Milk carnitine affects organ carnitine concentration in newborn rats

Previous studies suggest that exogenous milk carnitine may be necessary during the suckling period to maintain normal fat metabolism. To characterize the relationship between milk carnitine and carnitine in body organs, newborn rats were fed from birth a rat milk substitute with or without 300 micromol/L L-carnitine, corresponding to the concentration present in rat milk, for either 2 or 4 d. Carnitine concentrations in heart, skeletal muscle, liver and small intestine were compared with levels in rat pups that were never fed (d 0) and those that were nursed by their mothers for 4 d. Carnitine supplementation resulted in significantly higher concentrations of carnitine in all organs studied after 4 d compared with nursed controls. Relative intestinal carnitine pool size was 38.1 +/- 3.0, 22.6 +/- 1.0, 7.9 +/- 0.5 and 2.3 +/- 0.7 micromol/g body wt in supplemented, nursed, unsupplemented and never fed pups, respectively (P < 0.05, compared with one another). These results indicate that carnitine organ concentrations are related to dietary intake during the early suckling period and that the small intestine is a considerable and previously unrecognized proportion of the carnitine pool of suckling animals.

Treatment of a human breast cancer xenograft with an adenovirus vector containing an interferon gene results in rapid regression due to viral oncolysis and gene therapy

Treatment of a human breast cancer cell line (MDA-MB-435) in nude mice with a recombinant adenovirus containing the human interferon (IFN) consensus gene, IFN-con1 (ad5/IFN), resulted in tumor regression in 100% of the animals. Tumor regression occurred when virus was injected either within 24 hr of tumor cell implantation or with established tumors. However, regression of the tumor was also observed in controls in which either the wild-type virus or a recombinant virus containing the luciferase gene was used, although tumor growth was not completely suppressed. Tumor regression was accompanied by a decrease in p53 expression. Two other tumors, the human myelogenous leukemic cell line K562 and the hamster melanoma tumor RPMI 1846, also responded to treatment but only with ad5/IFN. In the case of K562 tumors, there was complete regression of the tumor, and tumors derived from RPMI 1846 showed partial regression. We propose that the complete regression of the breast cancer with the recombinant virus ad5/IFN was the result of two events: viral oncolysis in which tumor cells are being selectively lysed by the replication-competent virus and the enhanced effect of expression of the IFN-con1 gene. K562 and RPMI 1846 tumors regressed only as a result of IFN gene therapy. This was confirmed by in vitro analysis. Our results indicate that a combination of viral oncolysis with a virus of low pathogenicity, itself resistant to the effects of IFN and IFN gene therapy, might be a fruitful approach to the treatment of a variety of different tumors, in particular breast cancers.

Expression of estrogen receptor variants in normal and neoplastic human uterus

Estrogen receptor variants lacking internal exons and representing dominant positive and negative activity may be involved in the initiation and/or progression of endocrine dependent tumors. To assess the role of estrogen receptor in uterine disease, we have analyzed both normal and neoplastic uterine samples for the presence of variant estrogen receptors using the sensitive technique of RT-PCR and direct automated DNA sequencing of the amplified products. Our analysis was conducted to determine the presence of spliced variants lacking exons 3 through exon 8. We demonstrate that both the normal and neoplastic human uterus contains a number of spliced variants of the estrogen receptor that co-exist with the wild type receptor. Variants lacking exons 4, 5 and 7 but not exons 3 and 6 were detected. Also, a novel partial deletion in exon 8 was detected in both the normal and neoplastic tissues, although a total deletion of this exon was not observed. In addition another region of exon 8 deletion was found to be present in one tumor tissue which also contained an insertion within this region, however, other tumors did not contain this variant. In addition, double exon deletion variants were observed lacking exons 3 and 4, exons 4 and 5, and exon 7 with part of exon 8. Although our data represents a limited number of samples it suggests that splicing of the estrogen receptor message occurs in the normal physiological setting. There does not appear to be any association between the presence or absence of spliced variants of estrogen receptor and uterine tumor formation at the mRNA level.

