Direct Injection Electrospray Ionization Mass Spectrometry (ESI-MS) Analysis of Proteins with High Matrix Content:Utilizing Taylor-Aris Dispersion

This is the first work demonstrating the utility of the Taylor-Aris (TA) dispersion in avoiding serious interference issues commonly occurring in the electrospray ionization-mass spectrometric (ESI-MS) determination of therapeutic protein pharmaceuticals undergoing no pre-separation or sample purification. It was also pointed out that the TA dispersion conditions and its analytical utilization for proteomics can be easily accomplished in a commercial CE-MS instrument. In the proposed Taylor-Aris dispersion-assisted mass spectrometry (TADA-MS) analysis 0.5 μL sample is injected into a 65 cm long 50 μm i.d. capillary and pumped with 1 bar toward the MS. The procedure is efficient for the direct injection analysis of components having low diffusion coefficients (proteins) that are present in complex matrices of small organic and inorganic compounds.

Assessment of mould remediation in a healthcare setting following extensive flooding

BACKGROUND

A new hospital building was close to completion when a large pipe carrying clean water broke, causing extensive flooding.

AIM

To determine the flood-associated fungal risk to susceptible patients who would use that building.

METHODS

Though standard flood remediation by the builders was relatively straightforward, there was no model for specialist assessment of patient risk due to the flood-associated mould growth. As levels of background airborne fungal spores can be expected to vary significantly over time, we could not use absolute levels to indicate either an excess of airborne fungal spores or successful remediation. Therefore it was decided to use weekly settle plates, exposed at the same time in flooded (test) and equivalent non-flooded (control) areas to compensate for variations in background levels. Flood-related risk was estimated by the ratio between fungal colonies on the test and control sets of settle plates, rather than absolute number.

FINDINGS

Whereas the physical flood remediation, including the use of 'anti-fungal' treatments, was completed in three weeks post flooding, fungal contamination in flooded areas took 38 weeks to return to control levels and remained so for a further six weeks of observation.

CONCLUSION

By the use of this method, we were able to assure the absence of flood-associated fungal risk to susceptible patients who would use that building. We recommend that infection prevention and control teams consider using this approach should they be faced with similar situations.

CZE-MS peptide mapping: To desalt or not to desalt?

BACKGROUND

In "shotgun" approaches involving high-performance liquid chromatography or capillary zone electrophoresis (CZE), matrix removal prior to sample analysis is considered as an indispensable tool. Despite the fact that CZE offers a high tolerance towards salts, most publications reported on the use of desalting. There seems to be no clear consensus on the utilization of desalting in the CZE-MS community, most probably due to the absence of works addressing the comparison of desalted and non-desalted digests. Our aim was to fill this research gap using protein samples of varying complexity in different sample matrices.

RESULTS

First, standard protein digests were analyzed to build the knowledge on the effect of sample clean-up by solid-phase extraction (SPE) pipette tips and the possible stacking phenomena induced by different sample matrices. Desalting led to a somewhat altered peptide profile, the procedure affected mostly the hydrophilic peptides (although not to a devastating extent). Nevertheless, desalting samples allowed remarkable stacking efficiency owing to their low-conductivity sample background, enabling a so-called field-amplified sample stacking phenomenon. Non-desalted samples also produced a stacking event, the mechanism of which is based on transient-isotachophoresis due to the presence of high-mobility ions in the digestion buffer itself. Adding either extra ammonium ions or acetonitrile into the non-desalted digests enhanced the stacking efficiency. A complex sample (yeast cell lysate) was also analyzed with the optimal conditions, which yielded similar tendencies.

SIGNIFICANCE

Based on these results, we propose that sample clean-up in the bottom-up sample preparation process prior to CZE-MS analysis can be omitted. The preclusion of desalting can even enhance detection sensitivity, separation efficiency or sequence coverage.

