Pharmacokinetics and tissue distribution of florfenicol and florfenicol amine in snubnose pompano (Trachinotus blochii) following oral administration.

The present study reports the comparative pharmacokinetic profiles of florfenicol and its metabolite (florfenicol amine, FFA) in Trachinotus blochii under tropical marine conditions (salinity: 35 ± 1.4‰; temperature: 28.8 ± 0.54 °C) following a single in-feed oral administration of the recommended dose (15 mg/Kg). Furthermore, the study investigated the distribution of these two compounds in nine different tissues. The maximum florfenicol concentrations (Cmax) in plasma and tissues were observed within five hours (Tmax), except for bile. The Cmax ranged from 572 to 1954 ng/g or ml and was in the intestine > bile > muscle + skin > liver > gill = heart > plasma > kidney = spleen. The elimination half-life of FFC was significantly slower in the bile (38.25 ± 4.46 h). The AUC tissue/plasma was highest for bile (3.77 ± 0.22), followed by intestine > muscle + skin > heart > liver > kidney = gill = spleen. Tmax and t1/2ß were slower, and Cmax was lower for FFA than florfenicol in all tissues except Cmax of the kidney and bile. FFA t1/2ß was exceptionally slower in the kidney (46.01 ± 8.2 h). Interestingly, reaching an apparent distribution rate of > 0.5 was comparatively faster in the kidney, liver, and gills than in other tissues. The highest apparent metabolic rate was in the kidney (0.95 ± 0.01) and the lowest in plasma (0.41 ± 0.01). The generated data can be applied for formulating efficient therapeutic protocols in T. blochii, a promising mariculture species.

Microbial community composition associated with early developmental stages of the Indian white shrimp, Penaeus indicus.

Gut microbiota is known to influence the physiology, health, nutrient absorption, reproduction, and other metabolic activities of aquatic organisms. Microbial composition can influence intestinal immunity and are considered as health indicators. Information on gut microbial composition provides potential application possibilities to improve shrimp health and production. In the absence of such information for Penaeus indicus, the present study reports the microbial community structure associated with its early developmental stages. Bacterial community associated with the early developmental stages (egg, nauplii, zoea, mysis, PL1, PL6 and PL12) from two hatchery cycles were analysed employing 16S rRNA high throughput sequencing. Proteobacteria and Bacteroidetes, were the two dominant phyla in P. indicus development stages. Sequential sampling revealed the constant change in the bacterial composition at genus level. Alteromonas was dominant in egg and nauplii stage, whilst Ascidiaceihabitans (formerly Roseobacter) was the dominant genera in both PL6 and PL12. The bacterial composition was highly dynamic in early stages and our study suggests that the mysis stage is the critical phase in transforming the microbial composition and it gets stabilised by early post larval stages. This is the first report on the composition of microbiota in early developmental stages of P. indicus. Based on these results the formation of microbial composition seems to be influenced by feeding at early stages. The study provides valuable information to device intervention strategies for healthy seed production.

Abundance, community structure and diversity of nitrifying bacterial enrichments from low and high saline brackishwater environments.

The study reports diversity in nitrifying microbial enrichments from low (0·5-5‰) and high (18-35‰) saline ecosystems. Microbial community profiling of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) enrichments was analysed by sequencing 16S rRNA and was processed using Mothur pipeline. The α-diversity indices showed the richness of nitrifying bacterial consortia from the high saline environment and were clustering based on the source of the sample. AOB and NOB enrichments from both the environments showed diverse lineages of phyla distributed in both groups with 38 and 34 phyla from low saline and 53 and 40 phyla in high saline sources, respectively. At class level, α- and γ-proteobacteria were found to be more dominant in both the enrichments. AOBs and NOBs in enrichments from low saline environments were dominated by Nitrosomonadaceae, Gallionellaceae (Nitrotoga sp.) and Ectothiorhodospiraceae and Nitrospira, respectively. Though Chromatiaceae were present in both AOB and NOB enrichments, Nitrosoglobus and Nitrosococcus dominated the AOBs while NOBs were dominated by uncultured genera, whereas Rhizobiales were found in both the enrichments. AOBs and NOBs in enrichments from high saline environments were dominated by Nitrospira-like AOBs, Nitrosomonas and Nitrosococcus genera, whereas ammonia-oxidizing archaea (AOA) group included Nitrosopumilus and Nitrososphaera genera comprising and Nitrospirae, respectively. The majority of the genera obtained in both the salinities were found to be either uncultured or unclassified groups. Results of the study suggest that the AOB and NOB consortia have unique and diverse microbes in each of the enrichments, capable of functioning in aquaculture systems practised at different salinities (0-60 ppt).

