Vector optical field with the polarization varying along an arbitrary circular trajectory on the Poincaré sphere

As an inherent feature of vector optical field, the spatial distribution of polarization brings additional degrees of freedom to engineer the optical field and control the interaction between light and matters. Here we focus on the variation of polarization in single vector optical field, which can be defined by the trajectory on the Poincaré sphere. Based on the amplitude-phase-polarization joint modulation method we propose, vector optical field, whose variation of polarization follows arbitrary circular trajectory on the Poincaré sphere, can be generated. Moreover, the tightly focusing behaviors of the vector optical fields with the polarization varying along parallel circles on the Poincaré sphere are compared. Relations between the circular trajectory and the central intensity of the hollow focal field are concluded.

[Incidence of unintended pregnancy within 2 years after delivery and its influencing factors in China]

Objective: To investigate the present situation of unintended pregnancy within two years postpartum and its influencing factors in China. Methods: Participants who delivered a live birth at 60 hospitals in 15 provinces in the eastern, central and western regions of China during July 2015 to June 2016 were interviewed by using structured questionnaire. Information on occurrence of unintended pregnancy within 2 years after delivery, postpartum contraceptive use, sexual resumption, breastfeeding, and women's socio-demographic characteristics, and so on, were collected. Life-table analysis, cluster log-rank tests and a 2-level Cox regression model were used for data analysis. Results: A total of 18 045 postpartum women were investigated. The cumulative 1- and 2-year unintended pregnancy rates after delivery were 5.3% (95%CI: 4.5%－6.1%) and 13.1% (95%CI: 11.3%－14.8%), respectively. Cox regression model analysis showed that the risk of unintended pregnancy within 2 years postpartum were increased in younger women, ethnic minorities, women with abortion history, and those who had a vaginal delivery with short lactation time and late postpartum contraceptive initiation (all P<0.01). The risk of postpartum unintended pregnancy was not associated with geographic regions and hospitals where women gave a birth (all P>0.05). Conclusions: In China, the risk of unintended pregnancy within 2 years after delivery is relatively high. Service institutions and service providers should improve the quality of postpartum family planning services, promote the use of high effect contraceptive methods, and educate women to use a method at the time of their sexual resumption or even before.

Circadian Clock Disruption Suppresses PDL1+ Intraepithelial B Cells in Experimental Colitis and Colitis-Associated Colorectal Cancer

BACKGROUND & AIMS

The circadian clock is crucial for physiological homeostasis including gut homeostasis. Disorder of the circadian clock may contribute to many diseases including inflammatory bowel disease (IBD). However, the role and the mechanisms of circadian clock involvement in IBD still are unclear.

METHODS

Disorder of the circadian clock including chronic social jet lag and circadian clock gene deficiency mice (Bmal1-/-, and Per1-/-Per2-/-) were established. Dextran sulfate sodium (DSS) and/or azoxymethane were used to induce mouse models of colitis and its associated colorectal cancer. Flow cytometry, immunohistochemistry, immunofluorescence, Western blot, and reverse-transcription quantitative polymerase chain reaction were used to analyze the characteristics of immune cells and their related molecules.

RESULTS

Mice with disorders of the circadian clock including chronic social jet lag and circadian clock gene deficiency were susceptible to colitis. Functionally, regulatory B (Breg) cells highly expressing Programmed cell death 1 ligand 1 (PDL1) in intestinal intraepithelial lymphocytes (IELs) helped to alleviate the severity of colitis after DSS treatment and was dysregulated in DSS-treated Bmal1-/- mice. Notably, interleukin 33 in the intestinal microenvironment was key for Bmal1-regulated PDL1+ Breg cells and interleukin 33 was a target of Bmal1 transcriptionally. Dysregulated PDL1+ B cells induced cell death of activated CD4+ T cells in DSS-treated Bmal1-/- mice. Consequently, circadian clock disorder was characterized as decreased numbers of Breg+ PDL1+ cells in IELs and dysfunction of CD4+ T cells promoted colitis-associated colorectal cancer (CRC) in mice. In clinical samples from CRC patients, low expression of Bmal1 gene in paracancerous tissues and center area of tumor was associated closely with a poorer prognosis of CRC patients.

CONCLUSIONS

Our study uncovers the importance of the circadian clock regulating PDL1+ Breg+ cells of IELs in IBD and IBD-associated CRC.

Genetic variation in three mitochondrial genes among cattle tick Rhipicephalus microplus originating from four provinces of China

The cattle tick, Rhipicephalus microplus (formerly Boophilus microplus), is the most important blood-feeding ectoparasite of cattle in tropical and subtropical regions of the world. In this study, we examined sequence variability in three mitochondrial (mt) DNA (cox1, nad1, nad4) among cattle tick R. microplus originating from four provinces of China. A portion of cox1 (pcox1), nad1 (pnad1) and nad4 (pnad4) genes were amplified by polymerase chain reaction (PCR) separately from adult R. microplus individuals and the amplicons were subjected to sequence from both directions. The sequence of mt cox1, nad1, nad4 genes was 817 bp, 350 bp, and 794 bp in size, respectively. The intraspecific sequence variations within R. microplus were 0-8.6% for cox1, 0-4.9% for nad1 and 0-10.3% for nad4. However, the interspecific sequence differences among the members of the Rhipicephalus [R. sanguineus (JX416325) and R. turanicus (NC035946)] were significantly higher, being 16.9-20.5%, 18- 22.8%, 22.8-25.3% for pcox1, pnad1 and pnad4, respectively. In addition, genetic differences were 7.9-8.6% for cox1, 4.3-4.9% for nad1 and 10-10.3% for nad4 between the two detected lineages (R. microplus clade A and clade B). Phylogenetic analyses indicated that all the Rhipicephalus isolates from the present study represents R. microplus, supporting that R. microplus represents species complex. Our result provided an additional genetic evidence for the existence of species complex within R. microplus in China.

PCR-DGGE test for direct identification of intestinal bacterial flora in blood feeding ticks in China

Ticks are vectors of diseases that affect humans and animals worldwide. In current study, the intestinal bacterial flora associated with the blood feeding ticks (Haemaphysalis flava, Haemaphysalis longicornis, Rhipicephalus haemaphysaloides, Boophilus microplus and Dermacentor sinicus) were analyzed using polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE) and then sequenced. The five ticks were collected from cattle, dog, hedgehog and goats in Fujian, Shandong, Henan, Jiangxi, Hunan, Shanxi and Guangxi provinces, China. Our results show that nine distinct DGGE bands were found using PCR-DGGE method. Sequences analyses indicated that they belonged to Rickettsia peacockii, Rickettsia raoultii, Rickettsia helvetica, Rickettsia slovaca, Rickettsia tarasevichiae, Coxiella sp., Erwinia sp., Klebsiella pneumoniae and Pseudomonas aeruginos. The present results indicate that zoonotic pathogens are present in ticks in many provinces of China. This useful information will aid in the epidemiology of tick-borne zoonotic diseases in China as well as in raising awareness to avoid tick bites is an important measure to prevent the infection and transmission of zoonotic pathogens.

