Large-Scale Mapping Observations of the C i (3P1-3P0) and CO (J = 3-2) Lines toward the Orion A Molecular Cloud

Large-scale mapping observations of the 3P1-3P0 fine-structure transition of atomic carbon (C i, 492 GHz) and the J=3-2 transition of CO (346 GHz) toward the Orion A molecular cloud have been carried out with the Mount Fuji submillimeter-wave telescope. The observations cover 9 deg2 and include the Orion Nebula M42 and the L1641 dark cloud complex. The C i emission extends over almost the entire region of the Orion A cloud and is surprisingly similar to that of 13CO (J=1-0). The CO (J=3-2) emission shows a more featureless and extended distribution than C i. The C i/CO (J=3-2) integrated intensity ratio shows a spatial gradient running from the north (0.10) to the south (1.2) of the Orion A cloud, which we interpret as a consequence of the temperature gradient. On the other hand, the C i/13CO (J=1-0) intensity ratio shows no systematic gradient. We have found a good correlation between the C i and 13CO (J=1-0) intensities over the Orion A cloud. This result is discussed on the basis of photodissociation region models.

Maldevelopment of neural crest cells in patients with typical uveal coloboma

PURPOSE

To clarify the pathogenesis of ocular and systemic anomalies associated with typical uveal coloboma.

METHODS

The records of 72 patients with typical uveal coloboma (35 males and 37 females) treated at Nagoya City University Hospital during a 16-year period were reviewed.

RESULTS

Typical uveal coloboma was bilateral in 33 patients and unilateral in 35 patients; 4 patients were unclassified because of severe contralateral microphthalmos. Uveal coloboma was an isolated defect in 23 (37%) patients. Other ocular anomalies were present in 19 (31%) patients, systemic anomalies were found in 7 (11%) patients, and both other ocular and systemic anomalies were noted in 13 patients (21%). The associated ocular anomalies included microphthalmos in 28 eyes of 23 patients, persistent pupillary membrane in 28 eyes of 18 patients, and posterior embryotoxon in 20 eyes of 15 patients. The accompanying systemic anomalies included ear anomalies, retarded growth, and retarded development in 18 patients; heart anomalies in 13 patients; genital hypoplasia in 12 patients; and congenital facial palsy in 10 patients. The collection of malformations known as the CHARGE association was diagnosed in 14 (19%) patients.

CONCLUSION

Abnormal development of neural crest cells appeared to be responsible for the majority of associated ocular and systemic anomalies in patients in the present series, suggesting that typical uveal coloboma may be related to maldevelopment of the neural crest cells. The present findings indicated that ophthalmologists should be aware of the possible association of typical uveal coloboma with systemic anomalies.

[A visual mechanism in curve detection]

To investigate how a smooth curve is processed in the human visual system, we introduce a new grouping principle explaining perceptual organization. Five observers were presented with arrays of band-pass elements, and the detection performance of an undulating path among randomly oriented distractors was measured as a function of the number of path elements and the orientation differences between adjacent path elements. We found that the undulating path was better detected when the number of path elements was large or the orientation differences were small and constant. Based on these results, we propose a model that groups the path elements to be perceived as a contour; local orientation differences are detected by curvature channels, the outputs of these channels are globally pooled with lateral inhibition, and the signals are detected by contour detectors of a threshold device.

Anomalies associated with Axenfeld-Rieger syndrome

BACKGROUND

To detect the associated anomalies in patients with Axenfeld-Rieger syndrome is clinically important, because early treatment for such anomalies is crucial to both visual and systemic development. This study was conducted to clarify the associated anomalies in the syndrome.

METHODS

We evaluated 21 patients with Axenfeld-Rieger syndrome encountered at Nagoya City University Hospital over a 16-year period. Patients who presented with a prominent Schwalbe's line accompanying the iris strands were diagnosed as having Axenfeld-Rieger syndrome.

