The two largest chloroplast genome-encoded open reading frames of higher plants are essential genes

The chloroplast genomes of most higher plants contain two giant open reading frames designated ycf1 and ycf2. In tobacco, ycf1 potentially specifies a protein of 1901 amino acids. The putative gene product of the ycf2 reading frame is a protein of 2280 amino acids. In an attempt to determine the functions of ycf1 and ycf2, we have constructed several mutant alleles for targeted disruption and/or deletion of these two reading frames. The mutant alleles were introduced into the tobacco plastid genome by biolistic chloroplast transformation to replace the corresponding wild-type alleles by homologous recombination. Chloroplast transformants were obtained for all constructs and tested for their homoplastomic state. We report here that all transformed lines remained heteroplastomic even after repeated cycles of regeneration under high selective pressure. A balanced selection was observed in the presence of the antibiotic spectinomycin, resulting in maintenance of a fairly constant ratio of wild-type versus transformed genome copies. Upon removal of the antibiotic and therewith release of the selective pressure, sorting out towards the wild-type plastid genome occurred in all transplastomic lines. These findings suggest that ycf1 and ycf2 are functional genes and encode products that are essential for cell survival. The two reading frames are thus the first higher plant chloroplast genes identified as being indispensable.

Stable genetic transformation of tomato plastids and expression of a foreign protein in fruit

Transgenic chloroplasts offer unique advantages in plant biotechnology, including high-level foreign protein expression, absence of epigenetic effects, and gene containment due to the lack of transgene transmission through pollen. However, broad application of plastid genome engineering in biotechnology has been largely hampered by both the lack of chloroplast transformation systems for major crop plants and the usually low plastid gene expression levels in nongreen tissues such as fruits, tubers, and other storage organs. Here we describe the development of a plastid transformation system for tomato, Lycopersicon esculentum. This is the first report on the generation of fertile transplastomic plants in a food crop with an edible fruit. We show that chromoplasts in the tomato fruit express the transgene to approximately 50% of the expression levels in leaf chloroplasts. Given the generally very high foreign protein accumulation rates that can be achieved in transgenic chloroplasts (>40% of the total soluble protein), this system paves the way to efficient production of edible vaccines, pharmaceuticals, and antibodies in tomato.

Temporomandibular joint remodeling in adolescents and young adults during Herbst treatment: A prospective longitudinal magnetic resonance imaging and cephalometric radiographic investigation

The aim of this prospective study was to analyze and compare the temporomandibular joint adaptive mechanisms in 25 adolescent and 14 young adult Class II malocclusions treated with the Herbst appliance. Temporomandibular joint remodeling was analyzed by magnetic resonance imaging. In each subject, 4 magnetic resonance images of both temporomandibular joints were available: before treatment, at the start of treatment (when the Herbst appliance was placed), during treatment (6 to 12 weeks after appliance placement), and after treatment (when the appliance was removed). Furthermore, effective temporomandibular joint changes (the sum of condylar remodeling, fossa remodeling, and condyle-fossa relationship changes) were analyzed with the aid of lateral cephalometric radiographs from before and after treatment. All subjects were treated to Class I or overcorrected Class I dental arch relationships, and their mandibles became significantly (P <.001) more prognathic. After 6 to 12 weeks of Herbst treatment, signs of condylar remodeling were seen at the posterosuperior border in 48 of the 50 adolescent condyles and in 26 of the 28 young adult condyles. Bilateral remodeling of the mandibular ramus could be detected in 1 adolescent and 2 young adult patients. Signs of glenoid fossa remodeling at the anterior surface of the postglenoid spine were noted in 36 adolescent and 22 young adult temporomandibular joints. Effective temporomandibular joint changes during treatment were more horizontally directed and larger in both adolescents and young adult patients treated with the Herbst appliance than in an untreated group of subjects with ideal occlusion (Bolton standards). The increase in mandibular prognathism accomplished by Herbst therapy in both adolescents and young adults seems, in particular, to be a result of condylar and glenoid fossa remodeling. Because the Herbst appliance is most successful in Class II patients also at the end of the growth period, the treatment method could be an alternative to orthognathic surgery in borderline skeletal Class II cases. Magnetic resonance imaging renders an excellent opportunity to visualize the temporomandibular joint remodeling growth processes.

