Tuberculosis and its clinical consequences on Women's health

Mycobacterium tuberculosis causes tuberculosis, a fatal infection resulting in widespread illness and death. In 2020, approximately 10 million people were diagnosed with tuberculosis. The top 30 tuberculosis-endemic countries accounted for 86% of all estimated occurrence cases worldwide. In this context, eight of these accounted for two-thirds of the global total, with India having a prevalence of 26%. Aside from lung inflammation, the risk factors for tuberculosis in women include extra-pulmonary infection, particularly genital tuberculosis, tuberculous mastitis, and tuberculous in the peritoneum, intestine, and spine. Depending on the epidemiologic context and screening methods, different tuberculosis symptoms and disease diagnoses are more or less common among expectant mothers. The disease is almost certainly going to have a global impact. The social stigma and anxiety associated with tuberculosis may have a much more significant negative impact on women's health behaviors than men. Notably, the abdominal sites of miliary tuberculosis could mimic tumor likely, carcinoma and lymphoma. Also, the results of the diagnostic accuracy tests for the condition demonstrate that extra-pulmonary tuberculosis can be quickly and accurately diagnosed in various sites using both the T-SPOT assay and the GeneXpert/PCR test. Therefore, this review exemplified the prevalence of extra-pulmonary tuberculosis at various points in women's lives. On the contrary, it also illustrated the symptoms and dangers of TB as they relate to women's health.

A study of analysis on prevalence, serological marker and prognosis of tuberculosis in tertiary care hospital

BACKGROUND

Tuberculosis is an infectious disease responsible for a significant cause of ill health. According to the WHO global tuberculosis report 2021. 9.9 million cases fell sick with TB in 2020. Significantly, the prevalence of tuberculosis in India is 25%.

OBJECTIVE

To analyze the prevalence of tuberculosis in the suburban areas of the metropolitan city in South India. To analyze the serological marker and prognosis of tuberculosis among males and females. To determine the importance of molecular testing - PCR confirmation on TB after AFB smear.

METHODS

A retrospective study to analyze 462 patients enrolled by the respiratory medicine department on suspecting pulmonary- 356 (M-264 & F-92) and extra-pulmonary-106 (M-73&F-33) patients and diagnosed Zhiel-Neelsen staining, Mantoux test, Chip-based RT-PCR test, Erythrocyte sedimentation rate, and analyzed serological test such as C-Reactive Protein, Chemiluminescence immune assay.

RESULTS

23 patients were positive in Ziehl-Neelsen staining, 65 were positive in molecular True-Nat PCR test, Mantoux skin test induration in 10 patients, 98 TB Positive patients examined in the serological analysis, 1 & 3 patients reacted in HIV/HBsAg, and HBsAg test respectively, by chemiluminescence immunoassay, 8 PTB and 4 EPTB and 47 non-TB patients were positive in C-reactive protein, 46 TB and 94 non-TB patients detected abnormal values out of these 160 patients in ESR test.

CONCLUSION

The Prevalence of tuberculosis is significantly rising, especially in the middle-aged population. The rapid molecular diagnostics to detect TB are highly sensitive and specific. Serological markers are essential for the analysis of disease prognosis and need to focus on the guidance of DOTS and RNTCP to End TB.

Functional characterization of toxin-antitoxin system in Mycobacterium tuberculosis

Toxin-Antitoxin (TA) system is abundant in the microbial genome, especially in bacteria and archaea. Its genetic elements and addiction modules with the role of bacterial persistence and virulence. The TA system consists of a toxin and most unstable antitoxin that could be a protein or non-encoded RNA, TA loci are chromosomally determined and their cellular functions are mostly unknown. Approximately 93 TA systems were demonstrated and more functionally available in M. tuberculosis (Mtb), the organism responsible for tuberculosis (TB). It is an airborne disease, which is causing ill-health to humans. M. tuberculosis possesses higher TA loci than other microbes and non-tubercle bacilli, the following TA types have been identified such as VapBC, MazEF, HigBA, RelBE, ParDE, DarTG, PemIK, MbcTA, and one tripartite type II TAC-Chaperone system. Toxin-antitoxin Database (TADB) brings a detailed update on Toxin-Antitoxin classification in the different pathogens such as staphylococcus aureus, streptococcus pneumonia, Vibrio cholerae, Salmonella typhimurium, Shigella flexneri, and helicobacter pylori, etc. So, this Toxin-Antitoxin system is a master regulator for bacterial growth, and an essential factor in analyzing the properties and function of disease persistence, biofilm formation, and pathogenicity. The TA system is an advanced tool to develop a new therapeutic agent against M. tuberculosis.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Barbed sutures reduce arthrotomy closure duration compared to interrupted conventional sutures for total knee arthroplasty: a randomized controlled trial

BACKGROUND

The broad aim of this study was to compare the safety and efficacy of using barbed sutures versus standard-of-care sutures for closure of arthrotomy during total knee arthroplasty. Specifically, we compared the duration of arthrotomy closure, the number of sutures utilized for arthrotomy closure, and 90-day outcomes, including wound-related readmission, reoperation, and complications.

MATERIALS AND METHODS

A total of 60 patients undergoing primary total knee arthroplasty were enrolled in a prospective, blinded trial and randomized to receive either running closure of the arthrotomy with barbed sutures (n = 30) or interrupted closure with standard-of-care sutures (n = 30).

RESULTS

Arthrotomy closure time was significantly shorter in the barbed suture group (3 min ± 2 min) versus the standard-of-care group (13 min ± 5 min, p < 0.001). The average suture utilization for arthrotomy closure was 1 suture (range 1-2) versus 3 sutures (range 2-4) in the standard-of-care group (p < 0.001). The overall number of wound-related complications in the barbed suture group was 3/30 (10%) versus 3/30 (10%) in the standard-of-care group (p = 1.00). There was one dehiscence 1/30 (3%) in the standard-of-care group versus zero in the barbed suture group (p = 1.00). The rate of superficial surgical site infection was 1/30 (3%) in barbed suture versus zero in the standard-of-care groups (p = 1.00).

CONCLUSION

These results suggest barbed suture utilization may be faster and more resource-efficient than the use of standard-of-care sutures for arthrotomy closure in primary total knee arthroplasty without increased complications. CLINICALTRIALS.

GOV IDENTIFIER

NCT03285529.

