Clofazimine for Treatment of Cryptosporidiosis in Human Immunodeficiency Virus Infected Adults: An Experimental Medicine, Randomized, Double-blind, Placebo-controlled Phase 2a Trial

Background

We evaluated the efficacy, pharmacokinetics (PK), and safety of clofazimine (CFZ) in patients living with human immunodeficiency virus (HIV) with cryptosporidiosis.

Methods

We performed a randomized, double-blind, placebo-controlled study. Primary outcomes in part A were reduction in Cryptosporidium shedding, safety, and PK. Primary analysis was according to protocol (ATP). Part B of the study compared CFZ PK in matched individuals living with HIV without cryptosporidiosis.

Results

Twenty part A and 10 part B participants completed the study ATP. Almost all part A participants had high viral loads and low CD4 counts, consistent with failure of antiretroviral (ARV) therapy. At study entry, the part A CFZ group had higher Cryptosporidium shedding, total stool weight, and more diarrheal episodes compared with the placebo group. Over the inpatient period, compared with those who received placebo, the CFZ group Cryptosporidium shedding increased by 2.17 log2 Cryptosporidium per gram stool (95% upper confidence limit, 3.82), total stool weight decreased by 45.3 g (P = .37), and number of diarrheal episodes increased by 2.32 (P = .87). The most frequent solicited adverse effects were diarrhea, abdominal pain, and malaise. One placebo and 3 CFZ participants died during the study. Plasma levels of CFZ in participants with cryptosporidiosis were 2-fold lower than in part B controls.

Conclusions

Our findings do not support the efficacy of CFZ for the treatment of cryptosporidiosis in a severely immunocompromised HIV population. However, this trial demonstrates a pathway to assess the therapeutic potential of drugs for cryptosporidiosis treatment. Screening persons living with HIV for diarrhea, and especially Cryptosporidium infection, may identify those failing ARV therapy.

Clinical Trials Registration

NCT03341767.

Increased intracellular survival of Salmonella Typhimurium ST313 in HIV-1-infected primary human macrophages is not associated with Salmonella hijacking the HIV compartment

BACKGROUND

Non-typhoidal Salmonella (NTS) causes a severe invasive syndrome (iNTS disease) described in HIV-positive adults. The impact of HIV-1 on Salmonella pathogenesis and the molecular basis for the differences between these bacteria and classical diarrhoeal S. Typhimurium remains unclear.

RESULTS

Here, we show that iNTS-associated S. Typhimurium Sequence Type 313 (ST313) bacteria show greater intracellular survival in primary human macrophages, compared with a 'classical' diarrhoeal S. Typhimurium ST19 isolate. The increased intracellular survival phenotype of ST313 is more pronounced in HIV-infected macrophages. We explored the possibility that the bacteria take advantage of the HIV-associated viral-containing compartments created in human macrophages that have low pH. Confocal fluorescence microscopy and focussed ion beam-scanning electron microscopy tomography showed that Salmonella did not co-localise extensively with HIV-positive compartments.

CONCLUSION

The capacity of ST313 bacteria to survive better than ST19 bacteria within primary human macrophages is enhanced in cells pre-infected with HIV-1. Our results indicate that the ST313 bacteria do not directly benefit from the niche created by the virus in HIV-1-infected macrophages, and that they might take advantage from a more globally modified host cell.

SIGNIFICANCE

A better understanding of the interplay between HIV-1 and Salmonella is important not only for these bacteria but also for other opportunistic pathogens.

Nonspecific effects of oral vaccination with live-attenuated Salmonella Typhi strain Ty21a

Epidemiological and immunological evidence suggests that some vaccines can reduce all-cause mortality through nonspecific changes made to innate immune cells. Here, we present the first data to describe the nonspecific immunological impact of oral vaccination with live-attenuated Salmonella Typhi strain Ty21a. We vaccinated healthy adults with Ty21a and assessed aspects of innate and adaptive immunity over the course of 6 months. Changes to monocyte phenotype/function were observed for at least 3 months. Changes to innate and adaptive immune cell cytokine production in response to stimulation with vaccine and unrelated nonvaccine antigens were observed over the 6-month study period. The changes that we have observed could influence susceptibility to infection through altered immune responses mounted to subsequently encountered pathogens. These changes could influence all-cause mortality.

Assessment of HER2 gene amplification in adenocarcinomas of the stomach or gastroesophageal junction in the INT-0116/SWOG9008 clinical trial

BACKGROUND

Trastuzumab has been approved for patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic gastric carcinoma; however, relatively little is known about the role of HER2 in the natural history of this disease.

PATIENTS AND METHODS

Patients enrolled in the INT-0116/SWOG9008 phase III gastric cancer clinical trial with available tissue specimens were retrospectively evaluated for HER2 gene amplification by FISH and overexpression by immunohistochemistry (IHC). The original trial was designed to evaluate the benefit of postoperative chemoradiation compared with surgery alone.

RESULTS

HER2 gene amplification rate by FISH was 10.9% among 258 patients evaluated. HER2 overexpression rate by IHC was 12.2% among 148 patients evaluated, with 90% agreement between FISH and IHC. There was a significant interaction between HER2 amplification and treatment with respect to both disease-free survival (DFS) (P = 0.020) and overall survival (OS) (P = 0.034). Among patients with HER2-non-amplified cancers, treated patients had a median OS of 44 months compared with 24 months in the surgery-only arm (P = 0.003). Among patients with HER2-amplified cancers, there was no significant difference in survival based on treatment arm. HER2 status was not a prognostic marker among patients who received no postoperative chemoradiation.

CONCLUSION

Patients lacking HER2 amplification benefited from treatment as indicated by both DFS and OS.

CLINICAL TRIAL

INT-0116/SWOG9008 phase III.

Assessment of HER2 gene amplification in adenocarcinomas of the stomach or gastroesophageal junction in the INT-0116/SWOG9008 clinical trial

BACKGROUND

Trastuzumab has been approved for patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic gastric carcinoma; however, relatively little is known about the role of HER2 in the natural history of this disease.

PATIENTS AND METHODS

Patients enrolled in the INT-0116/SWOG9008 phase III gastric cancer clinical trial with available tissue specimens were retrospectively evaluated for HER2 gene amplification by FISH and overexpression by immunohistochemistry (IHC). The original trial was designed to evaluate the benefit of postoperative chemoradiation compared with surgery alone.

RESULTS

HER2 gene amplification rate by FISH was 10.9% among 258 patients evaluated. HER2 overexpression rate by IHC was 12.2% among 148 patients evaluated, with 90% agreement between FISH and IHC. There was a significant interaction between HER2 amplification and treatment with respect to both disease-free survival (DFS) (P = 0.020) and overall survival (OS) (P = 0.034). Among patients with HER2-non-amplified cancers, treated patients had a median OS of 44 months compared with 24 months in the surgery-only arm (P = 0.003). Among patients with HER2-amplified cancers, there was no significant difference in survival based on treatment arm. HER2 status was not a prognostic marker among patients who received no postoperative chemoradiation.

CONCLUSION

Patients lacking HER2 amplification benefited from treatment as indicated by both DFS and OS.

CLINICAL TRIAL

INT-0116/SWOG9008 phase III.

Review article: the aetiology, investigation and management of diarrhoea in the HIV-positive patient

BACKGROUND

Diarrhoea is a common presentation throughout the course of HIV disease.

AIM

To review the literature relating to aetiology, investigation and management of diarrhoea in the HIV-infected adult.

METHODS

The PubMed database was searched using major subject headings 'AIDS' or 'HIV' and 'diarrhoea' or 'intestinal parasite'. The search was limited to adults and to studies with >10 patients.

RESULTS

Diarrhoea affects 40-80% of HIV-infected adults untreated with antiretroviral therapy (ART). First-line investigation is by stool microbiology. Reported yield varies with geography and methodology. Molecular and immunological methods and special stains have improved diagnostic yield. Endoscopy is diagnostic in 30-70% of cases of pathogen-negative diarrhoea and evidence supports flexible sigmoidoscopy as a first line screening procedure (80-95% sensitive for CMV colitis), followed by colonoscopy and terminal ileoscopy. Radiology is useful to assess severity, distribution, complications and to diagnose HIV-related malignancies. Side effects and compliance with ART are important considerations in assessment. There is a good evidence base for many specific therapies, but optimal treatment of cryptosporidiosis is unclear and only limited data support symptomatic treatments.