Gene therapy with an adeno-associated virus carrying an interferon gene results in tumor growth suppression and regression

Adeno-associated virus (AAV) vectors were constructed containing both a synthetic type I interferon gene, (IFN-con1) and the bacterial neomycin-resistant gene. Recombinant virions were used to infect a number of human tumor cell lines, including 293, Hela, K562, and Eskol (a hairy cell leukemia-like cell), and geneticin-resistant cells were selected. All IFN-con1-transduced cell lines produced low levels of IFN-con1 and grew at the same rate as nontransduced cell lines. Although these cell lines were resistant to IFN in vitro, when injected into nude mice, 293, K562, and Eskol cells failed to form tumors up to 3 months after the initial inoculum, although mice receiving nontransduced cells developed tumors within 7 to 10 days. Transduced Hela cells grew much slower in vivo and formed much smaller tumors than did the parental cells. When equal numbers of transduced and nontransduced cells were injected into nude mice, tumors initially developed slowly and then completely regressed. Treatment of an established Eskol tumor (histologically a malignant immunoblastic lymphoma) with AAV/IFN-con1-transduced 293 cells resulted in tumor regression, whereas treatment of Eskol tumors with IFN-con1 resulted in a small decrease in tumor size. These results indicate that the human IFN-con1 gene in a viral vector can be used successfully in the treatment of tumors both directly and by tumor-targeted gene therapy.

[Reconstruction of TMJ condyle cartilage defects with autogenous free periosteal grafts]

How to reconstruct the damaged articular cartilage has been one of the main subjects in treatment of articular disease for a long time. In this experimental study, fullthickness cartilage defects of 4 mm x 5 mm in size were created in rabbit's TMJ condyle cartiage on the left sides. The autogenous free periosteum were transplanted to the defects by using biological gelatin. Postoperatively, the animals were killed at intervals of 1, 2, 4, 8, 12 and 16 weeks. The regenerative cartilage in the defects were examined by gross appearance and histology. The result showed that mesenchymal cells in the cambium layer of periostum can transform into chondroblasts under the mechanical stress.

Amifostine improves the antileukemic therapeutic index of mafosfamide: implications for bone marrow purging

One of the principal challenges of cancer chemotherapy is the relative inability of most anticancer drugs to distinguish between normal and neoplastic tissues. Consequently, a broad range of toxicities are experienced by patients, especially myelosuppression. Amifostine, a phosphorylated aminothiol, increases the selectivity of specific anticancer drugs for neoplastic cells by protecting normal tissues. One potential application of this protector is during bone marrow purging to selectively remove contaminating cancer cells. This study took normal or leukemic marrow from human subjects and evaluated the ability of amifostine to selectively protect normal bone marrow progenitor cells versus leukemic progenitor cells from the cytotoxic effect of mafosfamide. The dose response of mafosfamide amifostine on leukemia colony-forming units or normal marrow progenitor cells was determined and the LD95 was calculated. Amifostine pretreatment resulted in a statistically significant protection of granulocyte-macrophage colony-forming units and erythroid blast-forming units from the toxicity of mafosfamide (P = .031). Thus, amifostine protection of normal marrow progenitor cells allows a higher LD95 concentration of mafosfamide to be used in ex vivo purging. In contrast, amifostine pretreatment increased the cytotoxicity of mafosfamide on the fresh human leukemia progenitor cells (P = .006). The dual effect of amifostine protection of normal marrow progenitor cells coupled with amifostine-induced sensitization of the leukemia cells increases the possible cell-kill of leukemic stem cells. With amifostine pretreatment, at the LD95 concentrations of mafosfamide for marrow progenitor cells, there was an estimated 6 log increase in cell-kill of the leukemia cells. This selective cell-kill offers the potential for lowering the incidence of leukemic relapse, while preserving more normal stem cells for autologous transplantation.

