The weediness of wild plants: molecular analysis of genes influencing dispersal and persistence of johnsongrass, Sorghum halepense (L.) Pers

Many major weeds rely upon vegetative dispersal by rhizomes and seed dispersal by "shattering" of the mature inflorescence. We report molecular analysis of these traits in a cross between cultivated and wild species of Sorghum that are the probable progenitors of the major weed "johnsongrass." By restriction fragment length polymorphism mapping, variation in the number of rhizomes producing above-ground shoots was associated with three quantitative trait loci (QTLs). Variation in regrowth (ratooning) after overwintering was associated with QTLs accounting for additional rhizomatous growth and with QTLs influencing tillering. Vegetative buds that become rhizomes are similar to those that become tillers--one QTL appears to influence the number of such vegetative buds available, and additional independent genes determine whether individual buds differentiate into tillers or rhizomes. DNA markers described herein facilitate cloning of genes associated with weediness, comparative study of rhizomatousness in other Poaceae, and assessment of gene flow between cultivated and weedy sorghums--a risk that constrains improvement of sorghum through biotechnology. Cloning of "weediness" genes may create opportunities for plant growth regulation, in suppressing propagation of weeds and enhancing productivity of major forage, turf, and "ratoon" crops.

Soluble interleukin-2 receptor as a clinical parameter for nasopharyngeal carcinoma

We evaluated whether the serum soluble interleukin-2 receptor (sIL-2R) may be a parameter to monitor the efficacy of treatment for nasopharyngeal carcinoma (NPC). There were 177 NPC patients and 24 healthy controls. The level of sIL-2R was measured with a sandwich ELISA kit. Higher levels of sIL-2R than for controls were found in NPC patients before treatment and in patients with distant metastasis (p < 0.001). There was, however, no difference in sIL-2R levels between controls and NPC patients after radiotherapy in relapse-free or in primary relapse. The sIL-2R levels in sequential testing revealed good correlation with clinical response. The sIL-2R levels were found to be elevated when distant metastasis was detected. Two patients had elevated sIL-2R level up to 5 months before clinical detection of metastasis. These results indicate that serial measurements of sIL-2R levels are worthwhile for NPC patients in their clinical course. The sIL-2R level proved to be an adjunct clinical parameter to monitor the efficacy of treatment of NPC.

The primary structure of rat ribosomal protein L15

The amino acid sequence of the rat 60S ribosomal subunit protein L15 was deduced from the sequence of nucleotides in two recombinant cDNAs. Ribosomal protein L15 has 203 amino acids, the NH2-terminal methionine is removed after translation of the mRNA, and has a molecular weight of 24,000. Hybridization of the cDNA to digests of nuclear DNA suggests that there are 13 to 15 copies of the L15 gene. The mRNA for the protein is about 850 nucleotides in length. Rat L15 is related to ribosomal proteins from other eukaryotes. Rat L15 has the hexapeptide, TYKFFE, that also occurs in the amyloidogenic glycoprotein A4 which is associated with Alzheimer's disease and Down's Syndrome.

Epstein-Barr virus harboring in the parotid gland without tumor association

The purpose of this study is to clarify the relationship between Epstein-Barr virus (EBV) and tumors of the major salivary gland. EBV DNA was detected by polymerase chain reaction (PCR) in parotid secretions in 56% of patients (n = 32) regardless of the presence of tumors in the parotid gland and in tumor tissues in 19% of surgical specimens (n = 21). By Southern blot-hybridization analysis, we found type A EBV in three patients and type B EBV in one patient. In situ hybridization for EBV genome was positive in surgical specimens of salivary glands in 33% of patients (n = 21). Our results suggest that this virus may not play a role in the pathogenesis of most tumors of the major salivary gland. However, two patients with lymphoepithelial carcinoma were found to have a close relationship to EBV as shown by high titers of antibodies in the sera against EBV related antigens by standard immunofluorescent technique and by the presence of many copies of EBV genome in tumor cells using in situ hybridization.