CONCLUSIONS

The immunological response to HIV infection and Antiretroviral therapy remains incompletely understood. Antiretroviral therapy regimens need to be optimised to suppress HIV while minimising side effects. Effective agents for management of cryptosporidiosis are lacking. There is an urgent need for enhanced regional diagnostic facilities in countries with a high prevalence of HIV. The ongoing roll-out of Antiretroviral therapy in low-resource settings will continue to change the aetiology and management of this problem, necessitating ongoing surveillance and study.

A let-7 microRNA-binding site polymorphism in 3'-untranslated region of KRAS gene predicts response in wild-type KRAS patients with metastatic colorectal cancer treated with cetuximab monotherapy

PURPOSE

recent studies have found that KRAS mutations predict resistance to monoclonal antibodies targeting the epidermal growth factor receptor in metastatic colorectal cancer (mCRC). A polymorphism in a let-7 microRNA complementary site (lcs6) in the KRAS 3' untranslated region (UTR) is associated with an increased cancer risk in non-small-cell lung cancer and reduced overall survival (OS) in oral cancers. We tested the hypothesis whether this polymorphism may be associated with clinical outcome in KRAS wild-type (KRASwt) mCRC patients treated with cetuximab monotherapy.

PATIENTS AND METHODS

the presence of KRAS let-7 lcs6 polymorphism was evaluated in 130 mCRC patients who were enrolled in a phase II study of cetuximab monotherapy (IMCL-0144). Genomic DNA was extracted from dissected formalin-fixed paraffin-embedded tumor tissue, KRAS mutation status and polymorphism were assessed using direct sequencing and PCR restriction fragment length polymorphism technique.

RESULTS

KRAS let-7 lcs6 polymorphism was found to be related to object response rate (ORR) in mCRC patients whose tumors had KRASwt. The 12 KRASwt patients harboring at least a variant G allele (TG or GG) had a 42% ORR compared with a 9% ORR in 55 KRASwt patients with let-7 lcs6 TT genotype (P = 0.02, Fisher's exact test). KRASwt patients with TG/GG genotypes had trend of longer median progression-free survival (3.9 versus 1.3 months) and OS (10.7 versus 6.4 months) compared to those with TT genotypes.

CONCLUSIONS

these results are the first to indicate that the KRAS 3'UTR polymorphism may predict for cetuximab responsiveness in KRASwt mCRC patients, which warrants validation in other clinical trials.

A let-7 microRNA-binding site polymorphism in 3'-untranslated region of KRAS gene predicts response in wild-type KRAS patients with metastatic colorectal cancer treated with cetuximab monotherapy

PURPOSE

recent studies have found that KRAS mutations predict resistance to monoclonal antibodies targeting the epidermal growth factor receptor in metastatic colorectal cancer (mCRC). A polymorphism in a let-7 microRNA complementary site (lcs6) in the KRAS 3' untranslated region (UTR) is associated with an increased cancer risk in non-small-cell lung cancer and reduced overall survival (OS) in oral cancers. We tested the hypothesis whether this polymorphism may be associated with clinical outcome in KRAS wild-type (KRASwt) mCRC patients treated with cetuximab monotherapy.

PATIENTS AND METHODS

the presence of KRAS let-7 lcs6 polymorphism was evaluated in 130 mCRC patients who were enrolled in a phase II study of cetuximab monotherapy (IMCL-0144). Genomic DNA was extracted from dissected formalin-fixed paraffin-embedded tumor tissue, KRAS mutation status and polymorphism were assessed using direct sequencing and PCR restriction fragment length polymorphism technique.

RESULTS

KRAS let-7 lcs6 polymorphism was found to be related to object response rate (ORR) in mCRC patients whose tumors had KRASwt. The 12 KRASwt patients harboring at least a variant G allele (TG or GG) had a 42% ORR compared with a 9% ORR in 55 KRASwt patients with let-7 lcs6 TT genotype (P = 0.02, Fisher's exact test). KRASwt patients with TG/GG genotypes had trend of longer median progression-free survival (3.9 versus 1.3 months) and OS (10.7 versus 6.4 months) compared to those with TT genotypes.

CONCLUSIONS

these results are the first to indicate that the KRAS 3'UTR polymorphism may predict for cetuximab responsiveness in KRASwt mCRC patients, which warrants validation in other clinical trials.

Durhamycin, a Pentaene Antifungal Antibiotic from Streptomyces durhamensis sp. n

Durhamycin, derived from a previously undescribed soil isolate, is an apparently new antibiotic active against many of the fungi pathogenic for man and animals. Cultural and morphological characteristics and biochemical reactions of Streptomyces durhamensis are detailed. Methods of extraction of the antibiotic, physicochemical properties, antimicrobial spectrum, and results of mouse toxicity and protection tests are given.

Gender-related survival differences associated with polymorphic variants of estrogen receptor-β (ERβ) in patients with metastatic colon cancer

Estrogen replacement therapy in women has demonstrated a protective effect in the development of colonic carcinomas. Gender-related differences in the development of colonic carcinomas have also been reported. Estrogen receptor beta (ERβ) is expressed in colon carcinomas and has demonstrated prognostic value in colon cancer patients. This study investigated an ERβ 3’ non-coding polymorphism associated with transcriptional activity to determine clinical outcome in patients with metastatic colon cancer. Genomic DNA from 318 metastatic colon cancer patients, 177 males and 141 females, were collected from 1992 to 2003. These patients were analyzed for CA repeat polymorphism of the ERβ gene. Gender-related survival differences were associated with an ERβ (CA)_n repeat polymorphism (P for interaction=0.003, the likelihood ratio test). Female patients with any short <22 (CA)_n repeat alleles had shorter overall survival compared to female patients that had both long ≥22 (CA)_n repeat alleles. In the male patients the opposite overall survival difference was found. This study supports the role of an ERβ (CA)_n repeat polymorphism as a prognostic marker in metastatic colon cancer; however, this prognostic factor had opposite implications based on gender.

Frequency of late-stage breast cancer diagnoses despite high mammography screening rates in an HMO

1526

Background: Kaiser Permanente Southern California (KPSC) led the nation in screening women for breast cancer (BCa) with a mammography rate of nearly 90% in 2007 according to 2008 Healthcare Effectiveness Data and Information Set (HEDIS) measures. Despite successes in improving screening rates in this health plan that serves 3+ million diverse members, the percentage of women diagnosed with late stage BCa (stage III, IV) remained stable, varying from 12.9% (N∼323) in 2003 to 10.8% (N∼270) in 2007. To identify patient and health care factors associated with late stage diagnosis and the impact of its enhanced screening implementation guidelines, KPSC undertook this study. Methods: This cross-sectional study included a cohort of 10,580 BCa patients from 2003–2007. We compared women diagnosed with late stage disease versus those with early stage disease (stages I, II). P values (2-sided) were based on the chi-square distribution. Adjusted odds ratios and 95% confidence intervals were estimated using unconditional logistic regression. Results: Factors that were positively associated with late stage diagnosis in the univariate analyses included age, lack of recent mammography screening, worse tumor features, 80+ years of age, minority race, lower geocoded household income, increased healthcare visits, and use of Pap testing (P < 0.01 for all variables). Factors significantly associated with late stage diagnosis in the multivariate model included only lack of recent mammography screening (OR = 1.35, 95% CI: 1.14–1.58) and worse tumor features including high grade (grade 3, OR = 2.58, 95% CI: 1.96–3.40), positive lymph nodes (OR = 53.49, 95% CI: 39.90–71.72), and HER-2+ tumors (OR = 1.40, 95% CI: 1.13–1.72). Conclusions: Targeting older women, those with lower utilization, and women who did not have a recent mammogram may help further lower the prevalence of late stage diagnoses. However, given the extent of the health plan's previous efforts to enhance BCa screening rates, a ceiling effect may limit additional benefit. Additional efforts to decrease the rate of advanced tumor stage at diagnosis may include improving interpretation of mammograms or earlier detection of aggressive tumors by enhanced BRCA genetic testing.

No significant financial relationships to disclose.

