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Biomedical subjects

M Zimmermann

Publications and source records attributed to M Zimmermann.

At least 217 records · Page 12Linked to original sources

Prevention of delayed ischaemic deficits after aneurysmal subarachnoid haemorrhage by intrathecal bolus injection of tissue plasminogen activator (rTPA). A prospective study.

Among a series of 224 patients with aneurysmal subarachnoid haemorrhage (SAH) admitted over a period of three years, 52 patients were prospectively treated with intrathecal tissue plasminogen activator (rTPA). All of these patients were admitted and operated on within 72 h after SAH. SAH was confirmed by CT scan and the volume of blood accumulated in the basal cisterns was graded according to Fisher's scale. All patients had a SAH according to Fisher's grade III, as a prerequisite for inclusion into the study. In 21 patients additional intraventricular bleeding was detectable on CT scan. The diagnosis of a single intracerebral aneurysm as the bleeding source was established by pan-angiography, which also excluded additional cerebro-vascular malformations. The control group consisted of 68 patients, which were also treated within 72 h after SAH. Age and sex distribution as well as the clinical patterns were comparable to the rTPA group. In all patients the aneurysm was clipped using standard microsurgical techniques. After the aneurysm had been excluded from the parent vessel, 10 mg of rTPA, dissolved in 10 ml of its solution fluid, were slowly instilled into the basal cisterns in the treatment group. In patients with additional severe intraventricular bleeding, 5-10 mg of rTPA were injected into the ventricles via an intraventricular catheter at the end of the operation. Apart from the intrathecal application of the thrombolytic substance, the surgical protocol was identical in the patients of the control group. During the postoperative period, the patients in both groups were examined neurologically and by transcranial Doppler on a daily basis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Microsurgery of the cervical spine in elderly patients. Part 1: Surgery of degenerative disease.

The results of microsurgery for degenerative disease of the cervical spine are reported in 84 consecutive patients being 65 years of age or older at the time of surgery. Patients were suffering from either soft or hard disc disease or from advanced forms of cervical myelopathy. In 60 patients microsurgical resection of the involved cervical disc and posterior osteophytes was performed followed by anterior fusion. Spondylectomy, microsurgical decompression and osteosynthesis was performed in 24 patients with multi-level cervical stenosis. A multitude of accompanying systemic diseases was present in almost all patients. Evaluation of the peri-operative risk profile of the patients was performed using the American Society of Anesthesiology (ASA) Grading of Physical Status Score. In 82 patients a complete follow-up was available. Two patients died within seven days after surgery from heart attack and pulmonary embolism. Three patients died during the observation period from causes unrelated to their cervical disease or to surgery. Overall surgical results were as follows: 66 patients (79%) were improved by surgery, 14 patients (17%) were unchanged, two patients (2%) became worse, and two patients (2%) died. Postoperative recovery was significantly correlated to the pre-operative neurological status. Neither age, nor the pre-operative ASA score had a significant influence on the postoperative outcome. The incidence of peri-operative systemic complications was significantly correlated to the pre-operative physical status of the patients according to the ASA score. No significant correlation towards an increase of peri-operative complications with higher grades of pre-operative neurological deficits or with increasing age of the patients could be found.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Microsurgery of the cervical spine in elderly patients. Part 2: Surgery of malignant tumourous disease.

In this retrospective study, the results of surgery were examined in 25 patients, 65 years of age or older, suffering from malignant tumour growth along the cervical spine. The group consisted of 17 men and 8 women. The mean age was 73 years, ranging from 66 to 88 years. The pathology identified was metastasis in 23 patients, and plasmocytoma in two. The tumour localization involved a single segment of the cervical spine in 12 patients, two segments in 8 patients, three segments in 4 patients, and four segments in one patient. Pre-operatively, 8 patients (32%) suffered solely from severe pain. 6 patients (24%) showed severe pain and radicular nerve compression. 5 patients (20%) had incomplete para- or tetraparesis but were able to walk, and again 6 patients (24%) had incomplete para- or tetraparesis, and were unable to walk. A multitude of accompanying systemic diseases was present in the majority of patients. Evaluation of the peri-operative risk profile was performed using the American Society of Anaesthesiology (ASA) Grading of Physical Status Score. Operation consisted of microsurgical tumour removal, usually incorporating a single- or multi-level vertebrectomy, with radical epidural decompression, and grafting with bone cement followed by an appropriate osteosynthesis. Of the whole cohort of patients treated, four patients were still alive at the time of the last follow-up evaluation. 21 patients died. Four patients died within seven days after surgery. The remaining 17 patients died during the follow-up period. All of these patients died from systemic spread of their primary cancer.(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗

Expression of nitric oxide synthase and colocalisation with Jun, Fos and Krox transcription factors in spinal cord neurons following noxious stimulation of the rat hindpaw.

