The role of maternal VegT in establishing the primary germ layers in Xenopus embryos

VegT is a T-box transcription factor whose mRNA is synthesized during oogenesis and localized in the vegetal hemisphere of the egg and early embryo. We show that maternally expressed VegT controls the pattern of primary germ layer specification in Xenopus embryos. Reduction of the maternal store completely alters the fates of different regions of the blastula so that animal cell fate is changed from epidermis and nervous system to epidermis only, equatorial cell fate is changed from mesoderm to ectoderm, and vegetal cell fate is changed from endoderm to mesoderm and ectoderm. Vegetal cells lose their capacity both to form endoderm and to release mesoderm-inducing signals. These results show that a single maternally expressed gene controls the patterning of the Xenopus blastula.

Platelet-derived growth factor, insulin-like growth factors, fibroblast growth factors and transforming growth factor beta do not account for the cell growth activity present in bovine milk

Cation-exchange chromatography effectively concentrates the cell growth activity present in whey and we have used this process as a basis to characterise further the growth factors present in bovine milk. Under neutral conditions, total bioactivity in the growth factor-enriched cation-exchange fraction chromatographed with an apparent molecular mass of 80-100 kDa. In contrast, acid gel-filtration chromatography resolved two peaks of cell growth activity. A peak at 15-25 kDa contained the bulk of growth activity for Balb/c 3T3 fibroblasts while bio-activity for L6 myoblasts and skin fibroblasts eluted with a molecular mass of 6 kDa. A peak of inhibitory activity for Mv1Lu and MDCK cells also eluted at 15-25 kDa. Both IGF-I and IGF-II were purified from fractions that eluted at 6 kDa, although the IGF peptides alone did not account for the total bioactivity recovered. Platelet-derived growth factor (PDGF), identified by radioreceptor assay, eluted at a slightly higher molecular mass than the peak of growth activity for Balb/c 3T3 cells, and an anti-PDGF antibody was without effect on the growth of Balb/c 3T3 cells in response to the whey-derived factors. Further purification of the inhibitory activity for epithelial cells yielded a sequence for transforming growth factor beta (TGF-beta), and all inhibitory activity for Mv1Lu cells was immunoneutralised by an antibody against TGF-beta. In contrast, this antibody decreased the growth of Balb/c 3T3 fibroblasts in the whey-derived extract by only 10%. Finally, a cocktail of recombinant growth factors containing IGF-I, IGF-II, PDGF, TGF-beta and fibroblast growth factor 2 stimulated growth of Balb/c 3T3 cells to a level equivalent to only 51% of that observed in the milk-derived growth factor preparation. We conclude that: (i) cell growth activity recovered from bovine whey is present in acid-labile high molecular weight complexes; (ii) all cell growth inhibitory activity for epithelial cells can be accounted for by TGF-beta; (iii) IGF-I and IGF-II co-elute with the major peak of activity for L6 myoblasts and skin fibroblasts, although the IGF peptides alone do not explain the growth of these cells in the whey-derived extract; and (iv) neither PDGF nor TGF-beta account for the 15-25 kDa peak of Balb/c 3T3 growth activity. These data suggest the presence of additional mitogenic factors in bovine milk.

Involvement of polyamines in selenomethionine induced apoptosis and mitotic alterations in human tumor cells

The efficacy of dietary selenium supplementation is currently being evaluated in intervention trials. However, the biological mechanisms underlying the cancer chemopreventive effects of selenium supplementation have yet to be elucidated. Selenium metabolism and polyamine biosynthesis are linked in their common requirement for S-adenosylmethionine. Selenomethionine was the predominant form of selenium in the dietary supplement, therefore we evaluated the anti-tumorigenic effects of selenomethionine. We found that selenomethionine inhibited tumor growth (both in A549 lung and HT29 colon cancer cells) in a dose-dependent manner. At 24 and 72 h, polyamine content of A549 and HT29 cancer cell lines was decreased at doses that inhibited 50% of normal growth. Selenomethionine treatment induced apoptosis in both cancer cell lines. Exogenous spermine administration, which replenishes intracellular polyamine levels, prevented selenomethionine induced apoptosis. Selenomethionine administration to the cancer cell lines increased the number of cells in metaphase. This cell cycle effect appeared to be reversed with the co-administration of selenomethionine and spermine. These data suggested that at least part of the anti-carcinogenic effects of selenium supplementation might be due to a depletion in polyamine levels. This depletion of polyamines leads to an induction in apoptosis and perturbations in the cell cycle.

