Retinopathy of prematurity

Over the last decade major advances have been made in the understanding of the pathogenesis and evolution of retinopathy of prematurity (ROP). The increased survival of very small premature infants in modern neonatal intensive care units has led to the resurgence of this potentially blinding disease. ROP appears to be a multifactorial disease, the prevention of which is probably impossible even now, with the most accurate methods of blood gas monitoring and oxygen restriction. In addition to oxygen, there are a number of significant risk factors, such as birth weight and gestational age, ventilator hours, hyper and hypocarbia, hypoxia and acidosis, xanthine therapy and probably bright light. Current data suggest that the level of antioxidants in the immature retina is relatively low and therefore oxygen radicals which accumulate in the preterm baby's retina may play an important role in the pathogenesis of ROP. The treatment of the disease in both its "active" and "cicatricial" stages emphasizes the need for a new classification which could serve as a common international language through which results may be compared. Vitamin E was suggested in some studies to be helpful in preventing the severe stages of the disease, but its efficacy has yet to be proved. Treatment modalities such as photocoagulation, cryotherapy and vitrectomy are being tried as a means of therapy in the more advanced stages of the disease. Preliminary results of a large multicenter study support the efficacy of cryotherapy.     

Second generation shock wave lithotripsy: experience with the Siemens Lithostar

In 1980, extracorporeal shock wave lithotripsy (ESWL) was incorporated as a nonsurgical method of stone removal in the cases of nephrolithiasis and rapidly found worldwide acceptance. Several devices commonly designated "second generation" lithotripters vs "first generation" Dornier HM3 are now under experimental or clinical trial. We report our clinical experience of ESWL using a Siemens Lithostar and compared it with that obtained using a Dornier HM3. One hundred patients were treated during the period of April through October, 1986 using an HM3, and 100 other patients were treated using a Lithostar from April to August, 1988. More cases were treated with a Lithostar than with a HM3. Nearly 10% of all patients treated by ESWL required additional therapeutic approaches (excepted ureteral stent) either with HM3 or Lithostar. However, in the cases of ureteral stone, with the Lithostar more cases required adjuvant procedures (TUL) than HM3. Significantly more shock waves were needed with Lithostar than HM3 for complete fragmentation of the same size of renal and ureteral stones. The stone-free rate during a one month period after ESWL was nearly the same for HM3 and Lithostar (HM3: 84.3%, Lithostar: 83.5%). Lithostar is a multifunctional lithotriptor which has most of the advantages required by the lithotripter.     

The effects of vandellia cordifolia on renal functions and arterial blood pressure

Vandellia cordifolia (COLSM) G. DON of Scrophulariaceae (V. cordifolia) is an annual wild herb indigenous to Taiwan. It can be found in plains, low altitudes, swampy places, and paddy fields. Taiwanese folk physicians use it in "nephritis, uremia, furnucle, carbuncle." The LD50 (95% confidence limit) of the crude extract of V. codifolia given by the oral route was more than 10 g/kg in rats. By the intraperitoneal route, it was 4.6 g/kg (4.35-4.93). The extraction rate was 16.6%. We studied its effects on renal functions and blood pressure and found that (1) it had diuretic effect on normal rats, (2) it decreased glomerular filtration rate and renal blood flow on normal kidneys in rabbits, (3) it had no effects on glomerular filtration rate and renal blood flow on glycerin-induced insufficient kidneys in rabbits, (4) it had diuretic effects on both normal and glycerin-induced insufficient kidneys in rabbits, (5) it could inhibit Na+ and K+ reabsorption on normal and glycerin-induced insufficient kidneys in rabbits, (6) it had hypertensive effect and this effect could be blocked by phenoxybenzamine. From the above facts, we conclude that V. cordifolia has diuretic effect and it may act on renal tubules to inhibit Na+ and K+ reabsorption.     

Effects of the NMDA antagonists CPP and MK-801 on delayed conditional discrimination

N-methyl-D-aspartate (NMDA) receptor/channel antagonists have previously been shown to impair spatial working memory and hippocampal long-term potentiation. The present experiment investigated the effects of a variety of doses of NMDA antagonists on a working memory task in rats involving an auditory delayed conditional discrimination. Signal detection analysis and an exponential memory decay model were used to extract independent measures of stimulus discriminability and rate of forgetting. A competitive NMDA antagonist, (CPP, 0.33, 1.0, 10.0 mg/kg, IP) produced a reduction in discriminability which was linearly related to log dose, but which was only clear at the 10 mg/kg dose. Rate of forgetting was not increased by any dose. Similar results were obtained with a non-competitive antagonist (MK-801, 0.1, 0.33 mg/kg, IP). These data suggest that doses of NMDA receptor channel antagonists sufficient to disrupt hippocampal long-term potentiation and radial arm maze performance will also disrupt delayed conditional discrimination. The effect on delayed conditional discrimination is due to a disruption of stimulus discriminability and not to an increased rate of forgetting. The extent to which these effects relate to the reported changes in hippocampal long-term potentiation and radial arm maze performance remains to be determined.     

A microwave technique for double indirect immunostaining of human brain tissue cultures with mouse monoclonal antibodies.

The use of 2 monoclonal antibodies during double immunohistochemistry would enable the use of a greater variety of antibody combinations. Here, we demonstrate a simple, cost effective method of double indirect immunostaining of cultured cells using primary antibodies from the same species. This method uses microwaving of cell samples immediately after the application of the first secondary antibody, and significantly reduces the level of nonspecific staining. This technique does not elute the antibodies, nor raise the sample temperature above 37 degrees C.     

