[Acute vena cava thrombosis after insertion of Greenfield filter. A forgotten classic complication].
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Acute Kidney Injury↗
Biomedical subjects
H Lambert
Publications and source records attributed to H Lambert.
Increased survival after treatments with anticancer agents of Chinese hamster cells expressing the human Mr 27,000 heat shock protein.
A family of 10 thermoresistant cell lines cloned from Chinese hamster cells transfected with a plasmid containing the structural gene for the small human Mr 27,000 heat shock protein (HSP27) was used to assess the putative role of this heat shock protein in chemoresistance. These cells express varying amounts of human HSP27 in addition to the normal level of endogenous hamster HSP27. As previously observed in the case of thermoresistance, a significant positive linear correlation (P less than 0.05) was found between cell survival in response to doxorubicin and the total amount of HSP27 expressed. Some clones were also examined for resistance to other drugs and chemicals. A statistically significant increased survival relative to the parental cells was observed following treatment with daunorubicin (three clones studied), colchicine, vincristine, actinomycin D, hydrogen peroxide, and sodium arsenite (one clone studied). However, the clone which expressed the highest level of HSP27 was as sensitive as control cells to the cytotoxic action of bis-chloronitrosourea and 5-fluorouracil. The relationship between HSP27 overexpression and increased resistance to cytotoxic agents was also evaluated in three independent pooled cell populations stably transformed with both the human HSP27 and the xanthine-guanine phosphoribosyltransferase gene and selected on the basis of resistance to mycophenolic acid and aminopterin. The results indicated that these cells survived significantly better than the control cells transfected with the marker gene only when exposed to doxorubicin. HSP27-mediated cellular protection was not associated either with decreased drug accumulation or with overexpression of P-glycoprotein. It is suggested that HSP27 might be involved in some form of chemoresistance and could participate in the development of clinical resistance to antineoplastic drugs.
Animals↗
Phosphorylation of HSP27 during development and decay of thermotolerance in Chinese hamster cells.
The small molecular weight heat shock protein HSP27 was recently shown to confer a stable thermoresistant phenotype when expressed constitutively in mammalian cells after structural gene transfection. These results suggested that HSP27 may also play an important role in the development of thermotolerance, the transient ability to survive otherwise lethal heat exposure after a mild heat shock. In Chinese hamster O23 cells increased thermoresistance is first detected at 2 h after a triggering treatment of 20 min at 44 degrees C, attains a maximum at 5 hours, and decays thereafter with a half-life of 10 h. We found that the development and decay of transient thermotolerance cannot be solely explained on the basis of changes in the cellular concentration of HSP27. The cellular HSP27 concentration is not increased appreciably at 2 h after heat shock and attains a maximum at 14 h. Similar results were obtained in the case of another heat shock protein, HSP70. HSP70 follows slightly faster kinetics of accumulation (peaks at 10 h) and decays much more rapidly (ti/2 = 4h) than HSP27 (t1/2 = 13h). HSP27 has 3 isoelectric variants A, B, and C of which B and C are phosphorylated. In cells maintained at normal temperature, HSP27A represents more than 90% of all HSP27. Shifting the cell culture temperature from 37 to 44 degrees C induces the incorporation of 32P into the more acidic B and C forms, a process that occurs very rapidly since the reduction in the concentration of the A form and a corresponding increase in the level of B and C is detectable by immunoblot analysis within 2.5 min at 44 degrees C. Analyses performed at various times during development and decay of transient thermotolerance revealed a close relationship between the effect of heat shock on HSP27 phosphorylation and cell ability to survive. For example, fully thermotolerant cells (5 h post-induction) are refractory to induction of HSP27 phosphorylation by a 20-min heat shock. The induction of HSP27 phosphorylation was also studied in a family of clonal cell lines of O23 cells that are thermoresistant as a result of the constitutive expression of a transfected human HSP27 gene. In these thermoresistant cells, phosphorylation of the endogenous hamster HSP27 is induced to a level comparable to that found in the thermosensitive parental cells. However, phosphorylation of the exogenous human protein, which represents more than 80% of total HSP27 in these cells, was much less induced.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Improved electronic gate technique, for particle counting and sizing in liquids.
