The treatment of isolated ulnar fractures in adults: a systematic review

The treatment of isolated ulnar fractures remains controversial, with different authors recommending both surgical and non-surgical management. We undertook a systematic review of the current literature in order to assess whether any conclusions can be drawn. A total of 33 series involving 1876 patients were identified as suitable for analysis. Data from these papers were combined by method of treatment. The results of the non-operative treatment of minimally displaced ulnar fractures with a stable configuration were uniformly good. Below elbow plaster cast, functional brace and early mobilisation all produced similar results. An above elbow cast was unnecessarily restrictive. To preserve forearm rotation, widely displaced or unstable fractures are best treated by open reduction and internal fixation. Guidelines based on cadaveric and clinical studies exist to predict fracture stability and the extent of acceptable displacement. However, these have not been verified in clinical studies. Compression plate fixation gave reliable results in these cases. Other methods lacked sufficient published data to be recommended.

Esophageal candidiasis in pediatric acquired immunodeficiency syndrome: clinical manifestations and risk factors

BACKGROUND

Little is known about the epidemiology and clinical features of esophageal candidiasis (EC) in pediatric AIDS. We therefore investigated the clinical presentation and risk factors of EC in a large prospectively monitored population of HIV-infected children at the National Cancer Institute.

PATIENTS AND METHODS

We reviewed the records of all HIV-infected children (N = 448) followed between 1987 and 1995 for a history of esophageal candidiasis to characterize the epidemiology, clinical features, therapeutic interventions and outcome of esophageal candidiasis. To understand further the risk factors for EC in pediatric AIDS, we then performed a matched case-control analysis of 25 patients for whom control cases were available.

RESULTS

There were 51 episodes of EC documented in 36 patients with 23 male and 13 female patients (0.2 to 17 years; median CD4, count 11/microl), representing a frequency of EC of 8.0%. Concurrent oropharyngeal candidiasis (OPC) was the most common clinical presentation of EC (94%); other signs and symptoms included odynophagia (80%), retrosternal pain (57%), fever (29%), nausea/vomiting (24%), drooling (12%), dehydration (12%), hoarseness (6%) and upper gastrointestinal bleeding (6%). The causative organism documented in 36 episodes (18 from OPC, 17 from endoscopic biopsy and 1 from autopsy) was Candida albicans in all cases. Patients received treatment for EC with amphotericin B (63%), fluconazole (29%), ketoconazole (4%) or itraconazole (1%). A clinical response was documented in all 45 evaluable episodes. In 6 other cases, EC was a final event without contributing to the cause of death. By a conditional logistic regression model for matched data, the best predictor of EC was the presence of prior OPC (P<0.0001), followed by CD4 count and CD4 percentage (P = 0.0002) and use of antibacterial antibiotics (P = 0.0013). The risks associated with low CD4 count were independent of that of prior OPC.

CONCLUSION

EC in pediatric AIDS is a debilitating infection, which develops in the setting of prior OPC, low CD4 counts and previous antibiotics.

CD52 antibodies for prevention of graft-versus-host disease and graft rejection following transplantation of allogeneic peripheral blood stem cells

Graft-versus-host disease (GVHD) is a major cause of mortality and morbidity after allogeneic bone marrow transplantation, but can be avoided by removing T lymphocytes from the donor bone marrow. However, T cell depletion increases the risk of graft rejection. In this study, two strategies are used to overcome rejection: (1) use of high doses of stem cells obtained from peripheral blood (PBSC), (2) admixture with a CD52 monoclonal antibody in order to deplete both donor and residual recipient lymphocytes. Two antibodies are compared: CAMPATH-1G (rat IgG2b) and its humanized equivalent CAMPATH-1H (human IgG1). A total of 187 consecutive patients at six centers received PBSC transplants from HLA-matched siblings between 1997 and 1999. A wide spectrum of diseases, both malignant and non-malignant, was included. The recovery of CD34+ cells after antibody treatment was close to 100%. The risk of acute GVHD (grade 2 to 4) was 11% in the CAMPATH-1G group and 4% in the CAMPATH-1H group (P = NS). The risk of chronic GVHD (any grade) was 11% in the CAMPATH-1G group and 24% in the CAMPATH-1H group (P = 0.03) but the risk of extensive chronic GVHD was only 2%. The overall risk of graft failure/rejection was 2%, not significantly different between the two antibodies. Antibody treatment was equally effective at concentrations between 10 microg/ml and 120 microg/ml and it made no significant difference to the outcome whether the patients received post-transplant immunosuppression or not (87% did not). Transplant-related mortality in this heterogenous group of patients (including high-risk and advanced disease) was 22% at 12 months. It is proposed that treatment of peripheral blood stem cells with CAMPATH-1H is a simple and effective method for depleting T cells which may be applicable to both autologous and allogeneic transplants from related or unrelated donors. Special advantages of this approach are the simultaneous depletion of donor B cells (which reduces the risk of EBV-associated lymphoproliferative disease) and the concomitant infusion of CAMPATH-1H to deplete residual recipient T cells and thus prevent graft rejection.

Tumor necrosis factor alpha can contribute to focal loss of cartilage in osteoarthritis

OBJECTIVE; To evaluate the potential for tumor necrosis factor alpha (TNFalpha)-induced focal loss of cartilage in osteoarthritic (OA) knee joints.

DESIGN

Fresh cartilage from specified regions of OA joints was immunostained for TNF-receptor (R) bearing chondrocytes. Cartilage explants from the same regions were cultured with or without small amounts of TNFalpha and cumulative GAG release into supernatants measured. Concentrations of TNFalpha, p55 and p75 soluble (s) TNF-R in supernatants from cultured OA and non-arthritic (NA) synovium were measured by ELISA.

RESULTS

TNF-R bearing chondrocytes were identified in OA cartilage; more specimens contained p55 TNF-R- than p75 TNF-R-bearing chondrocytes and differences in TNF-R distribution were apparent in cartilage from different regions of the same knees. TNFalpha at 5, 1, 0.5 and 0.25 ng/ml (but not 0.1 ng/ml) significantly increased glycosaminoglycans (GAG) release from cartilage explants in a dose-dependent manner. Variation in susceptibility to TNFalpha was observed in explants from different sites. TNFalpha and p75 sTNF-R, but not p55 sTNF-R, concentrations were significantly higher in OA, as compared with NA, supernatants. A significant correlation between TNFalpha and p75 sTNF-R measurements was apparent only in NA supernatants.

CONCLUSIONS

Variations in chondrocyte TNF-R expression occur in OA cartilage in vivo. TNFalpha at concentrations produced by OA synovium in vitro, can degrade cartilage matrix. In most OA supernatants sTNF-R concentrations were insufficient to abrogate the effects of TNFalpha. Thus conditions exist in some OA knees for TNFalpha to contribute to focal loss of cartilage.

