Expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) on proliferating vascular endothelial cells in diabetic epiretinal membranes

The present study demonstrated the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), the proliferating status of the neovascular endothelial cells, and the activation of vascular endothelial cells bearing the two cell adhesion molecules in diabetic epiretinal membranes by using double immunofluorescence and APAAP techniques. The results showed that ICAM-1 was detected in 36 out of 40 (90%) proliferative diabetic retinopathy epiretinal membranes, VCAM-1 was found in 32 out of 40 cases (80%); in 21 out of 26 (81%) vascularised membranes the endothelial cells of the new vessels in the membranes were still in a proliferative stage (positive for proliferating endothelial cell marker EN 7/44) and, further, in 20 out of 26 cases (77%) ICAM-1 was detected on the proliferating endothelial cells and VCAM-1 was found in 21 cases (81%). The expression of cell adhesion molecules, especially ICAM-1 and VCAM-1 in diabetic epiretinal membranes suggests that cell to cell interactions may play a significant role in the development of PDR membranes. In particular, the expression of ICAM-1 and VCAM-1 on proliferating endothelial cells indicates the activation of these cells, which is the first critical step for lymphocyte/endothelial cell interactions and the initiation of immune responses. The significance of proliferating status of the neovascularisation in the membranes may be related to the clinical course and prognosis of the disease.

Proliferation and activation of vascular endothelial cells in epiretinal membranes from patients with proliferative diabetic retinopathy. An immunohistochemistry and clinical study

In the present study, we investigated the status of proliferation and activation of vascular endothelial cells in epiretinal membranes from patients with proliferative diabetic retinopathy (PDR) by means of immunohistochemical techniques and compared the findings with the main clinical features of the patients. The results showed that of 21 vascularized membranes, 17 (81%) contained proliferating endothelial cells (positive for proliferating vascular endothelial cell marker EN 7/44) and 19 (90%) were positive for endothelial cell activation marker anti-VCAM-1; Furthermore, by using a double-staining technique we found that in 15 of the 17 cases (88%) the proliferating vascular endothelial cells were activated (expressing VCAM-1). Of the 18 type I diabetics, 15 (83%) contained activated proliferating endothelial cells, whereas in the 3 type II patients, only 1 membrane contained activated proliferating endothelial cells, Preoperatively, 18 patients had severe vitreous hemorrhage, among whom 15 (83%) contained proliferating endothelial cells, which were activated in 13 cases, and 16 patients had tractional retinal detachment, among whom 12 contained proliferating endothelial cells, which were activated in 11 cases. In all, 7 patients (33%) had vitreous rebleeding within 8 months postoperatively, whose membranes in 6 cases contained proliferating and activated endothelial cells. In contrast, of the 4 patients who were negative for EN 7/44, none had rebleeding, and of the 6 patients who were negative for EN 7/44 and anti-VCAM-1, only 1 had rebleeding.(ABSTRACT TRUNCATED AT 250 WORDS)

Cloning and molecular characterization of three genes, including two genes encoding serine hydroxymethyltransferases, whose inactivation is required to render yeast auxotrophic for glycine

The genes encoding both the cytosolic and mitochondrial serine hydroxymethyltransferases (SHM2 and SHM1, respectively) and a third unidentified gene of the yeast Saccharomyces cerevisiae have been isolated and their nucleotide sequences determined. Analysis of the predicted amino acid sequence of the amino-terminal regions, sequence comparison with other genes encoding SHMT enzymes, and subcellular fractionation studies all suggested that the SHM1 gene encodes the mitochondrial SHMT, while the SHM2 gene encodes the cytosolic enzyme. The SHM2 gene but not the SHM1 gene has putative GCN4 sites upstream of the putative TATA box, suggesting regulation of its transcription by the general amino acid control system. Yeast mutants with disruptions at each SHM gene and in both genes were constructed and all mutants had the same growth requirements as the parental strains. Mutagenesis of the double-disrupted, shm1 shm2 yeast yielded strains of a single complementation group that are auxotrophic for glycine. Complementation of the glycine auxotrophy using a yeast genomic library retrieved the SHM1 and SHM2 genes and a third gene designated GLY1. Gene disruption studies demonstrated that inactivation of SHM1, SHM2, and GLY1 is required to yield yeast that are completely auxotrophic for glycine.