Particle counting and measurements of particle size distributions in liquids can be based on pulse height analysis of signals obtained from a changing gate impedance, upon particle transition. Signal-to-noise ratio is markedly improved, making use of a four-electrode detector. An instrumentation amplifier with a high-pass filter is used as a preamplifier. Cylindrical electrodes and a coaxial aperture location result in a decreased detector capacitance, lowering the signal detection level and contributing to improved pulse shape. Volume sampling is flexible and accurate, making use of a stepping motor actuated digital sampling system. A newly developed baseline restorer, combined with a log-antilog amplifier circuit, allows for linearisation of the pulse height/particle size relationship.
Electronics↗
Reduction of primary posttraumatic adhesion formation with the prostacyclin analog iloprost in a rodent model.
Recent evidence suggests that inhibition of postsurgical adhesion formation may be effected by modulation of the activities of inflammatory cells contributing to mesothelial repair. Iloprost, a stable analog of prostacyclin, has been shown to exert vasodilatory, antiinflammatory, fibrinolytic, and antithrombotic influences. To determine whether these properties of iloprost might protect mesothelial surfaces from perioperative damage and hence prevent adhesion formation, we evaluated the effect of iloprost on peritoneal healing in a hamster model for primary pelvic injury. Perioperative iloprost therapy significantly reduced posttraumatic adhesion formation when compared with that in vehicle-treated controls. Dose-response studies demonstrate adhesion prevention with doses ranging from 0.04 to 4 mg/kg per 8 hours given subcutaneously over the course of 3 days. These data demonstrate that iloprost is a potent positive modulator of peritoneal healing after pelvic trauma. Further studies to characterize the potential application of iloprost as an adjuvant in reproductive surgery are indicated.
Animals↗
Synergistic effect of intraperitoneally administered calcium channel blockade and recombinant tissue plasminogen activator to prevent adhesion formation in an animal model.
Previous reports have shown the benefits of calcium channel blockers and recombinant tissue plasminogen activator to prevent postoperative adhesion formation in animal models. To assess the potential benefit of synergistic therapy for the prevention of postoperative adhesion formation, these agents were studied in a rabbit uterine horn model. Four groups of New Zealand White rabbits (n = 8 per group) had a bilateral devascularization injury to the uterine horns. Before closure saline solution, verapamil hydrochloride (2.5 mu/kg/hour), recombinant tissue plasminogen activator (4 mg total dose), or a combination of verapamil and recombinant tissue plasminogen activator at the stated doses were instilled by means of an Alzet osmotic pump x 200 hours. Adhesion scores were evaluated after this time period by estimating the total uterine horn surface involved in adhesions at a terminal laparotomy and by clinically grading the response to determine whether minimal adhesions formed. Results of the total uterine horn surface scores were (mean score +/- SE): saline solution, 44% +/- 3.7%; verapamil, 19% +/- 4.8%; recombinant tissue plasminogen activator, 11% +/- 3.6%; combined, 3% +/- 1% (p less than 0.01 to control and p less than 0.05 to single-drug therapy). Results of the number of animals per group with minimal adhesions were as follows: saline solution, 0; verapamil, 1; recombinant tissue plasminogen activator, 3; combined, 8 (P less than 0.01). These results show a synergistic benefit of verapamil and recombinant tissue plasminogen activator to prevent postsurgical adhesion formation when delivered via the intraperitoneal route.
Analysis of Variance↗
Mechanism of analgesia induced by hypnosis and acupuncture: is there a difference?
Hypnosis and acupuncture can alleviate experimentally induced pain but the mechanism of analgesia remains unclear for both techniques. Experimental pain was induced by cold pressor test (CPT) in 8 male volunteers. Analgesic effect of hypnosis (HA) and acupuncture (AA) was assessed before and after double-blind administration of placebo or naloxone, in a prospective, cross-over study. We found that pain intensity was significantly lower with HA as compared with AA, both with naloxone (P less than 0.001) and placebo (P less than 0.001). Within HA or AA groups, pain scores did not differ significantly when naloxone or placebo was administered. During AA, however, pain scores were similar to control values when naloxone was given (P = 0.05) but decreased significantly with placebo (P less than 0.002). Analog scales for pain intensity and pain relief showed a good correlation (r = 0.94). Plasma levels of beta-endorphins did not change significantly in any combination. Heart rate, peripheral arterial blood pressure and skin conductance were very insensitive indices to assess pain intensity or relief, as well as intensity of acupuncture stimulation or depth of hypnotic trance. We conclude: (1) HA and AA can significantly reduce pain from CPT, and HA is more effective than AA: (2) HA and AA are not primarily mediated by the opiate endorphin system; and (3) plasmatic levels of beta-endorphins are not significantly affected by either HA or AA nor by naloxone or placebo administration.
