Epiphyseal fixation in revision total knee arthroplasty: a comparison between trabecular metal and titanium augments

INTRODUCTION

The purpose of this retrospective study was to compare the medium-term clinical and radiographic outcomes of two series of patients treated for revision TKA: one implanted with trabecular metal (TM) augments and one implanted with classic titanium augments.

MATERIALS AND METHODS

A total of 85 patients with a type 2 AORI defect underwent revision TKA and were treated either with TM epiphyseal augments directly screwed in the bone or with traditional titanium augments. There were 46 patients in the TM group and 39 patients in the titanium group included in the study. All the patients received the same varus-valgus constrained implant and no metaphyseal fixation devices were used.

RESULTS

After a mean follow-up of 66.4 months, no statistically significant difference was observed in terms of failure for aseptic loosening between the two groups (4% in the TM group and 7.8% in the titanium group, p = 0.35). The ten-year survival using aseptic loosening as endpoint was 90.5% (95% CI 94.1-98.6) in the TM group and 85% (95% CI 101.9-119.3) in the titanium group (p = 0.26). A statistically significant difference was detected for the presence of RLL. No RLL were found under the studied TM augments compared to 13.7% of the titanium augments (p = 0.01).

CONCLUSION

The use of TM augments directly screwed to the epiphysis of the femur and the tibia reduced the incidence of RLL compared to standard titanium augments during revision TKA with promising medium-term results.

Immunolocalization of Vasa, PIWI, and TDRKH proteins in male germ cells during spermatogenesis of the teleost fish Poecilia reticulata

Vasa, PIWI and TDRKH are conserved components of germ granules that in metazoans are involved in germline specification and differentiation, as documented by mutational experiments in some model animals. So far, investigations on PIWI during spermatogenesis of fish has been limited to a few species, and no information is available for TDRKH, another protein involved in the piRNA pathway. In this study, the immunolocalization of these three germline determinants was analyzed in male gonads of the teleost fish Poecilia reticulata to document their localization pattern in the different stages of germ cell differentiation. To analyze their distribution pattern during the different stages of spermatogenesis we performed immunohistochemistry (IHC) and immunofluorescence (IF) assays using primary polyclonal antibodies after testing their specificity with Western Blot. Moreover, sections of testis stained with haematoxylin and eosin clarified the structural organization of P. reticulata testis, while the use of the confocal microscope and the nuclear staining clarified the different stages of germ cell differentiation during spermatogenesis. The results showed that Vasa, PIWI and TDRKH were specifically immunolocalized in the germ cells of P. reticulata, with no specific signal detected in Sertoli cells and in other somatic cells of the gonad. These markers were detected in all stages of differentiation from early spermatogonia to advanced spermatids. Vasa staining was the strongest in spermatogonia, and then decreases throughout differentiation. Instead, both PIWI and TDRKH staining increases during differentiation, and their distribution pattern, similar to what observed in the mouse, suggests their concerted participation in the piRNA pathway also in this fish.

The flexion space is more reliably balanced when using the transepicondylar axis as compared to the posterior condylar line

PURPOSE

The purpose of this study was to evaluate the differences in flexion space balance when the femoral component is implanted parallel to the surgical transepicondylar axis (TEA) or with 3° of external rotation from the posterior condylar line (PoCoLi). It was hypothesized that implantation parallel to the TEA will produce a more reliably balanced flexion space.

METHODS

Forty-eight consecutive patients with a varus deformity were prospectively randomized to undergo total knee arthroplasty with a femoral component implanted parallel the TEA, or with 3° of external rotation from the PoCoLi. The posterior condylar angle (PCA) was measured. Intraoperative load measurements were taken at 10°, 45°, and 90° of flexion.

RESULTS

The PCA was similar between groups (TEA group: 4.2° ± 1.5° and PoCoLi group: 4.0° ± 1.3°; n.s.). The mean difference in load values between the medial and lateral compartments was significantly lower in the TEA group than in the PoCoLi group at the 45 (0 ± 8 vs. 9 ± 13 lbs; respectively, p = 0.008) and 90° flexion angles (1 ± 9 vs. 10 ± 15 lbs; respectively, p = 0.01). The PoCoLi group had a linear increase in the difference of load values between the medial and lateral compartments with increasing magnitude of the posterior condylar angle (45°, p = 0.0013; 90°, p = 0.0006), but this was not observed in the TEA group.

