Optimal treatment for asymptomatic neurosyphilis

In the pre-penicillin era, patients with asymptomatic neurosyphilis (ANS) were more likely to develop long-term neurological sequelae than those patients with normal cerebrospinal fluid (CSF). Although benzathine penicillin G cannot achieve treponemicidal levels in the CSF, decreased rates of neurological complications of syphilis and non-treponemal titre serological responses are usually observed after treatment with this antibiotic. We here a homosexual man with ANS successfully treated with benzathine penicillin G. This case suggests that reconsideration on the necessity of a lumbar puncture in HIV-infected patients with ANS is warranted.

Abstract 995: Transient low doses of DNA demethylating agents exert durable antitumor effects on hematological and epithelial tumor cells

Reversal of gene promoter DNA hypermethylation and associated abnormal gene silencing is an attractive approach to cancer therapy. The DNA methylation inhibitors, decitabine (5-aza-2′-deoxycytidine) and azacitidine (5-azacytidine) are proving efficacious clinically for hematological neoplasms, especially at lower, less toxic, doses. Experimentally, high doses induce rapid DNA damage and cytotoxicity, but these may not explain the prolonged time to response often seen in patients. We now show that transient exposure of cultured and primary leukemic and epithelial tumor cells to decitabine or azacitidine at clinically-relevant nanomolar doses, without causing immediate cytotoxicity, produces a “memory” for anti-tumor responses, including potent inhibition of subpopulations of cancer, stem-like cells which often resist other therapies. These inhibitory effects are accompanied by sustained decreases in genome-wide promoter DNA methylation with associated gene re-expression, and anti-tumor changes in multiple key cellular regulatory pathways, such as cell cycle events mediated through FOXM1, cell invasion and motility, and granulocyte and breast cancer cell maturation. Notably, most of the key pathways altered by decitabine or azacitidine involve high priority targets for pharmacologic anti-cancer strategies, which provides molecular basis for possible combination therapies. Thus, low dose decitabine and azacitidine regimens may potentially have broad applicability for cancer management.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 995. doi:1538-7445.AM2012-995

Transient low doses of DNA-demethylating agents exert durable antitumor effects on hematological and epithelial tumor cells

Reversal of promoter DNA hypermethylation and associated gene silencing is an attractive cancer therapy approach. The DNA methylation inhibitors decitabine and azacitidine are efficacious for hematological neoplasms at lower, less toxic, doses. Experimentally, high doses induce rapid DNA damage and cytotoxicity, which do not explain the prolonged time to response observed in patients. We show that transient exposure of cultured and primary leukemic and epithelial tumor cells to clinically relevant nanomolar doses, without causing immediate cytotoxicity, produce an antitumor "memory" response, including inhibition of subpopulations of cancer stem-like cells. These effects are accompanied by sustained decreases in genomewide promoter DNA methylation, gene reexpression, and antitumor changes in key cellular regulatory pathways. Low-dose decitabine and azacitidine may have broad applicability for cancer management.

Tracking stem cell differentiation in the setting of automated optogenetic stimulation

Membrane depolarization has been shown to play an important role in the neural differentiation of stem cells and in the survival and function of mature neurons. Here, we introduce a microbial opsin into ESCs and develop optogenetic technology for stem cell engineering applications, with an automated system for noninvasive modulation of ESC differentiation employing fast optogenetic control of ion flux. Mouse ESCs were stably transduced with channelrhodopsin-2 (ChR2)-yellow fluorescent protein and purified by fluorescence activated cell sorting (FACS). Illumination of resulting ChR2-ESCs with pulses of blue light triggered inward currents. These labeled ESCs retained the capability to differentiate into functional mature neurons, assessed by the presence of voltage-gated sodium currents, action potentials, fast excitatory synaptic transmission, and expression of mature neuronal proteins and neuronal morphology. We designed and tested an apparatus for optically stimulating ChR2-ESCs during chronic neuronal differentiation, with high-speed optical switching on a custom robotic stage with environmental chamber for automated stimulation and imaging over days, with tracking for increased expression of neural and neuronal markers. These data point to potential uses of ChR2 technology for chronic and temporally precise noninvasive optical control of ESCs both in vitro and in vivo, ranging from noninvasive control of stem cell differentiation to causal assessment of the specific contribution of transplanted cells to tissue and network function.

