Predictors of Time to Return to Work Following Surgical Reconstruction of Upper Limb Injuries in a Cosmopolitan City in Western Nigeria.

BACKGROUND: The management of upper limb injury is aimed at a timely return to work, and other activities of daily living. The modified hand injury severity score (MHISS) has been found to predict a return to work. Upper limb injuries are common in our subregion, but there is little or no data on the time to return to work. AIM: This study, therefore, aimed to determine the prevalence of return to work and to identify the predictors of time to return to work following reconstruction of upper limb injuries. METHOD: This was a cross-sectional analytic study carried out between April 2022 and March 2023. The statistical test was at a confidence interval of 95%, and statistical significance set at a P value of <0.05. RESULT: A total of 49 upper-limb-injured patients had reconstruction in the time under review. Male-to-female ratio was 4.4:1. The mean MHISS was 87.9 ± 79.2. Of the 43 patients who participated in the return-to-work analysis, 41.9% had returned to work, with a mean time of 14.3 ± 10.5 weeks. Work-related injuries (r = 0.357, P = 0.019), male gender (r = 0.354, P = 0.020), and MHISS (r = 0.333, P = 0.029) correlated significantly with late return to work. On multiple logistic regression, work-related injuries (ß =0.321, P = 0.037), MHISS (ß =0.376, P = 0.032), and male gender (ß =0.326, P = 0.044) were found to be the significant predictors of late return to work. CONCLUSION: There is a low prevalence of return to work, with a high mean time to return. Work-related injuries, MHISS, and male gender are significant predictors of time to return to work.

Multiple Trichoepitheliomas: A Disfiguring Lesion Successfully Treated with Excision and Skin Grafting.

BACKGROUND: Multiple trichoepitheliomas are rare benign adnexal tumours that present a unique challenge both to the patient and the managing physician. The multiple nature of the lesion and face being a common location often causes cosmetic concern and psychosocial challenges. Physicians on the other hand face the challenge of providing an ideal treatment with a satisfactory outcome. Dermabrasion and laser therapy have been used to treat this lesion successfully, though they require multiple sessions, and recurrence is common. These options are however either not available or unaffordable in low-resource countries such as Nigeria. Surgical excision though an option, has rarely been advocated due to scarring, leading some experts to offer no treatment at all in developing nations. We report a challenging case of sporadic multiple trichoepitheliomas successfully treated with surgical excision and full-thickness skin graft. METHOD: Following diagnosis, the patient was counselled on the procedure, the risks and benefits. She had en-bloc excision of the lesion, and full-thickness skin graft harvested from the right groin was transplanted and anchored with Monocryl 5-0. All wounds were dressed, and the graft site was reviewed on day 10. She was discharged for outpatient follow-up. RESULT: Graft take was 95%. Epidermolysis which was seen on postoperative day 10 resolved. Hypertrophic scar on the ala nasi is softening on scar massage, and the patient is very satisfied with the outcome. CONCLUSION: Surgical excision can be a valuable tool in low-resource settings for the management of multiple trichoepitheliomas.

CONTEXTE: Les trichoépithéliomes multiples sont des tumeurs annexielles bénignes rares qui présentent un défi unique à la fois pour le patient et le médecin traitant. La nature multiple de la lésion et le visage étant un site commun entraînent souvent des préoccupations esthétiques et des défis psychosociaux. Les médecins, de leur côté, sont confrontés au défi de fournir un traitement idéal avec un résultat satisfaisant. La dermabrasion et la thérapie au laser ont été utilisées avec succès pour traiter cette lésion, bien qu'elles nécessitent plusieurs séances et que la récidive soit fréquente. Ces options ne sont cependant pas disponibles ou abordables dans les pays à faibles ressources tel que le Nigeria. L'exérèse chirurgicale, bien qu'une option, a rarement été préconisée en raison des cicatrices, conduisant certains experts à ne proposer aucun traitement du tout dans les pays en dével oppement . Nous rappor tons un cas difficile de trichoépithéliomes multiples sporadiques traités avec succès par exérèse chirurgicale et greffe de peau totale. MÉTHODE: Après le diagnostic, la patiente a été informée de la procédure, des risques et des avantages. Elle a subi une exérèse en bloc de la lésion, et une greffe de peau totale prélevée dans l'aine droite a été transplantée et fixée avec du Monocryl 5-0. Toutes les plaies ont été habillées, et le site de la greffe a été examiné le 10e jour. Elle a été renvoyée pour un suivi en consultation externe. RÉSULTAT: La prise de greffe était de 95 %. L'épidermolyse observée le 10e jour postopératoire a disparu. La cicatrice hypertrophique sur l'aile du nez s'assouplit avec le massage de la cicatrice, et la patiente est très satisfaite du résultat. CONCLUSION: L'exérèse chirurgicale peut être un outil précieux dans les contextes à faibles ressources pour la prise en charge des trichoépithéliomes multiples. MOTS-CLÉS: Trichoépithéliomes multiples, Thérapie au laser, Électrocautérisation, Exérèse chirurgicale, Greffe de peau totale.

