Improving the quality of NHS out-patient clinics: the applications and misapplications of TQM

Presents and discusses the results of a monitoring programme instituted to comply with the objectives laid down in The Patient's Charter. Explores the dangers inherent in attempting to assess the quality of out-patient clinics by the use of single, simplistic indicators such as a waiting time. Examines the ways in which total quality management has been deployed in a health-service context and pays particular attention to the way in which the concept of ¿the customer¿ may need considerable refinement. Suggests incorporating more user-centered approaches into evaluations of quality in the National Health Service, such as the patient satisfaction survey and the application of the SERVQUAL model of consumer satisfaction. Refines the concept of ¿ecological validity¿ in an attempt to capture the perceptions and world views of all of the participants in episodes of out-patient care in order to derive more complete measures of quality.

Improving the quality of out-patient services in NHS hospitals: some policy considerations

One of the key objectives in the Patient's Charter was to reduce the amount of time typically spent waiting for treatment in NHS out-patient clinics, a documented source of discontent. Presents the results of a quality improvement programme instituted at Leicester General Hospital. Discusses some of the techniques and problems encountered in the measurement exercise. While the results of the monitoring exercise indicated that waiting times were being radically reduced, doubt is expressed as to whether this one simplistic indicator is sufficient to measure the overall quality of out-patient clinics. There is a danger that measurement systems have concentrated on that which is measurable rather than that which is significant. In particular, the voice of the patient is not incorporated into the league table approach to out-patient quality. Discusses several approaches to the measurement of overall quality and the problems and dangers inherent in adopting a league table approach to quality measurement.

Tests of an asymmetric monochromator to provide increased flux on a synchrotron radiation beamline

Asymmetric channel-cut monochromators have been tested at the SRS. Results from both focused and unfocused beamlines have shown a threefold improvement in flux when compared with the flux obtained from a symmetric cut Si(111) monochromator. Some problems with using such monochromators and possible modifications are described.

Mixing Symmetric and Oblique Bragg Reflections in Rigid Channel-Cut Crystals

Because the Bragg angle and Darwin range of total reflection in symmetric and oblique Bragg reflections vary with the angle between the Bragg planes and the crystal surface, it is generally believed that the resulting mismatch causes a loss of intensity in monolithic channel-cut crystals that is unacceptable in practice. It has been discovered that in the unique case of the 220 Bragg reflection from germanium no mismatch occurs, so that oblique and symmetric reflections can be mixed in one rigid channel-cut crystal. The results are valid for both X-ray and neutron channel-cut monochromators.

The effect of induced reflections on human arterial waveforms

1. External compression of the human brachial artery results in waveform reflection. 2. Resonant waves are found superimposed on the original blood pressure signal. 3. The mechanism may be likened to the operation of an organ pipe with reflections at both ends of an arterial segment. 4. This has implications for measurements in arteries where external pressure is applied.

Adaptive silicon monochromators for high-power wigglers; design, finite-element analysis and laboratory tests

Multipole wigglers in storage rings already produce X-ray power in the range up to a few kilowatts and planned devices at third-generation facilities promise up to 30 kW. Although the power density at the monochromator position is an order of magnitude lower than that from undulators, the thermal strain field in the beam footprint can still cause severe loss of performance in X-ray optical systems. For an optimized adaptive design, the results of finite-element analysis are compared with double-crystal rocking curves obtained with a laboratory X-ray source and, in a second paper [Quintana, Hart, Bilderback, Henderson, Richter, Setterson, White, Hausermann, Krumrey & Schulte-Schrepping (1995). J. Synchotron Rad. 2, 1-5], successful tests at wiggler sources at CHESS and ESRF and in an undulator source at HASYLAB are reported.

