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PubMed1995

Injection-site lesions in carcasses of cattle receiving injections at branding and at weaning.

Crossbred steer and heifer calves (n = 84) were given injections at branding and at weaning (using a completely randomized block design); 225 to 376 d later, pairs of two subprimal cuts from each animal were evaluated for incidence and severity of injection-site lesions. The four products compared were 1) a 2-mL clostridial, 2) a 5-mL clostridial, 3) vitamin AD3, and 4) a long-acting oxytetracycline antibiotic (OTC). Branding-age calves (mean 48.3 d of age) received intramuscular injections of two of the four products, in the semimembranosus (inside round) muscles (one in the left muscle and one in the right); at weaning age (mean 199.3 d of age), calves received injections of the remaining two products in the gluteus medius (top sirloin butt) muscles (one in the left and the other in the right). Injections at branding of 2 mL of clostridial, 5 mL of clostridial, vitamin AD3, and OTC caused injection-site lesions in 72.5, 92.7, 5.3, and 51.2%, respectively, of inside rounds from slaughter cattle. Incidence of injection-site lesions was lowest (P < .05) among inside rounds and top sirloin butts from animals given vitamin AD3 (as calves, and at both branding and weaning times) and was highest (P < .05) in inside rounds from cattle given, as calves, injections of 5 mL of clostridial at branding or of OTC at weaning. Less trimming was required to remove the lesions resulting from injections of all four products when they were given at weaning time. Before completion of the present study, it was thought that injection-site lesions were from damage that subsisted only briefly following an inoculation; these results make it abundantly clear that intramuscular administration of clostridials and certain antibiotics will cause damage so severe that it will be evident in beef muscle 7.5 to 12 mo later.

Aging↗

PubMed2001

Effect of injection volume on the pharmacokinetics of oil particles and incorporated menatetrenone after intravenous injection as O/W lipid emulsions in rats.

Oil-in-water lipid emulsions are promising drug carriers for lipophilic drugs, however, the pharmacokinetics after entering the circulation should be clarified at clinical injection volume in order to utilize them in a clinical situation. In the present study, the standard lipid emulsions, consisting of soybean oil, egg yolk phosphatides and menatetrenone with diameters of about 150 nm, were prepared using a microfluidizer system. The pharmacokinetics of menatetrenone and the oil particles after intravenous injection as standard lipid emulsions at various injection volumes, from the clinical injection volume (0.1 ml/kg) to the experimental injection volume (3.0 ml/kg), were examined in rats. The plasma concentrations of menatetrenone and the oil particles were similar after administration, showing that menatetrenone was not released even after entering the circulation. Menatetrenone was delivered to the liver and spleen at the clinical injection volume, and more menatetrenone was delivered to the liver at clinical injection volume compared with the experimental volume. Moreover, additional information on injection volume-dependency was also obtained from these findings. These results at various injection volumes suggested that the standard lipid emulsions can be utilized as a useful drug delivery system at the clinical injection volume, especially for liver and spleen targeting.

Animals↗

PubMed1998

Comparison of percutaneous acetic acid injection and percutaneous ethanol injection for small hepatocellular carcinoma.

BACKGROUND/AIMS: To assess whether ultrasound (US)-guided percutaneous acetic acid injection is more effective than percutaneous ethanol injection in the treatment of small hepatocellular carcinoma (HCC). METHODOLOGY: sixty patients with 1 to 4 HCC smaller than 3 cm entered a randomized controlled trial from August 1993 to September 1995. Thirty one and 29 patients were treated by percutaneous acetic acid injection using 50% acetic acid and percutaneous ethanol injection using absolute ethanol, respectively. There were no significant differences in clinical characteristics and biochemical data between the two groups. RESULTS: All original tumors were treated successfully by the chosen therapy. However, local recurrence occurred in 8% of the 38 tumors treated with percutaneous acetic acid injection and 37% of the 35 tumors treated with percutaneous ethanol injection P>0.001). The 1- and 2-year survival rates were 100% and 92% with percutaneous acetic acid injection and 83% and 63% with percutaneous ethanol injection (p=0.0017). Multivariate analysis of prognostic factors revealed that treatment was an independent predictor of survival. CONCLUSION: percutaneous acetic acid injection is more effective than percutaneous ethanol injection.