Prospective impact of Corona virus disease (COVID-19) related lockdown on shrimp aquaculture sector in India - a sectoral assessment.

The lockdown on account of the Coronavirus disease 2019 (COVID-19) adversely impacted the food production sector including aquaculture, globally. Unfortunately, it coincided with the major shrimp farming season in India which contributes 60% of the national annual shrimp production hence the impact was substantial. An on-line survey was carried out among the stakeholders of the shrimp farming sector to evaluate the prospective impact of COVID-19 related lockdown across the shrimp supply chain. The study estimated an economic loss of 1.50 billion USD to the shrimp aquaculture sector during the current year. It is expected that shrimp production and its export performance may be declining by 40% in the current season. The Garret ranking and Rank Based Quotient analyses projected severe constraints in shrimp seed production and supply, disruptions in the supply chain, logistics, farming, processing, marketing and loss of employment and income for the workers due to the pandemic. To mitigate the impact, the Government of India declared fisheries and aquaculture as an essential activity, facilitated the movement of inputs and services. Further, a major Fisheries Development Scheme(PMMSY) with a financial outlay of 267 million USD has been announced to usher in a blue revolution by strengthening the value chain, doubling the fisher/farmer income, employment generation, economic and social security for fishers/fish farmers adhering to the sustainability principles. Short and medium-term technical and policy measures are suggested to tide over the impact of COVID-19 related lockdown and related restrictions.

Effect of orally administered vibrio bacterin on immunity, survival and growth in tiger shrimp (Penaeus monodon) grow-out culture ponds.

Vibriosis is one of the important diseases causing economic loss to the shrimp industry worldwide. The present study reports field observations on the immune stimulatory effect of vibrio bacterin in commercial tiger shrimp (Penaeus monodon) grow-out culture ponds (n = 62) which were grouped under three stocking densities; low (6-8 nos per m2 ), medium (9-11 nos per m2 ) and high (12-14 nos per m2 ). The bacterin was administered in feed as a top dressing at final concentration equivalent to 2 × 108 CFU per kilogram feed twice a week throughout the culture period. In 20 representative ponds, total haemocyte count and prophenoloxidase activity in shrimp were significantly (P < 0·05) higher and anatomical deformities like, antennae cut (5·02 ± 2·42), tail rot (5·10 ± 1·74), rostrum cut (4·49 ± 2·19) and soft shell (10·05 ± 5·77) were significantly lower compared to controls in all the studied stocking densities. Significant (P < 0·05) improvement in production parameters like survival and production (kg ha1 ) was observed in all treatment ponds while similar improvement in average daily gain and feed conversion ratio could be observed in groups with low and medium stocking densities. Results of the study suggest that, oral administration of vibrio bacterin improves the immunity, reduces anatomical deformities and enhances the production in commercial shrimp culture operations. SIGNIFICANCE AND IMPACT OF THE STUDY: Administration of vibrio bacterin in feed as a top dressing induced immune stimulation as indicated by higher levels of total haemocyte count and prophenoloxidase. Further reduction in percentage of animals with anatomical deformities suggests the protection against subclinical bacterial infections. The overall improvement in the production parameters like, average daily gain, survival, feed conversation ratio and production in different shrimp stocking densities under commercial farming conditions suggested the possible development of an immune stimulant product based on the inactivated vibrio bacteria for improved health and production in Penaeus monodon shrimp farming.

Oral administration of formalin killed Vibrio anguillarum cells improves growth and protection against challenge with Vibrio harveyi in banana shrimp.

