Clinical and laboratory spectrum of culture-proven human granulocytic ehrlichiosis: comparison with culture-negative cases

We describe the clinical and laboratory manifestations of human granulocytic ehrlichiosis (HGE) in eight patients for whom cultures were positive for the HGE agent and compare them with 15 patients for whom cultures were negative but who fulfilled a modified New York State Surveillance definition for HGE. Polymerase chain reaction analysis was positive in 8 (100%) of 8 culture-positive cases vs. 3 (20%) of 15 culture-negative cases (P < .001), morulae were detected in 7 (100%) of 7 culture-positive cases in which tests were performed vs. 0 of 15 culture-negative cases (P < .001), and a fourfold change in antibody titer was demonstrated in 6 (75%) of 8 culture-positive cases vs. 9 (69%) of 13 culture-negative cases (P = not significant). Patients for whom cultures were positive had higher mean oral temperatures +/- SD at presentation than did patients for whom cultures were negative (38.6 degrees C +/- 0.7 degree C vs. 37.2 degrees C +/- 0.8 degree C, respectively; P = .002). Other symptoms and signs were not significantly different between the two groups. Multivariate analysis revealed that the lymphocyte count at presentation was significantly lower in culture-positive cases than in culture-negative cases. Clinical response to treatment was similar in the two groups. Culture confirmation of HGE is the gold standard for defining the sensitivity and specificity of other diagnostic tests presently being developed.

Effects of early postnatal dexamethasone therapy on calcium homeostasis and bone growth in preterm infants with respiratory distress syndrome

The effects of dexamethasone therapy on calcium homeostasis and bone growth were evaluated in 49 infants (24 placebo and 25 dexamethasone) who participated in a double-blind trial of early dexamethasone therapy for the prevention of chronic lung disease. Dexamethasone (0.25 mg kg(-1) b.i.d. on d 1-7; 0.12 mg kg(-1) b.i.d. on d 8-14; 0.05 mg kg(-1) b.i.d. on d 15-21; 0.02 mg kg(-1) b.i.d. on d 22-28) or saline placebo was given i.v. Serum calcium (Ca), phosphorus (P) and parathyroid hormone (PTH), and the corresponding urinary excretion of calcium (FECa) and phosphorus (FEP) were measured on d 2, 3, 7, 10, 14, 21 and 28 after starting the study. Radiographic evaluations of bone growth were also evaluated. Infants in the dexamethasone group had significantly higher PTH on d 2 (p < 0.01), 7 and 14 (p < 0.05) than infants in the placebo group. The dexamethasone-treated infants also had significantly higher FEP on d 2, 7 and 14 (p < 0.05) and lower FECa on d 7 and 14 (p < 0.05) than control infants. There was no significant difference between the groups in bone growth during the study. It was concluded that early dexamethasone therapy causes a transient elevation in PTH without apparent change in bone growth. The long-term effect remains to be evaluated further.

Regulation of G1/S transition and induction of apoptosis in HL-60 leukemia cells by fenretinide (4HPR)

We previously reported that all-trans retinoic acid (RA) and fenretinide (4HPR) suppress HL-60 leukemia cell growth and cause partial cell arrest in the G1-to-S phase. Moreover, 4HPR but not RA induces apoptosis in HL-60 cells. To investigate further the observed biological effects, cyclin D1 and cdk4 expression and the level of phosphorylation of the retinoblastoma protein Rb were assessed. Cyclin D1 and cdk4 expression and Rb phosphorylation were significantly reduced, by 40-75%, after 24 hr of treatment with RA or 4HPR; these decreases were either transient, e.g., only at 24 hr for cdk4, or sustained for 72 hr. In general, more pronounced decreases were seen in the 4HPR-treated cells. Evidence for 4HPR-induced apoptosis comes from (1) cleavage of the enzyme poly(ADP-ribose) polymerase (PARP) to an 89-kDa truncated product, (2) appearance of DNA ladders on agarose gel electrophoresis, and (3) higher incorporation in situ of digoxigenin nucleotides into the free 3'-ends of DNA. Overnight pretreatment with 0.5-5.0 microM of the CPP32 inhibitor DEVD, but not the ICE inhibitor YVAD, significantly reduced the specific processing of PARP, suggesting that CPP32 is involved in the mechanism of action of 4HPR. Analysis of 2 lipid-derived second messengers, ceramide and diacylglycerol (DAG), as a function of time of treatment with RA or 4HPR, showed ceramide but not DAG to be significantly albeit transiently increased 2-fold at 3 hr, by 4HPR. To test further whether ceramide may be involved in the signaling cascade that culminates in the induction of apoptosis in 4HPR-treated HL-60 cells, the effects of fumonisin B1, an inhibitor of ceramide synthase, were studied. Simultaneous treatment of cells with 4HPR and 25-100 microM fumonisin B1 resulted in a dose-dependent reduction in the elevation in ceramide, the extent of PARP cleavage, and induction of apoptosis. Pretreatment with DEVD or YVAD, on the other hand, had no effect on the 4HPR-induced increase in ceramide.