Statistical and parametric analysis of beta-2-microglobulin removal from uremic patients in high flux hemodialysis

Beta-2-microglobulin (beta 2M) associated amyloidosis has been seen in patients with chronic renal failure after long-term hemodialysis. However, the exact mechanism of beta 2M formation and accumulation is not clinically understood. In this investigation, the formation and removal kinetics of beta 2M were studied by compartmental modeling of a patient dialyzer system. Statistical and parametric analyses of model equations, coupled with clinical data from selected patients, enabled us to predict the behavior and influence of membrane materials upon the clearance characteristics of beta 2M during and between hemodialysis treatments.

Adaptive image region-growing

Proposes a simple, yet general and powerful, region-growing framework for image segmentation. The region-growing process is guided by regional feature analysis; no parameter tuning or a priori knowledge about the image is required. To decide if two regions should be merged, instead of comparing the difference of region feature means with a predefined threshold, the authors adaptively assess region homogeneity from region feature distributions. This results in an algorithm that is robust with respect to various image characteristics. The merge criterion also minimizes the number of merge rejections and results in a fast region-growing process that is amenable to parallelization.

Intracellular calcium and myosin light chain phosphorylation during U46619-activated vascular contraction

We investigated the relationship between [Ca2+]i, myosin light chain (LC20) phosphorylation and isometric force in guinea pig aortic strips during contractions activated by a thromboxane A2 analogue, (15S)-hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5Z, 13E-dienoic acid (U46619). Isometric force and [Ca2+]i were measured simultaneously using preloaded aequorin as the intracellular calcium indicator. LC20 phosphorylation levels were determined by two dimensional polyacrylamide gel electrophoresis in parallel preparations. Contractions induced by U46619 were accompanied by increases in [Ca2+]i and LC20 phosphorylation. The chelation of extracellular calcium with 2.5 mM EGTA significantly inhibited U46619-induced increases in [Ca2+]i, isometric force and LC20 phosphorylation. Steady-state force assumed a similar dependence on LC20 phosphorylation for contractions stimulated by potassium depolarization, alpha 1-adrenergic agonist phenylephrine and U46619 either in the presence or absence of extracellular calcium. On the contrary, the [Ca2+]i/force relation revealed that both U46619 and phenylephrine stimulated greater isometric force at lower [Ca2+]i than did KCl depolarization. The addition of a protein kinase C inhibitor, 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H-7), decreases force without significantly affecting either [Ca2+]i or LC20 phosphorylation levels. These results suggest that in guinea pig aortic smooth muscle U46619 increases the calcium sensitivity of the contractile apparatus but does not change the LC20 phosphorylation/force relation in comparison to K+ depolarization. Protein kinase C is activated during U46619-stimulated contraction and might be involved in mechanisms other than LC20 phosphorylation.

The conformation of the sarcin/ricin loop from 28S ribosomal RNA

The sarcin/ricin loop is a highly conserved sequence found in the RNA of all large ribosomal subunits. The cytotoxins alpha-sarcin and ricin both inactivate ribosomes by cleaving a single bond in that loop. Once it has been attacked, ribosomes no longer interact with elongation factors properly, and translation stops. We have determined the conformation of the sarcin/ricin loop by multinuclear NMR spectroscopy using E73, a 29-nucleotide RNA that has the sarcin/ricin loop sequence and that is sensitive to both toxins in vitro. The sarcin/ricin loop has a compact structure that contains several purine.purine base pairs, a GAGA tetraloop, and a bulged guanosine adjacent to a reverse Hoogsteen A.U pair. It is stabilized by an unusual set of cross-strand base-stacking interactions and imino proton to phosphate oxygen hydrogen bonds. In addition to having interesting structural features, this model explains many of the biochemical observations made about the loop's structure and its reactivity with cytotoxins, and it sheds light on the loop's interactions with elongation factors.

