Delineation of the human hematolymphoid system: potential applications of defined cell populations in cellular therapy

Hematopoietic stem cells (HSC) have the capacity to reconstitute all the blood cells in the body. HSC are rare, representing on average 0.05% of the mononuclear cells present in healthy human bone marrow. Due to their capacity for self-renewal and their pluripotent, long-term reconstituting potential, HSC are considered ideal for transplantation to reconstitute the hematopoietic system after treatment for various hematologic disorders or as a target for the delivery of therapeutic genes. Human HSC also have potential applications in restoring the immune system in autoimmune diseases and in the induction of tolerance for allogeneic solid organ transplantation. With the increased interest in human HSC for clinical applications, technology for the isolation of candidate HSC and knowledge of human hematopoiesis have been growing rapidly. In this article, we discuss the functional characterization of a human CD34+Thy-1+ HSC population which is essentially free of residual disease, our efforts to generate alternate monoclonal antibodies for the isolation of clinically useful stem or progenitor cell populations, and the identification of a novel lymphoid progenitor as part of an exploration towards defining progenitors with potential application as adjuncts to HSC-based cellular therapy.

Proposed guidelines for the internal quality control of analytical results in the medical laboratory

The factors involved in analytical quality relate to definition of quality, creation of quality, and control of quality, and errors arise from external and internal sources as well as from permanent and variable factors. Further, the two main types of error are classified as systematic and random errors. Internal quality control (IQC) systems can only operate on the variable factors which are related to batch-to-batch variations (external factors) and to the performance in the laboratory (internal factors). In creating an adequate internal control system, several problems are faced: (i) quality of control materials, (ii) types and frequency of possible errors, (iii) number and types of control materials, (iv) number of replicates of the control, (v) probability of error detection, (vi) probability of false rejection, (vii) consequences of reject signals, (viii) trouble-shooting systems, and (ix) prevention of errors among many other conditions. Gaussian distributions of control results are assumed and the statistical control rules are evaluated in relation to probability of false rejections, Pfr, and probability of error detection, Ped, for the different rules. Combinations of low Pfr and high Ped are obtained by combining results from e.g. four measurements of the same control sample by use of mean and range rules. Further, it is not possible to establish a common control system which can be used for all quantities and analytical procedures; on the contrary, each procedure should have its particular efficient IQC system. These aspects are discussed and a number of guidelines for statistical control rules and problem related internal quality control are presented.

Contralateral and ipsilateral EMG responses to transcranial magnetic stimulation during recovery of arm and hand function after stroke

We examined the relationship between the recovery of hand and arm function in a group of hemiplegic stroke patients and the presence of short-latency EMG responses to transcranial magnetic stimulation (TMS) in 4 different upper limb muscles (deltoid, biceps, extensor digitorum communis and the first dorsal interosseous). Twenty-one patients were examined within 5 weeks of stroke (median 2 weeks), and then at regular intervals over the next 12 months. Some patients recovered rapidly (Group A); in others, recovery was slow and incomplete (Group B). Even at the first test, Group A patients had responses to TMS in all muscles. Most Group B patients initially lacked responses in all tested upper limb muscles; in those that later were able to activate hand muscles, responses returned at or just before this stage of recovery. No such clear correlation between the presence of responses to TMS and ability to activate more proximal arm muscles was evident. Response latency was initially long and declined in a manner that was highly correlated with muscle strength and hand function test scores. Ipsilateral responses were elicited from both the affected and unaffected hemispheres. Ipsilateral responses from the latter were most common in the proximal muscles of the affected limb, and had latencies that were longer than those elicited in the contralateral (unaffected) arm. Nine cases of ipsilateral responses in hand muscles were found; such responses are not found in healthy subjects. Ipsilateral responses from the undamaged hemisphere were more prevalent in the poorly recovered patients; the underlying mechanisms may not be beneficial for recovery.

