Towards characterization of photo-excited electron transfer and catalysis in natural and artificial systems using XFELs

The ultra-bright femtosecond X-ray pulses provided by X-ray Free Electron Lasers (XFELs) open capabilities for studying the structure and dynamics of a wide variety of biological and inorganic systems beyond what is possible at synchrotron sources. Although the structure and chemistry at the catalytic sites have been studied intensively in both biological and inorganic systems, a full understanding of the atomic-scale chemistry requires new approaches beyond the steady state X-ray crystallography and X-ray spectroscopy at cryogenic temperatures. Following the dynamic changes in the geometric and electronic structure at ambient conditions, while overcoming X-ray damage to the redox active catalytic center, is key for deriving reaction mechanisms. Such studies become possible by using the intense and ultra-short femtosecond X-ray pulses from an XFEL, where sample is probed before it is damaged. We have developed methodology for simultaneously collecting X-ray diffraction data and X-ray emission spectra, using an energy dispersive spectrometer, at ambient conditions, and used this approach to study the room temperature structure and intermediate states of the photosynthetic water oxidizing metallo-protein, photosystem II. Moreover, we have also used this setup to simultaneously collect the X-ray emission spectra from multiple metals to follow the ultrafast dynamics of light-induced charge transfer between multiple metal sites. A Mn-Ti containing system was studied at an XFEL to demonstrate the efficacy and potential of this method.

Charge transfer to ground-state ions produces free electrons

Inner-shell ionization of an isolated atom typically leads to Auger decay. In an environment, for example, a liquid or a van der Waals bonded system, this process will be modified, and becomes part of a complex cascade of relaxation steps. Understanding these steps is important, as they determine the production of slow electrons and singly charged radicals, the most abundant products in radiation chemistry. In this communication, we present experimental evidence for a so-far unobserved, but potentially very important step in such relaxation cascades: Multiply charged ionic states after Auger decay may partially be neutralized by electron transfer, simultaneously evoking the creation of a low-energy free electron (electron transfer-mediated decay). This process is effective even after Auger decay into the dicationic ground state. In our experiment, we observe the decay of Ne²⁺ produced after Ne 1s photoionization in Ne-Kr mixed clusters.

Time-Resolved Measurement of Interatomic Coulombic Decay Induced by Two-Photon Double Excitation of Ne_{2}

The hitherto unexplored two-photon doubly excited states [Ne^{*}(2p^{-1}3s)]_{2} were experimentally identified using the seeded, fully coherent, intense extreme ultraviolet free-electron laser FERMI. These states undergo ultrafast interatomic Coulombic decay (ICD), which predominantly produces singly ionized dimers. In order to obtain the rate of ICD, the resulting yield of Ne_{2}^{+} ions was recorded as a function of delay between the extreme ultraviolet pump and UV probe laser pulses. The extracted lifetimes of the long-lived doubly excited states, 390(-130/+450)  fs, and of the short-lived ones, less than 150 fs, are in good agreement with ab initio quantum mechanical calculations.

Slow Interatomic Coulombic Decay of Multiply Excited Neon Clusters

Ne clusters (∼5000  atoms) were resonantly excited (2p→3s) by intense free electron laser (FEL) radiation at FERMI. Such multiply excited clusters can decay nonradiatively via energy exchange between at least two neighboring excited atoms. Benefiting from the precise tunability and narrow bandwidth of seeded FEL radiation, specific sites of the Ne clusters were probed. We found that the relaxation of cluster surface atoms proceeds via a sequence of interatomic or intermolecular Coulombic decay (ICD) processes while ICD of bulk atoms is additionally affected by the surrounding excited medium via inelastic electron scattering. For both cases, cluster excitations relax to atomic states prior to ICD, showing that this kind of ICD is rather slow (picosecond range). Controlling the average number of excitations per cluster via the FEL intensity allows a coarse tuning of the ICD rate.

Moths are not silent, but whisper ultrasonic courtship songs

Ultrasonic hearing is widespread among moths, but very few moth species have been reported to produce ultrasounds for sexual communication. In those that do, the signals are intense and thus well matched for long distance communication. By contrast, males of the Asian corn borer moth (Crambidae) were recently shown to whisper extremely low-intensity ultrasonic courtship songs close to females. Since low sound levels will prevent eavesdropping by predators, parasites and conspecific rivals, we predicted low intensity ultrasound communication to be widespread among moths. Here we tested 13 species of moths including members of the Noctuidae, Arctiidae, Geometridae and Crambidae. Males of nine species, 70%, produced broadband ultrasound close to females. Peak frequencies ranged from 38 to above 100 kHz. All sounds were of low intensity, 43-76 dB SPL at 1 cm [64±10 dB peSPL (mean ± s.d.), N=9 species]. These quiet and/or hyper-frequency ultrasounds are audible to nearby mates, but inaudible to unintended receivers. Although largely unknown because it is so inconspicuous, acoustic communication using low intensity ultrasound appears to be widespread among hearing moths. Thus, acoustic communication may be the norm rather than the exception.

Orbital inflammatory pseudotumor and ischemic vasculitis in Churg-Strauss syndrome: report of two cases and review of the literature

OBJECTIVE

To clarify the characteristics of ocular manifestations in Churg-Strauss syndrome (allergic granulomatosis and angiitis).

DESIGN

Two interventional case reports and literature review.

PARTICIPANTS

Two patients with Churg-Strauss syndrome with ocular manifestations are described; 15 previously reported cases and the present 2 cases of Churg-Strauss syndrome with ocular manifestations are reviewed.

INTERVENTION

Ocular manifestations were divided into two groups: orbital inflammatory pseudotumor and ischemic vasculitis.

MAIN OUTCOME MEASURES

The onset, conjunctival involvement, orbital imaging, antineutrophil cytoplasmic antibodies (ANCA), and visual prognosis were evaluated.