Adaptive Silicon Monochromators for High-Power Insertion Devices. Tests at CHESS, ESRF and HASYLAB

X-ray wigglers which produce tens of kilowatts of photon power within the white beam will soon become available at third-generation sources of synchrotron radiation. Insertion devices that produce several kilowatts already exist and we have used those at CHESS, ESRF and HASYLAB to test adaptive 111 silicon water-jet-cooled monochromators at up to 2 kW total incident beam power. This development from earlier work at the Brookhaven National Synchrotron Light Source (NSLS) uses the pressure in the water coolant to provide active compensation of the strain field in the thermal footprint, nulling its effect to within residual variations in Bragg angle of only a few arc s. The design is robust, vacuum compatible and uses no moving mechanical parts.

Improving out-patient clinic waiting times: methodological and substantive issues

In the Patients' Charter, a standard is laid down that all patients who attend out-patient clinics should be seen within 30 minutes of their appointment time. Discusses how a statistical monitoring system using a "low technology" approach was implemented at Leicester General Hospital during 1992-93. This was instrumental in raising the proportion of patients seen within 30 minutes from under 50 per cent to over 80 per cent in 15 months. Points to the fact that statistical monitoring alone is not sufficient to deliver quality improvements. Suggests that only enlightened management action which brings both management and clinicians into a quality improvement programme is likely to be effective. Discusses some of the measurement problems involved. Warns against the fact that over-reliance on purely quantitative measures (as indicated in "Charter" standards) to the neglect of more qualitative measures may be counterproductive. Suggests that qualitative approaches need to complement the normal statistical monitoring.

Investigation of the GTP-binding/GTPase cycle of Cdc42Hs using fluorescence spectroscopy

We have developed several high-resolution assays for the nucleotide state of a rho-subfamily low molecular weight GTP-binding protein, Cdc42Hs. The first involves the use of the fluorescent N-methylanthraniloyl derivative of GDP (mant-GDP). As has been shown for the ras protein, mant-dGDP fluorescence is significantly enhanced (approximately 20%) upon binding to Cdc42Hs. It was further found that the binding of mant-nucleotides results in an efficient energy transfer between the single tryptophan residue of Cdc42Hs and the mant moiety. The exchange of mant-dGDP for GDP bound to Cdc42Hs, as read-out either by the enhancement of the mant fluorescence or by energy transfer, is inhibited by physiological (mM) Mg2+ concentrations and correlates exactly to the rate of [3H]GDP exchange observed in filter-binding assays. Moreover, changes in the fluorescence of mant-dGDP are also sensitive to nucleotide dissociation induced by the dbl-oncogene product, a known nucleotide exchange factor for Cdc42Hs. A second fluorescence read-out for the nucleotide-bound state of Cdc42Hs involves the measurements of intrinsic fluorescence of a single tryptophan residue (W97) which is highly sensitive to whether GDP or GTP is bound in the nucleotide pocket. The hydrolysis of GTP to GDP by Cdc42Hs results in an approximately 30% enhancement of the protein fluorescence. The rate of this fluorescence change corresponds well to the rate of conversion of [gamma-32P]GTP to GDP plus [32P]Pi as measured by filter-binding assays.(ABSTRACT TRUNCATED AT 250 WORDS)

Narrowing the organ donation gap: hospital development methods that maximize hospital donation potential

The purpose of this article is to identify and describe this organ procurement organization's hospital development methods that have markedly increased the quantity and quality of organ donor referrals. Procedures used include the establishment of organ donor programs (hospital donor programs) within each donor hospital. The goal for these hospital donor programs is to monitor and maximize organ procurement within each institution. Routine quality assurance or death audits along with referral data from the organ procurement organization's database provide both the organ procurement organization and the hospital donor program with the necessary information to evaluate organ procurement strengths and weaknesses. This data is used in concert with ongoing development activities, which include, but are not limited to, physician and staff education and frequent marketing visits. Early referral to the organ procurement organization of all nonsurvivable head injuries for evaluation as potential organ donors, and a timely request for donation by the organ procurement organization coordinator are emphasized. The results of these efforts have been gratifying. In 1989, 138 referrals and 41 organ donations occurred. In 1990, 174 referrals and 66 organ donations occurred. In 1991, 213 referrals and 71 organ donations occurred. In 1992, 228 referrals and 70 organ donations occurred. In the first 6 months of 1993, 146 referrals and 40 organ donations occurred, for a prorated figure of 292 referrals and 80 organ donations annually. In conclusion, these results appear to validate the benefits of this approach and its significant contribution to narrowing the donation supply and demand gap.

