Epicardial versus endocardial "in mirror" changes in prostaglandin synthesis after short periods of ischemia and reperfusion.

Cardiac ischemia and reperfusion are associated with increased prostaglandin levels in the coronary venous effluent. This study implemented an in vivo-in vitro technique to investigate regional alterations in heart tissue PGE2 and PGF2 alpha de novo production. Canine endocardial and epicardial explants were incubated following 5 min regional ischemia, or 5 min ischemia with 10 min reperfusion, induced in vivo in two groups of animals (n = 10 and 6, respectively). Ischemia produced a significant upsurge in endocardial but not in epicardial prostaglandin synthesis as compared with the non-ischemic zone: 7.6 +/- 0.7 versus 4.5 +/- 0.5 pg/mg tissue per h in PGE2 (P < 0.001) and 8.8 +/- 1.2 versus 6.8 +/- 1.2 pg/mg per h PGF2 alpha (P < 0.01). Following reperfusion, PGE2 was higher in the apparently normal than in the affected endocardium (5.8 +/- 0.6 versus 4.4 +/- 0.5 pg/mg per h, P < 0.05). Opposite changes occurred in the reperfused epicardium: 8.2 + 0.9 versus 4.9 +/- 0.7 pg/mg per h PGE2 (P < 0.01) and 11.1 +/- 0.9 versus 6.0 +/- 0.6 pg/mg per h PGF2 alpha (P < 0.001), for the reperfused as compared to the "normal" region, respectively. Our findings imply that the left ventricular wall is not homogeneous in its eicosanoid response to ischemia and reperfusion. "In mirror" changes were found between endocardium end epicardium and between the injured and the apparently normal regions.


Metabolism of absorbed glucose in mouse jejunum: influence of arachidonic acid, non-steroidal anti-inflammatory drugs and eicosanoids.

The involvement of arachidonic acid and eicosanoids in glucose absorption and metabolism was investigated in isolated mouse jejunum. Characteristics of glucose absorption and its metabolic fate are reported. Reduction in the dietary precursor of arachidonic acid, linoleic acid, and inhibition of phospholipid hydrolysis with mepacrine reduced glucose absorption with no effect on metabolism, although mepacrine increased the proportion of luminal to serosal lactate release. Bradykinin and n-FMLP enhanced metabolism by 2.1- and 2.4-fold, respectively, both reducing the percentage of metabolised glucose converted to lactate, while neither influenced absorption. Both indomethacin and NDGA decreased absorption and enhanced metabolism. The percentage of metabolised glucose converted to lactate decreased and the ratio of luminal to serosal lactate release was unchanged. In the absence of inhibitors, PGE2 (5 microM) decreased absorption by 28%, metabolism by 24% and total lactate production by 32% and LTB4 (20 nM) increased only absorption by 32%. PGE2 release into the perfusates was predominantly serosal (1-10 nM) and was inhibited by indomethacin. PGE2 could not reverse the indomethacin-induced decrease in absorption, but reversed the enhancement of metabolism by 89% and total lactate production by 60%. In conclusion, while the specificity of the drug-related absorptive effects remain unclear, alterations in the utilisation of the absorbed glucose via drug-induced changes in arachidonic acid synthesis and metabolism are apparent. Furthermore, exogenous PGE2 may protect against the effects of indomethacin and itself reduces active glucose absorption, the metabolism of the absorbed glucose and the amount of lactate formed.


Loss of cytosolic 15-lipoxygenase activity in A23187-stimulated human leukocytes: involvement of a translocation process?

We focused our study on the subcellular redistribution of 15-lipoxygenase in human leukocytes challenged with A23187 and arachidonic acid (AA). We found that in cytosolic fractions of stimulated cells the 15-lipoxygenase (15-LO) activity, measured as 15-HETE, was 65% less than in controls. However, no activity was found in cell membranes. This effect was complete within 2 min of incubation and was correlated in a dose dependent manner to exogenously added AA. No significant difference in cytosolic distribution of 15-LO activity was observed when cells were stimulated in presence of various concentrations of Ca++. Immunoblot analysis showed that the loss of cytosolic 15-LO activity registered after challenging with A23187 was associated with a concomitant loss of the enzyme content in the cytosol, suggesting the possibility of a translocation process. Neither the 15-LO activity nor the enzyme was, however, found in the cell membrane under our present experimental conditions. But, addition of protease inhibitors showed a slight increase of 15-LO activity in the membrane fraction. Despite the small effect, this may indicate a translocation of 15-LO following challenge of human leukocytes with A23187.


Diet-induced atherosclerosis in rabbits alters vascular prostacyclin release.

Atherosclerosis is complicated by thrombosis and it has been suggested that a decreased prostacyclin and/or an increased thromboxane release from the vascular wall could play a part in this process. There are few reports dealing with determinations of prostanoid release from physiologically perfused normal and atherosclerotic vessel walls or from perfused atherosclerotic hearts. Therefore, fourteen rabbits were given 2% cholesterol added to the diet for 26 weeks, which led to atherosclerosis, verified by scanning electron microscopy. Five animals died, and in the surviving nine, as well as from ten healthy rabbits, the aorta was excised. The vessels were perfused with pulsatile flow at physiologic pressure five times for fifteen minutes with the addition of arachidonic acid to the last perfusate. Prostacyclin and thromboxane were determined as their stable degradation products 6-keto-PGF1 alpha and TxB2 by radio-immuno assay. Atherosclerotic and normal animals had the same initial release of prostacyclin but in the atherosclerotic animals the release did not decline with time as it did in the normal animals. The response to arachidonic acid was also higher in the atherosclerotic group. The release of thromboxane was not altered in the atherosclerotic group compared to the control group. It is concluded that prostacyclin release from aortas is altered in rabbits with diet-induced atherosclerosis compared to normal rabbit aortas, but that vascular thromboxane production is not.


[Peritoneal dialysis in the chick embryo with gastroschisis].

The ever increasing possibilities of prenatal diagnosis and intra-uterine treatment of malformations has created the need for simple and reproducible experimental models on which to build a better knowledge of the biology of the abnormal fetus. Using our own model of experimental gastroschisis (GX) in the chick embryo, we have undertaken to study whether transperitoneal exchanges of water and solutes take place after prolonged visceral exposure to the mixture of amniotic and allantoic fluids which has a greater content in Potassium, Urea, and Proteins and less sodium, chloride and glucose than fetal blood. After surgical evisceration of bowel on the 14th day, incubation was resumed until the 19th day and the embryos were then recovered for weighing and for blood sampling biochemical analysis. The chicks with GX had significantly increased serum Potassium and minimally increased Urea whereas Sodium and Chloride were moderately decreased. Our data confirm that a real peritoneal dialysis with transperitoneal exchange of water and solutes between extraembryonal fluids and the fetal internal environment does indeed take place in this model.


[Pulmonary surfactant in experimental congenital diaphragmatic hernia].

This paper examines the amounts of tensoactive phospholipids in the lung tissue of rat fetuses treated with Nitrofen (TOK) and in control animals. The herbicide led to congenital diaphragmatic hernia (CDH) in some fetuses and to pulmonary hypoplasia (PH) in all. The amounts of phosphatidylcholine (PC), phosphatidylglycerol (PG), phosphatidylinositol (PI) and phosphatidylethanolamine (PE) per gram of fresh lung tissue were significantly increased in comparison with the control animals, those of phosphatidylserine (PS) and sphingomyelin (SM) were also increased, but not significantly. Fetuses with HP alone had intermediate values. These findings are in agreement with our previous demonstration of an excess of type II pneumocytes in this model, and point to the existence of some trouble of the secretion or release of surfactant in it; although they do no clarify whether the amount of alveolar surfactant is in fact decreased.


[Skin graft protection by treatment of recipients with ultraviolet irradiated fragments of the donor spleen].

We have tested de possible protective effects of UVA radiated spleen fragments upon simultaneous skin allografts in 84 rats. Under these circumstances skin graft rejection was less evident with a 20 day graft disappearance rate of 46.87% rate in the treated series, that compares favourably with a 80% in the control series. This study shows a parallel increase in the mean survival time of skin grafts in treated specimens. The figures being 19.8 days in the treated series against 12.9 days in untreated controls. Spleen implants are finally shown to produce a healing stimulus in the skin graft zone. These differences are statistically significant.


[Protocol for the treatment of hypertrophic cicatrix with silastic gel. First results].

Functional limitation and scarring use to be common sequelaes of a burns injury in children. We report our initial experience with silicone gel (silastic gel shetting) in the treatment of 15 children with hypertrophic scars, without success to other alternatives therapies. Improvements in texture, colour and height of the lesion were noted in all cases.


[Urodynamic diagnosis and treatment in neurogenic bladder dysfunction].

A group of 55 patients (28M,27F) with neurogenic bladder dysfunction was studied. Patient age ranged from 1m. to 20 years (mean age 9.1 years). Most of the patients had neurogenic bladder secondary myelomeningocele (70%). The urodynamic investigations demonstrated detrusor hyperreflexia in 50 (poor compliance in 28p) detrusor arreflexia in 3 and normal bladder in 2. Six patients hadn't incontinence and didn't need treatment. The rest (49p), couldn't be dry more than 2 hours. After treatment (anticholinergic, alpha adrenergic agonist, alpha-betha adrenergic agonist, I. C. and bladder augmentation), the continence was improved satisfactorily in 38 patients (77.5%). In conclusión, we think that early treatment from neonatal period, supported with urodynamic studies may prevent lon-term renal damage and most patients with neurogenic bladder do not require surgical intervention to improve continence because it can be controlled satisfactorily by other means.


[Role of echography in septic arthritis of the hip in the newborn].

Pyogenic arthritis of the hip in neonates remains a serious problem. The sequelae of delay in diagnosis and treatment can be crippling. Five hips, in four neonates, with a presumed diagnosis of septic arthritis were examined with ultrasonography. In two hips ultrasonography found intracapsular effusion. In the remaining three hips there were no pathological findings. In the two hips with joint effusion an arthrotomy was performed, dislodging pus in both cases. Follow-up radiographs and ultrasonographies of the five hips showed normal joint anatomy. In neonates, ultrasonography provides an early and reliable evaluation of hips in which septic arthritis is suspected.


[Thymus in posterior mediastinum].

It is presented the clinical case of a mass of posterior mediastinum with diagnostic by C.T.Scan, and ratified by Pathologic Anatomy, as posterior prolongation of thymus. Comments of the importance of the diagnostic by image and the rarity of this entity are made.


[Solitary hepatic cyst. Presentation of a case diagnosed in neonatal period].

