The role of acetic acid in the prevention of salt-induced aggregation of snake venom cardiotoxins

Snake venom cardiotoxins (CTXs) exhibit a strong tendency to aggregate upon desalting and hence it is extremely difficult to prepare salt-free cardiotoxin(s). In the present study, we describe a new method for preparation of salt-free CTX based on dialysis against acetic acid. Based on experimental observation and the three dimensional solution structure of cardiotoxin analogue III from the Taiwan cobra (Naja naja atra), a molecular mechanism for the prevention of aggregation of cardiotoxins by acetic acid is discussed. In our opinion, the results obtained in the present study would pave way for elucidating the structural basis for the broad spectrum of biological activities exhibited by snake venom cardiotoxins.

Glomerular transforming growth factor-beta1 mRNA as a marker of glomerulosclerosis-application in renal biopsies

As transforming growth factor-beta1 (TGF-beta1) is implicated in the pathogenesis of glomerulosclerosis, the aim of the study was to demonstrate if levels of glomerular TGF-beta1 mRNA in renal biopsies correlated with glomerulosclerosis. Glomeruli were collected by microdissection from renal biopsies in patients with membranous nephropathy, lupus nephritis, diabetic nephropathy, minimal change disease and IgA nephropathy presented by proteinuria when serum creatinine was <3 mg%. Glomerular mRNAs were reverse transcribed and TGF-beta1, alpha2(IV) collagen, beta-actin cDNA quantitated by competitive polymerase chain reaction (PCR). By semiquantitative electron microscopy, a 3.5-fold increase of glomerular TGF-beta1/beta-actin mRNA ratio in the moderate sclerotic group (n = 23, p < 0.01) and a 1.5-fold increase in the mild sclerotic group (n = 22, p < 0.05) were observed when compared to the minimal sclerotic group (n = 12). A concordant increase of glomerular alpha2(IV) collagen mRNA was found with 2.2- and 1.3-fold in moderate and mild sclerotic groups, respectively. The TGF-beta1/beta-actin mRNA ratios were highest in membranous nephropathy (466.4 +/- 133.4, n = 11), followed by lupus nephritis (394.9 +/- 94.8, n = 12) and diabetic nephropathy (333.2 +/- 97.6, n = 10). Patients with minimal change disease(233.1 +/- 54.1, n = 15)and IgA nephropathy(185.3 +/- 39.6, n = 9) had low levels. The degree of glomerulosclerosis in each group followed the TGF-beta1/beta-actin mRNA ratios indicating that the level is the major determinant ofglomerulosclerosis but not the disease entities. Glomerular TGF-beta1/beta-actin mRNA ratio did not correlate with clinical parameters such as the urinary protein excretion and creatinine clearance. These results suggest that glomerular TGF-beta1/beta-actin mRNA ratio may be used as a marker of glomerulosclerosis in renal biopsy to reflect the local sclerotic process.

Malakoplakia of the prostate: a case report

Malakoplakia is an unusual chronic inflammatory disease that was first discovered in the urinary bladder but has subsequently been described in other sites. Characteristic gross and microscopic features of the lesions have been well described. The diagnosis of this tumor-like lesion can only be established by pathologic examination of the involved tissue. A case of prostatic malakoplakia with characteristic gross and microscopic features is reported in a 59-year-old man who presented with urinary frequency and a diminished urinary stream. Clinically the condition mimicked carcinoma of the prostate gland and the patient underwent a radical retropubic prostatectomy. Postoperative recovery was uneventful. The clinical and pathological findings, differential diagnosis and pertinent literature are reviewed. Preoperative needle biopsy or intraoperative frozen section for tissue diagnosis is recommended to avoid unnecessary radical surgery for this type of tumor-like lesion.

Differential screening of a subtracted cDNA library: a method to search for genes preferentially expressed in multiple tissues

We have developed a new strategy for differential screening of genes that are expressed in two or more tissues, and have used it to identify genes that are preferentially expressed in both testis and ovary. In this approach, testis-specific cDNAs were first generated using the suppression subtractive hybridization technique, cloned and arrayed in microplates. The inserts from the subtracted testis-specific library were amplified by PCR and spotted on filters. The dot blots were screened by hybridization using either testis- or ovary-specific subtracted cDNA mixtures as probes. By screening about 2000 putative clones from the subtracted testis-specific library, we identified 14 candidate genes that hybridized to both cDNA probes. Northern blot analysis showed that 12 clones were preferentially or exclusively expressed in testis and ovary. Nucleotide sequence analysis indicated that three of the identified clones represented cDNAs from novel genes.

