Spectrum of Glomerular Diseases in Adults: A Study from North Eastern India.

AIMS AND OBJECTIVES: To study the clinical profile of patients with glomerular diseases and to study pattern of glomerular diseases in adults. METHODOLOGY: A hospital based retrospective observational study from North Eastern India that includes biopsy proven glomerular disease (GD) in adults. Patients with inadequate biopsy sampling; incomplete medical data and biopsy of transplanted kidney were excluded. RESULTS AND OBSERVATIONS: A total of 102 patients were included of which 25 (24.5%) were male and 77(75.5%) were female with M: F ratio of 0.32:1. The mean age of presentation was 30.6 years. Nephrotic syndrome (57.8%) was the commonest clinical diagnosis followed by acute nephritic syndrome (31.4%), unexplained AKI (5.9%), unexplained CKD with normal kidney size (2.9%) and asymptomatic urine abnormality (1.9%). On histo-pathological analysis primary GD and secondary GD was diagnosed in 46(45.1%) and 53(52.0%) respectively. Overall Lupus nephritis (LN) was found to be the commonest (41.2%) GD. Among the primary GD, MCD (11.8%) was the most frequent followed by MPGN (10.8%), Membranous Nephropathy, (5.8%), IgA nephropathy (5.8%) and Focal segmental glomerulosclerosis (5.8%). Three (2.9%) patients did not have any specific diagnosis and were labelled as chronic glomerulo- nephritis.. CONCLUSIONS: As the pattern of glomerular disease varies from one region to another, the pattern of glomerular disease in the north eastern India also varies from the other regions of India. Nephrotic syndrome remains the most common indication of renal biopsy in this region similar to the other parts of India. Unlike other studies from outside North Eastern India, this study show that females are more commonly involved with majority of them having secondary GD and this is due to LN which was diagnosed as the most common GD in the present study.

Scrub typhus meningoencephalitis, a diagnostic challenge for clinicians: A hospital based study from North-East India.

UNLABELLED: Central nervous system (CNS) involvement is a known complication of scrub typhus which range from mild meningitis to frank meninigoencephalitis. AIMS AND OBJECTIVES: To study the clinical feature, laboratory parameters and response to treatment of scrub typhus meningitis/meningoencephalitis. METHODS AND MATERIALS: This is a hospital based prospective observational study from North Eastern India. Diagnosis was based on clinical features and positive serological test (Weil's Felix test and IgM antibody card test). RESULTS: 13 patients of scrub typhus with features of meningitis/meningoencephalitis were included. The mean duration of fever before presentation was 5.61±3.08 days and 4 (30.76 %) patients had eschar. Altered sensorium, headache, seizure and meningeal sign were present in 13 (100%), 13 (100%), 6 (46.15%) and 10 (76.92%) patients respectively. Mean CSF protein, glucose and Adenosine deaminase was 152.16±16.88mg/dl, 55.23±21.7mg/dl, and 16.98±7.37U/L respectively. Mean total count of CSF leukocyte and lymphocyte percentage was 46.07±131 cell/cumm and 98.66±3.09% respectively. Tablet doxycycline with or without injection azithromycin was used and that shows good response 15.38% of patients died and all of them had multi organ dysfunction. CONCLUSION: Meningoencephalitis is a common manifestation of scrub typhus and diagnosis requires high degree of clinical suspicion which if diagnosed early and specific treatment started, patients usually recover completely with few complications.

Chemical reaction-induced multi-molecular polarization (CRIMP).

Here we present a novel hyperpolarization method, Chemical Reaction-Induced Multi-molecular Polarization (CRIMP), which could be applied to the study of several in vivo processes simultaneously including glycolysis, TCA cycle, fatty acid synthesis and pH mapping. Through the use of non-enzymatic decarboxylation, we generate four hyperpolarized imaging agents from hyperpolarized 1,2-(13)C pyruvic acid.

Observation of standing waves of electron-hole sound in a photoexcited semiconductor.

Three-dimensional multicomponent plasmas composed of species with very different masses support a new branch of charge-density fluctuations known as acoustic plasmons. Here, we report on an ultrafast optical method to generate and probe coherent states of acoustic plasmons in a slab of GaAs, which relies on strong photoexcitation to create a large population of light electrons and heavy holes. Consistent with the random-phase-approximation theory, the data reveal standing plasma waves confined to these slabs, similar to those of conventional sound but with associated velocities that are significantly larger.