A human xenograft model for testing early events of epithelial neoplastic invasion

We report on a model of human prostate tumor cell invasion using the SCID (severe combined immunodeficient) mouse diaphragm. Tumor cells were injected into SCID mice intraperitoneally and the diaphragms harvested three to five weeks later. Electron microscopy showed tumor cell penetration of the mesothelial cell layer and adhesion to the underlying basement membrane on the inferior surface of the mouse diaphragm, where colonies developed. Immunohistochemistry showed invasion by tumor cells through the basement membrane into the muscle of the diaphragm, presence of human tumor cells among the muscle cells and the presence of selected proteins on the invasion front of the tumor cells. Digital image analysis enabled quantitative comparison of events in the metastatic cascade by variants of the tumor cell line and evaluation of the effectiveness of a putative tumor inhibitor. Results suggest that the SCID mouse diaphragm model is a convenient, effective, easily oriented and reproducible in vivo model of the early events associated with human prostate tumor cell invasion.

Maternal beta-catenin establishes a ‘dorsal signal’ in early Xenopus embryos

In previous work, we demonstrated that maternally encoded beta-catenin, the vertebrate homolog of armadillo, is required for formation of dorsal axial structures in early Xenopus embryos (Heasman, J., Crawford, A., Goldstone, K., Garner-Hamrick, P., Gumbiner, B., Kintner, C., Yoshida-Noro, C. and Wylie, C. (1994). Cell 79, 791–803). Here we investigated, firstly, the role(s) of beta-catenin in spatial terms, in different regions of the embryo, by injecting beta-catenin mRNA into individual blastomeres of beta-catenin-depleted embryos at the 32 cell stage. The results indicate that beta-catenin can rescue the dorsal axial structures in a non-cell-autonomous way and without changing the fates of the injected cells. This suggests that cells overexpressing beta-catenin send a ‘dorsal signal’ to other cells. This was confirmed by showing that beta-catenin overexpressing animal caps did not cause wild-type caps to form mesoderm, but did cause isolated beta-catenin-deficient marginal zones to form dorsal mesoderm. Furthermore beta-catenin-deficient vegetal masses treated with overexpressing caps regained their ability to act as Nieuwkoop Centers. Secondly, we studied the temporal activity of beta-catenin. We showed that zygotic transcription of beta-catenin starts after the midblastula transition (MBT), but does not rescue dorsal axial structures. We further demonstrated that the vegetal mass does not release a dorsal signal until after the onset of transcription, at the midblastula stage, suggesting that maternal beta-catenin protein is required at or before this time. Thirdly we investigated where, in relationship to other gene products known to be active in axis formation, beta-catenin is placed. We find that BVg1, bFGF, tBR (the truncated form of BMP2/4R), siamois and noggin activities are all downstream of beta-catenin, as shown by the fact that injection of their mRNAs rescues the effect of depleting maternally encoded beta-catenin. Interference with the action of glycogen synthase kinase (GSK), a vertebrate homolog of the Drosophila gene product, zeste white 3 kinase, does not rescue the effect, suggesting that it is upstream.

Reduced bile acid-induced apoptosis in "normal" colorectal mucosa: a potential biological marker for cancer risk

Dietary factors, including bile acids, are important in the causation of colorectal cancer (CRC). We have previously shown that in vitro exposure of colorectal mucosal biopsies to low concentrations of bile acids produces apoptosis selectively in goblet cells. Apoptosis is an important mechanism for clearing DNA-damaged cells. Inhibition of apoptosis would result in increasing accumulation of DNA-damaged cells, resulting in increased cancer risk. We compared the percentage of apoptosis induced by bile acids in mucosal biopsies from CRC patients with that of noncancer subjects. Mucosal biopsies from 15 to 20 cm from the anal verge were incubated in 1 mM sodium deoxycholate, and the percentage of goblet cells undergoing apoptosis was quantitated. Seven patients with a history of CRC within the previous 5 years were compared with 18 noncancer subjects [4 neoplasia free and 14 with small (< or = 9 mm) polyps only]. The CRC patients had a significantly lower percentage of apoptosis than noncancer subjects; the mean for CRC was 10.7% (range, 0.9-26%) and for noncancer subjects was 55.9% (range, 20.3-71%; P < or = 0.001). Two other noncancer patients had very high-risk lesions, i.e., large villous adenomas and multiple large polyps during several colonoscopies over the previous 6 years. Their percentage of apoptosis was in the cancer range, i.e., 6.2 and 10.7%. Reduced apoptotic ability may imply increased cancer risk. By applying a quantitative bile acid-induced apoptosis assay to colorectal mucosal biopsies, the percentage of apoptosis was found to be significantly reduced in CRC patients. This assay may prove to be a useful intermediate biological marker for identifying subjects at increased risk of cancer.