A LUMP MODEL FOR MEDICAL STUDENTS' CLINICAL EVALUATION.

Introduction: Soft tissue masses are commonly encountered in surgical and general medical practice. The graduating medical student should therefore be competent in the physical examination of a lump. Paucity of real patients makes it paramount that models be used for teaching and evaluation. This study purposed to describe the perception of graduating medical students to the use of a low-cost lump model for Objective Structured Clinical Examination (OSCE). Methods: This was a cross-sectional survey of final year medical students who participated in a surgery OSCE utilizing an innovative low-cost lump model. Results: One hundred and sixty students undertook the OSCE examination while 130 (81.3%) students completed the survey questionnaire. One hundred and forty students (87.5%) passed (score 3 5) the skills assessment using the lump model. The median age of the students who completed the questionnaire was 25 (range 24-27) years. There were more males N=84 (65.6%) than females N= 44 (34.4%). Two thirds (67.2%; n=84) of the students said the model simulated a true lump. Nearly all the students agreed that the signs of site (97.6%; n=127), size (97.6%; n=127), shape (95.4%; n=124) and transillumination (95.4%; n=124) were clearly demonstrable with the model. A lower proportion of agreements were seen with signs such as tenderness (64.6%; n=82), attachment (77.7%; n=80) and warmth (58.6%; n=75) while more students disagreed with pulsatility (51.5%; n=67). Conclusion: The medical students had a positive perception to the use of the model. However, further refinements would be needed for more signs to be demonstrable.

Cosmetic surgery procedures accessed by Nigerian women at a single private cosmetic surgery practice: A retrospective review.

Background: Little is known about the cosmetic surgery procedures sought by Nigerian women. Aim: We sought to report the proportion of cosmetic surgery procedures accessed by Nigerian women and determine any associations between the demographics and cosmetic procedures accessed. Patients and Methods: A retrospective review was conducted between January 2020 and July 2021 of all cosmetic surgery procedures at a single private cosmetic surgery practice. Data were analyzed using means, Mann-Whitney U-test, chi square test, and Fisher's exact test as appropriate. The statistical significance was set at P ≤ 0.05. Results: Of the 392 consultations for cosmetic procedures, 245 (62.5%) patients accessed cosmetic surgery. Most were women (239 (97.6%)) and single (178 (72.7%)). The median age of the patients at surgery was 29.0 years (IQR 26-33), the median weight was 78.8 kg (IQR 71.4-88.8), and the median body mass index (BMI) was 28.1 (IQR 25.7-32.3). Liposuction was the procedure accessed by nearly all the patients (224 (91.4%)). Next to this was bilateral buttock augmentation (199 (81.2%)). Other cosmetic procedures such as tummy tuck, facial cosmetic surgery, umbilicoplasty, and labiaplasty each constituted less than three percent of the patients. The abdomen (224 (91.4%)), back (219 (89.4%)), and arms (79 (32.2%)) were the most common regions of the body sought for liposuction, while the calves (2 (0.8%)) were the least. Liposuction of the arms was associated with the BMI (p < 0.003). Conclusion: Liposuction and bilateral buttock augmentation are the most common cosmetic surgery procedures accessed by this cohort of Nigerian women.