RESULTS

The series consisted of 9 males and 12 females, ranging in age from 1 month to 41 years, mean 15.4+/-12.7 (SD) years. The syndrome was bilateral in 17 cases and unilateral in 4 cases. Hypoplasia of the iris was observed in 10 eyes of 6 patients. The associated ocular anomalies included sclerocornea in 6 eyes of 3 patients, developmental glaucoma in 5 eyes of 3 patients, persistent pupillary membrane in 4 eyes of 2 patients, microphthalmos in 3 eyes of 2 patients, and typical iris coloboma in 1 eye. Of 10 eyes with hypoplasia of the iris, 5 exhibited glaucoma. The accompanying systemic anomalies included 9 cases of dental anomalies, 5 of facial anomalies, and 3 of Alagille syndrome.

CONCLUSIONS

All of the associated ocular and systemic anomalies appeared to arise from the maldevelopment of the neural crest cells. Patients with Axenfeld-Rieger syndrome should therefore be examined for the presence of anomalies in the tissues of neural crest origin. Patients with hypoplasia of the iris should be checked for glaucoma.

Vestibular evoked myogenic potentials in patients with bilateral profound hearing loss

We report vestibular evoked myogenic potentials (VEMPs) in 3 patients with bilateral profound hearing loss in order to confirm that they are not of cochlear origin. All of the 3 patients (31-year-old man, 67-year-old man and 47-year-old woman) had bilateral profound hearing loss. They were diagnosed as having congenital hearing loss, bilateral Ménière's disease and inner ear syphilis. Their pure-tone hearing ranged from 81 dB HL to nearly total hearing loss. Stimulation by click (95 dB nHL) evoked biphasic myogenic responses (p13-n23) on the sternocleidomastoid muscle ipsilateral to the stimulated ear. The ear in which the stimulation did not evoke biphasic myogenic responses did not have a caloric response either. These results suggested that VEMPs are not likely of cochlear origin but of vestibular origin.

Critical period for retinoic acid-induced developmental abnormalities of the vitreous in mouse fetuses

To elucidate the underlying developmental mechanisms of persistent hyperplastic primary vitreous (PHPV) in humans, we investigated a mouse model for PHPV induced by retinoic acid. We treated C57BL/6NJcl mice at various stages of pregnancy (gestation days 7, 8, 9, 10, 11, or 12) with the teratogen retinoic acid, which affects the migration of neural crest cells. Untreated pregnant mice served as a control group. The eyes of the fetuses were examined histologically on day 18 on gestation. Developmental abnormalities of the vitreous were defined as the presence of excessive mesenchymal tissue in the vitreous cavity. The incidence of developmental abnormalities of the vitreous in all groups, except for those treated on day 12 of pregnancy, significantly exceeded that in the control group (P<0.01). The histological characteristics of the observed vitreous abnormalities in mice resembled those found in PHPV clinically. Retinoic acid-induced abnormalities in mice can serve as an experimental model for PHPV by environmental factors. Results suggest that the critical period for these retinoic acid-induced abnormalities was during days 7 to 11 of gestation, which corresponds to a critical period of 2.5 to 7 weeks of gestation for PHPV in humans.

4-(trans-4-Methylcyclohexyl)-4-oxobutyric acid (JTT-608). A new class of antidiabetic agent

During an investigation of drugs for improving the beta-cell response to glucose, we found that 4-cyclohexyl-4-oxobutyric acid selectively improved glucose-stimulated insulin release and glucose tolerance in both normal and diabetic rats. A series of 4-cycloalkyl-4-oxobutyric acids and related compounds were synthesized and evaluated for their effects on the glucose tolerance test and fasting euglycemia. This study elucidated the structural requirements for drug activity and determined that the optimum compound was 4-(trans-4-methylcyclohexyl)-4-oxobutyric acid 7 (JTT-608). This compound improved glucose tolerance from an oral dose of 3 mg/kg and did not change fasting euglycemia even at an oral dose of 30 mg/kg. Selective improvement of glucose-induced insulin secretion was observed in studies using neonatal streptozotocin rats (nSTZ rats) and perfused pancreases isolated from nSTZ rats.