We reported one case of hepatic solitary cyst, in an infant seven days old. The precocious diagnostic was supported by the presence of an abdominal cyst mass in prenatal period. Different diagnostic and therapeutic consideration are made.


[Appendicular carcinoid tumor in childhood].

Apendicular Carcinoid tumors are very infrequent, being lower than 0.1% of the appendicectomies carried out. We report on the case of a 13 year-old girl, with Acute Appendicitis picture. The appendix was removed and the histological study revealed the presence of the carcinoid tumor with a diameter of a 6 mm. Where non-invasive treatment was decided on, and at present, after two years follow-up, there has been no recurrence.


[Idiopathic perforation of the colon with simultaneous acute appendicitis in a newborn. Presentation of a case].

We report a case of a three days old male newborn who suffered several apnea crisis. Radiologic studies revealed a pneumoperitoneum. Laparotomy proved it was caused by two intestinal perforations in the ascending colon. Histologic study showed a concomitant suppurated acute appendicitis. We discuss the case features, its possible etiopathogeny and the most frequent clinical aspects and treatment of intestinal perforation at this age.


[Ureteral valve associated with pyeloureteral stenosis].

We report a case of ureteric valve associated with pyeloureteral obstruction, exhibited as fistula after pyeloplasty. We analyst different features of ureteric valves: anatomical, location, symptoms and associated congenital anomalies. The writer consider necessary to achieve the sounding of ureteral stretch during the operation of pyeloplasty.


[Avoidable complications in the management of a patient with an artificial urinary sphincter].

All the patients who underwent implantation of an artificial urinary sphincter can have three types of complications: those coming from the own patient, mechanical complications and other aleatory ones. J. L. C. A., a 13-year-old boy with secondary neurogenic bladder, received the implantation of a model AUS 800 artificial urinary sphincter for urinary incontinence. After 15 months without problems, he was admitted in our hospital with pump erosion in the scrotum. He was operated on and the pump system was preserved. No plain roentgenograms were made neither before nor after surgical procedure. However, the balloon pressure reservoir was not seen in a control pielogram performed before his discharge from the hospital. Three months later the entire device should be removed because of infection. In the operation a cut off tube was found. A new artificial urinary sphincter was reimplanted and the cuff was placed around the bulbous urethra one year later. Retrospective analysis of this case can help to review the possible complications and their management.


Technologic advances in diagnostic radiology.

Technologic advances in radiographic equipment and procedures for four different areas of diagnostic radiology are reviewed: bone mineral assessments, musculoskeletal imaging, mammography, and chest imaging. For bone mineral assessments the accuracy and precision obtained using single- and dual-energy photon absorptiometry, dual-energy x-ray absorptiometry, and quantitative CT are summarized. Various digital systems employed in musculoskeletal imaging are reviewed. In mammography, papers related to accreditation and research interests are highlighted. The use of photo-simulated phosphor plates and scanned equalization radiographic systems for chest imaging are discussed. Finally advances in radiographic film processing are noted.


Imaging of degenerative disk diseases.

This review provides a new understanding of the areas of disk anatomy, degeneration, herniation, and lumbar canal stenosis. It discusses new findings on calcified disks, disk imaging, intraspinal synovial cysts and even intraspinal pigmented villonodular synovitis. Special attention has been given to percutaneous therapeutic procedures and the postoperative spine.


Osteoporosis and bone mineral densitometry.

Osteoporosis is a common cause of vertebral and hip fractures and although their occurrence depends on a variety of factors, bone mineral density (BMD) is the most important determinant. Methods of measuring BMD are therefore pertinent to identify individuals with reduced bone mass and at increased risk of fracture, and current techniques provide accurate and precise BMD measurements with low radiation dose. The methods most widely used are single photon absorptiometry; dual photon absorptiometry, which has been replaced by dual energy x-ray absorptiometry; and quantitative CT. Dual energy x-ray absorptiometry permits BMD measurement in the lumbar spine, femoral neck, forearm, and whole body. Bone strength is also related to trabecular width and arrangement. The newer techniques of broadband ultrasound attenuation and MR imaging (T2*) offer potential for investigating both trabecular bone mass and structure, as does high-resolution CT. These methods provide powerful tools for the study of the skeleton in health and disease and have established roles in appropriate clinical circumstances. Although BMD measurement can provide an estimate of fracture risk, there are limitations to fracture prediction in an individual subject, but efforts are being made to improve the discriminatory and predictive aspects of BMD.


Imaging of the postoperative spine.

In the current literature on the imaging modalities of the spine, several papers deal with the diagnostic evaluation of the postoperative spine. Particular attention is focused on the use of MR imaging in evaluating the postoperative spine in symptomatic and asymptomatic patients. Other papers discuss application of different radiologic modalities such as conventional tomography, CT, sonography, and scintigraphy. The effectiveness of various imaging techniques in evaluating the postsurgical changes in the spine is the subject of this review.


Radiology of Paget's disease.

A review of Paget's disease produces few surprises; however, several good articles have recently been published on its appearance, on MR imaging, sarcomatous degeneration, and the disease-related occurrence of multicentric giant-cell tumors. One recent paper illustrated the possible progression of fibrous dysplasia occurring in the skull after adolescence, a finding that does not occur elsewhere. An excellent review article on the normal and abnormal calcaneus is reviewed, and two brief reports on skeletal angiomatosis are discussed. Condensing osteitis of the clavicle is well described in one article that proves it to be an entity distinct from chronic recurrent multifocal osteomyelitis of the clavicle seen in children. Finally, a number of articles on congenital spinal anomalies are reviewed.


Magnetic resonance imaging of bone marrow.

The development of MR imaging has been a great advance in the imaging of bone marrow disorders. MR imaging exhibits excellent soft-tissue contrast and therefore has a greater sensitivity for marrow disease than did previously available modalities. This article reviews the normal morphology and appearance of bone marrow, describes the MR appearance of normal bone marrow, and discusses the MR findings associated with various marrow disorders.


Imaging of bone tumors.

In the recent literature on benign bone tumors, papers have highlighted the atypical appearances of intracapsular osteoid osteoma, the characteristic (yet not pathognomonic) feature of fluid-fluid levels on CT and MR imaging of aneurysmal bone cysts, the difficulties of MR imaging of giant cell tumors laden with hemosiderin following intratumoral hemorrhage, and the reliability of ultrasound in measuring the thickness of the cartilage cap in chondroid lesions. MR imaging remains preeminent in the staging of musculoskeletal tumors, although, as yet, there has been only limited success in using this modality for tissue characterization. One study has described certain distinctive patterns on MR associated with different histologies. In particular, peritumoral edema was only found in malignant bone tumors and giant cell tumors. Subjective MR criteria would appear not to be helpful in identifying osteosarcomas patients who are good responders to chemotherapy. Intra-arterial chemotherapy for osteosarcoma of the lower limb may be complicated by infarction of the distal femur, which on MR imaging should not be mistaken for metastatic or transarticular tumor spread.


Imaging of soft tissue tumors.

The evaluation of many soft tissue lesions remains a diagnostic dilemma for both the radiologist and the clinician. In recent years MR imaging has emerged as the modality of choice for the assessment of soft tissue tumors, with well-documented advantages over CT and other imaging techniques.


Muscle, tendon, and ligament evaluation.

Magnetic resonance imaging is the technique of choice for soft tissue evaluation. Muscle injuries occurring during physical activities are very frequent and are very well appreciated by MR imaging. Associated with 31P spectroscopy, MR imaging allows better understanding of physiopathologic phenomena and inflammatory lesions. An early and correct diagnosis is possible using MR imaging in cases of soft tissue pseudotumors, such as myositis ossificans. The quadriceps and Achilles tendons, which are superficial and thick, can be well evaluated using ultrasonography. Nevertheless, MR imaging is superior for deeply situated tendons and ligaments of the knee and ankle.


Imaging of the skeleton and soft tissues in children.

Sonographic applications to osteomyelitis, myositis ossificans, tropic pyomyositis, child abuse, synovitis, and slipped capital femoral epiphyses; MR imaging (including gadolinium-enhanced MR scans) in osteomyelitis, the normal and abnormal physis, physeal bars, normal marrow, Gaucher disease, cancer, dysplasia epiphysealis hemimelica, myositis, tenosynovitis, arthritis, and clubfoot; nuclear imaging in osteomyelitis, tibia valga, limp, and unexplained lower extremity pain; and CT in osteomyelitis, are reviewed. Routine long-bone radiography for patients with congenital syphilis is not recommended. Tibia valga after fracture has not been fully explained; tibia valga also follows treatment of renal failure. Nonsupracondylar humerus fractures in infants and femoral shaft fractures in the first year of life may suggest child abuse.


Radionuclide investigation of osteomyelitis.

The diagnosis of osteomyelitis in the presence of fracture and orthopedic appliances and in the diabetic foot can be a formidable challenge to radionuclide imaging. Radiophosphate is highly sensitive in detecting bone disease, but of low specificity; to improve specificity it must be complemented by 67Ga or radiolabeled leukocytes. These latter agents are not without limitations, and the search for new agents and novel imaging strategies continues. The relative roles of nuclear medicine and MR imaging are coming into focus, and a diagnostic algorithm based on the shortcomings of both methods is suggested.


Magnetic resonance imaging of the shoulder joint.

Because the shoulder is the most mobile joint in the body, it is naturally predisposed to several disorders. The most commonly encountered disorders requiring diagnostic imaging are rotator cuff disease and glenohumeral instability. Plain film radiography and arthrography have for many years been the mainstays of shoulder imaging. CT added a third dimension to shoulder imaging, improving its sensitivity with respect to glenoid labral pathology. Ultrasonography of the rotator cuff showed early promise in noninvasive evaluation of cuff tears, but it did not gain universal acceptance because of various negative factors, including inadequate visualization of the cuff, poor results regarding partial tears, and most importantly, operator dependency. The development of MR imaging afforded the radiologist improved comprehensive visualization of the shoulder joint in a noninvasive manner.


Magnetic resonance imaging of the knee: evaluation of meniscal disease.

The advent of MR imaging in musculoskeletal radiology, coupled with advances in the past decade in the treatment of knee disorders, has fueled an explosion of interest in MR imaging of the knee. Evaluation of meniscal pathology has been central to this development. The accuracy of MR imaging in the diagnosis of meniscal tears is now well established; attention has more recently been focused on the prevalence, natural history, and clinical significance of other intrameniscal signal abnormalities, as well as on the postoperative meniscus. Nonmeniscal knee disorders that may clinically mimic meniscal lesions are also reliably diagnosed with MR imaging. Technical advances in pulse sequences allow knee imaging with enhanced accuracy and efficiency.


