Distribution, targeting, and internalization of the sst4 somatostatin receptor in rat brain

Somatostatin mediates its diverse physiological effects through a family of five G-protein-coupled receptors (sst(1)-sst(5)); however, knowledge about the distribution of individual somatostatin receptor proteins in mammalian brain is incomplete. In the present study, we have examined the regional and subcellular distribution of the somatostatin receptor sst(4) in the rat CNS by raising anti-peptide antisera to the C-terminal tail of sst(4). The specificity of affinity-purified antibodies was demonstrated using immunofluorescent staining of HEK 293 cells stably transfected with an epitope-tagged sst(4) receptor. In Western blotting, the antiserum reacted specifically with a broad band in rat brain, which migrated at approximately 70 kDa before and approximately 50 kDa after enzymatic deglycosylation. sst(4)-Like immunoreactivity was most prominent in many forebrain regions, including the cerebral cortex, hippocampus, striatum, amygdala, and hypothalamus. Analysis at the electron microscopic level revealed that sst(4)-expressing neurons target this receptor preferentially to their somatodendritic domain. Like the sst(2A) receptor, sst(4)-immunoreactive dendrites were often closely apposed by somatostatin-14-containing fibers and terminals. However, unlike the sst(2A) receptor, sst(4) was not internalized in response to intracerebroventricular administration of somatostatin-14. After percussion trauma of the cortex, neuronal sst(4) receptors progressively declined at the sites of damage. This decline coincided with an induction of sst(4) expression in cells with a glial-like morphology. Together, this study provides the first description of the distribution of immunoreactive sst(4) receptor proteins in rat brain. We show that sst(4) is strictly somatodendritic and most likely functions in a postsynaptic manner. In addition, the sst(4) receptor may have a previously unappreciated function during the neuronal degeneration-regeneration process.

Lectin-binding pattern of primary malignant melanomas and melanocytic nevi

A panel of six biotinylated lectins was applied in order to study the composition and distribution of plasma membrane carbohydrate residues in 83 primary cutaneous melanomas (MMs) and in 85 melanocytic nevi (MN) with the avidin-biotin peroxidase technique. No clear-cut differences between MN and MMs were observed with regard to the staining with lectins. In MN and MMs derived from different patients, the lectin-binding pattern was variable and heterogeneous even within the individual nevi or melanomas. It seems reasonable, therefore, to assume that the lectin-binding pattern cannot be regarded as a reliable histochemical marker for the differentiation of MN from MMs. Moreover, because the pattern reveals no statistically significant correlation with the thickness or the depth of invasion of MM, it seems to lack prognostic significance.

[Serous peritoneal papillary tumor of low malignancy potential. Report of a case]

Papillary serous carcinoma with low malignant potential, similar to those described in the ovary, can also originate in the peritoneum. Characteristically they show peritoneal spread without involvement of the ovary and, if present, it corresponds to a superficial implant similar to those seen in the rest of the peritoneal cavity. Histologically they correspond to a low malignant potential tumor; they are slow growing and have good prognosis. They are common in young women, usually they present few symptoms and are frequently discovered during other surgical procedures. The treatment is surgical and it can be conservative in cases of women who want to preserve their fertility, without coadjuvant therapy. We report a 34 years old woman with a primary peritoneal serous carcinoma with low malignant potential and discuss its management.

Emittance growth during bunch compression in the CTF-II

Measurements of the beam emittance during bunch compression in the CLIC Test Facility (CTF-II) are described. The measurements were made with different beam charges and different energy correlations versus the bunch compressor settings which were varied from no compression through the point of full compression and to overcompression. Significant increases in the beam emittance were observed with the maximum emittance occurring near the point of full (maximal) compression. Finally, evaluation of possible emittance dilution mechanisms indicates that coherent synchrotron radiation was the most likely cause.

Comprehensive critical incident monitoring in a neonatal-pediatric intensive care unit: experience with the system approach

OBJECTIVE

To examine the occurrence of critical incidents (CIs) in order to improve quality of care.

DESIGN

Prospective survey.

SETTING

Multidisciplinary, neonatal-pediatric intensive care unit (ICU) of a non-university, teaching children's hospital.

