Medial Canthal Tendon Reflecting in Lower Eyelid Reconstruction After Palpebral Cancer Surgery: Description of a New Technique

PURPOSE

The aim of this article is to describe a new reconstructive technique of the lower eyelid in the surgery of tumors involving the medial canthal tendon.

METHODS

Our new technique consists of detaching and reflecting the most medial portion of the anterior medial canthal tendon and reinserting it into the posterior lamella. We describe the cases in which our technique can be useful, as well as the results we have obtained.

RESULTS

The result after a year of follow-up showed no disruption of the angulation of the lower eyelid line and no changes in eyelid position.

CONCLUSIONS

The medial canthal tendon reflection could provide both aesthetic and functional results that may be superior to the usual techniques.

Orbital myositis in a patient with Crohn's disease: A case report of two episodes

PURPOSE

To describe a case report of a 34 years-old patient with Crohn's Disease and two episodes of Ocular Myositis.

METHODS

The research methodology employed in this study consisted of a retrospective review of the patient's complete medical history.

RESULTS

Crohn's Disease is a chronic inflammatory bowel disorder known to be associated with a wide range of extraintestinal manifestations. Ocular abnormalities, such as episcleritis and uveitis, are commonly observed. However, orbital myositis is an extremely rare ocular extraintestinal manifestations characterized by acute ocular pain that worsens with eye movements and is often accompanied by diplopia. In this case report, we present the case of a 34-year-old woman with a confirmed diagnosis of Crohn's Disease, who experienced two episodes of acute orbital pain exacerbated by ocular movements and diplopia. The diagnosis was established through clinical evaluation and radiologic imaging, with confirmation after a good response to systemic corticosteroids. She responded favorably to systemic corticosteroid therapy on both episodes, and no additional treatment was required. As of now, she remains stable without any ocular sequelae.

CONCLUSION

It is important to note that orbital myositis is an uncommon ocular manifestation associated with Crohn's Disease, and prompt recognition and management are crucial to achieve successful outcomes.

Eyelid atypical fibroxanthoma: a rare challenging entity

Atypical fibroxanthoma (AFX) is a rare neoplasm, with a limited number of cases reported in the periocular region. In this case report, we detail a 63-year-old woman who presented with a polypoid, exophytic lesion on her right upper eyelid that had been progressing for a year. The lesion was meticulously excised with security margins and reconstructed using a glabellar flap. Following a thorough microscopic and immunohistochemical analysis, AFX was diagnosed. Despite its sometimes clinical and histological benign appearance, AFX is classified as a malignant neoplasm; however, it carries an excellent prognosis with low metastasis and recurrence rates. Complete excision with safety margins is essential and an adequate post-operative surveillance is recommended. Owing to its rarity, ophthalmologists should remain vigilant and include AFX in their differential diagnosis, as the tumor's benign appearance may lead to misdiagnosis of this malignant entity.

Chronic obstructive pulmonary disease (COPD) in Spain and the different aspects of its social impact: a multidisciplinary opinion document

Chronic obstructive pulmonary disease (COPD) is one of the most prevalent diseases in the World, and one of the most important causes of mortality and morbidity. In adults 40 years and older, it affects more than 10% of the population and has enormous personal, family and social burden. Tobacco smoking is its main cause, but not the only one, and there is probably a genetic predisposition that increases the risk in some patients. The paradigm of this disease is changing in Spain, with an increase of women that has occurred in recent years. Many of the physio pathological mechanisms of this condition are well known, but the psychological alterations to which it leads, the impact of COPD on relatives and caregivers, the limitation of daily life observed in these patients, and the economic and societal burden that they represent for the health system, are not so well-known. A major problem is the high under-diagnosis, mainly due to difficulties for obtaining, in a systematic way, spirometries in hospitals and health-care centers. For this reason, the Fundación de Ciencias de la Salud and the Spanish National Network Center for Research in Respiratory Diseases (CIBERES) have brought together experts in COPD, patients and their organizations, clinical psychologists, experts in health economics, nurses and journalists to obtain their opinion about COPD in Spain. They also discussed the scientific bibliometrics on COPD that is being carried out from the CIBERES and speculated on the future of this condition. The format of the meeting consisted in the discussion of a series of questions that were addressed by different speakers and discussed until a consensus conclusion was reached.