Imaging pediatric hip disorders and residual dysplasia of adult hips.

The application of newer imaging modalities such as ultrasound, CT, and MR imaging has made a major contribution to the understanding of pediatric hip disorders. Multiplanar imaging has been a major advancement in the depiction of the complex hip joint anatomy. Direct visualization of cartilage in the immature joint is now possible with MR imaging. Sophisticated computer software programs allow three-dimensional reconstruction of the joint from CT and MR data. Manipulation of three-dimensional images allows preoperative simulation of proposed surgical reorientation of hips with deformity resulting from dysplasia and Legg-Calvé-Perthes disease.


Evaluation of joint prostheses and orthopedic appliances.

Several recent articles describe imaging evaluation after joint replacement surgery. The following articles about total hip and knee replacement and silicone rubber prostheses are highlighted because they offer new observations or review typical problems after joint revision surgery.


Imaging of the normal spine, developmental anomalies, and trauma of the spine and extremities.

Many significant papers in the current literature have considered the spectrum of developmental and traumatic alterations in the spine. The increasing role of MR and CT imaging is stressed as well as the continued importance of conventional radiography. The distinguishing features and pathology of developmental anomalies and traumatic injuries and the importance of accurate and complete diagnosis are discussed. This review includes articles that emphasize imaging of the normal spine, congenital anomalies, and trauma of the spine and extremities.


[The complications of pulmonary resection surgery: the experience of 200 consecutive cases].

Postoperative complications observed in 200 patients after pulmonary resection (66 pneumonectomies--30%, 106 lobectomies--53% and 28 wedge resections--17%) are presented. Surgical operations were carried out in 86% of cases for cancer, in 16% for benign lesions. Major complications were: lobar atelectasis, bronchopneumonia, pulmonary embolism, respiratory insufficiency, bronchial fistula, ventricular tachyarrhythmia, altogether they concerned 21% of the cases. Their incidence was not significantly influenced by the extension of resection (the latter, on the contrary, influenced postoperative mortality as much as 4.5% after pneumonectomy, 2.8% after lobectomy and 0% after wedge resection), age of patients under or over 70 years, functional respiratory reserve, or associated cardiovascular diseases. On the contrary, the advanced stage of disease in neoplastic patients was significant for major complications. An adequate monitoring of minor respiratory and cardiac complications is recommended to reduce the incidence of major ones and their control when present. In authors' experience, in fact, postoperative mortality was overall 3% following such behaviour.


[Hepatic cystadenoma: a case report].

Hepatic cystadenoma is a rare tumor arising from the biliary system. Although ultrasound and CT scan show peculiar features, diagnosis is not easy preoperatively. Because of the unreliable natural history of cystadenoma, total excision of the neoplasm by hepatic resection seems to be the treatment of choice. A case of benign cystadenoma treated by minor liver resection is reported.


[Extensive resections in rectal carcinoma. Our experiences].

The authors review their experience in the surgical management of rectal cancer. They analyze rectal malignancies and their recurrences from natural history to surgical strategies and survival rates. In particular, the need to perform extended operations in order to offer patients a better prognosis is discussed.


[The functional recovery of the internal anal sphincter and the restoration of continence after rectopexy for rectal prolapse].

Eleven patients with full thickness rectal prolapse underwent ambulatory fine wire electromyography (EMG) of the internal anal sphincter (IAS), external anal sphincter and puborectalis muscle, and anorectal manometry using a computerised system. Examinations were performed preoperatively and at 3 months following rectopexy. The median preoperative IAS EMG frequency was 0.21 Hz (range = 0.05-0.30) and the median preoperative resting anal pressure (RAP) was 13 cmH2O (range = 2-84 cmH2O). A significant improvement in the IAS EMG frequency (median = 0.31 Hz; 0.23-0.47 Hz; p < 0.02) and RAP (median = 30 cmH2O; 20-84 cmH2O; p < 0.01) was noted post-rectopexy but these parameters remained significantly different from a group of normal controls (median IAS EMG frequency = 0.48 Hz; 0.25-0.61 Hz; median RAP = 76 cmH2O; 22-120 cmH2O). We suggest that repair of the prolapse allows the IAS to recover by removing the cause of persistent recto-anal inhibition.


[2 cases of chylothorax during total parenteral nutrition: the etiopathogenetic considerations].

The authors report the onset of bilateral chylothorax during postoperative total parenteral nutrition. They underline the peculiar origin of the complication. Therefore, attention is payed to the possible pathogenic causes. The overload of fluids, in the elderly with minimal functional reserves, may increase central blood pressure, so to adversely affect lymphatic drainage causing chylothorax.


[The osseous location of echinococcal cysts: comments on a clinical case].

Primary bone location of hydatid disease is extremely rare. The clinical case herein reported represents a primitive bone location of echinococcus in the ileal and sacral area. The aspecific symptoms did not allow for a preoperative diagnosis. The latter was possible only after a CT scan performed for other reasons. The patient underwent a CT scan and MIR which showed a diffuse involvement of the ilium and sacrum along with the presence of two cysts (anterior and posterior). Surgery was performed through an anterolateral extraperitoneal and posterior access in the gluteal region. Asportation "en bloc" of the cysts was not possible. Therefore, they were opened, aspirated and washed with hypertonic solution (33% NaCl). Following surgery Albendazole was prescribed to the patient. At 22 days from surgery, a CT scan confirmed the disappearance of the cysts along with the presence of bone lesions.


[The surgical treatment of laterocervical adenopathies due to malignant cervicofacial tumors].

Head and neck malignant tumors show a high tendency to spread to cervical lymph nodes. Therefore, surgical approach to these neoplasms is primary tumor exeresis associated with functional or radical neck dissection, unilaterally or bilaterally at the same time, in relation to T site and N stage. In this paper the validity of such approaches is evaluated by correlating clinical and histopathologic N involvement in 168 patients with head and neck malignancies, observed in a 5-year period (1986-1990), and submitted to radical (65 pts.) and functional (198 pts.) neck dissection. The histopathologic findings showed 31 patients (14.7%) with N0+ (false negatives). The incidence of occult latero-cervical metastases confirms the importance of elective functional neck dissections in N0 patients with head and neck malignant tumors even though the risk of performing many unnecessary surgical procedures may be considerable (180 cases out of 211 in the Authors experience). Rare false positives (overall 4 cases) did not represent a significant clinical problem while N3 showed massive neoplastic invasion with extracapsular spread.


[Cholecystectomy via video laparoscopy: the whys of a choice].

The management of calculous disease of the gallbladder has undergone significant change during the last decade. Recent years have seen the development of alternative methods for the treatment of biliary stones including dissolution therapy, endoscopic and percutaneous extraction, extracorporeal shock wave lithotripsy. Yet, despite these technologic advances, most surgeons have continued to consider cholecystectomy the safest, most effective and the only curative procedure. Open cholecystectomy, performed in the same fashion for more than a century has demonstrated low morbidity and minimal mortality rates. However, the operation does incur sizable expense in terms of hospitalization, cosmetic appearance and time lost from work. Laparoscopic cholecystectomy quickly emerged as an alternative to open cholecystectomy. The authors report their experience of laparoscopic cholecystectomy performed at the Surgical Department of Montecchio Maggiore Hospital (VI). Twenty-eight patients were operated on: in all but one laparoscopic cholecystectomy was successfully completed; in one case a fistula between gallbladder and the common bile duct led to T-tube drainage insertion via a laparotomy. In one patient laparoscopic cholecystectomy was performed after an endoscopic retrograde cholangio-sphincterotomy for associated stones of the common bile duct. Mean operative time was 69 minutes (range 46-210). Morbidity and mortality were 0%; maximal hospital stay was 48 hours. These data confirm that laparoscopic cholecystectomy may be considered the treatment of choice for stone disease of the gallbladder and it should enter into the cultural and technical background of a general surgeon.


A mechanistic model for morphogenesis and regeneration of limbs and imaginal discs.

When an amphibian limb, cockroach leg or Drosophila imaginal disc is subjected to a surgical operation, it is capable of regenerating or duplicating certain parts. Although the structure of the regenerated tissue varies depending on the location and mass of the amputated or transplanted part, it can be predicted from a set of formal rules, called the polar coordinate model [French et al., (1976) Science 193, 969-983; Bryant et al., (1981) Science 212, 993-1002]. In the polar coordinate model, it is assumed (and experimentally proven) that the juxtaposition of normally non-adjacent cells stimulates cell proliferation locally, which implies that the underlying mechanism which gives positional values to each cell, is also responsible for the control of cell growth. Because locally activated proliferation alters the shape and size of the developmental field, the question of how to control the cell growth is the central problem in the regeneration of the limbs and imaginal discs. In this paper, I propose a possible underlying mechanism for the 'polar coordinate rules', and show how this mechanistic model explains the experimental results using computer simulation. The proposed mechanism is an extension of Turing's model (1952). In addition to the reaction-diffusion of the molecules, cell proliferation is taken into consideration. With appropriate initial conditions, the computer simulation shows that a small mass of cells grows up to form a mature limb, and that the mature limb is able to respond to surgical operations as predicted by the polar coordinate model.


[The role of magnetic resonance in the follow-up of aortofemoral prosthetic reconstructions].

The authors report their experience with the use of Magnetic Resonance (MR) in the follow-up of patients undergone aortofemoral bypass or substitution procedures for aneurysmal and/or steno-occlusive lesions of the aortoiliofemoral vascular bed. Twenty-eight patients, at least 2 years from aorto-bifemoral revascularization were evaluated by means of coronal and parasagittal MR planes (mean follow up 78.9 months). One exam over 28 was found to be not diagnostic; whereas the technique showed great usefulness in the morphological and haemodynamic evaluation of each of the graft sites explored (proximal anastomosis, graft body and limbs, femoral anastomosis and periprosthetic tissues) in the remaining 27 cases. The use of this method, in spite of some setting up problems peculiar to the type of examination, according to the authors is very promising because of the chance to obtain morphological and functional data at once and because of the interesting current and future developments of this diagnostic device.


A Hox 3.3-lacZ transgene expressed in developing limbs.

We describe transgenic mouse lines that express lacZ under the control of the Hox 3.3 Promoter II. The correct anterior boundary can be fixed by 3.6 kb of promoter DNA (plus 1.6 kb of 5' transcribed sequences), both in tissues of ectodermal and mesodermal origin. The posterior border, however, is not respected, and lacZ expression continues into the tail region. One line has particularly strong graded expression in the anterior proximal limb bud. Other lines, containing a shorter promoter fragment (0.6 kb), have ectopic expression in the head region, including one line that has expression in the anterior half of the retina. Such mouse lines make it possible to molecularly distinguish cells in regions of the embryo that look otherwise identical and may be useful in studying the establishment of molecular differences in the mouse embryo.