Optimizing melphalan pharmacokinetics in regional melanoma therapy: does correcting for ideal body weight alter regional response or toxicity?

BACKGROUND

This study aims to determine what effect correcting melphalan dosing for ideal body weight (IBW) has on toxicity and response in isolated limb infusion (ILI) in patients with advanced extremity melanoma.

METHODS

This was an open observational study examining whether correcting the melphalan dose for IBW will influence response and toxicity in patients undergoing ILI for advanced extremity melanoma in 41 patients undergoing 42 procedures (13 without correction for IBW; and 29 with correction for IBW). Melphalan pharmacokinetics, limb toxicity, serologic toxicity, and response at 3 months were compared.

RESULTS

The corrected group had a lower estimated limb volume (V (esti)) to melphalan volume at steady state (V (ss)) (P < .0001) ratio as well as lower incidence of grade > or =3 regional toxicity, serologic toxicity, and compartment syndrome (P = .0249, P = .027, P = .02). There was a positive correlation of V (esti)/V (ss) to toxicity (P = .0127, r = .382). No significant difference in response (P = .3609) between the groups was found, although there was a trend of association between V (esti)/V (ss) and response (P = .051, r = .3383).

CONCLUSIONS

Correcting for IBW in ILI lowers toxicity without significantly altering response rates.

The impact of the cigarette market opening in Taiwan

OBJECTIVE

To assess the effect of the opening of the Taiwanese cigarette market on cigarette consumption, changes in market share, and the effects on tobacco control efforts.

METHODS

With the use of key word "Taiwan", the Legacy Tobacco Documents Library of the University of California, San Francisco, was searched for internal documents related to smuggling activities, promotion of light cigarettes, and market share analyses in Taiwan. Age adjusted smoking rates and cigarette and betel quid consumption before and after market opening were compared.

RESULTS

By 2000, the market share of imported cigarettes increased from less than 2% in 1986 to nearly 50%, and per capita cigarette consumption increased 15% following market opening. Because of the sharp increase in smuggling, with contraband cigarettes being as popular as legal imports, and the rapid proliferation of retail outlets, such as betel quid stalls, the market penetration by foreign tobacco companies was greater in Taiwan than among the other Super 301 Asian countries. Aggressive cigarette marketing strategies were associated with a 6% increase in adult male smoking prevalence, and with a 13% increase in the youth rate, within three years after market opening. The market opening also had an incidental effect on increasing the popularity of betel quid. Betel quid chewing has since become a major public health problem in Taiwan.

CONCLUSION

The opening of the cigarette market in 1987 had a long lasting impact on Taiwan. It increased smoking prevalence and the market has become dominated by foreign companies. The seriousness of smuggling and its associated loss of revenue by the government, the extent of increased youth smoking and its associated future health care costs, and the increased use of betel quid and the associated doubling of oral cancer mortality rates each pose significant problems to Taiwan. However, the market opening galvanised anti-smoking sentiment and forced the government to initiate and intensify a series of tobacco control efforts.

Excess injury mortality among smokers: a neglected tobacco hazard

OBJECTIVE

To assess the mortality risks from injuries for smokers and ex-smokers and to quantify the mortality burden of smoking from injury in Taiwan.

METHODS

Smokers' (and ex-smokers') mortality risks from injuries were compared with that of non-smokers in a merged cohort from Taiwan. A total of 64,319 male subjects were followed up for 12-18 years. Relative risks (RR) (adjusted for age and alcohol use) and 95% confidence intervals (CI) for cause specific injury deaths were calculated using the Cox proportional hazard model. Relative risks of injury mortality were also calculated to assess the presence of dose-response relations with daily smoking quantity.

RESULTS

Alcohol use adjusted relative mortality risks for all injuries (RR 1.69, 95% CI 1.39 to 2.05) including those from motor vehicle accidents (RR 1.88, 95% CI 1.44 to 2.45) and non-motor vehicle accidents (RR 1.48, 95% CI 1.11 to 1.99) were significantly higher for smokers than non-smokers. Mortality was also increased for most subtypes of non-motor vehicle injuries including falls, fires, and job related injuries. Furthermore, these increases were dose dependent, with the heaviest smokers having the highest risk and the lightest smokers the lowest risk, and ex-smokers, no increase. In 2001, over one fifth (23%) of all male injury deaths in Taiwan was associated with smoking.

CONCLUSION

This study demonstrated the significant association between fatal injuries and smoking. This relation adds further weight to smoking cessation campaigns.

Workplace smoking related absenteeism and productivity costs in Taiwan

OBJECTIVE

To estimate productivity losses and financial costs to employers caused by cigarette smoking in the Taiwan workplace.

METHODS

The human capital approach was used to calculate lost productivity. Assuming the value of lost productivity was equal to the wage/salary rate and basing the calculations on smoking rate in the workforce, average days of absenteeism, average wage/salary rate, and increased risk and absenteeism among smokers obtained from earlier research, costs due to smoker absenteeism were estimated. Financial losses caused by passive smoking, smoking breaks, and occupational injuries were calculated.

RESULTS

Using a conservative estimate of excess absenteeism from work, male smokers took off an average of 4.36 sick days and male non-smokers took off an average of 3.30 sick days. Female smokers took off an average of 4.96 sick days and non-smoking females took off an average of 3.75 sick days. Excess absenteeism caused by employee smoking was estimated to cost USD 178 million per annum for males and USD 6 million for females at a total cost of USD 184 million per annum. The time men and women spent taking smoking breaks amounted to nine days per year and six days per year, respectively, resulting in reduced output productivity losses of USD 733 million. Increased sick leave costs due to passive smoking were approximately USD 81 million. Potential costs incurred from occupational injuries among smoking employees were estimated to be USD 34 million.

CONCLUSIONS

Financial costs caused by increased absenteeism and reduced productivity from employees who smoke are significant in Taiwan. Based on conservative estimates, total costs attributed to smoking in the workforce were approximately USD 1032 million.

