Morphological variation of layer III pyramidal neurones in the occipitotemporal pathway of the macaque monkey visual cortex

We compared the morphological characteristics of layer III pyramidal neurones in different visual areas of the occipitotemporal cortical 'stream', which processes information related to object recognition in the visual field (including shape, colour and texture). Pyramidal cells were intracellularly injected with Lucifer Yellow in cortical slices cut tangential to the cortical layers, allowing quantitative comparisons of dendritic field morphology, spine density and cell body size between the blobs and interblobs of the primary visual area (V1), the interstripe compartments of the second visual area (V2), the fourth visual area (V4) and cytoarchitectonic area TEO. We found that the tangential dimension of basal dendritic fields of layer III pyramidal neurones increases from caudal to rostral visual areas in the occipitotemporal pathway, such that TEO cells have, on average, dendritic fields spanning an area 5-6 times larger than V1 cells. In addition, the data indicate that V1 cells located within blobs have significantly larger dendritic fields than those of interblob cells. Sholl analysis of dendritic fields demonstrated that pyramidal cells in V4 and TEO are more complex (i.e. exhibit a larger number of branches at comparable distances from the cell body) than cells in V1 or V2. Moreover, this analysis demonstrated that the dendrites of many cells in V1 cluster along specific axes, while this tendency is less marked in extrastriate areas. Most notably, there is a relatively large proportion of neurones with 'morphologically orientation-biased' dendritic fields (i.e. branches tend to cluster along two diametrically opposed directions from the cell body) in the interblobs in V1, as compared with the blobs in V1 and extrastriate areas. Finally, counts of dendritic spines along the length of basal dendrites revealed similar peak spine densities in the blobs and the interblobs of V1 and in the V2 interstripes, but markedly higher spine densities in V4 and TEO. Estimates of the number of dendritic spines on the basal dendritic fields of layer III pyramidal cells indicate that cells in V2 have on average twice as many spines as V1 cells, that V4 cells have 3.8 times as many spines as V1 cells, and that TEO cells have 7.5 times as many spines as V1 cells. These findings suggest the possibility that the complex response properties of neurones in rostral stations in the occipitotemporal pathway may, in part, be attributed to their larger and more complex basal dendritic fields, and to the increase in both number and density of spines on their basal dendrites.      

Open inguinal hernia repair with the use of a polyglycolic acid–trimethylene carbonate absorbable mesh: a pilot study

Purpose  

Tension-free repair with mesh placement has become the gold standard for open inguinal hernia surgery. Traditionally, non absorbable materials have been used for mesh manufacture. The purpose of this pilot study was to evaluate the efficacy of using a totally absorbable prosthetic mesh for open inguinal hernia repair.     

Correlation of estrogen receptor beta gene polymorphisms with spinal bone mineral density in peri- and post-menopausal Greek women

Estrogens play a significant role in bone physiology. Their action is mainly exerted through their receptors. Estrogen receptor alpha (ER) plays a major role in bone homeostasis and there is evidence suggesting that estrogen receptor beta (ERβ) has also an effect on BMD.

We investigated the possible effect of two ERβ gene polymorphisms on spinal bone mineral density (BMD) and metabolic bone markers in Greek women.

Spine BMD as well as biochemical bone markers were measured in 147 healthy peri- and post-menopausal women [mean age (S.D.) 54 (7.9) years]. Genotyping was performed for two restriction fragment length polymorphisms (RFLPs) of ERβ gene, RsaI in exon 5 and AluI in exon 8. For each polymorphism studied the cohort was divided into two groups: the “wild-type” group (RR and AA, respectively) and the “carrier” group including subjects with at least one allele with the restriction site (Rr&rr and Aa&aa, respectively).

The distribution of RsaI genotypes was RR: 91.2% (n = 134), Rr: 8.2% (n = 12), and rr: 0.6% (n = 1) and of AluI genotypes AA: 36.7% (n = 54), Aa: 57.2% (n = 84), and aa: 6.1% (n = 9). No linkage disequilibrium was found between the two polymorphic sites studied. Spine BMD did not differ significantly in the two groups of either polymorphism, after adjusting for age, weight, height, and years since menopause [mean BMD (S.D.) for RR 0.841 (0.17) g/cm² versus Rr&rr 0.798 (0.13) g/cm², p = 0.25, and mean BMD (S.D.) for AA 0.828 (0.16) g/cm² versus Aa&aa 0.848 (0.17) g/cm², p = 0.32]. No significant differences were noted in metabolic bone markers except for a marginal difference of RR versus Rr/rr in urinary hydroxyproline/creatinine ratio [median (IQR) 3.88 (6.04) μmol/mmol in RR versus 8.2 (4.32) μmol/mmol in Rr/rr, p = 0.05]. Furthermore, no interaction between the two polymorphisms on BMD was found.