Read Codes Version 3: a user led terminology

Version 3 of the Read Codes was designed in response to a new set of requirements generated by three new terming initiatives in the UK, the Clinical Terms Project, the Professions Allied to Medicine Terms Project and the Nursing Terms Project. The challenge was to cope with the detail required by clinical specialists for maintaining a computerised record, to capture the natural language used by clinicians in their everyday work, and to support efficient analysis across medical records required to extract information from clinicians' individual patient data. The structure of Version 3 allows a directed acyclic graph to replace the traditional hierarchy; permits multiple such graphs if necessary; introduces qualifiers, embedding these in an information model to support analysis; introduces one-to-many mapping to external classifications where this is necessary; and maintains the tradition of a dynamic terminology that stresses the inclusion of natural clinical terms.

Extraskeletal myxoid chondrosarcoma with intracisternal microtubules

A case of extraskeletal myxoid chondrosarcoma with intracisternal microtubules is presented. The microtubules were generally straight, parallel, closely packed, and evenly spaced, but they did not form geometric arrays. Aggregates of stromalike myxoid material were present in the cisternae and the adjacent cytoplasm. Microtubules were never found within the cytoplasm. A similar ultrastructural appearance was seen in 4 of 10 other examples of extraskeletal myxoid chondrosarcoma.

Effects of transforming growth factor beta 1 on growth and apoptosis of human acute myelogenous leukemia cells

Because limited studies examined effects of transforming growth factor (TGF) beta 1 on growth of human acute myelogenous leukemia (AML) cells, we used factor-dependent and primary AML cells to assess TGF-beta 1 effects on human AML cell growth. OCI-AML1 cells were growth inhibited by TGF-beta 1 regardless of which growth factor was used as a stimulus. In contrast, AML-193 cells were resistant to TGF-beta 1 when grown with or without growth factors. UCSD/AML1 cells were sensitive to TGF-beta 1 inhibition when grown with most cytokines but were relatively resistant to TGF-beta 1 in the presence of macrophage colony-stimulating factor (M-CSF). Although cells grown from 5 of 6 AML patients were inhibited by TGF-beta 1, cells from 1 AML patient were growth stimulated by TGF-beta 1 in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF), M-CSF, or mast cell growth factor (kit ligand). Thus, 3 growth patterns with TGF-beta 1 were observed: (a) sensitivity to growth inhibition; (b) resistance; and (c) factor-dependent resistance. Further studies showed that AML-193 and UCSD/AML1 cells expressed type II TGF-beta 1 receptors and that ability of TGF-beta 1 to decrease GM-CSF receptors did not correlate with growth inhibition. AML-193 cells and UCSD/AML1 cells grown with M-CSF could be propagated in 1 ng/ml TGF-beta 1, but UCSD/AML1 cells grown with GM-CSF and TGF-beta 1 died. Morphology and agarose gel analysis of DNA showed UCSD/AML1 cells underwent apoptosis when grown with GM-CSF and TGF-beta 1 but not with M-CSF and TGF-beta 1. Similar studies of OCI-AML1 cells showed that TGF-beta 1 induced apoptosis of cells grown in 5637 bladder cell-conditioned medium or GM-CSF. These studies indicate that human AML cells exhibit heterogeneous growth responses to TGF-beta 1 and that some effects of TGF-beta 1 on myeloid cells occur through programmed cell death.

Insulin reduces norepinephrine transporter mRNA in vivo in rat locus coeruleus

Acute and chronic in vitro insulin treatment can inhibit the uptake of norepinephrine (NE) by adult rat brain synaptosomes and slices, fetal neuronal cultures, and PC12 cells. In the present study we tested whether chronic in vivo insulin treatment could alter the biosynthetic capacity of rat locus coeruleus neurons for the NE transporter protein (NET). Chronic third ventricular insulin treatment resulted in a suppression of NET mRNA to about one third of the level of vehicle-treated controls. Our finding suggests that insulin may play a regulatory role in the synthesis of this transporter, thereby modulating activity in CNS noradrenergic pathways.