UNLABELLED: Larval rearing in hatcheries and highly intensive grow-out culture practices followed in shrimp production systems favour the growth of potential pathogenic bacterial loads. This study reports the efficacy of formalin-killed vibrio bacterin on growth, survival and protection to challenge with virulent Vibrio harveyi and Vibrio anguillarum in juveniles of banana shrimp Fenneropenaeus merguiensis. Postlarvae 15 (0·24 ± 0·01 g) were administered orally in different concentrations of bacterial preparation (0, 10(6) , 10(8) , 10(10) and 10(12 ) CFU kg(-1) feed) for a period of 6 weeks. Physicochemical and microbial quality of water in larval rearing tanks, and growth and survival of the postlarvae were monitored at regular intervals, and body composition was estimated at the end of the experiment. Shrimps were challenged with V. harveyi and V. anguillarum, and cumulative mortality was calculated. The group receiving 10(8)  CFU kg(-1) feed showed highest average weight gain (162·66 ± 22·94 mg) and survival (90·33 ± 4·5%) and lowest cumulative mortality following the challenge with V. anguillarum (26%) and V. harveyi (36·67%). The results of the study suggest that formalized vibrio administered orally to F. merguiensis postlarvae could induce both homologous and heterologous protection against V. anguillarum and V. harveyi. 'Vaccination' of shrimp postlarvae at hatcheries would help in preventing the losses due to vibriosis and the most susceptible stages of shrimp development. SIGNIFICANCE AND IMPACT OF THE STUDY: The study demonstrates the cross-protection offered by the oral feeding of formalin-killed Vibrio anguillarum against pathogenic V. harveyi challenge at the early developmental stages of banana shrimp, Fenneropenaeus merguiensis.

Molecular epidemiology of Mycobacterium avium subspecies paratuberculosis: IS900 PCR identification and IS1311 polymorphism analysis from ruminants in the Punjab region of India.

Johne's disease is chronic granulomatous infectious enteritis of animals caused by Mycobacterium avium subspecies paratuberculosis. A total of 153 animals from 19 dairy farms, 2 gaushalas (unproductive-animal rehabilitation centers), 2 goat and 2 sheep farms from different districts of the Punjab region were selected on the basis of clinical signs of disease. All samples from cattle (n=86), buffalo (n=34), goat (n=25) and sheep (n=26) were subjected to Ziehl-Neelsen staining and DNA extraction by a freeze and thaw method. Ziehl-Neelsen staining detected 71% samples positive for acid-fast bacilli whereas IS900 PCR detected 55% positive for Map DNA. IS1311 PCR-REA analysis of IS900 positive samples revealed 'Bison' type as the most prevalent (82%) genotype of Map, infecting all domestic ruminants. 'Cattle' type was present in a minority of cases (15%) from cattle, buffaloes and goats. This is the first report of 'Cattle' type Map from buffalo and goat species in India.

Molecular detection and typing of Mycobacterium avium subspecies paratuberculosis from milk samples of dairy animals.

Genotyping of Mycobacterium avium subspecies paratuberculosis (MAP) is important for precise classification of bacterium and for understanding the molecular epidemiology. The present study reports detection and typing of the MAP from milk. On the basis of clinical signs of diarrhea and/or weakness, the dairy animals suspected for Johne's disease were screened by Ziehl-Neelsen staining of fecal samples. The milk samples from 13 selected animals were processed for DNA extraction and direct IS900 polymerase chain reaction (PCR). MAP identified by IS900 PCR was genotyped using IS1311 PCR-restriction endonuclease analysis (REA). IS900 milk PCR revealed 30.8% animals positive for MAP, including 40% of the moderate and 50% of the heavy fecal shedders. All infected animals showed Bison type MAP in IS1311 PCR-REA. IS900 PCR can be used for screening of milk for MAP; however, the method needs to be evaluated for subclinical cases. IS1311 PCR-REA results indicated the predominance of Bison type MAP in the dairy animals of this region.

Sero-prevalence of bovine Johne's disease in buffaloes and cattle population of North India using indigenous ELISA kit based on native Mycobacterium avium subspecies paratuberculosis 'Bison type' genotype of goat origin.

