Halogen- and hydrogen-bonded self-assembled fibrillar networks of substituted 1,3:2,4-dibenzylidene-D-sorbitols (DBS).

Substituting the sole primary hydroxyl group of the low molecular weight organogelator (LMOG), 1,3:2,4-dibenzylidene-D-sorbitol (DBS), with a halogen atom (Cl, Br, or I; i.e., 6-Cl-DBS, 6-Br-DBS, or 6-I-DBS) drastically alters the supramolecular self-assembled fibrillar network (SAFiN) that forms when the molecules aggregate. The SAFiN varies depending on the solvent properties, impacting the role of non-covalent hydrogen- and halogen-bonding interactions along and between fibers. The halogenated DBS derivatives have more coherent crystalline fibers than DBS, with larger length-to-width aspect ratios. High-resolution synchrotron powder X-ray diffraction of each wet-state gel in toluene and DFT optimization obtained complete structures for the three halogenated DBS derivatives in their SAFiNs. The presence of a halogen atom reduces the reliance on hydrogen bonding by enabling new halogen bonding interactions that impact the self-assembly behavior, especially in solvents of higher polarity. For 6-I-DBS and 6-Br-DBS, the primary forces driving molecular self-assembly are C-H⋯π and intermolecular halogen-to-halogen interactions, and there is one unique molecule in each unit cell. However, the Cl atoms of 6-Cl-DBS are not close, and its SAFiN structures rely more on hydrogen bonding. As a result, the enhanced hydrogen bonding, electronic differences among the halogens, and spatial factors allow its unit cell to include two independent molecules of 6-Cl-DBS.

Phase formation and evolution in the silicon substituted tricalcium phosphate/apatite system.

The sintering of silicon doped calcium phosphate ceramics prepared from a basic colloidal hydroxyapatite (Ca5(PO4)3OH or HA) precipitate mixed with silica over 800 degrees C yields a phase mixture of tricalcium phosphate phases (TCP) designated Si-TCP, beta-TCP and a silicon substituted dehydrated apatite (Si-Ap). The Si-TCP phase is defined as a combination of a silicon stabilized TCP in which the silicon content attains a saturated value (Ca3(P0.9Si0.1O3.95)2 or Si-TCP(sat)) and alpha-TCP (Ca3(PO4)2). Si-TCP(sat) has the same crystalline space group (P2(1)/a) as alpha-TCP, but with characteristically different lattice parameters due to the substitution of silicon in tetrahedral phosphorus sites. The nucleation and growth kinetics of Si-TCP in samples of composition 0.2 mol SiO2:mol HA (0.2:1) and 1 mol SiO2:mol HA (1:1) can be understood in terms of the initial growth of alpha-TCP at a silica-HA interface followed by a transformation to Si-TCP(sat) or beta-TCP. A thermodynamic model for the formation of Si-TCP(sat) predicts a nucleation temperature of 795 degrees C, in close agreement with experiment. If sufficient silicon is available, the alpha-TCP transforms to Si-TCP(sat) during extended sintering. In the absence of sufficient silicon, the alpha-TCP transforms to beta-TCP.

National progress in dengue vector control in Vietnam: survey for Mesocyclops (Copepoda), Micronecta (Corixidae), and fish as biological control agents.

This paper describes the process of expanding a successful dengue control program in 3 provinces in northern Vietnam into a national one and demonstrates the presence of a rich, low-cost resource that could have similar applicability to other countries in the region. The cornerstone of the preventive strategy is larval control of Aedes aegypti (L.), the major vector, using predators such as copepods, Mesocyclops spp., aided by the corixid bug Micronecta quadristrigata Bredd, and fish in large water storage containers. From 1989 to 1998, 9 species of Mesocyclops (M. woutersi Van de Velde, M. aspericornis (Daday), M. ruttneri Kiefer, M. thermocyclopoides Harada, M. affinis Van de Velde, M. ogunnus Onabamiro, M. yenae Holynska, M. cf. pehpeiensis Hu, and M. dissimilis Defaye and Kawabata) were found in natural and artificial habitats in 26 provinces throughout Vietnam. The predatory capacities of 6 of these were evaluated in the laboratory. This indicated that daily consumption/killing averaged between 16 and 41 Ae. aegypti larvae per copepod. From detailed evaluations in 9 provinces, Mesocyclops spp. were surprisingly common in 8,413 artificial containers (concrete tanks, wells, ornamental ponds and in the south, large jars). Because of existing practices for washing and water transfer from ponds and lakes in Ha Tay and Ha Bac, Mesocyclops spp. already occurred in 60-100% of the water storage containers. When the relationship between the presence or absence of Mesocyclops and Aedes larvae in 5,111 containers was analyzed by the chi-square test, their distributions were significantly related, indicating control (odds ratio = 0.56). When 3,426 containers that did not contain Mesocyclops or fish were analyzed in relation to the distribution of Aedes larvae, those with Micronecta also had significantly less Aedes (odds ratio = 0.43). Therefore, this study demonstrates that there is an abundance of local Mesocyclops spp. in Vietnam that can be incorporated into specifically designed community-based control programs aided by Micronecta and fish.