CONCLUSION

Femoral component implantation parallel to the TEA resulted in a more balanced flexion gap as compared to implantation at 3° of external rotation from the PoCoLi. The intraoperative use of the TEA rather than the PoCoLi to set femoral component rotation may provide a more balanced flexion space and decrease the need for extensive soft tissue releases.

LEVEL OF EVIDENCE

II.

High performance of α-defensin lateral flow assay (Synovasure) in the diagnosis of chronic knee prosthetic infections

PURPOSE

This prospective study was undertaken to evaluate the diagnostic accuracy of the Synovasure™ α-defensin lateral flow assay to detect or exclude infection and to compare it to the sensitivity and specificity of other diagnostic criteria according to the International Consensus Group on Periprosthetic Joint Infection (PJI).

METHODS

All patients who have undergone revision total knee arthroplasty (TKA) from September 2015 to July 2016 were included: 16 chronic (more than 3 months after performing arthroplasty) infections and 35 aseptic joints were identified. The diagnostic performance of single test was assessed by receiver operating characteristic (ROC) curve analyses. The sensitivity and specificity were calculated for each of the cut-off values and the area under the curve (AUC) was also calculated.

RESULTS

The median synovial fluid (SF) leukocyte count, as well as the neutrophil percentage, was significantly higher in patients with PJI than in those with aseptic failure (p < 0.001). The sensitivity of α-defensin was 87.5% (95%; CI 74.6-94.7), the specificity was 97.1% (95% CI 86.9-99.7), the positive predictive value 93.3% (95% CI 81.8-98.1), and negative predictive value was 94.4% (95% CI 83.2-98.6). The results in terms of sensitivity and negative predictive value were greater than those of the other tests (cultures, synovial cell count, erythrocyte sedimentation rate, and C-reactive protein). The diagnostic accuracy of α-defensin, with an area under the curve of 0.92, was found to be higher than all the minor criteria for PJI.

CONCLUSIONS

In this study, the α-defensin lateral flow test was found to have the highest performance of all tests studied to identify PJI. Synovasure™ holds the potential to be included in the daily clinical practice.

LEVEL OF EVIDENCE

Level I diagnostic study.

Diagnostic accuracy of synovial fluid, blood markers, and microbiological testing in chronic knee prosthetic infections

INTRODUCTION

This retrospective study was undertaken to define cut-off values for synovial fluid (SF) leukocyte count and neutrophil percentage for differentiating aseptic failure and periprosthetic joint infection (PJI) and to evaluate the diagnostic accuracy of blood inflammatory markers, and microbiological testing according to the criteria proposed by the International Consensus Meeting (ICM) of Philadelphia.

METHODS

All patients who underwent revision total knee arthroplasty from January 2010 to July 2015 were included: we identified and classified 31 PJIs and 136 aseptic joints. The diagnostic performance of single test was assessed by receiver operating characteristic curve analyses. The sensitivity and specificity were calculated for each of the cut-off values and the area under the curve (AUC) was calculated.

RESULTS

The median SF leukocyte count as well as the neutrophil percentage and inflammatory markers were significantly higher in patients with PJI than in those with aseptic failure (p < 0.001). A leukocyte count of > 2.8 × 10³/μL had a sensitivity of 83.8% and a specificity of 89.7% whereas a neutrophil percentage of > 72% yielded a marginally higher sensitivity of 84% and a specificity of 91%. Applying the ICM criteria we found a significant correlation between all these diagnostic measures and PJI (p < 0.001) except for a single positive culture. The most accurate criterion of the ICM was the synovial neutrophil differential (AUC = 0.89; 95% CI 0.81-0.97), followed by SF leukocyte count (AUC = 0.86; 95% CI 0.78-0.94), increased inflammatory markers (AUC = 0.85; 95% CI 0.76-0.93), and two positive periprosthetic cultures (AUC = 0.84; 95% CI 0.73-0.94). The presence of sinus tract communicating with the joint and a single positive culture showed unfavourable diagnostic accuracy (AUC = 0.60, 95% CI 0.47-0.72; AUC = 0.49, 95% CI 0.38-0.61, respectively) CONCLUSIONS: The present study highlights the adequate ability of fluid cell count and neutrophil differential to distinguish between PJI and aseptic loosening. The clinical utility of fluid analysis in diagnosing infection can be improved by evaluation of other diagnostic criteria.

