original sources
PubMed1988

In vivo phosphorus 31 magnetic resonance spectroscopy of rat hind limb skeletal muscle during sepsis.

High-energy phosphate metabolism in skeletal muscle is altered during sepsis, although the chronology of events is uncertain. Phosphorus 31 magnetic resonance spectroscopy was used to measure changes in muscle energy stores of the left hind limb musculature of adult male rats during sepsis. Following control scans, cecal ligation and puncture were performed and scanning was repeated 6, 24, and 48 hours after surgery. The ratios of phosphocreatine (PCr) to inorganic phosphate (Pi), a measure of energy stores, and adenosine triphosphate (ATP) to Pi ratio, a measure of the energy available for immediate use, were determined from peak heights. Intracellular pH was calculated using the distance between Pi and PCr peaks. In surviving animals, a 40% decrease in PCr/Pi ratio (+/- SEM) was observed by 24 hours (22.3 +/- 3.0 at time 0 vs 13.3 +/- 2.8 at 24 hours), whereas energy availability (beta-ATP/Pi) was statistically unchanged (18.2 +/- 2.2 at time 0 vs 15.2 +/- 1.2 at 48 hours). Intracellular pH did not change. Both PCr/Pi and ATP/Pi ratios were inversely correlated with time. In this model of documented peritonitis, skeletal muscle energy metabolism is rapidly altered following severe infection, and these changes can be detected using 31P magnetic resonance spectroscopy.

Adenosine Triphosphate↗
PubMed1988

Effect of parenteral nutrition supplemented with short-chain fatty acids on adaptation to massive small bowel resection.

After massive small bowel resection, total parenteral nutrition (TPN) is prescribed to maintain nutritional status. However, TPN reduces the mass of the remaining intestinal mucosa, whereas adaptation to small bowel resection is associated with increased mucosal mass. Short-chain fatty acids (SCFAs) have been shown to stimulate mucosal cell mitotic activity. This study determined whether the addition of SCFAs to TPN following small bowel resection would prevent intestinal mucosal atrophy produced by TPN. Adult rats underwent an 80% small bowel resection and then received either standard TPN or TPN supplemented with SCFAs (sodium acetate, propionate, and butyrate). After 1 wk, jejunal and ileal mucosal weights, deoxyribonucleic acid, ribonucleic acid, and protein contents were measured and compared with the parameters obtained at the time of resection. Animals receiving TPN showed significant loss of jejunal mucosal weight, deoxyribonucleic acid, ribonucleic acid, and protein and ileal mucosal weight and deoxyribonucleic acid after small bowel resection, whereas animals receiving SCFA-supplemented TPN showed no significant change in the jejunal mucosal parameters and a significant increase in ileal mucosal protein. These data demonstrate that SCFA-supplemented TPN reduces the mucosal atrophy associated with TPN after massive bowel resection and thys may facilitate adaptation to small bowel resection.

Adaptation, Physiological↗
PubMed1988

Small bowel disaccharidase activity in the rat as affected by intestinal resection and pectin feeding.

This study investigated the effects of small bowel resection (SBR) and a pectin-supplemented elemental diet (ED) on intestinal disaccharidase activity. Rats underwent placement of feeding gastrostomy and swivel apparatus. Control animals were returned to their cages while resected animals underwent an 80% SBR. Postoperatively, animals received either a pectin-free ED or the ED supplemented with 2% pectin. After 2 wk jejunal and ileal mucosal sucrase, maltase, and lactase activities and protein content were determined. Feeding the ED after SBR resulted in significant increases in all three ileal segmental disaccharidase activities but only maltase activity was significantly increased in the jejunum. The pectin-supplemented ED, however, significantly enhanced the adaptation of jejunal and ileal segmental sucrase, maltase, and lactase activity to SBR with the increase in all three jejunal disaccharidase activities being significantly greater than that of the resected animals fed the ED alone.

Adaptation, Physiological↗
PubMed1987

Enteral nutrition in the critically ill.

Although total parenteral nutrition has greatly influenced the clinical management of the critically ill, enteral nutrition can provide much needed support in the intensive care unit. In order to employ the best enteral nutrition, one must understand its rationale, delivery principles, equipment, feeding techniques, and diets, as well as patient selection and monitoring.

