Preventing and managing childhood emergencies in schools

The Emergency Medical Services for Children (EMSC) program, initially funded in 1984, is jointly administered by the Health Resources and Services Administration and the National Highway Traffic Administration. The program is designed to reduce child and youth mortality and morbidity resulting from severe illness or trauma. Several initiatives, focused at the federal, state, and local levels, have established collaboration between the education and health communities. They include injury prevention education and programs in school settings; school and staff preparation for a medical emergency; and emergency care planning for school children with special health care needs. This article provides an overview of key issues.

Isospora tiaris n.sp. (Apicomplexa: Eimeriidae) from the sooty grassquit (Tiaris fuliginosa), a passeriform bird of South America

Isospora tiaris n. sp. is described from the feces of an adult bird, a sooty grassquit (Tiaris fuliginosa) from Venezuela. The oocysts are subspherical, 27.1 x 23.8 (24.7-30.0 x 21.2-26.5) microns with a bilayered, smooth, colorless wall. A micropyle and oocyst residuum are absent; an ellipsoidal polar granule is usually present. Sporocysts are ovoidal, 14.7 x 10.8 (12.4-16.8 x 8.8-12.4) microns with prominent Stieda and substieda bodies and a residuum composed of small uniform granules.

Impact of the Mammography Quality Standards Act on access in Minnesota

OBJECTIVES

The Minnesota Department of Health surveyed registered mammography facilities to assess their accreditation status prior to full implementation of the Federal Mammography Quality Standards Act (MQSA), which mandated accreditation of all mammography facilities by October 1994; to strategize on the steps that might be taken to avoid closure of facilities; and to evaluate the ultimate impact of the law on the availability of mammography in Minnesota.

METHODS

Mammography facilities registered with the Radiation Control Section of the state health department were surveyed five months prior to and four months after the October 1994 deadline. Data collected included accreditation status, plans for continuing service, number of mammograms performed, and areas in which technical assistance was needed. In October 1995, the number and distribution of facilities were determined from the Radiation Control Section registration database.

RESULTS

The pre-MQSA survey of 182 respondents found that 96% planned to continue mammography services but only 49% were accredited. The remaining 51% had applications in progress. In the post-MQSA survey, 70% of 182 facilities were found to be accredited, and 30% were operating under provisional certification. As of October 1995, although six facilities had closed, there was a net gain of four mammography facilities providing on-site service.

CONCLUSIONS

Despite fears to the contrary, access to mammography in the state of Minnesota was not adversely affected by full implementation of the Mammography Quality Standards Act.

Optic neuritis following measles/rubella vaccination in two 13-year-old children

Images

4-Hydroperoxycyclophosphamide purged autologous bone marrow transplantation in non-Hodgkin's lymphoma patients at high risk of bone marrow involvement

Between June 1990 and January 1994, 19 patients with non-Hodgkin's lymphoma (NHL) at high risk for bone marrow involvement underwent 4-hydroperoxycyclophosphamide (4-HC) purged bone marrow transplantation. Eleven patients had low grade, seven intermediate grade and one high grade NHL and 7/19 patients had received three or more previous chemotherapeutic regimens. Four patients were transplanted in first partial remission (PR) and the remainder in responsive relapse. Fourteen patients had bone marrow (BM) involvement at diagnosis and/or at relapse. The median times to granulocyte and platelet recovery were 26 and 29 days, respectively. There were two toxic deaths and one complete responder developed secondary AML at 31 months post-BMT. Seventeen of 18 evaluable patients achieved a complete remission (CR) and one patient a PR. Fourteen patients (74%) are progression-free at a median follow-up of survivors of 34 months (range 29-55). The 3 year event-free (EFS) and overall survival (OS) probabilities are both 67%. No statistically significant difference was seen between EFS or OS and BM involvement or histologic grade at diagnosis. At 29 months, 4/7 patients with a morphologically involved BM harvest had relapsed or died compared to 1/12 patients with negative BM (P = 0.03). These results are encouraging and warrant further investigation of 4-HC purging in NHL.

