[Point systems for evaluating coma in patients with injuries of the central nervous system (CNS)]

Paper reviews various coma scales which are used to monitor consciousness after sustaining severe injuries of CNS. Glasgow Coma Scale, at present the most frequently used, was compared to recently developed scales, which are more useful for monitoring persistent comas, allows to evaluate discrete changes in patient's state more precisely and to predict the outcome. The necessity of evoked potentials' measurements, such as Trigeminal-Auditory Glasgow (Coma Scale) has been stressed.

Stress proteins in cardiovascular research

This review article is dealing with the most important aspects of stress proteins expression in cardiovascular research focused mainly on myocardial ischaemia and reperfusion. The major role of heat shock protein 70 kDa in endogenous route of myocardial protection is widely discussed in the context of possible contribution of other stress proteins. On the basis of numeral classical and recent published scientific data the problem of cellular response to stress and its possible clinical implication are presented.

[Persistent vegetative state: medical, moral, legal and economic aspects]

The classical definition of persistent vegetative state describes patient who is wakeful but not awake, and indicates intact function of the brain stem and no function of brain cortex. The presence and the degree of awareness is most difficult to assess and causes moral and legal controversies concerning the management of persistent vegetative state. The absence of the perceptual awareness may be the most important clinical characterization for diagnosis. Differential diagnosis includes coma, brain death, locked-in syndrome and minimally responsive state. The pressure of economical factors (managed care) on medical care makes this problem even more complicated.

Circadian changes of heart rate in West syndrome

Patterns of circadian and ultradian rhythms in the heart rate (HR) are described in a full-term baby with birth asphyxia and convulsions. A 24h HR recording was carried out at the age of 1, 15, 56, 289, and 295 days; West syndrome diagnosis was made when the patient was 3 months old. The HR showed no circadian rhythm in the follow-up, whereas it is known that the circadian rhythm appears in healthy infants at the age of 1 month and remains thereafter. This observation may be an indirect indicator of the interference of West syndrome with centers of neurological maturity.

[Use of polymerase chain reaction in medical diagnosis]

Principles of the polymerase chain reaction (PCR) and its modifications are discussed: reverse transcription-PCR (RT-PCR), nested PCR, restriction fragment length polymorphism-PCR (RFLP-PCR). Different methods of the PCR products detection used in routine diagnostics and research are presented: electrophoresis and chromatography techniques, immunoenzymatic methods, hybridisation and sequencing. Applications of PCR reaction in diagnostics of infectious diseases (viral and bacterial), genetic diseases and genotyping in transplantation are discussed and examples of commercial tests based on PCR reaction and another molecular biology methods used in fast, routine diagnostics are listed.

Down-regulation of BRCA1 and BRCA2 in human ovarian cancer cells exposed to adriamycin and ultraviolet radiation

Germ-line mutations of the BRCA1 and BRCA2 genes predispose women to develop cancers of the breast and ovary, but the biologic functions of these genes remains unclear. We have investigated the responses of the BRCA1 and BRCA2 gene products to cytotoxic agents in 3 human ovarian cancer cell lines: SK-OV-3 (which contains a p53 deletion mutation), CAOV-3 (which over-expresses a mutant p53) and PA-1 (which expresses wild-type p53). In screening studies, we determined the effects of 7 different agents on BRCA1 and BRCA2 expression. We found that Adriamycin (ADR) and ultraviolet (UV)radiation significantly down-regulated BRCA1 and BRCA2 mRNA expression in SK-OV-3 cells. On the other hand, camptothecin, nitrogen mustard, taxol, vincristine and etoposide had no effect on BRCA1 or BRCA2 mRNA levels at doses that yielded degrees of cytotoxicity similar to or greater than ADR. The down-regulation of BRCA1 and BRCA2 mRNAs was dose and time dependent; significant down-regulation was first observed at 8-16 hr after exposure to ADR. BRCA1 protein levels were also down-regulated following treatment of SK-OV-3 cells with ADR. Similar results were observed in CAOV-3 and PA-1 cells treated with ADR, and this finding could not be directly attributed to ADR-induced changes in the cell cycle distribution. The ADR doses required for significant decreases of BRCA1 and BRCA2 were about 10-15, 5-10 and 2 microM, respectively, for SK-OV-3, CAOV-3 and PA-1; the IC50 doses for loss of cell viability (determined by Trypan blue dye exclusion) were 23, 14 and 0.4 microM, respectively. Thus, at equitoxic doses of ADR, PA-1 cells were more resistant to down-regulation of BRCA1 and BRCA2 than SK-OV-3 or CAOV-3. Our findings suggest that 1) BRCA1 and BRCA2 expression in human ovarian cancer cell lines is selectively down-regulated by 2 DNA-damaging agents (ADR and UV radiation); 2) these responses are not due to non-specific cytotoxicity; and 3) the BRCA1 and BRCA2 responses may be dependent, in part, on the p53 functional status of the cells. We speculate that the down-regulation of BRCA1 and BRCA2 may be part of a cellular survival response activated by certain forms of DNA damage.

