Slc26a3 deficiency is associated with loss of colonic HCO3 (-) secretion, absence of a firm mucus layer and barrier impairment in mice

AIM

Downregulated in adenoma (DRA, Slc26a3) is a member of the solute carrier family 26 (SLC26), family of anion transporters, which is mutated in familial chloride-losing diarrhoea (CLD). Besides Cl(-) -rich diarrhoea, CLD patients also have a higher-than-average incidence of intestinal inflammation. In a search for potential explanations for this clinical finding, we investigated colonic electrolyte transport, the mucus layer and susceptibility against dextran sodium sulphate (DSS)-induced colitis in Slc26a3(-/-) mice.

METHODS

HCO3 (-) secretory (JHCO3 (-) ) and fluid absorptive rates were measured by single-pass perfusion in vivo and in isolated mid-distal colonic mucosa in Ussing chambers in vitro. Colonocyte intracellular pH (pHi ) was assessed fluorometrically, the mucus layer by immunohistochemistry and colitis susceptibility by the addition of DSS to the drinking water.

RESULTS

HCO3 (-) secretory (JHCO3- ) and fluid absorptive rates were strongly reduced in Slc26a3(-/-) mice compared to wild-type (WT) littermates. Despite an increase in sodium/hydrogen exchanger 3 (NHE3) mRNA and protein expression, and intact acid-activation of NHE3, the high colonocyte pH in Slc26a3(-/-) mice prevented Na(+) /H(+) exchange-mediated fluid absorption in vivo. Mucin 2 (MUC2) immunohistochemistry revealed the absence of a firm mucus layer, implying that alkaline secretion and/or an absorptive flux may be necessary for optimal mucus gel formation. Slc26a3(-/-) mice were highly susceptible to DSS damage.

CONCLUSIONS

Deletion of DRA results in severely reduced colonic HCO3 (-) secretory rate, a loss of colonic fluid absorption, a lack of a firmly adherent mucus layer and a severely reduced colonic mucosal resistance to DSS damage. These data provide potential pathophysiological explanations for the increased susceptibility of CLD patients to intestinal inflammation.

[Delirium in the intensive care unit]

In recent years delirium in the intensive care unit (ICU) has internationally become a matter of rising concern for intensive care physicians. Due to the design of highly sophisticated ventilators the practice of deep sedation is nowadays mostly obsolete. To assess a ventilated ICU patient for delirium easy to handle bedside tests have been developed which permit a psychiatric scoring. The significance of ICU delirium is equivalent to organ failure and has been proven to be an independent prognostic factor for mortality and length of ICU and hospital stay. The pathophysiology and risk factors of ICU delirium are still insufficiently understood in detail. A certain constellation of pre-existing patient-related conditions, the current diagnosis and surgical procedure and administered medication entail a higher risk for the occurrence of ICU delirium. A favored hypothesis is that an imbalance of the neurotransmitters acetylcholine and dopamine serotonin results in an unpredictable neurotransmission. Currently, the administration of neuroleptics, enforced physiotherapy, re-orientation measures and appropriate pain treatment are the basis of the therapeutic approach.

Myocardial iron overload in transfusion-dependent pediatric patients with acute leukemia

For patients who regularly receive blood transfusions, cardiac failure is the major cause of death. This is most alarming because it progresses rapidly and is difficult to manage. We present three pediatric patients with acute leukemia whose therapy-induced anemia was treated with different amounts of red blood cell concentrates (RCC). In all patients, a liver iron overload was measured by super-conducting interference device (SQUID) biosusceptometry and magnetic resonance imaging (MRI). MRI is a rapid, noninvasive, and widely available method of determining early myocardial iron overload caused by multiple blood transfusion due to anemia during polychemotherapy.

Defective jejunal and colonic salt absorption and alteredNa(+)/H (+) exchanger 3 (NHE3) activity in NHE regulatory factor 1 (NHERF1) adaptor protein-deficient mice

