Magnesium sulfate potentiates morphine antinociception at the spinal level

Intrathecal magnesium sulfate coinfusion with morphine increases antinociception in normal rats; however, because magnesium also delays the onset of tolerance, it is not clear whether this additional antinociception is a result of potentiated analgesia or tolerance abatement. We examined the antinociceptive interaction of intrathecal (IT) bolus magnesium sulfate and morphine in morphine naive rats and those with mechanical allodynia after a surgical incision. After intrathecal catheter implantation, rats were given preinjections of magnesium or saline, followed by injections of morphine or saline. In morphine naïve rats, IT bolus magnesium sulfate 281 and 375 microg followed by IT morphine 0.25 or 0.5 nmol enhanced peak antinociception and area under the response versus time curve two-to-three-fold in the tail-flick test as compared with morphine alone. Likewise, in rats with incisional pain, IT bolus magnesium sulfate 188 and 375 microg followed by morphine 0.5 nmol reduced mechanical allodynia, whereas morphine 0.5 nmol alone did not. This study suggests that IT magnesium sulfate potentiates morphine at a spinal site of action.

IMPLICATIONS

Magnesium sulfate potentiates morphine analgesia when coadministered intrathecally in normal rats, and in an animal model of mechanical allodynia after a surgical incision. These results suggest that intrathecal administration of magnesium sulfate may be a useful adjunct to spinal morphine analgesia.

Generation of a spacing pattern: the role of triptychon in trichome patterning in Arabidopsis

Trichomes in Arabidopsis are single-celled hairs that exhibit a regular spacing pattern. Here, the role of TRIPTYCHON (TRY) in the generation of this spacing pattern is studied. By using genetic mosaics, we demonstrate that the formation of trichome clusters in try mutants is not correlated with cell lineage, indicating that TRY is required to single out trichome cells in a process involving cellular interactions. The genetic interactions of TRY, GLABRA1 (GL1), and TRANSPARENT TESTA GLABRA (T TG) in trichome patterning are assessed by determining the cluster frequency in various genetic combinations. It is shown that TRY acts as a negative regulator of GL1- and TTG-dependent pathways. Furthermore, it is demonstrated that trichome initiation in ttg-1, a strong ttg allele, is rescued almost to wild-type levels in a try background in which GL1 is expressed under the control of the cauliflower mosaic virus 35S promoter, indicating that T TG acts upstream of GL1 and TRY. These findings are incorporated into a model to explain the generation of a trichome spacing pattern from a homogeneous population of epidermal cells.

Isolation of ethyl methanesulfonate-induced gametophytic mutants in Arabidopsis thaliana by a segregation distortion assay using the multimarker chromosome 1

The life cycle of plants comprises two alternating generations, the diploid sporophyte (spore-bearing plant) and the haploid gametophyte (gamete-bearing plant). In contrast to animals, the postmeiotic cells give rise to haploid organisms whose function is to produce the gametes and to mediate fertilization. Analysis of gametophyte development and function has been hampered by the difficulty of identifying haplo-phase-specific mutants in conventional mutagenesis screens. Here we use a genetic strategy that is based on segregation distortion of nearby visible markers to screen for EMS-induced gametophytic mutants in Arabidopsis thaliana. Using the multiple marker chromosome mm1 we have isolated seven lines that displayed an altered segregation of markers. Reciprocal backcrosses of these lines showed a marked reduction of the transmission of the male and/or female gametes. Phenotypic analysis revealed that different aspects of either gametophytic development or function were affected. Three male gametophytic lines showed specific arrests during pollen development. One male gametophytic line was specifically defective in pollen tube elongation. Three gametophytic lines showed variable defects in both male and female gametophytic development.

[Results of oocyte donation in women with different indications, ages and therapeutic strategies]

PURPOSE

Compare the effectiveness of oocyte donation for various indications, ages and treatments.

METHODS

Retrospective analysis of 319 transfers for 184 couples (243 with fresh embryos and 76 with frozen embryos). Transfers are divided into: -7 groups according to indication: premature ovarian failure (POF) with normal caryotype n = 122, surgical POF n = 26, postchemotherapy and postradiation therapy POF n = 23, genetic disease carrier n = 11, IVF failure n = 69, primary amenorrhea n = 58, POF with abnormal caryotype n = 10. -2 groups according to the recipient's age (Group I < or = 40 years, Group II > 40 years); -3 groups according to the dose and the mode of administration of the treatment. Oocytes were donated by volunteer donors of less than 38 years having at last one child.

RESULT

According to the recipient's age 31.3% clinical pregnancies (CP) and 24.2% ongoing pregnancies (OP) for group I, versus 19.4% CP and 11.9% OP for group II. The results according to the indication were similar except for postchemotherapy and postradiation therapy POF for which the rate of CP as well as the rate of OP were particularly low. For the treatment groups there is a significant reduction of CP and OP as the treatment dose increases.

CONCLUSION

The recipient's age plays an important role for the development of pregnancy and this shows that apparently uterine ageing also plays an undeniable role for the decline of female fertility. Increasing doses of estradiol reduces the rate of CP and OP. Postchemotherapy and postradition therapy POF has much lower results than other indications.

