Causes of loss to follow-up from drug-resistant TB treatment in Khayelitsha, South Africa

Patients initiated on drug-resistant TB(DR-TB) treatment in 2019 in Khayelitsha, South Africa, with a loss to follow-up outcome were evaluated to better understand reasons for loss to follow-up and to determine if any had returned to care. Of a total of 187 patients, 28 (15%) were lost to follow-up (LTFU), 24 (86%) of whom were traced: 20/24 (83%) were found when they re-presented to facilities and 8/28 (29%) were linked back to DR-TB care. People with DR-TB continue to seek care even after being LTFU; thus better coordination between different components of the healthcare system are required to re-engage with these patients. Interventions to mitigate the socio-economic challenges of people on DR-TB treatment are needed. Many people who were LTFU and symptomatic were willing to re-engage with DR-TB care, which highlights the importance of for compassionate interventions to welcome them back.

Virtual reconstruction of the skeletal labyrinth of two lamnid sharks (Elasmobranchii, Lamniformes)

The first virtual reconstruction of the skeletal labyrinth of the porbeagle shark Lamna nasus and the shortfin mako shark Isurus oxyrinchus is presented here using high-resolution micro-computed tomography. The results, in comparison with previously published information, suggest relationships between skeletal labyrinth morphology and locomotion mode in chondrichthyans, but also show that further studies are required to establish such connections. Nevertheless, this study adds to the knowledge of the skeletal labyrinth morphology in two apex elasmobranch species.

Variants of the FTO gene in obese children and their impact on body composition and metabolism before and after lifestyle intervention

OBJECTIVE

To investigate the impact of variants of the FTO gene (rs1421085, rs17817449, rs9939609) in obese children before and after lifestyle intervention.

METHOD

DESIGN

Longitudinal, clinical intervention study with an increase in physical activity, and nutritional recommendations based on the 'Optimized Mixed Diet for German Children and Adolescents' (Research Institute of Child Nutrition, Germany).

STUDY POPULATION

75 overweight children (40 male, mean BMI 30.4±5.5 kg/m², mean age 12.6±2.6 years).

MEASUREMENTS

Genotyping by means of a TaqMan SNP genotyping assay. Lean and fat mass were determined by means of DXA.

RESULTS

For the whole study population, the 6-month lifestyle intervention resulted in a significant improvement (before intervention minus time point 6 months; mean±SD) in BMI-SDS (0.10±0.17, p<0.001), HOMA (1.41±3.19, p<0.001) and relative fat-mass-SDS (0.09±0.23, p=0.005). Before and after lifestyle intervention, there was no significant difference between heterozygote (n=52) and homozygote (n=21) carriers of the FTO gene in terms of BMI, body composition, and the metabolic profile (Insulin, HOMA, lipids, liver function tests).

CONCLUSION

Variants in the FTO gene are common in obese children but have no impact on body composition and metabolism before and after lifestyle intervention.

Investigation of myostatin serum levels before and after a 6-month lifestyle intervention program in obese children

OBJECTIVE

To investigate the relationship between myostatin serum levels and muscle mass, fat mass and HOMA before and after a 6-month lifestyle intervention program in obese children and adolescents.

DESIGN

A total of 57 overweight children and adolescents (female, n=27; age range, 6.0-16.1 years) were examined between 2007 and 2009. Mean BMI (±SD) was 31.1 (5.7) kg/m(2) corresponding to a mean BMI-SDS LMS of 2.2 (0.4). Muscle and fat mass were determined by means of DXA. Serum myostatin was measured by using a competitive ELISA. RESULTS [MEAN±SD]: After the 6-month intervention program, muscle mass (+2.1±2.7 kg, p<0.0001), and percentage myostatin serum levels (+23.7±26.7%, p<0.0001) were higher than before, whereas decreases in BMI (-0.4 kg/m(2)±1.5, p<0.0001), fat mass (-1.2±3.9 kg, p<0.0001), and HOMA insulin sensitivity index (-0.78±3.28 SD, p=0.0004) were observed. In 86% (n=49, p<0.0001) of all cases, the intervention program resulted in a higher level of myostatin. After lifestyle intervention, patients with the greatest increase of myostatin had a significantly lower increase of muscle mass (p=0.048) but did not differ for fat mass. There was no significant correlation between Myostatin and HOMA insulin sensitivity index before and after lifestyle intervention.

CONCLUSION

Both muscle mass and serum myostatin increased concordantly. Patients with the greatest rise of myostatin had a significantly lower increase of muscle mass suggesting a negative feedback loop between myostatin and muscle tissue. In our study, the change of myostatin serum levels was not associated with the amount of fat mass or HOMA insulin sensitivity index.

Dexamethasone does not significantly contribute to the response rate of docetaxel and estramustine in androgen independent prostate cancer

PURPOSE

We evaluated the independent response rate of dexamethasone before docetaxel and estramustine administration as measured by changes in serum prostate specific antigen (PSA) in patients with androgen independent prostate cancer.

MATERIALS AND METHODS

A total of 12 patients received 20 mg. dexamethasone orally every 6 hours for 3 doses repeated every 3 weeks before starting cytotoxic therapy with estramustine and docetaxel. After progression on dexamethasone 280 mg. estramustine orally 3 times daily on days 1 to 5 and 70 mg./m.2 docetaxel intravenously for 1 hour on day 2 were given.