Preliminary evidence for impaired estrogen receptor-alpha protein expression in osteoblasts and osteocytes from men with idiopathic osteoporosis

Although osteoporosis is usually associated with women, 1 in 12 men in the UK have the disease, and a third of these cases are idiopathic. Estrogen is now known to be associated with bone loss in older men, but we found, previously, that levels of this hormone were normal in younger cases of male idiopathic osteoporosis (MIO) in the age range 33-61 years. We therefore hypothesized that their estrogen responses in bone might be defective, through impaired estrogen receptor-alpha (ER)-alpha expression. Consequently, in the present study, we compared expression of ER-alpha by indirect immunofluorescence, semiquantitative image analysis, and in situ reverse transcription-polymerase chain reaction in bone sections from MIO patients (33-56 years) (N = 7); age-matched control men (N = 7); and, for reference, ovarian steroid (OS)-replete (N = 7) and OS-deficient women (N = 6). In the control men, 23 +/- 6% (mean +/- SEM) of osteoblasts and 14 +/- 2% of osteocytes expressed ER-alpha protein, similar to OS-replete women. Although receptor expression decreased in OS-deficient women, the loss of ER-alpha protein in MIO patients was more severe (1 +/- 0.5% osteocytes, 2 +/- 1% osteoblasts expressed receptor); however, ER-alpha messenger RNA (mRNA) was still expressed in controls and MIO patients. Bone loss in these patients may be due to deficient ER-alpha protein expression.

Emergence of resistance of Candida albicans to clotrimazole in human immunodeficiency virus-infected children: in vitro and clinical correlations

Oropharyngeal candidiasis (OPC) is a common opportunistic infection in human immunodeficiency virus (HIV)-infected patients and other immunocompromised hosts. Clotrimazole troches are widely used in the treatment of mucosal candidiasis. However, little is known about the potential contribution of clotrimazole resistance to the development of refractory mucosal candidiasis. We therefore investigated the potential emergence of resistance to clotrimazole in a prospectively monitored HIV-infected pediatric population receiving this azole. Adapting the National Committee for Clinical Laboratory Standards M27-A reference method for broth antifungal susceptibility testing of yeasts to clotrimazole, we compared MICs in macrodilution and microdilution assays. We further analyzed the correlation between these in vitro findings and the clinical response to antifungal therapy. One isolate from each of 87 HIV-infected children was studied by the macrodilution and microdilution methods. Two inoculum sizes were tested by the macrodilution method (10(3) and 10(4) CFU/ml) in order to assess the effect of inoculum size on clotrimazole MICs. The same isolates also were tested using a noncolorimetric microdilution method. Clotrimazole concentrations ranged from 0.03 to 16 microg/ml. Readings were performed after incubation for 24 and 48 h at 35 degrees C. For 62 (71.2%) of 87 clinical isolates, the MICs were low (< or =0.06 microg/ml). The MIC for 90% of the strains tested was 0.5 microg/ml, and the highest MIC was 8 microg/ml. There was no significant difference between MICs at the two inoculum sizes. There was 89% agreement (+/-1 tube) between the microdilution method at 24 h and the macrodilution method at 48 h. If the MIC of clotrimazole for an isolate of C. albicans was > or =0.5 microg/ml, there was a significant risk (P < 0.001) of cross-resistance to other azoles: fluconazole, > or = 8 microg/ml (relative risk [RR] = 8.9); itraconazole, > or =1 microg/ml (RR = 10). Resistance to clotrimazole was highly associated with clinically overt failure of antifungal azole therapy. Six (40%) of 15 patients for whom the clotrimazole MIC was > or =0.5 microg/ml required amphotericin B for refractory mucosal candidiasis versus 4 (5.5%) of 72 for whom the MIC was <0.5 microg/ml (P = 0.001; 95% confidence interval = 2.3 to 22; RR = 7.2). These findings suggest that an interpretive breakpoint of 0.5 microg/ml may be useful in defining clotrimazole resistance in C. albicans. The clinical laboratory's ability to determine MICs of clotrimazole may help to distinguish microbiologic resistance from the other causes of refractory OPC, possibly reducing the usage of systemic antifungal agents. We conclude that resistance to clotrimazole develops in isolates of C. albicans from HIV-infected children, that cross-resistance to other azoles may develop concomitantly, and that this resistance correlates with refractory mucosal candidiasis.

Accuracy of assessment of pregnancy duration by women seeking early abortions

BACKGROUND

Advances in medical abortion might allow women seeking early abortions to terminate their pregnancies safely and effectively without medical supervision. We investigated whether such women can calculate pregnancy duration accurately, a key step in unsupervised use.

METHODS

422 women seeking first-trimester abortions in two clinics (Pune, India, and Atlanta, USA) used a simple worksheet and calendar to calculate the duration of gestation from the date of last menstrual period (LMP) and/or of unprotected intercourse. Clinicians then used standard clinic practices to estimate pregnancy duration. We compared the two sets of estimates, focusing on women who fell into the "caution zone" (ie, had pregnancy durations >8 weeks according to providers, but < or =8 weeks by their own estimates).

FINDINGS

The participants were generally representative of the women seeking abortion at the two clinics. 217 (97.7%) of 222 women in Atlanta and 173 (86.5%) of 200 in Pune could produce an estimate of pregnancy duration. Most (85.4% in Atlanta; 93.6% in Pune) of these estimates were within 2 weeks of those made by providers. For estimates based on LMP, only 10.0% (exact 95% CI 6.2-15.0) of women in Atlanta and 9.8% (5.8-15.3) in Pune fell into the caution zone. For estimates based on a date of intercourse, just 7.7% (4.0-13.1) of women in Atlanta and 3.4% (0-17.8) in Pune fell into the caution zone, although fewer women could use this method.

INTERPRETATION

The vast majority of women seeking first-trimester abortion in this study could accurately calculate pregnancy duration within a margin of error clinically inconsequential for safe use of unsupervised medical abortion.

A phase II trial of triamcinolone hexacetanide for symptomatic recurrent malignant ascites

Ascites is a common complication of advanced cancer and frequently requires paracentesis to reduce symptoms of pain, anorexia, and dyspnea. For many patients repeat paracenteses are required at short intervals. We prospectively studied 15 patients with recurrent ascites of malignancy to determine if intraperitoneal triamcinolone hexacetonide, a slowly metabolized corticosteroid, produced objective and symptomatic responses. After biochemical, radiological, and symptom assessment and the establishment of the interval between paracenteses, patients underwent large-volume paracentesis followed by intraperitoneal triamcinolone hexacetonide 10 mg/kg. Patients were followed after treatment for assessment of symptoms and physical signs of ascites. Repeat paracentesis was performed when symptomatic ascites recurred. Symptomatic ascites recurred in 13 of 15 patients, but the interval between paracenteses was extended from 9.5 +/- 1.6 days to 17.5 days (P = 0.0086). Symptom questionnaire scores assessing well-being, nausea, abdominal pain, dyspnea, appetite, appearance, and change in abdominal size on a scale from 0 to 6 averaged 3.2 +/- 0.3 at entry and 2.5 +/- 0.2 at the 2-week assessment (P = 0.026). Self-assessed symptoms, feeling of well-being, abdominal distention, and physical appearance improved significantly. The mean serum cortisol decreased from baseline, suggesting that some systemic corticosteroid absorption occurred. Thirteen of 15 patients have died, with a median survival of 42 days. Potential adverse effects included 1 episode each of transient abdominal pain, bacterial peritonitis, and localized herpes zoster infection. In patients with ascites of malignancy, intraperitoneal triamcinolone hexacetonide appears to postpone the requirement for repeat paracentesis and improve symptoms of malignant ascites.