Bladder outlet obstruction treated with transurethral ultrasonic aspiration. One-year follow-up on 59 patients

Fifty-nine males with bladder outlet obstruction were treated with transurethral ultrasonic aspiration of the prostate. Utilizing a 26.5F urethral sheath, surgery was accomplished with a 10F, 0-700-micron-vibration-level ultrasonic tip with an excursion rate of 39 kHz. Complete removal of the adenoma was accomplished followed by transurethral electrocautery biopsies of both lateral lobes to compare pathologic specimens. One year follow-up revealed satisfactory voiding patterns in 57 of 59 men (96%). Bladder neck contractures developed in 2 men. Pathologic comparisons showed 100 percent correlation between aspirated and TUR specimens (56 BPH, 3 adenocarcinoma). Forty-seven men were active sexually preoperatively (6 with inflatable penile prostheses). Post ultrasonic aspiration, 46 men had erectile function similar to preoperative levels with 1 patient suffering erectile dysfunction. Forty men (85%) had antegrade ejaculation while 7 (15%) experienced retrograde or retarded ejaculation. No patients were incontinent.

Carboplatin, ifosfamide and etoposide with mid-course vincristine and thoracic radiotherapy for 'limited' stage small cell carcinoma of the bronchus

Forty-two patients with small cell lung cancer were treated with a combination of carboplatin, ifosfamide and etoposide. Vincristine was given on day 14 of each course, the courses being repeated every 28 days for a maximum of six. Thoracic radiotherapy was given 4 weeks after the last course of chemotherapy but no prophylactic cranial radiotherapy was administered. Thirty patients had clinically limited state disease, the remaining patients having contralateral neck lymphadenopathy and/or pleural effusions. Elevated enzyme levels (alkaline phosphatase, LDH, ALT, GGT) were noted in 69% of patients. Twenty-four patients (57%) achieved a complete response (CR) when assessed one month after the end of treatment. A further 21% of patients had a partial response (PR). Median duration of CR was 14 months and of PR 8 months. Cerebral metastases were the sole site of relapse in 13% of the CR patients. Myelosuppression was severe with a median nadir of neutropenia of 0.2 x 10(9) cells 1-1. However, 74% of the patient group received all six courses of chemotherapy and only 16 courses (7%) were delayed because of toxicity. There were three deaths associated with treatment-related neutropenia. The median survival of the total group was 14 months, with an actuarial 2 year survival of 37% and a minimum follow-up of 18 months. [A recent analysis, March 1989, demonstrated a 33%, 2 year actual survival.]

Evidence from family studies that the gene causing Huntington disease is telomeric to D4S95 and D4S90

A DNA probe (D4S95) that detects a variable number of tandem repeats and a single-site-variation polymorphism after digestion with a single restriction enzyme, AccI, has previously been described. The order of this probe relative to the gene for Huntington disease (HD) and other previously described markers has not been established. Analysis of 24 affected families with HD has shown that D4S95 is in tight linkage with the gene causing HD, with a maximal Lod score of 12.489 at a theta of .03. D4S90 is a probe which maps to 4p16.3, telomeric to D4S95, and detects polymorphisms with HincII and other enzymes. In one affected person, recombination has occurred between D4S10 and HD, between D4S95 and HD, and in all likelihood also between D4S90 and HD, which strongly suggests that the gene for HD is telomeric to all these DNA probes. This suggests that the gene causing HD is located in the most distal region of the short arm of chromosome 4, flanked by D4S90 and the telomere, and supports the locus order D4S10-D4S95-D4S90-HD-telomere. D4S95 is a most useful DNA marker for predictive testing programs, while D4S90 will serve as a useful starting point for identifying DNA fragments closer to the gene for HD.