LEVEL OF EVIDENCE

Level I Diagnostic Study.

Intraoperative Load-Sensing Variability During Cemented, Posterior-Stabilized Total Knee Arthroplasty

BACKGROUND

Load-sensing technology during total knee arthroplasty (TKA) provides objective measurements of ligamentous balance. The purpose of this study is to assess its intraoperative validity and reliability during TKA.

METHODS

Fifty-four patients underwent TKA using the OrthoSensor VERASENSE tibial insert to assist with ligament balance. The transepicondylar axis (TEA) was used to determine femoral component rotation, and the posterior condylar angle (PCA) was measured. Load measurements were documented at 10°, 45°, and 90° of flexion with the trial (TRIAL) components and with the definitive (FINAL) cemented implants. Adequate balance was defined as a load differential ≤15 pounds between compartments.

RESULTS

Adequate balanced with TRIAL and FINAL implants was observed in 89% TKAs. There was a significant linear correlation of the TRIAL and FINAL loads in the medial compartment throughout range of motion. No correlation between the TRIAL and FINAL loads was identified in the lateral compartment. There was no relationship between an increasing PCA and medial compartment loads at 45° (R² = 0.0006, Y = -0.10X + 7.3 ± 2.3; P = .86) and 90° (R² = 0.004, Y = -0.25X + 6.3 ± 2.1; P = .62) of flexion, suggesting that the compartment loads were not significantly altered with femoral rotation parallel to the TEA. A similar finding was observed in the lateral compartment at all poses.

CONCLUSION

Variability between the TRIAL and FINAL implant measurements was higher in the lateral compartment as compared to the medial compartment. Using the TEA and not the posterior condylar line as a landmark to guide femoral component rotation, the flexion gap is frequently balanced without the need for additional ligament releases.

Femoral Component Rotation in Total Knee Arthroplasty: A Comparison Between Transepicondylar Axis and Posterior Condylar Line Referencing

BACKGROUND

Proper rotational alignment of the femoral component is critical for a successful total knee arthroplasty (TKA). Controversy remains regarding the optimal intraoperative reference to determine femoral component rotation.

METHODS

Thirty-one patients who underwent magnetic resonance imaging of a TKA between April 2008 and November 2015 were retrospectively reviewed. A single surgeon performed the TKA using a posterior condylar angle of 3° (PCA group) or surgical transepicondylar axis (TEA group) to determine femoral component rotation. The hip-knee-ankle angle and the tibial plateau-tibial shaft angle (TPTSA) were measured on full-length x-rays, and the rotation of the femoral component was measured as compared to the TEA on magnetic resonance imaging (negative values indicate internal rotation).

RESULTS

The median measured rotational deviation of the femoral component from the TEA was significantly higher in the PCA group than in the TEA group (-3.8 ± 2.9° and -1.4 ± 1.9°, respectively) (P = .02). When knees with preoperative varus and neutral alignment were evaluated, the median measured rotational deviation of the femoral component was significantly higher in the fixed PCL group than in the TEA group (-3.4 ± 3.3° and -0.61 ± 1.3°, respectively) (P = .04). Linear regression used to evaluate the relationship between the TPTSA and femoral component rotational deviation from the TEA revealed similar near zero slopes (P = .90); however, the Y intercepts in the TEA group were significantly higher than the PCA group (-2.8 ± 0.7 and -5.5 ± 1.1, respectively) (P = .007).

CONCLUSION

The use of the surgical TEA as an intraoperative rotational reference is more reliable than the PCA in valgus, varus, and neutrally aligned knees independent from the magnitude of the TPTSA.

The role of tendon and subacromial bursa in rotator cuff tear pain: a clinical and histopathological study

PURPOSE

To evaluate a possible association of shoulder pain with the clinical features and the histopathological changes occurring in the ruptured tendon and subacromial bursa of patients with rotator cuff tear.

METHODS

One hundred and eighty patients were clinically evaluated with the constant score and the visual analogue pain scale. Radiographs and MRI were performed. The chronology of the rupture, the muscle fatty degeneration according to Goutallier's scale and the tear size were evaluated. For each patient, a biopsy of the supraspinatus tendon and subacromial bursa was performed during arthroscopic rotator cuff tear repair and the specimens were histopathologically analysed.

