Bilirubin-IXalpha and -IXbeta pigments, coproporphyrins and bile acids in meconium and stools from full-term and preterm neonates during the first month of life

Individual bilirubin pigments in the excreta were quantitated by newly developed methods. In meconium, bilirubin-IXbeta predominated, whereas bilirubin-IXgamma and -IXdelta remained undetectable. The daily excretion of bilirubin-IXalpha plus -IXbeta was 0.03-1.00 and 0.04-2.00 micromoles kg(-1) of birthweight in preterm and full-term infants, respectively. The ratio of bilirubin-IXalpha to -IXbeta in meconium was 0.25 +/- 0.34, 0.32 +/- 0.30 and 0.46 +/- 0.55 in newborns of gestational ages below 30, from 31 to 36 and above 36 wk, respectively. The predominance of bilirubin-IXbeta disappeared within the first week in those with gestational age >31 wk but more slowly in the very preterm group. The ratio of monoconjugated to diconjugated bilirubin-IXalpha was 4 to 5 in full-term infants, whereas this ratio was only reached after 1 mo in preterm infants. The ratio of glucuronide or glucoside to xyloside varied widely, independent of gestational age. No correlation between faecal UCB-IXalpha and beta-glucuronidase was observed. The daily coproporphyrin excretion fell from a median of 500 microg on day 1 to below 20 microg from day 7 onwards; this decrease correlated with that of bilirubin-IXbeta. The daily 3alpha-hydroxylated bile acid loss in the excreta was two- to fivefold higher than in the adult; this, together with the higher neonatal serum levels (12-90 nmoles ml(-1)), indicates an immature intestinal reabsorption and an enhanced bile acid synthesis.

CONCLUSION

Both zinc coproporphyrin and bilirubin-lXbeta are characteristic compounds of human meconium, diconjugated bilirubin-IXalpha is low or absent in meconium of very preterm infants, and faecal and serum bile acids are high.

Determination of pesticide residues in fruits and vegetables in Islamabad market

Pesticide residues in fruits and vegetable from Islamabad market, Pakistan were determined by GLC using Perkin Elmer Autosystem equipped with 63NECD and capillary column. Dimethoate was determined in the quantity of 0.032 mg kg-1 in apple, 0.110 mg kg-1 in banana, 0.004 mg kg-1 in brinjal, 1.80 mg kg-1 in cauliflower and 0.13 mg kg-1 in arvi, fenvalerate 0.010 mg kg-1 in apple and chlorpyrifos 0.004 mg kg-1 in brinjal. The importance of these pesticide residues with reference to human health is also briefly discussed.

Induction of the urokinase plasminogen activator system by oncostatin M promotes endothelial migration

Oncostatin M (OSM) is an inflammatory cytokine produced by activated macrophages and T-lymphocytes. We have previously demonstrated that OSM-induced endothelial cell migration, unlike endothelial cell proliferation and spindle formation, is independent of basic fibroblast growth factor expression (Wijelath et al. [1997] J. Cell. Sci. 110:871-879). To better understand the mechanism of OSM-induced endothelial cell migration, this study examined the potential role of the plasminogen activator system in promoting OSM mediated endothelial cell migration. OSM stimulated increased mRNA levels of urokinase-plasminogen activator (uPA) and urokinase-plasminogen activator receptor (uPAR) in a time and dose-dependent manner. Transcriptional run-off and mRNA stability analysis demonstrated that the increase in uPA and uPAR mRNA levels was due to both increased gene transcription and mRNA stability. The increase in mRNA correlated with increased protein levels of both uPA and uPAR. This increase was reflected in elevated levels of membrane-bound plasmin activity. OSM-induced endothelial cell migration was only partially dependent on plasmin activity since incubating endothelial cells without plasminogen or, in the presence of aprotinin, resulted in suppression of endothelial cell migration, indicating that OSM promoted endothelial cell migration through both a plasmin-dependent and -independent mechanism. Our results imply a role for OSM in promoting endothelial cell migration via a plasmin-dependent pathway and a uPAR-mediated pathway. Together, these and other recent studies support a role for OSM in modulating the different phases of angiogenesis.

Endoscopic plantar fasciotomy: a retrospective analysis of results in 53 patients

This retrospective study analyzes satisfaction of patients who had undergone an isolated endoscopic plantar fasciotomy (EPF) between January 1994 and January 1997. A subjective survey was completed and returned by 53 patients (a total of 69 feet), and a chart review was performed to determine final outcome. Postoperative follow-up averaged 7.2 months (range, 4-42 months). Postoperative pain levels were scored on a 7-point scale at 1 week, 1 month, and 6 months. Forty-three patients (81.1%) were satisfied with the EPF procedure and 10 patients (18.9%) were unsatisfied.