Statistical analysis of possible bias of clinical judgements due to observing an on-therapy marker variable

In certain double-blind clinical trials there is the possibility that certain 'marker variables' observable during the trial may in part unblind the trial, even at a subliminal level. At issue is whether or not this potential unblinding biases the investigators' clinical efficacy assessments. This issue arose after the completion of three clinical trials that compared tretinoin emollient cream (TEC) 0.05 per cent to its vehicle in patients with photodamaged skin. The question raised was whether or not possible 'subliminal unblinding' of the investigators and patients, due to the cutaneous irritation associated with topical tretinoin, might have caused a treatment bias in the study. To address this issue, we undertook a reanalysis of these three clinical trials. In doing so, we develop in this paper a statistical modelling approach to address issues of possible bias introduced by the ability to observe such marker variables. The approach utilizes a linear discriminant analysis to introduce an auxiliary categorical variable for the efficacy analysis. A suitable categorical data model permits the estimation of relevant bias effects. We illustrate this approach with data from the three TEC 0.05 per cent trials.

Histologic evaluation of the long term effects of tretinoin on photodamaged skin

Sustained improvement with prolonged topical tretinoin for photodamaged skin has been well documented for up to 22 months of continuous treatment. We now report long-term (4 years) histologic effects of topical tretinoin in photodamaged skin of 27 patients, the longest study to date. The observed decreases in dermal elastin content and perivascular inflammation and increase in epidermal mucin in facial biopsies obtained after up to 4 years of treatment may be partly responsible for the continued clinical improvement. Furthermore, the study shows that there are no untoward effects on keratinocytes or melanocytes during long-term use of topical tretinoin.

The role of self-help programs in the rehabilitation of persons with severe mental illness and substance use disorders

Substance abuse treatment programs in the United States frequently incorporate self-help approaches, but little is known about the use of self-help groups by individuals with dual disorders. This paper brings together several current studies on the role of self-help programs in treating substance use disorders among individuals with severe mental illness. These studies indicate that only a minority of individuals with dual disorders become closely linked to self-help. Psychiatric diagnosis and possibly social skills are correlates of participation. Dually disorders consumers often experience the use of 12-step philosophy and jargon by mental health professionals as alienating and unempathic. The authors propose suggestions for incorporating self-help approaches into the comprehensive community care of individuals with dual disorders.

A new system for fallopian tube sperm perfusion leads to pregnancy rates twice as high as standard intrauterine insemination

OBJECTIVE

To evaluate the relative efficacy of a new system for fallopian tube sperm perfusion in comparison with standard IUI in controlled ovarian hyperstimulation (COH) cycles.

DESIGN

Prospective randomized trial.

SETTING

Ovulation induction program of a tertiary outpatient care center, Hôpital Antoine Béclère, Clamart, France.

PATIENTS

We studied 74 infertile women aged 20 to 38 years undergoing 100 cycles of COH from December 1993 to May 1994 only excluding cases of age > 38 years, obstructed or severely damaged fallopian tubes, E2 levels per mature follicle < 250 pg/mL (conversion factor to SI unit, 3.671) on the day of hCG administration, spontaneous LH surge, and cases of marked sperm abnormalities.

INTERVENTIONS

Controlled ovarian hyperstimulation was achieved using three types of ovarian stimulation protocols: clomiphene citrate (CC) and hMG (n = 35). hMG alone (n = 35) or GnRH agonist and FSH and hMG (n = 30). Thirty-six hours after hCG administration, patients were assigned randomly to either IUI (group A, n = 50) or fallopian tube sperm perfusion (group B, n = 50). Intrauterine insemination was performed with 0.2 mL of sperm suspension according to a standard technique. Fallopian tube sperm perfusion was performed using a simple and reliable system that ensures a good cervical seal and allows to a pressurized injection of 4 mL of sperm suspension.

MAIN OUTCOME MEASURES

Feasibility of the fallopian tube sperm perfusion method, clinical pregnancy (presence of gestational sac with heart beats at 6 weeks of amenorrhea), and ongoing pregnancy rates (PRs) (> 12 weeks of amenorrhea), incidence of complications (multiple pregnancies and ovarian hyperstimulation syndrome [OHSS]).

RESULTS

Overall, the new fallopian tube sperm perfusion system was simple to handle and well tolerated by patients. In group A, we observed 10 clinical pregnancies (20% per cycle) of which 7 were ongoing (14%). In group B, 20 clinical pregnancies (40% per cycle) of which 17 ongoing pregnancies (34%) were obtained. These differences were statistically significant. The prevalence of twin and three or more sac pregnancies was similar in the two groups (3/10 and 0/10, respectively, in group A, and 5/20 and 2/20, respectively, in group B). No case of moderate or severe OHSS was observed in this series.

CONCLUSIONS

Our results indicate that the new system for fallopian tube sperm perfusion is not only simple and reliable but also may lead to PRs twice as high as standard IUI in COH cycles.

Nasotracheal airway-oropharyngeal alimentary canal: a microvascular technique for reconstruction of the upper airway after total laryngectomy

Every patient who has to be laryngectomized because of a carcinoma is concerned with the loss of his or her voice and the presence of a permanent tracheostoma in his or her neck. While various methods for producing a substitute voice are available (esophageal voice, voice devices, voice-shunt operations with or without voice prosthesis), it is usually impossible after laryngectomy to reconstruct a complete upper airway so that the tracheostoma can be closed. One potential method for reconstruction of the airway is its division into a nasotracheal airway and an oropharyngeal alimentary canal. Ten Alsatian dogs were laryngectomized, and a microvascularly anastomosed jejunal autograft was inserted as a junction between the tracheal stump and the circularly exposed nasopharynx, while the pharynx was reconstructed separately. One week postoperatively, oral feeding could be started again; at the same time breathing was possible via the reconstructed nasotracheal airway, which was kept open by insertion of a silicone tube. By means of this microvascular technique, a complete nasal airway could be reconstructed surgically after laryngectomy.