Graduate professional development programme dentistry

This paper describes the development and structure of a pilot programme of professional development for new graduates initiated by the New Zealand Dental Association, the Dental Council of New Zealand, and the Faculty of Dentistry of the University of Otago. The programme consisted of a series of monthly evening seminars, co-ordinated by a facilitator, and led by experienced practitioners. Initially provided in Auckland, the programme subsequently extended to Wellington, Christchurch, and Waikato-Bay of Plenty. The award of a New Zealand Dental Association Travelling Fellowship enabled the author to observe the United Kingdom Vocational Training Scheme, and attendance at the 1994 meeting of the Fédération Dentaire Internationale provided opportunity to study systems used in other countries. The pilot programme has now been replaced by the ongoing Graduate Professional Development Programme Dentistry, a programme which extends beyond the recent graduate, but remaining based on the concepts developed in the pilot programme.

False negative cytogenetic results following amniocentesis

We report 2 cases where prenatal cytogenetic studies following amniocentesis yielded false negative results. Both mothers requested termination of pregnancy but were reassured by the normal chromosome analysis and therefore continued their pregnancies. When cytogenetic studies were repeated in the neonatal period, they demonstrated chromosomal abnormalities, which were confirmed when the initial specimens from amniocentesis were reviewed. Because of our findings, we suggest that if prenatal chromosome analysis is reported as normal, where there is a high index of suspicion of a chromosome abnormality, the result should be questioned and neonatal chromosome analysis undertaken.

Effects of purine analogues on spontaneous alternation in mice

The Y-maze was used to examine the effects of purines acting at A1 and A2 adenosine receptors upon spontaneous alternation, a model of working memory, in mice. In support of previous work, scopolamine produced a loss of spontaneous alternation behaviour to the 0.5 chance level. The A1 receptor selective agonist N6- cyclopentyladenosine (CPA) did not change spontaneous alternation behaviour alone, but it prevented the decrease of spontaneous alternation scores produced by scopolamine. The A1 receptor selective antagonist 1,3-dipropyl-8-cyclopentylxanthine (CPX) blocked the effect of CPA in combination with scopolamine but had no effect alone. The A2 receptor selective agonist (N6-[2-(3,5-dimethoxyphenyl)-2-(2- methylphenyl)ethyl] adenosine (DPMA), and the A2 receptor selective antagonist 3,7-dimethyl-1-propargylxanthine (DMPX) had no effect of alternation behaviour alone and did not modify the effect of scopolamine. The results indicate the ability of A1 but not A2 receptor activation to modify working memory deficits induced by scopolamine, but suggest that endogenous adenosine does not normally participate in working memory processes.

Determination of dissociation constant and concentration of an anti-DNA antibody by using the light-addressable potentiometric sensor

The most sensitive assay possible is desired for quantitation of total DNA and DNA probe binding. To reduce background signal, which may reduce assay sensitivity, it is desirable to employ low antibody concentrations. This requires the use of a specific antibody with a high affinity for DNA.

Prospective study of patients aged 55 years or less with acute myocardial infarction between 1981 and 1985: outcome 7 years and beyond

OBJECTIVE

To determine the long-term prognosis of patients after a myocardial infarction (MI) at a young age.

DESIGN

Prospective cohort study of patients aged 55 years or less suffering a myocardial infarction.

SETTING

A single coronary care unit admitting patients from the community.

PATIENTS

255 consecutive patients (210 men) aged 55 years or less admitted between 1981 and 1985 after acute MI. Twenty four patients died in hospital or within 3 months of infarction and 11 were lost to further follow up after discharge. Of the remaining patients, 150 (mean (SD) age 48 (5.7) years) able to exercise 3 weeks after infarction and who agreed to undergo coronary angiography were recruited to a study group and seen 18 months, and 3, 5, and 7 years after MI. In addition, a cross sectional analysis of survival was made to a median of 120 months. Seventy 3 month survivors (mean (SD) age 48 (5.8) years) were not recruited to the study group but were traced for late survival through their general practitioners and family health service associations to a median of 130 months.

