Relationship between Hashimoto's thyroiditis and papillary thyroid carcinoma in children and adolescents.

OBJECTIVE: We investigated the relationship between Hashimoto's thyroiditis (HT) and papillary thyroid carcinoma (PTC) in children and adolescents. PATIENTS AND METHODS: We carried out a retrospective study of thyroidectomies performed from 2004 to 2017 at The First People's Hospital and the Tumor Hospital of Yunnan Province (Kunming, China). The occurrence and features of PTC and benign thyroid disease (BTD) in children and adolescents (age ≤ 20 years) were compared. RESULTS: We evaluated 258 consecutive thyroidectomies. Among children and adolescents with PTC, 23 cases were histopathologically confirmed as HT. Mean tumor diameter was smaller in children and adolescents with PTC than in those with BTD. Thyroid-stimulating hormone (TSH) level was abnormally elevated in a greater proportion of children and adolescents with PTC as compared to those with BTD or youths with PTC. The proportion of thyroglobulin antibody (TGAb)- and thyroid peroxidase antibody (TpoAb)-positive children and adolescents was higher in the PTC than in the BTD group. Among children and adolescents with PTC, 23 had HT as compared to two in the BTD group. The proportion of children/adolescents with abnormally elevated TSH levels was higher for the PTC combined with HT group than for the PTC without HT group. A multivariate conditional logistic regression analysis showed that elevated TGAb was an independent risk factor for PTC in children and adolescents. CONCLUSIONS: HT is associated with an increased occurrence of PTC in children and adolescents.

Trans-umbilical two-port laparoscopic suturing of the inguinal hernia defect with percutaneous assistance: a safe and efficient scarless surgery for pediatric inguinal hernia repair.

PURPOSE: This study was aimed to describe the technique of the modified trans-umbilical two-port laparoscopic suturing (M-TTLS), and show its feasibility and efficacy to treat pediatric inguinal hernia (PIH). METHODS: After general anesthesia, the patient was placed in the Trendelenburg position. Two trocars were set on umbilicus and a pneumoperitoneum was established at 8-12 mmHg. Under direct vision, a long syringe needle was punctured into the preperitoneal space above the internal inguinal ring (IIR). After the peritoneum separated by hydrodissection, the syringe needle was left in peritoneal cavity. A suture needle with 2-0 silk suture was periced into abdomen, and its tip was then inserted into the syringe needle hole by laparoscopic needle holder. Under the syringe's guidance, the peritoneum on the surface of the vessels and vas was sutured intactly by a single stitch. Subsequently, the rest peritoneum was sutured continuously in a clockwise direction. After a purse-string suture completed, the orifice of hernia sac was closed intracorporeally by a single-instrument tie technique. RESULTS: Overall, 139 patients with PIH underwent M-TTLS, including 130 boys and 9 girls. Median age was 46.8 months. All procedures were performed uneventfully without conversion. Median operation time was 12 min for unilateral and 17 min for bilateral operations. There were three minor extraperitoneal hematomas occurred during the operation. After a median follow-up of 13 months, no common complications developed and no visible scars were observed on the abdominal wall. CONCLUSIONS: M-TTLS is a safe and efficient scarless surgery for PIH repair.

A unique display of toll-like receptor 4 Asp299Gly and Thr399Ile polymorphisms in non-Han Chinese Hani population.

The toll-like receptor 4 (TLR4) polymorphisms, Asp299Gly and Thr399Ile, were investigated with PCR-RFLP and DNA sequencing methods in 938 and 980 individuals from the Yunnan Hani ethnic minority and the majority Han population, respectively. Six heterozygotes for both Asp299Gly and Thr399Ile were detected in the Hani, a polymorphism frequency of 0.6397%, whereas no variants were found amongst the Han.

Comparative study on the offset responses of simple cells and complex cells in the primary visual cortex of the cat.