Juvenile nasopharyngeal fibroma: androgen receptors and their significance for tumor growth

Since the publications of Martin, et al. (1948) and Schiff (1959), who were the first to report on the administration of sex hormones to juvenile nasopharyngeal fibroma (JNF) patients, several authors have described the different clinical effects and histologic changes after androgen and estrogen application. Since the mechanism of action of sex steroids in juvenile nasopharyngeal fibroma is almost unknown, the authors have studied androgen receptor binding in cultured tumor fibroblasts from three patients with JNF. Maximum androgen binding (Bmax) of the tumor fibroblasts approximated to that of genital skin fibroblasts, which served as a control androgen target tissue with high receptor density. Furthermore, in vitro experiments showed that the growth rate of tumor fibroblasts increased when testosterone was added to the culture medium, while the addition of two antiandrogens, cyproterone and flutamide, caused a reduction in growth rate. It is concluded from these results that JNF is a hormone-dependent tumor stimulated by testosterone whose growth rate may, at least in vitro, be reduced by antiandrogens such as cyproterone and flutamide.

Lipolysaccharide-induced monocyte retention in the lung. Role of monocyte stiffness, actin assembly, and CD18-dependent adherence

Blood monocytes and monocyte-derived macrophages accumulate in the lungs and can modulate pulmonary inflammatory and reparative processes through their elaboration of cytokines and growth factors. Endotoxemia, often a prelude to acute lung injury, induces a monocytopenia, likely resulting from monocyte accumulation in the lung. We hypothesized that LPS would induce monocyte lung retention by increasing monocyte stiffness and thereby diminishing the cell's ability to deform and transit the narrow pulmonary capillary network, and that LPS would induce CD18-dependent adhesion of monocytes to endothelium, prolonging their retention. LPS induced a rapid and concentration-dependent increase in human monocyte stiffness, net filamentous actin assembly, and retention in a filtration model of pulmonary capillaries. These LPS-induced responses were dependent on the integrity of actin filaments in that cytochalasin D, an agent that disrupts filamentous actin assembly, attenuated each of these processes. LPS induced CD18-dependent and -independent human monocyte adhesion to unstimulated human endothelial cell monolayers. In vivo, rabbit monocytes were retained in the lungs of animals rendered endotoxemic. Pretreatment of monocytes ex vivo with LPS enhanced their lung retention suggesting that LPS was acting directly on monocytes. Initial lung retention during endotoxemia was attenuated by inhibiting monocyte F-actin assembly with cytochalasin D. Anti-CD18 Abs caused a slight decrease in initial retention of monocytes, but led to a 90% inhibition of retention by 2 h. Control IgG had no effect. These data suggest that the initial retention of monocytes in the lung during endotoxemia is dependent on alterations in their stiffness and assembly/organization of F-actin, and that CD18-dependent adhesive mechanisms prolong monocyte retention in the lung during this process.

Lipolysaccharide-induced monocyte retention in the lung. Role of monocyte stiffness, actin assembly, and CD18-dependent adherence

Blood monocytes and monocyte-derived macrophages accumulate in the lungs and can modulate pulmonary inflammatory and reparative processes through their elaboration of cytokines and growth factors. Endotoxemia, often a prelude to acute lung injury, induces a monocytopenia, likely resulting from monocyte accumulation in the lung. We hypothesized that LPS would induce monocyte lung retention by increasing monocyte stiffness and thereby diminishing the cell's ability to deform and transit the narrow pulmonary capillary network, and that LPS would induce CD18-dependent adhesion of monocytes to endothelium, prolonging their retention. LPS induced a rapid and concentration-dependent increase in human monocyte stiffness, net filamentous actin assembly, and retention in a filtration model of pulmonary capillaries. These LPS-induced responses were dependent on the integrity of actin filaments in that cytochalasin D, an agent that disrupts filamentous actin assembly, attenuated each of these processes. LPS induced CD18-dependent and -independent human monocyte adhesion to unstimulated human endothelial cell monolayers. In vivo, rabbit monocytes were retained in the lungs of animals rendered endotoxemic. Pretreatment of monocytes ex vivo with LPS enhanced their lung retention suggesting that LPS was acting directly on monocytes. Initial lung retention during endotoxemia was attenuated by inhibiting monocyte F-actin assembly with cytochalasin D. Anti-CD18 Abs caused a slight decrease in initial retention of monocytes, but led to a 90% inhibition of retention by 2 h. Control IgG had no effect. These data suggest that the initial retention of monocytes in the lung during endotoxemia is dependent on alterations in their stiffness and assembly/organization of F-actin, and that CD18-dependent adhesive mechanisms prolong monocyte retention in the lung during this process.

