Energy transfer in LHCII monomers at 77K studied by sub-picosecond transient absorption spectroscopy

Energy transfer from chlorophyll b (Chl b) to chlorophyll a (Chl a) in monomeric preparations of light-harvesting complex II (LHCII) from spinach was studied at 77 K using pump-probe experiments. Sub-picosecond excitation pulses centered at 650 nm were used to excite preferentially Chl b and difference absorption spectra were detected from 630 to 700 nm. Two distinct Chl b to Chl a transfer times, approximately 200 fs and 3 ps, were found. A clearly distinguishable energy transfer process between Chl a molecules occurred with a time constant of 18 ps. The LHCII monomer data are compared to previously obtained LHCII trimer data, and both data sets are fitted simultaneously using a global analysis fitting routine. Both sets could be described with the following time constants: 140 fs, 600 fs, 8 ps, 20 ps, and 2.9 ns. In both monomers and trimers 50% of the Chl b to Chl a transfer is ultrafast (<200 fs). However, for monomers this transfer occurs to Chl a molecules that absorb significantly more toward shorter wavelengths than for trimers. Part of the transfer from Chl b to Chl a that occurs with a time constant of 600 fs in trimers is slowed down to several picoseconds in monomers. However, it is argued that observed differences between monomers and trimers should be ascribed to the loss of some Chl a upon monomerization or a shift of the absorption maximum of one or several Chl a molecules. It is concluded that Chl b to Chl a transfer occurs only within monomeric subunits of the trimers and not between different subunits.     

Psychosocial factors in children with idiopathic musculoskeletal pain: a prospective, longitudinal study

To explore the role of psychosocial factors in the development and persistence of idiopathic musculoskeletal pain (IMP) in children, 23 children with IMP and 52 children with juvenile chronic arthritis (JCA) were compared at first admission to hospital and at 9 y follow-up. Semistructured interviews were performed at both assessments. At first admission, the prevalence of psychiatric diagnoses was high both in patients with IMP and patients with JCA, but patients with IMP more often had pain models, reported more school stress and more often lived with one biological parent. At follow-up, overall psychosocial functioning and level of chronic family difficulties were improved in both groups, but patients with IMP had a higher prevalence of psychiatric diagnoses and more chronic family difficulties and life events than patients with JCA. The persistence of IMP at follow-up was related to pain models, school stress, less parental education and more chronic family difficulties at first admission. Findings support the association between psychosocial factors and childhood IMP.     

Hodgkin's disease in patients older than 70 years of age: a registry-based analysis

Between 1973 and 1993, 529 patients aged 15 years and over with Hodgkin's disease (HD) were entered into a lymphoma registry. Twenty-eight cases (1 only diagnosed at autopsy) of histologically proven HD in patients aged 70 years or older were identified. The distribution of sex, 'B' symptoms, histology and stage was not significantly different from that of younger patients, except for the fact that there were no patients aged 70 years or older with lymphocyte predominant HD. Nineteen patients were treated radically, 5 patients palliatively and 4 patients received no radiotherapy or chemotherapy. Three of the 14 patients treated with chemotherapy achieved the planned dose intensity. The cause-specific 5-year survival was 75% for patients aged 15-69 years and 28% for patients aged 70 years and over (logrank chi(2) = 43.7, P < 0.00001). The younger and older groups treated with radical intent had complete response rates of 97% and 74%, respectively (logrank chi(2) = 17.91, P < 0.00001) and relapse rates at 5 years of 27% and 56%, respectively (logrank chi(2) = 4.86, P = 0.0275). The main reason for the poorer prognosis of patients aged 70 years and over was the increasing difficulty of chemotherapy delivery associated with advancing age.     

Major depressive disorder in Taiwan defined by the Chinese diagnostic Interview Schedule

The lifetime prevalence rate of major depressive disorder (MDD), as defined by the Chinese Diagnostic Interview Schedule, is 1.14% in Taiwan. This is significantly lower than the lifetime prevalence rates reported in Western studies and similar to other studies in the Chinese population using similar methods for assessing cases of MDD. Epidemiological data from 136 MDD cases were analyzed to provide possible explanations for this difference in lifetime prevalence rates. The low rate of broken families in Chinese culture, low comorbidity rate, and older age of onset of MDD may suggest a reality of low lifetime prevalence rates of MDD in Taiwan.     