In conclusion, in a Greek female post-menopausal population, the two ERβ gene polymorphisms were not associated with BMD, or metabolic bone markers.     

Apolipoprotein E polymorphism is not associated with spinal bone mineral density in peri- and postmenopausal Greek women

OBJECTIVES: A number of studies have shown a positive relation between ApoE gene and osteoporosis or fracture risk but this finding has not been uniform in all populations studied. The aim of the present study was to determine the possible effect of ApoE gene polymorphism on spinal bone mineral density and metabolic bone markers in Greek women. METHODS: One hundred and forty-seven healthy peri- and postmenopausal women (mean age 54.3 +/- 7.8 years) participated in the study. In all participants, ApoE gene genotype was determined and spinal bone mineral density (BMD) as well as biochemical bone markers were measured. The ApoE genotypes distribution was 0.7% (n = 1) for E2/2, 5.4% (n = 8) for E2/3, 2% (n = 3) for E2/4, 73.5% (n = 108) for E3/3, 16.3% (n = 24) for E3/4 and 2% (n = 3) for E4/4. Participants were divided in two groups according to the presence of the E4 haplotype: E4 carriers (n = 30) and E4 non-carriers (n = 117). RESULTS: Spinal BMD was similar in the two groups, after adjusting for age, weight, height and years since menopause (mean +/- S.D., 0.835 +/- 0.16 g/cm2 in E4 non-carriers versus 0.831 +/- 0.16 g/cm2 in E4 carriers, P = 0.99). Serum osteocalcin levels did not differ significantly in the two groups (median (interquartile range, IQR), 0.55 (0.58) nmol/l in E4 non-carriers versus 0.51 (0.43) nmol/l in E4 carriers), whereas urinary hydroxyproline/creatinine ratio was significantly higher in the E4 non-carriers group (median (IQR), 5.18 (6.04) micromol/mmol in E4 non-carriers versus 1.73 (3.45) micromol/mmol in E4 carriers, P < 0.01). Urinary pyridinoline/creatinine and deoxypyridinoline/creatinine ratios, measured in a subgroup of 51 women, were similar between ApoE carriers and non-carriers, respectively (median (IQR), 25.1 (9.3) nmol/mmol in E4 non-carriers versus 21.8 (7) nmol/mmol in E4 carriers and 6.7 (3.1) nmol/mmol in E4 non-carriers versus 7 (2.2) nmol/mmol in E4 carriers). CONCLUSION: In conclusion, in a Greek female postmenopausal population, ApoE gene does not seem to play an important role in determining BMD and neither does it affect the majority of metabolic bone markers.     

Bicentric bipolar hip prosthesis: A radiological study of movement at the interprosthetic joint

Background:

The bipolar hip prostheses after some time functions as a unipolar device. There is a need to change the design of bipolar hip prostheses to make it function as a bipolar device over a prolonged period of time. A bicentric bipolar hip prosthesis was used as an implant for various conditions of the hip. We evaluated the movement of this newly developed prosthesis at the interprosthetic joint radiologically at periodic intervals.

Materials and Methods:

Fifty two cases were operarted with the Bicentric bipolar prosthesis for indications like fracture neck of femur and various other diseases of the hip and were followed up with serial radiographs at periodic intervals to evaluate, what fraction of the total abduction at the hip was occurring at the interprosthetic joint.

Results:

In cases of intracapsular fracture neck of femur, the percentage of total abduction occurring at the interprosthetic joint at 3 months follow-up was 33.74% (mean value of all the patients), which fell to 25.66% at 1.5 years. In indications for bipolar hemireplacement other than fracture neck of femur, the percentage of total abduction occurring at the interprosthetic joint at 3 months follow-up was 71.71% (mean value) and at 1.5 years it was 67.52%.

Conclusion:

This study shows the relative preservation of inner bearing movement in the bipolar hip prosthesis with time probably due its refined design. Further refinements are needed to make the prosthesis work better in patients of intracapsular fracture neck femur.