Smoking attributable mortality for Taiwan and its projection to 2020 under different smoking scenarios

OBJECTIVES

To estimate smoking attributable mortality (SAM) in Taiwan for the years 2001 through 2020 under scenarios of reductions in smoking rates by 0%, 2%, 4%, and 10% per year.

METHOD

The smoking attributable fraction (SAF) was used to calculate SAM from the risk experience in following up a large cohort (86 580 people) in Taiwan. Smoking rates were based on the 2001 National Health Interview Survey and other national surveys. An average 10 year lag was assumed between smoking rates and subsequent mortality.

RESULTS

In 2001, 18 803 deaths, or 1 out of 4 deaths (27%), in middle aged men (35-69 years old) were attributable to smoking. SAM has been increasing and will continue to increase if smoking rates remain constant or even if reduced annually by 2%. SAM would begin to decrease only if rates were to be reduced by at least 4% a year.

CONCLUSIONS

The projected SAM in this study illustrates the seriousness of smoking caused mortality. Current efforts in tobacco control would lead to a progressive increase in SAM, unless efforts were doubled and smoking rates reduced by more than 4% a year. The urgency in requiring stronger tobacco control programmes to attenuate the staggering death tolls is compelling.

Reducing health disparity in Taiwan: quantifying the role of smoking

OBJECTIVE

To assess the impact of smoking disparities on health disparities, in terms of gap in life expectancy, in Taiwan cities and counties.

METHODS

Using the decomposition method of life expectancy, the contribution of each disease category to the life expectancy gap was quantitatively expressed as the number of years of life. The smoking attributable fraction (SAF) was calculated for each city and county based on their respective smoking prevalence and relative risk for each smoking related disease. The smoking attributable gap (SAG) in life expectancy between two sites is the sum of the difference in SAF between two sites for each smoking related disease multiplied by the number of years this disease contributed to the life expectancy gap.

RESULTS

Significant health and smoking disparities were present among the 23 cities and counties in Taiwan. These health disparities and smoking disparities were highly correlated (R2 = 0.3676). Generally, the health gap increased with increasing smoking disparity. The disparity in smoking prevalence and intensity among cities and counties in Taiwan was responsible for up to 19% of the health disparity. The health disparity is also highly correlated (R2 = 0.3745) with SAG in life expectancy.

CONCLUSIONS

Reducing smoking is important to health, and reducing the smoking disparity is also important for reducing the health disparity observed in Taiwan. The larger the health disparity is, the more important the smoking attributable disparity could be. The reduction of smoking disparities could be a realistic and cost effective way toward reducing health disparities.

Role of parents and peers in influencing the smoking status of high school students in Taiwan

OBJECTIVES

To assess parental influence on smoking behaviour by high school students in an Asian culture and to compare the relative importance of parental and peer influence.

METHODS

A 5% nationally representative sample, including 44 976 high school students in 10th to 12th grade (aged 15-18 years) in Taiwan, were surveyed in 1995. Each completed a long self administered questionnaire. Parental influence was measured by examining both parental behaviour (smoking status) and attitudes (perceived "tender loving care" (TLC) by adolescents). Changes in smoking status were used to determine peer influence, defined as the increase in the likelihood of smoking from grade 10 to 12 in a steady state environment. Odds ratios (ORs) were calculated for parental and peer influence, using logistic regression.

RESULTS

Adolescents of smoking parents with low TLC had the highest smoking rates and those of non-smoking parents with high TLC had the lowest. The difference was more than twofold in boys and more than fourfold in girls. When either parental smoking status or TLC alone was considered, parental influence was similar to peer influence in boys, but larger than peer influence in girls. However, when smoking status and TLC were considered jointly, it became larger than peer influence for both groups (OR 2.8 v 1.8 for boys and OR 3.9 v 1.3 for girls).

CONCLUSION

When parental influence is taken as parental behaviour and attitude together, it plays a more important role than peer influence in smoking among high school students in Taiwan. This study, characterising such relationships among Asian populations for the first time, implies that future prevention programmes should direct more efforts toward the parental smoking and parent-child relationships, and not aim exclusively at adolescents in schools.

Are marketing campaigns in Taiwan by foreign tobacco companies targeting young smokers?

OBJECTIVE

To assess the impact of promotions on cigarette sales in Taiwan after the cigarette market opened to foreign companies, and to assess whether young smokers were targeted by these companies.

METHODS

Trends in cigarette sales, advertising expenditure, brand preference, and cigarette consumption were examined for the period following the 1987 opening of the cigarette market. Tobacco industry internal documents from Legacy Tobacco Documents Library of the University of California, San Francisco, were searched for corporate strategies on promoting youth consumption in Taiwan.

RESULTS

Between 1995 and 2000, the inflation adjusted advertising expenditures by all foreign firms increased fourfold. Much of the expenditure was spent on brand stretching the Mild Seven (Japan) and Davidoff (Germany) brands in television advertising. By 2000, the market share of foreign cigarettes exceeded domestics by three to one among young smokers and the leading brand preferred by this segment shifted from the most popular domestic brand (Long Life) to a foreign brand (Mild Seven). Furthermore, there was a sudden increase of 16.4% in smoking rates among young adults (from 36.1% to 42.0%) during the first five years after the market opened. This was also accompanied by increased per capita cigarette consumption and decreased age of smoking initiation. Industry documents confirmed the use of strategies targeted at the young. In particular, establishing new point of sale (POS) retail stores or promotional activities at POS were found to be more effective than advertising in magazines.

CONCLUSIONS

This study provides evidence that advertising increased with increased competition following the market opening, which, in turn, spurred cigarette sales and consumption. Foreign tobacco companies have deliberately targeted youth in Taiwan and succeeded in gaining three quarters of their cigarette purchases within a decade. Expanding youth consumption will incur excessive future health care costs borne by society. Foreign tobacco companies should be obligated to reimburse these expenses through higher tariffs on cigarettes.

Uncovering the relation between betel quid chewing and cigarette smoking in Taiwan

OBJECTIVE

To describe the characteristics of betel quid chewers and to investigate the behavioural and mortality relations between betel quid chewing and cigarette smoking.

METHOD

Prevalence and mortality risks of betel quid chewers by smoking status were calculated, based on the National Health Interview Survey in 2001 and a community based cohort, respectively. Cox's proportional hazards model was used to adjust mortality risks for age, alcohol use, and education.