Leptospirosis: an ignored cause of acute renal failure in Taiwan

Leptospirosis, caused by a spirochete, is the most common zoonosis in domestic or wild animals. Animals excrete infected urine in soil or water and may cause human infections through abrased wound, mucosa, conjunctiva, or by swallowing contaminated water. Clinical presentations of leptospirosis are mostly subclinical. Five to ten percent of leptospirosis are fatal, causing fever, hemorrhage, jaundice, and acute renal failure (Weil's syndrome). Leptospirosis has been ignored as a cause of acute renal failure in Taiwan. We report two patients with leptospirosis who presented with high fever, abdominal pain, jaundice, and acute renal failure. Patient 1 died on day 12 of admission of multiple organ failure associated with pancytopenia, hypogammaglobulinemia, and reactive hemophagocytosis. Leptospirosis was recognized after death. Patient 2 was admitted with similar presentations 2 weeks later. Penicillin and doxycycline were given early in the course, and azotemia, jaundice, respiratory failure, and aseptic meningitis gradually improved. Renal biopsy showed interstitial nephritis. Several tubular clearance tests showed proximal tubular defect with severe bicarbonate wasting (FeHCO3- 20.9%) and incomplete type II renal tubular acidosis without affecting the distal nephron. After 80 days of treatment, this patient was discharged with recovery of conscious level and renal function. This is the first leptospirosis patient with detailed tubular functional and morphological studies of the kidney. Diagnosis of leptospirosis was made by microscopic agglutination test (MAT) for antibody to leptospira and by polymerase chain reaction (PCR) for leptospira DNA in blood and urine (interrogans serogroup australis in case 1 and Leptospira borgpetersenii serogroup ballum in case 2). Because active surveillance has resulted in 13 cases diagnosed as leptospirosis islandwide thereafter, underestimation and ignorance of leptospirosis as a cause of acute renal failure may occur in Taiwan. Therefore, an area with a low leptospirosis incidence may actually have a very high incidence. Leptospirosis should be suspected in febrile patients with jaundice and renal failure when pathogens cannot be identified by traditional culture for microorganisms.

Deletions of the Aequorea victoria green fluorescent protein define the minimal domain required for fluorescence

The Green Fluorescent Protein (GFP) from the jellyfish Aequorea victoria is a widely used marker for gene expression and protein localization studies. Dissection of the structure of the protein would be expected to shed light on its potential applications to other fields such as the detection of protease activity. Using deletion analysis, we have defined the minimal domain in GFP required for fluorescence to amino acids 7-229. This domain starts at the middle of the first small alpha helix at the N terminus of GFP and ends immediately following the last beta sheet. Studies of the amino acids at both termini of the minimal domain revealed that positions 6 and 7 at the N terminus are Glu-specific. Change of the Glu residues to other amino acids results in reduction of GFP fluorescence. Position 229 at the C terminus of GFP, however, is nonspecific: the Ile can be replaced with other amino acids with no measurable loss of fluorescence. A total of only 15 terminal amino acids can be deleted from GFP without disrupting fluorescence, consistent with findings of a previous study of GFP crystal structure (Ormo, M., Cubitt, A. B., Kallio, K., Gross, L. A., Tsien, R. Y., Remington, S. J. (1996) Science 273, 1392-1395 and Yang, F., Moss, L. G., and Phillips, G. N., Jr. (1996) Nat. Biotechnol. 14, 1246-1251) that a tightly packed structure exists in the protein. We also generated internal deletions within the loop regions of GFP according to its crystal structure and found that all such deletions eliminated GFP fluorescence.