Acupuncture Analgesia↗
Penetration of zona-free hamster oocytes by ejaculated cryopreserved gorilla spermatozoa.
Semen obtained by electroejaculation from two lowland gorillas were cryopreserved in TEST yolk to evaluate the ability of spermatozoa to penetrate zona-free hamster oocytes. Thawed semen was processed through a two-layer Percoll density gradient to obtain motile spermatozoa for the SPA. The processed sperm penetrated greater than 25% of the zona-free hamster oocytes. Thus, the use of TEST yolk to cryopreserve gorilla semen and processing the thawed semen through Percoll gradient to concentrate motile spermatozoa may facilitate sperm capacitation and the ability to penetrate oocytes.
Animals↗
Problems with the single injection method for the measurement of the glomerular filtration rate in man.
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Glomerular Filtration Rate↗
Effects of Bordetella pertussis infection on human respiratory epithelium in vivo and in vitro.
Bordetella pertussis infection probably involves attachment to and destruction of ciliated epithelial cells, but most previous studies have used animal tissue. During an epidemic, nasal epithelial biopsy specimens of 15 children (aged 1 month to 3 1/2 years) with whooping cough were examined for ciliary beat frequency, percent ciliation of the epithelium, and ciliary and epithelial cell ultrastructure. In addition, the in vitro effects of filtrates from a 24-h broth culture and of tracheal cytotoxin derived from B. pertussis on human nasal tissue organ culture were measured. B. pertussis was cultured from nasal swabs from 12 children. The mean ciliary beat frequency of their nasal biopsy specimens, 11.3 Hz (range, 10.4 to 13.0 Hz) was similar to that found in biopsy specimens from 10 normal children (mean, 12.5 Hz; range, 11.8 to 13.5 Hz). The abnormalities of the epithelium observed in 14 of 15 patients were a reduction in the number of ciliated cells, an increase in the number of cells with sparse ciliation, an increase in the number of dead cells, and extrusion of cells from the epithelial surface. In vitro, neither culture filtrate nor tracheal cytotoxin had any acute effect on ciliary function, but culture filtrate and tracheal cytotoxin (1 and 5 microM, respectively) caused extrusion of cells from the epithelial surface of turbinate tissue, loss of ciliated cells, an increased frequency of sparsely ciliated cells, and toxic changes in some cells. These changes were dose dependent and progressive, and between 36 and 90 h ciliary beating ceased. The observations made with patient tissue confirm that B. pertussis infection damages ciliated epithelium, and the in vitro experiments suggest that tracheal cytotoxin may be responsible for the abnormalities observed in vivo.
Bacterial Adhesion↗
Full recovery after a chloroquine suicide attempt.
The nonfatal case of a 20 year-old woman who ingested 6 grams of chloroquine in a suicide attempt is reported. After initial ventricular fibrillation, she rapidly developed a pulmonary edema with cardiogenic shock. She was successfully treated with diazepam, epinephrine, dobutamine and mechanical ventilation. Plasma chloroquine levels showed an initial peak of 36 micrograms/mL. The patient was discharged fully recovered after 19 days. The interaction between chloroquine and diazepam is discussed, as is the need for careful management of epinephrine therapy.
Adult↗
Evaluation of the effect of the removal of the family income supplement (FIS) free school meal on the food intake of secondary schoolchildren.