Periumbilical fat auto-graft associated to a porous orbital implant for socket reconstruction after enucleation

Having to remove the sclera, fat and the optic nerve in patients undergoing an enucleation, translates in a larger volume that needs to be replaced to achieve good motility and aesthetic results. Using a 20 or 22 mm implant can only partially replace the removed volume. We report the results of our enucleation technique, which includes the use of a porous orbital implant combined with a primary fat graft to replace a higher percentage of the removed volume to achieve a better cosmetic outcome and to avoid implant related complications in high risk patients. Prospective, non-randomized study of enucleated patients for whom porous orbital implantation was performed with anterior placement of a fat auto-graft. The development of implant extrusion or exposure was recorded as well as the presence of conjunctival wound dehiscence and infection. Orbital volume was clinically and radiologically evaluated as well. Twenty-eight patients were included, with a postop follow-up of at least 6 months (6-79 months). No cases of migration or extrusion were found. One case of a large exposure resolved completely. All MRI demonstrated proper implant-graft integration and vascularisation. The aesthetic result and the symmetry were very adequate, with Hertel differences of less than 2 mm in all cases and good motility range. The fat graft is well tolerated, showing low incidence of implant-related complications whilst maintaining good volume and motility.

Tobramycin inhalation powder (TOBI Podhaler) for the treatment of lung infection in patients with cystic fibrosis

Cystic fibrosis (CF) is an autosomal recessive inherited disease secondary to a defect in the CF transmembrane conductance regulator gene (CFTR). Mortality in CF is associated with impairment of lung function in which bacterial infection plays a fundamental role. The microorganism Pseudomonas aeruginosa (P. aeruginosa) is a marker of poor prognosis. Tobramycin was the first parenteral antibiotic to be used as inhaled medication in CF. Owing to its beneficial effects; it was subsequently used in designed inhaled formulations. The first formulation was the inhalation solution, which improved lung function, lowered hospitalization rates, and reduced the courses of intravenous antibiotic. However, the high associated costs and time necessary to administer the medication negatively affected quality of life. The recent development of tobramycin inhalation powder has optimized treatment. The dry powder inhaler is a simple device that reduces administration time and improves adherence. As there is no risk of bacterial contamination, disinfection is unnecessary.

Direct frontalis flap with and without levator pulley for correction of severe ptosis with poor levator function in the same patient

PURPOSE

To compare two techniques of frontalis muscle flap suspension in different eyelids of the same patient for correction of severe ptosis with minimal levator function.

MATERIAL AND METHODS

A prospective study of four patients with severe bilateral ptosis and poor levator function, who underwent direct frontalis muscle flap on the right eyelid and frontalis muscle flap with levator pulley on the left eyelid was conducted. Eyelid studies measurements were taken at baseline, 2 months, one year and 5 years after surgery. The presence of complications, flap function and palpebral contour were evaluated.

RESULTS

Despite the surgical technique performed, good results in terms of functionality, contour and aesthetics were observed. In the eyes that underwent frontalis muscle flap (FMF)-direct, there were 2 cases with moderate anteriorization of eyelid margin in extreme upgaze and all patients showed eyelash ptosis that persisted one year after surgery, but improved after 5 years. In the eyes that underwent FMF-pulley, no upgaze anteriorization of eyelid margin was observed and three patients had eyelash ptosis of lesser extent than the fellow eye, improving after 1 year follow-up. FMF-pulley showed more long-term stability in eyelid height, compared with FMF-direct.

CONCLUSIONS

Frontalis muscle flap with a pulley in the levator aponeurosis prevents some complications caused by the excessive vertical component of the direct frontalis muscle flap, especially in deep-set eye patients, with better stability of the eyelid height and contour over time.

Accreditation and training on internal dosimetry in a laboratory network in Brazil: an increasing demand

In recent years, Brazilian Nuclear Programme has been reviewed and updated by government authorities in face of the demand for energy supply and its associated environmental constraints. The immediate impact of new national programmes and projects in nuclear field is the increase in the number of exposed personnel and the consequent need for reliable dosimetry services in the country. Several Technical Documents related to internal dosimetry have been released by the International Atomic Energy Agency and International Commission on Radiological Protection. However, standard bioassay procedures and methodologies for bioassay data interpretation are still under discussion and, in some cases, both in routine and emergency internal monitoring, procedures can vary from one laboratory to another and responses may differ markedly among Dosimetry Laboratories. Thus, it may be difficult to interpret and use bioassay data generated from different laboratories of a network. The main goal of this work is to implement a National Network of Laboratories aimed to provide reliable internal monitoring services in Brazil. The establishment of harmonised in vivo and in vitro radioanalytical techniques, dose assessment methods and the implementation of the ISO/IEC 17025 requirements will result in the recognition of technical competence of the network.