Lifestyle factors and human lung cancer: an overview of recent advances (review)

This article presents a review on the association between certain lifestyle characteristics and the risk for lung cancer in humans, using information derived primarily from epidemiological studies. Emphasis will be placed on more recently identified risk factors such as exposure to indoor air pollutants, psychosocial and behavioral influences, diet preferences, and fat intake. More traditional lifestyle factors such as cigarette smoking, occupation, and exposure to outdoor air pollutants will not be reviewed since their association with an increased risk for human lung cancer has been relatively well characterized and extensively reported. Evidence to date suggests that the indoor environment, life's events, and food choices may play a potentially important, albeit varying, role in the etiology of human lung cancer.

Cell cycle effects and induction of apoptosis caused by infection of HL-60 cells with human granulocytic ehrlichiosis pathogen measured by flow and laser scanning cytometry

Human granulocytic ehrlichiosis (HGE) is an occasionally severe and even fatal disease caused by an agent closely related to Ehrlichia equi and Ehrlichia phagocytophila, which is transmitted by ticks. Little is known about the pathogen itself, which only very recently has been isolated. The agent can be cultivated in vitro because it replicates in human promyelocytic leukemic HL-60 cells. Using multiparameter flow cytometry and laser scanning cytometry (LSC) we have investigated changes in HL-60 cells following their infection with the pathogen. Its presence within the infected HL-60 cells was detected and its intracellular level measured inmmunocytochemically using antibodies obtained from HGE-infected patients. The percentage of the infected cells measured by flow cytometry or LSC correlated well with the estimates by microscopy on the Giemsa-stained specimens. In the infected cultures, the cells had diminished levels of cyclins D3 and E as well as the cyclin dependent kinase inhibitor p21WAF1/CIP1 and were arrested predominantly in G0/1. The apoptosis-associated regulatory proteins were also affected by cell infection: expression of Bcl-2 was decreased in the infected cells whereas expression of Bax become more variable, with some cells showing higher levels of this protein. The infected cells developed numerous DNA strand breaks characteristic of apoptosis. The presence of the pathogen was also detected by LSC in cells from peripheral blood of the infected patients; after relocation and visual inspection ("CompuSort") the pathogen-positive cells were identified as leukocytes. This unique ability of LSC to detect, quantify, and visualize HGE in infected cells made this instrument particularly useful to measure the degree of infection in peripheral blood of the patients and study effects of the infectious agent on the cell cycle and apoptosis of the host cells.

Effects of blocked atrial beats on the atrioventricular nodal recovery property: facilitation or depression?

INTRODUCTION

Blocked atrial beats (A(B)) usually have concealed AV nodal penetration, which can change the nodal conduction time (AH) of a subsequent beat. However, without an output marker it is difficult to assess their effect on the node. In this report we used all possible parameters as nodal resting time after A(B) and plotted them against the AH of testing beats to study their effects on the node.