Simple and complex cells are two basic and distinct functional types of neurons in the mammalian primary visual cortex. Here, we studied the onset response and the offset response of simple and complex cells to a flashing visual stimulus in the cat's area 17. Compared with simple cells, complex cells exhibited greater similarity between the onset and offset responses in peak latency. For simple cells, onset response had greater peak amplitude and signal-to-noise ratio than offset response, and for complex cells, vice versa. For both types of cortical cells, the amplitude of offset responses increased with stimulus duration within 100 ms significantly, while the onset response did not. However, to elicit a detectable offset response, complex cells tended to require shorter stimulus duration than simple cells did. In regard to the similarity of psychophysical data, these results suggest that the rebound offset response of cortical cells to disappearance of a visual pattern might be correlated to visual persistence in humans.

Enhancement of oblique effect in the cat's primary visual cortex via orientation preference shifting induced by excitatory feedback from higher-order cortical area 21a.

It is often suggested that the oblique effect, the well-known phenomenon whereby both humans and animals are visually more sensitive to vertical and horizontal contours than to oblique ones, is due to the overrepresentation of cardinal orientations in the visual cortex. The functional role of feedback projections from higher-order cortical areas to lower-order areas is not fully understood. Combining the two issues in a study using optical imaging here, we report that the neural oblique effect was significantly enhanced (3.7 times higher than the normal) in the cat's primary visual cortex through orientation shifting induced by excitatory feedback from the higher-order cortical area 21a. This suggests that a reciprocal co-excitatory mechanism may underlie the perceptual oblique effect.

Posteromedial lateral suprasylvian motion area modulates direction but not orientation preference in area 17 of cats.

In visual cortices of cats there are two major, largely parallel, feedforward processing streams which conduct visual information from the primary visual cortices to the parietal and temporal visual cortices, processing motion and form information, respectively. In addition to the feedforward streams, there exist many feedback projections from higher-order visual cortices to lower-order visual cortices. Using the intrinsic signal optical imaging, this study has examined the influence of feedback signals originating from area posteromedial lateral suprasylvian (PMLS), the dominant motion-processing region of the parietal cortex, on responses of neurons, orientational maps, and directional maps in cats' area 17 (striate cortex). The inactivation of area PMLS by local application of GABA resulted in the reduction of the magnitude of responses of area 17 cells though area 17 of the cat is mainly involved in form information processing rather than motion. Furthermore, inactivation of area PMLS abolished the global layout of direction maps in area 17 but did not affect the basic structure of the orientation maps in area 17. Thus, it appears that higher-order cortical areas along one information processing stream may exert cross-stream modulatory effects on fundamental properties of neurons located in the lower-order areas along distinct information processing streams.

Transhemispheric functional reorganization of the motor cortex induced by the peripheral contralateral nerve transfer to the injured arm.

Peripheral nerve injury in a limb usually causes functional reorganization of the contralateral motor cortex. However, a dynamic process of the novel transhemispheric functional reorganization in the motor cortex was found in adult rats after transferring the seventh cervical nerve root from the contralateral healthy side to the injured limb. Initially the ipsilateral motor cortex activated the injured forepaw for 5 months after the operation. Then, both hemispheres of the cortex activated the injured forepaw, and finally the contralateral cortex exclusively controlled the injured forepaw. It is concluded an extensive functional shift occurred between two hemispheres based on neural plasticity in the CNS. The experimental results of the later lesions of the ipsilateral cortex suggest that maintaining transhemispheric functional reorganization does not depend on the corpus callosum, but depends on mechanisms involving central axonal sprouting. Possible mechanisms underlying the alternative changes in cortical functions were discussed in rats and in patients having similar operations.

Orientation bias of the extraclassical receptive field of the relay cells in the cat's dorsal lateral geniculate nucleus.