RESULTS

Almost all betel quid chewers were smokers, and most started chewing after smoking. Chewers were predominantly male, mostly in their 30s and 40s, more likely being among the lowest educational or income group, and residing in the eastern regions of Taiwan. On average, betel quid chewers who smoked consumed 18 pieces of betel quid a day, and smoked more cigarettes per day. Far more smokers use betel quid than non-smokers (27.5% v 2.5%), but ex-smokers quit betel quid more than smokers (15.1% v 6.8%). The significantly increased mortality of betel quid users who also smoked, for all causes, all cancer, oral cancer, and cancer of the nasopharynx, lung, and liver, was the result of the combined effects of chewing and smoking. Smokers who chewed betel quid nearly tripled their oral cancer risks from a relative risk of 2.1 to 5.9. Increasing the number of cigarettes smoked among betel quid chewers was associated with a synergistic effect, reflective of the significant interaction between the two.

CONCLUSION

To a large extent, the serious health consequences suffered by betel quid chewers were the result of the combined effects of smoking and chewing. Betel quid chewing should not be considered as an isolated issue, but should be viewed conjointly with cigarette smoking. Reducing cigarette smoking serves as an important first step in reducing betel quid chewing, and incorporating betel quid control into tobacco control may provide a new paradigm to attenuate the explosive increase in betel quid use in Taiwan.

The health benefits of smoking cessation for adult smokers and for pregnant women in Taiwan

OBJECTIVE

To assess the benefits of smoking cessation regarding mortality reduction after smokers quit, and regarding the health of newborns after smoking mothers quit.

METHODS

Relative mortality risks (RR) for smokers aged 35 or older who quit years ago were calculated from the follow up of 71 361 civil servants and teachers recruited since 1989. Data from the Pregnancy Risk Assessment Monitoring System in Taipei City were used to calculate the odds ratios of body weights of newborns born to mothers of different smoking status.

RESULTS

Mortality risk for ex-smokers was significantly lower than that of current smokers for all causes (18%), all cancer (22%), lung cancer (39%), and ischaemic heart disease (54%). These benefits were not distinguishable initially, up to five years, but by year 17 and thereafter, substantial benefits of cessation accrued. Two thirds of smoking women quit during the first trimester of pregnancy, and only 2.2% of mothers smoked throughout pregnancy. The newborns from smoking mothers were smaller than those from never smoking mothers, but, if these mothers quit early in the first trimester, birth weights were normal.

CONCLUSIONS

The health benefits of smoking cessation, rarely reported for Asian populations, have been largely ignored by smokers in Taiwan, where cessation activities have been extremely limited. Findings of this study that risks from smoking can be attenuated or reversed should be widely communicated to motivate smokers to quit. Smokers should quit early, including smoking mothers, and not wait till medical conditions surfaced, to have the maximal benefits of cessation.

Smoking attributable medical expenditures, years of potential life lost, and the cost of premature death in Taiwan

OBJECTIVE

To estimate the smoking attributable medical expenditures and productivity loss of people aged 35 and over in Taiwan in 2001 from a societal viewpoint.

METHODS

A prevalence based approach was used to estimate smoking attributable costs. Epidemiological parameters were obtained from two follow up studies and government statistics. Data on medical care utilisation and expenditure were extracted from the National Health Insurance claim data.

RESULTS

Total smoking attributable medical expenditures (SAEs) amounted to USD 397.6 million, which accounted for 6.8% of the total medical expenditures for people aged 35 and over. Mean annual medical expenditures per smoker was USD 70 more than that of each non-smoker. Smoking attributable years of potential life lost (YPLL) totalled to 217,761 years for males and 15,462 years for females, and the corresponding productivity loss was USD 1371 million for males and USD 18.7 million for females.

CONCLUSION

Medical expenditures attributable to smoking accounted for 6.8% of the total medical expenditure of people aged 35 and over for the year 2001 in Taiwan. Corresponding YPLL and productivity loss also demand that actions be taken to fight cigarette smoking.

Reconstruction of burn scar of the upper extremities with artificial skin

The management of upper-extremity burn contractures is a major challenge for plastic surgeons. After approval by the Food and Drug Administration, artificial skin (Integra) has been available in Taiwan since 1997. From January of 1997 to July of 1999, the authors applied artificial skin to 13 severely burned patients for the reconstruction of their upper extremities, resulting in an increased range of motion in the upper-extremity joints and improved skin quality. An additional benefit was the rapid reepithelialization of the donor sites. There were no complications of infection throughout the therapeutic course, and the overall results were satisfactory. During the 2-year study, scar condition was monitored between 8 and 24 months, and a good appearance and pliable skin were obtained according to the Vancouver Scar Scale. According to this evaluation of Oriental skin turgor, normal pigmentation was restored about 6 months after the resurfacing procedure. For patients with severe burns in whom there is insufficient available skin for a full-thickness skin graft or another appropriate flap for scar revision, Integra is an alternative. The two major concerns in dealing with artificial skin are (1) a 10- to 14-day waiting period for maturation of the neo-dermis, necessitating a two-stage operation, and (2) prevention of infection with antibiotics and meticulous wound care.

CD1b-mediated T cell recognition of a glycolipid antigen generated from mycobacterial lipid and host carbohydrate during infection

T cells recognize microbial glycolipids presented by CD1 proteins, but there is no information regarding the generation of natural glycolipid antigens within infected tissues. Therefore, we determined the molecular basis of CD1b-restricted T cell recognition of mycobacterial glycosylated mycolates, including those produced during tissue infection in vivo. Transfection of the T cell receptor (TCR) alpha and beta chains from a glucose monomycolate (GMM)-specific T cell line reconstituted GMM recognition in TCR-deficient T lymphoblastoma cells. This TCR-mediated response was highly specific for natural mycobacterial glucose-6-O-(2R, 3R) monomycolate, including the precise structure of the glucose moiety, the stereochemistry of the mycolate lipid, and the linkage between the carbohydrate and the lipid. Mycobacterial production of antigenic GMM absolutely required a nonmycobacterial source of glucose that could be supplied by adding glucose to media at concentrations found in mammalian tissues or by infecting tissue in vivo. These results indicate that mycobacteria synthesized antigenic GMM by coupling mycobacterial mycolates to host-derived glucose. Specific T cell recognition of an epitope formed by interaction of host and pathogen biosynthetic pathways provides a mechanism for immune response to those pathogenic mycobacteria that have productively infected tissues, as distinguished from ubiquitous, but innocuous, environmental mycobacteria.