RESULTS

Clinically, the shoulder was more painful in females, in the presence of a chronic cuff lesion and a low Goutallier's grade (P < 0.05). No association was found between pain and age of the patient and between pain and tear size. Histologically, hypertrophy and inflammation of the tendon and hypertrophy, inflammation, oedema and necrosis of the subacromial bursa were directly associated with pain (P < 0.05). Pain decreased significantly in the presence of fatty metaplasia and necrosis of the tendon (P < 0.05).

CONCLUSIONS

This study defines the main clinical and histopathological features of painful rotator cuff tear. In particular, a greater association of pain was observed with the histopathological changes in the bursa compared with those in the rotator cuff. Considering that the bursa plays also an essential role during the healing process, this "new" role of the subacromial bursa as pain generator has important repercussions in both pharmacological and surgical treatments of rotator cuff tears.

LEVEL OF EVIDENCE

IV.

The difficult primary total knee arthroplasty: a review

Primary total knee arthroplasty (TKA) is a reliable procedure with reproducible long-term results. Nevertheless, there are conditions related to the type of patient or local conditions of the knee that can make it a difficult procedure. The most common scenarios that make it difficult are discussed in this review. These include patients with many previous operations and incisions, and those with severe coronal deformities, genu recurvatum, a stiff knee, extra-articular deformities and those who have previously undergone osteotomy around the knee and those with chronic dislocation of the patella. Each condition is analysed according to the characteristics of the patient, the pre-operative planning and the reported outcomes. When approaching the difficult primary TKA surgeons should use a systematic approach, which begins with the review of the existing literature for each specific clinical situation.

The role of offset stems in revision knee arthroplasty

Revision total knee arthroplasty (TKA) represents a technically challenging procedure. The use of an offset stem extension can help in addressing some of the difficulties that can be encountered during surgery and, in particular, anatomical mismatch, malalignment, and gap balancing. Different offset stem extensions are available and can be classified according to four parameters: modularity, location of the offset, direction, and size of the displacement. Offset stem extensions can assist with implant alignment on the metaphysis if there is an offset diaphysis, can avoid medial-lateral or anterior-posterior component overhang, can reduce the incidence of coronal or sagittal malalignment, and can help in balancing the flexion and extension spaces by effectively translating the components. The aim of this study is to give an overview of the currently available evidence regarding the use of offset stem extensions in revision TKA as well as some useful surgical tips.

Tendon transfer for irreparable rotator cuff tears: indications and surgical rationale

BACKGROUND

treatment of symptomatic irreparable rotator cuff tears is extremely challenging because, at present, there are no ideal solutions to this problem. Many patients respond favorably to nonsurgical treatment. However, when conservative measures fail to improve the patient's pain and disability, surgery should be considered.

METHODS

different surgical techniques are available and the choice of the most appropriate procedure depends on the presenting symptoms, age of the patient, functional demand, medical comorbidities, joint stability and presence of arthritic changes. The transposition of the surrounding muscles to replace the rotator cuff function represents a viable option in the treatment of younger patients without glenohumeral osteoarthritis and with severe functional limitation.

PURPOSE

aim of this study is to give an overview of the currently available evidence regarding tendon transfer procedures for irreparable rotator cuff tears.

Osteochondroma as a cause of scapular winging in an adolescent: a case report and review of the literature

INTRODUCTION

Winged scapula is defined as the prominence of the medial border of the scapula. The classic etiopathology of scapular winging are injuries to the spinal accessory or long thoracic nerves resulting respectively in trapezius and serratus anterior palsy. To the best of our knowledge, there are only few reports of scapular lesions being mistaken for winging of the scapula. We report a rare case of a large scapular osteochondroma arising from the medial border and causing a pseudowinging of the scapula.

CASE PRESENTATION

A 17-year-old Caucasian boy came to us complaining about a winged left scapula. The patient had a complete painless range of motion, but a large hard bony swelling was palpable along the medial border of his left scapula. A grating sensation was felt when his arm was passively abducted and/or elevated causing discomfort. A lesion revealed on X-rays was diagnosed as an osteochondroma of the medial border of his scapula. After preoperative examinations, he underwent open surgery in order to remove the lesion. A histological examination confirmed the clinical diagnosis of osteochondroma. A clinical examination 3 months later showed a full and painless range of motion, the absence of the grating sensation during passive abduction and elevation and the complete disappearance of his left shoulder deformity. After 2 years of follow-up, there were no clinical or radiological signs of recurrence.

