Rubella virus and birth defects: Molecular insights into the viral teratogenesis at the cellular level

BACKGROUND

In utero rubella virus (RV) infection of a fetus can result in birth defects that are often collectively referred to as congenital rubella syndrome (CRS). In extreme cases, fetal death can occur. In spite of the availability of a safe and effective vaccine against rubella, recent worldwide estimates are that more than 100,000 infants are born with CRS annually.

RECENT PROGRESS

Recently, several significant findings in the field of cell biology, as well as in the RV replication and virus-cell interactions, have originated from the authors' laboratory, and other researchers have provided insights into RV teratogenesis. It has been shown that 1) an RV protein induces cell-cycle arrest by generating a subpopulation of tetraploid nuclei (i.e., 4N DNA) cells, perhaps representative of the tetraploid state following S phase in the cell cycle, due to its interaction with citron-K kinase (CK); 2) RV infection induces apoptosis in cell culture, and 3) CK functional perturbations lead to tetraploidy, followed by apoptosis, in specific cell types.

CONCLUSIONS

Based on several similarities between known RV-associated fetal and cellular manifestations and CK deficiency-associated phenotypes, it is reasonable to postulate that P90-CK interaction in RV-infected cells interferes with CK function and induces cell-cycle arrest following S phase in a subpopulation, perhaps representative of tetraploid stage, which could lead to subsequent apoptosis in RV infection. Taking all these observations to the fetal organogenesis level, it is plausible that P90-CK interaction could perhaps be one of the initial steps in RV infection-induced apoptosis-associated fetal birth defects in utero.

Reassessing autotransplantation for acute myeloid leukaemia in first remission – a matched pair analysis of autologous marrow vs peripheral blood stem cells

The role of autologous stem cell transplantation in adult patients with acute myeloid leukaemia (AML) in first remission is unclear, yet it has become standard treatment for myeloma and this paper explores whether the source of transplanted stem cells may explain this paradox. In total, 57 patients from the Royal Marsden Hospital who received an unpurged bone marrow transplant (ABMT) were matched with 114 patients from the EBMT registry who had undergone peripheral blood stem cell transplantation (PBSCT). Patients were matched for karyotype, FAB type, remission-autograft interval and age. In the PBSCT group, haematopoietic recovery was significantly faster and nonrelapse mortality at 4 years was significantly lower (13 vs 1%, P=0.04). The relapse rate and overall survival at 4 years (20 vs 31% and 77 vs 63%) were also better with PBSCT, although the differences were not statistically significant. Autografting should be reassessed in a randomised trial for first remission AML patients using peripheral blood as a source of stem cells rather than bone marrow.

High-dose melphalan and autotransplantation followed by post transplant maintenance chemotherapy for acute lymphoblastic leukemia in first remission

A total of 65 adults with acute lymphoblastic leukemia (ALL) received 200 mg/m2 melphalan and an autograft in first remission, with a plan to receive 6-mercaptopurine (6MP), methotrexate (MTX), and vincristine-prednisone (VP) for 2 years afterwards. There was no transplant-related mortality. In all, 69% of patients received 6MP, 54% received MTX, and 49% received VP. The cumulative incidence of relapse at 5 years was 52%. The 5-year probabilities of disease-free (DFS) and overall (OS) survival were 48 and 55%. Age >30 years, >4 weeks to attain remission, and t(9;22) or t(4;11) karyotypes were adverse prognostic features. Patients with 0 (standard risk), 1 (intermediate risk), and 2-3 (high risk) adverse features had 5-year cumulative incidences of relapse of 19, 59, and 100% (P<0.0001), and 5-year probabilities of DFS of 80, 41, and 0% (P<0.0001). The 5-year probabilities of DFS for patients receiving 0, 1, 2, and 3 maintenance therapy agents were 19, 40, 51, and 70% (P=0.0097). Maintenance therapy intensity was an independent determinant of outcome in Cox analysis. These data show that a high-dose melphalan-based autograft is safe and could be widely applicable in ALL in first remission, and that maintenance chemotherapy very likely contributes to improved outcome of autografted ALL patients.