Scatter factor protects epithelial and carcinoma cells against apoptosis induced by DNA-damaging agents

Scatter factor (SF) (hepatocyte growth factor) is a cytokine that may play a role in human breast cancer invasiveness and angiogenesis. We now report that SF can block the induction of apoptosis by various DNA damaging-agents, including cytotoxic agents used in breast cancer therapy. SF protected MDA-MB-453 human breast cancer cells, EMT6 mouse mammary tumor cells and MDCK renal epithelial cells against apoptosis induced by adriamycin (ADR), X-rays, ultraviolet radiation, and other agents. Protection was observed in assays of DNA fragmentation, cell viability (MTT), and clonogenic survival. Protection of MDA-MB-453 cells against ADR was dose- and time-dependent; maximal protection required pre-incubation with 75-100 ng/ml of SF for 48 h or more. Protection required functional SF receptor (c-Met), but was not dependent on p53. Western blotting analysis revealed that pre-treatment of MDA-MB-453 cells with SF inhibited the ADR-induced decreases in the levels of Bcl-XL, an anti-apoptotic protein related to Bcl-2; and the dose-response and time course characteristics for SF-mediated increases in the Bcl-XL protein levels of ADR-treated cells were consistent with the degrees of protection against apoptosis observed under the same conditions. Furthermore, Bcl-XL levels were not down-regulated by ADR in MDA-MB-231 breast cancer cells, consistent with the finding that SF failed to protect these cells against ADR, despite the fact that they contain functional c-Met receptor. In contrast to Bcl-XL, SF blocked ADR-induced increases in c-Myc and inhibited the expression of p21WAF1/CIP1 and of the BRCA1 protein in MDA-MB-453 cells. However, SF did not cause significant changes in the cell cycle distribution of ADR-treated cells. These findings suggest that SF-mediated protection of human breast cancer cells may involve inhibition of one or more pathways required for the activation of apoptosis and may particularly target the anti-apoptotic mitochondrial membrane pore-forming protein Bcl-XL as a component of the protective mechanism. By implication, the accumulation of SF within human breast cancers may contribute to the development of a radio- or chemoresistant phenotype.

Expression of interleukin-1beta in human breast carcinoma

BACKGROUND

Interleukin 1beta (IL-1beta) is a multifunctional cytokine that up-regulates the inflammatory response. It is not known whether IL-1beta plays a major role in human malignancy. To determine whether IL-1beta might be involved in breast carcinoma progression, the authors measured the IL-1beta content in tissue extracts from >200 invasive breast carcinomas and smaller numbers of ductal carcinoma in situ (DCIS) and benign lesions.

METHODS

IL-1beta content was measured by an enzyme-linked immunoadsorbent assay and analyzed to determine whether these values were correlated with the contents of scatter factor (SF) (an invasogenic and angiogenic cytokine), von Willebrand's factor (VWF) (a marker of endothelium), thrombospondin-1 (TSP1) (an antiadhesive and antiangiogenic glycoprotein), and tumor necrosis factor-alpha (TNF alpha) (another proinflammatory cytokine). Studies were also performed to determine whether IL-1beta content was correlated with other pathologic and immunochemical variables that have been utilized or proposed as prognostic indicators for breast carcinoma.