Comparative study on the deamidation of three recombinant human insulins using capillary electrophoresis

The applicability of capillary zone electrophoresis (CZE) for the separation of different recombinant human insulins and their deamidated isoforms was studied. The high resolving power of CZE is demonstrated by its ability to separate insulin isoforms differing only by 0.984 Da (different-fold deamidated forms) and even components having the exacts same mass but slightly different shapes (same-fold deamidated forms). From among the several insulins available, humulin, glargine and glulisine were selected for our study because their sequences and chemical parameters are quite similar, however, the small differences present in their amino acid sequences influence the deamidation processes. Using a background electrolyte with basic pH was favourable not only for the separation of the different types of insulin but also for the separation of deamidated protein forms even in a bare fused silica capillary. The LOD values ranged between 0.6 - 0.93 mg/L and 2.17 - 4.37 mg/L for UV and ESI-MS detection, respectively. At -20 - -80 °C, the deamidation is minimal, but at temperatures above +5 °C deamidation is accelerated. At +5 °C only 1-fold deamidation forms could be observed for each insulin. Acidified samples incubated for 1-month at room temperature showed varying levels of deamidation: 1-fold, 1-2-fold and 1-2-3-fold forms for glargine, glulisine and humulin, respectively.

Recombinant Expression in Pichia pastoris System of Three Potent Kv1.3 Channel Blockers: Vm24, Anuroctoxin, and Ts6

The Kv1.3 channel has become a therapeutic target for the treatment of various diseases. Several Kv1.3 channel blockers have been characterized from scorpion venom; however, extensive studies require amounts of toxin that cannot be readily obtained directly from venoms. The Pichia pastoris expression system provides a cost-effective approach to overcoming the limitations of chemical synthesis and E. coli recombinant expression. In this work, we developed an efficient system for the production of three potent Kv1.3 channel blockers from different scorpion venoms: Vm24, AnTx, and Ts6. Using the Pichia system, these toxins could be obtained in sufficient quantities (Vm24 1.6 mg/L, AnTx 46 mg/L, and Ts6 7.5 mg/L) to characterize their biological activity. A comparison was made between the activity of tagged and untagged recombinant peptides. Tagged Vm24 and untagged AnTx are nearly equivalent to native toxins in blocking Kv1.3 (Kd = 4.4 pM and Kd = 0.72 nM, respectively), whereas untagged Ts6 exhibits a 53-fold increase in Kd (Kd = 29.1 nM) as compared to the native peptide. The approach described here provides a method that can be optimized for toxin production to develop more selective and effective Kv1.3 blockers with therapeutic potential.

Determination of human insulin and its six therapeutic analogues by capillary electrophoresis - mass spectrometry

In this work, human insulin and its 6 analogues were separated and determined using CZE-MS. Three different capillaries (bare fused silica, successive multiple ionic-polymer layer (SMIL) and static linear polyacrylamide (LPA) coated) were compared based on their separation performances in their optimal operating conditions. Coated capillaries demonstrated slightly better separation of the components, although some components showed wide, distorted peaks. The highest plate number could be obtained in the SMIL capillary (192 000/m). For UV and ESI-MS detection relatively similar LOD values were obtained (0.3-1.2 mg/L and 1.0-3.4 mg/L, respectively). The application of MS detection provided useful structural information and unambiguous identification for insulins having similar or the same molecular mass. This work is considered to be important not only for the investigation of insulins but also for its potential contribution to the top-down analysis of proteins using CE-MS.

Study of the geometry of open channels in a layer-bed-type microfluidic immobilized enzyme reactor

This paper aims at studying open channel geometries in a layer-bed-type immobilized enzyme reactor with computer-aided simulations. The main properties of these reactors are their simple channel pattern, simple immobilization procedure, regenerability, and disposability; all these features make these devices one of the simplest yet efficient enzymatic microreactors. The high surface-to-volume ratio of the reactor was achieved using narrow (25–75 μm wide) channels. The simulation demonstrated that curves support the mixing of solutions in the channel even in strong laminar flow conditions; thus, it is worth including several curves in the channel system. In the three different designs of microreactor proposed, the lengths of the channels were identical, but in two reactors, the liquid flow was split to 8 or 32 parallel streams at the inlet of the reactor. Despite their overall higher volumetric flow rate, the split-flow structures are advantageous due to the increased contact time. Saliva samples were used to test the efficiencies of the digestions in the microreactors.