Expression of nitric oxide synthase (NOS) was investigated in neurons of lumbar spinal cord of adult rats following subcutaneous injection of formalin (FOR) in one hindpaw. NOS was visualized immunocytochemically using a specific antibody and by the NADPH-diaphorase reaction (NDP). In the untreated rat, NOS immunoreactivity (IR) and NDP were present in neurons of the superficial dorsal horn (sDH) predominantly in layers II-III, and in the deep dorsal horn (dDH) predominantly in layer X. Twenty-four hours following FOR, the numbers of neurons labelled for NOS and NDP and the density of NDP containing nerve fiber varicosities significantly increased in sDH of the ipsilateral L3-L4 segments. NOS-IR and NDP gave a rather congruent distribution of labelled neurons in the dorsal horn. In contrast, distinct NOS-IR but not NDP was visible in large diameter motoneurons and in the lateral spinal nucleus. Double labelling demonstrated that in sDH most of the NDP-reactive neurons show a close spatial relationship to fibers and varicosities immunoreactive for substance P and CGRP. These neuropeptides are considered mediators of synaptic input from nociceptive primary afferents. Colocalization of NDP with c-Jun, JunB, JunD, c-Fos, FosB and Krox-24 transcription factors was investigated in neurons of lumbar spinal cord. c-Jun, JunB, c-Fos and Krox-24 reached their maximal levels of expression 2 h after FOR and returned to basal levels after 10 h. FosB and JunD reached their maximal expression after 5 h, persisted up to 10 h and were still visible in 60%-70% of the maximal number of labelled nuclei after 24 h. This persistent expression of transcription factors might contribute to the up-regulation of NOS expression between 10 h and 24 h. In a low number of NDP neurons, suprabasal immunoreactivity of JunB, c-Fos and Krox-24 proteins was visible up to 10 h, and of JunD and FosB up to 24 h in sDH neurons; c-Jun was not expressed in NDP labelled neurons of sDH, but, similar as JunD, showed basal colocalization in preganglionic sympathetic and parasympathetic neurons. In dDH, colocalization of Jun, Fos and Krox-24 proteins in few neurons was only observed following a second FOR stimulus given 24 h after the first one. Double-staining also demonstrated that many Jun, Fos and Krox labelled neurons are in close proximity to NDP labelled nerve fibers suggesting a functional relationship between expression of immediate-early gene encoded transcription factors and presence of nitric oxide in the rat spinal cord.

Amino Acid Oxidoreductases↗

Application of morphine prior to noxious stimulation differentially modulates expression of Fos, Jun and Krox-24 proteins in rat spinal cord neurons.

The expression of Fos, Jun and Krox-24 proteins was investigated in spinal cord neurons of the rat 2, 4 and 8 h following noxious thermal stimulation of one hind-paw and pre-treatment with morphine. The number of neurons expressing c-Fos, c-Jun, Jun B and Krox-24 were maximal after 2 h and thereafter declined. The number of Fos B and Jun D immunoreactive neurons increased constantly for up to 8 h with Jun D showing expression above baseline only after 4 h following stimulation. Intravenous application of morphine (5 and 10 mg/kg) 20 min before noxious heat stimulation decreased the expression of all six proteins at any time-point with a predilective effect on neurons of deeper laminae of the dorsal horn. The suppressive effects of morphine were more pronounced with the higher dose of morphine and completely reversed by intravenous naloxone (1 and 10 mg/kg). The temporospatial patterns of expression following morphine were similar to those seen without morphine, but in a much smaller number of neurons and with a shorter time-course. However, despite the high dose of morphine and continuous halothane anaesthesia during the whole experimental procedures, a considerable number of neurons expressing the various genes remained in all laminae of the spinal cord. At 2 h following noxious heat stimulation morphine had decreased the number of labelled neurons for c-Fos, Fos B, Krox-24, c-Jun and Jun B to 30-60% of control levels in laminae I-II and to 10-30% in laminae III-VII,X of the spinal cord. At 4 h the level of reduction had further increased while Jun D was only moderately reduced to 75% in all laminae of the spinal cord. Eight hours following noxious heat plus morphine application we did not detect noxious evoked immunoreactivity for c-Fos, Krox-24, c-Jun and Jun B, while there was residual labelling for Fos B in the superficial dorsal horn and for Jun D in laminae I-VII and X of the spinal cord. The different temporospatial pattern of immediate early gene expression in neurons of the spinal cord dorsal horn following noxious stimulation suggest that variable transcription complexes may interact with DNA regulatory sequences and could thus activate alternative secondary response genes, even under protection of a high dosage of morphine applied before noxious stimulation.

