Systemic production of human granulocyte colony-stimulating factor in nonhuman primates by transplantation of genetically modified myoblasts

Clinical use of human granulocyte-colony stimulating factor (hG-CSF) to treat various diseases involving neutropenia has been previously shown to (1) successfully increase circulating neutrophils, (2) reduce condition-related infections, and (3) cause few side effects in patients. To alleviate the symptoms of neutropenia, the patient must receive frequent injections of recombinant hG-CSF. Permanent ways to deliver stable levels of the molecule to the patient are being investigated. Among them, the transplantation of hG-CSF-secreting cells has been proposed and performed successfully in rodents, using fibroblast cell lines and primary muscle cells. We thus investigated whether similar results could be obtained by intramuscular myoblast transplantation in a large animal model. When 1-3 x 10(8) myoblasts were injected into three Macaca mulatta, hG-CSF was detected at high levels (300-900 pg/ml), which in turn led to a four- to fivefold increase in circulating neutrophils. However, both the concentrations of hG-CSF and neutrophil levels were found to decrease over time. Nonetheless, neutrophils were found at higher levels from the fourth week until the end the experiment (up to 29 weeks) in G-CSF monkeys compared with control animals. These results show that transplantation of hG-CSF-secreting myoblasts may indeed be a therapeutic option for the treatment of neutropenic patients.     

Transrectal ultrasonography-guided biopsy does not reliably identify dominant cancer location in men with low-risk prostate cancer

Study Type – Diagnostic (exploratory cohort) Level of Evidence 2b What's known on the subject? and What does the study add? The widespread use of serum PSA testing followed by TRUS‐guided biopsy have resulted in profound prostate cancer stage migration with many patients presenting with focal rather than multifocal disease. There is increasing interest in the use of focal rather than whole‐gland treatment. However, current biopsy schemes may still miss cancer or, even when cancer is identified, its extent or grade might not be accurately characterized. In order for focal therapy to be effective, the area of highest tumour volume and/or grade needs to localized accurately. The aim of this study was to assess how well biopsy, as currently performed, locates the focus of highest prostate cancer volume and/or grade.

OBJECTIVE

• ? To evaluate the ability of transrectal ultrasonography (TRUS)‐guided extended core biopsy to identify the dominant tumour accurately in men with early stage prostate cancer.

PATIENTS AND METHODS

• ? Patients with early stage, low‐risk prostate cancer who subsequently underwent radical prostatectomy (RP) and had complete surgical specimens were identified.
• ? Re‐review was performed by a single uropathologist using ImageJ software to identify tumour location, dominant grade (DG) and dominant volume (DV).
• ? Pathology findings were then compared with biopsy results.

RESULTS

• ? A total of 51 men with early stage, low‐risk prostate cancer, who had undergone RP, had complete specimens for review and a median of 15 biopsy cores taken for diagnosis and grading.
• ? Sixteen men had a single diagnostic biopsy, 21 had one repeat biopsy, and 14 had two or more repeat biopsies.
• ? Compared with surgical findings, biopsy correctly identified the sextant with the largest tumour volume in 55% (95% CI 0.5–0.6) of specimens and the highest grade in 37% (95 CI 0.3–0.5).
• ? No demographic or clinical factors were significantly associated with identification of DG. Interval between last biopsy and RP, total tissue length taken and total length of tumour identified were significantly associated with correct identification of DV.

CONCLUSIONS

• ? Our findings show that TRUS‐guided biopsy detects and localizes DV better than it does DG.
• ? Even with an extended scheme, TRUS‐guided biopsy does not reliably identify dominant cancer location in this low‐risk cohort of men with early stage prostate cancer.
• ? TRUS‐guided biopsy may perform better in similar men with low stage, but higher volume disease.

     

Air pollutants and cough

Epidemiological studies have shown that exposure to air pollution is associated with respiratory symptoms and decreases in lung function. This paper reviews recent literature showing that exposure to particulate matter, irritant gases, environmental tobacco smoke (ETS), mixed pollutants, and molds is associated with an increase in cough and wheeze. Some pollutants, like particulate matter and mixed pollutants, appear to increase cough at least as much as wheeze. Others, like irritant gases, appear to increase wheeze more than cough. For ETS, exposure during childhood is associated with cough and wheeze in adulthood, suggesting that the pollutant permanently alters some important aspect of the lungs, immune system or nervous system. We have shown in animal studies that pollutants change the neural control of airways and cough. Second hand smoke (SHS) exposure lengthened stimulated apnoea, increased the number of stimulated coughs, and augmented the degree of stimulated bronchoconstriction. The mechanisms included enhanced reactivity of the peripheral sensory neurones and second-order neurones in the nucleus tractus solitarius (NTS). NTS effects were due to a substance P mechanism at least in part. Ozone and allergen increased the intrinsic excitability of second-order neurones in the NTS. The animal studies suggest that the cough and wheeze experienced by humans exposed to pollutants may involve plasticity in the nervous system.     