Experience with the Ultrex and Ultrex Plus inflatable penile prosthesis: new implantation techniques and surgical outcome

OBJECTIVE: To construct nomograms of the size of the fetal orbit and lens during gestation. SUBJECTS: The study group included 349 normal pregnant women at 14-36 weeks' gestation. METHODS: Routine biometric measurements were obtained in all the participants; these included biparietal diameter, head and abdominal circumferences, measurements of the long bones and the diameters of the fetal orbit and lens. The orbital and lens circumference measurements were also related to gestational ages. RESULTS: A linear growth function was observed between gestational age (GA) and orbital diameter (r = 0.94; p < 0.00001; y = -0.66 + 0.5 x GA), orbital circumference (r = 0.94; p < 0.00001; y = -2.1 + 1.5 x GA) and orbital area (r = 0.94; p < 0.00001; y = -98.1 + 8.3 x GA). Significant correlation was also found between femoral length (FL) and orbital diameter (r = 0.95; p < 0.00001; y = 3.3 + 1.9 x FL), orbital circumference (r = 0.95; p < 0.00001; y = 10.3 + 5.9 x FL) and orbital area (r = 0.93; p < 0.00001; y = -28.2 + 32.2 x FL). A linear growth function was observed between orbital circumference and biparietal diameter (r = 0.94; p < 0.00001) and head circumference (r = 0.95; p < 0.00001). A linear growth function was also observed between gestational age and the diameter of the lens (r = 0.89; p < 0.00001; y = 0.88 + 1.4 x GA) the circumference of the lens (r = 0.89; p < 0.00001; y = 2.78 + 0.4 x GA) and the area of the lens (r = 0.89; p < 0.00001; y = -7.95 + 1.0 x GA). The correlation was found between the ratios of the diameters, circumferences and areas of the lens and the orbit. CONCLUSIONS: These results provide normative data of the growth of the fetal orbit and lens and may aid future studies relating to fetal eye anomalies.     

Folate synthesized by bacteria in the human upper small intestine is assimilated by the host

BACKGROUND & AIMS: Some intestinal flora are known to synthesize folate. The aim of this study was to determine whether folate synthesized by small intestinal flora is assimilated by the human host. METHODS: Subjects with atrophic gastritis and healthy volunteers were studied before and after omeprazole administration. A double-lumen perfusion tube was placed in the duodenum. 3H-labeled P-aminobenzoic acid, a precursor substrate for bacterial folate synthesis, was perfused. Downstream intestinal aspirates and a 48-hour urine collection were obtained. RESULTS: Atrophic gastritis and omeprazole administration were associated with increases in duodenal pH and in small intestinal flora. Bacterially synthesized folates were isolated from the intestinal aspirates. Tritiated 5-methyltetrahydrofolate, a major metabolite of folate, was isolated from the urine of omeprazole-treated subjects in greater quantities than from drug-free subjects (P<0.01); the quantity of tritiated 5-methyltetrahydrofolate in the urine of the subjects with atrophic gastritis was similarly elevated. CONCLUSIONS: (1) Mild bacterial overgrowth caused by atrophic gastritis and administration of omeprazole are associated with de novo folate synthesis in the lumen of the small intestine; (2) the human host absorbs and uses some of these folates; and (3) the contribution to folate nutriture from this source remains unclear.     

Prolonged immunodepression after trauma and hemorrhagic shock

OBJECTIVE: To define and discuss the cytologic findings in six cases of nodular pseudoangiomatous stromal hyperplasia (PASH) of the breast. STUDY DESIGN: Retrospective evaluation of the medical records, cytologic and histologic material from six patients with palpable mammary PASH. Cases in which PASH was associated with other predominant mammary lesions were not included in the study. RESULTS: A total of six patients with histologically proven PASH underwent aspiration in nine occasions (three patients studied twice). Clinically, five patients were diagnosed as having fibroadenoma or another benign lesion, and in one patient carcinoma was suspected. In two patients, mammography disclosed rapid growth of the lesion. Seven aspirations, performed on five patients, were diagnosed as fibroadenoma (n = 5) or fibroadenomatous lesion (n = 2). An eighth aspiration was cystic and reported as fibrocystic disease. The last case was erroneously diagnosed as suspicious for carcinoma. Even after revision, the cytologic similarities of PASH with fibroadenoma were remarkable. Most smears were less cellular than those of conventional fibroadenomas. Epithelial clusters showed variable size, with a predominance of medium to small groups. Stromal elements were minimal or absent. Background cellularity was composed of round to oval naked nuclei and others with spindle shapes. Occasional epithelial clusters showed cellular dissociation and slight atypia. CONCLUSION: Due to the absence of specific cytologic features and similarities to fibroadenoma, a precise diagnosis of PASH cannot be made on cytologic material. However, the majority of cases can be diagnosed correctly as benign, allowing appropiate treatment.     

Preliminary study of electron-energy-loss spectra of YBa2 Cu3O7−δ

We have obtained the electron-energy-loss spectra below 1,000 eV for YBa₂Cu₃O_7?δ. The spectra show contributions from all elemental constituents, although the Y-signal is very weak owing to its small concentration. The low-loss region and the Ba-core losses are very similar to those obtained for BaO. The Cu absorption is similar to that seen in CuO with minor differences relating to Cu concentration and anisotropy. The oxygen 1s absorption has a shape that is quite different from that obtained in CuO and shows striking orientational anisotropy. Radiation damage in the microscope is a problem and leads to changes in the shape of the oxygen edge.