Targeted inactivation of a tobacco intron-containing open reading frame reveals a novel chloroplast-encoded photosystem I-related gene

The chloroplast genome of all higher plants encodes, in its large single-copy region, a conserved open reading frame of unknown function (ycf3), which is split by two group II introns and undergoes RNA editing in monocotyledonous plants. To elucidate the function of ycf3 we have deleted the reading frame from the tobacco plastid genome by biolistic transformation. We show here that homoplasmic Deltaycf3 plants display a photosynthetically incompetent phenotype. Molecular analyses indicate that this phenotype is not due to a defect in any of the general functions of the plastid genetic apparatus. Instead, the mutant plants specifically lack detectable amounts of all photosystem I (PSI) subunits analyzed. In contrast, at least under low light conditions, photosystem II subunits are still present and assemble into a physiologically active complex. Faithful transcription of photosystem I genes as well as correct mRNA processing and efficient transcript loading with ribosomes in the Deltaycf3 plants suggest a posttranslational cause of the PSI-defective phenotype. We therefore propose that ycf3 encodes an essential protein for the assembly and/or stability of functional PSI units. This study provides a first example for the suitability of reverse genetics approaches to complete our picture of the coding capacity of higher plant chloroplast genomes.

Stress, burnout and health in the clinical period of dental education

The study examined the extent of stress, burnout and health problems experienced by fourth and fifth year dental students from the three universities of Dresden, Freiburg and Bern. The objectives of the study were to: (i) identify frequent sources of stress and to report the prevalence rates of burnout and health problems in dental students, (ii) determine the rate of students suffering from severe burnout symptoms and (iii) identify stress factors related to the burnout symptoms of emotional exhaustion and depersonalization. A total of 161 dental students from Dresden, Freiburg and Bern participated in the study. They completed the Psychosocial Stress Inventory, the Maslach Burnout Inventory and the Health Survey Questionnaire. Frequent sources of stress were limitation of leisure time, examination anxiety and the transition stress that was related to the adaptation to the demands of the clinical phase of dental education. Few differences existed between the students of the fourth and the fifth study year. Study-related stress was lowest in Bern and considerably higher in Dresden. Differences of mean levels of burnout symptoms were found only for the burnout dimension of emotional exhaustion. Students from Dresden and Freiburg were more emotionally exhausted than students from Bern, students from Dresden also reported more health problems than students from Bern or Freiburg. Ten per cent of the dental students suffered from severe emotional exhaustion, 17% complained about a severe lack of accomplishment and 28% reported severe depersonalization symptoms. Forty-four per cent of the variance of emotional exhaustion was explained by study-related factors such as lack of leisure time, examination anxiety and transition stress. The only predictor of depersonalization was a lack of social integration, accounting for 3% of the variance. A lack of social integration may be an indicator of low social competence which may cause difficulties in dealing with patients adequately and therefore result in depersonalization. The results indicate a need to identify the group of students who may have insufficient social skills for dealing adequately with the patients, and to train them accordingly.

Targeted inactivation of the smallest plastid genome-encoded open reading frame reveals a novel and essential subunit of the cytochrome b(6)f complex

The smallest conserved open reading frame in the plastid genome, ycf6, potentially specifies a hydrophobic polypeptide of only 29 amino acids. In order to determine the function of this reading frame we have constructed a knockout allele for ycf6. This allele was introduced into the tobacco plastid genome by chloroplast transformation to replace the wild-type ycf6 allele. Homoplasmic Deltaycf6 plants display a photosynthetically incompetent phenotype. Whereas the two photosystems are intact and physiologically active, we found that the electron transfer from photosystem II to photosystem I is interrupted in Deltaycf6 plants. Molecular analyses revealed that this block is caused by the complete absence of the cytochrome b(6)f complex, the redox-coupling complex that interconnects the two photosystems. Analysis of purified cytochrome b(6)f complex by mass spectroscopy revealed the presence of a protein that has exactly the molecular mass calculated for the Ycf6 protein. This suggests that Ycf6 is a genuine subunit of the cytochrome b(6)f complex, which plays a crucial role in complex assembly and/or stability. We therefore propose to rename the ycf6 reading frame petN.