Acetic Acid↗

PubMed2000

Measuring injecting risk behaviour in the second decade of harm reduction: a survey of injecting drug users in England.

AIMS: To measure risk behaviour among injecting drug users (IDUs) using the Injecting Risk Questionnaire (IRQ). METHODS: Data were analysed from the first multi-site survey of injecting risk behaviour among IDUs not in contact with drug services in England. A total of 1214 IDUs were recruited from community settings in seven sites. FINDINGS: Fifty-two per cent reported sharing injecting equipment in the previous 4 weeks in response to a single question on sharing. This rose to 78% when asked more detailed and multiple questions on injecting risk practices. Levels of injecting risk behaviour did not differ substantially by gender, age, length of injecting career, main drug of injection, previous treatment contact or geographical location. However, sharing partners were restricted to a median of two others. CONCLUSION: These data raise questions concerning the extent to which levels of injecting risk behaviour have increased over recent years, or the extent to which previous monitoring systems underestimated levels of risk. None the less, the data confirm that the promotion of safer injecting continues to be an important public health issue with regard to reducing blood-borne infections.

Adolescent↗

PubMed2001

Between-city variation in frequency of injection among Puerto Rican injection drug users: East Harlem, New York, and Bayamon, Puerto Rico.

Frequency of injection has been consistently found to be higher among Puerto Rican Injection drug users (IDUs) than among other groups of IDUs. Several explanations have been suggested, but an empirical explanation has yet to be presented. This study compares the frequency of injection of Puerto Rican IDUs in East Harlem, New York, with that of IDUs in Bayamon, Puerto Rico. Study subjects comprised 521 Puerto Rican IDUs from East Harlem and 303 IDUs from Bayamon. The mean frequency of injection among IDUs in East Harlem was 2.8, the corresponding mean in Bayamon was 5.4. Younger IDUs reported a higher number of daily injection episodes than older IDUs, and the IDU group in Bayamon was 5 years younger than the group in East Harlem. The drug use variables accounted for a greater portion of the between-city difference than the demographic and psychosocial variables. Use of noninjected drugs, as well as the use of prescribed methadone, were found to be associated with a lower number of daily injections. Conversely, injection of cocaine, injection of cocaine mixed with heroin ("speedball"), and injection of larger amounts of drug solution were found to be associated with a higher number of daily injections.

Adult↗

PubMedDate not supplied

Endoscopic injection sclerotherapy with ligation versus endoscopic injection sclerotherapy alone in the management of esophageal varices: a prospective randomized trial.

BACKGROUND/AIMS: Endoscopic injection sclerotherapy with ligation is a technique by which endoscopic injection sclerotherapy is first carried out for a target esophageal varix using an endoscope equipped with a device for endoscopic variceal ligation, and subsequently, endoscopic variceal ligation is performed for the varix together with the injection site of the sclerosing agent. The aim of this prospective, randomized trial was to compare endoscopic injection sclerotherapy with ligation with endoscopic injection sclerotherapy techniques in utility for patients with esophageal varices. METHODOLOGY: Twenty-four patients with esophageal varices who were to undergo either an elective treatment of bleeding esophageal varices or a prophylactic treatment of non-bleeding esophageal varices underwent endoscopic injection sclerotherapy with ligation (n = 12) or without ligation (n = 12). The patients were followed for a mean of 19.9 +/- 8.1 months in the endoscopic injection sclerotherapy with ligation (EISL) group and 19.5 +/- 5.4 months in the Endoscopic injection sclerotherapy (EIS) group. RESULTS: The red color sign disappeared in 10 patients in the EISL group and 3 in the EIS group (P = 0.004) after initial treatment. The length of time required for initial treatment was 16.3 +/- 4.7 min for the EISL group and 27.2 +/- 6.2 min for the EIS group (P = 0.0003). For treatment-related complications, no significant difference was noted between the 2 groups and no serious complication were noted in the 2 groups. The total quantity of ethanolamine oleate used to attain the endpoint was 17.3 +/- 7.9 mL for the EISL group and 25.2 +/- 9.7 mL for the EIS group (P < 0.05). The cumulative non-relapse rate for 2 years following attainment of the endpoint [F1, RC(-)] was 81.5% for the EISL group and 47.5% for the EIS group, producing no significant difference between the 2 groups. The cumulative non-bleeding and survival rates were 100% in the 2 groups. CONCLUSIONS: Endoscopic injection sclerotherapy with ligation is more useful for esophageal varices than endoscopic injection sclerotherapy alone.