Animals↗

The role of initial laparotomy and second-look surgery in the treatment of abdominal B-cell non-Hodgkin's lymphoma of childhood. A report of the BFM Group.

The aim of this study was to determine the role of surgery in the treatment of abdominal B-cell non-Hodgkin's lymphomas (B-NHL) in children. We analyzed the effect of surgical variables of initial laparotomy and second-look surgery on event-free survival (EFS) of 177 patients with abdominal B-NHL enrolled into the three consecutive multicenter trials NHL-BFM 81, NHL-BFM 83, and NHL-BFM 86. The therapy regimen was comparable in all 3 trials as well as the overall outcome of the patients. Patients with stage II and complete resection received 3 courses of therapy (4 in trial NHL-BFM 81), patients with stage II not resected, stage III, and stage IV received 6 courses of therapy (8 in trial NHL-BFM 81). An initial laparotomy was performed in 161 patients, in 59 of them as an urgent procedure. Complete resection of the abdominal primary was performed in 43 patients, 40 of them had a localized bowel tumor. The probability of EFS (pEFS) at 5 years is 95%, 69%, 62%, and 67% for patients with complete resection, subtotal resection (n = 36), partial resection (n = 21), or biopsy only (n = 61), respectively. Complete resection was achieved in 30 out of 40 patients with stage II, but only in 12 of 113 and 1 of 24 patients with stage III and IV, respectively. pEFS at 5 years according to stage and completeness of resection is as follows: stage II complete resected 97%; stage II not complete resected 100%; stage III/IV complete resected 92%; stage III/IV not complete resected 63%.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Neoplasms↗

The role of elastic recoil after balloon angioplasty of rabbit arteries and its prevention by stent implantation.

Elastic recoil, neointima formation and vessel narrowing after balloon angioplasty or stent implantation were compared in 17 non-atherosclerotic New Zealand White rabbits. The implantation of a balloon-expandable Palmaz-Schatz stent was performed in one iliac artery and a balloon angioplasty alone was performed in the contralateral artery (n = 34 arteries). Quantitative histomorphometry was performed by a computer-assisted analysis 1 h and 4, 10 and 24 weeks after the initial procedure. The histological appearance of the neointima was similar to that of human restenosis. The amount of the neointima was increased within stented vessels as compared to balloon angioplasty alone (1.0 +/- 0.1 vs 0.4 +/- 0.1 mm2 at 4 weeks, P < 0.001). However, the neointimal lumen narrowing was smaller in the stented vessels due to persistent increase in vessel perimeter as compared to balloon angioplasty alone (16.5 +/- 0.9 vs 34.7 +/- 16.5% lumen narrowing at 4 weeks, P < 0.05). In conclusion, stent implantation enhances neointima formation as compared to angioplasty in non-atherosclerotic rabbits. The prevention of elastic recoil after stent implantation, however, reduces the neointimal lumen narrowing. This study supports clinical observations demonstrating lower restenosis rates after stent implantation compared to standard balloon angioplasty.

Angioplasty, Balloon, Coronary↗

Immunogenicity of polysaccharides conjugated to peptides containing T- and B-cell epitopes.