Analysis of intact proteins with capillary zone electrophoresis coupled to mass spectromery using uncoated and coated capillaries

Although, in general, the application of coated capillaries is recommended for the separation of intact proteins, bare silica capillary is still the most often used capillary due to its simplicity and cheapness. In this work, the performance of bare fused silica capillary for intact protein analysis was compared to that of different (dynamically coated polybrene (PB) and permanently coated linear polyacrylamide (LPA)) coated capillaries using capillary zone electrophoresis - mass spectrometry (CZE-MS). In cases where low pH (pH=1.8) was used in bare silica capillaries, good precision (0.56-0.78 RSD% and 1.7-6.5 RSD% for migration times and peak areas, respectively), minimal adsorption and separation efficiency (N= 27 000/m - 322 000/m) similar to or even better than those obtained with the coated capillaries (created by an intricate multi-step process) was achieved. The PB and the LPA capillaries demonstrated their slightly better resolving power in terms of separating the different forms/variants of the same protein (e.g., hemoglobin subunits). Among the studied capillaries the one with LPA coating showed the most stable separations in the long term (n=25: 0.18-0.49 RSD% and 3.1-4.9 RSD% for migration times and peak areas, respectively). For the separation of a few proteins or even a larger number of proteins in biological samples (e.g., snake venom) the application of the simple and cheap bare fused silica capillary can be considered as an efficient choice.

Baseline diet of an urban carnivore on an expanding range front

For the past 200 years, coyotes have steadily expanded their range eastward from the Midwestern USA. They have successfully colonized the contiguous landscape east of the Mississippi River and have been documented on Long Island, New York since 2009 with successful breeding confirmed in 2016. Occupying a diverse array of habitat types along the way, they are now commonplace in many urban and suburban landscapes as well. Using 149 scats and 13 stomachs collected from 2009 to 2017 and analyzed by traditional scat analysis methods, we described the diet of coyotes found in the New York City. The most common prey items, as a percentage of scats, were rodents (35.2%), birds (27.7%), followed by anthropogenic items (26.4%). These results were similar when compared to that of seven other urban centers in North America.

Fabrication of immobilized enzyme reactors with pillar arrays into polydimethylsiloxane microchip

This paper demonstrates the design, efficiency and applicability of a simple and inexpensive microfluidic immobilized enzymatic reactor (IMER) for rapid protein digestion. The high surface-to-volume ratio (S/V) of the reactor was achieved by forming pillars in the channel. It was found that pillar arrays including dimensions of 40 μm × 40 μm as pillar diameter and interpillar distance can provide both relatively high S/V and flow rate in the PDMS chip, the fabrication of which was performed by means of soft lithography using average research laboratory infrastructure. CZE peptide maps of IMER-based digestions were compared to peptide maps obtained from standard in-solution digestion of proteins. The peak patterns of the electropherograms and the identified proteins were similar, however, digestion with the IMER requires less than 10 min, while in-solution digestion takes 16 h.

Sleep quality is associated with vasopressin methylation in pregnant and postpartum women with a history of psychosocial stress

BACKGROUND

The relationship between disturbed sleep and stress is well-documented. Sleep disorders and stress are highly prevalent during the perinatal period, and both are known to contribute to a number of adverse maternal and foetal outcomes. Arginine vasopressin (AVP) is a hormone and a neuropeptide that is involved in stress response, social bonding and circadian regulation of the sleep-wake cycle. Whether the AVP system is involved in regulation of stress response and sleep quality in the context of the perinatal mental health is currently unknown. The objective of the present study was to assess the relationship between levels of cumulative and ongoing psychosocial risk, levels of disordered sleep and AVP methylation in a community sample of pregnant and postpartum women.