Aged↗

PubMed2000

Sildenafil versus intracavernous injection therapy: efficacy and preference in patients on intracavernous injection for more than 1 year.

PURPOSE: To our knowledge comparative data on the effectiveness of and patient preference for intracavernous injection therapy and sildenafil are still not available. We evaluated the efficacy of sildenafil as well as patient preference in a group of impotent men on intracavernous injection for more than a year. MATERIALS AND METHODS: Patients on intracavernous injection therapy for more than a year without neurological disease and/or a contraindication to sildenafil treatment were recruited for study. In phase 1 we determined the efficacy of 50 and 100 mg. sildenafil citrate at home. In phase 2 responders to sildenafil were asked to use the preferred dose orally for a month and choose intracavernous injection or sildenafil. In phase 3 patients were asked to continue either treatment for 3 more months. Patient preferences were reported at the end of phases 2 and 3. RESULTS: Of the 180 men recruited 155 with a mean age of 56.4 +/- 12.6 years on intracavernous injection for a mean of 26 +/- 9 months accepted and were included in our series. Overall 116 men (74.8%) responded to sildenafil during study phase 1. After 1 month of treatment 71 responders (61.2%) preferred to continue with the oral drug, 31 (26.7%) returned to intracavernous injection and 14 (12.1%) used each drug alternately. Three months later 74 of the 116 responders (63.8%) preferred oral treatment and 38 (32.8%) chose intracavernous injection, while 4 (3. 4%) continued to use each treatment alternately. CONCLUSIONS: Sildenafil is highly effective in intracavernous injection responders, although a certain group prefer to continue intracavernous injection. While sildenafil should be considered first line treatment, men with erectile dysfunction should be aware of all treatment options available because nonresponders to sildenafil may respond to intracavernous injection.

Adult↗

PubMed1997

Continued risky injection subsequent to syringe exchange use among injection drug users in New York City.

Although the vast majority of injection drug users (IDUs) attending syringe exchange programs in New York City have stopped risky injection (injecting with syringes used by someone else), there remains a subgroup of IDUs who continue to engage in high-risk injecting behaviors despite access to sterile syringes. Subjects were randomly recruited from five legally authorized syringe exchange programs in New York City between October 1992 and August 1994. Participants were asked about drug and sexual risk behavior 30 days prior to their first use of the syringe exchange as well as during the 30-day period prior to the interview while using the exchange. Of the 2,465 participants, 77.4% reported no risky injection during the 30 days prior to using syringes exchange. For this analysis we included only those who reported risky injection for the 30-day period prior to using syringe exchange (N = 556). We compared sociodemographics and behavioral characteristics of a group who continued risky injection while using the syringe exchange, "continuers," N = 158 (28.8%) with a group who reported risky injection prior to using the exchange and then ceased risky injection while using the exchange, "stoppers," N = 391(71.2%). Continuers were significantly more likely to report passing on dirty syringes to social network members and to inject cocaine at least daily. We present other predictors of continued risk and discuss the implications for interventions and make recommendations for syringe exchange programs.

Adult↗

PubMed1983

T-cell responses induced by the parenteral injection of antigen-modified syngeneic cells. II. Mechanisms, specificity, and cellular analysis of 2,4,6-trinitrophenol (TNP)-specific cytolytic response priming by intravenous versus subcutaneous injection with TNP-modified syngeneic cells.