An oxygen-rich atmosphere or systemic fluoxetine extend the time to respiratory arrest in a rat model of obstructive apnea

Audiogenic seizure-prone mice can be protected from seizure-associated death by exposure to an oxygen atmosphere or treatment with selective serotonergic reuptake inhibitors (SSRIs). We have shown previously in a rat model that epileptic seizure activity can spread through brainstem areas to cause sufficient laryngospasm for obstructive apnea and that the period of seizure-associated obstructive apnea can last long enough for respiratory arrest to occur. We hypothesized that both the oxygen-rich atmosphere and SSRIs function by prolonging the time to respiratory arrest, thus ensuring that seizure activity stops before the point of respiratory arrest to allow recovery of respiratory function. To test this hypothesis, we evaluated each preventative treatment in a rat model of controlled airway occlusion where the times to respiratory arrest can be measured. Adult male Sprague Dawley rats (median age = 66 days) were studied in the absence of any seizure activity. By directly studying responses to controlled airway occlusion, rather than airway occlusion secondary to seizure activity, we could isolate the effects of manipulations that might prolong respiratory arrest from the effects of those manipulations on seizure intensity. All group sizes were ≥ 8 animals per group. We found that both oxygen exposure and fluoxetine significantly increased the time to respiratory arrest by up to 65% (p < .0001 for 5 min oxygen exposure; p = .031 for 25 mg/kg fluoxetine tested 60 min after injection) and, given that neither treatment has been shown to significantly alter seizure duration, these increases can account for the protection of either manipulation against death in sudden death models. Importantly, we found that 30 s of exposure to oxygen produced nearly the same protection as 5 min exposure suggesting that oxygen exposure could start after a seizure starts (p = .0012 for 30 s oxygen exposure). Experiments with 50% oxygen/50% air mixtures indicate that the oxygen concentration needs to be above about 60% to ensure that times to respiratory arrest will always be longer than a period of seizure-induced airway occlusion. Selective serotonin reuptake inhibitors, while instructive with regard to mechanism, require impractical dosing and may carry additional risk in the form of greater challenges for resuscitation. We conclude that oxygen exposure or SSRI treatment prevent seizure associated death by sufficiently prolonging the time to respiratory arrest so that respiratory function can recover after the seizure abates and eliminates the stimulus for seizure-induced apnea.

Seizure-associated central apnea in a rat model: Evidence for resetting the respiratory rhythm and activation of the diving reflex

Respiratory derangements, including irregular, tachypnic breathing and central or obstructive apnea can be consequences of seizure activity in epilepsy patients and animal models. Periods of seizure-associated central apnea, defined as periods >1s with rapid onset and offset of no airflow during plethysmography, suggest that seizures spread to brainstem respiratory regions to disrupt breathing. We sought to characterize seizure-associated central apneic episodes as an indicator of seizure impact on the respiratory rhythm in rats anesthetized with urethane and given parenteral kainic acid to induce recurring seizures. We measured central apneic period onsets and offsets to determine if onset-offset relations were a consequence of 1) a reset of the respiratory rhythm, 2) a transient pausing of the respiratory rhythm, resuming from the pause point at the end of the apneic period, 3) a transient suppression of respiratory behavior with apnea offset predicted by a continuation of the breathing pattern preceding apnea, or 4) a random re-entry into the respiratory cycle. Animals were monitored with continuous ECG, EEG, and plethysmography. One hundred ninety central apnea episodes (1.04 to 36.18s, mean: 3.2±3.7s) were recorded during seizure activity from 7 rats with multiple apneic episodes. The majority of apneic period onsets occurred during expiration (125/161 apneic episodes, 78%). In either expiration or inspiration, apneic onsets tended to occur late in the cycle, i.e. between the time of the peak and end of expiration (82/125, 66%) or inspiration (34/36, 94%). Apneic period offsets were more uniformly distributed between early and late expiration (27%, 34%) and inspiration (16%, 23%). Differences between the respiratory phase at the onset of apnea and the corresponding offset phase varied widely, even within individual animals. Each central apneic episode was associated with a high frequency event in EEG or ECG records at onset. High frequency events that were not associated with flatline plethysmographs revealed a constant plethysmograph pattern within each animal, suggesting a clear reset of the respiratory rhythm. The respiratory rhythm became highly variable after about 1s, however, accounting for the unpredictability of the offset phase. The dissociation of respiratory rhythm reset from the cessation of airflow also suggested that central apneic periods involved activation of brainstem regions serving the diving reflex to eliminate the expression of respiratory movements. This conclusion was supported by the decreased heart rate as a function of apnea duration. We conclude that seizure-associated central apnea episodes are associated with 1) a reset of the respiratory rhythm, and 2) activation of brainstem regions serving the diving reflex to suppress respiratory behavior. The significance of these conclusions is that these details of seizure impact on brainstem circuitry represent metrics for assessing seizure spread and potentially subclassifying seizure patterns.

Laryngospasm, central and obstructive apnea during seizures: Defining pathophysiology for sudden death in a rat model

Seizure spread into the autonomic nervous system can result in life-threatening cardiovascular and respiratory dysfunction. Here we report on a less-studied consequence of such autonomic derangements-the possibility of laryngospasm and upper-airway occlusion. We used parenteral kainic acid to induce recurring seizures in urethane-anesthetized Sprague Dawley rats. EEG recordings and combinations of cardiopulmonary monitoring, including video laryngoscopy, were performed during multi-unit recordings of recurrent laryngeal nerve (RLN) activity or head-out plethysmography with or without endotracheal intubation. Controlled occlusions of a tracheal tube were used to study the kinetics of cardiac and respiratory changes after sudden obstruction. Seizure activity caused significant firing increases in the RLN that were associated with abnormal, high-frequency movements of the vocal folds. Partial airway obstruction from laryngospasm was evident in plethysmograms and was prevented by intubation. Complete glottic closure (confirmed by laryngoscopy) occurred in a subset of non-intubated animals in association with the largest increases in RLN activity, and cessation of airflow was followed in all obstructed animals within tens of seconds by ST-segment elevation, bradycardia, and death. Periods of central apnea occurred in both intubated and non-intubated rats during seizures for periods up to 33s and were associated with modestly increased RLN activity, minimal cardiac derangements, and an open airway on laryngoscopy. In controlled complete airway occlusions, respiratory effort to inspire progressively increased, then ceased, usually in less than 1min. Respiratory arrest was associated with left ventricular dilatation and eventual asystole, an elevation of systemic blood pressure, and complete glottic closure. Severe laryngospasm contributed to the seizure- and hypoxemia-induced conditions that resulted in sudden death in our rat model, and we suggest that this mechanism could contribute to sudden death in epilepsy.

Supplementation of ascorbic acid and α-tocopherol prevents arsenic-induced protein oxidation and DNA damage induced by arsenic in rats

Contamination of arsenic in drinking water is associated with several human diseases including cancer. It has been reported that oxidative stress plays a vital role in arsenic-induced biochemical and molecular alterations. The aim of the present study was to improve the understanding of arsenic-induced oxidative damage to proteins and to DNA and the role of antioxidants such as ascorbic acid and α-tocopherol in alleviating arsenic-induced damages in experimental rats. A significant increase in the levels of protein oxidation, DNA strand breaks, and DNA–protein cross-links was observed in blood, liver, and kidney of rats exposed to arsenic (100 ppm in drinking water) for 30 days. Co-administration of ascorbic acid and α-tocopherol to arsenic-exposed rats showed a substantial reduction in the levels of arsenic-induced oxidative products of protein and DNA. The results of this study support that free radical–mediated toxic manifestations of arsenic and also suggest that ascorbic acid and α-tocopherol supplementation can improve the arsenic-induced molecular alterations.

