Acute respiratory distress syndrome in poor prognostic germ cell tumor with multiple lung metastases: a case report

We report a case which is unique as this patient was diagnosed pathologically as adenocarcinoma of the endometrium but clinically progressed as germ cell tumor. This was evident by progressive and rapid raised tumor markers (BHCG & LDH) with the development of multiple bilateral lung metastases. She was treated by administrating low doses of systemic combination chemotherapy as per the literature. Unfortunately, she developed acute respiratory distress syndrome as the complication of treatment and died due to it.

Drug delivery to the spinal cord tagged with nanowire enhances neuroprotective efficacy and functional recovery following trauma to the rat spinal cord

The possibility that drugs attached to innocuous nanowires enhance their delivery within the central nervous system (CNS) and thereby increase their therapeutic efficacy was examined in a rat model of spinal cord injury (SCI). Three compounds--AP173 (SCI-1), AP713 (SCI-2), and AP364 (SCI-5) (Acure Pharma, Uppsala, Sweden)--were tagged with TiO(2)-based nanowires using standard procedure. Normal compounds were used for comparison. SCI was produced by making a longitudinal incision into the right dorsal horn of the T10-T11 segments under Equithesin anesthesia. The compounds, either alone or tagged with nanowires, were applied topically within 5 to 10 min after SCI. In these rats, behavioral outcome, blood-spinal cord barrier (BSCB) permeability, edema formation, and cell injury were examined at 5 h after injury. Topical application of normal compounds in high quantity (10 microg in 20 microL) attenuated behavioral dysfunction (3 h after trauma), edema formation, and cell injury, as well as reducing BSCB permeability to Evans blue albumin and (131)I. These beneficial effects are most pronounced with AP713 (SCI-2) treatment. Interestingly, when these compounds were administered in identical conditions after tagging with nanowires, their beneficial effects on functional recovery and spinal cord pathology were further enhanced. However, topical administration of nanowires alone did not influence trauma-induced spinal cord pathology or motor functions. Taken together, our results, probably for the first time, indicate that drug delivery and therapeutic efficacy are enhanced when the compounds are administered with nanowires.

Antibodies to serotonin attenuate closed head injury induced blood brain barrier disruption and brain pathology

Closed head injury (CHI) often results in profound brain swelling and instant death of the victims due to compression of the vital centers. However, the neurochemical basis of edema formation in CHI is still obscure. Previous studies from our laboratory show that blockade of serotonin synthesis prior to CHI in a rat model attenuates brain edema, indicating a prominent role for serotonin in head injury. Thus, neutralization of endogenous serotonin activity and/or blocking of its receptors will induce neuroprotection in CHI. Since serotonin has more than 14 receptors and selective serotonin antagonists are still not available, we used serotonin antiserum to neutralize its in vivo effects before or after CHI in a rat model. CHI was produced by an impact of 0.224 N on the right parietal skull bone under Equithesin anesthesia by dropping a weight of 114.6 g from a height of 20 cm through a guide tube. This concussive brain injury resulted in blood-brain barrier (BBB) disruption, brain edema formation, and volume swelling at 5 h that were most pronounced in the contralateral cerebral hemisphere. The plasma and brain serotonin levels were increased several-fold at this time. Intracerebroventricular administration of serotonin antiserum (1:20, monoclonal) into the left lateral cerebral ventricle (30 microL in PBS) 30 min before or 30 min (but not 60 min) after CHI significantly attenuated BBB disruption, brain edema formation, volume swelling, and brain pathology. The plasma and brain serotonin levels continued to remain high. These observations are the first to suggest that antiserum to serotonin when administered into the CSF during the early phase of CHI are capable of inducing neuroprotection.