Rubella virus P90 associates with the cytokinesis regulatory protein Citron-K kinase and the viral infection and constitutive expression of P90 protein both induce cell cycle arrest following S phase in cell culture

In utero infection of developing fetus by Rubella virus (RV) causes cell division inhibition of critical precursor cells in organogenesis, CNS-associated birth defects and induction of apoptosis in cell culture. The underlying mechanisms of RV-induced congenital abnormalities are not known. Here, we identified a novel interaction between RV replicase P90 protein and a cytokinesis-regulatory protein, the Citron-K kinase (CK), in a yeast two-hybrid cDNA library screen. Aberrations in cytokinesis and subsequent apoptosis do occur in specific cell types when the CK gene is knocked out or, its regulatory function is perturbed. Our analysis found that full-length P90 binds CK and in RV-infected cells P90 colocalizes with CK in the cytoplasm. Furthermore, during RV infection as well as cellular expression of P90 alone, we identified a discrete subpopulation of cells containing 4N DNA content, indicating that these cells are arrested in the cell cycle following S phase, suggesting that cellular expression of viral P90 during RV infection perturbs cytokinesis. Previous reports by others established that RV infection leads to apoptosis in cell culture. These observations together taken to the fetal organogenesis level, favor the idea that RV P90, by binding to cellular CK, invokes cell cycle aberrations resulting in the cell- and organ-specific growth inhibition and programmed cell death during RV infection in utero, which commonly is referred to as RV-induced teratogenesis.

Thalidomide after allogeneic haematopoietic stem cell transplantation: activity in chronic but not in acute graft-versus-host disease

Thalidomide was used to treat acute (n=21) or chronic (n=59) graft-vs-host disease (GVHD) in 80 haematopoietic stem cell allograft recipients after failure to respond to the combination of cyclosporine and corticosteroids with or without other agents. The median time to onset of acute GVHD was 11 days, and thalidomide was started at a median of 48 days post transplant. In addition to corticosteroids and cyclosporine, 13 patients had also received other agents before thalidomide. None of the patients responded and all died of acute GVHD. For chronic GVHD (limited in 13, extensive in 46), thalidomide was started at a median of 385 days post transplant. In addition to corticosteroids and cyclosporine, 34 patients received azathioprine concomitantly. In all patients, thalidomide was added to the ongoing immunosuppressive regimen. The median duration of therapy with thalidomide was 60 days (range, 11-1210; <2 weeks in 11). In total, 13 patients (22%) had complete response, eight (14%) partial response and 38 (64%) no response. Response rates were comparable for limited (39%) and extensive (33%) chronic GVHD. At a median of 53 months, 19 patients are alive, 13 without evidence of chronic GVHD. Survival was significantly better in patients who responded to thalidomide. The principal causes of death were progressive chronic GVHD (n=29) and relapsed leukaemia (n=7). In conclusion, thalidomide has no activity in acute GVHD, but has some activity in chronic GVHD in combination with other agents.

Posterior cruciate ligament at total knee replacement. Essential, beneficial or a hindrance?

We report the results of a prospective randomised trial which assessed the role of the posterior cruciate ligament (PCL) following total knee replacement (Genesis I; Smith and Nephew, Memphis, Tennessee). Over a four-year period, 211 patients underwent total knee replacement by the senior author (TJW). They were randomised at surgery to have the PCL either retained, excised or substituted with a posterior stabilised insert. If it was not possible to retain the ligament due to soft-tissue imbalance, it was released from its tibial insertion until suitable tension was obtained. This created a fourth group, those who were intended preoperatively to have the ligament retained, but in whom it was partially released as a result of findings at the time of surgery. All patients were evaluated using the Knee Society rating system (adapted from Insall). A total of 188 patients (212 knees) was available for follow-up at a mean of 3.5 years after surgery. Preoperatively, there was a varus deformity in 191 knees (90%) and a valgus deformity in 21 (10%). There were no statistical differences in the knee or function scores or the range of movement between the excised, retained and substituted groups. There were, however, significantly worse knee and function scores in the group in whom the PCL was released (p = 0.002).

Posterior cruciate ligament at total knee replacement

We report the results of a prospective randomised trial which assessed the role of the posterior cruciate ligament (PCL) following total knee replacement (Genesis I; Smith and Nephew, Memphis, Tennessee). Over a four-year period, 211 patients underwent total knee replacement by the senior author (TJW). They were randomised at surgery to have the PCL either retained, excised or substituted with a posterior stabilised insert. If it was not possible to retain the ligament due to soft-tissue imbalance, it was released from its tibial insertion until suitable tension was obtained. This created a fourth group, those who were intended preoperatively to have the ligament retained, but in whom it was partially released as a result of findings at the time of surgery.

All patients were evaluated using the Knee Society rating system (adapted from Insall). A total of 188 patients (212 knees) was available for follow-up at a mean of 3.5 years after surgery. Preoperatively, there was a varus deformity in 191 knees (90%) and a valgus deformity in 21 (10%).