Present pilot study is the first attempt in the country to estimate sero-prevalence of Bovine Johne's disease (BJD) by screening cattle and buffaloes representing large population belonging to farmer's and farm herds in the home tracts (Uttar Pradesh (UP) and Punjab) of Hariana cattle and Murrah buffaloes in North India. Indigenous and in-house plate ELISA kit (using protoplasmic antigen from native Mycobacterium avium subsp. paratuberculosis 'Bison type' strain of goat origin), originally developed for goats and sheep was standardized in bovines and used for screening. For this study, 33 villages of south and west UP were randomly selected and surveyed from 2001 to 2003. There were 7943 farmer's families having 38,251 livestock, including cattle, buffaloes, goats and sheep (per family 4.8% livestock). Numerically, buffaloes and cattle were 54.7% and 22.1%, respectively. Serum samples were collected from 726 animals (4.2% of 16, 981 livestock with 4375 farmer's families) located in 33 randomly surveyed villages. Serum samples (699), submitted to Epidemiology Department of Veterinary College (Punjab Agricultural University, Ludhiana), in the year 2004 by farmer's and organized farm herds (Buffaloes, 372, Cattle, 327), were screened by this ELISA kit. Soluble protoplasmic antigen was prepared from Map (S 5) 'Bison type' strain isolated from a terminally sick goat with Johne's disease. Of the total 1425 bovine (Buffaloes and cattle) serum samples screened using indigenous ELISA kit, sero-prevalence of Johne's disease was 29.0% (28.6% in buffalo and 29.8% in cattle) in Northern India. State-wise sero-prevalence was 31.9% and 23.3% in UP and Punjab, respectively. In UP, of the 601 randomly sampled buffaloes, sero-prevalence was 40.3% (16.6% in young and 40.9% adults) and 25.5% (10.5% in young and 26.3% adults) in south and west UP, respectively. Of the 125 cattle screened, sero-prevalence was 42.6% (nil in young and 44.4% adults) and 30.0% (nil in young and 30.6% adults) in south and west UP, respectively. Of the 699 serum samples screened from Ludhiana, Punjab, sero-prevalence of BJD was 23.0%. Sero-prevalence was 23.3% (12.1% in young and 24.4% in adults) and 26.9% (27.2% in young and 26.8% in adults) in buffaloes and cattle, respectively. High prevalence of BJD in buffaloes in native tract of Murrah breed, and Hariana breed of cattle correlated with poor per-animal productivity and BJD may be the major cause. Indigenous ELISA kit was rapid, economic and sensitive test for large-scale screening of buffaloes and cattle population against incurable BJD.

Immune responses of goats against foot-and-mouth disease quadrivalent vaccine: comparison of double oil emulsion and aluminium hydroxide gel vaccines in eliciting immunity.

The epidemiological role of small ruminants in foot-and-mouth disease (FMD) outbreaks has been generally neglected. Although, the disease in these species is sub-clinical in nature, their role as virus carriers represents a reservoir for further infection and spread of disease. Data on the usefulness of polyvalent FMD vaccine (FMDV) in goats is scant. Thus, the present study was undertaken to evaluate the benefits of a highly potent polyvalent FMDV in goats. In the present investigations, FMDV quadrivalent double oil emulsion (Montanide ISA 206) vaccines were tested in goats at reduced doses of 2 ml per animal (antigen payload 3.5 microg per serotype per dose). The oil adjuvant elicited superior immune response at any given period than aluminium hydroxide gel (AGS) vaccine and the rapidity of development of response was quicker. The duration of immunity also appeared to be maintained for long period. The differences in immune response between two adjuvant groups were statistically significant (P<0.05). The differences were apparent even in kinetics of immune response. Unlike cattle, goats were found to be late responders for oil-adjuvanted vaccine. Our results indicate possible universal usage of double oil emulsion vaccines for disease control programs irrespective of species of animals.

Early antibody responses of cattle for foot-and-mouth disease quadrivalent double oil emulsion vaccine.

Foot-and-mouth disease (FMD) is an economically important disease of cloven-hoofed animals. The multiplicity of FMDV serotypes in animals poses a central problem in the policy of vaccination and is of much concern to health authorities. Hence it is the practice of vaccination with polyvalent vaccine for prophylactic measure. In the present report, we analysed the early antibody responses elicited by FMDV quadrivalent (FMDV O, A, C and Asia 1 serotypes) double emulsion (Montanide ISA 206) vaccines in cattle. We observed variations between various viral serotypes in eliciting early antibody response although neutralizing antibody response against all the four serotypes were detected as early as fourth day following vaccination. The duration of immunity also appeared to maintain for long period. The neutralizing antibody titres were maintained well above 2log(10) even after 6 months of vaccination irrespective of serotypes. Thus, allows the possibilities of two vaccinations per year for the maintenance of herd immunity.