Secondary pulmonary hypertension does not adversely affect outcome after single lung transplantation

OBJECTIVE

Primary and secondary pulmonary hypertension have been associated with poor outcomes after single lung transplantation. Some groups advocate double lung transplantation and the routine use of cardiopulmonary bypass during transplantation in this population. However, the optimal procedure for these patients remains controversial. The goal of our study was to determine the safety of single lung transplantation without cardiopulmonary bypass in patients with secondary pulmonary hypertension.

METHODS

We retrospectively reviewed 76 consecutive patients with pulmonary parenchymal disease who underwent single lung transplantation from 1992 to 1998. Recipients were stratified according to preoperative mean pulmonary artery pressure. Secondary pulmonary hypertension was defined as parenchymal lung disease with a preoperative mean pulmonary artery pressure of 30 mm Hg or more. Patients with primary pulmonary hypertension or Eisenmenger's syndrome were excluded from analysis.

RESULTS

Eighteen of 76 patients had secondary pulmonary hypertension. No patient with secondary pulmonary hypertension required cardiopulmonary bypass, whereas 1 patient without pulmonary hypertension required bypass. After the operation, no significant differences were seen in lung injury as measured by chest radiograph score and PaO(2)/FIO(2) ratio, the requirement for inhaled nitric oxide, the length of mechanical ventilation, the intensive care unit or hospital length of stay, and 30-day survival. There were no differences in the forced expiratory volume in 1 second or 6-minute walk at 1 year, or the incidence of rejection, infection, or bronchiolitis obliterans syndrome greater than grade 2. Survival at 1, 2, and 4 years after transplantation was 86%, 79%, and 65%, respectively, in the low pulmonary artery pressure group and 81%, 81%, and 61%, respectively, in the group with secondary pulmonary hypertension (P >.2).

CONCLUSION

We found that patients with pulmonary parenchymal disease and concomitant secondary pulmonary hypertension had successful outcomes as measured by early and late allograft function and appear to have acceptable long-term survival after single lung transplantation. Our results do not support the routine use of cardiopulmonary bypass or double lung transplantation for patients with this disorder.

Hypocalvaria associated with intrauterine growth retardation, facial dysmorphism, congenital heart disease and camptomelia

We report an Omani child from an inbred family with a combination of hypocalvaria, intrauterine growth retardation, craniofacial disproportion, partial synostosis of the right coronal suture and a small mandible associated with congenital heart defect and bowing of the limbs. A literature search failed to reveal a similar case.

Generation and characterization of human smooth muscle cell lines derived from atherosclerotic plaque

The study of atherogenesis in humans has been restricted by the limited availability and brief in vitro life span of plaque smooth muscle cells (SMCs). We describe plaque SMC lines with extended life spans generated by the expression of the human papillomavirus (HPV)-16 E6 and E7 genes, which has been shown to extend the life span of normal adult human aortic SMCs. Resulting cell lines (pdSMC1A and 2) demonstrated at least 10-fold increases in life span; pdSMC1A became immortal. The SMC identity of both pdSMC lines was confirmed by SM22 mRNA expression. pdSMC2 were generally diploid but with various structural and numerical alterations; pdSMC1A demonstrated several chromosomal abnormalities, most commonly -Y, +7, -13, anomalies previously reported in both primary pdSMCs and atherosclerotic tissue. Confluent pdSMC2 appeared grossly similar to HPV-16 E6/E7-expressing normal adult aortic SMCs (AASMCs), exhibiting typical SMC morphology/growth patterns; pdSMC1A displayed irregular cell shape/organization with numerous mitotic figures. Dedifferentiation to a synthetic/proliferative phenotype has been hypothesized as a critical step in atherogenesis, because rat neonatal SMCs and adult intimal SMCs exhibit similar gene expression patterns. To confirm that our pdSMC lines likewise express this apparent plaque phenotype, osteopontin, platelet-derived growth factor B, and elastin mRNA levels were determined in pdSMC1A, pdSMC2, and AASMCs. However, no significant increases in osteopontin or platelet-derived growth factor B expression levels were observed in either pdSMC compared with AASMCs. pdSMC2 alone expressed high levels of elastin mRNA. Lower levels of SM22 mRNA in pdSMC1A suggested greater dedifferentiation and/or additional population doublings in pdSMC1A relative to pdSMC2. Both pdSMC lines (particularly 1A) demonstrated high message levels for matrix Gla protein, previously reported to be highly expressed by human neointimal SMCs in vitro. These results describe 2 novel plaque cell lines exhibiting various features of plaque SMC biology; pdSMC2 may represent an earlier plaque SMC phenotype, whereas pdSMC1A may be representative of cells comprising an advanced atherosclerotic lesion.