RESULTS

The most important findings of these studies were: 1) immunoreactive IL-1beta was detected in approximately 90% of invasive breast carcinomas; 2) IL-1beta levels were significantly higher in invasive carcinomas than in a group of DCIS and benign lesions; 3) high IL-1beta content in invasive carcinomas was significantly associated with higher contents of SF, VWF, and TSP1, but not TNF alpha; and 4) there was a trend toward higher IL-1beta content in invasive carcinomas with a group of other parameters that suggest a biologically more aggressive tumor (estrogen receptor negativity, high tumor grade, p53 positivity, and bcl-2 negativity); and the proportion of invasive tumors with these characteristics was significantly increased in a subgroup of tumors having very high IL-1beta content. The authors also found a correlation between high IL-1beta content and CD68 positivity, suggesting that macrophages may account for some of the IL-1beta present in human breast carcinoma tissue.

CONCLUSIONS

These findings suggest that significant titers of IL-1beta are present within the microenvironment of most breast carcinomas and that a high IL-1beta content is often associated with tumor invasiveness and with other pathologic features suggestive of an aggressive tumor biology.

Evidence for a Dual Colour Code for ‘Object Colour’ and ‘Illumination Colour’ in Centre-Surround Configurations with Inhomogeneous Surrounds

We provide evidence that the surround-dependent change in appearance of an infield in a centre - surround configuration is not to be understood as an elementary recoding of channels by a simple surround-dependent gain control but in fact mirrors the triggering of a much more complex mechanism for establishing a dual code for ‘object colour’ and ‘illumination colour’.

We constructed centre - surround configurations—referred to as Seurat configurations—whose surrounds are given by a random structure of overlapping circles of a fixed diameter. These surrounds have been spatially modulated along the red - green axis only (isoluminance condition), along the luminance axis only (isochromatic condition), and along both axes, while keeping the space average fixed. Unique yellow settings were made for the infield. Our results suggest that the visual system seems to interpret a reduced variance of receptor codes for the surround as an indication of an illuminant that has to be discounted at the location of the infield. Furthermore, for the case of an isoluminant surround with strong spatial red - green modulation only, the unique yellow settings strongly tend towards the ones of an achromatic surround, ie the surround seems to be almost ineffective with respect to a differential gain control.

While our data on Seurat configurations with same space-averaged surrounds refute simple notions of functional equivalence, they suggest an interpretation in terms of a triggering of elementary perceptual categories related to ‘object colour’ and ‘illumination colour’.

Clinical and echocardiographical study of the aortic homograft implantations in patients with Marfan syndrome

The aim of the study was to assess the long-term results of surgical treatment with homogenic aortic grafts (HAGs) implantation in patients with Marfan syndrome. There were 31 patients with Marfan syndrome and aortic aneurysm who were operated on between 1980 and 1996. Aortic dissection was diagnosed in 14 patients, DeBakey Type I in six patients and Type II in eight patients. Four patients had to be operated urgently in cardiogenic shock with cardiac tamponade. Sealing up and reinforcement with strip of felt or Gore-Tex has been applied in 22 patients. The surgical modifications mentioned above have been applied since 1987 in all patients with the diameter of the aortic ring exceeding 30 mm or with active infective endocarditis or during reoperation. In 16 patients the space between the aortic homograft and patients own aortic wall was joined to the right atrial auricle. Patients were followed up for 12-179 months (average: 94.6 +/- 499). Three patients died in the early postoperative period and four patients died in the late postoperative period. Rethoracotomy because of bleeding complications was necessary in five patients. HAG damage was responsible for six other reoperations-new HAGs have been implanted in three patients and artificial prostheses were implanted in the other three patients. In the late follow-up period significant improvement in cardiac performance was observed in 24 patients (NYHA I or II). Survival probability of 15 years for the whole group was 80%. The lowest survival probability has been shown in the group of patients with DeBakey Type I aortic dissection (35% survived 15 years after operation). Echocardiographic follow-up has shown that the pressure gradient in HAG was low (7.4 +/- 6.2 mmHg). Only in two patients did the HAG gradient exceeded 20 mmHg. There were no significant differences concerning aortic ring diameters, dimensions of HAG and echocardiographic parameters between the group with surgical modifications, i.e. sealing up and reinforcement with strip of felt or Gore-Tex applied and the group in which these modifications were not applied. Homogenic aortic graft implantation as a method of surgical treatment of aortic aneurysm in patients with Marfan syndrome avoids postoperative anticoagulation, results in substantial improvement of cardiac performance and prolongs life. Surgical treatment should be considered in asymptomatic patients with large aneurysms (exceeding 55-65 mm) in patients with Marfan syndrome because there is a high risk of death in this group of patients in the case of dissection.

