The Fragility Index of randomized controlled trials in pediatric anesthesiology

PURPOSE

The P value is a widely used measure of statistical importance but has many drawbacks and limitations, one being that it does not reflect the robustness of the results of a clinical trial. The Fragility Index (FI) was developed as a measure of how many outcome events would need to change to nonevents to render a significant P value nonsignificant (P ≥ 0.05). The FI of trials from other medical specialties is typically < 5. We aimed to determine the FI of pediatric anesthesiology randomized controlled trials (RCT) and to test for association with various characteristics of the included trials.

METHODS

We conducted a comprehensive systematic search of high-impact anesthesia, surgical, and medical journals from the last 25 years for trials comparing an intervention between two groups with a statistically significant P value (< 0.05) for a dichotomous outcome. We also compared FI values for variables that reflect the quality and importance of a trial.

RESULTS

The median [interquartile range] FI was 3 [1-7] and correlated positively with the number of participants (rS = 0.41; P < 0.001) and events (rS = 0.42; P < 0.001), and negatively with the P value (rPB = -0.36; P < 0.001). Other measures of trial quality and impact or importance were not strongly associated with the FI.

CONCLUSIONS

The FI of published trials in pediatric anesthesiology is similarly low as in other medical specialties. Larger trials with more events and P values ≤ 0.01 were associated with a higher FI.

Limberg Flap in Pilonidal Sinus: Experience in Shaheed Suhrawardy Medical College Hospital

Pilonidal sinus disease is a common anorectal condition usually seen in young adult patients. Various methods have been described over the years and there is ongoing debate regarding the ideal method. This study was conducted to evaluate the advantages, results of rhomboid excision and Limberg flap reconstruction in the management of sacrococcygeal pilonidal sinus disease. This cross-sectional study was conducted in Surgery Unit-I of Department of Surgery, Shaheed Suhrawardy Medical College Hospital, Dhaka, Bangladesh a tertiary care centre from July 2016 to November 2017. It includes 19 patients who were treated for sacrococcygeal pilonidal sinus disease by Limberg (Rhomboid) flap. All patients that underwent the procedure had good postoperative outcome with minimal postoperative discomfort and were discharged in 3-4 days. There were 3 cases with complications. Limberg flap coverage is very effective for pilonidal disease with low complication rates, reduced hospital stay, low recurrence rates, earlier healing and shorter time off-work. This technique can be easily mastered and used as an indispensable tool for treating sacrococcygeal pilonidal sinus disease.

Measuring Sensitivity, Specificity and Accuracy of HRCT of Chest and Comparison with Biomarkers in COVID-19 Suspected Patients: A Cross Sectional Study

COVID-19 is a declared pandemic by World Health Organization. The diagnostic tests are not of high specificity and sensitivity, so far. Pro-inflammatory biomarkers and High Resolution Computed Tomography (HRCT) of chest are the common investigations performed to evaluate the diagnosis and prognosis of COVID-19. The objective of this study was to estimate the sensitivity, specificity and accuracy of HRCT and to find out the relationship between the biomarkers and HRCT findings. This was a cross-sectional descriptive study carried out in the COVID-19 suspected isolation unit of a tertiary hospital from July 2020 to November of 2020. Data were collected from electronic medical record (EMR). Relationship test were done by t-test and one-way-ANOVA test. Total 123 cases were enrolled after matching with selection criterion. Mean age of male was 62.5 years and female 57.7 years. Highest frequency of participants was observed in the 60-69 year age group. According to HRCT% findings 4 groups were made. They are below 25%, 25%-50%, 51%-75% and 76%-100%. The distribution of case among these groups was 15%, 44%, 35% and 6% respectively. The relationship between biomarkers (NLR, D-dimer, Ferritin and CRP) and HRCT% was found significant (p<0.05). In HRCT 92.5% lesion were peripherally placed and 99.2% cases were affected by both lungs. The sensitivity and specificity of HRCT were found 46% and 72.6% respectively with 62% accuracy. Raised biomarkers are significantly related to the more lung involvement in case of COVID-19 suspected pneumonia patients. These biomarkers will be helpful as diagnostic and prognostic markers for this disease. HRCT percentage can play an important role as diagnostic and prognostic tool in case of COVID-19 suspected cases.