There were no statistical differences in the knee or function scores or the range of movement between the excised, retained and substituted groups. There were, however, significantly worse knee and function scores in the group in whom the PCL was released (p = 0.002).

Signaling events underlying thrombus formation

Recent in vivo studies have highlighted the dynamic and complex nature of platelet thrombus growth and the requirement for multiple adhesive receptor-ligand interactions in this process. In particular, the importance of von Willebrand factor (VWF) in promoting both primary adhesion and aggregation under high shear conditions is now well established. In general, the efficiency with which platelets adhere and aggregate at sites of vessel wall injury is dependent on the synergistic action of various adhesive and soluble agonist receptors, with the contribution of each of the individual receptors dependent on the prevailing blood flow conditions. In this review, we will discuss the major platelet adhesive interactions regulating platelet thrombus formation under high shear, with specific focus on the VWF (GPIb and integrin alphaIIbbeta3) and collagen receptors (GPVI and integrin alpha2beta1). We will also discuss the signaling mechanisms utilized by these receptors to induce platelet activation with specific emphasis on the role of cytosolic calcium flux in regulating platelet adhesion dynamics. The role of soluble agonists in promoting thrombus growth will be highlighted and a model to explain the synergistic requirement for adhesive and soluble stimuli for efficient platelet aggregation will be discussed.

Impact of cytogenetics on the outcome of autotransplantation for acute myeloid leukemia in first remission: is the benefit of intensive pretransplant therapy limited to patients with good karyotypes?

A total of 81 adults with acute myeloid leukemia (AML) (47% favorable karyotypes) were autografted in first remission after melphalan-total body irradiation, having received 0 (n=7), 1 (n=19), 2 (n=51), or 3 (n=4) consolidation chemotherapy cycles before harvest. The cumulative 5-year incidences of relapse and transplant-related mortality were 37 and 17%, respectively. The actuarial 5-year probability of disease-free survival (DFS) was 46%. In Cox analysis, favorable karyotypes, increasing numbers of consolidation cycles (0 vs > or =1 or 1 vs >1), and higher nucleated cell doses were associated with lower relapse rates and higher DFS. Patients with favorable karyotypes benefited from every additional cycle of consolidation therapy (0 vs > or =1 as well as 1 vs >1). Among patients with other karyotypes, while the benefit of one cycle of consolidation was clear (0 vs > or =1), there was no obvious beneficial impact of further consolidation therapy (1 vs >1). Administration of consolidation chemotherapy prior to harvest is essential in AML. While it is possible to enhance the benefit of consolidation with favorable karyotypes by delivering two cycles, its usefulness is limited in others. In them, it may be worthwhile exploring alternatives not normally used in AML (eg high-dose cyclophosphamide) that could have antileukemic effects while permitting mobilization of stem cells.

Haploidentical vs autologous hematopoietic stem cell transplantation in patients with acute leukemia beyond first remission

This is a retrospective comparison of partially mismatched related donor transplantation (PMRDT) and autotransplantation (ABMT) in advanced acute leukemia. Patients underwent T-cell-depleted PMRDT (n=164) or ABMT (n=131) for acute myeloid leukemia (n=130) or acute lymphoblastic leukemia (n=165). Fewer PMRDT patients were in remission (29 vs 85%; P<0.0001). The 5-year cumulative incidence of transplant-related mortality (TRM) was 52% after PMRDT and 16% after ABMT (P<0.0001). The 5-year cumulative incidence of relapse was 32% after PMRDT and 54% after ABMT (P=0.006). The actuarial unadjusted 5-year disease-free survival (DFS) was 16% after PMRDT and 30% after ABMT. In Cox's regression analysis, PMRDT (P<0.0001) and age >15 years (P=0.002) were associated with higher TRM, active disease (P=0.0021), ABMT (P=0.0074) and male sex (P=0.011) with higher relapse, and age >15 years (P=0.0007) and PMRDT (P=0.047) with lower DFS. Amongst second remission patients, TRM was higher after PMRDT (P=0.0003), relapse was higher after ABMT (P=0.034), and 5-year DFS was comparable (32% ABMT and 25% PMRDT). ABMT, if feasible, may be preferable to PMRDT in advanced acute leukemia patients since lower relapse after PMRDT is offset by higher TRM. If an autograft is not feasible because of nonavailability of autologous cells or very advanced disease, PMRDT is a potential alternative.