Cardiovascular surgery in the elderly

The elderly segment of the population is increasing rapidly, and surgeons are more frequently being requested to operate on this group of patients. A number of reports suggest that elderly patients have a significantly higher incidence of operative mortality and 30-day hospital mortality as compared with younger patients. Elderly patients also had a significantly higher increased incidence of complications, such as renal failure, prolonged ventilation, and incidence of strokes and postoperative cardiac arrest. Regarding coronary artery disease, elderly patients are more acutely sick on admission, are more likely to have triple-vessel disease, more likely have comorbid disease, and are usually less likely to receive an internal mammary artery graft. The presence of valvular disorders with concomitant coronary disease (especially mitral ischemic related valve disease) increases operative time, morbidity, and mortality. Efforts must continue to be made to gather data on outcomes of cardiac surgery in the elderly. Consideration must be given to modify the operative approach that minimizes cardiopulmonary bypass time, mitigates the multisystem organ injury associated with cardiopulmonary bypass, and decreases the likelihood of embolization from the ascending aorta. Future efforts must be made to develop measures to decrease the complications rate identified in elderly patients.

Snake bite experience at Pakistan Institute of Medical Sciences

We reviewed 40 cases of snake bite seen from January, 1996 to December, 1996. Most of the cases survived uneventfully but many developed complications which were either haematologic, (23 patients) or neurological (5 patients). Appropriate treatment was offered in every case. Polyvalent antisnake venom was administered to 30 patients (75%). Premedication used was steroids and antihistamines to prevent anaphylactic reactions. Antifibrinolytic therapy (tranxemic acid) was given to every bleeding patient. The species of offending snake could be recognized in one patient while in all others, it was not possible due to night time incidence and poor description by the patient.

The clinical significance of flow cytometry crossmatching in heart transplantation

BACKGROUND

Flow cytometry crossmatching is more sensitive than cytotoxic methods in identifying preformed antibodies to donor alloantigens. However, the significance of a positive flow crossmatch remains unknown for a recipient of a heart transplant who has a negative anti-human globulin crossmatch.

METHODS

Flow crossmatching was performed retrospectively for 92 recipients of a primary cardiac allograft who underwent transplantation with a negative AHG crossmatch.

RESULTS

Forty-six patients were flow crossmatch-positive for alloantibody: 20 were positive on both T and B lymphocytes, 12 were positive only on B lymphocytes, and 13 were positive only on T lymphocytes. Eleven had autoantibody invalidating the flow crossmatch with donor cells. Thirty-six patients had negative flow crossmatch. A significantly higher incidence of graft dysfunction with vascular rejection by 6 months was found for patients who had a positive flow crossmatch on B lymphocytes. This group also had an increased incidence of mortality within this same period. Patients who were flow crossmatch-positive on T and B lymphocytes were more likely to experience greater than two episodes of treated cellular rejection within the first 6 months. Flow crossmatch-positive patients stayed longer in the hospital in comparison to the other two groups, although the increases were not statistically significant. There were no differences between groups with regard to time to first rejection, absence of rejection episodes, episodes of decreased cardiac index (<2.3 L/m2), depressed left and right ventricular ejection fraction, or development of transplant atherosclerosis.

CONCLUSION

A positive flow crossmatch identified a subset of patients who are predisposed to development of vascular rejection or are more likely to have frequent cellular rejection.

Pattern of tuberculosis in general practice

An audit of 690 cases of tuberculosis out of 46,276 patients seen during the last 25 years in a busy general practice is reported. Of the 690 cases, 67% were pulmonary, 33% extra-pulmonary TB. Modes of both types of tuberculosis are described and the reason for increased incidence of extra-pulmonary tuberculosis are discussed.

Bioresorbable microporous stents deliver recombinant adenovirus gene transfer vectors to the arterial wall