Cyclophosphamide and carboplatin and selective consolidation in advanced seminoma

This prospective Phase II study assesses the clinical efficacy and complications of a treatment regimen of combination chemotherapy with cyclophosphamide and carboplatin and selective consolidation in advanced seminoma. Of 46 patients who entered the study between December 1992 and October 1998, 46 were evaluable. Thirty-two achieved a complete remission (70%; 95% confidence interval, 56-83%) after chemotherapy alone. Fourteen achieved a complete remission (30%; 95% confidence interval, 18-46%) after chemotherapy plus consolidation. Forty-three of the 46 patients (93%; 95% confidence interval, 82-97%) remained in remission after a median follow-up period of 27.4 months. No patient experienced nephrotoxic, neurotoxic, or ototoxic effects or hemorrhagic cystitis. No patient had neutropenic fever requiring hospitalization. Thirteen % required platelet transfusions, and 9% required transfusions of packed RBCs. For patients with advanced seminoma, treatment with cyclophosphamide and carboplatin and selective consolidation is safe and effective.

Asystole during inadvertent high spinal anesthesia in a high risk patient without morbidity

Sudden cardiac arrest following high spinal anesthesia (SA) in young and healthy patients with poor outcome has been reported. Extreme bradycardia, hypotension and/or asystole during SA has recently received worldwide attention. We report a high risk patient who developed cardiac arrest associated with two other episodes of extreme bradycardia, hypotension and verbal unresponsiveness during SA without adverse outcome.

Cutaneous barrier repair and pathophysiology following barrier disruption in IL-1 and TNF type I receptor deficient mice

Disruption of the permeability barrier elicits a homeostatic repair response which rapidly restores barrier function while repeated barrier perturbation results in cutaneous pathology. In response to barrier disruption there is a marked increase in epidermal TNF-alpha and IL-1 production. To determine the potential role of TNF and IL-1 in mediating the cutaneous changes that occur following barrier disruption we compared the kinetics of barrier recovery and the degree of epidermal hyperplasia and cutaneous inflammation in TNF type I (p55) receptor and IL-1 receptor type I (p80) deficient mice. No abnormalities in epidermal morphology were observed with light or electron microscopy in receptor deficient mice. Under baseline conditions epidermal barrier function was unchanged in receptor deficient mice. Following barrier disruption the kinetics of barrier recovery were similar in control vs TNF receptor deficient mice regardless if the barrier was disrupted by acetone treatment, SDS treatment, or tape stripping. In contrast, barrier recovery was slightly but significantly accelerated regardless of the method of barrier disruption in IL-1 receptor deficient mice. The degree of epidermal hyperplasia and cutaneous inflammation following repeated barrier disruption was similar in control, TNF receptor, and IL-1 receptor deficient mice. The present study demonstrates that barrier recovery is not delayed and the degree of epidermal hyperplasia and inflammation are not altered in either TNF receptor or IL-1 receptor deficient mice, indicating that neither TNF nor IL-1 alone are essential for either barrier repair or the cutaneous pathology induced by barrier perturbation. Whereas the increase in IL-1 following barrier disruption may delay components of the repair response, whether either TNF-alpha or IL-1 regulate aspects of the homeostatic response remains unresolved.

Episodic hyperglycaemia in pregnant women with well-controlled Type 1 diabetes mellitus: a major potential factor underlying macrosomia

AIMS

To test the common assumption that pregnant women who are sufficiently motivated to achieve very good HbA1c levels will record home blood glucose data accurately.

METHODS

A new device was used to download information from electronic blood glucose meters to assess the extent of selectivity in patient glucose diary-keeping.

RESULTS

In an index case, a woman with excellent ambient HbA1c (5.9%; upper limit of normal 6.1%) was observed to have 68% of preprandial blood glucose readings above the target range of 3.5-6.5 mmol/l and a mean (+/- SD) level of 8.9+/-3.9 mmol/l in the corresponding period. No such impression was conveyed by the home monitoring diary. Six pregnant women with well controlled Type 1 diabetes (mean HbA1c 6.6+/-0.2%) exhibited between 42 and 68% of preprandial readings above the target range.

CONCLUSIONS

The frequency of hyperglycaemia has hitherto been underestimated in well controlled pregnant women whose near-perfect home monitoring record is apparently corroborated by near-normal HbA1c levels. These observations provide a hypothesis for understanding of the disappointing continuance of macrosomia despite excellent HbA1c levels throughout pregnancy.

Effect of ovarian steroid deficiency on oestrogen receptor alpha expression in bone

The mechanism by which oestrogen and hormone replacement therapy (HRT) maintain bone mass in women is still unclear. It has previously been shown that cells of osteoblast lineage in vivo, particularly osteocytes, express oestrogen receptor alpha (ERalpha). Nevertheless, it is still debatable whether oestrogen and the ovarian steroids have a direct affect on osteocytes. If they could regulate osteocyte ERalpha expression, this would be strong evidence for the involvement of these cells in the hormonal regulation of bone mass. This study therefore aimed to compare bone biopsies from women who were replete with ovarian steroids (pre-ovariectomy or post-HRT) with those from the same women when hormone-deficient (post-ovariectomy or pre-HRT) for cellular localization of ERalpha protein or mRNA expression by indirect immunofluorescence, or by in situ hybridization combined with reverse transcriptase-polymerase chain reaction (IS-RT-PCR) respectively. Image analysis showed that proportions of osteocytes positive for immunodetectable ERalpha were higher in hormone-replete than in hormone-deficient women (25+/-SEM 3 per cent, 12+/-SEM 4 per cent, respectively; n=5), with similar but non-statistically significant changes in osteoblasts. This was observed even when HRT was commenced 18 years after menopause. In contrast, grain volume/unit cell area of osteoblast mRNA signal was markedly higher when hormone-deficient (0.055+/-0.01) than when hormone-replete (0.016+/-0.004), with similar but non-significant differences in osteocytes. This preliminary study indicates up-regulation of osteocyte ERalpha protein by ovarian steroids in these patients, which is accompanied by decreased osteoblast ERalpha mRNA expression, providing further evidence for the involvement of osteocytes in the regulation of skeletal structure by ovarian steroids.

