Effective PEGylation of gold nanorods

Standard procedures to coat gold nanorods (AuNR) with poly(ethylene glycol) (PEG)-based ligands are not reliable and high PEG-grafting densities are not achieved. In this work, the ligand exchange of AuNR with PEGMUA, a tailored PEG-ligand bearing a C10 alkylene spacer, is studied. PEGMUA provides AuNR with very high stability against oxidative etching with cyanide. This etching reaction is utilized to study the ligand exchange in detail. Ligand exchange is faster, less ligand consuming and more reproducible with assisting chloroform extraction. Compared to PEG ligands commonly used, PEGMUA provides much higher colloidal and chemical stability. Further analyses based on NMR-, IR- and UV/Vis-spectroscopy reveal that significantly higher PEG-grafting densities, up to ∼3 nm(-2), are obtained with PEGMUA. This demonstrates how the molecular structure of the PEG ligand can be used to dramatically improve the ligand exchange and to synthesize PEGylated AuNR with high chemical and colloidal stability and high PEG grafting densities. Such AuNR are especially interesting for applications in nanomedicine.

Zur chromatographischen Trennung der Vitamine der B12-Gruppe

In der Säulenchromatographie der Vitamine der B12-Gruppe bewährt sich besonders gut pulverförmige bzw. feinflockige Zellulose unter Verwendung von wasser-gesättigtem n-Butanol bzw. sek. Butanol mit bestimmtem Wassergehalt als Entwickler. Der Trenneffekt dieser Säule wird in Gegenwart von Kaliumperchlorat beträchtlich erhöht. Die Sättigung des Entwicklers (sek. Butanol-Wasser) mit Kaliumperchlorat verbessert auch in der Papierchromatographie die Trennschärfe.

Über das Verhalten der Vitamine der B12-Gruppe gegenüber Phenolen

Die Phenol-Löslichkeit der Vitamine der B12-Gruppe ist in gesetzmäßiger Weise von der Art der Substitution der Phenole und von der Art der B12-Vitamine abhängig; sie kann zu deren Charakterisierung dienen. Wäßrige Lösungen der B12-Vitamine geben mit sehr geringen Mengcn an Phenolen ölige, wasser-unlösliche Vitamin B12-Phenol-Komplexe, die mit Vorteil zur Isolierung der B12-Vitamine dienen können. Die Vitamine der B12-Gruppe werden aus phenol-haltigen organischen Lösungsmitteln durch sauerstoff-haltige polare Stoffe in die wäßrige Phase verdrängt, wodurch die Reinigung der Vitamine der B12-Gruppe wesentlich erleichtert wird.

Coa/Coß-Isom erie der Corrinoide. Partialsynthese und Escherichia coli -Aktivität weiterer Isomerenpaare der (Co-M ethyl)-corrinoide Coa/Co/Msomerism of Corrinoids. Partial Synthesis and Escherichia coli Activity of Further Isomer Pairs o f the (Co-methyl)-Corrinoids

Vitamin B 12 , Methylcorrinoids, Coα/Coβ-isomerism, E. coli Activity In 2-methyladenyl-(Coβ-methyI) -cobamide and in adenyl-(Coβ-methyl)-cobamide the nucleotide base is coordinated to the cobalt atom in neutral and weak acidic aqueous solutions (in the cor­ responding adenosylcorrinoids the nucleotide base is not coordinated). 2-Methylthioadenyl-(Coβ-methyl)-cobamide resembles, with regard to the coordination of the nucleotide base, the benz-imidazole-corrinoids.

The partial synthesis via cobalt (I) corrinoids results in a variable proportion: (Coα-methyl) iso­ mer/(Coβ-methyl) isomer, e .g . 7/93 (cobalamin) and 50/50 (p-cresylcobamide). This proportion is generally low, if in the corresponding cyanocorrinoid the nucleotide base is firmly coordinated; it is high, if the coordination in the corresponding cyanocorrinoid is weak or absent. These results are compatible with the assumption that in the cobalt (I) corrinoids the nucleotide base is to a certain extent coordinated.

In Escherichia coli 113-3 the examined (Coα-methyl)-corrinoids show a weaker bioactivity than the corresponding (Coβ-methyl) -corrinoids.