MAIN OUTCOME MEASURES

Survival in young patients after MI and the survival of 3 month survivors stratified by their ability to exercise and agreement to undergo angiography. The rate of coronary artery surgery (CAGB) and reinfarction during the first 7 years after index MI in patients recruited to the study group.

RESULTS

Sixteen patients (6%) died in hospital and eight (3%) within 3 months of the index infarction. The 7 and 11 year survival rates in the whole cohort of 255 patients were 80% and 66% respectively using life table methods. Survival 7 years after MI, in patients recruited to the study group was better than in those not recruited (93% v 79%, P = 0.001), but thereafter mortality in the study group accelerated and there was no significant difference in survival 11 years after infarction (76% v 67%, P = 0.05). There was a trend towards higher mortality in patients with multivessel disease and severely impaired left ventricular function. During the first 7 years after MI, 38 of 150 patients in the study group underwent CABG and 19 suffered reinfarction, which was fatal in three.

CONCLUSION

The medium-term prognosis of young survivors of MI is good, particularly in patients recruited to the study group. After 7 years there is an increase in mortality and the long-term prognosis is less favourable. This should be taken into account when planning future management and follow up of young patients after MI.

Psychological response to cervical screening

BACKGROUND

Few studies have examined the psychological costs of cervical screening, despite expressed concern over possible negative sequelae.

METHODS

Seventy-five women with mild or moderately dyskaryotic smears, under cytological surveillance, 75 women referred for colposcopy after a first-ever abnormal smear showing severe dyskaryosis, and 75 controls with recent negative cytology were interviewed at home, and their psychological adjustment was assessed.

RESULTS

Levels of distress were higher among women with an abnormal smear than among controls with a recent negative smear. Anxiety (Hospital Anxiety and Depression Scale range 0-21, "normal" range 0-7) was highest among those referred for colposcopy (mean 8.12, controls 5.88, P < 0.001); afterward, distress fell (mean 6.61, P < 0.001) but more problems of social adjustment were evident (surveillance vs controls, P < 0.01). High anxiety was associated with social maladjustment (colposcopy, P < 0.001; surveillance, P < 0.01) and negative feelings about the self (P < 0.05). Current anxiety was unrelated to knowledge about abnormal smears, but in the surveillance group was related to satisfaction with the explanation provided (P < 0.05).

CONCLUSION

A positive cervical smear may by psychologically traumatic for a significant minority of women, irrespective of management strategy.

Cytokine-mobilized peripheral blood CD34+Thy-1+Lin- human hematopoietic stem cells as target cells for transplantation-based gene therapy

Gene-therapy of blood-borne disorders may be best achieved using hematopoietic stem cells (HSC) which have extensive self renewal potential as well as multilineage repopulating potential as a cellular target. The human HSC, which is CD34+Thy-1+Lin- has been isolated from fetal, adult bone marrow and cytokine-mobilized peripheral blood (MPB) (1-3). Results presented in this study show that the degree of mobilization of HSC into peripheral blood of cancer patients is highly variable and that the combined use of high dose chemotherapy and GM-CSF as a mobilization strategy is superior to the use of G-CSF with regard to the mobilization of true HSC. A multistep cell isolation procedure has been developed which utilizes high speed flow-cytometric cell sorting and allows the isolation of sufficient numbers of HSC from MPB to permit their use as an hematopoietic graft for clinical transplantation. Hematopoietic stem cells isolated from MPB are capable of self-renewal and differentiation into multiple hematopoietic lineages as shown by their behavior in both in vitro and in vivo assays. Mobilized PB mononuclear cells isolated from cancer patients are frequently contaminated with tumor cells. Using this cell isolation procedure, HSC preparations from patients with multiple myeloma have been created with greatly reduced tumor cell burdens. These CD34+Thy-1+Lin- cells are capable of being stably transduced at high efficiency (32-75%) by co-culture on a cell line producing recombinant retroviruses containing the neomycin-resistant gene. These HSC cell populations are likely ideal targets for hematopoietic cell-based gene therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibody-antigen binding constants determined in solution-phase with the threshold membrane-capture system: binding constants for anti-fluorescein, anti-saxitoxin, and anti-ricin antibodies