The boomerang flap in managing injuries of the dorsum of the distal phalanx

Finding an appropriate soft-tissue grafting material to close a wound located over the dorsum of a finger, especially the distal phalanx, can be a difficult task. The boomerang flap mobilized from the dorsum of the proximal phalanx of an adjacent digit can be useful when applied as an island pedicle skin flap. The vascular supply to the skin flap is derived from the retrograde perfusion of the dorsal digital artery. Mobilization and lengthening of the vascular pedicle are achieved by dividing the distal end of the dorsal metacarpal artery at the bifurcation and incorporating two adjacent dorsal digital arteries into one. The boomerang flap was used in seven individuals with injuries involving the dorsal aspect of the distal phalanx over the past year. Skin defects in all patients were combined with bone,joint, or tendon exposure. The authors found that the flap was reliable and technically simple to design and execute. This one-step procedure preserves the proper palmar digital artery to the fingertip and has proven valuable for the coverage of wide and distal defects because it has the advantages of an extended skin paddle and a lengthened vascular pedicle. When conventional local flaps are inadequate, the boomerang flap should be considered for its reliability and low associated morbidity.

The effects of pretreatment with glycyrrhizin and glycyrrhetinic acid on the retrorsine-induced hepatotoxicity in rats

A wide variety of medicinal herbs contain hepatotoxic pyrrolizidine alkaloids (PAs), and often cause acute and chronic liver damages in man. Liquorice, a known antihepatitis, is commonly used with PA-containing herbs concurrently, and hepatotoxicity induced by such combined uses was not pronounced. The present study is to investigate effects of glycyrrhizin (GL) and 18beta-glycyrrhetinic acid (GA), the major biologically active ingredients of liquorice, against PA-induced hepatotoxicity in rats. Single dose (35 mg/kg, i.p.) of retrorsine (RET), a typical potent hepatotoxic PA, was given to rats to induce liver injury. A single dose pretreatment with GL or GA prior to retrorsine challenge did not show hepatoprotection. However, when rats were pretreated with either GL (200 mg/kg/day, i.p.) or GA (10 mg/kg/day, i.p.) for three consecutive days prior to retrorsine exposure, the elevated serum GOT and GPT levels induced by retrorsine were significantly reduced. Serum levels of transaminases almost returned to normal (GOT: 56+/-2 (control), 104+/-5 (RET), 64+/-3 (GL + RET) and 59+/-3 (GA + RET). GPT: 40+/-2 (control), 90+/-7 (RET), 45+/-2 (GL + RET) and 45+/-4 (GA + RET) SF units/ml). Furthermore, no extensive hepatocellular damages were observed. The results demonstrated that a three-day pretreatment with either GL or GA exhibited protective effect on retrorsine-induced liver damage in rats.

The comparison of early fluid therapy in extensive flame burns between inhalation and noninhalation injuries

Over the last half century, advances in treatment have changed the principal cause of death in burn patients from burn shock and wound sepsis to pulmonary sepsis, of which inhalation injury has always played a key role in morbidity and mortality. Even though Navar et al., Am. J. Surg. 1985;150:716-720 have noted that patients with inhalation injury had a mean fluid requirement of 5.8 ml/kg/% burn to achieve resuscitation from early burn shock, while patients without inhalation injury required only a mean fluid of 4.0 ml/kg/% burn, to achieve successful resuscitation in inhalation injured patients with minimum but adequate fluid has always been a challenge. To further define the difference of early fluid therapy between inhalation and noninhalation in extensively burned patients, a retrospective analysis was carried out in the Tri-Service General Hospital. Sixty-two flame burned patients (aged from 16 to 81 years-old with a mean age of 33.2+/-15.1 years: with burn size ranging from 30% to 98% TBSA with a mean burn size of 60.5+/-22.7%; 26 with inhalation injury; noninhalation 36) were reviewed during a 5-year period. The Parkland formula is the initial choice of fluid regimen with 4 ml/kg/% burn and the amount of replacement is monitored by urine output and is titrated to maintain urine output between 0.5 and 1.0 ml/kg/h. The mean amounts of fluid requirements of both inhalation and noninhalation burned patients were 3.1 +/- 1.0 and 2.3+/-0.8 ml/kg/% burn respectively (p < 0.05). Our study showed less fluid requirement for both inhalation and noninhalation injured patients in comparison with the Navar study and Parkland predictions in the first 24 h postburn. Furthermore, the inhalation injured patients definitely required volumes of fluid in excess of those required in noninhalation injured cases.

Induction of tumor-specific T cell response by cognating tumor cells with foreign antigen-primed Th cells

Sufficient CD4+ T cell help is very important in generating specific cytotoxic T cell responses. The inadequate activation of tumor-specific Th cells leads to failure of antitumor immunity. In general, each individual consists of some primed Th cells responding to certain antigens. If these tumor non-specific pre-primed Th cells can provide sufficient help, the generation of tumor-specific T cells may be enhanced. In the present study, we tested this hypothesis by cognating and reactivating pre-primed ovalbumin (OVA)-specific Th cells with OVA-pulsed tumor cells which could simultaneously present both OVA and tumor-associated antigen on the same cell. We clearly demonstrated that immunization of OVA-sensitized mice with OVA-pulsed P388 cells, but not unpulsed P388 cells, led to the induction of P388-specific cytotoxicity and tumor resistance. Both CD4+ and CD8+ tumor-specific cytotoxic T cells were detected in vitro, but only CD8+ T cells played the major effector role in preventing the growth of challenged tumor in vivo. Taken together, our study demonstrated that the immunogenicity of tumor cells can be enhanced effectively by cognating pre-primed foreign antigen-specific Th cells with tumor cells. These findings have potential implications in developing methods to control tumor growth.

Skin injury in the operating room

Skin injury occurring in the operating room may occur as a result of electrical current, thermal injury, chemical irritation and mechanical stress. Between 1 December 1996 and 28 February 1997, 19 cases of skin injury from a total of 3657 operations were noted in our hospital. These injuries tend to be ignored because of their early spontaneous healing. We suggest that medical staff should pay more attention to this complication and prevent it from occurring.

