Cutaneous mucormycosis with suspected dissemination in a patient with metastatic adrenocortical carcinoma

Mucormycosis is a frequently lethal fungal infection that most commonly affects patients with poorly controlled diabetes or other immunosuppressed states. We report the case of a suspected disseminated Rhizopus infection in a patient who was pursuing naturopathic treatment including mud baths for metastatic adrenocortical carcinoma. He was empirically treated with liposomal amphotericin B but opted to stop treatment following multiorgan failure. The patient passed away on the tenth day of his hospital admission.

Calcinosis cutis arising in morphea: a case series

Calcinosis cutis, although common in systemic sclerosis, has been rarely reported in patients with morphea. We describe four patients with calcinosis cutis arising within morphea plaques, discuss their treatments and outcomes, and review previously published cases. Current management recommendations for concomitant morphea and dystrophic calcinosis cutis are based on limited data and expert opinion, which has primarily focused on reduction of active inflammation and reduction of symptoms related to calcinosis or ulceration. In most cases, no improvement of calcinosis was noted. The use of intralesional corticosteroids to active lesions in conjunction with systemic treatment, including methotrexate when indicated, appear promising treatments to halt progression of the disease. Surgical excision seems to be the most definitive treatment for calcinosis affecting morphea plaques, but the current literature lacks details regarding disease recurrence following operative management.

Neutron diffraction strain tomography: Demonstration and proof-of-concept

Recently, a number of reconstruction algorithms have been presented for residual strain tomography from Bragg-edge neutron transmission measurements. In this paper, we examine whether strain tomography can also be achieved using diffraction instruments. We outline the proposed method and develop a suitable reconstruction algorithm. This technique is demonstrated in simulation, and a proof-of-concept experiment is carried out, where the strain field in an axisymmetric sample is reconstructed and validated using conventional diffraction strain scans.

Walking in the shoes of caregivers of children with obesity: supporting caregivers in paediatric weight management

To incorporate the perspectives and experiences of family caregivers of children with obesity, the KidFit Health and Wellness Clinic, a paediatric weight management programme, embedded feedback opportunities into various stages of programme development. Caregivers were eligible to participate if their children had completed initial 4-week group-based pilot programming or were currently receiving treatment in 10 or 12 week group-based programming. Data were collected through feedback session discussions, audio-recorded, transcribed verbatim and analysed thematically. In total, 6 caregivers participated in the pilot group feedback session and 32 caregivers participated in the structured group feedback sessions. Caregivers reported that healthy lifestyle strategies first communicated by clinic staff to children during group sessions provided expert validation and reinforcement when discussing similar messages at home. Caregivers reported feeling isolated and blamed for causing their children's obesity and appreciated the supportive forum that group-based programming provided for sharing experiences. Since experiences of blame and isolation can burden caregivers of children with obesity, paediatric weight management programmes might consider including peer support opportunities and discussion forums for ongoing social support in addition to education about lifestyle change.

Long-term non-invasive ventilation in muscular dystrophy

Long-term non-invasive ventilation (NIV) was introduced in the 1980s, initially mainly for patients with poliomyelitis, muscular dystrophy (MD) or scoliosis. The obesity-hypoventilation syndrome has since become the commonest reason for referral to most centres providing home-NIV. Patients with MD are numerically a much smaller part of the workload, but as their disease progresses the need for ventilatory support changes and they require regular comprehensive assessment of their condition. We have examined the trend in MD use of home-NIV in our unit over the last 25 years. The number of new referrals appears to be stabilizing at around 20-25 over a 5-year period, equivalent to approximately 0.5 per 100,000 of population per year. The mean age at commencement of home-NIV is now 37.5 years, with 5-year survival rates of 70-75%. Ten-year survival rates are just over 40%. The distance of usual place of residence from our unit is fairly stable, currently at a mean of 27 km. Excellent survival rates mean that patients with MD, while numerically small, are likely to remain an important part of the workload of centres providing home-NIV. Our data should prove useful in the planning of future services for this group of patients.