Intestinal pseudo-obstruction in adult spinal muscular atrophy

A 42-year-old woman with negative family history had the insidious onset of weakness in her lower extremities 8 years before, in 1983. The disorder slowly progressed to include cramps and muscle twitches. The diagnosis of adult spinal muscular atrophy (SMA) was made when electromyography showed large rapidly firing motor unit-potentials, positive waves, and fibrillation potentials, and when muscle biopsy of the quadriceps revealed severe alterations consistent with neurogenic atrophy. The patient also had severe chronic constipation for many years. More recently she had developed unremitting diarrhea. Gastrointestinal studies showed no evidence of peristaltic contractions in the rectum, delayed gastric emptying, and abnormal jejunal manometry with altered propagation of the migrating myoelectrical complex.

Clinical and morphologic features of a myopathy associated with a point mutation in the mitochondrial tRNA(Pro) gene

We studied a 9-year-old girl with progressive weakness of her extremities for two years. Her neurologic evaluation showed weakness of proximal muscles but no ophthalmoparesis. With the exception of elevated serum lactic acid, the general blood screen, EMG, nerve conduction velocity tests, and ECG were normal. Light and electron microscopy of a muscle biopsy showed proliferation of mitochondria containing disorganized cristae. Activities of respiratory chain enzymes containing mitochondrial DNA (mtDNA)-encoded subunits were significantly impaired in muscle homogenates. A G-->A transition at position 15990 previously detected in this patient's muscle was not present in peripheral blood cells of her mother or sister. However, the patient's WBCs appeared to contain a very small percentage of mutant mtDNAs, indicating that the mutation may have originated during early embryogenesis.

Interleukin-8 production by human peritoneal mesothelial cells in response to tumor necrosis factor-alpha, interleukin-1, and medium conditioned by macrophages cocultured with Staphylococcus epidermidis

Patients treated with continuous ambulatory peritoneal dialysis (CAPD) may suffer from recurrent peritonitis episodes caused by Staphylococcus epidermidis. Early recruitment of granulocytes from the peripheral blood is important for the peritoneal antibacterial defense of CAPD patients. In this study, human peritoneal mesothelial cells were shown to produce high levels of interleukin-8 (IL-8) in response to IL-1 beta and tumor necrosis factor-alpha (TNF alpha) but not lipopolysaccharide or S. epidermidis. Coculture of peritoneal macrophages with S. epidermidis induced high levels of IL-1 alpha, IL-1 beta, and TNF alpha in 24-h-conditioned medium. Preincubation of this medium with anti-TNF alpha, anti-IL-1 alpha, or anti-IL-1 beta partially blocked stimulation of IL-8 production by mesothelial cells. Added together, these antibodies abolished IL-8 production to a level just above background. Migration of granulocytes to the stimulated mesothelial cell-conditioned medium could be totally blocked with rabbit polyclonal anti-IL-8 antibody. Thus, mesothelial cells are important for the recruitment of granulocytes into the peritoneal cavity.

Needlestick injuries: the shock and reality

It has been a typically busy Saturday night in the emergency department. Then, near midnight, a trauma casualty was admitted and an incident occurred that would occupy Suzanne Smith's thoughts for months to come. When starting an intravenous line on this patient, Suzanne spiked herself with a needle. Later the patient was taken to the intensive care unit and placed on a ventilator. Suzanne was overcome with fear that she might have contracted AIDS. Her fears intensified when she learned that the patient, Mr. Norman, was a heroin addict.