Thyroid orbitopathy obscuring the diagnosis of a rare neuromuscular hamartoma of the superior rectus muscle in an adult

A neuromuscular hamartoma is a rare benign tumour that is most frequently associated with peripheral nerves. The authors present a case of a 61 year-old man with bilateral exophthalmos and lid retraction who developed further proptosis and chemosis in the left eye over a five month period. An initial diagnosis of thyroid orbitopathy was made and he had a limited response to two courses of oral steroid administered in another centre. He was subsequently referred to our institution for further management when his condition worsened following withdrawal of treatment. Orbital CT scan showed a thickening of the recti muscles and particularly the left superior rectus and overlying soft tissue. Given this unusual pattern of muscle involvement in thyroid orbitopathy, a muscle biopsy was performed. This showed the presence of a neuromuscular hamartoma without malignant features. The orbital fat biopsy showed no pathological findings. A neuromuscular hamartoma not associated with a peripheral nerve is a rare entity, especially when coupled with an extraocular muscle. We wish to highlight the importance of a muscle biopsy when faced with a clinical picture and radiological pattern of extraocular muscle enlargement not typical of what we know to occur traditionally in thyroid eye disease.

[Mohs micrographic surgery: our first 100 patients]

INTRODUCTION

Mohs surgery was first described by Frederic Mohs in 1941 to eliminate high-risk cutaneous tumors. The technique involves histological examination of the margins.

OBJECTIVE

The aim of this study was to describe the clinical findings and compare the grade and subclinical extension of the tumor as measured by the number of Mohs stages needed for complete elimination according to whether the tumor presented high-risk factors.

METHODS

We included 100 patients with 105 tumors. In all cases, age, sex, tumor site, tumor type, histological subtype in the case of basal cell carcinoma, size, recurrences, number of Mohs stages, and reconstruction technique were recorded.

RESULTS

The study group comprised 44 men and 56 women aged between 28 and 88 years (mean, 72.6 years). Of the tumors, 80 % corresponded to basal cell carcinoma, 12.38 % to squamous cell carcinoma, 4.76 % to dermatofibrosarcoma protuberans, 0.95 % to Merkel cell carcinoma, 0.95 % to microcystic adnexal carcinoma, and 0.95 % to lentigo maligna melanoma. Most tumors were located on the head and 60 % required more than one Mohs stage for complete elimination.

CONCLUSION

This series is characterized by a high percentage of high-risk cutaneous tumors. After assessing the risk factors independently, we found that the size of the tumor is the risk factor most closely related to grade and subclinical extension in the case of basal cell carcinoma, although similar conclusions cannot be drawn for the other types of tumor studied.

Amniotic membrane transplantation for conjunctival epithelization of exposed dermis-fat [corrected] graft

We report the use of amniotic membrane over dermis-fat graft to improve conjunctival epithelization when fat is exposed. A 38-year-old male with previous history of orbital implant extrusion managed with a dermis-fat graft, presented with exposed fat secondary to dermis retraction in its central area. This caused difficulty with the conjunctival growth. Eighteen days after the amniotic membrane graft placement, a complete conjunctival reepithelization and an appropriate ocular prosthesis adaptation were achieved. Therefore, the amniotic membrane graft is a useful method to improve conjunctival growth in cases of dermis-fat grafts with fat exposure and limited conjunctiva, are present.

Orbital Metastases From Male Breast Cancer in Two Cases

We present 2 cases of orbital metastases of male breast cancer, a very rare association in the context of a rare disease. We also provide a review of the literature on this topic including the 4 previously reported cases. Our cases presented with diplopia and proptosis. Orbital biopsies were performed that revealed metastases of infiltrative ductal carcinoma (ICD).

Frontalis Muscle Flap Advancement With a Pulley in the Levator Aponeurosis in Patients With Complete Ptosis and Deep-Set Eyes

PURPOSE

To offer an alternative to frontalis sling techniques to achieve a more horizontal traction vector force with the frontalis muscle flap. The proposed technique avoids malpositions such as pulling the upper eyelid in an anterior plane during maximum opening and ptosis of the eyelashes.

METHODS

The technique, performed in 5 patients with complete unilateral ptosis and an absence of levator function, consisted of advancing a flap of frontalis muscle and creating a pulley with the aponeurosis of the levator muscle. Mean follow-up was 12 months.

