Steroids modulate corticotropin-releasing hormone production in human fetal membranes and placenta

The levels of immunoreactive CRH are elevated in both maternal and fetal plasma in late gestation and labor, but fall precipitously after parturition. The major source of this peptide is thought to be the placenta. We determined if the placenta and also the amnion, chorion, and decidua produce CRH, whether this material has biological activity, and whether CRH output is modulated by glucocorticoids and progesterone. In an in vitro monolayer culture system CRH was produced by the fetal membranes and decidua. Media immunoreactive CRH concentrations averaged 625 +/- 45 (SE) pg/10(5) cells in amnion, 701 +/- 56 pg/10(5) cells in chorion, and 580 +/- 60 pg/10(5) cells in decidual tissue obtained at cesarean section. This output was similar to that by the placenta (906 +/- 121 pg/10(5) cells). These values increased in tissue obtained after spontaneous labor. A single peak of CRH immunoreactivity eluting at the same position as synthetic human CRH, and possessing biological activity, was found in all tissues. There was a dose-dependent increase in CRH output by all tissue types when cells were maintained in the presence of increasing concentrations of cortisol and dexamethasone. In contrast, increasing concentrations of progesterone decreased CRH output by all tissue types. We conclude that immuno- and biologically active CRH is produced not only in the human placenta, but also in the fetal membranes. CRH output by the placenta/fetal membranes is moderated by steroids, and changes with labor. These findings raise the possibility of a regulatory system similar to that of the hypothalamic pituitary axis, but residing within the placenta and fetal membranes.

Depression and tetrahydrobiopterin: the folate connection

Total biopterin, neopterin and creatinine were measured in spot urine samples from affective disorder patients on lithium therapy and control subjects. Folic acid was also measured in plasma in a sample of the patients. The mean neopterin: biopterin ratio was significantly higher in the 76 patients (3.2 +/- 0.5) than in the 61 controls (1.8 +/- 0.1). In female patients biopterin levels were significantly lower than in controls. In the control groups there was a significant correlation between the molar concentration of neopterin and biopterin. No such correlation was found in the patients. These data indicate that tetrahydrobiopterin (BH4) biosynthesis is reduced in this group. A significant positive correlation was found between plasma folate and urinary biopterin. It is suggested that folate deficiency may impair the synthesis of BH4, a cofactor essential for the synthesis of 5-HT and other monoamines that are involved in the pathogenesis of affective disorders.

Local stimulation of prostaglandin production by corticotropin-releasing hormone in human fetal membranes and placenta

Corticotropin-releasing hormone is produced by the human placenta and fetal membranes, but its physiological significance is not established. We examined the possibility that CRH might affect prostaglandin output by these intra-uterine tissues. Primary cultures of amnion, chorion, decidua and placenta were established from tissue obtained from women at term elective cesarean section were maintained in the presence of increasing concentrations of synthetic hCRH. PG output at 48h was measured by radioimmunoassay. hCRH stimulated PGE2 output by amnion, chorion and placenta, but not by decidual tissue. PGF2 alpha output was stimulated in amnion, decidua and placenta but not chorion, whereas output of 13, 14-dihydro-15-keto PGF2 alpha was stimulated in all four tissues. We conclude that hCRH stimulates prostaglandin output by human placenta, decidua and the fetal membranes, raising the possibility of paracrine or autocrine interactions between CRH and prostaglandins in vivo.

Effects of vibration on steady flow downstream of a stenosis

A physical model was used to test the effects of vibrations on the position of transition to turbulence (zt) downstream of a constriction. Constrictions were inserted in a length of clear plastic (Tygon) tubing and vibrated. Water was the fluid medium and flow was visualized with India ink. The frequency and velocity of vibration were monitored. For a given constriction and flow velocity, there was a band of frequencies which caused zt to move upstream. This band corresponded to frequencies of flow disturbances as measured with a hot-film anemometer without vibration. Both flow-visualization and hot-film frequencies were correlated via a Strouhal number to the Reynolds number and contraction ratio of the flow. Values of zt decreased with increasing vibration amplitude. The critical Reynolds number for turbulence was also decreased by vibration. These results are of importance in the diagnosis of vascular disease and the design of physical models of stenotic flows.