A model for the development of the CNS role in adolescent health promotion self-care

A meaningful definition of the CNS has been difficult to express because of the versatility of the role, yet a clear understanding of the role responsibilities is essential to ensure successful implementation of the CNS position within a select client population. Adolescence is a period in the life-span that represents such a population. Adolescents undergo certain cognitive changes that render them vulnerable to health-damaging behaviors often initiated during this stage of development. Health promotion self-care strategies by the CNS are important in helping the young person incorporate positive health practices in daily activities. A conceptual model, based on Orem's general theory of nursing, has been developed through literature review and refined through practical application. It is presented as a framework by which health promotion needs of the adolescent may be predicted, recognized, and satisfied through components of the CNS role, the basic concepts of Orem's model, and characteristics of adolescent cognitive development.

Aggressive surgical therapy for Klatskin tumors

Thirty-one patients underwent limited hepatic resection with Roux-en-Y biliary-enteric anastomosis and placement of biliary stents for cholangiocarcinoma of the hepatic duct bifurcation (Klatskin tumor). Resection included wide tumor excision and bile duct resection at the liver hilum without major hepatic resection and was undertaken in all patients unless precluded by intraoperative evidence of vascular invasion. All patients were operated on by a single surgeon during the 10 years between 1981 and 1991. Similar procedures were performed for both curative (n = 17) and palliative (n = 14) treatment of this disease entity. In this series, the overall mean postoperative survival of these patients was 17 months. The mean postoperative survival of patients undergoing surgery with curative intent was 21 months in contrast to 12 months for those undergoing planned palliation. One patient in this series has been alive for more than 6 years with no evidence of disease. Five patients experienced major postoperative complications (16%), and there were two perioperative deaths (6%). This retrospective review supports an aggressive surgical approach in patients with Klatskin tumor.

Screen detected high blood pressure under 40: a general practice population followed up for 21 years

OBJECTIVE

To assess hypertension detected under 40 in a general practice population.

DESIGN

Prospective case-control study.

SETTING AND SUBJECTS

Former coal mining community in south Wales. Systematic case finding for hypertension and associated risk factors applied to a mean total population of 1945 from age 20 on a five year cycle through 21 years. Mean population aged 20-39, 227 men and 213 women. Case criteria: age < 40 and mean systolic pressure > or = 160 mm Hg or diastolic pressure > or = 100 mm Hg. Age and sex matched controls randomly sampled from the same population.

MAIN OUTCOME MEASURES

Mean initial pressures and pressures at follow up in 1989 or preceding death, and all cardiovascular events.

RESULTS

25 men and 16 women met criteria. Estimated five yearly inceptions were 26/1000 for men and 18/1000 for women. Male group mean initial blood pressure was 164/110 mm Hg for cases, falling to 148/89 mm Hg at follow up. Five male cases died at mean age 47.8, compared with two controls at 49.5. Female group mean initial pressure was 172/107 mm Hg for cases, falling to 145/86 mm Hg at follow up. One female case died aged 50, no controls. 10 male cases had non-fatal cardiovascular events at mean age 40.2, compared with two controls at mean age 50.5. Four female cases had non-fatal events at mean age 47.2, compared with one control aged 58. Male differences were statistically significant.

CONCLUSIONS

Hypertension under 40 is dangerous, commoner in men than women, rarely secondary to classic causes, and may be controlled in general practice on a whole community basis.

Endotoxin and tumor necrosis factor-alpha-induced interleukin-8 release in humans

Neutrophil recruitment and activation are thought to play an important role in tissue damage observed in septicemia. Interleukin-8 (IL-8) is a small cytokine with important neutrophil-activating and chemoattractant properties. IL-8 release was studied after injection of human volunteers with low doses of either endotoxin (2 ng/kg of body weight) or tumor necrosis factor-alpha (TNF alpha) (50 micrograms/m2). After TNF-alpha injection, IL-8 appeared at 30 min, whereas increased levels were first observed after 90 min in endotoxin-challenged volunteers. Peak levels were measured at 120 min after both endotoxin (192 +/- 193 ng/L) and TNF alpha (500 +/- 236 ng/L) injection. These data indicate that IL-8 is released in humans after injection of endotoxin and TNF alpha and suggest that endotoxin-induced IL-8 release is mediated by TNF alpha.