The use of intravascular stents as an adjunct for percutaneous transluminal revascularization is limited by two principal factors, acute thrombosis and neointimal proliferation, resulting in restenosis. To overcome these limitations, we have investigated the potential of microporous bioresorbable polymer stents formed from poly(L-lactic acid) (PLLA)/poly(epsilon-caprolactone) (PCL) blends to function both to provide mechanical support and as reservoirs for local delivery of therapeutic molecules and particles to the vessel wall. Tubular PLLA/PCL stents were fabricated by the flotation-precipitation method, and helical stents were produced by a casting/winding technique. Hybrid structures in which a tubular sheath is deposited on a helical skeleton were also generated. Using a two-stage solvent swelling technique, polyethylene oxide has been incorporated into these stents to improve hydrophilicity and water uptake, and to facilitate the ability of these devices to function as drug carriers. Stents modified in this manner retain axial and radial mechanical strength sufficient to stabilize the vessel wall against elastic recoil caused by vasoconstrictive and mechanical forces. Because of the potential of direct gene transfer into the vessel wall to ameliorate thrombosis and neointimal proliferation, we have investigated the capacity of these polymer stents to function in the delivery of recombinant adenovirus vectors to the vessel wall. In vitro, virus stock was observed to readily absorb into, and elute from these devices in an infectious form, with suitable kinetics. Successful gene transfer and expression has been demonstrated following implantation of polymer stents impregnated with a recombinant adenovirus carrying a nuclear-localizing betaGal reporter gene into rabbit carotid arteries. These studies suggest that surface-modified polymer stents may ultimately be useful adjunctive devices for both mechanical support and gene transfer during percutaneous transluminal revascularization.

Prospective trial of catheter irrigation and muscle flaps for sternal wound infection

BACKGROUND

Sternal wound infection is a relatively rare but potentially devastating complication of open heart operations. The most common treatments after debridement are rewiring with antibiotic irrigation and muscle flaps. Here we present the results of a prospective trial to determine the appropriate roles of closed-chest catheter irrigation and muscle flap closure for sternotomy infection and to assess the effect of internal mammary artery bypass grafting on the outcome of each treatment modality.

METHODS

Between 1990 and 1994, 5,658 sternotomies were performed at the University of Washington Medical Center. Sternal dehiscence occurred in 43 patients, 25 of whom had infection (overall incidence, 0.44%). Because of the infrequency of this complication, a prospective, randomized trial was developed in which the initial approach to sternal dehiscence was rewiring and catheter irrigation. Muscle flaps were used as the primary treatment if the sternum could not be restabilized or as secondary treatment if catheter irrigation failed. Wound resolution, length of hospital stay, and complications were evaluated.

RESULTS

Sterile dehiscences were successfully closed with irrigation in 17 of 18 patients; the other patient required flap closure. Of the 25 patients with infection, 19 had irrigation and 6, closure with flaps primarily. In the group of infected patients, 17 of the 19 who received irrigation also had internal mammary artery bypass grafting. Irrigation failed in 15 (88.2%) of these 17 patients, and salvage was accomplished with muscle flap closure. All 6 patients with infection who were closed primarily with muscle flaps had a successful outcome. Hospitalization averaged 10.2 days when muscle flaps were used primarily and 14.3 additional days for unsuccessful irrigation. When irrigation was successful, the hospital stay averaged 11.2 days.

CONCLUSIONS

Catheter irrigation should be reserved for patients without infection or patients with infection but without internal mammary artery bypass grafts in whom dehiscence occurs less than 1 month after sternotomy. All others should have closure with muscle flaps.

Donor left ventricular hypertrophy increases risk for early graft failure

A review of factors contributing to early mortality after cardiac transplantation revealed that up to 25% of deaths were due to primary graft dysfunction unrelated to rejection or infection. In light of this finding, evaluation of a donor heart with regard to its suitability for transplantation takes on added importance. In an effort to screen the suitability of donor hearts in the region covered by the Northwest Organ Procurement Agency (USA), all donors are evaluated by two-dimensional transthoracic echocardiography as part of the initial evaluation. A total of 110 donor echocardiograms were reviewed and an attempt was made to correlate the 30-day outcome with the parameters measured. An unexpected finding was that the presence of left ventricular hypertrophy in the donor heart was associated with an increase in the incidence of donor heart dysfunction compared with donors with normal echocardiographic profiles (33% vs 3%, P = 0.007).

Corticosteroid use and abuse by medical practitioners for arthritis and related disorders in Pakistan

A total of 256 consecutive patients attending our out-patient clinic in Islamabad, Pakistan, with complaints of pain in or around the joints were evaluated for use of corticosteroids prescribed by medical practitioners they had seen earlier. The appropriateness of such prescriptions and their consequent effects were assessed. Of the 256 patients, 110 (i.e. 42.5%) were identified as steroid users; some of them were suffering from conditions known to be unresponsive to this form of therapy. One hundred and one of the 256 patients had rheumatoid arthritis and 67% of these had been using steroids, mostly in an irrational manner. The general practitioners and consultants (all non-rheumatologists) were responsible for the majority of steroid prescriptions. Steroid side-effects were observed in 42/110 (38.2%) cases. This prevalent practice in Pakistan is a reflection of the state of affairs in developing countries, and indicates a need for improvement and better regulation of health care in such countries.