RESULTS

None of the patients initially treated with dexamethasone monotherapy (median 1 cycle, range 1 to 5) had a PSA decline of 50% or greater. Median PSA increase on monotherapy was 47% (range 0% to 22%). On estramustine and docetaxel therapy PSA decreased 50% or greater in 11 patients (92%, 95% confidence intervals [CI] 60 to 99) and 80% or greater in 7 (58%, 95% CI 29 to 84), and normalized in 5 (42%, 95% CI 16 to 71), with a median duration of response of 153 (range 42 to 371), 132 (range 84 to 287) and 84 (range 21 to 174) days, respectively. Median times to reach 50% and 80% decreases in baseline PSA were 21 (range 21 to 209) and 63 (range 21 to 138) days, respectively. In 9 patients (75%, 95% CI 43 to 93) PSA decreased at least 50% by week 9. Of 4 patients with bidimensionally measurable disease 3 had a partial response. Median time to progression was 263 days (range 91 to 378).

CONCLUSIONS

Administration of 20. mg. dexamethasone orally every 6 hours for 3 doses every 3 weeks does not significantly contribute to the PSA response rate of estramustine and docetaxel.

Phase I/II studies of docetaxel (Taxotere) combined with estramustine in men with hormone-refractory prostate cancer

Evaluation of the combined regimen of estramustine and docetaxel (Taxotere; Rhône-Poulenc Rorer, Collegeville, PA) in men with hormone-refractory prostate cancer is in its early stages. While this combination is promising in terms of efficacy, adverse events associated with estramustine are a concern. Estramustine has been associated with side effects such as nausea, vomiting, edema, and serious vascular events. Reported here are the results of phase I and phase II trials in which 280 mg estramustine was given three times daily on days I to 5 in 21-day treatment cycles with docetaxel at varying doses. Data from patients evaluable thus far support the efficacy of this combination, both in chemotherapeutically naive patients and in those who have had prior therapy. A survival benefit from this combination appears achievable from these early studies. As significant antitumor activity can be achieved with docetaxel alone, future studies need to define the minimal dose of estramustine for this combination.

Phase I trial of docetaxel with estramustine in androgen-independent prostate cancer

PURPOSE

To evaluate the toxicity, efficacy, and pharmacokinetics of docetaxel when combined with oral estramustine and dexamethasone in a phase I study in patients with progressive metastatic androgen-independent prostate cancer.

PATIENTS AND METHODS

Thirty-four men were stratified into minimally pretreated (MPT) and extensively pretreated (EPT) groups. Estramustine 280 mg PO tid was administered 1 hour before or 2 hours after meals on days 1 through 5, with escalated doses of docetaxel from 40 to 80 mg/m2 on day 2. Treatment was repeated every 21 days.

RESULTS

Thirty-four patients were assessable for toxicity and 33 for response. In the MPT patients, dose-limiting myelosuppression was reached at 80 mg/m2, with six patients experiencing grade 3/4 granulocytopenia. In EPT patients, escalation above 70 mg/m2 was not attempted. Fourteen MPT (70%) and six EPT (50%) patients had a > or = 50% decline in serum PSA on two consecutive measurements taken at least 2 weeks apart. The overall 50% PSA response rate was 63% (95% confidence interval [CI], 28% to 81%). Of the 18 patients with bidimensionally measurable disease, five (28%; 95% CI, 11% to 54%) achieved a partial response. At the time of entry onto the study, 15 patients required narcotic analgesics for bone pain; after treatment, eight (53%) discontinued their pain medications. The area under the curve for docetaxel increased linearly from 40 to 70 mg/m2. At 80 mg/m2, the measured area under the curve was 8.37 (standard deviation, 0.724), which was significantly higher than the previously reported values.

CONCLUSION

The recommended phase II dose of docetaxel combined with estramustine is 70 mg/m2 in MPT patients and 60 mg/m2 in EPT patients. This combination is active in men with androgen-independent prostate cancer.

Inhibition of Na,K-ATPase by cadmium: different mechanisms in different species

The mechanism of action of Cd on Na,K-ATPase was investigated in two "classical" model systems, the shark rectal gland and rabbit kidney outer medulla. In lyophilized plasma membranes from dogfish rectal gland Cd inhibited Na,K-ATPase activity after 30 min of preincubation with an I50 of 1.3 x 10(-5) M. K-Dependent p-nitrophenylphosphatase (pNPPase) activity was inhibited 50% by Cd at 9.4 x 10(-6) M. Neither Na nor K altered the interaction of the enzyme with Cd. Decreasing the ATP concentration, however, lowered the apparent sensitivity of Na,K-ATPase to Cd. The inhibitory effect was also significantly reduced when the Mg concentration present during the preincubation was increased from 0.5 to 6.0 mM. The apparent Cd sensitivity of the K-dependent pNPPase is lower at 10 mM Mg than at 1 mM Mg. In initial rate experiments 4 x 10(-5) M Cd increased the apparent Km of the enzyme for Mg significantly from 0.88 +/- 0.29 mM to 1.73 +/- 0.3 mM whereas the Vmax (167 +/- 32 mumol/min x mg protein compared to 140 +/- 16 mumol/min x mg protein) remained essentially unchanged. In lyophilized rabbit kidney outer medulla, Cd was found to inhibit Na,K-ATPase activity with an I50 of 1.9 x 10(-5) M. K-Dependent pNPPase was inhibited 50% under identical conditions by Cd at a nominal concentration of 2.1 x 10(-4) M. Increasing K concentrations protected the enzyme from the inhibitory action of Cd as indicated by a 10-fold decrease in sensitivity of pNPPase when the K concentration was increased from 1 to 20 mM. K, 20 mM, delayed also the onset of inhibition by about 15 min at 37 degrees C. These studies suggest that the mode of action of Cd on Na,K-ATPase varies in different species. In rectal gland Cd competes with a Mg site (or sites) critically involved in ATP and pNPP hydrolysis, whereas in rabbit renal medulla Cd interacts with a potassium-binding site. Differences in the protein sequence, protein conformation, and/or in the kind of protein membrane-lipid interaction might contribute to this diversity observed in the inhibitory mechanisms.