CXCL13 activation of c-Myc induces RANK ligand expression in stromal/preosteoblast cells in the oral squamous cell carcinoma tumor-bone microenvironment

CXC chemokine ligand-13 (CXCL13) has been implicated in oral squamous cell carcinoma (OSCC) tumor progression and osteolysis. The tumor necrosis factor family member RANKL (receptor activator of NF-κB ligand), a critical bone resorbing osteoclastogenic factor, has an important role in cancer invasion of bone/osteolysis. Here, we show high-level expression of CXCL13 in primary human OSCC tumor specimens; however, human bone marrow-derived stromal (SAKA-T) and murine preosteoblast (MC3T3-E1) cells produce at very low level. Recombinant CXCL13 (0-15 ng/ml) dose dependently induced CXCR5 expression in SAKA-T and MC3T3-E1 cells. Conditioned media obtained from OSCC cell lines increased the RANKL expression and an antibody against the CXCL13 specific receptor, CXCR5 markedly decreased RANKL expression in these cells. Furthermore, CXCL13 increased hRANKL-Luc promoter activity. Superarray screening identified c-Myc and NFATc3 transcription factors upregulated in CXCL13-stimulated SAKA-T cells. Immunohistochemical analysis of OSCC tumors that developed in athymic mice demonstrated RANKL and NFATc3 expression in tumor and osteoblast cells, however, showed p-c-Myc expression specific to osteoblastic cells at the tumor-bone interface. We further identified NFATc3 expression, but not c-Myc activation in primary human OSCC tumor specimens compared with adjacent normal tissue. Also, CXCL13 significantly increased p-ERK1/2 in SAKA-T and MC3T3-E1 cells. siRNA suppression of c-Myc expression markedly decreased CXCL13-induced RANKL and NFATc3 expression in preosteoblast cells. Chromatin-immuno precipitation assay confirmed p-c-Myc binding to the hRANKL promoter region. In summary, c-Myc activation through CXCL13-CXCR5 signaling axis stimulates RANKL expression in stromal/preosteoblast cells. Thus, our results implicate CXCL13 as a potential therapeutic target to prevent OSCC invasion of bone/osteolysis.

Morphological properties of Ag₂SeTe nano thin films prepared by thermal evaporation

Semiconducting silver selenide telluride (Ag₂SeTe) thin films were prepared with different thicknesses onto glass substrates at room temperature using thermal evaporation technique. The structural properties were determined as a function of thickness by X-ray diffraction exhibiting no preferential orientation along any plane; however, the films are found to have peaks corresponding to mixed phase. The morphology of these films was studied using scanning electron microscope and atomic force microscopy respectively, and is reported. The morphological properties are found to be very sensitive to the thin film thickness. The composition of the films is also estimated using energy dispersive analysis using X-rays and are also reported.

‘The interpreter’ in the maxillofacial outpatient clinic

The role of an interpreter is crucial in an ethnically diverse city such as Leicester. Four hundred and seventy-three patients attending the outpatient department were studied. The majority could speak English to some degree. Thirty-one (7%) patients required an interpreter. This was most frequently a family member (70%) or multilingual clinician (27%). The latter are a valuable resource in the health service.

Oral habits in school going children of Delhi: a prevalence study

This study was conducted on 5554 children aged 5-13 years old with the objectives of recording the prevalence of oral habits among North Indian children according to sex. These children were selected from the schools of Delhi. The sample represented the entire school-going population of Delhi in the age group of 5-13 years. Statistical analysis was carried out using BMDP software and sex differences were calculated by using Fisher's exact test. The results showed that the prevalence of oral habits in Delhi school going children was 25.5%. Tongue thrust was the commonest habit (18.1%) followed by mouth breathing (6.6%). Thumb sucking was relatively less common habit and seen in only 0.7% of children. There were no significant differences between boys and girls for the prevalence of oral habits. However, for the specific habit types there was a sex difference. Thumb sucking was more common in girls (1.0%) when compared with boys (0.4%) and this difference was statistically significant (P < 0.001). There was a reverse trend for the mouth breathing, which was more common (P < 0.001) in boys (7.8%) than girls (5.3%). There were no differences for tongue thrust habit between boys (17.5%) and girls (18.6%).

Effect of chronic administration of 7alpha-methyl-19-nortestosterone on serum testosterone, number of spermatozoa and fertility in adult male bonnet monkeys (Macaca radiata)

Hormonal approaches to male contraception that are based on the suppression of LH secretion require androgen replacement treatment to maintain sexual behaviour and secondary sexual characteristics. Androgen supplementation not only involves large and frequent doses of testosterone esters but also results in undesirable effects on the prostate gland. In an attempt to avoid such problems, a synthetic androgen, 7alpha-methyl-19-nortestosterone (MENT), which is much more potent than testosterone, has been developed. In the present study, MENT was administered at different doses (25, 50, 100, 300 and 1000 microg day(-1)) either alone or in combination with oestradiol via Silastic implants for a specified period to adult male bonnet monkeys (Macaca radiata). Blood and semen samples were collected at specific intervals and analysed for serum testosterone and seminal parameters, respectively. The results of the present study clearly indicate that administration of MENT at all doses tested results in suppression of the nocturnal surge of testosterone (by day 3), as well as a decrease in the number of spermatozoa (by day 45). Co-administration of oestradiol resulted in a reduction in the dose of MENT required to suppress the nocturnal surge. None of the male bonnet monkeys treated with MENT were able to impregnate females, clearly demonstrating the efficacy of MENT in blocking fertility in male bonnet monkeys.

Quality of life with functional pharyngeal preservation in advanced carcinomas of the base tongue complex using an integrated trimodality approach

Standard management of advanced carcinoma arising from the base of the tongue or infiltrating that region from contiguous areas (henceforth referred to as base of tongue complex [BTC] tumors) with radical surgery and postoperative radiation therapy results in extensive loss of function affecting deglutition, speech, and physical appearance. From January 1995, 16 patients with advanced stage BTC tumors were entered in this phase II study. Eleven patients (74%) had N2-3 neck disease. To optimize neck control, those with clinical N+ nodes at presentation had neck dissection. This was followed by hyperfractionated radiotherapy at 120 cGy twice daily to a median dose of 7,320 cGy to the primary and 6,240 cGy to areas with pathologically positive nodes. Concomitant chemotherapy was administered during weeks 1 and 4 of the radiation therapy using bolus cisplatin 75 to 100 mg/m2 on day 1 and continuous infusional 5-fluorouracil 750 to 1,000 mg/m2/d from days 1 to 4 of each chemotherapy cycle. Survival curves were plotted for various events, using actuarial life table methods. A functional assessment was made at least 1 year after completion of treatment using a previously validated Head/Neck Performance Status Scale. The median follow-up period was 23 months. There was a 100% complete response to the treatment at the primary site. The actuarial 4-year local (primary site) control was 100%, locoregional control (including nodes) was 69%, and disease-specific survival was 70% at 4 years. The predominant acute toxicity (63% incidence) was reversible grade III mucositis resulting in a median of 9 days' interruption in treatment. All of the patients were able to complete the prescribed treatment course, and there were no treatment-related deaths. Quality of Life assessment after treatment examined all facets of oropharyngeal function. Of note, none of the patients required long-term tube feedings. For the nine patients who responded to the functional assessment questionnaire, the results were excellent (score >75). The mean score for ability to eat in public was 75, mean of 76 for normalcy of diet, and 91 for understandability of speech. Concomitant hyperfractionated chemoradiation therapy produced excellent functional preservation with good long-term control in this patient group with historically poor prognosis. A 4-year actuarial local control rate of 69% was obtained, which is comparable to results of radical surgery and adjuvant radiation therapy. Further studies with modifications of fractionation and use of newer chemotherapy agents/radioprotectors will improve on these gains while reducing toxicity.