We investigated the role of the Na(+)/H(+) exchanger regulatory factor 1 (NHERF1) on intestinal salt and water absorption, brush border membrane (BBM) morphology, and on the NHE3 mRNA expression, protein abundance, and transport activity in the murine intestine. NHERF1-deficient mice displayed reduced jejunal fluid absorption in vivo, as well as an attenuated in vitro Na(+) absorption in isolated jejunal and colonic, but not of ileal, mucosa. However, cAMP-mediated inhibition of both parameters remained intact. Acid-activated NHE3 transport rate was reduced in surface colonocytes, while its inhibition by cAMP and cGMP was normal. Immunodetection of NHE3 revealed normal NHE3 localization in the BBM of NHERF1 null mice, but NHE3 abundance, as measured by Western blot, was significantly reduced in isolated BBM from the small and large intestines. Furthermore, the microvilli in the proximal colon, but not in the small intestine, were significantly shorter in NHERF1 null mice. Additional knockout of PDZK1 (NHERF3), another member of the NHERF family of adaptor proteins, which binds to both NHE3 and NHERF1, further reduced basal NHE3 activity and caused complete loss of cAMP-mediated NHE3 inhibition. An activator of the exchange protein activated by cAMP (EPAC) had no effect on jejunal fluid absorption in vivo, but slightly inhibited NHE3 activity in surface colonocytes in vitro. In conclusion, NHERF1 has segment-specific effects on intestinal salt absorption, NHE3 transport rates, and NHE3 membrane abundance without affecting mRNA levels. However, unlike PDZK1, NHERF1 is not required for NHE3 regulation by cyclic nucleotides.

EEG changes and serum anticholinergic activity measured in patients with delirium in the intensive care unit

The aim of this study was to examine whether serum anticholinergic activity (SAA) is a reliable indicator of delirium in the ICU, and whether there is a significant correlation between SAA and quantitative electroencephalographic (EEG) data in delirious patients. In a prospective cohort study, we assessed ICU patients diagnosed with delirium (n = 37). EEG measurements and blood analysis including SAA were performed 48 h following ICU admission. The presence of delirium was evaluated using the Confusion Assessment Method for critically ill patients in ICU (CAM-ICU). The SAA level was measured using a competitive radioreceptor binding assay for muscarinergic receptors and quantitative EEG was measured using the CATEEM system. We found that, under comparable conditions, patients in the delirium group showed a higher relative EEG theta power and a reduced alpha power (n = 17) than did the non-delirious patients (n = 20). No difference in measured SAA levels were seen; therefore, there was no correlation between SAA and EEG measurements in delirious patients. We conclude that, in contrast to the EEG, the SAA level cannot be proposed as a tool for diagnosing delirium in ICU patients.

Interaction of artificial metallic objects with biosusceptometric measurements

In human subjects, metallic objects cause distortions of the magnetic fields used by magnetic resonance imaging (0.5 - 3.0 T) or by SQUID biomagnetic liver susceptometry (0.1 - 30 mT) and may lead to artifacts in the measurement of the relaxation rate or the magnetic susceptibility. In biosusceptometry, the measured signal will depend not only on the magnetic susceptibility of the object, but also on its distance to the sensor assembly, and in case of ferromagnetic objects, on the direction of its remanent field. The magnetic susceptibility of a vascular access port-a-cath and of surgical clips have been measured by a SQUID biosusceptometer. Additionally, the impact from port-a-caths and dental braces on liver iron concentration (LIC) measurements was measured in vivo with respect to their radial distance from the gradiometer center axis. For the port-a-cath, a mean magnetic volume susceptibility of (83.5 +/- 0.3).10(-6) SI-units was found, which may be compared with the magnetic susceptibility of titanium at room temperature of (180 +/- 2).10(-6) SI demonstrating the absence of ferromagnetic contamination. At a radial distance of 5 cm from the gradiometer center axis, the voltage amplitude is similar to the signal generated by a normal liver. Modern surgical clips have nearly no impact on LIC measurements. However, dental braces although further away from the center axis, often superimpose the signal even from an iron overloaded liver. Depending on the Ni-content, these objects reveal ferromagnetic properties and contribute in first order with a one parameter reciprocal distance function to the measured liver iron signal.

[SQUID-biosusceptometry in iron overloaded patients with hematologic diseases]

BACKGROUND

For the long-term survival of iron-loaded patients, early and well adjusted treatment with iron chelators is of crucial importance, especially in children. Basis of the adequate treatment are appropriate diagnostic parameters which are capable to monitor the range of the individual iron burden.

PATIENTS

In the time period between 1989 and 2001, the status of iron loading was investigated in 1112 patients with post transfusion siderosis.

METHODS

The iron concentration in liver and spleen was quantified by SQUID-biosusceptometry. Using these values, the whole body iron stores were calculated.

RESULTS AND DISCUSSION

Based on a large number of patients with secondary siderosis, the benefit of SQUID-biosusceptometry for non-invasive liver iron quantification was evaluated retrospectively. In patients under treatment with deferoxamin, a new therapeutic DFO-index was defined which respects liver iron concentration instead of serum ferritin. This results in a more reliable information about DFO overdosing in a given patient.