We have examined the underlying mechanisms accounting for the enhanced in vitro TNP-specific cytotoxic T-lymphocyte (CTL) response following the parenteral injection of syngeneic hapten-modified lymphoid cells. Augmented CTL activity noted following parenteral injection (iv vs sc) of 2,4,6-trinitrophenol-modified syngeneic spleen cells (TNP-SC) is most apparent when limiting numbers of TNP-modified stimulator cells are used in the in vitro sensitization phase. Enhanced CTL responses seen following sc and iv priming is due to distinct mechanisms. Spleen and lymph node (LN) cells from sc primed mice were found to contain significant levels of radioresistant helper activity upon coculture with either viable normal spleen cells in bulk culture or with thymocytes as the source of precursor CTLs in a limiting dilution assay. The helper activity was found to be mediated by a Lyt 1+2- T cells. In addition, Lyt 2-depleted spleen and LN cells from sc primed BALB/c mice could restore the ability of tolerant spleen cells from 2,4,6-trinitrobenzenesulfonic acid (TNBS)-injected BALB/c mice to generate TNP-specific CTLs. Conversely, Lyt 2-depleted spleen and LN cells from iv primed mice provided no measurable helper activity either in bulk culture or in the limiting dilution assay and did not restore the ability of TNBS-tolerant BALB/c spleen cells to generate TNP-specific CTLs. CTL priming via the iv route was found to be completely antigen specific as iv injection of either 2,4-dinitrophenol (DNP)- or fluorescein isothiocyanatel (FITC)-modified cells caused no enhanced CTL activity. Priming via the sc route exhibited a unique specificity pattern as it was shown that sc injection of both TNP-SC and DNP-SC, but not FITC-SC, resulted in enhanced TNP-specific CTL responses. CTL T-helper (Th)-cell induction via the sc route was correlated with (1) the presence of H-2 I region determinants on the inducer cells as the sc injection of TNP-modified erythrocytes led to no enhanced CTL responses or CTL Th activity (while iv injection of TNP-erythrocytes did lead to enhanced CTL responses without detectable helper activity) and (2) the detection of both hapten-specific T-cell proliferation and Interleukin 2 (IL-2) production upon restimulation in culture. We conclude that the sc injection of TNP-SC leads preferentially to an increase of specific Lyt 1+ helper activity, while iv injection leads preferentially to an apparent expansion of Lyt 2+ prelytic effector CTLs.

Animals↗

PubMed1998

Cutis/subcutis thickness at insulin injection sites and localization of simulated insulin boluses in children with type 1 diabetes mellitus: need for individualization of injection technique?

The study aimed to describe the variations of cutis/subcutis thickness at insulin injection sites in children with Type 1 diabetes mellitus and to localize the tissue position of a simulated insulin bolus in order to evaluate the need for individualization of injection technique in children. Cutis/subcutis thickness was measured by ultrasound in 47 children (25 girls and 22 boys) without compression (CSCUT) and with compression (CSCT) of the skin at 11 insulin injection sites. Tissue deposition of insulin was measured by ultrasound of a simulated insulin bolus of 200 microl of sterile air injected by the patients using their usual technique and site. On the thigh, 44% of girls and 95% of boys had a CSCT of less than 8 mm at one of the measured sites, while 16% of girls and 50% of boys had a CSCT of less than 6 mm at one injection site on the thigh and buttock. Significant differences in cutis/subcutis thickness in the same anatomical region were shown. CSCT was up to 35% less than CSCUT. The air bolus injection was placed inappropriately by 19% of children (using 8 mm needles). Unawareness of the skin thickness at the injection sites may contribute to inappropriate deposition. We propose that regular ultrasound measurements of subcutis depth at insulin injection sites be taken. This will allow the injection technique to be individualized (vertical or at an angle of 45 degrees). More children would be able to use the simpler vertical technique if 6 mm needles were used where available, or if even shorter (4 mm) needles were produced.

Adolescent↗

PubMed1994

Fate of allogeneic or syngeneic cells in intravenous or portal vein injection: possible explanation for the mechanism of tolerance induction by portal vein injection.