Four secondary schools in Southampton were chosen to study the effect of the changes in Social Security regulations in April 1988 on the food intake of schoolchildren. A self-completed questionnaire asking about food intake throughout the previous school day was given to each child by the form teacher on two occasions; one in March 1988 and again after the benefit changes in May 1988. All children who were entitled to a Family Income Supplement (FIS) free school meal in March were included in the study. This group (n = 50) was compared with an age- and sex-matched group of children entitled to a Supplementary Benefit (SB) free school meal (n = 49) and a control group (n = 100) of children. Before the benefit changes there were a few differences between the groups, mainly in the control group, who had different foods at lunchtime. After the benefit changes only 10 per cent of the FIS group had a school lunch compared with 66 per cent before. The major changes were at the lunchtime meal, with fewer in the FIS group eating burgers, pies, chips and ice-cream, and more eating crisps, sandwiches and fruit than had done so before the benefit changes.
Adolescent↗
Occurrence of serum antisperm antibodies in patients with cystic fibrosis.
OBJECTIVE: To determine if acquired obstruction of the vas deferens in men with cystic fibrosis (CF) induced the development of antisperm antibodies with genital tract obstruction similar to other men. DESIGN: Serum antisperm antibodies were assayed by an indirect immunobead test and an indirect immunofluorescence assay. Both homologous (human sperm/human zona) and heterologous (human sperm/zona-free hamster ova) sperm/egg interactions were evaluated in the presence of serum antisperm antibodies from patients with CF. SETTING: Cystic Fibrosis Clinic at the University of Oklahoma Health Sciences Center, a tertiary care referral center. PATIENTS: Fifteen CF patients (10 male and 5 female), 3 non-CF antisperm antibody-positive infertile patients (2 male and 1 female), 20 fertile controls (7 males and 13 females), and 9 fertile sperm donors were used. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Serum antisperm antibody levels in patients with CF. In those patients with antisperm antibodies, determine effect of these sperm antibodies on sperm/egg interactions and complement-mediated events. RESULTS: Sera from 3 (30%) of 10 men with CF demonstrated immunoglobulin (Ig)G, IgA, and/or IgM antisperm antibodies, whereas sera from all 5 CF women and the 20 control sera were negative for antisperm antibodies. The maximal titers for IgG, IgA, and IgM antisperm antibody were 1:8, 192, 1:256, and 1:64, respectively. The immunobead binding, which was restricted to the sperm head and tail-tip or the midpiece and tail-tip, correlated with the indirect immunofluorescence pattern. Antisperm antibody-positive sera from men with CF impaired both the binding and penetration of human zonae and the penetration of hamster ova by human sperm. CONCLUSIONS: Similar to other men with congenital or acquired obstruction of their genital tract, antisperm antibodies may occur in some men with CF. Antisperm antibodies may contribute to immune sperm dysfunction in some men with CF by activated complement-mediated events and interfering with sperm/egg interactions.
Adolescent↗
Immunomodulation in the treatment of endometriosis-associated subfertility: use of pentoxifylline to reverse the inhibition of fertilization by surgically induced endometriosis in a rodent model.
OBJECTIVE: To determine the effect of pentoxifylline on early reproductive performance in an animal model for endometriosis. DESIGN: Preclinical blinded study in a rodent model. SETTING: Animal research laboratory. PARTICIPANTS: Sexually mature female golden hamsters. INTERVENTIONS: At laparotomy, groups of hamsters were subjected to: (1) excision of the right uterine horn and (2) excision of the right uterine horn with explantation of four 2-cm2 uterine fragments onto the left uterine mesentery. Six weeks later, surgically treated hamsters and nonsurgically treated controls were subjected to ovulation induction with pregnant mare serum gonadotropin and human chorionic gonadotropin; subsequently, hamsters were divided into groups for periovulatory treatment with either pentoxifylline (2.5 mg/kg) or vehicle given subcutaneously every 8 hours. All hamsters were mated with proven males and killed after 48 hours. MAIN OUTCOME MEASURES: Numbers of unfertilized oocytes and embryos recovered from the left uterine horn at 48 hours after mating. RESULTS: Fertilization rates in surgical and nonsurgical control groups exceeded 90%. Fertilization was significantly impaired in saline-treated animals bearing uterine explants (mean of 2.3% +/- 1.9%). Administration of pentoxifylline dramatically reversed this effect (99.0% +/- 0.7% mean fertilization rate). CONCLUSION: These data suggest that periovulatory treatment with pentoxifylline abrogated the adverse influence of endometrial explants on fertilization in the rodent model. Periovulatory administration of nonteratogenic immunomodulatory agents may provide an alternative to conventional treatment for endometriosis.