Daphnoretin, a new protein kinase C activator isolated from Wikstroemia indica C.A. Mey

Daphnoretin, a biologically active principle isolated from Wikstroemia indica C.A. Mey., caused platelet aggregation in washed rabbit platelets, platelet-rich plasma and whole blood. The aggregation of and ATP release from platelets induced by daphnoretin were similar to phorbol ester- and diacylglycerol-induced aggregation and release. The EC50 values of daphnoretin-, phorbol 12,13-dibutyrate (PDBu)- and 1-oleoyl-2-acetylglycerol (OAG)-induced platelet aggregation in washed rabbit platelets were 17.2 +/- 2.8 microM, 20.6 +/- 2.1 nM and 38.6 +/- 1.7 microM respectively. Platelet aggregation induced by daphnoretin and PDBu was not inhibited by indomethacin, BN52021 or sodium nitroprusside. ADP-scavenging systems, apyrase and phosphocreatine/creatine kinase, showed weak inhibition of the aggregation, and EGTA, triflavin, verapamil and prostaglandin E1 markedly inhibited the aggregation. Staurosporine, a potent protein kinase C inhibitor, suppressed daphnoretin-, PDBu- and OAG-induced aggregation and ATP release in a concentration-dependent manner. The IC50 values of staurosporine on daphnoretin (50 microM)-, PDBu (100 nM)- and OAG (50 microM)-induced aggregation were 37.7 +/- 8.3, 52.2 +/- 6.3 and 42.8 +/- 8.9 nM respectively. Daphnoretin did not cause significant thromboxane B2 formation in rabbit platelets. Neither daphnoretin nor PDBu caused [3H]inositol monophosphate formation or an increase in intracellular Ca2+ concentration in myo-[3H]inositol-labelled and Fura-2-loaded platelets. Platelet cytosolic protein kinase C was activated by daphnoretin and PDBu in a concentration-dependent manner with an EC50 of 12.4 +/- 1.2 microM and 18.7 +/- 1.4 nM respectively. Membrane-associated protein kinase C activity was increased by either daphnoretin or PDBu. [3H]PDBu binding to washed rabbit platelets was inhibited by daphnoretin in a concentration-dependent manner with an IC50 value of 45.2 +/- 5.2 microM. These results indicate that daphnoretin is a protein kinase C activator in rabbit platelets.

Clinical experience and model analysis on beta-2-microglobulin kinetics in high-flux hemodialysis

Beta-2-microglobulin (beta 2M) is associated with amyloidosis. The study of beta 2M kinetics can provide information on the elimination of this uremic toxin. A beta 2M kinetic model modified from Gotch, considering the volume changes between intracellular, interstitial, and intravascular compartments and the generation stimulation and inhibition during hemodialysis is proposed. The clinical experiments on 8 stable hemodialysis patients treated with polysulfone (F80) and polymethyl methacrylate (PMMA, BK2.1p) 3 times a week were conducted. There was an 18% decrease of beta 2M clearance in the period from 30 to 180 min with a time-averaged beta 2M clearance of 48 ml/min using polysulfone dialyzers (F80). In PMMA dialyzers, there was a 64% decrease of beta 2M clearance from 30 to 180 min with a time-averaged clearance of 56.3 ml/min. During hemodialysis, the generation rate was 0.379 mg/min in polysulfone and 0.828 mg/min in PMMA dialyzers. There was a stimulation generation of 0.309 mg/min in polysulfone and 0.749 mg/min in PMMA during hemodialysis. In conclusion, we provide a beta 2M kinetic model including volume changes, polymerization, generation stimulation, and inhibition that is similar to the human physiological condition. This model can be used for further clinical study.

The distribution of lifetime cumulative exposures to radon for California residents

The distribution of individual lifetime exposures to radon was estimated using data from studies on radon concentrations, mobility, and time-activity patterns in the state of California. The distributions of radon concentrations in various geographic regions were obtained from the results of year-long radon measurements of 310 residences. The mobility patterns were acquired through a survey of the moving histories of the members of 507 households. The indoor and outdoor time-activity data were collected for 1,780 individuals in 1,596 households. Based on these data, a computer simulation technique was used to estimate the distribution of radon exposures with a parametric (lognormal model) and a nonparametric approach (bootstrap method). The estimated average lifetime exposure for radon was 2,448 Bq.m-3.yr for the lognormal model and 2,487 Bq.m-3.yr for the bootstrap method. The standard deviation was 1,130 and 1,145 Bq.m-3.yr respectively. Assuming no move over the lifetime, the estimated average lifetime exposure to radon was 2,052 Bq.m-3.yr for the lognormal model and 2,078 Bq.m-3.yr for the bootstrap method, while the standard deviation increased to 1,378 Bq.m-3.yr for the lognormal model and 1,514 Bq.m-3.yr for the bootstrap method.