Critical Care↗
PubMed1986

Assessing burn wound depth using in vitro nuclear magnetic resonance (NMR).

There is no accurate noninvasive method for differentiating between partial-thickness and full-thickness cutaneous burn wounds. Full-thickness burns (FTB) result in slower resorption of wound edema than partial thickness burns (PTB). Since proton NMR parameters, particularly the T1 relaxation time, correlate with tissue water content (TWC), the present study determined whether proton NMR could distinguish PTB from FTB. An area of upper dorsum (approximately 15% BSA) of 35 adult rats was immersed in boiling water for either 3 sec (PTB) or 10 sec (FTB). In 10 control rats, the same area was immersed in room temperature water. Rats were sacrificed at either 3 or 48 hr after burn, and skin samples were analyzed to determine spin-lattice (T1) and spin-spin (T2) relaxation times. TWC was then measured gravimetrically by desiccation. Both T1 and T2 times significantly correlated with TWC (T1: r = 0.74, P less than 0.0001; T2: r = 0.75; P less than 0.0001). Both PTB and FTB resulted in significant elevations of T1, T2, and TWC 3 hr after injury (P less than 0.001). At 48 hr postburn the T1, T2, and TWC of the PTB group had decreased to control values (P less than 0.05), while all FTB parameters remained significantly elevated as compared to both the control and the 48-hr PTB parameters (P less than 0.001). In vitro NMR measurements distinguish PTB from FTB in this rat model within 48 hr. These data provide a basis for investigating in vitro NMR techniques for the noninvasive assessment of burn wound depth.

Animals↗
PubMed1986

The effect of enteral feedings supplemented with pectin on the healing of colonic anastomoses in the rat.

The effect of the addition of pectin to an elemental diet on the healing of experimental colonic anastomoses was investigated. Transection and anastomosis of the ascending colon and feeding gastrostomy were performed in 24 Sprague-Dawley rats. All rats then received an elemental diet, and 12 of them had 1% (w/v) citrus pectin added to their diet. On the seventh postoperative day, animals that received pectin-supplemented diets had significantly greater bursting pressures at the anastomoses (266 versus 234 mm Hg, p less than 0.04) and significantly lower colonic mucosal pH (6.2 versus 6.8, p less than 0.001) than animals that received the elemental diet only. The colons from animals fed pectin also had significantly higher hydroxyproline content at the anastomosis than those of the control animals (46.6 versus 40.7 micrograms hydroxyproline nitrogen/mg tissue nitrogen, p less than 0.05). The decreased intracolonic pH is consistent with the hypothesis that improved healing is a local effect mediated by the presence of short-chain fatty acids resulting from the fermentation of pectin.

Animals↗
PubMed1986

Effects of intraluminal infusion of short-chain fatty acids on the healing of colonic anastomosis in the rat.

The effects of an intracolonic infusion of short-chain fatty acids (SCFA) on the healing of colonic anastomosis in the rat were investigated. Thirty-three Sprague-Dawley rats underwent transection and anastomosis of the descending colon and transection and diversion of the ascending colon. The proximal limb of the ascending colon was exteriorized as an end colostomy, and the distal (defunctionalized) limb was cannulated for continuous infusion. Rats received either no infusion (N = 11) or an infusion of either electrolytes (N = 11) or SCFA (acetate, propionate, and butyrate; N = 11) into the defunctionalized colonic segment. On the sixth postoperative day bursting pressure (BP) and bowel wall tension (BWT) were determined. The occurrence of spontaneous anastomotic dehiscence was significantly less for the SCFA group (0/11) compared with the no infusion group (5/11, p less than 0.01). The anastomotic suture line burst in significantly fewer colons from the SCFA group (1/11) than either the electrolyte infusion (8/11, p less than 0.003) or the no infusion (6/6, p less than 0.001) groups. BP and BWT were significantly higher for the SCFA group (BP: 147 +/- 10 mm Hg; BWT: 59 +/- 1.0 dyne 10(3)/cm) than for either the electrolyte (BP: 99 +/- 30 mm Hg, p less than 0.002; BWT: 45 +/- 19, p less than 0.03) or no infusion (BP: 111 +/- 42, p less than 0.02; BWT 36 +/- 15, p less than 0.007) groups. The results of this study indicate that intracolonic infusion of SCFA resulted in significantly stronger colonic anastomosis in the rat.