Overweight across the life course and adipokines, inflammatory and endothelial markers at age 60-64 years: evidence from the 1946 birth cohort

Background/Objectives:

There is growing evidence that early development of obesity increases cardiovascular risk later in life, but less is known about whether there are effects of long-term excess body weight on the biological drivers associated with the atherosclerotic pathway, particularly adipokines, inflammatory and endothelial markers. This paper therefore investigates the influence of overweight across the life course on levels of these markers at retirement age.

Subjects/Methods:

Data from the Medical Research Council National Survey of Health and Development (n=1784) were used to examine the associations between overweight status at 2, 4, 6, 7, 11, 15, 20, 26, 36, 43, 53 and 60–64 years (body mass index (BMI)⩾25 kg m⁻² for adult ages and gender-specific cut-points for childhood ages equivalent to BMI⩾25 kg m⁻²) and measurements of adipokines (leptin and adiponectin), inflammatory markers (C-reactive protein (CRP), interleukin-6 (IL-6)) and endothelial markers (E-selectin, tissue plasminogen activator (t-PA) and von Willebrand factor) at 60–64 years. In addition, the fit of different life course models (sensitive periods/accumulation) were compared using partial F-tests.

Results:

In age- and sex-adjusted models, overweight at 11 years and onwards was associated with higher leptin, CRP and IL-6 and lower adiponectin; overweight at 15 years and onwards was associated with higher E-selectin and t-PA. Associations between overweight at all ages earlier than 60–64 with leptin, adiponectin, CRP and IL-6 were reduced but remained apparent after adjustment for overweight at 60–64 years; whereas those with E-selectin and t-PA were entirely explained. An accumulation model best described the associations between overweight across the life course with adipokines and inflammatory markers, whereas for the endothelial markers, the sensitive period model for 60–64 years provided a slightly better fit than the accumulation model.

Conclusions:

Overweight across the life course has a cumulative influence on adipokines, inflammatory and possibly endothelial markers. Avoidance of overweight from adolescence onwards is likely important for cardiovascular disease prevention.

Birth weight and growth from infancy to late adolescence in relation to fat and lean mass in early old age: findings from the MRC National Survey of Health and Development

Objective:

High birth weight and greater weight gain in infancy have been associated with increased risk of obesity as assessed using body mass index, but few studies have examined associations with direct measures of fat and lean mass. This study examined associations of birth weight and weight and height gain in infancy, childhood and adolescence with fat and lean mass in early old age.

Subjects:

A total of 746 men and 812 women in England, Scotland and Wales from the MRC National Survey of Health and Development whose heights and weights had been prospectively ascertained across childhood and adolescence and who had dual energy X-ray absorptiometry measures at age 60–64 years.

Methods:

Associations of birth weight and standardised weight and height (0–2 (weight only), 2–4, 4–7, 7–11, 11–15, 15–20 years) gain velocities with outcome measures were examined.

Results:

Higher birth weight was associated with higher lean mass and lower android/gynoid ratio at age 60–64 years. For example, the mean difference in lean mass per 1 standard deviation increase in birth weight was 1.54 kg in males (95% confidence interval=1.04, 2.03) and 0.78 kg in females (0.41, 1.14). Greater weight gain in infancy was associated with higher lean mass, whereas greater gains in weight in later childhood and adolescence were associated with higher fat and lean mass, and fat/lean and android/gynoid ratios. Across growth intervals greater height gain was associated with higher lean but not fat mass, and with lower fat/lean and android/gynoid ratios.

Conclusion:

Findings suggest that growth in early life may have lasting effects on fat and lean mass. Greater weight gain before birth and in infancy may be beneficial by leading to higher lean mass, whereas greater weight gain in later childhood and adolescence may be detrimental by leading to higher fat/lean and android/gynoid ratios.