Cancer epigenetics: linking basic biology to clinical medicine

Cancer evolution at all stages is driven by both epigenetic abnormalities as well as genetic alterations. Dysregulation of epigenetic control events may lead to abnormal patterns of DNA methylation and chromatin configurations, both of which are critical contributors to the pathogenesis of cancer. These epigenetic abnormalities are set and maintained by multiple protein complexes and the interplay between their individual components including DNA methylation machinery, histone modifiers, particularly, polycomb (PcG) proteins, and chromatin remodeling proteins. Recent advances in genome-wide technology have revealed that the involvement of these dysregulated epigenetic components appears to be extensive. Moreover, there is a growing connection between epigenetic abnormalities in cancer and concepts concerning stem-like cell subpopulations as a driving force for cancer. Emerging data suggest that aspects of the epigenetic landscape inherent to normal embryonic and adult stem/progenitor cells may help foster, under the stress of chronic inflammation or accumulating reactive oxygen species, evolution of malignant subpopulations. Finally, understanding molecular mechanisms involved in initiation and maintenance of epigenetic abnormalities in all types of cancer has great potential for translational purposes. This is already evident for epigenetic biomarker development, and for pharmacological targeting aimed at reversing cancer-specific epigenetic alterations.

Abstract LB-88: Transient exposure to low-dose decitabine and azacytidine reprograms cancer cells to produce a prolonged antitumor response

Reversing abnormal promoter DNA hypermethylation to induce expression of abnormally silenced genes is an attractive cancer therapeutic strategy. The DNA methylation inhibitors, decitabine (5-aza-2′-deoxycytidine) and azacytidine (5-azacytidine), have proven clinically effective against hematological neoplasms especially with use of low, minimally toxic, doses. While, experimentally, high doses of these drugs induce DNA damage and cytotoxicity, the prolonged time for patient responses does not suggest acute tumor cell lysis. We now separate, for these drugs, cytotoxic effects at high doses from cellular reprogramming effects at low nanomolar doses. These latter subsequently reduce tumorigenicity of human leukemia and solid tumor cells, and for leukemia cells, blunt long term self-renewal. We correlate these effects with sustained, genome wide, promoter DNA de-methylation and gene re-expression, and an anti-tumor reprogramming of multiple central cancer pathways which regulate cell cycle entry, mitosis, proliferation, apoptosis, and dependence upon anaerobic glycolysis. Thus, decitabine and azacytidine represent drugs that can, at low nanomolar doses, simultaneously reverse major cancer pathways each of which are the focus of intense drug targeting efforts. This suggests these drugs are broadly applicable to cancer management.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-88.

Progressive chromatin repression and promoter methylation of CTNNA1 associated with advanced myeloid malignancies

Complete loss or deletion of the long arm of chromosome 5 is frequent in myelodysplastic syndrome (MDS) and acute myelogenous leukemia (AML). The putative gene(s) deleted and responsible for the pathogenesis of these poor prognosis hematologic disorders remain controversial. This study is a comprehensive analysis of previously implicated and novel genes for epigenetic inactivation in AML and MDS. In 146 AML cases, methylation of CTNNA1 was frequent, and more common in AML patients with 5q deletion (31%) than those without 5q deletion (14%), whereas no methylation of other 5q genes was observed. In 31 MDS cases, CTNNA1 methylation was only found in high-risk MDS (>or=RAEB2), but not in low-risk MDS (<RAEB2), indicating that CTNNA1 methylation might be important in the transformation of MDS to AML. CTNNA1 expression was lowest in AML/MDS patients with CTNNA1 methylation, although reduced expression was found in some patients without promoter methylation. Repressive chromatin marks (H3K27me3) at the promoter were identified in CTNNA1-repressed AML cell lines and primary leukemias, with the most repressive state correlating with DNA methylation. These results suggest progressive, acquired epigenetic inactivation at CTNNA1, including histone modifications and promoter CpG methylation, as a component of leukemia progression in patients with both 5q- and non-5q- myeloid malignancies.