A multidisciplinary pulmonary rehabilitation program for patients with moderately severe chronic obstructive pulmonary disease

A multidisciplinary pulmonary rehabilitation program was conducted for 13 outpatients (mean age 66 +/- 6.7 yr) with moderately severe chronic obstructive pulmonary disease. Changes in pulmonary function and blood gas data were not significant. Exercise capability, including 6-minute walking distance (WkD6), maximal work load (WkLmax), endurance time, and maximum heart rate, improved significantly (p < 0.05), as did subjective symptoms and quality of life. Of the observed changes, only baseline PaO2 and oxygen saturation were positively correlated with changes in maximum heart rate. The initial maximum heart rate was inversely related to both the absolute and percentage improvement. There were no significant relationships between improvement in WkD6 and age, initial arterial blood gas, or pulmonary function, but a significant relationship was found between baseline forced expired volume in the first second (FEV1) and percentage change in WkLmax. Our results indicate that patients with moderately severe chronic obstructive pulmonary disease can improve their exercise capacity, subjective symptoms, and quality of life through a pulmonary rehabilitation program. All patients can increase their endurance, regardless of their initial exercise performance. Maximum heart rate and FEV1 are predictors of exercise capability improvement.

Assessment of dialysis adequacy using the dialysate urea monitor: preliminary experience of the dialysate urea monitor

Numerous studies have identified a strong linkage between the delivered dialysis dose (Kt/V) and the survival of hemodialysis (HD) patients. However, the current method used to calculate Kt/V requires multiple blood samples and the process is complex and time consuming. We evaluate the performance of a recently developed on-line monitor (Biostat 1000 dialysate urea monitor, Baxter) that measures the urea concentration in the effluent dialysate and displays Kt/V and nPCR immediately after hemodialysis. To verify the performance of the urea monitor, we selected 21 hemodialysis patients, calculated their Kt/V and nPCR values from blood samples obtained during each hemodialysis, and compared the results with data obtained using the urea monitor. The Kt/V and nPCR values calculated by the urea monitor were both significantly correlated with those obtained using blood samples (R = 0.804, p < 0.001 in Kt/V and R = 0.749, p < 0.001 in nPCR). Our results suggest that the urea monitor may be used for on-line assessment of dialysis adequacy and obviates the need for blood sampling.

Demographic characteristics and medical aspects of menopausal women in Taiwan

This report describes the medical and demographic characteristics of menopausal women in Taiwan in order to provide information for consideration during future healthcare planning. The medical and demographic data analyzed were taken from officially published materials of the Government of the Republic of China on Taiwan, our own studies, and those of other researchers. In 1994, the average lifespan of men in Taiwan was 71.8 years and that of women was 77.7 years. The age of menarche was 13.6 years and the age of menopause was 49.5 years. Women aged 50 and over accounted for 18.3% of the total female population and 8.9% of the total population in Taiwan. In 1994, 68.9% of women in Taiwan aged 50 and over were married. The most frequently occurring menopausal symptoms in Taiwanese women were lumbago or low backpain (68%), fatigue (59%), impairment of memory (55%), vaginal dryness (50%), and hot flushes and sweating (49%). The spinal bone mineral density of women decreased markedly after the age of 50 years. The prevalence of vertebral fracture in women 65 years and over was 19.8%, which was higher than the 12.5% in men of the same age group. The prevalence of hypertension and coronary heart disease in women 50 years or older was also higher than in men. The most frequent sites of cancer in women in 1992 were the cervix uteri, breast, sigmoid colon and rectum, lungs, liver, stomach, thyroid, ovaries, hemopoietic and reticuloendothelial systems, and skin. There were 14,298 newly reported cases of malignant neoplasms in women in 1992. About 60% of these occurred in women aged 50 years or more. The median age of occurrence of cervix uteri, breast, and ovarian cancers was 48 to 49 years, which is very close to the menopause age. About 30% of menopausal women in Taiwan are currently living without a husband. Although 18.3% of women in Taiwan were at least 50 years old, approximately 60% of all malignant neoplasms in the female population occurred in this group. There is an urgent need for menopausal women in Taiwan to receive psychologic support and comprehensive medical care.

Respiratory drive and pulmonary mechanics during haemodialysis with ultrafiltration in ventilated patients