In vivo magnetic resonance imaging of hyperpolarized silicon particles.

Silicon-based micro- and nanoparticles have gained popularity in a wide range of biomedical applications due to their biocompatibility and biodegradability in vivo, as well as their flexible surface chemistry, which allows drug loading, functionalization and targeting. Here, we report direct in vivo imaging of hyperpolarized (29)Si nuclei in silicon particles by magnetic resonance imaging. Natural physical properties of silicon provide surface electronic states for dynamic nuclear polarization, extremely long depolarization times, insensitivity to the in vivo environment or particle tumbling, and surfaces favourable for functionalization. Potential applications to gastrointestinal, intravascular and tumour perfusion imaging at subpicomolar concentrations are presented. These results demonstrate a new background-free imaging modality applicable to a range of inexpensive, readily available and biocompatible silicon particles.

Multidrug-resistant Enterobacteriaceae including metallo-ß-lactamase producers are predominant pathogens of healthcare-associated infections in an Indian teaching hospital.

PURPOSE: A study was carried out in an Indian teaching hospital in 2009 to detect the rate of surgical site infections (SSI) and peripheral vascular access site infections. MATERIALS AND METHODS: The study was a point-prevalence study involving over 300 patients. The presence of infection was determined according to the CDC criteria. Swabs were taken from the infected sites and identification and sensitivity were carried out using VITEK® 2 automated system. Characterisation of ß-lactamase was carried out at ARRML, Colindale, London. RESULTS: The rate of SSI was 15% for the clean and clean-contaminated categories while that for the dirty contaminated category was 85% (NNIS risk index 0). Cultures yielded definite or probable pathogens from 64% (9/14) of the patients with SSI. In 1/3 rd of the cultures, Staphylococcus aureus was grown and the rest had Enterobacteriaceae, either extended-spectrum ß-lactamase (ESBL) producers or Amp-C hyperproducers and, alarmingly, three isolates were positive for newly recognised New Delhi metallo-ß-lactamase-1 (NDM-1). In medicine, 87% (n = 99) of the patients had a peripheral IV access device, 55% developed associated phlebitis/infection and, in seven, probable pathogens were isolated (Candida species and Escherichia coli producing ESBL and NDM-1, respectively, Staphylococcus aureus and Enterococcus faecium). All ESBL and metallo-ß-lactamase producers were resistant to multiple classes of antimicrobials, the latter being sensitive only to colistin and tigecycline. The study also found that all post-operative patients were on antibiotics, 92% on IV [213 defined daily doses (DDD)/100 post-op patients] limited mainly to the third-generation cephalosporins (26%) and aminoglycosides (24%) and imidazole derivatives (30%). In medicine, 83% (n = 82) were on IV antibiotics (123 DDD/100 bed-days), limited mainly to the third-generation cephalosporins (74%). CONCLUSION: Indiscriminate use of antibiotics is a major problem predisposing patients to harm by multi-resistant pathogens. Carbapenems were in little use in this hospital, but the selection pressure exerted by cephalosporins and other unrelated classes was sufficient to select NDM-1-producing strains due to co-selection, suggesting a role of single plasmid carrying resistance genes to multiple classes.

Raman coherence beats from entangled polarization eigenstates in InAs quantum dots.

The homodyne-detected transient four-wave-mixing response of InAs/GaAs self-assembled quantum dots shows temporal oscillations of the optically induced Raman coherence arising from two entangled polarization eigenstates of the exciton. The phase sensitive nature of the homodyne detection enables us to follow the time evolution of the nonradiative quantum coherence between the polarization states, providing a measurement of the fine-structure splitting in the dots, which is much less than the inhomogeneous broadening, and the corresponding decoherence rate of the entangled state.

Influence of intervening mismatches on long-range guanine oxidation in DNA duplexes.