Affinities of various monoclonal and polyclonal antibodies for fluorescein-containing antigens, saxitoxin and ricin, were determined by using a light addressable potentiometric sensor-based system (Threshold). The dissociation constants, determined from Scatchard plots, ranged from 2 x 10(-7) to approximately 3 x 10(-12) M. Dissociation constants for fluorescein and saxitoxin were compared with values determined by independent means. This technique was found to be quick, simple, reproducible, and accurate.

Assessment of the residual efficacy of lambda-cyhalothrin. 1. A laboratory study using Anopheles arabiensis and Cimex lectularius (Hemiptera: Cimicidae) on treated daub wall substrates from Natal, South Africa

Laboratory assessment of the residual efficacy of lambda-cyhalothrin (Icon) 10% AI against Anopheles arabiensis and Cimex lectularius was carried out. The insecticide was applied to daub substrates, simulating the wall surface of houses from 3 areas within the endemic malaria area of Natal, South Africa. Variability in residual efficacy was found between different areas and appeared to correlate to organic content of the substrate. Residual efficacy against An. arabiensis ranged from as little as 2 wk in some areas to in excess of 14 wk in others. Residual efficacy against C. lectularius was 4 wk for all 3 areas, but was 10 wk in only 2 areas.

Infertility--epidemiology and referral practice

A questionnaire-based study of infertility has been carried out in two age cohorts of women in a defined geographical region. Women were aged 36-40 years or 46-50 years at the time of the survey. The prevalence of infertility (no conception after 2 years of trying) was approximately 14% in both age cohorts. However, a significantly higher proportion of younger women had sought medical help. In both age cohorts there was a higher incidence of spontaneous abortion among infertile women. These findings suggest no significant increase in the prevalence of infertility over a decade but a considerable increase in the use of medical services.

Some factors in the choice of male or female sterilisation in Aberdeen

In a random sample of 84 men and 167 women, medical considerations, an intransigent attitude of one partner or a fear of adverse effects, were related to the decision on which partner should seek sterilisation. Only 19% of couples felt that they had a real choice between male and female sterilisation.

Menstrual symptoms in women with pelvic endometriosis

OBJECTIVE

To investigate menstrual symptoms in relation to pelvic pathology.

DESIGN

A prospective questionnaire-based study.

SETTING

Aberdeen Royal Infirmary, Scotland.

SUBJECTS

1250 questionnaires were sent out prior to planned admission and 1200 women (96%) brought the completed questionnaires. They comprised 598 women undergoing laparoscopic sterilization, 312 having laparoscopy because of infertility, 156 having laparoscopy because of chronic pelvic pain and 134 women undergoing abdominal hysterectomy for dysfunctional uterine bleeding.

MAIN OUTCOME MEASURES

The occurrence of dysmenorrhoea, menorrhagia, menstrual regularity, premenstrual spotting, deep dyspareunia and pelvic pain in women with either endometriosis and post infective pelvic adhesions or a normal pelvis.

RESULTS

Menorrhagia, menstrual irregularity and premenstrual spotting occurred with equal frequency in all groups. Deep dyspareunia, pain after intercourse and recurrent pain unrelated to menstruation or coitus was more common in women with endometriosis and those with post infective pelvic adhesions than in those with a normal pelvis. Dysmenorrhoea appears to be more prevalent among women having endometriosis.