Temporomandibular joint growth adaptation in Herbst treatment: a prospective magnetic resonance imaging and cephalometric roentgenographic study

The aim of this investigation was to analyze three possible adaptive TMJ growth processes contributing to the increase in mandibular prognathism accomplished by Herbst appliance therapy: (1) condylar remodeling; (2) glenoid fossa remodeling; and (3) condyle-fossa relationship changes. The subjects were 15 consecutive Class II malocclusions (11 males and four females, aged 11.5-17.5 years) treated with the Herbst appliance for an average period of 7 months. Condylar remodelling, glenoid fossa remodelling, and condyle-fossa relationship changes were analyzed by means of magnetic resonance imaging (MRI). From each subject, four MR images were evaluated: before treatment, start of treatment (when the Herbst appliance was placed), during treatment (6-12 weeks after appliance placement), and after treatment (when the appliance was removed). 'Effective condylar growth' (= the sum of condylar remodelling, fossa remodelling, and condyle-fossa relationship changes) was analyzed with the aid of pre- and post-treatment lateral cephalometric roentgenograms. In all 15 subjects, Herbst therapy resulted in an increase in mandibular prognathism. After 6-12 weeks of treatment MRI-signs of condylar remodelling were seen at the posterior-superior border in 29 of the 30 condyles. MRI-signs of glenoid fossa remodelling at the anterior surface of the postglenoid spine were noted in 22 of the joints. Condylar remodelling seemed to precede fossa remodelling. The condyle-fossa relationship was, on average unaffected by Herbst therapy. 'Effective condylar growth' during treatment was, on average, approximately five times larger in the Herbst group than in an untreated group with ideal occlusion (Bolton Standards) and the direction of the growth changes was relatively more horizontal in the treated cases. The results indicate that condylar as well as glenoid fossa remodelling seem to contribute significantly to the increase in mandibular prognathism resulting from Herbst treatment, while condyle-fossa relationship changes are of less importance. MRI renders an excellent opportunity to visualize temporomandibular remodelling growth processes.

Does orthodontic proclination of lower incisors in children and adolescents cause gingival recession?

In this investigation we sought to assess the effect of orthodontic proclination of lower incisors in children and adolescents with respect to the possible development of gingival recession. Ninety-eight children with a mean +/- SD start-of-treatment age of 12.8 +/- 1.4 years, treated with the Herbst appliance, were surveyed, for a total of 392 lower incisors. Lateral head films, dental casts and intraoral photographs were analyzed with respect to the degree of orthodontic proclination, crown height, and gingival recession. In all subjects, Herbst treatment resulted in varying degrees of lower-incisor proclination (mean = 8.9 degrees, range = 0.5 degrees to 19.5 degrees). In 380 of the surveyed teeth (97%), either no recession developed or preexisting recession remained unchanged during Herbst therapy. In only 12 teeth (3%) did recession develop or preexisting recession deteriorate during treatment. No interrelation was found between the amount of incisor proclination and the development of gingival recession. In conclusion, orthodontic proclination of lower incisors in children and adolescents seems not to result in gingival recession.