The roles of estrogen and progestin in producing deciduosarcoma and other lesions in the rabbit

The interactions of estrogens and progestins in producing decidualization, deciduosarcoma. and other lesions in the rabbit were explored. Steroids were delivered by silicone elastomer implants placed subdermally except for oral dosing in 1 experiment. Varying doses of levonorgestrel (LNG) were given with and without estradiol (E2) and varying doses of E2 with and without LNG. LNG alone delivered at an estimated mean dose of 233 microg/day did not result in endometrial decidualization or deciduosarcoma. Both conditions occurred when E2 was added to the regimen and increased as the dose of E2 was increased. Sixty microg of E2 per day produced endometrial decidualization in all test animals in a 2-month exposure, but deciduosarcoma occurred only when LNG was also supplied and increased as the LNG dose was increased. Progesterone given with E2 resulted in deciduosarcoma in most rabbits. Ethynylestradiol alone at 30 microg/day delivered by implants produced splenic and ovarian deciduosarcomas in 1 of 5 test animals. Adding LNG resulted in more numerous and widespread deciduosarcomas. These experiments indicate that exogenous estrogen is necessary for decidualization of the endometrium and to production of deciduosarcoma in the nonpregnant rabbit. Exogenous progestin promotes the process. Necrosis of the uterine wall tended to increase with increasing dose of estrogens.

Powered instrumentation for transcervical removal of gigantic intrathoracic thyroid

BACKGROUND

It is widely accepted that almost all intrathoracic goiters can be removed through the neck. For those rare gigantic goiters that cannot be removed transcervically, median sternotomy is usually recommended. During the last 11 years we used intracapsular volume reduction techniques to facilitate transcervical removal of extremely large intrathoracic goiters. Materials and Methods Of 149 patients with intrathoracic goiters, 11 patients had gigantic lesions that could not be removed transcervically. Instead of sternotomy, we used the arthroscopic or sinus microdebrider or a large-bore suction device for controlled intracapsular volume reduction. This was followed by complete removal of the gland through the neck.

RESULTS

The thyroid gland was removed completely in all 11 patients. None of the patients had any evidence of intraoperative spillage of thyroid tissue. No major complications were noted.

CONCLUSIONS

We have found the use of the microdebrider and/or suction device for intracapsular volume reduction to be extremely helpful for transcervical removal of gigantic intrathoracic goiters.

Estrogen receptor-beta expression in relation to the expression of luteinizing hormone receptor and cytochrome P450 enzymes in rat ovarian follicles

Changes in mRNA expression for estrogen receptor (ER beta) in relation to mRNAs for LH receptor (LHr) and cytochrome P450 enzymes were examined in granulosa and theca cells from proestrous rat ovarian follicles. Of the 30 ovaries harvested from 15 adult rats, 24 were processed for in situ hybridization, and the remaining were used for reverse transcription-polymerase chain reaction. Messenger RNAs for ER beta, LHr, cytochrome P450 side-chain cleavage enzyme (P450(scc)), 17 alpha-hydroxylase (P450(c17)), aromatase (P450(arom)), and steroidogenic acute regulatory protein (StAR) were localized in cross sections of ovaries by in situ hybridization and quantified in granulosa and theca cell layers by a computer-image analyzing system. Ovarian follicles were classified as healthy or atretic. Healthy follicles were divided into four size groups: very small (40-100 microm), small (101-275 microm), medium (276-450 microm), and large (451-850 microm). Atretic follicles were divided into medium (276-450 microm) or large follicles (451-850 microm). A low level of ER beta mRNA expression was first detected in granulosa cells of very small healthy follicles, and the expression increased progressively up to medium-sized follicles. The expression of ER beta mRNA was highest (P < 0.01) in medium-sized follicles that was followed by a decrease (P < 0.01) in large follicles. Messenger RNAs for LHr, P450(scc), and P450(arom) were first detected in granulosa cells of medium-sized healthy follicles, while mRNAs for LHr, P450(scc), P450(c17), and StAR were first detected in theca cells associated with very small follicles. The highest expression of LHr, P450(scc), P450(c17), P450(arom), and StAR was seen in granulosa and/or theca cells of large healthy follicles. In atretic follicles, level of gene expression was relatively low in both granulosa and theca cells. In conclusion, stage-specific expression of ER beta mRNA was observed in granulosa cells during follicular development. The increased expression of ER beta and a concomitant initiation of LHr, P450(scc), and P450(arom) expression in granulosa cells of medium follicles may signify a role for estrogen in follicular development. Also, a strong correlation between ER beta mRNA expression in granulosa cells, and the expression of mRNAs for LHr, P450(scc), P450(c17), and StAR in theca cells associated with growing follicles suggests a possible role for estrogen in steroidogenesis.

Nestorone: a progestin with a unique pharmacological profile

Nestorone(R) (Nestorone 16-methylene-17alpha-acetoxy-19-norpregn-4-ene-3,20-dione), formerly referred to as ST 1435, is a potent progestin when given parenterally via sustained release formulations. The pharmacological profile of Nestorone was compared with that of levonorgestrel and 3-keto-desogestrel by steroid receptor binding studies and by in vivo bioassays in rats and rabbits. 3-Keto-desogestrel showed the highest binding affinity to progesterone receptors (PR) followed by Nestorone, levonorgestrel, and progesterone. The binding affinity of Nestorone to androgen receptors (AR) was 500- to 600-fold less than that of testosterone. However, both levonorgestrel and 3-keto-desogestrel showed significant binding (40 to 70% of testosterone) to AR. None of the progestins bound to estrogen receptors (ER). The progestational activity of Nestorone, levonorgestrel, and progesterone was compared using McPhail index in immature rabbits and pregnancy maintenance and ovulation inhibition tests in rats after subcutaneous (s.c.) administration. In all three tests, Nestorone was the most potent progestin. The progestational activity of Nestorone was also compared after oral and s.c. administration in rabbits. The potency of Nestorone was over 100-fold higher upon s.c. administration than via the oral route. The androgenic activity of progestins, based on the stimulation of ventral prostate (androgenic target) and levator ani (anabolic target) growth in castrated immature rats, showed good correlation with their binding affinity to AR. Nestorone showed no androgenic or anabolic activity. Nestorone did not bind to sex hormone binding globulin (SHBG), whereas both levonorgestrel and 3-keto-desogestrel showed significant binding to SHBG. The estrogenic/antiestrogenic activity of Nestorone was investigated in immature ovariectomized rats. In contrast to estradiol and levonorgestrel, Nestorone showed no uterotropic activity in ovariectomized rats. Despite significant binding to glucocorticoid receptors (GR), Nestorone showed no glucocorticoid activity in vivo. It is concluded that a strong progestational activity, combined with lack of androgenic, estrogenic, and glucocorticoid-like activities, confer special advantages to Nestorone for use in contraception and hormone replacement therapy.

Long-term effects of nitrous oxide anaesthesia on laboratory and clinical parameters in elderly Omani patients: a randomized double-blind study

AIMS

This study examined the long-term effects of nitrous oxide anaesthesia on serum levels of cobalamin and folate, red cell folate levels and haematological parameters, and neurological status in elderly Omani patients.

