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PubMed1992

Enhancement of the pancreas after single bolus injection combined with spiral scanning. A comparative study with conventional incremental scanning after biphasic contrast injection.

The combination of a rapid single bolus injection (72 ml of a 60% concentrated iodinated contrast medium) with spiral scanning versus dynamic sequential scanning with a conventional biphasic bolus injection (150 ml of 60% concentrated iodinated contrast medium) is compared. 60 patients with normal pancreatic morphology were included in this study. 30 patients were examined with dynamic sequential scanning (cycle times of 5 seconds) during a biphasic bolus injection, 30 patients were examined with spiral scanning (cycle times of 1 second) after a single uniphasic bolus injection. For both scanning techniques, mean attenuation values of the pancreas were measured before and at different time intervals after contrast injection. The difference in attenuation values of the pancreas before and after contrast injection reflects the level of contrast enhancement in both methods. The level of contrast enhancement of the pancreas after bolus injection was not statistically significantly different in spiral scanning versus in dynamic sequential scanning. In comparison with conventional scanning, spiral scanning allows to reduce the injected dose of contrast by 50% without compromising the contrast resolution.

Adult↗
PubMedDate not supplied

Depletion of penicillin G residues in tissues, plasma and injection sites of market pigs injected intramuscularly with procaine penicillin G.

Procaine penicillin G was administered by intramuscular (i.m.) injection to groups of healthy 100 kg market pigs at the approved label dose (15,000 IU/kg body weight), once daily for three consecutive days; or an extra-label dose (66,000 IU/kg body weight), once daily for five consecutive days. Penicillin G residue depletion was followed in plasma, tissue and injection sites using a liquid chromatographic method. Groups of pigs were killed 1, 2, 3, 4, 5 and 8 days after the last injection with the label dose. Penicillin G was not detected in liver after 1 day of withdrawal, in muscle and fat after 2 days of withdrawal, in plasma after 4 days of withdrawal, in skin after 5 days of withdrawal, or in kidney and the injection sites after 8 days of withdrawal. Other groups of pigs were killed 1, 2, 3, 5 and 7 days after injection with the extra-label dose. In these pigs penicillin G was not found in liver after 2 days of withdrawal, in fat after 3 days of withdrawal, or in the muscle, skin, plasma and injection sites after 7 days of withdrawal. Penicillin G was found at all times in the kidneys of the groups of pigs that received the high dose. The technique used for neck injections was critical to obtain intramuscular rather than intermuscular injections. The Bureau of Veterinary Drugs, Health Protection Branch, Health Canada calculated that the appropriate withdrawal period for pigs was 8 days for a dose of 15,000 IU procaine penicillin G/kg body weight and 15 days for a dose of 66,000 IU/kg.

Adipose Tissue↗
PubMed1996

Stability of cidofovir in 0.9% sodium chloride injection and in 5% dextrose injection.

The stability of cidofovir in i.v. admixtures under refrigerator and room temperature conditions was studied. Admixtures of cidofovir 0.21 and 8.12 mg/mL in 0.9% sodium chloride injection or 5% dextrose injection and of 0.085 and 3.51 mg/mL in 5% dextrose and 0.45% sodium chloride injection were prepared in triplicate in polyvinyl chloride (PVC) or polyethylene-polypropylene containers and i.v. administration sets and stored for 24 hours at 2-8 or 30 degrees C. The lower concentration of cidofovir corresponded to an assumed dose of 0.5 mg/kg for a 40-kg patient, and the higher concentration to an assumed dose of 10 mg/kg for a 100-kg patient. Samples were removed at 0 and 24 hours and analyzed for cidofovir concentration by high-performance liquid chromatography. Physical compatibility was also studied. The stability of cidofovir in 0.9% sodium chloride injection and in 5% dextrose injection at low- and high-dose concentrations was unaffected by storage at either temperature. All admixtures were clear, colorless, and free of visible particles or precipitation. There were no substantial changes in pH or number of particles of > or = 10 microns in diameter. Cidofovir 0.21 and 0.12 mg/mL was stable in 0.9% sodium chloride injection and 5% dextrose injection in PVC and polyethylene-polypropylene containers and i.v. administration sets for up to 24 hours at 2-8 and 30 degrees C. Cidofovir was compatible with the injectable solutions studied.