METHODS AND RESULTS

Atrial extrastimulation studies were done in 21 patients in whom one blocked atrial beat (A(2B)) was observed. Nodal recovery curves were obtained for basic pacing (A1), after a conducted premature beat (A2), and after A(2B). In six patients there were 2 to 3 consecutively blocked beats (A(nB)) and recovery curves were constructed after each A(nB). Nodal recovery curves were plotted with AH of the testing beat against different nodal resting parameters and fitted to a single exponential equation. We found contradicting phenomena when using different formats. (1) For recovery curves of A(2B), there was a rightward shift from that of the basic curve when using H1A3 or A1A3 as the gauge (depression phenomenon). On the contrary, there was a leftward shift of the curves when using A(2B)A3 (facilitating phenomenon). (2) For recovery curves after multiple blocked beats there was a marked rightward shift of all curves except A(n-1)(B)An-curves, which were all leftward shifted.

CONCLUSION

Because these contradicting phenomena were dictated by the presenting formats, the terms "depression" and "facilitation" cannot be considered intrinsic AV nodal properties outside of the strict context of the pacing protocol and the format of data presentation.

Inhibiting Ras prenylation increases the radiosensitivity of human tumor cell lines with activating mutations of ras oncogenes

The influence of activated ras oncogenes on the sensitivity of human tumor cells to killing by radiation has been an unresolved question in radiobiology. We have examined this question by measuring the radiation sensitivity of human tumor cell lines with oncogenic mutations in their H- or K-ras genes after treatment with prenyltransferase inhibitors that prevent the posttranslational modification of ras required for its activity. Using two measures of clonogenic survival, we have demonstrated radiosensitization in cell lines with oncogenic H-ras mutations or with oncogenic K-ras mutations when ras processing was inhibited by prenyltransferase inhibitor treatment. In contrast, the inhibition of ras processing in cell lines expressing wild-type ras had no effect on radiation-induced cell death. The prenyltransferase inhibitors themselves inhibited clonogenic survival in some cases, but this inhibition did not correlate with ras mutational status. Although treatment with prenyltransferase inhibitors and radiation resulted in a greater reduction of clonogenicity than either treatment alone in cells with wild-type ras, treatment with both agents had a synergistic effect on cell killing in tumor cells with ras mutations. Our results demonstrate that the inhibition of oncogenic ras activity in human tumor cells can reduce the radiation survival of these cells, suggesting that oncogenic ras can contribute to radiation resistance in human tumors. These results further demonstrate the potential of using prenyltransferase inhibitors in combination with radiotherapy in the treatment of human malignancies.

In situ hybridization for gastrin-releasing peptide receptor (GRP receptor) expression in prostatic carcinoma

Bombesin-like peptides (BLPs), which have been implicated in the regulation of growth of prostatic carcinoma cells, are a product of neuroendocrine cells frequently found in prostate tissue and are postulated to play a role in the initiation or progression of prostatic carcinoma. In this report, we examined the expression, in human prostate tissue, of mRNA encoding the 3 known receptors that respond to BLPs in humans, i.e., gastrin-releasing peptide (GRP) receptor, neuromedin B (NMB) receptor and bombesin receptor subtype 3 (BRS-3). Competitive rt-PCR experiments demonstrated the widespread but variable expression of GRP receptor mRNA in fresh-frozen specimens of prostatic carcinoma (12 cases) and benign prostatic hypertrophy (6 cases). NMB receptor mRNA expression was also widespread, but its level was less variable than GRP receptor message. In contrast, we could not detect BRS-3 mRNA in most tissue samples by rt-PCR. To address which cells in the prostate express the GRP receptor, we used in situ hybridization methods to stain selectively GRP receptor mRNA. GRP receptor mRNA was expressed predominantly in the luminal and basal epithelial cells in both histologically normal and cancerous glands within sections of normal (3 cases) and diseased (37 cases) tissue. GRP receptor mRNA staining in cancerous tissue ranged widely from very intense to not detectable (about 30% of the cases), while normal tissue consistently displayed a low level of message staining. Taken together, our results demonstrate expression of the GRP receptor in a high percentage of basal and/or luminal epithelial cells of normal and diseased prostate tissues.