[Study of sperm-cervical mucus interaction in controlled cycles: feasibility of a new approach]

We report a prospective trial of in vitro sperm-mucus penetration test performed in hormonally controlled environment. To enhance the quality of the cervical mucus (CM), prevent spontaneous ovulation and to eliminate the possibility that results may be biased solely because of CM inadequacy, we conceived a 28-day physiological hormonal replacement regimen. For this women received oral estradiol valerate (E2-V) (4 mg/day) from cycle 1 to 28. CM was collected on days 13 (n = 17), 14 (n = 38) or 15 (n = 16), according to patients' individual preferences. The in vitro sperm-mucus penetration test was performed approximately 30 minutes later. On the same day, measurements of P and E2 levels were done to eliminate the possibility of spontaneous ovulation. Plasma E2 on the day of testing were 220 +/- 100 pg/ml (mean +/- SD). In all patients, except 4, P levels were low (< 1 ng/ml) on the day of the test. Our results indicate that a hormonal preparation with E2/P can be clinically useful for preventing spontaneous ovulation and reliably assuring CM quality when sperm/mucus penetration tests are performed.

Acute and long-term effects of adrenocorticotropin and dexamethasone on the auditory brainstem response in multiple sclerosis patients

Auditory brain-stem responses (ABRs) were compared in two groups of multiple sclerosis (MS) patients receiving standard treatment with adrenocorticotropin (ACTH) and with dexamethasone (DEX). ABRs were recorded prior to treatment, on the 1st and 8th day of therapy, and 21 days after the hormonal treatment had been discontinued. ABRs in MS patients were within the normal range of variability. Latencies of ABR components increased with increasing rate of presentation, and with decreasing intensity of the click stimuli. Changes in ABRs displayed a consistent pattern in patients treated with ACTH, but showed less coherence after DEX. In ACTH treated patients' latencies of the late ABR waves V and Vn were prolonged after clicks of high intensity, and reduced following clicks of low intensity resulting in a decreased slope of the latency-intensity function of these ABR waves. This pattern became most prominent in the recordings after the treatment had been discontinued, and could reflect an improved transmission across both afferent excitatory and recurrent inhibitory synapses in the auditory pathways. The findings indicate that--besides a common anti-inflammatory action--therapies with ACTH and DEX differ with regard to their influence on central nervous functioning.

Development of a multispecies identification field test by modified agar-gel immunodiffusion

A multispecies identification field test (MULTI-SIFT) was developed for detection of beef, poultry, pork, sheep, horse, and deer in a wide variety of raw meat products. The test is an adaptation of previously developed field screening immunodiffusion tests for detection of single species. MULTI-SIFT was demonstrated to be specific, relatively sensitive, and accurate in the complete speciation of 100 meat samples.

Mechanisms of lipopolysaccharide-induced neutrophil retention. Relative contributions of adhesive and cellular mechanical properties

Intravascular LPS rapidly induces neutrophil sequestration in pulmonary capillaries by mechanisms that, although currently unknown, must take into account the size difference between the neutrophil and capillary diameter. To determine whether LPS alters neutrophil stiffness, and hence the ability of neutrophils to traverse capillaries, neutrophil passage through pulmonary capillaries was modeled by passage through filters with 6.5-microns pores. LPS increased retention in the pores in a concentration-dependent fashion that required the presence of heat-inactivated platelet-poor plasma, and was evident as early as 10 min after stimulation. The effect of LPS on the structural properties of the neutrophil was then studied. LPS induced f-actin reorganization in neutrophils in the presence of plasma. Disruption of actin organization and assembly with cytochalasin D completely inhibited early LPS-induced retention and attenuated retention at later timepoints, indicating that LPS-stimulated retention depends on filament organization. LPS-induced actin assembly and retention were abrogated by an antibody directed against CD14, a putative LPS receptor. CD18-dependent adherence of neutrophils contributed significantly to retention only at later timepoints with no significant contribution to retention at 20 min as determined by inhibition of adherence with the mAb 60.3. Morphometric assessment of neutrophil accumulation in the lungs of rabbits given 1 microgram LPS showed a marked increase in apparent neutrophil number, which was unaltered by antibodies to CD18, suggesting that mechanisms other than adhesion may account for accumulation in vivo. Direct measurements showed that neutrophil stiffness increased with exposure to LPS in a fashion similar to LPS-induced retention and actin organization. Pretreatment of neutrophils with cytochalasin D attenuated the increased stiffness. These data suggest that reorganization of filamentous-actin induced by LPS leads to cell stiffening and retention in capillary-sized pores. Although the organization of f-actin continues to be important in retention at later time points, adherence of cells also contributes significantly to cell retention. The changes in mechanical properties of the neutrophil may be important in the sequestration of neutrophils in pulmonary capillaries noted in endotoxemia.

Mechanisms of lipopolysaccharide-induced neutrophil retention. Relative contributions of adhesive and cellular mechanical properties