Interleukin-8 in sepsis: relation to shock and inflammatory mediators

Because of its neutrophil-activating properties, interleukin-8 (IL-8) may play an important role in the pathophysiology of sepsis. We measured circulating IL-8 levels in 47 patients with clinical sepsis. Levels on admission were elevated in 42 of the 47 patients (89%) and were comparable in patients with gram-positive or gram-negative infections. Patients with shock had significantly higher IL-8 levels than normotensive patients (P = 0.0014, Wilcoxon-Mann-Whitney test), whereas no differences in IL-8 levels were found between patients with or without adult respiratory distress syndrome. Patients who died had higher IL-8 levels on admission than the patients who survived. The largest differences in IL-8 levels between survivors and nonsurvivors was found when only patients with positive cultures were considered (P = 0.0342). IL-8 levels appeared to correlate significantly with lactate levels and inversely with leukocyte and platelet numbers and mean arterial pressure. In addition, the IL-8 level in the sepsis patients was found to correlate significantly with levels of IL-6, elastase-alpha 1-antitrypsin, and C3a. Serial observations revealed that in most patients IL-8 levels decreased, irrespective of the outcome. Thus, our results demonstrate that IL-8 levels are increased in most patients with sepsis and correlate with some important clinical, biochemical, and inflammatory parameters. These findings suggest a role for IL-8 in the pathophysiology of sepsis.

Occupational asthma in a beet sugar processing plant

A patient with occupational asthma in the beet sugar processing industry is described. Symptomatology, skin testing, immunologic testing, and specific bronchoprovocation testing indicate exposure to moldy sugar beet pulp was the cause of the patient's occupational asthma. Cooperation between the treating physician and public health authorities is encouraged.

Modulation of B cell maturation and migration to the thymus of SJL mice. B cell migration to the thymus

The direct linkage of the B cell maturation process and infiltration of the thymus with mature B cells was studied in SJL mice. Phenotypically and functionally, B cells in the thymus of old SJL mice are mature B cells; IgM+, IgD+, Ly-1-, and evince a high proliferative response to lipopolysaccharide and a low one to dextran sulphate. Memory B cells can be found in the thymus of mice immunized with T-dependent or T-independent antigens. Chronic depletion and B cell maturation arrest induced by fractionated total lymphoid irradiation or by neonatal splenectomy eliminate B cells from the thymus and block their migration from the periphery to the thymus. When examined in adoptive transfer experiments, thymus B cells were found to possess a normal migration pattern and homing receptors; their migration pattern did not differ from that of lymph node or splenic B cells. It is evident, therefore, that the large number of normal functioning B cells in the thymus of SJL mice reflects a massive infiltration of the thymus by mature B cells from the periphery due to thymus dysfunction rather than to an abnormal in situ differentiation of intrathymic B cell precursors.

Multicenter controlled trial comparing high-frequency jet ventilation and conventional mechanical ventilation in newborn infants with pulmonary interstitial emphysema