In this report we examine the fate of donor cells injected via different routes. When PKH-26-labeled C57BL/6 (B6) spleen cells were intravenously (i.v.) injected into BALB/c mice, the donor cells were rejected within 3 days. In contrast, when the same B6 spleen cells were portal venously (p.v.) injected, they were trapped in the recipient liver. When allogeneic or syngeneic whole bone marrow cells (BMC) or cells in a hemopoietic stem cell (HSC)-enriched fraction were either i.v. or p.v. injected, the cells accumulated in the liver. The cells trapped in the liver were found to be wheat germ agglutinin (WGA)-positive HSC. When B6 thymocytes were p.v. or i.v. injected into BALB/c mice, they were rapidly rejected. When BALB/c mice were i.v. preimmunized with unlabeled B6 spleen cells, BMC or thymocytes, the p.v. or i.v. injected PKH-26-labeled B6 spleen cells were rejected rapidly (within 2 days). In contrast, when BALB/c mice were p.v. preimmunized with B6 spleen cells or BMC, the p.v. or i.v. injected PKH-26-labeled B6 spleen cells were not rejected. The cells responsible for the tolerance induction were found to be HSC trapped in the liver. Delayed-type hypersensitivity assays revealed that the tolerance could be maintained for more than 49 days by p.v. injection plus i.v. injection (at intervals of 2 weeks) of HSC. These findings indicate that HSC trapped in the liver play a crucial role in the induction and maintenance of p.v. tolerance.

Animals↗

PubMed2005

Magnetic resonance imaging guided corticosteroid injection of sacroiliac joints in patients with spondylarthropathy. Are multiple injections more beneficial?

Efficacy of a second magnetic resonance (MR) imaging guided corticosteroid injection of inflamed sacroiliac joints (SIJ) in patients with spondylarthropathy. Thirty-one patients received 50 injections in an outpatient basis. Fifteen of 31 patients who relapsed or were non-responders received a second injection. All had MR guided injection of 40 mg triamcinolone acetonide into SIJ using an open 0.2 Tesla unit. Twenty of 31 patients after the first injection, and 9 of 15 patients after the second injection reported subjective improvement, which lasted for a mean of 8.7+/-10.9 and 16.1+/-15.8 months for each group. Subchondral bone marrow edema resolved in 15 of 20 patients who reported subjective improvement, after the first injection. No complications occurred. MR guided steroid injection of SIJ is effective and safe. Since there is no exposure to radiation it could be performed many times. Repeated injections seem to be beneficial for primary non-responders and patients who relapsed.

Adolescent↗

PubMed1980

Cerebral ventricular injections of CCK-octapeptide and feed intake: the importance of continuous injection.

CCK-octapeptide (CCK-OP) is a potent suppressor of feed intake when administered as a continuous injection into the lateral cerebral ventricles of sheep. We compared the effect on feeding of CCK-OP given as bolus and continuous injections to assess the importance of the continuous injection method. A total dose of 30.6 pmoles of CCK-OP given as one, four, or weight bolus injections had no effect on feed intake; whereas the same total dose given as a 45 min continuous injection reduced feed intake 80 percent. We also compared the effects of beginning the continuous injection immediately before, 5 min before, and 15 min before the sheep began a meal. Feed intakes were significantly lower when CCK-OP injection was begun 15 min before the meal, than whe n injection was begun immediately before or 5 min before the meal, suggesting that the site of action of CCK-OP for its effect on feeding is not the immediate vicinity of the lateral ventricles. The complete lack of effect of bolus injections of CCK-OP is unexpected; the explanation probably awaits further information on kinetics of CSF formation and CCK-OP degradation, site of action of CCK-OP, and the role of the CSF in transport of the peptide.

Animals↗

PubMed1996

Stability of revex, nalmefene hydrochloride injection, in injectable solutions.