Sonographic findings in bladder haematoma

The medical imaging and clinical histories of three cases of haematoma of the urinary bladder in paediatrics were reviewed retrospectively. The sonographic findings are unique and diagnostic. Three distinctive sonographic features were observed. The haematomas were large, occupying most of the bladder lumen. They showed an echogenic thick, smooth rim and, in two cases, a laminated appearance with concentric layers of alternating hyperechogenicity and hypo-echogenicity.

Differential contribution by conserved glutamate residues to an ion-selectivity site in the L-type Ca2+ channel pore

In voltage-gated cation channels, it is thought that residues responsible for ion-selectivity are located within the pore-lining SS1-SS2 segments. In this study, we compared the ion permeation properties of mutant calcium channels in which highly conserved glutamate residues, located at analogous positions in the SS2 regions of all four motifs, were individually replaced. All of the mutants exhibited a loss of selectivity for divalent over monovalent cations. However, the permeation properties of the individual mutants varied in a position dependent manner. The results provide strong evidence that these glutamate residues, positioned at equivalent locations in the aligned sequences, play significantly different roles in forming the selectivity barrier of the calcium channel, and are probably arranged in an asymmetrical manner inside the ion-conducting pore.

Molecular localization of regions in the L-type calcium channel critical for dihydropyridine action

Sensitivity to dihydropyridines (DHPs) is a distinct characteristic that differentiates L-type Ca2+ channels from T-, N-, and P-type Ca2+ channels. To identify regions necessary for the functional effects of DHPs, chimeric Ca2+ channels were constructed in which portions of motif III or motif IV of a DHP-insensitive brain Ca2+ channel, BI-2, were introduced into the DHP-sensitive cardiac L-type Ca2+ channel. The resultant chimeric Ca2+ channels were expressed in Xenopus oocytes, and the effects of a DHP agonist and antagonist were studied. The results show that the linker region between S5 and S6 in motif IV of the L-type Ca2+ channel is a major site for DHP action. The DHP agonist and antagonist molecules interact with distinct sites on the alpha 1 subunit of the L-type Ca2+ channel. The data further show that the SS2-S6 region of motif III is not involved in DHP action but may be an important structural component of inactivation.

Characterization and developmental expression of Tlx-1, the murine homolog of HOX11

HOX11, a human homeobox gene with putative oncogenic potential, was originally discovered at the chromosome 10 breakpoint in T-cell acute lymphoblastic leukemias bearing the chromosomal translocation t(10;14)(q24;q11). To provide insight into the possible roles of this gene in development, we isolated and characterized its murine homolog, Tlx-1, and examined its profile of expression. Tlx-1 transcripts are first detected at E8.5 in the surface ectoderm and central mesenchyme of the first branchial arch. This expression subsequently extends to the 2nd, 3rd, and 4th branchial arches, as well as the presumptive pharynx, as these structures develop. Between E12.5 and E15.5, the profile of Tlx-1 expression becomes more complex; expression is observed in the developing pancreas and salivary glands, as well as in several components of the nervous system, including the trigeminal, glossopharyngeal and vestibulocochlear ganglia, the spinal cord, and the curvature of the pons-medulla. In addition, expression is seen in the pinna and external auditory meatus of the outer ear, the tooth primordia, and specific cell populations of the mandible and tongue. These complex patterns of expression are consistent with multiple and varied roles for Tlx-1 in development and suggest that Tlx-1 marks, amongst other cell populations, structures derived from cranial neural crest cells and migratory paraxial mesoderm that arise at corresponding levels along the rostral-caudal axis of the developing embryo.