METHODS

A sample of 316 participants completed a battery of questionnaires during the second trimester of pregnancy (PN2, 12-14 weeks gestation), third trimester (PN3, 32-34 weeks gestation), and at 7-9 weeks postpartum (PP). Disordered sleep was measured using the Sleep Symptom Checklist at PN2, PN3 and PP; cumulative psychosocial risk was assessed with the Antenatal Risk Questionnaire (ANRQ) at PN2; salivary DNA was collected at the follow-up (FU, 2.9 years postpartum); and % methylation were calculated for AVP and for two of the three AVP receptor genes (AVPR1a and AVPR1b). Women were separated into high (HighPR) and low (LowPR) psychosocial risk groups, based on their scores on the ANRQ.

RESULTS

Women in the HighPR group had significantly worse sleep disturbances during PN2 (p < .001) and PN3 (p < .001), but not at PP (p = .146) than women in the LowPR group. In HighPR participants only, methylation of AVP at intron 1 negatively correlated with sleep disturbances at PN2 (r_s=-.390, p = .001), PN3 (r_s=-.384, p = .002) and at PP (r_s= -.269, p = .032). There was no association between sleep disturbances and AVPR1a or AVPR1b methylation, or between sleep disturbances and any of the AVP methylation for the LowPR group. Lastly, cumulative psychosocial stress was a moderator for the relationship between AVP intron 1 methylation and disordered sleep at PN2 (p < .001, adjusted R² = .105), PN2 (p < .001, adjusted R² = .088) and PP (p = .003, adjusted R² = .064).

CONCLUSIONS

Our results suggest that cumulative psychosocial stress exacerbates sleep disorders in pregnant women, and that salivary DNA methylation patterns of the AVP gene may be seen as a marker of biological predisposition to stress and sleep reactivity during the perinatal period. Further research is needed to establish causal links between AVP methylation, sleep and stress.

Crystal chemistry of the 4,4'-dimethyl-2,2'bipyridine/copper bromide system

The reaction of 4,4'-dimethyl-2,2-bipyridine (henceforth dmbp) with copper(I) and/or copper(II) bromide under a wide variety of conditions has led to the isolation of 10 different crystalline materials. These include one Cu(I) salt, [Cu(dmbp)(2)]Br (a distorted tetrahedral Cu species and a lattice Br(-) ion); two mixed valence Cu(I,II) compounds, [Cu(dmbp)(2)Br][CuBr(2)] (discrete 5-coordinated Cu(II) and linear Cu(I) species) and Cu(dmbp)(2)BrCu(2)Br(3) (linked 5-coordinate Cu(II) and trigonal planar Cu(I) species); and seven Cu(II) compounds, (dmbp)CuBr(2) (stacked planar monomers), [(dmbp)CuBr(2)](2)(five coordinate bibridged dimers), (dmbp)Cu(2)Br(4) (stacked planar bibridged dimers), (dmbp)CuBr(2)(DMSO) (five coordinate monomers), [Cu(dmbp)(2)Br]OH.5(1)/(2)H(2)O and [Cu(dmbp)(2)Br](Br/OH).5(1)/(2)H(2)O (five coordinate monomers), and (dmbpH(2))CuBr(4).H(2)O (distorted tetrahedral monomers). The crystal structure determinations of these materials are reported. A common thread in their structural chemistry is the supramolecular architecture developed through interdigitation of the dmbp rings on neighboring molecular species. The interdigitation leads to layer structures in many of the materials. The distances between the interdigitated dmbp rings are in the range 3.4-3.7 A. The Cu(dmbp)(2)Br(+) species exhibits an exceptionally large distortion from tetrahedral geometry due to deviation of the dihedral angle between the mean planes of the Cu(dmbp) fragments from 90 degrees. The Cu(dmbp)(2)Br(+) cations have distorted trigonal bipyramidal geometry, the Br(-) ion occupying an equatorial position. The length of the Cu-Br bond in the Cu(dmbp)(2)Br(+) species is correlated with the change in dihedral angle between the planes of the two dmbp ligands. The mono-dmbp complexes show a greater variation in coordination geometry for the Cu(II) species, including distorted trigonal bipyramidal and augmented square planar 4 + 1 and 4 + 2 coordination.