Zur Kenntnis der Phosphorsäureester der Benzimidazolriboside

1-(5′-Trityl-α-D-ribofuranosyl)-5.6-dimethylbenzimidazol läßt sich mit Hilfe des β-Cyanoäthylphosphats in Pyridin in Gegenwart von Dicyclohexylcarbodiimid am C′ (3) bzw. C′ (2) phosphorylieren. Cycl. 2′.3′-Phosphorsäureester der Benzimidazol-α-riboside werden in reiner kristalliner Form dargestellt; sie sind wenig löslich in Wasser und zeichnen sich durch relativ hohe Schmelzpunkte aus. Ausgehend vom 5′-Phosphorsäureester des 1-α-D-Ribofuranosyl-5.6-dimethylbenzimidazols (des α-Ribazols) wird cycl. α-Ribazol-3′.5′-phosphat, ebenfalls in krist. Form, dargestellt. α-Ribazol-5′phosphat läßt sich in Gegenwart von Dicyclohexylcarbodiimid mit 1-(Benzyloxycarbonylamino)-2-propanol kondensieren; nach hydrogenolytischer Abspaltung der Carbobenzoxygruppe und chromatographischer Reinigung an Amberlite XE-64-H und DEAE-Zellulose reagiert der so dargestellte Diester mit Faktor Via zu einem neuen Analog des Vitamins B12, in dem der Phosphorsäurerest am C5′ (statt am C3′) der Ribose gebunden ist. Schließlich wird ein Weg zur Darstellung von P-Estern der α-Ribazol-3′ (2′)-phosphorsäure, ausgehend von 5′-Trityl-α-Ribazol, Pyrophosphorylchlorid und Alkoholen, beschrieben; bei Verwendung von 1-Amino-2-propanol als Alkoholkomponente werden zwei Diester erhalten, deren Kondensation mit Faktor Via Vitamin B12 und sein C2′-Analog ergibt.

Successful haploidentical hematopoietic stem cell transplantation in a patient with SCID due to CD3ε deficiency: need for IgG-substitution 6 years later

BACKGROUND

The CD3 co-receptor complex is essential for signal transduction after specific binding of the T-cell receptor (TCR). CD3E encodes the CD3ε chain, one of the protein components (γ-, δ-, ε- and ζ-chain) of the CD3 co-receptor. As previously reported in one family CD3ε deficiency causes SCID.

PATIENT

We report on a patient with SCID due to CD3ε deficiency treated by HLA-haploidentical stem cell transplantation (SCT) (donor: mother) 15 years ago which resulted in development of normal T- and B-cell immunity. Despite conditioning donor cell engraftment was confined to T cells, while all other blood cell lineages remained of patient origin (split chimerism). In spite of normal functions, T-cell numbers never reached normal levels and naïve CD45+RA+ T-cells remained low. At 6 years after SCT the patient developed signs of humoral immunodeficiency, requiring regular substitution of IgG.

RESULTS

In a retrospective genetic work up 11 years after SCT, a homozygous splice site mutation in CD3E was identified resulting in the loss of CD3ε protein. The loss of B-cell function as observed in the patient was reflected by a lack of switched memory B cells. To rule out a primary role of CD3ε in B-cell function we studied expression of CD3E in B-cells which was found not to be expressed.

DISCUSSION

The clinical presentation of a secondary loss of specific humoral immunity in this constellation of split chimerism after allogeneic haploidentical SCT is unusual and unexpected in a patient with a primary T-cell defect. A most likely explanation is the gradual loss of T-helper-cell function.

Hematopoietic stem cell transplantation from matched unrelated donors in chronic granulomatous disease

We report on 12 patients with chronic granulomatous disease transplanted with hematopoietic stem cells from matched unrelated (n = 9) or matched sibling donors (n = 3). The most common infectious complication was pulmonary aspergillosis, which nine patients had previously developed. Only 5 of 12 individuals had normal lung function prior to transplantation. At a mean follow-up of 53 months 9 of the 12 patients are alive including 7 of 9 following matched unrelated donor (MUD) transplantation. One patient died from ARDS, another from systemic BK virus infection, the third from complications of chronic graft-versus-host disease. Seven of nine surviving patients have normal lung function now. HSCT from a MUD is an option worth considering when no matched family donor is available. Restricted lung function prior to HSCT does not appear to be a limiting factor for such treatment.

Patients with early relapse of primary hemophagocytic syndromes or with persistent CNS involvement may benefit from immediate hematopoietic stem cell transplantation

Primary hemophagocytic syndromes represent a group of rare immunodeficiencies, which are characterized by development of life-threatening systemic inflammatory manifestations, so-called accelerated phases. Immunosuppressive therapies are only temporarily effective to control this complication and the prognosis is dismal unless treated by hematopoietic SCT (HSCT). At present, optimal modalities of this potentially curative approach remain incompletely defined. In this study, we analyzed our experience in 18 patients with primary hemophagocytic syndromes treated since 1984 in our center by HSCT. Ten of these patients had previously developed accelerated phases and were in remission at the time of HSCT, whereas five patients had findings of active disease, with two cases in early phases of recurrences of less than 2 weeks duration and three cases with persistent central nervous system disease, whereas three patients had never experienced accelerated phases. In the group with active disease, four of five patients are long-term survivors and are well, whereas one patient died of CMV pneumonia. This outcome compares favorably with results in patients transplanted in remission, where 6 of 10 are long-term survivors. Our findings indicate that HSCT can have a favorable prognosis even in patients with active disease of primary hemophagocytic syndrome.

