Haemorrhagic cystitis in bone marrow transplantation patients: possible increased risk associated with prior busulphan therapy

Following bone marrow transplantation employing conditioning including 'high-dose' cyclophosphamide, 65 patients were studied for the subsequent development of symptomatic haemorrhagic cystitis. There was no protection from the urothelial toxicity of cyclophosphamide metabolites afforded by the concurrent administration of 2-mercaptoethane sodium sulphonate (mesna) if timing errors in administration were made. Other factors which might increase the risk of haemorrhagic cystitis due to cyclophosphamide administration include the prior administration of busulphan to patients with chronic granulocytic leukaemia, in whom the incidence of haemorrhagic cystitis was 36% compared with 4% in all other patients. We have also investigated the use of intravesical prostaglandin E2 as a treatment for haemorrhagic cystitis in eight patients, two of whom appeared to obtain major benefit.

Calcified renal masses

A review of the literature and the University of Kentucky Medical Center/Lexington Veterans Administration Medical Center experience regarding calcification of renal masses was undertaken. Twenty per cent of calcified renal masses cannot be easily characterized by CT scan as malignant or benign and are indeterminate. These lesions must be followed closely with follow-up CT scanning or undergo surgical exploration, as 40 per cent may be malignant.

MR relaxation times of cerebrospinal fluid

A review of 15 recent publications purporting to provide the relaxation times of CSF reveals a considerable disparity in the quoted results, by a factor of five in terms of T1 (range 1,000 to 5,500 ms) and by a factor of 16 for T2 (range 166 to 2,640 ms). In this article measurements are performed independently on both a spectrometer and an imager. The results indicate that for CSF T1 is greater than 3,000 ms and T2 is approximately 2,000 ms at 6 MHz. The vast differences in relaxation behaviour between CSF and other body tissues have considerable clinical implications and present profound diagnostic opportunities. The application of this knowledge to ventriculography, myelography, and image contrast methodology is discussed.

Translational requirement of La Crosse virus S-mRNA synthesis: in vitro studies

The exceptional requirement of La Crosse virus mRNA synthesis for ongoing protein synthesis in vivo was examined in vitro by using purified virions and a reticulocyte lysate. Transcription from the S genome produced two incomplete transcripts (110 and 205 nucleotides [nt]) in the absence of the lysate, whereas S-mRNA (900 nt) was predominantly made when the lysate was present. The addition of drugs which inhibit protein synthesis also inhibited the synthesis of S-mRNA, and in some cases led to the reappearance of the 205-nt RNA. Reconstruction experiments demonstrated that the incomplete transcripts were not the result of rapid and selective degradation of S-mRNA but were due to premature termination of the polymerase at defined sites. The requirement for ongoing protein synthesis for productive transcription in vitro is not at the level of chain initiation but for elongation of the nascent RNA beyond these sites.

Human cranial CSF volumes measured by MRI: sex and age influences

Accurate measurements of CSF volumes would assist in the diagnosis of several important neurological conditions. Using Magnetic Resonance Imaging (MRI) we have devised a method to measure both total intracranial CSF volume and ventricular volume. This initial study, in normal humans, provides an answer to two longstanding questions: first, do these volumes differ between the sexes; second, do both total and ventricular CSF volumes increase with normal aging? We found that the total cranial CSF volume and skull size of males were significantly greater than those of females, but that there was not a statistically significant difference between the ventricular volumes of the sexes. Total cranial CSF volume increased steeply with age in both sexes but although there was an increase in ventricular volume with age in males, no significant increase with age could be demonstrated in females.

Accuracy of stereotaxic localisation using MRI and CT

The accuracy of stereotaxic coordinates determined using the Leksell apparatus with CT and MRI was investigated using an Agar filled head phantom. Both imaging techniques were found to produce an accuracy of better than 2 mm with the exception of the Z coordinate as measured by CT (2.3 mm). This latter error is greater because of the 3 mm slice width used. Direct coronal views were used to determine Z more accurately using MRI. The measurement procedures are described and it is shown that the Leksell system of using orthogonal coordinates enables the scaling of images, which is particularly necessary with MRI, to be done easily.