PATIENTS

Four hundred and sixty-seven admissions over a 1-year period.

METHODS

A CI is any event which could have reduced, or did reduce, the safety margin for the patient. Comprehensive, anonymous, non-punitive CI monitoring was undertaken. CI severity with respect to actual patient harm was graded: major (score 3), moderate (2) or minor (1). The system approach incorporates the philosophy that errors are evidence of deficiencies in systems, not in people. We undertook 2-monthly analyses of CIs.

RESULTS

There were 211 CI reports: 30 % major, 25 % moderate, 45 % minor. The CI categories were management/environment 29 %, drugs 29 %, procedures 18 %, respiration 14 %, equipment dysfunction 7 %, nosocomial infections 3 %. The respiratory CIs were the most severe, the drug-related CIs the least severe (score mean, SD: 2.9, 0.26 vs 1.4, 0.76; p < 0.001). However, 20 out of 62 drug-related CIs were potentially life-threatening. Thirteen percent of drug CIs were decimal point errors. Eleven of the 29 respiratory CIs were accidental extubations (2.6/100 ventilator days). CIs were most often precipitated by consultants (32 %), followed by residents (23 %, over-represented in drug CIs, 22/62) and specialized nurses (21 %). Doctors had a greater proportion of major CIs than nurses (p < 0.01). Fifty percent of the CIs were detected by routine checks. The most important method of detection was patient inspection (44 %), alarms accounted for only 10 %. Contributing factors were human errors (63 %), communication failure (14 %), organizational problems (10 %), equipment dysfunction (7 %) and milieu (3 %).

CONCLUSIONS

CIs are very common in pediatric intensive care. Knowledge of them is a precious source for quality improvement through changes in the system.

Endoscopic removal of an intraorbital "tumor": a vital surprise

We present the first case report of an endoscopic removal of a living worm, species Dirofilaria repens, from the orbital cavity. As of today, over 410 cases of Dirofilaria repens infections in man are recorded in world literature, six of which were localized in the orbital cavity. In Austria we know of four cases of an infection with this parasite, but none in the orbit. Dirofilaria repens is widespread only in the Old World, particularly in Southern and Eastern Europe, in Asia Minor, and in Central and Southern Asia. The highest prevalence of the disease is recorded in Italy (181 cases). In clinical practice, the infections have mostly been misdiagnosed as a neoplasia, usually benign but sometimes malignant. Under the assumption of an intraorbital tumor, the endoscopic transnasal revision of the orbital cavity was performed, as this approach promised to be least traumatic and best suited for the lesion, resulting in complete removal of the live worm. In unclear lesions in the head and neck, and infection with Dirofilaria repens should be considered as a differential diagnosis.

Fixation technique influences osteogenesis of comminuted fractures

Comminuted fractures most often are associated with compromised soft tissue conditions and diminished vascularization leading to a reduced osteogenesis. In contrast to stable fixation by compression plating with lag screws, the less stable but also less invasive techniques of external fixation, unreamed nailing, or bridging plates have become increasingly popular. The aim of this study was to compare the bone healing and osteogenesis of these fixation techniques. A triple wedge osteotomy of the sheep tibia was used as a bone healing model. Internal compression plate fixation of all fragments with lag screws was used in one group. In the other three groups, only the main proximal and distal fragments were fixed by external fixation, unreamed interlocking nail, or bridging plate. The sheep with compression plate fixation and lag screws showed the worst results after 12 weeks. The periosteal and endosteal osteogenesis and the apparent density of the newly formed bone in the fracture gaps were significantly lower than those seen in the sheep in the other three technique groups. The best results were found for the bridging plate and external fixator. From these results, it can be concluded that compression plate fixation should be avoided for treatment of comminuted fractures.