Integrity of GH-loop of foot-and-mouth disease virus during virus inactivation: detection by epitope specific antibodies.

Vaccine against foot-and-mouth disease (FMD) is prepared after inactivating the virus produced in cell culture. Inactivation of the FMD virus (FMDV) was earlier done by formaline. However, several vaccine outbreaks, which occurred in Europe revealed that the formaline treatment is not highly effective for virus inactivation. Subsequently, binary ethyleneimine (BEI) was identified as an effective inactivation reagent for FMDV. However, these chemical reagents are likely to have effect on whole virus particle whose integrity is essential for vaccine potency. Therefore, a need is felt to develop non-chemical methods. We have studied induction of endonucleolytic activity as an alternative method for virus inactivation. This method of inactivation was compared with the chemical methods, and found to be highly effective for virus inactivation. The effects of endonucleolytic activity on the integrity of virus capsid was studied using antibodies raised against recombinant proteins, which elicited antibodies against major epitopes present on the surface of the virus. Further, the effect of the agents on the integrity of the virus capsid was studied by using antigen capture PCR (Ag-RT/PCR) which detects the whole virus. The studies showed that inactivation of the virus by induction of endonucleolytic activity is more effective besides maintaining virus integrity. The effect of various inactivating agents on four serotypes of FMDV has also been studied and found to have varying effects, depending on serotype.

Protective immune response to 16 kDa immunoreactive recombinant protein encoding the C-terminal VP1 portion of Foot and Mouth Disease Virus type Asia 1.

Recombinant protein of Foot and Mouth Disease Virus (FMDV) type Asia 1 corresponding to the C-terminal half of VP1 was expressed in Escherichia coli. As an alternative to the synthetic peptide, this selected C-terminal region was used as a protein vaccine in guinea pigs in order to study the immune response with various adjuvant formulations: immune stimulatory complexes (ISCOMs), Montanide ISA 206, Freund's incomplete adjuvant (FIA), lipopolysaccharide (LPS) and cytokine mixture. A primary dose of 40 microg/animal followed by a booster of the same dose was injected after a 21-day interval. The sera were collected at intervals of 21, 42 and 63 days after the booster. The humoral response to vaccine was monitored by sandwich enzyme-linked immunosorbent assay (ELISA) and a serum neutralization test (SNT). The guinea pig sera showed high titers both in ELISA and SNT, which could be protective. Further, irrespective of the adjuvant preparation used, the vaccine conferred protection against the challenge virus 105 days post-vaccination in 13 of 15 animals (86%). The results indicated that a combination of recombinant protein ISCOMs and Montanide ISA 206 would be a better choice for achieving early protective titers and longer lasting immunity and that the C-terminal half of the VP1 protein may be tried as a safe vaccine for secondary immunization.

The quality of swallowing for patients with operable esophageal carcinoma: a randomized trial comparing surgery with radiotherapy.

BACKGROUND: Surgery is considered the standard treatment for operable esophageal carcinoma, although there is no compelling evidence that surgery can achieve better results than radiotherapy. There has previously been no direct randomized comparison of these two modalities with survival or disease specific outcome end points. METHODS: Ninety-nine patients with operable squamous cell carcinoma of the esophagus were randomly allocated to surgery or radiotherapy after stratification for tumor length (< or = or >5 cm). Those randomized to surgery underwent transthoracic esophagectomy with limited lymphadenectomy, whereas those in the radiotherapy arm received 50 gray in 28 fractions followed by a 15-gray boost to the primary tumor. Disease specific outcome was assessed for 4 subgroups: 1) disease specific symptoms, 2) physical symptoms, 3) ability to work, and 4) social/family interaction and global perception of disease specific outcome. The questionnaire was given prior to treatment and posttreatment at 3-month intervals for 1 year. Death was a secondary end point. RESULTS: There was an overall improvement in the quality of swallowing in both treatment arms after treatment and with the passage of time. The swallowing status was better in the surgery arm than in the radiotherapy arm at 6 months after treatment (P = 0.03, Fisher's exact test). Logistic regression analysis showed randomization arm (P = 0.035), time since treatment (P = 0.003), and pretreatment swallowing status to be significant determinants of posttreatment swallowing status. Surgery was twice as likely to result in improvement in swallowing than radiotherapy after correction for time and pretreatment swallowing status. Overall survival was better in the surgery arm than in the radiotherapy arm (P = 0.002, log rank test) (OR = 2.74 with 95% confidence intervals 1.51-4.98; P < 0.009, Cox proportional hazards model). CONCLUSIONS: Both surgery and radiotherapy can improve the quality of swallowing significantly for patients with operable esophageal carcinoma. Surgery is marginally superior to radiotherapy in improving the quality of swallowing. In this trial, survival in the surgery arm was significantly better than in the radiotherapy arm, although the small number of patients is a limitation.