CONCLUSIONS

Despite its rarity osteochondroma should be considered in the differential diagnosis for any adolescent presenting with a winging of the scapula.

Periprosthetic shoulder infection

Shoulder arthroplasty is considered the most effective surgical procedure for endstage shoulder pain from different causes including osteoarthritis, cuff-tear arthropathy, trauma, and tumors. Although uncommon and less frequent than knee or hip periprosthetic infection, periprosthetic shoulder infection represents a devastating complication and, despite treatment, is associated with unsatisfactory results. The most commonly identified microorganisms in periprosthetic shoulder infections are Staphylococcus aureus, coagulase-negative Staphylococci and Propionibacterium acnes. Diagnosis is not always easy and mainly derives from the integration of clinical symptoms, laboratory exams, radiological studies and microbiological swabs. Different options are available for treatment, including antibiotic therapy, lavage and debridement with retention of the prosthesis, one-stage reimplantation, two-stage reimplantation with antibiotic-impregnated cement spacer and resection arthroplasty. The aim of this review is to describe the current knowledge regarding risk factors, etiology, diagnosis and treatment of periprosthetic shoulder infection.

Primate embryonic stem cells create their own niche while differentiating in three-dimensional culture systems

Rhesus monkey embryonic stem cells (ESCs) (R366.4), cultured on a three-dimensional (3D) collagen matrix with or without human neonatal foreskin fibroblasts (HPI.1) as feeder cells, or embedded in the collagen matrix, formed complex tubular or spherical gland-like structures and differentiated into phenotypes characteristic of neural, epithelial and endothelial lineages. Here, we analysed the production of endogenous extracellular matrix (ECM) proteins, cell-cell adhesion molecules, cell-surface receptors, lectins and their glycoligands, by differentiating ESCs, forming a micro-environment, a niche, able to positively influence cell behaviour. The expression of some of these molecules was modulated by HPI.1 cells while others were unaffected. We hypothesized that both soluble factors and the niche itself were critical in directing growth and/or differentiation of ESCs in this 3D environment. Creating such an appropriate experimental 3D micro-environment, further modified by ESCs and modulated by exogenous soluble factors, may constitute a template for adequate culture systems in developmental biology studies concerning differentiation of stem cells.

Cell proliferation and growth-associated protein 43 expression in the olfactory epithelium in Poecilia reticulata after copper solution exposure

This study investigated the regeneration in the olfactory mucosa of the teleostean fish Poecilia reticulata when returned to dechlorinated tap water after 4-day exposure to 30 microg/L of Cu(2+). The regeneration process in the olfactory tissue was examined in fishes at 0, 3, 6 and 10 days of recovery in well water. Jade B staining permitted to evaluate the rate of the damage which was especially extended to olfactory neurons. Immediately after the end of exposure, a massive mitotic activity in the basal region of the mucosa was detected by immunostaining with PCNA. After 3 days of recovery the nuclei of the newly formed cells had already finished their migration to the upper portion of the epithelium, and cellular division was much less intense. Simultaneously, immunoreactivity for the neural growth-associated phosphoprotein GAP-43 increased respect to control levels, revealing that the new differentiating PCNA-positive elements belonged to immature neurons. After 6 days in well water no mitotic activity was detected, while the GAP-43 labelling appeared particularly concentrated in the apical surface of the olfactory epithelium. After 10 days the aspect of the olfactory epithelium was almost identical to the control. The present results suggest that after 10 days regeneration seems to be complete and integrity of the tissue restored. Furthermore, the epithelium reconstitution does not show apparent divergence from other fishes or mammals.

Lectin-binding patterns in the olfactory system of the lizard, Physignathus lesueurii

Lectin binding histochemistry was performed on the olfactory system of Physignathus lesueurii to investigate the distribution and density of defined carbohydrate terminals on the cell-surface glycoproteins of the olfactory and vomeronasal receptor cells and their terminals in the olfactory bulbs. The lectin staining patterns indicate that the vomeronasal and olfactory receptor cells are characterized by glycoconjugates containing alpha-D-galactose and N-acetyl-D-glucosamine terminal residues. The presence of specific glycoproteins, whose terminal sugars are detected by lectin binding, might be related to the chemoreception and transduction of the odorous message into a nervous signal or to the histogenesis and development of the olfactory system. The olfactory and vomeronasal receptor cells are vertebrate neurons that undergo a continual cycle of proliferation not only during development but also in mature animals.