[Seroepidemiological study on hepatitis C virus infection among blood donors from various regions in China]

A total of 2,273 blood donors from various regions in China were tested for serum anti-HCV antibodies in a seroepidemiological study. The prevalence of anti-HCV in Volunteer blood donors was 0-1.10%, which was lower than that in professional blood donors from Liaoning and Anhui Provinces (1.49% and 3.14%, respectively), whereas the positivity rate of anti-HCV was as high as 30.13% in the professional blood donors from Hebei Province and 31.86% in those from Inner Mongolia Autonomous Region. The prevalence of anti-HCV was significantly higher in the blood donors with history of hepatitis and abnormal ALT levels than those without hepatitis and with normal ALT. Plasma donation was the main cause of HCV infection. However, the prevalence of anti-HCV showed no significant sex and age differences even though the anti-HCV activity profile showed geographic difference.

Study on application of the silicone oil in the reattachment of complicated retinal detachment

Sixty eyes with complicated retinal detachment were treated by vitrectomy combined with silicone oil tamponade (27 eyes of PVR grade D, 15 eyes of giant retinal tears with posterior flat folded-over, 13 eyes of posterior or macular hole, 5 eyes of traumatic PVR). After 3-24 months follow-up, the study showed retinal anatomic reattachment in 48 eyes in which the visual acuity of 32 eyes was 0.05 or better. The authors consider that vitrectomy and peeling make the silicone oil tamponade perfect the vitreous surgery and improve the successful rate. The theory of silicone oil tamponade, the indications, advantages and disadvantages of silicone oil tamponade are discussed in this paper.

Two-dimensional scanning laser slope gauge: measurements of ocean-ripple structures

A compact, two-dimensional scanning laser slope gauge has been developed for measuring ocean ripples, leading to the determination of their directional slope spectrum in the wavelength range of 4.5-81 mm. A telecentric scanning mechanism is used to enhance the dynamic range of slope measurements and to eliminate constraints caused by water-surface undulations associated with long waves. Successful laboratory tests and field trials have been performed; sample results are provided.

Molecular localization of ion selectivity sites within the pore of a human L-type cardiac calcium channel

A highly conserved position of negatively charged amino acids is present in the SS2 segments of the S5-S6 linker regions among calcium channels. We report here that replacing Glu residues at this position alters the ion selectivity of the human cardiac calcium channel. Substituting Glu334 in motif I or Glu1086 in motif III with Lys produced mutant calcium channels that permeated sodium ions 10-fold more effectively than barium ions. More conservative changes such as substitution of Glu1086 with Gln or substitution of Glu1387 with Ala also increased sodium permeation through the mutant calcium channels. Sodium currents through the mutant calcium channels could be modulated by dihydropyridines and blocked by external divalent cations. These results suggest that Glu334, Glu1086, and Glu1387 are part of a ring of glutamate residues formed in the pore-lining SS1-SS2 region and are critical in determining ion selectively and permeability of a human cardiac calcium channel.

[The changes in the levels of angiotensins and angiotensin converting enzyme and effects of captopril in patients with hypoxic pulmonary hypertension]

The levels of angiotensin I, II (ATI, II) and angiotensin converting enzyme (ACE) were measured in 28 patients with hypoxic pulmonary hypertension and 23 normal individuals. The effects of captopril were observed in 8 of 28 patients. The results showed that the average level of ATII in the patients was significantly higher than that in normal control (P < 0.05), but the average level of ACE in the patients was significantly lower than that in the controls (P < 0.05). In 8 patients, after the use of captopril, an ACE inhibitor, for two weeks, the levels of ATII, ACE and mean pulmonary arterial pressure (mPAP) were markedly decreased (P < 0.05). But the other 20 patients treated with antibiotics, antiasthmatics, diuretics and oxygen therapy for two weeks did not show any alterations in the levels of ATII, ACE and mPAP.

Clinical and immunohistochemical correlation of herpetic keratitis with the expression of HLA-DR antigen

The corneal buttons after corneal graft of 22 patients with herpetic keratitis were studied (16 male, 6 female; 7-87 years of age). Ten still had active inflammation, while 12 had stabilized by the time of the study. Different degrees of neovascularization were observed in 19 cases. HLA-DR antigen was detected in the corneal epithelium in 7 of 22 cases (32%), in the corneal stroma in 17 of 22 cases (77%), and in the endothelium in 9 cases (41%) by using the immunohistochemical technique. The expression of HLA-DR antigen was more common and more marked in active herpetic keratitis (90%) and in neovascularized corneas (84%). The frequency and density of HLA-DR expression in perforating corneal ulcers were no higher than in other cases, but anterior synechia was accompanied by strong expression of HLA-DR antigen in the corneas. The expression of HLA-DR antigen was not only detected in the peripheral, but also in the central area of the specimens. The cells expressing HLA-DR antigen in corneas were mainly corneal cells. The results showed a close relationship between HSV-keratitis and the expression of HLA-DR antigen, which may be induced during the clinical course of the disease. The expression of HLA-DR might be one of the factors in the recurrent onset of the disease and a significant sign of the prognosis of corneal transplantation for these patients.