Effects of enadoline on the development of pentylenetetrazol kindling, learning performance, and hippocampal morphology

Opioids are involved in the development of epileptic seizures. Recently, interest has been focused on the role of the kappa-opioid receptor agonists as novel approaches to the treatment of epilepsy. In the present study we investigated the effects of the kappa-opioid receptor agonist enadoline (Ena) on pentylenetetrazol (PTZ) induced seizures, PTZ kindling, shuttle-box performance and hippocampal neuromorphology. Ena injected i.c.v. in doses of 1 and 10 nmol did not affect acute PTZ seizures. In the course of PTZ kindling development, co-treatment (1 nmol) with the kappa-opioid receptor agonist suppressed seizure strength. Eight days after kindling completion the animals received a challenge dose of PTZ. In reaction to challenge, kindled animals which were pretreated with Ena reached significantly lower seizure scores. Kindling resulted in diminished shuttle-box performance. Learning performance in kindled animals pretreated with Ena was not normalised. Kindling resulted in increased glutamate binding. Interestingly, in comparison with the saline/saline group, neither in the Ena/saline nor in the Ena/PTZ treated groups changes in glutamate binding were found. That means that Ena prevented the increase in glutamate binding in the kindled group. In kindled animals significant cell loss in CA1 of the dorsal hippocampus was found and this was efficaciously counteracted by Ena. However, Ena alone did induce similar cell loss compared to kindled animals. It is hypothesised that the effects of enadoline are mainly due to interferences with glutamatergic systems.

Orbital dirofilariasis: MR findings

Dirofilariasis is a helminthic zoonosis occurring in many parts of the world. We report the findings in a 61-year-old woman who had painless right exophthalmos caused by orbital dirofilariasis. A vivid worm was embedded inside an inflammatory nodule in the right orbit. On T1-weighted MR images, the parasite was visible as a discrete, low-intensity, tubular signal in the center of the nodule surrounded by contrast-enhancing inflammatory tissue.

Oligonucleotide and plasmid DNA packaging into polyoma VP1 virus-like particles expressed in Escherichia coli

The drug delivery system described here is based on the properties of the capsoid or capsid-like structure resulting from the assembly of polyoma virus capsid protein VP1 expressed in Escherichia coli. The capsid protein VP1 was expressed as a fusion protein with a completely removable N-terminal His6 affinity tag. The pentameric morphology of the recombinant VP1 protein was confirmed by electron microscopy after affinity chromatography and factor Xa cleavage under conditions of low ionic strength. The self-assembly of VP1 capsoids can be induced from purified VP1 pentamers by increasing the ionic strength with (NH4)2SO4. These VP1 capsoid particles were packed in vitro with anti-sense oligonucleotides and plasmid DNA. The loading with DNA was pH-dependent. We observed the highest efficiency at pH 5. DNase I treatment of particles with encapsidated material showed that 37-55% of the bound oligonucleotides and fragments of 1.5-1.8 kb double-stranded DNA were protected against degradation.

Sequence peculiarity of gnetalean legumin-like seed storage proteins

The development of seeds as a specialized organ for the nutrition, protection, and dispersal of the next generation was an important step in the evolution of land plants. Seed maturation is accompanied by massive synthesis of storage compounds such as proteins, starch, and lipids. To study the processes of seed storage protein evolution we have partially sequenced storage proteins from maturing seeds of representatives from the gymnosperm genera Gnetum, Ephedra, and Welwitschia-morphologically diverse and unusual taxa that are grouped in most formal systems into the common order Gnetales. Based on partial N-terminal amino acid sequences, oligonucleotide primers were derived and used for PCR amplification and cloning of the corresponding cDNAs. We also describe the structure of the nuclear gene for legumin of Welwitschia mirabilis. This first gnetalean nuclear gene structure contains introns in only two of the four conserved positions previously characterized in other spermatophyte legumin genes. The distinct phylogenetic status of the gnetalean taxa is also reflected in a sequence peculiarity of their legumin genes. A comparative analysis of exon/intron sequences leads to the hypothesis that legumin genes from Gnetales belong to a monophyletic evolutionary branch clearly distinct from that of legumin genes of extant Ginkgoales and Coniferales as well as from all angiosperms.

