Probabilistic risk and benefit assessment of nitrates and nitrites by integrating total diet study-based exogenous dietary exposure with endogenous nitrite formation using toxicokinetic modeling

The impacts of dietary nitrates and nitrites on human health have been a controversial topic for many years. However, the risk and benefit assessment of nitrates and nitrites is complicated by the large variation in nitrate and nitrite intake among people and the endogenous nitrite formation in the body. This study conducted a probabilistic risk-benefit assessment of dietary nitrates and nitrites based on internal dose by integrating exogenous and endogenous exposures with human trial data on cardiovascular benefits. A total diet study was carried out to quantify the age-specific dietary intakes of nitrates and nitrites. A previously well-validated human toxicokinetic model was used to predict internal doses for different age groups. In addition, the integrated approach was applied to different populations from different countries/regions based on reported exposure estimates to conduct a comprehensive risk-benefit assessment of dietary nitrates and nitrites. The results demonstrated that vegetable consumption was the main contributor to the internal nitrate and nitrite levels in all age groups. Exposure to nitrates and nitrites exceeding acceptable daily intakes in a variety of foods showed cardiovascular benefits. The probabilistic risk assessment showed that the exposure to nitrates and nitrites did not pose an appreciable health and safety risk. Therefore, the present results suggest that dietary nitrates and nitrites have clear cardiovascular benefits that may outweigh potential risks. Our analysis contributes significantly to addressing the controversy regarding risks and benefits from dietary nitrates and nitrites, and our approach could be applied to other dietary constituents with the potential for both risks and benefits.

Incorporating Exogenous and Endogenous Exposures into Dietary Risk Assessment of Nitrates and Nitrites in Vegetables: A Probabilistic Integrated Toxicokinetic Modeling Approach

This study aimed to estimate the dietary risk of nitrates and nitrites in vegetables based on internal dose in a probabilistic manner by integrating exogenous exposure based on measured concentrations in vegetables with endogenous exposure using a toxicokinetic (TK) model. We optimized and validated a previous TK model and incorporated Monte Carlo simulations to account for variability across different age populations for predicting internal dose. High levels of nitrates were detected in leafy vegetables (from 545 ± 274 to 1641 ± 873 mg/kg). Nitrite contents of vegetables were generally low (from 1.26 ± 1.40 to 8.20 ± 14.1 mg/kg). The dietary risk was found to be different based on internal versus external dose, suggesting that it is critical to include endogenous nitrite formation into risk assessment. Nitrate and nitrite exposure from vegetables is unlikely to result in appreciable risks for most populations but may be a potential risk for preschoolers.

Time-resolved inline digital holography for the study of noncollinear degenerate phase modulation

Recent works demonstrated that digital time-resolved holography is the prospective approach to study nonlinear light-matter interaction processes. In this Letter, we present a straightforward inline holographic approach for studying degenerate phase modulation induced by an inclined collimated pump beam in the isotropic sample. The method is based on a minimization of the difference between experimentally acquired data and simulated inline holograms obtained from a numerical model of pump-probe interaction in optical nonlinear media. A sophisticated experimental data processing algorithm is implemented to provide high sensitivity and a signal-to-noise ratio eligible for soft interaction with a collimated pump beam. The integral phase shift determined by our method can be used to estimate the nonlinear refractive index and the relaxation time for material with a low damage threshold. We validated our approach for the case of soda-lime and BK7 glasses.

Epithelioid leiomyosarcoma of the uterus: computed tomography findings

Uterine epithelioid leiomyosarcoma is a rare neoplasm. There have been no previous reports describing computed tomography (CT) findings for this tumor. A 31-year-old woman presented with a heterogeneous enhancing mass, with internal septa, in the uterus, which was shown on CT images. Histological diagnosis was compatible with epithelioid leiomyosarcoma.

