Double-Dose Desogestrel: Is it Effective in Adolescent Menstrual Dysfunction?

STUDY OBJECTIVE

Adolescent menstrual dysfunction (AMD) is a common cause of iron deficiency anemia and absences from school. The management of AMD with single- and double-dose desogestrel is largely on the basis of anecdotal evidence. Our aim was to describe the effectiveness and safety of both dosing strategies in our clinic cohort to help guide future management.

DESIGN

Local service evaluation with retrospective analysis of clinic notes.

SETTING

Adolescent gynecology clinic in a tertiary pediatric center in the North West of England.

PARTICIPANTS

Adolescent girls (10-18 years of age) with AMD (n = 129).

INTERVENTIONS

Single-dose (75 µg) desogestrel vs double-dose (150 µg) desogestrel.

MAIN OUTCOME MEASURES

Prevalence of amenorrhea and light spotting, side effects, and discontinuation rates of both dosing regimens.

RESULTS

Forty-three of 87 (49%) adolescent girls who started treatment with a double dose of desogestrel were amenorrheic/experienced light spotting, compared with 7/40 (18%) of girls who started treatment with a single dose (P = .001). Patients taking a double dose of desogestrel were less likely to discontinue overall (double: 45/89 [51%]; vs single: 35/40 [88%]; P < .001) and there was no evidence of an increase in nonbleeding side effects (double: 30/89 [34%]; vs single: 15/40 [38%]; P = .68).

CONCLUSION

Our findings provide evidence that a double dose of desogestrel is associated with a higher prevalence of amenorrhea and light spotting compared with a single dose in adolescent girls with AMD. However, larger studies are needed to further inform clinical guidelines.

Natural cytotoxicity of NC-2+ cells against the growth and metastasis of WEHI-164 fibrosarcoma

We have previously reported a new receptor (NC-2) for natural cytotoxicity (NC) on murine leucocytes, identified by monoclonal antibody D9 (mAb D9). Pretreatment of mouse spleen cells with different concentrations of mAb D9 in vitro blocked NC against WEHI-164, whereas natural killing (NK) activity against YAC-1 was unaffected. This paper reports the immune surveillance against the growth of WEHI-164 tumour cells in mice by NC-2(+) Cells. The kinetics of in vivo reduction in NC activity were investigated by treating BALB/c and (CBA × C57BL/6) F1 mice with a single injection of 40 μg of mAb D9 and monitoring splenic NC activity by (51) Cr-release assay at intervals from 24 h to 3 weeks. Control mice were injected with OKT8 irrelevant antibody. Results showed a significant (P < 0.05) reduction in splenic NC activity within 24 h which persisted for up to 1 week. Similar results were also obtained when (CBA × C57BL/6) F1 mice were employed (P<0.001). In vivo tumour studies were undertaken to investigate the role of NC-2(+) cells in surveillance against tumour growth and metastasis of the WEHI-164 fibrosarcoma. When syngeneic BALB/c mice were injected with 40 μg of mAb D9 and then challenged with 5 × 10(5) WEHI-164 cells, results showed significantly increased growth rate of the transplanted WEHI-164 fibrosarcoma and tumour nodules in the lungs of animals, when compared to control mice with normal NC activity. Our data support an innate surveillance in metastasis and growth of WEHI-164 fibrosarcoma in mice.

Simulation of phase separation in alcohol/water mixtures using two-body force field and standard molecular dynamics

Standard molecular dynamics simulations have been carried out on pure alcohols and alcohol/water mixtures. A simple atom-atom force field consisting of Lennard-Jones potentials plus coulombic terms over atomic point charges, but without explicit polarization terms, has been specifically fitted to reproduce several experimental properties of the pure alcohols, and has been used for mixtures by developing combination rules with the TIP3P water model. Densities, enthalpies of vaporization, radial distribution functions, self-diffusion coefficients, and rotational correlation functions of the pure alcohols are well reproduced and compare favorably with those from more sophisticated force fields. Some key aspects of the phase behaviour are correctly reproduced by the molecular dynamics simulation, showing a distinct demixing process for the n-butanol/water mixture as opposed to the stability of the t-butanol/water mixtures. The results demonstrate the ability of a molecular dynamics simulation, even in its standard form and with easily accessible time ranges, but with a carefully optimized force field, to simulate and, to a certain extent, predict the properties of binary mixtures.

General practitioner screening for melanoma: sensitivity, specificity, and effect of training

OBJECTIVE

To measure the performance of trained and untrained general practitioners (GPs) in screening men and women aged 50 or more for melanomas.

METHODS

GPs trained in melanoma diagnosis, untrained GPs, and skin cancer specialists examined groups of volunteers, each of which included a small number of subjects with prediagnosed suspicious pigmented lesions (SPLs) that were subsequently excised for histopathological examination.

RESULTS

Trained and untrained GPs achieved mean sensitivities of 0.73 and 0.71, and mean predictive values of 0.40 and 0.37, respectively, for the detection of prediagnosed SPLs. When the SPLs had been excised and examined histopathologically, reanalysis showed mean sensitivities of 0.98 and 0.95, mean specificities of 0.52 and 0.49, and mean positive predictive values of 0.24 and 0.22 for the detection of subjects with melanomas by trained and untrained GPs respectively. Trained GPs were significantly better than untrained GPs at diagnosing as melanomas SPLs that subsequently proved to be melanomas (p = 0.04).

CONCLUSIONS

GPs in this study achieved high sensitivities in screening older Australian men and women for melanomas, but at the cost of low specificities and positive predictive values. Training in melanoma diagnosis had no significant effect on sensitivity, specificity, and positive predictive value for screening. Data from the study were tested in a model of population screening for melanomas, and costs per life year saved for men aged 50-70 ranged from $A11,852 to $A40,259 depending upon the screening interval and whether the GPs excised the SPLs diagnosed, or referred all patients to skin cancer specialists; this would be as cost effective as cervical cancer screening.