CONCLUSIONS

Menstrual symptoms, while raising a high index of suspicion for endometriosis, are not entirely reliable as indicators of disease. Dysmenorrhoea is the most common reported symptom in endometriosis sufferers. Diagnostic laparoscopy should be considered before institution of treatment in women complaining of pelvic pain and menstrual symptoms.

Non-invasive brain stimulation reveals reorganized cortical outputs in amputees

EMG responses to non-invasive electromagnetic brain stimulation (EMS) were recorded from arm muscles of congenital amputees. Responses were obtained with lower thresholds on the amputated than on the intact side and were evoked from a larger cortical area. Contracting muscles showed increased responses to EMS; the increase was more pronounced on the amputated side. Similar findings were obtained in one traumatic amputee who suffered an early amputation, but not in another patient with a late amputation. We conclude that in congenital amputees there is substantial reorganisation of the corticospinal system and that this may also occur in early traumatic cases.

The epidemiology of infertility in Aberdeen

OBJECTIVE

To study the prevalence of infertility, both primary and secondary, outcome of pregnancy, occupation, and uptake of medical services in a total population of women from a geographically defined area.

DESIGN

A postal questionnaire survey of an age cohort of women who had completed their fertility, and who were randomly selected from the Grampian Health Board's primary care register.

SETTING

Aberdeen city district.

SUBJECTS

1024 Women in the age group 46-50, of whom 130 had to be excluded. Of the remaining 894 women, 766 (86%) responded to the questionnaire.

MAIN OUTCOME MEASURES

Response to questionnaire on pregnancy history, the length of time taken to become pregnant each time, and whether medical advice had been sought.

RESULTS

Among the 766 women contacted, 602 (79%) reported no difficulties in having children, 56 (7%) had chosen not to have children, and the remaining 108 (14%) had experienced infertility, defined as having difficulty in becoming pregnant for more than two years. In total 68 (9%) women had primary infertility, of whom 41 (5%) eventually conceived. Of the 40 (5%) with secondary infertility, 23 (3%) conceived. Overall, 52 (7%) of the population were left with an unresolved problem of infertility. Only 67 (62%) infertile women had made use of hospital services, and a further 8 (7%) had consulted their general practitioners. Among those who conceived there was no difference in the proportion who sought advice compared with those who did not.

CONCLUSION

The overall prevalence of infertility was 14%, although half of these women eventually conceived. Primary infertility was more common than secondary infertility. Only 62% of infertile women attended a hospital clinic for treatment of their infertility.

Recovery of elbow function in voluntary positioning of the hand following hemiplegia due to stroke

Elbow movement during voluntary positioning of the hand (with the arm supported against gravity) is described in a longitudinal study of five patients recovering from hemiplegia due to stroke. Over a twelve month period, four of the patients improved their speed of movement, three exhibiting slightly better recovery of elbow extension, one of flexion. In some instances co-contraction of the elbow agonist and antagonist (measured just before the onset of movement) decreased with time after stroke. The effects of contrasting movements at the shoulder on elbow movement were also studied. Estimates of recovery were generally similar whether patients kept the shoulder still or made movements that were synergic or counter-synergic to those of the elbow.

Mode of delivery and future fertility

A cohort of 22,948 women from a stable homogeneous population who gave birth for the first time between 1964 and 1983 were followed up prospectively. Analysis by mode of delivery showed that of those delivered by caesarean section 23.2% fewer had another pregnancy than those who had a spontaneous vaginal delivery. Women delivered by forceps were in an intermediate group. Miscarriage was more common in women who had been delivered by caesarean section. The relative infertility after caesarean section could not be accounted for by early sterilization, was not associated with maternal height or social status, and was only partly attributable to age.

Can platelet volume predict progressive hypertensive disease in pregnancy?