Cellular and genetic properties of two melanoma cell lines established from the same tumor

We report here the detailed cellular and genetic analysis of two new human melanoma cell lines established from the same tumor biopsy. Although derived from the same tumor biopsy, the two lines differed in their method of in vitro culture establishment with one line (HA-A) grown first in agar culture and then transferred to liquid culture, while the second cell line (HA-L) was established directly from cells grown in liquid culture. Detailed characterization of both cell lines was performed using techniques to analyze their cytogenetic, surface marker, morphology (light and electron microscopy), growth (in agar and in nude mice), and drug sensitivity profiles in comparison to the original tumor biopsy. Our results revealed no significant biologic or genetic difference between the two cell lines established by different culture techniques. Our results suggest that in some cases agar culture prior to liquid culture may be useful in establishment of human tumor cell lines.

Maternal serum alpha-fetoprotein is a marker for fetal anomalies in pediatric surgery

Maternal serum alpha-fetoprotein (MS-AFP) screening has become part of routine obstetric care. Although elevated MS-AFP was originally associated with neural tube defects (NTD), it is also able to detect several fetal anomalies of interest to a pediatric surgeon, ie, ventral abdominal wall defects, intestinal atresias, and sacrococcygeal teratomas. Previously, decreased MS-AFP had only been associated with fetal trisomies, but not surgically correctable lesions. In the present study, we review our recent experience with both elevated and decreased MS-AFP as a marker to detect fetal anomalies of concern to the pediatric surgeon. Forty-one fetal anomalies were associated with 333 pregnancies referred for follow-up after abnormal MS-AFP screening results from November 1985 through November 1986. One hundred ninety-six were elevated and 139 were decreased. In most cases, evaluation included counseling, repeat MS-AFP, level II ultrasound, and amniocentesis. This revealed elevated MS-AFP to be associated with 32 (16.3%) anomalies (2 NTD, 5 anencephalics, 5 ventral abdominal wall defects, 1 stage IV-S neuroblastoma, 1 renal anomaly, 1 ventriculomegaly, 15 fetal demises, and 2 fetal-maternal bleeds). Decrease in MS-AFP was associated with nine (6.4%) anomalies (2 congenital diaphragmatic hernias, 3 Down's syndrome, 1 Turner's syndrome, 2 duodenal atresias, and 1 choroid plexus cyst). In this study, MS-AFP detected several fetal anomalies known to be associated with abnormal MS-AFP and three anomalies not previously described (congenital diaphragmatic hernia, neuroblastoma, and choroid plexus cyst). Elevated as well as decreased MS-AFP are significant and should be pursued by a full prenatal evaluation.(ABSTRACT TRUNCATED AT 250 WORDS)

Suppression of basal and Corynebacterium parvum-augmented NK activity during chemically induced tumor development

C3H mice were injected subcutaneously (s.c.) with a tumorigenic dose (150 micrograms/mouse) of 3-methylcholanthrene (MC), followed by a 24-h injection and subsequent weekly injections of Corynebacterium parvum (CP) i.p. for a total of 100 days. Basal and CP-augmented NK cell activities were measured in controls and treatment groups during pre-tumor and tumor development stages. Basal NK activity in spleen, peripheral blood and lung tissue was enhanced by CP, but was suppressed by MC. A resulting transient MC induced suppression of splenic NK activity at 10 days was partially restored and sustained by CP treatment and immunosuppression was again observed in tumor-bearing compared to control mice. Mice treated with MC alone showed a higher tumor incidence than animals treated with MC + CP at 45-60 days, while there was no difference in tumor incidence in these two treatment groups at 100 days post injection. The mechanism of the observed transient immunosuppression induced by MC appears to be related to an early toxic effect on large granular lymphocytes (LGL) which was decreased at 10 days and again at 100 days in tumor-bearing mice. Although MC did not appear to exert an effect on effector:target cell conjugate formation, an early suppression in the lytic activity of LGL, may have predisposed the animal to malignant transformation of susceptible cells at the site of MC injection.

T cell profiles in vitiligo

The purpose of our investigation was to quantitatively assess T cell profiles in vitiligo and to correlate any aberrations in these findings with the spectrum of clinical disease. Twenty randomly selected vitiligo patients and sixteen healthy matched control subjects were studied. The immunofluorescence and complement-mediated cytotoxicity assays were used to determine the percentages of total T (OKT3), helper (OKT4), and suppressor (OKT8) cells in the peripheral blood of patients and controls. Both assays gave comparable results. Patients with vitiligo had a statistically significant decrease in helper cells and helper/suppressor ratios in comparison with control subjects (p less than 0.01). In addition, there was a statistically significant decrease in helper cells among patients with a disease duration of less than 1 year (p less than 0.01) and in patients who produced serum autoantibodies (p less than 0.05). These findings tend to suggest that aberrations in cell-mediated immunity may be operative in the pathogenesis of vitiligo.