Monoclonal antibody anti-NC-2 identifies a second receptor on cells mediating natural cytotoxicity in mice

We have previously reported the identification by the murine monoclonal antibody (mAb) 1C4 of the first leucocyte receptor which is involved in natural cytotoxicity (NC) against WEHI-164; the NC-1.1 receptor. We report herein the identification and characterization of a second leucocyte receptor which is involved in NC, NC-2 (MW 50,000), identified by a rat anti-mouse mAb D9 (immunoglobulin G2a; IgG2a). Flow cytometric analysis showed that NC-2 was expressed on < 6% of splenic leucocytes of different inbred mouse strains and 96% of the cells of a mast-cell line which has high NC activity. In vitro treatment of splenic leucocytes with the D9 mAb blocked effector cell-WEHI-164 target cell conjugation and NC by approximately 50% without affecting natural killing (NK). Western blot analysis of affinity purified NC-2 and NC-1.1 using the D9 and 1C4 mAbs showed specific reactivity of the proteins with D9 and 1C4, respectively. Pretreatment of splenic leucocytes with both mAbs blocked NC 84%, a result which almost doubled that caused by either mAb alone. Flow cytometric screening of 16 different mouse cell lines showed that 19% of the cell lines expressed both receptors, 6% expressed only NC-2, 44% expressed mainly or only NC-1.1 and the remaining cells expressed neither receptor. These data indicate that D9 identifies a xeno-antigen, NC-2, which is expressed on cells mediating NC and not NK, and that it is not the previously described NC-1.1 allo-antigen. We conclude that NC-2 is likely to be one of a number of receptor molecules on cells mediating NC against tumour cells.

The antitumor effects of levamisole in mice are mediated by NC-1.1+ cells

Murine natural cytotoxicity, which is a major component of the innate immune response in cancer, is mediated by leukocytes that express the NC-1.1 receptor. Mice depleted of natural cytotoxicity by treatment with an anti-NC-1.1 mAb show enhanced growth of certain transplantable tumors, so agents that enhance natural cytotoxicity by NC-1.1+ cells have the potential to be effective anticancer therapeutic agents. We have examined the immunomodulatory effect of levamisole on natural cytotoxicity mediated by NC-1.1+ cells against the BALB/c WEHI-164 murine fibrosarcoma. Administration of levamisole to BALB/c mice significantly enhanced in vitro splenic natural cytotoxicity against 51Cr-labeled WEHI-164 tumor cells. The effect was most marked 48 h after levamisole treatment, at a dose of 10 mg/kg body weight. This enhancement of natural cytotoxicity by levamisole could be completely abrogated by pretreatment of mice with an anti-NC-1.1 mAb. Treatment of BALB/c mice with 10 mg/kg levamisole significantly reduced the growth of WEHI-164 and this effect was abrogated by pretreatment of mice with anti-NC-1.1, indicating that the antitumor effect of levamisole was mediated, at least in part, via NC-1.1+ cells.

TNF-alpha is not the sole mediator of WEHI-164 tumour cell killing in natural cytotoxicity

Using a mAb to NC-1.1, a receptor involved in recognition of tumour targets, the authors have examined the dogma that murine natural cytotoxicity (NC) is exclusively mediated by TNF-alpha. Three different NC-1.1+ spleen cells, WEHI-3BR1 myelomonocytic cells and an uncloned mast cell line-MCL) were reacted with NC-sensitive WEHI-164 targets in vitro, and the induction of TNF-alpha mRNA, surface expression of TNF-alpha, and the appearance of apoptotic bodies in the culture were simultaneously measured. NC-1.1+ spleen cells and WEHI-3BR1 cells showed marked induction of TNF-alpha mRNA within 30 min and this was maintained for up to 18 h. Only transient TNF-alpha mRNA induction was observed in MCL cells at 30 min. Surface TNF-alpha was detected on WEHI-3BR1 cells by 4 h, but was not detected on MCL cells. All three effector cell types mediated NC against WEHI-164 targets within 18 h, but they responded differently to the addition of anti-TNF-alpha mAb: anti-TNF-alpha completely blocked WEHI-3BR1 NC, blocked NC-1.1+ spleen cell NC by approximately 70%, and did not block NC by MCL cells. This indicates that TNF-alpha is induced during NC by WEHI-3BR1 effectors and NC-1.1+ spleen cells, is the sole mediator of NC by WEHI-3BR1, and appears to play no role in NC by MCL cells.

Phosphorylation of the NC-1.1 receptor and regulation of natural cytotoxicity by protein kinase C and cyclic GMP-dependent protein kinase

Natural cytotoxicity (NC) against cancer involves receptor-ligand interactions between lymphohemopoietic cells that mediate NC against tumor cells. The only candidate for a receptor on cells mediating NC is NC-1.1, identified using mAb 1C4. In this study we showed that mAb 1C4 blocked NC-1.1+ cell conjugation to WEHI-164 tumor cells, indicating that NC-1.1 is a surface protein required for cell-cell interaction. Affinity-purified NC-1.1 was a 45-kDa monomeric protein. It was a good in vitro substrate for cyclic GMP (cGMP)-dependent protein kinase (PKG) and protein kinase C (PKC) and a relatively poor substrate for cAMP-dependent protein kinase (PKA). Phosphopeptide mapping revealed one phosphopeptide phosphorylated by PKG and PKA, and two additional peptides phosphorylated by PKC. Phosphorylation by PKG or PKA abolished phosphorylation at the PKC sites, while coincubation of NC-1.1 with both PKG and PKC reduced phosphorylation of all sites. NC-1.1 was also a phosphoprotein after immunoprecipitation from intact spleen cells and its phosphorylation was increased after cell stimulation with PKC or PKG activators (phorbol esters or 8-bromo-cGMP). The possible consequences of intracellular signaling were tested in functional assays for NC. Phorbol ester activation of spleen cells increased NC, while 8-bromo-cGMP and 8-bromo-cAMP had little effect. However, coincubation with both phorbol ester and either 8-bromo-cGMP or 8-bromo-cAMP virtually abolished NC without affecting cell conjugation. These results suggest that NC-1.1 is a receptor for a ligand on certain tumor cells and reveal that key intracellular signaling pathways involving PKC, PKG, and PKA interact to effect a coordinated control of NC.