Financing health care in rural China: preliminary report of a nationwide study

One unforeseen consequence of the change from collective to household production in rural China has been that the financial basis of the rural health services has been eroded. The majority of peasants now pay for health care on a fee-for-service basis. A major initiative aimed at the establishment of prepayment schemes for funding rural health services is underway. A nationwide survey which compared health utilization and expenditure under different financing mechanisms was carried out in 1988. This paper presents the preliminary findings of that study. There is evidence that hospital charges were a barrier to inpatient care for those not covered by an insurance scheme. The data were less clearcut with regard to access to outpatient care. There is a need for further study which focuses on poor households and those living in remote villages. The study found that drug charges are an important source of revenue for the rural health services. The impact of this on prescription practices is an area which requires additional research. The cost of rural health services was relatively low. It is feasible to finance them almost entirely out of local resources in the more developed regions. The situation in the poorer provinces is more complicated. In spite of the fact that average health expenditure was almost 5% of household income in 1988, there was evidence of lack of access. This suggests that it may be more difficult to develop prepayment schemes to cover the full range of rural health services in the less developed regions.

Cells of the immune system and their cytokines in epiretinal membranes and in the vitreous of patients with proliferative diabetic retinopathy

In the present study, we specifically investigated the presence of the main immune cells, namely T helper/inducer lymphocytes, T suppressor/cytotoxic lymphocytes, B lymphocytes and macrophages, for HLA-DR antigen expression and the cytokines IL-1 alpha and IL-2 in epiretinal membranes of proliferative diabetic retinopathy (PDR) using immunohistochemical staining. The levels of the two cytokines (IL-1 alpha and IL-2) in the vitreous were measured by ELISA. The results show that 18 out of the 32 epiretinal specimens reacted positively with monoclonal anti-CD4 (marker for T helper/inducer cell subset) antibody (56%), 21 reacted with monoclonal anti-CD8 (marker for T suppressor/cytotoxic subset) antibody (66%), 15 reacted with monoclonal anti-CD22 (marker for B lymphocytes) antibody (47%), and 25 (78%) were positive for monoclonal anti-macrophage and anti-HLA-DR antibodies. IL-1 alpha and IL-2 were detected in the epiretinal membranes in 8 out of 13 tested cases (62%). However, in the vitreous, IL-1 alpha was detected in only 3 out of 13 cases (70, 75 and 80 pg/ml, respectively), while IL-2 was not detected in any of the vitreous samples. The results clearly demonstrate that immune cells and their cytokines were found in about half of the epiretinal membrane specimens. The invasion of the immunocompetent cells in the membranes seems to be a secondary event. They would not participate in the pathogenesis of PDR, but probably induce unspecific reactions and thus complicate the disease.

[A patient with severe ventricular tachycardia who was saved by prolonged extracorporeal lung and heart assist]

A 47-y-o man had been suffering from cardiac failure due to refractory ventricular tachycardia (VT) after myocardial infarction. He underwent resection of the left ventricular aneurysm and cryocoagulation of the arrhythmogenic foci. On the 2nd post-operative day, VT often recurred in spite of repeated cardioversion and drug therapy, and threatened his life, even under IABP. Therefore, a veno-arterial bypass route was made and extracorporeal lung and heart assist, ECLHA, was started with a heparin bonded Maxima lung on the following day. Even under ECLHA, VT continued to recur. Cryocoagulation of the VT foci was tried again, without immediate success. A record high dose of beta-blockers, given under the circulatory support by ECLHA, stopped VT on the following day. The patient was weaned from the ECLHA circuit 12 days after the first operation, then from IABP on the 14th day. During the 10 day course of surgeries and ECLHA, the patient had almost 100 defibrillations. But for ECLHA, we may say that the patient couldn't have survived two open heart surgeries, administration of a great amount of beta-blockers, and repeated cardiac arrest without neurological sequelae.