A systematic investigation of the efficiency of oxidative damage at guanine residues through long-range charge transport was carried out as a function of intervening base mismatches. A series of DNA oligonucleotides were synthesized that incorporate a ruthenium intercalator linked covalently to the 5' terminus of one strand and containing two 5'-GG-3' sites in the complementary strand. Single base mismatches were introduced between the two guanine doublet steps, and the efficiency of transport through the mismatches was determined through measurements of the ratio of oxidative damage at the guanine doublets distal versus proximal to the intercalated ruthenium oxidant. Differing relative extents of guanine oxidation were observed for the different mismatches. The damage ratio of oxidation at the distal versus proximal site for the duplexes containing different mismatches varies in the order GC approximately GG approximately GT approximately GA > AA > CC approximately TT approximately CA approximately CT. For all assemblies, damage found with the Delta-Ru diastereomer was found to be greater than with the Lambda-diastereomer. The extent of distal/proximal guanine oxidation in different mismatch-containing duplexes was compared with the helical stability of the duplexes, electrochemical data for intercalator reduction on different mismatch-containing DNA films, and base-pair lifetimes for oligomers containing the different mismatches derived from 1H NMR measurements of the imino proton exchange rates. While a clear correlation is evident both with helix stability and electrochemical data monitoring reduction of an intercalator through DNA films, damage ratios correlate most closely with base-pair lifetimes. Competitive hole trapping at the mismatch site does not appear to be a key factor governing the efficiency of transport through the mismatch. These results underscore the importance of base dynamics in modulating long-range charge transport through the DNA base-pair stack.

Nuclear (DNA, RNA, histone and non-histone protein) and nucleolar changes during growth and senescence of may apple leaves.

Quantitative interference microscopy was used to determine changes in nuclear and nucleolar indices (dry mass and cross-sectional area) in upper and lower epidermal cells and adjacent leaf-margin hair cells of the May apple (Podophyllum peltatum L.) leaves over a 42-day period (after leaves emerged above the ground litter). These indices decreased in a highly correlated manner. A ploidy variation may exist between epidermal cells and leaf-margin hair cells. Using the leaf-margin hair cells model, six nuclear macromolecule indices (total nucleic acid, DNA, RNA, total nuclear protein, histone and non-histone protein), nuclear volume, nucleolar volume and perinucleolar volume (measured using quantitative epifluorescence-phase contrast microscopy) all declined with age (42-day study) in a highly correlated manner. The degeneration of the nucleus and nucleolus in the three leaf locations studied followed the patterns observed for programmed cellular senescence and death (necrosis) in epidermal cells of onion leaf bases (stored tissue; leaf bases did not contain chlorophyll) and human epithelial cells (buccal; cervical). We conclude that the epidermal cells and leaf-margin hair cells from green leaves of the May Apple are ideal for the study of programmed cell senescence and death in plants, especially for the partitioning of this process into the study of: the point-of-no-return (solubilization of the karyoskeleton and loss of non-histone proteins and RNA associated with the karyoskeleton from the nucleus); nuclear pycnosis (loss of nuclear dry mass and volume and loss of nuclear internal support structure); chromatin condensation, margination along the inner nuclear envelope; and DNA-histone degeneration; degeneration of the nucleolus and loss of the perinucleolar zone of exclusion. The characterization of chlorenchyma cells during the 42-day period should now be undertaken (leaf senescence as indicated by the beginning of yellowing about 35 days after emergence) to determine whether these cells with functional chloroplasts undergo nuclear changes like those lacking functional chloroplasts.

Nuclear degeneration in epidermal cells of drying onion bulb leaf bases.

We tested the null hypothesis 'that activated nuclei and nucleoli in outer-epidermal cells of newly exposed equatorial tissue of the turgid leaf bases of white onions (exposed to the ambient atmosphere by removal of two dry and two turgid leaf bases) remained in that state as the tissue dried' by following nuclear macromolecules (total nucleic acid, DNA, RNA, total protein, histone, and non-histone protein; compared with T0 = 100%) and nucleolar morphologies over a 5-day period. The nuclei became activated within 6 h and remained in that state for 2-3 days [increases in RNA, non-histone protein, and volume of major nucleoli occurred by T12 (about 191, 177, and 289%, respectively) and appearance of the minor nucleoli between T12 and T24 (activation of silent rRNA cistrons)]. Combined nucleolar (major and minor) volumes decreased to 228% by T24 and to 150% by T48. Minor nucleoli were visible at T24 and T48. DNA (DAPI) remained unchanged over that period of time. At the T96 sampling, all nuclear indices had decreased to levels below those obtained at the time of exposure to the ambient atmosphere; minor rRNA cistrons had became silent genes; nuclear volume was about 89% of the original volume; and, nucleolar volume (major nucleoli) was about 93%. The percentages for nuclear indices at T120 were DNA, 85% of T0; RNA, 35%; histone, 87%; non-histone protein, 47%; nuclear volume, 81%; and nucleolar volume, 67%. Of interest is the lack of change in major nucleolar morphologies between T96 and T120 although they decreased in volume during that period. We infer that the karyoskeleton (nuclear matrix) had undergone irreversible degeneration after T48 and that the cells had passed the point-of-no-return in the senescence pathway by T120. We propose that this model for cell senescence and death (drying of turgid leaf bases to form the dry, dead outer covering of the bulbs) simulates post-harvest storage conditions and will prove helpful to those studying cellular senescence mechanisms and associated host-pathogen interactions in plants.