Heparin-induced thrombocytopenia associated with intra-tumour haemorrhage in cavernous sinus after cardiac myxoma surgery

Heparin-induced thrombocytopenia (HIT) is a life-threatening disorder that is associated with heparin exposure. The incidence of HIT in patients undergoing cardiac surgery is relatively rare. We present a case of intratumor haemorrhage in the cavernous sinus 1 week after cardiac surgery. The pathogenesis may be venous thrombosis and haemorrhagic infarct caused by HIT following cardiopulmonary bypass surgery. This is a rare case and has not been reported previously.

Phasic firing in dopaminergic neurons is sufficient for behavioral conditioning

Natural rewards and drugs of abuse can alter dopamine signaling, and ventral tegmental area (VTA) dopaminergic neurons are known to fire action potentials tonically or phasically under different behavioral conditions. However, without technology to control specific neurons with appropriate temporal precision in freely behaving mammals, the causal role of these action potential patterns in driving behavioral changes has been unclear. We used optogenetic tools to selectively stimulate VTA dopaminergic neuron action potential firing in freely behaving mammals. We found that phasic activation of these neurons was sufficient to drive behavioral conditioning and elicited dopamine transients with magnitudes not achieved by longer, lower-frequency spiking. These results demonstrate that phasic dopaminergic activity is sufficient to mediate mammalian behavioral conditioning.

Abnormal DNA methylation of CD133 in colorectal and glioblastoma tumors

Much recent effort has focused on identifying and characterizing cellular markers that distinguish tumor propagating cells (TPC) from more differentiated progeny. We report here an unusual promoter DNA methylation pattern for one such marker, the cell surface antigen CD133 (Prominin 1). This protein has been extensively used to enrich putative cancer propagating stem-like cell populations in epithelial tumors and, especially, glioblastomas. We find that, within individual cell lines of cultured colon cancers and glioblastomas, the promoter CpG island of CD133 is DNA methylated, primarily, in cells with absent or low expression of the marker protein, whereas lack of such methylation is evident in purely CD133+ cells. Differential histone modification marks of active versus repressed genes accompany these DNA methylation changes. This heterogeneous CpG island DNA methylation status in the tumors is unusual in that other DNA hypermethylated genes tested in such cultures preserve their methylation patterns between separated CD133+ and CD133- cell populations. Furthermore, the CD133 DNA methylation seems to constitute an abnormal promoter signature because it is not found in normal brain and colon but only in cultured and primary tumors. Thus, the DNA methylation is imposed on the transition between the active versus repressed transcription state for CD133 only in tumors. Our findings provide additional insight for the dynamics of aberrant DNA methylation associated with aberrant gene silencing in human tumors.

Fever of Unknown Origin in Taiwan

BACKGROUND

Fever of unknown origin (FUO) is a challenging problem worldwide. There was no prospective study of FUO in the past two decades in Taiwan. A prospective study was conducted.

MATERIALS AND METHODS

The prospective study was undertaken from March 2001 to May 2002. All patients fulfilling the modified criteria for FUO, either admitted, referred or consulted in a medical center in southern Taiwan, were enrolled for analysis.

RESULTS

A total of 94 cases met the criteria of FUO. The final diagnoses of FUO consisted of 54 infectious diseases (57.4%), 8 hematologic/neoplastic (8.5%), 7 noninfectious inflammatory (7.4%), 8 miscellaneous (8.5%) and 17 undiagnosed (18.1%) cases. The single most common cause of FUO was tuberculosis. Some infectious diseases, such as rickettsiosis and melioidosis, were rarely reported in western countries. Three patients with hemophagocytotic syndrome without ascertainable etiologies were present with FUO in this study. Between the patients with and those without a final diagnosis, the short-term survival (3 months) was compared by the Kaplan-Meier analysis, which revealed no difference.