Recipient bed vascularity and the survival of ischaemic flaps

The purpose of this study was to identify the length of the ischaemic period required to induce the 'no-reflow' phenomenon in a rat epigastric flap on an avascular recipient site. The vascularity of the recipient bed may affect flap survival in the early postischaemic stage after flap transfer. Initially, we designed epigastric flaps in 300-350 g Sprague-Dawley rats and separated the rats into four groups of 5 rats each (total 20 rats). In groups 1, 2, 3, the flaps were made ischaemic for 1 hour, 6 hours and 10 hours, respectively, by temporarily clipping the epigastric artery and vein. In group 4, the epigastric artery and vein were divided to create permanent ischaemia. In groups 1, 2 and 3, ischaemia was ended by removing the clips. After the ischaemic flaps were reperfused, their viability was studied by measuring the flap survival rate at postoperative day 7. Flap survival was studied by direct observations, laser Doppler flowmeter measurement of flap blood flow, histopathology, and carbon particle perfusion of the flap vasculature. Ischaemic flaps of groups 1 and 2 recovered almost completely after reperfusion due to the short period of ischaema. In a second series of experiments, in order to evaluate the contribution to flap survival of the recipient vascularised bed, another four groups of epigastric flaps (of 5 animals each, using the same time periods as above) were raised and a piece of Biobrane was interposed between the flap and the recipient bed before the flap wound was closed, to eliminate all nutrient supply from the recipient bed. THe results showed that the combined effect of the reperfused flap vasculature plus the metabolic contribution of the recipient bed significantly (P < 0.01) increased the extent of flap survival of the 6- and 10-hour ischaemic flaps as well as the divided pedicle flaps, which were never reperfused. An absolute 'no-reflow' rat model flap for further flap salvage studies was also developed.

Management of pancreatic lesions in von Hippel-Lindau disease

Twelve patients with von Hippel-Lindau disease were collected in our institute from 1981 to 1995. All had a family history of the disease. Eleven patients underwent abdominal computed tomography, sonography, or angiographic studies. Ten had pancreatic involvement that included cystic lesions in nine and a solid lesion in one. Seven patients were asymptomatic. Another three presented with obstructive jaundice or upper gastrointestinal (UGI) bleeding. Except for case 8, who died of a central nervous system complication soon after diagnosis of the pancreatic lesion, the other patients had been found to have pancreatic involvement for a variable period of time, ranging from 1 to 13 years (median 5 years). Serous cystadenoma was proved pathologically in two with cystic lesions, and pancreatic endocrine tumor was diagnosed in one with a solid mass. One patient (case 1) underwent biliary bypass due to obstructive jaundice and died of cholangitis and pneumonia 6 years later. One patient (case 3) had total pancreatectomy and lived well with good diabetic control for more than 5 years. The patient with a solid lesion was explored because of repeated UGI bleeding. Surgical resection was impossible owing to advanced tumor with vascular involvement, and a pancreatic endocrine tumor was diagnosed pathologically. He was followed for 1 year. The other seven patients remained asymptomatic during the successive follow-up period. From a literature review and our own experience, we suggest that conservative measures are adequate for the cystic lesions; however, aggressive resection is mandatory for a solid pancreatic lesion in von Hippel-Lindau disease.

Use of a porcine dermis template to enhance widely expanded mesh autologous split-thickness skin graft growth: preliminary report

To answer the question whether a xenograft dermal substitute could enhance skin grafting, we used porcine dermis as a template for a widely expanded mesh autologous split-thickness skin (ASTS) graft in a rat model. Four groups of rats had received widely expanded meshed skin autografts to cover an excised back wound. Group 1 had a bed of autologous dermis, group 2 had porcine xenograft dermis, group 3 had widely expanded meshed autograft alone, and group 4 had no graft with the wound healing by contraction alone. Wounds were studied by clinical inspection for texture and contraction, and by histologic and immunofluorescent techniques. At 2 weeks, there was acceptable ASTS graft take, and most of the wound healed completely by 3 weeks. The integrity of this complex skin graft was maintained for 4 months but wound contraction gradually decreased overall wound size. Size was maintained better in the ASTS-autodermis and ASTS-xenodermis groups at postgraft 4, 5, and 6 weeks when compared with the ASTS graft, and there was no difference between the ASTS-autodermis and ASTS-xenodermis groups. Thus both allodermis and xenodermis provided a similar template to enhance widely expanded mesh skin growth and delay wound contraction. The pathologic studies indicate that the xenodermis collagen was replaced either by fibrosis or by biodegradation to rat collagen. The immunofluorescent study also reflected that anti-porcine antibody activity was hugely diminished in the ASTS-xenodermis graft wound after long-term follow-up. In conclusion, either autodermis or xenodermis enhances widely expanded mesh ASTS survival in a rat model, and could significantly maintain the original wound size better than ASTS graft without a template. In a long-term follow-up study, the porcine dermis was replaced either by fibrosis or biodegradation to rat dermis.

Prederivatization and high-performance liquid chromatographic analysis of alkaloids of bulbs of Fritillaria

A method of prederivatization and HPLC with UV detection was developed for the simultaneous analysis of five major steroidal alkaloids of the Fritillaria species: verticine, verticinone, isoverticine, ebeiedine, and ebeiedinone. Derivatization was carried out by esterification of the hydroxyl-containing Fritillaria alkaloids to the corresponding naphthoates with 1-naphthoyl chloride. Reaction conditions were optimized and the yields of the derivatization were between 94 and 100% for all test alkaloids. Derivatized alkaloids were characterized by mass spectrometry and HPLC-MS. The validated HPLC-UV method demonstrated linear UV response at the sampling ranges used, and a test limit of 1 microgram/mL was determined for all analytes. This analytical method is simple, convenient, and readily reproducible. The developed method was applied to the analysis of the major pharmacologically active alkaloids in three medicinally used Fritillaria species: F. cirrhosa, F. thunbergii, and F. hupehensis. Five major Fritillaria alkaloids were simultaneously analyzed qualitatively and quantitatively from crude extracts of each of these herbs.

Surgical management of axillary bromidrosis--a modified skoog procedure by an axillary bipedicle flap approach

We developed a modified Skoog procedure to treat axillary bromidrosis and hyperhidrosis that creates a bipedicle flap over the axillary fold with two parallel incisions to achieve a complete excision of the sweat glands. If necessary, the flap can be extended by making another parallel incision for a larger axillary hair-bearing area. Between 1988 and 1992, 110 patients were operated on using this method, but only 92 of the 110 patients, with an average follow-up period of 29.5 months, were available for this follow-up study. In this series, 86.9 percent of patients gave a family history of axillary bromidrosis. This follow-up review demonstrated that 93.5 percent of patients experienced no odor or occasional very mild axillary odor postoperatively. Postoperative scar formation was either nonvisible or excellent in 95.1 percent of patients, and 82.6 percent of patients reported either a hairless axilla or a marked decrease of axillary hair. Most importantly, 92.4 percent of patients reported a marked decrease in axillary sweat. Four axillary fossae developed postoperative subcutaneous hematomas, and six wounds had mild dehiscence. All of the wounds eventually healed satisfactorily after minor procedures. We concluded that for the treatment of extensive axillary apocrine bromidrosis, this new method achieves complete excision of the sweat glands and provides excellent functional and cosmetic results.