Kallikrein 4 expression is up-regulated in epithelial ovarian carcinoma cells in effusions

We immunohistochemically analyzed kallikrein 4 protein (hK4) expression in patients with epithelial ovarian carcinoma (181 malignant effusions and 103 solid carcinoma lesions). Expression of hK4 was also studied in 32 effusions using immunoblotting. Carcinoma cells expressed hK4 in 144 (79.6%) of 181 effusions and 85 (82.5%) of 103 solid tumors. Expression was seen in 51% or more of tumor cells in 70 effusions but often was limited to 5% or fewer cells in solid tumors (P = .009, primary tumors vs effusions; P = .002, metastases vs effusions). Immunoblotting showed hK4 expression in 31 of 32 specimens. Stromal cell hK4 expression, seen in 48 (46.6%) of 103 lesions, was significantly higher in primary tumors than metastases (26/43 vs 22/60, P = .019). hK4 expression in tumor cells was significantly lower in International Federation of Gynecology and Obstetrics stage IV than stage III tumors (P = .004, all lesions; P = .012, primary tumors). hK4 expression in carcinoma cells was associated with longer overall survival (not significant; P = .14, peritoneal effusions). hK4 is expressed widely in ovarian carcinoma; levels in carcinoma cells are highest in effusions, which might be related to loss of stromal contribution and/or altered microenvironment. hK4 expression in carcinoma cells of effusions or solid tumors does not predict survival.     

Lymphoepithelioma-like carcinoma of the bladder: three cases with clinicopathological and p53 protein expression study

Lymphoepithelioma-like carcinoma of the bladder is an uncommon neoplasm, of which 49 cases have been described in the English literature, none of which has been studied for p53 protein expression. We studied three muscle-infiltrating cases of this tumor using immunohistochemical, in situ hybridization and polymerase chain reaction (PCR) methods. The three cases were positive for epithelial markers and negative for lymphoid antigens in the tumoral syncytial areas. The intensive infiltrate of small cells was negative for epithelial and positive for lymphoid markers. This population was mainly made up of cytotoxic T-lymphocytes, positive for TIA-1. p53 protein was intensely positive in more than 90% of the epithelial component nuclei, being negative in the lymphoid cells. PCR study did not show mutations on p53. Both lymphocytes and epithelium were negative for Epstein–Barr virus markers, such as the latent membrane protein and EBER (Epstein–Barr-encoded RNA). The prognosis was very good after radiotherapy and chemotherapy treatment, preserving the bladder despite the muscle infiltration. The presence of an intense cytotoxic T-lymphocyte population may be related to this good prognosis. Both aspects, p53 protein status and T-lymphoid population, had never been studied before in bladder lymphoepithelioma-like carcinoma.     

基因探针监测巨细胞病毒潜伏感染的母儿间传播

本文采用基因探针检测孕妇静脉血及新生儿脐静脉血白细胞中CMVDNA，同时应用ELISA检测其血清中IgG、IgM．结果：10例孕妇CMV-DNA阳性，占8．7％(10／115)，这10例孕妇血IgG均阳性，IgM均阴性；17例新生儿CMV—DNA阳性．占14．3％(17／119)，其中IgM阳性2例，占1．7％(2／119)。本次研究中配对者79例，母儿CMV—DNA均阳性者8例，新生儿CMV—DNA阳性而母亲阴性者4例。上述CMV-DNA阳性者均无临床症状。研究结果提示基因探针可监测CMV的潜伏感染，从而进一步研究CMV感染的母儿传播机制。     

Marden-Walker syndrome: case report, literature review and nosologic discussion

Schrander-Stumpel C, de Die-Smulders C, de Krom M, Schyns-Fleuren S, Hamel B, Jaeken D, Fryns J-P. Marden-Walker syndrome: case report, literature review and nosologic discussion.
Clin Genet 1993: 43: 303–308. © Munksgaard, 1993
The Marden-Walker syndrome is characterized by psychomotor retardation, a mask-like face with blepharophimosis, micrognathia and a high-arched or cleft palate, low-set ears, kyphoscoliosis and joint contractures. We report on a male patient with the clinical features of the syndrome. In addition, he had a Dandy-Walker malformation with hydrocephalus and vertebral abnormalities. During pregnancy, there were feeble fetal movements and polyhydramnios. We propose that Marden-Walker syndrome is one of the etiologic possibilities in children with the heterogeneous fetal a(hypo)kinesia deformation sequence (FADS). Differential diagnosis is discussed. The etiology is probably heterogeneous.     

The effect of surface chemistry modification of titanium alloy on signalling pathways in human osteoblasts

Establishing and maintaining mature bone at the bone–device interface is critical to the long-term success of prosthesis. Poor cell adhesion to orthopaedic and dental implants results in implant failure. Considerable effort has been devoted to alter the surface characteristics of these biomaterials in order to improve the initial interlocking of the device and skeleton. We investigated the effect of surface chemistry modification of titanium alloy (Ti–6Al–4V) with zinc, magnesium or alkoxide-derived hydroxy carbonate apatite (CHAP) on the regulation of key intracellular signalling proteins in human bone-derived cells (HBDC) cultured on these modified Ti–6Al–4V surfaces. Western blotting demonstrated that modifying Ti–6Al–4V with CHAP or Mg results in modulation of key intracellular signalling proteins. We showed an enhanced activation of Shc, a common point of integration between integrins and the Ras/Mapkinase pathway. Mapkinase pathway was also upregulated, suggesting its role in mediating osteoblastic cell interactions with biomaterials. The signalling pathway involving c-fos (member of the activated protein-1) was also shown to be upregulated in osteoblasts cultured on the Mg and CHAP modified Ti–6Al–4V. Thus surface modification with CHAP or Mg may contribute to successful osteoblast function and differentiation at the skeletal tissue–device interface.