Phosphorylation of the NC-1.1 receptor and regulation of natural cytotoxicity by protein kinase C and cyclic GMP-dependent protein kinase

Natural cytotoxicity (NC) against cancer involves receptor-ligand interactions between lymphohemopoietic cells that mediate NC against tumor cells. The only candidate for a receptor on cells mediating NC is NC-1.1, identified using mAb 1C4. In this study we showed that mAb 1C4 blocked NC-1.1+ cell conjugation to WEHI-164 tumor cells, indicating that NC-1.1 is a surface protein required for cell-cell interaction. Affinity-purified NC-1.1 was a 45-kDa monomeric protein. It was a good in vitro substrate for cyclic GMP (cGMP)-dependent protein kinase (PKG) and protein kinase C (PKC) and a relatively poor substrate for cAMP-dependent protein kinase (PKA). Phosphopeptide mapping revealed one phosphopeptide phosphorylated by PKG and PKA, and two additional peptides phosphorylated by PKC. Phosphorylation by PKG or PKA abolished phosphorylation at the PKC sites, while coincubation of NC-1.1 with both PKG and PKC reduced phosphorylation of all sites. NC-1.1 was also a phosphoprotein after immunoprecipitation from intact spleen cells and its phosphorylation was increased after cell stimulation with PKC or PKG activators (phorbol esters or 8-bromo-cGMP). The possible consequences of intracellular signaling were tested in functional assays for NC. Phorbol ester activation of spleen cells increased NC, while 8-bromo-cGMP and 8-bromo-cAMP had little effect. However, coincubation with both phorbol ester and either 8-bromo-cGMP or 8-bromo-cAMP virtually abolished NC without affecting cell conjugation. These results suggest that NC-1.1 is a receptor for a ligand on certain tumor cells and reveal that key intracellular signaling pathways involving PKC, PKG, and PKA interact to effect a coordinated control of NC.

Natural cell-mediated cytotoxicity (NCMC) against NK-sensitive tumours in vitro by murine spleen Ly-6C+ natural T cells

Ly-6C+ cells constitute 13 +/- 3% of freshly isolated (CBA x C57BL/6)F1 mouse spleen leukocytes. Three distinct populations were identified: CD3 epsilon +NK-1.1- conventional T cells (6%), CD3 epsilon -NK-1.1- granulocytes (5%) and CD3 epsilon +NK-1.1+ T cells (approximately 2%). The CD3 epsilon +NK-1.1+ cells displayed a predominantly large granular leukocyte morphology and were the only Ly-6C+ cell subset identified by MAb 2B6-F2 to spontaneously lyse the NK-sensitive YAC-1 tumour in vitro. On further phenotypic analysis, these cells co-expressed high levels of TCRV beta 8.1/8.2 and CD11b, moderate levels of CD90 and low levels of CD4 or CD8. The removal of CD4+ and CD8+ cells prior to Ly-6C+ cell sorting showed that it was the CD4-CD8- double-negative (DN) CD3 epsilon +NK-1.1+ T-cell subset which was responsible for killing YAC-1. These results indicate that we have identified a DN Ly-6C+ subset of the recently designated NK-1.1+TCR alpha beta low natural T (NT) cells, which are capable of natural cell-mediated cytotoxicity (NCMC) against the NK-sensitive YAC-I tumour in vitro. Additionally, these cells mediated the in vitro killing of 2 further NK-sensitive tumours, murine B16 melanoma and human Jurkat T lymphoma. YAC-1 and Jurkat expressed Fas and were susceptible to anti-Fas MAb or rhuman Fas ligand (rhFasL)-induced lysis. Furthermore, anti-human Fas MAb M3 was shown to block sorted Ly-6C+ splenocyte in vitro killing of Jurkat. In contrast, B16 did not express cell-surface Fas and was resistant to anti-Fas MAb-induced lysis. Taken together, these results show that not only do Ly-6C+ NT cells kill NK-sensitive tumours in vitro but they mediate this activity via multiple cytotoxic mechanisms including Fas.

An IL-3-induced splenic NC-1.1+ mast cell line mediates natural cytotoxicity independent of TNF-alpha

Long-term culture of mouse spleen cells in IL-3-conditioned medium induced a stable mast cell line. This mast cell line (MCL) which could not be cloned expressed NC-1.1, a receptor on cells which mediate natural cytotoxicity (NC), and CD32/CD16 but no markers of T cells, B cells, macrophages, or NK cells. The MCL cells were large and granular, with abundant cytoplasm and >90% stained with Alcian blue, a mast cell-specific stain. Probing total RNA with cDNA encoding a mast cell-specific proteinase mMCP-5 identified the approximately 1-kb mMCP-5 transcript which was confirmed at the protein level. MCL cells mediated very high NC against WEHI-164 which increased with time in culture and which was blocked by anti-NC-1.1 but not by anti-TNF-alpha. When incubated with WEHI-164 tumor cells, MCL cells showed transient induction of TNF-alpha mRNA, but no detectable surface protein. Thus long-term culture of murine spleen cells in IL-3 induces mast cells which express the NC-1.1 receptor of cells which mediate NC, and utilize a cytotoxic effector mechanism which is not TNF-alpha.