[Osteoporosis in anorexia nervosa. New aspects of pathogenesis and therapy]

Osteoporosis has been shown to be a relatively common complication of anorexia nervosa (AN). So far the exact mechanisms which are implicated are not fully clarified. Several factors such as malnutrition, reduced body weight, amenorrhea, and hypercortisolaemia seem to be involved. There is a strong relationship with the duration of amenorrhea and--in some studies--with the age of onset. Osteoporosis is for a long time a "silent" disease and the first symptoms such as back pain, loss of height, kyphosis, and fractures are late complications. Therefore, routine screening methods for bone density measurements should be established. The most accurate is the dual energy X-ray absorptiometry (DEXA). Therapeutically the primary aim should be to reach restoration of both normal body weight and regular menses. As AN is a chronic disease clinicians should be aware of the dangers of osteoporosis and start with the treatment and/or prevention of osteoporosis early. However, at this stage it is difficult to provide an evidence-based management plan for osteoporosis in AN. Hormone replacement therapy (HRT) as well as calcium and vitamin D-supplementation are under discussion, however, further controlled investigations are warranted.

Osteopenia in anorexia nervosa: specific mechanisms of bone loss

Osteopenia is a well recognized medical complication of anorexia nervosa (AN). The mechanism of bone loss is not fully understood and there is uncertainty about its management. New markers of bone turnover have been developed. C-terminal type 1 propeptide (PICP) is a measure of bone formation and urinary pyridinolines such as deoxypyridinoline (DPYRX) and serum carboxyterminal crosslinked telopeptide (ICTP) are markers of bone resorption. The aim of this study was to examine these bone markers in patients with AN. Twenty female patients with AN and 12 healthy controls were included in the study. Bone mineral density (BMD) of AN patients was measured by dual energy X-ray absorptiometry (DEXA). Lumbar bone density was significantly reduced in the AN group compared to standardised values of thirty year old adults (t-score 83.2%, S.D. 12.1). Femoral neck bone density showed an even greater reduction (t-score 79.4%, S.D. 13.5). We found a significant negative correlation between femoral BMD and the duration of the illness. Femoral BMD correlated significantly with minimal body weight (r(16) = 0.504, p = 0.033). The markers of bone resorption were significantly higher in the patients with AN compared to the values of the control group (ICTP t(30) = -2.15, p = 0.04, DPYRX t(25) = -2.26, p = 0.033), whereas the markers of bone formation did not differ significantly between the groups. AN appears to be a low turn over state associated with increased bone resorption without concomitant bone formation. This pattern differs from osteopenia in menopausal women and should, therefore, lead to the development of specific therapeutic strategies in AN associated osteopenia. Hormone replacement therapy as well as calcium and vitamine D-supplementation are so far discussed controversially. Long-term treatment studies are warranted.

Outcome of IVF in patients with endometriosis in comparison with tubal-factor infertility

PURPOSE

The aim of this retrospective study was to compare the outcome of in vitro fertilization and embryo transfer in women with endometriosis and a control group with tubal-factor infertility.

METHODS

Forty-eight patients with endometriosis underwent 65 cycles of in vitro fertilization and embryo transfer at Huddinge University Hospital. The matched control group with tubal-factor infertility consisted of 98 cycles in 98 patients. These groups were retrospectively analyzed regarding stimulation, fertilization, embryo development, implantation, and pregnancy outcome.

RESULTS

The fertilization rate was significantly lower in women with endometriosis, but the cleavage, implantation, and pregnancy rates did not differ.

CONCLUSIONS

Our results show that women with endometriosis have a lower fertilization rate compared with women with tubal-factor infertility. However, once the oocyte is fertilized, it seems that the preembryo has a normal chance of implantation, leading to similar pregnancy rates.