Eradication of Aedes aegypti from a village in Vietnam, using copepods and community participation.

In northern Vietnam, copepods of the genus Mesocyclops were used for biological control of Aedes aegypti, the principal vector of dengue viruses, by inoculation into wells, large cement tanks, ceramic jars, and other domestic containers that served as Ae. aegypti breeding sites. The use of Mesocyclops was complemented by community participation with respect to recycling to eliminate unused and discarded containers that collected rainwater and provided Ae. aegypti breeding sites that could not be treated effectively with Mesocyclops. Aedes aegypti disappeared from 400 houses of the treated village in August 1994 and has not reappeared, a result of particular significance, because there are virtually no other recorded instances of eradicating this mosquito anywhere in the world during the past 25 years, and certainly not with community-based approaches. When used in combination with community recycling, Mesocyclops is an easy and inexpensive method of Ae. aegypti control that should be effective for many communities in Vietnam and elsewhere.

Immunologically defined prognostic subgroups as predictors of response to BCG immunotherapy.

Fifty-two stage I and II patients with nonsmall cell lung cancer were randomized after resection to no further therapy, BCG, or BCG plus allogeneic tumor cells. Patients have been observed for 16-65 months (mean 39.5). When the two immunotherapy arms were combined and plotted against controls, trend analysis suggested (P = 0.088) an increase in disease-free interval (DFI) only for stage I patients. The one-way mixed lymphocyte culture (MLC) values were depressed in some patients prior to any immune stimulation. Immunotherapy significantly benefited DFI among patients with a depressed MLC.

A comparison of surgery for neurogenic thoracic outlet syndrome between laborers and nonlaborers.

OBJECTIVE: To determine factors of outcome following surgical intervention for neurologic thoracic outlet syndrome (NTOS). METHODS: In a retrospective study of patients surgically treated for NTOS, outcome was evaluated by postoperative symptoms and the ability of patients to return to work. RESULTS: Good, fair, and poor results were obtained in 26 (48%), 21 (39%), and 7 (13%) patients, respectively. The best predictor of a good outcome was occupation. Nonlaborers were more likely to have good outcome (21 of 32, 66%) when compared with laborers (5 of 22, 23%; P = 0.0025). Only 6 of 20 (30%) laborers were able to return to their original occupation compared with 17 of 26 (65%) nonlaborers (P = 0.036). CONCLUSIONS: Laborers with NTOS are less likely to have a good result from surgical intervention, are unlikely to return to their original occupation, and may require retraining for a non-labor-intensive occupation if they cannot return to their original work.

Activity and kinetic properties of basal aryl hydrocarbon hydroxylase during proliferation in the transformable C3H 10T1/2 CL8 cell line.

Basal aryl hydrocarbon hydroxylase (AHH) activity and its kinetic properties were studied as a function of proliferation in C3H mouse embryo 10T1/2 CL8 cells. Activity was low in freshly plated cells, increased during exponential growth, peaked at confluency, and then declined. The apparent Km-values for benzo[a]pyrene (BP) and NADPH were less in proliferating (approx. 0.37 microM BP, 3.3 nM NADPH) than in confluent cells (0.74-1.39 microM BP, 33.4-53.4 nM NADPH). Cells at different growth states responded differently to benz[a]anthracene (BA) and aminophylline, an inhibitor of cyclic nucleotide phosphodiesterases. When cells were harvested at the mid log phase of growth, 12 h of exposure to aminophylline caused maximum induction, while 24 h of BA treatment were required. In contrast, at early confluence, 12 h of BA treatment gave the greatest levels of activity, while exposure to aminophylline did not induce AHH. In fact, decreases in activity were observed. These differences are indicative of different regulatory mechanisms for BA and aminophylline induction. They also suggest the regulation of basal AHH by cyclic nucleotides changes during growth. The exposure times giving maximum activity were used to determine the kinetic properties of BA-induced activity. As with basal AHH, the Km-value for BP was less in log phase (0.2-0.4 microM BP) than in confluent cells (0.64-1.05 microM BP). Moreover, the Km-values for BP and NADPH in control cultures at confluency (0.10-0.14 microM BP, 15.4-23.2 nM NADPH) were less than those for BA-treated cells (0.64 microM BP, 37.9-54.8 nM NADPH) under the same nutritional conditions. The finding that the Km-values for BP is lower in rapidly dividing cells than in confluent cells may help to explain why proliferating cells are more susceptible to transforming agents.