Paravertebral anaesthesia with or without sedation versus general anaesthesia for women undergoing breast cancer surgery

BACKGROUND

Breast cancer is one of the most common cancers among women. Surgical removal of the cancer is the mainstay of treatment; however, tumour handling during surgery can cause microscopic dissemination of tumour cells and disease recurrence. The body's hormonal response to surgery (stress response) and general anaesthesia may suppress immunity, promoting tumour dissemination. Paravertebral anaesthesia numbs the site of surgery, provides good analgesia, and blunts the stress response, minimising the need for general anaesthesia.

OBJECTIVES

To assess the effects of paravertebral anaesthesia with or without sedation compared to general anaesthesia in women undergoing breast cancer surgery, with important outcomes of quality of recovery, postoperative pain at rest, and mortality.

SEARCH METHODS

On 6 April 2020, we searched the Specialised Register of the Cochrane Breast Cancer Group (CBCG); CENTRAL (latest issue), in the Cochrane Library; MEDLINE (via OvidSP); Embase (via OvidSP); the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) search portal; and ClinicalTrials.gov for all prospectively registered and ongoing trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) conducted in adult women undergoing breast cancer surgery in which paravertebral anaesthesia with or without sedation was compared to general anaesthesia. We did not include studies in which paravertebral anaesthesia was given as an adjunct to general anaesthesia and then this was compared to use of general anaesthesia.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted details of trial methods and outcome data from eligible trials. When data could be pooled, analyses were performed on an intention-to-treat basis, and the random-effects model was used if there was heterogeneity. When data could not be pooled, the synthesis without meta-analysis (SWiM) approach was applied. The GRADE approach was used to assess the certainty of evidence for each outcome.

MAIN RESULTS

Nine studies (614 participants) were included in the review. All were RCTs of parallel design, wherein female patients aged > 18 years underwent breast cancer surgery under paravertebral anaesthesia or general anaesthesia. None of the studies assessed quality of recovery in the first three postoperative days using a validated questionnaire; most assessed factors affecting quality of recovery such as postoperative analgesic use, postoperative nausea and vomiting (PONV), hospital stay, ambulation, and patient satisfaction. Paravertebral anaesthesia may reduce the 24-hour postoperative analgesic requirement (odds ratio (OR) 0.07, 95% confidence interval (CI) 0.01 to 0.34; 5 studies, 305 participants; low-certainty evidence) compared to general anaesthesia. Heterogeneity (I² = 70%) was attributed to the fixed dose of opioids and non-steroidal analgesics administered postoperatively in one study (70 participants), masking a difference in analgesic requirements between groups. Paravertebral anaesthesia probably reduces the incidence of PONV (OR 0.16, 95% CI 0.08 to 0.30; 6 studies, 324 participants; moderate-certainty evidence), probably results in a shorter hospital stay (mean difference (MD) -79.39 minutes, 95% CI -107.38 to -51.40; 3 studies, 174 participants; moderate-certainty evidence), and probably reduces time to ambulation compared to general anaesthesia (SWiM analysis): percentages indicate vote counting based on direction of effect (100%, 95% CI 51.01% to 100%; P = 0.125; 4 studies, 375 participants; moderate-certainty evidence). Paravertebral anaesthesia probably results in higher patient satisfaction (MD 5.52 points, 95% CI 1.30 to 9.75; 3 studies, 129 participants; moderate-certainty evidence) on a 0 to 100 scale 24 hours postoperatively compared to general anaesthesia. Postoperative pain at rest and on movement was assessed at 2, 6, and 24 postoperative hours on a 0 to 10 visual analogue scale (VAS). Four studies (224 participants) found that paravertebral anaesthesia as compared to general anaesthesia probably reduced pain at 2 postoperative hours (MD -2.95, 95% CI -3.37 to -2.54; moderate-certainty evidence). Five studies (324 participants) found that paravertebral anaesthesia may reduce pain at rest at 6 hours postoperatively (MD -1.54, 95% CI -3.20 to 0.11; low-certainty evidence). Five studies (278 participants) found that paravertebral anaesthesia may reduce pain at rest at 24 hours postoperatively (MD -1.19, 95% CI -2.27 to -0.10; low-certainty evidence). Differences in the methods of two studies (119 participants) and addition of clonidine to the local anaesthetic in two studies (109 participants), respectively, contributed to the heterogeneity (I² = 96%) observed for these two outcomes. Two studies (130 participants) found that paravertebral anaesthesia may reduce pain on movement at 6 hours (MD-2.57, 95% CI -3.97 to -1.17) and at 24 hours (MD -2.12, 95% CI -4.80 to 0.55; low-certainty evidence). Heterogeneity (I² = 96%) was observed for both outcomes and could be due to methodological differences between studies. None of the studies reported mortality related to the anaesthetic technique. Eight studies (574 participants) evaluated adverse outcomes with paravertebral anaesthesia: epidural spread (0.7%), minor bleeding (1.4%), pleural puncture not associated with pneumothorax (0.3%), and Horner's syndrome (7.1%). These complications were self-limiting and resolved without treatment. No data are available on disease-free survival, chronic pain, and quality of life. Blinding of personnel or participants was not possible in any study, as a regional anaesthetic technique was compared to general anaesthesia. Risk of bias was judged to be serious, as seven studies had concerns of selection bias and three of detection bias.

