Cytotoxicity of (2,2':6',2'-terpyridine)platinum(II) complexes to Leishmania donovani, Trypanosoma cruzi, and Trypanosoma brucei

A range of (2,2':6',2'-terpyridine)platinum(II) complexes are shown to possess antiprotozoal activity in vitro against Leishmania donovani, Trypanosoma cruzi, and Trypanosoma brucei,the causative organisms of tropical diseases leishmaniasis and trypanosomiasis. The best compounds caused 100% and 78% inhibition of growth of the intracellular amastigote forms of L. donovani and T. cruzi, respectively, at a concentration of 1 microM and 100% inhibition of growth of the bloodstream trypomastigote forms of T. brucei at a concentration of 0.03 microM. The results obtained with complexes in which the fourth ligand to platinum(II) is capable of being substituted with a substitution inert hydroxyethanethiolate complex are compared. The ammine complexes show high antiprotozoal activity suggesting that the trans influence of the 2,2':6',2'-terpyridine ligand has a profound effect on the ease of displacement of the fourth ligand in (2,2':6',2' -terpyridine)platinum(II) complexes, although nonbonded interaction between the ammine ligand and the 6 and 6' ' hydrogens probably also weakens the ligation to Pt(II).     

Prognostic significance of DNA ploidy in Ta/Tl bladder cancer: A southwest oncology group study

While 80% of transitional cell carcinomas (TCC) present as Ta Tl lesions, they account for only 15% of deaths caused by TCC. We have evaluated the ability of DNA ploidy analysis to predict outcome in 228 patients with Ta Tl TCC. All patients were judged to be at increased risk for tumor recurrence due to having two occurrences of Stage TI tumor within 56 weeks, or three or more tumors presenting simultaneously within 16 weeks of registration. Concurrent carcinoma in situ was acceptable. All patients were treated with either bacillus Calmette Guerin (BCG) immunotherapy or mitomycin-C (MMC) intravesical chemotherapy. Patients with nondiploid tumors had higher hazard rates for both tumor progression and death (p = 0.007 and p = 0.016, respectively); however, the prognostic information of DNA ploidy was not additive to tumor grade.     

Anomalous kinetic visual fields found in family members of patients with a confirmed diagnosis of Gilles de la Tourette syndrome.

Three visual manifestations of Gilles de la Tourette syndrome (TS), a neuropsychiatric disorder, have been previously reported. In this paper we report anomalies in the measured kinetic paracentral visual field of TS patients and their family members. We found that 96% of TS patients exhibited paracentral kinetic visual field defects (nasal and temporal steps, enlargement, "ringing," and/or baring of the blind spot). Ninety-three percent of fathers of TS children and, surprisingly, about 80% of mothers exhibit these characteristic visual field anomalies. Sample data and examples of family studies are reported.     

Structural studies on tazobactam.

Tazobactam (3, C10H12N4O5S) is an effective inhibitor of bacterial beta-lactamases. It crystallizes with unit cell dimensions a = 10.230 (2) A, b = 14.396 (2) A, and c = 17.291 (2) A in space group P2(1)2(1)2(1). Compared to the related inhibitor sulbactam (2), which lacks the triazole ring, crystalline tazobactam exhibits very similar beta-lactam geometry and the same S(1) envelope conformation of the thiazolidine ring. However, in both independent molecules of 3 a triazole ring nitrogen atom accepts an intermolecular hydrogen bond; similar interaction by this moiety of 3 with a hydrogen-bond donor on the enzyme, which is impossible for 2, could account for its enhanced inhibitory power. Semiempirical molecular orbital calculations show pronounced negative potential there. Molecular mechanics supports the hypothesis that the carboxyl group can rotate freely and the triazole ring can "flip".     

Flow cytometric measurement of cell components other than DNA: virtues, limitations, and applications in gynecologic oncology.

Flow cytometry is a high-precision technique for rapid analysis and sorting of cells and particles. In theory, it can be used to measure any cell constituent, provided that a fluorescent tracer is available that reacts specifically and stoichiometrically with that constituent. The technique provides statistical accuracy, reproducibility, and sensitivity and allows simultaneous measurement of several constituents on a cell-to-cell basis. The main drawback of flow cytometry is the lack of visual control and structural information in solid tissues. Careful sample preparation, quality control of all staining and instrumentation procedures, and the use of immunohistologic or cytologic controls are essential for high-quality flow cytometric analysis. The technique has been used successfully for simultaneous measurement of DNA and tumor-associated antigens, oncogene products, proliferation markers, and markers for multidrug resistance in cultured cell lines and in cell suspensions prepared from solid tumors and cervical smears. Flow cytometry has the potential to play an important role in the study of carcinogenesis. With an appropriate panel of monoclonal antibodies, the technique can be used for screening, "biochemical" diagnosis of neoplasia, and rapid drug, hormone, and radiotherapy sensitivity tests.     