Very late antigen (VLA) expression by normal and neoplastic human plasma cells; including an assessment of antibodies submitted to the Vth International Workshop on Leucocyte Differentiation Antigens using human myeloma cell lines

The biology of normal plasma cells and the pathophysiology of human multiple myeloma remain poorly understood. Functional assays are scarce and at present cell phenotyping is providing the most information about how human plasma cells may behave. Three different types of human plasma cells: normal, fresh neoplastic myeloma cells and plasma cell lines, have been studied for their reactivity with antibodies to the beta-1 integrins (Very Late Antigens; VLAs), including a panel obtained from the Vth International Workshop on Leucocyte Differentiation Antigens. Most plasma cell targets express VLA-4 (CD49d positive) and the common beta chain recognized by CD29. CD49e (VLA-5) was occasionally positive. Other VLAs were not usually expressed. These data suggest the wide use by plasma cells of VLA-4, possibly as a ligand with fibronectin and high endothelial venules (HEV). Of other adhesion structures expressed by plasma cells, only CD44 is seen as frequently, and this is also a HEV ligand.

Centrocytes rapidly adopt a memory B cell phenotype on co-culture with autologous germinal centre T cell-enriched preparations

B cells, after mutating their Ig B-region genes in germinal centres (GC), undergo apoptosis, unless they receive antigen-dependent selection signals. The signals appear to be delivered by GC T cells, require CD40 ligand expression and may induce differentiation to memory cells. Cultured GC B cells are prevented from entering apoptosis by ligating their surface CD40, but the resulting phenotype is not associated with B cells found in vivo. Conversely, GC B cells rapidly adopt a memory B cell phenotype on culture with autologous memory CD4(+) T cells that have been induced to express CD40 ligand transiently. This effect is prevented by blocking CD40 ligand. Naive CD4(+) T cells, induced to express CD40 ligand, do not prevent GC B cells undergoing apoptosis.

Evaluation of 99Tcm-tetrofosmin as a myocardial perfusion agent in routine clinical use

Recent trials with selected patients have indicated that 99Tcm-tetrofosmin is a suitable agent for myocardial perfusion imaging. We performed 99Tcm-tetrofosmin perfusion imaging in an unselected group of 297 patients routinely referred to our department. Single photon emission tomographic (SPET) imaging was performed 45-60 min post-injection using a 2-day stress and rest protocol. Altogether, 192 patients were stressed on a treadmill and 105 using intravenous dobutamine. Comparison with angiography was possible in 86 patients, 65 of whom had atheromatous coronary artery disease and 21 of whom had normal coronary arteries (6 of whom fulfilled the criteria for syndrome X). The sensitivity for the detection of coronary artery disease was 94% (93% for exercise stress and 95% for dobutamine). The overall specificity was 85% (87% for exercise stress and 80% for dobutamine in the 15 normal patients and the segments supplied by disease-free coronary vessels in patients with disease elsewhere). We conclude that 99Tcm-tetrofosmin is a highly sensitive and specific agent for the detection of coronary artery disease, using both exercise and dobutamine stress, with few limitations.

Becker muscular dystrophy presenting with complete heart block in the sixth decade

Becker muscular dystrophy may be associated with myocardial abnormalities which are usually diagnosed after the onset of weakness. We present a patient who developed complete heart block 6 years before the onset of muscle weakness which occurred unusually late at the age of 62 years.

Early complications of permanent pacemaker implantation: no difference between dual and single chamber systems

OBJECTIVE

To evaluate the incidence of intraoperative and early postoperative complications (up to two months after implant) of endocardial permanent pacemaker insertion in all patients under-going a first implant at a referral centre.