Severe combined immunodeficiency signalized by eosinophilia and lymphopenia in rotavirus infected infants

BACKGROUND

Severe combined immunodeficiency (SCID) is a heterogeneous disease consisting of several different subtypes. Most subtypes present during infancy and without treatment, infections usually lead to early death. Diagnosis of SCID can be difficult as new subtypes are expected to be discovered soon. Late diagnosis is associated with a poorer outcome. Infections like rotavirus enteritis cannot be cleared in children with SCID due to impaired immunity. The aim of our study was to identify clues in children with rotavirus enteritis that aid to diagnose SCID early.

PATIENTS AND METHODS

Total white blood counts in a cohort of SCID patients with persistent rotavirus infection at diagnosis (n=18) were compared to total white blood counts in matched control patients without SCID but with rotavirus infection.

RESULTS

Relative and absolute lymphopenia and eosinophilia were more common in SCID patients (p<0.005).

CONCLUSION

In infants with rotavirus infection, a full blood count should be performed: Eosinophilia and/or lymphopenia raise a high suspicion of SCID.

ICF syndrome: high variability of the chromosomal phenotype and association with classical Hodgkin lymphoma

We report on two sibs with ICF syndrome (immunodeficiency, centromeric heterochromatin instability, and facial anomalies) diagnosed in the elder brother based on the typical chromosomal abnormalities present in 56% of metaphases from cultured lymphocytes. In a previous cytogenetic analysis this diagnosis had been missed due to low manifestation of the ICF chromosomal phenotype. Hypomethylation of classical satellites 2 and 3, and of alpha-satellite DNA was shown in the lymphocytes of the younger sister. At 7 years of age the boy presented with hemiplegia due to tumerous invasion of the right brachial plexus. Histopathology revealed classical Hodgkin lymphoma, a neoplasia which might have been facilitated by the underlying genetic defect.

Relapse, not regimen-related toxicity, was the major cause of treatment failure in 11 children with Down syndrome undergoing haematopoietic stem cell transplantation for acute leukaemia

We report a retrospective analysis of 11 children with Down syndrome (DS) treated by SCT in eight German/Austrian SCT centres. Indications for transplantation were acute lymphoblastic leukaemia (N=8) and acute myeloid leukaemia (N=3). A reduced intensity conditioning (RIC) containing 2 Gy TBI was given to two patients, another five received a myeloablative regimen with 12 Gy TBI. Treosulphan or busulphan was used in the remaining four children. Four of eleven (36%) patients are alive. All of them were treated with a myeloablative regimen. One of the four surviving children relapsed 9 months after SCT and is currently receiving palliative outpatient treatment. The main cause of death was relapse (5/11). Two children died of regimen-related toxicity (RRT), one from severe exfoliative dermatitis and multiorgan failure after a treosulphan-containing regimen, the other from GvHD-related infections after RIC. Acute GvHD of the skin was observed in 10 of 10 evaluable patients, and chronic GvHD in 4 of 8. Our data show that DS patients can tolerate commonly used, fully myeloablative preparative regimens. The major cause of death is relapse rather than RRT resulting in an event-free survival of 18% and over all survival of 36%.

Stem cell transplantation in children with infantile osteopetrosis is associated with a high incidence of VOD, which could be prevented with defibrotide

Malignant infantile osteopetrosis (MIOP) is a rare hereditary disorder of osteoclast function, which can be reversed by hematopoietic stem cell transplantation (SCT). We observed a high incidence of hepatic veno-occlusive disease (VOD) in transplanted patients and explored the prevention of this complication by using defibrotide (DF) as a prophylaxis. Twenty children with MIOP were consecutively transplanted in our center between 1996 and 2005. Eleven of these patients were transplanted between 1996 and 2001 and experienced an overall incidence of VOD of 63.6% (7/11). VOD was severe in three patients and one patient succumbed to VOD-related multi-organ failure. Owing to this very high incidence of VOD, DF prophylaxis was initiated in nine patients consecutively transplanted between 2001 and 2005. In this group, only one patient (11.1%) was diagnosed with moderate VOD. We report here a very high risk in patients with MIOP to develop VOD after transplantation. Prophylactic DF was implemented in our current transplant protocol and reduced the VOD rate significantly in this high-risk population.