Eggshell modifications in captive American kestrels resulting from aroclor® 1248 in the diet

American kestrels (Falco sparverius) were fed diets containing 3 g/g Aroclor^® 1 1248 or control diets from mid-January until July. Eggs were removed from first clutches 2 to 4 days after laying ceased and shell thickness and shell dimensions were measured. Contents of the third egg of each clutch, the carcasses of all adults that received Aroclor^® 1248 and of three males and three females that received the control diet were analyzed for DDE, Aroclors^® 1248, 1254 and 1260, and dieldrin. Concentrations of PCBs, DDE and dieldrin were significantly higher (P < 0.03) in eggs and carcasses from treated adults than in controls. Shell thickness and shell thickness index of eggs from treated adults were reduced 5.0% (P < 0.0001) and 4.8% (P < 0.0001), respectively, from those of controls.     

Features of structural brain abnormality detected in first-episode psychosis

OBJECTIVE: Structural magnetic resonance imaging (MRI) studies that focus on first-episode psychosis avoid some common confounds, such as chronicity of illness, treatment effects, and long-term substance abuse. However, such studies may select subjects with poor short-term treatment response or outcome. In this study, the authors focus on structural brain abnormalities in never or minimally treated patients who underwent MRI scanning early in their first episode of psychosis. METHOD: The authors examined 37 patients (13 medication naive, 24 previously treated) who were experiencing their first episode of psychosis; the mean duration of symptoms was short (31 weeks). These patients were comparable in age, gender, handedness, ethnicity, and parental socioeconomic status to a group of 25 healthy comparison subjects. A three-dimensional, inversion recovery prepared, fast spoiled gradient/recall in the steady state scan of the whole brain that used 1.5-mm contiguous sections was performed to acquire a T(1)-weighted data set. Human ratings of volumetric measurement of brain structures were performed with stereological techniques on three-dimensional reconstructed MRIs. RESULTS: The patient group had significant deficits in cortical gray matter, temporal lobe gray matter, and whole brain volume as well as significant enlargement of the lateral and third ventricles. Structural deviations were found in both treatment-naive and minimally treated subjects. No relationships were found between any brain matter volumes and positive or negative symptoms. CONCLUSIONS: Structural brain abnormalities were distributed throughout the cortex with particular decrement evident in gray matter. This feature is consistent with altered cell structure and disturbed neuronal connectivity, which accounts for the functional abnormality of psychosis.     

Parents' and patients' preferences and concerns in idiopathic adolescent scoliosis: a cross-sectional preoperative analysis

STUDY DESIGN: A multicenter cross-sectional study of parents' and patient's concerns and preferences regarding surgery for idiopathic scoliosis. OBJECTIVES: The purpose of this study was to analyze independently both the parents' and patients' assessments of upcoming surgery for idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: No group has recently reported querying patients and their parents regarding expectations, preferences, reasons, and concerns about and for surgical treatment of adolescent idiopathic scoliosis. METHODS: Ninety-one sets of parents and patients were separately asked to complete questionnaires regarding the patients' upcoming idiopathic scoliosis surgery. Patients' ages ranged from 9 to 18 years, and data were collected from four centers and seven surgeons (all active members of the Scoliosis Research Society) from April through December 1998. Thirty-nine questions covered concerns (n = 6), reasons for surgery (n = 14), expectations (n = 9), assessment of life as is (n = 5), and scar preference (n = 5). RESULTS: The greatest concern about the surgery expressed by both parents and patients was neurologic deficit. The least concern for both was location and appearance of the scar. The highest expectation and main reason for having the surgery was to reduce future pain and disability as an adult. Families would be either somewhat or very dissatisfied to spend the rest of life "as is." CONCLUSION: Although parents and patients had similar ratings and concerns, the parents' concerns were higher, and expectations were greater than the patients'.     

Metabolism-based inactivation of neuronal nitric-oxide synthase by components of cigarette and cigarette smoke.

It has been shown that administration of cigarette smoke to rats leads to loss of neuronal nitric-oxide synthase (nNOS) activity and nNOS protein in penile tissue. The exact mechanism for this loss of activity and protein is not known. In the current study, we investigated whether extracts prepared from cigarette smoke or from the cigarette itself could directly inhibit nNOS activity. We discovered that the cigarette smoke extract and the cigarette extract cause a time-, concentration-, and calmodulin-dependent inactivation of nNOS in an in vitro system containing the purified enzyme. L-Arginine, but not D-arginine, protects nNOS from this time-dependent inactivation, suggesting an active site directed event. The kinetics of inactivation are consistent with the metabolism-based or suicide inactivation of nNOS. Based on studies with other metabolism-based inactivators, this cigarette-mediated inactivation may render nNOS more susceptible to proteasomal degradation and thereby may explain the loss of nNOS protein in vivo. The component(s) responsible for nNOS inactivation is not volatile, is not retained by a 3,000 molecular weight cut-off membrane, binds to activated charcoal, and is highly water-soluble under both acidic and basic conditions. The discovery of a direct inactivation of nNOS by an organic, cationic compound(s) present in tobacco and tobacco smoke provides a basis for further study of not only the mechanisms responsible for the biological effects of tobacco but also a search for a potentially novel inactivator of nNOS.     

Syncope after effort

A 29-year-old man developed recurrent syncope following exertion. Cardiac investigations revealed no evidence of structural heart disease, but during exercise testing, in the recovery phase, he sustained a bradycardia and then asystole for a prolonged period. Before cardiac massage could be instituted a tonic-clonic fit occurred, and this initiated a return to sinus rhythm. His symptoms were abolished following the implantation of a dual-chamber pacemaker.