AUTHORS' CONCLUSIONS

Moderate-certainty evidence shows that paravertebral anaesthesia probably reduces PONV, hospital stay, postoperative pain (at 2 hours), and time to ambulation and results in greater patient satisfaction on the first postoperative day compared to general anaesthesia. Paravertebral anaesthesia may also reduce postoperative analgesic use and postoperative pain at 6 and 24 hours at rest and on movement based on low-certainty evidence. However, RCTs using validated questionnaires are needed to confirm these results. Adverse events observed with paravertebral anaesthesia are rare.

Ultrasound is a reliable and faster tool for confirmation of endotracheal intubation compared to chest auscultation and capnography when performed by novice anaesthesia residents - A prospective controlled clinical trial

Background

Anesthesia trainee may initially take longer time to intubate and unintentionally place the endotracheal tube (ETT) in the esophagus. The present study determined if ultrasound is the fastest method of confirmation of correct placement of ETT compared to capnography, and chest auscultation in trainees.

Methods

First year anesthesia residents performed intubation in 120 patients recruited after ethical clearance and informed consent. Time to visualize flutter in trachea, double trachea sign, time to appearance of first and sixth capnography, and time to execute chest auscultation was noted.

Results

Ultrasonography was statistically fastest method to determine endotracheal intubation (36.50 ± 15.14 seconds) vs unilateral chest auscultation (50.29 ± 15.50 seconds) vs bilateral chest auscultation (51.90 ± 15.98 seconds) vs capnography first waveform (53.57 ± 15.97 seconds) vs capnography sixth waveform (61.67 ± 15.88 seconds).

Conclusion

When teaching endotracheal intubation to novice anesthesia residents using conventional direct laryngoscopy, ultrasonography is the fastest method to confirm correct ETT placement compared to capnograph and chest auscultation. Mentor can guide trainee to direct ETT towards trachea and can promptly detect esophageal intubation by double trachea sign.

The Spectrum of Focal Segmental Glomerulosclerosis from Eastern India: Is It Different?

Focal segmental glomerulosclerosis (FSGS) is a disease that is defined entirely by its histopathological appearance. The recent Columbian classification has grouped this disease into various types based on the light microscopic description. There is a paucity of data describing the distribution of its various subtypes from the Indian subcontinent. This study was undertaken with the aim to throw light on the epidemiology and clinical features of primary FSGS in Eastern India. This retrospective study includes our cohort of biopsy-proven FSGS who presented to us from June 2009 to July 2011 and the analysis of their presenting clinical and histopathological features from our center in East India. Out of 347 patients diagnosed with FSGS in this period, 224 patients were included in the study. A total of 167 cases were of not otherwise specified (NOS) variant (74.5%), 30 tip variant (13.39%), 14 perihilar (6.25%), 8 cellular (3.57%), and 5 to the collapsing variant (2.23%). The maximum proteinuria at presentation was seen with the tip variant (7.98 ± 6.6 g/24 h), and the renal functions were most deranged at presentation with the collapsing variant. These findings were different from those described in other populations including higher prevalence of the tip and the perihilar variant, significant difference in the degree of hypertension, proteinuria, and renal dysfunction among the different variants. The Columbian classification has helped to stratify the outcomes of this glomerular disease with respect to its clinical presentation as well as histopathological features. However, the characteristics of the various variants do show a distinctive pattern in various populations based on ethnicities.