Natural control of larval Anopheles albimanus (Diptera: Culicidae) by the predator Mesocyclops (Copepoda: Cyclopoida).

Forty-two ground water sites on the Pacific and Atlantic coasts of Colombia were sampled quantitatively with a plankton net to assess the abundance of mosquito larvae and associated fauna. Many of the sites contained substantial numbers of Anopheles albimanus Wiedemann larvae, but the larvae were virtually absent wherever there were large populations of the copepods Mesocyclops venezolanus, M. longisetus, or M. aspericornis. Mesocyclops were observed to prey readily upon first-instar An. albimanus larvae in the laboratory, but smaller genera of cyclopoid copepods did not kill An. albimanus larvae. We conclude that Mesocyclops may prove useful for biological control of Anopheles.

Control of larval Aedes aegypti (Diptera: Culicidae) by cyclopoid copepods in peridomestic breeding containers.

Mesocyclops longisetus (Thiébaud), Mesocyclops thermocyclopoides Harada, Mesocyclops venezolanus Dussart, and Macrocyclops albidus (Jurine) were tested for their effectiveness in controlling Aedes aegypti (L.) larvae in a variety of containers around homes in El Progreso, Honduras. All four cyclopoid species killed > 20 larvae per cyclopoid per d under container conditions. M. longisetus was most effective, not only because it was the most voracious predator, but also because it survived best in the containers. M. longisetus maintained long-term populations in 200-liter drums, tires, vases, and cement tanks (without drains), providing the cyclopoids were not dried or poured out. M. longisetus reduced third- and fourth-instar Ae. aegypti larvae by > 98% compared with control containers without cyclopoids. M. longisetus should be of practical value for community-based Ae. aegypti control if appropriate attention is directed to maintaining it in containers after introduction.

Endobronchial Hodgkin's disease.

Endobronchial involvement with Hodgkin's disease has been reported infrequently. A 26-year-old woman with previously diagnosed nodular sclerosing Hodgkin's disease had substernal chest pain and a right middle lobe infiltrate. Fiberoptic bronchoscopy showed nodular endobronchial lesions located at the carina, the right mainstem bronchus, and the right middle lobe orifice. A biopsy specimen of one of these lesions showed Hodgkin's disease. The patient was then treated with sequential systemic chemotherapy. Repeated bronchoscopy showed complete resolution of the endobronchial lesions, and the patient has remained in complete remission for 24 months.

Granulocytic sarcoma (chloroma) initially seen as acute mastoiditis.

Granulocytic sarcoma (chloroma) is a localized tumefaction of immature granulocytes that is typically seen in association with myelogenous leukemia. The primitive cell population seen in biopsy material may be misinterpreted as histiocytic lymphoma or other sarcoma unless additional studies are performed. We saw a 36-year-old woman with promyelocytic leukemia in remission who had the signs and symptoms of an acute coalescent mastoiditis. Histologic examination of the surgical specimen, however, demonstrated a granulocytic sarcoma. Our case exemplifies some of the difficulties that may be encountered in the diagnosis of granulocytic sarcoma and illustrates the point that symptoms of an inflammatory process in a patient with a diagnosis of leukemia must be regarded with a degree of suspicion.

Leukocyte migration inhibition assay in patients with prostate adenocarcinoma.