Ly-6C+ natural T (NT) cells mediate immune surveillance against NK-sensitive and NK-resistant transplantable tumours in certain strains of mice

We have previously shown that anti-Ly-6C monoclonal antibody (MAb) 2B6-F2 identifies a subset of (CBA +/- C57BL/6)F1 splenic NK-1.1+ natural T (NT) cells which kill the NK-sensitive YAC-1 target in vitro. Furthermore, these Ly-6C+ cells are responsible for 40-50% of in vitro YAC-1 killing in all mouse strains tested. In BALB/c and DBA/2 mice, these cells killed not only YAC-1 but also the NK-resistant WEHI-164 M1/16 target via a receptor that recognises a shared determinant on these targets in vitro. In the present study, the anti-tumour role of Ly-6C+ cells against the NK-sensitive B16 melanoma and NK-resistant tumours WEHI-7 T lymphoma and WEHI-164/1C fibrosarcoma was studied in vitro and in vivo. In vitro, B16, WEHI-7 and WEHI-164/1C tumour cell lines were highly sensitive to Ly-6C+ cell killing. In vivo, these same tumours showed significantly increased growth when transplanted s.c. into syngeneic mice treated with 2B6-F2 (0.05 < or = p < 0.0005), and this was most marked in the first 15 days following tumour appearance, when tumours were <15 mm in diameter. Our results show that Ly-6C+ cells play a role in controlling the growth of transplantable NK-sensitive B16 melanoma, and in BALB/c mice, at least, the repertoire of susceptible tumours is extended to include NK-resistant WEHI-7 and WEHI-164/1C. We conclude that Ly-6C+ NT cells play a role in immunosurveillance against NK-sensitive as well as NK-resistant tumours in certain strains of mice.

Has mortality from melanoma stopped rising in Australia? Analysis of trends between 1931 and 1994

OBJECTIVE

To describe recent trends in mortality from melanoma in Australia.

DESIGN

An analysis of trends in age standardised and age and sex specific mortalities by year of death and median year of birth (cohort).

SETTING

Australia.

SUBJECTS

All deaths from melanoma registered in Australia between 1931 and 1994.

RESULTS

Melanoma mortality rose steadily from 1931 to 1985. From 1959 the annual rate of increase was 6.3% in men and 2.9% in women, resulting in mortalities of 4.82 and 2.51 per 100,000 person years in 1985 and 1989, respectively. Mortalities for both sexes seem to have plateaued from June 1985 onwards. In 1990-4 the rate rose by 3.7% in men to 5.00 per 100,000 and in women it fell by 5.2% to 2.38 per 100,000. The non-significant increase after 1985 in mortality in men was restricted to those aged over 70 years of age, whereas the fall in rates in women was mostly in those aged under 55 years. This pattern was generally reflected in the state trends, though with some variation: rates for women in Queensland had peaked in the late 1970s; while rates for men in New South Wales continued to rise in 1990-4, placing them above those for Queensland. Examination of mortalities specific for age, period, and cohort for Australia as a whole showed several salient features. Rates in men rose steeply in cohorts born before about 1930; were stable in cohorts born between 1930 and 1950; and fell in more recent cohorts. Rates in women showed similar changes but about five years earlier.

CONCLUSION

Melanoma mortality in Australia peaked in about 1985 and has now plateaued. On the basis of trends in cohorts it can be expected to fall in coming years.

Screening for melanoma by primary health care physicians: a cost-effectiveness analysis

BACKGROUND AND DESIGN - Australia has the highest rates of skin cancer in the world, and the incidence is estimated to be doubling every 10 years. Despite advances in the early detection and treatment of melanoma about 800 people still die nationally of the disease each year. A possible strategy for further reducing the mortality from melanoma is an organised programme of population screening for unsuspected lesions in asymptomatic people. Arguments against introducing melanoma screening have been based on cost and the lack of reliable data on the efficacy of any screening tests. To date, however, there has been no systematic economic assessment of the cost effectiveness of melanoma screening. The purpose of this research was to determine whether screening may be potentially cost effective and, therefore, warrants further investigation. A computer was used to simulate the effects of a hypothetical melanoma screening programme that was in operation for 20 years, using cohorts of Australians aged 50 at the start of the programme. Based on this simulation, cost-effectiveness estimates of melanoma screening were calculated. RESULTS - Under the standard assumptions used in the model, and setting the sensitivity of the screening test (visual inspection of the skin) at 60%, cost effectiveness ranged from Aust$6853 per life year saved for men if screening was undertaken five yearly to $12 137 if screening was two yearly. For women, it ranged from $11 102 for five yearly screening to $20 877 for two yearly screening. CONCLUSION - The analysis suggests that a melanoma screening programme could be cost effective, particularly if five yearly screening is implemented by family practitioners for men over the age of 50.

Current melanoma epidemic: a nonmetastasizing form of melanoma?

During the mid to late 1980s in white populations in Australia, New Zealand, and Scotland, melanoma incidence increased sharply above preceding long-term trends. Most of this increase was in thin melanomas (< 1.50 mm thick), and men were more affected than women. Thick melanomas also generally increased in incidence, particularly in men 65 years or older. Although advancement of the time of diagnosis was a likely factor in the increase in melanoma incidence, the maintenance of new higher incidence levels and the increase in the incidence of thick lesions indicated that earlier diagnosis did not explain most of the increase. Real increases in incidence due to continuation of long-term trends and the increasing diagnosis of a preexisting, nonmetastasizing form of thin melanoma probably explain most of the recent increases in melanoma incidence.