Trace metal excretion in patients with homozygous hypercholesterolaemia

In patients with familial hypercholesterolaemia regular therapeutic apheresis is acknowledged to have long-term benefit. A previously unrecognised complication of such intervention is the development of anaemia that reflects a sub-optimal dietary iron intake coupled with accelerated loss of this trace metal in the fluid discarded after each procedure. Additional contributions result from enhanced urinary excretion as a result of chelation to citrate used as an anticoagulant and frequent blood sampling. The underlying pathophysiologic process appears to be reduced deformability. We now document similar and significant losses of zinc, copper and chromium in these circumstances. In the case of the latter three elements, no associated clinical syndromes have thus far been identified, probably because deficiency states are less well-recognised than that due to iron loss and, additionally, because critical reductions are avoided by their replenishment during a normal food intake. These studies are, nevertheless, relevant since they are the basis for recommending prophylactic supplementation during this form of management.

Spinal anesthesia for cesarean section: isobaric versus hyperbaric solution

BACKGROUND

The present study was undertaken to compare the outcomes of hyperbaric versus isobaric spinal anesthesia in Cesarean delivery.

METHODS

The anesthetic solution was administered in sitting position as this posture is commonly used in this clinical setting. Except for the baricity of the anesthetic solution, identical technique was employed for every parturient in the study. Following administration of anesthetic solution the parturient immediately resumed horizontal supine position. The solutions used were 2.0 mL of 0.5% tetracaine in 5% dextrose (hyperbaric) for Group H (n = 30) and in cerebrospinal fluid (isobaric) for Group I (n = 30).

RESULTS

Both hyperbaric and isobaric tetracaine given in sitting position provided adequate analgesic levels. However, hyperbaric tetracaine solution produced a slightly higher median peak level of wilder range, and caused a higher incidence of hemodynamic changes and subjective sensation of "feeling sick" than isobaric tetracaine. Additionally, the duration of surgical anesthesia was shorter and the sacral block was longer for hyperbaric tetracaine solution than for isobaric tetracaine solution at same dose and concentration. Only one mother in Group H needed supplemental inhalation anesthesia for a subsequent hysterectomy due to uncontrollable bleeding. There were no complications, including postpuncture headache in either group.

CONCLUSIONS

Our results indicated that numerous variables must be taken into consideration in predicting the outcome of a spinal anesthesia. Alternation in the technique and individual patient factor may individually or collectively produce different results.

Elevated plasma levels of F2 alpha isoprostane in cystic fibrosis

Cystic fibrosis (CF) is associated with chronic lung infection, inflammation, and elevated indices of oxidative stress. Recently, isoprostanes were shown to be a reliable in vivo marker of oxidant injury with 8-iso-PGF2 alpha, shown to cause airflow obstruction and plasma exudation in guinea pig lung. The present study was designed to examine the relationship between 8-iso-PGF2 alpha levels, plasma antioxidants, and clinical status in CF. We hypothesized that plasma 8-iso-PGF2 alpha levels would be higher in subjects with CF compared to healthy controls. Plasma 8-iso-PGF2 alpha levels were prospectively measured in 22 subjects with CF and nine healthy controls using an 8-isoprostane enzyme immunoassay kit along with plasma vitamins A, E, and beta-carotene. Plasma 8-iso-PGF2 alpha levels were shown to be significantly elevated in the CF subjects compared to controls (319.6 +/- 52.6 vs. 145.0 +/- 21.0 pg/mL, P = 0.005). Plasma levels of antioxidants were significantly lower for the CF subjects compared to the controls (vitamin A, P < 0.003; vitamin E, P < 0.001; and beta-carotene, P < 0.01). This study confirms significantly elevated lipid peroxidation in CF using 8-iso-PGF2 alpha levels.

Approaches to managing carboplatin-induced thrombocytopenia: focus on the role of amifostine

Thrombocytopenia is a significant problem for patients receiving prolonged or aggressive chemotherapy for malignancy. For carboplatin, it is the predominant dose-limiting toxicity and it is cumulative in nature. A number of agents have been evaluated for efficacy in reducing the problem of thrombocytopenia. Some have proved valueless and have been discarded. Others (eg, recombinant thrombopoietin) are under current study, and one (interleukin-11 or oprelvekin) is now commercially available. In addition, the currently available cytoprotectant, amifostine (Ethyol; Alza Pharmaceuticals, Palo Alto, CA/US Bioscience, West Conshohocken, PA), has been shown to reduce the severity and duration of thrombocytopenia caused by carboplatin. Because of the short half-life of amifostine relative to that of carboplatin, multiple doses of amifostine have been administered in conjunction with carboplatin. The optimal dosing regimen with amifostine and carboplatin needs to be further evaluated in clinical studies. Future trials will also expand these observations to carboplatin-containing combination chemotherapy regimens and will further define the role of amifostine as a multilineage bone marrow protectant. The ability of amifostine to demonstrate multilineage bone marrow protection differentiates it from currently available growth factors and fulfills a medical need, including reducing the need for platelet transfusions and maintaining the desired chemotherapy dose intensity.

Isobaric spinal anesthesia for paraplegic patients

It has long been understood that patients with spinal cord injury (SCI) above T6-7 may develop autonomic hyperreflexia (AH) and pose an anesthetic challenge. To date, there is no consensus regarding anesthesia management of these patients among anesthesiologists. Many anesthetic techniques have been proposed and used with varying success, but none of them is uniformly successful. Topical anesthetics may not block the stretch receptors and AH might still be initiated. A deep anesthesia with potent volatile agents is often necessary to prevent or treat AH. Thus, the incidence of hypotension is no different than that associated with neuraxial anesthesia. Failures with potent vasodilators such as sodium nitroprusside also have been reported. Currently, the block of the afferent pathways by neuraxial anesthesia is considered to be the most effective means of preventing AH. However, because the level of neuraxial anesthesia is difficult to detect in SCI patients, excessive high level block and subsequent severe hypotension may occur. When an isobaric solution is used, due to the lack of baricity/patient position interaction, migration of the local anesthetic is usually insignificant, so the level of anesthesia is easier to control and predict. In the past fifteen years (1982-1997), we have used isobaric spinal anesthesia (ISA) in thirteen patients with SCI for various surgical procedures. Although four of these patients had previous history of AH, there was not a single incidence of AH during the perioperative period. Our favorable experiences lead us to believe that ISA is a useful anesthetic technique for SCI patients undergoing surgery.