The spatial properties of the extraclassical receptive fields (ECRF) of neurons responding to a stimulus restricted to it and its interaction with the classical receptive field (CRF) in visual information processing were investigated in 74 relay cells in the dorsal lateral geniculate nucleus (LGNd) of anesthetized cats. The results demonstrate that the ECRF of most relay cells in the LGNd responded preferentially to a grating stimulus of low spatial frequency through a mechanism of spatial summation. These biased cells showed a significant orientation bias which was relatively smaller than that of the CRF. The preferred orientations of the ECRF were not correlated with those of the CRF in most relay cells. The orientation biased ECRFs and CRFs interacted with each other in a non-linear way, resulting in a great diversity of response properties. Overall, the CRF played a more significant role than the ECRF in determining a cell's orientation bias and preferred orientation. The ECRF mostly showed a modulatory role mainly in suppressing and/or in partially facilitating the neural response to stimulation in the CRF although in some cases, the ECRF did determine a cell's responsiveness and orientation sensitivity. These results suggest that the ECRF might contribute to the ability of the LGNd neurons to detect some complex features such as texture segmentation and provide a subcortical contribution to the integrative field of visual cortical cells through receiving inputs from retinal ganglion cells with similar orientation biased extended surrounds [Neuroscience 98 (2000) 207].

The receptive fields of cat retinal ganglion cells in physiological and pathological states: where we are after half a century of research.

Studies on the receptive field properties of cat retinal ganglion cells over the past half-century are reviewed within the context of the role played by the receptive field in visual information processing. Emphasis is placed on the work conducted within the past 20 years, but a summary of key contributions from the 1950s to 1970s is provided. We have sought to review aspects of the ganglion cell receptive field that have not been featured prominently in previous review articles. Our review of the receptive field properties of X- and Y-cells focuses on quantitative studies and includes consideration of the function of the receptive field in visual signal processing. We discuss the non-classical as well as the classical receptive field. Attention is also given to the receptive field properties of the less well-studied cat ganglion cells-the W-cells-and the effect of pathology on cat ganglion cell properties. Although work from our laboratories is highlighted, we hope that we have given a reasonably balanced view of the current state of the field.

Activation of gamma-aminobutyric acid(B) receptors by baclofen improves visual temporal property of relay cells in the cat lateral geniculate nucleus.

The role of gamma-aminobutyric acid(B) (GABA(B)) receptors in spatial and temporal properties of the neurons was investigated in the cat dorsal lateral geniculate nucleus (dLGN) using flashing spot and drifting grating stimuli. Iontophoresis of baclofen, the selective GABA(B) receptor agonist significantly decreased the spontaneous and visual evoked responses (decreased to 38+/-7%), in which only the sustained component was suppressed sharply. Baclofen affected neither the center-surround antagonism of receptive fields nor the optimal spatial frequency of stimulating gratings. However, baclofen shortened cells' response duration and elevated their temporal frequencies that evoked the maximum and the half maximum response. In contrast, 2-OH-sacrofen, a GABA(B) antagonist showed no significant effect on dLGN cells' spatio-temporal properties. In conclusion, the activation of GABA(B) receptors may improve the temporal response properties of dLGN cells' via the sustained pathway, rather than change the spatial properties.

The responses to illusory contours of neurons in cortex areas 17 and 18 of the cats.

Responses to illusory contours (ICs) were sampled from neurons in cortical areas 17 and 18 of the anesthetized cats. For ICs sensitive cells, the differences of receptive field properties were compared when ICs and real contour stimuli were applied. Two hundred orientation or direction selective cells were studied. We find that about 42 percent of these cells were the ICs sensitive cells. Although their orientation or direction tuning curves to ICs bar and real bars were similar, the response modes (especially latency and time course) were different. The cells' responses to ICs were independent of the spatial phases of sinusoidal gratings, which composed the ICs. The cells' optimal spatial frequency to composing gratings the ICs was much higher than the one to moving gratings. Therefore, these cells really responded to the ICs rather than the line ends of composing gratings. For some kinds of velocity-tuning cells, the optimal velocity to moving ICs bar was much lower than the optimal velocity to moving bars. The present results demonstrate that some cells in areas 17 and 18 of cats have the ability to respond to ICs and have different response properties of the receptive fields to ICs and luminance boundaries via different neural mechanisms.