The germinal center kinase (GCK)-related protein kinases HPK1 and KHS are candidates for highly selective signal transducers of Crk family adapter proteins

Adapter proteins function by mediating the rapid and specific assembly of multi-protein complexes during the signal transduction which guards proliferation, differentiation and many functions of higher eukaryotic cells. To understand their functional roles in different cells it is important to identify the selectively interacting proteins in these cells. Two novel candidates for signalling partners of Crk family adapter proteins, the hematopoietic progenitor kinase 1 (HPK1) and the kinase homologous to SPS1/STE20 (KHS), were found to bind with great selectivity to the first SH3 domains of c-Crk and CRKL. While KHS bound exclusively to Crk family proteins, HPK1 also interacted with both SH3 domains of Grb2 and weakly with Nck, but not with more than 25 other SH3 domains tested. The interaction of HPK1 with c-Crk and CRKL was studied in more detail. HPK1-binding to the first SH3 domain of CRKL is direct and occurs via proline-rich motifs in the C-terminal, non-catalytic portion of HPK1. In vitro complexes were highly stable and in vivo complexes of c-Crk and CRKL with HPK1 were detectable by co-immunoprecipitation with transiently transfected cells but also with endogenous proteins. Furthermore, c-Crk II and, to a lesser extent, CRKL were substrates for HPK1. These results make it likely that HPK1 and KHS participate in the signal transduction of Crk family adapter proteins in certain cell types.

"Effective condylar growth" and chin position changes in Herbst treatment: a cephalometric roentgenographic long-term study

In 98 Class II Division 1 malocclusions treated with the Herbst appliance "effective condylar growth" (a summation of condylar remodeling, glenoid fossa remodeling, and condylar position changes within the fossa) and its influence on the position of the chin was analyzed. Lateral head films in habitual occlusion from before and after 0.6 years of Herbst treatment as well as 0.6 years and 3.1 years posttreatment were evaluated. All patients were treated to Class I or overcorrected Class I dental arch relationships. During the treatment period, effective condylar growth was relatively more backward directed and about three times larger than that in untreated subjects with ideal occlusion (Bolton Standards). During the first posttreatment period of 0.6 years, effective condylar growth recovered with respect to both the direction and amount of changes. During the second posttreatment period of 2.5 years, effective condylar growth was "normal." The corresponding chin position changes during the different examination periods were a mirror image of effective condylar growth provided no mandibular autorotation occurred. In cases with anterior mandibular autorotation, relatively more forward and in cases with posterior mandibular autorotation relatively more backward directed chin position changes resulted.

Long-term TMJ effects of Herbst treatment: a clinical and MRI study

The long-term effects of the Herbst appliance on the temporomandibular joint were assessed in 20 patients (10 girls and 10 boys) who had completed treatment an average of 4 years previously. The TMJ analysis comprised of: (1) an anamnestic questionnaire (2) a clinical investigation (manual functional analysis) and (3) magnetic resonance imaging of the left and right joints. The results revealed that the incidence of anamnestic and clinical signs and symptoms of temporomandibular disorders was within the range of "normal" reported in the literature. The frequency of disk displacement was not higher than in asymptomatic populations. When summarizing the anamnestic, clinical and magnetic resonance imaging findings five subjects (25%) exhibited moderate to severe signs of temporomandibular disorders ranging from partial to total disk displacement or "deviation in form" of the condyle. Another three subjects (15%) showed mild symptoms of temporomandibular disorders with either small condylar displacement or subclinical soft tissue lesion. In conclusion, it can be said that Herbst treatment does not seem to have an adverse long-term effect on the temporomandibular joint.

Comparison of six different specimen types for Epstein-Barr viral load quantification in peripheral blood of pediatric patients after heart transplantation or after allogeneic hematopoietic stem cell transplantation

BACKGROUND

Epstein-Barr Virus (EBV) a gamma-herpes virus is associated with a spectrum of lymphoid and epithelial malignancies including posttransplant lymphoproliferative disorders (PTLD). EBV-load measurement has been shown to be important for the monitoring of these patients. However, in contrast to the viral quantification of human immunodeficiency virus or human hepatitis C virus, the EBV-load measurement has not been completely standardized as yet.