[Thixotropic properties of whole blood in children with congenital heart disease]

The thixotropic parameters of whole blood in two groups of children with congenital heart disease (CHD) were measured. Group 1. cyanotic heart disease (CCHD), 20 cases; Group 2. acyanotic heart disease (ACHD), 30 cases. Fifty healthy children were controls matched with the patients in sex and age. Their thixotropic parameters were compared; the paired t-test was used. In the children with CCHD, the hematocrit (HCT), the yield stress (tau 0) the Newtonian contribution of viscosity (mu), the equilibrium value of the structural parameter (A), the apparent viscosity at 2.37 sec-1 (eta s) and the Non-Newtonian contribution of viscosity (eta s-mu) were significantly higher than those in corresponding control groups. In the children with ACHD, only the values of tau 0, eta s-mu, and eta s were higher than those in control groups. All of the thixotropic parameters in CCHD group were significantly higher than those in ACHD group. Thus we described quantitatively CHD in terms of thixotropy of blood. The thixotropic parameters of blood could be used as indexes of severity for pathologic changes of CHD.

Lack of human immunodeficiency virus type 1 (HIV-1) replication and accumulation of viral DNA in HIV-1-infected T cells blocked in cell replication

Human immunodeficiency virus type 1 (HIV-1) infection of the CD4+ SupT and CEM cell lines, blocked in cell replication by the polymerase alpha inhibitor aphidicolin (APC), was studied. The APC-treated cells showed a lack of viral production, but the presence of single cell killing. High levels of unintegrated viral DNA forms were found in the infected APC-treated cells as compared with untreated cells. Moreover, an increased rate of viral replication occurred in the remaining viable cells following removal of APC. The results indicate that HIV-1 entry and reverse transcription can take place in cells blocked in the S phase of the cell cycle. Replication of infectious progeny virions appears to require de novo cell division. Finally, accumulation of viral DNA in cells during APC treatment can result in cytopathological effects and subsequent enhancement of virus production.

[Changes in plasma glucagon concentration in patients with diabetes mellitus and its clinical significance]

To investigate the role of glucagon in the pathogenesis of diabetes, we observed change of plasma glucagon concentrations during glucose loading in normal subjects and patients with impaired glucose tolerance (IGT) and non-insulin dependent diabetes mellitus (NIDDM) using specific radioimmunoassay. The results showed that the fasting plasma glucagon levels in patients with IGT and NIDDM were similar to those of the normal subjects. The nadir of plasma glucagon level in the normal control occurred at 1-h after glucose loading and the changes of glucagon, glucose and insulin levels synchronized; but peaks of plasma glucose and insulin levels in the IGT and NIDDM patients were delayed at 2-h after glucose loading with the lowest glucagon level at 3-h. It was suggested that there were relative hyperglucagonemia and decrease of sensitivity of islet A cell to glucose in IGT and NIDDM patients. The present study also showed that hyperglucagonemia is related to the reduction of insulin secretion and might play an important role in the development of postprandial hyperglycemia in NIDDM.

[Study on the mechanisms and influential factors of intrauterine infection of hepatitis B virus]

Molecular hybridization methods were used to study the intrauterine HBV infection in induced abortions. HBV-DNA was detected not only in fetal liver, but also in spleen, Pancreas, kidney and placenta. The results suggested that HBV might probably pass through placental barrier or infect the placenta leading to the intrauterine HBV infection. Even a possible vertical transmission of HBV via the germ line might exist. However, it might not be the main way by which the maternal blood entered fetal circulation through placental leakage leading to intrauterine infection of HBV. In maternal blood, HBeAg positivity, especially also positive for HBV-DNA was important for intrauterine infection. But maternal anti-HBc antibody may not be able to suppress HBV antigens expression and HBV replication in fetal tissue.