RESULTS

The characteristics of the orbital inflammatory pseudotumor type (eight cases) are chronic onset, positive conjunctival involvement, abnormalities in orbital imaging studies, negative ANCA, and good visual prognosis. The ischemic type (nine cases) is characterized by sudden onset, no conjunctival involvement or abnormalities in imaging studies, positive ANCA, and occasional poor visual prognosis.

CONCLUSIONS

Orbital inflammatory pseudotumor and ischemic vasculitis may represent two essential characteristics of Churg-Strauss syndrome, granulomatosis and angiitis, respectively. The clinical features of the two types are so distinct that differentiation may be meaningful for diagnosis and treatment of Churg-Strauss syndrome with ocular manifestations.

Expression of a bioactive bovine interleukin-12 using baculovirus

Recombinant baculoviruses that express recombinant bovine interleukin-12 (rboIL-12) subunits, p35 and p40 subunits were constructed. A recombinant virus containing the p40 subunit gene expressed the p40 subunit as a 40kDa monomer and an 80kDa disulfide-linked homodimer in the infected insect cells and in the culture supernatant. The p35 subunit was expressed in a 30kDa monomer in the infected cells but not in the supernatant. Superinfection of both recombinant viruses into the cells in a spinner flask resulted in the formation of a 70kDa disulfide-bonded heterodimer detected in the supernatant by immunoblotting using anti-p40 and anti-p35 subunits antibodies. The superinfected culture supernatant showed induction of IFNgamma mRNA synthesis and IFNgamma production in bovine peripheral blood mononuclear cells. Thus, the bioactive rboIL-12 was produced in large scale using a baculovirus expression system.

The role of oval cells in rat hepatocyte transplantation

BACKGROUND

Oval cells are liver cells capable of differentiating into either hepatocytes or biliary epithelial cells. We compared growth of hepatocytes and biliary epithelial cells between spleens transplanted with oval cell-free and oval cell-enriched rat liver cells.

METHODS

Oval cell-enriched liver cells were obtained from livers of adult rats that had undergone treatment with acetylaminofluorene and partial hepatectomy, although oval cell-free liver cells were obtained from livers of untreated rats. Hepatocyte and biliary epithelial cell growth in the spleen was evaluated by counting periodic acid-Schiff-positive cells and cytokeratin 19-positive cells respectively in sections from transplanted spleens.

RESULTS

Spleens transplanted with oval cell-free liver cells and spleens transplanted with oval cell-enriched liver cells contained similar numbers of hepatocytes after 2 weeks. Numbers of hepatocytes in spleens transplanted with oval cell-free liver cells decreased markedly at 4 and 8 weeks, then increasing slightly until 32 weeks. In spleens transplanted with oval cell-enriched liver cells, numbers of hepatocytes decreased only slightly at 4 weeks and then increased markedly. At 4, 8, 12, 16, 24, and 32 weeks, numbers of hepatocytes in spleens transplanted with oval cell-enriched liver cells respectively were 2.3, 3.5, 4.5, 6.7, 6.3, and 15.1 times hepatocyte numbers in spleens transplanted with oval cell-free liver cells. Numbers of biliary epithelial cells in spleens receiving oval cell-enriched liver cells showed changes similar to those in spleens transplanted with oval cell-free liver cells, increasing markedly at 4 weeks and then markedly and rapidly decreasing.

CONCLUSIONS

Intrasplenic transplantation of oval cell-enriched liver cells enhanced growth of hepatocytes compared with transplantation of oval cell-free liver cells; this was not true for biliary epithelial cells.

Inhibition by an angiogenesis inhibitor, TNP-470, of the growth of a human hepatoblastoma heterotransplanted into nude mice

BACKGROUND/PURPOSE

The effect of TNP-470, an angiogenesis inhibitor, on the growth of a hepatoblastoma transplanted into nude mice was examined.

METHODS

A hepatoblastoma obtained from a 3-year-old girl was serially transplanted into nude mice subcutaneously, and the transplant tumors of the seventh and eighth generations were used for experiments. Expression of various markers in the tumors was examined immunohistochemically. TNP-470 was injected subcutaneously every other day into tumor-bearing mice from 3 weeks after tumor transplantation. The proliferation of tumor cells and endothelial cells was estimated by means of the bromodeoxyuridine labeling index.

RESULTS

The original hepatoblastoma showed the histology of the epithelial type, consisting of both the fetal and embryonal subtypes and was positively stained with anti-alpha-fetoprotein (AFP), anti-cytokeratin-19 and polyclonal anticarcinoembryonic antigen antibodies, and an antihuman hepatocyte antibody (hepatocyte paraffin 1). The transplant tumors consisted of solid nests of tumor cells with numerous vascular lakes of various sizes, and showed positive staining with all antibodies that reacted positively with the original hepatoblastoma. Injections of TNP-470 at the doses of 15 mg and 30 mg/kg body weight suppressed the tumor growth and the increase in the serum level of AFP dose dependently. Injections of TNP-470 also suppressed the proliferation of tumor cells and endothelial cells in the tumors.

CONCLUSIONS

Hepatoblastomas maintained in nude mice retained the immunohistochemical characteristics of the original hepatoblastoma, and TNP-470 suppressed the growth of hepatoblastomas transplanted into nude mice. TNP-470 may be worth investigating further as to its usefulness as a therapy for hepatoblastomas.

Fluorophotometric detection of intravitreal peroxides after panretinal laser photocoagulation

PURPOSE

To develop a highly sensitive method for in vivo quantitation of intravitreal peroxides by vitreous fluorophotometry with 2',7'-dichlorofluorescin (DCFH), a hydrogen peroxide (H2O2)-sensitive fluorescent dye, and to measure peroxides in the vitreous humor after panretinal laser photocoagulation (PRP).