Intravascular LPS rapidly induces neutrophil sequestration in pulmonary capillaries by mechanisms that, although currently unknown, must take into account the size difference between the neutrophil and capillary diameter. To determine whether LPS alters neutrophil stiffness, and hence the ability of neutrophils to traverse capillaries, neutrophil passage through pulmonary capillaries was modeled by passage through filters with 6.5-microns pores. LPS increased retention in the pores in a concentration-dependent fashion that required the presence of heat-inactivated platelet-poor plasma, and was evident as early as 10 min after stimulation. The effect of LPS on the structural properties of the neutrophil was then studied. LPS induced f-actin reorganization in neutrophils in the presence of plasma. Disruption of actin organization and assembly with cytochalasin D completely inhibited early LPS-induced retention and attenuated retention at later timepoints, indicating that LPS-stimulated retention depends on filament organization. LPS-induced actin assembly and retention were abrogated by an antibody directed against CD14, a putative LPS receptor. CD18-dependent adherence of neutrophils contributed significantly to retention only at later timepoints with no significant contribution to retention at 20 min as determined by inhibition of adherence with the mAb 60.3. Morphometric assessment of neutrophil accumulation in the lungs of rabbits given 1 microgram LPS showed a marked increase in apparent neutrophil number, which was unaltered by antibodies to CD18, suggesting that mechanisms other than adhesion may account for accumulation in vivo. Direct measurements showed that neutrophil stiffness increased with exposure to LPS in a fashion similar to LPS-induced retention and actin organization. Pretreatment of neutrophils with cytochalasin D attenuated the increased stiffness. These data suggest that reorganization of filamentous-actin induced by LPS leads to cell stiffening and retention in capillary-sized pores. Although the organization of f-actin continues to be important in retention at later time points, adherence of cells also contributes significantly to cell retention. The changes in mechanical properties of the neutrophil may be important in the sequestration of neutrophils in pulmonary capillaries noted in endotoxemia.

[Silver nitrate burn after Credé's preventive treatment. A roentgen analytic and scanning electron microscopy study]

Following Credé's prophylaxis with silver-nitrate, the cornea of a newborn presented greyish-brown, lime-like plaques on the nasal part of the right eye. A paracentral ulcerating stromal opacification undermined these appositions, when the patient was admitted to the eye-clinic at Aachen. In the material taken in a lamellar keratectomy scanning electron microscopical examination was able to prove the existence of granules, previously described in light-microscopy. These granules measured 100 to 300 nm in diameter and were placed up to 110 microns deep into the corneal stroma of the specimen. An earlier chemical analysis of necrotic material showed no silver specific reaction. By means of EDX-Analysis these granules could be identified as silver-containing. This was once reassured by a newly developed modification of van-Kossa's-staining-method. The fact that the granular deposits contained mainly silver proves that the onset of a sodium-chloride-irrigation did not promote an intended therapeutic silver-chloride-precipitation and therefore had no effects on the silver-nitrate's penetration abilities. Injuries by silver-nitrate-solutions used for Credé's prophylaxis are seldom but still reported. The mechanism of injury in this case of a child, born by sectio remains unknown. Neither the use of an unusual silvernitrate solution, that was taken from a disposable ampoule (Mova-Nitrat) was reported, nor any corneal injury during sectio mentioned.(ABSTRACT TRUNCATED AT 250 WORDS)

Biophysical properties and microfilament assembly in neutrophils: modulation by cyclic AMP

The microfilament lattice, composed primarily of filamentous (F)-actin, determines in large part the mechanical (deformability) properties of neutrophils, and thus may regulate the ability of neutrophils to transit a microvascular bed. Circulating factors may stimulate the neutrophil to become rigid and therefore be retained in the capillaries. We hypothesized that cell stiffening might be attenuated by an increase in intracellular cAMP. A combination of cell filtration and cell poking (mechanical indentation) was used to measure cell deformability. Neutrophils pretreated with dibutyryl cAMP (db-cAMP) or the combination of prostaglandin E2 (PGE2, a stimulator of adenylate cyclase) and isobutylmethylxanthine (IBMX, an inhibitor of phosphodiesterase) demonstrated significant inhibition of the n-formyl-methionyl-leucyl-phenylalanine (fMLP)-inducing stiffening. The inhibition of cell stiffening was associated with an increase in intracellular cAMP as measured by enzyme-linked immunoassay (EIA) and an increase in the activity of the cAMP-dependent kinase (A-kinase). Treatment with PGE2 and IBMX also resulted in a decrease in the F-actin content of stimulated neutrophils as assayed by NBD-phallacidin staining and flow cytometry or by changes in right angle light scattering. Direct addition of cAMP to electropermeabilized neutrophils resulted in attenuation of fMLP-induced actin assembly. Neutrophils stimulated with fMLP demonstrated a rapid redistribution of F-actin from a diffuse cortical location to a peripheral ring as assessed by conventional and scanning confocal fluorescence microscopy. Pretreatment of neutrophils with the combination of IBMX and PGE2 resulted in incomplete development and fragmentation of the cortical ring. We conclude that assembly and redistribution of F-actin may be responsible for cell stiffening after exposure to stimulants and that this response was attenuated by agents that increase intracellular cAMP, by altering the amount and spatial organization of the microfilament component of the cytoskeleton.

Skin replica analysis of photodamaged skin after therapy with tretinoin emollient cream

Computerized image analysis of silicone replicas, a reproducible, objective technique for measuring skin topography, was used in addition to clinical measures in two multicenter, double-blind, randomized, controlled studies of tretinoin emollient cream, a new formulation for treating photodamaged skin. Previously, the skin replica technique had been successfully used in a pilot study of tretinoin 0.05% cream by one investigator. In the present studies, subjects treated for 24 weeks with tretinoin emollient 0.05% cream consistently showed more improvement in skin topography than did vehicle-treated patients. A 0.01% concentration of tretinoin emollient cream also improved skin topography to a greater extent than the vehicle, while the lowest concentration tested (0.001%) showed little difference from vehicle. These results, reflecting a smoothening of the skin surface in tretinoin emollient cream-treated subjects, were consistent with clinical data showing greater improvement in fine wrinkling and roughness after tretinoin emollient cream therapy than after vehicle therapy. Findings from these multicenter studies confirm the value of the skin replica technique and help establish the efficacy of tretinoin emollient 0.05% cream for photodamaged skin.