[The complications of diagnostic colonoscopy].

Major complications of diagnostic colonoscopy based on a series of 17.583 procedures performed from 1980 throughout 1991 are reported. No higher risk of colon perforation was registered either performing total or partial colonoscopy, for the site of perforation was in most cases the sigmoid colon.


Expression of mouse PDGF-A and PDGF alpha-receptor genes during pre- and post-implantation development: evidence for a developmental shift from an autocrine to a paracrine mode of action.

We examined the expression of platelet-derived growth factor (PDGF)-A and the PDGF alpha-receptor in pre-implantation and early post-implantation mouse embryos. At two-cell and blastocyst stages, all cells express mRNA and protein for both ligand and receptor. In contrast, early post-implantation embryos express PDGF-A chain mRNA in both embryonic ectoderm and in the ectoderm lining the ectoplacental cavity, while mRNA for PDGF alpha-receptor is localized to the mesoderm layers of both embryonic and extra-embryonic membranes. At days 3.5 and 7.5, receptors are demonstrably functional in response to exogenous PDGF-AA. We propose that chronic autostimulation of PDGF alpha-receptors occurs in pre-implantation embryos, whereas, following implantation, early mesoderm development is dependent on stimulation by ectodermally produced PDGF-A.


Treatment of hypertension in the elderly--the end of the story?

The elderly constitute a high-risk group in which the benefit of treatment of hypertension is now obvious. The initial drug should be a low-dose diuretic, followed by a beta-blocker. At present there are no data favoring the use of an ultra low-dose diuretic, such as 12.5 mg hydrochlorothiazide, unless there is coexisting prediabetes or gout.


Treatment of the older hypertensive: paradigms, practices, and proofs.

Recent outcome trials in patients above age 60 with systolo-diastolic hypertension are reviewed. The meta-analysis suggests that antihypertensive drug therapy can decrease cardiovascular and coronary mortality in selected patients. Based on these studies it is suggested that antihypertensive drug therapy is indicated in patients between age 60 and 75 when the diastolic pressure remains above 95 mmHg after repeated measurements. A target for systolic b.p. is not definitely established but a pressure of 150 mmHg may serve as a temporary proposal. Whether uncomplicated isolated systolic hypertension in symptomless patients should be treated is still under investigation.


Treatment of hypertension in the elderly--what have we learned from the recent trials?

Treatment of hypertension in the elderly has so far mainly been based on clinical judgment and very few large controlled trials. During the last year several large new trials have been published, the so-called STOP-Hypertension, SHEP, and MRC trials. All have shown that drug treatment of hypertension in the elderly (65-85 years) with permanent diastolic hypertension or isolated systolic hypertension reduces stroke incidence. Most patients have needed combined drug treatment with diuretics and beta-blockers. When thiazide diuretics are used, serum potassium should be followed very closely and most likely amiloride should be added to the thiazide therapy, since this was done both in the STOP and the MRC trials. Since many elderly patients with hypertension suffer from other diseases that might represent contraindications to thiazide diuretics or beta-blockers, the choice of drug must be made after careful clinical evaluation. With the newer classes of antihypertensive agents (calcium antagonists, ACE inhibitors and alpha-blockers) side effects are probably seen less often, but long-term data on morbidity and mortality are still lacking.


Treatment of hypertension in the elderly.

Treatment of hypertension in the elderly is beneficial, and benefit exceeds risk, but in some individuals it may be difficult to decrease blood pressure to goal or normotensive levels. Recent data suggest that the use of diuretics and, in some instances, beta-adrenergic inhibitors will reduce morbidity and mortality in elderly hypertensives and will probably not alter metabolic parameters to a clinically significant degree in most individuals.


The case for antihypertensive drug treatment in subjects over the age of 60.

The already strong case for drug treatment of hypertensive patients aged over 60 has been reinforced by the reports on the SHEP, STOP, and, to a lesser extent, MRC trials. SHEP showed benefit in "isolated systolic" hypertension, mainly in relation to stroke, but with a strong trend towards also reducing myocardial infarction. SHEP demonstrated advantages from low-dose chlorthalidone, especially if hypokalemia was prevented. STOP in patients aged 70-84 at entry demonstrated a reduction in stroke and all-cause mortality but not in myocardial infarction; benefit was apparent in women as well as men. The MRC trial, in subjects over 65, many of whom had "isolated systolic" hypertension, found a reduction in stroke but not in coronary events or all-cause mortality. Extensive cross-contamination of allocated treatment groups restricted worthwhile evaluation of different drug regimens in MRC. Potential benefits from antihypertensive drug treatment in old people are substantial but are in danger of being discredited because of intemperate and inaccurate claims.


Hypertension in the elderly.

Publication of the SHEP study (Systolic Hypertension in the Elderly Programme) leaves no doubt that isolated systolic hypertension in the elderly should be treated. There are, however, a number of important outstanding questions: (a) the mechanism of reduction of morbidity, (b) because antihypertensive therapy appears to be more effective in elderly patients than in the young, when should treatment be started in relation to progression of age?, (c) besides the blood pressure elevation, what are the exact mechanical factors responsible for degeneration of the arterial wall?, and (d) what in 1993 is the definition of hypertension? These are questions that now need to be answered.


Iontophoretically enhanced transdermal delivery of an ACE inhibitor in induced hypertensive rabbits: preliminary report.

Both conventional direct current (DC) and pulsed-mode DC constant-current iontophoresis were used to investigate enhanced transdermal delivery of the angiotensin-converting enzyme (ACE) inhibitor captopril to rabbits with acutely induced hypertension. Passive transdermal captopril administration and pulsed DC constant-current iontophoresis of the vehicle were studied as control experimentation. Mean arterial pressure (MAP) was not significantly (p > 0.05) altered following passive transdermal delivery of captopril (n = 4) or after iontophoretic delivery of the vehicle alone (n = 4). Pressure reduction was evident within 10 minutes of iontophoretic enhancement of transdermal captopril delivery. DC mode constant-current (n = 4) iontophoretic transdermal captopril administration caused MAP to fall by 21% from a mean hypertensive level of 66 +/- 5 mmHg to a mean post-treatment level of 52 +/- 6 mmHg (p < 0.05) within 60 minutes. Pulsed DC mode constant-current (n = 4) iontophoresis of captopril caused mean MAP to fall on average by 27% from 62 +/- 6 to 45 +/- 5 mmHg (p < 0.05), also within 60 minutes. This paper provides the first report on the enhanced efficiency during iontophoretic delivery of an ACE inhibitor. We have concluded that both modes of constant-current iontophoresis of captopril offer a safe and effective means of pressure reduction in rabbits with induced hypertension and that there is no significant difference in efficacy between the two forms of enhanced delivery. These results have potential applications for enhanced transdermal delivery of ACE inhibitors in humans.


Vascular relaxation to omega-3 fatty acids: comparison to sodium nitroprusside, nitroglycerin, papaverine, and D600.

The vasorelaxant activity of the omega-3 fatty acids--docosahexaenoic (DHA) and eicosapentaenoic (EPA) acids--in comparison with other known vasodilators--sodium nitroprusside, nitroglycerin, papaverine, and D600--were studied in the isolated rat aorta. The relaxant responses of these vasodilators and fatty acids at concentrations of 1-100 microM were assessed in aortic rings contracted with norepinephrine (NE 10(-6) M) or with KCl (30 mM). Cyclic nucleotide enhancers (sodium nitroprusside, nitroglycerin, papaverine) were more effective in producing relaxation, regardless of the contractile mechanism, i.e., alpha-adrenoceptor stimulation or depolarization. In contrast, the omega-3 fatty acids produced augmented relaxation in NE-contracted vessels. Relaxations produced by DHA (15 +/- 2% to 45 +/- 10%) were similar to D600 (16 +/- 2% to 60 +/- 7%) in NE-contracted rings, but not in KCl contracted rings. The responses to D600 and DHA in KCl-contracted vessels were 79 +/- 2% to 104 +/- 3% and 5 +/- 1% to 21 +/- 3%, respectively. In another set of experiments, the effects of omega-3 fatty acids in the presence of albumin were examined; no significant differences in the induced relaxant responses were noted. These results suggest that the mechanisms of vascular relaxation, such as cyclic nucleotide elevation and calcium antagonism of potential-operated channels, are different from those induced by the omega-3 fatty acids.


Effects of sodium nitroprusside (MR7S1) and nitroglycerin on the systemic, renal, cerebral, and coronary circulation of dogs anesthetized with enflurane.

In beagle dogs anesthetized with enflurane-nitrous oxide, effects of sodium nitroprusside (SNP; MR7S1) and nitroglycerin (NTG) on hemodynamics and main organ circulation were studied to evaluate their effectiveness and safety as hypotensive agents during anesthesia. SNP (MR7S1) infusion (1-10 micrograms/kg/min) decreased arterial blood pressure in a dose-dependent manner. The hypotension was stable during the infusion. After discontinuation of infusion, the blood pressure rapidly returned to the initial level. The hypotension was associated with decreases in cardiac output and total peripheral resistance. NTG infusion (3-10 micrograms/kg/min) decreased arterial blood pressure, too, but the hypotension was less marked and not dose dependent, and the recovery was slower. Neither drug changed the heart rate. Infusion of SNP (MR7S1) and NTG did not change the hypotension induced by the injection of adenosine, SNP, and NTG. Furthermore, cerebral blood flow, cerebral oxygen consumption, and renal blood flow were unchanged during the hypotension produced by either drug. Coronary blood flow was decreased, but this was due to decreases in cardiac oxygen consumption. In conclusion, SNP (MR7S1) is superior to NTG as a hypotensive agent during anesthesia in efficacy, clear dose dependency, and rapid recovery. The hypotension induced by NTG as well as SNP (MR7S1) seems to have no undesirable effects on the circulation of important organs.


Effect of simvastatin on high density lipoprotein subfractions and apolipoproteins in type IIa hypercholesterolemia.