The subfornical organ and relaxin-induced inhibition of reflex milk ejection in lactating rats

Experiments were carried out on anaesthetized, lactating rats to investigate the possible role of the subfornical organ in mediating relaxin-induced inhibition of reflex milk ejection. Milk ejection was judged by the behavioural response of the sucklings and by transient rises in intramammary pressure. Radiofrequency lesions of the subfornical organ, or control lesions in adjacent areas of the cerebrum, did not affect the pattern or the magnitude of intramammary pressure changes at reflex milk ejection. Purified porcine relaxin given by either i.v. (5 micrograms) or intracerebroventricular (50 ng) injection suppressed reflex milk ejection in intact, sham-lesioned and control-lesioned rats, but had no effect on either the pattern or magnitude of reflex milk ejection in rats with lesions of the subfornical organ. The subfornical organ, which is situated at the interface between the blood, brain and the cerebrospinal fluid appears to mediate, at least in part, the relaxin-induced inhibition of reflex milk ejection in the rat.

Effects of chronic infusion of porcine relaxin on oxytocin release in lactating rats

The effects of chronic infusion of porcine relaxin on oxytocin release were studied in lactating rats. Infusion of relaxin (4.2 micrograms/h for either 4 or 6 days) suppressed reflex milk ejection and reduced litter weight gain for 48 h compared with saline-infused controls. After 2 days, neither the rate of growth nor the frequency of milk ejection were significantly different from controls. For 24 h after the infusion of relaxin ended, litters gained weight more quickly than controls but there was no difference seen in the frequency of milk ejection. The effects on oxytocin release of stopping an infusion of relaxin after 3 days were investigated. There was a significant (P less than 0.01) rise in plasma oxytocin (up to 90 pmol/l) 30 min after the infusion was stopped, followed by a sustained rise in intramammary pressure. Treatment of relaxin-infused rats with naloxone (0.1 mg/kg) when the infusion was halted caused a more rapid release of oxytocin (within 2 min), a greater release of oxytocin (up to 140 pmol/l) and a prolonged rise in intramammary pressure.

NMR spectrometry. A new method for total stool fat quantification in chronic pancreatitis

In the present investigation, suitability of nuclear magnetic resonance (NMR) spectrometry for total stool fat quantification in patients with normal or impaired exocrine pancreatic function (chronic pancreatitis) has been analyzed in comparison with a conventional chloroform-methanol extraction technique. Basic temperature-dependence studies of NMR spectrometry (90 degrees/180 degrees radiofrequency pulse sequence) on 21 chloroform-methanol extracted pure total stool lipid standards (weight range: 0.05-1.6 g) revealed significantly (P less than 0.05) improving correlations between NMR signal amplitudes and corresponding weights at increasing temperatures (r = 0.952/40 degrees C, r = 0.965/60 degrees C, r = 0.988/80 degrees C), thus indicating 80 degrees C as optimal temperature for NMR spectrometric total stool fat quantification. In subsequent comparative measurements of lyophilized stool samples, NMR spectrometry (at 80 degrees C) and conventional chloroform-methanol extraction provided significantly (P less than 0.001) correlated results with respect to total fecal fat contents/day of quantitatively collected and homogenized stools in 93 patients with known exocrine pancreatic function (secretin-pancreozymin test), irrespective of whether correlations were determined for all 93 patients (r = 0.983) or separately for patients with normal (N = 45; r = 0.867), moderately reduced (N = 31; r = 0.946), or highly reduced (N = 17; r = 0.992) exocrine pancreatic function and correspondingly increased total fecal fat excretions.

Analysis of break frequencies downstream of a constriction in a cylindrical tube

Experiments were performed to correlate steady-flow power spectra downstream of a stenosis in a cylindrical tube with the flow geometry and velocity. The experiments were motivated by the need to improve quantitative phonoangiography. An objective break frequency (fb) was computed from spectra of velocity fluctuations, as measured with a hot film anemometer. Least squares fits with two independent variables were used to find an empirical relationship between a Strouhal number (S2), the contraction ratio (ds/D) and the Reynolds number (Re). The variables D and ds, are, respectively, the unobstructed tubing diameter and the inner diameter of the stenosis. The relationship found was S2 = Re 0.72(ds/D)0.26 The contraction ratio ds/D, can be found from the empirical relation in terms of known parameters. For the hot wire data the average error between the computed value of ds/D and the known value was 2.3%.

Nucleotide sequence analysis of the gene for protein A from Staphylococcus aureus Cowan 1 (NCTC8530) and its enhanced expression in Escherichia coli

Nucleotide sequence analysis of the gene (spa) for staphylococcal protein A (SPA) from Staphylococcus aureus strain Cowan 1 (NCTC8530) shows that the sequence differs from previously reported SPA nucleotide sequences, especially in the number of repeat units in the cell-wall-binding region of the gene. Dot matrix comparison with streptococcal protein G and the macrophage receptor for the constant fragment (Fc) of immunoglobulins shows a limited but significant homology. The homology to the latter probably identifies the Fc-binding region in the immunoglobulin-binding domains of SPA. Enhanced production of SPA in Escherichia coli was achieved using the lac promoter immediately upstream from the spa gene.