Glial fibrillary acidic protein and vimentin immunoreactivity of astroglial cells in the central nervous system of adult Podarcis sicula (Squamata, Lacertidae)

The present immunoperoxidase cytochemical study describes the distribution of glial intermediate filament molecular markers, glial fibrillary acidic protein (GFAP) and vimentin, in the brain and spinal cord of the adult lizard, Podarcis sicula. GFAP immunoreactivity is abundant and the positive structures are mainly represented by fibres of different lengths which are arranged in a rather regular radial pattern throughout the CNS. They emerge from generally immunopositive radial ependymoglia and are directed from the ventricular wall towards the meningeal surface. The glial fibres give origin to endfeet which are apposed to the blood vessel walls and subpial surface where they form the continous perivascular and subpial glia envelopes, respectively. In the optic tectum and spinal cord, star-shaped astrocytes coexist with radial glia. In the spinal cord, cell bodies of immunopositive radial glia are displaced from the ependyma. While vimentin immunoreactive elements are almost completely absent in the brain except for a few diencephalic radial fibres, the spinal cord ependyma exhibits a clearly vimentin positivity and no GFAP staining. In the Podarcis CNS the immunocytochemical response of the astroglial intermediate filaments appears typical of mature astroglia cell lineage since it fundamentally expresses GFAP immunoreactivity. Moreover, this immunocytochemical study shows that the Podarcis fibre pattern with predominant radial glial cells is morphologically more immature than in avians and mammalians, a condition suggesting that reptiles represent a fundamental step in the phylogenetic evolution of vertebrate astroglial cells.

Structural and spatial organisation of brain parenchymal vessels in the lizard, Podarcis sicula: a light, transmission and scanning electron microscopy study

The structure and 3-dimensional pattern of the intraparenchymal microvessels in the brain of the lizard, Podarcis sicula, were studied by a combination of light and transmission electron microscopy as well as scanning electron microscopy of vascular corrosion casts. The angioarchitecture pattern consists of narrow hairpin-shaped microvascular loops of different length originating from the meningeal surface. In each loop, descending and ascending vessels are closely apposed to one another throughout their length and are connected by a narrow U-shaped terminal loop at their tips. The 2 limbs of the vessel pairs show a slightly different diameter but lack other structural differences. While some paired vessels give rise to a secondary hairpin-shaped loop with 2 possible branching patterns, there are no anastomotic intraparenchymal connections with analogous neighbouring structures. The cerebral vascular pattern of Podarcis sicula resembles that found in a few representatives of other vertebrate classes. All cerebral vessels structurally appear to be capillaries. Also the observations carried out on semithin and thin sections strongly support the capillary loop model in the Podarcis brain vasculature and, in accordance with studies carried out on various vertebrates, the general submicroscopic features of the brain capillary wall suggest the presence of an endothelial type blood-brain barrier.

Lectin cytochemical localisation of glycoconjugates in the olfactory system of the lizards Lacerta viridis and Podarcis sicula

To investigate the presence of defined carbohydrate moieties on the cell surface of the olfactory and vomeronasal receptor cells and the projections of the latter into the olfactory bulbs, a lectin binding study was performed on the olfactory system of the lizards: Lacerta viridis and Podarcis sicula. Both lizards showed a high lectin binding for N-acetyl-glucosamine in the sensory neurons. The lectin binding patterns in Lacerta indicated that the main olfactory system possessed a moderate density of N-acetyl-galactosamine residues and detectable levels of galactose ones. The vomeronasal system on the other hand contained a high density of N-acetyl-galactosamine moieties and a moderate density of glucosamine ones. In Podarcis the main olfactory system and vomeronasal organ contained respectively detectable and moderate levels of galactose residues. The expression of specific glycoconjugates may be associated with outgrowth, guidance and fasciculation of olfactory and vomeronasal axons.

Lectin characterization of the olfactory system in brachiopterygian fish

Lectin binding was performed on the olfactory system of Polypterus and Erpetoichthys, the living genera of the subclass of Brachiopterygii. The lectin histochemical patterns and the Western-blot analysis indicate that the receptor cells of the olfactory mucosa are characterized by high density of specific glycoconjugate residues. The presence of glycoproteins, whose terminal sugars are detected by lectin binding, might be related to the reception of an odor stimulus and its transduction into a nervous signal or to the histogenesis of the olfactory system.