The short-term stability of Revex, nalmefene hydrochloride injection, was determined in a number of diluents commonly employed for intravenous use. An HPLC method was used to follow the potency of the diluted solutions, and was fully validated for its intended concentration range prior to its use. Dilutions of Revex were prepared separately in 0.9% sodium chloride injection, 0.45% sodium chloride injection, 5% dextrose injection, 5% dextrose and 0.45% sodium chloride injection, lactated Ringer's injection, 5% dextrose and lactated Ringer's injection and 5% sodium hydrogencarbonate injection. Each admixture was stored at 4 degrees C, room temperature (21 degrees C) and 40 degrees C, with samples being tested after storage at each temperature for 0, 24, 48 and 72 h. Defining stability as the retention of at least 95% of the initial drug concentration at the end of the storage period, it was concluded that the diluted solutions of Revex were uniformly stable for up to 72 h in all of the injectable solutions maintained at either 4, 21 or 40 degrees C.

Chromatography, High Pressure Liquid↗

PubMed2007

Histopathologic study of minced and injected expanded polytetrafluoroethylene (Gore-Tex) in quadriceps muscle of rats for injection laryngoplasty.

OBJECTIVE: Gore-Tex has not yet been used as an injection material, and no animal study has been performed. The purpose of this study was to investigate the histopathological and volumetric changes of minced and injected expanded polytetrafluoroethylene (Gore-Tex) in the quadriceps muscle of rats to find out its possibility as an injection material in future injection laryngoplasty. DESIGN: A prospective study was performed in 13 Wistar rats. METHODS: The 50+/-5 mg Gore-Tex vascular graft was minced until it was fine enough to pass through a 16G injection cannula. To create viscosity in order to avoid precipitation, minced Gore-Tex was mixed with sodium hyaluronate (SH) gel. 0.5 ml of this mixture was injected into the middle part of the right quadriceps muscle of each subject. Then, pure SH (0.5 ml) was injected into the middle part of the left quadriceps muscle of each subject. To compare the volumetric and histopathological changes of the injection area occupied by the materials over the time, two rats were sacrificed 1 day after the procedure, four rats after 1 month, four rats after 3 months and three rats after 6 months. RESULTS: In pure SH: SH was observed as an effusion in the muscle of one subject on the first day only. We did not detect SH in the muscle in the first, third and sixth months and, as a result, there was no augmentation. Inflammation and fibrosis was not detected in any of these applications of SH. In minced Gore-Tex+SH gel mixture: SH was again eliminated from the muscle in a very short period of time, but the remaining Gore-Tex created a 15.8% volumetric gain. Fibrosis and capsule formation began in the first month and, in the sixth month; we observed connective tissue surrounding the Gore-Tex material. Ingrowth of connective tissue into the Gore-Tex, though not present in the first month, occurred partially in the third and significantly in the sixth month. In addition, we observed foreign body granuloma formation after the third month. CONCLUSIONS: Pure SH, though easily applicable, was immediately eliminated leaving no trace. In the relatively difficult applications of Gore-Tex mixed with SH, however, there was residual Gore-Tex present in all subjects throughout the study. Gore-Tex may be an applicable material for injection laryngoplasty.

Animals↗

PubMed2003

Growth hormone (GH) replacement in GH-deficient adults: a crossover trial comparing the effect on metabolic control, well-being and compliance of three injections per week versus daily injections.

Growth hormone (GH) replacement therapy regimens in adults using daily subcutaneous (sc) injections may not be optimal with respect to carbohydrate and lipid metabolism. The aim of this study was to compare the efficacy of three times weekly injections with daily sc GH injections in terms of serum IGF-I, IGFBPs, lipoprotein levels, serum bone markers, glucose metabolism, body composition, compliance and well-being. Twenty hypopituitary men, 46-76 years, on a course of stable conventional GH replacement therapy for more than 12 months, were included in a 16-week crossover trial. During the first 8 weeks GH was administered three times per week followed by 8 weeks with daily sc injections with the same weekly dose of GH. Fasting serum samples were collected at baseline and on two consecutive days at the end of each 8-week period. Serum IGF-I and IGFBP-3 concentrations were lower both the first and second morning after the last injection during the period with three injections per week. The second morning after the last GH injection in this period the IGF-I/BP-3 ratio, plasma insulin and FFA were lower whereas IGFBP-1 was increased as compared with values obtained during the period with daily injections. Serum Lp(a) levels, body composition, fat distribution, well-being and compliance were not differently affected by the two treatment regimens. These results suggest that the same weekly dose of GH given as three injections per week reduces serum IGF-I and IGFBP-3 levels without affecting Lp(a) levels. The day-to-day variation in glucose metabolism and FFA serum levels differs considerably between the two modes of GH administration.