Polymorphisms in VEGF and IL-8 predict tumor recurrence in stage III colon cancer

BACKGROUND

Identifying molecular markers for tumor recurrence is critical in successfully selecting patients with stage III colon cancer who are more likely to benefit from adjuvant chemotherapy. The present study analyzed a subset of 10 polymorphisms within eight genes involved in the tumor angiogenesis pathway and their impact on prognosis in stage III colon cancer patients treated with adjuvant chemotherapy.

PATIENTS AND METHODS

Blood samples were obtained from 125 patients with locally advanced colon cancer at University of Southern California medical facilities. DNA was extracted from peripheral blood and the genotypes were analyzed using PCR-restriction fragment length polymorphism and 5'-end [gamma-(33)P] ATP-labeled PCR protocols.

RESULTS

Polymorphisms in vascular endothelial growth factor (VEGF) (C+936T; P = 0.003, log-rank test) and interleukin-8 (IL-8) (T-251A; P = 0.04, log-rank test) were independently associated with risk of recurrence in stage III colon cancer patients. In combined analysis, grouping alleles into favorable versus nonfavorable alleles, high expression variants of VEGF C+936T and IL-8 T-251A were associated with a higher likelihood of developing tumor recurrence (P < 0.001).

CONCLUSION

High expression variants of VEGF C+936T and IL-8 T-251A were associated with shorter time to tumor recurrence, indicating that the analysis of angiogenesis-related gene polymorphisms may help to identify patient subgroups at high risk for tumor recurrence.

Polymorphisms in estrogen receptor beta, interleukin-8, and interleukin-8 receptor associated with clinical outcome in metastatic colorectal cancer (mCRC) patients treated with 5-fluorouracil/oxaliplatin

4130

Background: Many factors contribute to the progression of colorectal cancer and to chemoresistance. Two factors that have recently gained attention are angiogenesis and sex hormones. Interleukin-8 and its receptors play a critical role in angiogenesis, and polymorphisms in these genes have previously been reported to predict clinical outcome and resistance to therapy in a variety of cancer types. In addition, gender and the subsequent varied levels of sex hormones between males and females may also have an impact on colorectal cancer progression. Sex hormones such as estrogen exert their effects on the cell by binding to steroid receptors such as estrogen receptor beta (ER-β). It is known that ER-β is predominantly expressed in the colon, and that differential expression of this gene is predictive of clinical outcome. Therefore, functional polymorphisms within ER-β, IL-8, and the IL-8 receptors may prove to be molecular markers for predicting clinical outcome in colorectal cancer patients. Methods: 173 patients were enrolled in this phase II study. 152 patients were evaluable for genotyping and statistical analysis. There were 74 females and 78 males, and median age was 60 (range 25–87). The dose of oxaliplatin was 130mg/m2 every 3 weeks and 5-FU was 200mg/m2/day CI for 10 weeks followed by 2 weeks rest. Polymorphisms in estrogen receptor beta, IL-8, and CXCR2 (IL-8 receptor) were tested by PCR. Results: Median follow-up was 18.6 months, response rate 19%, median time to tumor progression 4.2 months and median survival 10.3 months. IL-8 T251A polymorphism was predictive of time to tumor progression (p=0.04, log-rank test). ER-β CA repeat polymorphism was predictive of tumor response as well as time to tumor progression (p=0.015, p=0.012, respectively). ER-β A730G SNP was also predictive of time to tumor progression (p=0.03). Polymorphism in CXCR2 was predictive of tumor response (p=0.034). Conclusions: Our results suggest that polymorphisms within IL-8, CXCR2, and ER-β may affect the progression of colorectal cancer and subsequent clinical outcome. These results highlight the importance of angiogenesis and hormone levels in colorectal cancer.

No significant financial relationships to disclose.

Use of sex-specific genomic profile to predict clinical outcome in metastatic colorectal cancer (mCRC) patients treated with 5- fluorouracil/oxaliplatin

4122

Background: There is increasing evidence that gender plays a significant role in the development and progression of colorectal cancer (CRC). Rates of CRC incidence are higher among males, and it has been shown that hormone replacement therapy in postmenopausal women reduces the risk of developing CRC, indicating a protective effect of female hormones. These findings indicate that physiological differences between the sexes may contribute to differential tumor development and progression. In the current study, we tested the hypothesis whether males and females would have different genomic profiles that would predict clinical outcome in 5-FU/oxal-treated mCRC. Methods: One hundred seventy-three patients were enrolled in this phase II study. One hundred fifty-two patients were evaluable for genotyping and statistical analysis. There were 74 females and 78 males, and median age was 60 (range 25–87). Twenty-four polymorphisms in 12 genes involved in cancer progression were tested by PCR. CART analysis was used to test for association of polymorphisms with overall survival (OS), time to tumor progression (TTP), and tumor response. Separate regression trees were developed for males and females. Results: Median follow-up was 18.6 months, response rate 19%, median time to tumor progression 4.2 months and median survival 10.3 months. CART analysis by gender generated significantly different regression trees for men versus women. For TTP, males carrying polymorphisms in the ER-β and SCN1A genes had improved TTP, while females carrying polymorphisms in the XPD and EGFR genes had improved TTP. For OS, male patients carrying ER-β and MTHFR polymorphisms had improved OS, while female patients carrying polymorphisms in SCN1A and PLA2 had improved OS. It is notable that analysis of males and females in combination produced a different regression tree than when separated by gender. Conclusions: Our results suggest for the first time that genomic profiling to predict clinical outcome of patients with mCRC depends on gender. Taking gender into account when examining the genetic profile of patients may help to more specifically identify those who will benefit from 5-FU/oxal chemotherapy.

No significant financial relationships to disclose.

VEGF and VEGF receptor-2 (VEGFR2) gene polymorphisms predict tumor recurrence in stage II and III colon cancer

4004

Background: Despite recent advances in the treatment of metastatic colorectal cancer, tailoring adjuvant treatment of stage II and III colon cancer patients remains controversial. Identifying a reliable panel of prognostic and predictive markers for tumor recurrence is critical in selecting an individualized and tailored chemotherapy. Tumor angiogenesis plays an important role in tumor development, progression and metastasis. In this retrospective study, we tested whether a specific pattern of 40 functionally significant polymorphisms in 37 genes involved in angiogenesis and tumor microenvironment will predict the risk of tumor recurrence in stage II and III colon cancer patients treated with adjuvant chemotherapy. Methods: Between 1999 and 2006 blood specimens from 140 patients (69 females and 71 males with a median age of 59 years; range=28–86) were obtained at the University of Southern California/Norris Comprehensive Cancer Center (USC/NCCC). Sixty-three patients had stage II and 77 had stage III colon cancer. The median follow-up was 5.4 years (range=2.0–16.8). 51 of 140 patients (36.4%) developed tumor recurrence with a 5-year probability of 0.28 ± 0.06 for stage II and 0.40 ± 0.06 for stage III colon cancer patients. Genomic DNA was extracted from peripheral blood and genotypes were determined using PCR based RFLP. Results: Polymorphisms in VEGF (C936T; p=0.009, log-rank) and VEGFR2 (+4422 AC- repeat; p=0.04, log-rank and +1416 T/A; p=0.0009, log-rank) were associated with risk of tumor recurrence in stage III colon cancer patients (n=77). VEGFR2 AC-repeat polymorphisms were additionally associated with risk of recurrence in Stage II colon cancer patients (n=63, p=0.02, log-rank). Conclusion: VEGF C936T and VEGFR2 (+4422 AC-repeat and +1416 T/A) polymorphisms may help to identify Stage II and III colon cancer patients who are at increased risk for developing tumor recurrence. Angiogenesis seems to play a crucial role in tumor recurrence, thus targeting VEGF and VEGFR2 may be of clinical benefit for stage II and stage III colon cancer patients. Large prospective trials are needed to validate these preliminary data.

No significant financial relationships to disclose.