Effects of bicuculline on direction-sensitive relay cells in the dorsal lateral geniculate nucleus (LGNd) of cats.

The direction sensitivity of relay cells in the cat's dorsal lateral geniculate (LGNd) was measured using sinusoidal grating stimuli before and during local bicuculline administration. One hundred and twenty-eight LGNd relay cells were recorded in laminae A and A1, of which 44 relay cells (34%) were found to be sensitive to direction of stimulus movement. The direction-sensitive LGNd relay cells could be differentiated into two subgroups based on different measures of their response amplitude. Type I cells exhibited their direction sensitivity when the fundamental Fourier component (FFC) of the poststimulus time histograms (PSTHs) was used as response measure, but did not show significant direction sensitivity when mean firing rate was used. Type II cells exhibited their direction sensitivity, no matter whether the FFC or mean firing rate was used as the measure. Of 35 cells analyzed, 27 cells remained direction sensitive during bicuculline administration. At the population level, the direction bias of type I cells did not change systematically, while the direction bias of type II cells decreased significantly during bicuculline administration. These results suggest that the direction bias of these two types of relay cells are mediated by different neural mechanisms. The direction bias of type I cells may involve multiple inputs from spatio-temporally separate subunits within retinal ganglion cells receptive fields. The direction bias of type II cells may involve GABAergic neuronal circuits within the LGNd.

Orientation biased extended surround of the receptive field of cat retinal ganglion cells.

Here we report that the extended surround outside the classical receptive center (hereafter called the extended surround) of most retinal ganglion cells in the cat exhibit significant orientation bias to grating stimuli, and that the center and the extended surround show different orientation biases at different spatial frequencies. As a result, some retinal ganglion cells possess a complex receptive field structure, which allows them to detect sophisticated image segmentation (e.g. texture segmentation) in addition to simple luminance edges. This property was previously thought to exist primarily in the visual cortex. Moreover, in about one quarter of 128 cells studied the center did not exhibit an orientation bias. Thus, these surrounds alone may determine the cells' orientation bias.In conclusion, the extended surround may play an important role in processing more complex pattern in natural scenes since the classical receptive field is too small to describe all the properties of a retinal ganglion cell.

[The detection of disparity evoked potentials in anisometropes].

OBJECTIVE: To investigate the affection of anisometropia on stereopsis and its mechanism. METHODS: A new set of static random-dot stereograms was utilized as a stimulus to elicit evoked potentials in 20 anisometropes and 40 normal subjects. RESULTS: Under the stimulus of different degrees of disparity in anisometropes, the P(250) waves related to stereopsis could be recorded. However, the percentage of their P(250) wave amplitude over the plane figure was significantly lower than that of normal persons (P < 0.05). The P(250) wave mean amplitude of severe anisometropes (aniseikonia >or= 5%) in fine disparity (14' and 23') was lower than that in mild anisometropes (aniseikonia < 5%, P < 0.05). CONCLUSIONS: Anisometropia may affect and disturb the stereopsis. The degree of disturbance is related to the degree of anisometropia. The higher the degree of anisometropia, the lower the amplitude of the P(250) potential, and the main defect is at the part of fine disparity.

Ultraviolet blood irradiation and oxygenation affects free radicals and antioxidase after rabbit spinal cord injury.