Changes in plasma concentrations of high density lipoproteins (HDL) and triglycerides may partly explain the ability of cholesterol-lowering drugs to decrease the incidence of coronary heart disease. We measured the response of fasting plasma lipids, lipoproteins, and apolipoproteins in 46 subjects with Type IIa hypercholesterolemia treated with simvastatin for 3 months. The initial dose of simvastatin (10 mg/day) was subsequently increased up to 40 mg/day if the plasma cholesterol concentration had not fallen below 5.2 mmol/l. Plasma concentrations of HDL cholesterol and of the apolipoproteins AI and AII were increased by simvastatin. The increase in HDL cholesterol (9%) was due to increases in both subfractions (HDL2 17%; HDL3 7%), changes that would be consistent with a beneficial effect on cardiovascular risk. Simvastatin decreased plasma triglyceride concentrations by 25%. Plasma total cholesterol concentrations fell by 35% after 3 months of treatment; this fall was proportional to the initial concentration and was due almost entirely to a 45% fall in low density lipoprotein cholesterol. In contrast, plasma concentrations of lipoprotein Lp(a) were not affected by simvastatin.


The effect of transdermal nitroglycerin on exercise tolerance in relation to patch application time--a meta-analysis.

Disagreeing results have been reported in the many studies on continuous treatment with nitroglycerin patches. The effects on exercise tolerance are partly studied at the end of a 24-hour application period, and partly examined only a few hours after patch renewal. The present meta-analysis estimates the overall efficacy of nitroglycerin patches in trials with and without concomitant antianginal therapy, and investigates if the treatment effect depends on the patch application time. A computed search (MEDLINE) identified 110 publications, of which 17 trials on nitrate patch monotherapy and six trials on combined therapy satisfied the inclusion criteria. Data on "exercise duration" and "ST-segment depression" were converted to a standardized treatment effect size d, and pooled to an overall treatment effect size d+. In tests 2-5 hours after patch renewal, moderate but significant effects of nitrate monotherapy were observed; d+ was 1.20 with regard to "ST-segment depression" and 0.39 with regard to "exercise duration" (both p < 0.0001). In contrast, 24 hours after patch application, the values for d+ were 0.09 (not significant) and 0.36 (p < 0.01), respectively. When adding the results from the six trials on combined therapy, d+ with regard to "exercise duration" was reduced to 0.28 (p < 0.0001) 2-5 hours after renewal and to 0.17 (p = 0.04) after 24 hours. Thus, the efficacy of continuous nitroglycerin patch treatment is moderate but evident during exercise tests 2-5 hours after patch renewal; however, it is reduced after 24 hours of patch application.


Successful treatment of postoperative external biliary fistula by selective nasobiliary drainage.

A 25-year old man presented with a high output external biliary fistula after an operation for a giant hydatid cyst of the liver. Endoscopic sphincterotomy was inadequate to close the fistula. A nasobiliary tube was selectively inserted into the leaking hepatic duct and bile was continuously aspirated. The fistula and the residual cavity healed completely. Details of the patients' management using this alternative technique, are discussed.


Multiple biliary papillomatosis.

Diffuse biliary papillomatosis is a rare bile duct tumour. We report a case of multiple biliary papillomatosis treated surgically with a transhepatic stent. Diffuse biliary papillomatosis involving intra and extrahepatic bile ducts is extremely rare. It is regarded as having low grade malignant potential. In this report a case of diffuse biliary papillomatosis with obstructive jaundice is presented.


Acute calculous cholecystitis. What is new in diagnosis and therapy?

The management of patients with acute calculous cholecystitis has changed during recent years. The etiology of acute cholecystitis is still not fully understood. Infection of bile is relatively unimportant since bile and gallbladder wall cultures are sterile in many patients with acute cholecystitis. Ultrasonography is first choice for diagnosis of acute cholecystitis and cholescintigraphy is second best. Percutaneous puncture of the gallbladder that can be used for therapeutic drainage has also diagnostic qualities. Early cholecystectomy under antibiotic prophylaxis is the treatment of choice, and has been shown to be superior to delayed surgery in several prospective trials. Mortality can be as low as 0.5% in patients younger than 70-80 years of age, but a high mortality has been reported in octogenerians. Selective intraoperative cholangiography is now generally accepted and no advantage of routine cholangiography was shown in clinical trials. Percutaneous cholecystostomy can be successfully performed under ultrasound guidance and has a place in the treatment of severely ill patients with acute cholecystitis. Laparoscopic cholecystectomy can be done safely in patients with acute cholecystitis, but extensive experience with this technique is necessary. Endoscopic retrograde drainage of the gallbladder by introduction of a catheter in the cystic duct is feasible but data are still scarce.


Experimental and clinical evaluation of capsular and parenchymal total liver perfusion. Liver microcirculation.

Liver blood flow measurements obtained from both the liver surface and deep within the parenchyma, were correlated in an effort to assess the usefulness of laser-Doppler flowmetry for non-invasive monitoring of total liver blood flow, the probe being positioned on either the surface or within the liver parenchyma. In 23 Wistar rats and 10 biliary surgery patients, anaesthetized prior to gallbladder removal, liver microcirculation was measured at 4 points on the capsular surface, and consequently at 4 points deep within the parenchyma, using probes connected to a laser-Doppler flowmeter. The findings revealed that laser-Doppler measurements on the liver surface and within the parenchyma were well correlated, as no statistically significant differences were found either in rats or humans. It is concluded that laser-Doppler flowmetry for monitoring of total liver perfusion can be applied either on the capsular surface or within the hepatic parenchyma.


Fostering research growth in a nursing department.

Introducing research objectives in nursing departments is presenting challenges for nurse administrators. Where does one begin? The Nursing Department at Toronto General Hospital implemented a number of strategies to make the vision, "research integrated with daily practice", a reality. The strategies served to translate the vision into concrete actions. Three broad themes are used to describe the strategies--bringing resources together, raising awareness about research and conducting research projects. This article describes some of the strategies we implemented in anticipation that other Nursing Departments may benefit from our experiences.


Development of a research committee at a community hospital.

This paper describes the process undertaken in setting up a nursing research committee in a community hospital in British Columbia. The primary goal of the committee is to increase awareness among bedside nurses of the value of research in their practice. This goal is based on the belief that research conducted by practicing nurses validates existing practice and promotes quality patient care, important concerns for nurse administrators.


Five years in the life of a nursing research and professional development division.

The Nursing Research and Professional Development Directorate was established to support the growth of research of professional practice in the Nursing Department. Designed as an innovative work structure, it elicited high commitment from its members, contributed to their satisfaction and freed their creative potential. The organizational structure and processes were designed to satisfy the important work criteria of involvement in decision-making, equity, dignity, security, job challenge, autonomy, mutual trust and open communication. The Directorate not only brought together expertise in research and professional development but also created mechanisms to ensure the expertise was available at the bedside. With a mandate of developing and transmitting knowledge, the availability of that knowledge in the practice arena is a mark of our success. This article describes our formative experiences including the structure, processes and outcomes of our work. The challenges we faced are also discussed.


[Tuberculous meningitis in patients without HIV infection. Presentation of 21 cases].

Tuberculous meningitis accounts for 5% to 12% of all extrapulmonary tuberculosis cases in western-hemisphere population non infected by HIV virus, and carries a high mortality rate. We analyze retrospectively 21 patients with tuberculous meningitis in HIV negative patients seen from 1975 to 1989, with emphasis on clinical, laboratory and therapeutic features. In 48% of cases there were not typical meningeal signs, and 61% of patients showed neurological focal signs and/or seizures. CSF examination revealed a clear fluid with high cell counts (mostly lymphocytes), high protein and low sugar levels in 67% of cases. However, the microbiologic examination had a low yield of diagnosis (33%). The clinical course is prolonged, and treatment is usually delayed. Morbidity and mortality were high (34% and 10% of cases). In this study, the use of steroids did not show a significant reduction in mortality nor in neurological sequelae. Tuberculous meningitis in HIV negative patients is a chronic infection, without meningeal signs in most cases and linked to a high rate of neurological defects. The microbiologic tests have low yield of diagnosis. Steroid drugs seem to be indicated only if there are additional complications.


Job sharing: impact on the general well-being of female nurses.

Women today have more life choices than ever before: career, marriage, motherhood, or any combination of the three. Unfortunately little has been done to make up for the competing demands of these roles. Job sharing may be the alternative choice which allows working women to cope with the multiple stressors of having it all--career and family without having to sacrifice their sense of well-being. Nursing administrators stand to benefit from a work schedule alternative which promotes a healthy balance between work and family. Job sharing may offer a solution to the loss of valued staff nurses who require less than full-time employment. In order to compare the general well-being of female nurses who are employed in full-time, casual part-time, and job sharing positions a descriptive correlation study was conducted. One hundred female nurses between the ages of 22 and 40 who have their children living at home with them completed the 18-Item General Well-Being Questionnaire. Additional questions regarding job satisfaction, physical health status, and demographic data were also included. The results of the analyses of variances revealed there were no statistical differences between the general well-being scores of women working full-time, casual part-time, or job sharing. However, crosstabulations showed the job sharing nurses had the highest ratings for job satisfaction and physical health status.


[Septic shock: epidemiology and prognosis].

As part of an infection control program in ICU, we studied prospectively 1500 consecutive patients admitted to a medical and surgical ICU from January 1988 to July 1990. Over this period of time, 69 patients developed septic shock, and 38 of them died (55.1%). Primary source of infection was the lower respiratory tract or intraabdominal in more than 50% of cases, and were related to a high mortality rate, however SS arising from a biliary tract infection is associated with a mortality rate below 20%. In the univariate analysis, nosocomial origin (p = 0.0001), creatinine serum level > 175 mumol/l (p = 0.005), multiple organ failure in the first 24 hours after shock started (p = 0.02), underlying cancer disease (p = 0.02) or liver cirrhosis (p = 0.03) were associated with a statistically significant higher risk for dying. No differences were found regarding age, sex, admission date, coma, recent surgery, prior cardiac arrest, diabetes, organ transplantation, corticosteroid therapy, cancer chemotherapy, absence of fever, bacteriology of the infection and appropriate antibiotic therapy. The multivariate analysis further identified that creatinine serum level > 175 mumol/l (p = 0.004), underlying cancer disease (p = 0.005), liver cirrhosis (p = 0.02) and nosocomial-acquired infection (p = 0.02) were independently associated to a higher risk for dying. These data allows the identification of factors related to a worst outcome. The high mortality rates recorded for septic shock still recommends the rapid transfer of the patient to an ICU as well as the use of aggressive therapy in all cases.


[Molecular study of ampicillin resistance in clinical isolates of Salmonella].