Microwave Spectrum of the SD+3 Ion: Molecular Structure

The J = 1-0 to 4-3 spectral lines of SD+3 were measured in the 152-610 GHz region using a source-modulated microwave spectrometer. The SD+3 ion was generated in a free space absorption cell by a hollow-cathode discharge in a gas mixture of D2S and D2. The rotational constant B0 and the centrifugal distortion constants DJ and DJK were determined from the measured frequencies. A vibration-rotation analysis was carried out and the rz structures of SH+3 and SD+3 were derived from their zero point averaged rotational constants, expressed as SH+3: rz = 1.36512(22) Å and thetaz = 94.098(26) degrees, and SD+3: rz = 1.36086(16) Å and thetaz = 94.1211(195) degrees, where the difference between thetaz(HSH) and thetaz(DSD) was assumed to be the same as that between thetaz(HPH) of PH3 and thetaz(DPD) of PD3. From the shift between the rz structures of SH+3 and SD+3, the re structure of SH+3 was estimated to be re = 1.35001(113) Å, thetae = 94.181(135) degrees. Copyright 1998 Academic Press.

Far-Infrared Laser Sideband Spectroscopy of the NH2 Radical

We have constructed a far-infrared (FIR) laser sideband spectrometer for carrying out pure rotational spectroscopy of fundamental radicals and ions in the FIR or "terahertz" frequency region. The tunable FIR source is obtained by sideband generation of a carbon dioxide laser-pumped FIR laser with a GaAs Schottky barrier diode. The minimum detectable absorption coefficient of the spectrometer achieved so far is 1 x 10(-6) cm-1 at 1600 GHz. Observation of the pure rotational spectrum of the NH2 radical in the 2B1 ground electronic state was demonstrated as the first example. Spectra were measured by utilizing the double modulation technique; i.e., the Zeeman effect was used in addition to the normal frequency modulation technique in order to flatten the baseline and to appreciate full system sensitivity. The radical was generated by a DC glow discharge of a mixture of ammonia and helium. Nine Q- and R-branch rotational transitions were measured in the frequency range between 1300 and 2600 GHz. Zero-field transition frequencies were obtained with an accuracy of around 1 MHz. The line frequencies were analyzed with previous microwave spectroscopic results, and the rotational and spin-rotation constants with their centrifugal correction terms were revised. With the aid of the revised rotational constants, it becomes possible to predict the line frequency of certain low N transitions of the radical to within about 1 MHz for the first time. Copyright 1998 Academic Press.

Developmental eye abnormalities in mouse fetuses induced by retinoic acid

To clarify the relationship between neural crest cells and various developmental eye abnormalities, pregnant mice were administered an intraperitoneal injection of 12.5 mg/kg retinoic acid (RA) suspended in corn oil on day 7 of pregnancy (RA group). Control mice received an equal volume of corn oil only (control group). The fetuses were removed by laparotomy on day 18 of gestation. The fetal mortality was 46.3% in the RA group and 2.2% in the control group. The live fetuses in both groups were observed grossly, and the eyes were examined histologically in serial sections. In the RA group, gross malformations were observed, including microphthalmos (95.5%), cleft lip and palate (36.4%), and central nervous system anomalies (31.8%). In the control group, these malformations were seen in only 6.7%, 0%, and 2.2%, respectively. Histologic examinations in the RA group revealed microphthalmos (47.7%), anophthalmos (38.6%), faulty closure of the embryonic fissure (36.4%), developmental abnormalities of the vitreous (34.1%), aphakia (22.7%), goniodysgenesis (18.2%), and faulty separation of the lens vesicle (15.9%). They were detected in only 3.3%, 1.1%, 3.3%, 8.9%, 1.l%, 2.2%, and 2.2%, respectively, of the control group. These developmental eye abnormalities arose from abnormal migration of neural crest cells.