OBJECTIVE: To investigate the effects of ultraviolet blood irradiation and oxygenation (UBIO) on free radicals and antioxidase after spinal cord injury in rabbits. METHODS: Totally, 186 rabbits were used and divided randomly into four experimental groups: control (n = 6), blood transfusion (n = 24), injured (n = 96) and treatment (n = 60) groups. The relative intensity of free radical (FR) signals, malondialdehyde (MDA) content, as well as the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) were compared among the four groups at 6, 24, 48, and 72 hours and 6 days after injury. RESULTS: The relative intensity of FR signals in spinal cord tissue in the injured group increased at 48 hours and showed a striking difference compared with the control group; in the treatment group, it decreased and showed a striking difference compared with the injured group. MDA content in blood in the injured group increased and showed a striking difference at 6, 24 and 48 hours and showed a significant difference at 72 hours and 6 days after injury compared with the control group. In the treatment group, MDA content in blood decreased and showed a significant difference at 48 hours compared with the injured group. MDA content in spinal cord tissue increased in the injured group and showed a striking difference compared with the control group; in the treatment group, it decreased and showed a striking difference compared with the injured group at the corresponding times. The activity of SOD in blood and spinal cord tissue decreased in the injured group and showed a striking difference compared with the control group; in the treatment group, it increased and showed a striking difference compared with the injured group at the corresponding times. The changes in activity of GSH-PX in blood and spinal cord tissue were similar to that in SOD. No significant difference was observed between the blood transfusion and control groups. CONCLUSION: UBIO can ease free radical damages and elevate the activity of antioxidases after spinal cord injury in rabbits.

[Spatial frequency tuning characteristics of cat primary visual cortex at different topological locations by optical imaging].

Using optical imaging based on intrinsic signals, we studied spatial frequency tuning characteristics of cat primary visual cortex at different visual topological locations. We found that the areas representing the peripheral visual field had null or very weak responses to high spatial frequency grating stimuli, whereas the areas representing the central visual field responded to the stimuli of a wide range of spatial frequencies with greater responses to high spatial frequencies. The more centered the corresponding visual field of the cortical area, the higher the cutoff spatial frequency. The spatial frequency tuning curves also tended to have a smooth shift along the cortical surface. The results above demonstrate that spatial frequency tuning characteristics of the primary visual cortex change according to different visual topological locations of the cortical areas, in addition to the existence of spatial frequency columns. It is suggested that the distribution of spatial frequency columns may be related to visual topology.

[The oblique effect revealed by optical imaging in primary visual cortex of cats].

The oblique effect is a ubiquitous visual psychological effect. To explore its underlying neural basis, we quantitatively analyzed the proportion and response amplitude of the cardinal preferred areas and the oblique preferred areas in a fairly large region of the primary visual cortex of cats, using optical imaging based on intrinsic signals. The results show that cardinal preferred areas were larger than oblique preferred areas, with a mean difference of 4.7%. Overall, the responses evoked by cardinal stimuli were generally greater than those by oblique stimuli. The present work provides an explanation for the differences in electrophysiological results reported for this issue, and gives a new insight into the neural basis of the oblique effect.

Pattern adaptation of relay cells in the lateral geniculate nucleus of binocular and monocular vision-deprived cats.

To test whether the pattern adaptation in thalamus is dependent upon postnatal visual experience during early life, the responses of relay cells to prolonged drifting grating stimulation were recorded extracellularly from the dorsal lateral geniculate nucleus (dLGN) of cats reared with binocular and monocular lid suture. In binocular vision-deprived cats, 68% of cells recorded showed significant adaptation to prolonged grating stimuli within 30 s, with a mean response decrease of 33%, and then stabilized gradually. This adaptation was stronger than that of relay cells in normal cats. In monocular vision-deprived cats, 53% of the cells driven by the deprived eye showed similar adaptation as did 44% of the cells driven by the non-deprived eye. These results indicate that pattern adaptation could be maintained or even enhanced after visual deprivation in early life. It is suggested that pattern adaptation is a general and intrinsic property of the dLGN cells, which may be mainly determined by genetic factors.

Comparative study on direction selectivity and functional organization of the primary visual cortical cells in monkeys and cats.

Although the directionally selective cells in many visual cortical areas are organized in columnar manner, the functional organization of direction selectivity of area Vl in the monkey still remains unclear. We quantitatively studied the proportion of directionally selective cells, direction selectivity and the functional organization of the striate cortical cells in the monkey and compared those with the cat. The results show that the direction selectivity and directional organization of striate cortical cells in the monkey are significantly weaker than those in the cat, suggesting that the species difference between the two kinds of animal is related to their different anatomic pathways.