Relaxin acts centrally to inhibit oxytocin release during parturition: an effect that is reversed by naloxone

Experiments were carried out to establish whether infusion of relaxin prolongs gestation and labour in the rat by suppressing release of oxytocin, and whether the effects of relaxin on birth could be reversed by the opioid antagonist naloxone. Female rats were implanted with subcutaneous osmotic minipumps for the infusion of purified porcine relaxin into the jugular vein for 84 h from either day 19 or day 20 of gestation. Infusion of relaxin delayed the onset of labour and in those animals which delivered during relaxin infusion, delivery was longer by approximately 45 min. Plasma oxytocin levels 40 min after delivery of the first fetus were 45.25 +/- 3.6 pmol/l (mean +/- S.D.) in unoperated controls and significantly (P less than 0.01) depressed (23.89 +/- 3.9) in rats that delivered during infusion of relaxin. Rats that delivered after the infusion of relaxin had finished, gave birth significantly (P less than 0.05) faster than controls and plasma oxytocin levels were significantly (P less than 0.01) raised (77.87 +/- 15.9 pmol/l). Naloxone treatment (1 mg/kg; i.m.) given immediately after the delivery of the first fetus reversed the inhibitory effect of relaxin and the interval between successive deliveries was slightly faster than that of controls. Plasma oxytocin levels in relaxin-infused naloxone-treated rats were significantly (P less than 0.01) higher than values in unoperated control rats. The results confirm that relaxin suppresses oxytocin release possibly through an opioid system and this may be important in the control of the timing of birth.

Effects of porcine relaxin on the length of gestation and duration of parturition in the rat

Experiments were carried out to investigate the effects of porcine relaxin on the course of gestation and delivery in the rat. Plasma relaxin was maintained at approximately 600 nmol/l from day 19 to day 23 of gestation by i.v. infusion from chronically implanted minipumps. Relaxin significantly (P less than 0.001) prolonged the length of gestation in 17 rats compared with controls, without causing dystocia or affecting the number of live births. Six rats gave birth during relaxin infusion. In these animals there was a significant (P less than 0.001) increase in the interval between successive deliveries compared with control animals, resulting in prolonged labour. The remaining 11 rats gave birth after the infusion was completed, when the interval between successive deliveries was significantly (P less than 0.025) shorter than controls. The results are consistent with the hypothesis that relaxin has a central action suppressing the release of oxytocin as well as a peripheral action on the myometrium and cervix.

Smoking in hospital--a survey of staff attitudes at Westminster Hospital

A survey of staff attitudes to smoking and facilities for smokers and non-smokers at Westminster Hospital and associated buildings revealed widespread support for firmer measures to limit and control smoking on health service premises. The survey was eventually undertaken with the agreement of staff side union representatives who had initially resisted the health authority's wish to implement a policy on smoking. In the event, the results provided support to the TUC's 1981 Resolution calling for increased smoking restrictions in workplaces as part of an overall policy to reduce smoking prevalence among working people, which has been followed up in local initiatives by unions throughout the country.

Monoclonal antibody with hemagglutination, immobilization, and neutralization activities defines an immunodominant, 47,000 mol wt, surface-exposed immunogen of Treponema pallidum (Nichols)

Radioimmunoprecipitation (RIP) analyses performed on 125I-surface-labeled Treponema pallidum cells using various immune sera revealed the presence of six major surface antigens (immunogens) with apparent molecular weights of 47 K, 36 K, 34 K, 32 K, 29 K, and 13 K. Among these, the 47 K surface antigen was most abundant. Radioimmunoprecipitation assays using 125I-labeled T. phagedenis biotype Reiter or immunoblot analyses using the same strain, failed to reveal the presence of the 47 K mol wt antigen in the representative nonpathogenic treponeme. Preabsorption of anti-T. pallidum immune rabbit serum (IRS) with the Reiter organism did not remove anti-T. pallidum antibodies from immune serum that reacted with the 47 K mol wt immunogen or other immunogens of T. pallidum present in the characteristic antigenic profile. Monoclonal antibodies (mAb) directed specifically against the 47 K mol wt immunogen of T. pallidum also failed to react with an analogous 47 K mol wt component in Treponema phagedenis biotype Reiter, further suggesting the unique presence of this antigen in pathogenic treponemes. The presence of the 47 K mol wt surface immunogen in pathogenic treponemes other than T. pallidum subspecies pallidum was also observed (43). Anti-47 K immunogen mAb was nonreactive against rabbit IgG or IgM. mAb directed specifically against the 47 K mol wt immunogen of T. pallidum was examined for strategic functional activities. It was found to be reactive in the microhemagglutination assay for T. pallidum antibodies, the T. pallidum immobilization test, and was found to be capable of significant blockage of attachment of virulent T. pallidum to host cells in tissue culture. Additional significant biological activity for the anti-47 K mol wt immunogen mAb was revealed through results of the in vitro-in vivo neutralization test of Bishop and Miller, in which a 99% or 100% neutralizing activity was demonstrated. The combined data of this study suggest that the 47 K mol wt immunogen of T. pallidum represents an abundant, immunodominant, surface-exposed immunogen possessing potential biological importance in the pathogenesis and immunology of T. pallidum infection. These studies serve to establish the first functionally defined immunogen for T. pallidum, which may represent the major immunogen of the organism.