Digital mapping of multi-parameter contrast functions in magnetic resonance (MR) imaging using a standard MR computer system and digital display

A technique is described which utilises the full analysis and display capabilities of a commercial MRI system to produce digital maps of multi-parameter functions produced by MR contrast theory. The technique is utilised to determine the effects of nominating specific overall scan times on the optimum solutions as produced by the theory and it is shown that different solutions are obtained when the theory is applied using typical clinical constraints. The digital mapping approach is potentially of great value in prospectively determining pulse timing parameters to produce optimum contrast images, in producing contrast maps to aid retrospective image interpretation, and as a training aid for clinicians inexperienced in the interpretation MR images.

Recovery of immunoglobulin isotypes following T-cell depleted allogeneic bone marrow transplantation

After conventional bone marrow transplantation serum IgG, IgM and IgA levels fall from pre-transplant levels and may not return to normal for 3-12 months. In contrast IgE may rise to supranormal levels, an event that may be associated with graft-versus-host disease. We have investigated the recovery of immunoglobulin isotypes in the recipients of allogeneic marrows depleted of T-cells to prevent graft-versus-host disease. We find that pre-transplant IgG, IgM and IgA levels are maintained throughout the post-transplant period but that there is a short-lived rise in IgE about 3 weeks after transplantation: this rise occurs in the absence of clinically detectable graft-versus-host disease. We conclude that specific T-cell depletion does not impair and may actually enhance the functional recovery of B cells after allogeneic BMT.

Standardization of T-cell depletion in HLA matched bone marrow transplantation

The IBM 2991 Blood Cell Processor has been used to isolate a mononuclear cell (MNC) fraction from the marrow of 31 allogeneic donors. The MNC fraction was then incubated with a combination of two murine monoclonal antibodies MBG6 (CD6) and RFT8 (CD8) followed by two rounds of treatment with rabbit complement resulting in a marrow inoculum significantly reduced in the number of T-lymphocytes. We report here new specifications for the use of Ficoll-Metrizoate, the method used to calculate T-lymphocyte depletion and the details of our attempts to improve T-depletion. Following marrow transplantation with this T-depleted fraction, 29 patients are evaluable for engraftment, one patient failed to engraft and one died too early for evaluation. Twenty-two had no acute graft-versus-host disease (aGvHD), at a minimum of 60 d, six had grade I acute GvHD and one grade III. No correlation was found between the absolute number of MNC infused and time to engraftment, nor any relationship between the number of residual viable T-lymphocytes in the infused marrow and the incidence of GvHD, but the patient with the most severe aGvHD also had the highest number of T-lymphocytes infused.

The contribution of large granular lymphocytes to B cell activation and differentiation after T-cell-depleted allogeneic bone marrow transplantation

Immunoglobulin and specific antibody levels are well maintained in the recipients of T-cell-depleted allogeneic bone marrow transplants (BMT), even though up to 99% of mature T cells are removed from the donor graft. For 3-8 weeks after the procedure, natural killer (NK) cells with an activated pattern of target cell killing have been shown to circulate in the recipient. This study investigates whether these recipient NK cells spontaneously secrete lymphokines that modulate B cell function in a way analogous to that of in-vitro-activated NK cells from normal individuals. Large granular lymphocytes (LGLs) (which contain a high proportion of NK cells) have been prepared from the peripheral blood of 11 recipients of T-cell-depleted major-histocompatibility-complex-matched allografts. In the first 4-6 weeks after BMT these LGLs were found spontaneously to secrete interleukin 2, interferon gamma and B cell differentiation factor. While secretion of these factors declines by 20-24 weeks after BMT, the quantities are still greater than those seen from control donors. Patient LGLs are also able to activate autologous (donor) B cells, rendering them potentially responsive to the secreted factors. It appears likely that activated NK cells (or LGL) play a significant role in maintaining B cell function in vivo after T-cell-depleted BMT.