The purpose of this work was to study the molecular basis of beta-lactamase production in ampicillin-resistant strains of Salmonella spp. It was performed analytical isoelectric focusing of beta-lactamases produced by a group of 33 strains selected in basis of their resistance phenotype. Plasmid profile analysis and assays of transferable drug resistance were developed. The study was completed by hybridization experiments with an intragenic TEM probe which allowed the location of the bla-TEM gene. By analytical isoelectrofocusing we found that 26 out of the 27 ampicillin-resistant strains produced beta-lactamases with pl 5.4 and/or 5.6 corresponding to TEM-1 and/or TEM-2 type. Analysis of plasmid DNA revealed in almost all strains plasmids ranging in size from 1.1 to 125 Mdal. This plasmids were responsible of the resistance and, moreover, were able to transfer the resistance by conjugation mechanisms. Southern blot analysis detected the gene that code the TEM beta-lactamase at the 125, 8 and 5.8 Mdal plasmids. Resistance to ampicillin in the strains of Salmonella studied was due to the presence of TEM type beta-lactamases coded by conjugative plasmids. These plasmids coded also resistance to other antimicrobial agents. Our results showed that the use of a DNA probe to the detect TEM-type beta-lactamases using a non radioactive probe, could be a suitable alternative to isoelectric focusing.


[Prevalence and treatment of bacteriuria in the geriatric population].

The aim of this study was to evaluate the prevalence of asymptomatic bacteriuria and its prognostic factors in a geriatric population living in a nursing home. Seventy-eight patients (68 females, 10 males) with a mean age of 82 +/- 6 years (range: 60-94) were studied. Once symptomatic infection is ruled out and the risk factors had been analyzed, a urine culture was performed in all cases. We then identified two different population groups: asymptomatic bacteriuria without risk factors (group A), and asymptomatic bacteriuria with risk factors (group B). Overall prevalence of asymptomatic bacteriuria was 38.5% (Group A: 23%, group B: 63%; p < 0.001). Considering all patients with bacteriuria, 50% of cases (15 out of 30 patients) had urine incontinence, 40% suffer from severe limitation of movements and 70% had a past history of pregnancy. The same figures for the population with negative urine culture were 12.5%, 14.5%, and 46% respectively (p < 0.01). In group B, 79% of cases had more than one RF, including all patients with the association of urine incontinence, movement limitation and diabetes. In group A, 93% of asymptomatic bacteriuria were due to E. coli with low adhesin expression (27%) whereas in group B, E. coli was isolated in 44% asymptomatic bacteriuria cases, with high adhesin expression (71.5%), other enteric gram-negative bacilli (31%), non-fermentative gram-negative bacilli (19%) and gram-positive cocci (6%). Group A patients were treated with a single dose of ciprofloxacin (500 mg) with elimination of bacteria in urine in 91% of cases (at one week) and 73% of cases (at one month).(ABSTRACT TRUNCATED AT 250 WORDS)


[Pulmonary cryptococcosis in AIDS].

We present here three AIDS patients with disseminated cryptococcal infection and lung involvement. Two patients presented with respiratory symptoms and in the third one, pulmonary disease was only a radiologic finding. Chest X-ray films showed an interstitial pattern in two cases and pulmonary cavitation in one case. One patient has also simultaneous infection by P. carinii. Diagnosis was established by culture from bronchoalveolar lavage in all cases and also by non-induced sputum exam in two cases. All patients were treated with amphotericin B, with good clinical outcome, and without relapses under maintenance therapy with fluconazole. Cryptococcosis must be included in differential diagnosis of AIDS patients with diffuse interstitial lung infiltrates. The presence of C. neoformans in respiratory samples does not rule out the existence of other opportunistic infections, and therefore bronchoalveolar lavage is advisable.


[Mycobacteriosis during 1980-1990 in a Madrid hospital].

To assess the incidence and features of environmental mycobacteria that can produce disease over a ten years period (1980-1990) in an University Hospital from Madrid (Spain). Medical records of all patients in whom and environmental mycobacteria that can produce disease had been isolated were reviewed and classified as definite, possible or not clinically significant isolates, according to clinical features and microbiologic findings. Mycobacterium species were isolated in 415 patients (491 clinical samples over a total of 3003, 16.3%). In 29 patients a environmental mycobacteria that can produce disease was identified. Medical records from 25 patients were retrieved, being this mycobacteria isolated classified as with definite clinical significance in 8 cases, with possible clinical significance in 4, and without clinical significance in 13 cases. Clinical features in the significant cases were: lung infection (3 cases), pleural and pericardial disease (1 case), peritonitis (1) and soft tissue infection (1) Two patients died. Surgical excision of the lesion was performed in the remaining patients, and clinical cure was achieved in five cases. The most prevalent mycobacterial infection in our environment is still due to M. tuberculosis infection, followed by M.avium-intracellulare. Surgical treatment is a valid approach in patients with localized infection by environmental mycobacteria that can produce diseases.


Surfactin/iturin A interactions may explain the synergistic effect of surfactin on the biological properties of iturin A.

Iturin A and surfactin are two lipopeptides extracted from a same strain of Bacillus subtilis. Iturin A possesses antibiotic and antifungal activities and surfactin is a strong surfactant. The presence of surfactin, at a concentration at which, alone, it is inactive, increases to a very large extent the haemolysis percent induced by iturin A. This synergistic effect seems to be in relation with interactions between iturin A and surfactin. Iturin A adsorbs to and penetrates into surfactin monolayers. Iturin A and surfactin are miscible and interact specifically in mixed monolayers.


Expression of the full-length rabbit prolactin receptor and its specific domains in baculovirus infected insect cells.

The prolactin receptor is a membrane protein mainly involved in the development of the mammary gland and in lactation in mammals. We used specific cDNA constructs and the insect/baculovirus expression system and produced independently and in large amounts several recombinant forms of the rabbit mammary gland prolactin receptor: the full-length receptor (L1, L2), a truncated membrane form (S), a secretable form of the extracellular domain (E) and two forms of the intracellular domain (I1, I2). Of these forms, the L1 and L2 are associated with the membrane fraction, the E is predominantly secreted into the medium and the I1 and I2 are expressed as soluble proteins and surprisingly, a great portion accumulates in the culture medium. The molecular mass (94 kDa) of the expressed full-length receptor corresponds to the translation product of the entire cDNA coding region. The receptor biochemically identified in the rabbit mammary gland is however much shorter. Thus, in the mammary gland, the receptor presumably undergoes post-translational modifications. The receptor forms L1, L2 and S bind prolactin with specificity and affinity similar to those reported for the native receptor. They also interact with two monoclonal antibodies, M110 and A917, specific for the native conformation of the hormone-binding site. The I1 and I2 forms do not bind prolactin, whereas the E form does. Thus, the hormone binding site is located in the extracellular domain which can function autonomously as a PRL-binding soluble protein. However, the E form binds prolactin with a higher affinity than the native receptor and it does not bind one of the two antireceptor monoclonal antibodies, known to be hormone binding-site specific. Thus, the conformation of the native receptor and that of the E form differ.


Organization of repetitive DNA sequences in the genome of the echinoderm Holothuria tubulosa.

The abundance of repetitive DNA in the haploid sea cucumber genome has been determined by screening a Holothuria genomic DNA library for clones containing repeated sequences using reverse genome hybridization. Analysis by in situ plaque hybridization of a set of 1132 clones has revealed the presence of repetitive DNA sequences in about 38.1% of the clones screened. The distribution of the reiterated DNA has been further analyzed by restriction endonuclease digestion of seven randomly selected repetitive clones. The repeated sequences have a fairly uniform distribution of lengths with an average length value of 7.3 kb. Analysis of the measurements suggests that the repetitive sequences are interspersed among longer single copy sequences with an average spacing interval of about 47.3 kb indicating that the repetitive and single copy DNA in the Holothuria genome are arranged in a long-period interspersion pattern.


Detection of satellite DNA in Palorus ratzeburgii: analysis of curvature profiles and comparison with Tenebrio molitor satellite DNA.

Very abundant and homogenous satellite DNA has been found in the flour beetle Palorus ratzeburgii, representing 40% of its genome. Sequencing of 14 randomly cloned satellite monomers revealed a conserved monomer length of 142 bp and an average A+T content of 68%. Sequence variation analysis showed that base substitutions, appearing with a frequency of 2.3%, are predominant differences among satellite monomers. The satellite sequence is unique without significant direct repeats and with only two potentially stable inverted repeats. After electrophoresis of satellite monomers on native polyacrylamide gel retarded mobilities characteristic for curved DNA molecules are observed. The curvature profiles and DNA helix axis trajectory are calculated on the basis of three different algorithms. These calculations predict that P ratzeburgii satellite DNA forms a left-handed solenoid superstructure. Comparison of described features with other satellite DNAs reveals some striking similarities with satellite DNA from related species Tenebrio molitor, which belongs to the same family of Tenebrionidae. Both satellites are very abundant and homogenous with the same, highly conserved monomer length, although there is no homology at the nucleotide level. Their monomers, as well as multimers, exhibit very similar retarded electrophoretic mobilities. The calculated curvature profiles predict two bend centers in monomers of each satellite, resulting in a model of left-handed solenoid superstructures of similar appearance.


Refined conditions for selective modifications of rabbit skeletal myosin light chains.

We selectively modified the LC1 and LC2 N-terminus as an approach to understand the function of skeletal myosin light chains and their possible implication in some diseases. Three new myosin isoforms were thus created, namely: myosin-[(P)LC1'], myosin-[(T)LC2'] and myosin-[(CT)LC2"] in which the N-terminus was selectively cleaved at Lys7 in (P)LC1', Arg8 in (T)LC2' and Phe19 in (CT)LC2". In order to obtain species with a minimum amount of secondary cleavages, eight to 12 different conditions were screened for each species and the two most efficient conditions were tested at the preparative scale.


Purification of a heparin binding FGF receptor (HB-FGFR) from adult bovine brain membranes.

A new form of high affinity fibroblast growth factor receptor has been purified from adult bovine brain membranes. Purification was performed by chromatography on DEAE-Trisacryl and wheat germ agglutinin-agarose followed by FGF-2 affinity chromatography. Affinity labeling of purified fractions with 125I-FGF-2 showed after cross-linking a 170-kDa complex, suggesting the existence of a 150-kDa FGF receptor. No cross-reactivity with anti-FGF receptor 1 (FGFR-1 or flg) or with anti-receptor 2 (FGFR-2 or bek) antibodies could be detected with this partially purified receptor. Heparitinase treatment of the partially purified FGF receptor abolished the formation of the ligand receptor complex. The complex was restored in the presence of heparin in a dose dependent fashion, supporting the idea that heparin-like molecules are needed for proper binding. Further purification of the receptor was achieved by heparin-Sepharose affinity chromatography and yielded a purification of over 320,000-fold. The purified receptor fraction was radiolabeled and loaded on RPLC C4 column. Eluted fractions were analysed by SDS-PAGE. A major 150-kDa band was detected. These data show for the first time a new form of FGF receptor isolated from bovine brain membranes. This purified receptor displays affinity for heparin and was therefore named heparin binding FGF receptor (HB-FGFR). It remains unclear whether the receptor is a proteo-heparin sulfate or whether heparans are strongly associated and therefore are copurified. Large scale preparations are in progress for core protein structure studies.