Antiviral Agents↗
PubMed1980

Lumbar extradural injection pressures in pregnant women. An investigation of relationships between rate of infection, injection pressures and extent of analgesia.

Before the induction of labour in 34 pregnant women 1.5% lignocaine 10 ml was injected into the lumbar extradural space at constant rates between 0.143 and 0.333 ml s-1. Injection pressures and residual pressures were recorded and the extent of analgesia to pinprick was assessed. No significant correlation was found between the rate of injection and injection pressures or residual pressures over the range investigated. Analgesia was significantly more extensive on the side dependent during injections, but there was no significant correlation between the overall extent of analgesia and the rate of injection, injection pressures or residual pressures in the extradural space. It is concluded that there is no advantage from rapid extradural injections.

Adolescent↗
PubMed1993

Induction of unresponsiveness in rats after either intraportal injection of donor antigen or intravenous injection combined with splenectomy.

Recently, we reported that hepatic allografts are permanently accepted when transplanted after intraportal injection (IP) of donor spleen cells (SPCs). The mechanism of this effect was investigated using various protocols for antigen injection. ACI (RT1a) and Buffalo (RT1b) rats were used as donors and recipients, respectively. Experimental groups were divided into the following groups depending on treatment: IP, intravenous injection (IV), splenectomy (Spx), and intravenous injection after splenectomy (IV+Spx). Accumulation of donor antigen in the various organs was examined by injecting 51Cr-labeled SPCs. Cellular and humoral responses after SPC injection was assessed by delayed-type hypersensitivity response and complement-dependent cytotoxicity (CDC) assay. Heterotopic cardiac transplantation and orthotopic hepatic transplantation were performed 10 days after each treatment. The accumulation ratio in the liver was significantly higher in the IP and IV+Spx groups than in the IV group. Delayed-type hypersensitivity responses were lower in the IP and IV+Spx groups than in the IV or Spx groups. The CDC titer 7 days after inoculation was significantly lower in the IP and IV+Spx groups than in the IV group. In order to examine whether the treatment actively suppressed the immune response, the animals were rechallenged with SPCs given intravenously 10 days after the initial injection. Elevation of CDC titer was suppressed in the IP and IV+Spx groups, but not in the IV and Spx groups. Significant prolongation of cardiac allograft survival was not observed in the IV and Spx groups. Prolongation was observed in the IP and IV+Spx groups. The survival of hepatic allografts in the IV group was decreased. No significant prolongation of graft survival was observed in the Spx group. In contrast, all hepatic allotransplants in the IP and IV+Spx groups survived over 45 days. These findings suggest that the accumulation of donor SPCs in the liver may play an important role in inducing unresponsiveness after intraportal injection of donor SPCs.

Animals↗
PubMed1997

Randomised comparison between adrenaline injection alone and adrenaline injection plus heat probe treatment for actively bleeding ulcers.

OBJECTIVE: To compare endoscopic adrenaline injection alone and adrenaline injection plus heat probe for the treatment of actively bleeding peptic ulcers. DESIGN: Randomised prospective study of patients admitted with actively bleeding peptic ulcers. SETTING: One university hospital. SUBJECTS: 276 patients with actively bleeding ulcers detected by endoscopy within 24 hours of admission: 136 patients were randomised to endoscopic adrenaline injection alone and 140 to adrenaline injection plus heat probe treatment. MAIN OUTCOME MEASURES: Initial endoscopic haemostasis; clinical rebleeding; requirement for operation; requirement for blood transfusion; hospital stay, ulcer healing at four weeks; and mortality in hospital. RESULTS: Initial haemostasis was achieved in 131/134 patients (98%) who received adrenaline injection alone and 135/136 patients (99%) who received additional heat probe treatment (P = 0.33). Outcome as measured by clinical rebleeding (12 v 5), requirement for emergency operation (14 v 8), blood transfusion (2 v 3 units), hospital stay (4 v 4 days), ulcer healing at four weeks (79.1% v 74%), and in hospital mortality (7 v 8) were not significantly different in the two groups. In the subgroup of patients with spurting haemorrhage 8/27 (29.6%; 14.5% to 50.3%) patients from the adrenaline injection alone group and 2/31 (6.5%; 1.1% to 22.9%) patients from the dual treatment group required operative intervention. The relative risk of this was lower in the dual treatment group (0.17; 0.03 to 0.87). Hospital stay was significantly shorter in the dual treatment group than the adrenaline injection alone group (4 v 6 days, P = 0.01). CONCLUSION: The addition of heat probe treatment after endoscopic adrenaline injection confers an advantage in ulcers with spurting haemorrhage.