METHODS

In the presence of H2O2 and lipid hydroperoxides, nonfluorescent DCFH was oxidized to highly fluorescent 2',7'-dichlorofluorescein (DCF; excitation, 495 nm; emission, 520 nm), which is detectable by vitreous fluorophotometry. Reactions of DCFH, including hematin with various concentrations of H2O2, were investigated in vivo. Fluorophotometry with DCFH was performed 1, 7, 14, and 28 days and 2 months after argon laser PRP. Untreated eyes served as the controls.

RESULTS

Exogenously applied H2O2 oxidized DCFH to DCF in a dose-dependent manner, ranging from 6 x 10(-8) mol/l to 6 x 10(-5) mol/l in concentration in vivo. Intravitreal DCF concentration was 83.7 +/- 6.8 nmol/l in control eyes. A significant increase of DCF was detected 1 day after PRP (330.7 +/- 123.8 nmol/l, P < 0.002). The increase peaked on day 7 (352.4 +/- 239.5 nmol/l, P < 0.002) and remained elevated at 2 months after PRP (161.8 +/- 51.4 nmol/l, P < 0.01).

CONCLUSIONS

This method allowed a highly sensitive quantitation of intravitreal peroxides in vivo. The authors' findings indicated that PRP induces increased production of peroxides in rabbit vitreous for 2 months. The data suggested that persistently high levels of peroxides in the vitreous humor affect the development of vitreous liquefaction after PRP.

Fluorophotometric quantitation of oxidative stress in the retina in vivo

PURPOSE

To establish a new fluorophotometric method to quantitate oxidative stress in the retina in vivo with a hydrogen peroxide (H2O2)-sensitive fluorescent dye.

METHODS

For in vitro fluorophotometric study, nonfluorescent 2',7'-dichlorofluorescein (DCFH) was incubated with H2O2 (10 pM to 100 nM), and the production of fluorescent 2',7'-dichlorofluorescein (DCF) was measured with fluorophotometric analysis. The inhibitory effect of catalase was also examined. For in vivo fluorophotometric study, rabbit eyes received vitrectomy and were perfused with 5 microM 2',7'-dichlorofluorescein diacetate (DCF-DA) or 2',7'-dichlorofluorescein diacetate (DCFH-DA). For oxidative stress, 300 microM H2O2 was infused after perfusion of DCFH-DA. Fluorophotometric measurements of the chorioretinal peak were performed. The eyes were enucleated for fluorescent microscopic examination to determine the localization of DCF fluorescence.

RESULTS

H2O2 converted DCFH to DCF in a dose-dependent manner, which was inhibited by catalase dose dependently. In vivo fluorophotometric study showed DCF-DA and DCFH-DA caused production of 2006 +/- 274 picomole/ml (mean +/- SD, n = 5) and 8.35 +/- 1.11 picomole/ml (n = 5), respectively, in the chorioretinal peak. DCFH-DA with stimulation by H2O2 induced 30.7 +/- 13.1 (n = 4) picomole/ml DCF. Fluorescent microscopy showed DCF production in the retina was significant in the eye treated with DCF-DA and minimal in the eye treated with DCFH-DA. Moderate DCF production in the nerve fiber layer was observed in the eye treated with DCFH-DA and H2O2.

CONCLUSIONS

This new fluorophotometric method with DCFH-DA may be useful in quantitatively evaluating oxidative stress in the retina in vivo.

Long-term prognosis of extracapsular cataract extraction and intraocular lens implantation in diabetic patients

Although cataract extraction with intraocular lens implantation (IOL) is being used for increasing numbers of patients, there is still insufficient information regarding the long-term outcome for these patients. In this retrospective study of 140 eyes of 102 patients, 97 eyes (69%) achieved a best visual acuity of 20/40 or better. After a minimum 6-month postoperative period, 26 eyes (19%) had developed retinopathy: eight eyes progressed from nonproliferative to proliferative retinopathy. Glycosylated hemoglobin levels and fasting blood glucose were significantly higher at time of surgery in the eight that progressed than in those who did not (P = 0.002, P = 0.034). There were 65 unilateral IOL implantations; in 10 (15%) of these eyes, retinopathy progressed. Retinopathy also progressed in 70% of the fellow eyes of these patients. In patients whose retinopathy did not progress, 95% of the fellow eyes also showed no progression. Also, patients with progression in the pseudophakic eye frequently had progression in the fellow unoperated eye. Postoperative progression was symmetrical (P = 0.0001). Our analysis suggests that progression of diabetic retinopathy following IOL implantation can be correlated to diabetic control at the time of surgery.

Biodegradable polymeric device for sustained intravitreal release of ganciclovir in rabbits

PURPOSE

A scleral plug made of biodegradable polymer implanted at the pars plana was evaluated to determine its ability to control the intravitreal release of ganciclovir.

METHODS

Scleral plugs containing 25% ganciclovir were prepared with poly(lactic-glycolic acid) (molecular weight, 121 kDa). The release of ganciclovir was evaluated in vitro by spectrophotometry. In vivo intravitreal ganciclovir concentrations were measured by high performance liquid chromatography following plug implantation in pigmented rabbits. The biocompatibility of the device was determined by indirect ophthalmoscopy, electroretinography, and light and electron microscopy.

RESULTS

The in vitro study showed that the plug released ganciclovir throughout a 10-week period. The in vivo study demonstrated that the plugs maintained the drug concentration in the vitreous in a therapeutic range adequate to treat cytomegalovirus (CMV) retinitis for 12 weeks. No significant retinal toxicity was observed.

CONCLUSIONS

This study demonstrated that this drug delivery system can potentially be useful to treat CMV retinitis.

[Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (1995). I. Susceptibility distribution]

The frequencies of isolation and susceptibilities to antimicrobial agents were investigated on 704 bacterial strains isolated from patients with urinary tract infections (UTIs) in 11 hospitals during the period of June 1995 to May 1996. Of the above bacterial isolates, Gram-positive bacteria accounted for 29.8% and a majority of them were Enterococcus faecalis. Gram-negative bacteria accounted for 70.2% and most of them were Escherichia coli. Susceptibilities of several isolated bacteria to antimicrobial agents were as followed; 1. Enterococcus faecalis Ampicillin (ABPC) and imipenem (IPM) showed the highest activities against E. faecalis isolated from patients with UTIs. The MIC90S of them were 1 microgram/ml. Vancomycin (VCM) and piperacillin (PIPC) were also active with the MIC90S of 2 micrograms/ml and 4 micrograms/ml, respectively. The others had low activities with the MIC90S of 16 micrograms/ml or above. 2. Staphylococcus aureus including MRSA VCM showed the highest activities against S. aureus isolated from patients with UTIs. Its MIC90 was 1 microgram/ml against both S. aureus and MRSA. Arbekacin (ABK) was also active with the MIC90 of 2 micrograms/ml. The other except minocycline (MINO) had very low activities with the MIC90S of 64 micrograms/ml or above. 3. Staphylococcus epidermidis ABK and MINO showed the strongest activities against S. epidermidis isolated from patients with UTIs. The MIC90S of them were 0.25 microgram/ml. VCM was also active with the MIC90 of 1 microgram/ml. The MIC90S of cephems ranged from 2 micrograms/ml to 16 micrograms/ml in 1994, but they ranged from 8 micrograms/ml to 128 micrograms/ml in 1995. These results indicated that some resistances existed among S. epidermidis to cephems. 4. Streptococcus agalactiae All drugs except gentamicin (GM) were active against S. agalactiae. ABPC, cefmenoxime (CMX), IPM, erythromycin (EM), clindamycin (CLDM) and clarithromycin (CAM) showed the highest activities. The MICs for all strains were lower than 0.125 microgram/ml. The MIC90S of the others were 2 micrograms/ml or below. 5. Citrobacter freundii IPM showed the highest activity against C. freundii isolated from patients UTIs. Its MIC90 was 1 microgram/ml. GM was also active with the MIC90 of 2 micrograms/ml. Cefpirome (CPR), cefozopran (CZOP) and amikacin (AMK) were also active with the MIC90S of 4 micrograms/ml. Penicillins and cephems except CMX, CPR and CZOP showed low activities with MIC90S of 256 micrograms/ml or above. 6. Enterobacter cloacae IPM showed the highest activity against E. cloacae. The MICs for all strains were equal to or lower than 1 microgram/ml. MINO and tosufloxacin (TFLX) were also active with the MIC90S of 8 micrograms/ml. Penicillins and cephems except CPR and CZOP showed lower activities with the MIC90S of 256 micrograms/ml or above. 7. Escherichia coli. Most of the antimicrobial agents were active against E. coli. Particularly CPR, CZOP and IPM showed the highest activities against E. coli. The MICs for all strains were equal to or lower than 0.5 microgram/ml. CMX and TFLX were also active with the MIC90S of 0.125 microgram/ml or below. Penicillins were slightly active with MIC90S of 128 micrograms/ml or above. 8. Klebsiella pneumoniae K. pneumoniae was susceptible to all drugs except penicillins, with MIC90S of 2 micrograms/ml or below. Carumonam (CRMN) had the strongest activity against K. pneumoniae, the MICs for all strains were equal to or lower than 0.125 microgram/ml. Comparing with the result of 1994, the sensitivities of K. pneumoniae against all drugs had obviously changed into a better state. For example, the MIC90S of cephems ranged from 0.25 microgram/ml to 16 micrograms/ml in 1994, but they were all lower than 2 micrograms/ml in 1995. 9. Proteus mirabilis P. mirabilis was susceptible to a majority of drugs. CMX, ceftazidime (CAZ), cefixime (CFIX), and CRMN showed the highest activities against P. mirabilis isolated from patients with UTIs. MICs of CRMN for all

Granulomatous myositis: pathologic re-evaluation by immunohistochemical analysis of infiltrating mononuclear cells

To characterize the non-caseating granuloma formation in granulomatous myositis, we analyzed infiltrating mononuclear cells in 7 patients including 2 sarcoid patients, using monoclonal antibodies with a modified immunoperoxidase method. All granulomas consisting of epithelioid, infiltrating mononuclear cells and multinucleated giant cells had markedly increased numbers of CD45Ro-positive cells. The infiltrating inflammatory cells were mostly T lymphocytes and macrophages. The majority of T lymphocytes behaved as T helper/inducer subtype, expressing CD4 positivity. Although the ratio of CD4- to CD8-positive cells in the granuloma in muscle biopsies was not significantly different from that in other organs seen in systemic sarcoidosis, T helper/inducer and T suppressor/cytotoxic cells showed some characteristic distributions: CD4-positive cells accumulated in the center of, and CD8-positive cells at the periphery of, the granuloma. The distribution of infiltrating cells did not differ between muscle biopsies from patients with and without systemic sarcoidosis, suggesting that both groups share the same pathogenetic mechanism in granuloma formation.

In vivo quantitation of peroxides in the vitreous humor by fluorophotometry

PURPOSE

To detect intravitreal peroxides in vivo by a new fluorophotometric method with a hydrogen peroxide (H2O2)-sensitive fluorescent dye.

METHODS

The authors used a 2',7'-dichlorofluorescin (DCFH) assay to measure oxidative status in the rabbit vitreous. In the presence of H2O2 and lipid hydroperoxides, nonfluorescent DCFH in the vitreous is oxidized to highly fluorescent 2',7'-dichlorofluorescein (DCF; excitation, 495 nm; emission, 520 nm) that is detectable by fluorophotometry. Reactions of DCFH with various concentrations of H2O2 were investigated in vitro and in vivo. An inhibitory effect of catalase also was monitored. Vitreous fluorophotometry with DCFH was performed immediately and at 3, 7, and 28 days after constant light exposure to the retina (1800 lux, 24 hours) as an oxidative stress.