Albumin affects erythrocyte aggregation and sedimentation

Erythrocyte aggregation and sedimentation is determined by the concentration of high molecular plasma proteins such as fibrinogen and immunoglobulins. The role of albumin, the most abundant plasma protein, is controversial. We analysed the influence of human albumin (0-80 g L-1) on sedimentation behaviour of erythrocytes suspended (haematocrit 35%) in fibrinogen-enriched normal plasma, plasma from patients with hypoalbuminaemia, solutions of dextran 70 in buffer, and mixtures of fibrinogen, immunoglobulins and albumin in buffer. Sedimentation was measured by the Westergren method, viscometry was performed at low and high shear rate. The addition of albumin to normal plasma, hypoalbuminaemic plasma, or dextran solutions in buffer decreased the erythrocyte sedimentation rate. In contrast, in a mixture of fibrinogen and immunoglobulins in buffer, albumin increased erythrocyte sedimentation. When either fibrinogen or immunoglobulins were omitted, or fibrinogen was replaced by dextran, albumin did not increase sedimentation, which indicates that increased sedimentation was due to an interaction of all three compounds. The viscosity of erythrocyte suspensions was increased by albumin. It is concluded that the influence of albumin on erythrocyte aggregation is complex and depends on the technique used; low shear viscosity is increased, but erythrocyte sedimentation, i.e. under no flow conditions, is decreased. The inhibitory action of albumin on the erythrocyte sedimentation rate has clinical implications and must be known by physicians. It may help to interpret sedimentation rates more correctly and prevent misinterpreting presumed therapeutic successes or failures.

Testicular cancer

Although testicular cancer accounts for approximately 1% of all male malignancies, it has a significant impact on the social, economic, and emotional status of the young population in which it occurs. TSE is the best available tool for early detection of testicular cancer. Only 15 to 20 years ago, testicular cancer was often fatal because of the rapidity of metastasis to the lungs and other vital organs. Because of progress in surgical technique and chemotherapy, it is today one of the most curable cancers. The use of serum markers and early diagnosis and treatment are of great importance in the management of testicular cancer.

Phase III double-blind comparison of intravenous ondansetron and metoclopramide as antiemetic therapy for patients receiving multiple-day cisplatin-based chemotherapy

BACKGROUND

Ondansetron hydrochloride is a selective serotonin subtype 3 (5HT3) receptor antagonist that has been shown to be an effective antiemetic in patients receiving cisplatin chemotherapy.

METHODS

This double-blind study compared the safety and efficacy of intravenous ondansetron with metoclopramide in patients receiving a 4- or 5-day regimen of cisplatin (20-40 mg/m2/day) combination chemotherapy. Forty-five patients were enrolled, and efficacy of the drug therapy could be studied for all 45. Patients were randomly assigned (1:1) to receive three daily intravenous doses of either 0.15 mg/kg ondansetron or 1 mg/kg metoclopramide. All patients were monitored daily for the number of emetic episodes (vomiting or retching), severity of nausea, adverse events, and laboratory safety parameters.

RESULTS

Seven (30%) patients who received ondansetron had no emetic episodes throughout the entire study period compared with two (9%) who received metoclopramide (P = 0.077). The greatest difference in antiemetic efficacy was seen on day 1, when 18 (78%) patients who received ondansetron had no emetic episodes compared with 3 (14%) patients who received metoclopramide (P < 0.001). Significantly fewer antiemetic treatment failures (more than five emetic episodes or withdrawal from the study) occurred with patients given ondansetron (9%) than with those given metoclopramide (50%) during the entire study period (P = 0.002). The most commonly reported adverse event associated with ondansetron therapy was headache (controlled with acetaminophen), whereas diarrhea and restlessness were the most commonly reported adverse events associated with metoclopramide therapy. Extrapyramidal symptoms were judged to have occurred in 13 patients who received metoclopramide and 1 patient who received ondansetron. However, the patient who received ondansetron subsequently was judged to have had an anxiety attack. In patients with low or normal baseline transaminase values, a greater percentage who received ondansetron had transient increases as great as twice the upper limit of normal in aspartate transaminase (5% versus 0%) and alanine transaminase (17% versus 6%) than those who received metoclopramide.

CONCLUSIONS

Ondansetron is superior to metoclopramide as antiemetic therapy for multiple-day cisplatin-based chemotherapy.