Endometrial stromal sarcoma mimicking submucosal myoma protruding to the vagina: MRI findings

A 46-year-old woman complained of persistent abnormal vaginal bleeding over ten days. Her intrauterine device had been removed two years before. Soon after, she suffered from menorrhagia and metrorrhagia. An incidental finding of severe anemia was also noted. In this admission, our initial T2-weighted magnetic resonance imaging (MRI) revealed a well-demarcated mass predominantly in the uterine cavity. The mass was depicted by an isointense signal relative to the myometrium on T1-weighted images, high signal intensity on T2-weighted images, and slightly heterogeneous enhancement on post-contrast images. The patient refused surgery. After two years, follow-up MRI showed a pedunculated mass protruding into the upper third of the vagina with a stalk connecting to the posterior wall of the uterine cavity, simulating submucosal myoma. Histological diagnosis was compatible with low-grade endometrial stromal sarcoma.

Ductal adenocarcinoma of the prostate with endometrioid features in a 69-year-old man

We describe a case of ductal adenocarcinoma of the prostate with endometrioid characteristics presenting as painless hematuria and intraurethral tumor. A 69-year-old man had intermittent painless hematuria for 2 months. The serum prostate-specific antigen concentration was elevated (22.0 ng/mL). An enlarged prostate with a necrotic tumor was noted in the right lobe of the prostate on computerized tomography and magnetic resonance imaging studies. A polypoid and worm-like tumor was found within the prostatic urethra near the verumontanum. The tumor had a distinctly papillary configuration with a focal glandular structure on microscopy. Radical prostatectomy was performed and histology of the tumor specimen revealed it to be composed of a closely packed glandular structure lined by single layers of high columnar cells with focal stratification. Frequent papillary projections of glandular epithelium and intraglandular bridging were noted, with a histopathologic appearance similar to endometrioid carcinoma of the uterus. Androgen deprivation therapy was started immediately following surgery. No evidence of recurrence or metastasis was found at follow-up 27 months postoperatively. Distinct features of ductal adenocarcinoma of the prostate include intraurethral papillary tumor close to the verumontanum, urethral obstruction, and easy bleeding of the tumor. Its more aggressive behavior than classical microacinar adenocarcinoma of the prostate makes early recognition of this type of prostatic malignancy important.

Investigation of the extent of gastric metaplasia in the duodenal bulb by using methylene blue staining

BACKGROUND AND AIMS

The existence of gastric metaplasia (GM) of the duodenal mucosa has been considered to be highly related to the recurrence of duodenal ulcers (DU). The aims of this study are to evaluate the usefulness of methylene blue staining in the detection of GM, and to clarify the relationship between GM and the deformity of the duodenal bulb.

METHODS

Fifteen patients with healed DU and four patients with symptoms of dyspepsia without evidence of ulcers were enrolled into this endoscopic study. During each endoscopy, methylene blue was sprayed evenly on the duodenal bulb, and biopsies were taken from blue-stained and unstained areas. The existence and extent of GM were assessed histologically and grossly. The correlation between duodenal bulb deformity and the extent of GM was also studied.

RESULTS

The mean score of methylene blue non-staining (MBNS) was 0, 1.30 +/- 0.15, and 3.00 +/- 0.00 in group A (non-ulcer patients), group B (patients with healed DU and with normal-shaped bulb) and C (patients with healed DU and with deformed duodenal bulb), respectively; showing significant differences among the groups (P < 0.05 in each). Both the existence and the grading of GM were higher in unstained specimens than in blue-stained specimens (100 vs 16.6%, P < 0.0001 and 3.62 +/- 0.09 vs 0.19 +/- 0.06, P < 0.001, respectively).

CONCLUSIONS

Methylene blue non-staining can be applied to investigate the existence and extent of GM in the duodenal bulb accurately. The incidence of GM in the duodenal bulb was higher in patients with healed ulcers than in non-ulcer patients. Patients with deformed duodenal bulbs have a higher extent of GM than those without deformed duodenal bulbs.