Abcb1, ugt1a1 and oatp-c polymorphisms predict Irinotecan (CPT-11) toxicity

3074

Background: Irinotecan (CPT-11), a topoisomerase I inhibitor, is approved for the use of both first- and second-line chemotherapy in metastatic colorectal cancer (CRC) patients. As of yet, only few reliable molecular markers have been identified for predicting CPT-11 toxicity. In this study, we tested specific gene polymorphisms that are known to be involved in the Irinotecan metabolic pathway: the ATP-binding cassette transporter subfamily (ABCB1, ABCG2 and ABCC2), carboxylesterase 1 (CES1), carboxylesterase 2 (CES2), uridine-diphosphoglucuronosyltransferase 1A1 (UGT1A1),hepatic organic anion transport protein (OATP-C) and cytochrome P450 (CYP3A4). Methods: We ran PCR-RFLP assays using genomic DNA from the blood of 54 advanced CRC patients treated with first-line 5FU/LV and CPT-11 at USC between 1999 and 2003. Results: Our cohort was comprised of 31 men (57%) and 23 women (43%) with a median age of 56 years (range: 34–77 years). Participants represented four ethnicities: 29 Caucasian (54%), 12 Asian (22%), 10 Hispanic (19%), and 3 African-American (6%). Three patients (6%) demonstrated complete response (CR), 20 patients (38%) showed partial response (PR), 24 patients (45%) continued with stable disease (SD), and six patients (11%) were found to have progressive disease (PD). One patient was invaluable for response data. Twenty-four patients (46%) experienced Grade 0–2 toxicity, while 29 (54%) experienced Grade 3–4 toxicity. One patient was inevaluable for toxicity data. The median progression-free survival was 10.9 months (95% CI, 7.6 to 12.1 months), and the median overall survival time was 27.9 months (95% CI, 21.3 to 56.6+ months) with median follow up of 30.0 months (range: 11.2 to 59.9 months). We found that the combination of at least one OATP-C 521 wild-type T allele, at least one ABCB1 1236 C allele and at least one UGT1A1*28 variant 7 repeat demonstrated a statistically significant association with Grade 3/4 toxicities (P=0.002, Fisher’s exact test). Conclusion: This is the first study to combine three independent gene polymorphisms within the same metabolic pathway in order to explain common CPT-11 grade 3–4 toxicity.

[Table: see text]

Polymorphisms of DNA-repair genes associated with clinical outcome in metastatic breast cancer (MBC) patients treated with gemcitabine/cisplatin (GC) (California Cancer Consortium)

675

Background: DNA repair enzymes may play an important role in determining efficacy of chemotherapy in MBC. In particular, GC combination therapy may be dependent on activity of DNA repair enzymes in host cells, since cisplatin acts by inducing DNA damage. Cancer cells with increased DNA repair capacity may be resistant to GC, and specific genes may be responsible for this increased repair capacity. We examined whether polymorphisms in genes related to DNA repair were associated with clinical outcome in MBC patients treated with GC, enrolled in a parent phase II clinical trial (Ph II-14 A & B). Methods: Fifty-five patients with MBC were evaluated. Patients received the following regimen: 25 mg/m2 cisplatin on days 1–4; 1000 mg/m2 gemcitabine on days 2 and 8 of 21-day cycle. Thirteen polymorphisms in 10 cancer-related genes were tested for association with overall survival, time to tumor progression, and tumor response using a PCR RFLP based assay. Results: Of 55 patients evaluated, there were 17 responders (31%) and 33 non-responders (60%). Five patients (9%) inevaluable for response. Of 33 non-responders, 15 had stable disease, 18 had progressive disease. Median survival: 11.7 months with median follow-up 32.4 months for 4 patients alive at time of analysis. Median progression-free survival: 4.2 months. XPD Lys751Gln polymorphism was associated with overall survival and time to tumor progression (p=0.0003, p=0.006, respectively, log-rank test). Thirty-five patients carried Lys/Lys genotype, of which 29% resopnded. Fourteen patients carried Lys/Gln genotype, of which 54% resopnded. Five patients carried Gln/Gln genotype, with no responders. XRCC3 Thr241Met polymorphism was associated with time to tumor progression and tumor response (p=0.03, p=0.002, respectively). Eighteen patients had Met/Met genotype, of which 47% responded. Twenty-six patients had heterozygous genotype, of which 17% responded. Five patients had homozygous Thr/Thr, of which 100% responded. Conclusions: Our results suggest that polymorphisms in DNA repair genes XPD and XRCC3 may be important markers in predicting clinical outcome in MBC patients treated with GC. Supported by the following NCI grant: N01 CM1701.

[Table: see text]

Magnitude of microelectrode refinement in pallidotomy and thalamotomy

The relative accuracy of starting point algorithms in microelectrode-guided stereotactic pallidotomy and thalamotomy was evaluated using postoperative magnetic resonance imaging (MRI) data. Multiplanar reformations were performed to align postoperative MRI in anterior-posterior, dorsal-ventral and mediolateral planes. Three-dimensional distance and direction from the pallidal and thalamic stereotactic starting points to the respective radiofrequency lesions were measured. Similar magnitude of microelectrode refinement in pallidotomy and thalamotomy suggested similar accuracy of algorithms used to set the stereotactic starting point. Fewer microelectrode-recording tracts were required to identify optimal lesioning sites in thalamotomy compared to pallidotomy. Lesions were consistently localized anterior and superior to the starting point and a refined starting point algorithm may reduce the number of microelectrode recording tracts.

Are intestinal helminths a risk factor for non-typhoidal Salmonella bacteraemia in adults in Africa who are seropositive for HIV? A case-control study

In Africa, invasive, non-typhoidal Salmonella (NTS) infections are a common but life-threatening complication in adults who are seropositive for HIV. The high prevalence of human infection with intestinal helminths which penetrate the gut could explain the greater importance of NTS bacteraemia in Africa compared with that in industrialized countries. If helminth infection is a major risk factor for NTS it would provide a locally relevant, public-health target. Intestinal helminth carriage in 57 HIV-positive patients with NTS bacteraemia (the cases) was compared with that in 162 HIV-positive controls who were similar to the cases in terms of age, sex, urban dwelling and socio-economic factors. The prevalence of helminth infection, 29% overall, was lower among the cases (18%) than among the controls (33%), giving a crude odds ratio of 0.40 [with a 95% confidence interval (CI) of 0.21-0.9] and an adjusted odds ratio (aOR) of 0.79 (CI = 0.4-1.8). Five (9%) of the cases and 12 (7%) of the controls were infected with nematodes which penetrate the gut (Ascaris lumbricoides and/or Strongyloides stercoralis). The aOR for infection with these penetrating worms, corrected for age, sex, urban dwelling and phase of study, was 1.40 (CI = 0.4-4.5). The present results do not exclude the possibility that helminths play a role in invasive NTS infections, but are not consistent with helminths being a sufficient risk factor in this population to be a public-health target. Anthelmintics are unlikely to have a major impact on preventing NTS bacteraemia in patients diagnosed HIV-positive in Africa.

Lack of heritability of circulating leptin concentration in humans after adjustment for body size and adiposity using a physiological approach

OBJECTIVE

To construct a simple physiological model of leptin kinetics, based on measures of body size and composition, which is suitable for investigating the influence of genetic and other influences on circulating leptin levels in humans.

METHODS

Consideration of the kinetics of the secretion and clearance of leptin led to a predicted linear relationship between ln(leptin), ln(fat mass), and a function of non-fat body compartments. Results obtained from this model were compared with those from two published empirical models based on adjustment for fat mass alone or for body mass index. Overnight fasted leptin levels, body composition data (dual-energy X-ray absorptiometry) and questionnaire responses were obtained from 527 twin pairs (127 monozygotic, 400 dizygotic; 37 male (age 18-68 y, BMI 18-32 kg/m2), 489 female (age 18-71, BMI 17-44) drawn from the St Thomas' UK Adult Twin Registry.

RESULTS

In a partial correlation analysis ln(fat mass) and ln(height) (r=0.80, P<0.0001) and r=-0.22, P<0.0001 respectively) were independent predictors of ln(leptin) in females but ln(lean mass) was not (r=-0.01). A regression model incorporating ln(fat mass), ln(height) and a second order polynomial in age provided an adequate fit of the ln(leptin) data in females (r2=71%). ln(Leptin) values adjusted for body size and composition using the model were not significantly heritable (P=0.11), were significantly related to gender (r2=2.3%) and to ln(insulin) (r2=5.7%), but not to menopausal status (r2=0.7%), hormone replacement therapy (r2=0.4%), past or current smoking (r2=1.1%), or percentage trunk fat (r2=0.5%). Both empirical models found significant heritability (h2=36-42%), overestimated the effect of gender in the data (r2=14-16%), and produced significant relationships between adjusted ln(leptin) and percentage trunk fat (r2=4-12%).