CONCLUSIONS

Mycobacteriosis is still the leading cause of FUO in Taiwan and it is important to identify this treatable disease from all causes of FUO. This study has showed geographical variation among the studies of FUO.

Stromal cell-derived inducing activity, Nurr1, and signaling molecules synergistically induce dopaminergic neurons from mouse embryonic stem cells

To induce differentiation of embryonic stem cells (ESCs) into specialized cell types for therapeutic purposes, it may be desirable to combine genetic manipulation and appropriate differentiation signals. We studied the induction of dopaminergic (DA) neurons from mouse ESCs by overexpressing the transcription factor Nurr1 and coculturing with PA6 stromal cells. Nurr1-expressing ESCs (N2 and N5) differentiated into a higher number of neurons (approximately twofold) than the naïve ESCs (D3). In addition, N2/N5-derived cells contained a significantly higher proportion (>50%) of tyrosine hydroxylase (TH)+ neurons than D3 (<30%) and an even greater proportion of TH+ neurons (approximately 90%) when treated with the signaling molecules sonic hedgehog, fibroblast growth factor 8, and ascorbic acid. N2/N5-derived cells express much higher levels of DA markers (e.g., TH, dopamine transporter, aromatic amino acid decarboxylase, and G protein-regulated inwardly rectifying K+ channel 2) and produce and release a higher level of dopamine, compared with D3-derived cells. Furthermore, the majority of generated neurons exhibited electrophysiological properties characteristic of midbrain DA neurons. Finally, transplantation experiments showed efficient in vivo integration/generation of TH+ neurons after implantation into mouse striatum. Taken together, our results show that the combination of genetic manipulation(s) and in vitro cell differentiation conditions offers a reliable and effective induction of DA neurons from ESCs and may pave the way for future cell transplantation therapy in Parkinson's disease.

Induction of inducible nitric oxide synthase by Epstein-Barr virus B95-8-derived LMP1 in Balb/3T3 cells promotes stress-induced cell death and impairs LMP1-mediated transformation

The latent membrane protein 1 (LMP1) of Epstein-Barr virus (EBV) causes cellular transformation and activation of several intracellular signaling events. In this report, we show that BLMP1 (encoded by the LMP1 gene derived from the B95-8 strain of EBV) triggers the expression of inducible nitric oxide synthase (iNOS) in Balb/3T3 fibroblasts. Intriguingly, NLMP1, a natural sequence variant of LMP1 identified in EBV-positive nasopharyngeal carcinoma biopsy, does not similarly induce iNOS expression. BLMP1-induced iNOS in Balb/3T3 cells is active to produce nitric oxide (NO), and NO production can be blocked by several iNOS inhibitors. When subjected to environmental stress, Balb/3T3 cells that produce NO lose viability more rapidly than non NO-producing cells. Blockage of NO generation by iNOS inhibitors enhances the viability of NO-producing cells under stress conditions. The activities of caspase-3 and c-Jun N-terminal kinase, two important regulators mediating stress-induced apoptosis, are significantly potentiated following heat shock treatment of BLMP1-expressing/NO-producing cells, compared to parental and NLMP1-expressing cells. Furthermore, treatment with iNOS inhibitor augmented the cloning efficiency (in culture) and tumor growth (in nude mice) of BLMP1-expressing/NO-producing cells. Collectively, the results demonstrate that BLMP1 induces iNOS expression and NO production in Balb/3T3 cells, which leads to the alteration of cell functions, including sensitivity to environmental stress, capability to colonize independent of anchorage and tumorigenicity in nude mice. Our data additionally implicate that the differential iNOS induction potential of the two LMP1 forms may represent the basis of a functional difference between the two LMP1 proteins.