On velocity estimation using speckle decorrelation

Quantitative estimation of blood velocity using Doppler techniques is fundamentally limited because only the axial component can be detected. Speckle decorrelation resulting from scatterer motion may be used to compute non-axial components and to obtain quantitative flow information. Based on both simulations and experimental results, it is shown that the decorrelation technique is feasible only for constant flows. If flow gradients are present, the correlation between two signals along the same line of observation may be significantly affected by the gradients. Therefore, the decorrelation method cannot be used for quantitative flow estimation if flow gradients are not accurately measured and effects on signal correlation are not fully compensated. Results in this paper show that accurate estimation of flow gradients is practically difficult. It is further shown that effects of signal-to-noise ratio (SNR) on the correlation must also be taken into account for quantitative flow analysis.

Either sufentanil or fentanyl, in addition to intrathecal bupivacaine, provide satisfactory early labour analgesia

PURPOSE

The study was aimed primarily at comparing the duration of analgesia produced by intrathecal fentanyl 25 microg with sufentanil 5 microg when added to bupivacaine 1.25 mg as the initial component of the combined spinal epidural (CSE) technique in early labour.

METHODS

Forty healthy parturients were randomly assigned into two groups to receive either intrathecal sufentanil 5 microg plus bupivacaine 1.25 mg (Group S) or intrathecal fentanyl 25 microg plus bupivacaine 1.25 mg (Group F). Apart from the duration of analgesia, pain scores and side effects were also evaluated.

RESULTS

There was no significant difference in the duration of analgesia (mean 109 +/- SD 49 min in Group F vs 118 +/- 54 min in Group S, P=0.9). Group F had a more rapid onset of analgesia (P <0.05) and a higher cephalad block (median T4 vs T7, P <0.05) in the first 30 min after the block. No difference in the side effects was detected.

CONCLUSION

Fentanyl 25 microg is a good alternative to sufentanil 5 microg when added to bupivacaine 1.25 mg for early labour analgesia.

Expression of cyclooxygenase-2 in prostate adenocarcinoma and benign prostatic hyperplasia

Elevated expression of cyclo-oxygenase (COX)-2 has been found in several human cancers, including prostate adenocarcinoma. To evaluate the potential prognostic role of COX-2 in prostate cancer, we assessed the expression of COX-2 in benign prostatic hyperplasia (BPH) and prostate cancer samples employing immunohistochemistry. COX-2 was over-expressed in 15 out of 18 (83%) prostate cancer samples whereas it was detected in only 22% (4 of 18) paired benign tissues. The intensity of immunostaining correlated with the tumor grading. In addition, COX-2 was expressed in 7 of the 22 (32%) BPH samples examined. The significance a COX-2 expression in the BPH samples is not known at present. This data suggest that COX-2 is over-expressed in prostate cancer and COX-2 inhibitors may be useful in combination chemotherapy or chemoprevention for prostate cancer.

A unique xanthine derivative KMCP-98 with activation of adenosine receptor subtypes

