Use of an in vitro model of tissue-engineered human skin to study keratinocyte attachment and migration in the process of reepithelialization

To produce a stable epidermis, keratinocytes need to be firmly attached to the basement membrane. However, following wounding, keratinocytes are required to develop a migratory phenotype in order to reepithelialize the wound. To investigate some of the issues underlying reepithelialization, we have developed a three-dimensional in vitro model of tissue-engineered skin, comprising sterilized human dermis seeded with human keratinocytes and dermal fibroblasts. Using this model, we have shown that the inclusion of fibroblasts within the model increases the stability of keratinocyte attachment. We have also demonstrated that keratinocyte migration occurs most effectively in the absence of a basement membrane and following the inclusion of fibroblasts in the model. In addition, subjecting the keratinocyte layer to mechanical trauma induces a migratory phenotype. We conclude that this three-dimensional in vitro wound model can be used to increase our understanding of the factors that enhance keratinocyte migration and hence wound healing in vivo.     

The in vitro pharmacological profile of KR31080, a nonpeptide AT1 receptor antagonist

Summary— KR31080 (2-butyl-5-methyl-6-(1-oxopyridin-2-yl)-3-[[2'-(1H-tetrazol-5-yl) biphenyl-4-yl]methyl]-3H-imidazo[4,5-b] pyridine) is a potent inhibitor of angiotensin type 1 (AT₁) receptors in rabbit aorta and human recombinant AT₁ receptors. In the isolated rabbit thoracic aorta, KR31080 caused a nonparallel shift to the right of the concentration-response curves to angiotensin II (All) with decreased maximal response (pD'₂ = 10.1 ± 0.1), but had no effect on the contractile response induced by norepinephrine. KR31080 inhibited specific [¹²⁵I]AII binding to rabbit aortic membranes (AT, receptors) and [¹²⁵I][Sar¹, Ile⁸]AII binding to human recombinant AT₁ receptors in a concentration-dependent manner with IC₅₀ values of 0.84 ± 0.08 nM and 1.92 ± 0.15 nM, respectively, but did not inhibit specific [¹²⁵I)AII binding to bovine cerebellum membranes (ÀT₂ receptors). In the Scatchard analysis, KR31080 interacted with rabbit aortic AT₁ receptors in a competitive manner, similar to losartan. These results demonstrate that KR31080 is a potent and AT₁ selective angiotensin receptor antagonist which exerts a competitive antagonism in the [¹²⁵I]AII binding assay and insurmountable AT₁ receptor antagonism in the functional study.     

A Chinese adolescent girl with Fechtner-like syndrome

We describe a 15-y-old girl with Fechtner-like syndrome, who is the first Chinese reported to have this rare syndrome. She presented with left homonymous hemianopia and neuroimaging revealed haemorrhage in both parietal and occipital lobes. Peripheral blood smear showed macrothrombocytopenia and intracytoplasmic inclusion bodies inside leucocytes. Thrombocytopenia and proteinuria responded to intravenous immunoglobulin and pulsed methylprednisolone. This case illustrates that life-threatening haemorrhage can occur in patients with Fechtner syndrome. Although there was no effective treatment reported in the literature, high dose steroid and immunoglobulin seemed to be useful in our patient. Our patient also had nephritic-nephrotic syndrome with renal insufficiency, which is unusual in adolescent female patients.     

Segmental Liver Transplantation from Non-Heart Beating Donors—An Early Experience with Implications for the Future

We report our experience of pediatric liver transplantation with partial grafts from non-heart beating donors (NHBD). Controlled donors less than 40 years of age with a warm ischemia time (WI) of less than 30 min were considered for pediatric recipients. Death was declared 5 min after asystole. A super-rapid recovery technique with aortic and portal perfusion was utilized. Mean donor age was 29 years and WI 14.6 min (range 11–18). Seven children, mean age 4.9 years (0.7–11), median weight 20 kg (8.4–53) received NHBD segmental liver grafts. Diagnoses included seronegative hepatitis, neonatal sclerosing cholangitis, familial intrahepatic cholestasis, hepatoblastoma, primary hyperoxaluria and factor VII deficiency (n = 2).The grafts included four reduced and one split left lateral segments, one left lobe and one right auxiliary graft. Mean cold ischemia was 7.3 h (6.2–8.8). Complications included one pleural effusion and one biliary collection drained percutaneously. At 20 months (10–36) follow-up all children are alive and well with functioning grafts.
Donation after cardiac death is a significant source of liver grafts for adults and children with careful donor selection and short cold ischemic times.     

Symptoms of irritable bowel syndrome in a British urban community: consulters and nonconsulters.