[Biomorphometry of corneal epithelium with slit lamp-adapted optical coherence tomography]

INTRODUCTION

The purpose of this study was to evaluate the biomorphometry of the corneal epithelium with slitlamp-adapted optical coherence tomography (OCT).

PATIENTS AND METHODS

In a clinical study, slitlamp-adapted OCT of the cornea was performed in 15 patients before and immediately after therapeutic corneal abrasion. Central corneal epithelium thickness measurements were compared to the pre- and postoperative central corneal thickness.

RESULTS

Preoperatively, the corneal epithelium could be visualised from the highest OCT light reflections at the interfaces air-tear film and epithelium-Bowman's membrane. The preoperative mean geometrical central epithelial thickness determined with OCT ranged from 65 +/- 12 microns to 72 +/- 14 microns (45-92 microns). The mean difference of the pre- and postoperative central corneal thickness was 48 +/- 19 microns (9-79 microns). This resulted in a deviation from the direct epithelial thickness measurements of 26-33%. The reproducibility of the geometrical epithelial thickness was +/- 9 microns.

CONCLUSIONS

Slitlamp-adapted OCT enabled a noncontact evaluation of the corneal epithelium. The difference between direct and indirect corneal epithelium thickness measurements could be related to the partial optical inclusion of the precorneal tear film and the Bowman's membrane. With some restrictions the biomorphometry of the corneal epithelium with slitlamp-adapted OCT seems to be a valuable technique to monitor therapeutical and refractive procedures of the cornea.

[Examination of the cornea using optical coherence tomography]

INTRODUCTION

This study evaluated the clinical use of optical coherence tomography (OCT) for two-dimensional representation of the cornea.

PATIENTS AND METHODS

Noncontact slitlamp-adapted OCT was used in selected cases to evaluate pathologically altered corneas and to measure the central corneal thickness and curvature.

RESULTS

OCT provided correlation between differences in reflection and morphological changes. Scar tissue resulted in hyper-reflective light scattering, whereas cystic lesions were hyporeflective. Precise biomorphometry also allowed representation of intrastromal and retrocorneal changes. Central corneal thickness measured by OCT yielded reproducible values and corneal curvature could be calculated from the optical signals of the corneal surface.

CONCLUSIONS

OCT provides high-resolution representation of the cornea and exact evaluation of its morphology, thickness, and curvature. Due to the noncontact, simple, and rapid examination using the slitlamp the corneal OCT method is a promising additional diagnostic modality.

Corneal optical coherence tomography before and immediately after excimer laser photorefractive keratectomy

PURPOSE

To investigate the representation of the corneal structure with optical coherence tomography before and immediately after excimer laser photorefractive keratectomy.

METHODS

Twenty-four eyes of 24 patients with myopia and myopic astigmatism were prospectively studied. The corneal thickness and the corneal profile were assessed with slit-lamp-adapted optical coherence tomography preoperatively and immediately after excimer laser photorefractive keratectomy.

RESULTS

The attempted mean spherical equivalent of the refractive corrections was -6.7 +/- 3.6 (mean +/- SD) diopters with a mean calculated stromal ablation depth of 91 +/- 38 microm. The corneal optical coherence tomography was reproducible in all patients, demonstrating a mean decrease of central corneal thickness after epithelial debridement and excimer laser photorefractive keratectomy of 118 +/- 45 microm. The comparison of the calculated stromal ablation depth and the corneal thickness changes determined by corneal optical coherence tomography revealed a significant linear relationship with a correlation coefficient of 0.88 (P <.001). The flattening of the corneal curvature was confirmed in all patients with the optical coherence tomography system and correlated with the attempted refractive correction (r =.82, P <.001).

CONCLUSIONS

The slit-lamp-adapted optical coherence tomography system presented in this study allowed noncontact, cross-sectional, and high-resolution imaging of the corneal configuration. This initial clinical evaluation demonstrated that corneal optical coherence tomography could be a promising diagnostic modality to monitor corneal changes of thickness and curvature before and after excimer laser photorefractive keratectomy.