Possible non-sexual transmission of genital human papillomavirus infections in young women

Human papillomaviruses were detected by an in vitro enzymatic DNA amplification method in cells obtained from vulvar swabs of 9 of 61 (14.8%) young women without prior experience of sexual intercourse and in 7 of 57 (12.3%) young women with prior experience. The prevalence of human papillomavirus DNA in these two groups of women was not significantly different (x2 = 0.16, p > 0.5; 95% confidence interval -0.165 to 0.215). These results suggest that genital human papillomavirus is not sexually transmitted in all cases and that it may be acquired by modes other than sexual contact.

CIS-19, a novel platelet activating factor receptor antagonist: in vitro and in vivo studies

The effects of CIS-19 (cis-2-(3,4-dimethoxyphenyl)-6-isopropoxy-7-methoxyl-1-(N-methylforma mido)-1,2, 3,4-tetrahydronaphthalene) was determined in vitro in rabbit platelets and in vivo in rats and guinea-pigs. CIS-19 inhibited in a selective and concentration-dependent manner the aggregation and ATP release reaction of rabbit platelets induced by PAF (4 nM). The IC50 values of CIS-19 on PAF-induced aggregation of washed platelets and platelet-rich plasma were 11.3 +/- 2.7 and 16.8 +/- 3.0 microM respectively. BN52021 also inhibited PAF-induced aggregation of washed platelets with an IC50 value of 11.7 +/- 2.8 microM. CIS-19 inhibited [3H]PAF (4 nM) binding to washed rabbit platelets with an IC50 value of 1.5 +/- 0.2 microM. The concentration-response curve of PAF-induced aggregation of washed platelets was shifted rightwards by CIS-19 with pA2 and pA10 values of 7.1 (6.8-7.3 for 95% confidence limit) and 6.1 (5.8-6.2) respectively. The thromboxane B2 formation of washed platelets caused by AA, collagen or thrombin was not affected by CIS-19 of concentrations below 400 microM. CIS-19 (25 microM) completely blocked PAF-induced, but not collagen- or thrombin-induced [3H]inositol monophosphate formation of washed platelets. When CIS-19 (2.5 and 5 mg/kg) was injected i.v. into the femoral vein, it did not affect the blood pressure of rats, but antagonized PAF (2.5 micrograms/kg, i.v.)-induced hypotensive shock either preventively or curatively. CIS-19 (2.5 and 5 mg/kg) also blocked PAF (50 ng/kg)-induced, but not AA (50 micrograms/kg)-induced, bronchoconstriction in guinea-pigs. It is concluded that CIS-19 is an effective PAF receptor antagonist not only in vitro, but also in vivo.

Transcriptional regulation of precore and pregenomic RNAs of hepatitis B virus

Hepatitis B virus (HBV) infection, either acute or chronic, has been one of the leading health problems in the world. To understand the HBV life cycle and disease process, we set out to study the regulation of viral gene expression. In this paper, we report the characterization of the HBV core promoter: two 3.5-kb transcripts, precore and pregenomic, are made from it. The latter is itself a template for viral genome replication and also encodes viral proteins essential for both viral replication and virion assembly. We identify a short sequence (from nucleotides [nt] 1744 to 1851, referred to as the basic core promoter [BCP]) that is sufficient to direct correct initiation of both precore and pregenomic messages. In addition, the two appear to be regulated in a coordinate manner. Sequences upstream of the BCP (from nt 1636 to 1744, referred to as the core upstream regulatory sequence [CURS]), have a strong stimulating effect on the BCP. Addition of the CURS to the BCP leads to a dramatic increase in both the transcription of two 3.5-kb messages and the production of 42-nm virions from transiently transfected hepatoma cells. The CURS stimulates the BCP in a position- and orientation-dependent manner. Therefore, it is unlikely that the effect is mediated through enhancer II, which has been localized to the same sequence. Deletion analysis of the CURS suggests that it contains multiple regulatory elements that control the BCP in an interactive manner. In accord with this hypothesis, the CURS is found to be bound with many distinct protein factors in footprinting experiments. Among these elements, box alpha (from nt 1646 to 1668) and box gamma delta (from nt 1671 to 1703) are two regulatory elements which individually stimulate promoter activity more than 100-fold.