Biological microemulsions V: mutual mixing of oils, amphiphiles and water in ternary and quaternary combinations.

The mixing behaviour of plant oils (ricebran, saffola and clove) with water in presence of amphiphiles (Triton X-100, Tween-60, Aerosol OT, Igepal, Na-oleate, ethanol and cinnamic alcohol) in various ternary and quaternary combinations has been studied. The phase behaviour at different mass proportions and temperature has been investigated in the absence and presence of additives such as NaCl, glucose, urea and cholesterol. Of all the combinations studied, those with ethanol plus sodium oleate as amphiphile have shown maximum extent of single phase microemulsion formation. The presence of urea in the aqueous medium has further increased the monophasic extent whereas NaCl has decreased it. Cholesterol in oil and glucose in water have apparently shown inert effects. The effects of the additives on the formation of biphasic or triphasic formulations, on the other hand, have been found to be distinct and well-dependent on [H2O]/[amphiphile] mole ratio and temperature. Spectral measurements of I3- in the aqueous micropool in microemulsion of clove oil/(ethanol + Na-oleate)/water have shown the microenvironment to be physicochemically different from bulk water.

Myocardial perfusion in new-onset angina patients with single vessel disease.

The aim of this study was to investigate myocardial perfusion of the left ventricle during stress (exercise scintigraphy with thallium-201) in 25 patients having new-onset angina (NA) with single-vessel disease. In 14 cases (56%) the lumen of the vessel was obstructed by more than 75% and in 6 cases (24%) it was totally occluded. Angiographically visible collaterals to the occluded arteries from other vessels were present in all these cases. All of the patients studied had some form of myocardial perfusion disturbance. In 13 patients (52%) perfusion defects were limited to distribution within the obstructed artery; the other 9 patients (36%) had defects in the pool of the intact artery with or without defects in the pool of the obstructed artery. In the 4 patients (44.4%) having a totally occluded artery, perfusion defects were observed only in the pool of the intact artery supplying the collaterals, while in 5 patients (55.6%) perfusion defects were found both in the pool of the intact artery supplying the collaterals as well as in the obstructed vessel. We conclude that in patients with NA, stress dependent perfusion defects are present not only in the pool of the obstructed artery but also in the intact artery supplying the collaterals. This point to the possible presence of 'steal' syndrome in these patients.

Biological microemulsions: Part IV--Phase behaviour and dynamics of microemulsions prepared with vegetable oils mixed with aerosol-OT, cinnamic alcohol and water.

Microemulsification of vegetable oils (ricebran, saffola, soyabean, sesame, palm and linseed) with water using aerosol-OT and cinnamic alcohol as mixed amphiphiles was studied. The biological microemulsions formed covered on the average approximately 27% of single phase area in the triangular phase diagram. The multiphasic zone for saffola was studied in detail, two- and three-phase zones were identified with patches of thick gel. The effect of temperature on the multiphase formation in the range 29-55 degrees C was also studied. The formation of multiphase and their proportions found to depend on the type of oil. The biological microemulsions at reasonable water/AOT mole ratio showed moderate increase in conductance with temperature. The viscosity of the microemulsions was high. Of the studied systems (sesame, saffola and ricebran) the viscosity of the first two decreased with the rate of shear whereas that of ricebran increased. When cinnamic alcohol was used as the oil, the trend of viscosity was similar to that of sesame and saffola.

Changes in nuclear macromolecules and nucleolar volume associated with selective ribosomal cistron activation by ethylene.