The improvements of respiratory drive and pulmonary mechanics which follow haemodialysis with ultrafiltration in mechanically ventilated renal failure patients seem predictable but have not been studied before. In this study, 14 renal failure patients with stable haemodynamics mechanically ventilated with pressure support ventilation (PSV) were enrolled. Respiratory drive (represented as P0.1), pulmonary mechanics, breathing pattern, arterial blood gas and haemodynamics were measured according to the time schedule: pre-dialysis (Time 0), and at 60, 120, 180, 240 minutes thereafter. Following the removal of excess lung water during haemodialysis, auto-PEEP and patient's work of breathing (WOBp) decreased gradually. P0.1 lessened progressively along with the improvement in pulmonary mechanics. The changes in auto-PEEP and WOBp correlated closely to the pre- and post-dialysis decline of P0.1 (delta P0.1). There was a negative, moderately significant correlation between the amount of fluid ultrafiltrated during dialysis (delta UF) and the delta P0.1 (R = -0.54). The breathing pattern remained stable during dialysis. No hypoventilation or hypoxaemia occurred despite the development of metabolic alkalosis induced by bicarbonate dialysate. We have shown that respiratory drive decreases gradually during bicarbonate haemodialysis. The improvements of pulmonary mechanics, rather than the rapid alkalization of body fluids, responds to the decrease of P0.1 in renal failure patients ventilated with PSV.

Automated on-line sample pretreatment system for the determination of trace metals in biological samples by inductively coupled plasma mass spectrometry

A fully automated on-line sample pretreatment system combining microwave digestion with sample preconcentration/matrix separation for the determination of trace metals (Fe, Ni, Cu, Zn, and Pb) in blood and serum samples by inductively coupled plasma mass spectrometry (ICPMS) was designed and evaluated. The samples were mixed with an appropriate reagent and digested in a flow-through, focused microwave-heated oven. After digestion, the sample solution was transferred on-line to a column packed with iminodiacetate-based resin for separation of matrix elements like Na, K, Ca, Mg, Cl, P, and S that might interfere with the measurement by ICPMS. The analytes chelated on the resin were subsequently eluted and led to ICPMS for multielement determination. The whole sample pretreatment process was automatically controlled by a self-designed expert system. The analytical reliability of data from this on-line system was confirmed to be good with the analysis of SRM samples (Seronorm Whole Blood and NIST SRM 1598 Bovine Serum), and the limits of detection (3 sigma) for Fe, Ni, Cu, Zn, and Pb were 68, 0.34, 3.5, 13.4, and 0.22 microgram/L, respectively. With this fully automated on-line system, the determination of analytes in biological fluid samples down to micrograms-per-liter levels has been proven to be feasible, and the sample throughput can achieve up to 6 samples/h.

Nitric oxide signalling is required for the generation of anoxia-induced long-term potentiation in the hippocampus

The involvement of nitric oxide in anoxia-induced long-term potentiation (anoxic LTP) of synaptic transmission was investigated in CA1 neurons of rat hippocampal slices using intracellular recording techniques in vitro. In response to superfusion of an anoxic artificial cerebral spinal fluid saturated with 95% N2-5% CO2, the excitatory postsynaptic potential (EPSP) generated in hippocampal CA1 neurons by stimulation of the Schaffer collateral/commissural afferent pathway was completely abolished within 10 min of anoxia. On return to reoxygenated medium, the EPSP returned to the control value within 10 min and was subsequently and progressively potentiated to reach a plateau 15-20 min after return to oxygen. This anoxia-induced persistent increase in synaptic transmission lasted for more than 1 h. Application of the nitric oxide synthase inhibitors 7-nitroindazole (7-NI) or L-N(G)-nitroarginine (NOARG) produced no effects on the baseline EPSP amplitude, but effectively attenuated the anoxic LTP. The inhibitory effects of both 7-NI and NOARG on the anoxic LTP were blocked by L-arginine, a substrate for nitric oxide synthase. These results suggest that nitric oxide is required for the generation of anoxia-induced LTP of glutamatergic synaptic transmission in the CA1 region of the rat hippocampus.

Level of transforming growth factor beta 1 is elevated in cerebrospinal fluid of children with acute bacterial meningitis

We investigated the levels of transforming growth factor beta 1 (TGF-beta 1) in cerebrospinal fluid (CSF) in children with meningitis, with a view to prognostic relevance. CSF TGF-beta 1 levels on admission were measured by a sandwich enzyme immunoassay in children with bacterial meningitis (n = 16), aseptic meningitis (n = 12), and control subjects without evidence of central nervous system (CNS) infection (n = 16). Patients were followed up for a mean duration of 13 months, and neurodevelopmental sequelae was determined for those with bacterial meningitis. On admission, CSF TGF-beta 1 levels were significantly higher in children with bacterial meningitis (mean, standard error, 32.92, 2.36 pg/ml) as opposed to those with aseptic meningitis (25.26, 1.72 pg/ml) (P = 0.0155), or control subjects (20.53, 1.05 pg/ml) (P < 0.0001). The CSF TGF-beta 1 levels in children with aseptic meningitis were higher than those in the control group, but without significance (P = 0.02). No apparent correlation existed between CSF TGF-beta 1 levels and CSF protein or cell counts in patients with bacterial meningitis. No significant difference in CSF TGF-beta 1 levels was found between patients with or without major sequelae following bacterial meningitis.