Potency testing of tissue culture rinderpest vaccine in rabbits.

Rinderpest (RP) vaccine potency testing requires virulent bovine rinderpest virus (RPV). Use of virulent RPV is a biosafety hazard. In this study we had vaccinated rabbits with tissue culture RP vaccine at different doses and thereafter challenged with lapinized virus. No thermal reaction in vaccinated rabbits was observed. Serum neutralizing antibody response to vaccine was dose dependent until the second week post-vaccination but by the fourth week post-vaccination all the rabbits had similar neutralizing antibody titres. Vaccinated rabbits exhibited mild clinical signs as compared to unvaccinated controls after challenge. All the vaccinated rabbits survived challenge while only 40% unvaccinated rabbits survived challenge with virulent lapinized RPV. A strong anamnestic response in all the vaccinated rabbits was observed after challenge with lapinized virus. This study shows that rabbits could be used for potency testing of RP vaccine virus.

Historical control bias: adjuvant chemotherapy in esophageal cancer.

UNLABELLED: Conclusion based on historical controls are known to be fallible in assessing efficacy of treatment due to selection bias. Historical controls have been repeatedly used in investigating efficacy of newer treatment avenues in esophageal cancer. The aim of the study was to assess the efficacy of adjuvant chemotherapy in esophageal cancer after correction for an historical control bias. PATIENTS AND METHODS: The database of 433 patients treated surgically for cancer of the esophagus at our institute between 1980 and 1989 was analyzed. The analysis was carried out using the Cox model for known prognostic factors without any correction for historical bias. Database was reanalysed after introducing registration year as a variable in the model to correct for historical control bias, which was further examined by carrying out a case-control study comparing chemotherapy (n = 83) vs contemporary control (n = 164) matched for lymph-node status, age and sex randomly selected from the same database. RESULTS: The analysis without correction for historical control bias showed lymph-node metastasis (P = 0.000), female sex (P = 0.002), depth of invasion (P = 0.001) and adjuvant chemotherapy (P = 0.03) as significant predictors of survival. On introduction of registration year as a variable, lymph-node metastasis, sex and depth of invasion continued to be significant factors but chemotherapy was replaced by registration year (P = 0.02). The database with contemporary control showed lymph-node metastasis (P = 0.000), depth of invasion (P = 0.008) and female sex (P = 0.001) as significant factors. Chemotherapy had no effect on survival. CONCLUSION: Results from historical controls are unreliable in detecting modest treatment benefits. Adjuvant chemotherapy in esophageal cancer should be tested within the tenets of randomized controlled trials with adequate-sample size to ascertain its efficacy.

Intrathoracic anastomosis after oesophageal resection for cancer.

Cervical anastomosis has been advocated to avoid the pulmonary complications and life-threatening anastomotic disruptions following intrathoracic oesophagogastric anastomosis. This is a retrospective review of 111 oesophageal resections followed by an intrathoracic anastomosis. These resections were performed between September 1993 and August 1994 within a residency training program. The left thoracoabdominal approach was used for distal tumours and the Ivor Lewis technique for more proximal tumours. Squamous cell carcinoma accounted for 72% patients (n = 80), adenocarcinoma for 25% (n = 28), and others for 2.7% patients (n = 3). Of the patients, 69% had pathologic Stage III tumours. Operative mortality rate was 1.8% (two patients). Perioperative complications occurred in 39 patients, including anastomotic leak in 10 patients and myocardial infarction in 2 patients. In the absence of a leak, there were no major pulmonary complications requiring intensive care or ventilatory support. Of those patients with anastomotic disruption, 80% were salvaged by early clinical diagnosis and appropriate treatment. We conclude that transthoracic oesophagectomy with an intrathoracic anastomosis is a safe procedure that can be performed with low mortality and acceptable morbidity.