KMCP-98 is a newly synthesized adenosine receptor agonist by alkylation at the 7-position of the xanthines nucleus. We first investigated the pharmacological activities of KMCP-98 under in vivo and in vitro conditions. Acute intravenous injection of KMCP-98 (1.0, 2.0 and 3.0 mg/kg) produced a temporary fall in blood pressure and heart rate, followed by a sustained fall in heart rate in pentobarbital-anesthetized Wistar rats. The hypotensive and bradycardiac responses were inhibited by pretreatment with an A(1) adenosine receptor antagonist 8-phenyltheophylline (8-PT, 0.5 mg/kg). Both KMCP-98 and adenosine (0.3-100 microM) produced negative inotropic activity in isolated guinea pig left atria. The negative inotropic activity of KMCP-98 was significantly blocked by pretreatment with A(1) receptor antagonists 8-PT (10 microM) and xanthine amine congener (XAC, 10 microM), a nonselective adenosine antagonist theophylline (10 microM), a K(+) channel blocker tetraethylammonium (TEA, 10 mM) and a K(ATP) channel blocker glibenclamide (1 microM). KMCP-98 (0.03-30 microM) produced concentration-dependent relaxations in carbachol (1 microM) precontracted guinea pig tracheal smooth muscle. The trachea relaxant response of KMCP-98 was markedly inhibited by A(2), A(2a) and A(2b) adenosine receptor antagonists 3,7-dimethyl-1-propargylxanthine (DMPX, 10 microM), 8-(3-chlorostyryl)caffeine (CSC, 10 microM) and alloxazine (10 microM), respectively, the nitric oxide synthase (NOS) inhibitor L-NAME (100 microM) and also by TEA and glibenclamide. In addition, KMCP-98 (0.03-30 microM) elicited relaxant response in norepinephrine (3 microM) precontracted rat thoracic aorta in a concentration-dependent manner. The thoracic aorta relaxant response of KMCP-98 was also significantly inhibited by DMPX, CSC, alloxazine, L-NAME, TEA and glibenclamide. Furthermore, the binding characteristics of KMCP-98, adenosine and 5'-N-ethylcarboxaminoadenosine (NECA) were evaluated in [(3)H]DPCPX and [(3)H]CGS 21680 binding to rat cortex and striatum, respectively. The K(i) values of KMCP-98 for predominate A(1) and A(2) adenosine receptor sites were 3908+/-952 and 158+/-10 nM, respectively. In conclusion, KMCP-98 was found to be a xanthine-based adenosine receptor agonist associated cardiac depression, tracheal and aortic smooth muscle relaxations.

Doppler angle estimation using correlation

Conventional Doppler techniques can only detect the axial component of blood flow. To obtain the transverse flow component, an approach based on the dependence of Doppler bandwidth on Doppler angle has been widely investigated. To compute the bandwidth, a full Doppler spectrum is often required. Therefore, this approach has not been applied to real-time, two-dimensional Doppler imaging because of the long data acquisition time. To overcome this problem, a correlation-based method is proposed. Specifically, variance of the Doppler spectrum is used to approximate the square of the Doppler bandwidth. Because variance is computed efficiently and routinely in correlation-based color Doppler imaging systems, implementation of this method is straightforward. In addition, the two-dimensional velocity vector can be calculated and mapped to different colors using the color mapping function of current systems. Simulations were performed, and experimental data were also collected using a string phantom with the Doppler angle varying from 23 degrees to 82 degrees . Results indicate that the correlation-based method may produce significant errors if only a limited number of flow samples are available. With averaging, however, the Doppler angles estimated by the correlation-based method can achieve good agreement with the true angles by using only four flow samples with proper variance averaging.

Surgical treatment of pseudosyndactyly of the hand in epidermolysis bullosa: histological analysis of an acellular allograft dermal matrix

Recessive dystrophic epidermolysis bullosa is an inherited mechanobullous disorder of skin and mucous membranes. The most striking clinical characteristic of the disease is the formation of blisters following trivial trauma. Repeated cycles of blistering and scarring result in gradual encasement of the hand in an epidermal "cocoon." The authors treated an 11-year-old boy with recessive dystrophic epidermolysis bullosa who presented with hand contractures and interdigital pseudosyndactyly. Treatment included release of contractures and application of a biosynthetic dermal analog. This report is a histological analysis of the dermal matrix 1 year after initial placement of the allograft. Fibroblasts repopulating the dermal allograft had a normal synthetic phenotype and lacked the myofibroblastic features seen in the ungrafted control biopsy. Collagen and elastin in the repopulated dermal allograft had normal dermal orientation and maturity in contrast to the sparse, immature collagen and lack of elastin compared with the dermis of an ungrafted control region. Results of this histological study indicate that treatment of recessive dystrophic epidermolysis bullosa with an acellular human dermal allograft may restore some features of normal dermal architecture. Although the initial results are encouraging, longer follow-up is required before definitive conclusions can be made.