The medical dictionary for regulatory activities (MedDRA)

The International Conference on Harmonisation has agreed upon the structure and content of the Medical Dictionary for Regulatory Activities (MedDRA) version 2.0 which should become available in the early part of 1999. This medical terminology is intended for use in the pre- and postmarketing phases of the medicines regulatory process, covering diagnoses, symptoms and signs, adverse drug reactions and therapeutic indications, the names and qualitative results of investigations, surgical and medical procedures, and medical/social history. It can be used for recording adverse events and medical history in clinical trials, in the analysis and tabulations of data from these trials and in the expedited submission of safety data to government regulatory authorities, as well as in constructing standard product information and documentation for applications for marketing authorisation. After licensing of a medicine, it may be used in pharmacovigilance and is expected to be the preferred terminology for international electronic regulatory communication. MedDRA is a hierarchical terminology with 5 levels and is multiaxial: terms may exist in more than 1 vertical axis, providing specificity of terms for data entry and flexibility in data retrieval. Terms in MedDRA were derived from several sources including the WHO's adverse reaction terminology (WHO-ART), Coding Symbols for a Thesaurus of Adverse Reaction Terms (COSTART), International Classification of Diseases (ICD) 9 and ICD9-CM. It will be maintained, further developed and distributed by a Maintenance Support Services Organisation (MSSO). It is anticipated that using MedDRA will improve the quality of data captured on databases, support effective analysis by providing clinically relevant groupings of terms and facilitate electronic communication of data, although as a new tool, users will need to invest time in gaining expertise in its use.

Regulation of IL-5 and IL-5 receptor expression in the bone marrow of allergic asthmatics

BACKGROUND

Following consistent demonstrations of the clinical relevance of fluctuations in eosinophil-basophil (Eo-B) progenitors in the blood of patients with a variety of allergic airway disorders, we have turned our attention recently to hemopoietic events occurring in the bone marrow of allergic asthmatic subjects, utilizing a model of airway allergen challenge.

METHODS

Flow-cytometric analyses of CD34/45+ progenitors for coexpression of surface alpha-receptor subunits for IL-3, IL-5 and GM-CSF, as well as in situ hybridization and in situ PCR methodologies to detect mRNA for IL-5 and GM-CSF in developing Eo-B in colony and liquid culture assays were employed before and after in vivo allergen challenge.

RESULTS

An early, specific upregulation of IL-5R alpha expression on CD34/45 progenitors was observed after allergen challenge, concomitant with the development of the late-phase asthmatic response. Protein and mRNA for both GM-CSF and IL-5 were expressed in a time-dependent manner ex vivo, in developing (beta 7-integrin-positive), colony-derived Eo-B after allergen challenge in vivo. Both retinoic acid and corticosteroids were able to downregulate IL-3- and IL-5-induced expression of IL-5R on cord-blood-derived as well as HL-60 cloned Eo-B progenitors.

CONCLUSION

These studies indicate the critical involvement of IL-5 and IL-5R in the induction of Eo-B differentiation and eosinophilic airway inflammation in allergic asthmatics, and point to these events as potential targets for long-term therapy of atopic disease.

Demonstration of delayed recovery from fatiguing exercise in chronic fatigue syndrome

Patients with the chronic fatigue syndrome (CFS) complain consistently of delay in recovery of peripheral muscle function after exercise. The purpose of this study was to try to confirm this observation. A fatiguing exercise test was carried out on the quadriceps muscle group of ten patients and ten control subjects. The test consisted of 18 maximum voluntary contractions (MVCs) with a 50% duty cycle (10 s contraction, 10 s rest), and the force generated by each contraction was recorded using a KinCom dynamometer. This was followed by a recovery phase lasting 200 min in which quadriceps strength was evaluated at increasing intervals, and a follow-up session at 24 h post-exercise involving three 10 s MVCs. Throughout the exercise period, the MVCs obtained from the control group were significantly higher than those of the patient group (P = 0.006), but both groups showed a parallel decline in force over the 18 contractions, in keeping with a similar endurance capacity. Recovery was prolonged in the patient group, however, with a significant difference compared to initial MVCs being evident during the recovery phase after exercise (P = 0.001) and also at 24 h (P < 0.001). In contrast, the control group achieved MVCs which were not significantly different from initial values during the recovery phase, and maintained these at 24 h. These findings support the clinical complaint of delayed recovery after exercise in patients with CFS.

2'-Chlorodeoxyadenosine Effectively Induces Complete Remission in Hairy Cell Leukaemia

Hairy cell leukaemia, previously known as leukaemic reticuloendotheliosis, is an indolent lymphoproliferative disorder of unknown etiology. It typically affects males, causes marked splenomegaly and moderate enlargement of the liver, whilst lymphadenopathy is inconspicuous. Pancytopenia is characteristic with unusually profound monocytopenia, variable reduction in platelets, and the presence in the peripheral blood and marrow of abnormal small lymphocytes having irregular cytoplasmic margins. Ultrastructure, combined with cytochemistry and flow cytometry, have refined diagnosis. A variant exists between this classical entity and B prolymphocytic leukaemia, where blastic transformation or massive lymph node enlargement are found, and this is of ominous significance. In all these patients with this entity conventional chemotherapy is ineffective and shortens survival. Our previous experience with splenectomy results in excellent clinical control for long periods of time, but without disease eradication. There followed a vogue for the use of interferon but this is limited by high cost and dose-dependent side-effects. Contemporary management centres on the purine analogues, where durable responses are possible with fludarabine and deoxycoformycin, but best with 2'chlorodeoxyadenosine (2-CDA). To document the efficacy of the latter agent, we analysed the outcome in seventeen consecutive patients treated over the last five years. Four were ineligible for analysis, although two had 2-CDA. The other thirteen, managed on a standard seven-day course of 0.1 mg/kg 2-CDA given as a continuous intravenous infusion, all responded promptly. Apart from transient leucopenia complications have been minimal, and oral co-trimoxazole prophylaxis for pneumocystis carinii was maintained during the first one year. In all thirteen there was a rapid return to normal of peripheral blood count and marrow on aspiration and trephine biopsy. Even in the longest follow-up clinical and haematologic remission has been maintained and no patients have required retreatment. One individual has relapsed in the marrow at two years. Despite the relative expense of the agent the excellent treatment outcome and patient acceptability, coupled with its safety, leads to the recommendation that in South Africa-as elsewhere in the world-this be regarded as the first line of treatment.

Oral immunization with enterocoated microbeads induces antigen-specific cytolytic T-cell responses

A cytolytic T-lymphocyte (CTL) response has been generated to a protein antigen via oral administration in an experimental murine system. This was achieved by the formulation of the test antigen ovalbumin (OVA) in a pH-sensitive microsphere particle (microbead) with an acrylic-based coating to avoid its degradation by gastric enzymes. Comparative studies of orally administered enterocoated microbead-OVA particles, versus the more traditional formulation of OVA in adjuvant (DETOX-PC) given subcutaneously as immunogen, were conducted; both elicited comparable responses in the generation of antigen-specific lymphoproliferative and CTL responses. CTL lines generated via oral administration of antigen were shown to be CD3(+), CD4(-), and CD8(+). CTL lysis of OVA peptide-pulsed targets was shown to be inhibited by anti-CD8 antibody. Whereas oral administration of pH-sensitive enterocoated microbeads containing proteins has previously been shown to elicit antibody and lymphoproliferative T-cell responses to protein antigens, this is the first demonstration of the generation of an antigen-specific cytolytic T-cell response via oral administration of a protein immunogen formulated in such microbeads.