OBJECTIVES

In this study, we compared the EBV DNA levels in whole blood (WB), plasma, peripheral mononuclear cells (PBMC) and B-cells (BC) in children and adolescents after heart transplantations (HTx) and allogeneic hematopoietic stem cell transplantations (HSCT).

STUDY DESIGN

In a period of 2 years (from May 2007 to May 2009) we collected 547 samples of 96 cardiac transplant recipients and 248 samples of 37 patients who underwent HSCT. For EBV DNA quantification we used a duplex real-time PCR (ABI Prism 7500, Applied Biosystems). Additionally, EBV-load of PBMC and BC were normalized with respect to endogenous cell DNA.

RESULTS

In both patient populations we found no significant difference of test sensitivity for the EBV detection. In PBMC as well as BC, there was a high correlation between the analysis of cells with and without normalization in both populations. Spearman's correlation coefficient ρ between PBMC without and PBMC with normalization was ρ=0.98 (P<0.0001) in patients after HTx and ρ=0.99 (P<0.0001) in patients after HSCT. Correlation between BC with and without normalization was ρ=0.98 (P<0.0001) in patients after HTx and ρ=0.995 (P<0.0001) in patients after HSCT. When comparing the different blood compartments for EBV quantification in both populations, the strongest correlations were found between the EBV DNA levels in WB and PBMC (HTx: ρ=0.93, P<0.0001; HSCT: ρ=0.81, P<0.0001) followed by PBMC and BC (HTx: ρ=0.87, P<0.0001; HSCT: ρ=0.81, P<0.0001) as well as WB and BC (HTx: ρ=0.86, P<0.0001; HSCT: ρ=0.75, P<0.0001). In contrast, the correlation coefficients between plasma and the other blood compartments (WB as well as PBMC or BC) were lower. Six patients developed seven episodes of PTLD (five patients after HTx and one after renal transplantation). Analyzing the different blood compartments, we found that a threshold of WB ≥20,000EBV-copies/ml and plasma ≥1000EBV-copies/ml had the highest sensitivities and specificities (WB: sensitivity 100%, specificity 87% and plasma: sensitivity 88%, specificity 98%).

CONCLUSION

Normalization towards an endogenous control does not seem to be necessary for EBV quantification in peripheral blood. The analysis of whole blood correlates well with B-cells and PBMC. Routine screening of EBV DNA in whole blood appeared to be a useful tool supplemented by EBV-load measurement in plasma to discriminate chronic high EBV-load carrier without risk for PTLD from those who are at risk for PTLD. Values in whole blood higher than 20,000EBV-copies/ml WB and plasma values higher than 1000EBV-copies/ml plasma indicated PTLD in our series.

The effect of Herbst appliance treatment on the mandibular plane angle: a cephalometric roentgenographic study

The purpose of this investigation was to assess the individual reaction pattern and the long-term effect of Herbst appliance treatment on the vertical jaw base relationship, as expressed by the mandibular plane angle (ML/NSL). In the evaluation special reference was given to the pretreatment vertical jaw base relationship (hypodivergent, normodivergent or hyperdivergent). Lateral head films of 80 patients (47 males and 33 females) from before, at start (when the appliance was placed) and at the end of Herbst treatment (when the appliance was removed) as well as 6 months and 4.5 to 5 years posttreatment were analyzed. The ML/NSL angle was on the average unaffected by Herbst therapy. Posttreatment, a continuous decrease in the ML/NSL took place. Male subjects showed a larger angular decrease than female subjects. However, a large interindividual variation existed. No statistically significant differences were found between hypodivergent, normodivergent, and hyperdivergent subjects.