Association between cytomegalovirus-specific reactivity of T cell subsets and development of cytomegalovirus retinitis in patients with acquired immunodeficiency syndrome

The association between cytomegalovirus (CMV)-specific reactivity of T cell subsets and development of CMV retinitis (CMV-R) was prospectively studied in 50 CMV-seropositive AIDS patients. The frequency of CMV-specific CD69 expression on CD8 T cells was similar in patients with and patients without CMV-R (median, 1.0% vs. 1.2%; P=.14). However, the frequency of CMV-specific CD69 expression on CD4 T cells was significantly lower in patients with CMV-R than in those without CMV-R (median, 0.4% vs. 2.25%; P<.001). CMV-specific CD4 T cell reactivity in patients who developed CMV-R shortly after starting highly active antiretroviral therapy (HAART) remained low, although the CD4 cell counts increased markedly. Therefore, development of CMV-R is associated with a poor CMV-specific reactivity of CD4 T cells but not with poor reactivity of CD8 T cells. Development of CMV-R after initiation of HAART is associated with a poor reconstitution of CMV-specific immune response, rather than with immune rebound.

Kinetics of antigen-induced phenotypic and functional maturation of human monocyte-derived dendritic cells

Dendritic cells (DCs), a critical component of innate immunity, are the most potent APCs. When DCs mature, they can elicit strong T cell responses. We studied the kinetics of Ag-induced phenotypic and functional maturation of human monocyte-derived DCs using an in vitro T cell-independent culture system. With this model, we herein show that an Ag that has recently or repetitively been exposed ("exposed Ag") rapidly induces a high level of maturation; however, an Ag that has never or only remotely been exposed ("unexposed Ag") slowly induces a low level of maturation. The kinetics of Ag-induced maturation of DCs possibly implies a novel mechanism for immunological memory that would provide maximal host protection from repetitively invading pathogens in the environment.

Pneumocystis carinii pneumonia in systemic lupus erythematosus: a report of two cases

Patients with systemic lupus erythematosus (SLE) have increased susceptibility to infection by Pneumocystis carinii, but this condition has rarely been reported in Taiwan. Here, we describe two cases of patients with SLE who developed Pneumocystis carinii pneumonia (PCP). The first patient was a 39-year-old woman presenting with fever and dyspnea that had lasted 2 weeks. Chest roentgenography disclosed bilateral interstitial and alveolar infiltrates. The second patient was a 22-year-old woman presenting with a 4-day history of malaise, cough, dyspnea, and fever. She had concomitant Mycobacterium tuberculosis infection. Both patients had been treated with varying doses of corticosteroids and/or cytotoxic drugs within 4 months before presentation. Diagnosis was established based on the findings of bronchoalveolar lavage (BAL) and transbronchial lung biopsy (TBLB). Both patients received trimethoprim-sulfamethoxazole (20 mg.kg-1.d-1 trimethoprim), but finally died of nosocomial septicemia (Acinetobacter baumanni and Pseudomonas aeruginosa bacteremia in one, P. aeruginosa bacteremia in the other). These two cases demonstrate that PCP should be included in the differential diagnosis of patients with SLE presenting with pneumonic processes. In addition, a second opportunistic pathogen should be suspected. Bronchoscopic examination should be performed if the diagnosis is not clear and should include TBLB and BAL.

Eosinophilic meningitis caused by Angiostrongylus cantonensis: report of 17 cases

PURPOSE

To describe two outbreaks of Angiostrongylus cantonensis infection that occurred in Kaohsiung, Taiwan, during 1998 and 1999, and to characterize the source of the outbreaks and the clinical manifestations of the disease.

SUBJECTS AND METHODS

We performed a retrospective cohort study among Thai laborers with eosinophilic meningitis who ate raw snails (Ampullarium canaliculatus), as well as an environmental surveillance of larvae in snails.