Self-organization and evolution in a simulated cross catalyzed network

Motivated by an alternative to the concept of a prebiotic soup in the form of interacting crystal growth close to hot vents, we investigate a model system in which the growth rate of a particular entity is modified (enhanced or reduced) by other entities present, thus forming a web of cross catalysis. Initially random interactions are imposed, but the entities compete for a common source, and some entities may thus vanish in the competition. New entities, or mutations (error copies), with randomly selected interactions to the web are then introduced, and the concentrations of the entities are followed as solutions to stiff ordinary differential equations. Entities with positive growth may create new related entities with slightly randomly modified interactions to the web. Extinctions, wild-type survival and replacement, and self-organization to sustain periodic external variations, are studied. It is shown that even systems with mostly cross-inhibition and no initial autocatalysis may eventually create highly stable self-organized systems. We find that an already established cross catalyzed system often wins over a selfreplicating invader (or mutant).

First experimental and clinical results with transscleral optical coherence tomography

BACKGROUND AND OBJECTIVE

To evaluate the potentials of optical coherence tomagraphy (OCT) using long wavelength to penetrate highly scattering tissues of the eye and visualize the anterior chamber angle and the ciliary body.

METHODS

OCT images were generated by an experimental prototype in enucleated porcine eyes using as light source a superluminiscent diode with a wavelength of 1310 nm and a scan frequency of 60 Hz. The number of lateral scans was variable in a range from 100 to 400.

RESULTS

Infrared OCT was able to penetrate the sclera. The anterior chamber angle could be visualized completely and the ciliary body could be identified. However, it was not possible to penetrate the highly reflective iris pigment epithelium.

CONCLUSION

The use of infrared OCT allows penetration of the sclera, thus, providing complete visualization of the anterior chamber angle and limited demonstration of the ciliary body. Because of its higher resolution, it may represent an interesting noninvasive alternative to ultrasound biomicroscopy.

Slit-lamp-adapted optical coherence tomography of the anterior segment

PURPOSE

To evaluate the diagnostic potential of a slit-lamp-adapted optical coherence tomography (OCT) system as an in vivo imaging device for routine clinical examination of the anterior segment of the eye.

PATIENTS AND METHODS

In a pilot study, healthy volunteers and patients with different pathologies of the anterior segment were examined with a slit-lamp-adapted OCT system using 100-200 axial scans with 100-Hz line-scan frequency. The scan length is variable up to 7 mm, and the axial depth is 1.5 mm in tissue.

RESULTS

The slit-lamp-adapted OCT system allowed direct biomicroscopic imaging of the measured area. Anatomic structures and morphological changes anterior to the attenuating iris pigment epithelium could be visualized with high accuracy. Biometric analyses of the cornea, the chamber angle, the iris and secondary cataract were possible. Complete demonstration of the chamber angle was difficult due to the backscattering properties of the anterior part of the sclera and the consequent shadowing of the most peripheral part of the iris.

CONCLUSIONS

Slit-lamp-adapted OCT is a useful diagnostic tool which allows in vivo microscopic cross-sectional imaging of the anterior segment and precise measurement of ocular structures.

Standard- and high-dose etoposide, ifosfamide, carboplatin, and epirubicin in 107 patients with non-small-cell lung cancer: a mature follow-up report

BACKGROUND

We conducted a phase I-II trial to assess the activity of standard-dose (SDC) and high-dose chemotherapy (HDC) with etoposide, ifosfamide, cis/carboplatin, and epirubicin (VIP-E, VIC-E) in 107 patients with limited-stage (LS, stage I-IIIB) and extensive stage (ES, stage IV) non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Updated results of a previously published trial are presented.

RESULTS

Response rates and survival after VIP-E were comparable to those of other standard-dose combination chemotherapies in NSCLC. Treatment-related mortality (TRM) in SDC was 3% in LS-NSCLC, and 8% in ES-NSCLC. TRM was 4% in patients selected for HDC by response rate and performance score. Five-year survival in LS-NSCLC was 12% after SDC, and 18% after HDC; it was 0% for both treatment protocols in ES-NSCLC.

CONCLUSIONS

The activity of VIP-E SDC and VIC-E HDC is not superior to that of established protocols in the treatment of NSCLC. In view of the toxicity and TRM associated with this protocol, less aggressive regimens should be preferred for most patients. Whether selected patients with chemosensitive disease could benefit from VIP-E SDC and/or VIC-E HDC in an adjuvant or neo-adjuvant setting could not be determined within the scope of this study.