The leukocyte migration inhibition (LMI) assay was used to determine the cell-mediated immune reactivity of prostate cancer patients to putative tumor antigens present in potassium chloride extracts of surgically removed prostate tumor tissue. Using an extract prepared from prostate tumor tissue, inhibition of leukocyte migration was found more frequently in prostate tumor patients (61%) than in patients with benign prostate hyperplasia (37%), patients with nonprostate cancers (26%), or normal donors (10%). Control extracts prepared from normal prostate tissue, benign prostate hyperplasia tissue, and unrelated tumor tissue were statistically less reactive in the LMI assay than the prostate tumor extract when reacted against leukocytes from prostate tumor patients. These results suggest that the LMI assay might be potentially useful for measuring the tumor-directed, cell-mediated immune responses in patients with prostate cancer.

Immunomodulatory effects of poly(I,C)-LC in cancer patients.

Poly(I,C)-LC was administered in low (1 mg/m2) and intermediate (4 mg/m2) doses to cancer patients by intramuscular injection or intravenous infusion to evaluate the immunomodulatory effects. Natural killer cell (NK) activity was elevated slightly at the low dose and remained unchanged overall, but some depression was observed at the 4 mg/m2 intravenous dose. Monocyte function was elevated in all groups of patients, as was the interferon-induced enzyme 2'5'-oligo-A synthetase. These increases were observed at the 1 mg/m2 intramuscular dose, despite a lack of detectable circulating serum interferon (IFN). In regard to cell surface markers, poly(I,C)-LC induced an increase in OKT10-positive cells and a small but consistent trend toward increases in the ratio of Leu-3/Leu-2-positive cells. Lymphocyte proliferation in response to concanavalin A was depressed by poly(I,C)-LC administration. Although an optimum immunomodulatory dose and schedule was not determined, the data indicate that low doses produce significant changes in immune function and that induction of detectable levels of circulating interferon is not required for poly(I,C)-LC to have biological effects.

Sequential postoperative assessment of left ventricular performance with gated cardiac blood pool imaging following aortocoronary bypass surgery.

The comparative effects of normothermic intermittent ischemic arrest (IIA) and cardioplegia (C) on left ventricular (LV) performance were assessed by gated cardiac blood pool imaging in 57 patients undergoing aortocoronary bypass surgery. In 34 patients, IIA was employed; 23 patients received C. Patients were studied preoperatively, sequentially in the immediate postoperative period at 30-minute intervals, and at 1 week after the operation, C and IIA groups did not differ in mean (+/- SEM) age, anginal class, number of diseased vessels, previous myocardial infarction, or preoperative ejection fraction (EF)(50 +/- 3% vs 50 +/- 2% [p = ns]). Aortic cross clamp time was greater with C than IIA (50 +/- 5 minutes vs 28 +/- 3 minutes [p = 0.001]). During the six sequential postoperative studies, transient LV dysfunction (greater than or equal to 7% decrease in absolute EF) was observed in 10 patients receiving C and in 16 patients receiving IIA. By time of discharge, 24 of 26 patients had returned to preoperative EF. Mean EF at discharge in the cardioplegia group did not differ compared to preoperative EF; in the IIA group, EF increased compared to preoperative EF (50 +/- 2% vs 55 +/- 2% [p < 0.01]). These data suggest that in patients with normal preoperative LV performance both C and IIA afford satisfactory myocardial preservation during aortocoronary bypass surgery.

Left ventricular diastolic performance at rest and during exercise in patients with coronary artery disease. Assessment with first-pass radionuclide angiography.

We used first-pass radionuclide angiocardiography to assess filling fraction during the first third of diastole, peak filling rate and peak filling rate during the first third of diastole as indexes of left ventricular diastolic performance at rest and after upright bicycle exercise in 32 normal patients and 68 patients with coronary artery disease. The mean filling fraction was unchanged from rest to exercise in normal patients (47+/- 15% vs 46 +/- 13%; NS). Even in 49 coronary patients with normal (greater than or equal to 50%) ejection fraction at rest, filling fraction was less than that in normal patients at rest (35 +/- 11% vs 47 +/- 15%, p less than 0.001). Despite similar resting heart rates, patients with coronary disease had lower (p less than 0.001) peak filling rate and peak filling rate during the first third of diastole than normal patients. With exercise, filling fraction decreased (p less than 0.001) from the resting value in coronary patients. These data suggest that (1) indexes of diastolic performance can be noninvasively assessed at rest and during exercise using first-pass radionuclide angiocardiography, (2) abnormalities in early diastolic performance are often present at rest in patients with coronary artery disease despite normal systolic performance, and (3) exercise-induced ischemia results in increased early diastolic dysfunction in patients with coronary disease.