Adult↗
PubMed1976

Tissue damage and concentration at the injection site after intramuscular injection of chemotherapeutics and vehicles in pigs.

Intramuscular injection sites were examined for macroscopical and microscopical changes and for residues of drugs six and 30 days after injection of chemotherapeutic preparations or vehicles in swine. The chemotherapeutic preparations contained sulphonamide and/or trimethoprim. All the chemotherapeutic preparations and the vehicles except physiological saline and sterile water caused macroscopical and microscopical changes, mainly appearing as areas of necrotic muscle tissue six days after the injection and as scar tissue 30 days after the injection. Residues of drugs were found at nearly all the injection sites six days after the injection, while 30 days after the injection only residues of sulphonamides were detectable in nearly half of the injection sites.

Animals↗
PubMed1993

Effects of injection site and flow rate on the distribution of injected solutions in an extracorporeal membrane oxygenation circuit.

The effects of injection site and flow rates on drug distribution within an extracorporeal membrane oxygenation (ECMO) circuit were studied. Two commercially available reservoirs (30 mL and 50 mL) were connected to a closed ECMO circuit that did not include the membrane oxygenator and heater. The circuit was filled with 150-170 mL of a 9.5% dextran solution in deionized, distilled water with a viscosity approximating that of blood. Flow rates of the circulating solution were set at 75 mL/min and 375 mL/min. Bordeaux red dye was injected into an ECMO circuit at prereservoir, postreservoir, and intrareservoir sites, and samples were obtained from these sites for analysis. Gentamicin was also injected at the prereservoir site, with samples obtained from the reservoir, reservoir tubing, and the prereservoir and postreservoir sites. Postreservoir dye injections resulted in complete mixing at any flow rate. Prereservoir injections at flow rates less than 250 mL/min resulted in incomplete mixing of dye, whereas intrareservoir injections resulted in incomplete mixing at any flow rate. Gentamicin injection was also affected by flow rate, resulting in higher concentrations within the reservoir and reservoir tubing. In patients on ECMO, drug distribution may be substantially altered if drugs are given as a bolus at prereservoir or intrareservoir sites. Efforts should be made to select injection sites that will provide safe and therapeutic drug delivery while minimizing the effects of the ECMO circuit on drug distribution.

Critical Care↗
PubMedDate not supplied

Does a needleless injection system reduce anxiety in children receiving intramuscular injections?

Previous studies have shown that needle injections are very stressful for children. This study examined if a needleless injection system would be associated with lower anxiety levels in children by comparing children's responses to a traditional needle injection to their responses to the Biojector, a needleless system. Seventy-four sixth-grade students of two public middle schools, all scheduled to receive the Hepatitis B vaccine, were enrolled. The study used a cross-over design. The children's anxiety levels were measured both before and after each of the two types of injections using the Spielberger State Trait Anxiety Index for Children (STAIC). Data analysis found no significant difference in levels of anxiety associated with the Biojector injections when compared with anxiety levels associated with needle injections. When asked to choose the injection method for their third injection, however, students showed a preference for the Biojector (61%), which indicated a trend towards significance (p = .08).

Anxiety↗
PubMed1986

The effect of dose, route, number of injections and the use of adjuvant on the clearance of and immune response to, haemocyanin following injection into brown trout (Salmo trutta).

The primary and secondary immune responses were investigated in trout injected with haemocyanin (HCN) intramuscularly (IM) or intraperitoneally (IP), with or without adjuvant. HCN was detected in the blood 30 min after injection and clearance times varied after one injection from 8 to 56 days. Fish given two and three injections cleared the antigen faster. Precipitins against HCN were first detected 21 to 30 days after injection and were still present on Day 56. However, antibodies detectable by indirect haemagglutination (IHA) and complement fixation (CFA) were initially demonstrated 7 to 21 days after a single injection and highest titres were reached between 33 and 56 days according to the experimental protocol. In fish given two injections, maximum titres were reached between Days 42 and 56 (IM), and Days 50 and 56 (IP). With three injections, maximum CFA and IHA values occurred on Days 62 and 66 respectively in the case of IP, and on Days 103 and 106 respectively with IM. Overall, higher titres were found with IHA than by CFA.