METHODS

Prospective evaluation of all endocardial pacemaker implantation procedures performed from April 1992 to January 1994 carried out by completion of standard audit form at implant. Patients' demographic data, medical history, details of pacemaker hardware used, and any complications were noted. Follow up information was also collected prospectively onto standard forms at pacemaker outpatient clinic.

SETTING

United Kingdom tertiary referral cardiothoracic centre.

PATIENTS

1088 consecutive patients underwent implantation of their first endocardial permanent pacemaker from April 1992 to January 1994. Implant and follow up data were available for 1059 (97.3%) patients at analysis. The median (range) age was 77 years (16-99); 51.2 % were male.

RESULTS

Dual chamber units were implanted in 54.1% of patients, single chamber atrial in 5.2%, and ventricular in 40.7%. A temporary pacing lead was present at implant in 22.9% of patients. Most (93.6%) implants were performed via the subclavian vein. Immediate complications were rare: eight (0.8%) patients developed pneumothorax requiring medical treatment and 11 (1.0%) an insignificant pneumothorax. There was no significant difference in the pneumothorax rate for dual chamber (DDD) compared with single chamber systems. Arterial puncture without sequelae was documented in 2.7% of attempts at subclavian vein cannulation. A total of 35 patients (3.3%) required reoperation; the reoperation rate for dual chamber (3.5%) was similar to that for single chamber (3.1%) systems. Electrode displacement (n = 15, 1.4%) was the most common reason for reoperation. Atrial lead displacement (n = 10, 1.6% of atrial leads) was significantly more common than ventricular lead displacement (n = 5, 0.5% of ventricular leads, P = 0.047). There was no difference in electrode displacement rates for dual (1.6%) compared with single (1.2%) chamber systems. Pacemaker pocket infection led to reoperation in 10 patients (six dual, four single chamber, P = not significant) and was significantly more common in patients who had a temporary pacing lead in place at implant (2.9%) than in those who did not (0.4%, P = 0.0014). Five patients (0.5%) required reoperation for generator erosion (two dual, three single chamber, P = not significant). and a further five for drainage of haematoma or a serous fluid collection (three dual, two single chamber, P = not significant). Complications that did not require reoperation were also rare. Undersensing occurred in 10 patients (0.9%). Atrial undersensing (n = 8) was significantly more common than ventricular undersensing (n = 2, P = 0.017). All patients were successfully treated by reprogramming of sensitivity. Superficial wound infection was treated successfully with antibiotics in nine patients (six dual, three single chamber, P = not significant). Three patients with DDD generators developed sustained atrial fibrillation: two required reprogramming to VVI mode and one required cardioversion.

CONCLUSIONS

Permanent pacing in a large tertiary referral centre with experienced operators carries a low risk. Infection rates are low, < 1% overall but significantly higher in patients who undergo temporary pacing before implantation. Lead displacement and undersensing are more likely to occur with atrial than ventricular leads. The overall complication rate for dual chamber pacing, however, is no higher than for single chamber pacing.

Detection of immunoglobulin M (IgM), IgA, and IgG Norwalk virus-specific antibodies by indirect enzyme-linked immunosorbent assay with baculovirus-expressed Norwalk virus capsid antigen in adult volunteers challenged with Norwalk virus