Analysis of public education and the implications with regard to nonprogressive thin melanomas

Public education campaigns to encourage early diagnosis of melanoma have been conducted in a number of countries with predominantly white populations for more than a decade. During the mid to late 1980s the incidence of melanoma has increased sharply above long-term trends in some of these populations. There is evidence that these campaigns can lead to earlier diagnosis of the disease, and thus advancement of the time of diagnosis certainly accounts for some of the recent incidence increases. However, it is possible that earlier diagnosis has also uncovered a preexisting nonfatal (nonmetastasizing) form of melanoma, and that this accounts for a substantial proportion of increases in incidence. Although this should not alter public education for early diagnosis of melanoma, it should give caution to current enthusiasm for population screening for the disease.

Monoclonal antibody 2B6-F2 identifies a subset of murine natural killer cells with receptors for YAC-1 and WEHI-164 targets

This study reports the generation of rat MoAb 2B6-F2 (IgG2a) that identifies a subpopulation of murine NK cells in the spleen, bone marrow, peripheral blood, lung, and peritoneal leukocytes. By flow cytometry, 2B6-F2 reacted with 10% of naive CBA (immunizing strain) spleen leukocytes of which 3% exhibited small lymphocyte morphology while 7% were large granular leukocytes. This pattern of binding was similarly obtained for BALB/c, C57BL/6, CE, and DBA/2 mice. 2B6-F2 and complement reduced splenic NK activity 40-57% in CBA, C57BL/6, BALB/c, CE, and DBA/2 strains. In CBA, C57BL/6, and CE mice < or = 15% reduction in splenic NC activity was observed while DBA/2 and BALB/c mice displayed 55-73% reduction. Cellular competitive inhibition studies showed that 2B6-F2+ NK cells in BALB/c and DBA/2 mice bind and kill YAC-1 and WEHI-164 target cells via a receptor that recognizes a shared determinant on these targets. Western blot and radioimmunoprecipitation studies indicated that 2B6-F2 identifies a 14-kDa monomeric cell surface molecule.

Recent incidence trends imply a nonmetastasizing form of invasive melanoma

In the mid- to late-1980s white populations in Australia, New Zealand and Scotland showed a sharp increase in melanoma incidence above preceding long-term trends, in some cases as much as doubling in as little as 2 years. Most of this increase was in thin melanomas, (< 1.50 mm thick), and males were more affected than females. Thicker melanomas also generally increased in incidence, particularly in males aged 65 years or older. Examination of Australian Medicare and pathology laboratory data indicated that excision of skin lesions and laboratory diagnosis of pigmented lesions also rose sharply in this period, suggesting that advancement of the time of diagnosis was a likely factor in the increase in melanoma incidence. However the maintenance of new higher incidence levels and the increase in incidence of thicker lesions suggests that advancement of diagnosis cannot explain all of the increase. A real increase in incidence and increasing diagnosis of a preexisting, non-metastasizing form of thin melanoma may also have contributed.

Phenotype and morphology of murine NC-1.1+ natural cytotoxic cells

The morphology and phenotype of cells identified by the anti-NC-1.1 mAb, 1C4, were studied in CBA and (CBA x C57BL/6) F1 mice. This mAb blocked splenic natural cytotoxic (NC) cell activity in vitro and in vivo. Single colour flow cytometric analysis showed that 6 +/- 1% of all CBA splenocytes were NC-1.1+, and that granular cells of varying sizes, as defined by their forward and side light scatter, contained the highest proportion of NC-1.1+ cells (29 +/- 7%). When analysed by two colour flow cytometry, the large and the granular NC-1.1+ spleen cells in CBA mice were shown to co-express Thy-1.2 and L3T4 (< or = 33%), Mac-1 (< or = 26%), IgM (< or = 60%) and FcR gamma II and J11d (< or = 100%). In contrast, T cell markers were not co-expressed on the small agranular NC-1.1+ spleen cells. This pattern of marker expression was evident in CBA spleens from 2 days of age. When (CBA x C57BL/6) F1 spleen cells were similarly analysed, 82% of granular NC-1.1+ cells also co-expressed NK-1.1. Single colour analysis of CBA bone marrow, thymus, lymph node and peripheral blood leucocytes revealed that < or = 10% of all cells examined were NC-1.1+ while the most granular cells in these organs were 16-43% NC-1.1+. These results support the 'horizontal lineage' theory that NC cells are cells of different lymphohaemopoietic cell lineages at particular stages of differentiation.

Allogeneic blood transfusion reduces murine pulmonary natural killer (NK) activity and enhances lung metastasis of a syngeneic tumour

A model was established whereby C57BL/6 (B6) blood injected i.v. into C3H mice 7 days prior to i.v. injection of syngeneic UV-2237 tumour cells significantly increased the number of pulmonary metastases counted 21 days later as compared with levels observed in mice treated with saline, C3H or NZW blood or SRBC. This regimen of B6 allogeneic blood transfusion of C3H mice also significantly depressed splenic and pulmonary NK activity as assayed by lysis of 51Cr YAC-I in vitro and by clearance of 111In YAC-I in vivo respectively. Anti-asialo GMI treatment, which depletes NK activity in vivo, and Poly I:C treatment, which enhances NK activity in vivo, were associated with significantly increased and decreased pulmonary metastasis of UV-2237, respectively, in C3H mice. Depletion of CD4+ and CD8+ T cells had no effect. Cyclophosphamide pretreatment which, among other effects, depletes NK cells, significantly increased pulmonary metastasis of UV-2237 in C3H mice. This was corrected by adoptive transfer of normal C3H spleen cells but not spleen cells from anti-asialo GMI-treated C3H mice or B6-blood-transfused C3H mice. Furthermore, a 1:1 mixture of normal C3H spleen cells with spleen cells from B6-blood-transfused C3H mice also failed to reconstitute the cyclophosphamide-pre-treated C3H mice. We conclude that allogeneic blood transfusion augments pulmonary metastasis of the UV-2237 sarcoma in C3H mice and that the mechanism involves suppression of NK activity.