Standard- and high-dose etoposide, ifosfamide, carboplatin, and epirubicin in 100 patients with small-cell lung cancer: a mature follow-up report

BACKGROUND

We conducted a phase I-II trial to assess the feasibility and activity of a combination chemotherapy regimen with etoposide, ifosfamide, cisplatin or carboplatin, and epirubicin in limited-disease (LD, stages I-IIIB) and extensive-stage (ED, stage IV) small-cell lung cancer (SCLC).

PATIENTS AND METHODS

Standard-dose chemotherapy (SDC) consisting of etoposide (500 mg/m2), ifosfamide (4000 mg/m2), cisplatin (50 mg/m2) and epirubicin (50 mg/m2) (VIP-E), followed by granulocyte colony-stimulating factor (G-CSF), was given to 100 patients with SCLC. Thirty patients with qualifying responses to VIP-E proceeded to high-dose chemotherapy (HDC) with autologous peripheral blood stem-cell transplantation (PBSCT) after etoposide (1,500 mg/m2), ifosfamide (12,000 mg/m2), carboplatin (750 mg/m2) and epirubicin (150 mg/m2) (VIC-E) conditioning. RESULTS OF STANDARD-DOSE VIP-E: Ninety-seven patients were evaluable for response. The objective response rate was 81% in LD SCLC (33% CR, 48% PR; excluding patients in surgical CR) and 77% in ED SCLC (18% CR, 58% PR). The treatment-related mortality (TRM) of SDC was 2%. Two additional patients in CR from their SCLC developed secondary non-small-cell lung cancers (NSCLC), and both were cured by surgery. The median survival was 19 months in LD SCLC and 6 months in ED SCLC. The five-year survivals were 36% in LD and 0% in ED SCLC. RESULTS OF HIGH-DOSE VIC-E: HDC was feasible in 16% of ED-, and 58% of LD-patients. All HDC patients (n = 30) improved or maintained prior responses. Four patients died of early treatment-related complications (TRM 13%). Two additional patients in CR from their SCLC developed secondary malignancies (esophageal cancer, secondary chronic myelogenous leukemia). The median survivals were 26 months in LD SCLC, and 8 months in ED SCLC. The five-year survival was 50% in LD and 0% in ED SCLC.

CONCLUSIONS

Despite high response rates, survival after VIP-E SDC and VIC-E HDC in patients with ED SCLC is not superior to that achieved with less toxic traditional regimens. The high five-year survival rates achieved with these protocols in LD SCLC probably reflect both patient selection (high proportion of patients with prior surgical resection) and the high activity of our chemotherapy regimen in combination with radiotherapy. A study comparing protocols using simultaneous radiation therapy and chemotherapy, and other dose-escalated forms of SDC with HDC is needed to further define the role of this treatment modality in SCLC. Given the high rate of secondary malignancies observed in patients in CR > 2 years in our study, close follow-up and early treatment of these neoplasms may contribute to maintaining overall survival in patients with SCLC.

Assessment of iron stores in children with transfusion siderosis by biomagnetic liver susceptometry

To investigate the applicability of noninvasive Superconducting Quantum Interference Device (SQUID) biomagnetic liver susceptometry and its limitations in thalassemic children, 23 patients with beta-thalassemia major and other iron loading anemias (age: 4-16 years) and 16 age-related normal children were studied. Liver iron concentrations ranged from 600 to 11,000 microg/g(liver) for thalassemic patients and from 60 to 340 microg/g(liver) for normal patients. Measuring the respective organ volumes by sonography, liver and spleen iron stores, accounting for 80% of total body iron stores, were estimated. Nonliver contributions from the lung or intestine to the measured SQUID signals in the small-sized patients were not observed. Moreover, livers in thalassemia were found to be enlarged by 18% per 1,000 microg/g (r = 0.75, P < 10(-3)). Serum ferritin values correlate significantly with iron stores (r = 0.64, P < 10(-3)), but predict iron stores only within large error intervals of 4,000 microg/g(liver). Analyzing the experimental data from biomagnetometry and from related transfusion and chelation treatment data within the framework of a two-compartment model, we were able to derive additional information on total body iron elimination and chelation therapy efficacy. The exponential decline of iron stores allows forecast of steady-state conditions of the final iron load for a particular transfusion and chelation therapy regimen.