RESULTS

In vitro study revealed that H2O2 oxidized DCFH to DCF in a dose-dependent manner, ranging from 0.1 to 100 mmol/1 in concentration. Catalase inhibited DCF production. Vitreous fluorophotometry demonstrated that H2O2 oxidized DCFH to DCF in vivo in a dose-dependent manner, ranging from 0.06 to 60 mmol/1 in concentration. DCF production in the vitreous significantly increased immediately (P = 0.03) and at 3 days (P = 0.01) and 7 days (P = 0.01) after light exposure, and it returned to the pretreatment level by day 28.

CONCLUSIONS

The results suggest that this fluorophotometric method quantitatively can detect intravitreal peroxides in vivo. This method will be helpful to study the oxidative status in some experimental pathologic conditions.

Implantable biodegradable polymeric device in the treatment of experimental proliferative vitreoretinopathy

We investigated the use of a scleral plug of biodegradable polymer implanted at the pars plana to create a controlled drug-delivery system in the vitreous. We evaluated the efficacy of a plug containing doxorubicin hydrochloride to treat experimental proliferative vitreoretinopathy (PVR) in pigmented rabbits. An implantable device on the sclera, which imitates a scleral plug, containing 1% doxorubicin, was prepared with poly(lactic acid) (molecular weight, 20,000). The release of doxorubicin in phosphate-buffered saline was evaluated by spectro-photometry. After pars plana vitrectomy and plug implantation, concentrations of doxorubicin in the vitreous humor of the rabbits were measured by high performance liquid chromatography. The release profiles were evaluated during 5 weeks in vitro and 4 weeks in vivo. Cultured homologous fibroblasts were injected into the vitreous space to induce experimental PVR after gas compression of the vitreous. The scleral plugs were implanted at the pars plana in treatment animals (n = 11). Control rabbits (n = 11) were followed up without implantation after PVR induction. All eyes of the control group developed tractional retinal detachment at day 28, while the incidence of retinal detachment was decreased to 64% in the treated eyes. (P = 0.002). The implantation of the scleral plug effectively inhibited intravitreous proliferation of fibroblasts. This study demonstrated that the scleral plug of biodegradable polymers may have potential as a treatment modality for PVR.

[Long-term prognosis of intraocular lens implantation in diabetic patients]

We retrospectively studied 255 eyes of 190 diabetic patients who underwent cataract extraction with posterior chamber intraocular lens (IOL) implantation. One hundred forty-six eyes (57.3%) achieved the best visual acuity of 20/30 or better and 221 eyes (86.7%) achieved the acuity of 20/100 or better. Among 161 eyes that were followed up over 6 months, 26 eyes (16%) showed a progression of the retinopathy. Eight eyes developed proliferative retinopathy from non-proliferative retinopathy. The level of glycosylated hemoglobin of the progression group at the time of surgery was significantly higher than that of the non-progression group (8.0 +/- 2.4% vs 6.8 +/- 1.6%, p < 0.05). Sixty-five patients received IOL implantation in one eye. Of these patients, 10 eyes (15%) showed progression of the retinopathy. Seventy percent of the fellow eyes also showed the progression, where as 95% of the non-progression group did not show progression in the fellow eyes. The results suggested that the progression of diabetic retinopathy after IOL implantation was correlated with diabetic control at the time of surgery. Additionally, patients who developed the progression of the retinopathy in pseudophakic eyes frequently showed the progression in the fellow unoperated eyes.

[A case of Klippel-Trenaunay-Weber syndrome associated with intracranial multiple angiomas]

A case of Klippel-Trenaunay-Weber syndrome associated with multiple intracranial angiomas was reported. Intracranial angiomas with Klippel-Trenaunay-Weber syndrome is very rare. Only 4 cases are known to this day. A 24-year-old man fell at his workplace and suffered a head injury. He was admitted to our hospital. Neurological examination revealed no abnormality. However, physiological examination demonstrated hyperplasia and cutaneous hemangiomas of left lower leg, malformation of the left eyelid and clouding of the left cornea. CT showed left hemispheric atrophy and subdural effusion. MRI demonstrated multiple flow voids at the left cerebellar hemisphere and at pons. Cerebral angiogram demonstrated left cerebellar AVM and pontine angioma. Feeding arteries of the AVM were left superior cerebellar artery and left posterior inferior cerebellar artery. Those of the pontine angioma could not be identified. No spinal angiomas were revealed. While spinal angiomas associated with this syndrome are known, association of intracranial lesions are rare. Reported anomalies are angiomas, hemi-hypertrophy of skull and brain, carotid occlusion, megadolicoanomaly of the basilar artery, meningioma and glioma. Our case report with cerebral angiomas is the first one in Japan. We postulate that anomaly of our case originated at the Streeter's 2nd-3rd stage or that multiple anomalies occurred. We emphasize that intracranial, spinal or visceral angiomas, which can be fatal if it bleeds, should be routinely examined in Klippel-Trenaunay-Weber syndrome.