Poor pre-dialysis glycaemic control is a predictor of mortality in type II diabetic patients on maintenance haemodialysis

BACKGROUND

In type II diabetic patients, a better glycaemic control has been reported to slow down the progression of nephropathy. The effect of pre-dialysis glycaemic control on the long term prognosis in type II diabetics on haemodialysis is still uncertain. The purpose of this study is to evaluate the effect of glycaemic control before starting maintenance haemodialysis on the clinical outcome in type II diabetic haemodialysis patients.

METHODS

One hundred and thirty-seven type II diabetics receiving regular haemodialysis in a single university hospital were enrolled. The patients were classified as either good or poor glycaemic control group according to their glycaemic control within 6 months before starting haemodialysis. Serum albumin, haematocrit, cholesterol, triglyceride, residual renal function, diabetic complications, and patient survival were analysed in both groups.

RESULTS

There was no significant difference in age, gender, predialysis albumin level, cholesterol level, triglyceride level, and residual renal function between the two groups. The 1-year (94.5% vs 80.0%), 3-year (82.9% vs 58.1%), and 5-year (75.8% vs 21.8%) cumulative survival rates were lower in the poor glycaemic control group than in the good glycaemic control group (P < 0.001). The poor glycaemic control group also had more cardiovascular morbidity during the period of dialysis (P < 0.001). The increase in cardiovascular complications also accounted for the increased mortality during the course of haemodialysis.

CONCLUSIONS

We conclude that poor glycaemic control before starting dialysis is a strong predictor of cardiovascular morbidity and survival for type II diabetics on haemodialysis. These results imply that better glycaemic control before dialysis might be important in improving the long-term prognosis in type II diabetics on haemodialysis.

Micropatterning gradients and controlling surface densities of photoactivatable biomolecules on self-assembled monolayers of oligo(ethylene glycol) alkanethiolates

BACKGROUND

Bioactive molecules that are covalently immobilized in patterns on surfaces have previously been used to control or study cell behavior such as adhesion, spreading, movement or differentiation. Photoimmobilization techniques can be used, however, to control not only the spatial pattern of molecular immobilization, termed the micropattern, but also the surface density of the molecules--a characteristic that has not been previously exploited.

RESULTS

Oligopeptides containing the bioactive Arg-Gly-Asp cell-adhesion sequence were immobilized upon self-assembled monolayers of an oligo(ethylene glycol) alkanethiolate in patterns that were visualized and quantified by autoradiography. The amount and pattern of immobilized peptide were controlled by manipulating the exposure of the sample to a UV lamp or a laser beam. Patterns of peptides, including a density gradient, were used to control the location and number of adherent cells and also the cell shape.

CONCLUSIONS

A photoimmobilization technique for decorating surfaces with micropatterns that consist of variable densities of bioactive molecules is described. The efficacy of the patterns for controlling cell adhesion and shape has been demonstrated. This technique is useful for the study of cell behavior on micropatterns.

Age differences in remote pointing performance

The purpose of this study was to investigate age differences in remote pointing movements. The subjects were recruited from three age groups (ages 18-22 yr., 40-50 yr., and 60-70 yr., with 9 men and 9 women in each group). They were required to perform cursor-positioning tasks using a remote pointing device, in which the dependent measures were the time taken to reposition the cursor and the accuracy of subjects' movement trajectories. The movement time was further separated into two components, First Submovement duration and Adjustment Submovement duration. Analysis indicated that age groups showed reduced performance on remote pointing. Moreover, remote positioning movement for the young-adult group was mostly completed in their First Submovement phase, while the elderly subjects spent most of their movement time on the Adjustment Submovement phase. These results support the proposition that different age groups exhibit different kinds of movement patterns.