Animals↗
PubMed1995

Changes in the injecting risk behaviour of injecting drug users in London, 1990-1993.

OBJECTIVE: To describe changes in the injecting risk behaviour of injecting drug users (IDU) in London between 1990 and 1993. DESIGN: Injecting risk behaviour was measured over 4 years (1990-1993) in a serial point HIV prevalence study of 2062 IDU recruited in both drug treatment and non-treatment community-based settings within greater London. The study used a structured questionnaire and common sampling and interview strategy developed by a World Health Organization technical group and implemented in 13 cities. METHODS: Log-linear models were used to assess patterns of change over years and of differences in injecting risk behaviour, including syringe sharing and syringe hygiene between 1990 and 1993. The log likelihood chi 2 statistic, G2, was used to test statistical significance. Changes in the mean values were assessed first using parametric tests assuming normality and the results were compared with Kruskal-Wallis (non-parametric) tests. Pearsons chi 2 was used to measure differences in frequency of sharing occasions and partner selectivity. RESULTS: An overall reduction in injecting risk behaviour was observed during the first 2 years of this study, including a decline in syringe sharing (both accepting and passing on used syringes), the number of sharing partners and the frequency of sharing occasions. Most sharers restricted sharing to sexual partners and close friends. The majority of sharers reported always cleaning injecting equipment. Main source of sterile equipment was pharmacies and syringe exchanges. Indirect sharing (of spoons, filters, and by front- or backloading) was reported. Since 1991 there has been a stabilization in risk behaviour. CONCLUSIONS: The data indicate that IDU in London have made positive reductions in risk behaviour. Levels of syringe sharing were substantially lower than those reported up to 1987 before AIDS awareness and the introduction of HIV prevention measures. The majority did not share syringes or confined their sharing to close friends and sexual partners, and if shared, cleaned their syringes. Continuation of indirect sharing indicates the need for more detailed prevention messages. While the initial decline in syringe-sharing rates may be attributed to the wide availability of sterile injecting equipment and other preventive measures, it may now be necessary to look beyond current intervention initiatives to develop interventions which seek to change the social etiquette of sharing and move towards the long-term maintenance of low levels of injecting risk behaviour.

Adult↗
PubMed1998

Injecting behaviours and prevalence of hepatitis B, C and D markers in New Zealand injecting drug user populations.

AIM: To determine the seroprevalence of hepatitis C virus (HCV), hepatitis B virus (HBV) & hepatitis D virus (HDV) markers of infection among injecting drug user populations in New Zealand and to examine the relationship between demographic features, risk behaviours and infection. METHODS: A total of 323 current injecting drug users completed a questionnaire that explored their needle and syringe using behaviours. Information was collected on injection pattern, sharing behaviours and methods of cleaning needles and syringes. Two hundred and forty-one respondents gave blood samples which were tested for hepatitis B, C and D markers. RESULTS: Over half the respondents (59%) were male and 41% were female. Most (89%) identified as European. Sixty-four percent were anti-HCV positive. The likelihood of infection increased with age and duration of injecting. Forty-one percent (33/81) of those aged 25 or under, sixty-four percent (45/70) of those aged 26-30 and eighty-seven percent (78/90) over 30 were anti-HCV positive. Those who tested anti-HCV positive had been injecting for an average of 12.0 years compared to 6.0 years for those were anti-HCV negative. The results for hepatitis B are to be reported fully at a later date. Sharing behaviour was also a factor although this was less important as an independent factor. Comparisons with earlier surveys suggested that there has not been a significant decline in the rate of sharing needles and syringes since the initial period following introduction of the needle exchange programme. CONCLUSION: The prevalence of hepatitis C infection is common among injecting drug users of all ages. Without a significant reduction in sharing behaviour, particularly among younger injecting drug users, it is unlikely that the prevalence of hepatitis C among injecting drug users will decline in the future. Evidence suggests that the carriage of hepatitis C is higher than that of hepatitis B which would help explain the differing rates of prevalence. However, the risk of future transmission of other parenterally transmitted diseases remains high without a further significant decline in sharing behaviour.

Adolescent↗
PubMed1995

A multicentred phase III comparative clinical trial of Mesigyna, Cyclofem and Injectable No. 1 given by intramuscular injection to Chinese women. II. The comparison of bleeding patterns.