To develop a general model of polysaccharide-peptide vaccine, we have investigated the efficiency of linear peptides derived from protein SR, and adhesin of the I/II protein antigen family of oral streptococci, to act as carriers for two T cell-independent polysaccharides: serogroup f polysaccharide from Streptococcus mutans OMZ 175 (poly f) and Saccharomyces cerevisiae mannan. Peptide 3 (YEKEPTPPTRTPDQ) and peptide 6 (TPEDPTDPTDPQDPSS), accessible on the native SR protein as demonstrated by their reactivity in enzyme-linked immunosorbent assays with rat antisera raised against protein SR, correspond to immunodominant regions of SR. Peptide 3 contains at least one B- and one T-cell epitope, as demonstrated by its ability to induce peptide- and SR-specific antibody responses without any carrier and to stimulate the proliferation of rat lymph node cells primed either with free peptide or native SR, whereas peptide 6 contains only B-cell epitope(s). Peptide 3 was then covalently coupled though reductive amination to either poly f or mannan, and peptide 6 was coupled to poly f. Subcutaneous immunizations of rats with poly f-peptide 3 or mannan-peptide 3 conjugates produced a systemic immunoglobulin M (IgM) and IgG antibody response, and the elicited antibodies reacted with free poly f or mannan, peptide 3, protein SR, and S. mutans or S. cerevisiae whole cells. Rats immunized with poly f-peptide 6 did not develop any antipeptide or anti-SR response. Furthermore, a booster immunization of animals with poly f-peptide 3 or mannan-peptide 3 conjugates induced high titers of anti-peptide 3, anti-poly f, and antimannan antibodies, which occurred quickly. The response is anamnestic for the peptide and the polysaccharides and is characterized by an Ig switch from IgM to IgG. The data presented here confirm that the presence of B- and T-cell epitopes is necessary to induce an anamnestic antipeptide response and that a peptide containing relevant B- and T-cell epitopes can act as a good carrier in improving an antipolysaccharide anamnestic immune response.

Amino Acid Sequence↗

Ventricular late potentials and spontaneous ventricular arrhythmias after surgical repair of tetralogy of Fallot: do they have prognostic value?

OBJECTIVE: To determine the prognostic significance of ventricular late potentials and spontaneous ventricular arrhythmias detected early after surgical repair of tetralogy of Fallot. DESIGN: Prospective observational. SETTING: Cardiology department of a teaching hospital. METHODS: Between June 1984 and June 1991, 104 children (63 boys, 41 girls) were studied by signal averaging and 24 hour ambulatory monitoring after surgical repair of tetralogy of Fallot. Mean (SD) age at operation was 6 (3) years, mean interval between operation and evaluation was 8 (25) months, and the follow up after evaluation was one to 88 (mean 30) months. RESULTS: Ventricular late potentials were detected in 24/104 patients (23%) and spontaneous ventricular arrhythmias in 39/96 patients (38%); usually (in 81%) these were unifocal and rare. Patients with ventricular late potentials were older at operation than patients without late potentials (9 (3) v 6 (3) years, P = 0.002). No correlation was found between the presence of ventricular late potentials and the presence or complexity of spontaneous ventricular arrhythmias early after operation. During the mean follow up of 2.5 years no case of sudden death or sustained ventricular tachycardia was found. CONCLUSION: Short-term prognosis after surgical repair of tetralogy of Fallot is good; ventricular late potentials and spontaneous ventricular arrhythmias are often detected shortly after operation, but in the medium term follow up they do not predict sudden death or serious ventricular arrhythmias.

Adolescent↗

Successful treatment strategy for Ki-1 anaplastic large-cell lymphoma of childhood: a prospective analysis of 62 patients enrolled in three consecutive Berlin-Frankfurt-Munster group studies.

PURPOSE: To prove prospectively the efficacy of a short-pulse chemotherapy for treatment of Ki-1 anaplastic large-cell lymphoma (ALCL) of childhood. PATIENTS AND METHODS: From October 1983 to December 1992, 62 patients (median age, 9.7 years) with newly diagnosed Ki-1 ALCL were enrolled onto Non-Hodgkin's Lymphoma-Berlin-Frankfurt-Munster (NHL-BFM) studies 83, 86, and 90. The most frequent immunophenotype was T cell. Ki-1 ALCL differed from other subsets of NHL of childhood by the more frequent involvement of bone, soft tissue, and skin, and by the lack of bone marrow (BM) disease. A 5-day prephase course (prednisone/cyclophosphamide) was followed by two different 5-day courses of chemotherapy: course A consisted of dexamethasone, methotrexate (MTX) 0.5 g/m2 (24-hour infusion), intrathecal chemotherapy, ifosfamide, cytarabine (Ara-C), and etoposide (VP-16); course B consisted of cyclophosphamide and doxorubicin instead of ifosfamide, and Ara-C/VP-16, respectively. Treatment was stratified into three branches. Branch 1 (stage I and stage II resected) received three courses; branch 2 (stage II not resected, stage III), six courses; and branch 3 (stage IV), six intensified courses containing MTX 5 g/m2, and Ara-C 2 g/m2. Local radiotherapy was not performed. RESULTS: Four patients failed to enter remission, and one died of infection. Seven patients relapsed within 9 months after diagnosis; two patients had isolated local relapses, but BM and CNS were never involved. Fifty patients have been in first continuous complete remission (CR) for 0.6 to 9.7 years (median, 2.5), and 56 are alive. The probabilities for survival and event-free survival (EFS) at 9 years are 83% +/- 7% (SE) and 81% +/- 5%. Skin involvement was the only negative prognostic parameter. CONCLUSION: Short-pulse chemotherapy over 2 to 5 months without local therapy modalities is effective in the treatment of Ki-1 ALCL.