Corrective osteotomy for post-traumatic malunion of the phalanges in the hand

Rotation, angulation, deviation, shortening or a combination of deformities can occur due to phalangeal malunion and can lead to impairment of hand function. A historical cohort study of 57 patients who had phalangeal corrective osteotomies for posttraumatic malunion between 1978 and 1990 was undertaken. 59 rotational, radial/ulnar deviation, flexion/extension, length adjustment procedures, and combinations thereof were performed, using rigid internal fixation. Concurrent tenocapsulolysis was done in 50% of the cases. Satisfactory correction was obtained in 76% of the patients. Bony union was obtained in all cases. A net gain in active range of motion was achieved in 89% of the patients. Excellent and good results were obtained in 96% of the patients who had corrective osteotomies for malunion involving only the bone and in 64% of the patients who had corrections for malunion with involvement of multiple structures (P < 0.01).

Mandibular articular disk position changes during Herbst treatment: a prospective longitudinal MRI study

The aim of this prospective longitudinal study of 15 consecutively treated Class II malocclusions was to assess any possible changes in the relative position of the articular disk to the condyle during different phases of Herbst therapy. Using a disk position index, parasagittal MRIs (central, medial and lateral slices) of the right and left TMJ were analyzed at five occasions: before Herbst treatment (T1), at start of treatment when the appliance was placed (T2), after 6 weeks of treatment (T3), after 13 weeks of treatment (T4), and after 7 months of treatment when the appliance was removed (T5). In all subjects Herbst treatment resulted in Class I or overcorrected Class I dental arch relationships. Condyle position was on average unchanged during Herbst treatment (T1 to T5). Before treatment (T1) the articular disk was in a slight protrusive position relative to the condyle. At start of treatment (T2) the mandible was advanced to an incisal edge to edge position. Because of the physiologic relative movement of disk and condyle on mandibular protrusion the disk attained a pronounced retrusive position. At the end of treatment (T5), the disk had almost returned to its original pretreatment position. In several cases, however, a slight retrusive disk position prevailed. In conclusion, Herbst treatment did not result in any adverse changes in articular disk position. On the contrary, the Herbst appliance could possibly be useful in the therapy of patients with anterior disk displacement.

Complete RNA editing of unspliced and dicistronic transcripts of the intron-containing reading frame IRF170 from maize chloroplasts

The maize plastome harbors within the rps4-rps14 gene cluster the reading frame IRF170, which is interrupted by two introns. Although the function of the encoded peptide of 170 amino acids is not known, the conservation of IRF170 homologs in other plastomes is a strong indication that IRF170 is a functional gene. Amplification and sequence analyses of IRF170 specific cDNAs reveals two C-to-U editing events occurring within each of the first two exons. This situation allows an analysis of the temporal order between editing and splicing of a chloroplast transcript. By using intron-specific primer combinations, cDNAs derived from partially or even unspliced IRF170 transcripts could be amplified which in all cases showed complete editing. Complete editing was also observed with a cDNA derived from a transcript in which the proximal rps4 and the 5' half of IRF170-encoded sequences were still linked. This demonstrates that editing of the IRF170 transcript is an early processing step preceding both splicing and cleavage to monocistronic mRNA.

[Indirect MR Arthrography of the wrist in the diagnosis of TFCC-Lesions]

PURPOSE

The objective of this prospective study was to assess the value of the indirect MR arthrography (MR-AR) of the wrist in the detection of lesions of the TFCC.

MATERIAL AND METHODS

Indirect MR-AR was performed in 45 patients (23 f/22 m) with unclear ulnar wrist pain. After i. v. injection of 0.1 mmol/kg Gd-DTPA and after a motion-phase of the wrist (15 minutes) MRI was performed in a coronal plane. We used a STIR-, a fatsaturated (fs) T1-SE and a 3D-DESS sequence. The images were evaluated by two radiologists using a consensus score. The lesions were assigned to the system of Palmer and correlated with arthroscopy.