METHODS

Sixty-nine consecutive patients undergoing ophthalmic surgery were randomly and double-blind assigned to nitrous oxide or propofol anaesthesia. They met the following entry criteria: age 55 years or above, no major organ failure, no clinical signs or symptoms of cobalamin or folate deficiency, mean cell volume (MCV) </= 96 fl, haematocrit (Hct) higher than 0.3 and no cobalamin and/or folate substitution therapy during the preceding months. Serum levels of cobalamin and folate, red cell folate levels, and haematological parameters were measured prior to anaesthesia and 3-5 weeks later. At that time, the patients also underwent thorough neurological examination.

RESULTS

Data of 51 patients were complete and considered for analysis. In both nitrous oxide and propofol group, the range of exposure time was comparable (+/-1 h). In the nitrous oxide group, a slight but significant decrease in haemoglobin, Hct, and red blood cell count (RBC) (P < 0.001) was observed, whereas there was a mild increase in mean cell haemoglobin (MCH) and mean cell volume (P < 0.05). In addition, there was a significant decrease in serum folate levels (P < 0.05). Hct and RBC decreased slightly in the propofol group (P < 0. 05), whereas there was a small increase in MCH. There was no difference between the two anaesthetics with regard to serum cobalamin and red cell folate levels, but there was a significant decrease in serum folate levels in the nitrous oxide group compared to those in the propofol group. Three patients with pre-existing low red cell folate levels, who were randomized to nitrous oxide anaesthesia, developed clinical symptoms of folate deficiency.

CONCLUSION

This study showed that short-term (40-80 min) nitrous oxide anaesthesia did not affect cobalamin levels but reduced serum folate levels in this elderly population. Although this reduction was clinically irrelevant, some patients with pre-existing asymptomatic folate deficiency developed nitrous oxide-induced folate deficiency.

Synthesis and biological activity of a new progestogen, 16-methylene-17alpha-hydroxy-18-methyl-19-norpregn-4-ene-3, 20-dione acetate

The progestational activity of second- and third-generation progestins in oral contraceptives were markedly increased by addition of an 18-methyl group. A new progestin, the 18-methyl analog of Nestorone, 16-methylene-17alpha-hydroxy-18-methyl-19-norpregn-4-ene-3,2 0-dione acetate (10), was synthesized. The relative binding affinity and biologic activity of 10 was compared with Nestorone, levonorgestrel, and progesterone using a binding assay for rat progesterone receptors, the Clauberg assay in the rabbit, and by assessing pregnancy maintenance in the rat. These studies, as summarized in Table 4, show that 10 is three to ten times more potent than Nestorone. The addition of the 18-methyl group to Nestorone markedly increased its potency as noted above, but is unlikely to change its rate of delivery from sustained release systems. 10 should be ideally suited for administration by implants or small skin patches.

The antigonadotropic action of testosterone but not 7alpha-methyl-19-nortestosterone is attenuated through the 5alpha-reductase pathway in the castrated male rat pituitary gland

The enzyme 5alpha-reductase plays a significant role in the prostate to amplify the action of testosterone (T) by converting it to a more potent androgen, dihydrotestosterone (DHT). The role of 5alpha-reductase in the testosterone feedback inhibition of gonadotropin secretion from the pituitary has not been elucidated. Therefore, we investigated the role of 5alpha-reductase on T action in in vitro and in vivo models. Castration has been reported to increase the 5alpha-reductase activity in pituitary glands. Hence, the effect of castration duration on the conversion of T to DHT by pituitary homogenates and the responsiveness of pituitary monolayer cell cultures to gonadotropin-releasing hormone (GnRH) challenge exposure were investigated. Incubation of [3H]-T with pituitary homogenates showed that the conversion of T to 5alpha-reduced metabolites was two- to threefold greater in pituitaries from rats who had been castrated for 14 days compared with those castrated for 1 day. In addition, the GnRH-stimulated release of LH from monolayer cell cultures of pituitaries from rats castrated for 1 day was twofold greater, whereas that from rats castrated for 2 weeks was six- to sevenfold greater compared with basal luteinizing hormone (LH) release. Hence we used rats castrated for 2 weeks to elucidate the role of 5alpha-reductase in T feedback inhibition. The inhibitory effects of the androgens T, 19-nortestosterone (19-NT), and 7alpha-methyl-19-nortestosterone (MENT) at 3 different concentrations (10(-9), 10(-7), and 10(-5) mol/L) on GnRH-stimulated LH release from monolayer cell cultures of pituitaries from rats castrated for 2 weeks were examined. All 3 androgens showed dose-dependent inhibition of LH release. MENT showed the greatest inhibition, followed by 19-NT and T. In the presence of finasteride (a 5alpha-reductase inhibitor), the inhibition of LH released by T and 19-NT were significantly greater. The inhibitory effect of MENT, which does not undergo 5alpha-reduction, was not altered by finasteride. In an in vivo study, rats castrated for 2 weeks received T with or without finasteride. There was a significantly greater suppression of serum LH in rats receiving T plus finasteride compared with those receiving T alone. These results suggested that 5alpha-reductase in the pituitary is not obligatory for the inhibitory action of T on gonadotropin secretion in the castrated rat. The action of MENT, a nonreducible androgen, on the pituitary is not affected by 5alpha-reductase.

Outcome differences in younger and older patients with laryngeal cancer: a retrospective case-control study

PURPOSE

Younger or older age has a significant impact on the outcome of patients with head and neck cancer. However, the data regarding outcomes based on age are conflicting. The aim of this article is to determine the impact of age on the outcome of laryngeal cancer.

MATERIALS AND METHODS

A retrospective study was performed including all patients with squamous cell carcinoma of the larynx for over a 9-year period. The patients were divided into 3 groups based on age. The younger age group included patients 40 years of age and younger, the older group included patients over 80 years of age, and the remaining patients served as the control group. Descriptive statistics were used to summarize study data. Nonparametric quantitative and qualitative analyses were performed using the Mann-Whitney U test and Fisher's exact test, respectively. Survival analysis was performed using the generalized Wilcoxon test. The Cox proportional hazards model was used for multivariate analysis.

RESULTS

Of the 209 patients with laryngeal carcinoma presenting to our institution over a 9-year period, 20 (10%) were < or =40 years and 15 (7%) were > or =80 years of age. No differences in TNM stage at presentation, treatment, or treatment-associated complications were observed based on age. However, younger patients were less likely to report tobacco (50%; P < .001) or alcohol (57%; P = .03) use and more likely to have human immunodeficiency virus infection (50%; P< .001). Older patients showed a trend toward having a worse baseline medical status. Recurrence was significantly more common in older patients (P = .02) and cause-specific survival significantly poorer for both younger and older patients (P = .002).

CONCLUSIONS

The presentation and outcome of laryngeal cancer is influenced by the age at presentation. The differences may be related exact reason for the observed survival differences needs to be determined.