Assessment of iron stores in children with transfusion siderosis by biomagnetic liver susceptometry

To investigate the applicability of noninvasive Superconducting Quantum Interference Device (SQUID) biomagnetic liver susceptometry and its limitations in thalassemic children, 23 patients with beta-thalassemia major and other iron loading anemias (age: 4-16 years) and 16 age-related normal children were studied. Liver iron concentrations ranged from 600 to 11,000 microg/g(liver) for thalassemic patients and from 60 to 340 microg/g(liver) for normal patients. Measuring the respective organ volumes by sonography, liver and spleen iron stores, accounting for 80% of total body iron stores, were estimated. Nonliver contributions from the lung or intestine to the measured SQUID signals in the small-sized patients were not observed. Moreover, livers in thalassemia were found to be enlarged by 18% per 1,000 microg/g (r = 0.75, P < 10(-3)). Serum ferritin values correlate significantly with iron stores (r = 0.64, P < 10(-3)), but predict iron stores only within large error intervals of 4,000 microg/g(liver). Analyzing the experimental data from biomagnetometry and from related transfusion and chelation treatment data within the framework of a two-compartment model, we were able to derive additional information on total body iron elimination and chelation therapy efficacy. The exponential decline of iron stores allows forecast of steady-state conditions of the final iron load for a particular transfusion and chelation therapy regimen.

Multimodality treatment including early high-dose chemotherapy with peripheral blood stem cell transplantation in limited-disease small cell lung cancer

Combined-modality treatment for limited-disease small cell lung cancer using conventional chemotherapy and chest irradiation achieves high response rates, but most patients relapse over a period of 12 to 16 months. To improve current results, we performed a phase II trial including high-dose chemotherapy and peripheral blood progenitor cell transplantation (PBPCT) as part of an early intensification strategy after two cycles of induction therapy. Moreover, to reduce the risk of local recurrence, the protocol included surgical resection in stages I to IIIA patients as well as chest irradiation. Between January 1991 and July 1994, 16 consecutive patients (median age, 50 years; age range, 30 to 59 years) were treated in this single-center trial. The patients received two cycles of conventional chemotherapy consisting of etoposide 500 mg/m2, ifosfamide 4 g/m2, cisplatin 50 mg/m2, and epirubicin 50 mg/m2 plus granulocyte colony-stimulating factor 5 microg/kg at a 3-week interval, followed by PBPC collection and subsequent high-dose etoposide 1,500 mg/m2, ifosfamide 12 g/m2, carboplatin 750 mg/m2, and epirubicin 150 mg/m2 with PBPCT. The duration of the entire chemotherapy program was 9 weeks. Six of 10 patients in stages I to IIIA and one of six patients in stage IIIB received neoadjuvant or adjuvant surgery before high-dose chemotherapy, followed by thoracic (50 Gy) and prophylactic (30 Gy) cranial irradiation. Hematopoietic reconstitution after high-dose chemotherapy occurred within 11 days (range, 9 to 17 days) for both neutrophils (>0.5 x 10(9)/L) and platelets (>20 x 10(9)/L). Oral mucositis (World Health Organization grade 2 to 4) was the predominant nonhematologic toxicity, which was observed in 12 of 16 patients. One patient developed neutropenic septicemia with fatal multiorgan failure. At a median follow-up of 44 months (range, 32 to 77 months) after PBPCT, nine patients are alive and well, resulting in a disease-free and overall survival rate of 56.3% +/- 12.4%. The median overall survival has not yet been achieved. None of the patients who had surgery relapsed or died after therapy. All relapses occurred within the first 12 months after PBPCT. Patients in stages I to IIIA (10 patients) had a 70% +/- 14% overall survival rate at 4 years, while patients in stage IIIB (six patients) had a 33% +/- 19% survival rate at 4 years, with a median survival of 17 months posttransplant. These data demonstrate that a multimodality treatment including early high-dose chemotherapy with PBPCT may lead to a prolonged disease-free survival in the majority of patients. A randomized phase III study has now been initiated to prospectively investigate the role of high-dose chemotherapy, surgery, and chest irradiation in the multidisciplinary approach to limited-disease small cell lung cancer.

Screening for hereditary hemochromatosis in prospective blood donors

Prospective blood donors (n = 1,265, mean age 26 years) were screened for elevated serum ferritin and serum iron. Final diagnosis for hereditary hemochromatosis was made by liver iron concentration (noninvasive biomagnetometry), transferrin saturation, and 59Fe absorption in 3 male subjects. This preliminary result confirms for the first time the current frequency estimation of homozygous hemochromatosis (0.2-0.6%) in a group of young North-Germans.

A comparative efficacy trial in Germany in infants who received either the Lederle/Takeda acellular pertussis component DTP (DTaP) vaccine, the Lederle whole-cell component DTP vaccine, or DT vaccine

BACKGROUND

The goal of the trial was to determine the efficacy of a multicomponent acellular pertussis vaccine against Bordetella illnesses in comparison with a whole-cell product and DT.