Because the prevalence of the irritable bowel syndrome (IBS) in the general population is unknown, a questionnaire of intestinal symptoms was administered to a stratified random sample of 1058 women and 838 men. Subjects were asked if they had consulted a physician about such symptoms. One or more symptoms occurred frequently in 47% of women and 27% of men. Diagnosable IBS, defined as three or more symptoms, was present in 13% of women and 5% of men. Abdominal pain was the most common symptom, and recurrent intestinal pain was reported by 20% of women and 10% of men. All symptoms were more common in women except runny or watery stools. Most symptoms including pain were unrelated to age. Only half the people with diagnosable IBS had consulted a physician about it. The likelihood of consulting a physician was directly proportional to the number of symptoms and was similar in men and women after controlling for the number of symptoms. Of individual symptoms, the one most strongly associated with consulting was abdominal pain, especially in men. It is concluded that IBS is prevalent at all ages, especially in women, that it is nearly always painful, and that people with multiple symptoms are more likely to consult a physician.     

Surgical management and prognostic factors in patients with subungual melanoma.

OBJECTIVE: Forty-six cases of subungual melanoma were reviewed to identify significant clinicopathologic prognostic factors, determine the role of DNA content analysis in the biologic assessment of these tumors, and evaluate the effectiveness of amputation level, lymph node dissection (LND), and regional limb perfusion on the survival of these patients. BACKGROUND: Subungual melanoma is a unique and rare subtype of melanoma, constituting only 1% to 3% of cases. Thus, little is known about prognostic factors and optimal management of patients with this disease. Moreover, the appropriate level of amputation and LND and limb perfusion in the management of subungual melanoma remain controversial. METHODS: Forty-six patients underwent amputation alone or in combination with LND and/or regional limb perfusion for primary subungual melanoma. The effects of these treatment modalities and the prognostic significance of patient and tumor-related variables, including DNA flow cytometric data, on overall survival were assessed. RESULTS: Univariate statistical analysis identified six factors that significantly affected patient survival. They were stage at diagnosis (p = 0.0001), percentage of aneuploid cells (p = 0.01), presence of ulceration (p = 0.02) or bone invasion (p = 0.02), thickness of the primary lesion (p = 0.03), and percentage of cells in S-phase (p = 0.03). Multivariate analyses identified tumor stage and S-phase fraction as independent prognostic factors in these patients. Survival did not differ among patients who received amputation alone or those who underwent amputation in combination with LND or perfusion (p = 0.90); however, the use of limb perfusion reduced the incidence of locally recurrent disease. The level of amputation did not affect patient survival (p = 0.74) or the incidence of local recurrence. CONCLUSIONS: The study identified several significant prognostic factors, including DNA flow cytometric parameters, in patients with subungual melanoma. In addition, it showed that conservative amputation of the affected digit at the level of the proximal interphalangeal or metacarpophalangeal/metatarsophalangeal joint appears to be safe, provided that clear margins are obtained. Although isolated limb perfusion may reduce the incidence of local recurrence, LND, or limb perfusion in the routine management of subungual melanoma remains controversial.     

Solid and papillary epithelial neoplasms of the pancreas: CT findings

Five female patients and one male patient with solid and papillary epithelial neoplasms of the pancreas were examined with computed tomography (CT). The mean age of the patients was 27 years (range, 13-46 years). All cases showed well-encapsulated, round or lobulated masses consisting of both cystic and solid areas. Cystic portions showed CT numbers that suggested hemorrhagic necrosis. There were no internal septations within the masses. In three tumors located in the head of the pancreas, dilatation of the biliary tree was absent or minimal, although the masses were large. Two tumors contained calcifications. One tumor demonstrated metastatic deposits in liver and lymph nodes. Metastatic masses appeared similar to the primary pancreatic mass. Solid and papillary neoplasm of the pancreas should be the primary diagnostic consideration when characteristic CT findings are detected in a young female patient.     

The influence of muscle-conditioned media on chick embryo brainstem neurons in culture

Brainstem pieces from the trigeminal region of the metencephalic basal plate of 10-day chick embryos were dissociated and cultured in control conditions or in the presence of muscle-conditioned medium (MCM). The MCM was derived from age-matched target tissue relevant to this neuronal region (jaw musculature), from relevant target tissue of an age at which innervation would initially be taking place (4 days), and from nonrelevant target tissue also of an early stage (4-day limb bud). Neuronal survival and differentiation was assessed daily, for 7 days. Survival and differentiation were significantly enhanced by the 4-day jaw MCM compared to both the controls and the cultures grown with 10-day jaw MCM and 4-day limb MCM. These measures in the presence of 10-day jaw MCM and 4-day limb MCM did not differ, but surpassed that seen in control cultures. The results are compared to the more specific responsiveness seen in earlier (2-day) neural tube cultures, and their relationship to in vivo regenerative nerve fiber outgrowth is considered.