Pre- and postexposure sera collected from 17 adult volunteers challenged with Norwalk virus as described previously (D. Y. Graham, X. Jiang, T. Tanaka, A. Opekun, P. Madore, and M. K. Estes, J. Infect. Dis. 170:34-43, 1994) were examined for Norwalk virus-specific immunoglobulin M (IgM), IgA, and IgG by indirect enzyme-linked immunosorbent assays with recombinant Norwalk virus antigen bound to the solid phase. Sixteen of the 17 volunteers had evidence of past infection, all presenting with preexisting IgG antibody of high avidity; only one volunteer had no evidence of previous infection. Virus infection was detected in 14 of the 16 volunteers with evidence of past infection, and 9 of the infected volunteers had symptomatic illness. A significant rise in both virus-specific IgA and IgG titers was detected after challenge in all of the volunteers who became ill. Five of the asymptomatic volunteers who were infected had rising titers of virus-specific IgG, but only two of the five had a concomitant rise in their virus-specific IgA antibody titers. Antibody rises were detectable in eight of nine ill volunteers 8 to 11 days after challenge but in the asymptomatic volunteers only after more than 15 days had elapsed. Virus-specific IgM was detected after challenge in all 14 infected volunteers. Between symptomatic and asymptomatic volunteers there were no significant differences in titers of virus-specific IgG and IgA in serum before challenge; however, there were significantly higher titers in symptomatic volunteers between 8 and > 90 days after challenge for virus-specific IgG and 8 and 24 days after challenge for virus-specific IgA.

Benzodiazepine-induced outcome revaluation and the motivational control of instrumental action in rats

It has been argued that the control of instrumental action by motivational states is indirect, being mediated by the effects these states have on the incentive value of the instrumental outcome (A. Dickinson & B. W. Balleine, 1994). In this study, the benzodiazepine agonist midazolam was found to control instrumental action in a similar manner. Midazolam (1 mg/kg) increased rewarded instrumental performance in rats trained undeprived but only elevated performance in extinction when rats were reexposed to the instrumental outcome under midazolam before the test. This effect of reexposure under midazolam did not transfer to a test conducted under food deprivation, suggesting that it was not produced by drug-induced hunger. Finally, in animals trained hungry, midazolam was found to block outcome devaluation induced by a reduction in food deprivation, indicating that midazolam and food deprivation affect outcome value via a common substrate.

The international mobility of nurses: a United Kingdom perspective

This paper examines available information on the flows of qualified nurses to and from the United Kingdom, and reports on the results of a questionnaire survey of U.K.-based nurses who had worked abroad. The data examined reveals an upward trend in both "inflow" and "outflow" of nurses in the period 1984-91, with indications of a net outflow. The survey results indicated that Australia was the most common destination; most nurses working abroad had moved to the English-speaking countries of North America and Australasia. Barriers and incentives to international mobility of nurses are discussed, and likely future trends in mobility are examined.

The role of ultrasound in the management of zone 1 flexor tendon injuries

We have reviewed 22 flexor tendon repairs in zone 1 undertaken in Hobart, Tasmania, during the period 1986 to 1991. The repairs were assessed using both ultrasound and Strickland's clinical criteria. The results are presented, and the two methods of assessment compared. A new method of grading results is proposed based on the ultrasound findings. We have demonstrated that ultrasound has an important role to play in assessing tendon repairs, both in the on-going management and as an objective method of measuring the results of repair.

46,XY pure gonadal dysgenesis (Swyer-James syndrome)--Y or Y not?: a review

The designation "pure gonadal dysgenesis" is applied to a particular variety of defective organo-genesis, in which phenotypically female patients with a 46,XY karyotype have complete lack of functioning gonadal tissue. The latter are represented anatomically by the presence of bilateral, elongated, nonfunctioning, rudimentary "streak" gonads composed of fibrous tissue, although normal female internal genitalia are present. The purpose of this review is to present the existing literature accumulated from 1955 to 1992 pertaining to 46,XY pure gonadal dysgenesis (Swyer-James syndrome), add the findings of a personally observed patient, and highlight the complexities in attempting to determine the etiology of this rare condition.

Alcohol education courses for offenders: ten years after

Data from a survey of U.K. agencies are presented. Trends in service provision for drinking offenders are reported, in the context of two previous surveys. National development of service provision is examined, since the original survey, reported in 1982. Findings from the survey have suggested that the field has become stagnant, due to a failure to merge research and practice. Alcohol educators who continue to ignore lessons from such surveys may face extinction from the field.