Kinetics of extracellular potassium concentration in irradiated red blood cells

BACKGROUND

Irradiation of cellular blood components prevents onset of transfusion-associated graft-versus-host disease. The present study was designed to monitor the post-irradiation changes of the extracellular potassium concentration in red blood cells (RBC) stored in SAG-M (saline adenine glucose-mannitol), in order to estimate the right time for their prophylactic irradiation and the right span of post-irradiation storage.

MATERIALS AND METHODS

Ten units each of fresh, 10 days and more than 20 days stored SAG-M RBCs were divided into 2 equal portions each. One portion was gamma-irradiated with 30 Gy (137Cs-source). Another 10 fresh RBC units were separated, and portions were irradiated with 15, 30, 60 or 120 Gy. The determination of potassium was performed simultaneously in corresponding irradiated and non-irradiated portions; immediately after irradiation, after 1 and 5 days, and every 10 days of additional storage (up to 30 days). All measurements were performed in the cell-free supernatant, using flame emission photometry.

RESULTS

The extracellular potassium concentration increased permanently with the duration of storage both in non-irradiated and irradiated specimens. At the end of the period of storage this increase in the irradiated portions was approximately 2 times the potassium concentration of the non-irradiated portions (60 mmol/l vs. 38 mmol/l, p < 0.001). Thereby no significant differences of the potassium efflux rates were estimated at the end of the period of storage between fresh RBCs irradiated and stored RBCs irradiated. The mean 5 days post-irradiation potassium release from fresh RBC units was similar to that in 25-30 days stored non-irradiated portions (34.3 mmol/l vs. 38 mmol/l). The extracellular potassium increase was irradiation dose-dependent (r = 0.89, p < 0.001).

CONCLUSIONS

SAG-M RBCs can be irradiated with 30 Gy immediately post-harvest and subsequently stored for a couple of days prior to transfusion without producing critically high extracellular potassium concentrations.

Energetic state of the postischemic myocardium and its relation to contractile failure

We used the isolated working rabbit heart preparation as a model to study the relationship between postischemic myocardial dysfunction and the energetic state of the heart in terms of mitochondrial function and myocardial high energy phosphate (HEP) contents. Normothermic global myocardial ischemia (10, 20 and 30 min) was induced. Cardiac function, mitochondrial function and myocardial HEP contents were measured. Viability of the postischemic myocardium was assessed by electron microscopy. Myocardial tissue was found to be intact up to 20 min of ischemia plus reperfusion. Areas of irreversibly damaged myocardium were found after 30 min of ischemia. Myocardial contractile function was significantly depressed after 10 and 20 min of ischemia and severely depressed after 30 min of ischemia. Postischemic myocardial dysfunction was associated with normal mitochondrial function and HEP content after 10 min of ischemia, with near-normal mitochondrial function and HEP content after 20 min of ischemia and with pathologic values after 30 min of ischemia. It is concluded that postischemic myocardial stunning is not associated with a disturbance of the energy producing processes. More severe ischemia however leads to progressive deterioration of mitochondrial function which may contribute to complete deterioration of myocardial contractile function upon reperfusion.

Effects of unloaded reperfusion on mitochondrial function in the postischemic myocardium

The effect of mechanical unloading on recovery of postischemic myocardial performance, high energy phosphate content, and mitochondrial function was tested in an isolated working rabbit heart model. After 30 min of global ischemia, prolonged unloaded reperfusion could prevent complete loss of contractility, deterioration of mitochondrial function, and depletion of the ATP pool as was found when only short-term unloading was performed. Aortic flow recovered to 21% of preischemic control, and left ventricular dP/dt max to 46% (p < 0.05 vs. short-term unloading). OPR and ADP/O stabilized at 42 and 72%, respectively (p < 0.05 vs. short-term unloading), and ATP at 33% of control (p < 0.05 vs. short-term unloading). These results show the beneficial effect of prolonged unloading in postischemic hearts.