Surgical Management of Breast Cancer under Local Anaesthesia: A Surgeon's Perspective

Background: Treatment of breast cancer without surgery may not be effective. But in elderly patients with lots of co-morbidities, surgical management often cannot be done due to the significant risks of general anesthesia. The need for a safe, easy and effective alternative anaesthetic technique that can provide adequate peroperative analgesia as well as reduced anxiety in such group of patients was the main indication for this study.Materials and method: This prospective study was done on eleven patients, with coexisting medical conditions and who were not at all fit for general anaesthesia, and underwent breast cancer surgery under local anaesthesia. The patients were studied with regard to intraoperative analgesia, haemodynamic stability and complications related to technique. The study was done in Delta Medical College Hospital, Dhaka, Bangladesh.Results: Mean±SD of study patients were 64.7±7 years old and all were suffering from coexisting medical conditions. Following local anaesthesia, mean intraoperative heart rate was 81.5±11.8 beats/min and the mean blood pressure was 127.3/79±9.6/7.0 mmHg. Patients felt no pain after infiltration of local anaesthetics, but experienced it if any place was missed before dissection. No complication occurred due to this procedure. All the candidates were fully satisfied with the procedure.Conclusion: Local anaesthesia provides satisfactory pain control along with keeping haemodynamics stable for surgical treatment of breast cancer among elderly patients having co-morbid conditions.Delta Med Col J. Jul 2017 5(2): 63-67

The Epidemiology, Clinical Features, and Outcome of Infection-related Glomerulonephritis from East India: A Single Center Experience

Infection-related glomerulonephritis (IRGN) is an example of immunological renal injury due to non-renal infections. With the changing face of IRGN over the years, renal biopsy definitely has an important role to play in differentiating this disease from the other masquerades and helps in prognosticating the long-term outcomes. This prospective study includes biopsy-proven IRGN cases who presented to us from July 2010 to July 2013 from a single center in East India. Of the 168 patients suspected and screened, 137 patients were proved to have IRGN. About 11.67% cases were proven to be immunoglobulin A-IRGN variant. The mean age of presentation was 22.7 ± 15.8 years with a slight male preponderance. A nephrotic range of proteinuria was seen in 13.8% cases and 17.5% patient required renal replacement therapy at presentation. Around 8.75% patients had persistent proteinuria despite normal renal function beyond 6 months of follow-up and 8.09% patients progressed to chronic kidney disease. It may no longer be classified as a glomerular disease with the definite favorable outcome as an important number of patients may progress to chronicity following this disease. Renal biopsy plays an important role in the assessment of prognosis of IRGN and detection of the presence of other underlying glomerulonephritis and should be considered early, especially in patients with atypical presentation.

Luteolin, an abundant dietary component is a potent anti-leishmanial agent that acts by inducing topoisomerase II-mediated kinetoplast DNA cleavage leading to apoptosis

BACKGROUND

Plant-derived flavonoids, which occur abundantly in our daily dietary intake, possess antitumor, antibacterial, and free radical scavenging properties. They form active constituents of a number of herbal and traditional medicines. Several flavonoids have been shown to exert their action by interacting with DNA topoisomerases and promoting site-specific DNA cleavage. Therefore, flavonoids are potential candidates in drug design. We report here that, although the flavonoids luteolin and quercetin are potent antileishmanial agents, luteolin has great promise for acting as a lead compound in the chemotherapy of leishmaniasis, a major concern in developing countries.

MATERIALS AND METHODS

Kinetoplast DNA (kDNA) minicircle cleavage in drug-treated parasites was measured by electrophoresis of the total cellular DNA, followed by Southern hybridization using 32P labeled kDNA as a probe. Cell cycle progression and apoptosis were measured by flow cytometry using propidium iodide and fluorescein isothiocyanate (FITC)-labeled Annexin V.

RESULTS

Luteolin and quercetin inhibited the growth of Leishmania donovani promastigotes and amastigotes in vitro, inhibited DNA synthesis in promastigotes, and promoted topoisomerase-II-mediated linearization of kDNA minicircles. The IC50 values of luteolin and quercetin were 12.5 microM and 45.5 microM, respectively. These compounds arrest cell cycle progression in L. donovani promastigotes, leading to apoptosis. Luteolin has no effect on normal human T-cell blasts. Both luteolin and quercetin reduced splenic parasite burden in animal models.