Between 1988 and 1992, a randomized phase III clinical trial was conducted in China to compare three monthly injectable contraceptives: Mesigyna, Cyclofem and Injectable No. 1. This paper presents a detailed analysis of the menstrual diaries provided by 5098 (89%) of the subjects. In total, 902, 903 and 913 diaries were analyzed to compare bleeding patterns induced by Mesigyna, Cyclofem and Injectable No. 1. The first withdrawal bleeding usually occurs 14-20 days after the first injection for all three of these preparations. Thereafter, 50% of Mesigyna users had precisely 3 bleeding/spotting episodes every 90 days, 50% of Cyclofem users had 2-3 and 50% of Injectable No. 1 users had 3-4 episodes every 90 days. Relative to users of Mesigyna or Cyclofem, Injectable No. 1 users had 2-3 more bleeding/spotting days, and a shorter length of bleeding/spotting-free intervals in each period. 63.7%, 41.4% and 60.6% of subjects using Mesigyna, Cyclofem and Injectable No. 1, respectively, had bleeding patterns similar to their untreated patterns in the first 90-day period. The percentages increased to 82.2% 67.8% and 75.0% in the fourth 90-day period. A total of 1815 diaries for Mesigyna and 1802 for Cyclofem were analyzed for more in depth comparison of these two methods. The number of bleeding/spotting days over four periods showed little difference between the two group, but there were more spotting days and there was greater individual variability among Cyclofem users.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Influence of concentration and injection volume on the bioavailability of subcutaneous growth hormone: comparison of administration by ordinary syringe and by injection pen.

In order to study whether the bioavailability of subcutaneously injected growth hormone (GH) is dependent on the concentration/volume injected, the relative GH bioavailability was evaluated in 14 GH-deficient patients. In a cross-over study the patients received, in random order two separate subcutaneous GH injections (Norditropin) 4 IU administered by means of an ordinary syringe (4 IU ml) and an injection pen with cartridge (Nordiject 24) (12 IU/ml). Blood samples were drawn over a 14 hr period and assayed for serum concentrations of GH and IGF-I. The mean value (+/- S.D.) of the relative absorption fraction (Fpen/sy) was 1.09 +/- 0.39. Mean values of Cmax were 8.6 ng/ml +/- 4.8 and 8.3 ng/ml +/- 7.5 for syringe and pen respectively. Corresponding values for Tmax were 311 min. +/- 131 for syringe and 309 min. +/- 104 for pen. Although a considerable interindividual variation was seen, the relative absorption fraction did not differ significantly from 1 (2 P = 0.78). Further there was no significant difference in neither Cmax (2 P = 0.39) nor Tmax (2 P = 0.55). IGF-I serum profiles tended to be higher following syringe compared to pen injection (2 P = 0.054). On the basis of this study we conclude that in this dosage regimen. GH bioavailability following pen injection equals that of injection by syringe (i.e. no effect of a three fold increase/decrease in GH concentration/volume respectively).

Adult↗
PubMedDate not supplied

Prolongation of cardiac allograft survival by intraportal injection of donor antigens--differential mechanisms according to the timing of injection.

Recently, we reported that intraportal (IP) injection of donor spleen cells (SPCs) before transplantation as well as at the time of transplantation significantly prolongs cardiac allograft survival in rats (7). Long-term establishment of chimerism induced by intraportal administration of SPCs could be a part of this prolongation. In this study, we examined the effect of irradiation of SPCs as a source of donor antigens on cardiac allograft survival. Experiments were carried out using DA (RT1a) as the donor and BUF (RT1b) as the recipient strain. Fifty million irradiated or nonirradiated SPCs were injected either intravenously (i.v.) or intraportally (i.p.) on day -10 or day 0, the day of cardiac allografting. Untreated animals rejected allografts within a mean survival time (MST) of 7.2 +/- 0.8 days (n = 5). Injection (i.p.) of SPCs on both day -10 (n = 4) and day 0 (n = 6) induced significant prolongation of MST over the control (19.0 +/- 4.7, 14.2 +/- 2.1 days; p < 0.001 vs. control), while i.v. injection of SPCs on either day -10 (n = 4) or day 0 (n = 4) failed to do so (9.2 +/- 1.0, 8.5 +/- 0.6 days). Significant prolongation was still observed when irradiated SPCs were injected on day -10 (n = 4; MST: 19.0 +/- 5.4 days, p < 0.002 vs. control), but not when injected on day 0 (n = 5; MST: 9.4 +/- 2.1 days). These data suggest that the immunosuppressive effect of i.p. injection of donor SPCs could be induced by differential mechanisms according to the timing of inoculation of donor antigens.