RESULTS

Ptosis was corrected in all 5 patients, with good aesthetic outcome. There were no cases of anterior eyelid advancement, entropion, or eyelash ptosis. The only complication was 1 case of lagophthalmos with corneal erosion.

CONCLUSIONS

In this preliminary series, the technique was safe and effective for correcting severe blepharoptosis, with good aesthetic and functional results even in patients with deep-set eyes and without the eyelid malpositions that commonly occur in frontalis sling techniques.

The Web as an educational tool for/in learning/teaching bioinformatics statistics

Statistics provides essential tool in Bioinformatics to interpret the results of a database search or for the management of enormous amounts of information provided from genomics, proteomics and metabolomics. The goal of this project was the development of a software tool that would be as simple as possible to demonstrate the use of the Bioinformatics statistics. Computer Simulation Methods (CSMs) developed using Microsoft Excel were chosen for their broad range of applications, immediate and easy formula calculation, immediate testing and easy graphics representation, and of general use and acceptance by the scientific community. The result of these endeavours is a set of utilities which can be accessed from the following URL: http://gmein.uib.es/bioinformatica/statistics. When tested on students with previous coursework with traditional statistical teaching methods, the general opinion/overall consensus was that Web-based instruction had numerous advantages, but traditional methods with manual calculations were also needed for their theory and practice. Once having mastered the basic statistical formulas, Excel spreadsheets and graphics were shown to be very useful for trying many parameters in a rapid fashion without having to perform tedious calculations. CSMs will be of great importance for the formation of the students and professionals in the field of bioinformatics, and for upcoming applications of self-learning and continuous formation.

[Antithrombotic treatment in non-rheumatic atrial fibrillation. Do we follow the recommendations of clinical trials?]

OBJECTIVES

Several clinical trials have demonstrated that antithrombotic treatment may be effective in prevention of stroke in nonrheumatic atrial fibrillation (AF). The aim of this study was to assess if we follow clinical trial recommendations in community practice.

METHODS

We analyzed 225 medical records of patients diagnosed of nonrheumatic AF in Cáceres, during February and March 1998. Patients who were contraindicated to follow antiagreggation or anti-coagulation treatment were excluded. We compared patients with and without antithrombotic treatment with different demographic characteristics and embolic risk factors.

RESULTS

205 patients were included in the study, 149 (72.6%) had high embolic risk. 62 (30.2%) followed anticoagulation, 94 (45.8%) antiaggregation treatment, 5 (2.4%) both treatment and 49 (24%) were not receiving therapy. We didn't findings differences between age, sex, presence of ischemic heart disease, hypertension and congestive heart failure in last three months compared with the patients in respect to the group of patients with anticoagulation and antiaggregation therapy or without it. We determinate as well that previous stroke and echocardiographical finds (valve disease, valve calcification, ventricular dysfunction) were more frequent in the anticoagulation and antiaggregate patients than in those without therapy.

CONCLUSION

A high range of nonrheumatic AF patients take any kind of antithrombotic preventive therapy, though a great number of patients with high embolic risk could still get benefits from anticoagulation therapy. We should considerate in the therapy assessment some other clinical characteristics as hypertension, isquemic heart disease and heart failure apart from echocardiographical findings.

Decreased susceptibility of penicillin-resistant pneumococci to twenty-four beta-lactam antibiotics

The in-vitro activity of 24 beta-lactam antibiotics was compared using three groups of pneumococci and an agar dilution method comprising 100 penicillin-susceptible, 100 intermediately penicillin-resistant, and 100 highly penicillin-resistant pneumococcal strains. Our results show that intermediately penicillin-resistant and highly penicillin-resistant pneumococci had decreased sensitivity to other beta-lactam agents. According to their relative in-vitro activity, the antimicrobials were classified into three groups. The first group included drugs more active than penicillin (imipenem, meropenem, cefotaxime, ceftriaxone, and cefpirome), which could be useful for the treatment of infections due to penicillin-resistant strains. The second group showed slightly lesser activity than did penicillin, and included: ampicillin, cefdinir, cefuroxime, cefoperazone, azlocillin, mezlocillin, piperacillin, cephalothin, and cefamandole. The remaining antibiotics (oxacillin, cefixime, ceftizoxime, cefetamet, cefaclor, ceftazidime, cefoxitin, cefonicid, and latamoxef) showed poor activity against penicillin-resistant strains, precluding their use for empirical treatment in areas with a high prevalence of penicillin-resistant strains.

