Interfollicular fibroblasts in the human thyroid gland: recognition of a CD34 positive stromal cell network communicated by gap junctions and terminated by autonomic nerve endings

While epithelial structure and functions have been substantially investigated in many organs, the mesenchymal elements have received less attention. Compared with follicular epithelial cells, there are a few morphological studies on the stroma of human thyroid gland. In order to characterize more fully and assess its possible functions, 15 samples of surgical and autopsy human thyroid tissue were studied by classical histology, immunohistochemistry, transmission electron microscopy, electron microscopic immunohistochemistry, and scanning electron microscopy. In human thyroid gland, the interfollicular connective tissue surrounding the follicles contained collagenous matrix, fibroblasts, unmyelinated nerve fibers with Schwann cells, small blood vessels, lymphatics, lymphocytes, plasma cells, macrophages, and mast cells. At the ultrastructural level, gap junctions between the cytoplasmic processes of interfollicular fibroblasts constituted a novel observation. Immunohistochemistry using a monoclonal antibody against Cx43 confirmed the distribution of gap junctions between stromal fibroblastic cells, which was compatible with the ultrastructural findings. The frequent and intimate association of fibroblastic processes with nerve terminals was also shown. Interfollicular stromal fibroblasts also stained with CD34. The main constituent of the human thyroid stromal tissue was a CD34 positive reticular network involving fibroblasts, mononuclear cells and nerve terminals. It represents a highly ordered stroma, with potential structural and functional similarities to the stroma of bone marrow (Yamazaki and Allen, 1990).     

Stroke therapy in children

OBJECTIVE: To evaluate the treatment modalities used in children (ages 1-18 years) with cerebral infarction. BACKGROUND: [corrected] Cerebrovascular disease in children is more common than once suspected but its treatment has not been rigorously studied. MATERIAL AND METHODS: We reviewed all cases of cerebral infarction at the James Whitcomb Riley Hospital for Children at the Indiana University Medical Center from 01.01.80 to 31.12.95. RESULTS: Ninety-three children who experienced ischemic strokes were followed over the past fifteen years. Fifty-seven males and thirty-six females comprised the sample. Mean age was 6.9 years at the time of stroke. No medication or surgical intervention was the therapeutic recommendation in 44% of patients. For cardioembolic strokes, warfarin was used later in the course for a few patients who went on to have atrial fibrillation or valve replacement. Aspirin was used in all patients with carotid artery dissections. Aspirin was used in most children with Moya-Moya, with calcium channel blockers and surgical intervention used in later cases. Exchange transfusion followed by monthly transfusion and chelation therapy has been the treatment of choice for children with cerebral infarction complicating sickle cell disease. CONCLUSIONS: In most instances, treatment was widely disparate, probably reflecting the lack of firm therapeutic guidelines for this age group, with a better understanding of the etiology and pathophysiology of strokes in children, multicenter, international, randomized therapeutic trials based strictly on an etiological basis should be organized in the future.     

VEGF mRNA induction correlates with changes in the vascular architecture upon spinal cord damage in the rat

The multiple cellular and molecular processes induced by injury to the central nervous system (CNS) are still poorly understood. In the present study, we investigated the response of the vasculature and the expression of mRNA for the angiogenic vascular endothelial growth factor (VEGF) following X-irradiation of the spinal cord in the newborn and following traumatic spinal cord injury in the adult rat. Both lesion models induced changes in the density and the distribution pattern of blood vessels: while X-irradiation led to a permanent local increase in vascular density in the fibre tracts of the exposed segments, a transient local sprouting of vessels was induced upon traumatic spinal cord injury. In situ hybridization showed that an increase of VEGF mRNA anticipated and overlapped with the vascular responses in both lesion models. In addition to the temporal correlation of VEGF expression and vascular sprouting, there was a clear correlation in the spatial distribution patterns. Following X-irradiation, the expression of VEGF mRNA was restricted to the fibre tracts, precisely the areas where the changes in the vasculature were observed later on. Upon transection in the adult animal, VEGF was mainly detectable at the border of the lesion area, where the transient increase in vascular density could be observed. Interestingly, according to the type of lesion applied, astrocytes (X-irradiation) or inflammatory cells (presumably microglial cells or macrophages; traumatic lesion) are the cellular sources of VEGF mRNA. Our results strongly indicate that VEGF is crucially involved in mediating vascular changes following different types of injury in the CNS.     

Phase Transitions in Liquid Crystal Doped with Magnetic Particles of Different Shapes in Combined Electric and Magnetic Fields

We have studied the influence of electric and magnetic fields on the orientational structure of ferronematics based on a thermotropic nematic 4-trans-4 \(^{\prime }\) -n-hexylcyclohexyl-isothiocyanato-benzene (6CHBT). The 6CHBT liquid crystal has been dissolved in phenyl isothiocyanate and doped with rod-like or chain-like magnetic particles. In such a mixture, the phase transition from an isotropic to a nematic phase is via a droplet state, i.e., coexistence of nematic and isotropic phases. The obtained results showed that a combination of the electric and magnetic fields can change the character of a phase transition from the isotropic to the nematic phase via the droplet state in such systems. Moreover, magneto-dielectric measurements of structural transitions showed the magnetic field induced a shift of the phase transition temperature from the isotropic to the droplet state.     

Seeking medical care for a breast cancer symptom: Determinants of intentions to engage in prompt or delay behavior.

Examined the cognitive structures underlying women's intentions to seek medical care for a breast cancer symptom. 134 women imagined that they had discovered a change in their breast and chose between 2 alternatives based on I. Ajzen and M. Fishbein's (1980) theory of reasoned action: immediately calling the doctor (prompt behavior) or monitoring the breast change on one's own (delay behavior). Results show that intentions to delay were positively associated with favorable attitudes toward delay (FATDs) and with perceived social pressure to delay. The attitudinal factor was more influential than the social factor in determining intentions. Underlying FATDs were beliefs that delay would result in maintaining control and avoiding disruption, without negative health outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sexually transmitted disease acquisition among women infected with human immunodeficiency virus type 1

Recent evidence suggests that sexually transmitted diseases (STDs) enhance the transmission of human immunodeficiency virus (HIV) type 1. In 143 HIV-infected women enrolled in a university-based longitudinal HIV clinic over 16 months (mean), the STD point prevalence was examined at enrollment and the cumulative prevalence was calculated at follow-up. At enrollment, 35 women (25%) had > or = 1 STD. These included trichomoniasis in 16 women (11%); syphilis, 9 (6%); genital herpes, 8 (6%); gonorrhea, 5 (4%); chlamydia, 5 (4%); genital warts, 2 (1%); and pelvic inflammatory disease (PID), 1 (1%). STDs were found in 55 (42%) of the 125 patients who returned for at least one follow-up visit: trichomoniasis in 23 (18%); genital herpes, 20 (12%); gonorrhea, 9 (7%); syphilis, 7 (6%); genital warts, 7 (6%); chlamydia, 5 (4%); and PID, 4 (3%). Despite counseling at both enrollment and follow-up, these women had a very high cumulative prevalence of STDs, indicating persistent high-risk sexual behavior.     

No passport is required to incorporate cultural appreciation into perioperative nursing practice

As you read this issue of the Journal and celebrate OR Nurse Week, think about your daily opportunities to practice the principles of international nursing. Look for chances to appreciate cultural values different from your own as you provide patient care and interact with visiting international colleagues. Adopt a global perspective to perioperative nursing.