CONCLUSIONS

We conclude that our physiologically based model provides an adequate description of the relationship between leptin and body composition and provides a more reliable framework than current empirical approaches for the investigation of other influences on circulating leptin levels. Heritable variations in the control of leptin secretion are unlikely to contribute significantly to variations in leptin levels at the population level.

Bacteraemia and mortality among adult medical admissions in Malawi--predominance of non-typhi salmonellae and Streptococcus pneumoniae

OBJECTIVES

The high seroprevalence of HIV in Malawi might be expected to alter the pattern of pathogens isolated from bacteraemic patients. We aimed to describe the frequency and seasonal pattern of bacterial isolates from blood, their antibiotic susceptibility, and patient outcome, in order to provide data on which to base empirical antibiotic therapy and further studies of pathogenesis.

METHODS

Over a 12-month period, blood cultures were taken from all febrile adult medical admissions to Queen Elizabeth Central Hospital, Blantyre.

RESULTS

A total of 2789 out of 9298 adult general medical admissions had blood culture performed, of whom 449 (16.1%) grew significant pathogens. Non-typhi salmonellae (NTS) (37%) and Streptococcus pneumoniae (30%) were the two commonest isolates. Mortality was 18% among general medical admissions and 38% among bacteraemic patients. Mortality for individual pathogens was: NTS 33%; S. pneumoniae 36%; Escherichia coli 54%; Klebsiella spp. 58%; Neisseria meningitidis 44%; Salmonella typhi 17%. Despite an overwhelming association between the major pathogens and HIV infection (95% of S. pneumoniae cases and 92% of NTS cases were seropositive for HIV), a seasonal pattern was preserved. Streptococcus pneumoniae was more frequently isolated in the cold dry months, while STM isolates increased following a rise in temperature. A case of bacteraemia with Vibrio cholerae (serotype 01) was detected during a cholera outbreak in the rainy season. Although S. pneumoniae isolates were relatively susceptible to penicillin (88%) and chloramphenicol (74%), S. typhimurium isolates were fully susceptible only to chloramphenicol.

CONCLUSIONS

This large study confirms the dominance of NTS and S. pneumoniae in bacteraemia in an area affected by HIV-1 and allows comparison of mortality by individual pathogens. It demonstrates a preserved seasonal pattern of bacteraemia for these major pathogens, despite an overwhelming association with HIV infection.

Three cases of bacteremia caused by Vibrio cholerae O1 in Blantyre, Malawi

We report three fatal cases of bacteremia (two adults, one neonate) caused by Vibrio cholerae O1 (Ogawa), which occurred in the context of a community outbreak of cholera diarrhea in Blantyre, Malawi. Only four cases of invasive disease caused by V. cholerae O1 have previously been reported. We describe the clinical features associated with these rare cases and discuss their significance.

Iron status and stores decline with age in Lewis rats

In the context of a larger study examining the interaction of vitamin A (VA) status and age on immune function, we examined age-related changes in hematologic and iron status variables in male Lewis rats. Animals were fed a nutritionally adequate purified diet containing either 0.35 (marginal), 4.0 (control) or 50 (supplemented) mg retinol equivalents (as retinyl palmitate) per kg of diet from the time of weaning until killing at 8-10 (middle-aged) or 20-22 (old) mo of age. Neither VA nor VA and age interaction effects were significant for most iron variables examined. After controlling for body weight, old rats had significantly lower hemoglobin, hematocrit and plasma iron than middle-aged rats. This decrease in hematologic and transport iron variables was not accompanied by a shift of iron into other storage compartments. Old rats also had significantly lower total iron content and iron concentration in liver, spleen and bone marrow. Hemosiderin iron in marrow smears correlated significantly (r = 0.43-0.76, P: < 0.05) with chemical estimates of iron in storage, transport and functional pools. Old rats also tended to have less stained iron in femur marrow smears. Thus, body iron in functional, transport and storage compartments, namely the liver, spleen and bone marrow, were significantly lower in old than in middle-aged rats. Although iron stores and status are usually considered to increase with advancing age, our data show a consistent pattern of lower hematologic and storage iron variables in old than in middle-aged Lewis rats. Future research is indicated to understand the biology and functional consequences of the observed age-associated decline in body iron.

Comparison of actual pallidotomy lesion location with expected stereotactic location

Accuracy of pallidotomy lesion placement was assessed by comparing actual lesion locations with expected pallidotomy lesion locations based on stereotaxy. Actual and expected lesions were compared in anteroposterior, dorsoventral and lateral axes. In 22 pallidotomies, actual lesion locations were determined using axial MR images. Expected lesion locations were calculated using a starting point derived from preoperative computerized tomography, displacements from the starting point based on microelectrode-driven electrophysiological refinement, and the trajectory angle of the lesioning tract relative to the anterior-posterior commissural plane. On average, actual lesion locations were found 2.91 +/- 2.23 mm posterior, 3.22 +/- 2.49 mm ventral, and 0.05 +/- 1.80 mm lateral compared to the expected lesion location. Discrepancies between the actual lesion and expected lesion locations may be mostly accounted for by posterior and ventral lesion spread from the exposed electrode tip, in-plane and volume averaging effects associated with MR images, and possible brain shifting during surgery. However, despite the remaining small differences between actual and expected lesion location, good clinical outcome of reduced dyskinesias and 'off' time along with UPDRS-based improvement in mentation, motor and activity of daily living measures was observed.

Bacterial meningitis in Malawian adults: pneumococcal disease is common, severe, and seasonal

We prospectively collected laboratory details and outcome data on all patients with laboratory-confirmed cases of meningitis that presented to our unit in Blantyre, Malawi, from 1 April 1998 through 31 March 1999. There were 502 patients with cases of meningitis; the most common causative organisms were Cryptococcus neoformans and Streptococcus pneumoniae. This pattern probably reflects the local human immunodeficiency virus (HIV) seroprevalence (31%) and is different from the pattern in 1974, when Neisseria meningitidis was the most common isolate. There has been an 8-fold increase in the number of meningitis cases per year since 1974, and a doubling of the percentage of medical admissions due to meningitis. The inpatient mortality rate among patients with cases of pneumococcal meningitis was 61%, and in the group as a whole was 41%. Despite the HIV-related pattern of infecting pathogens among these cases of meningitis and the increased incidence of the condition, there was evidence that the typical seasonal pattern of pneumococcal meningitis, which peaks in the cold, dry season, was preserved.

Postoperative prophylactic administration of beta-adrenergic blockers in patients at risk for myocardial ischemia

Perioperative myocardial ischemia (MI) is associated with postoperative cardiac morbidity. Postoperative sympatholysis may reduce the incidence of MI. This study evaluated such a reduction postoperatively with the administration of prophylactic beta-blockers in patients undergoing elective total knee arthroplasty with epidural anesthesia and postoperative epidural analgesia. One hundred seven patients were preoperatively randomized into two groups, control and beta-blockers, who received postoperative esmolol infusions on the day of surgery and metoprolol for the next 48 h to maintain a heart rate less than 80 bpm. Patients were followed for ST segment depression by using a Holter monitor and adverse cardiac outcomes. Postoperative electrocardiographic ischemia was significantly more prevalent in the control group compared with the beta-blocker group during esmolol blockade (0 of 52 vs 4 of 55; P = 0.04) and tended to be more common in the control group the next two days (8 of 55 vs 3 of 52; P = 0.135). In addition, the number of ischemic events (control, 50; beta-blockers, 16) and total ischemic time (control, 709 min; beta-blocker, 236 min) were also significantly different from the control group. Myocardial infarctions and cardiac events were more common in the control group, but these differences were not significant. Our results suggest that the use of prophylactic beta-blocker therapy may reduce the incidence of postoperative MI.

IMPLICATIONS

Prophylactic beta adrenergic blockade administered after elective total knee arthroplasty was associated with a reduced prevalence and duration of postoperative myocardial ischemia detected with Holter monitoring.