DESIGN

In a randomized, double-blind fashion, 2- to 4-month-old infants received 4 doses of either DTP or DTaP vaccine at 3, 4.5, 6, and 15 to 18 months of age. The controls received 3 doses (3, 4.5, 15 to 18 months of age) of DT vaccine. The DTP vaccine was Lederle adsorbed vaccine (licensed in the United States) and DTaP was Lederle/Takeda adsorbed vaccine. Follow-up for vaccine efficacy started 2 weeks after the third dose (DTP/DTaP) and at the same age (6.5 months) in DT recipients. Reactogenicity of all doses of all three vaccines was documented by standardized parent diary cards. In addition, all subjects were monitored for respiratory illnesses and serious adverse events by biweekly phone calls.

RESULTS

From May 1991 to January 1993, a total of 10 271 infants were enrolled: 8532 received either DTP or DTaP and 1739 received DT. Specific efficacy against B pertussis infections with cough >/=7 days duration was 83% (95% confidence interval [CI]: 76-88) and 72% (95% CI: 62-79) for DTP and DTaP, respectively; results for DTP and DTaP based on >/=21 days of cough with either paroxysms, whoop or posttussive vomiting (PWV) were 93% (95% CI: 89-96) and 83% (95% CI: 76-88), respectively. For DTaP vaccine, efficacy was higher after the fourth dose as compared with its efficacy after the third dose (78% vs 62% for cough >/=7 days and 85% vs 76% for cough >/=21 days with PWV). For DTP vaccine, efficacy was less varied after the third and fourth dose (78% vs 85% for cough >/=7 days and 93% vs 93% for cough >/=21 days with PWV). In contrast with DTP, the DTaP vaccine had some efficacy against B parapertussis infection (point estimate for cough >/=7 days: 31% [95% CI: -10-56]). All vaccines were generally well-tolerated. However, side reactions were significantly less after DTaP compared with DTP.

CONCLUSIONS

Like other multicomponent acellular pertussis vaccines, the Lederle/Takeda DTaP vaccine demonstrated good efficacy against mild and typical pertussis due to B pertussis infections. Interestingly, it also may have some efficacy against B parapertussis. Based on the results of this trial, the vaccine was licensed in the United States in December 1996 for all 5 doses of the currently recommended immunization schedule in this country.

Optical coherence tomography of the human skin

BACKGROUND

Optical coherence tomography (OCT) is a new diagnostic method for tissue characterization.

OBJECTIVE

We investigated normal and pathologic structures in human skin in several locations to evaluate the potential application of this technique to dermatology.

METHODS

Based on the principle of low-coherence interferometry, cross-sectional images of the human skin can be obtained in vivo with a high spatial resolution of about 15 microns. Within a penetration depth of 0.5 to 1.5 mm, structures of the stratum corneum, the living epidermis, and the papillary dermis can be distinguished.

RESULTS

Different layers could be detected that were differentiated by induction of experimental blisters and by comparison with corresponding histologic sections. Furthermore, OCT images of several skin diseases and tumors were obtained.

CONCLUSION

OCT is a promising new imaging method for visualization of morphologic changes of superficial layers of the human skin. It may be useful for noninvasive diagnosis of bullous skin diseases, skin tumors, and in vivo investigation of pharmacologic effects.

Downregulation of the proinflammatory cytokine response to endotoxin by pretreatment with the nontoxic lipid A analog SDZ MRL 953 in cancer patients

Interfering with the endotoxin-mediated cytokine cascade is thought to be a promising approach to prevent septic complications in gram-negative infections. The synthetic lipid A analog SDZ MRL 953 has been shown to be protective against endotoxic shock and bacterial infection in preclinical in vivo models. As part of a trial of unspecific immunostimulation in cancer patients, we conducted a double-blind, randomized, vehicle-controlled phase I trial of SDZ MRL 953 to investigate, first, its biologic effects and safety of administration in humans and, second, its influence on reactions to a subsequent challenge of endotoxin (Salmonella abortus equi). Twenty patients were treated intravenously with escalating doses of SDZ MRL 953 or vehicle control, followed by an intravenous application of endotoxin (2 ng/kg of body weight [BW]). Administration of SDZ MRL 953 was safe and well-tolerated. SDZ MRL 953 itself increased granulocyte counts and serum levels of granulocyte colony-stimulating factor (G-CSF) and interleukin-6 (IL-6), but not of the proinflammatory cytokines tumor necrosis factor-alpha (TNF-alpha), IL-1beta, and IL-8. Compared with vehicle control, pretreatment with SDZ MRL 953 markedly reduced the release of TNF-alpha, IL-1beta, IL-8, IL-6, and G-CSF, but augmented the increase in granulocyte counts to endotoxin. Induction of tolerance to the endotoxin-mediated cascade of proinflammatory cytokines by pretreatment with SDZ MRL 953 in patients at risk may help to prevent complications of gram-negative sepsis.