Animals↗
PubMed1984

Hemodynamic effects of calcium chloride injection following cardiopulmonary bypass: response to bolus injection and continuous infusion.

To determine the hemodynamic effects of intravenous injection of calcium chloride, 26 patients were studied immediately after termination of extracorporeal circulation. Eighteen patients (Group A) had injection of a single bolus of CaCl2; in the other 8 patients (Group B), the bolus injection was followed by infusion of CaCl2 at a rate of 1.5 mg/kg/min for 10 minutes. Myocardial contractile element velocity (Vpm), aortic blood flow, electrocardiograms, and left ventricular, systemic arterial, pulmonary arterial, and left atrial pressures were recorded continuously. The baseline ionized calcium level after bypass was 3.6 +/- 0.6 mg/100 ml (normal range, 3.9 to 4.5 mg/100 ml); this increased to 5.4 +/- 0.5 mg/100 ml 1 minute after CaCl2 injection. The ionized calcium level was 4.7 +/- 0.6 mg/100 ml 6 minutes after CaCl2 injection in Group A, and was 5.9 +/- 0.2 mg/100 ml and 6.4 +/- 0.2 mg/100 ml at 6 and 10 minutes, respectively, in Group B. There was significant early hemodynamic improvement after CaCl2 injection, including increases in Vpm (p less than 0.001), cardiac index (p less than 0.001), mean blood pressure (p less than 0.01), and stroke volume index (p less than 0.001). A similar pattern of hemodynamic response was observed in both groups. Approximately 1 minute after CaCl2 injection, cardiac index returned to control level, Vpm and mean blood pressure remained elevated, and heart rate declined (p less than 0.01). Systemic vascular resistance gradually increased and was significantly elevated (p less than 0.05) in Group B at 3 minutes and in Group A at 6 minutes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1997

The Blood-Injection Symptom Scale (BISS): assessing a structure of phobic symptoms elicited by blood and injections.

Assessments for blood-injury-injection phobia measure feared stimuli and overt behaviours, but they have not systematically addressed the symptoms of fear and faintness. The Blood-Injection Symptom Scale (BISS) was developed to overcome this omission. An exploratory factor analysis grouped symptoms triggered by blood and injections into three internally consistent factors (faintness, anxiety and tension). A confirmatory factor analysis replicated the factor structure in a new sample. To test the construct validity of the BISS, an attempt was made to reproduce Ost's (1992, Journal of Abnormal Psychology, 101, 68-74) finding that fear was stronger among people with concerns about injections, while faintness was stronger among people with concerns about blood. A community sample of 80 individuals with concerns (i.e. fear or fainting) about blood or injections completed the BISS. Controlling faintness, individuals with concerns about injections reported more fear than people with concerns about blood. In contrast, controlling for fear, the latter reported more symptoms of faintness. These data suggest that the BISS generates stable and internally consistent subscales useful in the measurement of symptoms elicited by blood and injections.

Adult↗
PubMed1983

Influence of diet or intrarectal bile acid injections on colon epithelial cell proliferation in rats previously injected with 1,2-dimethylhydrazine.

The effects of varying colon bile acid concentrations on rat colon epithelial cell proliferation were studied. Bile acid concentrations were altered by intrarectally injecting either deoxycholic or lithocholic acid for 4 weeks or by increasing the dietary fat or fiber (wheat bran, agar, or carrageenan) intake for 4 weeks. 1,2-Dimethylhydrazine (DMH) was s.c. injected into half of the rats 1 week before treatments began. Colon epithelial cell proliferation was measured by [3H]thymidine autoradiography of colon crypts. Rats injected with DMH had more DNA-synthesizing cells per crypt. Neither bile acid injection nor any of the diets altered the number of DNA-synthesizing cells per crypt. DMH injections, deoxycholic and lithocholic acid intrarectal injections, and dietary agar and wheat bran all increased the total number of cells per crypt. High fat diets and dietary carrageenan did not affect cell number. All diets containing fiber lowered total fecal bile acid concentrations, but increasing the fat content of the diet did not affect them. These results indicate that the bile acid injections and dietary agar and wheat bran induce a slight hyperplasia in the colon.

Animals↗