Pallidotomy microelectrode targeting: neurophysiology-based target refinement

OBJECTIVE

Microelectrode recording can refine targeting for stereotactic radiofrequency lesioning of the globus pallidus to treat Parkinson's disease. Multiple intraoperative microelectrode recording/stimulating tracks are searched and assessed for neuronal activity, presence of tremor cells, visual responses, and responses to kinesthetic input. These physiological data are then correlated with atlas-based anatomic data to approximate electrode location. On the basis of these physiological properties, one or more tracks are selected for lesioning. This study analyzes the track physiological factors that seem most significant in determining the microelectrode recording track(s) that will be chosen for pallidal lesioning.

METHODS

Thirty-six patients with Parkinson's disease underwent microelectrode-guided pallidotomy. Between one and five microelectrode recording tracks were made per patient. Usually, one (n = 23) or two (n = 12) of these tracks were lesioned. Electrode positions in the x (mediolateral) and y (anteroposterior) axes were recorded and related to track neurophysiological findings and final lesion location. The stereotactic location and sequence of microelectrode tracks were recorded and plotted to illustrate individual search patterns. These patterns were then compared with those noted in other patients. Neurophysiological data obtained from recording tracks were analyzed. A retrospective analysis of track electrophysiology was performed to determine the track characteristics that seemed most important in the surgeon's choice of the track to lesion. Track physiological properties included general cell spike amplitude, tremor synchronous neuronal firing, kinesthetically responsive neuronal firing, and optic track responses (either phosphenes reported by the patient during track microstimulation or neuronal firing in response to light stimulus into the patient's eyes). Orthogonally corrected postoperative magnetic resonance images were used to confirm the anatomic lesion locations.

RESULTS

In patients who had a single mapped track lesioned, specific track electrophysiological characteristics identified the track that would be lesioned most of the time (20 of 24 patients). Tracks that exhibited a combination of tremor synchronous firing, joint kinesthesia, and visual responsivity were lesioned 17 (85%) of 20 times. Analysis of intraoperative electrode movement in the x and y axes indicated a significant subset of moves but did not result in microelectrode positioning closer to the subsequently lesioned track. Accuracy of initial electrode movement in the x and y axes was most highly correlated with a measure of first-track electrophysiological activity. The number of microelectrode recording tracks did not correlate with clinical outcome. Anatomic analysis, using postoperative magnetic resonance imaging, revealed that all lesions were placed in the globus pallidus. Most patients (35 of 36) improved after surgery.

CONCLUSION

The level of electrophysiological activity in the first track was the best predictive factor in determining whether the next microelectrode move would be closer to the ultimately lesioned track. The analysis of electrode track location and neurophysiological properties yields useful information regarding the effectiveness of microelectrode searching in the x and y axes. Within an institution, the application of this modeling method may increase the efficiency of the microelectrode refinement process.

An interesting observation of the position of some electronegative atoms in the taxol molecule

A study of the absolute energy-minimized configuration of the taxol molecule revealed that many oxygen atoms in this molecule and a nitrogen atom on the side chain are located on the same plane. A comparison of these electronegative atoms with information provided from existing literature indicated that most of these noted atoms conform with the reported structure--activity relationship (cytotoxicity, antineoplastic activity, tubulin assembly property, etc.). This observation may assist investigators in their future design of simpler, possibly clinically efficacious molecules related to taxol.

Dose response relationships for isobaric spinal mepivacaine using the combined spinal epidural technique

Mepivacaine, a local anesthetic with similar physiochemical properties to those of lidocaine, is an adequate alternative for patients undergoing ambulatory procedures, and is associated with a lower incidence of transient neurologic symptoms (TNS) than lidocaine. We studied the dose-response characteristics of isobaric intrathecal mepivacaine using the combined spinal epidural technique for patients undergoing ambulatory arthroscopic surgery of the knee. Seventy-five patients were randomized prospectively to receive one of three doses of isobaric mepivacaine for spinal anesthesia: 30 mg (2 mL 1.5%), 45 mg (3 mL 1.5%), or 60 mg (4 mL 1.5%). An observer, blinded to the dose, recorded sensory level to pinprick and motor response until resolution of the block. In addition, the incidence of TNS was determined. An initial intrathecal dose of 30 mg of isobaric mepivacaine 1.5% produced satisfactory anesthesia in 72% of ambulatory surgical patients undergoing unilateral knee arthroscopy with a significantly shorter duration of sensory (158 +/- 32 min) and motor blockade (116 +/- 38 min) than doses of 45 and 60 mg. An intrathecal dose of 45 mg produced satisfactory anesthesia in all patients with a shorter duration of sensory (182 +/-38 min) and motor blockade (142 +/- 37 min) than 60 mg of mepivacaine 1.5% (203 +/- 36 min and 168 +/- 36 min, respectively). The incidence of TNS was 7.4% overall (1.2%-13.6% confidence intervals), less than the rates previously reported after spinal anesthesia with lidocaine in ambulatory surgical patients undergoing knee arthroscopy. We conclude that mepivacaine can be used as an adequate alternative to lidocaine for ambulatory procedures.

IMPLICATIONS

This study evaluated the postoperative duration of spinal anesthesia after varying doses of isobaric mepivacaine and the incidence of transient radiating back and leg pain. We found that 45 mg of mepivacaine provided adequate anesthesia, a timely discharge, and a lower incidence of back pain than that previously reported after lidocaine spinals.

Primary biliary cirrhosis shows association with genetic polymorphism of tumour necrosis factor alpha promoter region

BACKGROUND/AIMS

Primary biliary cirrhosis is an autoimmune disease in which increased prevalence in first-degree relatives and an association with HLA DR8 suggest a genetic background. TNFalpha is a mediator of inflammation and immunity, and is implicated in the pathogenesis of primary biliary cirrhosis, ex vivo studies having shown reduced production of TNFalpha by lymphocytes from patients. Our group has previously described a biallelic promoter-region polymorphism of the TNFA gene at position -308, and demonstrated that the rare allele, TNF*2, has increased promoter function compared with the common allele, TNF*1. A further biallelic base change has been described in the TNFA gene at -238. We conducted a case-control study to assess association of these gene polymorphisms with primary biliary cirrhosis.

METHODS

Ninety-one patients and 213 controls were genotyped for both TNFA loci using restriction fragment length polymorphism analysis of PCR products.

RESULTS

The high production TNFA-308*2 allele was significantly under-represented among subjects with primary biliary cirrhosis (27.5% PBC, 41.6% controls, p=0.02, pc=0.04, OR for carriage of TNF*1/*1 genotype=1.89, CI=1.10-3.32). No association was shown with the TNFA -238 polymorphism.

CONCLUSION

Primary biliary cirrhosis is associated with reduced carriage of TNF*2. This is in keeping with a protective role of TNFalpha against the disease.

The use of metoprolol and glycopyrrolate to prevent hypotensive/bradycardic events during shoulder arthroscopy in the sitting position under interscalene block

Sudden profound hypotensive and/or bradycardic events (HBE) have been reported in >20% of patients undergoing shoulder arthroscopy in the sitting position under interscalene block anesthesia. Retrospective studies suggest that the administration of beta-blockers is safe and may decrease the incidence of these episodes. We performed a randomized, prospective study to evaluate prophylaxis of these events. One hundred fifty patients were randomized to one of three groups (placebo; prophylactic metoprolol to achieve a heart rate <60 bpm or a maximal dose of 10 mg; or prophylactic glycopyrrolate to achieve a heart rate >100 bpm or a maximal dose of 6 microg/kg) immediately after the administration of the interscalene block. Blood pressure control was achieved with IV enalaprilat as needed. The incidence of HBE was 28% in the placebo group versus 5% in the metoprolol group (P = 0.004). The rate of 22% in the glycopyrrolate group was not significantly different from placebo. Preoperative heart rate and arterial blood pressure, intraoperative sedation score, IV fluids, and enalaprilat use were similar in those patients who had a HBE compared with those who did not. Many aspects of this clinical setting are similar to tilttable testing for patients with recurrent vasovagal syncope, in which beta-adrenergic blockade with metoprolol has also been shown to be effective. We conclude that the Bezold-Jarisch reflex is the most likely mechanism for these events.

IMPLICATIONS

Episodes of acute hypotension and bradycardia occur during shoulder arthroscopy in the sitting position under interscalene block. In this study, we demonstrate that metoprolol, but not glycopyrrolate, markedly decreases the incidence of these episodes when given prophylactically immediately after the administration of the block.