THE EFFECT OF SKIN ANTISEPSIS AFTER PRIMARY SKIN CLOSURE ON THE INCIDENCE OF SURGICAL SITE INFECTION AFTER ABDOMINAL SURGERY FOR SEPSIS: A PRELIMINARY REPORT OF A RANDOMISED CONTROLLED TRIAL.

Background: The role of skin antisepsis after skin closure in abdominal surgery for sepsis is not well reported. This study assessed the effect of skin antisepsis following primary skin closure on surgical site infection (SSI) after contaminated and dirty abdominal surgery. Methods: This was a randomised controlled trial involving adult patients undergoing laparotomy for sepsis. Patients were randomised into a Control (C) group where the wound edge was cleaned once with 70% isopropyl alcohol before being covered with a dry sterile gauze dressing and a Povidone-iodine (PI) group in whom the wound edge was cleaned once with 70% isopropyl alcohol, then covered with a 10% povidone iodine-soaked gauze dressing. Both groups were compared for the presence of SSI. Statistical significance was set at a p value of < 0.05. Results: Thirty-seven patients (C group = 18; PI group = 19) were recruited. The median age was 36 years (Interquartile range, IQR = 72) with a male-to-female ratio of 2.7:1. The overall incidence of SSI was 48.6% (n = 18), comparable between the C group (n=10, 55.6%) and PI group (n = 8; 42.1%) (p = 0.413). In-hospital mortality rate was 10.8 % (n = 4), equally distributed between the groups (p = 1.000). The length of hospital stay was 8 days (IQR = 15) in the C group and 7 days in the PI group (IQR =9) (p = 0.169). Conclusion: In laparotomy for sepsis, skin antisepsis after primary skin closure had no effect on the incidence of surgical site infection.

PRE-INCISION SKIN ANTISEPSIS: PRACTICE PATTERNS AMONG SURGEONS IN NIGERIA.

Background: Although studies are rife on preoperative skin antisepsis, little is known about what surgeons in Nigeria practice. Objective: To describe the pattern of practice of skin antisepsis prior to skin incision among surgeons in select tertiary hospitals in Nigeria. Methods: This was a questionnaire-based descriptive cross-sectional survey involving surgeons and surgeons in training in the departments of surgery, obstetrics and gynaecology (O&G), otorhinolaryngology (ENT), and oral & maxillofacial surgery (OMS) of 26 select tertiary hospitals from all six geopolitical zones in Nigeria. Data was analysed using version 23 of the SPSS for Windows. Results: A total of 200 surgeons participated in the study with a male-to-female ratio of 9:1. The mean age was 37.2 ± 5.2 years. Senior registrars constituted 60.5% (n=121), followed by registrars (24%; n= 48) and consultants (15.5%; n= 31). The respondents performed a mean volume of 4 surgeries per week. Their most common practice is to perform skin preparation with 3 antiseptic agents with skin scrubbing lasting for 3-4 minutes. Skin scrubbing was performed for longer duration amongst consultants compared with senior registrars and registrars. Of all the surgical wounds encountered in their practice, 57%were clean. The common complications associated with the use of these antiseptic agents include allergic dermatitis and blisters. Conclusion: The practice of pre-incision skin antisepsis varies widely among Nigerian surgeons. The majority use 3 antiseptic agents for skin antisepsis although most of the procedures performed were clean surgeries. We recommend further studies to standardize our practice locally.

ANTENATAL EVENTS AMONGST MOTHERS OF BABIES WITH OROFACIAL CLEFTS.

BACKGROUND: Exogenous factors occurring in the antenatal period could be contributory to the formation of orofacial cleft. This study sought to determine the antenatal events in mothers that may have contributed to orofacial cleft deformity of their children. METHODOLOGY: It was a prospective observational cross sectional study of consenting mothers of babies with orofacial cleft who met the inclusion criteria. The study instrument was a questionnaire. RESULTS: Seventy-two mothers participated in the study. Most of these mothers were below 35 years of age and more than half, 43 (59.7%) were of the low-intermediate socioeconomic status. Although majority, 70 (97.2) of the mothers had antenatal care, the mean gestational age at commencement of antenatal care was 4 months. Almost all, 69 (95.8%) mothers had ultrasound scans however the detection of the orofacial cleft was in only 2 (2.8%) mothers. The commonest medication taken was haematinics, 26 (36.1%). Herbal medication, 15 (20.8%) and antimalarial, 12 (16.7%) were the other drugs more frequently taken. The mean age of pregnancy at commencement of these medications was 3.6 months. CONCLUSION: Although uptake of antenatal service was common practice among mothers of babies with orofacial clefts in this study, no antenatal predisposing factors were identified.