Blood ionized magnesium concentrations during cardiopulmonary bypass and their correlation with other circulating cations

BACKGROUND AND AIM

The recent introduction of new measurement technology (using ion specific electrodes) makes intraoperative evaluation of blood ionized magnesium (Mg2+, or iMg)--the bioactive fraction of circulation magnesium--possible. The goals of this study were: (1) to examine the longitudinal pattern(s) of change in blood iMg during cardiopulmonary bypass (CPB); and (2) to determine the relationship of iMg to Ca2+ (iCa), K, pH, Na, and hematocrit (Hct) during CPB.

METHODS

Blood was collected serially before, during, and after CPB on 30 patients undergoing elective coronary artery bypass graft procedures and the iMg was measured with an AVL Scientific Corp., model 988-4 instrument.

RESULTS

Overall, 73% of iMg results were abnormally low, 50% during CPB. Some cases had both hypo- and hyperionized magnesemic episodes. There were low iCa during CPB in 97% of cases. Using Spearman's rank order correlations and p < 0.05, iMg and K were directly correlated before, during, and after bypass, suggesting their parallel movement between tissue and blood. iMg and iCa were directly correlated before, and inversely correlated after, CPB, but unassociated during bypass. iMg and Na were inversely correlated after bypass in all cases. iMg was inversely correlated to pH and positively correlated to Hct during CPB only, and only in patients with concurrent association of iMg and iCa.

CONCLUSIONS

Blood iMg depletion occurs frequently in CPB patients. iMg changes are not readily predictable. The association of intraoperative iMg depletion with postsurgical atrial fibrillation--reported to have a hypomagnesemic connection- should be investigated.

Improved bioresorbable microporous intravascular stents for gene therapy

Drug imbibing microporous stents are under development at a number of centers to enhance healing of the arterial wall after balloon coronary angioplasty procedures. The authors improved the mechanical strength and reservoir properties of a biodegradable microporous stent reported to this Society in 1994. A combined tubular/helical coil stent is readily fabricated by flotation/precipitation and casting/ winding techniques. A two stage solvent swelling technique allows precise adjustment of the surface hydrophilic/hydrophobic balance. These developments permit seven-fold improvement in drug capacity without significantly altering mechanical properties. Stents modified in this manner retain tensile and compressive strength and are suitable for remote deployment. Elution kinetics of these modified stents suggest they are suitable for gene delivery. Successful gene transfer and transmural expression have been demonstrated after implantation of stents impregnated with a recombinant adenovirus carrying a nuclear localizing beta-galactosidase reporter gene into rabbit carotid arteries. These studies suggest that surface modified, bioresorbable polymer stents ultimately may be useful adjunctive devices for gene transfer during percutaneous transluminal revascularization.

Serum alpha 1 antitrypsin and pulmonary emphysema

Using isoelectric focusing (IEF) and radial immunodiffusion (RID) techniques, serum samples from 100 normal healthy adults and 21 patients with pulmonary emphysema were analysed to identify various alpha 1 antitrypsin phenotypes and the serum concentrations. Ten percent of the patients had low serum values. The normal or most common genetic form, MM, is the predominant phenotype in both controls and patients.

Oral presentation of posttransplantation lymphoproliferative disorders. An unusual manifestation

Cyclosporine, an immunosuppressive agent widely used in organ transplantation, has several undesirable side effects, including gingival hyperplasia, which occurs in up to 70% of patients. Another complication associated with use of cyclosporine and other immunosuppressants is an increased incidence of malignancies. Long-term use of cyclosporine also is associated with a spectrum of hyperproliferative disorders ranging from reactive lymphoid hyperplasia to aggressive malignant lymphomas. While cyclosporine-related lymphoproliferative disorders have been widely reported, they have not been described in the oral cavity as the first manifestation of this disease. We report on two cardiac transplantation patients with a history of cyclosporine use who presented initially with oral symptoms of lymphoproliferative disorder. Both had erythematous to cyanotic and hyperplastic gingiva. On gingivectomy, the fixed tissue was soft, glistening, and tan colored, in contrast to the usual firm, white, cyclosporine-associated, benign gingival fibrous hyperplasia. Histologically, a dense, diffuse infiltrate of lymphoplasmacytoid cells with vesicular nuclei, prominent nucleoli, a moderate amount of cytoplasm, and high mitotic activity was observed. Immunocytochemical studies confirmed that the cells were monoclonal for lambda light chains in one patient and kappa light chains in the other. The cells from one patient were positive for CD45, while both patients were negative for CD20 and all nonhematopoietic antigens tested. Both tissues were strongly positive for Epstein-Barr virus. Morphology and immunocytochemistry findings are consistent with a posttransplant lymphoproliferative disorder. These are the first two reported cases of cyclosporine-associated posttransplant lymphoproliferative disorders presenting as gingival hyperplasia.