Chronic toxicity and reversibility of antifertility effect of immunization against gonadotropin-releasing hormone in male rats and rabbits

The chronic systemic toxicity of immunization with gonadotropin-releasing hormone, conjugated to tetanus toxoid (GnRH-TT), was investigated in male rats and rabbits in order to start Phase I clinical trials. Groups of rats and rabbits were immunized with GnRH-TT dissolved in aqueous adjuvant. The antigen was administered at weeks 0, 4, and 8, followed by boosters to maintain high antibody titers. At termination (8-9 months after first immunization), twenty rats and ten rabbits exhibiting the highest mean anti-GnRH titers and all the controls were selected for complete toxicological evaluation. In the rat study, a castrated control group was included for comparison with the immunized group. The hematological and serum chemistry parameters of immunized rats and rabbits were not affected in a significant manner. Most of the changes in serum chemistry of immunized rats were also found in castrated rats, indicating that the changes are most likely due to the withdrawal of androgenic support. The weights of the testes, epididymides, and sex accessory glands were lower in all immunized animals. There was significant atrophy of the germinal epithelium, which, however, sustained a population of Sertoli cells, spermatogonia, and pachytene spermatocytes. Other morphological changes in the prostate, seminal vesicles, pituitary, and mammary gland reflected the effect of androgen withdrawal. The decrease in the weight of liver, kidney, and heart seen in the immunized rats was also present in castrated rats and was not associated with any histopathological changes. The reversibility of immunization-induced infertility was investigated by mating the rats with normal females. Four months after the start of immunization, 9 out of 10 immunized rats were infertile whereas by nine months, all rats had regained fertility. Thus, it is concluded that immunization with GnRH-TT had no systemic toxicological effects in the adult male rats and rabbits for the period studied. The results also indicated that the GnRH-TT immunization had an antifertility effect in male rats. Fertility was restored following cessation of immunization and decline in anti-GnRH antibody titers.

7alpha-methyl-19-nortestosterone, a synthetic androgen with high potency: structure-activity comparisons with other androgens

CNNT. There was a good correlation between bioactivity and binding affinity to AR for the 7alpha-substituted androgens compared to T. In contrast, relative to their binding affinity to AR, the androgenic potency of DHT and 19-NT was lower compared to T. The reason for the lower in vivo androgenic activity of 19-NT is attributable to its enzymatic conversion to 5alpha-reduced-19-NT in the prostate. In the case of DHT, the lower bioactivity could be attributed to its faster metabolic clearance rate relative to T. The correlation was further investigated in vitro by co-transfection of rat ARcDNA expression plasmid and a reporter plasmid encoding the chloramphenicol acetyl transferase (CAT) gene driven by an androgen inducible promoter into CV-1 cells. All the androgens led to a dose-dependent increase in the CAT activity. MENT was found to be the most potent followed by DHT, 19-NT, T, and CNNT. The specificity of the androgenic response was confirmed by its inhibition with hydroxyflutamide, an antiandrogen. Thus, there was a good correlation between binding affinity and in vitro bioactivity in the transient transfection assay for the androgens. This suggests that the in vivo bioactivity of androgens could be influenced not only by binding affinity to receptors but also by factors such as absorption, binding to serum proteins and metabolism. However, the high potency of MENT is primarily related to its higher affinity to AR.

7Alpha-methyl-19-nortestosterone maintains sexual behavior and mood in hypogonadal men

The synthetic steroid 7alpha-methyl-19-nortestosterone (MENT) is a potent androgen that is resistant to 5alpha-reductase. It thus has decreased activity at the prostate and may have advantages over testosterone-based regimens in long term treatment or as part of a male contraceptive. Administration to eugonadal men results in suppression of gonadotropins, but its ability to support androgen-dependent behavior has not been investigated. For sustained release administration, MENT acetate was used, because its diffusion characteristics were more suitable for use in implants. However, upon release the acetate is rapidly hydrolyzed, and MENT is the biologically active moiety in circulation. We studied the effects of MENT on sexual interest and activity, spontaneous erection, and mood states in comparison with testosterone enanthate (TE) in 20 Caucasian and Chinese hypogonadal men recruited in Edinburgh and Hong Kong (n = 10 in each center). Outcomes were measured using a combination of daily diaries, semistructured interviews, and questionnaires. Nocturnal penile tumescence (NPT) was also recorded in the Edinburgh group. After withdrawal of androgen replacement treatment (wash-out phase) for a minimum of 6 weeks, subjects were randomized to two groups in a cross-over design. Drug treatment regimens were of 6-week duration and consisted of two implants, each containing 115 mg MENT acetate, inserted s.c. into the upper arm and removed after 6 weeks and two injections of TE (200 mg, i.m.) 3 weeks apart. MENT treatment resulted in stable plasma MENT concentrations of 1.4 +/- 0.1 nmol/L after 3 weeks and 1.3 +/- 0.1 nmol/L after 6 weeks (mean +/- SEM; all men). Nadir testosterone concentrations were 3.6 +/- 0.6 nmol/L at the end of the wash-out phase and 9.4 +/- 0.6 nmol/L 3 weeks after each injection. There were no differences in hormone concentrations between centers. There were no adverse toxicological effects. There were only minor differences between the two treatments. Both MENT and TE treatment resulted in significant increases in sexual interest and activity, spontaneous erection (both by self-report and NPT measurement), and increases in positive moods, with decreases in negative moods in the Edinburgh group. In the Hong Kong group, both treatments increased waking erection, with a trend toward increased sexual interest and activity. Mood states appeared to be less affected during the wash-out phase than in Edinburgh men and showed no significant response to either treatment. These results demonstrate that MENT has similar effects on sexual activity and mood states as testosterone in hypogonadal men. As NPT is a physiological androgen-dependant outcome, these data provide further evidence for the androgenicity of MENT. The lack of detected effect of either androgen in Hong Kong men other than on waking erection illustrates the importance of the cultural context of symptomatology and its measurement. The appropriate dose of MENT remains to be determined, but these results support its development as a potential androgen replacement therapy.

Latissimus dorsi myocutaneous flap for secondary head and neck reconstruction

PURPOSE

To review our experience and results with the use of pedicled latissimus dorsi myocutaneous flap (LDMF) for secondary reconstruction in head and neck surgery.

METHODS

Twenty-two patients had LDMF, 17 of them for secondary reconstruction. Data were collected regarding the primary surgery, primary method of reconstruction, indication for secondary reconstruction, and outcome.

RESULTS

Seventeen LDMF procedures were performed for secondary reconstruction. Flap success rate was 100%. Reconstructive goals were achieved immediately in 16 (94.1%) patients.

CONCLUSION

LDMF is a thin flap with a large surface area and a long pedicle that allows it to reach any region in the head, neck, and scalp. Its main disadvantages are the need for lateral positioning of the patient and the fact that its pedicle is not protected with muscle. In our experience, LDMF provides an excellent reconstructive option especially in complicated cases of secondary reconstruction. It may be used in cases where a free flap is usually used, but with significantly reduced surgical time.