Familial Alzheimer's disease. A pedigree with a mis-sense mutation in the amyloid precursor protein gene (amyloid precursor protein 717 valine-->glycine)

Ten affected individuals are described from a kindred with autosomal dominant familial Alzheimer's disease in which a mutation in the amyloid precursor protein gene results in a valine to glycine substitution at amyloid precursor protein 717 which co-segregates with the disease. The mean age at onset of symptoms was 52 years with a range from 40 years to 67 years. The median duration of the disease was 11 years, with a range of 7-16 years. All individuals fulfilled the National Institute for Neurological and Communicative Disorders and Stroke criteria for probable Alzheimer's disease. A homogeneous clinical and neuropsychological pattern was evident within the family. Myoclonic jerks, seizures, depression and a lack of insight were common features. Positron emission tomography demonstrated biparietal bitemporal hypometabolism in the one affected individual who was studied. The diagnosis was confirmed histopathologically in one individual.

Multiple myeloma: the biology of malignant plasma cells

Multiple myeloma remains a difficult disorder to treat and cures are virtually unknown. Most modalities of treatment have been tried on an empirical basis, and a greater understanding of the nature of myeloma progenitors may lead to more specific therapies. In the past few years interest in the biology of myeloma plasma cells has increased and the current state of knowledge is summarised in this review. Myeloma clonogenic, or colony, assays have been attempted by many groups. Despite this, no direct equivalent is available of the CFU-GM assay for granulocyte-macrophage progenitors in normal marrow. No published methods have been exported widely to other laboratories. Recently, myeloma plasma cells were found to express a wide range of adhesion molecules permitting cell to cell and cell to stroma interactions. This finding may explain the difficulty of myeloma colony assays, since adhesive clumping must be prevented. The observation that interleukin (IL)-6 can stimulate myeloma plasma cells led to further work with other cytokines such as IL-3 and GM-CSF. The precise role of IL-6 in the usual case of bone marrow myeloma remains unclear however.

Discrimination of moving events which accelerate or decelerate over the listening interval

Grantham [Grantham, J. Acoust. Soc. Am. 79, 1939-1949 (1986)] has proposed that subjects are able to resolve the velocity of a moving sound source simply by determining the distance traveled and the time required to complete the movement. In the current experiment, subjects were able to discriminate between accelerated and decelerated movements which were identical on both parameters; that is, the accelerated and decelerated movements began and ended at the same locus and required the same amount of time to be completed. The minimum duration required to discriminate between these two movement patterns was 310 and 90 ms, respectively, for displacements of 9 degrees and 18 degrees. These results suggest that, under some conditions, the perception of velocity in the auditory modality may be based upon something more than a simple comparison of the total distance traveled and the time required to complete the movement.

The role of adhesion molecules in multiple myeloma

Human myeloma plasma cells had been considered to express few surface antigens until recently. The past two International Workshops on Leucocyte Differentiation Antigens have shown that myeloma cells can express a range of surface molecules, and it has become clear that many of these have adhesive functions. The identification of ICAM-1 (CD54) and H-CAM (CD44) on human plasma cells was the initial observation, and other antigens such as N-CAM (CD56) and LFA-3 (CD58) have been confirmed as features of malignant plasma cells in particular. The degree of expression of LFA-1 (CD11a) remains to be characterised fully. It seems probable that the loss of some adhesion structures may be associated with increased malignancy and plasma cell leukaemia. At the present time there are few studies relating to the function of these molecules, although homotypic adhesion appears to occur, and it is likely that such studies will shed light on the pathogenesis of myeloma.