[Hormone dependence of juvenile nasopharyngeal fibroma]

Since Martin (1948) and Schiff (1959) first reported the use of sex hormones in JNF patients, many authors have described the various clinical effects and histological changes found after administration of androgens or estrogens. In 1980, Johns attempted unsuccessfully to detect estrogen receptors in the tissue of tumors from JNF patients. In 1987, however, Farag et al. succeeded in the demonstration of androgen receptors in homogenates of such tumor tissue.--In 1989, the authors were able to determine the uptake and receptor-binding of radioactively labelled dihydrotestosterone in cultured fibroblasts from a tumor from a 16-year-old JNF patient, and to confirm this result in two other cases. The maximum levels of hormone binding to the fibroblasts was much the same as is found with genital skin fibroblasts, included in the study as a control androgenic target-tissue with high receptor-density. At the same time it was demonstrated that it was possible to stimulate the tumor fibroblasts in vitro by adding testosterone to the culture medium. The attempt to block cell growth with the antiandrogen cyproterone acetate, was not successful, however. This can possibly be put down to the high progestogenic activity of this antiandrogen. Further in vitro studies with substances which are purely androgenic (e.g., flutamide) or with the acetate-free form of cyproterone (which has no progestogenic activity) will possibly be of help in the search for a substance capable of blocking tumor growth.

Development of a rapid equine serological test (REST) by modified agar-gel immunodiffusion

A rapid equine serological test (REST) has been developed for detection of horse meat in a wide variety of raw meat products. The test is an adaptation of previously developed field screening immunodiffusion tests for beef, poultry, pork, and sheep detection. Results show that the REST test was specific, sensitive, and accurate in the analysis of 101 samples.

Activation of mechanical responses in leukocytes

Different kinds of leukocytes undergo cytoskeleton-dependent mechanical responses associated with their specific physiological functions. We have investigated cellular stiffening of several types of leukocytes using a method which measures the force resisting cellular indentation. We have found that lymphocytes stiffen in response to crosslinking cell surface antigens in a process associated with the much studied capping and patching processes. Further studies of myosin-deficient mutants of the ameba Dictyostelium discoideum suggest that this stiffening process results from a myosin dependent contractile process. Rat basophilic leukemia cells and pancreatic islet cells stiffen when triggered to secrete. The function of these cytoskeleton dependent processes is now unknown, but, at least in the islet cells, may be related to a regulation of the rate of secretion. Primary neutrophils stiffen in response to the chemotactic agent, fMet-Leu-Phe. This stiffening may be responsible for retention of these cells in the pulmonary microcirculation during response to inflammation. These observations pose the challenge of determining the structural basis, mechanism, and physiological function of each of these cellular responses.

Retention of leukocytes in capillaries: role of cell size and deformability

Leukocytes within the circulation are in dynamic equilibrium with a marginated pool, thought to reside mainly within the pulmonary capillaries. The size discrepancy between the mean diameter of circulating leukocytes (6-8 microns) and that of the pulmonary capillaries (approximately 5.5 microns) forces the cells to deform in order to transit the capillary bed. Consequently, we investigated the hypothesis that the biophysical properties of cell size and deformability determined differential leukocyte retention in the lung. Comparison of the filtration properties of human neutrophils, lymphocytes, monocytes, platelets, and erythrocytes through polycarbonate filters (5-micron pore diameter) revealed that the largest leukocytes (neutrophils and monocytes) were retained to the greatest extent and the smaller cells (lymphocytes and platelets) the least. Undifferentiated HL-60 cells, of greater diameter than their differentiated counterparts, were also retained to a greater extent, confirming that cell size was one important determinant of retention in these model capillaries. However, compared with neutrophils, which are of similar diameter, monocytes were retained to a greater extent, suggesting that monocytes might be less deformable than neutrophils. To test this hypothesis, deformability was measured directly using the cell poker. Monocytes were found to be the stiffest, neutrophils the softest, and lymphocytes intermediate. Glutaraldehyde treatment of neutrophils markedly increased their stiffness and decreased their ability to transit the pores of the filters in vitro and the pulmonary microvasculature of rabbits without changing their adhesive properties or size. These observations support the hypothesis that biophysical properties of leukocytes (size and deformability) determine in part their ability to transit the pulmonary capillaries and may determine the magnitude of their marginated pools.

Actin polymerization induces a shape change in actin-containing vesicles

We have encapsulated actin filaments in the presence and absence of various actin-binding proteins into lipid vesicles. These vesicles are approximately the same size as animal cells and can be characterized by the same optical microscopic and mechanical techniques used to study cells. We demonstrate that the initially spherical vesicles can be forced into asymmetric, irregular shapes by polymerization of the actin that they contain. Deformation of the vesicles requires that the actin filaments be on average at least approximately 0.5 micron long as shown by the effects of gelsolin, an actin filament-nucleating protein. Filamin, a filament-crosslinking protein, caused the surfaces of the vesicles to have a smoother appearance. Heterogeneous distribution of actin filaments within the vesicles is caused by interfilament interactions and modulated by gelsolin and filamin. The vesicles provide a model system to study control of cell shape and cytoskeletal organization, membrane-cytoskeleton interactions, and cytomechanics.