Supplemental premolars in a 13 year old child--a case report

A case of 13 old year is presented with supernumerary maxillary premolars one on either side. Radiograph revealed presence of five more supernumerary teeth unerupted in both maxilla and mandible. The implications of early diagnosis and management to prevent further complications are discussed.

Patients' recollection of day case knee arthroscopy procedure

A prospective study of 103 consecutive patients who underwent day case knee arthroscopy was performed. The purpose was to evaluate the information delivery system, patient comprehension, and issues of informed consent pertaining to day case arthroscopy procedures. There were 34 females and 69 males in the study group and their mean age was 38.6 years (range: 14.4 to 74.9 years). The diagnosis, procedure, and aftercare were explained to the patients in the outpatients clinic by a trained nurse and by the operating surgeon just prior to the operation. The nurse before the operation gave the patients an information booklet. Postoperatively the patients were informed about the findings and diagnosis prior to their discharge from the day care facility. Patients were requested to complete a questionnaire. Three weeks later they were given the same questionnaire, prior to consultation, in the outpatient clinic. These two forms were compared with the operative findings and diagnosis documented in the copy, of the questionnaire completed by the surgeon as well as the case notes. Most patients (38.8%; 40 patients) had no recollection; 3.9% (4 patients) had partial recollection at their consultation three weeks later; 19.4% (20 patients) found that the arthroscopic photograph was not helpful in making them understand the procedure; and 9.7% (10 patients) found the information booklet to be unhelpful. Further, 23.3% (24 patients) said that it would not help if the booklet were sent to them prior to the operation. The recollection rate was also correlated to their position on the operating list, to ascertain the effect of the anesthetic. There was a 65.9% (58 patients) recollection rate in those patients who were on the first half of the list and there was only a 33.33% recollection rate in those patients who were last or second to the last [p = 0.0225]. We recommend regular evaluation and improvement in the communication and information delivery system provided to patients.

Response to induction chemotherapy is not essential to obtain survival benefit from high-dose melphalan and autotransplantation in myeloma

Two hundred and twenty-two myeloma patients autografted after 200 mg/m(2)melphalan were studied to examine the relationship between response to induction chemotherapy and outcome. Induction comprised cyclophosphamide, vincristine, doxorubicin and methylprednisolone (C-VAMP) every 3 weeks for one cycle beyond maximum response. 81% responded to C-VAMP (chemosensitive) with 40 complete (CR) and 139 partial (PR) remissions, and 43 did not respond (NR; <50% reduction in paraprotein; primary refractory). Overall, 130 patients (59%) attained or remained in CR post-transplant; including 40% of NR, 53% of PR, and 97% of CR after C-VAMP (P < 0.0001). Amongst these 130 patients, the 5-year OS was independent of response to C-VAMP (NR 79%, PR 74%, CR 60%; P = 0.69). Similarly, among the 69 patients in PR post-transplant, the 5-year OS was independent of response to C-VAMP. In Cox analysis, lack of response to C-VAMP did not affect outcome significantly. These data show that lack of response to induction therapy does not automatically predict poor long-term outcome in myeloma, since a substantial proportion of these patients attain CR after autograft and enjoy extended survival. Myeloma patients should not be disqualified from an autograft based upon lack of response to induction chemotherapy.

Collection of peripheral blood stem cells in newly diagnosed myeloma patients without any prior cytoreductive therapy: the first step towards an 'operational cure'?

We have shown that primary therapy with non-myeloablative (140 mg/m(2)) high-dose melphalan (HDM) without hematopoietic support results in high response rates in untreated myeloma and very long-term survival of some patients. This study was designed to see if sufficient CD34 (+) cells can be harvested at presentation in newly diagnosed patients to administer myeloablative HDM (200 mg/m(2); HDM200) with autograft as primary therapy. This may improve outcome by rapid achievement of complete remission (CR) and possible avoidance of late myelodysplasia as a consequence of non-transplant induction chemotherapy. Thirty untreated patients received 1 g/m(2) methylprednisolone daily (days 1-6) and 12-16 micro g/kg G-CSF daily (days 3-6), and underwent leukapheresis on days 6 and 7. The median CD34(+) cell yield was 1.31 x10(6)/kg (range, 0.23-5.63), and was > or =1 x10(6)/kg in 73%. Cell yields were significantly lower than in 82 historical controls apheresed after completion of induction chemotherapy (median 2.16 x 10(6)/kg), and improved in patients who were apheresed again after induction chemotherapy. Three patients received primary therapy with HDM200 and autograft using these cells and attained CR. We conclude that it is possible to harvest stem cells in three-quarters of untreated myeloma patients. Increasing the number of apheresis procedures is needed to improve the number of CD34(+) cells collected.