Prevalence of genital human papillomavirus infections in patients at a sexually transmitted diseases clinic

The human papillomavirus was detected in cervicovaginal cells by the polymerase chain reaction in 14 of 37 (37.8%) patients attending a sexually transmitted disease (STD) clinic and in 6 of 43 healthy young women (14.0%) undergoing routine gynecologic examinations who served as controls. The results indicated that even the more malignant types of human papillomaviruses were not uncommon among the control group, and that the prevalence of human papillomavirus infection was significantly higher in STD clinic patients than in the control group. These findings confirm the suggestion that factors other than human papillomavirus infections may be involved in the pathogenesis of cervical cancer.

Intraneural anatomy of the median nerve provides "third web space" donor nerve graft

To determine the feasibility of using the fascicular group to the third web space as a source of nerve graft material for bridging of median nerve gaps, a study of the intraneural anatomy of the median nerve was carried out in 23 fresh cadaver specimens. The pattern of plexus formation between the third web-space group and the remainder of the median nerve was determined. The average length of the third web-space fascicular group that could be separated from the median nerve proper prior to plexus intermingling was 24.5 cm. Cross-sectional areas of the graft and the remaining nerve were 4.43 mm2 and 13.76 mm2, respectively. The number of nerve fibers in the third web-space group was 4,847 and in the remaining median nerve, 13,486. Between February, 1989 and October, 1991, this technique has been used on 11 patients to provide donor nerve material for nerve gaps of 3 to 6 cm in the median nerve.

Possible transplacental transmission of human papillomaviruses

OBJECTIVE

The objective of this study was to examine the possibility of intrauterine human papillomavirus infection of fetuses by transplacental transmission of human papillomavirus before delivery.

STUDY DESIGN

Specimens of cervicovaginal cells and peripheral blood mononuclear cells were obtained from 52 consecutive pregnant women in the third trimester of pregnancy. Cord blood specimens were also obtained from the neonates born to these mothers. Presence of human papillomavirus types 16 and 18 deoxyribonucleic acid was analyzed by an in vitro enzymatic deoxyribonucleic acid amplification method.

RESULTS

Human papillomavirus type 16 deoxyribonucleic acid was found in 6 (11.5%) cervicovaginal and in 9 (17.3%) peripheral blood mononuclear cell specimens. Seven cord blood specimens from neonates born to mothers who were positive for peripheral blood mononuclear cell human papillomavirus type 16 deoxyribonucleic acid were found to contain human papillomavirus type 16 deoxyribonucleic acid. One cervicovaginal and two peripheral blood mononuclear cell specimens contained human papillomavirus type 18 deoxyribonucleic acid, but none of the cord blood specimens contained human papillomavirus type 18 deoxyribonucleic acid.

CONCLUSION

These results seem to suggest possible transplacental transmission of the virus and the potential association of such transmission with the status of human papillomavirus in peripheral blood mononuclear cells.

[Metastasis in oral squamous cell carcinoma]

A precise evaluation of the presence of metastasis is mandatory in the management of head and neck malignancies. Squamous cell carcinoma is the most common malignant tumor of the oral cavity, representing slightly more than 90% of all oral malignancies. The present study included 330 consecutive patients with oral squamous cell carcinoma seen at the Oral and Maxillofacial Surgery Division of the Department of Dentistry, Veterans General Hospital-Taipei from June 1975 to December 1990. Among these cases, the tongue (31.2%) was the most frequently involved site. According to AJCC staging system, 37.3% of the patients were at stage IV, the highest among stages of patients. The overall incidence of regional lymph node metastasis was 49.4%. The incidence of regional lymph node metastasis was significantly correlated with the location of the primary tumor, especially the low metastatic rate of palate and lip carcinoma (p less than 0.05). Distant metastases were detected in 14 (4.2%) cases. The rate of distant metastasis increased with the advance of staging (6.2% for stage III and IV, p less than 0.05). The lungs were the most common sites of distant metastasis. Due to the poor awareness and socio-economic condition of the patients, a majority of them presented with advanced diseases. The distant metastasis rate was low since all the patients were not kept followed up till death, nor was any autopsy study carried out.