PATTERN OF SPEECH ARTICULATION ERRORS IN NIGERIAN INDIVIDUALS WITH CLEFT LIP AND OR PALATE ANOMALIES FOLLOWING REPAIR.

The occurrence of cleft lip and palate anomaly can impact on an affected individual's quality of life. Cleft of the palate particularly significantly affects the production of speech. This article aims to describe the speech errors following palatoplasty procedures observed from cleft centres within Nigeria. Ability to produce high pressure sounds, frequencies of speech errors and speech intelligibility were analysed from data collated from five cleft centres. The speech services in these centres were provided in partnership with Smile Train, a nongovernmental organization based in the United States of America. Glottal stop was the commonest speech error while the speech intelligibility was considered mild in the majority of cases. This report serves as a form of preliminary overview of the speech pattern of individuals with repaired cleft palate in our environment.

PERIOPERATIVE ANTIBIOTIC THERAPY IN OROFACIAL CLEFT SURGERY. WHAT IS THE CONSENSUS?

Clefts of the primary and secondary palate represent one of the commonest congenital anomaly for which surgical correction is required. The perioperative care of the patients varies widely across centers and among surgeons and range from preoperative swab of palatal clefts for microbiological studies to prophylactic and or therapeutic antibiotic care. These practices have economic implications especially in the Low and Middle Income Countries (LMIC) where the cost of care are borne directly by the parents. The clinical implications of indiscriminate antibiotic use may also include development of resistant strains and hypersensitivity reactions which may be life threatening. Surgical site infections and its possible sequelae of dehiscence and fistulae is another concern for the surgeon and the patient. This review examines the microbiological pathogens, surgeon's perspectives as well as the current evidences for the use of perioperative antibiotic therapy in orofacial cleft surgery and concludes with a need for a large multicenter randomized clinical trial to answer critical aspects of the subject.

STATE DISTRIBUTION OF NEW PATIENTS PRESENTING WITH CLEFT LIP AND PALATE TO THE UNIVERSITY COLLEGE HOSPITAL: A PILOT STUDY.

BACKGROUND: The UCH/Smile Train partnership, which offers free cleft surgeries to patients provides succor. OBJECTIVE: The objective of the study was to determine the state distribution of new patients presenting with cleft lip and palate, to The UCH. METHODS: A retrospective review of all new cleft patients presenting to The UCH between January 2012 and June 2015. The data obtained were their local government area of residence, age of the patients, gender of the patients and the type of cleft. Descriptive statistics was used to analyze the distribution of patients seen while Chi square test was used to analyze the influence of gender and laterality on the type of cleft. RESULTS: Sixty-seven eligible patients were seen within the study period. Majority (83.6%) of patients seen were from 14 of the 33 Local Government Areas (LGA's) in Oyo state. Patients were seen from LGA's in proximity to UCH. A few (16.4%) of the patients came from outside the state. Iwajowa, the LGA with the least number of patients (1.8%) was furthest from UCH. Left sided clefts were significantly more than bilateral or right-sided clefts (p=0.001). Most of the patients from Oluyole LGA had CP while no patient with CP was seen from Lagelu and Akinyele LGA's. CONCLUSION: There is the need to intensify cleft awareness programs. Further studies into the health habits, cultural beliefs and genetic profile of communities may explain some regional distribution of cleft types seen.

Management of split skin graft donor site in the West African sub region: survey of plastic surgeons' practice.