[Isolation and purification of alpha fetal protein utilizing Act-Ultrogel AcA 22 affinity chromatography]

In the present communication, we report a method for the isolation and purification of alpha FP from fetal corpse homogenate in a single-step procedure using Act-Ultrogel AcA 22 affinity chromatogrpahy column. This method proves to be better than the conventional method in simplicity, fastness and validity with recovery, purity and immunoreactivity. The immunoreactivity of the purified alpha FP labelled by the method of Hunter and Greenwood (1962) was 50-60% (B/T%). This was similar to alpha FP standard (WHO). The results indicate that the 125I-alpha FP is suitable for alpha FP radioimmunoassay.

[Study on thixotropic parameters of whole blood from healthy children]

With low shear-30 rheometer, the authors used a modified protocol to measure thixotropic parameters of whole blood from 200 healthy newborns and children, so as to suggest the normal range of blood thixotropic parameters in four age groups, namely, the newborns, 1 year- group, 5 year- and 10-15 year group. The results demonstrated that the thixotropic parameters in the newborn group were higher than those in other three groups. However, these thixotropic parameters in the group 1-10 years were lower than those in the 10-15 year group. No significant sex differences were noted among the fore three groups, but sex differences appeared obviously in the 10-15 year group. It implied that the changes relying on the age is consistent with children's growth, development and physiologic activities.

[Study on the HBV intrauterine infection and its rate]

In thirty-five fetuses induced from HBsAg-positive pregnant women, the fetuses were examined for HBV markers. Another 10 fetuses were used as control and none of the fetuses was infected by HBV in utero. Among 35 fetal serum samples, HBsAg and anti-HBcIgM were detected in 4 and 5 fetuses (in 7 fetuses) respectively. One out of 17 fetal liver sections was HBcAg positive by ABC stain. Twelve out of 27 fetal livers were HBV-DNA positive. Thus, the rate of intrauterine infection of HBV was 20.0% (7/35), 5.9% (1/17) and 44.4% (12/27) respectively, by serological test, immunohistochemical test and molecular hybridization using P-labeled HBV DNA as a probe. The results showed that HBV intrauterine infection was an important mode of HBV transmission.

[New approach for management of retinal detachment with macular hole]

Three kinds of unconventional methods were used to treat retinal detachment with macular hole in 17 cases (17 eyes). A combination of vitrectomy, transscleral drainage and intraocular air injection was used for the cases of retinal detachment with macular hole and evident vitreous traction. Transscleral drainage combined with air injection was used for those of macular hole without vitreous traction. For the cases of combined peripheral and macular holes, we treated only peripheral holes, ignoring the macular hole. After a 3-16 months follow-up, 15 out of the 17 eyes obtained retinal anatomic reattachment (88.2%), 10 eyes had their vision improved, 4 eyes remained unchanged, 9 eyes obtained a visual acuity of better than 0.05 postoperatively. Compared with the conventional method of macular buckling, these procedures have the advantages of less damage to macula, less complications and more satisfactory visual improvement.

Fast profilometer for the automatic measurement of 3-D object shapes

A fast technique for automatic 3-D shape measurement is proposed and verified by experiments. The technique, based on the principle of phase measurement of the deformed grating pattern which carries the 3-D information of the measured object, can automatically and accurately obtain the phase map or the height information of a measured object at every pixel point without assigning fringe orders and interpreting data in the regions between the fringe orders. Only one image pattern is sufficient for obtaining the phase map. In contrast to the fast Fourier transform based technique, the technique processes a fringe pattern in the real-signal domain instead of the frequency domain by using demodulation and convolution techniques, can process an arbitrary number of pixel points, and is much faster. Theoretical analysis, simulation results, and experimental results are presented.