Differential expression of PDGF A- and B-chain genes and production of AA and AB dimers by activated human blood monocytes.

Platelet-derived growth factor (PDGF) is composed of two chains (A and B) bound by disulfide bridges. Blood monocytes (BM) express the c-sis proto-oncogene, the gene coding for PDGF B-chain, and release PDGF. To evaluate PDGF release and A- and B-chain gene expression by BM, normal BM were cultured with LPS and specific transcripts for PDGF A- and B-chain genes were detected by Northern analysis and PDGF dimers by specific Elisas. Normal BM did not spontaneously express either A- or B-chain gene while, when activated, PDGF B-chain expression was precocious (maximum at 1 h) and decreased over 24 h; PDGF A-chain transcripts were present after 4 h and progressively increased over 24 h. Furthermore, activated BM released more AB dimers than AA dimers and almost no BB dimers. This observation confirms the concept of PDGF A- and B-chain separate gene regulation, and defines the specific molecular pattern of PDGF released by activated BM.


20-alpha-Hydroxysteroid dehydrogenase from pseudopregnant rat ovary: obtention and characterization of a monoclonal antibody against the enzyme activity.

The enzyme 20-alpha-hydroxysteroid dehydrogenase (20-alpha-HSD) was purified from pseudopregnant rat ovaries and used as antigen for the development of a monoclonal antibody by the hybridoma technique. Spleen cells of BALB/c mice immunized with purified 20-alpha-HSD were fused with SP2/0 mouse myeloma cells. Among the colonies of hybrid cells, one (designated mAb-HSD 11) was found to be secreting antibodies (IgM) able to inhibit 20-alpha-HSD activity. The antibody-secreting hybridome was amplified by ascitic fluid production and the monoclonal antibody purified by Bakerbond ABx procedure. Purified mAb-HSD 11 was able to inhibit 20-alpha-HSD activity in a dose-dependent manner. Studies of Michaelis constants of 20-alpha-HSD indicate that this monoclonal antibody increases the Km for 20-alpha-dihydroprogesterone and decreases the Vmax.


[Changes in the epidemiological profile of dentofacial anomalies and in the status of orthodontic treatment between 1979 and 1989 in the city and district of Leipzig (an ICS-I replication study). International Study of Dental Manpower System].

Ten years after the Leipzig ICS-I-Study a replication study was performed in analogous fashion and in the same territory. Using the COCSTOC methods changes in the prevalence of dental-facial anomalies and the orthodontic state of treatment were determined in a random sample of 13-14-year-old school children. The prevalence of anomalies had decreased within a decade from 43% to 35%. At the same time the percentage of children not under treatment decreased from 14% to 10%. The causes are seen mainly in the area under consideration and the related preservation of the support zone until the physiological replacement of teeth as well as a reduced extraction rate for primary and permanent teeth.


[The follow-up of the orthodontic treatment of facial cleft patients with the Göttingen computer-supported documentation system].

The care of patients with cleft lip, alveolus, and palate demands supervision of the development and progress over a long period of time. It also requires a standardized and systematic basic documentation. In our cleft center the documentation is summarized on one sheet of paper with DIN-A4 formation (297 x 210 mm). The use of electronic data processing improves the documentation. The storage of general and medical data has been supplemented by a personal computer system, PC-System. Five years after developing of this computer aided documentation system several patients are shown as examples for the application of this system for longterm control patients with cleft lip, alveolus, and palate.


[Mandibular condyle fractures in childhood--the clinico-roentgenological follow-up].

In a clinical and roentgenographical follow-up study in 35 children, who had suffered a fracture of the condylar process of the lower jaw, the following observations were made on the average 61 months after conservative treatment: The clinical outcome ranged from "satisfactory function" to "restitutio ad integrum". Best results were achieved after unilateral displaced fractures, while only few children showed a "restitutio ad integrum" after bilateral fractures or/and after fracture dislocations. In children, who were less than 8 years old, the results were much better than in older ones. Roentgenographically the morphological regeneration after fracture dislocations was frequently incomplete--in the contrary to fractures with displacement.


[Changes in the condyle path following fractures with dislocation of the maxilla].

In spite of rigid internal fixation with miniplates after midfacial fractures, dislocation of the previously mobilized fragment in the dorsal direction is conceivable. Thus, the mandible would be forced into a dorsal position over the occlusion. As a result, changes of the condyle paths, such as limitations or deviations from the normal, would be possible. Six patients, who had sustained midfacial fractures with mobilization or dislocation of the maxilla, were followed up. The condyle paths were recorded at the earliest time possible after rigid internal fixation and after removal of the miniplates. We used the electronic computer-assisted registration system (ECRS), which allows three-dimensional registration without occlusal interferences. The patterns of the TMJ movements were not impaired, arguing against the dorsal transposition of the maxilla. The extent of the movements during the first postoperative weeks, however, was significantly reduced in some cases, even if intermaxillary fixation was not carried out. In our opinion, this is due to the periarticular infiltration and a varying elasticity of the articular capsule in different directions.


[The bacteriological and clinical aspects of odontogenic soft-tissue infections].

The antibiotic treatment is proved to be an effective supplement for the surgical therapy of odontogenic soft-tissue infections. For the use of antibiotics the knowledge of the oral bacterial flora and its state of resistance is very essential. In a catamnestic study the clinical records of 250 patients with orofacial infections, who were under stationary treatment in the Dept. of Maxillofacial Surgery, University Clinic Göttingen, were analyzed. The results show, that the bacterial flora has not changed basically during the last decade. Predominantly mixed aerobic and anaerobic infections can be found. Increasing importance must be attached to penicillin-resistant Staphylococci and anaerobic pathogens. Penicillins must be further considered as antibiotics of the first choice. For an extension of the antimicrobial activity the combination with a betalactamase inhibitor is useful.


[Necrotizing sialometaplasia].

The necrotising sialometaplasia is a rare disease of the orofacial system. The minor salivary glands of the palate are the main localisation. It's clinical importance consists in the possibility of confusion with squamous cell carcinoma or the mucoepidermoid tumor. The authors report on 3 cases and discuss the etiology and the diagnostic of this disease.


[The limits of root planing in the furcation area. A mathematical comparison of the radii of curvature on the root surfaces and on the curettes].

In order to draw some conclusions about the furcation region accessibility for periodontal instruments and their cleaning effect, the curvature radii of the root faces of 31 lower molars were mathematically determined and compared with the curvature radii of the working end of normally available curettes. From the results of this work it can be seen, that the Gracey curettes have an essential greater curvature radius as the curvature radius of the root faces. On the other site the special curettes for root planing in the furcation region have a smaller curvature radius as that of the root faces. Using the instruments included in this study, it is not possible to achieve an optimal root planing.


Cloning, expression and characterization of ovine interleukins 1 alpha and beta.

Ovine interleukin 1 alpha (IL-1 alpha) c-DNA, obtained by polymerase chain reaction, has been cloned into pTZ18R and pTZ19R. The resulting DNA sequence shows close homology with the bovine sequence. The derived amino-acid sequence shows conserved motifs similar to those observed in all species studied so far. No signal peptide is seen. Northern blots of RNA from lipopolysaccharide (LPS)-stimulated ovine alveolar macrophages show IL-1 beta m-RNA to be produced earlier than and to be more transient than IL-1 alpha m-RNA. c-DNAs coding for the IL-1 alpha proprotein and IL-1 alpha and IL-1 beta mature proteins have been cloned and expressed in the yeast Ty-VLP system as fusion proteins. The resultant IL-1 protein preparations, cleaved from their fusion partners by the action of activated coagulation Factor Xa, are 80-95% pure and show biological activity in standard thymocyte co-mitogen and cartilage degradation assays for IL-1. Some species specificity is observed in that sheep thymocytes are more responsive to ovine rIL-1 than are mouse thymocytes. The presence of a Factor Xa cleavage site in the IL-1 alpha proprotein suggests that Factor Xa may be involved in the processing of ovine IL-1 alpha to its mature form.


Gene transfer investigations of p56-LCK function in IL-2-dependent T-cell lines: implications for mechanisms of IL-2-signal transduction.

Recently, the SRC-like non-receptor protein tyrosine kinase p56-LCK has been shown to physically associate with the interleukin-2 receptor (IL-2-R) complex and to undergo rapid elevations in its tyrosine kinase activity upon stimulation of T lymphocytes with IL-2. The functional significance of p56-LCK kinase activation for IL-2-mediated lymphocyte responses, however, has never been directly assessed. Using gene transfer approaches, we have achieved markedly elevated levels of p56-LCK kinase activity in the IL-2-dependent cytolytic T-cell line CTLL-2 and the helper line HT-2. CTLL-2 and HT-2 cells that were stably transfected with expression plasmids encoding either the normal human p56-LCK or a constitutively active version of the mouse p56-LCK kinase (LCK[Y505]) contained striking elevations in the levels of tyrosine phosphorylation on several proteins (34-36, 50-60, 62-68, 77-78, 104-110 kDa), as determined by immunoblot analysis using anti-phosphotyrosine antibodies. CTLL-2 and HT-2 LCK- and LCK(Y505F)-transfected cells remained dependent on IL-2 for their growth and survival in culture despite the findings that (i) IL-2 specifically stimulated elevations in the activity of the endogenous p56-LCK in untransfected CTLL-2 cells without affecting the activities of the other SRC-like kinases in these cells (p59-FYN, p62-YES) and that (ii) IL-2-mediated regulation of p56-LCK correlated with IL-2-driven proliferation of these T cells. Specifically, no elevation in the proliferation (DNA synthesis) or growth of these T cells was found at any of the concentrations of IL-2 examined (0.01-25 U/ml), relative to untransfected and control transfected cells. Furthermore, when cultured in the absence of IL-2, transfected T cells whose relative levels of p56-LCK activity were elevated by approximately 20-50-fold died with the same kinetics as control cells and underwent apoptosis, as defined by uptake of trypan blue dye and DNA fragmentation assays, respectively. Taken together, these data indicate that while IL-2 can up-regulate the enzymatic activity of p56-LCK, elevated levels of p56-LCK tyrosine kinase activity are insufficient to stimulate IL-2-mediated pathways required for T-cell growth and survival. These findings thus imply the existence of other signal-transducing molecules, besides p56-LCK, that physically participate in IL-2R complexes and that are necessary for initiation of the biochemical events ultimately responsible for IL-2's pleiotropic actions on lymphocytes.