Purification of SV40 T-antigen by SV40 DNA-sepharose affinity chromatography

T-antigen from SV40-infected BSC-1 cells was purified approximately 30,000 fold using a rapid purification procedure consisting of ammonium sulfate fractionation followed by chromatography on hydroxylapatite, blue-sepharose, and SV40 DNA-sepharose. The SV40 DNA-sepharose was optimized for the binding of T-antigen by the covalent attachment of the SV40 DNA at its BamHI site to cyanogen bromide activated sepharose. The most highly purified T-antigen appeared as a single polypeptide of 94 K daltons by polyacrylamide gel electrophoresis.

Adult-onset acid maltase deficiency: a postmortem study

In a postmortem study of a patient with adult-onset acid maltase deficiency (AMD), morphological abnormalities were confined to skeletal muscle and consisted of a vacuolar myopathy. Acid maltase activity, however, was approximately 6% of normal in muscle, liver, and brain, and 3% of normal in heart. Kinetic characteristics, and inhibition by antibodies and Zn++, showed that the residual activity was "authentic" acid maltase. Neutral maltase activity was normal in muscle and liver, but decreased in brain (55% of normal) and heart (19% of normal). Although the relative decrease of acid maltase was similar in different tissues, absolute residual activity was lowest in skeletal muscle: this may explain the selective involvement of this tissue in late-onset AMD.

The in vivo development of plasma cells: a morphologic study of human cerebrospinal fluid

This is a case study of a patient with the clinical diagnosis of meningoencephalitis. It demonstrates the in vivo development of plasma cells in the central nervous system. All the stages of in vitro mitogen-induced lymphocyte transformation previously described by light and electron microscopy are recapitulated in this analysis of cerebrospinal fluid. It is postulated that this represents a local humoral immune reaction in the central nervous system and provides morphologic support for the concept that the gamma globulin in cerebrospinal fluid is produced locally in part, in addition to its origin from the plasma proteins.

Basophilic meningitis secondary to lymphoma

In this case report of basophilic meningitis, the patient was a 5-year-old girl under treatment for a diffuse lymphocytic lymphoma. She presented with headache and bilateral papilledema. Cerebrospinal fluid examination showed 60 percent basophils. Subsequent specimens showed a rare blast. It is postulated that after the lymphoma cells had spread to the meninges, a cell-mediated immune reaction was initiated with the appearance of basophils in the exudate.

Incontinentia pigmenti achromians

A patient with incontinentia pigmenti archromians, who was born to consanguineous parents, is described. This is the first reported case from Iran, to our knowledge. A number of features of this disease belong more properly to classical incontinentia pigmenti.

Hyperthyroid myopathy. Intracellular electrophysiological measurements in biopsied human intercostal muscle

Morphological and electrophysiological studies were performed on intercostal muscle biopsies from 2 thyrotoxic patients. The diseased fibers had numerous areas of subsarcolemmal glyogen accumulations and abnormal membranous projections. Both Type I and Type II muscle fibers were atrophied. Diseased fibers were substantially depolarized and when artifically hyperpolarized showed earlier inactivation of the sodium conductance as a function of membrane potential, and a critical depolarization potential more depolarized than in normal fibers. When stimulated at 20 pulses/sec, or faster, the diseased fibers could not generate normal action potentials due to membrane depolarization and the appearance of a marked after-hyperpolarization. Muscle weakness associated with hyperthyroidism is attributed to the reduced membrane excitability.

Predicting offender-patients' reconvictions

In 1963–4 the Oxford University Penal Research Unit managed to collect information about 90 per cent of the offender-patients who were admitted to N.H.S. and Special Hospitals under hospital orders made by criminal courts: this cohort has been described in Crime and Insanity, Vol. II, by Walker and McCabe (1973). One of the by-products of the follow-up of these offender-patients was a rough and ready scoring system for predicting reconvictions (within a two-year follow-up) of 456 offender-patients who were allowed to leave hospital within a year of admission. A prediction system can be used to assist human decision-making (though it should not be a substitute for it)∗ and can also be used to assess the efficacy of measures—such as after-care—by seeing whether individuals with equal predicted reconviction-rates do better with than without the measure (Mannheim and Wilkins, 1955).