Sclerosis multiplex in gypsies

MS rarely occurs in gypsies in Hungary despite the high DR2 frequency. When it does occur, it has special features more resembling that of Asians than Central Europeans. In order to find correlation between the clinical observations and the immunogenetical data, the distribution of DQw1 subtypes was investigated by means of Eco RV - DQ beta RFLP in DR2 positive healthy gypsies and Hungarians, as well asin DR2-positive Hungarian and unselected gypsy MS patients. DQw6 correlated with MS susceptibility in Hungarians. This allotype was completely absent in healthy DR2-positive gypsies. DR2-positive gypsy MS patients, however, carried DQw6. No correlation of complement allotypes with the occurrence of MS was found in Hungarians, while a striking elevation of C4 Q0 occurred in gypsy MS patients compared with healthy individuals in the gypsy group. The absence of the DR2, DW2, DQw6 haplotype, and the frequency of C4A Q0 in healthy gypsies seems to be associated with the low MS prevalence, but genes outside this region might also influence the MS susceptibility.

Experimental autoimmune neuropathy with anti-GM1 antibodies and immunoglobulin deposits at the nodes of Ranvier

Antibodies to GM1 or Gal(beta 1-3)GalNAc are associated with motor or sensorimotor neuropathy and with motor neuron disease. To investigate the role of these antibodies in the neurological disorder, rabbits were immunized with GM1 or with Gal(beta 1-3)GalNAc-BSA, and studied serologically, electrophysiologically and pathologically. Development of antibodies to the immunizing antigens was associated with a fall in the ratio of the amplitudes of the compound muscle action potential evoked by proximal versus distal stimulation of the sciatic nerve. Pathological studies revealed mild axonal degeneration and immunoglobulin deposits at the nodes of Ranvier in peripheral nerve, resembling those reported in a patient with motor neuropathy, motor conduction block and anti-GM1 antibodies. These studies provide evidence that anti-GM1 or anti-Gal(beta 1-3)GalNAc antibodies cause conduction abnormalities and indicate that the antibodies may exert their effect, in part, by binding at the nodes of Ranvier in peripheral nerve.

Ondansetron: a new antiemetic for patients receiving cisplatin chemotherapy

GR 38032F (ondansetron) is a selective serotonin subtype-3 receptor antagonist with reported antiemetic efficacy in patients receiving cisplatin. This study evaluated the safety and efficacy of ondansetron in three consecutive nonrandomized groups of patients who were receiving a 4- or 5-day regimen of cisplatin (20 to 40 mg/m2/d) combination chemotherapy. Thirty-six patients were enrolled. Thirty-five patients were assessable for efficacy. All patients received three daily intravenous doses of 0.15 mg/kg of ondansetron. Twenty-four patients had received no prior chemotherapy. Twelve of these received ondansetron every 2 hours and 12 received ondansetron every 6 hours. Twelve additional patients who had received at least one prior course of chemotherapy were administered ondansetron every 6 hours. All patients were monitored for emetic episodes (vomiting or retching), adverse events, and laboratory safety parameters. Ten patients (29%) had no vomiting or retching throughout the entire study period and 18 patients (51%) experienced two or fewer emetic episodes during the entire study period. The greatest antiemetic efficacy was on day 1 when 27 patients (77%) had no emesis. The chemotherapy-naive patients responded better than the nonnaive patients on all study days. Reported adverse events were minor, with the most common possibly drug-related event being headache (14% of patients). No extrapyramidal symptoms were observed. Transient increases in total SGOT, and SGPT were observed in some patients.

Neuropsychologic and CT examinations in leukemic patients surviving 10 or more years

Long-term survivors of childhood leukemia were studied to determine their neuropsychologic status. All had had cranial irradiation 10 or more years before. The results were 1. The IQ and academic performance of 56 cured leukemic patients show no significant difference from the normal population. 2. More exact neuropsychological tests (attention, reaction time, visual-motor coordination, memory) reveal important deficits. 3. The frequency of CT aberrations in 33 study patients was 45% and showed no correlation with either the IQ or other neuropsychological results.