Monoclonal antibody analysis of specific antigenic similarities among pathogenic Treponema pallidum subspecies

Murine monoclonal antibodies directed against a 47,000-dalton immunodominant surface-exposed antigen of Treponema pallidum subsp. pallidum (Nichols) were isolated. These monoclonal antibodies cross-reacted with analogous 47,000-dalton antigens of two other virulent treponemes, T. pallidum subsp. pertenue and T. pallidum subsp. endemicum (Bosnia A), as determined by radioimmunoassay and immunoblot analyses. Immunoelectron microscopy confirmed that the 47,000-dalton antigen of T. pallidum subsp. pallidum was a surface-associated cellular component. Surface binding assays and immunoelectron microscopic studies also suggested that the analogous 47,000-dalton antigenic component of T. pallidum subsp. pertenue may not have been oriented toward the bacterial surface in the same way as the T. pallidum subsp. pallidum antigen or that the relevant antigenic determinant(s) may not have been exposed to the outer surface in the same way. The significance of this antigen relative to its apparent conservation among pathogenic treponemes and its possible diagnostic and vaccinogenic potentials are discussed.

Cloning and expression of the Staphylococcus aureus protein A gene in Escherichia coli

A gene bank of Staphylococcus aureus strain Cowan I was established using an E. coli HB101/pBR327 host-vector system. Recombinants expressing staphylococcal protein A (SPA) were detected using an IgG-binding assay. A 3.2 Kb DNA fragment directing the synthesis of SPA in E. coli was identified. SPA produced by E. coli was characterised in minicells and by Western blotting and double diffusion experiments.

Assessment of drugs for activity in established type II collagen arthritis

Arthritis was induced in a proportion of rats sensitized with type II collagen and Freund's incomplete adjuvant. Rats which developed arthritis had significantly higher antibody titres and significantly greater delayed hypersensitivity responses to type II collagen than rats which did not develop arthritis. Anti-inflammatory and anti-rheumatic drugs were evaluated against type II collagen arthritis. Dexamethasone reduced inflammatory swelling, reduced both the antibody titre and delayed hypersensitivity to type II collagen and exerted joint protection. Indomethacin reduced inflammatory swelling. Azathioprine, Clozic, Levamisole, D-Penicilamine and Sulphapyridine did not exert significant beneficial activity in this test.

A method for the selection of deletion mutations in the L-proline catabolism gene cluster of Aspergillus nidulans

Interest in the selection of mutations affecting L-proline catabolism inAspergillus nidulansis heightened by the involvement of one of the very few examples of a cluster of functionally related genes in an eukaryote and by an increasing awareness of the biological phenomena in which proline and proline catabolism participate. ThesasA-60 (semialdehyde sensitive) mutation inA. nidulansresults in toxicity of catabolic precursors of L-glutamic γ-semialdehyde (or its internal Schiff base L-Δ1-pyrroline-5-carboxylate) and succinic semialdehyde, apparently without affecting the catabolic pathways concerned. AssasA-60 is unlinked to theprngene cluster, specifying the gene products necessary for L-proline catabolism and as L-proline, a precursor of L-glutamic γ-semialdehyde, is highly toxic tosasA-60 strains, this forms the basis of a powerful positive selection technique for obtaining a number of types ofprnmutations. Many of theseprnmutations can be directly classified according to the gene product(s) affected on the basis of growth phenotype with respect to L-arginine and L-ornithine utilization, proline-dependent resistance to certain toxic amino acid analogues and effect on supplementation of proline auxotrophies. The availability of both a positive selection technique and an extensive nutritional screening system has enabled the identification of fourteen spontaneous deletion mutations, recognized as extending into theprnB gene, specifying the principal L-proline permease, and into at least one otherprngene. These deletion mutations have been partially characterized both genetically and biochemically. In particular their use has greatly facilitated fine-structure mapping of theprncluster and aided studies of the regulation ofprngene expression.