Long-term remission of APL with a second allogeneic BMT after CNS relapse following HLA-identical allogeneic BMT

Second allogeneic bone marrow transplantation (BMT) for AML relapsing after an initial BMT has a poor prognosis, with a probability of a 2-y disease-free survival below 30 per cent, caused both by treatment-related mortality (TRM) and high relapse rate. While TRM is most likely due to heavy pretreatment, AML relapse after BMT may be due to resistant disease or to a poor graft-versus-leukaemia (GvL) effect of the transplant. The degree of GvL may depend on individual donor/recipient immunoreactivity. In most published cases of second allogeneic BMT, both transplants were performed from the same donor. Here, we describe a patient who was first transplanted for acute promyelocytic leukaemia (APL) (AML FAB M3v) from his HLA-identical brother and received intensive immunotherapy including donor lymphocytes and IL2. He remained free from GvHD >I degrees, but developed CNS relapse. After a second BMT from another HLA-identical brother, he spontaneously developed GvHD III degrees, and has now been disease free for nearly 3 years. In this patient, long-term remission of AML relapsing after BMT was achieved by combining remission induction using an individual chemotherapy protocol with a second BMT from an alternative matched related donor and transient GvHD III degrees, which probably conferred a GVL effect.

Severe pulmonary hypertension: a frequent complication of stem cell transplantation for malignant infantile osteopetrosis

This report describes eight infants who developed acute severe pulmonary arterial hypertension (PAH) at days -2 to +89 after allogeneic stem cell transplantation (SCT) for malignant infantile osteopetrosis (MIOP). They were taken from a total of 28 children (frequency 29%) transplanted for this disease at three institutions between 1996 and 2002. Typical presentations were acute dyspnoea, hypoxia and brady/tachycardia usually in the absence of fever, crepitations or other evidence of infection. Six patients (75%) required assisted ventilation and five (62%) died. There was clinical or pathological evidence of veno-occlusive disease (VOD) in three children, but absence of VOD in the remaining five suggests that a separate disease process may be responsible for the PAH. Responses to nitric oxide (NO), defibrotide (DF), nicardipine and steroids in varying combinations were disappointing. Three children showed sustained improvement after administration of epoprostenol (EP, prostacyclin) in conjunction with NO and/or DF and remain well and free of PAH 25, 31 and 32 months post-transplant. PAH must therefore be excluded in any child who becomes acutely breathless after SCT for osteopetrosis.

Long-term outcome of haematopoietic stem cell transplantation in autosomal recessive osteopetrosis: an EBMT report

A retrospective analysis was made of 122 children who had received an allogeneic haematopoietic stem cell transplantation (HSCT) for autosomal recessive osteopetrosis between 1980 and 2001. The actuarial probabilities of 5 years disease free survival were 73% for recipients of a genotype HLA-identical HSCT (n=40), 43% for recipients of a phenotype HLA-identical or one HLA-antigen mismatch graft from a related donor (n=21), 40% for recipients of a graft from a matched unrelated donor (n=20) and 24% for patients who received a graft from an HLA-haplotype-mismatch related donor (n=41). In the latter group, a trend towards improvement was achieved at the end of the study period (17% before 1994, 45% after 1994, P=0.11). Causes of death after HSCT were graft failure and early transplant-related complications. Severe visual impairment was present in 42% of the children before HSCT. Conservation of vision was better in children transplanted before the age of 3 months. Final height was related to height at the time of HSCT and better preserved in children transplanted early. Most children attended regular school or education for the visually handicapped. At present, HSCT is the only curative treatment for autosomal recessive osteopetrosis and should be offered as early as possible.

Chronic cutaneous sclerodermoid graft-versus-host disease: evaluation by 20-MHz sonography

BACKGROUND

Chronic graft-versus-host disease (GVHD) is an immunological disorder frequently occurring as a late consequence of allogeneic bone marrow transplantation. Two variants, cutaneous lichenoid and sclerodermoid, have been described, based on clinical and histopathological examinations. It is, however, difficult to determine non-invasively the degree of cutaneous GVHD in vivo. Ultrasonographic methods have recently provided us with the means for objective and non-invasive monitoring of the dynamics of many chronic skin diseases.

AIM, PATIENTS AND METHODS

In five patients with chronic cutaneous sclerodermoid GVHD skin thickness was measured with a 20-MHz B-mode ultrasound scanner (DUB 20S, taberna pro medicum, Lüneburg, Germany) in a clinically well-defined target skin lesion. Additionally cutaneous GVHD was assessed histologically before and after treatment.

RESULTS

In all patients before treatment the corium of sclerotic skin was thicker than the corresponding areas of healthy skin. The skin thickness was increased from 45% to 83%. In the subcutaneous tissue proper echo-rich reflexes were prominent, representing the correlate of subcutaneous fibrotic trabeculae. In all patients ultrasonographic evidence of regression was shown (decrease of skin thickness by 18-83%). Moreover, it was demonstrated that quantitative assessment of skin thickness is feasible.

CONCLUSIONS

In this paper we describe the detailed sonographic features of cutaneous sclerodermoid GVHD for the first time. As the method is simple and non-invasive, repeated examinations are possible. This provides the basis for monitoring treatment effects and efficient follow-up in these chronically progressive clinical conditions after bone marrow transplantation.