Protective effects of cortistatin (CST-14) against kainate-induced neurotoxicity in rat brain

Cortistatin (CST-14) is a recently discovered endogenous peptide which shares similarity to somatostatin and binds to somatostatin receptors. In this study, we show that CST-14 exhibits anticonvulsive and neuroprotective effects in rats. Injection of rats with kainic acid (KA; 10 mg/kg; i.p.) generated a strong seizure activity which was attenuated by the i.c.v. application of 1 and 10 nmol CST-14 when given 10 min before KA. Moreover, 3 days after KA injection, a marked loss of neurons in cortex and hippocampus of rats was observed which was inhibited by pretreatment with CST-14. An immunohistochemical analysis using specific antibodies revealed that KA reduced immunoactive sst2A and sst3 somatostatin receptors in the hippocampus-an effect which was largely prevented by pretreatment with CST-14. Superfusion of hippocampal slices with CST-14 also reduced the stimulated release of 3H-d-aspartate. We conclude that CST-14 exerts neuroprotective effects by binding to somatostatin receptors which in turn leads to a reduced release of excitotoxic neurotransmitters.

Combinatorial action of HNF3 and Sp family transcription factors in the activation of the rabbit uteroglobin/CC10 promoter

It has been reported that respiratory epithelium-specific transcription is mediated by thyroid transcription factor 1 and members of the HNF3/forkhead family of transcription factors. Here, we show that the uteroglobin/Clara cell 10-kDa promoters from rabbit and man are regulated by HNF3alpha and HNF3beta but not by HFH-4 and TTF-1. We have identified two HNF3-responsive elements in the rabbit uteroglobin/CC10 promoter located around 95 and 130 base pairs upstream of the transcriptional start site. Both elements contribute to promoter activity in H441 cells expressing uteroglobin/CC10 and HNF3alpha. Gene transfer experiments into Drosophila Schneider cells that lack many mammalian transcription factor homologs revealed that HNF3alpha and HNF3beta on their own cannot activate the uteroglobin/CC10 promoter. However, HNF3alpha and HNF3beta strongly enhanced Sp1-mediated promoter activation. Synergistic activation by HNF3alpha and Sp1 was absolutely dependent on the integrity of two Sp1 sites located at around -65 and -230. We show further that multiple activation domains of Sp1 are required for cooperativity with HNF3alpha. These studies demonstrate that transcription from the rabbit uteroglobin/CC10 promoter in lung epithelium is controlled by the combinatorial action of the cell-specific factor HNF3alpha and the ubiquitous factor Sp1.

A gene encoding a vicilin-like protein is specifically expressed in fern spores. Evolutionary pathway of seed storage globulins

The isolation and characterisation of a cDNA coding for a vicilin-like protein of the fern Matteuccia struthiopteris is described. The corresponding gene is specifically expressed during late stages of spore development. Extensive sequence comparisons suggest that the fern protein can be considered as a molecular missing link between single-domain germin/spherulin-like proteins and two-domain seed storage globulins of gymnosperms and angiosperms. Further, evidence is provided for the existence of a superfamily of structurally related, functionally different proteins which includes storage globulins of the vicilin and legumin families, a membrane-associated sucrose-binding protein of soybean, a Forssman antigen-binding lectin of velvet bean, the precursor of the vacuolar membrane bound proteins MP27/MP32 of pumpkin, the embryogenesis-specific protein Gea8 of carrot, the fern-spore-specific protein described here as well as the functionally diverse family of germins/germin-like proteins and the spherulins of myxomycetes. We propose that seed storage globulins of spermatophytes evolved from desiccation-related single-domain proteins of prokaryotes via a duplicated two-domain ancestor that is best represented by the extant fern spore-specific vicilin-like protein.

Lateral neck cysts--the branchial theory revisited. A critical review and clinicopathological study of 97 cases with special emphasis on cytokeratin expression