Glial fibrillary acidic protein and vimentin in radial glia of Ambystoma mexicanum and Triturus carnifex: an immunocytochemical study

The molecular characterization of glial lineage cells in two urodele species, Ambystoma mexicanum and Triturus carnifex, has been investigated immunocytochemically with antibodies directed against intermediate filament proteins, glial fibrillary acidic protein (GFAP) and vimentin. Ambystoma astroglia shows clear GFAP-immunopositivity and vimentin-immunonegativity. The condition in Triturus is quite the opposite, showing only a strong vimentin immuno-reaction. In these urodele brain the astroglia is represented by radial glial cells with their somata lining cerebral ventricles (tanycytes). Each of them originates a thick process which radially crosses the periventricular gray matter and branches within the neuropil. These glial fibers originate endfeet on the subpial surface and on blood vessel wall. Only in the spinal cord cell bodies of immunopositive radial glia are displaced from the ependyma of the central canal which is almost immunonegative except the tanycytes forming the dorsal and ventral septum. No mammalian-like astrocytes appear neither in brain nor in spinal cord. The interspecific difference in the intermediate filament protein expression in radial glial cells could suggest that as regards this character Triturus retains a more immature condition than Ambystoma.

Identification of surface glycoconjugates in the olfactory system of turtle

Lectin binding histochemistry was performed on the olfactory system of Pseudemys scripta to investigate the distribution and density of defined carbohydrate terminals on the cell surface glycoproteins of the olfactory receptors and their terminals in the olfactory bulbs. The lectin staining patterns indicate that the receptor cells of the olfactory mucosa are characterized by glycoconjugates containing alpha-D-galactose and N-acetyl-D-glucosamine terminal residues. The vomeronasal receptor cells contain instead alpha-N-acetyl-D-galactosamine, N-acetyl-D-glucosamine and alpha-D-galactose residues. The results demonstrate that the vomeronasal receptor cells contain high density of alpha-N-acetyl-D-galactosamine sugar residues that are not expressed by receptor cells of the olfactory mucosa. The presence of specific glycoproteins, whose terminal sugars are detected by lectin binding, might be related to the chemoreception and transduction of the odorous message into a nervous signal or in the histogenesis of the olfactory system. In fact, the olfactory receptors are the only known neurons in the vertebrate nervous system that undergo a continual cycle of proliferation not only in developing animals but also in mature ones. Moreover the results show that BSA-I-B4, an alpha-D-galactosyl-specific isolectin, targets the terminal sugar residues in the ramified microglial cells.

Histochemical study by lectin binding of surface glycoconjugates in the developing olfactory system of rat

Lectin-binding histochemistry was used to investigate the distribution and density of defined carbohydrate sequences on the cell surface glycoproteins of the olfactory receptors of rat during development. The olfactory and vomeronasal receptors showed a positive labelling after biotinylated Lycopersicum esculentum lectin binding on embryonic day 16 (E16), while horseradish peroxidase-labelled Glycine max, Bandeiraea simplicifolia (BSA-I) and its B4 isomer BSA-I-B4 agglutinins started to label from day 18 (E18). From this stage onward there was a progressive increase in the intensity and number of lectin-binding olfactory receptors. The first lectin-labelled bundles of axons penetrating the olfactory bulb were observed on E20; from E21 it was possible to identify the first labelled glomeruli that, on the first day (P1) of postnatal life, showed a feature very similar to that of the adult. The lectin staining patterns indicate that during development there are differences in the kind and distribution of saccharidic moieties on the surface of rat olfactory neurons. The possible role of carbohydrate-containing glycoproteins in the reception and transduction of the odours and in the modulation of the cell-cell interactions in the olfactory system is discussed.

Lectin histochemistry of cell-surface glycoconjugates in the primary olfactory projections of the newt

The binding of 14 lectins were performed on paraffin-embedded sections of the olfactory bulb of Triturus to identify specific glycoconjugates on the cell surface of primary olfactory projections. The histochemical lectin staining patterns indicate that the membrane of olfactory neurons terminating in the main olfactory bulb contained prevalently oligosaccharides with alpha-acetyl-D-galactosamine as terminal residues. In the accessory olfactory bulb, instead, the primary olfactory projections possess a high density of alpha-D-galactose as sugar residues. The selective lectin binding on the surface of primary olfactory axons suggests that specific cell surface glycoproteins may have a role in the axonal growth due to the continual cycle of proliferation and death of olfactory receptors.