Split skin graft (SSG) is one of the most commonly performed operations on any Plastic Surgery service. Rate of donor site healing is affected by various factors including the type of dressing applied. The aim of this study was to survey the practice of plastic surgeons in the sub region with respect to management of SSG donor site and see how it conforms to international standards. Structured questionnaires on various aspects of the harvest and management of SSG donor sites were administered to plastic surgeons during the 53rd annual conference of the West African College of Surgeons (WACS) at Lome, Togo in March 2013. The data were analyzed using descriptive statistics. There were 47 respondents out of 55 plastic surgeons from four West African countries, which represented 85.4% of registered participants at the plastic surgery section of the conference. All the respondents performed SSG regularly, and the thigh was the most commonly used donor site. Different types of paraffin gauze remained the most commonly used primary donor site dressing. Only 17% of the respondents apply a topical local anaesthetic agent on the donor site. The choice of SSG donor site dressing in the sub region was driven mainly by availability. Concerted efforts must be made to access newer wound care products for optimum management of this commonly performed operation.

Les greffes de peau mince font partie des opérations les plus fréquemment réalisées dans tout service de chirurgie plastique. La qualité de cicatrisation du site donneur dépend de plusieurs facteurs, dont le type de pansement utilisé. Le but de cette étude est d'enquêter sur la pratique des chirurgiens plasticiens en Afrique de l'Ouest, vis-à-vis de la gestion du site donneur de peau mince et de vérifier si elle est en accord avec les standards internationaux. Des questionnaires structurés sur les différents aspects du prélèvement cutané de peau mince ont été remis aux chirurgiens plasticiens pendant la 53e Conférence annuelle des chirurgiens du Collège des Chirurgiens de l'Afrique de l'Ouest(WACS) à Lomé, Togo en Mars 2013. Les données ont été analysées à l'aide de statistiques descriptives. Ont été recueillies 47 réponses sur 55 chirurgiens plastiques de 4 régions de l'Afrique de l'Ouest, soit 85 8,4 % des participants inscrits à la section chirurgie plastique de la Conférence. Toutes les réponses émanaient de chirurgiens pratiquant des greffes de peau mince de façon régulière et la cuisse était la zone la plus communément utilisée. Différents types de pansements à la paraffine étaient le plus souvent utilisés en première intention. Seulement 17 % des réponses signalaient l'utilisation d'un topique anesthésiant local sur le site donneur. Le choix de pansement du site donneur dépendait principalement de sa disponibilité. Des efforts concertés doivent être faits pour avoir accès aux nouveaux produits cicatrisants, afin d'obtenir une meilleure prise en charge de ce type d'intervention couramment pratiquée.

NORMAL VALUES OF KEY PINCH STRENGTH IN A HEALTHY NIGERIAN POPULATION.

BACKGROUND: With the severity of machine hand injuries in our environment, the need to determine the normal values for key pinch strength with which to compare restorative surgeries was justified. METHOD: A cross sectional survey of participants who had no previous hand injuries limiting hand function. Data obtained included age, gender, body mass index, hand dominance and hand span. The Baseline Hydraulic Pinch Gauge was used to obtain key pinch strength. The influence of the above variables on measured pinch strength was analyzed using independent sample t-tests and Pearson's correlation. RESULTS: Of the 242 recruited participants, age range between 20 and 80 years, 163(67.4%) were male and 79 (32.6%) were female. Males had higher pinch strength (right-8.3±2.7kg, left-7.6±2.5kg) than females (right-6.3±1.5kg, left- 5.8±1.5kg). Pinch strength varied with age peaking in the fifth decade in males and females. Interestingly, the left handed dominant female had higher right pinch strength than her right handed counterpart (p<0.009). Height, and hand span correlated with pinch strength in females. CONCLUSION: Normal values for key pinch strength in this Nigerian population are lower than that of Caucasians.

Demographic characteristics and prognostic indicators of childhood burn in a developing country.