Histamine receptors influence blood-spinal cord barrier permeability, edema formation, and spinal cord blood flow following trauma to the rat spinal cord

The role of histamine in edema formation, blood-spinal cord barrier (BSCB) permeability, and spinal cord blood flow (SCBF) following spinal cord injury (SCI) was examined using modulation of histamine H1, H2, and H3 receptors in the rat. Focal trauma to the spinal cord at the T10-11 level significantly increased spinal cord edema formation, BSCB permeability to protein tracers and SCBF reduction in the T9 and T12 segments. Pretreatment with histamine H1 receptor antagonist mepyramine (1 mg, 5 mg, and 10 mg/kg, i.p.) did not attenuate spinal pathophysiology following SCI. Blockade of histamine H2 receptors with cimetidine or ranitidine (1 mg, 5 mg, or 10 mg/kg 30 minutes before injury) significantly reduced early pathophysiological events in a dose dependent manner. The effects of ranitidine were far superior to cimetidine in identical doses. Pretreatment with a histamine H3 receptor agonist alpha-methylhistamine (1 mg and 2 mg/kg/i.p.), that inhibits histamine synthesis and release in the CNS, thwarted edema formation, BSCB breakdown, and SCBF disturbances after SCI. The lowest dose of histamine H3 agonist was most effective. Blockade of histamine H3 receptors with thioperamide (1 mg, 5 mg/kg, i.p.) exacerbated spinal cord pathology. These observations suggest that stimulation of histamine H3 receptors and blockade of histamine H2 receptors is neuroprotective in SCI.

Recurrent epithelial ovarian cancer (EOC): What determines the outcome?

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Background: Recurrent EOC is a common clinical problem and treatment is not curative. We retrospectively analyzed the data on 354 patients with recurrent EOC to determine the impact of various prognostic factors on outcome. Methods: Between August, 1989 and June, 2005, 354 patients (median age 49 years, range, 28 to 80 years) were diagnosed as recurrent EOC. 259 patients received chemotherapy alone, 44 were treated with combination of secondary debulking surgery and chemotherapy or radiotherapy. Remaining 51 (14.4%) patients had no treatment. Main types of salvage chemotherapy included- cisplatin + cyclophosphamide (CP, n = 53), CP + adriamycin (CAP, n = 68), paclitaxel + carboplatin/cisplatin (TP, n = 78). 10 factors were analyzed for survival. Results: 56.5% of patients responded to chemotherapy; complete (CR)-34.2% and partial response (PR) in 22.3% of patients. 124 (35%) patients had no response or progressive disease. 10 (2.8%) died of chemo-toxicity and in remaining 20 status was not known. Median overall survival for patients who received treatment is 19 months vs 3 months for 51 patients who did not receive treatment, p < .001. Predictors of survival were - response to salvage chemotherapy (20 vs 8 months, p < .001), treatment-free interval (>6 months vs ≤ 6 months, 23 vs 9 months p < .001), site of relapse (single vs multiple, 22 vs 16 months, p < .001), Chemotherapy regimen (CP vs CAP vs Paclitaxel + carboplatin) p < .003 on univariate analysis. Age (≤50 years vs >50 years, p = 0.02), initial stage (I vs II vs III vs IV, p = 0.079), histology (serous vs others, p = 0.849), site of relapse (vault vs others, p = 0.156) were not significant predictors. On multivariate logistic regression analysis- response to salvage chemotherapy (HR 0.21, 95% CI 0.15–0.30), treatment-free interval (HR 0.36, 95% CI, 0.20–0.64), and site of relapse (vault vs others, HR 1.22, 95% CI 0.78–1.94) attained significance among 10 factors analyzed. Conclusions: Present study confirms that all patients with recurrent EOC should receive treatment. Response to salvage chemotherapy, a longer treatment-free interval (>6 months) and single site of metastasis are predictors of significantly superior outcome.

No significant financial relationships to disclose.

Maintenance therapy in epithelial ovarian cancer (EOC): Could EGFR inhibitor- gefitinib be a candidate drug? A pilot study