Characterization of the anoxia-induced long-term synaptic potentiation in area CA1 of the rat hippocampus

1. The purpose of the present study was to characterize the mechanisms underlying the anoxia-induced long-term potentiation (LTP) of glutamatergic synaptic transmission in the CA1 region of rat hippocampus by use of intracellular recordings in vitro. 2. In response to superfusion of an anoxic medium equilibrated with 95% N2 - 5% CO2, the initial slope (measured within 3 ms from the onset of the synaptic response) of the excitatory postsynaptic potential (e.p.s.p.) generated in the hippocampal CA1 neurones by stimulation of Schaffer collateral-commissural afferent pathway was significantly decreased by 91.3 +/- 4.9% (n = 10) within 10 min of the anoxic episode. The reduction of the initial slope of the e.p.s.p. was accompanied by a transient membrane hyperpolarization followed by a sustained depolarization (10.8 +/- 1.7 mV, n = 10), along with a reduction in membrane input resistance (69.3 +/- 4.8% of control, n = 10). On return to reoxygenated medium, the e.p.s.p. slope returned to the control value within 8-10 min and was subsequently and progessively potentiated to reach a plateau (195.6 +/- 14.7% of control, n = 10) 15-20 min after return to control ACSF. This anoxic episode-induced persistent potentiation of synaptic transmission lasted for more than 1 h and was termed anoxic LTP. 3. The anoxic episode induced a persistent potentiation of the initial slopes of both pharmacologically isolated alpha-amino-3-hydroxy-5-methyl-4-isoxazola-propionate (AMPA) receptor-mediated e.p.s.p. (e.p.s.p.AMPA) and N-methyl-D-aspartate (NMDA) receptor-mediated e.p.s.p. (e.p.s.p.NMDA) with a similar time course and magnitude. The sensitivity of postsynaptic neurones to NMDA (10 microM), but not to AMPA (10 microM) was also persistently potentiated following the anoxic episode. In addition, the anoxia-induced LTP of the initial slope of e.p.s.p.AMPA was accompanied by a decrease in the magnitude of paired-pulse facilitation (PPF; from 106.8 +/- 17.6 to 46.6 +/- 18.4%, n = 6), a phenomenon which was associated with presynaptic transmitter release mechanisms. 4. The induction of the anoxic LTP is dependent on the extracellular Ca2+ concentration. The induction of the anoxic LTP was completely abolished when the external Ca2+ was removed and substituted with equimolar Mg2+. Moreover, the anoxic LTP was completely abolished in neurones intracellularly recorded with Ca2+ chelator bis-(O-aminophenoxy)-N,N,N',N'-tetraacetic acid (BAPTA, 500 mM). 5. Occlusion experiments were performed to examine whether the sustained enhancement of the initial slope of the e.p.s.p. produced by tetanic stimulation and the anoxic episode share common cellular mechanisms. Three episodes of tetanic stimulation were delivered to saturate the LTP, following which a long period (15 min) of anoxia failed to cause a further potentiation of the initial slope of the e.p.s.p. Similarly, prior induction of anoxic LTP also significantly attenuated the subsequent synaptic potentiation induced by a high-frequency tetanic stimulation (100 Hz for 1 s duration). These data imply that these two forms of synaptic plasticity may share a common cellular mechanism. 6. These results provide strong evidence that the generation of the anoxia-induced LTP of glutamatergic synaptic transmission in the CA1 region of rat hippocampus probably involves both of the presynaptic and postsynaptic loci. The mechanisms underlying the persistent potentiation are likely to be attributable to an enhancement of presynaptic glutamate release and a selective upregulation of postsynaptic NMDA receptor-mediated synaptic response through the Ca2+-dependent processes.