Children constitute a significant proportion of burn victims in most studies from the developing countries. While there has been a progressive improvement in the outcome from childhood burn in many developed nations, the morbidity and mortality remains high in many low and middle income countries. The aim of our study is to evaluate the demographic characteristics and prognostic indicators of childhood burn in a major referral teaching hospital in a developing country. A review of the records of 638 patients with acute burns managed over a 10-year period from January 2001 to December 2010 at the University College Hospital, Ibadan Nigeria was done. The clinical and epidemiological data were retrieved from computerized data base using the ISBI proforma. Information obtained includes Biodata, Etiology, location, TBSA, presence of Inhalation injury and the treatment outcome. Data of patients aged 16 years and below were analyzed using the SPSS version 16. The main outcome measure was the patient's survival. 289 children representing 45.3% of the total number of burn patients were managed over the period. The M:F ratio was 1.1:1. The median age of the cohort was 4.0 years while the median TBSA was 21.0%. Non-intentional causes were responsible for 89.6% cases. Most of the injuries (88.6%) occurred at home. Eighty-three patients had inhalation injury out of which 57 (68.7%) deaths were recorded. The overall mortality rate in the cohort was 39.5% with an LA50 of burn size of 45%. The TBSA was also found to be a determinant of outcome. Majority of childhood burns are from preventable causes with attendant dismal mortality figures. Effective burn prevention strategies and improved quality of care remain pivotal in reducing childhood burn morbidity and mortality in the developing countries.

Awareness and attitude of doctors and nurses at a teaching hospital to skin donation and banking.

INTRODUCTION: This study sought to determine the awareness and attitude of doctors and nurses in a teaching hospital to skin donation and banking, and to identify needs for personnel educational programmes. METHODS: A cross sectional survey on doctors and nurses was carried out using a 44-item questionnaire that included a Likert scale on attitudes. Predictors of favourable attitudes were determined. RESULTS: Eighty (49.7%) doctors and 81 (50.3%) nurses participated in the study. Many participants, 126 (78.3%), knew that skin could be donated, but only 96 (59.6%) participants were aware of skin banking. The main source of information was during professional training (17.4%). Only 41 (25.5%) participants were willing to donate skin after death. Body disfigurement was the major reason (20.5%) against skin donation. Participants who were doctors, were aware of skin banking, and who were previous blood donors had higher attitudes scores (p<0.001, p=0.004, p=0.007 respectively). Being a doctor and having heard of skin banking were predictors of favourable attitudes to skin donation and banking. CONCLUSION: Knowledge transfer during health professional training on the usefulness of banked skin in patients with major burns may lead to improved attitude of health professionals and acceptance of this modality of burn management.

The use of cytoenzymological changes in some parasitic protozoa for screening the carcinogenicity of chemicals.

Changes in the Golgi bodies and in hydrolytic enzymes were observed in parasitic ciliates (Nyctotheroides puytoraci) and flagellates (Opalina sudafricana and Protoopalina sp.) after the administration of a single dose of 0.5 mg beta-naphthylamine (BNA) to their host, Bufo regularis. The experiment was carried out during the host's pre-breeding season, from November to February (when only trophozoites are available); the trophozoites were examined 21 days after the injection of BNA. Use of the silver impregnation technique showed an increase in the size of the granular argentophilic Golgi bodies in all three trophozoites after administering BNA to their host. In addition, a larger number of acid phosphatase and nonspecific esterase granules was found in the endoplasm of the three parasites after the injection. The localization of acid phosphatase and nonspecific esterase was found to be similar to the distribution of the Golgi bodies in both the control and the treated preparations. The results could be useful, in that some protozoans could be employed for the quick detection of chemical carcinogenicity if changes in their hydrolytic enzyme content are used as a diagnostic feature.

Partial characterization of a fibroblast-stimulating factor produced by cloned murine T lymphocytes.

T cells may regulate tissue fibrosis through the elaboration of soluble factors that stimulate fibroblast growth. The authors previously identified a factor produced by cloned Schistosoma mansoni antigen-specific T cells which served as a competence factor for murine fibroblasts. In the present report, they further characterize this fibroblast-stimulating factor (FsF) and differentiate it from a number of other T-cell-derived lymphokine activities. Crude supernatants from concanavalin-activated cloned T cells were fractionated by gel filtration, ion exchange, or reversed-phase high-pressure liquid chromatography. FsF has an apparent molecular weight of 17,000 and could be differentiated from colony-stimulating factor (CSF), interleukin-3 (IL-3), and interferon (IFN) on the basis of chromatographic characteristics. Highly purified or recombinant IL-2, IL-3, CSF, and IFN had no significant effect on fibroblast proliferation. Furthermore, a monoclonal anti-B-cell-stimulating factor-1 antibody only partially blocked the fibroblast proliferation induced by T-cell supernatants.