A quantitative index of ventricular and extraventricular intracranial CSF volumes using MR imaging

A new technique is described that utilises a novel magnetic resonance pulse sequence to produce a quantitative index both for ventricular and, for the first time, extraventricular intracranial CSF volumes. The pulse sequence is a combination of a null-point inversion recovery sequence with an extended spin-echo read (echo time = 400 ms), which produces a contrast of CSF to white or grey matter of approximately 120:1. A series of experiments are performed on phantoms representing CSF filled ventricles and sulci over a wide range of volume values, and it is found that the standard deviation of differences between true and estimated values is 3.9% for ventricles, 4.6% for total cranial CSF, and 7.9% for CSF within the sulci. Normal volunteer reproducibility studies revealed corresponding standard deviations of less than 5.5%. Using the technique to produce absolute estimates of CSF volumes in normal subjects and patients produced results in good agreement with previously published necropsy studies. The technique has wide neurological and neurosurgical applicability particularly in terms of differential diagnosis and as an objective monitor of therapy or progression in conditions such as hydrocephalus, atrophy, and benign intracranial hypertension.

Use of magnetic resonance imaging to measure intracranial cerebrospinal fluid volume

Magnetic resonance imaging was used to measure intracranial extraventricular and ventricular cerebrospinal fluid (CSF) volume. In 10 normal subjects lateral ventricular and extraventricular intracranial CSF volumes were 25.3 +/- 4.6 ml (mean +/- SD) and 97.6 +/- 6.6 ml, respectively (total 122.8 +/- 38.7). These volumes were measured in 4 patients and the results were: 11.0 ml ventricular volume, 68.7 ml total cranial CSF in the patient with benign intracranial hypertension; 606.6 ml ventricular, 174.1 ml total in the patient with hydrocephalus due to a blocked ventriculo-peritoneal (V-P) shunt; 83.4 ml ventricular, 108.5 ml total in the patient with normal pressure hydrocephalus; and 52.7 ml ventricular, 181.0 ml total in the patient with cerebral atrophy due to Alzheimer's disease. The technique gave highly reproducible results (SD less than 5.7% of mean value). It may be useful in differential diagnosis and as an objective means of monitoring therapy or progress in conditions such as cerebral atrophy, hydrocephalus, and benign intracranial hypertension.

Graft rejection following HLA matched T-lymphocyte depleted bone marrow transplantation

Bone marrow graft rejection following HLA-matched bone marrow transplantation (BMT) for leukaemia has been a rare problem. However, with the introduction of T-lymphocyte depleted BMT, graft rejection is recognized as a new complication. At the Royal Free Hospital (RFH) in London T-depletion is achieved using two monoclonal antibodies with complement mediated lysis. The methodology was extended to other centres and in total 56 patients have received T-depleted, HLA matched BMT. Twelve of 56 patients have had graft rejection. At the RFH three of 41 (7%) patients have had rejection whereas at collaborating centres nine of 15 (60%) patients have had rejection. We have investigated these rejections in order to identify factor(s) responsible. Rejection was not restricted by patient or donor characteristics, nor disease status. Patient management, chemotherapy conditioning, efficiency of T-depletion, graft versus host disease (GvHD), and infection post BMT, were not consistently implicated. The major difference between the RFH and all other centres was in the radiotherapy (RT) conditioning: The RFH prescribed a single fraction of 7.5 Gy total body irradiation (TBI) whilst collaborating centres gave 10 or 12 Gy fractionated TBI. We conclude that the different incidence of rejection (7% v. 60%) relates primarily to the RT conditioning although the mechanisms(s) of rejection remain unknown. We conclude that where T-depleted BMT is used, compensation by more intensive RT conditioning is required in order to avert graft rejection.

La Crosse virus small genome mRNA is made in the cytoplasm

The cellular site of La Crosse virus S genome mRNA synthesis was examined by pulse-labeling infected cells for various times and determining the amount of labeled S mRNA in both the cytoplasmic and nuclear fractions. With pulse times as short as 3 min, La Crosse virus S genome transcription was found to be localized in the cytoplasm.

The application of prolonged electroencephalographic monitoring and video recording to the diagnosis of epilepsy

This study reports the results of the application of intensive monitoring by electroencephalogram (EEG) combined with video recording as an aid to the diagnosis of epilepsy. A group of 622 patients was investigated; useful information was obtained in approximately 50% of these patients. Ten per cent of the patients with suspected epilepsy had a seizure during the period of recording. The combined analysis of the video recording and the EEG provided valuable evidence in the analysis of complex partial seizures and highlights the high prevalence of pseudoseizures in patients who are suspected of having epilepsy.