Chemotherapy for carcinoma of the esophagus: a comparison of evidence from meta-analyses of randomized trials and of historical control studies.

BACKGROUND: Chemotherapy (CT) has been used as an adjunct to local treatment (surgery or radiotherapy) in esophageal carcinoma. A meta-analysis of all published randomized clinical trials and historical control studies which have used cisplatinum-based combination CT was carried out to asses the effect of chemotherapy on survival for esophageal cancer. MATERIALS AND METHODS: A computer-based literature search was performed for the period from January 1988 to March 1995 using the index terms "Esophageal neoplasms' and "Chemotherapy'. The frame of reference was further narrowed to include only cisplatinum-based combination chemotherapy. Twelve randomized clinical trials (RCT) and eight historical control (HC) studies were included in the meta-analysis. RESULTS: In the overview of HC studies a highly significant reduction in odds of death with CT was observed (68% +/- 8% OR = 0.32, 95% CI 0.24-0.42). On the other hand, the overview of RCTs showed a relative reduction in odds of death for the CT group of 4.2% +/- 23.7% (OR = 0.96, 95% CI 0.75-1.22). CONCLUSIONS: There was a gross overestimation of treatment effect in the studies using HC as compared to RCTs, despite the use of cisplatinum-based chemotherapy in both groups. The meta-analysis of RCTs reveal no significant survival benefit from cisplatinum-based adjuvant/neoadjuvant chemotherapy in esophageal cancer.

Impact of age and sex on survival after curative resection for carcinoma of the esophagus.

BACKGROUND: The impact of age and sex-related changes in the endogenous hormonal milieu on survival after curative resection for esophageal epithelial cancer is explored. Adami et al. have suggested that the event of puberty has a favorable impact on survival after treatment of epithelial cancers. METHODS: The database consisted of 469 patients with esophageal cancer treated surgically with an intent to cure (without any gross residual disease at the end of the primary treatment) at Tata Memorial Hospital between 1980 and 1989. RESULTS: Life-stable analysis revealed a significantly better 5-year survival for women younger than 49 years (35%, CI 24-48) compared with men of the same age (16%, CI 8-27) (P < 0.008). There was no difference in survival between men (17%, CI 12-23) and women (26%, CI 16-37) older than 49 years (P = 0.08). A Cox proportional hazard model showed sex to be the second most significant determinant of survival (P = 0.002) after lymph node metastasis (P < 0.0001). CONCLUSION: The finding that the survival benefit is confined to women younger than 49 years is consistent with the hypothesis that the endocrine milieu in premenopausal women may prevent the establishment of micrometastases and thus improve the prognosis for esophageal epithelial cancer.

Cancer of the esophagus in young adults.

Clinicopathological features and survival data of squamous cell carcinoma of the esophagus were analyzed from the viewpoint of age differences in 453 patients treated at the Tata Memorial Hospital, Bombay, India. Two groups were studied: group A, aged 35 years or less; and group B, aged above 35 years. There was no significant difference among the two groups with regard to sex distribution, site and length of the tumor, operability, morphology, histological grade, vascular and lymphatic invasion, and lymph node metastasis. The primary lesion was more advanced and the rate of incomplete resections was higher in younger patients. The incidence of cardiopulmonary complications and postoperative deaths was significantly lower in younger patients. Recurrence of the disease following complete resection was more frequent in the younger age group (chi 2 = 2.61; P = .1063), although the pattern of recurrence remained the same in both groups. Disease-free survival in younger patients following complete resection of the tumor was poorer as compared to the older patients, but the difference is statistically not significant (chi 2 = 1.882; P = .1701). These findings suggest either a delayed diagnosis or a biologically sinister disease in the younger group; further studies of the two groups vis-a-vis their biologic parameters (DNA ploidy, etc.) are in progress and will form the subject of another communication.