Human papillomaviruses and small cell carcinoma of the uterine cervix

The in vitro DNA amplification technique of polymerase chain reaction was used to evaluate the possible presence of human papillomavirus (HPV) in small cell carcinoma of the uterine cervix. None of the 12 cases examined contain detectable amounts of either HPV type 16, 18, 31, or 33 DNA. On the other hand, HPV types 16 and 18 DNA were found in 14 (93.3%) and 9 (60.0%) of 25 invasive cervical squamous carcinoma tissues. The results seem to suggest that these types of HPV are not present or are present in extremely small quantities in cervical small cell carcinoma. Such an absence of HPV DNA makes it unlikely that these types of HPV play any etiological role in the pathogenesis of cervical small cell carcinoma.

Surgical management of resistant idiopathic congenital clubfoot

For neglected clubfeet or clubfeet resistant to conservative treatment, there is an increasing tendency towards early and tailored release. From November 1983 to November 1987, we operated on 37 children with 53 neglected or resistant clubfeet which included 23 with limited release and 30 with radical release. Their ages ranged from 4 months to 8 years with an average age of 1 year 5 months. Operative treatment was indicated if the clubfeet had been neglected or had shown no corrective change after 12 weeks of intensive plaster treatment. We used the Cincinnati incision for one-stage release. The average follow-up was 3.5 years (range 2-5.5 years). Evaluation criteria included physical, functional and roentgenographic findings. The results were good or excellent in 96% of the feet based on the modified Magone rating scale. There was no significant difference in the operation results between different age groups. Both the limited and the radical release groups had a high rate of satisfaction. The limited procedure only effectively improved the tibio-calcaneal angle to a significant degree (p less than 0.01), while the radical operation changed every angle significantly (p less than 0.01). Complications included calf muscle atrophy in 4 feet, overcorrection in 3 feet, undercorrection in 3 feet, superficial skin necrosis in one foot, pin tract infection in one foot and residual metatarsal adductus in one foot. In conclusion, neglected or resistant clubfeet can be treated by early and adequate release with a high rate of success. Complications can be avoided by a thorough understanding of their pathoanatomy and by a meticulous surgical approach and release.

Elevated levels of soluble interleukin 2 receptor and tumor necrosis factor in nasopharyngeal carcinoma

Depressed cell-mediated immunity as a measure of the mitogenic response of mononuclear cells in patients with nasopharyngeal carcinoma is well documented, but the mechanism is still unclear. The enzyme-linked immunosorbent assay was used to measure soluble interleukin 2 receptor and tumor necrosis factor levels in 295 patients with nasopharyngeal carcinoma and 97 age-matched control subjects. Soluble interleukin 2 receptor levels in patients with nasopharyngeal carcinoma were elevated and correlated with clinical staging. Higher soluble interleukin 2 receptor levels were found in patients with bone metastasis but not in patients with intracranial involvement. The levels of tumor necrosis factor in nasopharyngeal carcinoma were higher than in control subjects but did not correlate with clinical staging. These data suggest that soluble interleukin 2 receptor levels might be more useful than soluble tumor necrosis factor levels that indicate tumor bulk. Soluble interleukin 2 receptor serves as a blocking factor that competes with interleukin 2 function, resulting in a decreased mitogenic response in patients with nasopharyngeal carcinoma. The usefulness of the levels of soluble interleukin 2 receptor to monitor the efficacy of treatment in patients with nasopharyngeal carcinoma with bone metastasis requires further study.

Congenital central alveolar hypoventilation syndrome (Ondine's Curse): effectiveness of early home ventilation for normal development

An 8 month old Caucasian girl, with congenital central alveolar hypoventilation syndrome (Ondine's Curse), was discharged with her home ventilation managed by her parents. Her subsequent neurophysical development assessed at 22 months of age was satisfactory.