Natural killer cell activity following T-cell depleted allogeneic bone marrow transplantation

We have examined the recovery of natural killer (NK) cell function in seven recipients of MHC matched T cell depleted bone marrow allografts. NK cell activity against the erythroblastoid line K562 recovers 2-3 weeks after transplantation. Recipients also show a high level of killing of the T cell target HSB2 and of EBV transformed lymphoblastoid cell lines (B-LCL). This activity peaks at 4-6 weeks and declines towards normal by 12-14 weeks after transplantation. Although killing of HSB2 and B-LCL is usually the property of activated NK cells, few of these patients had any obvious 'trigger' of such activation: none had CMV infection, there were no episodes of graft rejection, and only two patients had mild and transient grade I graft versus host disease (GvHD). We conclude that T cell depletion does not affect the reconstitution of NK cell function and that NK cell activation occurs after T depleted bone marrow transplantation even in the absence of clinically detectable GvHD, graft rejection or CMV infection.

The significance of host haemopoietic cells detected by cytogenetic analysis of bone marrow from recipients of bone marrow transplants

Bone marrow from 39 patients who received a bone marrow transplant (BMT) from a matched donor of different sex were studied by chromosome analysis for evidence of mixed haemopoietic chimaerism (MC). Recipient metaphases were detected in the bone marrow of 10 patients after BMT. Patients in whom MC was detected within 6 weeks of BMT did not all have a poor outcome. Two of seven are disease-free survivors at greater than 470 and greater than 632 d. All three patients in whom MC was diagnosed more than 6 weeks after BMT subsequently relapsed. Four factors appear to be important in determining the probability of relapse when MC is detected in a patient after BMT: the timing of detection of residual recipient cells; the proportion of these cells in the bone marrow; persistence of these cells in increasing proportions; and the karyotype of the recipient metaphases detected. Cytogenetic assessment may provide the earliest indication of relapse in these patients. In addition, this study provides further evidence that cyclophosphamide and total body irradiation, as used in these patients, may be inadequate conditioning therapy for BMT.

The dopamine withdrawal test following surgery for intracranial aneurysms

Cerebral blood flow was measured in eight patients who were being treated with dopamine in order to maintain cerebral perfusion after the onset of delayed postoperative ischaemia following intracranial aneurysm surgery. Measurements were made whilst on treatment and repeated either during a reduction in the dosage or withdrawal of dopamine. There was a significant fall in cerebral blood flow in both hemispheres in all eight patients. Clinical deterioration was observed in seven of nine instances in which cerebral blood flow fell by 25% or more of the value while on dopamine treatment. There were no episodes of deterioration in six tests where the fall in cerebral blood flow was less than 25% of the starting value. It is suggested that cerebral blood flow measurement can be useful in predicting when it is safe to withdraw dopamine treatment in these patients. Hypertensive treatment should be maintained if a withdrawal test is associated with a fall in cerebral blood flow of 25% or more.

Valproate metabolite concentrations in brain increase with chronic administration of sodium valproate

Rats were treated chronically with sodium valproate for varying periods of time up to eight weeks. A statistically significant negative correlation between plasma concentrations of valproate-derived substances (VDS) and length of treatment was observed while a statistically significant positive correlation was found between brain VDS concentration and length of treatment. Liver VDS concentrations showed a tendency to decrease with time but this trend was not statistically significant. A new procedure was developed to measure the tissue levels of VDS.

Specificity in the reactivation of infant memory

In three experiments the specificity of an effective reactivation stimulus, or reminder, was examined. Two weeks after learning to produce movement in a crib mobile by footkicking, 3-month-old human infants showed no retention of the response-reinforcer contingency. A reactivation procedure 24 hours prior to the long-term retention test was effective if the reminder was a brief noncontingent exposure to the original 5-component training mobile or a mobile containing one novel substitution. When more than one novel component were substituted into the original mobile, the reminder was ineffective. This was predicted by the discrimination function 24 hours following training. A reminder containing only a single familiar (predictive) component and four novel ones was also moderately effective. In subsequent studies, we explored different interpretations of the reminder specificity effect. We hypothesize that reminder specificity is of particular adaptive value for developing organisms in providing a buffer against memory retrieval in inappropriate contexts.