One hundred forty-four newborn infants with pulmonary interstitial emphysema were stratified by weight and severity of illness, and randomly assigned to receive treatment with high-frequency jet ventilation (HFJV) or rapid-rate conventional mechanical ventilation (CV) with short inspiratory time. If criteria for treatment failure were met, crossover to the alternate ventilatory mode was permitted. Overall, 45 (61%) of 74 infants met treatment success criteria with HFJV compared with 26 (37%) of 70 treated with CV (p less than 0.01). Eighty-four percent of patients who crossed over from CV to HFJV initially responded to the new treatment, and 45% ultimately met success criteria on HFJV. In contrast, only 9% of those who crossed over from HFJV to CV responded well to CV (p less than 0.01), and the same 9% ultimately met success criteria (p less than 0.05). Therapy with HFJV resulted in improved ventilation at lower peak and mean airway pressures, as well as more rapid radiographic improvement of pulmonary interstitial emphysema, in comparison with rapid-rate CV. Survival by original assignment was identical. When survival resulting from rescue by the alternate therapy in crossover patients was excluded, the survival rate was 64.9% for HFJV, compared with 47.1% for CV (p less than 0.05). The incidence of chronic lung disease, intraventricular hemorrhage, patent ductus arteriosus, airway obstruction, and new air leak was similar in both groups. We conclude that HFJV, as used in this study, is safe and is more effective than rapid-rate CV in the treatment of newborn infants with pulmonary interstitial emphysema.

A comparison of Collins and UW solutions for cold ischemic preservation of the rat liver

A new solution which can extend successful preservation times for hepatic allografts was recently developed at the University of Wisconsin (UW). To examine the mechanism of improved viability using this solution, we developed a model of orthotopic hepatic transplantation in the rat. As a baseline study, we compared parameters of viability of allografts preserved in Collins solution to those preserved in UW, including survival, bile output, peak AST, and allograft weight change during storage. Seventy-four rats were transplanted following storage in Collins solution and 70 rats were transplanted after storage in UW. Cold-storage time varied between 2 and 24 hr. The survival with preservation in UW was significantly better than that with Collins when storage time was greater than 2 hr. The preservation time for a viable organ using UW was greater than double that using Collins. The peak AST using UW was lower than that with Collins for cold ischemic times (CIT) up to 10 hr, with significance demonstrated at 5-6 and 7-8 hr when compared with Collins. Prolonged CIT resulted in an increase in liver weight with Collins-preserved livers and a decrease in weight with UW-preserved livers. Using a model of orthotopic liver transplantation in the rat, we demonstrated a doubling of preservation time when UW solution was substituted for Collins. Similar improvements in recipient survival and biochemical parameters of injury have been demonstrated in the canine model and in human clinical trials.

Twenty five years of case finding and audit in a socially deprived community

OBJECTIVE

To evaluate audit and case finding (whole population care) in a community over 25 years.

DESIGN

Contemporary screening for and audits of care of chronic disease and risk factors; retrospective review of computerised practice records; and comparisons of mortality and social indices with neighbouring communities.

SETTING

One general practice in Glyncorrwg, West Glamorgan.

SUBJECTS

1800 people registered with the practice in 1987 and 558 people who died from 1964 to 1987, whose records had been retained.

MAIN OUTCOME MEASURES

Detection of high blood pressure, smoking, airways obstruction, obesity, diabetes, and alcohol problems in adults aged 20-79; prevalence of smoking in this population and in hypertensive and diabetic groups; age standardised mortality ratios in relation to indices of social deprivation.

RESULTS

In the population aged 20-79 (1207 patients) 249 (21%) had peak expiratory flow rate less than 50% of expected value or which improved by 15% or more with an inhaled beta agonist, 207 (17%) had body mass index at or over 30 kg/m2, 118 (10%) had untreated mean arterial pressures greater than 159/104 mm Hg (three readings), 80 (7%) (65 (16%) men, 15 (4%) women) had recognised alcohol problems, and 35 (3%) had diabetes. The proportion of men aged 20-64 who said they smoked fell from 61% (290/476) in 1968-70 to 36% (162/456) in 1985 whereas that of women who smoked was unchanged (43%, 187/436 v 42%, 190/448 respectively). In 116 screened hypertensive patients group mean blood pressure fell from 186/110 mm Hg before treatment to 146/84 mm Hg at 1987 audit, as did the proportion of smokers (56% v 20%), but body mass index and total cholesterol concentration showed no significant change. In 34 diabetic patients mean blood pressure and the proportion of smokers fell (171/93 mm Hg v 155/81 mm Hg; 44% v 12%). The age standardised mortality ratio in 1981-6 was lower than in a neighbouring village without a developed case finding programme (actual to expected deaths less than 65 = 21 to 22 in Glyncorrwg, 48 to 30 in control village).