Trends in antimicrobial resistance of clinical isolates of Streptococcus pneumoniae in Bellvitge Hospital, Barcelona, Spain (1979-1990)

From January 1979 to December 1990 we studied the susceptibility of 1,492 pneumococcal strains isolated from adult patients in Bellvitge Hospital, Barcelona, Spain, to nine antimicrobial agents. Among clinically significant pneumococci, the incidence of penicillin-resistant strains increased from 4.3% in 1979 to 40% in 1990, and that of erythromycin-resistant strains also rose from 0% in 1979 to 9.4% in 1990. On the other hand, the incidence of strains resistant to tetracycline decreased from 76.1% to 37.6%, as did that of chloramphenicol-resistant strains, from 56.5% to 29.4%. The incidence of co-trimoxazole-resistant strains was about 40% throughout the study. Even more alarming was the finding that about 70% of penicillin-resistant strains showed multiple resistance to non-beta-lactam antibiotics. All pneumococci were susceptible to vancomycin, and all but six were susceptible to rifampin. We observed that isolates from cerebrospinal fluid and the respiratory tract were significantly more resistant to penicillin than were isolates from blood. The majority of strains (95%) belonged to serogroups or serotypes included in the 23-valent pneumococcal vaccine and 77.6% of penicillin-resistant strains belonged to groups 23, 6, 9, and 19.

Aztreonam vs. cefotaxime in the treatment of gram-negative spontaneous peritonitis in cirrhotic patients

Aztreonam and cefotaxime were compared in 44 cirrhotic patients who had 52 episodes of gram-negative spontaneous peritonitis. Patients were randomized into two therapeutic groups of similar characteristics. Group A (28 episodes) received 0.5 gm of aztreonam every 8 hr, and group B (24 episodes) received 1 gm of cefotaxime every 6 hr, for a planned 14-day period. Peak and trough serum and ascitic fluid levels of both antibiotics were several times higher than the minimum inhibitory concentrations of causative microorganisms. Eleven patients (21%) died within the first 48 hr after beginning therapy, which included seven in the aztreonam group and four in the cefotaxime group. In the remaining patients, signs and symptoms of infection were promptly controlled, and ascitic fluid cultures became negative after 48 hr in all cases, except in one patient from the aztreonam group, who was a clinical failure. Two patients from the aztreonam group and one from the cefotaxime group relapsed after treatment. The overall mortality rate was 50%, which was lower than classically reported: 12 patients (43%) died in the aztreonam group, and 14 (58%) died in the cefotaxime group (p = 0.265, NS). Hepatorenal syndrome and digestive tract hemorrhage were the most frequent causes of death occurring after the first 48 hr of treatment. Streptococcal superinfections developed in three patients (14.2%) in the aztreonam group. We conclude that both antibiotics at the low doses used in this study are similarly well tolerated and effective in controlling this infection. Because the use of aztreonam as the initial empirical treatment requires a concomitant antibiotic against gram-positive infections and the possibility of streptococcal superinfections, cefotaxime seems to be a more advantageous therapeutic alternative for this patient population.

[Our experience with Kufs disease: familial form and sporadic case]

Our experience on Kufs' disease includes a familiar, neurovisceral form and a sporadic case. The familiar form shows an autosomal, dominant inheritance, and belongs to Berkovic's type B. A variability on the age of onset was observed, being more protracted in women. The sporadic case belongs to Berkovic's type A. Her EEG showed a periodic, short-interval, activity for a long period of illness. NMR findings were nonspecific for the diagnosis. All cases showed granular osmiophilic deposits, but not storage characterized by fingerprint profiles. Visceral storage in many cases on Kufs' disease suggests the utility of visceral biopsy evaluation for the diagnosis during life.

Increased intracellular glycerophosphoinositol is a biochemical marker for transformation by membrane-associated and cytoplasmic oncogenes

Transformation of rodent fibroblasts by cytoplasmic (mos, raf) and membrane-associated (ras, src, met, trk), but not nuclear (myc, fos) oncogenes results specifically in a very significant elevation of intracellular levels of glycerophosphoinositol (GPI). This elevation is specifically associated with the transformed state of the cells and not merely with their active state of proliferation. The basal phospholipase A2 (PLA2) activity of the same cells is also significantly stimulated in vivo. Our results are consistent with the notion that the elevated levels of GPI result from deacylation of lysophosphatidylinositol released by the enhanced PLA2 activity. GPI is a water-soluble, easily detectable metabolite which may constitute a convenient biochemical marker for malignant transformation by this particular group of oncogenes.