A viral long terminal repeat expressed in CD4+CD8+ precursors is downregulated in mature peripheral CD4-CD8+ or CD4+CD8- T cells

The long terminal repeat from a thymotropic mouse mammary tumor virus variant, DMBA-LV, was used to drive the expression of two reporter genes, murine c-myc and human CD4, in transgenic mice. Expression was observed specifically in thymic immature cells. Expression of c-myc in these cells induced oligoclonal CD4+ CD8+ T-cell thymomas. Expression of human CD4 was restricted to thymic progenitor CD4- CD8- and CD4+ CD8+ T cells and was shut off in mature CD4+ CD8- and CD4- CD8+ T cells, known to be derived from the progenitor double-positive T cells. These results suggest the existence of similar and common factors in CD4+ CD8- and CD4- CD8+ T cells and support a model of differentiation of CD4+ CD8+ T cells through common signal(s) involved in turning off the expression of the CD4 or CD8 gene.

Expression of adhesion molecules LFA-3 and N-CAM on normal and malignant human plasma cells

Normal and malignant plasma cells were investigated for the expression of seven cellular adhesion molecules by immunofluorescence microscopy. The antigens investigated were CD2 and its ligand, LFA-3 (CD58). LFA-1 alpha (CD11a) and LFA-1 beta (CD18) and their ligand ICAM-1 (CD54), H-CAM (lymphocyte homing receptor; CD44) and N-CAM (CD56). Marrow from 18 patients with myeloma, two with plasma cell leukaemia (PCL), four with monoclonal gammopathy of uncertain significance (MGUS) and 10 normal allogeneic bone marrow donors was studied. All plasma cells from normals and multiple myeloma patients were negative for CD2, CD11a and CD18. All normal and myeloma marrow plasma cells were positive for ICAM-1. 16/18 myeloma cases tested, and all other samples (normal, MGUS and PCL), contained plasma cells positive for H-CAM. Only one normal, but 12/16 myelomas tested were positive for N-CAM (P less than 0.02). One of four MGUS cases was moderately positive and one other weakly positive for N-CAM. Both PCLs were N-CAM negative. 12/18 myelomas were positive for LFA-3, but only two normals (P less than 0.05). All MGUS cases were negative for LFA-3, as was one PCL, the other being weakly positive. Three cases were negative for both adhesion molecules, three cases expressed only N-CAM or LFA-3 and 10 cases expressed both. LFA-3 and N-CAM are expressed significantly in myeloma rather than normal plasma cells. Cases of MGUS may express N-CAM but not, in this small series, LFA-3. Plasma cells in the peripheral blood (PCL) and plasma cell lines express little or no LFA-3 or N-CAM.

Normal and neoplastic human plasma cells express bcl-2 antigen

The bcl-2 (B-cell leukaemia/lymphoma 2) proto-oncogene is associated with the 14;18 translocation in follicular lymphoma juxtaposing bcl-2 with the immunoglobulin heavy chain region. bcl-2 has been cloned and sequenced and a monoclonal antibody to amino acids 41 to 54 of the bcl-2 protein has been raised. The expression of bcl-2 in follicular lymphoma has been demonstrated by immunohistological staining and also in normal lymphocytes. The presence of the bcl-2 onco-protein has been demonstrated by immunofluorescence using conventional and confocal microscopy in normal and malignant plasma cells from myeloma patients and myeloma cell lines. Plasma cells from 8/8 normal donors were positive, although the proportion of positive cells and the intensity of staining varied. Eight of 10 patients with myeloma or plasma cell leukaemia had positive plasma cells, and 6/11 plasma cell lines and one lymphoma cell line also expressed the onco-protein. bcl-2 expression is a feature of normal plasma cells and data from the cell lines confirm that expression is not dependent on the presence of the 14;18 translocation.

Characterisation of a series of human immunodeficiency virus isolates derived sequentially from a single patient

Five HIV-1 isolates were obtained sequentially from a single seropositive individual during the later stages of AIDS. Four of these isolates were adapted to grow in a continuous human T-lymphocytic cell line. Comparative biological and biochemical studies of the virus isolates were made using persistently infected cultures or virus derived from these systems respectively. The data obtained clearly shows that viruses with different biological properties can be isolated from the same individual at different times during the course of clinical AIDS.