A reevaluation of the 512-Hz Rinne tuning fork test as a patient selection criterion for laser stapedotomy

OBJECTIVE

This study aimed to challenge the classical hypothesis that a negative preoperative 512-Hz Rinne tuning fork test (bone conduction greater than air conduction) is a necessary condition to allow consistent objective and subjective hearing improvement with surgery for otosclerosis.

STUDY DESIGN

The study design was retrospective (chart review and questionnaire).

SETTING

The study was conducted at a Florida Ear and Sinus Center at Sarasota, Florida, a tertiary otology-neurotology referral center.

PATIENTS

Patients who underwent primary laser stapedotomy with equivocal (air=bone) preoperative 512-Hz Rinne test results participated.

INTERVENTION

KTP laser stapedotomy was performed.

MAIN OUTCOME MEASURES

Audiologic measurements of air-bone gap closure and patient assessment of hearing improvement and satisfaction were conducted.

RESULTS

The air-bone gap was closed to within 10 dB in all cases. There were no complications. Eighteen patients were questioned about their results. Hearing improvement was subjectively described as "excellent" or "good" by 17 (94%), and 16 (89%) thought the surgery was "absolutely" worthwhile.

CONCLUSIONS

The preoperative 512-Hz Rinne test results need not be negative to achieve significant air-bone gap closure and subjective appreciation of improved hearing.

Pharmacokinetics of pentoxifylline and its metabolites in healthy mice and in mice infected with Candida albicans

Pentoxifylline has immunomodulatory properties and has been shown to decrease organ damage and improve survival in animals with gram-negative sepsis or endotoxemia. This effect is mediated by a reduction in endotoxin-induced production of tumor necrosis factor alpha (TNF-alpha) by the host. In earlier studies, we observed an unexpected increase in mortality in mice infected with Candida albicans that were given pentoxifylline even though concentrations of TNF-alpha in serum were not affected. The current study was designed to determine whether the pharmacokinetics of pentoxifylline and its metabolites were altered in C. albicans-infected mice and, if so, whether these changes could have contributed to the increased mortality. Noninfected mice and mice infected with C. albicans were treated with pentoxifylline (60 mg/kg of body weight) intraperitoneally every 8 h. Serum was collected from animals after one (day 0), four (day 1), or seven (day 2) injections of pentoxifylline or saline (controls). The first dose was administered 6 h after C. albicans infection. Serum was pooled. Concentrations of pentoxifylline and metabolites I, IV, and V were determined by capillary gas chromatography. Renal function and hepatic profiles were assessed. Pharmacokinetic parameters (maximum concentration of pentoxifylline in serum, half-life, and area under the concentration-time curve from 0 h to infinity [AUC(0)-infinity]) for all noninfected mice were similar and did not differ from those for day 0-infected mice. For day 1-infected mice, values of these three pharmacokinetic parameters for pentoxifylline and metabolite I were increased two- to fourfold over values for noninfected and day 0-infected mice. For metabolites IV and V, the AUC(0)-infinity was increased approximately eightfold over control values. In addition, day 1-infected mice demonstrated evidence of renal and hepatic dysfunction. In summary, C. albicans infection produced marked changes in the pharmacokinetics of pentoxifylline and its metabolites in the mice. The high concentrations of pentoxifylline and its metabolites in serum attained in infected mice may have contributed to the increased mortality of mice with systemic candidiasis.

Pallidotomy lesion locations: significance of microelectrode refinement

OBJECTIVE

To determine whether stereotactic pallidotomy requires refinement using microelectrode recording to ensure proper lesion placement.

METHODS

The experiment approach was based on retrospective comparisons of microelectrode-refined radiofrequency lesion locations with hypothetical unrefined lesion positions. Actual and hypothetical pallidotomy lesions were classified based on their lesion center (thermocoagulative zone) locations and their total lesion areas (surrounding edematous zone) relative to the pallidal target. Assessments were made using postoperative T2-weighted magnetic resonance axial images, which showed both the lesion and globus pallidus (GP). The magnitude of microelectrode refinement from an initial preoperative starting point determined by computed tomography was calculated using stereotactic coordinates and included corrections for the lesioning tract trajectory angle.

RESULTS

In all 25 patients, the center of the actual pallidotomy lesion was within the GP. Without microelectrode refinement, 13 of 25 hypothetical lesion positions would have been localized such that the lesion center would not have remained in the GP. In eight cases, microelectrode refinement resulted in no significant change in lesion location, but in one case, microelectrode refinement resulted in lesion center placement away from the GP.

CONCLUSION

Kinesthetically driven microelectrode refinement in pallidotomy lesioning seems to be required to ensure proper lesion location within the GP.

Analysis of pallidotomy lesion positions using three-dimensional reconstruction of pallidal lesions, the basal ganglia, and the optic tract

OBJECTIVE

To assess the position of radiofrequency pallidotomy lesions placed using microelectrode stimulation and cellular recordings in relation to a stereotactically defined starting point. Radiofrequency lesion locations were also evaluated in relation to the putamen, posterior limb of the internal capsule, and optic tract.

METHODS

Magnetic resonance images obtained from 23 patients with Parkinson's disease who underwent pallidotomy at the University of Kansas Medical Center were analyzed. Using computerized techniques, lesion positions in relation to the midcommissural point and a hypothetical starting point were determined. Data segmentation and three-dimensional reconstruction of pallidal lesions, the internal capsule, and the optic tract allowed assessment of lesion position in relation to internal anatomy. Clinical outcome of pallidotomy was assessed using both the Unified Parkinson's Disease Rating Scale and the Dementia Rating Scale.

RESULTS

Pallidal lesions were usually placed anterior and dorsal to the stereotactically defined starting point. The position of pallidal lesions in the men were observed, in four trials, to be significantly more dorsal than the lesions in the women. The outer zone of the lesion was usually adjacent to the internal capsule and the putamen and relatively close to the optic tract. The inner zone of the lesion was usually several millimeters removed from anatomic boundaries of the putamen, internal capsule, and optic tract. Patients achieved favorable outcomes, with reduced dyskinesias and "off" time and improvement of their Parkinsonian symptoms, as evidenced by clinical assessment, the Unified Parkinson's Disease Rating Scale, and the Dementia Rating Scale.

CONCLUSION

Microelectrode stimulation and cellular recordings usually led to a final pallidotomy lesion position that deviated from the stereotactically defined starting point. The pallidotomy lesions in the men were observed to be more dorsal than the lesions in the women. Clinical outcomes were not correlated with either lesion location relative to the starting point or distances between the pallidal lesion and the putamen, internal capsule, or optic tract. Kinesthetically responsive cells may be localized generally more anterior and dorsal to the starting point (within the globus pallidus) and may be grouped variably from patient to patient in relation to other basal ganglia structures. Although the primary lesion site is most likely within the sensorimotor region of the globus pallidus internus, the more dorsal locations of responsive cell groups may indicate that some lesion sites may be localized within the globus pallidus externus.

Three-dimensional computerized reconstruction. Illustration of incremental articular cartilage thinning

RATIONALE AND OBJECTIVES

The authors have addressed the ability of magnetic resonance (MR) imaging to resolve incremental thinning of articular cartilage by assessment of three-dimensional (3-D) and two-dimensional (2-D) representations.

METHODS

Using a porcine knee model, sequential cartilage shavings were characterized using a 3-D fat suppressed spoiled gradient-echo (SPGR) MR imaging protocol that provided good contrast between high-signal articular cartilage and lower signal surrounding tissues. Lesion dimensional measurements were made on both MR images and 3-D computerized reconstructions. Volumes of cartilage removed were approximately 0.06 mL.

RESULTS

Incremental articular cartilage thinning typically was apparent on 3-D reconstructed images. Three-dimensional articular cartilage reconstructions were effective in depicting location and orientation of shaved cartilage regions. Average percent error associated with length and with measurements based on 2-D MR images was approximately 19% for observer 1 and 33% for observer 2 when compared with direct measurements of the shaved cartilage. Average percent error of thickness measurements based on 2-D MR was approximately 21% for observer 1 and 37% for observer 2. Overall average errors associated with length, width, and thickness measurements were approximately 25%.

CONCLUSIONS

Incremental thinning of articular cartilage can be tracked qualitatively and quantitatively using 3-D computerized reconstructions and 2-D MR images. Errors associated with the quantitative measurements can be attributed to limitations of measurement methods and intrinsic limitation of MR resolution.