Perinatal anoxia degrades auditory system function in rats

Little is known about the neural bases of the reduced auditory and cortical processing speeds that have been recorded in language-impaired, autistic, schizophrenic, and other disabled human populations. Although there is strong evidence for genetic contributions to etiologies, epigenetic factors such as perinatal anoxia (PA) have been argued to be contributors, or causal, in a significant proportion of cases. In this article, we explored the consequences of PA on this elementary aspect of auditory behavior and on auditory system function in rats that were briefly perinatally anoxic. PA rats had increased acoustic thresholds and reduced processing efficiencies recorded in an auditory behavioral task. These rats had modestly increased interpeak intervals in their auditory brainstem responses, and substantially longer latencies in poststimulus time histogram responses recorded in the primary auditory cortex. The latter were associated with degraded primary auditory cortex receptive fields and a disrupted tonotopy. These processing deficits are consistent with the parallel behavioral and physiological deficits recorded in children and adults with a history of language-learning impairment and autism.     

Posttransplantation: future therapies

Recent advances in prophylaxis and treatment of hepatitis B virus (HBV) infection after liver transplantation have improved the outcome of liver transplantation for hepatitis B. Currently, the long-term use of hepatitis B immune globulin (HBIG) and/or nucleoside analogues are the only effective therapies to prevent or ameliorate HBV recurrence in liver transplant patients. However, they are very expensive, and breakthrough infections due to resistant HBV mutants are not infrequent. New strategies are being sought to decrease the risks of breakthrough infection and to increase the cost-effectiveness of liver transplantation for hepatitis B. Vaccination to prevent de novo infection is strongly recommended before transplantation, despite a decreased response in this immunosuppressed population. Adoptive transfer of immunity with such therapies as bone marrow or cytotoxic T lymphocyte transplants or xenotransplantation of an organ from a donor, which is not susceptible to infection by HBV may be effective in preventing or treating recurrent HBV posttransplantation. In addition, gene therapies and use of nucleoside and nucleotide analogues to disrupt various stages of the HBV life cycle may prevent or slow viral replication or assembly of the virus. Ultimately, the most effective therapy for the prevention of recurrent hepatitis B after liver transplantation will involve a combination of HBIG with one or more of the new antiviral agents.     

Passive smoke effects on cough and airways in young guinea pigs: role of brainstem substance P

Children raised with extended exposure to environmental tobacco smoke (ETS) experience increased cough and wheeze. This study was designed to determine whether extended ETS exposure enhances citric acid-induced cough and bronchoconstriction in young guinea pigs via a neurokinin-1 (NK-1) receptor mechanism at the first central synapse of lung afferent neurons, the nucleus tractus solitarius. Guinea pigs were exposed to ETS from 1 to 6 weeks of age. At 5 weeks of age, guide cannulae were implanted bilaterally in the medial nucleus tractus solitarius at a site that produced apnea in response to the glutamate agonist D,L-homocysteic acid. At 6 weeks of age, either vehicle or a NK-1 receptor antagonist, SR 140333, was injected into the nucleus tractus solitarius of the conscious guinea pigs who were then exposed to citric acid aerosol. ETS exposure significantly enhanced citric acid-induced cough by 56% and maximal Penh (a measure of airway obstruction) by 43%, effects that were attenuated by the NK-1 receptor antagonist in the nucleus tractus solitarius. We conclude that in young guinea pigs extended exposure to ETS increases citric acid-induced cough and bronchoconstriction in part by an NK-1 receptor mechanism in the nucleus tractus solitarius.     

The allopurinol load test lacks specificity for primary urea cycle defects but may indicate unrecognized mitochondrial disease

Thirty-three children ranging from 2 weeks to 12 years of age were selected for allopurinol loading, 16 on the basis of an increased urinary orotate excretion detected by routine organic acid analysis (group A), and 17 for clinical reasons suggesting a urea cycle defect (group B). The allopurinol load test proved positive in 13 of 16 patients from group A, mean peak orotate 64.0mol/mmol creatinine (upper limit of reference range, 13.2) and 11 of 17 patients from group B, mean peak orotate 41.0mol/mmol creatinine (upper limit of reference range, 13.2). Thorough investigation of these patients including urinary and plasma amino acid analysis and, in 17 cases, liver biopsy for histology and measurement of ornithine carbamyltransferase (OCT) and carbamyl-phosphate synthetase (CPS) activity failed to identify any evidence of a urea cycle disorder. However, muscle biopsies performed in 11 patients showed some evidence of mitochondrial disease in four cases, two defined on the basis of reduced respiratory chain enzyme activity and two on the basis of mtDNA abnormalities. These findings indicate that an increased excretion of orotate in sick children may not be uncommon and that a positive allopurinol load test result may not indicate a specific inherited urea cycle defect. In addition, these results raise the interesting possibility that defective ureagenesis may be a feature of mitochondrial disease in some individuals.