Bone marrow contribution to eosinophilic inflammation

Allergen-induced bone marrow responses are observable in human allergic asthmatics, involving specific increases in eosinophil-basophil progenitors (Eo/B-CFU), measured either by hemopoietic assays or by flow cytometric analyses of CD34-positive, IL-3R alpha-positive, and/or IL-5-responsive cell populations. The results are consistent with the upregulation of an IL-5-sensitive population of progenitors in allergen-induced late phase asthmatic responses. Studies in vitro on the phenotype of developing eosinophils and basophils suggest that the early acquisition of IL-5R alpha, as well as the capacity to produce cytokines such as GM-CSF and IL-5, are features of the differentiation process. These observations are consistent with findings in animal models, indicating that allergen-induced increases in bone marrow progenitor formation depend on hemopoietic factor(s) released post-allergen. The possibility that there is constitutive marrow upregulation of eosinophilopoiesis in allergic airways disease is also an area for future investigation.

Structure-function studies of ligand-induced epidermal growth factor receptor dimerization

We present a novel 96-well assay which we have applied to a structure-function study of epidermal growth factor receptor dimerization. The basis of the assay lies in the increased probability of EGFRs being captured as dimers by a bivalent antibody when they are immobilized in the presence of a cognate ligand. Once immobilized, the antibody acts as a tether, retaining the receptor in its dimeric state with a resultant 5-7-fold increase in binding of a radiolabeled ligand probe. When the assay was applied to members of the EGF ligand family, murine EGF, transforming growth factor alpha, and heparin-binding EGF-like growth factor were comparable with human EGF (EC50 = 2nM); betacellulin, which has a broader receptor specificity, was slightly less effective. In contrast, amphiregulin (AR1-84), which has a truncated C-tail and lacks a conserved leucine residue, was ineffective unless used at >1 microM. We further probed the involvement of the C-tail and the conserved leucine residue in receptor dimerization by comparing the activities of two genetically modified EGFs (the chimera mEGF/TGFalpha44-50 and the EGF point mutant L47A) and a C-terminally extended form of AR (AR1-90) with those of two other unrelated EGF mutants (I23T and L15A). The potency of these ligands was in the order EGF > I23T > mEGF/TGFalpha44-50 > L47A = L15A >> AR1-90 > AR1-84. Although AR was much worse than predicted from its affinity, this defect could be partially rectified by co-localization of the immobilizing antibody with heparin. Thus, it seems likely that AR cannot dimerize the EGFR unless other accessory molecules are present to stabilize its functional association with the EGFR.

The effects of skin brushing on H reflex amplitude in normal human subjects

Experiments were performed on twenty-two neurologically normal subjects in order to investigate the effects of skin brushing on H reflex excitability in triceps surae. H reflex amplitude was observed to decrease during brushing of a 2 cm x 10 cm area of skin overlying triceps surae, returning to control levels when brushing ceased. Alterations in the duration of the brushing period did not affect the magnitude of the H reflex inhibition, although increased frequency of brush strokes per minute slightly increased the amount of inhibition observed. Brushing of smaller skin areas overlying the muscle only sometimes resulted in H reflex inhibition. Brushing over other skin areas of the lower limb produced only slight effects on triceps surae H reflex amplitude. Removal of cutaneous input from the skin overlying triceps surae abolished any effects of brushing in this area on H reflex amplitude. These results demonstrate an inhibitory effect of brushing on H reflex excitability in normal subjects. If such results are confirmed in subjects with neurological deficit, they could have implications for the use of brushing in clinical practice.

Intra-specific variation in the photosynthetic responses of cyanobiont lichens from contrasting habitats

The photosynthetic properties of cyanobiont lichens from contrasting habitats were measured to identify whether the increased assimilation rates which characterized Peltigera membranacea (Ach.) Nyl. from an exposed habitat were correlated with increased carbon-concentrating mechanism (CCM) activity. The results were contrasted with data obtained from two populations of Peltigera praetextata (Flörke ex Sommerf.) Zopf collected from dry and damp microhabitats within a shaded woodland and Peltigera leucophlebia (Nyl.) Gyelnik, which has been shown to lack a carbon-concentrating mechanism. The differences in assimilation rates between the cyanobiont lichens were not accounted for by differences in chlorophyll content. Peltigera membranacea from the exposed habitat which had the highest assimilation rates had the lowest Gamma; and K_0·5 values and accumulated the greatest C_i -pool indicating that increased C_i accumulation contributed towards the higher assimilation rates shown by these species. The convexity of the light response curve for the cyanobiont lichens decreased with increasing assimilation rates. This might have indicated a diversion of electron transport to energize the carbon-concentrating mechanism. The apparent quantum efficiency of CO₂ assimilation (ΦCO₂ ) was correlated with the genus of lichen photobiont. All cyanobiont lichens had comparable values for ΦCO₂ which were greater than that of the tripartite Peltigera leucophlebia. Light compensation points reflected the exposure of the habitats with higher compensation points characterizing the cyanobiont population from the exposed crag and the tri-partite population from the open grassland. Carbon isotope discrimination values for organic matter and measured instantaneously were the same for all cyanobiont lichens and were comparable with values recorded for species with a carbon-concentrating mechanism. Carbon isotope measurements for P. leucophlebia were typical of those recorded for species without a carbon-concentrating mechanism. Variation in source isotope signature and refixation of respiratory CO₂ were considered to be significant factors in determining organic matter and instantaneous carbon-isotope discrimination. These factors might have masked any subtle variation in carbon-isotope discrimination which resulted from variable CCM activity. The functional significance of increased carbon-concentrating mechanism activity in cyanobiont lichens occupying exposed habitats is discussed.

Results of a phase III, double-blind, placebo-controlled trial of megestrol acetate modulation of P-glycoprotein-mediated drug resistance in the first-line management of small-cell lung carcinoma

The objective of this study was to determine if the addition of megestrol acetate (MA), a modulator of P-glycoprotein-mediated drug resistance, to first-line cytotoxic therapy in patients with limited and advanced stage small-cell lung cancer (SCLC) would improve median time to disease progression and median overall survival. Secondary outcomes evaluated were response rates and patient symptom profile. Between 1992 and 1995, 130 eligible patients were randomized in a double-blind fashion to receive standard first-line therapy consisting of alternating courses of cyclophosphamide/doxorubicin/vincristine and etoposide/cisplatin (and thoracic radiotherapy for limited stage patients), along with either placebo or MA 160 mg t.i.d. for 8 days commencing 3 days before initiation of each cycle of chemotherapy. Treatment was continued for a maximum of six cycles. A total of 130 eligible patients were randomized, 65 to each arm. Fifty-two per cent of patients had limited disease and 48% had advanced disease. The median time to disease progression in limited stage disease was 46 weeks in the placebo arm and 43 weeks in the MA arm (P = 0.71) and in advanced stage disease was 28 weeks in the placebo arm and 27 weeks in the MA arm (P = 0.92). The median overall survival in limited stage disease was 75 weeks in the placebo arm and 75 weeks in the MA arm (P = 0.56) and in advanced stage disease was 41 weeks in the placebo arm and 39 weeks in the MA arm (P = 0.96). There was no consistent statistical difference in response rates or patient symptom profiles between the two treatment arms. The addition of MA, in the dose and schedule used, to standard first-line cytotoxic therapy in SCLC did not result in a significant improvement in response rates, symptom profile, median time to disease progression or overall survival.