Texture analysis of cerebral white matter in SIV-infected macaque monkeys

Image texture analysis is used in a wide variety of applications in medical research. Neurovirulent simian immunodeficiency virus (SIV) infection in monkeys is considered a good model for HIV-1 infection in humans and causes neuropathological changes in white matter which can include diffuse myelin pallor, subtle white matter astrocytosis, perivascular macrophage infiltrates, and microglial nodules with multinucleated giant cells. The ability of image texture analysis to quantify these changes was evaluated. Sections of thionin-stained brain tissue from eight male rhesus macaques ranging in age from 42-59 months were used. Four animals served as controls and four animals were infected with neurovirulent SIVmac239/17E-R71 by bone marrow inoculation. Images of cerebral white matter were captured and analyzed by calculating 13 textural features based on statistical analysis of spatial co-occurrence matrices. Statistical analysis of the results included multiple comparisons using the Newman-Keuls multiple range test. The effect of variation in background illumination used at image acquisition was also evaluated. Ten of the 13 textural features used in this study successfully discriminated between tissue from control and SIV-infected animals and were consistent with independent neuropathological assessment. Three textural features were highly sensitive to variation in background illumination and found not useful in this application.

Magnetic resonance image evaluation of pallidotomy lesions: a volumetric and shape analysis

Determination of acute pallidotomy-produced lesion volumes, pre- and postpallidotomy globus pallidus (GP) volumes, and assessment of lesion shape using magnetic resonance (MR) imaging-based computerized segmentation (contouring) and three-dimensional rendering was made in 19 patients. Magnetic resonance image slice thickness (1.5 mm or 6 mm) was not found to be a significant factor influencing contour-based pallidotomy lesion volume estimates. Previously reported lesion volumes produced by pallidotomy have often been estimated using the ellipsoid volume formula. Using 1.5-mm-thick MR sections, contour-based pallidotomy-produced lesion volumes were significantly different from those volumes estimated by the ellipsoid formula. Globus pallidus volumes, estimated by contouring T2-weighted MR images, were bilaterally similar (2.4 ± 0.37 ml [right]; 2.2 ± 0.45 ml [left]). Postoperative GP volumes were found on the contralateral, unlesioned side to be 2 ± 0.45 ml and on the lesioned side to be 1.25 ± 0.45 ml. Using the contralateral, unlesioned side as a reference volume, approximately 39 ± 14% of the GP was visibly affected on the lesioned side. Seventeen of 18 patients had a favorable outcome with reduced dyskinesias and "off" time with improvement in parkinsonian symptoms.

Analysis of computerized three-dimensional rendering of pallidotomy-produced lesions based on MR images showed no relationship between lesioning technique and resulting lesion shape. Important factors in the volumetric analysis of pallidotomy lesions are identified and allow reasonable assessment of the pallidotomy lesion volume and shape and the extent of the affected GP.

Case report: pathomorphology of an experimental disseminated Aspergillus fumigatus infection in rabbits

In following a formerly successful protocol designed to produce antibodies to A. fumigatus (Fres) we observed a disseminated, lethal fungal infection in healthy, specific pathogen-free (SPF) rabbits. The pathomorphological findings included multiple miliary to avenaceous whitish nodules in the livers and kidneys, mycotic mesencephalitis, nephritis, hepatitis, myocarditis, hemorrhagic enteritis, and splenitis. The hyphae were surrounded by necrosis, which also occurred in the liver without the hyphae. Comparative gas chromatographic and metabolic investigations on this strain and some environmental A. fumigatus strains showed significant differences. The findings are discussed with particular reference to the pathogenicity of A. fumigatus.

Textural parameters based on the Spatial Gray Level Dependence Method applied to melanocytic nevi

The purpose of this study is to evaluate the Spatial Gray Level Dependence Method (SGLDM) of texture analysis with respect to its ability to discriminate between melanocytic nevi and normal skin. Thirteen textural features based on the SGLDM were evaluated with respect to their relative sensitivities to both texture and tone. Ten features were found to be more sensitive to texture than tone and were selected for further study. Twenty-four digitized images of benign melanocytic nevi were obtained from six volunteers. Ten textural features were analyzed for each nevus and for surrounding sections of normal skin. Of these 10 features, 8 features can distinguish between textural properties of melanocytic nevi and surrounding skin.

Analysis of three-dimensional computerized representations of articular cartilage lesions

RATIONALE AND OBJECTIVES

The authors assess the accuracy of three-dimensional (3D) computer representations based on magnetic resonance images of articular cartilage lesions, using actual cartilage lesions as reference standards.

METHODS

Grade 2 and grade 3 articular lesions were created on articular surfaces of five porcine knee joints. The knees were then imaged using 3D fat-suppressed SPGR acquisition at four different slice thicknesses. Magnetic resonance imaging data sets were transferred to a computer workstation for image processing and 3D reconstruction. Lesion dimensions (length, width, and depth) based on the 3D reconstructed image were compared with the dimensions measured using actual lesions.

RESULTS

The average percent error of lesion length, width, and depth based on the 3D images ranged from approximately 8% to 12% when using the thinnest magnetic resonance slice thickness (0.7 mm).

CONCLUSIONS

Three-dimensional reconstructed images derived from thin-slice magnetic resonance imaging can provide reasonable representations of true articular cartilage lesion dimensions.

Right ventricular function during revision total hip arthroplasty

Total hip arthroplasty (THA) is associated with pulmonary embolization of cement-bone marrow debris leading to cardiopulmonary complications including cardiac arrest. These complications are more prevalent during revision THA. This report assessed right ventricular function using a right ventricular ejection fraction pulmonary artery catheter (RVEF) and transesophageal echocardiography (TEE) in 18 patients undergoing revision THA. During femoral prosthesis insertion, all patients exhibited hemodynamic changes, but most of these were small and clinically insignificant. Four patients demonstrated a decrease in RVEF > or = 10% and an increase in mean pulmonary artery pressure > or = 10 mm Hg, requiring physician intervention. Two of these patients exhibited signs of pulmonary embolization postoperatively. All patients studied by TEE had detectable intracardiac emboli during femoral arthroplasty. The acute decreases in RVEF and increases in mean pulmonary artery pressures during hip arthroplasty, suggest a role for the embolization of bone marrow debris in the development of the "bone cement implantation syndrome."

Effect of pentoxifylline on the course of systemic Candida albicans infection in mice

Pentoxifylline can decrease the production of tumour necrosis factor alpha (TNF alpha) by endotoxin-stimulated macrophages and may improve survival in animals with overwhelming bacterial sepsis. In this study various doses of pentoxifylline were administered to mice with systemic Candida albicans infection to determine its effect on serum TNF alpha levels, organ fungal burden, and host survival. Intraperitoneal injections of pentoxifylline at 20 mg/kg every 8 h did not affect these endpoints. However, fungal counts were significantly higher in kidneys of animals that received 30 and 60 mg/kg of pentoxifylline every 8 h when compared to controls. Injection of 60 mg/kg of pentoxifylline at 8 h intervals also significantly shortened mean survival from 5.8 to 3.8 days (P = 0.01). Pentoxifylline did not affect peripheral WBC counts, serum TNF alpha and interleukin-6 levels, or the density of neutrophils in tissues. In vitro, pentoxifylline decreased the production of TNF alpha by C. albicans-stimulated macrophages in a dose-dependent manner, but only at concentrations greater than 100 mg/L. In contrast, pentoxifylline suppressed TNF alpha production by endotoxin-stimulated macrophages at concentrations as low as 10 mg/L. Thus, higher doses of pentoxifylline are detrimental in systemic C. albicans infection. However, the detrimental effect is not mediated by alterations in serum TNF alpha or interleukin-6 levels or the aggregation of neutrophils in tissues.

Serum therapy for Cryptococcal meningitis

Three patients were treated with combined amphotericin B and rabbit anticryptococcal antibody in the 1960s. Rabbit antibody was administered intravenously and was well tolerated. For each patient, administration of rabbit antibody resulted in the appearance of serum Cryptococcus neoformans agglutinins. For two patients the administration of rabbit antibody resulted in negative serum latex tests for cryptococcal antigen. This limited experience with adjunctive antibody therapy provides valuable precedents if antibody therapy is used again for treatment of human cryptococcosis.