The immunological effect of 8-methoxypsoralen and UVA treatment on murine T-cell leukemia

8-Methoxypsoralen (8-MOP) plus long-wavelength UV radiation (UVA, 320-400 nm) have been used to treat various diseases such as cutaneous T-cell lymphoma, systemic scleroderma, rheumatoid arthritis and rejection of heart transplants. However, the immunological mechanism of this treatment remains unknown. In this report, we investigated the effect of 8-MOP/UVA on the modulation of the immunogenicity of a T-cell leukemia cell line (RL male 1 cells). The results demonstrated that the stimulator function of the in vitro 8-MOP/UVA-treated RL male 1 cells was enhanced in both RL male 1-specific allogeneic and syngeneic immune responses. Furthermore, the enhancement of the immunogenicity of the 8-MOP/UVA-treated RL male 1 cells was found to be strongly associated with the increase of intercellular adhesion molecule-1 expression on these 8-MOP/UVA-treated tumor cells. Therefore, our findings suggested that the alteration of the expression of the immune-related cell surface molecules might be an important effect of 8-MOP/UVA treatment on the elevation of the immunogenicity of the 8-MOP/UVA-treated tumor cells.

Human keratinocyte culture using porcine pituitary extract in serum-free medium

Extensive burn wound coverage remains a major problem in acute and reconstructive stages due to shortage of autologous skin donor sites. Many reports have described successful coverage of extensive burn wounds by using cultured keratinocytes sheet graft alone or overlaying a glycosaminoglycan substrate, allodermis or xenodermis. In our experience, the use of Boyce and Ham's serum-free medium made the preparation of keratinocyte cultures simple and the cell growth was prompt. In this study, one of the supplements in Boyce's culture medium, the bovine pituitary extract (BPE at concentration of 140 micrograms/ml), was replaced by different concentrations of fresh frozen porcine pituitary extract (PPE). The protein concentration of the original preparation of PPE was also 140 micrograms/ml but in which 375 +/- 21 pg/ml (1/10 dilution) of platelet-derived growth factor (PDGF) was detected by immunoassay (PDGF ELISA). Our results proved that PPE is an ideal supplement for the in vitro growth of keratinocytes, and when its protein concentration is 350 micrograms/ml will induce a significant keratinocyte growth by day 9 when compared to the regular BPE and also to the other concentrations of PPE (P < 0.05).

Disseminated tuberculomas in spinal cord and brain demonstrated by MRI with gadolinium-DTPA

Intramedullary tuberculoma is rare, and there has been no report of concurrent intramedullary and intracerebral tuberculomas. We report a 30-year-old man with miliary tuberculosis of the lung. He suffered sudden paraplegia due to tuberculomas in the thoracic spinal cord and MRI showed more tuberculomas in the cervical spinal cord, brain stem, and cerebral and cerebellar hemispheres. The tuberculomas were isointense on the T1-weighted images, and hyperintense on the T2-weighted images; there was marked enhancement with intravenous gadolinium-DTPA. All the tuberculomas were very small 1 year after antituberculous chemotherapy.

Effects of granulocyte-macrophage colony-stimulating factor and interleukin 6 on the growth of leukemic blasts in suspension culture

We examined the stimulatory effects of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin 6 (IL)-6 on the in vitro proliferation of leukemic blast cells from patients with acute leukemia. Bone marrow or peripheral blood leukemic blast cells were obtained from 21 patients, including 14 cases of acute myeloblastic leukemia (AML), four cases of acute lymphoblastic leukemia (ALL), two cases of acute undifferentiated leukemia, and one case of acute mixed-lineage leukemia. The proliferation of leukemic blast cells was evaluated by measuring the incorporation of 3H-thymidine into cells incubated with various concentrations of cytokines for 3 days. GM-CSF stimulated the DNA synthesis (with greater than 2.0 stimulation index) of blast cells in 9 of 14 (64%) AML cases, two cases of acute undifferentiated leukemia and one case of acute mixed-lineage leukemia. Only two cases of AML blasts responded to IL-6 to grow in the short-term suspension cultures. GM-CSF and IL-6 did not display a synergistic effect on the growth of leukemic cells. Moreover, GM-CSF and IL-6 did not stimulate the proliferation of ALL blast cells. Binding study also revealed the specific binding of GM-CSF on the blast cells of acute undifferentiated leukemia and acute mixed-lineage leukemia. Our results indicated that leukemic blast cells of acute undifferentiated leukemia and acute mixed-lineage leukemia possessed functional GM-CSF receptors.

The effect of recombinant human erythropoietin on hemostatic status in chronic uremic patients

The hemostatic effects of recombinant human erythropoietin (rHuEP) were investigated in 20 patients with end-stage renal disease (thirteen on hemodialysis, seven without dialysis) receiving this hormone. We studied their hemograms and coagulation profiles before and at 1 month after initiation of rHuEP therapy. One month after rHuEP administration, improvement in anemia (16/20, 80%) and shortening of bleeding time (17/19, 89.5%) were observed. Shortening or correction of bleeding time was achieved in three patients without any increase of the hemoglobin level. This means that factors other than the increased hematocrit level might contribute to shortening bleeding time in uremic patients receiving rHuEP treatment. The platelet count, prothrombin time, partial thromboplastin time, and fibrinogen level did not change over the course of rHuEP therapy. Thrombosis of vascular access was not observed, and heparin doses were not increased in this short-term period. A significant decrease was found in the plasminogen level, from 108.5% to 88.2% (p less than 0.05), in uremic patients on hemodialysis. The antithrombin III level also decreased, from 98.8% to 89.8% (p less than 0.05), and its level dropped to below normal ranges in six of thirteen patients (46%) on hemodialysis after treatment with rHuEP. No significant change was noted in the levels of antithrombin III, plasminogen, and alpha 2-antiplasmin in uremic patients not receiving dialysis. These results suggest that rHuEP administration induces increased extracorporeal dialyzer clotting and consumption coagulopathy, and that this extracorporeal consumption coagulopathy may play a role in the genesis of thrombotic complications.

A novel -32 (C-A) mutant identified in amplified genomic DNA of a Chinese beta-thalassemic patient

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Internal carotid artery occlusion in painful ophthalmoplegia

Two patients with left painful ophthalmoplegia, caused by infiltrating lesion in left superior orbital fissure and/or cavernous sinus, subsequently developed left cerebral infarction associated with occlusion of the proximal portion of left internal carotid artery demonstrated by CT and angiogram. It thus is worthy to remind that painful ophthalmoplegia may have the possibility of resulting in cerebral infarction associated with carotid occlusion.