British Dietetic Association evidence-based guidelines for the dietary management of irritable bowel syndrome in adults

BACKGROUND

 Irritable bowel syndrome (IBS) is a chronic debilitating functional gastrointestinal disorder. Diet and lifestyle changes are important management strategies. The aim of these guidelines is to systematically review key aspects of the dietary management of IBS, with the aim of providing evidence-based guidelines for use by registered dietitians.

METHODS

Questions relating to diet and IBS symptom management were developed by a guideline development group. These included the role of milk and lactose, nonstarch polysaccharides (NSP), fermentable carbohydrates in abdominal bloating, probiotics and empirical or elimination diets. A comprehensive literature search was conducted and relevant studies from January 1985 to November 2009 were identified using the electronic database search engines: Cinahl, Cochrane Library, Embase, Medline, Scopus and Web of Science. Evidence statements, recommendations, good practice points and research recommendations were developed.

RESULTS

Thirty studies were critically appraised. A dietetic care pathway was produced following a logical sequence of treatment and formed the basis of these guidelines. Three lines of dietary management were identified. first line: Clinical and dietary assessment, healthy eating and lifestyle management with some general advice on lactose and NSP. Second line: Advanced dietary interventions to improve symptoms based on NSP, fermentable carbohydrates and probiotics. Third line: Elimination and empirical diets. Research recommendations were also identified relating to the need for adequately powered and well designed randomised controlled trials.

CONCLUSIONS

These guidelines provide evidence-based details of how to achieve the successful dietary management of IBS.

A phase II clinical trial of gemcitabine and split dose cisplatin in advanced non-small cell lung cancer in an outpatient setting

In response to increasing pressure on inpatient services and a meta-analysis indicating that cisplatin (C) is superior to carboplatin, we report a phase II trial of gemcitabine (G) and split-dose C in advanced non-small cell lung cancer (NSCLC) in an outpatient setting. Patients with stage IIIB/IV NSCLC received: G/C 1250/40 mg/m(2); G and C were given on day (d) 1 and d8 in a 21d cycle. Patients with performance status 0-2, adequate bone marrow function and calculated glomerular filtration rate (GFR) >50 ml/min were eligible. Forty-two patients were enrolled: 25 male; median age 62 (range 37-78) years. There were 26 patients (62%) with stage IV disease. One hundred and thirty-eight cycles of chemotherapy were delivered. Chemotherapy was well tolerated, allowing maintenance of planned dose intensity (DI) with mean dose delivered of 780.1 mg/m(2) (93%) and 25.6 mg/m(2) (96%) for G and C, respectively. The overall response rate was 43%. Median survival was 12.5 months with a median follow-up of 13.5 months. One year survival rate was 51%. G plus C both given on d1 and d8 (q21d) is a very active, well tolerated and convenient outpatient schedule, which maintains DI.

A feasibility/phase II study of gemcitabine (G) and split dose cisplatin (C) in advanced or metastatic non-small cell lung cancer (NSCLC) in an outpatient setting