CONCLUSION

Luteolin and quercetin are effective antileishmanial agents. Quercetin has nonspecific effects on normal human T cells, but luteolin appears nontoxic. So, luteolin can be a strong candidate for antileishmanial drug design.

Metallic ion concentration during menstrual cycle in normally menstruating women

Plasma concentration of metallic ions levels during menstrual cycle of twenty normally menstruating women were observed in four phases i.e. menses, follicular, ovulatory and luteal. The concentration of magnesium, zinc, selenium and manganese was highest during menses and lowest at ovulatory phase. There was rise in ionic levels of magnesium and selenium, while fall in zinc and manganese during luteal phase. Findings demonstrate changes in metallic ions (Magnesium, zinc, selenium and manganese) level in relation to hormonal status during menstrual cycle in women.

Multiple calvarial cavernous haemangiomas: case report and review of the literature

Multiple cavernous haemangiomas of the skull with erosion of the inner table and symptomatic intracranial extension were observed in a middle-aged woman. Plain radiographic and CT features are described. The literature relevant to these unusual features is briefly discussed.

Spermatogenic and steroidogenic impairment after chromium treatment in rats

Feeding of hexavalent chromium at doses of 20, 40 and 60 mg/kg daily for 90 days caused cellular impairment in rat testis. Spermatogenic inhibition coupled with deminution in testicular protein, DNA and RNA was significant at the doses 40 and 60 mg kg chromium. Decline of Leydig cell population and nuclear diameter indicated the steroidogenic impairment and the effect was confirmed by the significant inhibition of 3 beta-delta 5-hydroxy steroid dehydrogenase along with low level of serum testosterone.

Steroidogenic impairment after lindane treatment in male rats

The effect on testicular steroidogenesis after lindane (delta-isomer of hexachlorocyclohexane) administration of 4 and 8 mg/kg, i.p. daily for 45 days to male mature rats was investigated. A significant decline in testicular weight of both test groups was observed. Cellular degeneration in Leydig cells of the 8 mg/kg treated group was conspicuous. A sharp decline in the Leydig cell's population and morphological deformation were supported by the decreased activities of testicular hyaluronidase and 3 beta delta 5-hydroxysteroid dehydrogenase. A high level of testicular cholesterol and depletion of ascorbic acid were also responsible for steroidogenic impairment in the treated groups. These impairments also led to a significant diminution in serum testosterone.

Testicular toxicity of methylmercury: analysis of cellular distribution pattern at different stages of the seminiferous epithelium

Stage-specific distribution of methylmercury (MM) and spermatogenic changes were analyzed in rats administered 5 or 10 micrograms MM/kg, ip, daily for 15, 30, 60, and 90 days. MM deposition, as grain number/cm2 was noted in basal portions at later stages on day 15, which increased gradually by day 90. MM deposition was in the order of stages IV, VII, XIV, IX, being higher in adluminal portions on days 30 and 60. MM-enriched cytoplasmic masses leaked out through disintegrated tubular membrane on days 60 and 90. Epithelial damage, at stages late XIV through IV, V through VI, VII through VIII, XIII through mid-XIV, and IX through XII, accorded with the gradual deposition of MM. As profound cell death occurred between zygotenes to pachytenes and dividing spermatocytes to step 1 spermatids, the spermatids were conspicuously decreased at later times. It is possible that MM distorts the barrier system at stages IX through XII, gets distributed within the tubule, and hence may pose a direct or Sertoli cell mediated effect at stages XII through early XIV in a dose-duration-MM burden related manner.

Steroidogenic inhibition in testicular tissue of formaldehyde exposed rats

Three groups of rats (n = 10) were subjected to intraperitoneal treatment of formaldehyde daily at doses of 5, 10 and 15 mg/kg body weight over a period of 30 days. Gradual diminution in body and testicular weight was observed in all treated groups. Leyding cell impairement was conspicuous in those given doses of 10 and 15 mg/kg. Inhibition of 3 beta-delta 5-hydroxy steroid dehydrogenase and accumulation of sudanophillic materials in testicular tissue of formaldehyde treated rats was recorded histochemically. Significant decline of serum testosterone was also observed in the same groups. Structural and functional impairement of Leydig cells after formaldehyde treatment caused steroidogenic inhibition.