[An experimental study on the effect of operation at one side of the temporomandibular joint on the opposite side]

Condylectomy and menisectomy were performed in left TMJ of 14 rabbits, of them, 7 were treated with periosteal interposition and 7 without. Sixteen weeks after operation, condylar cartilage of the right side were studied and compared with 7 normal rabbits by means of histology and histochemistry. The results show that an operation of high condylectomy and menisectomy with or without interposition on one side of TMJ will result in degenerative changes in the other side (non-operated side). The degenerative changes in the rabbits without any interposition are more serious than those with periosteal interposition.

Amifostine (WR-2721) protects normal haematopoietic stem cells against cyclophosphamide derivatives' toxicity without compromising their antileukaemic effects

We compared the effects of amifostine (WR-2721) on the cytotoxicity of mafosfamide or 4-hydroperoxycyclophosphamide (4-HC) in normal marrow progenitor cells (CFU-GM) and leukaemic progenitor cells (CFU-L) during ex vivo purging for autologous bone marrow transplantation (ABMT). Mononuclear cells (MNC) were incubated with amifostine 3 mg/ml for 15 min, washed, and subsequently tested for their sensitivity to mafosfamide or 4-HC (20-200 micrograms/ 10(7) MNC/ml). The LD95 was significantly higher among amifostine-treated cells for PCM-CFU-GM in 6 of 13 patients and for 5R-CFU-GM in 4 of 10 patients (P < 0.05). In contrast, amifostine exhibited no protective effects upon CFU-L. The results of this study will show that amifostine protects normal late and early progenitor cells for the toxic effects of cyclophosphamide derivatives while preserving their antileukaemic effects. These results suggest that amifostine has therapeutic value as a protective agent for normal marrow progenitor cells during ex-vivo purging of bone marrow for ABMT.

Inflammatory intermediates produced by tissues encasing silicone breast prostheses

Silicone prostheses, when implanted within the soft tissues of the breast, evoke an inflammatory reaction. In response to silicone exposure, inflammatory mediator production by individual cells has been observed in various experimental studies. In this study, inflammatory mediator production by periprosthetic tissues (whole organ) was measured. The mediator levels were correlated with both the tissue histopathology of the periprosthetic capsules and the clinical symptoms noted by each patient. Tissue surrounding breast implants removed at surgery from ten women (average age and implant duration 40 and 7 years respectively) was cultured in vitro for 24 hours. Control tissues consisting of (a) augmentation mammaplasty skin scars from eight additional patients and (b) knee synovium from seven orthopedic surgery patients with arthritis undergoing primary joint arthroplasty were similarly cultured. The mediators [interleukin-2 (IL-2), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and prostaglandin E2 (PGE2)] liberated into the culture media were measured by an enzyme linked immunosorbent assay. When compared to controls, the mediator levels of IL-6 and TNF-alpha were substantially greater, although IL-2 and PGE2 were lower. Levels varied greatly from patient to patient: in pg/ml per 10 g tissue, IL-2 ranged from 10 to over 1,000; TNF-alpha from 100 to 1,000; IL-6 from 100 to 1,000,000; and PGE2 from 100 to 10,000. The correlation between TNF-alpha and PGE2 levels was .5 between IL-6 and PGE2 was .6, and between IL-6 and TNF-alpha was .77. The correlation between TNF-alpha and IL-6 was statistically significant at a p-value less than .01. Elevated levels of TNF-alpha production were associated with an increased number of macrophages and overall tissue cellularity (p < .05). No significant relationship was observed between mediator production and clinical symptoms. We conclude that overall cellularity, specifically macrophages, in the periprosthetic capsule may lead to TNF-alpha production but that cytokine production by periprosthetic tissues alone is not a predictor of clinical symptomatology in patients with silicone breast prostheses.