Optical response of the indicator chlortetracycline to membrane potential

Chlortetracycline is a fluorescent, Ca2+ indicator commonly used to monitor the internal Ca2+ concentration of membrane vesicles and organelles. We have found that the intensity of chlortetracycline fluorescence in the presence of Ca2(+)-loaded liposomes is dependent on the membrane potential of the vesicles as well as the intravesicular Ca2+ concentration. The fluorescence of chlortetracycline was lower when an inside-negative membrane potential was placed across the liposome membrane. Since chlortetracycline diffuses across the membrane in the zwitterionic form, the distribution of chlortetracycline across the membrane should not be strongly dependent on the membrane potential. However, because the proton permeability of phospholipid vesicles is relatively high, the intravesicular proton concentration is dependent on the membrane potential. The binding of Ca2+ to chlortetracycline is dependent on pH in the range of pH 6 to pH 8. Therefore, changes in the intravesicular pH as a result of a change in the membrane potential causes relatively large changes in the chlortetracycline fluorescence signal even when there isn't a change in the Ca2+ concentration.

[Pancreatic glucagon receptor radioassay with liver cell plasma membrane in normal and streptozotocin-induced diabetic rats]

Pancreatic glucagon receptor radioassay has been developed with rat liver cell plasma membrane prepared with sucrose gradient centrifugation. 125I-glucagon was prepared in this laboratory and the separation of B/F was done by low speed centrifugation with addition of PEG (W/V, 20%) and normal human serum. The specific binding of 125I-glucagon was 25%-35% and nonspecific binding was less than 5%. Reproducibility within and between- assay was 6.83% and 8.40% (CV%), respectively. Binding characteristics of glucagon receptor of normal and streptozotocin-induced diabetic rats were determined by using two methods, receptor dilution and conventional competitive binding assay. The results showed that there were no marked differences concerning high and low binding affinities between normal and diabetic rats, but the concentration of binding sites for both high and low affinity receptors was significantly higher for diabetic rats than normal rats. The possible mechanisms for the above results have been discussed.

Cross-induced polarization changes in single-mode fibers

The polarization changes induced by a strong wave on a copropagating weaker wave in a single-mode birefringent fiber are investigated. Quantitative analysis and measurements are presented for the dependence of these polarization changes on the relative input state of polarization of the two waves as well as on their frequency separation.

Prospective hormone study of hypothalamic-pituitary function in patients with nasopharyngeal carcinoma after high dose irradiation

With the aim of evaluating the effect of high dose irradiation (6,500 cGy/36 fractions or higher) to pituitary fossa, a prospective study was carried out in patients with nasopharyngeal cancer by a serial determination of several hormones in the serum, before and after the course of radiation therapy (RT). The radiation treatment field was at least 1 cm above the skull base with bilateral parallel opposing fields. Hormone assays were performed three times on each patient: (1) prior to, (2) one month after, (3) 15-18 months after radiation therapy. The study included determination of serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), thyroid-stimulating hormone (TSH), cortisol, growth hormone (GH) and prolactin concentrations and LH-releasing hormone, thyrotrophin-releasing hormone stimulation and insulin tolerance tests were also carried out. Complete profiles were obtained in 24 patients (16 males and 8 females), aged 16-67 years. The results showed a significant decrease in the level of serum peak value of LH in males 18 months after therapy, and also in GH both one month and 18 months after therapy. A significant increase in the peak value of serum TSH observed after therapy. Decreased serum FSH, cortisol and prolactin levels were noted, but these did not reach statistical significance. The decrease in GH level appeared earlier and was more sensitive than that found for the other hormones, and could prove to be a useful parameter for clinical evaluation. None of the patients showed any clinically recognizable symptoms or signs of hormone deficiency in the 18-33 months following completion of the radiation therapy.

Silicone oil in the anterior chamber

A total of 42 cases (42 eyes) with silicone oil in the anterior chamber after pars plana vitrectomy (PPV) and after silicone oil injection into the vitreous cavity (SIV) were analyzed. The main complications caused by silicone oil were corneal endothelial cell damage and secondary glaucoma. Specular microscopy showed decreased cell density, apparent pleomorphism of endothelial cells, and increased corneal thickness. In some cases, edematous and necrotic endothelial cells were found. The characteristic optical artifacts resulting from silicone oil coming into contact with the endothelium, such as a bright reflex, reversed pattern of illumination, and interference fringes, were also observed. There was a definite correlation between elevated intraocular pressure (IOP) and the presence of silicone oil in the anterior chamber; the IOP dropped significantly on removal of the oil. The treatment and prevention of conditions involving silicone oil in the anterior chamber are briefly discussed.