The effects of brefeldin A (BFA) on cell cycle progression involving the modulation of the retinoblastoma protein (pRB) in PC-3 prostate cancer cells

PURPOSE

To investigate the effects of brefelding A (BFA) on the growth of the androgen-independent human prostate cancer PC-3 cells, focusing on cell cycle regulation.

MATERIALS AND METHODS

BFA is a fungal macrocyclic lactone with an antiviral activity. PC-3 cells were cultured with various concentrations of BFA for indicated times and cell growth was monitored at each time point. Cell cycle analysis was performed to explore the mechanism of BFA-induced growth inhibition. To further investigate the cell cycle regulation, cell cycle-controlling factors, such as the retinoblastoma gene product (pRB) and its regulatory components cdk2, cdk4, and cyclin D1, were analyzed by Western immunoblots.

RESULTS

BFA was a potent growth inhibitor at a concentration of 30 ng./ml., resulting in a > 70% reduction in cell number at 3 days. Cell cycle analysis revealed a cell arrest in the G1 to S phase transition. Western blots further showed that BFA induced dephosphorylation of pRB accompanied by down regulation of cdk2, cdk4, and cyclin D1 expression. The extended pRB dephosphorylation in control cell lysates was also observed by the addition of BFA-treated lysates, but was prevented by the inclusion of phosphatase inhibitors in assay mixtures.

CONCLUSION

These results suggest that BFA may be a potent cell cycle modulator, which post-translationally regulates pRB phosphorylation possibly by down-regulating cdk2, cdk4, and cyclin D1 and/or by up-regulating a phosphatase(s) capable of dephosphorylating pRB. Thus, BFA-induced growth inhibition in PC-3 cells appears to be at least partially due to the modulation of a pRB-mediated growth pathway.

Laryngeal candidiasis in children

Candidiasis of the larynx is rare and often related to immunocompromised hosts. We here report a case of laryngeal candidiasis in an immunocompetent infant. The diagnosis was obtained by direct fibre-optic laryngoscopy with specimens submitted for culture. He received anti-fungal medication and was quite well at 1-year follow up. The pertinent literature is also reviewed.

Trifascicular block with intermittent complete atrioventricular block in a child

Trifascicular block, which consists of impaired conduction in the three main fascicles of the ventricular conduction system, may progress to high-grade or complete atrioventricular block. It rarely occurs in children with a structurally normal heart. We report a case of trifascicular block in a previously healthy 9-year-old girl. The patient presented with repetitive seizures. The electrocardiogram showed a complete right bundle branch block, left axis deviation, PR interval prolongation, and intermittent high-degree and complete atrioventricular block. She was successfully treated with a temporary pacemaker and her electrocardiogram returned to a normal sinus rhythm in 3 days. She has remained well over a 4-year follow-up. Although her cardiac enzyme levels were normal, the clinical course and electrocardiography findings suggested myocarditis. We emphasize the diagnosis of trifascicular block using electrocardiography; clinical outcome is good, if the patient is managed properly.

Developmental changes of atrioventricular nodal recovery properties

Atrioventricular (AV) nodal recovery properties can be studied by a periodic premature stimulation protocol performed at a slow basic rate. Developmental aspects of these properties have not been determined. The purpose of this study was to determine the developmental changes of AV nodal recovery properties. Forty-three children and young adults (male:female ratio 25:18) without AV nodal disease (aged 3.3 to 21.9 years) were studied by delivering premature atrial extrastimuli coupled to basic driven atrial beats. The individual recovery curve was fitted to the equation: A2H2 = A0H0 + exp(alpha -H1A2/tau) for H1A2 > or =theta, where A0H0 is the minimum AH interval, H1A2 is any recovery interval that exceeds the nodal effective refractory period, A2H2 is the corresponding nodal conduction time at any given H1A2, alpha is a constant, tau is the recovery time constant, and theta is the nodal effective refractory period. We found that: (1) A0H0 and alpha constant did not change significantly with age; (2) both tau (r = 0.324; p <0.05) and theta (r = 0.401; p <0.05) had a positive correlation with age; and (3) the maximum change in A2H2 with a 10-ms decrement in H1A2 was 32 ms and did not change significantly with age. Our results suggest that AV nodal recovery properties are age-dependent and both the recovery time constant and effective refractory period lengthen with age.