[Critical time for developmental eye abnormalities induced by retinoic acid in mouse fetuses]

To identify the critical time for developmental eye abnormalities, pregnant C 57 BL/6 NJcl mice were injected intraperitoneally once with 12.5 mg/kg of retinoic acid on days 7 (day-7 group), 8 (day-8 group), 9 (day-9 group), 10 (day-10 group), and 11 (day-11 group) of pregnancy. Each group consisted of 5 pregnant mice. The fetuses were observed grossly on day 18 of gestation, and the eyes were examined histologically in serial sections. Various gross malformations such as microphthalmos, cleft lip and palate, and central nervous system anomalies were observed in the day-7 group. However, microphthalmos was the only gross malformation found in the day-8 group, and there were no gross malformations in the other 3 groups. The histological examination indicated that the critical time for anophthalmos was day 7 of gestation or earlier because of its appearance in the day-7 group alone. The critical time for microphthalmos, faulty closure of the embryonic fissure, aphakia, and faulty separation of the lens vesicle was day 8 of gestation or earlier considering their occurrence in both day 7 and day 8 groups, and the time for goniodysgenesis was day 9 of gestation or earlier because of its appearance in the day 7, day 8, and day 9 groups.

High-Resolution Terahertz Spectroscopy by a Compact Radiation Source Based on Photomixing with Diode Lasers in a Photoconductive Antenna

We demonstrate generation of continuous-wave terahertz radiation and its application to molecular spectroscopy. The radiation source is based on the photomixing of two diode laser beams in a low-temperature-grown GaAs photoconductive antenna, which offered output power of several tens of nanowatts at frequencies up to 2 THz with its long term frequency stability being about 5 MHz. The pure rotational spectra of CH3CN and isotopomers of CO were measured with this source, and 1% of absorption was clearly detected with a simple amplitude modulation technique. This indicates that the present system has a potential capability for high-resolution and high-sensitivity molecular spectroscopy. Copyright 1998 Academic Press. Copyright 1998Academic Press

Clinical evaluation of posterior embryotoxon in one institution

To elucidate the pathogenesis of posterior embryotoxon, we estimated its incidence in our clinic and evaluated its associated ocular and systemic anomalies. Slit-lamp and gonioscopic examinations were performed on 440 randomly selected patients at Nagoya City University Hospital over a 10-month period. Posterior embryotoxon was detected in 107, 50 bilateral and 57 unilateral, cases (24.3%). Twelve (11.2%) of the 107 cases had open-angle glaucoma. Accompanying ocular anomalies included six cases of sclerocornea, two each of persistent pupillary membrane and familial exudative vitreoretinopathy, and 1 each of melanocytoma of the optic nervehead, choroidal nevus and subconjunctival dermoid cyst. Associated systemic anomalies included three cases of Alagille syndrome, two of congenital biliary atresia, and one each of congenital facial palsy with microtia, congenital adrenal hyperplasia, empty sella syndrome, Hirschsprung disease and Wilson disease. Many of these ocular and systemic anomalies were caused by the maldevelopment of neural crest cells. Patients with posterior embryotoxon should be examined for the possible presence of open-angle glucoma and for ocular and systemic anomalies related to maldevelopment of neural crest cells.