17048

Background: This is a feasibility/phase II trial with GC on a 21-day cycle, with G and C split between d1, 8. Split dose C allowed administration in an outpatient setting. Objectives: To document the toxicity and define the objective response rate; and determine progression free and overall survival. Methods: Pts with stage III/IV NSCLC received: G/C 1250/40mg/m2 (G and C given on d1, 8 every 3 wks). Eligibility: ECOG PS 0–2, adequate bone marrow/liver function, calculated GFR > 50 ml/min. Results: 56 pts enrolled, all evaluable for toxicity; 47 evaluable for response; 4 patients too early for response assessment and 5 patients did not complete 1 cycle of chemotherapy. Characteristics: 70% male, median age 66 yrs (41–77), 25% GFR 50- 60 ml/min, 62% Stage IV. Radiotherapy was allowed after completing chemotherapy. 165 cycles have been delivered. Cycles with hematological toxicity: Grade 3: 5 anaemia, 17 neutropenia, 6 thrombocytopenia; Grade 4: 7 neutropenia, 4 thrombocytopenia. There were 3 episodes of febrile neutropenia. Cycles with non-hematological toxicity: Grade 4: 1 myocardial infarction (MI), 1 gastrointestinal (GI) bleed, 1 pulmonary embolism, 1 stroke; Grade 3: 3 nausea, 1 deep vein thrombosis, 4 chest infection, 1 hypomagnesemia; Grade 2: 3 renal toxicity, 2 seizure, 1 hypomagnesemia. Five cycles were deferred due to grade 4 neutropenia; 2 for renal toxicity (in one patient with diabetes and hypertension renal function declined after 1 cycle necessitating discontinuation of chemotherapy). 2 deaths occurred on treatment: 1 MI (patient with a previous history of MI); 1 GI bleed (on aspirin). Overall ITT RR was 33% (17/52: 1 CR+ 16 PR) (36% [17/47] for assessable pts). Median survival is 310-days. 1- year survival rate is 38%. Conclusion: G plus C in a 21-day schedule is active and well tolerated in an outpatient setting. This modified regimen with C split between d1 and d8, and, eligibility criteria of GFR as low as 50mls/min widens the spectrum of patients receiving cisplatin-based chemotherapy. Phase III trial is warranted.

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Evidence that the type-2 gonadotrophin-releasing hormone (GnRH) receptor mediates the behavioural effects of GnRH-II on feeding and reproduction in musk shrews

Gonadotrophin-releasing hormone (GnRH) is a regulatory neuropeptide of which there are multiple structural variants. In mammals, a hypothalamic form (GnRH-I) controls gonadotrophin secretion whereas a midbrain form (GnRH-II) appears to have a neuromodulatory role affecting feeding and reproduction. In female musk shrews and mice, central administration of GnRH-II reinstates mating behaviour previously inhibited by food restriction. In addition, GnRH-II treatment also decreases short-term food intake in musk shrews. GnRH-II can bind two different mammalian GnRH receptors (type-1 and type-2), and thus it is unclear which receptor subtype mediates the behavioural effects of this peptide. Adult female musk shrews implanted with i.c.v. cannula were food restricted or fed ad lib and then tested for sexual behaviour or food intake. One hour before testing, animals were pretreated with vehicle or Antide, a potent type-1 GnRH receptor antagonist (at a dose that blocks GnRH-I or -II mediated ovulation). Twenty minutes before testing, females were infused a second time with either GnRH-II or vehicle. Additional females were tested after an infusion of 135-18, a type-1 receptor antagonist that displays agonist actions at the primate type-2 receptor. GnRH-II treatment increased sexual behaviour in underfed female shrews; pretreatment with Antide did not block this action, suggesting that the effects of GnRH-II are not mediated via the type-1 receptor. Similarly, the inhibitory effects of GnRH-II on short-term food intake were not prevented by pretreatment with Antide. The behavioural effects of the type-2 receptor agonist 135-18 were similar to those seen in GnRH-II-treated females, with 135-18 promoting sexual behaviour and decreasing food intake. Collectively, these results indicate that GnRH-II does not act via the type-1 GnRH receptor to regulate mammalian behaviour but likely activates the type-2 GnRH receptor.

Employment retention after moderate-severe traumatic brain injury (TBI) in the British Army 1989-98

AIMS

To examine retention in employment of subjects with moderate-severe traumatic brain injury (TBI) in the British Army.

METHODS

Comparative groups study of retention in Army employment after TBI using 564 TBI, 368 lower limb fracture, and 25 575 healthy subjects. Kaplan-Meier survival analysis was used to examine, stratifying for age, continuation in Army employment for six years after TBI.

RESULTS

Subjects in the younger groups (mean ages 23 years and 27 years respectively) with either TBI or lower limb fracture remained in employment longer than healthy peers (median time for TBI, 3.91 years, lower limb fracture, 4.39 years, and healthy, 1.74 years). This trend changed through age stratification and for older subjects the reverse pattern was seen. In group 4 (mean age 41 years), median retention time for TBI was 3.33 years, for lower limb fracture, 3.75 years, healthy 5.55 years. Older subjects also showed a marked drop out rate at one year after injury; 32.7% of those with TBI in group 3 (mean age 31 years) had left Army employment at the end of year one compared with 19% in age group 1 (mean age 23 years).