In vitro and in vivo evidence that autoimmune reactivity to collagen develops spontaneously in Schistosoma mansoni-infected mice.

Egg-induced granuloma formation in murine schistosomiasis mansoni results from vigorous anti-parasite reaction by activated T cells, macrophages, eosinophils, and fibroblasts. The present study suggests that strain-specific, autoimmune T-cell reactivity directed against host matrix proteins might also contribute to granulomatous hypersensitivity. T cells from infected C57B1/6, but not from CBA or BALB/c mice, proliferative in vitro in response to denatured collagen. T cells from uninfected mice, previously immunized with soluble egg antigen (SEA), did not respond in vitro to collagen. Spleen cells from acutely infected mice, but not chronically infected or uninfected animals, formed granulomas around collagen-coupled polyacrylamide beads in vitro. This response was blocked by anti-collagen antibodies that had no inhibitory effect on in vitro granuloma formation around SEA-coupled beads. In related in vivo studies, granuloma formation was quantitated after iv injection of SEA-, collagen-, or uncoated beads into normal or infected recipients. The mean diameter of lung granulomas induced by collagen-coupled beads in infected mice was significantly greater than the diameter of granulomas around either collagen beads in uninfected mice or uncoated beads in infected mice. these observations indicate that anti-collagen responses develop spontaneously in Schistosoma-infected mice and suggest that such reactivity might play a secondary role in granuloma formation and the pathogenesis of hepatic fibrosis.

Production of a fibroblast-stimulating factor by Schistosoma mansoni antigen-reactive T cell clones.

Fibrosis in schistosomiasis is the terminal event of a complex pathophysiologic cascade involving interactions between fibroblasts and both host and parasite products. In the present study, the effect of lymphokines produced by cloned Schistosoma mansoni antigen-reactive T cells on the proliferation of murine fibroblasts was investigated. These T cells previously have been shown to proliferate, produce lymphokines, mediate delayed-type hypersensitivity responses, and generate in vitro granulomas in response to soluble egg antigen (SEA). T cells, co-cultured with irradiated antigen-presenting cells and pulsed with SEA, produced levels of fibroblast-stimulating factor (FSF) comparable to equivalent numbers of dispersed hepatic granuloma cells isolated from infected mice. Supernatants of cloned T cells pulsed with Con A (in the absence of macrophages) contained no detectable interleukin 1 activity, but did stimulate fibroblast activation and growth. T cell FSF activity was trypsin-sensitive, was stable at 56 degrees C but not to boiling, and was retained by Con A Sepharose. Activity was associated with HPLC fractions corresponding to an m.w. of 10,000 to 40,000. Neither recombinant interferon-gamma nor affinity-purified interleukin 2 was capable of stimulating fibroblast proliferation. In functional studies, the degree of fibroblast proliferation was related to the length of exposure to the factor. In addition, quiescent fibroblasts were maximally stimulated by T cell FSF only if a second co-factor such as insulin or epidermal growth factor was present. The synergism between T cell FSF and known progression factors suggests that FSF-T may provide a competence signal to fibroblasts. The present results suggest that a direct molecular link may exist between T cells and fibroblasts in schistosomiasis.

In vitro granuloma formation using defined antigenic nidi.

The in vitro granuloma model provides an excellent tool to study granulomatous hypersensitivity. In our studies of granuloma formation in schistosomiasis, we have demonstrated the utility of the model with respect to analysis of human PBL responses, cloned T cells, purified antigens of the parasite, and regulatory mechanisms. We have also presented data which demonstrate the applicability of this model to other antigenic systems. While the suggestion that this model may be suitable for the study of sarcoidosis may be premature, we would propose that the system may be adapted to screen potentially causative antigens. Furthermore, with the identification of the critical antigen(s), the in vitro granuloma model will facilitate studies at the clinical level.