CONCLUSIONS

Whole population care through organised case finding and audit is feasible but only with a labour intensive approach combining accessibility, flexibility, and continuity, as well as a planned and structured approach, which requires substantial expansion of staff numbers and assiduous recording. It may reduce risks for at least some high risk groups. Despite their shortcomings the available data are consistent with the hypothesis that whole population care helps reduce mortality. Incentives in the new contract, which encourage the uncritical development of structured process, may diminish health outputs.

Structure-function analysis of human IL-6. Epitope mapping of neutralizing monoclonal antibodies with amino- and carboxyl-terminal deletion mutants

To study the active site(s) of IL-6 we combined mutagenesis of IL-6 with epitope mapping of IL-6 specific mAb. In addition to amino-terminal deletion mutants we described previously, carboxyl-terminal deletion mutants were prepared. Functional analysis showed that deletion of only five carboxyl-terminal amino acids already reduced the bioactivity 1000-fold. A panel of mAb to IL-6 was subsequently analyzed by antibody competition experiments and binding to the amino- and carboxyl-terminal deletion mutants. On the basis of the competition experiments the six neutralizing mAb were divided in two groups (I and II). The binding pattern with the deletion mutants suggested that the region recognized by the four mAb in group I is composed of residues of amino- and carboxyl-terminus: binding of two mAb was abolished after deletion of amino acid Ala I-Ile26, of the third mAb after deletion of the four carboxyl-terminal amino acids whereas the fourth mAb did not bind to either mutant. Group II mAb retained binding to these mutants. Taken together these data suggest that in the native IL-6 molecule amino acid residues of amino and carboxyl terminus are in close proximity and that together they constitute an active site. Furthermore our data suggest that the part of the molecule recognized by group II antibodies is a second site involved in biologic activity.

Structure-function analysis of human IL-6. Epitope mapping of neutralizing monoclonal antibodies with amino- and carboxyl-terminal deletion mutants

To study the active site(s) of IL-6 we combined mutagenesis of IL-6 with epitope mapping of IL-6 specific mAb. In addition to amino-terminal deletion mutants we described previously, carboxyl-terminal deletion mutants were prepared. Functional analysis showed that deletion of only five carboxyl-terminal amino acids already reduced the bioactivity 1000-fold. A panel of mAb to IL-6 was subsequently analyzed by antibody competition experiments and binding to the amino- and carboxyl-terminal deletion mutants. On the basis of the competition experiments the six neutralizing mAb were divided in two groups (I and II). The binding pattern with the deletion mutants suggested that the region recognized by the four mAb in group I is composed of residues of amino- and carboxyl-terminus: binding of two mAb was abolished after deletion of amino acid Ala I-Ile26, of the third mAb after deletion of the four carboxyl-terminal amino acids whereas the fourth mAb did not bind to either mutant. Group II mAb retained binding to these mutants. Taken together these data suggest that in the native IL-6 molecule amino acid residues of amino and carboxyl terminus are in close proximity and that together they constitute an active site. Furthermore our data suggest that the part of the molecule recognized by group II antibodies is a second site involved in biologic activity.

Analysis of human IL-6 mutants expressed in Escherichia coli. Biologic activities are not affected by deletion of amino acids 1-28

We have constructed and analyzed amino terminally deleted analogs of IL-6. Progressively shortened variants of mature IL-6 were constructed at the cDNA level and expressed in Escherichia coli. Mutant proteins were recovered from refractile bodies by solubilizing in 6 M guanidine-HCl. The mutant protein concentration in these preparations was estimated by Western blotting by using an IL-6-specific mAb and the biologic activity was measured in the B9 (hybridoma growth factor) assay. The first 28 amino acids of mature IL-6 could be removed without significantly affecting biologic activity. A further removal of amino acids 29 and 30 resulted in an approximately 50-fold decrease, whereas removal of amino acids 31 to 34 virtually abolished the activity. The mutants showed the same reaction pattern in three other IL-6 assays: induction of murine thymocyte proliferation, induction of fibrinogen synthesis by a human hepatoma cell line (HepG2), and the induction of IgM synthesis by an EBV-transformed B cell line. This suggests that a single functional domain might be responsible for all four activities of IL-6.