CONCLUSIONS

Younger soldiers with either TBI or lower limb fracture are retained in Army employment longer than their healthy peers. This may be due to sheltered employment, the availability of ongoing support, or transience of the healthy population. Since these results were drawn from incidence data on moderate and severe TBI it may be that those who serve on after TBI will do so with some degree of disability which affects occupational performance. There may be a significant unmet rehabilitation need for this group which is the focus of ongoing research.

The phenotype of limb-girdle muscular dystrophy type 2I

BACKGROUND

Mutations in the fukutin-related protein gene FKRP cause limb-girdle muscular dystrophy (LGMD2I) as well as a form of congenital muscular dystrophy (MDC1C).

OBJECTIVE

To define the phenotype in LGMD2I.

METHODS

The authors assessed 16 patients from 14 families with FKRP gene mutations and LGMD and collected the results of mutation analysis, protein studies, and respiratory and cardiac investigations.

RESULTS

Thirteen patients, most with adult presentation, were homozygous for the common C826A mutation in FKRP. The three other cases were compound heterozygotes for C826A and two of them presented in childhood, with more progressive disease. The pattern of muscle involvement, frequently including calf hypertrophy, was similar to dystrophinopathy. Complications in patients with LGMD2I were common and sometimes out of proportion to the skeletal muscle involvement. Six patients had cardiac involvement, and 10 had respiratory impairment: five required nocturnal respiratory support. All patients had serum creatine kinase at least 5 to 70 times normal. The most consistent protein abnormality found on muscle biopsy was a reduction of laminin alpha2 immunolabeling, either on muscle sections or immunoblotting alone.

CONCLUSIONS

LGMD2I due to FKRP mutations appears to be a relatively common cause of LGMD, with respiratory and cardiac failure as prominent complications.

Brain stem compression by a giant vertebrobasilar aneurysm mimicking seronegative myasthenia

A patient is described with a vertebrobasilar aneurysm who was erroneously thought to have myasthenia gravis on the basis of the clinical presentation and investigations, which were interpreted as supportive of a disorder of the neuromuscular junction. Despite the correct diagnosis being made at a late stage the patient made a full recovery after radiological intervention.

Elastase-induced matrix degradation in arterial organ cultures: an in vitro model of aneurysmal disease

PURPOSE

Abdominal aortic aneurysms are characterized by degradation of the extracellular matrix, induction of endogenous metalloproteinases (MMPs), and development of a chronic inflammatory infiltrate. Despite intensive analysis of end-stage tissue, aneurysm pathogenesis remains obscure. The aim of this study was to develop an in vitro model of aneurysmal disease.

METHODS

Porcine aortic organ cultures were preincubated with pancreatic elastase before culture in standard conditions for up to 14 days. The extent of matrix degradation at various time points was determined by quantitative histologic estimation of collagen and elastin concentration. Endogenous metalloproteinase production within the tissue was quantified by gel enzymography and immunoblotting. A separate series of experiments was performed to investigate the effect of incorporating autologous leukocytes into the culture system.

RESULTS

Although exogenous elastase was removed after 24 hours, substantial degradation of the aortic extracellular matrix occurred in the subsequent 13 days in tissue culture. Analysis of samples preincubated with elastase (100 U/ml) for 24 hours before tissue culture demonstrated that elastin degradation occurred in a time-dependent manner (p < 0.001) and was not confined to the initial phase of exogenous elastase activity. Gelatin gel enzymography revealed a time-related production of metalloproteinases (55 to 250 kDa) within the aortic tissue. The presence of MMPs-1, 2, 3, and 9 was determined by immunoblotting. Immunohistochemistry identified the vascular smooth-muscle cell as the source of MMPs-1, 2, and 3. Addition of autogenous leukocytes to elastase-pretreated tissue initiated an inflammatory infiltrate within the aortic wall, which further enhanced both matrix degradation and MMP production (p < 0.001).