Endolymphatic sac surgery for Meniére's disease. A cumulative study of twelve years' experience

This paper analyzes a total of 861 endolymphatic-mastoid shunt procedures (ELS) during 12 years. The review of long-term results following surgery for patients with intractable Meniére's disease indicates that ELS often provides temporary remission of severe disabling symptoms. Overall results, according to AAOO criteria, showed long-term vertigo control in 71.90% of cases. Using AAO-HNS guidelines, vertigo was completely or substantially controlled in 85.89% of the cases. In addition, hearing gains were frequently sustained and hearing deterioration often prevented over the years. A positive dehydration test and/or fluctuating hearing indicate a greater likelihood of hearing improvement after surgery. Furthermore, these findings augment our previous studies that comparable results can be obtained regardless of method employed. Thus, ELS is still indicated as a primary choice of surgical treatment when surgery is mandatory. Finally, there seem to be chronological peaks of recurrence of symptoms at about 2 years and again at 6 or more years after ELS. This not only accentuates the efficacy of revision surgery, but opens new areas of investigation into the underlying etiology of this elusive disease.

Early effects of cranial irradiation on hypothalamic pituitary function

Hypothalamic pituitary functions were studied in 25 patients before and 6 months after cranial irradiation with or without radiosensitizing chemotherapy for nasopharyngeal carcinoma. The estimated average total dose was 5,000 cGy to the hypothalamus and pituitary gland. The radiosensitizing chemotherapy used was endoxan, 4900 +/- 873 mg and/or methotrexate 113 +/- 30 mg. All patients had normal pituitary function before radiotherapy. Six months after radiotherapy, there was a significant increase in baseline serum thyrotropin (TSH) and follicle-stimulating hormone (FSH) levels. The TSH response to thyrotropin-releasing hormone (TRH) was significantly increased, suggesting primary hypothyroidism due to neck irradiation. The peak serum TSH response to TRH became delayed in 21 patients, suggesting a defect in TRH release. In male patients who did not receive radiosensitizing chemotherapy, the FSH response to luteotropic hormone-releasing hormone (LHRH) increased while the luteinizing hormone (LH) response decreased. But in male patients who also received radiosensitizing chemotherapy, both the FSH and LH responses to LHRH increased. The adrenocorticotropic hormone (ACTH) response to ovine corticotropin-releasing hormone (CRH) did not change, while the integrated cortisol response increased. The growth hormone (GH) response to growth hormone-releasing hormone (GRH) did not change. The GH response to insulin tolerance test (ITT) increased and may be explained by the more severe hypoglycemia induced by the same dosage of insulin after radiotherapy or the recovery from the previous wasting caused by radiotherapy. There was no significant increase in serum prolactin. In conclusion, we demonstrated impairment of the hypothalamus-pituitary-endocrine gland axes as early as 6 months after cranial irradiation with or without chemotherapy.

A forearm free flap based on an occluded radial artery: its salvage and avoidance

The salvage of a radial forearm free flap based on an occluded radial artery is reported. Circulation to the flap was restored by resection and reconstruction of the nonpatent arterial segment within the flap. A simple test is recommended for preoperative assessment of forearm radial artery patency in which proximal pulsation is felt after distal compression of the radial artery at the wrist.

3 x 3 single-mode star coupler made from 2 x 2 couplers

An optical network made from two 3-dB and one 1.76-dB 2 x 2 single-mode couplers can perform as a 3 x 3 star coupler. One version is particularly suitable for polarization-preserving components and requires adjustment of the phase in one arm; it can also perform the three-point discrete Fourier transform by suitable adjustment of other phases. Experimental verification of the principle is presented.