Human B cell lines express the interferon gamma gene.

Interferon gamma (IFN-gamma) production has been attributed exclusively to activated T cells and NK cells. We sought to determine whether human B cells express IFN-gamma. We studied 28 B cell lines including Epstein-Barr virus (EBV)+ normal lymphoblastoid B cell lines (N = 7), EBV+ B cell lines derived from patients with Burkitt's lymphoma with (N = 6) or without AIDS (N = 8), as well as seven EBV- B cell lines. All cell lines were studied by reverse transcription-polymerase chain reaction (RT-PCR). We detected constitutive expression of IFN-gamma in every B cell line. The tumor promoters PMA and teleocidin appeared to enhance this IFN-gamma expression in nearly every B cell line. The 517 bp amplicons spanning the entire protein coding region of the IFN-gamma mRNA from three representative lines were sequenced, definitively establishing that B cell IFN-gamma is identical to IFN-gamma from activated T cells and is not altered by derivation of the B cell lines from AIDS patients or by EBV status. Detection of IFN-gamma in the entire panel of EBV+ and EBV- cell lines suggests that the IFN-gamma gene is broadly expressed by human B cells. Our data imply that human B cells can be activated to produce IFN-gamma, further enmeshing B cells in the dynamics of immunoregulation.


Multiple cytokine secretion by IL-7-stimulated human T cells.

The induction of cytokine secretion by human peripheral blood (PB) T cells was examined. Highly purified T cells stimulated with interleukin 7 (IL-7), in the absence of co-mitogen, secreted IL-2, IL-4, IL-6 and interferon gamma (IFN-gamma) upon restimulation with phorbol ester and ionomycin. In contrast, induction of T-cell cultures initiated with IL-2 or IL-4 yielded only low levels of IL-6 and virtually undetectable levels of IL-4 or IFN-gamma, while IL-2 secretion was reduced. No difference was seen in the ability of CD4+ and CD8+ subpopulations, grown in IL-7, to produce cytokines. In contrast, subdivision of T cells into memory and naive populations using the CD45RO monoclonal antibody (mAb) UCHL1, revealed that almost all of the potential to secrete IL-4 and IL-6 in response to IL-7 resided in the CD45RO+ memory population. Stimulation of cytokine-secreting cells appeared to be a direct effect of IL-7 as neutralizing antibodies directed against IL-2 and IL-4 had no effect on the levels of cytokines produced. The differences observed in the ability of IL-2, IL-4, and IL-7 to potentiate cytokine production was supported by measurement of cytokine mRNA levels by PCR. The elevated levels of cytokine secretion seen in cells cultured with IL-7 was not due simply to increased viability in these cultures compared with those containing IL-2 or IL-4, as these populations showed comparable cloning frequencies in phytohemagglutinin (PHA) + IL-2. These results demonstrate that IL-7, in the absence of co-mitogen, is a potent initial stimulus for multiple cytokine production by human T cells upon restimulation.


The in vitro growth of murine high proliferative potential-colony forming cells is not enhanced by growth in a low oxygen atmosphere.

The growth of primitive murine hematopoietic progenitors, high proliferative potential colony-forming cells (HPP-CFC), has been reported to be improved in low O2 tension cultures. In this report we investigated the growth of HPP-CFC stimulated by combinations of interleukin (IL)-1, IL-6, kit-ligand (KL), granulocyte (G) colony-stimulating factor (CSF), macrophage-CSF (M-CSF), granulocyte-macrophage-CSF (GM-CSF) and IL-3 in clonal cultures incubated at 7% or 21% O2 tension. Neither the numbers of HPP-CFC colonies nor the number of cells per HPP-CFC colony differed significantly between cultures grown under 7% or 21% O2 tension. The mean number of cells per HPP-CFC colony was found to range from 3.9 x 10(4) to 2.2 x 10(5). The smallest HPP-CFC colonies were stimulated by the cytokine combination IL-1 + IL-6 + KL, whereas the largest colonies were stimulated by a combination of all seven cytokines tested. The growth of erythroid colonies from murine or human bone marrow did, however, show some enhancement when cultured at a lower O2 tension. These results demonstrate that the growth of murine HPP-CFC was not compromised when cultured at ambient O2 concentration.


Activated human Langerhans cells express mRNA for IL-1 alpha and IL-1 beta and produce these cytokines but do not secrete them.

Human Langerhans cells (LC) were isolated from epidermal cell preparations by panning with mouse anti-CD1 monoclonal antibody. RNA was prepared and probed for the presence of mRNAs for various cytokines using radiolabeled cDNAs. After stimulation with phorbol myristate acetate LC express RNA for interleukin 1 alpha (IL-1 alpha) and interleukin 1 beta (IL-1 beta) and produce proteins but do not secrete them at detectable levels. LC-associated IL-1, particularly IL-1 alpha, may play a role in antigen presentation. PMA did not induce IL-6 expression in LC. The addition of lipopolysaccharide, a muramyl dipeptide analog, ionomycin, IL-1 alpha, tumor necrosis factor-alpha, insulin-like growth factor-1 or IL-6 did not induce IL-1 mRNA in LC. UVB augmented IL-1 beta mRNA expression. Glucocorticoids did not detectably affect IL-1 alpha or IL-1 beta mRNA levels following PMA induction, however, staurosporin inhibited IL-1 beta mRNA synthesis. Thus the inducers and regulators of IL-1 formation in human LC and monocytes are not identical.


Endotoxin and Staphylococcus aureus enterotoxin A induce different patterns of cytokines.

The effects of Staphylococcus aureus enterotoxin A (SEA) and lipopolysaccharide (LPS) in cytokine production were assessed at the single cell level in cells obtained from healthy blood donors. Cytokine production was studied with UV-microscopy of fixed and permeabilized cells stained with cytokine specific monoclonal antibodies. The cytokines evaluated included tumour necrosis factor (TNF)-alpha, interleukin (IL)-1 alpha, IL-1 beta, IL-6, IL-8, IL-10, IL-2, IL-4, interferon (IFN)-gamma and TNF-beta. LPS exhibited marked production of IL-1 alpha, IL-1 beta, TNF-alpha, IL-6 and IL-8. After LPS stimulation IL-1 alpha, IL-1 beta, TNF-alpha and IL-8 were the dominating products, all peaking at or before 4 hours after cell stimulation. In addition, IL-10 production was evident after 12 hours of cell stimulation. The T-lymphocyte-derived cytokines TNF-beta, IL-2, IFN-gamma and IL-4 were never detected in the cultures. All cytokine production, except IL-8, was downregulated at 96 hours. In contrast, peak production of IL-1 alpha, IL-1 beta and IL-8, which were the dominant products, occurred after 12 hours in the SEA-stimulated cultures. Further, a significant T-lymphocyte production of TNF-beta, TNF-alpha, IFN-gamma and IL-2 was found with peak production 12-48 hours after initiation. Only low amounts of IL-6 were evident. The two types of cytokine pattern and kinetics found may correspond to the different clinical conditions after invasive Gram-negative Escherichia coli vs Gram-positive Staphylococcus aureus infections in humans, with a much more rapid onset of disease after E. coli infections.(ABSTRACT TRUNCATED AT 250 WORDS)


Induction of HLA class I mRNA by cytokines in human fibroblasts: comparison of TNF, IL-1 and IFN-beta.

Expression of HLA class I antigens is known to be regulated by various cytokines at both the mRNA and protein levels. We have examined the induction of HLA-B7 by tumor necrosis factor alpha (TNF), interleukin 1 alpha (IL-1) and interferon beta (IFN-beta) in normal human diploid FS-4 fibroblasts. Optimal induction of HLA-B7 by TNF at 24 h was shown to require a continuous presence of TNF. Since TNF also induces IFN-beta in these cells and the latter cytokine itself has the capacity to upregulate HLA class I expression, we investigated the role of autocrine IFN-beta in the induction of HLA-B7 by TNF. Experiments with neutralizing polyclonal antibodies to recombinant IFN-beta showed that the induction of HLA-B7 mRNA by TNF was partially dependent on autocrine IFN-beta. However, TNF and IFN-beta induced HLA-B7 mRNA with similar kinetics and treatment with saturating concentrations of both TNF and IFN-beta resulted in an additive or possibly synergistic response. The latter findings support the idea that induction of HLA class I by TNF is not mediated solely by autocrine IFN-beta produced in response to TNF. In addition, experiments with the protein synthesis inhibitor cycloheximide suggested that the induction of mRNAs for both the heavy and light (beta 2-microglobulin) chains of the HLA class I antigen by TNF did not require de novo protein synthesis. IL-1 was also shown to increase steady-state mRNA levels of HLA-B7 with kinetics similar to those of TNF and IFN-beta in FS-4 cells.(ABSTRACT TRUNCATED AT 250 WORDS)


Identification of a monocyte-derived factor which regulates synthesis of insulin receptors on activated T-lymphocytes (MIRRF).

The regulation of the insulin receptor on the activated T-lymphocyte was studied. It has been previously shown that the monocyte with its constitutive insulin receptor can signal the quiescent T-lymphocyte with respect to ambient insulin concentration which regulates the copies of insulin receptors synthesized during the lymphocyte activation event. In this communication it is shown that the vehicle by which the monocyte signals the T-lymphocyte is a soluble, small molecular weight protein. Initially a bioassay was established to test the putative monocyte-derived factor in which freshly prepared purified populations of monocytes were incubated with insulin, extensively washed, and replated with lymphocytes in microwells or across a 3 microns filter from lymphocytes using the appearance of insulin receptors on T lymphocytes responding to lectin as measured by a radioligand binding assay as the outcome variable. Dose response and time course relationships were established to develop the ideal conditions for the bioassay. It was shown that the monocyte-derived insulin receptor regulatory factor (MIRRF) could be readily detected in conditioned medium of insulin-incubated and then washed monocytes as a starting point for attempts at later purification. Using rats fed an essential fatty acid deficient diet (EFAD), incapable of generating standard prostanoids, it was demonstrated that the MIRRF was readily detectable in our standard bioassay revealing that the factor was not a member of the arachidonic acid family. Lastly, it was shown that MIRRF is cycloheximide sensitive and either is a protein or requires protein synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)