CONCLUSIONS

These data demonstrate that aortic samples pretreated with elastase before tissue culture undergo matrix degradation with MMP production and the development of an inflammatory infiltrate. These changes mirror the pathophysiological events within established aneurysms. It is suggested that this model may be useful in understanding early pathogenic events within aneurysmal tissue.

An outbreak of gastroenteritis in a psycho-geriatric hospital associated with a small round structured virus

An outbreak of gastroenteritis in a psycho-geriatric hospital is described. Small round structured viruses, morphologically similar to Norwalk agent, were seen in stool samples from four patients. Although the illness was mild, 67 patients and 30 nurses on four wards were affected over a period of 4 weeks. Because of shortage of staff and isolation facilities, difficulty was experienced in introducing effective control measures.

Physical characterization and molecular cloning of the Shope fibroma virus DNA genome

DNA from several independent strains of Shope fibroma virus, a tumorogenic leporipoxvirus of rabbits, was isolated and analyzed by restriction endonuclease digestion and Southern blotting. The restriction profiles indicated a high degree of sequence conservation among the isolates but blotting under standard stringencies revealed no detectable cross homology with a member of the orthopoxvirus group, vaccinia. The genome of the fibroma virus was calculated to be in excess of 160 kilobases and shown to possess two features analogous to the orthopoxvirus group: (1) the terminal restriction fragments possess covalently closed hairpin structures; and (2) the terminal sequences are present as inverted repeats of greater than 10 kilobases. The terminal 3.6 kilobase BamHI restriction fragment was cloned in pBR322 after removal of the hairpin structure with mung bean single strand-specific endonuclease and addition of BamHI linkers. SFV sequences within this terminal region were shown, using 32P SFV cloned terminal probe, to have none of the sequence heterogeneity characteristic of vaccinia DNA termini. The remaining 20 internal SFV BamHI restriction fragments were propagated in bacterial plasmids either as intact fragments, or after secondary digestion with HindIII, and together constitute the complete cloned SFV sequence library.

Comparison of antisera in the fluorescent antibody test for detection of Bacteroides spp in clinical specimens

Twenty-two known strains of the Bacteroides fragilis group of organisms and 67 clinical specimens from a variety of sites were examined by fluorescent antibody test (IFA) using two different antisera fro the rapid detection of B fragilis group of organisms. A previously reported Barts' pooled antisera was compared with a commercially produced Fluoretec kit antisera and the findings were related to routine anaerobic culture and gas liquid chromatography for short chain fatty acids. The Barts' antisera was more sensitive (88%) but less specific (88%) than the kit (sensitivity 50%, specificity 98%). This indicates that Barts' antisera picks up more positive cultures than the kit. The predictive value of a positive test was 82% for Barts' antisera and 93% for the kit. There were higher numbers of false-negatives with the kit (13/26) than with the Barts' (3/26). The predictive value of a negative test was 92% for Barts' antisera and 75% for the kit, indicating that a negative IFA test with Barts' antisera is a reliable index of the absence of the B fragilis group of organisms from clinical specimens. The implications for the use of this test in a routine laboratory are discussed.

Epstein-Barr virus antibodies in patients with ataxia-telangiectasia and other immunodeficiency diseases