Pulsed high-dose dexamethasone therapy in children with chronic idiopathic thrombocytopenic purpura

PURPOSE

The effectiveness of pulsed high-dose oral dexamethasone therapy in children with refractory chronic idiopathic thrombocytopenic purpura (ITP) is evaluated.

PATIENTS AND METHODS

Seven children (5 to 16 years old) who were refractory to 2 to 5 conventional standard therapies were included in the study. Dexamethasone was administered orally at a dosage of 40 mg/m2 per day (maximum 40 mg/day) for 4 consecutive days as a cycle. The cycle was repeated once a month for 6 months.

RESULTS

One month after the first cycle, partial responses of platelet counts (> or = 50 x 10(9)/L and < 150 x 10(9)/L) were observed in three patients (43%). At the end of the sixth cycle, two patients (29%) had complete responses (> 150 x 10(9)/L) and one had a partial response. However, only one patient (14%) remained partially responsive 1 year after completion of therapy.

CONCLUSIONS

In contrast to what was observed in adults, this preliminary study suggests that pulsed high-dose oral dexamethasone therapy was not uniformly effective in children with chronic ITP.

Effects of fenretinide (4-HPR) on prostate LNCaP cell growth, apoptosis, and prostate-specific gene expression

BACKGROUND

Although fenretinide (4-HPR) is currently being evaluated in a phase II clinical study for the chemoprevention of prostate cancer [Greenwald et al.: CA 45:31-49, 1995], the mechanism underlying its antineoplastic activity has not been elucidated.

METHODS

Androgen-dependent human prostatic LNCaP cells cultured with fetal bovine serum (FBS) were treated with 4-HPR and evaluated for effects on cell growth and cell cycle phase distribution, induction of apoptosis, and changes in proliferating cell nuclear antigen (PCNA), prostate-specific antigen (PSA), and androgen receptor (AR) levels.

RESULTS

LNCaP cells treated with 4-HPR for 6 days showed 82-95% suppression of cell growth, with accompanying time- and dose-dependent downregulation of PCNA, a partial arrest in G1 phase of the cell cycle, and a marked increase in the percentage of apoptotic cells. Apoptosis was demonstrated by the characteristic DNA fragmentation pattern seen on agarose gels, and by flow cytometric analysis. 4-HPR-induced prostate-specific phenotype changes included significant downregulated expression of both intracellular and secreted forms of PSA, which were preceded by a reduction of AR expression.

CONCLUSIONS

These data suggest that 4-HPR acts as a pleiotropic effector of prostate cell growth and specific gene expression.

Effects of IL-1 beta on receptor-mediated poly-phosphoinositide signaling pathway in immortalized astrocytes (DITNC)

Astrocytes are known to play multi-functional roles in support of many homeostatic mechanisms in the central nervous system including host defense mechanisms. Despite the ability of cytokines to alter gene expression and cellular activity, their effect on receptor-mediated poly-phosphoinositide (poly-PI) signaling pathway has not been examined in detail. In this study, an immortalized astrocyte cell line (DITNC) was used to test the effect of IL-1 beta exposure on the poly-PI signaling pathway. Similar to primary astrocytes, DITNC cells exhibit P2-purinergic receptor response to ATP and UTP leading to transient increases in inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] and intracellular calcium concentration, [Ca2+]i. Upon exposure of DITNC cells to IL-1 beta (100 U/ml) for 24 hrs, an increased response to the poly-PI agonists was observed. The increase in ATP-mediated Ins(1,4,5)P3 release could not be attributed to a shift in the ATP dose or an alteration of the time profile for the release of Ins(1,4,5)P3. Since the increase in response required a lag time of 4 hr after IL-1 beta exposure, it is unlikely that this effect was due to a direct interaction of IL-1 beta with the purinergic receptor. On the other hand, an increase in ATP response could be observed in DITNC cells exposed to conditioned medium obtained after IL-1 beta treatment. It can be concluded that exposure of astrocytes to cytokines may lead to an increase in receptor-mediated poly-PI signaling activity and this may involve compounds secreted into the culture medium, e.g., the secretory phospholipase A2.