Theories regarding the origin of lateral neck cysts (LNC) range from congenital branchial pouch abnormalities to acquired salivary gland inclusions within lymph nodes. We analyzed 97 LNC histologically and evaluated their cytokeratin (CK) profile in a search for their derivation. 77/97 LNC were located in soft tissues, 20/97 within lymph nodes. LNC of young patients and of recent symptomatic presentation in older patients were lined by respiratory epithelium with scant lymphoid tissue, with expression of "simple epithelial" CK in ciliated cells and bimodal expression of "simple" and "stratified-epithelial-type" CK in basal cells. In longer standing symptomatic LNC, respiratory epithelium alternated with transitional-type pseudostratified epithelium with intraepithelial Langerhans cells and lymphoid hyperplasia, or consisted exclusively of squamous epithelium. We propose that respiratory epithelium is the "native" epithelium of LNC and squamous metaplasia results from inflammation induced stem cell hyperplasia in respiratory epithelium, evidenced by co-expression of "simple" and "stratified-epithelial-type" CK in all cells of transitional-type pseudostratified epithelium, the early stage in metaplastic transformation. Respiratory epithelium predominates in early LNC, lines pharyngeal tonsils and the recessus tonsillo-tubalis, and is a minor constituent of palatine tonsil but is not present in salivary glands. None of the LNC contained dysplasia, atypia, or carcinoma, or were associated with a primary carcinoma of tonsils or head and neck. We demonstrate that LNC arise from developmental remnants (congenital) of the 2nd branchial pouch, which may lie dormant for many years. Symptomatic enlargement, squamous metaplasia and lymphoid hyperplasia ensue as a consequence of immunologic stimulation a development reflected in hyperplastic palatine tonsils.

[Fine needle capillary cytology versus fine needle aspiration cytology--a comparison of quality between puncture techniques in the ENT area]

BACKGROUND

Needle aspiration is currently a widely used technique in the diagnosis of unclear lesions in the head and neck region. We present a modified technique of fine needle biopsy in ENT, "fine needle capillary technique". The basics of this technique were developed by Zajdela and coworkers (1987) as a cytological method of fine needle biopsy in benign and malignant mammary tumors. Fine needle capillary technique does not require aspiration of cell samples via negative pressure created by a syringe. A thin 25 G needle (outer diameter 0.50 mm, length 25 mm) is introduced into the lesion with one hand. The cells are detached by the cutting edge of the needle and are conducted into the lumen by capillary force. The needle is removed and the cellular material is expelled onto a glass slide, spread, and immediately fixed.

METHOD

In a series of 166 patients with unclear lesions in the head and neck region, we compared the fine needle capillary technique with the classic fine needle aspiration technique in each patient. Regarding quality and assessment of the cytological smear the fine needle capillary technique proved clearly superior in most of the cases. Lymph nodes, tumors of the salivary glands, thyroid glands, branchiogenic cysts, one atheroma, one lipoma, and one skin metastasis of a squamous cell carcinoma were punctured.

RESULTS

In our study fine needle capillary technique showed a very good quality of the cytological smear in 24.7% of all cases, while fine needle aspiration technique reached 12.1% only. A good quality was obtained in 51.2% with fine needle capillary technique and in 51.8% with fine needle aspiration technique, poor quality in 24.1% with fine needle capillary technique and in 36.1% with fine needle aspiration technique. Nondiagnostic cytology was obtained in 21.7% with fine needle capillary technique and in 32.5% with fine needle aspiration technique. Both techniques together showed insufficient material in 10.8%. The quality of the cytological smear in each region was always better with fine needle capillary techniques than with fine needle aspiration technique except five punctures of the submandibular gland. Of 166 patients 113 (68.1%) underwent surgery, and a correlation of the cytologic report to the surgical specimen showed agreement in 95.7% with fine needle capillary technique and in 90.5% with fine needle aspiration technique. In 17.7% with fine needle capillary technique and in 25.7% with fine needle aspiration technique it was not possible to compare the cytological smear with the histological results because of poor quality of the cytological smear. In four cases (4.3%) with fine needle capillary technique the cytological diagnosis was wrong. With fine needle aspiration technique, a wrong diagnosis occurred eight cases (9.5%).

CONCLUSIONS

Fine needle capillary technique offers several advantages. Without aspiration trauma to cells and tissues is reduced. Less blood in the samples results in higher quality of the cytological smear. These circumstances make it easier for the pathologist to comment the cytological findings. The handling of the needle is practiced with a wrist movement and not from the shoulder joint as in aspiration method using the Cameco syringe holder. This allows for a more sensitive puncture technique touching the lesion during sampling with the finger tips. The puncture causes less pain than the aspiration technique. Our results demonstrate that fine needle capillary technique is the better method of fine needle biopsy in the head and neck region.