Reticular dysgenesis: HLA non-identical bone marrow transplants in a series of 10 patients

Reticular dysgenesis is a very rare congenital immunodeficiency classified within the severe combined immunodeficiencies (SCID) and characterized by impairment of both lymphoid and myeloid cell development. We report our experience in 10 patients with RD, treated between 1979 and 1999 with HLA-haploidentical hematopoietic stem cell transplantation (HSCT). All children but one were symptomatic within the first days of their lives. Five patients required two HSCT. Five patients received conditioning therapy with busulfan (16 mg/kg) and cyclophosphamide. Three of them are alive and well with myeloid and T and B cell lymphoid reconstitution, whereas two patients died (one chronic graft-versus-host disease, one pneumonitis). Transplantation without or with other conditioning regimens in the other five cases led to absent or incomplete engraftment and none of these cases survived. These results demonstrate the mandatory need for intensive conditioning before haploidentical HSCT in RD to achieve full lymphoid and myeloid engraftment.

Allogeneic and autologous transplantation for haematological diseases, solid tumours and immune disorders: definitions and current practice in Europe

The Accreditation Sub-Committee of the EBMT regularly publishes special reports on current practice of haemopoietic stem cell transplantation for haematological diseases, solid tumours and immune disorders. Major changes have occurred since the last report in 1998. Haemopoietic stem cell transplantation today includes allogeneic and autologous stem cells derived from bone marrow, peripheral blood and cord blood. With reduced intensity conditioning regimens in allogeneic transplantation, the age limit has increased, permitting the inclusion of older patients. New indications have emerged, such as autoimmune disorders and AL amyloidosis for autologous, and solid tumours for allogeneic transplants. Other indications, such as autologous transplantation for breast cancer have been challenged. An updated report with revised tables and operating definitions is presented here.

Eradication of a dysfunctional HLA-haploidentical T cell system by a second HLA-identical BMT

A 12-year-old boy treated for SCID at 1 month of age by HLA-haploidentical BMT developed a lymphoproliferative disease of unknown etiology at the age of 9 years characterized by sustained, marked elevation of circulating CD8+ donor T cells and by diffuse infiltration of the liver by CD8+ T cells. Because of progressive liver disease, the patient underwent a second BMT from a younger HLA-matched sister. This treatment induced an effective graft-versus-graft reaction and led to complete replacement of the HLA-nonidentical, dysfunctional T cell system, resolution of the hepatopathy and full reconstitution of T and B cell functions.

The impact of social change on child mental health in Eastern Europe

The transition of the Eastern European countries in the past 12 years from totalitarian, communist societies to democratic societies has had a broad impact on children's mental health, both positively and negatively. This transition has not been without economic difficulties. All countries in the region experienced a significant deterioration of output that has affected the availability of commodities and services. Although recovery has been achieved in some Eastern European countries and is in progress in other countries, reversal of the cutbacks in allocations to necessary services that protect children and families may take longer to achieve. Movement toward a free market economy and greater individualism also has focused attention away from the role of society to protect and provide care for its citizens, especially the most vulnerable. On the positive side, mental health, as a concept for children and adults, comes to be appreciated only in a society that values and safeguards individual rights. Democratic process within the family, the depoliticization of mental illness, the passage of laws assuring basic children's rights, services for and public awareness about children abuse, reforms in education, the proliferation of mental health clinics and support centers, and the resumption of training of mental health professionals all set a tone to first consider, then assure, the positive development of children's mental health.

Transplacentally acquired maternal T lymphocytes in severe combined immunodeficiency: a study of 121 patients

A study in 121 infants with severe combined immunodeficiency (SCID) was performed to determine the prevalence of an engraftment by transplacentally acquired maternal T cells and to explore clinical and immunological findings related to this abnormality. Each newly diagnosed patient with SCID presenting with circulating T cells was evaluated for chimerism by performing selective HLA typing of T cells and non-T cells. In patients with engraftment, maternal T cells were characterized phenotypically and functionally, and results were correlated with clinical findings in the patients. Maternal T cells were detected in the circulation in 48 patients; these cells ranged from fewer than 100/microL in 14 cases to more than 2000/microL in 4 cases (median, 415/microL). Clinical signs of graft-versus-host disease (GVHD) were absent in 29 patients. In the other cases, manifestations of GVHD were present, involving the skin and in 14 cases also the liver. Skin GVHD was mild in 8 patients. In these patients, as well as in patients with no signs of GVHD, maternal T cells were predominantly CD8(+) and, with one exception, failed to respond to mitogen stimulation. In 9 patients, manifestations of skin GVHD were prominent. T cells in these cases were predominantly CD4(+) and responded, with one exception, to mitogen stimulation. In 8 of the cases with prominent skin GVHD, the underlying SCID variant was characterized by the absence of B cells. In this study, further understanding is provided of a phenomenon that is responsible for the significant heterogeneity of clinical and immunological findings in SCID.