Adolescent↗

Differential regulation of c-fos, fosB, c-jun, junB, bcl-2 and bax expression in rat skin following single or chronic ultraviolet irradiation and in vivo modulation by antisense oligodeoxynucleotide superfusion.

Single ultraviolet (u.v.) irradiation of mammalian cells in culture evokes the transcriptional activation of various proto-oncogenes, among them members of the fos/jun family which are known to play an important role in cell proliferation and differentiation. u.v. exposure of mammalian skin results in growth arrest and cell death followed by hyperproliferation of epidermal cells. To obtain information in vivo about a possible relationship between u.v.-induced proto-oncogene expression and cellular alterations, we have analysed the expression of c-fos, fosB, c-jun, junB, bcl-2 and bax in rat epidermis after single and chronic u.v. irradiation. We present data demonstrating that the transcripts of these genes are constitutively expressed in the epidermis and that expression is differentially modulated by u.v. exposure. Single u.v. irradiation causes a rapid and sustained increase in c-jun, junB and c-fos mRNA and a decline in bcl-2 transcripts, whereas expression of bax remained unchanged. c-Fos and c-Jun immunoreactivity was localized throughout the epidermal cell layers 1.5 h after single irradiation, but restricted to basal cells at 48 h suggesting an involvement in both u.v.-induced apoptosis and hyperproliferation. 48 h after chronic exposure a significantly higher induction and a totally different pattern of epidermal proto-oncogene expression was detectable which may be associated with malignancy. Superfusion of rat skin with c-fos antisense oligodeoxynucleotides inhibited the increase in c-Fos immunolabeled epidermal cells 1.5 h after single u.v. irradiation demonstrating that antisense oligodeoxynucleotides are capable of penetrating mammalian skin and modulating the u.v. response in vivo. However, suppression of the early c-Fos activation did not significantly affect the formation of sunburn cells in the u.v.-exposed epidermis. Thus, c-Fos does not seem to play a major role in u.v.-induced apoptosis or other members of the fos/jun family may compensate for a loss in c-Fos.

Animals↗

[Malignant hyperthermia in swine during isoflurane anesthesia].

A case of porcine malignant hyperthermia (MH) is reported, which occurred during a cardiological animal experiment under general anaesthesia using isoflurane as inhalational anaesthetic. Initially, tachycardia (238 bpm) and a sudden increase of end-exspiratory pCO2 were noticed. Discontinuation of isoflurane followed by administration of dantrolene (7 mg/kg body weight) led to a rapid recovery. Two days later, no difference in clinical state was apparent in comparison with the remaining swine. After regular euthanasia, acute muscle necrosis was seen macroscopically in back and glutaeal muscles, which was confirmed by histological examination. The rise of end-tidal pCO2 was the striking symptom thus allowing the detection of the incipient malignant hyperthermia. Early onset of dantrolene therapy is shown to be sufficient in termination of this hyperacute complication, and may prevent its deleterious outcome. Therefore, the administration of dantrolene should be taken into account in case of porcine MH, especially in time-consuming and costly series of animal experiments.

Anesthesia, Inhalation↗

[Role of transesophageal echocardiography in the diagnosis of cardiac disorders].

Transesophageal echocardiography provides a new window for ultrasound examination of the heart. The approach allows ultrasonic access to the heart in patients with transthoracic images of inadequate quality. Furthermore, transesophageal examination may provide information additional to that from the conventional transthoracic approach in the search for lesions including complications of endocarditis, mitral prosthesis dysfunction, aortic dissection, embolism of cardiac origin and selected cardiac malformations.

Echocardiography, Transesophageal↗

JUN, FOS, KROX, and CREB transcription factor proteins in the rat cortex: basal expression and induction by spreading depression and epileptic seizures.