Pieces of leaf base tissue from the equatorial region of the third turgid onion (Allium cepa L.; yellow, sweet Spanish, quiescent tissue) leaf base with two visible major nucleoli (volume = 0.51 microns3) and two inactive minor nucleolar organizer regions (NORs) in the outer epidermal cells were placed in shallow water (time = T0 control). After 3 h (T3 control), the two visible nucleoli enlarged (178% of T0) and changed shape (from 88% round and 12% oval at T0 to 5% round, 68% oval, 20% elongated-oval, and 7% dumbbell). The minor NORs remained inactive. Nuclear RNA and non-histone protein (nHP) increased (RNA = 128% and nHP = 134%, compared with T0 data, set at 100%). The content of DNA and histone protein (H) in nuclei remained unchanged. Major nucleoli in pieces of onion placed in 10(-5) M ethylene enlarged and minor nucleoli became visible in 33% of the nuclei; i.e., ethylene acted as a selective ribosomal cistron regulator. The nucleolar volume (212% of T0) was statistically greater than those for T0 and T3. DNA and H remained unchanged (not statistically different) but RNA (159% of T0) and nHP (169% of T0) were greater (statistically significant) than those for T0 and T3 controls. Cobalt chloride (10(-5) M Co) alone or in 10(-5) M ethylene (Co + E) inhibited the enlargement of some of the major nucleoli and completely inhibited the appearance of minor nucleoli. The nucleolar volumes for the cobalt and for cobalt-ethylene treatments were significantly less than those for T3 controls and ethylene treatment at T3. DNA and histone did not change.(ABSTRACT TRUNCATED AT 250 WORDS)

Experimental visceral leishmaniasis: role of trans-aconitic acid in combined chemotherapy.

We previously reported the effectiveness of trans-aconitic acid (TAA) as an antileishmanial compound. Inhibitory effects of TAA along with other antileishmanial compounds on transformation and in vitro multiplication in macrophage cultures of Leishmania donovani have been assessed. The efficacy of TAA in combined chemotherapy of experimental visceral leishmaniasis has also been evaluated along with those of commonly used antileishmanial compounds such as sodium stibogluconate, pentamidine, and allopurinol. TAA (2 mM) inhibited transformation of L. donovani amastigotes to promastigotes by 95.2%, whereas in combination with pentamidine (5 micrograms/ml), allopurinol (10 micrograms/ml), and sodium stibogluconate (50 micrograms of Sb per ml), it inhibited transformation by about 100, 99, and 98.5%, respectively. Sodium stibogluconate (20 micrograms of Sb per ml), pentamidine (2 micrograms/ml), and allopurinol (5 micrograms/ml) suppressed the amastigote burden in peritoneal macrophage cultures from BALB/c mice by 32.6, 56.1, and 46.3%, respectively. When these three drugs were used along with TAA (5 mM), the parasite loads were reduced by 100, 100, and 88.1%, respectively. TAA (5 mM) alone suppressed the amastigote burden by 59.5%. In experimental visceral leishmaniasis in hamsters (1-month model), TAA at a dose of 200 mg/kg of body weight per day suppressed the spleen parasite load by 73.5%, and TAA in combination with sodium stibogluconate (50 mg of Sb per kg per day), pentamidine (8 mg/kg/day), and allopurinol (15 mg/kg/day) inhibited the spleen parasite load by 98, 98.9, and 97%, respectively. Individually, these three drugs inhibited the parasite load by 35, 20, and 22%, respectively. TAA (400 mg/kg/day) inhibited the spleen parasite load by 99.8%, but an inhibitory effect of approximately 100% was noted when TAA was supplemented with an antileishmanial drug. TAA was administered in experimental animals through oral, intraperitoneal, and intramuscular routes; the intramuscular route was most effective.

Perinatal mortality in caesarean section: a disturbing picture of unfulfilled expectations.

Indications for caesarean section had been studied in a 2-year period and the incidences were compared to that of the same 15 years back. Though there are more incidences of caesarean section, still perinatal death is a major concern to all. The study included a total of 291 perinatal deaths of which there were 208 early neonatal deaths and 83 stillbirths over a period of 2 years from January, 1990 to December, 1991. Caesarean section is being increasingly performed for foetal interest, but this study reveals that perinatal mortality is still high though cesarean section rate has increased in recent times.