Successful HLA-identical bone marrow transplantation in a patient with PNP deficiency using busulfan and fludarabine for conditioning

PNP deficiency is an autosomal recessive metabolic disorder characterized by severe combined immunodeficiency and by complex neurological symptomatology including ataxia, developmental delay and spasticity. Patients usually die in the first or second decade of life due to recurrent infections. The only curative treatment is bone marrow transplantation (BMT). We describe a 22-month-old girl who underwent BMT from her HLA-identical brother. Conditioning consisted of busulfan and fludarabine only, resulting in low toxicity and prompt engraftment. At 18 months after BMT, the girl has developed normal immunological functions, and her neurological status has improved.

Disturbed surface properties in preterm infants with pneumonia

Congenital pneumonia in preterm infants is often associated with respiratory insufficiency requiring mechanical ventilation. This study was performed to show whether pneumonia in these infants is associated with an inhibition or deficiency of surfactant. The ratio of lecithin and sphingomyelin (L/S ratio) and minimal surface tension were determined in pharyngeal aspirates from 90 term born infants (healthy) and in tracheal aspirates from preterm infants with wet lung (n = 13), congenital pneumonia (n = 21) and respiratory distress syndrome (RDS) (n = 90). The L/S ratio was lower (p < 0.0001) in the RDS group (8.6) when compared with healthy (48.6), wet lung (42.9) and pneumonia (28.9). Surface tension was higher (p < 0.001) in RDS (37 mN/m) and pneumonia (33.7) when compared with healthy (22.9) or wet lung (21.2). For infants with RDS, L/S ratio <16.5 detects surfactant deficiency with 96% specificity and 70% sensitivity, surface tension >29 mN/m represents surfactant inhibition (specificity 97%, sensitivity 92%). Using these cut-off values in infants with pneumonia, 81% had a sufficient amount of surfactant but only 21% of infants with pneumonia had appropriate surface tension. Our study shows that lung effluent of respiratory insufficient infants with pneumonia, who need mechanical ventilation, has disturbed surface properties despite a sufficient amount of surfactant. In these infants, surfactant substitution could be beneficial.

Loss of the ClC-7 chloride channel leads to osteopetrosis in mice and man

Chloride channels play important roles in the plasma membrane and in intracellular organelles. Mice deficient for the ubiquitously expressed ClC-7 Cl(-) channel show severe osteopetrosis and retinal degeneration. Although osteoclasts are present in normal numbers, they fail to resorb bone because they cannot acidify the extracellular resorption lacuna. ClC-7 resides in late endosomal and lysosomal compartments. In osteoclasts, it is highly expressed in the ruffled membrane, formed by the fusion of H(+)-ATPase-containing vesicles, that secretes protons into the lacuna. We also identified CLCN7 mutations in a patient with human infantile malignant osteopetrosis. We conclude that ClC-7 provides the chloride conductance required for an efficient proton pumping by the H(+)-ATPase of the osteoclast ruffled membrane.

V(D)J recombination defects in lymphocytes due to RAG mutations: severe immunodeficiency with a spectrum of clinical presentations

Severe combined immunodeficiency (SCID) comprises a heterogeneous group of primary immunodeficiencies, a proportion of which are due to mutations in either of the 2 recombination activating genes (RAG)-1 and -2, which mediate the process of V(D)J recombination leading to the assembly of antigen receptor genes. It is reported here that the clinical and immunologic phenotypes of patients bearing mutations in RAGs are more diverse than previously thought and that this variability is related, in part, to the specific type of RAG mutation. By analyzing 44 such patients from 41 families, the following conclusions were reached: (1) null mutations on both alleles lead to the T-B-SCID phenotype; (2) patients manifesting classic Omenn syndrome (OS) have missense mutations on at least one allele and maintain partial V(D)J recombination activity, which accounts for the generation of residual, oligoclonal T-lymphocytes; (3) in a third group of patients, findings were only partially compatible with OS, and these patients, who also carried at least one missense mutation, may be considered to have atypical SCID/OS; (4) patients with engraftment of maternal T cells as a complication of a transplacental transfusion represented a fourth group, and these patients, who often presented with a clinical phenotype mimicking OS, may be observed regardless of the type of RAG gene mutation. Analysis of the RAG genes by direct sequencing is an effective way to provide accurate diagnosis of RAG-deficient as opposed to RAG-independent V(D)J recombination defects, a distinction that cannot be made based on clinical and immunologic phenotype alone.