[Neurologic tests in children having recovered from leukemia]

56 long-term survivors of childhood ALL have been investigated with CT and neuro-psychological methods. At the CT examination we found that 45.4% of the cured patients had alterations. Short-term memory, attention, visual-motor coordination and IQ were found to be slightly impaired in this group. Nevertheless they didn't influence the social integration and educational achievement of long-term survivors of ALL.

Ifosfamide: a clinical review

Although ifosfamide first underwent clinical trials 15 years ago, it has largely been ignored by the American oncology community until the last few years. Earlier concerns about dose-limiting hemorrhagic cystitis have been mitigated by the development of effective urothelial protectors such as mesna. Furthermore, ifosfamide is not completely cross-resistant with cyclophosphamide. Ifosfamide has activity in a variety of disseminated refractory solid tumors that do not traditionally respond to conventional alkylating agent therapy, specifically refractory germ cell tumors, soft tissue sarcomas, and malignant lymphomas. The decreased myelosuppression and lack of apparent cross-resistance compared with cyclophosphamide make ifosfamide an ideal drug for inclusion in combination chemotherapy. While clarification of the differences between ifosfamide and cyclophosphamide is ongoing, ifosfamide may eventually replace cyclophosphamide in conventional combination chemotherapy regimens for a variety of solid tumors. At present, it has clear-cut major activity in refractory germ cell tumors and has become an integral component of a curative salvage regimen.

Nabilone: an effective antiemetic in patients receiving cancer chemotherapy

Eighty evaluable patients receiving chemotherapy were entered on a random prospective double-blind study to evaluate the effectiveness of nabilone, a synthetic cannabinoid, compared to prochlorperazine. Most of these patients received cisplatin, a drug that universally produces severe nausea and vomiting, as part of a combination chemotherapy regimen. The patients served as their own controls, receiving either nabilone or prochlorperazine during two consecutive treatment courses with the identical chemotherapy. Side effects consisting of hypotension and lethargy were more pronounced with nabilone. Toxicity, in general, did not preclude antiemetic treatment and in no way interfered with chemotherapy. Sixty patients (75 per cent) reported nabilone to be more effective than prochlorperazine for relief of nausea and vomiting. Of these 60 patients, 46 required further chemotherapy and continued taking nabilone as the antiemetic of choice.

Follow-up study of 281 schizophrenic patients treated with high dosage fluphenazine decanoate

281 newly admitted female schizophrenic patients were treated with high dosage fluphenazine decanoate intramuscularly, starting with 250 mg per injection together with antiparkinsonian and antidepressant drugs. On a set day the 3 groups 'with neuroleptics' (NL) (n = 54), 'without NL' (n = 152) and 'relapsed when without NL' (n = 42) were compared concerning age, diagnosis, hereditary disposition, first admission and readmissions, number of admissions and global judgement. From the differences no clear conclusion for practical clinical work could be obtained. The good tolerance is discussed using the list of side effects including tardive dyskinesia and laboratory data.

Superiority of nabilone over prochlorperazine as an antiemetic in patients receiving cancer chemotherapy

Two double-blind, crossover trials comparing the antiemetic effectiveness of nabilone, a new synthetic cannabinoid, with that of prochlorperazine were conducted in patients with severe nausea and vomiting associated with anticancer chemotherapy. Of 113 patients evaluated, 90 (80 per cent) responded to nabilone therapy, whereas only 36 (32 per cent) responded to prochlorperazine (P less than 0.001). Complete relief of symptoms was infrequent, occurring only in nine patients (8 per cent) given nabilone. When both drugs were compared, both nausea (P less than 0.01) and vomiting episodes (P less than 0.001) were significantly lower in patients given nabilone. Moreover, patients clearly favored nabilone for continued use (P less than 0.001). Predominant side effects noted by patients were similar for both agents and included somnolence, dry mouth and dizziness but were about twice as frequent and more often severe in patients receiving nabilone. In addition, four patients (3 per cent) taking nabilone had side effects (hallucinations in three, hypotension in one) that required medical attention. Euphoria associated with nabilone was infrequent (16 per cent) and mild.