Mechanics of stimulated neutrophils: cell stiffening induces retention in capillaries

The effect of peptide chemoattractants on neutrophil mechanical properties was studied to test the hypothesis that stimulated neutrophils (diameter, 8 micrometers) are retained in pulmonary capillaries (5.5 micrometers) as a result of a decreased ability of the cell to deform within the capillary in response to the hydrodynamic forces of the bloodstream. Increased neutrophil stiffness, actin assembly, and retention in both 5-micrometer pores and the pulmonary vasculature were seen in response to N-formyl-methionyl-leucyl-phenylalanine. These changes were abolished in cells that had been incubated with 2 micromolar cytochalasin D, an agent that disrupts cellular actin organization. A monoclonal antibody directed at the CD11-CD18 adhesive glycoprotein complex did not inhibit the increase in stiffness or retention in pores. These data suggest that neutrophil stiffening may be both necessary and sufficient for the retention that is observed. Hence, neutrophil sequestration in lung and other capillaries in the acute inflammatory process may be the result of increased stiffness stimulated by chemoattractants.

Cell poking: quantitative analysis of indentation of thick viscoelastic layers

A recently introduced device, the cell poker, measures the force required to indent the exposed surface of a cell adherent to a rigid substratum. The cell poker has provided phenomenological information about the viscoelastic properties of several different types of cells, about mechanical changes triggered by external stimuli, and about the role of the cytoskeleton in these mechanical functions. Except in special cases, however, it has not been possible to extract quantitative estimates of viscosity and elasticity moduli from cell poker measurements. This paper presents cell poker measurements of well characterized viscoelastic polymeric materials, polydimethylsiloxanes of different degrees of polymerization, in a simple shape, a flat, thick layer, which for our purposes can be treated as a half space. Analysis of the measurements in terms of a linear viscoelasticity theory yields viscosity values for three polymer samples in agreement with those determined by measurements on a macroscopic scale. Theoretical analysis further indicates that the measured limiting static elasticity of the layers may result from the tension generated at the interface between the polymer and water. This work demonstrates the possibility of obtaining quantitative viscoelastic material properties from cell poker measurements and represents the first step in extending these quantitative studies to more complicated structures including cells.

Development of serological ovine field test (SOFT) by modified agar-gel immunodiffusion

A serological ovine field test (SOFT) has been developed for detection of lamb or sheep tissue in a wide variety of raw meat products. The test is an adaptation of previously developed field screening immunodiffusion tests for beef, poultry, and pork detection. The SOFT test was demonstrated to be specific, sensitive, and accurate in the analysis of 104 samples.

Development of porcine rapid identification method (PRIME) by modified agar-gel immunodiffusion

A porcine rapid identification method (PRIME) has been developed for detection of pork in a wide variety of meat products. The test is an adaptation of previously developed field screening immunodiffusion tests for beef and poultry detection. The PRIME test was demonstrated to be specific, sensitive, and accurate in the analysis of samples in the laboratory and in a commercial meat processing establishment.

Detection of poultry and pork in cooked and canned meat foods by enzyme-linked immunosorbent assays

Enzyme-linked immunosorbent assays (ELISA) are described for the detection of poultry and pork in cooked and canned meat foods. These assays are based on species-specific, polyclonal antibodies raised against heat-resistant antigens. The heat-resistant antigens were isolated from raw skeletal muscle tissue of pork and chicken and were found to be immunoreactive even after heating to 120 degrees C for 15 min. The poultry ELISA could detect chicken or turkey at the 126 ppm level, and the pork ELISA could detect pork at the 250 ppm level. Samples of frankfurters, bolognas, pressed meats, canned baby foods, and canned spreads were prepared by simple aqueous extractions.

Health care of the chronically mentally ill: the culture broker model

The chronically mentally ill tend to receive inadequate medical care for nonpsychiatric illnesses and to have poor health care status. Their medical problems lead to excessive morbidity and mortality and adversely affect their adjustment to psychiatric illness. The authors argue that many of the barriers to medical care for these patients can be overcome by using case managers as "culture brokers"-persons who provide bridges between the worlds of the chronically mentally ill and medical providers. This paper presents the culture broker model and its roots in anthropology, and illustrates its application to the medical care of the chronically mentally ill with case examples.

Microinjection of gelsolin into living cells

Gelsolins are actin-binding proteins that cap, nucleate, and sever actin filaments. Microinjection of cytoplasmic or plasma gelsolin into living fibroblasts and macrophages did not affect the shape, actin distribution, deformability, or ruffling activity of the cells. Gelsolin requires calcium for activity, but the NH2-terminal half is active without calcium. Microinjection of this proteolytic fragment had marked effects: the cells rounded up, stopped ruffling, became soft, and stress fibers disappeared. These changes are similar to those seen with cytochalasin, which also caps barbed ends of actin filaments. Attempts to raise the cytoplasmic calcium concentration and thereby activate the injected gelsolin were unsuccessful, but the increases in calcium concentration were minimal or transient and may not have been sufficient. Our interpretation of these results is that at the low calcium concentrations normally found in cells, gelsolin does not express the activities observed in vitro at higher calcium concentrations. We presume that gelsolin may be active at certain times or places if the calcium concentration is elevated to a sufficient level, but we cannot exclude the existence of another molecule that inhibits gelsolin. Microinjection of a 1:1 gelsolin/actin complex had no effect on the cells. This complex is stable in the absence of calcium and has capping activity but no severing and less nucleation activity as compared with either gelsolin in calcium or the NH2-terminal fragment. The NH2-terminal fragment-actin complex also has capping and nucleating activity but no severing activity. On microinjection it had the same effects as the fragment alone. The basis for the difference between the two complexes is unknown. The native molecular weight of rabbit plasma gelsolin is 82,500, and the extinction coefficient at 280 nm is 1.68 cm2/mg. A new simple procedure for purification of plasma gelsolin is described.

