Intracavitary liposome-mediated p53 gene transfer into glioblastoma with endogenous wild-type p53 in vivo results in tumor suppression and long-term survival

A cavitary glioblastoma model was created by injection of RT-2 cells, which express endogenous wild type p53, into the peritoneal cavity of nude mice. This model developed multiple layers of tumor cells invading the peritoneal surface and was used to mimic the postoperative surgical cavity remaining after glioblastoma (GBM) excision in patients. Rhodamine labeled DMRIE/DOPE + DNA complexes were found to penetrate at least 20 tumor cell layers. Injection of p53 gene/liposome complexes into the intraperitoneal cavity after the tumor was established resulted in massive tumor necrosis. Prominent staining of human p53 protein using the DO-1 antibody was found in tumor cells near the necrotic lesions. Tumor explants expressed human p53 protein and showed a 54% growth reduction in an in vitro growth assay. Further, DMRIE/DOPE mediated p53 gene transfection significantly increased the mean survival time of tumor bearing mice compared to vector control. These results demonstrate the efficiency of using exogenous wild type p53 to suppress glioblastoma cell with endogenous wild type p53 in vivo through liposome mediated transfection method.

Converting an alcohol to an amine in a cationic lipid dramatically alters the co-lipid requirement, cellular transfection activity and the ultrastructure of DNA-cytofectin complexes

Cytofectins are positively charged lipophilic molecules that readily form complexes with DNA and other anionic polynucleotides. Normally, cytofectins are combined with an activity-augmenting phospholipid such as dioleoylphosphatidylethanolamine (DOPE), and a film of dried, mixed lipid is prepared and hydrated to form cationic liposomes. The liposome solution is then mixed with a plasmid DNA solution to afford cytofectin-DNA complexes which, when presented to living cells, are internalized and the transgene is expressed. One of the most potent cytofectins, dimyristoyl Rosenthal inhibitor ether (DMRIE), is presently being used to deliver transcriptionally active DNA into human tumor tissues. Here we report the remarkable consequences of replacing the alcohol moiety of DMRIE with a primary amine. The resulting cytofectin, called beta-aminoethyl-DMRIE (betaAE-DMRIE), promoted high level transfection over a broad range of DNA and cationic lipid concentrations. A comparison of in vitro transfection activity between DMRIE and betaAE-DMRIE in 10 cell types revealed that betaAE-DMRIE was more active than DMRIE, and that betaAE-DMRIE, unlike DMRIE, was maximally effective in the absence of colipid. The consequences of the alcohol-to-amine conversion on the structure of the cytofectin/DNA complex was also examined by Atomic Force Microscopy. Strikingly dissimilar images were found for plasmid DNA alone and for the plasmid complexes of betaAE-DMRIE and DMRIE/DOPE.

Control of long-term perfusion Chinese hamster ovary cell culture by glucose auxostat

The strategies for control of the feed rate in high-density perfusion cultures of animal cells are limited to several simple schemes. While in an industrial environment simplicity is seen as a major advantage, the need for more elaborate closed-loop control methods that can improve process stability in long-term continuous cultures is also well understood. What has prevented the application of the advanced control strategies known from theory is the lack of reliable real-time information that can be used to close the feedback loop. Among the variables that are appropriate for direct feedback control of the perfusion rate, high priority should be given to the glucose concentration. Unlike some other environmental variables, such as dissolved oxygen and pH, it provides unambiguous information which facilitates the selection of the right feed rate. The present paper describes the application of a closed loop control scheme, known as a "glucose-stat", to the long-term cultivation of Chinese hamster ovary cells in a high-density (35-40 million cells/mL) perfusion process. The monitoring and control system worked successfully for more than 2.5 months without any signs of performance degradation. In targeting industrial application, issues such as reliability, sterility, and accuracy, are given high priority. The implementation of the glucose monitoring system, which is the main part of the control complex, is addressed in details. The performance of the perfusion culture was evaluated at four different glucose set points, providing essential information about process optimization. It became evident that the perfusion culture was operated in the so-called "high-gain" zone (where the system is highly sensitive to the dilution rate), which justifies the application of a feedback control. The on-line glucose concentration was also used by an embedded expert system which drove the process through the batch and the perfusion phase, achieving total computer control of the feed rate. In summary, the proposed glucose monitoring and control technique proved to be a reliable biotechnology tool which can be applied with confidence at an industrial scale to either microbial or mammalian cell cultures.

Penetration of cefprozil into middle ear fluid of patients with otitis media

Penetration of cefprozil into the middle ear fluid was investigated in patients with chronic otitis media. A total of 89 patients ranging from 7 months to 11 years old participated in the study. The middle ear fluid was removed by ventilation tubes inserted through the tympanic membrane at times ranging from 0.38 to 5.97 h after oral administration of a single dose of 15 or 20 mg/kg of body weight. A blood sample was also collected as soon as the middle ear fluid was removed. Plasma samples were analyzed for the concentration of cefprozil by a high-performance liquid chromatographic assay. Middle ear fluid samples were analyzed for the concentration of cefprozil by a microbiological assay. The concentrations of cefprozil in plasma ranged from 0.38 to 15.97 micrograms/ml at the 15-mg/kg dose level and from 1.28 to 21.47 micrograms/ml at the 20-mg/kg dose level. The corresponding middle ear fluid concentrations of cefprozil ranged from 0.06 to 4.44 micrograms/ml and from 0.17 to 8.67 micrograms/ml, respectively. Cefprozil penetrates well into middle ear fluid in patients with chronic otitis media.