An unusual antibody response to the Epstein-Barr virus (EBV) has been noted in patients with ataxia-telangiectasia. Of a group of 16 such patients 8 were found to have antibodies in their serum to the EBV viral capsid antigen (VCA), and 4 of them also had antibodies to the EBV early antigen (EA); antibodies to the nuclear antigen (EBNA), however, were absent in 3 of the 8. The antibody pattern persisted for more than 2 years in the patients available for follow-up study. In comparison, of 24 patients with various other immunodeficiency syndromes 9 were found to have EBV-VCA antibodies in their serum, but none of the 9 had EA antibodies and 3 lacked EBNA antibodies. Two other groups of subjects, all of whom had EBV-VCA and EBNA antibodies in their serum late after an EBV infection, were also studied; 82 had infectious mononucleosis and 55 were healthy and had no such history. EA antibodies were detected in 45 of the first group during the acute phase of the illness but persisted in only 6 of the 68 who were followed up for more than 2 years, and they were detected in only 7 of the second group.All eight lymphoblastoid cell lines established from the peripheral blood of the four patients with ataxia-telangiectasia who are still available for follow-up study express EBV-VCA, whereas most similar cell lines established from normal individuals express only EBNA. In two of these patients cell-mediated immunity, as assessed from lymphocyte transformation induced by mitogens, was markedly decreased but autologous cell-mediated immune regression of EBV-induced transformation of B (bone-marrow-derived)-lymphocytes was normal. The percentage of T (thymus-derived)-helper cells was greatly decreased in two of the three patients in whom it was measured, and the percentage of T-suppressor cells was greatly increased in one of them, but the percentage of total T-lymphocytes was within normal limits in all three.The possible significance of these findings - in particular, the persistence of EA antibodies and the diminished restriction of expression of EA - in the late development of tumours after an EBV infection in patients with ataxia-telangiectasia deserves careful attention. Finally, the apparent correlation between immunoglobulin deficiency and poor or absent EBNA antibody response warrants further study.

Relative lack of Epstein Barr virus (EBV) receptors on B cells from persistently EBV seronegative adults

Viral receptors are essential for the entry of the virus into the cell. EBV receptors can be detected on fresh lymphocytes by a technique that uses EBV-coupled tanned red blood cells that form rosettes with lymphocyte-bearing receptors. This technique was found to detect viral receptors only and not surface immunoglobulins. T cell depletion of the lymphocyte population showed that these receptors were present on B lymphocytes. Study of the presence of these EBV receptors on the surface of fresh lymphocytes from 66 subjects (age 2 to 66), selected out of a group of over 2000 individuals, showed that the majority of these donors had receptors for the virus. However, a few of these adults persistently failed to develop anti-EBV antibodies, even if they were in close contact with the infectious agent. The lymphocytes of 11 such individuals were found to be lacking EBV receptors. Transformation assay of these lymphocytes did not give rise to lymphoblastoid cell lines whereas lymphocytes from 4 individuals, who were EBV seropositive or seronegative but receptor positive, yielded permanent lymphoblastoid cell lines. This would suggest that a few EBV seronegative adults (less than 0.5%) display natural resistance to EBV transformation of their lymphoid cells as a result of absolute or relative lack of EBV receptors on these cells.

Relative lack of Epstein Barr virus (EBV) receptors on B cells from persistently EBV seronegative adults

Viral receptors are essential for the entry of the virus into the cell. EBV receptors can be detected on fresh lymphocytes by a technique that uses EBV-coupled tanned red blood cells that form rosettes with lymphocyte-bearing receptors. This technique was found to detect viral receptors only and not surface immunoglobulins. T cell depletion of the lymphocyte population showed that these receptors were present on B lymphocytes. Study of the presence of these EBV receptors on the surface of fresh lymphocytes from 66 subjects (age 2 to 66), selected out of a group of over 2000 individuals, showed that the majority of these donors had receptors for the virus. However, a few of these adults persistently failed to develop anti-EBV antibodies, even if they were in close contact with the infectious agent. The lymphocytes of 11 such individuals were found to be lacking EBV receptors. Transformation assay of these lymphocytes did not give rise to lymphoblastoid cell lines whereas lymphocytes from 4 individuals, who were EBV seropositive or seronegative but receptor positive, yielded permanent lymphoblastoid cell lines. This would suggest that a few EBV seronegative adults (less than 0.5%) display natural resistance to EBV transformation of their lymphoid cells as a result of absolute or relative lack of EBV receptors on these cells.