Hepatitis in patients with end-stage renal disease

Hepatitis B and hepatitis C are two common pathogens causing chronic hepatitis in patients with end-stage renal disease (ESRD). With the acceptance of hepatitis B s antigen (HBsAg) screening, infected patients have been identified and isolated over the past 20 years. Consequently, hepatitis B is now being seen less frequently in dialysis units. Even though hepatitis B has become less of a problem, non-A, non-B hepatitis has been recognized as a significant problem since 1979. With the availability of serological testing for hepatitis C virus (HCV), more specific information is now available in regard to HCV infection in dialysis patients. The prevalence of anti-HCV in haemodialysis (HD) patients is quite variable, ranging from 5 to over 50%. Anti-HCV positivity is associated with previous blood transfusions, mode of therapy and duration of haemodialysis. In Spain and Italy, the annual seroconversion rates of HCV antibodies in dialysis patients are 2-9%; this rate was much higher in Taiwan (15%). Whether patients with HCV infection should be identified and isolated during HD treatment is an issue of controversy. Transplantation is associated with increases in hepatitis B virus (HBV) replicative markers. The survival disadvantage in HBsAg-positive recipients usually did not become apparent until 8 years after transplantation. Hepatitis C virus-infected renal transplant recipients are presumably in a similar situation to patients with hepatitis B, although confirmatory data are currently lacking. Coinfection of HBV and HCV may lead to aggressive liver disease and cirrhosis. A hepatitis B vaccine is recommended for all susceptible dialysis patients. Dialysis patients have lower response rates to hepatitis B vaccines than do other people. Currently, no vaccine is available for hepatitis C. To date, there are no effective treatments available for hepatitis B and hepatitis C. Combination therapy with interferon/lamivudine for hepatitis B and interferon/ribavirin for hepatitis C may offer a promise of effective control of viral replication in the future.

Detection of serum transforming growth factor-alpha in patients of primary epithelial ovarian cancers by enzyme immunoassay

Transforming growth factor-alpha (TGF-alpha) is a potent mitogenic polypeptide. It is secreted by a variety of transformed cells and tumors, modifying tumor growth through autocrine or paracrine mechanism. In the present study, serum levels of TGF-alpha were determined by enzyme-linked immunosorbent assay (ELISA) in 27 normal females, 116 patients with benign ovarian tumors, and 42 patients with epithelial ovarian cancers (10 with stage I, 7 with stage II, 19 with stage III, and 6 with stage IV). The ELISA assay could detect a minimum level of serum TGF-alpha concentration at 10 pg/ml. Serum samples were obtained from normal females and from patients with benign or malignant ovarian tumors before initial surgery. The detectable rates were 11% (3/27) in normal females, 28% (32/116) in benign ovarian tumors, and 62% (26/42) in ovarian cancers. The detectable rates in serous and endometrioid ovarian cancers were 71 and 70%, respectively, which were higher than the rate of 33% in mucinous type. However, there was no obvious relationship between the detectability of serum TGF-alpha and the stages of ovarian cancers. The mean concentration of TGF-alpha in ovarian cancer was 159.8 pg/ml, which was significantly higher than 27.7 pg/ml in benign ovarian tumors (P < 0.001) as well as 15 pg/ml in normal females (P < 0.001). The mean concentrations of serum TGF-alpha in stages I to IV ovarian cancers were 133.5, 96.2, 194.8, and 178.3 pg/ml, respectively. The mean concentration of serum TGF-alpha in any two stages of ovarian cancers was not statistically different. In conclusion, measurement of serum TGF-alpha can be used as a supplementary tumor marker to differentiate a malignant ovarian tumor from a benign one. However, the concentration of serum TGF-alpha has no special relation with the stage of ovarian cancer itself. Because of the small number of stage I ovarian cancers with detectable TGF-alpha in the present investigation, it would probably not be feasible to differentiate a stage I ovarian cancer from a benign ovarian tumor based only on the level of TGF-alpha in serum.

Combined-modality therapy for squamous carcinoma of the buccal mucosa: treatment results and prognostic factors

BACKGROUND

Reports on locoregional control and survival of squamous cell carcinoma of buccal mucosa are scarce in literature. In this study, a single institutions's experience of combined surgery and postoperative radiotherapy (RT) for buccal mucosal malignancy with favorable results was analyzed and presented. The prognostic factors on locoregional control were also discussed.

METHODS

From January 1988 to July 1994, 57 patients with squamous cell carcinoma of buccal mucosa treated by surgery and RT were reviewed. The distributions according to American Joint Committee on Cancer (AJCC) staging were: stage II, 6; stage III, 21; and stage IV, 30 patients. Total dose of RT at the buccal area ranged from 45 Gy to 68.4 Gy, median 61.2 Gy. Tumor-related factors (AJCC stage, T stage, histologic grading, pathologic tumor invasion to skin of cheek, adjacent bony structures, and regional lymph nodes) and treatment-related factors (surgical margin, radiation dose, and the time interval between operation and RT) were analyzed to determine their influence on locoregional control.