Real-time biomass-concentration monitoring in animal-cell cultures

The accurate, on-line measurement of cell concentration in animal-cell cultures is an on-going problem in bioprocess engineering, and the development of new monitoring techniques is an area of intensive and fruitful research. This article summarizes the recent advances, trends and problems in this field and focuses, in particular, on optical sensors, including the latest laser and infrared probes. Alternative methods, such as multiple-extinction fluorimetry, real-time imaging and particle-size analysis, are also discussed. Although many of these techniques are still at an experimental stage, we believe that some of them have been developed sufficiently that we advocate their routine use in bioprocess monitoring and control.

Ibuprofen overdose complicated by renal failure, adult respiratory distress syndrome, and metabolic acidosis

Acute ingestion of ibuprofen commonly results in no symptoms, or minor gastrointestinal or central nervous system manifestations. While most cases of ibuprofen overdose do well, serious toxicity may occur, and is difficult to predict. A case of ibuprofen overdose is presented in which the course was complicated by metabolic acidosis, adult respiratory distress syndrome, and renal failure necessitating prolonged dialysis.

Analysis of the Chinese hamster P-glycoprotein/multidrug resistance gene pgp1 reveals that the AP-1 site is essential for full promoter activity

Recent studies have revealed that the expression of P-glycoprotein/multidrug resistance genes is crucial for the development of resistance to a number of lipophilic cancer chemotherapeutic agents. To better understand the regulatory mechanisms of pgp gene expression, we isolated and characterized a DNA fragment containing the 5' portion of a Chinese hamster pgp gene. DNA sequence analysis revealed that this gene is pgp1, the hamster homologue of murine mdr3/mdr1a. This gene is expressed at a higher level in intestines than in kidney and liver, consistent with the expression pattern for the murine mdr3/mdr1a gene. The major transcription start site, determined by the S1 nuclease protection, RNase protection, and primer extension methods, lies 67 nucleotides upstream of the murine and human downstream transcription start site. A chimera containing 101 base pairs upstream from this start site and the chloramphenicol acetyltransferase (CAT) gene was able to direct CAT expression in transient transfection experiments. The AP-1 site, located at -48 base pairs, was crucial for the full pgp1 promoter activity, as demonstrated by site-directed mutagenesis of this site, enhancement of the CAT expression by cotransfection with the expression vectors encoding c-Jun/c-Fos genes, but sequestration with those containing retinoic acid receptor genes. The sequestration effect could be partially abolished when c-Jun/c-Fos genes were also included in cotransfection. An AP-1 or AP-1-like site is also present at the same location in both human and mouse mdr homologues. The involvement of AP-1 in the expression of mammalian pgp1-class genes is discussed.

An examination of O-2-isocephems as orally absorbable antibiotics

The synthesis and structure-activity relationships of a series of orally absorbed O-2-isocephems are described. These compounds possessed a D-[(p-hydroxyphenyl)glycyl]amino substituent at the 7-position while the substituent at the 3-position was varied. Relative to the analogous cephems, the O-2-isocephems exhibited comparable to better activity against Gram-positive organisms. Against Gram-negative organisms, their activity was variable but did indicate a lower beta-lactamase stability. Following oral administration, the O-2-isocephems generally exhibited longer half-lives but lower Cmax's and urinary recoveries.

Genetic studies on murine susceptibility to herpes simplex keratitis

We studied the influence of lgh-linked genes on the development of keratopathy after corneal inoculation with herpes simplex virus (HSV). Using congenic strains of mice, we found that the lgh-1 gene locus, or genes closely linked to it, influence the clinical expression of HSV infection. Mice with the lgh-1e or lgh-1d allotype routinely developed severe keratopathy after HSV corneal inoculation, whereas congenic strains with lgh-1a or lgh-1b allotype were less susceptible. Cell-mediated immune responses to HSV also differed between susceptible and resistant murine strains. We interpret our results to imply a genetic influence on cell-mediated, acquired immune responses to HSV infection.

Voluntary and nonvoluntary childlessness: personality vs. structural implications

"A 'deviant behavior' interpretation of childlessness has led many researchers to view this phenomenon as psychosocial in nature. Married persons who decide to remain childless are seen as having a unique set of personality and behavioral characteristics that go beyond the simple decision not to have children. An alternative explanation for these differences could center around the structural factor of childlessness per se, in that a family with one or more children may be a totally different social system than the dyadic-type relationships which comprise the childless couple. This paper reports research findings from an empirical test of the extent to which a national sample of [U.S.] respondents who are members of voluntary or nonvoluntary childless couples differ in terms of 12 psychosocial characteristics selected either on the basis of past research findings, or predicted on the basis of these findings....Findings showed that the two groups of respondents did strongly differ, but in ways opposite to those predicted on the basis of past research. An argument is presented that these strong, but contrary findings might be better explained by structural, as opposed to psychosocial, factors."