Gonadotrophin and testosterone suppression by 7alpha-methyl-19-nortestosterone acetate administered by subdermal implant to healthy men

The synthetic androgen 7alpha-methyl-19-nortestosterone (MENT) is a potent suppressor of gonadotrophin that has several advantages for long term administration to normal or hypoandrogenic men. The aim of this study was to examine MENT serum concentrations following subdermal insertion of MENT acetate (MENT Ac) implants and their effects on gonadotrophins, testosterone, dihydrotestosterone (DHT), sex hormone-binding globulin, prostate specific antigen and insulin-like growth factor-1 serum concentrations in normal men. A total of 45 healthy men were recruited at three clinics. Each subject received one, two or four implants for 28 days. Serum samples were obtained before insertion and on days 8, 15, 22, 29, 36 and 43 after implant insertion. The average daily dose delivered in vivo by one implant was approximately 500 microg. One, two or four MENT Ac implants produced dose dependent and sustained serum MENT concentrations for the entire duration of treatment of 0.7 +/- 0.1, 1.2 +/- 0.1 and 2.0 +/- 0.1 nmol/l respectively. This treatment induced a dose dependent decrease in gonadotrophin and androgen serum levels. Two and four implants induced maximal suppression that was maintained throughout treatment and was completely reversed after removal of the implants. The mean decreases were 93 +/- 1% for testosterone, 80 +/- 3% for DHT, 97 +/- 1% for luteinizing hormone and 95 +/- 1% for follicle stimulating hormone. No serious adverse reactions were reported by the volunteers and no consistent changes in clinical chemistry and haematology were found. These results indicate that MENT Ac implants are an efficient way of MENT administration and confirm the potent gonadotrophin and androgen suppressive effect of this drug.

The impact of comorbidity and age on survival with laryngeal cancer

Previous studies have evaluated the effects of comorbidity on survival in patients with cancer. We applied the Charlson comorbidity index (CCI) to a cohort of patients with laryngeal cancer to validate its use and to assess the prognostic impact of age. Our study population consisted of 152 patients with laryngeal cancer who were seen over a 10-year period. Patients were assigned CCI scores and were categorized into low- and high-grade comorbidity groups for comparison. Age adjustments were performed by adding 1 point to the Charlson score for each decade over the median age. Low- vs. high-grade comorbidity was a valid predictor of survival independent of TNM (tumor, nodes, and metastases) stage. Low-grade comorbidity was present in 126 patients; their median survival was 41 months. High-grade comorbidity was present in 26 patients; their median survival was 8 months (p = 0.0002). The addition of the age factor to the CCI did not improve our prognostic ability. There was no difference in CCI groups with respect to tobacco and alcohol use, gender, treatment modality, or mean time to recurrence. The incidence and severity of complications were also similar in the two groups. We conclude that the CCI is a strong predictor of survival in patients with laryngeal cancer. The confounding effects of comorbidity should be considered in the TNM staging of laryngeal cancer to improve our prognostic ability. Further investigations are necessary to assess the validity of this index in patients with other head and neck cancers.

Prostate-sparing effects in primates of the potent androgen 7alpha-methyl-19-nortestosterone: a potential alternative to testosterone for androgen replacement and male contraception

7alpha-Methyl-19-nortestosterone (MENT) is a potent synthetic androgen that cannot be converted to dihydrotestosterone. In this study we determined the relative androgenic, antigonadotropic, and anabolic potencies of testosterone vs. MENT in the nonhuman primate M. fascicularis. In castrated monkeys, dose-response relationships were generated for the effects of testosterone and MENT on gonadotropin levels, prostate growth, body weight, and lipid metabolism. In a pilot study, four monkeys were castrated, and magnetic resonance imaging (MRI) was used to document a 50% loss of prostate volume within 8 weeks, verifying that MRI is a reliable means to measure prostate size in this species. Two additional groups of six monkeys each were then castrated and serially administered four graded dosages of testosterone or MENT via osmotic minipumps over 20 weeks. Complete suppression of LH was achieved with a minimum of 0.3 mg/day MENT, compared to 3.0 mg/day testosterone. MENT supported body weight 10 times more potently than did testosterone. Baseline prostate volumes were maintained with 0.1-0.2 mg/day MENT vs. 0.3 mg/day testosterone. Thus, in monkeys, MENT is 10 times more potent than testosterone with regard to the clinically desirable end points of gonadotropin suppression and anabolism, but only twice as potent at stimulating prostate growth. These results suggest that MENT may have a wider therapeutic index than testosterone for human androgen replacement and male contraception.

Estrogenic and progestational activity of 7alpha-methyl-19-nortestosterone, a synthetic androgen

Synthetic androgens exhibit estrogenic/antiestrogenic and progestational activities in addition to their androgenic effects. To investigate the pharmacological action of the synthetic androgen, 7alpha-methyl-19-nortestosterone (MENT), we examined its action in female rodents. The criteria employed for estrogenic/antiestrogenic effects were, uterine weight increase, vaginal cornification, induction of progesterone receptors (PR) synthesis and stimulation of peroxidase activity in the uteri of ovariectomized rats and mice. MENT increased uterine weight in a dose dependent manner, but did not cause vaginal cornification or stimulate PR synthesis in the uterus. The uterotropic activity of MENT was 200-fold lower than that of estradiol. Estrogen receptor (ER) bound [3H]-E2 was displaced by E2 and MENT with ED50 values of 70 pg and 250 ng, respectively, a 3,500 fold difference in their binding affinity. The low binding of MENT to ER, in contrast to its relatively high uterotropic action, suggested that receptors other than ER may be involved in its action on the uterus. The progestational activity of MENT in immature rabbits using the McPhail index assay was comparable to that of progesterone. Binding affinities of MENT and progesterone to PR were also comparable. However, the action of MENT on the uterus does not seem to be a progestational effect since mifepristone, an antiprogestin, had no effect on MENT-induced uterine growth. Specific androgen receptors (AR) in uterine cytosol were demonstrated. The involvement of AR in MENT action was confirmed by using an antiandrogen (flutamide) and an antiestrogen (ICI-182) in ovariectomized mice. Although MENT did not block the uterotropic effect of E2, it inhibited the E2-induced cornification of vaginal epithelium, induction of uterine PR synthesis and increase in uterine peroxidase activity in ovariectomized rats. The antiestrogenic effect of MENT was also blocked by flutamide. These results suggest that the uterotropic and antiestrogenic effects of androgens are mediated via AR. It is concluded that the increase in uterine weight caused by MENT is attributable to its anabolic effects.

Branchial cleft cyst carcinoma: myth or reality?

Skepticism has surrounded the existence of branchial cleft carcinoma since the entity was first described in 1882. However, a landmark work of 1950 established four criteria for the diagnosis of branchial cleft carcinoma, the most important criterion being histologic proof of carcinoma arising from a normal cyst epithelium. Of the 43 cases found in an extensive review of the literature, only 7 cases have satisfied all four of the criteria. To this we add 2 patients who had recurrent infections of a cervical cyst as children and later developed carcinoma within these structures. Additionally, we propose a minor modification to the 1950 criteria and a paradigm for diagnosis and management of these lesions.

Sonographic versus endoscopic retrograde cholangiographic measurements of the bile duct revisited: importance of the transverse diameter

OBJECTIVE

The purpose of this study was to investigate how frequently the cross section of the bile duct is oval versus round on sonography and whether the transverse diameter of the bile duct (DTRV) on sonography corresponds better than the conventional anteroposterior diameter (DAP) to measurements on endoscopic retrograde cholangiography (ERC).

SUBJECTS AND METHODS

In 44 consecutive patients with a DAP greater than or equal to 8 mm, DTRV was measured on short-axis sonograms. Diameter of the bile duct measured on ERC (DERC) was compared with DAP and DTRV in patients who underwent ERC shortly after sonography.