RESULTS

We enrolled 17 Thai laborers in whom severe headache and eosinophilia developed within 4 to 23 days after eating raw snails. Twelve (71%) developed eosinophilic meningitis. Third-stage larvae were found in the cerebrospinal fluids of 2 patients and in all 12 tested snails. Specific antibodies to A. cantonensis were detected in serum from 16 of the patients and in cerebrospinal fluid from 5 of the patients. Central nervous system manifestations included headache (n = 17 [100%]), fever (n = 11 [65%]), Brudzinski's sign/stiff neck (n = 11 [65%]), hyperesthesia (n = 3 [18%]), cranial nerve palsy (n = 2 [12%]), diplopia (n = 2 [12%]), and ataxia (n = 1 [6%]). Laboratory findings included peripheral eosinophilia (n = 15 [88%]) and cerebrospinal fluid eosinophilia (n = 12 [71%]); elevated immunoglobulin (Ig) E levels (n = 13 [100%]); and transient increases in white blood cell count (n = 7 [41%]) and in serum levels of creatine kinase (n = 7 [41%]), transaminase (n = 3 [18%]), and lactate dehydrogenase (n = 2 [12%]). The severity of illness and eosinophilia were correlated with the number of ingested snails. Meningeal and basal ganglion enhancement was noted on magnetic resonance imaging in several patients. Treatment with mebendazole combined with glucocorticosteroids appeared to shorten the course of the infection, but not the number of relapses. The eosinophil count fell to normal within 3 months, but IgE levels remained elevated for as long as 6 months. All patients recovered with minimal neurologic sequelae.

CONCLUSION

Eosinophilic meningitis caused by A. cantonensis should be considered in patients who have headache or central nervous system manifestations after eating raw snails.

Diabetic ketoacidosis and hypogonadotropic hypogonadism in association with transfusional hemochromatosis in a man with beta-thalassemia major

We report a 23-year-old man with beta-thalassemia major and transfusional hemochromatosis, which manifested as diabetic ketoacidosis and hypogonadotropic hypogonadism. This unusual presentation of diabetic ketoacidosis in hemochromatosis has rarely been reported. Magnetic resonance imaging of the abdomen showed decreased signal intensity in the liver, spleen, and pancreas. In addition, the pituitary gland also showed heterogeneous low signal intensity, compatible with hemochromatosis. He was treated with insulin supplements and pulsatile human chorionic gonadotropin administration. Clinical improvement was noted after hormone replacement. Intensive iron chelation therapy was given to prevent cardiac complications, and to restore his gonadal function. During follow-up, the patient experienced improvement in libido and sexual potency.

Comparative study of the efficacy and safety of valaciclovir versus acyclovir in the treatment of herpes zoster

Acyclovir, a specific and selective inhibitor of the replication of Herpesviridae family, has well-documented efficacy and tolerability in the treatment of herpes zoster. Its limited oral bioavailability and short half-life, however, necessitates frequent dosing. Valaciclovir, the l-valyl ester of acyclovir, could be rapidly converted to acyclovir after oral administration, resulting in a three- to five-fold increase in acyclovir bioavailability compared with oral acyclovir in humans. Valaciclovir allows less frequent dosing and maintains the safety profiles of the parent drug. During the period from October 1996 through May 1998, a randomized, prospective study was performed in the Kaohsiung Veterans General Hospital to compare the safety and efficacy of valaciclovir with acyclovir in the treatment of herpes zoster in Taiwanese patients. Patients presenting with herpes zoster within 72 h after the onset of rash were enrolled and randomized to receive one of the following treatments: 1000 mg valaciclovir three times daily for 7 days or acyclovir 800 mg five times daily for 7 days. Patients were followed up for 29 days beginning with the start of therapy. A total of 57 patients were enrolled and randomized to receive valaciclovir (n = 32) or acyclovir (n = 25). Five patients in the valaciclovir group and three in the acyclovir group did not complete the study. The intent-to-treat analysis (57 patients) showed that valaciclovir significantly accelerated the resolution of herpes zoster-associated pain compared with acyclovir; on day 29, the valaciclovir group was 23% superior to the acyclovir group. There was no clinically significant difference in the nature, frequency or severity of adverse events between these two groups, although one and three adverse events were reported in the acyclovir and valaciclovir group, respectively. Thus, we conclude that in the management of herpes zoster, valaciclovir accelerates the resolution of pain and offers a simpler dosing, and maintains the favorable safety profile of acyclovir.