Eugenodilol: a third-generation beta-adrenoceptor blocker, derived from eugenol, with alpha-adrenoceptor blocking and beta2-adrenoceptor agonist-associated vasorelaxant activities

Eugenodilol, derived from natural eugenol, was first investigated with in vivo and in vitro models. In our in vivo study, eugenodilol (0.5, 1.0, and 1.5 mg/kg, i.v.) produced dose-dependent hypotensive and bradycardic responses in pentobarbital-anesthetized Wistar rats. Eugenodilol also inhibited the tachycardia and arterial pressor effects induced by (-)isoproterenol and phenylephrine, respectively. In our in vitro study, eugenodilol competitively antagonized (-)isoproterenol-induced positive inotropic and chronotropic effects and tracheal-relaxation responses on isolated guinea pig tissues in a concentration-dependent manner. The apparent pA2 values were 7.88+/-0.12 for right atria, 7.52+/-0.05 for left atria, and 7.33+/-0.15 for trachea, indicating that eugenodilol was a nonselective beta-adrenoceptor blocker. In thoracic aorta experiments, the apparent pA2 values of alpha-adrenoceptor blockade were 7.05+/-0.25 and 6.87+/-0.08 for eugenodilol and labetalol, respectively. In addition, eugenodilol produced cumulative relaxation responses on isolated guinea pig tracheal strips. The effects were competitively antagonized by ICI 118,551 (10(-8)-10(-6) M), a relatively selective beta2-adrenoceptor antagonist. In the radioligand-binding assay, the Ki values of [3H]CGP-12177 binding to rat ventricle and lung membranes were 9.72 and 48.29 nM, respectively, and the value of [3H]prazosin binding to rat brain membrane was 38.72 nM. These results further confirmed the alpha/beta-adrenoceptors-blocking activities of eugenodilol reported in the functional studies. We conclude that eugenodilol is a novel third-generation beta-adrenoceptor blocker with ancillary blocking activity at alpha-adrenoceptors and weak sympathomimetic activity at beta2-adrenoceptors.

Isoeugenolol: a selective beta1-adrenergic antagonist with tracheal and vascular smooth muscle relaxant properties

Isoeugenolol (1.0, 3.0, 5.0 mg/kg, i.v.) produced a dose-dependent bradycardia and a decrease in blood pressure in anesthetized Wistar rats. Isoeugenolol inhibited the tachycardia effects induced by (-)isoproterenol, but had no blocking effect on the arterial pressor responses induced by (-)phenylephrine. In isolated guinea pig tissues, isoeugenolol antagonized (-)isoproterenol-induced positive inotropic and chronotropic effects on the atria and tracheal relaxations in a concentration-dependent manner. The apparent pA2 values for isoeugenolol on right atria, left atria and trachea were 7.63+/-0.03, 7.89+/-0.12 and 6.12+/-0.05, respectively, indicating that isoeugenolol was a highly selective beta1-adrenoceptor blocker. On the other hand, isoeugenolol produced a mild direct cardiac depression at high concentration and was without intrinsic sympathomimetic activity (ISA). In isolated rat thoracic aorta, isoeugenolol relaxed more potently the contractions induced by (-)phenylephrine (10 microM) and 5-HT (10 microM) than those by high K+ (75 mM). In isolated guinea pig trachea, isoeugenolol attenuated the carbachol (1 microM)-con-tracted trachea more significantly than those contracted with high K+. Furthermore, the binding characteristics of isoeugenolol and various beta-adrenoceptor antagonists were evaluated in [3H]CGP-12177 binding to rat ventricle, lung and interscapular brown adipose tissue (IBAT) membranes. The -log IC50 values of isoeugenolol for predominate beta1-, beta2- and beta3-adrenergic receptor sites were 5.82+/-0.09, 4.74+/-0.05 and 4.73+/-0.12, respectively. In conclusion, isoeugenolol was found to be a highly selective beta1-adrenoceptor antagonist with tracheal and vascular smooth muscle relaxant activities, but was devoid of alpha-adrenoceptor-blocking action.