Regulation of polyamine synthesis and transport by fibroblast growth factor in aortic smooth muscle cells

Basic-FGF (FGF2) is implicated as a regulator of smooth muscle cell proliferation that develops after arterial injury. Polyamines are essential for cell growth and differentiation and may mediate some of the FGF2-elicited responses. To examine this possibility, the effect of FGF2 on polyamine synthesis and uptake was tested on rat arterial smooth muscle cells. Exposure of cells to FGF2 for 24 and 48 h resulted in increased intracellular polyamine content. Ornithine decarboxylase (ODC) activity increased in FGF2-treated cells after 6 h of treatment, whereas no increases were detected in ODC mRNA steady-state levels. Basic-FGF increased maximal polyamine transport rate without changes in Km. Treatment with actinomycin D decreased polyamine transport. The effect of cyclohexamide on polyamine uptake was dose dependent. These studies indicate that treatment of vascular smooth muscle cells with FGF2 results in increases in intracellular polyamine content, polyamine synthetic activity, and polyamine transport.

Inhibition of pulmonary surfactant biophysical activity by cationic polyamino acids

PURPOSE

The purpose of this study is to investigate the interaction of cationic polyamino acids, polylysine and polyarginine, with rat pulmonary surfactant at the air/water interface.

METHODS

Surface pressure measurements of rat pulmonary surfactant in the presence and absence of polyamino acids were carried out in both dynamic and static modes.

RESULTS

In dynamic cycle studies, compression and expansion of adsorbed surfactant films in the presence of the cationic polyamino acids resulted in a delayed attainment of the plateau surface pressure. In area studies of spread surfactant films at constant surface pressure, cationic polyamino acids in the subphase resulted in an increase in film area. Increased film area was also observed when a polyamino acid was injected beneath films of dipalmitoyl-phosphatidylcholine/phosphatidylglycerol. In the presence of the cationic polyamino acids, the equilibrium surface pressure (at constant film area) of pulmonary surfactant was elevated in a concentration- and molecular weight-dependent manner.

CONCLUSIONS

These data indicate that the model cationic peptides interact with surfactant lipid, possibly electrostatically with phosphatidylglycerol. It is concluded that the surface activity of pulmonary surfactant is significantly inhibited by the presence of the polycations, possibly by the formation of a mixed lipid/polyamino acid film.

Transplant arterial vasculopathy: evidence for a dual pattern of endothelial injury and the source of smooth muscle cells in lesions of intimal hyperplasia

With use of this straight artery model of transplantation for studying TGVD, we have shown the following: 1. Intimal thickening occurs in a time-dependent predictable manner only in allografts. 2. Endothelial injury as a result of procurement, preservation, and reperfusion by itself does not result in the development of intimal thickening. Additional endothelial injury associated with the presence of an early mononuclear infiltrate is necessary for the development of TGVD. 3. The development of intimal hyperplasia is initially cellular, consisting mainly of macrophages and a smaller proportion of lymphocytes. The macrophages are later replaced by SMCs. These findings are summarized in Figure 16. 4. The source of the SMCs in intimal lesions is most likely the recipient media.

Are non-specific reactions to tuberculin common?

Three thousand four hundred eighty-five BCG scar negative school children were given tuberculin test. Results showed very little non-specific reactions, suggesting BCG should produce high levels of protection in our population.

Endothelial loss and regeneration in a model of transplant arteriosclerosis

Early endothelial injury may play a role in the development of transplant arteriosclerosis. The present study documents early endothelial changes using a rat aortic graft model. Abdominal aortic allografts from PVG rats were orthotopically transplanted to DA rats. Controls were DA to DA transplants. Endothelial cell (EC) injury, regeneration, and leukocyte infiltration in the intima were evaluated using scanning electron microscopy and histological and immunocytochemical techniques. Nontransplanted aortic segments showed partial loss of ECs after 1 or 2 hr of preservation. Control isografts demonstrated extensive EC denudation and neutrophil adherence to residual ECs at 1 day post-transplantation. After 3 days, isografts showed continued regeneration of ECs in the central area and ingrowth of endothelium from both clamped sites in the recipient aorta. Reendothelialization was complete by day 14. Allografts showed similar findings to isografts up to day 3. In contrast to isografts, however, there was a secondary EC loss beginning at day 7. Monocytes/macrophages and T cells were noted to be adherent to residual ECs in 7- and 14-day allografts. At 20 days, ECs were absent from the luminal surface in the center of allografts. Endothelium did extend from clamped sites toward the midgraft region as in isografts. By 60 days allografts were completely reendothelialized. These results demonstrate that in both isografts and allografts there is initial EC loss due to mechanical trauma and ischemia/reperfusion injury, followed by partial reendothelialization. This latter process continues unabated in isografts, whereas in allografts the secondary EC loss occurs due to an allogenic response. This is followed by complete reendothelialization that occurs during the concurrent development of significant intimal hyperplasia.