Atypical presentations of tuberculous meningitis--a case report

A case of tuberculous meningitis, proved by cerebrospinal fluid (CSF) cultures, is reported due to atypical findings in CSF. This 19-year-old man developed subacute headache and fever for 2 weeks, followed by focal seizure and left hemiparesis. Initial CSF study showed hemorrhagic lymphocytic pleocytosis with mildly elevated protein and normal sugar content, mimicking viral or postinfectious meningoencephalitis. Follow-up CSF studies showed polymorphonuclear pleocytosis. A concomitant bacterial meningoencephalitis was suspected, though repeated CSF cultures did not isolate any bacteria. The activity of adenosine deaminase in CSF was 12 U/L, highly suggestive of tuberculous meningitis. Magnetic resonance imaging (MRI) showed only a focal meningoencephalitis in the right lateral frontal cortex. Due to progressive deterioration of the clinical status, umbrella therapy, including antimycobacterial drugs and strong antibiotics were given. At a later time, growth of tubercle bacilli was reported in the CSF cultures. Follow-up study of MRI 4 months later, showed thick abnormal enhancement in the basal cisterns and obstructive hydrocephalus, typical findings of chronic basal meningitis.

Distribution of cerebral infarcts on computed tomography

Locations of cerebral infarcts on computed tomography were analyzed on all patients admitted for ischemic stroke or status lacunaris in 1984. Patients who had only one symptomatic infarct, without histories of strokes or transient ischemic attacks, were allocated to group A, the rest made up group B. Group A showed that 47.6% of symptomatic infarcts were lacunes with similar percentages in the following areas: lenticular nucleus (12.7%), internal capsule (12.7%), and subcortical white matter (11.1%). In group A, the cortex (49.2%) was the most common site of infarction, while in group B, it was the subcortical white matter (31.7%). However, if the structures supplied by the basal perforating arteries (basal ganglia, thalami, and internal capsules) were considered as a whole, this area (41.8%) was the most common site for infarcts in group B. Thus, asymptomatic infarcts and those of status lacunaris contributed greatly to the overall distribution of cerebral infarcts.

Timed overnight sodium and potassium excretion and blood pressure in steel workers in North China

Three timed overnight urinary sodium (Na), potassium (K) and creatinine measurements, standardized to 8 h, as well as three blood pressures on corresponding consecutive days were obtained on a sample of 90 steel workers (40 men, 50 women) aged 34-56 years in Beijing, North China. For three indices of electrolyte excretion - absolute Na and K output/8 h, Na:K ratio and 8 h creatinine output - the ratios of intra- to inter-individual variations were less than 1.0 for men, but higher for women in contrast to findings for U.S. population groups of similar age. This fact, probably reflecting greater stability of day to day electrolyte intake by Chinese than Americans, enables reasonably precise characterization of dietary electrolyte intakes of individual Chinese, particularly men, with only a few timed overnight urine specimens. With 3-day mean values for each person, nominally significant (i.e. not adjusted for multiple testing) positive simple correlations were found for urinary Na, Na:K and Na:creatinine with blood pressure [both systolic (SBP) and diastolic (DBP)] for men; and women for Na:K with SBP and DBP, but Na:creatinine with SBP only. With control for age, body mass index and pulse in multivariate analyses, only the relationship of Na:K and Na:creatinine to SBP and DBP remained significant for men; a similar, though less strong and consistent, trend was found for women, and K was inversely related to SBP for women. These data are consistent with an association between habitual intake of sodium and risk of hypertension, and also suggest that habitual potassium intake may have a countervailing influence in this regard.

Determination of Indole-3-acetic Acid in Douglas Fir Using a Deuterated Analog and Selected Ion Monitoring: Comparison of Microquantities in Seedling and Adult Tree

Indole-3-acetic acid (IAA) content in shoot tips of Douglas fir (Pseudotsuga menziesii [Mirb.] Franco) trees and seedlings was determined by combined gas chromatography-mass spectrometry using a deuterated analog (d(2)-IAA) as an internal standard and the technique of selected ion monitoring. Ratios of the peak heights of the deuterated analog internal standard to endogenous IAA revealed a slightly higher content of IAA in seedlings compared with the shoot tips collected in June. The relatively high level of IAA (2.9 micrograms per gram fresh weight) in seedlings is discussed in relation to in vitro propagation of this species.

Regeneration of Douglas Fir Plantlets Through Tissue Culture

Douglas fir plantlets were produced in tissue culture under defined conditions from cotyledon explants obtained from 2- to 4-week-old seedlings. Tissue pieces were cultured on the surface of a fabric tissue support (100 percent polyester) saturated with liquid nutrient medium; this facilitated periodic changes of the medium to meet the requirements at successive developmental stages without transfer of cultured tissues. Plant growth regulators were needed to stimulate adventitious bud formation. Plantlets were regenerated by rooting excised shoots at 19 degrees C on agarsolidified medium containing sucrose and the auxin naphthalene-2-acetic acid. After root initiation, plant growth regulators were removed; this resulted in stimulation of root elongation and the subsequent development of plantlets, which were then established in soil.

Organogenesis from Callus Culture of Hordeum vulgare

Rapidly proliferating callus cultures from the apical meristem of Hordeum vulgare L., cultivars "Himalaya" and "Mari", were established on a defined medium supplemented with auxin and cytokinin. A frequency of organ differentiation of ca. 85% was obtained by transfer to the same medium but without any growth regulators. All regenerated plants had the diploid chromosome number of 14 (2n).

The influence of genomes on autonomous growth of pith cultures of Nicotiana glauca-Langsdorffii hybrids

A differential influence of the two parental genomes on cell proliferation and morphogenesis in pith tissue explants can be observed among the various tumorous hybrid combinations between Nicotiana glauca Grah. and N. langsdorffii Weinm.: the F1 hybrid (GL), its amphiploid (GGLL), and two different triploids (GGL and GLL). This influence was evident when the explants were cultured in the presence of exogenous auxin (indole-3-acetic acid, 2.5 μM), supplied either continuously or for a brief period of time. Compared with the F1 and the amphiploid, the higher proportion of N. glauca genomes in GGL cells resulted in greater growth, the higher proportion of N. langsdorffii genomes in GLL cells in lesser growth. In addition, shoots are produced on the GGL callus, while only roots are formed on calli of the other types in the same medium. When, in addition to auxin, a cytokinin [6-(3-methyl-2-butenyl-amino)purine] was added to the culture medium, the differential growth of the different tissue types was less pronounced; at 1.0 μM of the cytokinin, all tissues grew at about the same rate and remained undifferentiated, regardless of their genomic composition.