Dopamine D2-receptor isoforms expressed in AtT20 cells inhibit Q-type high-voltage-activated Ca2+ channels via a membrane-delimited pathway

Dopamine D2 receptors both acutely and chronically inhibit high-voltage-activated Ca2+ channels (HVA-CCs). Two alternatively spliced isoforms, D2L (long) and D2S (short), are expressed at high levels in rat pituitary intermediate lobe melanotropes but are lacking in anterior lobe corticotropes. We stably transfected D2L and D2S into corticotrope-derived AtT20 cells. Both isoforms coupled to inhibition of Q-type calcium channels through pertussis toxin-sensitive G proteins. Thus, we have created a model system in which to study the kinetics of D2-receptor regulation of Ca2+ channels. Rapid inhibition of HVA-CCs was characterized using a novel fluorescence video imaging technique for the measurement of millisecond kinetic events. We measured the time elapsed (lag time) between the arrival of depolarizing isotonic 66 mM K+, sensed by fluorescence from included carboxy-X-rhodamine (CXR), and the beginning of increased intracellular Ca2+ levels (sensed by changes in indo 1 fluorescence ratio). The lag time averaged 350-550 ms, with no significant differences among cell types. Addition of the D2-agonist quinpirole (250 microM) to the K+/CXR solution significantly increased the lag times for D2-expressing cells but did not alter the lag time for AtT20 controls. The increased lag times for D2L- and D2S-transfected cells suggest that at least a fraction of the Ca2+ channels was inhibited within the initial 350-550 ms. As this inhibition time is too fast for a multistep second messenger pathway, we conclude that inhibition occurs via a membrane-delimited diffusion mechanism.

Potential value of urinary intercellular adhesion molecule-1 determination in patients with bladder cancer

OBJECTIVE

Intercellular adhesion molecule-1 (ICAM-1) is known to play a role in immunity against bladder cancer and can be detected in the supernatants of cultured bladder cancer cells that constitutively express ICAM-1. This study was performed to examine the relevance of the ICAM-1 urine test in patients with bladder cancer.

METHODS

A total of 53 patients with bladder carcinoma, 35 with history of bladder cancer, and 30 normal control subjects were included in this analysis. Urinary ICAM-1 (ulCAM-1) levels were measured by immunoassay and corrected for hydration status.

RESULTS

Levels of ulCAM-1 were significantly elevated in patients with bladder cancer or those at tumor-free status compared with normal control subjects (P=0.001). However, there was no apparent difference between the two groups of urothelial disorders (P >0.1). ulCAM-1 did not correlate with clinicopathologic variables of bladder cancer or patient outcome (P >0.1). Six patients at tumor-free status had multiple ulCAM-1 determinations during the study period. Three of these 6 patients had elevated ulCAM-1 levels and proved to have recurrent tumors; 3 of the 6 had stable ulCAM-1 levels and were still free of disease.

CONCLUSIONS

Our results suggest that urinary excretion of ICAM-1 is elevated in the early stage of bladder carcinogenesis, but is independent of biologic properties of bladder cancer. Serial monitoring of ulCAM-1 may be helpful in selecting patients who are at risk of tumor recurrence.

Immunohistochemical and ultrastructural study of malignant plasmacytoid myoepithelioma of the maxillary sinus

Myoepithelioma is a rare salivary gland tumor which is composed exclusively of myoepithelial cells. Histologically, it can be divided into three cell types: spindle, plasmacytoid and mixed type. Malignant myoepithelioma is characterized by invasive growth. In March 1995, a 60-year-old man presented with a left cheek tumor which he had first noted 2 years previously. Computed tomography revealed a large expansile tumor in the maxillary sinus with invasion into the surrounding soft tissue. Partial resection of the tumor was performed because of extensive involvement of the surrounding tissue. The patient died due to spread to the brain 5 months after surgery. Histologically, the tumor was composed exclusively of plasmacytoid cells, with bone destruction. Immunohistochemically, these cells were negative for immunoglobulin light chains (kappa and lambda) and heavy chains (Ig G, A, M) but positive for S-100, cytokeratin, actin and vimentin.Ultrastructurally, the tumor cells contained numerous randomly oriented actin-like microfilaments in the cytoplasm, and had desmosomes on the cell membrane. Malignant plasmacytoid myoepithelioma of the maxillary sinus was diagnosed. In addition to our case, only five cases of pure plasmacytoid myoepithelioma have been reported. Plasmacytoid myoepithelioma tends to occur in the minor salivary glands and has more aggressive behavior than spindle cell myoepithelioma. Morphologically, it is very difficult to differentiate plasmacytoid myoepithelioma from plasmacytoma and immunohistochemical staining is necessary to make a correct diagnosis.