Home environment and peer relations of addicted and nonaddicted university students

This study was designed to examine the differences between addicted and nonaddicted university students on measures of home environment and peer relations. Participants were 45 addicts and 45 nonaddicts with mean ages of 23 years drawn from three Pakistani universities located in Islamabad, Lahore, and Peshawar. The two groups were matched for age, gender, education, area of residence, and marital status. A booklet containing an Index of Family Relations and a Peer Relations Questionnaire was administered. Results showed that the addicts perceived more stress in their families than the non-addicts did. Family income of the addicts was greater than that of the nonaddicts. Addicts were under greater peer influence and had more deviant and drug-using friends than the nonaddicts.

University of Wisconsin solution provides superior myocardial preservation compared with Stanford cardioplegic solution

The efficacy of the University of Wisconsin solution to safely prolong preservation times for kidney, pancreas, and liver transplantation is established, but its efficacy in enhancing myocardial preservation is not yet clear. We studied the effects of Stanford cardioplegic solution and the University of Wisconsin solution both in preserving the myocardium and in protecting it from the effects of reperfusion injury after 6 hours of preservation. In 28 rat hearts we measured changes in high-energy phosphate content (with magnetic resonance spectroscopy) and histologic changes (edema, endothelial changes, myocyte architecture) during preservation and changes in high-energy phosphate content, histologic status, and performance (aortic systolic and diastolic pressure, heart rate, rhythm) in Langendorff and working hearts during reperfusion. No significant differences in the kinetics of high-energy phosphate changes were noted between the two cardioplegic solutions during preservation. However, at the end of 6 hours of preservation, hearts in the Stanford cardioplegic solution group were more edematous (p < 0.01) than those in the University of Wisconsin group. During reperfusion, no significant differences in the kinetics of high-energy phosphates were noted between the two cardioplegic solutions. None of the hearts in the University of Wisconsin solution group developed ventricular fibrillation at the start of reperfusion, but all hearts in the Stanford group did so. Once sinus rhythm was established no significant differences in developed pressure or heart rate were found between the two solutions. After 2.5 hours of reperfusion, hearts in the Stanford group were more edematous (p < 0.002) and had a greater disruption of myocyte architecture (p < 0.002) and greater arteriolar endothelial injury (p < 0.004). In conclusion, the University of Wisconsin solution better protects the myocardium in this rat model than does Stanford solution. The mechanism for this beneficial effect of the University of Wisconsin solution appears to be due to its better preservation of the microvasculature rather than differences in preservation of high-energy phosphates.

Clinical experience with the Wiktor stent in native coronary arteries and coronary bypass grafts

OBJECTIVES

To evaluate the results of implantation of Wiktor tantalum wire coronary stents in stenosed or occluded coronary vessels or in saphenous vein bypass grafts.

DESIGN

A retrospective analysis of clinical and angiographic data from patients treated with tantalum wire stents implanted by one operator at two centres.

PATIENTS

52 patients undergoing conventional balloon angioplasty had 67 lesions treated by stents after acute or threatened closure of the target vessel, or because the lesions concerned were considered to be at particularly high risk of becoming restenosed, or because the result of primary angioplasty was inadequate.

RESULTS

65 of the 67 lesions were successfully stented although in two cases the first attempt failed and a second stent was then implanted successfully. There were no cases of stent occlusion and no myocardial infarctions in hospital or in the follow up period of 1-20 months. Eight patients had haemorrhagic complications that were minor in 4. One patient later had coronary bypass surgery after failure to stent a lesion. Angiographic follow up at a mean of 6 months after stenting showed restenosis associated with 4 of 47 stents studied. All patients with chest pain had had repeat angiography, and 84% of those without symptoms also agreed to reinvestigation after about 6 months.

CONCLUSIONS

The Wiktor tantalum wire stent is an effective means of treating acute complications during angioplasty and seems to offer hope of a significant reduction in the rate of late restenosis in both native coronary vessels and saphenous vein bypass grafts. A prospective comparison of balloon angioplasty and stenting is needed.

E-selectin expression in human cardiac grafts with cellular rejection

BACKGROUND

E-selectin expression has recently been documented to occur with lymphocytic infiltration in the skin and synovium. The question of whether E-selectin is expressed in the context of cardiac graft rejection was addressed in this study.