Distribution of mercury and evaluation of testicular steroidogenesis in mercuric chloride and methylmercury administered rats

Intraperitoneal administration of methylmercury chloride (MMC) and mercuric chloride (MC) to male rats in doses of 5, 10 micrograms MMC/kg or 50, 100 micrograms MC/kg for 90 days induced cellular disintegration of Leydig cells which was conspicuous on day 30 and onwards in the exposed groups. Progressive degeneration of Leydig cells and decrease in their nuclear diameter and population were associated with gradual increase in deposition of mercury. Gradual diminution of 3 beta-hydroxy-delta 5-steroid dehydrogenase activity in Leydig cells after MMC or MC treatment was correlated with different structural deformations of the cells over 90 days. Moreover, a significant decrease in serum testosterone levels by day 90 confirmed steroidogenic impairment after MMC or MC treatment.

BHC induced testicular impairments in rats

Benzene hexachloride (BHC) was fed to mature male rats weighing 160 g at dosages of 3 and 6 mg/kg body weight over a period of 180 days. Significant decrease in testicular weight and degeneration of seminiferous tubules with deformed spermatogenic cells were noted at a dose of 6 mg/kg BHC. Marked increase in BHC residue in testis revealed that the drug was able to cross blood-testis barrier.

Methylmercury induced biochemical and histochemical alterations in rat testis

The methylmercurry chloride (MMC) administered at doses of 5 and 10 micrograms/kg over a period of 90 days to male rats caused enzymatic impairments in testicular tissue. The study at intervals of 15, 30, 60 and 90 days showed gradual diminution of testicular weight and gradual decrements in testicular protein and inhibition in testicular succinic dehydrogenase activity. Histochemical and biochemical studies revealed that testicular acid phosphatase activity was also inhibited at both the doses of MMC treatment. The inhibition of enzyme activity in testicular tissues after MMC treatment caused the impairment of both spermatogenesis and steroidogenesis in rats.

Methylmercury- and mercuric-chloride-induced alterations in rat epididymal sperm

Four-week-old male albino rats weighing 70 +/- 5 g were treated intraperitoneally daily with 0, 5 and 10 micrograms methylmercuric chloride (MMC)/kg or 0, 50 and 100 micrograms mercuric chloride (MC)/kg body weight, respectively, over a period of 90 days. Studies were carried out a intermittent intervals, i.e. on days 0, 15, 30, 60 and 90 of the experiment. Gradual decrements in body and epididymal weights were observed from day 30 onwards in both the MMC- and MC-treated groups. Morphological deformations of epididymal epithelium were noted from day 30 onwards in the mercurial-treated groups. MMC treatment caused severe degeneration of the epididymal epithelium on days 60 and 90 in comparison to MC treatment. Total sperm count was significantly less in the MC-treated groups, while motile sperm count was affected most in the MMC-administered groups. The frequency of sperm abnormality increased consistently at both doses of mercurial treatment over a period of 90 days. Maximum sperm abnormality among the treated groups was noted in the groups given 10 micrograms MMC/kg. The observations revealed that MMC and MC have variable potency to alter epididymal structure and the sperm.

Histological and pharmacological changes in vas deferens of rats exposed to hexachlorocyclohexane

The effect of hexachlorocyclohexane (HCH) treatment in male albino rats at dosages of 3 and 6 mg/kg body weight by force-feeding were studied over a period of 180 days. Histological observations revealed graded degeneration in the muscular layer of vas deferens. Moreover, the accumulation of HCH residue in serum and vas deferens is highly significant in the experimental group. The contractility of muscles showed marked inhibition by in vitro study.

Trace elements in the endometrium of infertile women

Some essential trace elements were estimated in endometrium of regularly menstruating fertile women and in women with infertility due to cervical factors. The distribution of the trace elements zinc, copper, iron, selenium and manganese at any particular phase of cycle remains more or less semilier between control (i.e. fertile) and infertile (primary and secondary) subjects.