An analysis of a melanoma epidemic

Between 1986 and 1988 the annual incidence of invasive melanoma in the Hunter area of New South Wales, Australia, almost doubled to 52.5 per 100,000 in men and 42.9 per 100,000 in women. These rates have been maintained and are similar to those reported for 1987 in Queensland, Australia, which are the highest in the world. Most of the increase in incidence was in melanomas less than 1.50 mm in thickness, and adults of both sexes and all ages were affected. Thicker melanomas also increased in incidence but only in adults 45 years and older, and mainly in men. An analysis of health insurance data on treatment of skin lesions and data from a histopathology laboratory suggested that diagnosis and treatment of skin lesions generally in the Hunter area had increased almost 2-fold over this period. Advancement of the time of diagnosis and a real increase in incidence were likely explanations for some of the observed trends. Increasing diagnosis of a non-metastasising form of thin melanoma, consequent upon increasing removal of pigmented skin lesions by medical practitioners, may also explain some of the observed increase in the incidence of the disease. This possibility has important implications for proposed population screening programs, and methods are needed to distinguish such lesions, if they exist, from potentially fatal melanoma.

The effect of the Cmv-1 resistance gene, which is linked to the natural killer cell gene complex, is mediated by natural killer cells

The resistance of mice to lethal infection by murine CMV (MCMV) is under complex host genetic control with contributions from both H-2 and non-H-2 genes. We have previously shown that an autosomal, non-MHC encoded gene, Cmv-1, controls MCMV replication in the spleen. We have investigated the mechanism by which the Cmv-1 resistance gene confers protection against MCMV infection. Using H-2 compatible irradiation bone marrow chimeras, the enhanced resistance to MCMV infection that is associated with the Cmv-1l allele in the C57BL background was shown to be mediated by an irradiation-sensitive bone marrow-derived cell population, or a factor produced by these cells. The lack of correlation between serum IFN titers and the strain distribution pattern of Cmv-1 in CXB recombinant inbred mouse strains suggests that IFN does not mediate resistance conferred by this gene. Similarly, the lack of effect of in vivo depletion of mature CD4+ and CD8+ T cells on virus replication in C57BL/6J mice indicates that T cells are unlikely to be involved. In contrast, in vivo depletion of NK cells by injection of the anti-NK1.1 mAb PK136 abrogated restricted splenic virus replication in C57BL/6J----BALB.B chimeric mice and in the Cmv-1l CXB strains. These data indicate that the effect of the Cmv-1 gene is mediated by NK cells. The significant augmentation in NK cell activity after MCMV infection of the susceptible Cmv-1h strains (BALB/cBy), CXBG/By, CXBH/By, CXBI/By, and CXBK/By) indicates the existence in these mice of NK cells that are functionally and phenotypically distinct from those in Cmv-1l strains. NK cells present in the Cmv-1h strains are unable to restrict efficiently splenic MCMV replication in vivo, possibly due to a lack of specificity for virus-infected target cells. Finally, flow cytometric analysis of NK1-1 expression in CXB and BXD RI mice together with MCMV replication studies in the BXD RI strains indicate that Cmv-1 is closely linked to NK1.1 and other loci that reside on a distal segment of murine chromosome 6 in a region that has recently been defined as the natural killer complex.

The effect of the Cmv-1 resistance gene, which is linked to the natural killer cell gene complex, is mediated by natural killer cells

The resistance of mice to lethal infection by murine CMV (MCMV) is under complex host genetic control with contributions from both H-2 and non-H-2 genes. We have previously shown that an autosomal, non-MHC encoded gene, Cmv-1, controls MCMV replication in the spleen. We have investigated the mechanism by which the Cmv-1 resistance gene confers protection against MCMV infection. Using H-2 compatible irradiation bone marrow chimeras, the enhanced resistance to MCMV infection that is associated with the Cmv-1l allele in the C57BL background was shown to be mediated by an irradiation-sensitive bone marrow-derived cell population, or a factor produced by these cells. The lack of correlation between serum IFN titers and the strain distribution pattern of Cmv-1 in CXB recombinant inbred mouse strains suggests that IFN does not mediate resistance conferred by this gene. Similarly, the lack of effect of in vivo depletion of mature CD4+ and CD8+ T cells on virus replication in C57BL/6J mice indicates that T cells are unlikely to be involved. In contrast, in vivo depletion of NK cells by injection of the anti-NK1.1 mAb PK136 abrogated restricted splenic virus replication in C57BL/6J----BALB.B chimeric mice and in the Cmv-1l CXB strains. These data indicate that the effect of the Cmv-1 gene is mediated by NK cells. The significant augmentation in NK cell activity after MCMV infection of the susceptible Cmv-1h strains (BALB/cBy), CXBG/By, CXBH/By, CXBI/By, and CXBK/By) indicates the existence in these mice of NK cells that are functionally and phenotypically distinct from those in Cmv-1l strains. NK cells present in the Cmv-1h strains are unable to restrict efficiently splenic MCMV replication in vivo, possibly due to a lack of specificity for virus-infected target cells. Finally, flow cytometric analysis of NK1-1 expression in CXB and BXD RI mice together with MCMV replication studies in the BXD RI strains indicate that Cmv-1 is closely linked to NK1.1 and other loci that reside on a distal segment of murine chromosome 6 in a region that has recently been defined as the natural killer complex.