Comparison of some control strategies for three-compartment PK/PD models

In drug therapy, effective dosage strategies are needed to maintain target drug effects. The relationship between drug dose and drug effect is often described by pharmacokinetic/pharmacodynamic (PK/PD) models where typically the PK model has a multicompartment form and the PD model is the sigmoidal Emax model. The parameters in the PK/PD model are generally unknown in the individual patient, although prior knowledge may be available and can be updated after measurements of drug effect are taken during the therapy. This fact, together with the complexity of the PK/PD model, makes the control problem complex. This paper investigates several control strategies in the framework of a three-compartment PK model plus an effect site with a PD model. Using computer simulations under different assumptions, we show that a MAP (maximum a posteriori) Bayesian type of strategy is effective, nevertheless in high-risk situations a stochastic control strategy hedging against estimation errors provides better performance at computational cost.

Comparative effects of amifostine (Ethyol) on normal hematopoietic stem cells versus human leukemic cells during ex vivo purging in autologous bone marrow transplants

The protective action of amifostine (Ethyol, US Bioscience, Inc. West Conshohocken, PA) against the toxic effects of cyclophosphamide derivatives on the normal progenitor/stem cell pool was investigated. Early and late normal progenitor/stem cells were studied in the presence of placenta-conditioned medium (placenta-conditioned medium-granulocyte-macrophage colony-forming units); in the presence of granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, interleukin-3, erythropoietin, stem cell factor (5R-CFU-GM); stimulated granulocyte-macrophage colony-forming and in a long-term culture-initiating cell assay. The preservation of an antileukemic effect was investigated by growing leukemic progenitor cells in the presence of phytohemagglutinin and leukocyte feeder layer with or without 25u interleukin-2. In 10 of 13 cases, a statistically significant (P < .05) protective effect was found on PCM-granulocyte-macrophage colony-forming units, in four of 10 cases on factor-stimulated granulocyte-macrophage colony-forming units, and in two of six cases on long-term culture-initiating cell. In contrast, amifostine exhibited no protective effect (none of nine cases) on leukemic progenitor cells. From the experimental data, it seems that amifostine is able to protect human normal progenitor/stem cells from cyclophosphamide derivative toxicity, while preserving their antileukemic effects. The therapeutic usefulness of such protection in autologous bone marrow transplantation with purged marrow is obvious.

Phosphorylation of PHAS-I by mitogen-activated protein (MAP) kinase. Identification of a site phosphorylated by MAP kinase in vitro and in response to insulin in rat adipocytes

PHAS-I is a heat- and acid-stable protein that is phosphorylated on Ser/Thr residues in response to insulin and growth factors. To investigate the phosphorylation of PHAS-I, the protein was expressed in bacteria and purified for use as substrate in protein kinase reactions in vitro. Recombinant PHAS-I was rapidly and stoichiometrically phosphorylated by mitogen-activated protein (MAP) kinase. At saturating MgATP, the Km and Vmax observed with PHAS-I were almost identical to those obtained with myelin basic protein, one of the best MAP kinase substrates. PHAS-I was also phosphorylated at a significant rate by casein kinase II and protein kinase C. To investigate sites of phosphorylation, PHAS-I was digested with collagenase and phosphopeptides were resolved by reverse phase high performance liquid chromatography. Almost all of the phosphate introduced by MAP kinase was recovered in the peptide, Leu-Met-Glu-Cys-Arg-Asn-Ser-Pro-Val-Ala-Lys-Thr. 32P was released in the seventh cycle of Edman degradation, identifying the Ser (Ser64) as the phosphorylated residue. Ser64 was also phosphorylated in response to insulin in rat adipocytes. We conclude that PHAS-I is a substrate for MAP kinase both in vivo and in vitro. As PHAS-I is one of the most prominent insulin-stimulated phosphoproteins in adipocytes, it may qualify as the major MAP kinase substrate in these cells.