[Sarcoidosis of the paranasal sinuses as the etiology of therapy refractory dacryocystitis]

BACKGROUND

Sarcoidosis is a chronic systemic disease of unknown etiology characterized by non-caseating granulomatous inflammation of various organs. The clinical findings when nasal mucosa is involved include nasal crusting, epistaxis, pain and/or anosmia, nasal polyps, or submucosal nodularity.

CASE REPORT

We describe a case of sarcoidosis of the paranasal sinuses. In a 33-year-old man, the first symptom was therapy resistant putrid dacryocystitis. Further there had been symptoms of chronic sinusitis. A CT scan revealed swelling of the mucosa in the anterior ethmoid, frontal recess, and maxillary sinus. As the disease obviously affected the region of the nasolacrimal duct with consecutive stenosis of this canal, we opted for endoscopic sinus surgery. A few days after this endoscopic procedure, the dacryocystitis had healed.

RESULTS

The histopathological examination showed the typical picture of sarcoidosis that had its primary manifestation in the paranasal sinuses. According to these findings further explanation of the patient was necessary. The diagnosis of sarcoidosis was confirmed by lavage and biopsy material of bronchoscopically suspect lung areas. Consequently, the patient underwent a long-term corticoid therapy and today, 10 months after the surgical intervention, the patient is free of symptoms. Follow-up endoscopy of the paranasal sinuses showed no further pathological findings.

CONCLUSION

Our case demonstrates that the first manifestation of sarcoidosis can be in the paranasal sinuses.

[Sucking and drinking behavior as criteria of vitality in newborn calves]

Newborn dairy calves (n = 82) were investigated for relations between frequency and intensity of sucking movements at the one hand and course of parturition, values of a modified Apgar-Score, time between birth and first standing as well as parameters in the blood (lactate, glucose, immunoglobulins, pH, base excess, pCO2) and the incidence of newborn diseases at the other hand. In another group 101 dairy and 533 crossbred calves (dairy x beef) were compared with regard to the course of parturition, vitality, sucking behaviour and the ability to stand and drink without help 12 hours post natum. Sucking behaviour can be recommended as a criterion of vitality alone or as part of a modified Apgar-Score. A frequency of 80 and more intensive sucking movements/min sucking time and the ability to stand and drink without human help within 12 hours post natum are physiological. In milk x beef crossbred calves this ability can be impaired even in cases of normal birth.

[Therapy of nocturnal asthma: salmeterol versus nocturnal administration of retard theophylline--comparison of effectiveness and tolerance]

The aim of the present study was to compare the efficacy and the tolerability of salmeterol and theophylline in patients with nocturnal asthma. 16 patients were entered into a randomized, double-blind, crossover trial. Using a double-dummy technique, salmeterol (50 micrograms b.i.d. by MDI) or theophylline (Uniphyllin; 600 mg nocte orally) were given for periods of 7 days with a wash-out period of 7 days between treatment periods. With salmeterol the number of nights with an overnight fall in peak expiratory peak flow rate (PEFR) of at least 20% was reduced by about 20% compared to about 10% with theophyllin (p < 0.05 for the difference between salmeterol and theophylline). With respect to nocturnal symptoms 62.6% of the patients had rare or non symptoms without and 84.7% with salmeterol, compared to 46.5% without and 67.3% with theophylline (p < 0.05). With respect to the improvement of early morning symptoms, the increase of nights with none or rare symptoms was 46.2% with salmeterol compared to 25.8% with theophylline. The overall parameter of efficacy defined as a) the number of nights with an overnight fall in PEFR or less than 20% als well as b) none or rare nocturnal symptoms and c) none or rare early morning symptoms increased from 23.4% at baseline to 75.1% during treatment with salmeterol compared to an increase from 24.5% at baseline with 54.8% during treatment with theophylline (p < 0.05). 12 patients preferred salmeterol over theophylline (p < 0.05). 3 patients had gastrointestinal disturbances during theophylline treatment. It can be concluded that both salmeterol and theophylline are effective in the treatment of nocturnal asthma. With respect to the overall efficacy and the tolerability salmeterol is superior to theophylline.