Analysis of human IL-6 mutants expressed in Escherichia coli. Biologic activities are not affected by deletion of amino acids 1-28

We have constructed and analyzed amino terminally deleted analogs of IL-6. Progressively shortened variants of mature IL-6 were constructed at the cDNA level and expressed in Escherichia coli. Mutant proteins were recovered from refractile bodies by solubilizing in 6 M guanidine-HCl. The mutant protein concentration in these preparations was estimated by Western blotting by using an IL-6-specific mAb and the biologic activity was measured in the B9 (hybridoma growth factor) assay. The first 28 amino acids of mature IL-6 could be removed without significantly affecting biologic activity. A further removal of amino acids 29 and 30 resulted in an approximately 50-fold decrease, whereas removal of amino acids 31 to 34 virtually abolished the activity. The mutants showed the same reaction pattern in three other IL-6 assays: induction of murine thymocyte proliferation, induction of fibrinogen synthesis by a human hepatoma cell line (HepG2), and the induction of IgM synthesis by an EBV-transformed B cell line. This suggests that a single functional domain might be responsible for all four activities of IL-6.

An analysis of the determinants of hepatic allograft rejection using stepwise logistic regression

Hepatic allograft rejection is currently diagnosed using both histologic and clinical criteria. The purpose of this study is to extract data from the allograft biopsy, which can establish the diagnosis of rejection with more precision. A total of 566 allograft biopsies were examined in 56 patients following orthotopic liver transplantation, and 35 variables were examined. Using stepwise logistic regression, only six of these variables affected the diagnosis of rejection. These were portal tract spillover, portal tract eosinophilia, portal vein endothelialitis, portal tract neutrophilia, central vein endothelialitis, and cholestasis. Coefficients of these variables were determined, and could be used to calculate the probability of rejection for a given biopsy. Using this model the probability of having rejection can be calculated using histologic data alone.

Blood and graft eosinophilia as predictors of rejection in human liver transplantation

This study attempts to define the relationship of blood and graft eosinophilia to acute hepatic allograft rejection. Sixty liver transplant patients were studied for the first 30 days postoperatively, with daily serum bilirubin and liver enzyme levels, white blood cell counts and differential counts, and biweekly core liver biopsies. Graft eosinophilia was established if 7% or greater of the cells infiltrating the portal triads were eosinophils. Blood eosinophilia is an absolute eosinophil count greater than 500 cells/mm3 occurring on any of the 5 days preceding the day of rejection. Acute rejection was diagnosed when 2 days of hepatic allograft dysfunction occurred with histologic evidence of rejection. The 2nd day of dysfunction with appropriate histologic findings was arbitrarily chosen as the day of rejection. Graft eosinophilia predicted rejection with 92% sensitivity and 98% specificity. Blood eosinophilia occurred on the average on the day of rejection and on the 2 preceding days, while graft eosinophilia occurred on the day of rejection and on 1 preceding day. Blood eosinophilia followed by graft eosinophilia specifically occurred in cases of rejection. Blood eosinophilia not followed by graft eosinophilia was not associated with rejection. Following treatment of rejection with high-dose corticosteroids, blood and graft eosinophil counts decreased markedly. In summary: (1) graft eosinophilia is very sensitive and specific for acute hepatic allograft rejection; (2) blood eosinophilia closely precedes and parallels graft eosinophilia specifically during acute hepatic allograft rejection; and (3) elevated blood and graft eosinophil counts are markedly reduced following treatment of rejection with high-dose corticosteroids.