[Histological study of hydroxylapatite mixed with collagen as osseous implant in mandible]

By using five Taiwan Macaca monkeys as experimental animals, three bony defects about 5 x 5 x 3 mm in size were created at each of their buccal region of mandible. Bovine skin collagen and particulate hydroxylapatite were used as implant materials. The artificial defects implanted with hydroxylapatite/collagen mixture were experimental group and the defects implanted with collagen or without any implantation were control groups. The monkeys were sacrificed at the time of 1,2,3,6,9 months after implantation surgery and were injected with tetracycline according to the above intervals at one week before being sacrificed. The specimens were divided into two parts, one of which was decalcified and stained with hemotoxylineeiosin for observation under optic light microscope, the other without decalcification was made into ground section for observation under fluorescent microscope. The result revealed that the healing processes of the two control groups were similar with each other. Bone formation was delayed in HA/Collagen group because it took almost five months to achieve complete bony repair of the mandibular defect. However bone formation at the HA/Collagen implant site was earlier than that at the pure HA implant site in our similar study. What's the role of collagen that played during bone formation still needed further investigation. The tissue response was good without obvious inflammatory cells infiltration. Clinical application of block form of dried HA/Collagen mixture was suggested for it was easier to handle and could decrease the flow of HA particles after implantation.

Unified study of color sampling

In this study, we unify some previous research work on the design of optimal color sensors and the reconstruction of color signals from color samples. We show that they are all based on a simple linear vectorspace representation derived from the Karhunen-Loeve (K-L) expansion theorem. We also show how this idea works by two simulation examples. We believe that the theoretical results derived in this study may prove useful both in machine and human color vision research.

Basal joint reconstruction in a punch injury of the hand

Severe hand trauma caused by an industrial accident resulted in composite tissue loss in the basal joint area of the right hand. The crushed metacarpal bone was replaced, and ligamentous and capsular reconstruction was performed with flexor carpi radialis tendon and additional tendon graft. We present our experience, with a follow-up of one year and eight months.

One-stage salvage of fractured nasal prosthesis with immediate calvarial bone grafting

An open fracture of a nasal prosthesis usually means the primary removal of the prosthesis and a secondary reconstruction. A case with this problem was treated by a one-stage reconstruction using a calvarial bone graft.

Three successful digital replantations in a patient after 84, 86, and 94 hours of cold ischemia time

Three successful digital replantations were performed on a patient after 84, 86, and 94 hours of prolonged cold ischemia time. Both the intraoperative and postoperative courses were smooth. Functional evaluation 8 months after operation revealed a normal speed of sensory recovery and nail growth. The atrophic changes in all three replants are mild. Total active movement was 45, 100, and 70 degrees in the replanted left thumb, left index finger, and right thumb, respectively. There is no cold intolerance. The overall functional result is satisfactory. Replantation of an amputated digit that is properly cooled immediately after injury should be attempted in selected patients even after prolonged ischemia time.

Simultaneous determination of gastrodin and its metabolite by HPLC

A rapid and specific HPLC method for the simultaneous determination of gastrodin and its metabolite gastrodigenin (p-hydroxybenzyl alcohol) in rat plasma, bile, liver, urine and faeces is described. The separation was achieved by using a reversed phase column (YWG-C18) eluted with methanol-water (2.5:97.5 v/v). Phloroglucinolum was used as internal standard and the peaks were detected at UV 221 nm. The protein precipitation with ethanol was a very simple and rapid method for sample preparation. The gastrodin and gastrodigenin were quantitated by measuring the peak-height ratios. There was a linear concentration range of 10-320 micrograms/mL in the assay for both compounds. The coefficients of variation (within-day) for samples spiked with gastrodin and gastrodigenin were 2.94% and 3.08%, respectively. The method demonstrated a high specificity and was suitable for use in pharmacokinetic studies.

On the solution of equations for feel-better hemodialysis

In this paper, a scheme for "feel better" or optimal hemodialysis (OPTHD) based on a two-compartmental model has been proposed. Contrary to the conventional constant blood flow dialysis (CVTHD), this scheme suggests that the blood flow rate should vary in stages in order to avoid or minimize the disequilibrium syndromes during dialysis. A set of equations for computing the intracellular and extracellular solute concentrations during the OPTHD operation is developed and the computed results are illustrated. Comparing to the CVTHD, the OPTHD has the advantages of operating at a lower and smoother solute concentration difference between compartments for the same length of dialysis time, or it may achieve the same specific degree of blood cleansing within a shorter period of dialysis time.