Kinetic evidence for protein complexes between thioredoxin and NADP-malate dehydrogenase and presence of a thioredoxin binding site at the N-terminus of the enzyme

The kinetics of activation of NADP-malate dehydrogenase (MDH; EC 1.1.1.82) from soybean and spinach leaves by the chloroplast thioredoxins isolated from the same plants, by the corresponding storage forms of the soybean chloroplast thioredoxins from soybean seeds, and by the bacterial Escherichia coli thioredoxin have been studied. The Hill equation has been applied to evaluate the saturation kinetics. The observed variable thioredoxin saturation characteristics (Vmax 0.37-14.5 mumol NADPH min-1 mg enzyme-1; K0.5 0.15-1.33 microM; Hill coefficient h 0.90-3.04) indicate that the activation of NADP-MDH depends strongly on the individual thioredoxin used. Thus, thioredoxin action is not solely due to simple reductive activation of the NADP-MDH. Specific thioredoxin complex formation between thioredoxin and NADP-MDH must be included into the mechanism of the activation process. To study the regulatory consequences of the specific thioredoxin/NADP-MDH complexes we investigated the saturation kinetics of the substrates NADPH and oxaloacetate in presence of different concentrations of each individual thioredoxin species. The kinetic characteristics of the substrates (S0.5, Vmax, and Hill coefficients h) varied individually in response to the different thioredoxin species substantiating our model of thioredoxin/ NADP-MDH complex formation. Aminopeptidase-K-truncated pea NADP-MDH has been used to demonstrate that the N-terminal 37 amino residues are involved in providing a specific thioredoxin binding site. The fact that the versatile light-dependent regulation of numerous enzyme activities by only two thioredoxin species in chloroplasts cannot be accomplished without the formation of thioredoxin/target enzyme complexes is discussed in detail.

A vicilin-like seed protein of cycads: similarity to sucrose-binding proteins

Seed storage globulins of the 7S and 11S type are synthesized in the seeds of angiosperms and gymnosperms. We have isolated and characterized a vicilin-like gene expressed in the cycad Zamia furfuraceae. Sequence comparisons reveal clear similarities to a sucrose-binding protein isolated from soybean. We suggest the existence of a superfamily of related genes including both vicilin-like and legumin-like seed globulin genes as well as genes coding for spherulins, germins and sucrose-binding-proteins.

Ultrafast computed tomography and three-dimensional image processing of CT sialography in patients with parotid masses poorly defined by magnetic resonance imaging

The purpose of this study was to determine the efficacy of ultrafast computed tomography (UF CT) in patients with parotid masses poorly defined by magnetic resonance imaging (MRI) and to evaluate the diagnostic potential of three-dimensional (3-D) UF CT sialography when compared with conventional CT sialograms. Thirteen patients with clinical suspicion of a parotid mass, in whom MRI was degraded by motion, underwent UF CT of the parotid region. Two radiologists independently assessed the CT and MR with respect to tumor localization, intraglandular tumor location, tumor margin characteristics, and infiltration of surrounding tissue. In 9 patients, CT sialography was performed using 3-D image processing. Anatomical details and pathologic findings were assessed by three readers using a numerical grad and compared with the findings derived from conventional CT sialography. Histopathologic specimens were obtained in all cases and correlated with the radiographic findings in a consensus manner following the blinded interpretations. UF CT and (suboptimal) MRI provided the same diagnostic information for the evaluation of tumor localization, and intraglandular location. UF CT was superior to MRI in the detection of tumor infiltration, and definition of tumor margins in 2 cases (15%), resulting in a substantial difference in treatment. Three-dimensional CT sialography offered significant improvement in demonstration of anatomic detail (2.5 +/- 0.2 vs 1.5 +/- 0.1, respectively) and pathologic findings (2.6 +/- 0.1 vs 1.3 +/- 0.2, respectively) when compared with conventional CT sialography. UF CT is a viable alternative in uncooperative patients with parotid masses. UF CT 3-D sialography has the potential to allow more precise pre-surgical planning and contributes to the diagnosis and therapy planning of parotid masses.