Reperfusion after brief repetitive ischemia in porcine myocardium does not alter expression of creatine kinase MM or mitochondrial ATPase mRNAs

We examined whether the mRNA expression of creatine kinase MM isozyme (CKMM) and mitochondrial F1-ATPase, the key enzymes of intracellular energy transduction, are altered in porcine myocardium subjected to repeated brief periods of ischemia followed by reperfusion. The left anterior descending coronary artery was occluded for two cycles of 10 min with 30 min reperfusion in between, followed by the reperfusion up to 210 min. Systolic wall thickening was significantly decreased at 30 min reperfusion after both occlusions and remained depressed during reperfusion. In Northern blot analysis 1.5 kb CKMM and 1.9 F1-ATPase mRNA species were detected in sham, nonischemic and ischemic myocardial tissues. Densitometric analysis of signals showed a 30% decrease of the CKMM mRNA expression (p < 0.05 as compared to nonischemic area of the same heart and sham operated animals) only during the first period of ischemia. Reperfusion as well as the subsequent period of ischemia did not alter expression of CKMM mRNA. The expression of F1-ATPase mRNA remained unchanged during ischemia and reperfusion. We conclude that reperfusion after brief myocardial ischemia in swine is not associated with changes in CKMM and F1-ATPase mRNA expression. Our findings would support the hypothesis that myocardial stunning is not caused by altered expression of energy transducing enzymes.

Relationship of the polymerase chain reaction for cytomegalovirus to the development of hepatitis in liver transplant recipients

In a pilot study, the polymerase chain reaction was found to be more sensitive than standard viral culture methods for the detection of cytomegalovirus, particularly from blood and tissues. We therefore applied this technique to 71 serially collected liver biopsies from 16 orthotopic liver transplant patients. All patients were CMV-seropositive (n = 15) or seroconverted (n = 1). Seven patients (9 biopsies) had histologically proved CMV hepatitis, and all these biopsies were CMV PCR-positive. Six of these 7 patients had a prior liver biopsy that was CMV PCR-positive, but culture and histology-negative, an average of 13.2 +/- 6.9 days before the histologically positive biopsy. The 7th patient was not biopsied prior to the diagnostic biopsy. Three patients had 7 liver biopsies that were CMV PCR-positive, but histologically negative for CMV hepatitis. Two of these three had CMV infection confirmed by viral culture of blood or liver biopsy. The remaining 6 patients had a total of 26 liver biopsies that were negative for CMV by PCR, culture, and histology. Among liver transplant patients, CMV PCR performed on liver biopsy specimens correctly identified all histologically proven cases of CMV hepatitis. CMV PCR positivity in liver tissue did not correlate with latent infection and preceded the development of CMV hepatitis or other meaningful CMV infection in 8 of 10 patients.

Improvement of pregnancy rates with oocyte donation in older recipients with the addition of progesterone vaginal suppositories

Pregnancy rates and implantation rates with oocyte donation in recipients 40 years of age and older were significantly lower than those obtained in recipients under the age of 40. This difference was eliminated when P vaginal suppositories were added to the luteal regimen in older recipients. Our experience suggests that uterine aging may play a role in the successful initiation of a pregnancy, but this may be overcome with the preparation of the uterus with P vaginal suppositories.

Expression of heat shock proteins in the normal and stunned porcine myocardium

OBJECTIVE

The aim was to examine the expression of ubiquitin (Ub), 27 kDa heat shock protein (hsp27), and hsp60 mRNA in normal and briefly ischaemic and reperfused porcine myocardium:

METHODS

The left anterior descending coronary artery was occluded for two periods of 10 min separated by 30 min of reperfusion. After the second occlusion the myocardium was reperfused up to 210 min. Tissue from ischaemic, ischaemic-reperfused, and non-ischaemic regions of the heart was analysed by northern and slot blot hybridisation and nuclear run-on transcription assays employing radiolabelled cDNA probes for Ub, hsp27, and hsp60, as well as by western blot using monoclonal antibodies recognising Ub protein conjugates and antiserum recognising hsp27.

RESULTS

Systolic wall thickening was significantly decreased at 30 min reperfusion after both occlusions and remained depressed at longer periods of reperfusion. Using northern blot hybridizations, several mRNAs encoding Ub, 0.9 kb mRNA encoding hsp27, and 2.2 kb mRNA encoding hsp60 were detected in sham operated, non-ischaemic, and ischaemic myocardial tissues. Densitometric analysis of northern and slot blot hybridisation signals showed significant increase of basal tissue levels of Ub mRNA in stunned regions only during the 30 min of the second reperfusion period. Increased levels of hsp27 mRNA in stunned tissue were already noted at the first ischaemic period and were sustained compared to control during the subsequent periods of reperfusion. Changes in hsp60 mRNA tissue levels were not observed during ischaemia and subsequent reperfusions. Transcription of the Ub and hsp27 genes was increased during 30 and 120 min of the second reperfusion period. The transient enhancement of tissue levels of Ub mRNA was associated with temporary formation of new Ub-protein conjugates. However, the increased synthesis of mRNA encoding hsp27 was not followed by changes of hsp27 protein content in myocardial tissue.