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Background: We aimed to evaluate the role of EGFR inhibitor, gefitinib among patients with advanced & recurrent EOC to prolong progression-free survival (PFS). Methods: Between Nov. 2004 and Dec. 2005, 32 patients (median age 45 years, range 33 to 63) have been recruited. The study subjects were - (i) eleven patients with EOC stage IIIC-IV who had gross residual disease (≥1 cm) after primary debulking surgery and had achieved complete response (CR) following six cycles of paclitaxel and carboplatin (Group-I) (ii) Group II - includes 21 patients who achieved CR following salvage chemotherapy for relapsed EOC (1st relapse- 8, 2nd- 8, 3rd -3 & 4th relapse in 2 patients). All Patients received gefitinib 250 mg once daily till evidence of relapse. Patients were examined every month and toxicity (CTC version II) was recorded. Serum CA-125 was done once in 2 months and CAT scan of abdomen & pelvis at 6 monthly interval. The study was approved by Institute Ethics Committee and informed written consent was obtained from each patient before starting Gefitinib. Results: The mean duration of treatment is -5.6 months (Gp-I: 7.7 months, Gp-II: 4.5 months). Toxicity was mild, mainly in the form of skin rash & diarrhoea. Skin rash occurred in 10 patients (31.3%); Group I - 8 patients (grade IV-2, III-2, I-4) & in 2 patients in group II (grade III-1, II-1). Diarrhoea occurred in 7 patients (22%); Group I-1, group II-6) all grade I. No pulmonary or hematological toxicity was observed. Currently, 18/32 patients are on Gefitinib (mean duration of treatment 6.1 months); in 12 patients gefitinib has been discontinued due to relapse (group I- 4, Group II-10). Among 10 patients with skin toxicity (Gp I-8, Gp II-2), 6 continue to be disease-free (Group I- 5, Group II-1) compared to 12 of 22 without skin toxicity. Conclusions: Toxicity to gefitinib was mild, and limited to skin and GIT. Correlation between EGFR expression vs. response can help in identifying patients who possibly might benefit with gefitinib therapy.

No significant financial relationships to disclose.

Zinc protoporphyrin IX attenuates closed head injury-induced edema formation, blood-brain barrier disruption, and serotonin levels in the rat

The role of heme oxygenase (HO) in closed head injury (CHI) was examined using a potent HO and guanylyl cyclase inhibitor, zinc protoporphyrin (Zn-PP) in the rat. Blood-brain barrier (BBB) permeability to Evans blue and radioiodine, edema formation, and plasma and brain levels of serotonin were measured in control, CHI, and Zn-PP-treated CHI rats. CHI was produced by an impact of 0.224 N on the right parietal bone by dropping 114.6 g weight from a height of 20 cm in anesthetized rats. This concussive injury resulted in edema formation and brain swelling 5 hours after insult that was most pronounced in the contralateral hemisphere. The whole brain was edematous and remained in a semi-fluid state. Microvascular permeability disturbances to protein tracers were prominent in both cerebral hemispheres and the underlying cerebral structures. Plasma and brain serotonin showed pronounced increases and correlated with edema formation. Pretreatment with Zn-PP (10 mg/ kg, i.p) 30 minutes before or after CHI attenuated edema formation, brain swelling, plasma and brain serotonin levels, and microvascular permeability at 5 hours. Brain edema, BBB permeability, and serotonin levels were not attenuated when the compound was administered 60 minutes post-CHI suggesting that HO is involved in cellular and molecular mechanisms of edema formation and BBB breakdown early after CHI.

Bioavailability and bioequivalence: an FDA regulatory overview

Bioavailability and/or bioequivalence studies play a key role in the drug development period for both new drug products and their generic equivalents. For both, these studies are also important in the postapproval period in the presence of certain manufacturing changes. Like many regulatory studies, the assessment of bioavailability and bioequivalence can generally be achieved by considering the following three questions. What is the primary question of the study? What are the tests that can be used to address the question? What degree of confidence is needed for the test outcome? This article reviews the regulatory science of bioavailability and bioequivalence and provides FDA's recommendations for drug sponsors who intend to establish bioavailability and/or demonstrate bioequivalence for their pharmaceutical products during the developmental process or after approval.

Blockade of histamine H2 receptors attenuate blood-brain barrier permeability, cerebral blood flow disturbances, edema formation and cell reactions following hyperthermic brain injury in the rat

Role of histamine H2 receptors in blood-brain barrier (BBB) disturbances, cerebral blood flow (CBF), brain edema formation, and cell injury caused by heat stress in a rat model was examined using the pharmacological approach. Blockade of histamine H2 receptors by cimetidine or ranitidine significantly attenuated the BBB permeability to Evans blue albumin and [131]I-sodium extravasation, brain edema formation and cell injury following 4 h heat stress in rats at 38 degrees C. These drug treatments also restored the CBF to near normal values. These beneficial effects in heat stress were most marked in rats treated with ranitidine compared to cimetidine given in identical dosage. Our observations suggest that blockade of histamine H2 receptor is beneficial in hyperthermic brain injury and indicates that histamine is involved in the pathophysiology of heat stress induced brain dysfunction. Our study strongly suggests further need to develop more specific and sensitive histaminergic H2 receptor blockers for the treatment of neurological ailments.