Chemical characterization of pheomelanogenesis starting from dihydroxyphenylalanine or tyrosine and cysteine. Effects of tyrosinase and cysteine concentrations and reaction time

Two types of melanin pigment are produced in mammals; the brown-to-black eumelanins and the yellow-to-reddish-brown pheomelanins. The switch from one type of melanin to the other appears to be regulated by the levels of tyrosinase and thiols, such as cysteine and glutathione. This study examines the process of pheomelanin formation starting from dihydroxyphenylalanine (dopa) or tyrosine and cysteine. We prepared pheomelanins by tyrosinase oxidation of dopa or tyrosine in the presence of cysteine. Experimental variables were reaction time, tyrosinase concentration, and dopa or tyrosine to cysteine ratio. Following the reactions, we measured concentrations of tyrosine, dopa, cysteine and cysteinyldopas, amounts of total melanin (TM) by Soluene-350 solubilization and aminohydroxyphenylalanine (AHP), a specific indicator of pheomelanin, formed by hydriodic acid hydrolysis, and absorbance ratio, A650/A500. It was found that (1) mixed melanogenesis is a heterogeneous process in which pheomelanogenesis proceeds first, followed by eumelanogenesis, as shown by changes in the tyrosine and cysteinyldopa concentrations, the AHP/TM ratio, and the A650/A500 ratio during the course of melanogenesis and (2) lower tyrosinase concentration favors pheomelanogenesis even when the availability of cysteine is limited, as shown by AHP/TM ratios that were higher than the corresponding tyrosine to cysteine ratios. These results indicate that the switch from eumelanogenesis to pheomelanogenesis can be achieved by lowering the tyrosinase activity, which conforms to our proposal that tyrosinase activity is the major factor controlling the course of melanogenesis.

[Four cases of persistent hyperplastic primary vitreous]

We evaluated four cases of persistent hyperplastic primary vitreous (PHPV) encountered at Nagoya City University Hospital in 1995. PHPV was seen unilaterally in three cases and bilaterally in one. The series comprised two males and two females, ranging in age from three to eight months, with an average of 4.8 months. Case 1 had a white strand running from the optic disc to the posterior surface of the lens in the left eye. Case 2 showed leukocoria in the right eye and central corneal opacity in the left. Magnetic resonance imaging (MRI) revealed total retinal detachment in both eyes. Case 3 exhibited retinal folds running from the optic disc to the posterior surface of the lens in the left eye. Case 4 showed elongation of the ciliary processes and leukocoria in the right eye. Ipsilateral total retinal detachment was seen in MRI. Three eyes of two cases were microphthalmic. Associated ocular anomalies included, posterior embryotoxon, sclerocornea, hypoplasia of the iris stroma and peripapillary staphyloma. There were accompanying systemic anomalies such as arachnoidal cyst, syndactyly, microcephalus, heart anomalies, pulmonary atresia and asplenia. Patients with PHPV should be carefully examined for the possible presence of other ocular and systemic anomalies caused by neural crest disorders.

Chemical characterization of eumelanins with special emphasis on 5,6-dihydroxyindole-2-carboxylic acid content and molecular size

Mammalian melanins exist in two chemically distinct forms; the brown to black eumelanins and the yellow to reddish pheomelanins. Eumelanins are derived from copolymerization of 5,6-dihydroxyindole (DHI) and 5,6-dihydroxyindole-2-carboxylic acid (DHICA). Eumelanins can be quantified by HPLC analysis of the oxidation product pyrrole-2,3,5-tricarboxylic acid (PTCA) and by our spectrophotometric method (Sp.EM). We also developed a spectrophotometric method for assaying the total amount of eu- and pheomelanins by dissolving them in Soluene-350 (TM). In addition, we previously showed that Sp.EM/TM and PTCA/TM ratios are significant parameters in characterizing eumelanins produced in follicular melanocytes. The objectives of this study were (1) to clarify the significance of Sp.EM/TM and PTCA/TM ratios in synthetic eumelanins and (2) to apply these methods to characterizing natural eumelanins with various DHI/ DHICA ratios and molecular sizes. The results obtained show that (1) the Sp.EM/TM ratio of synthetic eumelanins increases as polymerization proceeds, (2) the Sp.EM/TM and PTCA/TM ratios in copolymers of DHI and DHICA correlate to the percentage content of DHICA-derived units, and (3) combination of the Sp.EM/TM and PTCA/TM ratios serves to estimate the DHICA content and the degree of polymerization in natural eumelanins.