Adjuvants, Immunologic↗
Poloxamer 407 as an intraperitoneal barrier material for the prevention of postsurgical adhesion formation and reformation in rodent models for reproductive surgery.
Comtemporary adhesion-prevention regimens for infertility surgery emphasize the use of barrier materials to effect physical separation of injured surfaces before reperitonealization. Poloxamer 407 is a biocompatible polymer that displays reverse thermal gelation characteristics; that is, the material exists as a liquid at room temperature and as a solid at body temperature. These properties make it an ideal material for use in laparoscopic surgery. The antiadhesion properties of poloxamer 407 were evaluated in two models. In the first experiment, Golden hamsters were subjected to a standardized adhesion-producing lesion in the left uterine horn. Poloxamer solutions in concentrations ranging from 15-35% were applied to the injured horn. Location, thickness, and extent of adhesion formation were assessed 14 days later. Significant reduction in post-traumatic adhesion formation was observed following treatment with the 30-35% solutions. The second experiment was designed as a paradigm of the typical situation encountered in infertility surgery: prevention of adhesion reformation after lysis of established adhesions. New Zealand White rabbits were subjected to three laparotomies at 14-day intervals for placement of the adhesion-producing lesion, evaluation (prescore) and surgical lysis of induced adhesions, and subsequent evaluation of adhesion reformation (post-score). The effect of applying poloxamer 407 after adhesiotomy was compared with controls (no treatment). Adhesion reformation (post-score) was markedly reduced by poloxamer-407 treatment. Further trials of this material in the clinical setting are indicated.
Animals↗
Immunomodulation with pentoxifylline abrogates macrophage-mediated infertility in an in vivo model: a paradigm for a novel approach to the treatment of endometriosis-associated subfertility.
Although present consensus holds that endometriosis-associated subfertility is the result of an adverse effect of hyperactivated macrophages on early reproductive events, most treatments for endometriosis are directed at the suppression of endometriotic implants. We hypothesized that periovulatory immunomodulation of macrophage activation and inflammatory mediator production might be a more effective approach to this problem. In this experiment, heterologous transfer of activated peritoneal inflammatory cells within a syngeneic strain of mice was used as an in vivo model for the peritoneal inflammatory environment of the endometriosis patient. Intraperitoneal transfer of hyperactivated macrophages, but not basal state macrophages, significantly inhibited fertilization. This activity was reversed by periovulatory pentoxifylline treatment. Immunomodulation of peritoneal inflammatory cell hyperactivation with pentoxifylline may represent a new modality for the treatment of endometriosis-associated subfertility.
Adjuvants, Immunologic↗
Periovulatory calcium channel blockade enhances reproductive performance in an animal model for endometriosis-associated subfertility.
Current evidence suggests that peritoneal inflammatory cell hyperactivation may be the essential pathologic abnormality in patients with endometriosis-associated subfertility. In these experiments we utilized an animal model to evaluate the use of an immunomodulatory agent as an alternative treatment for endometriosis-associated subfertility. The right uterine horn of 12 golden hamsters was resected and 2 x 2 mm squares were explanted onto the left uterine mesentery. Controls included hamsters undergoing uterine horn resection without endometrial explantation (n = 6) and nonsurgically treated animals (n = 6). Ovulation induction was initiated 6 weeks postoperatively with 40 IU of pregnant mare's serum gonadotropin on day 1 and 40 IU of human chorionic gonadotropin on day 3. Groups of six explant-bearing hamsters and six nonsurgical control hamsters were treated with verapamil (250 micrograms/kg every 8 hours subcutaneously), a calcium channel-blocking agent known to inhibit macrophage activation, from day 1 to 48 hours after administration of human chorionic gonadotropin. Animals were then killed and the number of embryos and oocytes in left tube counted as a reflection of reproductive performance. Fertilization was completely inhibited in animals bearing uterine explants. Treatment with verapamil dramatically reversed this effect. These data suggest that periovulatory treatment with an immunomodulatory agent such as verapamil may be an effective alternative to conventional treatment for endometriosis-associated subfertility.
Animals↗
[Acquired deficiency of coagulation factor VIII in post partum with transplacental passage].
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Adult↗