The infant mortality-fertility debate: some international evidence

"The aim of this paper is to analyze empirically the causal relationship, if any, between infant mortality and fertility in thirty-five developing countries." The focus is on possible relationships between the infant mortality rate and the fertility rate. "The hypothesis that infant mortality causes fertility is tested. The possibility of a 'reverse causation' is also analyzed. A one-sided distributed lag test as proposed by Granger...is employed." The results are analyzed in light of several versions of the mortality-fertility proposition, including demographic transition theory, choice theory, Ricardian theory, and the modern economic theory of population.

Effect of lead on erythropoietic system of intact and splenectomized rats

Erythropoietic alterations in normal and splenectomized mature male rats treated with aqueous lead acetate intraperitoneally at dosages of 4 mg/kg and 6 mg/kg body weight were observed over a period of 30 days. Significant retardation in growth might be due to gradual increases in lead toxicity. The elevated blood lead level, increased urinary delta-amino-levulinic acid (ALA-U) excretion, depletion in RBC and haemoglobin content and more number of reticulocytes in peripheral blood indicated the increased intensity of lead toxicity and inhibitory effect on haem biosynthesis. The accelerating action of lead on erythropoietic cellular series i.e. pronormoblast, early and intermediate normoblast and late normoblast was evident by the significant increase in number of cellular count both in intact and splenectomized rats after treatment with lead.

Testicular regulation and sub-cellular distribution of zinc in the epididymis and vas deferens of rhesus monkey (Macaca mulatta)

The zinc concentration in the epididymis (caput, corpus and cauda regions), vas deferens and caudal lobe of prostate of adult rhesus monkeys was determined by atomic absorption spectrophotometry. Zinc content (microgram/g wet weight) was found to be maximum in the prostate (709 micrograms) followed by epididymis and vas deferens. The three segments of the epididymis did not differ from one another in their zinc content (165-177 micrograms). On a protein basis maximum concentration of zinc was present in the nuclear fraction followed by microsomal, cytosolic and mitochondrial fractions in that order. Ligation of testicular efferent ducts or castration 90 days prior to autopsy caused a marked reduction in zinc concentration in different sub-cellular fractions of the organs examined; castration was relatively more effective in this regard. The importance of androgen and other testicular products in controlling zinc content and the possible physiological role of zinc in the male genital tract are discussed.

Effect of lead on human semen

Semen qualities were studied in workers with an average age of 30 years and occupationally exposed to lead in a printing press. Another sample with the same average age but not exposed to lead were taken as control subjects. The average lead content in blood and seminal plasma of the exposed group were 42.5 mcg/100 ml and 14.80 mcg/100 ml, respectively. Their sperm counts and percentage of motile sperm were significantly affected. Significantly higher percentages of abnormal spermatozoa were also observed in these semen samples. The levels of seminal acid phosphatase, succinic dehydrogenase, and fructose in them were also significantly found to be low compared with those from the unexposed subjects. Cytochemical study of sperm head DNA in the exposed groups showed a low surface reaction.

Inhibition of 3 beta-hydroxy-delta 5-steroid dehydrogenase in rat testicular tissue by mercuric chloride

Histochemical investigations of 3 beta-hydroxy-delta 5-steroid dehydrogenase (delta 5-3 beta OHD) activity in the testicular tissue of rats administered mercuric chloride (HgCl2) at dosages of 0.05 mg/kg and 0.1 mg/kg (i.p.) daily for 90 days reveal a graded inhibition of delta 5-3 beta OHD activity which was positively related to dosage and to the duration of treatment with this compound. This phenomenon may be mainly responsible for the inhibition of spermatogenesis, observed as a toxic manifestation of mercury compounds.

Thyroid-testis interrelationship during the development and sexual maturity of the rat

The effects of thyroidectomy and treatment with thyroxine (T4) were studied in immature male rats to evaluate the role of the thyroid in the development of testicular functions. Thyroidectomy inhibited gametogenesis and development of the Leydig cell in these rats. However, the effects could be reversed by administration of 10 micrograms T4 (i.p.) daily for 30 days.

Role of thyroid in testicular development of immature rat

Prepubertal spermatogenic cells in immature rats show pronounced dependency on thyroid hormone. In thyroidectomized immature male rats widespread regression of these cells were observed. These changes could be prevented by administration of small doses of thyroxine. In unthyroidectomized immature rats, thyroxine in the same dosage, caused an increased degree of growth and development of testicular tissues as compared to control.