Increase in platelet size has been found in conditions with increased platelet destruction and use. This increase in platelet size can be found in patients with moderate or severe hypertension in pregnancy, even in the presence of a normal platelet count. The goal of this study was to investigate whether an increase in platelet size was present before the manifestation of the disease and therefore could be used to predict the progression of the disease before it is clinically apparent. Three hundred normal primigravid pregnancies were studied between 28 and 30 weeks' gestation, and blood was taken to assess platelet count and mean platelet volume. Two hundred sixteen patients had no hypertensive problems during their pregnancy, 84 developed hypertension, 62 had mild hypertension only with diastolic blood pressures between 90 and 99 mm Hg, 13 had moderate hypertension with diastolic blood pressures between 100 and 109, and nine had severe hypertension with diastolic blood pressure above 110. No difference was found between these groups in the parameters measured. Therefore it was felt that platelet volume may not be a useful screening test in a low-risk population. A second study was carried out to investigate the serial changes in these parameters in patients at risk of progressive disease. Thirty-four patients with essential hypertension were followed from 24 weeks with serial blood sampling to study changes in platelet size. An additional 40 patients with mild pregnancy-induced hypertension were also studied. From these patient groups, 20 patients developed severe hypertension. The mean platelet volume increased significantly at least 1 week before the hypertension became clinically apparent. There was no change in platelet count at this time. It is concluded that increasing platelet size can predict which patients are likely to progress to severe disease before it becomes clinically obvious.

Negative intrathoracic pressure decreases independently left ventricular filling and emptying

The mechanism for the fall in left ventricular (LV) stroke volume with normal and obstructed inspiration is controversial with changes proposed in LV preload and afterload. During respiration extending over several cardiac cycles, changes in both LV filling and emptying could occur, rendering demonstration of any responsible mechanism difficult. To evaluate the independent effects of negative intrathoracic pressure (NITP) on LV filling and emptying, we have analyzed the effects of NITP confined to either diastole or systole using electrocardiogram (ECG)-triggered phrenic nerve stimulation in six anesthetized closed-chest dogs. Lung volume was either maintained by completely obstructing the airway or allowed to increase during NITP. With diastolic NITP and the airway obstructed during phrenic nerve stimulation, LV filling volume (integrated mitral flow) significantly decreased (-37 +/- 6.1% SE) associated with increases in LV and right atrial filling pressures at end diastole relative to both atmospheric and esophageal pressures. Right atrial pressure relative to either atmospheric or esophageal pressure increased significantly more than left atrial pressure. The ensuing LV stroke volume (integrated ascending aortic flow) decreased significantly (-30.8 +/- 5.9%). With NITP confined to systole and at constant LV preload, LV stroke volume also decreased (-12.9 +/- 2.5%) associated with an increase in LV systolic pressure relative to esophageal pressure. Similar significant changes were observed despite a smaller fall in esophageal pressure when lung volume was allowed to increase during either diastolic or systolic NITP. We conclude that 1) NITP confined to diastole decreases LV filling and the ensuing LV stroke volume, most likely by ventricular interdependence; 2) NITP confined to systole also decreases LV stroke volume, presumptively by imposing an increased afterload on the LV; 3) both diastolic and systolic mechanisms should contribute to a decreased LV stroke volume during normal and obstructed inspiration; and 4) if the effects of intrathoracic pressure changes were to extend over several cardiac cycles, mechanisms exist to account for either increases or decreases in LV volumes.

The assessment factor most nurses forget

Wakefulness, temperature, and cardiovascular function are just three of more than a hundred patterns that the human body follows every day. You can use the latest findings on these biological rhythms to deliver better care.