[Imaging of laser thermokeratoplasty lesions by optical low coherence tomography and polarization microscopy after Sirius Red staining]

BACKGROUND

Information on the extent and degree of the thermal effect produced is of great importance for control of the laser dosage in laser thermokeratoplasty (LTK) and for postoperative follow-up. We investigated on acute LTK effects which information images obtained by optical low coherence tomography (OCT) offer compared to those obtained by polarization microscopy.

METHODS

Porcine eyes were irradiated through a 400 microns quartz fiber using light from a laser diode emitting up to 300 mW at a wavelength of 1.86 microns. Thermal lesions of varying strength were scanned using an experimental OCT device with about 25 microns lateral and 20 microns axial resolution. Histologic evaluation of the scanned areas was done by polarization microscopy after Sirlus-Red staining, and similar lesions were also analyzed by TEM.

RESULTS

Both methods differentiated three damage zones a transition zone, a zone of moderate coagulation, and a central zone of strong coagulation. In the transition zone, increased birefringence was seen in polarization microscopy, which correlated with increased light scattering seen in the OCT images. In the moderately coagulated zone, a decrease in birefringence was associated with an even stronger increase of the OCT signal. In the central zone, a loss of the fibrillar tissue structure was observed, which led to a complete loss of birefringence and a strong reduction of the OCT signal.

CONCLUSIONS

Although OCT does not provide the detailed information on thermal changes of tissue seen by the histologic method, it offers information on the extent and degree of tissue changes without preparation artifacts and provides a non-invasive method of immediate and follow-up control of LTK lesions. A quantitative analysis of changes in corneal thickness and curvature is much simpler than by a slit lamp. Time-resolved measurements of corneal light scattering may be used for on-line control of the laser-light dosage during LTK.

[Optical coherence tomography of the cornea and the anterior eye segment]

TARGET

The method of optical coherence tomography (OCT) was investigated regarding its suitability and limits for measuring the cornea and the anterior segment of the eye. Furthermore, the stromal expansion of thermally induced lesions in the cornea directly after irradiation was determined within the scope of the laser thermokeratoplasty (LTK).

MATERIAL AND METHODS

With the experimental scanning OCT system, x-z sections of the anterior eye segment were made with an optical resolution of about 20 microns axially and 25 microns laterally. Freshly enucleated, tonicized porcine eyes were used as model eyes. Thermal lesions were applied with a continuously emitting laser diode (lambda = 1.86 microns) and various radiation parameters. Before and after coagulation, the cornea was viewed from limbus to limbus in a central OCT scan and the individual coagulation source was measured.

RESULTS

Global and local changes of the thickness of the cornea as well as the distance between cornea and lens were measured with high precision. Thermal lesions in their expansion can be dearly presented and matching well with the histologically stained sections, but are not as exactly defined at the edges due to the limited optical resolution, as known from histological preparations.

CONCLUSION

With the OCT method quantitative measuring of the anterior eye segment can be performed in vitro and with reduced resolutions also in vivo. Due to the qualitatively good correspondence regarding the dimensions of thermal damage of the cornea with histologically obtained morphometric results, this method can be used for supervision of coagulation directly after LTK as well as for examination of the individual healing process.

Contrast limits of coherence-gated imaging in scattering media

The fundamental difference between time-resolved and coherence-gated imaging modalities in scattering media is analyzed in terms of their optical transfer functions. The effectiveness of coherence gating for multiple-scattering rejection is shown by imaging a 100-mum-thick razor blade hidden in the scattering phantoms (i.e., Intralipid suspensions) with different scattering coefficients. We found that the imaging contrast is limited by multiple scattering and speckle effects in high-scattering media, and the measured effective penetration depth of optical coherence tomography is approximately equal to six mean free paths under the experimental conditions of a numerical aperture of less than 0.1 and a scattering anisotropy of approximately 0.8.