Ocular penetration and pharmacokinetics of topical fluconazole

The high bioavailability and low toxicity of fluconazole, a stable, water-soluble, low-molecular-weight bis-triazole antifungal, makes it a good candidate for consideration as a topical ocular agent. The penetration of fluconazole (0.2%) into the corneas and aqueous humors of New Zealand white rabbits was assayed by gas liquid chromatography (GLC). Peak corneal levels occurred essentially immediately at 5 min in the corneas [debrided, 8.2 +/- 1.2 micrograms/g; nondebrided, 1.6 +/- 0.6 microgram/g; (mean +/- SEM)] and at 15 min after application in the aqueous [debrided, 9.4 +/- 2.3 micrograms/ml; nondebrided, 1.6 +/- 0.6 microgram/ml; (mean +/- SEM)]. Estimating from semilogarithmic plots of the data, the halflife (t1/2) in the debrided eyes was 15 min; in the nondebrided eyes, t1/2 was 30 min. A loading dose of a 20-microliter drop per min for 5 min yielded levels of 59.9 +/- 11.3 micrograms/g (mean +/- SEM) in the debrided corneas and 32.4 +/- 1.9 micrograms/ ml (mean +/- SEM) in the corresponding aqueous humor. A regimen consisting of this loading dose followed by one 20 microliters drop/h for 6 h showed 45.9 +/- 3.5 micrograms/g (mean +/- SEM) in the debrided corneas and 8.8 +/- 1.7 micrograms/ml (mean +/- SEM) in the corresponding aqueous. The same regimen yielded values of 3.1 +/- 0.2 micrograms/g in the nondebrided corneas and 1.3 +/- 0.2 micrograms/ml (mean +/- SEM) in the aqueous. Minimal inhibitory concentrations (MIC) at 24 h for yeasts ranged from < 1.25 to 20 micrograms/ml, for hyaline molds from 2.5 to > 20 micrograms/ml, and dematiaceous molds from < 1.25 to > 20 micrograms/ml. Topical fluconazole exhibits pharmacokinetics and selective MICs that merit further evaluation for its ophthalmic use as a topical antifungal agent.

Late infantile type neuronal ceroid lipofuscinosis: report of one case

A 4-year-10-month-old boy with late infantile type neuronal ceroid lipofuscinosis was reported. He presented with progressive dementia, loss of visual acuity, gradual regression of speech and motor functions, and myoclonic jerks. A hyperactive deep tendon reflex was noted, but there was neither muscle weakness nor hepatomegaly. Serum lactate, pyruvate and ammonia levels were within normal limits. The funduscopic examination showed diffuse mottling of the retinal pigmented epithelium. The electroencephalogram showed irregular bilateral spike-and-waves or polyspike-and-waves and isolated focal spikes from the bilateral parieto-occipital regions. The wave forms of visual evoked potentials were flat. The electroretinogram was unrecordable. The somatosensory evoked potentials showed prolonged central conduction times from bilateral median nerves. The brainstem auditory evoked potentials were within normal limits. Diffuse cerebral and cerebellar atrophy were noted on magnetic resonance imaging. The diagnosis was confirmed by the electron-dense cytoplasmic inclusion bodies within the conjunctival squamous epithelial cells. No specific treatment was available. Regular anticonvulsants were not given during follow-up because seizures attacked him only on occasion. His visual acuity was progressively impaired. In addition to nearly total absence of speech, an inability to communicate and walk independently was also noted. The clinical features according to the subtypes, radiology, pathology, managements and prenatal diagnosis for this case are discussed.