Nonuniform epicardial depolarizations during coronary occlusion in dogs

Epicardial electrograms were recorded before and after occlusion of the left anterior descending coronary artery. The greatest difference between the post-occlusion and pre-occlusion depolarization times were determined. These times were referred to as the normalized times of greatest disparity, delta tmax. It was found that following both one- and two-stage occlusion of the LAD there was a significant increase in delta tmax in the ischemic area of the myocardium. This indicates increased asynchrony of depolarization. However, no significant change in depolarization times occurred in the unaffected area. In one-stage occlusion with an increase in delta t max there was a linear correlation with the development of ventricular arrhythmias, especially ventricular premature beats and tachycardia. Thus, there is evidence which links the increase in depolarization times with the mechanism of reentry and ventricular arrhythmias.

Effects of thioridazine (Mellaril) on ventricular electrophysiologic properties

The effects of therapeutic and toxic doses of thioridazine (Mellaril) (10 and 50 mg/kg body weight, respectively) on ventricular electrophysiologic properties were studied in 12 anesthetized dogs. Threshold pacing currents (diastolic threshold), effective refractory period and conduction time were significantly increased, and idioventricular automaticity was suppressed after administration of 10 mg/kg of thioridazine; the effects were much more pronounced after administration of 50 mg/kg. Rapidly repetitive responses or tachycardia could be induced in the ventricle by two early premature beats in 9 of the 12 dogs after the 50 mg/kg dose, but they did not occur before drug administration or after the 10 mg/kg dose. These results indicate that the antiarrhythmic and arrhythmogenic effects of thioridazine are dose-dependent and that careful monitoring with frequent electrocardiograms is needed for patients receiving large doses of this drug.

Fiberendoscopic removal of long foreign bodies from the stomach using a colon stiffening tube as a protective sheath

A colonoscopic stiffening tube was effectively used as a protective sheath in the esophagus during the endoscopic removal of a long ballpoint pen and a writing pencil from the stomach.

Scanning electron microscopy of nerve sheath neoplasms

Neurofibromas and schwannomas were clearly differentiable by scanning electron microscopy of thin microscopic sections. Neurofibromas exhibited ordered laminations of collagen with scattered fibroblast-like cells interspersed. Schwannomas contained proliferations of smooth tube-forming cells. These neoplastic characteristics were compared with cellular characteristics of normal nerve sheaths to determine the cell of origin in each neoplasm.

Aortocaval fistula detection using a Swan-Ganz catheter

The placement of a Swan-Ganz catheter into the abdominal vena cava by the femoral route is recommended for all patients presenting with severe congestive heart failure and an abdominal aortic aneurysm. If an aortocaval fistula exists, its presence can be determined immediately by noting increased vena caval pressure and higher than normal oxygen content. Immediate recognition of this condition is essential. Fluid overloading is avoided, immediate surgical treatment is instituted and the defect is closed. Minimal manipulation is done in an effort to prevent pulmonary embolization. If the results of catheter studies show no evidence of an aortocaval communication, it may be advisable to make an effort to correct the congestive heart failure before surgically correcting the aneurysm.

A technique for closure of the lesser curvature of the stomach used in the von Eiselberg-Hofmeister reconstruction after subtotal gastrectomy

A technique for closing the lesser curvature of the stomach after subtotal gastrectomy has been used in 847 subtotal gastrectomies. In this group, one patient had transient postoperative bleeding and none had anastomotic leakage. The technique is recommended as a simple method of obtaining a secure and hemostatic closure which can be accomplished rapidly and which does not require the use of special instruments or material.

Special problems associated with abdominal aneurysmectomy in spinal cord injury patients

There were 8 patients with spinal cord injury in the last 100 consecutive patients with abdominal aortic aneurysm resected at the Long Beach Veterans Administration Hospital. Emphasis is placed upon the problems in management not found in individuals without spinal cord injury. A successful outcome is dependent upon: (a) aggressive control of foci of infection, (b) early diagnosis and planned surgical intervention, (c) continuous intraoperative arterial and central venous pressure monitoring and (d) alertness to the prevention of postoperative complications, with emphasis upon careful tracheal toilet and anticipation of delayed wound healing.