A randomised controlled trial of outpatient versus inpatient cervical cerclage

Fifty patients with cervical incompetence were randomised to have cervical cerclage either as inpatients, spending 3 days in hospital post-procedure on supervised bed rest or as outpatients spending the time at home on bed rest. Both groups had a clinical diagnosis of cervical incompetence and both had either McDonald or Shirodkar cerclage with mersilene tape. Both groups were given salbutamol tablets for tocolysis, postoperatively. There were no significant difference in the demographic variables between the groups such as previous cerclage, gestational age at insertion, parity and gestational age at delivery. There were also no significant differences in early complications such as bleeding. Most late complications were also not different, including the spontaneous abortion rate, premature rupture of membranes, cervical dystocia and preterm delivery. However, more patients in the outpatient group had premature contractions (26.1% vs. 4.3% P=0.0479). More patients in the inpatient group had a delivery of a live neonate, 86.9% vs. 78.3%, but the difference was not statistically significant. In conclusion, out patient cerclage appears to be a valid option, the higher rate of premature contraction in this group is not a cause for concern in view of the similar mean gestational age at delivery.

Prevalence and incidence of hepatitis B virus infection in STD clinic attendees in Pune, India

OBJECTIVES

To estimate the prevalence and incidence of hepatitis B virus (HBV) infection among patients attending three STD clinics in Pune, India, and to identify associated risk factors.

METHODS

Of the 2098 patients screened at STD clinics in Pune during 1996, 497, who returned for at least one follow up visit, were screened for various markers of HBV infection (HBsAg, anti-HBs, anti-HBc), HIV antibody, and VDRL.

RESULTS

Of the 497 participants 3.6%, 26.5%, and 43.2% were positive for HBsAg, anti-HBs, and anti-HBc respectively. Tattooing (AOR 1.64, 95% CI 1.03 to 2.64) was found to be independently associated with presence of core antibody. Additionally, history of being in commercial sex work and history of a genital ulcer were independently associated with a positive anti-HBc antibody test (AOR 12.45, 95% CI 5.58 to 27.82 and AOR 1.70, 95% CI 1.09 to 2.66, respectively). 72 out of 497 (14.5%) participants were HIV positive at baseline. HIV-1 antibody positive patients were more likely to have a positive anti-HBc test (69.4% v 39.0%, p<0.001). 30 out of 282 participants, negative for anti-HBc antibody at enrolment, seroconverted subsequently, resulting in an incidence of 10.86 per 100 person years (95% CI 7.2%, 14.5%) (mean and accumulated follow up of 11.7 months and 276.17 person years, respectively).

CONCLUSIONS

A high prevalence and incidence of HBV infection, seen in STD clinic attendees underscore the need to provide HBV vaccine to commercial sex workers and their clients in India.

Does donor-recipient ABO incompatibility protect against relapse after allogeneic bone marrow transplantation in first remission acute myeloid leukemia?

It is not known if donor-recipient ABO blood group incompatibility contributes to graft-versus-leukemia after allogeneic BMT. One hundred and nineteen patients with acute myeloid leukemia in first remission underwent non-T cell-depleted marrow allografts from HLA-identical siblings after TBI and cyclophosphamide (n = 72) or melphalan (n = 47). GVHD prophylaxis comprised cyclosporine alone or cyclosporine-methotrexate. Twenty-two patients relapsed at 3-46 months (median 7): 18 of 76 patients with ABO-matched donors and four of 43 patients with ABO-mismatched donors (actuarial 5-year probabilities 33 +/- 6% vs 12 +/- 6%; P = 0.028). The incidence of acute and chronic GVHD was not affected by ABO mismatch. The following factors were studied in Cox analysis for effect on outcome: gender, age, FAB subtype, ABO mismatch, CR-transplant interval, conditioning, TBI dose, nucleated cell dose, lymphocyte recovery, acute GVHD, and chronic GVHD. Donor-recipient ABO match was the only factor independently associated with a higher risk of relapse (RR = 3.7; 95% Cl, 1.1-12.6; P = 0.04). ABO mismatch was also associated with superior overall and disease-free survivals. We conclude that ABO incompatibility may influence relapse rates and survival favorably after allogeneic BMT. It is not known if this holds true for allogeneic blood stem cell transplants.