RESULTS

Indirect MR-AR showed in 35 of 45 patients a lesion of the TFCC, but arthroscopy only revealed a defect in 32 cases. This means three false positive but no false negative assessments by MRI. Using this MRI protocol sensitivity and specificity in the detection of TFCC lesions were calculated as 100 % and 77 %. The accuracy was 93 %. Small degenerative changes of the fibres were most common (Palmer type II A). In trauma patients the ligaments usually showed tears near the insertion at the ulna (Palmer type I B). The sensitivity and specificity was 88 % and 95 % for evaluation of the scapho-lunate (SL) ligament, the accuracy was 93 %. Arthroscopy and MRI did not diagnose any rupture of the lunate-triquetral (LT) ligament.

CONCLUSION

Indirect MR-AR is a non-invasive method with a high sensitivity in the evaluation of the TFCC and associated injuries. Therefore, it is an excellent screening procedure to assess the indication for therapeutic arthroscopy.

Stress-induced changes in the functional electromyographic activity of the masticatory muscles

The present study was undertaken to assess the effect of a non-experimental emotional stress situation on the functional electromyographic (EMG) activity of the masticatory muscles. The material comprised 15 dental students without signs and symptoms of disorders from the temporomandibular system. The activity of the masseter and anterior temporalis muscles was recorded bilaterally by means of surface EMG. The subjective degree of helplessness of the subjects was assessed and related to the EMG activity response, to assess a possible interrelation. The EMG activity during the stress situation was significantly greater than for the non-stress situation. This shift in EMG activity was seen for all the muscles and all the functions analyzed. No significant gender differences were found. When the subjective degree of helplessness is taken into consideration, women showed significantly higher ratings than male subjects. The Helplessness Scale ratings correlated with the changes in EMG activity.

Smoking accelerates the progression of hypertension-induced myocardial hypertrophy to heart failure in spontaneously hypertensive rats

OBJECTIVE

Myocardial hypertrophy often develops in response to hypertension, and it is causal to and an independent predictor of heart failure. Several risk factors modify the progression of hypertrophy, the associated progressive impairment of myocardial function, and eventually the transition to overt congestive heart failure. The aim of the present study was to investigate the effects of smoking on the progression of pressure-dependent myocardial hypertrophy.

METHODS

Spontaneously hypertensive rats (SHR) were used as a model for pressure-dependent hypertrophy. SHR were exposed to mainstream smoke from the Kentucky reference cigarette 2R4F (450 microg total particulate matter/l) or to fresh air (control), 5 days a week, twice for 1 h per day with a 30-minute fresh air exposure break for 30, 60, or 90 days. Endpoints for hypertrophy-associated changes were heart weight to body weight ratio, ventricular expression of hypertrophy-associated genes, ischemic tolerance, and inotropic responsiveness to isoprenaline in post-ischemic hearts.

RESULTS

Smoke-exposed SHR showed a significant elevation in heart weight to body weight ratio, increased mRNA expression of atrial natriuretic factor (ANF), transforming growth factor (TGF)-beta(1), ornithine decarboxylase (ODC), and parathyroid hormone-related protein in both ventricles compared to controls. Hearts from smoke-exposed SHR showed a reduced recovery after 30 min global ischemia during the first 5 min of reperfusion and loss of inotropic stimulation after 30 min reperfusion. Smoke cessation was sufficient to reverse most of these alterations. WKY exposed to smoke did not develop similar changes.

CONCLUSION

Our data indicate that several aspects of myocardial hypertrophy are accelerated by smoking.

Dentoskeletal effects and facial profile changes in young adults treated with the Herbst appliance

This prospective Herbst study analyzed the sagittal dental and skeletal changes contributing to Class II correction in young adults. Additionally, the alteration in skeletal and soft tissue convexity occurring during treatment was assessed. Early adolescent subjects in the permanent dentition who had been treated with the Herbst appliance were used for comparison. Lateral headfilms from before and after an average treatment period of 8.5 months for the young adults and 7.1 months for the adolescents were evaluated. All adult and adolescent subjects were treated to either Class I or overcorrected Class I occlusal relationships. In both groups the improvement in sagittal incisor and molar relationships was achieved more by dental changes than by skeletal ones. The amount of skeletal change contributing to overjet and molar correction was smaller in the young adult group (22% and 25%, respectively) than in the early adolescent group (39% and 41%, respectively). Skeletal and soft tissue facial profile convexity was reduced in adults and adolescents. Facial profile improvement did not differ between the two groups. The results of this study revealed that the Herbst appliance is most effective in the treatment of Class II malocclusion in young adults. It is suggested that this treatment method could be an alternative to orthognathic surgery in borderline Class II cases.