Improved accuracy in direct automated DNA sequencing of small PCR products by optimizing the template concentration

Data are presented illustrating the optimum concentration range of reverse transcription PCR-generated products under 500 bp for accurate base calling with direct automated DNA sequencing. A 357-bp fragment of the human estrogen receptor, which includes the DNA binding domain of the protein, was used as a representative example of a gene fragment that can be rapidly amplified and sequenced. Using the Taq DNA polymerase dye terminator sequencing protocol and automated sequencing apparatus from Applied BioSystems, 0.1 to 1.0 pmol of PCR product in a 20-microL reaction volume provided > 97% accurate base detection. Concentrations greater or lower than this range increased the number of ambiguous bases due to alterations in the signal-to-noise ratios. This procedure has been successfully utilized with 140-440-bp PCR products within the optimum concentration range. These results show that low amounts of PCR products are necessary and sufficient for direct sequence analysis.

[Stereoscopic visual evoked potential elicited by static random dot stereogram]

Using 16.56' visual disparity stimulation produced by television random dot stereogram (TVRDS), we recorded visual evoked potentials (VEPs) elicited from 35 normal subjects with and without breaking their stereopsis and 28 stereoblind subjects. The results showed that a constant negative-positive wave complex was observed in 33 of 35 normal subjects; this negative-positive wave-complex disappeared when the stereopsis was artificially inhibited by a prism and in the stereoblind group, and no VEP wave was elicited in all of the stereoblind patients except in one with paralytic strabismus. The results revealed that under this condition the VEPs elicited by TVRDS were specific VEPs related to visual disparity stimulation and were stereoscopic ones. The TVRDS is an effective electro-physiological means to examine the stereopsis objectively and a new way to approach the occurrence and development of stereopsis.

Molecular cloning and tissue distribution of PHAS-I, an intracellular target for insulin and growth factors

Although the actions of insulin and a number of growth factors that signal via protein-tyrosine kinase receptors are believed to involve increased phosphorylation of key intracellular proteins, relatively few of the downstream phosphoproteins have been identified. In this report we describe a cDNA encoding one of the most prominent insulin-stimulated phosphoproteins in rat adipocytes. The cDNA encodes a protein, designated PHAS-I, which has 117 amino acids and a M(r) of 12,400. When translated in vitro and subjected to SDS/PAGE, PHAS-I migrates anomalously, having an apparent M(r) of 21,000. The predicted amino acid composition is interesting in that approximately 45% of the PHAS-I protein is accounted for by only four amino acids--serine, threonine, proline, and glycine. The PHAS-I gene is expressed in a variety of tissues, although the highest levels of mRNA are present in fat and skeletal muscle, two of the most insulin-responsive tissues. The nucleotide and deduced amino acid sequences of PHAS-I differ from any that have been reported, and homology screening provided no clues concerning the function of the protein. However, in view of its tissue distribution and the fact that the protein is phosphorylated in response to insulin, we speculate that PHAS-I is important in insulin action.

The chromatographic behaviour of cephalosporins in gel filtration chromatography, a novel method to separate high molecular weight impurities

The interaction between cephalosporins and the dextran matrix of Sephadex gel in gel filtration chromatography has been thoroughly studied. Twelve cephalosporins with specific structures were examined under different chromatographic conditions, including 12 different mobile phases comprising inorganic or organic compounds of different charge or/and density of electrons on their negative ions, different types of Sephadex gel (Sephadex G-10 and Sephadex G-50) and different flow rates. It was found that the more negative the charge or/and density of electrons on the negative ions of buffer components, the more was the adsorption of cephalosporins on the solid phase; this indicated tht the mobile phase played an important rôle in gel filtration chromatography for cephalosporins. By choice of suitable chromatographic conditions, optimum separation of high molecular weight impurities from cephalosporins could be achieved. The novel method could be used as a routine method for the quality control of cephalosporin preparations.