[Free amino acids and activities of folate-derivative converting enzymes in nervous system of rats administered with beta, beta'-iminodipropionitrile]

Swelling of proximal axon is a morphological similarity between patients with amyotrophic lateral sclerosis (ALS) and beta, beta'-iminodipropionitrile (IDPN)-injected animals. In order to investigate whether these two states have something in common biochemically with each other, we measured free amino acids (FAAs) and activities of folate-derivative converting enzymes which participate in the metabolic turnover of the folate cycle. Thirty male Wistar rats weighing about 125 g were administered intraperitoneally with 2 g/kg of IDPN. These rats and 10 control rats injected with physiological saline were sacrificed 1, 3 and 6 weeks after injection. Subsequently organs were immediately removed and stored at -80 degrees C until analyzed. FAAs were quantitated by a JLC-6AH amino acid analyzer, and activities of the enzymes were measured by established methods. Changes in FAAs were detected not only in the central and peripheral nervous systems, but also in the other tissues examined, suggesting diverse action of IDPN. Among the various changes, elevation of taurine content in the cerebrum and spinal cord seems to be important, because the same alteration has been reported in the central nervous system (CNS) of ALS patients. In relation to the increase in taurine, metabolic slowing-down of the folate cycle which has been reported in ALS was suggested from reduced activity of N5,N10-methylenetetrahydrofolate reductase (MTR), one of the three enzymes of this metabolic cycle.(ABSTRACT TRUNCATED AT 250 WORDS)

[Cerebral edema extending to the posterior limb of the internal capsule on MR imaging]

The features of edema extending to the posterior limb of the internal capsule (PLIC) were investigated in a review of MR imaging (MRI), with the following results. Edema was seen along the lateral and medial margins of the PLIC, although the PLIC itself was resistant to edema. The edema along the lateral and medial margins tended to extend into the lentiform nucleus and thalamus, respectively, and was considered to be edema of the extrapyramidal and thalamocortical tracts. When edema was abundant, the PLIC was traversed by many edematous tracts which seemed to connect the lentiform nucleus with the thalamus. The PLIC looked like a comb, and this finding was a good anatomical landmark on MR T 2-weighted images. We have used the term "comb appearance" to describe this finding.

CD48 is a counter-receptor for mouse CD2 and is involved in T cell activation

CD2 is an intercellular adhesion molecule that has been implicated in T cell activation and differentiation both in humans and mice. Although the ligand for human CD2 has been defined as LFA-3, that for murine CD2 has not been identified yet. To identify the ligand for mouse CD2, we generated a chimeric molecule consisting of the extracellular domain of mouse CD2 and human immunoglobulin (Ig)G1 Fc (mCD2Rg). A hamster monoclonal antibody (mAb), HM48-1, was established by screening mAbs that could block the binding of mCD2Rg to T cell lines at the ligand site. The putative mouse CD2 ligand recognized by this mAb was a glycosyl phosphatidylinositol-anchored glycoprotein with an apparent molecular mass of 45 kD, which were shared characteristics with human LFA-3. However, its expression was predominantly restricted to hematopoietic cells, unlike human LFA-3. Protein microsequencing analysis for the NH2-terminal 18 amino acid residues of the affinity-purified HM48-1 antigen revealed that it is almost identical with mouse CD48. This identity was further confirmed by the reactivity of HM48-1 with a soluble recombinant CD48 (sCD48) protein and the molecule recognized by a rat mAb raised against sCD48. A rat anti-CD48 mAb blocked the mCD2Rg binding as well as HM48-1. Moreover, sCD48 also inhibited the mCD2Rg binding to the cellular ligand. Finally, like anti-CD2 mAb, HM48-1 inhibited the phytohemagglutinin response and, when crosslinked, augmented the anti-CD3 response of splenic T cells. These results indicate that CD48 is a ligand for mouse CD2 and is involved in regulating T cell activation.

Outcome of White pump shunt surgery for neovascular glaucoma in Asians

We compared the effect of seton (White pump shunt) surgery (16 eyes) with that of trabeculectomy and 5-fluorouracil (31 eyes) in treating 38 Asian patients with medically uncontrollable neovascular glaucoma. We found the probability of long-term success (intraocular pressure < or = 26 > or = 5 mm Hg) of seton surgery (53.0% at 3 years) to be similar to that obtained following trabeculectomy with adjunctive 5-fluorouracil (45.4% at 3 years). However, 3 years postoperatively, the probability of the preservation of visual acuity was significantly greater following trabeculectomy than seton surgery (67.1% vs 23.1%; P < .05). In addition, the prevalence of postoperative complications was higher with the seton procedure (P < .001). The loss of endothelial cells 6 months postoperatively was more marked with seton surgery than with trabeculectomy, whether the shunt device touched the cornea (P < .000001) or not (P < .0005). In conclusion, White's pump shunt was effective in lowering the IOP of eyes with neovascular glaucoma. However, care must be taken to prevent postoperative complications, the incidence of which exceeded those observed following trabeculectomy with adjunctive 5-fluorouracil.

[Cell proliferation in a triple gastric cancer--a study using the isolated organ perfusion system]

So as to study the cell proliferation in a case with triple gastric cancers, we labeled an operated whole stomach with bromodeoxyuridine (BrdU) by the isolated organ perfusion system using artificial blood. Anti-BrdU immunohistochemical staining of sections from every part of the stomach was performed, and 3 separated cancerous lesions were all diagnosed as well differentiated adenocarcinomas. The labeling index (L.I.) of the cancerous lesions were found to differ from part to part. However, the L.I. tended to be higher in the superficial mucosal areas and in the cell-dense areas of the submucosa. In the almost normal fundic glands, the labeled zone was localized in the neck of the glands. The more metaplastic gastritis was advanced, the more the labeled zone shifted irregularly toward the bottom of the glands. Whenever the interstinal metaplasia was completed, the labeled zone was localized in the bottom of the glands. This method was found useful in studying the cell proliferation in the stomach without causing any harm to the human body.