Dihydro-1,4-benzothiazine-6,7-dione, the ultimate toxic metabolite of 4-S-cysteaminylphenol and 4-S-cysteaminylcatechol

4-S-Cysteaminylphenol (4-S-CAP) and the corresponding catechol 4-S-cysteaminylcatechol (4-S-CAC) have been evaluated for melanocytotoxicity. It was shown recently that tyrosinase oxidation of these substrates produces a violet pigment, dihydro-1,4-benzothiazine-6,7-dione (BQ). In this study we examined whether BQ is the ultimate toxic metabolite produced in melanoma cells from 4-S-CAP/4-S-CAC. Biochemical experiments showed that (1) BQ was formed by autoxidation of 4-S-CAC as well as by tyrosinase oxidation of 4-S-CAP/4-S-CAC, (2) BQ reacted rapidly with thiols such as reduced glutathione (GSH), and (3) BQ inhibited the activity of alcohol dehydrogenase, an SH enzyme. In vitro experiments showed that (1) the cytotoxicity of 4-S-CAC was mostly prevented by catalase and superoxide dismutase, (2) BQ was highly cytotoxic to B16 melanoma cells (IC50 being 3.9 microM as compared with 507 microM for 4-S-CAP), (3) BQ was metabolized rapidly to a GSH adduct in melanoma cells, and (4) the same GSH adduct was also formed upon incubation of melanoma cells with 4-S-CAP, the reaction being tyrosinase dependent. In vivo experiments showed that intratumoral administration of BQ (0.5 micromol) inhibited the subcutaneous growth of B16 melanoma nearly as effectively as 4-S-CAP/4-S-CAC (20 micromol). These results indicate that BQ is the ultimate toxic metabolite produced by tyrosinase oxidation of 4-S-CAP/4-S-CAC. BQ deprives melanoma cells of GSH and may inactivate SH enzymes essential for DNA synthesis and cell proliferation by covalent binding through their cysteine residues, thereby exerting melanocytotoxicity. Cytotoxicity of 4-S-CAC depends mostly on autoxidation producing BQ and active oxygens.

[Developmental eye abnormalities in mouse fetuses induced by retinoic acid]

To clarify the relationship between neural crest cells and ocular anomalies, pregnant mice were treated intraperitoneally with 12.5 mg/kg retinoic acid suspended in corn oil on day 7 of pregnancy (RA group). Control mice were given an equal volume of corn oil (control group). Each group consisted of 5 mother mice, and the offsprings were removed on day 18 of gestation. The fetal mortality was 46.3% in the RA group and 2.2% in the control group. Twenty-two live fetuses of the RA group and 45 of the control group were grossly observed, and the eyes were examined histologically. In the RA group, gross malformations such as microphthalmos (95.5%), cleft lip and palate (36.4%), and central nervous system anomalies (31.8%) were observed, and in the control group, malformations such as microphthalmos (6.7%), central nervous system anomalies (2.2%), and low set ears (2.2%) were seen. Histological examination revealed microphthalmos (47.7%), anophthalmos (38.6%), faulty closure of the embryonic fissure (36.4%), developmental abnormalities of the vitreous (34.1%), aphakia (22.7%), goniodysgenesis (18.2%), and faulty separation of the lens vesicle (15.9%) in the RA group. These anomalies arose from abnormal neural crest cell migration induced by retinoic acid. They were detected in only 3.3, 1.1, 3.3, 8.9, 1.1, 2.2 and 2.2%, respectively of the control group.