CONCLUSIONS

The findings support the hypothesis that molecular damage occurs in stunned myocardium; however, the target molecules remain to be recognised.

Creation of a Spanish nephrological nursing accrediting course

In 1989, the Spanish Association of Nephrological Nursing (Sociedad Espanola de Enfermeria Nefrologica--SEDEN) created a course directed to all graduates in nephrological nursing in Spain to answer a need for further training. This article details the objectives, methodology, and results of the Course for Accrediting Specialized Knowledge in Nephrological Nursing since it was created.

Influence of the freezing-thawing-washing procedure on the cytomegalovirus DNA content of cellular blood products

There is a proven relation between cytomegalovirus (CMV) infection in seronegative immunocompromised patients and transfusion of random CMV unscreened cellular blood products (BP), where the leukocytes are thought to be the vector of transmission. We examined whether freezing, thawing, and washing, in attempt to reduce the quantity of leukocytes, also reduces the CMV-DNA-carrying cells of BP of CMV-seropositive donors and their infectivity for fibroblasts, using the polymerase chain reaction (PCR). The leukocyte contamination of the thawed-washed erythrocyte concentrates was < 1 x 10(8)/l and of the thawed-washed platelet concentrates, approximately 2.5 x 10(8)/l. All plasma samples and most samples of BPs of the CMV-seronegative controls were PCR-CMV-DNA-negative. The differences of the PCR results with the samples of CMV-seropositive donors before and after freezing were not significant. Thus we concluded that freezing-thawing-washing of cellular BP could not eliminate all CMV-DNA-bearing leukocytes. Plasma carries low risk for CMV infection, if at all.

TGF-beta receptors

The nature and role of cell surface proteins that bind members of the TGF-beta family has been investigated. TGF-beta, activins, and BMPs each bind to receptors of 55 kDa (type I) and 70 kDa (type II). In the TGF-beta system, these receptors are implicated in the mediation of multiple responses. A member of the type II receptor family has been cloned that encodes four alternatively spliced versions of a transmembrane serine/threonin kinase receptor related to the recently cloned mouse activin receptor and C-elegans daf-1 gene. Inhibitors of serine/threonine kinase activity block transcriptional and growth inhibitory responses to TGF-beta. In addition to the signaling receptors, many cell types express the TGF-beta binding proteoglycan betaglycan. Betaglycan has been purified, molecularly cloned, and shown to bind TGF-beta via its core protein and basic fibroblast growth factor via its heparan sulfate chains. In addition to receptors I and II and betaglycan, some cells express a newly identified set of membrane proteins that specifically bind either TGF-beta 1 or TGF-beta 2. Three of the four isoform-restricted binding proteins are bound to the membrane via phospholipid anchors. Like betaglycan, these proteins might function to regulate the interaction between TGF-beta and their target cells.

Contractile proteins in globally "stunned" rabbit myocardium

The isolated working rabbit heart preparation was used to study whether the "contractile machinery" remains unchanged in globally stunned myocardium. The function of the heart has been measured in nonischemic and postischemic conditions. The effect of isoprenaline or calcium chloride administration in both conditions was also studied. Myocardial contractile function was significantly depressed after 20-min global ischemia and returned to normal after CaCl2 and supranormal values after isoprenaline administration. From hearts used in experiments myofibrils were prepared and their ATPase activity was determined. It was observed that myofibrils prepared from "stunned" myocardium showed about 50% increase in ATPase activity in the presence of CaCl2. Subjection of the heart to ischemia caused a decrease in calcium sensitivity of the myofibrillar ATPase. Myofibrils obtained from ischemic hearts but subjected to isoprenaline or CaCl2 administration exhibited increased calcium sensitivity over that of control heart. These effects were accompanied by changes in the extent of phosphorylation of troponin I (TNI) and myosin light chains. The modification of contractile apparatus in the postischemic period described in this paper may contribute to the overall mechanism of myocardial stunning.