[Intra-arterial chemotherapy of malignant glioma after osmotic blood-brain barrier disruption]

Reversible transient osmotic blood-brain barrier disruption was used to increase drug delivery to the brain. The authors treated 10 cases of malignant gliomas with intra-arterial chemotherapy after osmotic blood-brain barrier disruption. Ten patients received intra-arterial anticancer drugs (5-FU, ACNU, IFN-beta) after intra-arterial infusion of 20% mannitol to open the blood-brain barrier at the tumor site. Clinical responses in 9 evaluable cases were 1 Complete Response, 3 Partial Responses, 5 No Change and no Progressive Disease in CT examination. Response rate was 44.4% (4/9). The most untoward effect of this method was myelosuppression. Platelet and leukocyte count diminished below 20,000 and 2,000, respectively in 3 cases, and 2 out of these 3 cases died of severe infection. The other complications were eye pain during mannitol infusion in all cases, when the selective catheterization of the internal carotid artery failed to pass the origin of the ophthalmic artery. Decreased activity was seen in 70%, nausea and vomiting in 50%, swelling of external decompression area in 33%, increased neurological deficit in 20%, but all these side effects were transient. This method was considered an effective treatment for malignant gliomas.

[Effect of breathing fluctuations on cerebral blood flow in demented patients and its correction method using end-tidal CO2 concentration]

During mouthpiece respiration of Xe-133 for a measurement of regional cerebral blood flow (rCBF), the breathing pattern of patients fluctuated and it caused a change of end-tidal CO2 concentration that had an excellent correlation with PaCO2 in patient without respiratory disease. The end-tidal CO2 concentration of demented patients varied within lower ranges than senile control group. The range of fluctuation on the end-tidal CO2 concentration was dependent on the type and the degree of dementia, and it fluctuated most widely at the middle stage of Alzheimer disease. Mean cerebral blood flow increased by 13.9% for each 1% increase in end-tidal CO2 concentration (3.6%/mmHg PaCO2) in the case of demented patients without cerebrovascular disease. To improve the reliability of rCBF in demented patients, especially in Alzheimer disease, the correction of rCBF data for end-tidal CO2 concentration should be performed.

Assessment of demented patients by dynamic SPECT of inhaled xenon-133

We studied the potential for using dynamic single photon emission computed tomography of inhaled xenon-133 (133Xe) gas in the assessment of demented patients. An advanced ring-type single photon emission computed tomography (SPECT) "HEADTOME" with improved spatial resolution [15 mm in full width at half maximum (FWHM)] was used for tomographic measurement of regional cerebral blood flow (rCBF). All 34 patients underwent a detailed psychiatric examination and x-ray computed tomography scan, and matched research criteria for Alzheimer's disease (n = 13), senile dementia of the Alzheimer type (n = 9), or multi-infarct dementia (n = 12). In comparison with a senile control group (n = 7), mean CBF of both the whole brain and the temporo-parietal region was significantly less in the Alzheimer's disease and senile dementia Alzheimer type groups, but no significant difference was seen between the senile control group and multi-infarct dementia group. The correlation was 0.72 (p less than 0.004) between the mean CBF of the whole brain and the score of Hasegawa's Dementia Scale, and 0.94 (p less than 0.0001) between rCBF of the temporo-parietal region and the scale in Alzheimer's disease. In the senile dementia Alzheimer type group, the correlations were 0.77 (p less than 0.01) and 0.83 (p less than 0.004) respectively. No significant correlations were found in the multi-infarct dementia group. A temporo-parietal reduction in the distribution of the rCBF characteristic in the Alzheimer's disease group and a patchy whole brain reduction characteristic in the multi-infarct dementia group was detected. The ability of our improved SPECT to provide both quantitative measurement of rCBF and characteristic rCBF distribution patterns, makes it a promising tool for research or routine examination of demented patients.

Sensitivity and accuracy in recording His-Purkinje activity by surface-averaged electrocardiography

A clinical evaluation of the surface-averaged ECG (SAE) to record His-Purkinje activity (HPA) was made on 70 patients who underwent His bundle electrograms (HBE). The recorded signals first judged as HPA in 43 patients by the noninvasive method alone were later verified in 37 patients by HBE; the accuracy of the HPA recordings (predictive value) was 86.0%. The HPA-V interval measured noninvasively had a high correlation with the HV interval by HBE (r = 0.89, p less than 0.01). The verified detection rate in all 70 patients was 52.9%: HPA was detected in 12 of 18 patients (66.7%) with sclerotic and hypertensive heart disease (Group I), five of 19 patients (26.3%) with rheumatic heart disease (Group II), 11 of 17 patients (64.7%) with congenital heart disease (Group III), and nine of 16 patients (56.2%) with miscellaneous conditions (Group IV). The detection rate was markedly lower in Group II than in other groups (Group II vs Group I or III, p less than 0.025). The PR segment was significantly longer in the patients in whom HPA was detected than in those in whom it was not detected (71.5 +/- 22.3 msec vs 43.9 +/- 19.5 msec, p less than 0.001). His-Purkinje activity (HPA) was detected in 32 of 52 recordings (61.5%) with sinus rhythm and seven of 20 recordings (35.0%) with atrial fibrillation, including two recordings in each of two cardioverted patients (p less than 0.05). We conclude that the surface-averaged ECG (SAE) has clinically acceptable sensitivity and accuracy except in patients with rheumatic heart disease, short PR segments or atrial fibrillations.

Three-dimensional vectorcardiography (3-D VCG) by computer graphics in old myocardial infarction

By using computer graphics we rotated the vector loop and three coordinate axes to find the viewpoint where the infarctional changes are maximally exposed and demonstrated the advantage of the "3-D VCG" over the conventional VCG by defining the quantitative "MI index." The orthogonal electrocardiogram recorded by the Frank lead system was digitally measured and processed by a microcomputer. The loops and axes were rotated about the X axis (X-rot) and the Y axis (Y-rot). The spatial vector loop and orthogonal coordinates can be presented as viewed from any spheric direction. Eight quadrants were illustrated with four colors and red circles. The subjects consisted of 30 patients with old anterior myocardial infarction (MI) and 15 patients with old inferior MI. We measured the area of "Bite" in anterior MI and superior displacement in inferior MI. The MI index was defined and averaged in 361 directions. In anterior MI, the maximum mean index was obtained when X-rot is +90 degrees and Y-rot -40 degrees, viewed from upward and leftward, whereas in inferior MI it was obtained when X-rot is -50 degrees and Y-rot -80 degrees, viewed from downward and leftward. These values were significantly higher than those in conventional VCG projections, substantiating superior diagnostic sensitivity of 3-D VCG.