PIP: In India, obstetricians compared cesarean section rates at Eden Hospital of the Medical College in Calcutta between 1990-1991 and 1976-1978 to examine cesarean section-associated perinatal mortality. During 1990-1991, there were a total of 291 perinatal deaths (208 early neonatal deaths and 83 fetal deaths) for a perinatal mortality rate of 89.6/1000 total births. Cesarean section rates increased for almost all indications between 1976-1978 and 1990-1991, except repeat cesarean sections antepartum hemorrhage, and malpresentation. Between the 2 periods, perinatal mortality increased despite the increase in cesarean sections. Most stillbirths (67.5%) were a result of antepartum hemorrhage, while most neonatal deaths (53.4%) were a result of nonprogress of labor. Yet, between the 2 periods, the use of cesarean section for nonprogress of labor almost doubled (9.7-17.5%). 25% of early neonatal deaths occurred among elective cesarean section cases. 10 of these infants weighed less than 2 kg. Asphyxia brought on by prematurity was responsible for many perinatal deaths. These findings suggested that the increase in cesarean sections did not improve perinatal deaths.

Clinical course and left ventricular function in patients with acute myocardial infarction following delayed recanalization of infarct-related artery.

The effect of delayed recanalisation of the infarct related artery on clinical course and left ventricular functions was studied in 23 patients with acute myocardial infarction (Group 2). Another 82 patients with acute myocardial infarction served as controls: 48 patients with immediate recanalisation of the infarct related artery following intracoronary thrombolytic therapy (Group 1) and 34 patients with unsuccessful thrombolysis with the artery remaining occluded on repeat angiography (Group 3). Baseline clinical characteristics and left ventricular ejection fractions in the three groups did not differ statistically. Following intracoronary thrombolysis the clinical features and left ventricular functions in the three groups, respectively were as follows: post infarction angina--45.8%, 13.1% and 11.8% (1 vs. 2 and 3, P < 0.05); reinfarction--29.2%, 8.7% and 11.8% (1 vs. 2 and 3, P < 0.05); mortality--0%, 0% and 11.8% (1 and 2 vs. 3; P < 0.05); aneurysm--16.7%, 21.7% and 52.9% (1 and 2 vs. 3, P < 0.05); heart failure--20.8%, 21.7% and 47.1% (1 and 2 vs. 3, P < 0.05). Left ventricular ejection fractions on the second and on days 10-14 were, respectively, 47.6 +/- 1.1%, 42.8 +/- 1.1% and 39.2 +/- 1.6% (1 vs. 2 and 3, P < 0.05) and --52.1 +/- 1.0%, 48.9 +/- 1.1% and 44.3 +/- 1.5% (1 and 2 vs. 3, P < 0.05). Thus following delayed recanalisation of the infarct related artery the clinical course and left ventricular function improved significantly in comparison to patients without recanalisation.

Temperature invariance of quantum well modulators using a feedback circuit based on the quantum confined Stark effect.

We report the design and performance characteristics of a voltage feedback circuit which can rapidly compensate for the temperature-dependent shift of the excitonic peak energy positions in quantum confined Stark effect modulators. The energy position remains invariant over a temperature shift of 10 degrees . The circuit is simple and can be operated with a single device or an array of modulators.

Evaluation of antileishmanial activity of trans-aconitic acid.

TAA, an inhibitor of the enzyme aconitase, inhibits the growth of L. donovani promastigotes. Morphogenic transformation of the amastigote to the promastigote (table; see text) form in vitro was also inhibited by 2 mM TAA. TAA also reduced multiplication of the parasite in macrophage culture. In the hamster model of leishmania, TAA significantly reduced the parasitic burden of liver. In acute toxicity tests with BALB/c mice no deaths were recorded even at a dose level of 2 g/kg body wt/day.

Thermodynamics of water-induced precipitation of cholesterol and its acetate, benzoate and stearate derivatives dissolved in 1,4-dioxane and 2-propanol.

The energetics of the precipitation process depended on the solute-solvent combination and the enthalpy and entropy of precipitation compensated each other. The partial molal volumes of the lipids in both the solvents were greater than the anhydrous molar volumes, except for cholesterol in 1,4-dioxane and cholesteryl acetate in 2-propanol where the order was reverse. While the partial molal compressibilities of all the solutes studied were negative in 1,4-dioxane, those of cholesterol and cholesteryl acetate in 2-propanol were, respectively, negative and positive. The negative values were supported by considerable solvation of the solutes, particularly in 1,4-dioxane.