Discrepancies between the affinities of binding and action of the novel beta-adrenergic agonist BRL 37344 in rat brown adipose tissue

The novel brown adipose tissue (BAT) selective beta-adrenergic agonist, BRL 37344, is 31-fold more potent than (-)-isoproterenol in stimulating the respiratory rate of interscapular BAT fragments. BRL 37344 is also more potent (9-fold) than (-)-isoproterenol in stimulating adenylate cyclase activity of IBAT purified plasma membranes whereas, in the same preparation, it is 81-fold less potent than (-)-isoproterenol in competition displacement studies with the beta-adrenergic ligand, [125I]cyanopindolol. We have previously demonstrated that the photoaffinity reagent [125I]cyanopindolol-diazirine selectively labels a 62 kDa protein in IBAT plasma membranes that displays pharmacological properties of a beta 1-adrenergic subtype. Relatively high concentrations of BRL 37344 (10 microM) are required to displace [125I]cyanopindolol-diazirine binding to the 62 kDa protein. Taken together, the results suggest that two different populations of beta-adrenergic receptors may co-exist in BAT plasma membranes: a small population (about 15%) of atypical beta-receptors and a large population of beta 1-receptors that exhibit high and low affinities for BRL 37344, respectively.

Ectopic pregnancy in Aberdeen 1950-1985

The reported incidence of ectopic pregnancy in Aberdeen City and suburbs (1950-1985), using as denominators maternities, pregnancies and women aged 15-44 years, has increased threefold since 1970 to 6.4/1000 pregnancies. This increased incidence persisted after the exclusion of previously sterilized women. A total of 11,128 women were sterilized in Aberdeen City and suburbs between 1960 and 1982; 36 ectopic pregnancies occurred in this sterilized population. The prevalence of ectopic pregnancy was 3.55/1000 sterilizations. This did not alter significantly over the period of study despite changes in the method of sterilization. However, due to the increased popularity of sterilization, the proportion of ectopic pregnancies in women who had been sterilized increased from 0% in the 1950s to 21% in the quinquennium 1975-1979.

Chromosomal distribution of the RTVL-H family of human endogenous retrovirus-like sequences

We have analyzed the chromosomal distribution of a large family of human endogenous retrovirus-like sequences termed RTVL-H. In situ hybridizations suggest that these sequences are found on all human chromosomes. These results also indicate that clusters or concentrations of RTVL-H elements may exist on chromosomes 1p and 7q. Southern blotting experiments using somatic cell hybrids containing either the human chromosome 3 or the X chromosome confirm the presence of multiple dispersed RTVL-H sequences on these two chromosomes. These experiments also demonstrate that distinct RTVL-H banding patterns can be detected for each chromosome. Thus, RTVL-H probes may be useful in genome mapping studies.

A comparison of incidence trends for esophageal atresia and tracheoesophageal fistula, and infectious disease

There has been a suggestion that esophageal atresia with tracheoesophageal fistula (EA/TEF) may be related to the occurrence of infectious disease in the population during the time of early gestation. There is therefore a need for further data on trends in incidence related to infectious diseases. Data on the occurrence of EA/TEF with and without additional congenital malformations may also be relevant. The British Columbia Health Surveillance Registry is population-based with excellent case ascertainment of birth defects, and data are available on the incidence of infectious diseases for B.C., allowing comparison of trends to be made. One hundred forty-nine cases of EA/TEF occurred among 534,834 consecutive livebirths during the period 1966-1980 for an incidence rate of 1/3,590. No significant (p less than 0.05) annual, seasonal or monthly incidence trends were observed. In addition, the occurrence of EA/TEF could not be correlated with the prior incidence of infectious hepatitis, rubella, salmonella, or rubeola. Fifty-five percent of individuals with EA/TEF had congenital malformations in other systems, most frequently cardiovascular, gastrointestinal, and genitourinary. Most individuals with additional congenital malformations had multiple system involvement.