Aged↗

PubMed1993

Influence of cardiac output, injection time and injection volume on the initial mixing of drugs with venous blood after i.v. bolus administration to sheep.

The aim of this study was to quantitate factors affecting the initial "peak" of the pulmonary artery (PA) drug concentrations after i.v. bolus drug administration, which is a determinant of the subsequent drug uptake into both the lungs and other well-perfused organs. Indocyanine green (ICG) was used as a marker drug in anaesthetized (1.5% halothane) sheep prepared with an inferior vena cava injection catheter and a large-gauge pulmonary artery blood sampling catheter. For three ranges of cardiac output, 2.5-mg doses of ICG were injected in the following combinations: 10 ml injected over 1, 5 or 10 s; 5 or 25 ml injected over 1 s. On-line PA ICG concentrations were recorded for approximately 60 s using a densitometer. The mean maximum PA ICG concentrations (2-8 mg litre-1), the mean times at which they occurred (7-18 s after injection) and the time lags before ICG was detected in the PA (4-9 s), were inversely related to cardiac output, but linearly related to the time over which the injection was made. The area under the curve of the peak was related inversely to cardiac output only, while the aspect ratio of the peak was related inversely to the time over which the injection was made only. The injectate volume had no effect on any of the measured values. We conclude that, in some circumstances, the rate of injection of drugs with narrow margins of safety should be tailored to the cardiac output of an individual.

Animals↗

PubMed2006

Injection of somatic cell cytoplasm into oocytes before intracytoplasmic sperm injection impairs full-term development and increases placental weight in mice.

This study investigated the effects on fertilized embryo development of somatic cytoplasm after its injection into intact mouse oocytes. Mature oocytes collected from female B6D2F1 mice were injected with cumulus cell cytoplasm of different volumes and from different mouse strains (B6D2F1, ICR, and C57BL/6), or with embryonic cytoplasm. After culture for 1 h, B6D2F1 sperm were injected into those oocytes by intracytoplasmic sperm injection (ICSI). The oocytes were examined for pre- and postimplantation developmental competence. Increases in the volume of the somatic cytoplasm from onefold to fourfold resulted in an impairment of blastocyst development and full-term development (28% and 7%, respectively, vs. 96% and 63%, respectively, in the control group; P < 0.01). An increase in the volume of somatic cytoplasm reduced the expression of POU5F1 (more commonly known as OCT4) in expanded blastocysts. The frequency of embryos that developed to the blastocyst stage did not differ when B6D2F1 or ICR somatic cytoplasm was injected, but injection of C57BL/6 somatic cytoplasm induced a two-cell block in embryo development. Injection of the cytoplasm from fertilized embryos did not reduce the frequency of embryos attaining full-term development. Interestingly, somatic cytoplasm significantly increased the placental weight of ICSI embryos, even the injection of onefold cytoplasm (0.20 +/- 0.02 [n = 32] vs. 0.12 +/- 0.02 in the control group [n = 87]; P < 0.01). These findings indicate that the injection of somatic cytoplasm into oocytes before ICSI causes a decrease in preimplantation development, clearly impairs full-term development, and causes placental overgrowth in fertilized embryos. To our knowledge, placental overgrowth phenotypes are only caused by interspecies hybridization and cloning, and in genetically modified mice. Here, we report for the first time that somatic cytoplasm causes abnormal placentas in fertilized embryos. This study suggests that somatic cell cytoplasmic material is one cause of the low rate of full-term development in cloned mammals.

Animals↗