Iron status in low birth weight infants on breast and formula feeding

Iron status in 15 low birth weight infants, 1000-2499 g, on breast feeding was studied longitudinally for the first 6 months of age, and the findings compared to those of 30 low birth weight infants receiving a proprietary iron-fortified formula. The two groups received no iron supplement until they developed iron deficiency. The incidence of iron deficiency at 6 months was significantly greater in the breast-fed group than in the formula-fed group (86% v 33%). The breast-fed group had significantly lower serum ferritin and hemoglobin values after 4 months of age. The findings indicate that breast-fed low birth weight infants have a higher risk of developing iron deficiency and should receive iron supplementation from 2 months of age.

[Functional reserve of the ischemic left ventricle with ventricular aneurysm to afterload stress: digital subtraction angiographic assessments]

Digital subtraction angiography (DSA) has been confirmed to be an accurate method for determining left ventricular function. It is a relatively non-invasive technique without inducing premature ventricular complexes. The response of left ventricular function to afterload stress was assessed using DSA for eight patients with old anterior myocardial infarction and ventricular aneurysm including that of the anterior wall (averaging 30.3 months after the acute episodes). Their ages ranged from 36 to 65 years and one patient was a woman. Prior to the investigation, we confirmed that a single DSA procedure did not alter left ventricular function in a pilot study of one patient (No. 8). After initial DSA in the basal state, methoxamine was infused intravenously (1 to 2 mg/min). When aortic systolic blood pressure increased by 30 to 50 mmHg, a second DSA was performed for each patient. Left ventricular volumes and ejection fractions were calculated by the area-length method, and regional wall motion was assessed by the visual method according to the AHA classification and the curvature radius of the apical ventricular aneurysm was calculated. Methoxamine induced neither acute heart failure nor angina pectoris in the present series. The heart rates decreased, and there were a significant increase in end-systolic volumes (p less than 0.05), end-systolic radii (p less than 0.05), and a significant decrease in ejection fractions (p less than 0.02) after methoxamine infusion. In 32 of 40 segments, regional wall motion was unchanged by methoxamine as assessed by the visual method; whereas, in the other eight, there was a deterioration.(ABSTRACT TRUNCATED AT 250 WORDS)

An altered distribution and elimination of digoxin in anemic patients and experimentally induced anemic rats

Digoxin was administered orally to eight anemic patients in their anemic and convalescent stages, and serum digoxin concentration was determined by radioimmunoassay. In the anemic patients a significantly lower level of serum digoxin concentration was observed in anemic state compared with convalescent stage at 72 hours after the drug administration (p less than 0.01). In usual clinical use, a full digoxin effect is expected to be attained as 72 hours. Tritiated digoxin was administered intravenously to anemic and control rats and the tritium in samples of the blood, myocardium and urine were counted in a liquid scintillation counter. The anemic rats showed significantly lower level of serum 3H-digoxin at 6 hours (p less than 0.01) and lower myocardial concentration at 24 hours (p less than 0.01). Larger amount of urinary excretion of 3H-digoxin was observed in the anemic rats 6 hours after the drug administration. No significant difference in fecal excretion of 3H-digoxin was found between the anemic and control rats.

Noninvasive recording of His-Purkinje activity in patients with complete atrioventricular block. Clinical application of an "automated discrimination circuit"

In seven patients with complete atrioventricular (AV) block, His bundle electrograms (HBEs), standard ECG recordings, bipolar esophageal ECGs and highly amplified, filtered, bipolar chest lead ECGs were simultaneously recorded. The filtered chest lead ECG was averaged to determine His-Purkinje activity (HPA). A simplified device, the "automated discrimination circuit," was used to selectively eliminate the superimposed atrial and ventricular potentials that are characteristic of complete AV block and unsuitable for signal averaging. The processed chest lead ECG was amenable to conventional techniques of signal averaging. In four patients with block proximal to the AV node diagnosed by HBE, there was no activity after the P wave in the surface-averaged ECGs. HPA was consistently recorded before the QRS in the surface-averaged ECG. The measurements of the HV and HPA-V intervals were very close, with a difference of less than 2 msec. Three patients with block distal to the His bundle by HBE showed a loss of electrical potential before the QRS in the surface-averaged ECG, but had a consistent HPA after the P waves. The P-HPA intervals coincided well with PH intervals, with a maximal difference of 5 msec.

The metabolism of digitoxin in hepatic cirrhosis of human subjects

Digitoxin, 1 mg, was orally administered to 12 cirrhotic patients (the 6 in a clinically compensated and the 6 in a decompensated state) and their serum concentrations were measured at 6 hours and everyday through 7 days by radioimmunoassay. The serum half-life of digitoxin in these groups and normal subjects, determined from the serum concentrations, was as follows: 4.7 +/- 0.55 days for controls, 4.9 +/- 0.45 days for the compensated group and 5.3 +/- 0.35 days for the decompensated group. No statistically significant difference could be found in half-life among these groups. (P less than 0.2). The same dose of digitoxin was orally administered to 6 cirrhotic patients and 6 control subjects and their left ventricular systolic time intervals, LVET and QS2, were determined at 6 hours and every morning for 7 days. Cardiac responses, exhibited by decrease in the systolic time intervals, in both control subjects and cirrhotic patients dissipated in fair parallel during the ensuing 4 days and returned to base line level by 5 days. From these both biological half-life and physiological effect, it may be concluded that overall metabolism of digitoxin in cirrhotic patients is not disturbed.