The expression of the nuclear c-JUN, JUN B, JUN D, c-FOS, FOS B, KROX-24, and CREB transcription factors was investigated in the cortex of adult rats by immunocytochemistry. The expression patterns were studied in untreated rats and up to 24 hours following topical application of 1 M KCl to the cortical surface (KCl) or i.v. injection of bicuculline (BIC). Topical KCl induced cortical spreading depression and systemic injection of bicuculline evoked generalized tonic-clonic seizures. In untreated rats, JUN B, c-FOS, and FOS B were expressed in a small number of neurons in the piriform, perirhinal, entorhinal, and insular cortex and in layers II, III, and VI of all neocortical areas. In contrast, c-JUN, JUN D, and KROX-24 were expressed in all cortical layers but with different intensities of immunoreactivity (IR): c-JUN-IR was generally weak and predominantly present in layers II, III, and VI. JUN D-IR was equally strong in all layers. KROX-24 showed a prominent expression in layers II, IV, and VI. The CREB protein exhibited a slight preponderance in layer II and piriform cortex. Following KCl or BIC, a strong induction was seen for c-FOS, JUN B, and KROX-24, whereas c-JUN, JUN D, and FOS B showed only a moderate increase compared to basal levels. Changes of CREB-IR could not be detected. The localization of induced JUN, FOS, and KROX proteins reflected the pattern of labelling in untreated animals but demonstrated a higher intensity of labelling and an increased number of immunoreactive nuclei. The intensity and persistence of IR as well as the number of labelled cells following BIC exceeded those following KCl. Following BIC, increased levels of FOS B and JUN D were still present after 24 hours. Counterstaining with cresyl-violet and GFAP, a marker for astrocytes, revealed that JUN, FOS, and KROX proteins were expressed in neurons but not in glial cell populations. The present data demonstrate that CREB, JUN, FOS, and KROX transcription factors exhibit a layer-specific expression in the cerebral cortex with only slight area-specific differences both in untreated rats and following stimulation with KCl and BIC. The expression of transcription factor proteins indicate complex molecular genetic changes in cortical neurons due to pathophysiological events such as seizure activity and spreading depression.

Activating Transcription Factor 1↗

Hsc70, immunoglobulin heavy chain binding protein, and Hsp90 differ in their ability to stimulate transport of precursor proteins into mammalian microsomes.

Ribonucleoparticle-independent transport of precursor proteins into mammalian microsomes is stimulated by 70-kDa heat shock proteins (Hsc70) and an additional cytosolic protein. Here we addressed the question of whether other molecular chaperones can replace Hsc70 in facilitating protein transport into the endoplasmic reticulum. Specifically, we asked if members of the same family of stress proteins, i.e. the microsomal protein immunoglobulin heavy chain binding protein or the bacterial protein DnaK, can substitute for Hsc70. Furthermore, we investigated whether molecular chaperones with a proven role in protein folding and belonging to the other two major families of stress proteins, i.e. Hsp60 or Hsp90, can substitute for Hsc70. We show that none of these stress proteins was able to substitute for Hsc70 in facilitating protein transport into mammalian microsomes. GroEL (the bacterial member of the Hsp60 family) and Hsp90, however, competed with Hsc70 for binding of the non-native precursor protein. Therefore, we conclude that there are both substrate and functional specificity in the action of molecular chaperones.

Animals↗

Long-lasting increase of nitric oxide synthase immunoreactivity, NADPH-diaphorase reaction and c-JUN co-expression in rat dorsal root ganglion neurons following sciatic nerve transection.

Changes of NADPH-diaphorase reaction (NDP) and nitric oxide synthase immunoreactivity (NOS-IR) in neurons of dorsal root ganglia (DRG) were investigated following transection and ligation of rat sciatic nerve. In untreated rats, 2.7% of L4/L5 DRG neurons were labelled by NDP. After 3 days, intensity of NDP and number of labelled neurons increased and reached a maximal level between 10 and 20 days in 26.8% neurons which persisted up to 50 days. After 150 days, 8.7% of DRG neurons were still labelled. In contralateral L4/L5 DRG, but not L1 and T10 DRG, the number but not the intensity of NDP labelled neurons slightly increased between 10 and 50 days. The patterns of NOS-IR and NDP were congruent. Ipsilaterally, 76% to 92% of NDP neurons showed co-expression with the c-JUN transcription factor which is supposed to play a crucial role in the regeneration process. NDP accumulated in the peripheral nerve stump and was increased in the superficial dorsal horn between 10 and 30 days, whereas motoneurons were not labelled by NOS and NDP.

Amino Acid Oxidoreductases↗