Similar pattern of thymic-dependent T-cell reconstitution in infants with severe combined immunodeficiency after human leukocyte antigen (HLA)-identical and HLA-nonidentical stem cell transplantation

Donor T cells after stem cell transplantation reconstitute by 2 different pathways: by expansion from grafted, mature T cells and by intrathymic maturation from progenitor cells. This study characterized thymic-dependent reconstitution of CD4(+) T cells following different transplant modalities in patients with severe combined immunodeficiency (SCID). Three groups of patients were studied: one group after transplantation from human leukocyte antigen (HLA)-identical siblings with unmanipulated grafts without conditioning, a second group after transplantation from HLA-nonidentical parents with T-cell-depleted grafts without preconditioning, and a third group with prior conditioning. Reconstitution of the T-cell compartment was monitored by determining the expression of CD45 isoforms by developing CD4(+) cells in the peripheral blood and in discriminating expanded (CD45RO(+)) and newly generated (CD45RA(+)) T cells. Concomitantly, changes in the size of the thymus were evaluated sequentially by ultrasonography. Reconstitution of CD4(+)CD45RA(+) cells was delayed in all patients for several months, including patients after HLA-identical transplantation, and was always paralleled by normalization of the size of the thymus. No engraftment of donor progenitor cells was observed, as studied in one patient transplanted without conditioning. CD4(+)CD45RO(+) cells were detected early after transplantation only in patients given unmanipulated grafts. The study showed that thymic-dependent T-cell maturation in these patients with SCID runs an autonomous course, independent of graft manipulation, of major HLA disparities, and of whether conditioning is used or not. In addition, thymic maturation may not require engraftment of donor-derived CD34(+) cells in the marrow. (Blood. 2000;96:4344-4349)

The stable microbubble test on tracheal aspirate samples from newborn babies for diagnosis of surfactant deficiency and/or surfactant malfunction

For predicting the risk of respiratory distress syndrome (RDS), lung surfactant in amniotic fluid can be assessed by observation of stable microbubbles (< 15 microns diameter). It was investigated if the stable microbubble test (MT) developed on amniotic fluid could be applied on tracheal aspirate samples (TA) obtained from newborn infants. Forty-four TA from 29 newborn infants without pulmonary diseases (group 1) and 65 TA from 21 newborn infants with respiratory insufficiency (group 2) were analyzed by the MT for predicting surfactant deficiency and/or surfactant malfunction. Ten microbubbles/ mm2 was defined as cutoff value of the MT. A specificity of 90% and a sensitivity of 52% was obtained with this cutoff value. A much lower rate of false negative results (sensitivity 91%) was noted after surface tension measurement of TA. The sensitivity of the MT (52%) does not encourage the use of the MT on TA.

Mutations in the a3 subunit of the vacuolar H(+)-ATPase cause infantile malignant osteopetrosis

Although the gene defects for several mouse mutants with severe osteopetrosis are known, the genes underlying human infantile malignant recessive osteopetrosis remain elusive. Osteopetrosis is thought to be caused by a defect in osteoclast function. These cells degrade bone material in a tightly sealed extracellular compartment that is acidified by a vacuolar (V)-type H(+)-ATPase. Genes encoding components of the acidification machinery are candidate genes for osteopetrosis. In five of ten patients with infantile malignant osteopetrosis, we now demonstrate five different mutations in OC116, the gene encoding the a3 subunit of the V-ATPase from osteoclasts. Two independent patients were homozygous for mutations that predict a total loss of function by severely truncating the protein. By affecting a splice site, another homozygous mutation deletes 14 amino acids within the N-terminus, which interacts with other subunits of the proton pump. On the other hand, in four patients no mutations were found, and one patient from a consanguineous family did not show homozygosity at the OC116 locus, suggesting that mutations in at least one different gene may underlie osteopetrosis. Our work shows that mutations in the gene encoding the a3 subunit of the proton pump are a rather common cause of infantile osteopetrosis and suggests that this disease is genetically heterogeneous.

Retrovirus-mediated transduction of primary ZAP-70-deficient human T cells results in the selective growth advantage of gene-corrected cells: implications for gene therapy

Humans lacking the ZAP-70 protein tyrosine kinase present with an absence of CD8+ T cells and defective CD4+ T cells in the periphery. This severe combined immunodeficiency is fatal unless treated by allogeneic bone marrow transplantation. However, in the absence of suitable marrow donors, the development of alternative forms of therapy is desirable. Because lymphocytes are long-lived, it is possible that introduction of the wild-type ZAP-70 gene into CD4+ ZAP-70-deficient T cells will restore their immune function in vivo. Initial investigations evaluating the feasibility of gene therapy for ZAP-70 deficiency were performed using HTL V-I-transformed lymphocytes. Although transformation was useful in circumventing problems associated with the maintenance of ZAP-70-deficient T cells and low gene transfer levels, the presence of HTL V-I precluded any biological studies. Here, we investigated a retrovirus-mediated approach for the correction of primary T cells derived from two ZAP-70-deficient patients. Upon introduction of the wild-type ZAP-70 gene, TCR-induced MAPK activation, IL-2 secretion and proliferation were restored to approximately normal levels. Importantly, this gain-of-function was associated with a selective growth advantage of gene-corrected cells, thereby indicating the feasibility of a gene therapy-based strategy.