Effect of PUVA on plasma and skin immunoreactive alpha-melanocyte stimulating hormone concentrations

Plasma alpha-melanocyte stimulating hormone (alpha-MSH) concentrations were measured in patients receiving PUVA therapy as treatment for mycosis fungoides, and PUVA or UVB as treatment for psoriasis. Skin immunoreactive alpha-MSH was also measured in those patients who received PUVA. The mean plasma and skin alpha-MSH concentrations after 2-3 weeks of PUVA were not significantly different from pre-treatment values and showed no relationship either to skin type or to the degree of tanning that occurred in response to PUVA. Plasma alpha-MSH concentrations were also unchanged after UVB. There was also no short term change in plasma alpha-MSH concentrations in patients after receiving their first treatment with PUVA. It would appear that circulating and skin alpha-MSH levels are unaffected by UV and show no causal relationship to PUVA induced pigmentation.

A routine method for cytogenetic analysis of small urinary bladder tumor biopsies

A method that allows routine cytogenetic analysis of small cystoscopic biopsies from urothelial tumors is described. This method is based on prolonged mild collagenase disaggregation, a 12-16 hour culture, and harvesting procedures adapted to give maximal metaphase recovery. In addition to providing a means for cytogenetic studies of small biopsies from urinary bladder tumors, this method provides the advantages of direct preparations, with chromosome morphology and banding sufficient for karyotypic analysis. Conventional cell synchronization techniques, applied to this system, should enable high-resolution banding and optimize analysis.

Use of modified resistogram to type Candida albicans isolated from cases of vaginitis and from faeces in the same geographical area

Ninety strains of Candida albicans were isolated from vaginal swabs taken by general practitioners from cases of vaginal candidosis. One hundred and nine strains were also isolated from 300 specimens of faeces received from outpatients living in the same geographical area. These strains were typed using a modification of the resistotyping method. We were unable to find any significant differences between the two populations of strains. This suggests that no particular resistotype has an increased ability to cause vaginitis.

Strain differentiation of Candida albicans by morphotyping

Strains of Candida albicans can be differentiated by the morphological features of streak colonies developed on malt agar. A morphotyping system is proposed, where numerical codes are assigned primarily on the basis of the nature and extent of marginal fringing and the surface topography of the streak colony. The system allows ready differentiation to be made of morphotypes, requires no specialized equipment or expertise and provides a simple and reproducible means for epidemiological studies of candida and candidosis.

Fluorodeoxyuridine synchronization of hemopoietic colonies

A method that allows the routine cytogenetic analysis of colonies growing in semisolid medium and containing as few as 50 cells is described. This method is based on the sequential addition of fluorodeoxyuridine and then thymidine to achieve higher mitotic yields by the synchronization of colony cells. In this study the schedule outlined was specifically optimized for application to small granulopoietic colonies from patients with Philadelphia chromosome (Ph)-positive chronic myeloid leukemia. In addition to increasing the spectrum of colony sizes yielding analyzable metaphases, this method significantly improved the general quality of the chromosome preparations obtained. Minor changes should enable this method to be applied to the analysis of colonies derived from a variety of other normal or malignant clonogenic cell types.

Platelet studies in normal pregnancy and pregnancy-induced hypertension

The platelet count does not appear to change during normal pregnancy but a rise in the mean platelet volume (MPV) and platelet distribution width was found in the third trimester in this study of 208 healthy pregnant women. Alteration of all three platelet parameters was seen following delivery in 40 women studied sequentially. Moderately severe pregnancy-induced hypertension (PIH) was associated with no alteration of platelet parameters when compared with gestation-matched controls. Platelet abnormalities in severe PIH appeared to be related to the time of presentation and may be a reflection of the rate of progression of the underlying condition.

The extent and antecedents of uncertain gestation

The extent and genesis of uncertainty of gestation has been studied in a total obstetric population, using in all cases a best clinical estimate of gestation made according to a specific protocol. In 73.2% of patients, the estimate was assessed as certain, in 19.7% as approximate, and in 7.1% as uncertain. Uncertainty assessed in this way has several antecedents, and coding of only of these (presence or absence of a precise date for the last menstrual period) is insufficient in data to be used for research in which gestation length is to be used as a variable.