Choroidal and iris angioarchitecture of the newt: a scanning electron-microscopic study of vascular corrosion casts

The corrosion cast technique provided for the first time an excellent three-dimensional visualization of the vascular pattern of the choroid and iris in the newt eye. The results show the presence of a single arterial afference to the choroidal and iris capillaries: the ophthalmic artery is the origin of both ciliary arteries and the long posterior ciliary artery. Slightly behind the equatorial circumference of the eyeball the venous drainage consists of a single vessel on the dorsal side and two distinct vessels on the ventral one. It receives blood from both iris and choroid. The surface of the plastic endocasts shows some details of fine luminal structures of the endothelial cells. Shallow depressions may be regarded as imprints of endothelial cell nuclei, and they are distinctly different for arteries and capillaries. The angioarchitecture of the newt eye differs from that of brain in that hairpin-shaped capillary loops are not observed at all.

[Biochemical study of the dental pulp in the calf]

A biochemical study of dental pulp of calves has been performed concerning: a) peroxydability b) A, E, C vitamins content c) glutation (GSH) content d) presence of paramagnetic compounds e) phosphorylation ratio The dental pulp from incisors of 5-months-old calves has been preserved. Immediately after decapitation the pulp was immersed in liquid nitrogen. Chromatographic (HPLC) and spectroscopic (NMR-ESR) techniques have been used. GSH in dental pulp are present and dosable (4.56 +/- 0.08 n moles/mg prot.) and GSSG (1.05 +/- 0.01 n moles/mg prot.). Because of blood traces in the extracted pulps, the AA. have determined the hemoglobin (Hb) dosage and GSH of erythrocytic derivation (Fig. 1). After deduction of GSH of erythrocytic derivation, the GSH really present in the pulp was 4.41 n moles/mg prot. and the GSSG was 0.90 n moles/mg prot. Peroxydability of the dental pulp has been evaluated with Lowry method with dental pulp homogenate and rat liver homogenate (see Table 1). The ESR spectre shows 4 resonances with the following values: g. 2.24-2.04-2.00-1.97; there are some free intermediary radicals (gr.-2.00) (Fig.2). The NMR spectre shows the presence of ATP (0.22 n moles/g) of inorganic phosphate (16.58 n moles g) (Fig.3). The pulp seems to have a lot of antioxidant factors. The next researches will be to study E, A and C vitamins concentrations. This high presence of GSH and GSSG may be an embryonic peculiarity.

[Morphological research on the dental pulp of the calf]

Morphological researches have been carried out through histological studies with fine and semifine sections at the electronic scan microscope on the dental pulp of calves. The general aim was to identify the antioxidant properties of pulp and study cellular density and microfibrillar architecture. The dental pulps of calves of 5-6 months taken immediately after slaughtering were used with immersions into the fixing liquid. The scan microscope showed fibroblasts in the deepest regions of the pulp in a stroma of collagenic fibres, not organised but scattered among the cells of the connective tissue. The odontoblasts presented well ordered one beside the others with well visible details such as the swollen basal portion, the nucleus and a very tight villosity. No clear interodontoblastic connections were evident. The electron transmission microscope revealed typical cells with histiocyte appearance with microfilaments evident in the cytoplasma (myofibroblasts) presenting a wide variety of cytoplasmatic interconnections with interdigitations.

[Survey of childhood handicaps in the Unità Sanitaria Locale No. 22 "Valtiberina"]

An epidemiological research about the infantile handicaps has been carried out to make a quantitative and etiological valuation of the existing cases in the social, economic and cultural sphere of U.S.L. number 22 "Valtiberina". Considering an infantile population of 5,063 subjects, 55 cases, corresponding to 1.08% have been examined; 32 of them are male children and 23 are female children. The research which has been carried out shows that there are more cases of psychological handicaps (35 cases out of 55) rather than of organic handicaps. It seems that it is possible to find a connection between this high percentage and the social, economic and cultural situation of the territory. At the same time an efficacious work has been carried out by the Social and Medical Services of U.S.L. and by the school to recognise, to point out, to diagnose and to study these pathologies. Such a study can result useful if we want to plan a campaign to prevent and to treat as soon as possible the infantile handicaps.