Surfactant protein SP-B counteracts inhibition of pulmonary surfactant by serum proteins

In addition to the primary surfactant deficiency in newborns with respiratory distress syndrome (RDS), in the later course of RDS substantial protein leakage into the alveolar spaces can occur by damage to the alveolocapillary membrane. Acute lung injury results in surfactant dysfunction due in part to inhibition by serum proteins. The aim of this study was to investigate the influence of SP-B on the inhibitory effects of albumin (alb) and fibrinogen (fib) on the surface activity of pulmonary surfactant, using a) surface tension measurement with the pulsating bubble surfactometer in suspensions and b) in surfactant films applying the hypophase exchanger. After hypophase exchange a preformed film of Survanta is very resistant to the inhibitory activity of alb or fib. The surface tensions of suspensions are significantly higher (p <0.001) than the surface tensions of preformed surfactant films if alb or fib were added, e.g., 42 (41 to 43) mN/m vs. 21 (19 to 22) mN/m for Survanta with 20 mg alb/ml. After additional supplementation of Survanta with SP-B the surface activity of Survanta/1% SP-B films did not show inhibition by fib (2 mg/ml), (surface tension 8 (4 to 13) mN/m). These results indicate that SP-B can play an important role to protect the pulmonary surfactant film from inactivation by serum proteins.

Alternative antigen receptor (TCR) signaling in T cells derived from ZAP-70-deficient patients expressing high levels of Syk

ZAP-70-deficient patients present with nonfunctional CD4+ T cells in the periphery. We find that a subset of primary ZAP-70-deficient T cells, expressing high levels of the related protein-tyrosine kinase Syk, can proliferate in vitro. These cells (denoted herein as Syk(hi)/ZAP-70(-) T cells) provide a unique model in which the contribution of Syk to TCR-mediated responses can be explored in a nontransformed background. Importantly, CD3-induced responses, such as tyrosine phosphorylation of cellular substrates (LAT, SLP76, and PLC-gamma1), as well as calcium mobilization, which are defective in T cells expressing neither ZAP-70 nor Syk, are observed in Syk(hi)/ZAP-70(-) T cells. However, Syk(hi)/ZAP-70(-) T cells differ from control T cells with respect to the T cell antigen receptor (TCR)-mediated activation of the MAPK cascades: extracellular signal-regulated kinase activity and recruitment of the JNK and p38 stress-related MAPK pathways are diminished. This distinct phenotype of Syk(hi)/ZAP-70(-) T cells is associated with a profound decrease in CD3-mediated interleukin 2 secretion and proliferation relative to control T cells. Thus, ZAP-70 and Syk appear to play distinct roles in transducing a TCR-mediated signal.

Ultrasonic surfactant nebulization with different exciting frequencies

Intratracheal bolus instillation of natural lung surfactant is the treatment of choice in neonatal respiratory distress syndrome and an increasing part in adults' therapy. For reasons of hemodynamics, surfactant distribution and efficiency the application mode should be improved. Nebulization seems to have some advantages but its technical realization is difficult. The aim of the present study was to investigate if ultrasonic nebulization with exciting frequencies higher than 2.8 MHz can improve the efficiency of surfactant nebulization without changing the surface-active properties of the material. Exciting frequencies of 1.7, 3.3 and 4.0 MHz were used to produce a surfactant aerosol. The phospholipid content in the liquefied aerosol and particle size distinctly dropped with higher frequencies. The surface activity was not altered in the produced aerosol and neither in the surfactant remaining in the nebulizer. Although possible, ultrasonic nebulization of surfactant suspensions is ineffective because of a striking decrease in phospholipid content.

Epstein-Barr virus-negative boys with non-Hodgkin lymphoma are mutated in the SH2D1A gene, as are patients with X-linked lymphoproliferative disease (XLP)

X-linked lymphoproliferative disease (XLP) is a primary immunodeficiency, which most often manifests itself after Epstein-Barr virus (EBV) infection. The main clinical phenotypes include fulminant or fatal infectious mononucleosis, dysgammaglobulinaemia and malignant lymphoma. We have recently cloned the SH2D1A gene, which has been shown to be mutated in approximately 70% of XLP patients. Now we report five novel SH2D1A mutations in patients from five unrelated XLP families. No mutations were found in another three XLP families. In three boys with early onset non-Hodgkin lymphoma (NHL) from two unrelated families a deletion of SH2D1A exon 1 and a splice site mutation were found, respectively. These patients did not show any laboratory or clinical signs of a previous EBV infection. A fourth EBV-uninfected and unrelated boy with a stop mutation in the SH2D1A gene shows only signs of dysgammaglobulinaemia. Development of dysgamma-globulinaemia and lymphoma without evidence of prior EBV infection in four of our patients suggests that EBV is unrelated to these phenotypes, in contrast to fulminant or fatal infectious mononucleosis. The role of SH2D1A as a putative tumour suppressor gene remains to be investigated.