Cost Effectiveness of G:CSF in Chemotherapy and Transplant-related Neutropenia

Sustained fever over 38°C is potentially lethal when neutrophil counts remain below 0.1 × 10(9)/L. To determine whether the addition of a haematopoietic stimulatory peptide to conventional supportive care and antibiotic management was cost-effective, 74 such episodes were analysed. Group I (5μg/kg G: CSF: n = 41); Group II (10 μg/kg: n = 19) and Group III (controls: n = 14): these were similar in respect of race, gender, age and body weight. The median days and range of neutrophil count below 0.1 × 10(9)/Lw as 6 (0-12), 7 (0-20) and 8 (0-20) and the corresponding figures for 0.5 × 10(9)/L were 8 (0-19), 8 (1-23) and 13.5 (3-30) days respectively, while the median hospital period was 26 (18-49), 30 (9-86) and 35 (13-44). Mean, standard deviation and range for bed costs in Group I was R9,528 (2125:6120-1660), the corresponding figures for Group II were Rll,453 (5570:3060-2924), and for Group III Rll,366 (2755: 4420-1496). The approximate fate of exchange is: Rl = US$5.87. When expenditure for growth factor was integrated these figures were approximately R26,071, R37,787 and R27,376. There were no advantages in 10 over 5 μg/kg G: CSF. More red cell transfusions were needed in Group III. The days requiring antimicrobial therapy were 14, 16 and 20 respectively. It is concluded from this study, carried out in reverse isolation at a University Teaching Hospital, that duration of neutropenic fever was significantly shortened on G: CSF but there was no benefit in using the higher dose. Additionally, at equivalent cost, there was a shorter period of hospitalisation thereby reducing risk of acquiring nosocomial infections. Finally, there was concurrently a decreased exposure to potentially nephrotoxic antibiotics. Accordingly, this regimen can be justified in the routine management of this category of patient.

Refractory Castleman's Disease

Angiofollicular lymph node hyperplasia is an uncommon low-grade lymphoproliferative disorder first described by Castleman. It is typically asymptomatic with diagnosis incidentally made in young males on chest radiology. Biopsy, in 90% of cases, shows the hyaline vascular variant. In contrast the plasma cell sub-type is accompanied by fever, sweating, weight loss, anaemia, lymphadenopathy, splenomegaly and hypergammaglobulinaemia. Treatment, when necessary because of symptoms, has variable outcome in response to corticosteroids, combinations of cytotoxic drugs, or radiotherapy. Failure to promptly achieve disease control has ominous significance and most patients die. High-dose chemoradiotherapy with bone marrow salvage, using haematopoietic stem and progenitor cells derived from bone marrow or peripheral blood, has precedent in this situation. We report a second successful outcome to this procedure in a 37 year old man with profound constitutional complaints of weight loss, drenching sweats, relentless high fevers and massive organomegaly, resistant to all previous therapy. After conditioning with total body irradiation, cyclophosphamide and high-dose melphalan followed by total nodal irradiation, he underwent peripheral blood stem cell allograft from an HLA-compatible sister. Despite his course being complicated by pulmonary tuberculosis he achieved immediate complete remission, and restaging at one year confirms this to be durable. This further anecdotal case report supports this option in refractory aggressive variants of this disease.

Myeloma Presenting with Massive Splenomegaly

Myeloma typically presents with skeletal damage, renal failure, metabolic disturbances and anaemia. Less usual associations are polyneuropathy, solitary plasmacytomas, and only rarely is lymphadenopathy found. Discomfort and left upper quadrant pain due to marked splenomegaly appears unknown, particularly as the initial symptom. Accordingly, two cases are reported in which this was the reason for seeking medical attention. In both splenectomy was unavoidable because of size and symptomatic infarction. The dominant histologic feature in the first was striking proliferation of sinus lining cells engorged with the IgA paraprotein. In the second there was dramatic expansion of the red pulp. In neither, despite using appropriate immunohistochemical techniques, could the enlargement of the spleen be attributed to infiltration by plasma cells that in the peripheral and blood and marrow had a distinctively unusual morphology. In these two individuals the pathophysiology remains obscure. In the first, although considered, it was not possible to meet the criteria for this being an example of littoral cell angioma. In the second, a postulated disseminated plasmacytoma with primary splenic sequestration remains unproven. This unique finding is, therefore, presented as descriptive pathology without recognisable explanation.

Effects of creatine supplementation on repetitive sprint performance and body composition in competitive swimmers

In a double-blind and randomized manner, 18 male and female junior competitive swimmers supplemented their diets with 21 g.day-1 of creatine monohydrate (Cr) or a maltodextrin placebo (P) for 9 days during training. Prior to and following supplementation, subjects performed three 100-m freestyle sprint swims (long course) with 60 s rest/recovery between heats. In addition, subjects performed three 20-s arm ergometer maximal-effort sprint tests in the prone position with 60 s rest/recovery between sprint tests. Significant differences were observed among swim times, with Cr subjects swimming significantly faster than P subjects following supplementation in Heat 1 and significantly decreasing swim time in the second 100-m sprint. There was also some evidence that cumulative time to perform the three 100-m swims was decreased in the Cr group. Results indicate that 9 days of Cr supplementation during swim training may provide some ergogenic value to competitive junior swimmers during repetitive sprint performance.

Nurses preparing for change: their needs and concerns

As a result of decreased lengths of stay and cost-containment initiatives, fewer nurses are needed in acute care settings. The trend for community-based health care is broadening employment opportunities for nurses to work in community settings. As nurses are considering options to base their practice in community settings, it is important to understand their concerns about making this transition. The results of a qualitative study conducted to examine the concerns and educational needs of acute care nurses related to working in the community are reported. Clinical, professional, and intrapersonal skills important for a successful transition to community-based practice are identified and discussed.

Efficacy and safety of oral immunotherapy with short ragweed extract

BACKGROUND

Oral immunotherapy, if proven safe and effective, could be an alternative to subcutaneous immunotherapy.

OBJECTIVE

This pilot study investigated the clinic and immunologic effects of ragweed immunotherapy using a new microencapsulated, pH-sensitive, oral delivery system.