A case of progressive encephalomyelitis with rigidity and positive antiglutamic acid decarboxylase antibodies [corrected]

A 50 year old woman developed progressive encephalomyelitis with rigidity over a three year period. Her CSF contained oligoclonal bands and both her serum and CSF contained antibodies directed against GABA-ergic synapses (antiglutamic acid decarboxylase [corrected] antibodies). These antibodies have recently been described in cases of stiff man syndrome. Both disorders may be part of a clinical spectrum that has an underlying autoimmune basis.

Surface antigen expression of human neoplastic plasma cells includes molecules associated with lymphocyte recirculation and adhesion

The surface phenotype of neoplastic plasma cells from peripheral blood of plasma cell leukaemia patients and bone marrow of patients with myelomatosis was investigated with two monoclonal antibody panels including 50 selected from the B cell panel of the IVth International Workshop on Leucocyte Differentiation Antigens. The majority of myelomas expressed CD24 (HB8 epitope only), CD38, CD44, CD54, and the antigen recognized by the monoclonal antibody 8A. A range of other antigens may also be expressed including CD10, CD32 (FcR II), CD19, CD20 and MHC Class II. Antigens expressed by myeloma plasma cells can be considered in three groups: (a) antigens associated with lymphocyte and plasma cell differentiation: (b) antigens which are not lineage specific: and (c) molecules concerned with lymphocyte recirculation and intercellular adhesion (CD44 and CD54). The significance of CD44 and CD54 expression by plasma cells and the potential interaction of plasma cells with T lymphocytes and monocytes is discussed.

Characterization of new IgG lambda myeloma plasma cell line (EJM): a further tool in the investigation of the biology of multiple myeloma

A new IgG lambda myeloma plasma cell line known as EJM was established from a peritoneal effusion from a patient with extramedullary myeloma. The EJM cells have a plasmablastic morphology with abundant rough endoplasmic reticulum and grow in liquid culture with a doubling time of 72 h and a labelling index of 36%. In addition to cytoplasmic IgG lambda, the cells are positive for CD9, 20, 32, 38, 44, 54, 71, 78, MHC Class II DR, DP and DQ. Studies on the control of the cell line proliferation by cytokines have demonstrated stimulation with interleukin 6. In contrast interferon alpha produces marked inhibition of proliferation in doses of greater than 100 units/ml. The culture conditions and the importance of accessory cells and cytokines in supporting myeloma plasma cell growth in vitro are discussed.

Rapid assessment of haemophilia A carrier state by non-invasive techniques using the polymerase chain reaction

The polymerase chain reaction (PCR) was used to amplify two polymorphic regions in the factor VIII gene. In vitro synthesis of DNA was achieved using samples obtained from buccal cells, urine, and hair follicles in addition to purified genomic and crude DNA samples prepared from whole blood. Female members of two kindreds affected with haemophilia A were assessed for carrier state using direct restriction fragment length polymorphism analysis of amplified gene products in the Bc1I and XbaI regions. It is concluded that this is a non-invasive, rapid, and inexpensive technique for carrier detection.

Schizophrenia as an anomaly of development of cerebral asymmetry. A postmortem study and a proposal concerning the genetic basis of the disease

Schizophrenia is associated with structural changes (eg, a mild degree of ventricular enlargement) in the brain, although whether these precede onset of illness or progress with episodes is not established. In a postmortem study, we find that ventricular enlargement affects the posterior and particularly the temporal horn of the lateral cerebral ventricle. By comparison with controls and with patients suffering from Alzheimer-type dementia (in which there is also temporal horn enlargement), the change is highly significantly selective to the left hemisphere. This deviation was not accompanied by an increase in glial cell number (examined chemically by assay of diazepam-binding inhibitor immunoreactivity and microscopically by density of staining with the Holzer technique). The findings are consistent with the view that schizophrenia is a disorder of the genetic mechanisms that control the development of cerebral asymmetry.