RESULTS

Three-year actuarial locoregional control rate, overall survival rate, and disease-specific survival rates were 64%, 55%, and 62%, respectively. Ten of these 22 patients (45%) with recurrent tumors were reoperated, but only 2 patients were successfully salvaged. Positive surgical margin and tumor invasion to skin of cheek were significantly poor prognostic factors on locoregional control by univariate analysis. In multivariate analysis, tumor invasion to skin of cheek was the only prognostic factor (p = .0014).

CONCLUSIONS

Locoregional failure was the major cause of death for squamous buccal mucosa cancers managed with surgery and RT. Few recurrences could be detected early and successfully salvaged. Skin of cheek involvement is an important prognostic factor for buccal mucosa cancers.

Streptococcal toxic shock syndrome complicating varicella in children

The most common complication in children with varicella is cutaneous superimposed infection with pyogenic bacteria. Group A beta-hemolytic streptococci, which are known to cause life-threatening infections in both previously healthy children and those with underlying diseases, are the most frequently associated pathogens. A newly recognized disease, called streptococcal toxic shock syndrome, is associated with severe morbidity and mortality. We report a 3-year-old boy with a diagnosis of this syndrome who presented with increasing fever, vomiting, and lethargy 7 days after the development of a classic varicella skin lesion. In spite of aggressive fluid supply, administration of inotropic agents, and cardiopulmonary resuscitation, a rapidly deteriorating clinical course led to death 4 hours after hospitalization. This is the first report of this association in Taiwan. Pediatricians evaluating children with varicella must be mindful of the potential for Group A beta-hemolytic streptococcal infection.

Formation of microscale gradients of protein using heterobifunctional photolinkers

Gradients of biological molecules on a microscale have been postulated to elicit cellular responses, such as migration. However, it has been difficult to prepare such gradients for experimental testing. A means for producing such gradients has been developed using a heterobifunctional photolinking agent with laser light activation. The photolinking agent synthesized includes an N-hydroxysuccinimide group and a photoreactive benzophenone (BP) separated by a tetraethylene glycol (TEG) spacer. The presence of the tetraethylene glycol spacer renders the photolinker hydrophilic, a desirable trait for conjugation in aqueous solutions. The linker was then conjugated to R-phycoerythrin (R-PE), a fluorescent protein. The resulting photolinker-R-phycoerythrin conjugate (BP-TEG-PE) was then immobilized onto a polystyrene surface by laser irradiation on a motorized stage. By varying exposure time of the sample to the beam, the amount of BP-TEG-PE immobilized on the surface was changed over an order of magnitude over a distance of 250 microns. This method can be applied to prepare gradients of proteins that elicit biological responses, such as extracellular matrix proteins or growth factors, and to study the biological effects of such gradients.

Risk factor of complications requiring neurosurgical intervention in infants with bacterial meningitis

Among 50 consecutive cases of bacterial meningitis in infants aged 6 months or less, 9 (Group I) were confirmed to have complications requiring neurosurgery during the first 2 weeks of antibiotic treatment. Neurosurgery was performed in 40, 33, and 30% of cases caused by Streptococcus pneumoniae, Pseudomonas aeruginosa, and Escherichia coli, respectively. There were 5 cases of subdural empyema, 1 case of brain abscess, 1 case of subdural empyema and brain abscess, and 2 cases of ventriculitis with severe hydrocephalus. All complications requiring neurosurgery were initially detected by cranial ultrasonography. The other 41 patients who did not undergo neurosurgery were classified as Group II. Comparison of clinical presentations and laboratory findings between the two groups showed that Group 1 contained more patients with a history of inadequate treatment, and longer duration of illness before diagnosis. Except for prolonged disturbance of consciousness, there was no difference between the two groups in clinical and laboratory data on admission or in clinical course during therapy. Due to the high incidence of complications requiring neurosurgical treatment, cost-effective cranial ultrasound is recommended for screening every young infant with bacterial meningitis, especially in cases caused by S. pneumoniae.

Cutaneous sinus tract caused by vertical root fracture

This report presents a rare case of odontogenic cutaneous sinus tract caused by a vertical root fracture. The root-fractured molar was probably caused by an accidental blow by a cow 3 years ago. Despite all treatments by physicians and surgeons for nearly 1 year, the sinus tract recurred repeatedly. After diagnosis and extraction of the fractured molar by the dentist, the sinus tract healed uneventfully in a month.