METHODS

A double-blind, placebo-controlled trial was conducted in 23 patients with allergic rhinitis to short ragweed. Following a baseline nasal challenge with ragweed allergen, oral immunotherapy with encapsulated short ragweed extract or placebo was administered once daily, 6 days/week. Dosed began at 3 micrograms Amb a 1 per day and were increased by 3 micrograms every three days as tolerated, to a maximum daily maintenance dose of 24 micrograms. A nasal challenge was repeated 6 weeks, later, followed by the continuation of maintenance therapy through the natural ragweed season. Daily allergy symptoms and relief medication usage was recorded. A final nasal challenge was performed at the end of the natural season. Short ragweed-specific serum IgE, IgG, and IgG4 antibody levels were measured every 2 weeks during the study.

RESULTS

Maximum tolerated doses ranged from 6 to 24 micrograms Amb a 1 per day (74% reached 24 micrograms). Adverse events were not serious or different between the active and placebo groups. The active group showed increased in short ragweed-specific serum IgG and IgG4 antibody levels. Symptom scores during the natural season were numerically but not statistically lower in the active treatment group. This group also experienced a greater reduction from baseline in nasal reactivity as assessed by nasal challenge.

CONCLUSIONS

These pilot data suggest that the encapsulated, pH-sensitive oral immunotherapy delivery system was safe, induced a brisk serologic response, and attenuated the symptomatic response to both experimental and environmental ragweed exposure.

Bone marrow progenitors in allergic airways diseases: studies in canine and human models

In a canine model of Ascaris suum-inducible bronchial hyperresponsiveness, we previously demonstrated that bone marrow-derived myeloid progenitors rise within 24 h of allergen inhalation; this effect is abolished by pretreatment with inhaled budesonide. We now report that this allergen-induced bone marrow response is observable in human asthmatics, and involves increases in both neutrophil-macrophage and eosinophil-basophil progenitors, within 6 h of allergen inhalation, as measured either by hematopoietic colony assays or by flow cytometric analyses of CD34+, IL-3R alpha+, and/or IL-5-responsive cell populations. In dogs, but not in humans, a transferrable serum hematopoietic activity accounts for the marrow response to inhaled allergen. These findings suggest that allergen-induced increases in bone marrow progenitor formation depend either on a serum hematopoietic factor(s) released after allergen challenge, or upon constitutive marrow upregulation of specific progenitors in allergic airway disease. Further studies to characterize the serum hematopoietic factor(s) and to determine the nature of any atopy-related progenitor profile are in progress.

Reversal of Life-Threatening Vascular Occlusion by Apheresis in Fulminating Plasmodium Falciparum Malaria

Plasmodium falciparum parasitisation can result in a systemic inflammatory response characterised by profound neurologic complications, renal failure, adult respiratory distress syndrome and disseminated intravascular coagulation with high morbidity and mortality. Complete obstruction to medium sized arteries seems not to have been reported before while the role of sequential whole blood and plasma exchange may be an under-utilised intervention that is life-saving in selected cases. A 25 year old patient was referred with mental confusion, rapidly deteriorating vision, hypotensive and oliguric, massive generalised oedema compressing muscles leading to rhabdomyolysis and impending gangrene of both lower limbs. 1,555 mL of whole blood was exchanged in the cell separator to reverse the haemoglobin of 35g/L, remove parasitised and effete red cells while simultaneously correcting hypovolaemia. Thereafter 4,000mL of fresh frozen plasma was similarly exchanged and 3 × 10(11) platelets given to treat the advanced disseminated intravascular coagulation. Anti-malarial therapy was continued with quinine sulphate and doxycycline for the chloroquin-resistant parasites. The tense swelling of the limbs gradually resolved, thereby avoiding fasciotomies, arterial occlusion reversed and microvascular perfusion was re-established with resolution of all symptoms. Tissue loss was eventually limited to fore foot amputation on the left. The patient has been physically and psychologically rehabilitated and discharged after six weeks in hospital. Malaria, when associated with multiple organ failure, is frequently fatal. Where appropriate, complications-due to vascular occlusion-can be promptly reversed with suitable apheresis. This practical approach is relatively inexpensive and should be available in all centres responsible for managing such patients.

Iron Deficiency Developing in Patients with Homozygous Hypercholesterolaemia on Long-term Plasmapheresis is Significantly Contributed to by Extracorporeal Haemolysis

Patients with homozygous hypeicholesterolaemia are notoriously refractory to pharmacologic intervention, leaving regular long-term plasmapheresis as one of the most effective forms of therapy. In this situation we noted the universal development of anaemia; accordingly, its pathogenesis was investigated in a stable cohort of patients over a two year period. Radionuclide studies were carried out in 8 of the 9 available individuals: of these 3 who were not on treatment and 3 out of 5 on the apheresis programme had mean red cell lifespan below the lower level of our normal range. The creation of an arterio-venous fistula and subsequent performance of plasma exchange procedures every two weeks was followed by a falling haemoglobin concentration and the appearance of hypochromasia and microcytosis. The latter was the result of substantial loss of iron through venesection, in the discard plasma and by a transient peak of the iron in the urine: the last two compartments were studied using inductively coupled plasma atomic emission spectrometry (ICP-AES). Such depletion could not be compensated for by a dietary intake of iron that barely met the recommended daily allowance whereas the anaemia reversed readily on oral supplementation. This is the first report of extracorporeal haemolysis in this clinical setting and recognition of its pathophysiology directly influences management. Thus, oral iron supplementation should prevent anaemia and its symptoms whilst also circumventing the paradoxical hyperviscosity that might otherwise occur from iron deficiency.

The interaction of an epidermal growth factor/transforming growth factor alpha tail chimera with the human epidermal growth factor receptor reveals unexpected complexities

It has been assumed that substitution of homologous regions of transforming growth factor alpha (TGF-alpha) into epidermal growth factor (EGF) can be used to probe ligand-receptor recognition without detrimental effects on ligand characteristics for the human EGF receptor (EGFR). We show that a chimera of murine (m) EGF in which the carboxyl-terminal tail is substituted for that of TGF-alpha (mEGF/TGF-alpha44-50) results in complex features that belie this initial simplistic assumption. Comparison of EGF and mEGF/TGF-alpha44-50 in equilibrium binding assays showed that although the relative binding affinity of the chimera was reduced 80-200-fold, it was more potent than EGF in mitogenesis assays using NR6/HER cells. This superagonist activity could not be attributed to differences in ligand processing or to binding to other members of the c-erbB family. It appeared to be due, in part, to choice of an EGFR-overexpressing target cell where high receptor number compensated for the low affinity of the ligand; it also appeared to be related to the ability of the chimera to activate the EGFR tyrosine kinase. Thus, when EGFR autophosphorylation was measured, mEGF/TGF-alpha44-50 was more potent than EGF, despite its low affinity. When tested using chicken embryo fibroblasts, substitution of the TGF-alpha carboxyl-terminal tail into mEGF failed to enhance its binding affinity for chicken EGFRs; however, the chimera was intermediate in potency between TGF-alpha and mEGF in mitogenesis assays. Our results suggest a contextual requirement for EGFR recognition which is ligand-specific. Further, the unpredictable responses to chimeric ligands underline the complex nature of the processes of ligand recognition, receptor activation, and the ensuing cellular response.