Myocarditis with complete atrioventricular block associated with herpes simplex virus infection: report of one case

Myocarditis with complete atrioventricular block is a very unusual complication of the herpex simplex infection. We report a 10-year-old boy infected very likely by the herpes simplex virus and who presented with high fever, erythema multiforme, complete atrioventricular block, and Adams-Stokes seizures. Emergent temporary pacemaker was performed for bradycardia. A sixteen-fold rise in herpes simplex antibody titer by a complement fixation method occurred within two weeks. Normal cardiac rhythm recovered 11 days later with a sequela of complete right bundle branch block after 2 years follow-up.

Lying-on position of total skin electron therapy

PURPOSE

A technique for whole-body electron therapy with the patient in a lying position has been developed. This technique allows Total Skin Electron Therapy (TSET) for those patients who were previously unable to be treated in a conventional standing position.

METHODS AND MATERIALS

This study was carried out on a Varian 2100C linear accelerator with a 6 MeV high dose rate electron beam. The collimator was open to a width of 36 x 36 cm. There were two main procedures, with six dual-field techniques: 1) two static AP/PA vertical dual fields (VDF): the patient laid on the floor transversely under the collimator when the gantry was in a vertical position. A 0.6 cm acrylic board was placed 15 cm away from the patient, then the gantry was rotated 25 degrees clockwise and counterclockwise to treat the patient in the supine and prone positions, respectively. 2) Four oblique junction fields (OJF): the patient laid on the floor in a prone and supine position parallel to the wave guide at (227 - body thickness x tan 60 degrees) cm away from the vertical axis of the gantry, then the gantry was rotated 60 degrees toward the patient. A 0.6 cm acrylic board was placed 15 cm away from the patient perpendicular to the beam. The patient was move along the field central axis. It allowed the patient's body to be within the 160 cm effective treatment profile. When the patient's body axis move 5 degrees toward the lateral side of the field central axis, we could obtain a better dose distribution in the vertex of the scalp and the soles of the feet. The angle of the VDF was measured by chamber detectors to obtain the effective treatment profile. Likewise, the optimal profile for the OJF was determined by the same procedures. The Rando phantom was used to measure the superficial dose of the body.

RESULTS

The dimension of effective treatment profile for the VDF was 188 x 72 cm at 87% dose level For the OJF, we had to move the patient along the field central axis to obtain the effective treatment profile in a 180 x 85 cm dimension at a 87% dose level. The vertex and sole dose measured in this setup was in the range of 80-88%.

CONCLUSIONS

The empirical data showed that the lying-on position for TSET was technically feasible. The dose distribution in the body surface was also compatible with the Stanford standing technique. The nonambulatory skin malignancy patient can be treated in a comfortable and reproducible position.

Regulation of androgen receptor (AR) and prostate specific antigen (PSA) expression in the androgen-responsive human prostate LNCaP cells by ethanolic extracts of the Chinese herbal preparation, PC-SPES

As part of the study on the potential use of natural product-based combination therapy for treating prostate cancer, we have investigated the effects of a "HPLC standardized" herbal preparation, PC-SPES, on the prostate LNCaP cell line. Proliferation of the LNCaP cells was inhibited by a 4-6 day incubation with ethanolic extracts of PC-SPES. Decrease of cell growth was accompanied by a 60-70% down-regulation of the proliferating cell nuclear antigen (PCNA) and level of secreted PSA. A smaller and more variable decrease (20-40%) in the level of intracellular PSA was also observed. The PC-SPES-modulated PSA changes occurred concurrently with the decrease of AR expression, based on Western blot analysis and binding to the radioactive ligand [3H]R1881. A 60% decrease in R1881 binding occurred after a 24 h incubation with PC-SPES. These results suggest that PC-SPES negatively affects cell growth in part through its ability to modulate changes in PCNA, and may decrease PSA levels indirectly by suppressing AR expression.