An individual bioequivalence criterion: regulatory considerations

Over the years, concerns have been raised regarding the appropriateness of using the average bioequivalence approach for evaluation of comparability between formulations. In lieu of average bioequivalence, scientists from academia, industry and regulatory agencies have spent considerable effort and time in exploring the concepts of population and individual bioequivalence, and developing the statistical methods to assess the bioavailability metrics using these approaches. Recently, the Food and Drug Administration (FDA) has published a preliminary draft guidance entitled 'In vivo bioequivalence studies based on population and individual bioequivalence approaches'. The concept of prescribability and switchability underscores the difference between the population and individual bioequivalence approaches. The most important consideration for individual bioequivalence, the focus of this paper, rests on the assurance that products deemed bioequivalent can be used interchangeably in the target population (switchability). In addition to the comparison of averages, the individual bioequivalence approach compares within-subject variabilities and assesses subject-by-formulation interaction. The proposed criterion represents substantial departure from the current practice and thus has resulted in extensive public discussion. In contrast to the current average bioequivalence procedure, the proposed individual bioequivalence approach offers flexible equivalence criteria based on the individual therapeutic window and variability of the reference drug product. The proposed criterion rewards manufacture of less variable drug products, allows scaling criteria for highly variable/narrow therapeutic range drugs, and promotes the use of subjects from the general population in bioequivalence studies. The FDA is currently considering various approaches for resolution of issues raised from the public debate on the subject-by-formulation interaction term, statistical methods and resource implications.

An individual bioequivalence criterion: regulatory considerations

Over the years, concerns have been raised regarding the appropriateness of using the average bioequivalence approach for evaluation of comparability between formulations. In lieu of average bioequivalence, scientists from academia, industry and regulatory agencies have spent considerable effort and time in exploring the concepts of population and individual bioequivalence, and developing the statistical methods to assess the bioavailability metrics using these approaches. Recently, the Food and Drug Administration (FDA) has published a preliminary draft guidance entitled 'In vivo bioequivalence studies based on population and individual bioequivalence approaches'. The concept of prescribability and switchability underscores the difference between the population and individual bioequivalence approaches. The most important consideration for individual bioequivalence, the focus of this paper, rests on the assurance that products deemed bioequivalent can be used interchangeably in the target population (switchability). In addition to the comparison of averages, the individual bioequivalence approach compares within-subject variabilities and assesses subject-by-formulation interaction. The proposed criterion represents substantial departure from the current practice and thus has resulted in extensive public discussion. In contrast to the current average bioequivalence procedure, the proposed individual bioequivalence approach offers flexible equivalence criteria based on the individual therapeutic window and variability of the reference drug product. The proposed criterion rewards manufacture of less variable drug products, allows scaling criteria for highly variable/narrow therapeutic range drugs, and promotes the use of subjects from the general population in bioequivalence studies. The FDA is currently considering various approaches for resolution of issues raised from the public debate on the subject-by-formulation interaction term, statistical methods and resource implications.

Subject-by-formulation interaction in bioequivalence: conceptual and statistical issues. FDA Population/Individual Bioequivalence Working Group. Food and Drug Administration

PURPOSE

The FDA has proposed replacing the current average bioequivalence criterion with population and individual bioequivalence criteria that consider variances in addition to the difference of averages. One of these variances in the individual bioequivalence criterion measures subject-by-formulation interaction, the extent to which the test-reference difference varies from person to person. This paper discusses conceptual and statistical issues raised in various publications and presentations with respect to the presence and estimation of such an interaction.

METHODS

We focus on the importance of subject-by-formulation interaction, an understanding of what is a large interaction, and the assessment of the magnitude of this interaction in bioequivalence studies. Simulation studies, examples from the literature, and data from FDA files are used to demonstrate the magnitude of the interaction and its distribution under various conditions.