Correlation of growth of tumours in NC-cell-depleted mice with NC- and NK-cell-mediated lysis in vitro

The anti-tumour surveillance activity of natural cytotoxic (NC) cells was studied in vivo using the transplantable tumours WEHI-164 fibrosarcoma, MPC-II plasmacytoma, WEHI-7 T-lymphoma, B16 melanoma and EL-4 thymoma in syngeneic and semi-allogeneic mice. Experimentally, mice were treated with the anti-NC-I.I monoclonal antibody (MAb) IC4 to abrogate splenic NC activity. This was followed by s.c. inoculation of MTD100 doses of the tumours. Comparison of the diameters of the tumours in the anti-NC-I.I-treated mice with control mice using non-parametric statistics showed significantly faster growth of WEHI-164 (p less than 0.01), MPC-II (p less than 0.05) and WEHI-7 (p less than 0.05) when the mean tumour diameters were less than 15 mm in the anti-NC-I.I-treated mice. Significantly faster growth was also observed in anti-NC-I.I-treated mice with the B16 tumour (p less than 0.05), but at a later stage of growth, when the tumour diameter was greater than 15 mm. In vitro, WEHI-164, MPC-II and WEHI-7 were shown to be predominantly sensitive to lysis by mouse splenic NC cells, while B16 was predominantly lysed by splenic natural-killer (NK) cells. Anti-NC-I.I treatment of mice did not affect the growth of EL-4 in vivo and in vitro experiments with anti-NK-I.I and anti-NC-I.I MAb indicated that this tumour was lysed by sub-sets of NK and NC cells distinct from those which lysed the other tumours. We conclude that, in mice at least, NC cells have an in vivo role in controlling the growth of some transplantable tumours, and this correlates with the in vitro NC cell lysis of these same tumours.

Studies on murine natural killer (NK) cells. V. Genetic analysis of NK cell markers

This paper attempts to clarify the number and nomenclature of murine natural killer (NK) cell specific alloantigens by defining the genetic relationships between them, that is, are they coded by loci which are independent, allelic, or linked. Strain typing and F2 analyses using five alloantisera (C3H X BALB/c)F1 anti-CE, CE anti-CBA, NZB anti-BALB/c, C3H anti-ST, and BALB/c anti-DBA/2 revealed that (a) the alloantigens NK-1.1 and NK-3.1 are determined by distinct loci which are linked on the same chromosomes, (b) the alloantigen NK-2.1 is determined by an independently segregating locus to those coding for NK-1.1 and NK-3.1, (c) the alloantisera, CE anti-CBA and NZB anti-BALB/c, which have been designated anti-NK-2.1 alloantisera recognize different alloantigens coded by independent genetic loci. Thus, these five alloantisera detect four NK cell specific alloantigens which, based on the chronology of their discovery, have been designated NK-1.1-(C3H X BALB/c)F1 anti-CE, NK-2.1-CE anti-CBA, NK-3.1-C3H anti-ST, and BALB/c anti-DBA/2 and NK-4.1-NZB anti-BALB/c.

Factors related to the presentation of patients with thick primary melanomas

OBJECTIVE

To identify any characteristics of patients that are associated with presentation with thick primary melanoma.

DESIGN

This was a retrospective survey of the clinical records of 1300 patients attending the Newcastle Melanoma Unit. Characteristics of 131 patients with thick melanomas (defined as 3 mm or greater in thickness) were compared with those of 543 patients with thin melanomas (defined as 0.75 mm or less in thickness). Comparisons were made using contingency table analysis, Wilcoxon rank sum tests, log rank analysis and logistic regression.

SETTING

The Newcastle Melanoma Unit is a tertiary referral centre for the treatment of primary melanoma.

PATIENTS

We surveyed all 1300 patients attending the Newcastle Melanoma Unit over the years 1981-1990. They represented approximately 90% of the patients in the Hunter region of New South Wales who developed melanoma during this period. Excluded from analysis were 39 patients with occult primary melanomas, 79 with multiple primary melanomas, 51 with primary melanomas of unknown thickness and seven with incomplete records, leaving 1124 patients in the study.

MAIN OUTCOME MEASURES

These were selected before the results were known. The hypothesis was generated following analysis of the data.

RESULTS

Patients with thick primary melanoma were more likely to be men (68% men and 32% women in the thick melanoma group, compared with 45% and 55% respectively in the thin melanoma group, P less than 0.005) over 60 (75% were over 50 years of age in the thick group versus 33% in the thin melanoma group, P less than 0.001) with nodular melanoma (62%, versus 2% in the thin melanoma group, P less than 0.001) and with melanoma on the head and neck (27%, versus 12% in patients with thin melanoma, P less than 0.005). The time from detection of a change in skin to diagnosis was not longer for those with thick compared to those with thin melanomas.

CONCLUSION

The greatest problem of those with thin melanomas.

CONCLUSION

The greatest problem of detecting melanoma at an early (surgically curable) stage appears to be in patients over the age of 50 who have nodular melanoma, particularly in the head and neck.

Production of a monoclonal allo-antibody to murine natural cytotoxic cells

A mouse IgG1 monoclonal antibody (1C4), which recognizes a cell surface molecule on murine natural cytotoxic (NC) cells was produced. By flow cytometry, 1C4 preferentially reacted with less than 5% of fresh CBA spleen cells and 20-50% of CBA-interleukin-3 (IL-3) cells, an in vitro derived NC-like cell line. In vitro treatment of spleen cells from a number of inbred mouse strains either with 1C4 alone or 1C4 coupled to dynabeads markedly decreased or abolished NC activity of the cells against 51Cr-labelled WEH1-164 targets. Splenic NC activity of these same mouse strains was also reduced or abolished by in vivo administration of 1C4. The effect was evident within 2 h of treatment and persisted for at least 1 week. In contrast 1C4 had little or no effect on splenic NK activity against 51Cr-labelled YAC-1 targets over the same range of experiments in vitro and in vivo. Results of strain surveys for both in vitro and in vivo reduction of splenic NC activity by 1C4 treatment showed that CBA, C57BL/6, BALB/c and NZB mice were positive and CE and DBA/2 mice were negative, indicating that 1C4 recognizes an allo-antigen on mouse NC cells. This allo-antibody has been designated NC-1.1, and thus 1C4 is an anti-NC-1.1 monoclonal antibody.