Induction of apoptosis and altered nuclear/cytoplasmic distribution of the androgen receptor and prostate-specific antigen by 1alpha,25-dihydroxyvitamin D3 in androgen-responsive LNCaP cells

In addition to suppressing prostate cell growth, vitamin D also up-regulates the expression of androgen receptor (AR) and prostate-specific antigen (PSA). To study the mechanism involved in the control of these proteins, LNCaP cells were treated with 10 nM 1alpha,25-dihydroxyvitamin D3 and separated into cytosol and nuclear fractions. AR and PSA were analyzed by western blot analysis. A second approach involved incubating control and treated cells with [3H]R1881, fractionating the cells into the cytosolic and nuclear components, and quantifying the amount of radioactivity associated with the respective fractions. Alternatively, immunohistochemical assays were performed by staining cells with cognate antibodies for AR and PSA. Both biochemical and immunohistochemical analyses show proportionately greater increased presence of AR in the nucleus, accompanied by relatively reduced AR in the cytosol, following treatment of LNCaP cells with vitamin D3. Surprisingly, PSA was found to be present in the nuclear fraction in both control and treated cells. These results suggest that vitamin D3 promotes the translocation of AR from the cytosol to the nucleus. The presence of PSA in the nucleus of LNCaP cells raises the possibility of an autogenous mode of control of PSA gene expression.

High-dose-rate intracavitary brachytherapy (HDR-IC) in treatment of cervical carcinoma: 5-year results and implication of increased low-grade rectal complication on initiation of an HDR-IC fractionation scheme

PURPOSE

To report the treatment results and rectal/bladder complications of cervical carcinoma radically treated with high-dose-rate intracavitary brachytherapy (HDR-IC). The current policy of using three-fraction scheme was examined.

METHODS AND MATERIALS

Between November 1987 and August 1990, 173 patients with cervical carcinoma were treated with curative-intent radiation therapy. Whole pelvic irradiation was administered with 10-MV X ray. Dose to the central cervix was 40-44 Gy in 20-22 fractions, following by pelvic wall boost 6-14 Gy in three to seven fractions with central shielding. 60Co sources were used for HDR-IC, and 7.2 Gy was given to Point A for three applications, 1-2 weeks apart. Duration of follow-up was 5-7.8 years.

RESULTS

Twenty-eight patients (16%) developed central-regional recurrences. Overall 5-year actuarial pelvic control rate was 83%. By stage, 5-year actuarial pelvic control rates were 94%, 87%, and 72% for Stages IB + IIA, IIB + IIIA, and IIIB + IVA, respectively. Thirty-one patients (18%) developed distant metastasis. Overall 5-year actuarial survival rate was 58%. By stage, 5-year actuarial survival rates were 79%, 59%, and 41% for Stages IB + IIA, IIB + IIIA, and IIIB + IVA, respectively. Sixty-six (38%) and 19 patients (11%) developed rectal and bladder complications, respectively. For rectal complication, the overall actuarial rate was 38% at 5 years. By grade, 5-year actuarial rectal complication rates were 24%, 15%, 4%, and 3% for Grades 1-4, respectively. Overall prevalence of rectal complications was 37% and 14% at 2 and 5 years, respectively. Prevalence of low-grade rectal complication (Grades 1 and 2) was dominant at 2 years (30%), but declined to 8% at 5 years. Prevalence of high-grade, severe rectal complication (Grades 3 and 4) remained steady at 2 and 5 years (7% and 6%, respectively). Five-year actuarial bladder complication was 9%. Five-year prevalence of bladder complication was 2%.

CONCLUSION

Using a three-fraction scheme, survival rate appeared comparable with the existing results of the low-dose-rate technique. The incidence of rectal complication with this scheme remained relatively high. The increased part of rectal complication was predominantly low grade. This result suggested that therapeutic gain with this scheme may not be good enough to circumvent its biologic disadvantage. Numbers of fractions >3 must be considered in future trials.