Optical restoration of photorefractive holograms through self-enhanced diffraction

For the first time to our knowledge, we demonstrate the use of self-enhanced diffraction to optically restore weak dynamic volume holograms. This restoration process is achieved through the use of a novel beam-toggling scheme that significantly enhances the steady-state diffraction efficiency of volume index gratings stored in photorefractive media. Experiments demonstrating and confirming theory are presented and discussed.

Percutaneous lumbar discectomy: indications and surgical results in 35 consecutive cases

Thirty-five patients (27 men and eight women) who met our criteria of case selection for percutaneous lumbar discectomy (PLD) were treated by this method during the period May 1992 to June 1993. Thirty-six spaces, including one man with double disc disease, were decompressed. Patients ranged in age from 14 to 64 years. All patients but one were followed up for a minimum of six months. The operative results, evaluated by a more objective functional grading system, revealed a short-term (two months) success rate of 83% and a mid-term (six months) success rate of 76%. This discrepancy resulted from two recurrences of sciatic symptoms. It indicates that the medical conditions of those who have received PLD are by no means static, but instead may fluctuate. The operative result was similar to that of open discectomy, averaging 81.1% in reported series. Our "functional grading system" reflects these fluctuations quantitatively. With respect to the operative success rate, there was a statistical difference between the very good, good and fair-poor indication groups of patients, as were categorized by our major criteria of indications that included three clinical manifestation criteria and the other three radiographic findings. This result emphasizes the critical role of case selection in the operative success rate. Complications consisted of one disc infection which cleared without sequelae. This study provides an objective means of selecting cases and evaluating surgical results which, in turn, makes the use of this procedure convincing and predictable.

Recovery of motile sperm using the osmolality-gradient technique

A simple, effective method for collecting motile sperm from ejaculates is developed. One hundred semen samples were obtained from both fertile and infertile men. Following initial semen dilution (1: 1) to 4 mL in a hypoosmotic medium (210 mOsm/kg), the mixture was layered into the specially designed tube filled with 1 mL recovery medium in the bottom and 1 mL isolation medium in the second layer to form three discrete layers. During the next hour the highly motile sperm out-distanced the other seminal contents to reach the bottom of the tube. Compared with the parent ejaculates, the recovered specimens exhibited an increased percentage of motile sperm with significantly enhanced sperm velocity and linearity (p less than .001). This method isolated motile sperm with higher velocity than those obtained using the swim-up technique.

A new sperm collection method for treatment of retrograde ejaculation

Retrograde ejaculation is an uncommon but treatable form of male infertility. Successful recovery of motile spermatozoa from a post-ejaculatory urine for artificial insemination is dependent on careful regulation of osmolarity and acidity of the bladder contents into which the ejaculate emanates, and the separation of the motile spermatozoa from the debris and cells which are found in these specimens. A pregnancy established by artificial insemination of spermatozoa recovered from bladder contents of a patient suffering from retrograde ejaculation is presented. The techniques for preparing the urinary bladder for spermatozoal survival and the removal of debris and cells by delicate centrifugation are discussed.

Hydroxyl radicals do not crosslink a DNA-lysozyme complex

The ionic complex between lysozyme and either Escherichia coli DNA or pBR322 DNA was not crosslinked by two systems capable of producing nanomolar amounts of hydroxyl radicals, the oxidation of xanthine by xanthine oxidase and the iron catalyzed oxidation of ascorbic acid. Nor did effective crosslinking occur with micromolar quantities of hydroxyl radicals raised by the addition of adenosine nucleotides to ferrous iron and hydrogen peroxide. In this case, radical content was estimated by colorimetric analysis of formaldehyde following hydroxyl radical oxidation of dimethyl sulfoxide. Similar amounts of radicals generated by pulse radiolysis in a nitrous oxide atmosphere failed also to induce crosslinking. These findings do not support a role for hydroxy radicals in the N-acetoxy-2-acetylaminofluorene induced crosslinking of DNA to lysozyme proposed earlier.