METHODS AND RESULTS

One hundred ninety-five human posttransplant cardiac biopsy specimens were immunoreacted with antibodies to E-selectin and VCAM-1, and endothelial expression of both adhesion molecules was recorded as present or absent. Cardiac graft rejection was graded in blinded fashion. The frequency of E-selectin expression was 11% in biopsies without rejection, 36% in mild rejection, and 58% in moderate rejection, a significant correlation (P < .001). VCAM-1 expression was present in 11% of biopsies with no rejection, 37% with mild rejection, and 85% with moderate rejection, corroborating the previously reported strong correlation between VCAM-1 expression and graft rejection (P < .0001). In 71% of specimens, E-selectin expression coincided with VCAM-1 expression. In the remaining 29% of specimens in which E-selectin and VCAM-1 expression were not both present, isolated E-selectin expression was found more frequently in biopsies with early, increasing rejection, whereas isolated VCAM-1 expression was found more frequently in specimens with established moderate rejection and later, resolving rejection.

CONCLUSIONS

E-selectin is expressed in cardiac allograft rejection and may play a role in recruitment of lymphocytes into the graft. Rejection trend analysis suggests that E-selectin expression may be prominent early in the course of rejection.

A reduction in accelerated graft coronary disease and an improvement in cardiac allograft survival using low molecular weight heparin in combination with cyclosporine

Heparin compounds are a complex mixture of mucopolysaccharides that, in addition to their anticoagulant properties, have immunosuppressive activities and affect the reparative aspects of the response to arterial injury. Heparin inhibits smooth muscle cell migration and proliferation and can alter the accumulation of the components of the extracellular matrix after arterial injury. Heparin also interacts specifically with the endothelium. Our hypothesis was that if heparin compounds do affect the immune system, coagulation, smooth muscle cell proliferation, and the endothelium, then heparin combined with cyclosporine should improve allograft survival, reduce rejection, and prevent accelerated graft coronary disease. Low molecular-weight heparins are derived from the larger molecular-weight unfractionated heparin. We chose to use low molecular-weight heparins because of their longer half-life, better bioavailability, and decreased incidence of induced thrombocytopenia and bleeding. With a rat intraabdominal heterotopic model of heart transplantation (Lewis-Brown Norway to Lewis), low molecular-weight heparin in combination with a low dose of cyclosporine (0.5 mg/kg/day) significantly improved allograft survival compared to controls and either low molecular-weight heparin or cyclosporine alone. Histologically, smooth muscle cells are an important cellular component of the lesions of accelerated graft coronary disease. In comparison to animals treated with cyclosporine alone (2 mg/kg/day), the addition of low molecular-weight heparin to cyclosporine (2 mg/kg/day) reduced the frequency and the severity of accelerated graft coronary disease and the extent of parenchymal rejection.

Byssinosis in ginning factories of rural Sindh

Frequency of byssinosis in 276 workers from 5 ginning factories of rural Sindh are described. Twenty-four (9%) had byssinosis, 178 were asymptomatic and the remaining 74 had other respiratory symptoms. Chronic obstructive pulmonary disease was present both in symptomatic and asymptomatic workers and was equally distributed amongst smokers and non-smokers. A possible involvement of some factors other than cigarette smoking is discussed.

Diagnosis of pleural effusions

Sixty patients of pleural effusion with different aetiology are described. Various microbiological and biochemical parameters were done simultaneously in blood and pleural fluid to differentiate tuberculosis and non-tuberculosis effusions. Some biochemical tests were thought to be helpful in differential diagnosis but no single parameter was found diagnostic. Routine investigations of pleural fluid, sputum and pleural biopsy still remain the best method of diagnosis.

Variation of the hyperacuity gap function with age

Responses to hyperacuity stimuli are processed in quite a different manner by the central nervous system than many other stimuli such as resolution targets or increment threshold stimuli. With increased attention being paid to visual response in aging individuals, it is important to study how these response paradigms are affected by age. In this analysis, otherwise normal observers 20 to 85 years of age were studied. The hyperacuity gap test was used. As defined, this is a vernier test using a two-point test array. This particular format was chosen because the resultant data are less distorted by image blur, scatter, and astigmatism than other designs we have studied. The gap or feature separation between the two small targets (which were aligned vertically) was increased logarithmically using octave steps and the hyperacuity threshold (setting variance) was measured for each step. No systematic variation of vernier hyperacuity threshold was found with increasing age within the range of ages or gaps tested. This is important because it can serve as a valuable control and reference for other clinical studies of aging.