Development of the frontal sinus in relation to somatic and skeletal maturity. A cephalometric roentgenographic study at puberty

The development of the frontal sinus in relation to somatic and skeletal maturity was analysed in 26 male subjects aged 9-22 years by means of longitudinal data obtained from lateral head films, handwrist radiographs and body height growth curves. These were grouped together and analysed in a cross-sectional manner. The results revealed that the final size of the frontal sinus varied considerably. Analogous to body height growth at puberty, the enlargement of the frontal sinus exhibited a similar pattern with a well-defined peak, which on average occurred 1.4 years after the body height peak. In comparison with skeletal maturity, 65 per cent of the subjects reached the sinus peak during the hand radiographic stages MP3-G or MP3-H, while the body height peak coincided with an earlier maturity stage (MP3-FG).

Tissue-specific and differential editing of the two ycf3 editing sites in maize plastids

The hypothetical chloroplast open reading frame 3 (ycf3) of maize, consisting of three exons and two group II introns, contains two editing sites. Both of these sites were investigated with respect to the extent of editing in various tissues and different developmental stages. Northern blot analyses show nearly identical transcript patterns of ycf3 in all tissues investigated. In leaf plastids, both editing sites are completely edited, independent of light conditions and developmental stage. In non-leaf plastids, however, one editing site of ycf3 is only partially edited in unspliced transcripts and in one type of partially spliced transcripts. In different developmental stages of the same tissue, on the other hand, no differences in editing efficiency were found. These results indicate that, in partially spliced transcripts, different editing sites of one and the same gene can be edited with different efficiencies in a tissue-specific manner.

Frontal sinus development as an indicator for somatic maturity at puberty?

The possibility of predicting the stage of somatic maturity by analyzing frontal sinus growth was evaluated. The study was performed on 53 adolescent boys, and the frontal sinus size development was assessed on lateral head films. The accuracy of the prediction procedure was tested by comparing the prediction stage with the longitudinal growth data for body height of the subjects. The results revealed that: If the only prediction was whether the pubertal growth peak in height has been passed (group B), the precision of the method was rather high (approximately 90%). However, if the age of body height peak was to be predicted, the method accuracy was lower (approximately 55%). No significant difference existed between the 1- and 2-year prediction intervals. The study suggests that the somatic maturity stage may be predicted rather accurately by analyzing frontal sinus development on pre-existing lateral head films.

[Diagnosis and therapy of necrotizing fasciitis]

Necrotizing fasciitis is a soft tissue infection with a lethality ranging up to 80%. Infection causes the activation of interleukin, tumor necrosis factor alpha, and gamma-interferon through a triggering mechanism. This results in a capillary thrombosis with necrosis of the fascia, cutis, and subcutis. The patient's history often reveals a triggering event in the form of a recent minimal trauma or operative procedure. In a fulminant necrotizing fasciitis, the development of sepsis with consecutive multiple-organ failure mainly determines the outcome of the disease. Diagnosis is made initially upon clinical findings with a rapid progression of the disease and confirmed later by histologic and microbiologic findings. Radical surgical debridement within the first 24 h with postoperative treatment in an intensive care unit represents the cornerstone of therapy. Between January 1992 and March 2001, we treated 15 patients with necrotizing fasciitis. Lethality was 33%. There was a significant correlation between risk factors (present in 86% of the patients) and morbidity. Diagnosis and therapy should be performed by an experienced surgeon. In this contribution, we discuss the most important criteria that lead to the diagnosis and the therapeutic consequences.