Alterations of G-protein coupling function in phosphoinositide signaling pathways of cells transformed by ras and other membrane-associated and cytoplasmic oncogenes

We showed previously that transformation by cytoplasmic and membrane-associated oncogenes including ras results in uncoupling between surface stimulation by platelet-derived growth factor, bombesin, and serum and activation of intracellular phospholipase C (PLC); this uncoupling does not involve alterations at the receptor or effector enzyme levels (T. Alonso, R. O. Morgan, J. C. Marvizon, H. Zarbl, and E. Santos, Proc. Natl. Acad. Sci. USA 85:4271-4275, 1988). In this study, we stimulated normal and oncogene-transformed NIH 3T3 cells with fluoroaluminate (AIF4-), thus directly activating PLC-associated G protein(s) and bypassing the receptor step. A1F4(-)-elicited PLC responses were significantly impaired in transformed cells when compared with those in their normal counterparts, suggesting that the uncoupling of PLC is the result, at least in part, of functional impairment at the G-protein level. Transformation by ras oncogenes has also been reported to result in enhanced PLC response to bradykinin resulting from increased receptor numbers (G. Parries, R. Hoebel, and E. Racker, Proc. Natl. Acad. Sci. USA 84:2648-2652, 1987; J. Downward, J. de Gunzburg, R. Riehl, and R. Weinberg, Proc. Natl. Acad. Sci. USA 85:5774-5778, 1988). We demonstrate here that transformation by other membrane-associated and cytoplasmic oncogenes also results in increased responsiveness to bradykinin ("supercoupling") and enhanced receptor numbers. However, there is no direct correlation between the number of receptors and the enhancement in responsiveness, suggesting that other factors besides receptor number are also involved in the enhanced responses. We propose that a common effect of transformation by cytoplasmic and membrane-associated oncogenes is functional alteration of coupling G proteins and that a similar modification of different kinds of G proteins may account for the pleiotropic alterations of signal transduction (uncoupling and supercoupling) observed.

Preparation, characterization and properties of monoclonal antibodies against intact H-ras p21 proteins

Monoclonal antibodies against intact normal (Gly12) and transforming (Lys12) BALB p21 ras proteins have been prepared and characterized. Their reactivity against the purified antigen proteins as well as against cellular ras proteins present in cell lines transformed by various alleles of ras genes was determined. Although some of the antibodies recognized preferentially either the normal or the activated form of BALB p21, none of them recognized exclusively either one. Deletion fragments of Ha-ras proteins were used in ELISA to determine the region of the protein encompassing the epitope recognized by each antibody. Two regions (amino acid stretches 23-69 and 89-106) accounted for the epitopes of about 75% of the mAbs raised in this study, suggesting that they encompass the most exposed and immunogenic domains in native ras p21 proteins. The affinity of these antibodies for p21 was higher than that of other ras mAbs described previously and allowed for (i) more quantitative immunoprecipitation of ras proteins, (ii) the use of selected mAbs in immunoaffinity purification of ras proteins and (iii) improved immunohistochemical detection of p21 in fixed tissues (Ward et al., accompanying manuscript). Finally, one of the mAbs described here appeared to recognize specifically a related antigenic molecule besides ras p21.

Malignant transformation by ras and other oncogenes produces common alterations in inositol phospholipid signaling pathways

The role of ras proteins in signal transduction was assessed by studying inositol phospholipid metabolism and inositol phospholipid-mediated cellular responsiveness to agonists in cells transformed by ras and other oncogenes. Specific alterations were observed in the inositol phospholipid cycle of ras-transformed fibroblasts, but similar changes were also produced by spontaneous transformation or transformation mediated by either membrane-associated oncogenes, such as src, met, or trk, or cytoplasmic oncogenes, mos and raf; the nuclear oncogenes fos and myc did not produce these changes. The alterations included (i) stimulation of phospholipase A2 activity as indicated by elevated levels of glycerophosphoinositol and nonesterified arachidonic acid and (ii) specific uncoupling between surface receptor-mediated stimulation by platelet-derived growth factor, bombesin, or serum and activation of intracellular phospholipase C. These findings suggest the existence of common biochemical pathways for transformation by cytoplasmic and membrane-associated oncogenes and are not consistent with the hypothesis that 21-kDa ras proteins (p21) are direct or distinct regulatory elements of phospholipase C or phospholipase A2 in inositol phospholipid signal transduction pathways.