Animals↗
PubMedDate not supplied

Prospective randomized trial of early initiation and hospital discharge on a liquid diet following elective intestinal surgery.

Length of hospital stay after elective intestinal surgery may be related to patient tolerance of a diet. We hypothesized that early initiation and discharge home on a clear liquid diet would decrease the length of hospital stay without increasing morbidity. The aim of this study was to determine if early initiation and discharge on a clear liquid diet decreases the length of hospital stay and is safe. Forty-four patients were randomly assigned to either a standard diet or a clear liquid diet. A standard diet (n = 17) was begun after the passage of flatus or stool, and consisted of clear liquids to a volume of approximately 750 ml, then three solid meals, and discharge thereafter. Patients randomized to a clear liquid diet (n = 27) received 30 ml/hr of clear liquids on postoperative day 2, unlimited clear liquids on postoperative day 3, and were dismissed on a clear liquid diet on postoperative day 4. All patients were followed by a daily telephone call and clinic visit. The primary outcome variable was length of hospital stay. The incidence of postoperative intestinal-related sequelae, complications, and readmission rates did not differ between groups. Postdischarge intestinal symptoms were common in both groups but tended to resolve faster in the patients on a standard diet. The length of hospital stay was decreased in the patients on a clear liquid diet compared to those on a standard diet (6.1 +/- 1.1 days vs. 4.4 +/- 0.2 days; P = 0.09), but total hospital costs did not differ. Early initiation and hospital discharge on a clear liquid diet after elective intestinal surgery decreases the length of hospital stay and is safe.

Diet↗
PubMedDate not supplied

Complete fundoplication is not associated with increased dysphagia in patients with abnormal esophageal motility.

Abnormal esophageal motility is a relative contraindication to complete (360-degree) fundoplication because of a purported risk of postoperative dysphagia. Partial fundoplication, however, may be associated with increased postoperative esophageal acid exposure. Our aim was to determine if complete fundoplication is associated with increased postoperative dysphagia in patients with abnormal esophageal motor function. Medical records of 140 patients (79 females; mean age 48 +/- 1.1 years) who underwent fundoplication for gastroesophageal reflux disease (GERD) were reviewed retrospectively to document demographic data, symptoms, and diagnostic test results. Of the 126 patients who underwent complete fundoplication, 25 met manometric criteria for abnormal esophageal motility (#30 mm Hg mean distal esophageal body pressure or #80% peristalsis), 68 had normal esophageal function, and 33 had incomplete manometric data and were therefore excluded from analysis. Of the 11 patients who underwent partial fundoplication, eight met criteria for abnormal esophageal motility, two had normal esophageal function, and one had incomplete data and was therefore excluded. After a median follow-up of 2 years (range 0.5 to 5 years), patients were asked to report heartburn, difficulty swallowing, and overall satisfaction using a standardized scoring scale. Complete responses were obtained in 72%. Sixty-five patients who underwent complete fundoplication and had manometric data available responded (46 normal manometry; 19 abnormal manometry). Outcomes were compared using the Mann-Whitney U test. After complete fundoplication, similar postoperative heartburn, swallowing, and overall satisfaction were reported by patients with normal and abnormal esophageal motility. Likewise, similar outcomes were reported after partial fundoplication. This retrospective study found equally low dysphagia rates regardless of baseline esophageal motility; therefore a randomized trial comparing complete versus partial fundoplication in patients with abnormal esophageal motility is warranted.

Deglutition Disorders↗
PubMedDate not supplied

Pentoxifylline alters class-specific immunoglobulin synthesis in resuscitated burn injury.