Mammary serum antigen (MSA) in advanced breast cancer

An Enzyme Linked Immunosorbent Assay (ELISA) based on a monoclonal antibody, 3E1.2, was used to measure circulating Mammary Serum Antigen (MSA) in a study of 123 advanced breast cancer patients. Fifty two patients were monitored serially to investigate whether measurements of circulating MSA levels were of value in the management of advanced breast cancer patients on palliative therapy. Analysis of variance showed that circulating MSA levels at first presentation correlated with disease status both at initial presentation (p = 0.01) and also 4 months later (p = 0.003). At first presentation, the circulating MSA level also significantly correlated with the number of metastatic sites (p = 0.04), but this did not hold at 4 months. The circulating MSA levels did not at any time correlate with the type of treatment given nor age of the patient. We conclude that MSA might ultimately be useful in the management of advanced breast cancer patients as a prognostic marker for the course of the disease and for monitoring patient response to palliative hormonal therapy and chemotherapy.

Studies on natural killer (NK) cells IV NK-3.1: a new NK cell specific alloantigen

A new murine natural killer (NK) cell alloantigen, NK-3.1, has been identified by analysis of the complement dependent anti-NK cell activity of C3H anti-ST and BALB/c anti-DBA/2 alloantisera. Flow cytometric studies with a specific antiserum made in backcross mice indicate that this alloantigen is expressed by 2-3% of the spleen cells of NZB and C57BL/6 mice, positive strains, but is undetectable on the spleen cells of C3H mice, a negative strain. Since NK-1.1 and NK-2.1 are also expressed on 2-3% of spleen cells of positive strains we suggest that all three alloantigens identify the NK cells in normal mouse spleen which lyse the lymphoma target cell line YAC.

Factors affecting MSA levels in normal women and women with breast cancer

Blood from 1497 women who were either non-pregnant, pregnant at all stages of gestation, lactating after parturition, postmenopausal, or who had benign breast lumps, primary breast cancer or advanced breast cancer were tested for their peripheral blood mammary serum antigen (MSA), using the 3E1.2 monoclonal antibody (MoAb) in an inhibition enzyme linked immunosorbent assay test system. The study aimed to establish normal ranges for comparison with MSA levels in breast cancer and benign breast disease. Compared with normal premenopausal women, which included women measured 8-10 times throughout their menstrual cycle, circulating MSA levels were significantly elevated throughout pregnancy (P less than 0.0001), in postmenopausal women (P less than 0.05), in women with primary breast cancer (P less than 0.05) and women with advanced (metastatic) breast cancer (P less than 0.0001). As a group, the 30 women with benign breast disease did not demonstrate significantly different MSA level from normal. However, 3% of the group did have levels above the 'cut off' for normal (400 IU/mL). Analysis of the normal premenopausal women according to age, parity and stage of the menstrual cycle and during lactation showed that these parameters did not affect MSA levels. It is concluded that the test is potentially valuable in the detection of metastatic but not primary breast cancer, and the effects of pregnancy and postmenopausal status on the circulating MSA levels need to be considered in the interpretation of MSA measurements.

Expression of natural killer (NK) cell-specific alloantigens on a mouse NK-like cell line

As part of the strategy for screening for natural killer (NK) cell-specific monoclonal antibodies (MoAb) we have raised a number of murine NK-like cell lines in media containing interleukin-2 (IL-2). The detection of specific NK cell alloantigens on a C57BL/6 cell line in long-term culture in IL-2 is the subject of this paper. The C57BL/6 cell line has the morphology of large granular lymphocytes (LGL) and exhibits strong cytolytic activity against the archetype NK cell target, YAC-1. Absorption of three anti-NK antiserum, NZB anti-BALB/c (anti-NK-2.1), BALB/c anti-DBA/2 (anti-NK-3.1) and CE anti-CBA (anti-NK-4.1), with the C57BL/6 cell line removed the anti-NK activity from these antisera. Flow cytometric studies of the C57BL/6 cell line demonstrated significant binding of the anti-NK-1.1 MoAb produced by hybridoma PK136. Our results suggest that the C57BL/6 NK-like cell line exhibits some of the properties of naive NK cells and expresses all the known NK cell-specific alloantigens, NK-1.1, NK-2.1, NK-3.1 and NK-4.1 and therefore is potentially useful in selecting NK specific hybridomas and in studying the biology of NK cells.

Effects of captopril on circulating T lymphocyte subsets

Six patients treated with captopril for severe essential hypertension were studied to determine whether the drug significantly altered circulating peripheral blood T (Thymus derived) lymphocytes and T lymphocyte subsets. OKT3+ (functionally mature T lymphocytes), OKT4+ (class II major histocompatibility complex [MHC] reactive T lymphocytes) and OKT8+ (class I MHC reactive T lymphocytes) T lymphocytes were monitored using monoclonal antibodies and flow cytometry before commencement of treatment and then at intervals during 14 months of captopril administration. Results showed a significant increase in the absolute numbers of OKT4+ cells at 2 h (p less than 0.05) and a decrease at 12 weeks (p less than 0.01) during captopril treatment. These findings indicate that captopril has an effect on cellular immunity in vivo.