Detection of beef and poultry by serological field screening tests (ORBIT and PROFIT): collaborative study

Ten laboratories each analyzed 30 raw meat and raw meat product samples in a collaborative study of the ORBIT (overnight rapid bovine identification test) and PROFIT (poultry rapid overnight field identification test) serological field screening tests for the detection of beef and poultry. Versatility of the tests was shown in the analysis of whole tissue, ground, or emulsified raw meat products. Both tests were demonstrated to be reliable and were capable of detecting adulterants present at the 10% level. The method has been adopted official first action.

The influence of concentration and relaxation on the EEG power spectra during a CNV paradigm

EEG segments of 1 sec duration, beginning 1 sec before the imperative stimulus were analysed by Fast Fourier Transformation in a CNV paradigm with interstimulus intervals (ISI) of different durations (1, 3, 5 sec) and with constant (K1, K3, K5) and randomized (R1, R3, R5) ISI presentation. In the alpha band, there were found differences in the power spectra between the constant and the longer randomized (R3, R5) ISI conditions, the latter having a slower center frequency, a smaller radius of gyration and a higher kurtosis. This describes a sharper alpha line of slower frequency in the R3 and the R5 ISI condition, due to pronounced synchronisation of alpha activity. It is discussed as an expression of increased relaxation and reduced concentration. In the theta band, differences appeared between the short ISI conditions (K1, R1) and the longer ones.

Development of poultry rapid overnight field identification test (PROFIT)

A poultry rapid overnight field identification test (PROFIT) has been developed as a screening test which is practical, economical, and easy to perform and interpret for use in field environments to determine the presence of poultry tissue (chicken and turkey) in raw whole tissue or ground/formulated meat products. The basis of the test is an agar-gel immunodiffusion technique used with a printed template pattern and stabilized reagent paper discs. The test shows adequate sensitivity and specificity for its intended purpose. Key components are stable for at least 1 year if they are stored at refrigerator conditions. The design of the test is such that it can be made commercially available as a complete, stable, test kit suitable for use by any type of inspection program concerned with verification of poultry species in meat and/or poultry products that are subject to regulatory or quality controls.

Development of an overnight rapid bovine identification test (ORBIT) for field use

An Overnight Rapid Bovine Identification Test (ORBIT) has been developed as a serological screen test for species verification of raw, whole tissue, bovine meat products. The test, an agar-gel immunodiffusion technique, uses stabilized reagent paper discs and prepared agar plates that have a printed template for correct placement of test components. This test is reliable, practical, economical, and easily performed in the field, such as at a meat import inspection station. The only nonbovine species found to react in the test are the bovine-related species of American bison (buffalo) and water buffalo (from Australia); however, these rare-occurring species do not present a problem for the intended application of the test. Stability of all test components, when stored in a refrigerator, is excellent for at least 1 year. The nature and stability of the test make it suitable for commercial development into test kits which should be highly practical and economical for wide availability and application of this procedure to meat inspection programs concerned with species verification.

Detection and quantitation of chloramphenicol by competitive enzyme-linked immunoassay

A competitive enzyme-linked immunoassay for the detection and quantitation of chloramphenicol has been developed. The binding of specific rabbit antibody to solid-phase-bound chloramphenicol was competitively inhibited by free chloramphenicol in the sample to be assayed. Antibody not displaced was indicated by using a commercially available, enzyme-linked, anti-rabbit immunoglobulin preparation and reacted with added substrate. Enzyme activity, measured spectrophotometrically, was inversely proportional to the concentration of chloramphenicol in the sample. Quantitation of the antibiotic was linear to 100 ng/ml, with a lower limit of detection of 1 ng/ml (P less than 0.05). Specificity was demonstrated by the lack of inhibition by any of 31 selected antimicrobial agents or chemicals tested in the assay. Chloramphenicol sodium succinate and thiamphenicol, an experimental antibiotic similar in structure to chloramphenicol, were the only drugs found to produce cross-reactions. In addition to excellent sensitivity and specificity, the assay was shown to have good precision and economy and could be completed in approximately 24h.

[Infiltrating retinoblastoma - a difficult differential diagnosis (author's transl)]

The diffuse infiltrative retinoblastoma closely resembles uveitis, because of a pseudohypopyon and vitreous infiltration. Since late diagnosis endangers the lives of the children affected, the authors describe two cases of this rare and unusual clinical picture.

[Pigmented paravenous retino-choroidal atrophy (author's transl)]

A 22-year-old man presented a typical appearance of pigmented paravenous retino-choroidal atrophy. Fluorescein angiography demonstrated a profound loss of the choriocapillaris in the affected areas. The amplitude of the scotopic and photopic electroretinogramme response was reduced. The electro-oculographic light rise was normal.