Legionnaires' disease in an immunocompetent young adult

Infection with Legionella pneumophila (LP) is a rare cause of pneumonia in previously healthy young adults. Pleural effusion is relatively common in Legionnaires' disease but is usually clinically insignificant. Herein we describe an immunocompetent, 19-year-old female with LP respiratory infection that presented with pleural effusion and mild interstitial infiltrates in the lower lungs. She received 3 weeks' treatment with erythromycin and rifampin and recovered completely. Diagnosis was based on serology testing with a four-fold rise of the antibody titer in the acute and convalescent phase. Legionnaires' disease should be considered in the differential diagnosis of culture-negative pleural effusion in immunocompetent young adults.

Restoration of cellular immunity against tuberculosis in patients coinfected with HIV-1 and tuberculosis with effective antiretroviral therapy: assessment by determination of CD69 expression on T cells after tuberculin stimulation

Whether immunity against opportunistic pathogens can be fully restored by control of HIV-1 replication remains open to question. This longitudinal study was conducted to measure anti-tuberculosis (TB) cellular immunity in 13 HIV-1/TB-coinfected patients effectively treated by highly active antiretroviral therapy (HAART) in a period of 12 months. In this study, anti-TB cellular immunity was assessed by determining the frequencies of CD 69 expression on CD4+ and CD8+ T cells in response to purified protein derivative (PPD) stimulation (abbreviated as %CD4+CD69 to PPD and %CD8+CD69 to PPD). Here, we show that %CD4+CD69 to PPD correlated with the results of tuberculin skin tests and interferon-gamma (IFN-gamma) production from PPD-stimulated CD4+ T cells, and %CD8+CD69 to PPD also correlated with CD8+ T cell-mediated PPD-specific cytolysis. In overall analysis for these 13 patients, both %CD4+CD69 to PPD and %CD8+CD69 to PPD increased significantly during the 12 months (p =. 003 and p <.001, respectively). However, we found %CD4+CD69 to PPD or %CD8+CD69 to PPD failed to increase substantially in some patients (i.e., immunologic nonresponders). A significantly higher proportion of patients whose baseline CD4+ count was <50 cells/mm3 were considered to be CD4+ nonresponders compared with those whose baseline CD4+ count was >50 cells/mm3. Furthermore, baseline CD4+ cell count in nonresponders is significantly lower than that in responders, although the effectiveness of HAART did not differ between them. Our results indicate that PPD-specific frequencies of CD69 expression may be used as surrogate markers of anti-TB cellular immunity. By this method, we show that full reconstitution of anti-TB cellular immunity in HIV-1/TB coinfected patients may not necessarily be achieved by "successful" HAART and may be influenced by the baseline immune status when HAART is started. These data suggest that the decision to discontinue secondary prophylaxis for opportunistic infections should be cautiously made, even when the CD4+ cell count has significantly increased.

Radiation-induced hearing impairment in patients treated for malignant parotid tumor

Radiation-induced hearing loss was evaluated in 21 patients with unilateral malignant parotid tumors treated with surgery and radiotherapy. The contralateral ear was used as a control. Eight patients (38%) were found to have a reduction in static compliance of the tympanic membrane (type B tympanogram) in the irradiated ear. By audiometry, significant hearing loss was found in 9 patients (43%). These hearing losses were mainly sensorineural, as shown by a similar reduction in both air and bone conduction, although mixed-type hearing loss existed in some patients. A statistically significant difference in incidence of 67% versus 0% (p = .0085) was noted for patients with a cochlear dose of greater than or equal to 60 Gy, in comparison to those receiving doses of less than 60 Gy. A type B tympanogram was also found to be a prognostic factor for significant sensorineural hearing loss. Patients with type B tympanograms had a much higher incidence of significant sensorineural hearing loss than those with type A tympanograms (88% versus 15%, p = .02). This study clearly shows that radiotherapy can induce significant hearing impairment, especially when the cochlear doses are higher than 60 Gy.