Pentoxifylline (PTXF) is a hemorheologic agent that can attenuate microvascular alterations induced by injury, resulting in improved microcirculatory flow. Burn injury-induced immunologic suppression may be caused by alterations in microvascular flow. We studied the effects of PTXF on humoral immunity in resuscitated burn injury. Male AKR mice (n = 80) were randomized to four groups: SHAM, BURN, PTXF-BURN, and NS-BURN (saline burn). Animals were resuscitated with Ringer's lactate and morphine sulfate and put to death at days 1 and 4 after injury. PTXF-BURN animals received PTXF (50 mg/kg intraperitoneally) at the time of resuscitation. Splenic lymphocytes (1 x 10(6) cells/well) were cultured with lipopolysaccharide (LPS) (2.5 and 10 micrograms/ml)). LPS-stimulated in vitro class-specific immunoglobulin (Ig) production was determined by enzyme-linked immunosorbent assay from splenic cell culture supernatants. Burn injury induced a reduction in immunoglobulin (Ig) M synthesis on postburn day 4. PTXF treatment was associated with an increase in IgG production, but a greater depression in IgM synthesis than burn injury alone. PTXF administration during resuscitation in burn injury does not ameliorate the burn-induced depression in IgM synthesis and results in significant potential adverse modulation of humoral immune function.

Animals↗
PubMedDate not supplied

Harry M. Vars award. The effect of a pectin-supplemented elemental diet on intestinal adaptation to massive small bowel resection.

The effect of a pectin-supplemented elemental diet on intestinal adaptation to massive small bowel resection in the rat was investigated in this study. Sixty adult Sprague-Dawley rats underwent placement of a feeding gastrostomy and swivel apparatus. Control animals (N = 16) were then returned to their cages while the remaining animals underwent an 80% small bowel resection and anastomosis (resected, N = 44). Postoperatively, animals were randomly assigned to receive either a fat- and fiber-free elemental diet (no pectin) or the same diet supplemented with 2% pectin (pectin). After 8 days of full strength diet, samples of jejunum, ileum, and colon were obtained for analysis. The weights per unit length of the ileum and colon were significantly greater in the resected pectin group than either the resected no pectin or pectin control groups. Mucosal parameters (unit weight, DNA, RNA, and protein content) were significantly increased in the jejunum and ileum of both the resected pectin and resected no pectin groups relative to their respective control groups. However, jejunal and ileal mucosal parameters were significantly greater (1.3- to 2-fold) for the resected pectin group than for the resected no pectin group. All the mucosal parameters of the colons were significantly greater for the pectin resected group than for the pectin control group, while only colonic mucosal RNA was significantly greater for the no pectin resected group than for the no pectin control group. These data indicate that the addition of pectin to an elemental diet significantly enhanced intestinal adaptation to massive small bowel resection in the rat.

Adaptation, Physiological↗
PubMedDate not supplied

Isotonic tube feeding formula induces liquid stool in normal subjects: reversal by pectin.

Diarrhea is one of the most common complications in patients who receive tube-feeding formulas. Since the colon is the final site of water and electrolyte absorption and ultimately determines fecal composition, diarrhea during tube feeding may result from altered colonic function. The lack of dietary fiber, such as pectin, in tube-feeding formulas may be one of the means by which colonic function is affected. The purpose of this study was to determine the effect of a standard, liquid, commercially available, isotonic tube-feeding formula (ITFF) and the effects of supplementing the ITFF with pectin on colonic function as measured by stool consistency and colonic fluid composition in 13 normal adults. Data were obtained when subjects consumed their regular diet, ITFF, and ITFF supplemented with pectin using the technique of in vivo dialysis of colonic fluid. Ingestion of the ITFF resulted in a significant increase in the percentage of liquid stools compared to a regular diet [median (interquartile range) = 0% (0), 60% (64); p less than 0.01]. Ingestion of the ITFF also resulted in significant decreases in the concentrations of sodium, potassium, and short-chain fatty acids, and increases in pH and osmotic gap in colonic fluid compared to the subjects' regular diet. Supplementing the ITFF with pectin significantly reduced the incidence of liquid stools [0% (0)] and promoted a normalization of colonic fluid composition. The results suggest that the addition of pectin may enhance tolerance to ITFFs.

Adult↗