[A case of nonrhegmatogenous retinal detachment in Dandy-Walker Syndrome]

A 2-month-old female presented with nonrhegmatogenous retinal detachment in Dandy-Walker syndrome. At the fist examination, coloboma involving the optic disc in both eyes was detected. The left eye showed microphthalmos with sclerocornea, persistent pupillary membrane, hypoplasia of the iris stroma, and bullous retinal detachment near the optic disc. Chromosomal analysis revealed a mosaic pattern: 46, XX/47, XXX. Increased intracranial pressure associated with Dandy-Walker syndrome was detected by a neurosurgeon at the age of 3 months. The patient was followed for several weeks, and then nonrhegmatogenous retinal detachment appeared in the right eye. Subretinal fluid alternately increased and decreased in both eyes. A ventriculo-peritoneal shunt was performed at the age of 6 months, and the retinal detachment was remarkably reduced in both eyes after lowering of intracranial pressure. Coloboma involving the optic disc, sclerocornea, persistent pupillary membrane, hypoplasia of iris stroma, and Dandy-Walker syndrome were thought to be caused by the abnormal development of neural crest cells. We surmised that the retinal detachment in this case might have resulted from a communicating pathway between the subarachnoid space and the subretinal space. We concluded that the etiology of retinal detachment associated with optic disc anomaly should be investigated to determine adequate treatment.

Spectrophotometric characterization of eumelanin and pheomelanin in hair

Mammalian melanins exist in two chemically distinct forms: the brown to black eumelanins and the yellow to reddish-brown pheomelanins. They can be quantified by HPLC analysis of pyrrole-2,3,5-tricarboxylic acid (PTCA) and aminohydroxyphenylalanine (AHP). We recently developed a spectrophotometric method for assaying the total amount of eu- and pheomelanins by dissolving melanins in Soluene-350 plus water. In this study, we examined whether absorbance at 500 nm (A500) of the Soluene-350 solution reflects the total amount of melanins obtained by the HPLC methods, and whether the ratio of absorbances between 650 and 500 nm reflects the eumelanin/total melanin ratio in mouse hair, sheep wool, and human hair. Our findings were as follows: (1) Total melanin levels calculated from A500 values correlate well with those obtained from PTCA and AHP values by multiplying with the following factors: for mice, PTCA x 45 + AHP x 2.5; for sheep, PTCA x 40 + AHP x 15; and for humans, PTCA x 160 + AHP x 10. (2) The A650/ A500 ratios were higher (0.25-0.33) in black to brown hair while they were significantly lower (0.10-0.14) in yellow to red hair. These results indicate that (1) the A500 value can be used to quantify the total combined amount of eu- and pheomelanins, and (2) the A650/A500 ratio can serve as a parameter to estimate the eumelanin/total melanin ratio. The present method provides a convenient way to qualitatively characterize eu- and pheomelanins in melanins produced in follicular melanocytes.

[Histochemical studies on two cases of Peters' anomaly]

We examined glycosaminoglycan molecular species in the corneal stroma and the sclera histochemically in two cases of Peters' anomaly. Paraffin-embedded sections were stained with either hematoxylin-eosin or sensitized high iron diamine combined with enzyme digestion and then examined with a light microscope. In the center of the cornea, the histological specimens revealed defects of the corneal endothelium and Descemet's membrane, together with a local defect of the corneal stroma. Disorganized lens materials were detected in the corneal stroma. In the peripheral cornea, the undifferentiated iris adhered to the corneal posterior surface. Based upon the findings mentioned above, these two cases were diagnosed as having Peters' anomaly caused by faulty separation of the lens vesicle. The sclera showed normal structures in the specimen stained with hematoxylin-eosin. In both cases, the corneal stroma involved nearly equal amounts of chondroitin sulfate A/C and B. The sclera, on the other hand, contained a large amount of chondroitin sulfate A/C and a relatively small amount of chondroitin sulfate B. Keratan sulfate was never detected in either the cornea or the sclera. Thus, disorders of glycosaminoglycan molecular species were detected in the sclera as well as in the corneal stroma.