Two-dimensional characterization of prostatic acid phosphatase, prostatic specific antigen and prostate binding protein in expressed prostatic fluid

Specimens of pooled prostatic fluid, collected by rectal massage from men under 50 years of age with no apparent prostatic disorders, were subjected to two-dimensional gel electrophoresis to study the composition of its proteins. In a preliminary study, a total of 57 major protein groups were detected. In the present study, we attempted to identify, in the two-dimensional gels, those that are related to prostate-associated proteins, i.e., prostatic acid phosphatase (PAP), prostatic specific antigen (PSA), and prostate binding protein (PBP). Individual proteins were recognized by the procedure of Western Blot using specific antisera with peroxidase-antiperoxidase as the staining reagent. Each protein spot in the two-dimensional gel was expressed, along the abscissa, by its isoelectric point (pI) and, along the ordinate, by the molecular weight (MW). PAP consisted of a train of more than ten protein spots that occupied an area in the gel from pI 7.0, MW 45,000 to pI 6.0, MW 50,000. Four protein spots with a MW of 34,000 and a pI range of 8.2-8.8 were identified as PSA. PBP was observed as having three protein spots that were located at pI 5.6-6.6 with a single MW of 15,000. For PAP and PSA, additional protein spots with lower MWs also stained positively with the specific antisera, suggestive of the presence of degradative products of these proteins. Following the removal of the serum-related proteins by an extensive absorption with anti-human serum antibody by affinity chromatography, the prostatic fluid contained 27 major groups of non-serum proteins. These non-serum proteins in the prostatic fluid included PAP, PSA, PBP, and their related smaller molecular species. These results indicate that the prostatic fluid contains PAP, PSA, PBP and that their presence and the patterns of their distribution in the two-dimensional gels should be considered as the characteristic property of the prostatic secretions.

Proteins of the rat prostate: I. Preliminary characterization by two-dimensional electrophoresis

The rat prostate consists of three distinct lobes: the ventral, lateral, and dorsal. Proteins in the three lobes of the prostate were studied with the ISO-DALT system for high-resolution two-dimensional electrophoresis. Proteins were detected with ammoniacal silver stain. Comparison of patterns from the three lobes of the prostate of control, noncastrated rats revealed that while there was a remarkable overall similarity, six groups of proteins showed lobe-specific differences. When prostatic regression was induced by castration, androgen-dependent proteins showed a decrease in staining intensity. A group of proteins, with pI 5.0-6.0 and MW 65,000-70,000, was consistently observed only during the active phase of prostatic regression (days 3-7 postcastration). Their presence during this specific interval may play a role in tissue involution.

[Nutritional support in surgery: with special reference to fat emulsion and carnitine]

Energy metabolism of fat emulsion has been studied in rats with various conditions including postoperative catabolism, chronic and acute hepatic dysfunction, diabetes and sepsis. The results indicate that fat emulsion is rapidly eliminated from the blood stream and metabolized readily even in such conditions. Based on these findings, we have actively employed fat emulsion clinically as energy source. In septic rats, it was demonstrated that levels of carnitine decreased and that this decrease was based upon a decrease of synthesis. When carnitine was administrated together with fat emulsion, the energy metabolism returned to approximately normal level. This report also describes the tissue concentrations of carnitine in diabetic rats and the blood and urine concentrations of carnitine in postoperative patients.

Anion exchange and volume regulation during metabolic blockade of renal cortical slices

1. The development of swelling of rat and guinea-pig renal cortical slices was studied after metabolic blockade (hypoxia plus glycolytic blockade with iodo-acetic acid) and/or exposure to 'isotonic' high potassium, no sodium solution. 2. Swelling was greater after exposure to oxygenated high potassium solution than after metabolic blockade in physiologic Krebs-Henseleit solution. Swelling was reduced after metabolic blockade in high potassium solution compared to incubation in oxygenated high potassium solution. Increasing periods of transient metabolic blockade in Krebs-Henseleit solution progressively blunted swelling when slices were subsequently incubated in oxygenated high potassium solution. 3. Metabolic blockade in Krebs-Henseleit solution resulted in marked reductions in potassium and increases in sodium. Incubation in high potassium solution resulted in marked increases in potassium and similar low levels of sodium regardless of associated interventions. Metabolic blockade in both media resulted in significantly greater increases in renal cortical chloride than in monovalent cations (potassium plus sodium). Incubation in oxygenated high potassium solution was associated with similar increases in renal cortical chloride and total monovalent cations. 4. Renal cortical losses of solids and protein and increases in renal cortical inulin space were greater after metabolic blockade than after incubation under oxygenated conditions regardless of the incubation media. 5. These data support the conclusion that during metabolic blockade there is a significant replacement of larger intracellular anions by extracellular chloride. The loss of osmotically active intracellular anions limits the increase in renal cortical volume during metabolic inhibition and exposure to high potassium solution.