Mitochondrial function in myocardial stunning

Mitochondrial respiration parameters were studied in mitochondria isolated from normal, ischemic and post-ischemic rabbit hearts. Mitochondrial function was related to tissue content of high energy phosphates (HEP) and cardiac function in the isolated working rabbit heart preparation. It was found that after 10 and 20 mins of global normothermic ischemia followed by 20 mins of Langendorff reperfusion, mitochondrial function and HEP content of the myocardium were not significantly diminished. Myocardial creatine phosphate even showed a significant overshoot as compared to the pre-ischemic condition. When these hearts were allowed to perform work, recovery of cardiac function was incomplete while mitochondrial function and HEP content remained in the normal range. Prolonged ischemia (30 mins) resulted in a significant depression of mitochondrial function and myocardial ATP content during and after ischemia. Recovery of contractile function was severely depressed. These results show that impaired cardiac function after a mild ischemic insult (myocardial stunning) can be associated with near normal mitochondrial function and HEP contents.

Transforming growth factor-beta receptors and binding proteoglycans

Transforming growth factors-beta (TGFs-beta) are representative of a superfamily whose members were first identified as regulators of morphogenesis and differentiation, and subsequently found to be structurally related. Other members of the family include the activins and inhibins, BMPs, MIS, the DPP-C gene product and Vg-1. When assayed by affinity-labelling techniques, TGFs-beta bind to three distinct cell surface proteins which are present on most cells. These proteins are all of relatively low abundance but bind TGFs-beta with affinities consistent with the biological potency of the factors. The Type I and Type II binding proteins are glycoproteins with estimated molecular weights of 53 and 73 x 10(3) Mr, respectively. They both bind TGF-beta 1 significantly better than TGF-beta 2. The Type I receptor has been identified as the receptor which mediates many of the responses of TGFs-beta, based on somatic cell genetic studies of epithelial cell mutants unresponsive to TGFs-beta. Betaglycan is the third binding protein present on many, but not all, cell types and is a large proteoglycan (approximately 280 x 10(3) Mr) with 100-120 x 10(3) Mr core proteins. A soluble form of this molecule is present in conditioned media of many cell lines and may be derived from the cell surface-associated molecule by cleavage of a small membrane anchor. Betaglycan binds TGF-beta 1 and TGF-beta 2 with similar affinity and this binding is to the core proteins, not the glycosaminoglycan side chains. This molecule may have a function in the localization and delivery or the clearance of activated TGFs-beta.(ABSTRACT TRUNCATED AT 250 WORDS)

Three-wheel and four-wheel all-terrain vehicle injuries in children

In January 1988, sales of new three-wheel all-terrain vehicles (ATVs) were banned in the United States because of the high incidence of injury associated with their use, especially by children. Four-wheel ATVs remain on the market. A retrospective review of all ATV injuries seen in a level I pediatric trauma center was conducted to compare the nature and severity of injuries in three-wheel vehicles with those associated with four-wheelers. A total of 36 ATV injuries were seen from April 1986 to August 1988. All patients were less than 16 years of age; 72% were less than or equal to 12 years of age. Of the patients, 56% were boys; 44% were girls. Although 56% of incidents involved three-wheelers, a larger number of more serious injuries, defined as the presence of indicators of injury severity (eg, death, Injury Severity Score greater than or equal to 10, intensive care unit admission, or need for surgery), involved four-wheel vehicles. A total of 15 injuries occurred in 1987; 12 injuries, including the first death involving an ATV at the pediatric trauma center, occurred in the 7 months since the sales ban. Immature judgment and/or motor skills were the most common factors contributing to injury. Existing information regarding injuries involving three-wheel ATVs is supported by our data, according to which it is suggested that four-wheel vehicles may be dangerous in the hands of immature or unskilled operators less than 16 years of age. Injury prevention efforts should be directed at prohibiting any ATV use by persons less than 16 years of age.

Congenital pancreatic hypoplasia: a syndrome of exocrine and endocrine pancreatic insufficiency

We describe two brothers with small size at birth, early-onset insulin-dependent diabetes, and pancreatic exocrine insufficiency. In contrast to the findings in pancreatic aplasia, their serum C-peptide and glucagon levels were measurable. These findings, in concert with their clinical courses, are consistent with the diagnosis of congenital pancreatic hypoplasia.