RESULTS

The concept of a large interaction is tied to the concept of a large mean difference. We suggest that an interaction greater than 0.15 is a conservative criterion for a large interaction. Magnitudes of estimated interaction are affected by variability, sample size, and the selection of data sets that pass average bioequivalence.

CONCLUSIONS

Examples of substantial interactions are beginning to appear. More data is needed before reaching definitive conclusions regarding the frequency and importance of observed interactions.

Bioequivalence of methylphenidate immediate-release tablets using a replicated study design to characterize intrasubject variability

PURPOSE

To determine the relative bioavailability of two marketed, immediate-release methylphenidate tablets. The study used a replicated study design to characterize intrasubject variability, and determine bioequivalence using both average and individual bioequivalence criteria.

METHODS

A replicated crossover design was employed using 20 subjects. Each subject received a single 20 mg dose of the reference tablet on two occasions and two doses of the test tablet on two occasions. Blood samples were obtained for 10 hr after dosing, and plasma was assayed for methylphenidate by GC/MS.

RESULTS

The test product was more rapidly dissolved in vitro and more rapidly absorbed in vivo than the reference product. The mean Cmax and AUC(0-infinity) differed by 11% and 9%, respectively. Using an average bioequivalence criterion, the 90% confidence limits for the Ln-transformed Cmax and AUC(0-infinity), comparing the two replicates of the test to the reference product, fell within the acceptable range of 80-125%. Using an individual bioequivalence criterion the test product failed to demonstrate equivalence in Cmax to the reference product.

CONCLUSIONS

The test and reference tablets were bioequivalent using an average bioequivalence criterion. The intrasubject variability of the generic product was greater and the subject-by-formulation interaction variance was borderline high. For these reasons, the test tablets were not individually bioequivalent to the reference tablets.

E. coli-based in vitro transcription/translation: in vivo-specific synthesis rates and high yields in a batch system

A highly efficient Escherichia coli-based, batch in vitro protein synthesis system using circular plasmid DNA is described. Compared to a presently available commercial kit, this improved system produced several hundredfold greater yields of the rDNA human protein thrombopoietin (ca. 450 micrograms/mL). The system is capable of obtaining specific synthesis rates similar to those in vivo, approximately a 1000-fold increase compared to the original methods previously described. It compares favorably in rates and yields to the recently published semicontinuous methods but with the convenience of a true batch system.

Mean difference vs. variability reduction: tradeoffs in aggregate measures for individual bioequivalence. FDA Individual Bioequivalence Working Group

Aggregate criteria for individual bioequivalence allow a tradeoff between difference in average bioavailability and reduction in within-subject variability. That is, a large difference in the average bioavailability between a test and a reference formulation can be offset by a sufficient reduction in variability of the test formulation. This offset could allow the test formulation to pass many individual bioequivalence criteria. We have identified 4 possible approaches for dealing with this tradeoff issue: say "No problem," since a reduction in variability is desirable; use disaggregate criteria; use general weighted forms of the individual bioequivalence criteria that weight the variance terms; and change the acceptable upper limits to reduce the impact of scaling to the reference formulation's within-subject variability. A dataset with a 14% increase in average bioavailability and a 48% reduction in within-subject standard deviation is used as an example of these issues.

Fluticasone propionate (0.05%) cream compared to betamethasone valerate (0.12%) cream in the treatment of steroid-responsive dermatoses: a multicentric study

Fluticasone propionate is a new topical steroid developed as a result of modification of the 19-carbon androstane structure. In the present study, efficacy of this steroid was compared with betamethasone valerate cream in patients with psoriasis and eczema. Though fluticasone propionate was marginally more effective than betamethasone valerate, this difference was not statistically significant.

House mouse ancestor from late Pliocene Siwalik sediments of India

A well preserved mouse skull has been recovered from a pedogenically modified mudstone layer (c. 2 millions years (MY) old) of Pinjor Formation (Upper Siwaliks) exposed east of Chandigarh, India. Comparison of the present skull with those of the extant species of the subgenus Mus reveals its closer relationship towards the house mouse Mus musculus lineage. The present fossil evidence is very much in line with the molecular, allozymic and ecological proposals for the time and place of origin of the subgenus Mus.