RESULTS

The cross section of the bile duct was oval in 31 patients (70%). In 20 patients who underwent ERC after sonography, mean DERC was statistically indistinguishable from mean DTRV but statistically different from mean DAP. Comparing both DAP and DTRV with DERC in each patient, we found no statistically significant difference between DERC and DTRV, but we did find a statistically significant difference between DERC and DAP.

CONCLUSION

An oval cross section is common in bile ducts with a DAP greater than or equal to 8 mm. The discrepancy between measurements of the bile duct made sonographically and those made on ERC is largely attributable to different cross-sectional diameters. Because DTRV correlates better than conventional DAP with DERC, measurement of DTRV can be helpful in confirming or excluding true biliary dilatation in patients with a DAP larger than normal.

Pharmacokinetics of 7 alpha-methyl-19-nortestosterone in men and cynomolgus monkeys

Testosterone and its esters are widely used for androgen replacement therapy. In the prostate, testosterone ins 5 alpha-reduced to dihydrotestosterone (DHT), which leads to an amplification of its stimulatory activity in this and other tissues that have significant 5 alpha-reductase activity. While this amplification is essential during fetal development, it has potentially undesirable consequences during adult life. 7 alpha-Methyl-19-nortestosterone (MENT) is a potent synthetic androgen that does not undergo 5 alpha reduction and is therefore being investigated for long-term clinical use because it is expected to be less stimulatory to the prostate. Since we anticipate using MENT acetate (MENT Ac) rather than MENT as the form of this androgen in humans, the bioavailability of MENT following the administration of MENT and MENT Ac was investigated in cynomolgus monkeys. Equimolar concentrations of MENT or MENT Ac were administered as a continuous subcutaneous infusion via Alzet osmotic pumps. Serum MENT levels were measured by radioimmunoassay (RIA) in blood samples collected daily for 4 days during steady state. The serum MENT levels were not significantly different in the two groups (11.3 +/- 1.6 vs. 13.1 +/- 1.2 nmol/L). This suggested that MENT Ac was rapidly converted to MENT in circulation. The hydrolysis of MENT Ac to MENT was confirmed by the in vitro incubation of MENT Ac with blood or plasma and the demonstration of MENT in products following separation by high-performance liquid chromatography (HPLC). Following the demonstration of the safety of MENT Ac in subchronic toxicity studies in rats and rabbits, a pharmacokinetic study was performed in men. In normal men, a single intravenous bolus of 500 micrograms of MENT led to peak serum MENT levels at 3 minutes after dosing (when the first samples were collected), followed by an exponential decline, reaching undetectable levels by 180 minutes. The average terminal half-life and the metabolic clearance rate (MCR) were calculated to be 40 minutes and 2,360 L/day, respectively. The results of the pharmacokinetic studies show that in both men and monkeys, the MCR of MENT is much faster than the values reported for testosterone. The faster MCR can be attributed, in part, to the finding that, in contrast to testosterone, MENT showed no binding to sex hormone binding globulin (SHBG).

Pharmacokinetics and pharmacodynamics of 7alpha-methyl-19-nortestosterone after intramuscular administration in healthy men

7alpha-Methyl-19-nortestosterone (MENT) is a potent synthetic androgen that is resistant to 5alpha-reductases and therefore less prone to over-stimulate the prostate. It is a good candidate for implant administration in long-term androgen replacement therapy for hypogonadal men or as part of a male contraceptive system. To investigate the pharmacokinetics of MENT after i.m. administration, single i.m. injections of 2, 4 or 8 mg of micronized MENT were given in aqueous suspension to 18 healthy men in two clinics. Blood was sampled frequently for 8 h and 1, 2, 3, 4 and 9 days after the injections. Serum MENT concentrations were determined by radioimmunoassay. Peak MENT concentrations were dose-dependent and were reached about 1-2 h after the injections. Doubling the dose of MENT resulted in an increase of 60% in peak serum MENT concentrations. The mean +/- SE clearance rate was 1790 +/- 140 l/day. The antigonadotrophic activity of MENT was investigated by giving six consecutive daily i.m. injections of 1, 2 or 4 mg of MENT to 24 healthy men in two clinics. Blood was sampled before each injection and up to 24 days after the last injection. Serum testosterone and gonadotrophin concentrations (determined by radioimmunoassay and fluoroimmunoassay respectively) decreased in a dose-dependent and statistically significant manner. The highest dose caused a 74% fall in testosterone, a 70% fall in luteinizing hormone, and a 57% fall in follicle stimulating hormone concentrations. MENT injections did not cause any side-effects. The results show that MENT is a potent antigonadotrophic agent in men.

Altered expression of delayed excitation in medial NTS neurons of spontaneously hypertensive rats

The spontaneously hypertensive (SH) rat has an exaggerated sympathetic discharge which may result from an enhanced neuronal excitability in the central nervous system. To test this hypothesis, we examined the electrophysiological properties of neurons in the medial region of the nucleus of the solitary tract (mNTS), a central nucleus involved in the processing of baroreceptor afferent information, in SH rats and normotensive Sprague-Dawley (SD) rats. An in vitro brainstem slice preparation was used to record intracellularly from 18 neurons in 4-5-month-old SH rats and 16 neurons in 4-5-month-old SD rats. Between the two groups there was no significant differences in resting membrane potential, input resistance, and spontaneous firing frequency, or in action potential amplitude, duration, and after-hyperpolarization (AHP). There were no significant differences in spike frequency adaptation and post-tetanic hyperpolarization (PTH). Delayed excitation (DE), a manifestation of A-current, occurred in 88% in SH and SD mNTS neurons, but the duration of DE was significantly (P < 0.05) shorter in SH mNTS neurons. We propose that attenuated expression of A-current may contribute to increased sympathetic drive in SH rats.

7 alpha-methyl-19-nortestosterone facilitates sexual behavior in the male Syrian hamster

Steroid hormones from the testes promote attraction to estrous females and facilitate copulation in the male Syrian hamster. We compared the ability of testosterone (T) and MENT, a potent synthetic androgen that does not undergo 5 alpha-reduction, to maintain sexual behavior in castrated males. Steroid treatment was initiated immediately after castration at three levels by means of Alzet osmotic pumps in sexually experienced adult male hamsters. Daily doses were 5, 25, or 100 micrograms T and 1, 5, or 25 micrograms MENT (n = 5/group). Additional castrated males (n = 5) remained untreated. Sexual behavior was recorded during two 10-min tests before, and at 2, 4, 6, and 8 weeks after orchidectomy. MENT and T maintained equivalent levels of behavior at each corresponding dose of androgen (high, medium, or low). The low dose of T or MENT failed to sustain mating behavior. Eight weeks after castration, males receiving the high and medium doses of androgens continued to express intromissions and ejaculations at gonadally intact levels. However, only males receiving the high dose showed anogenital investigation at the same level as intact males. From these data, we conclude that MENT sustains mating behavior in the male hamster, and that chemoinvestigatory behavior requires higher levels of androgens than those necessary for copulation.

Effects of testosterone and 7 alpha-methyl-19-nortestosterone (MENT) on sexual and aggressive behaviors in two inbred strains of male mice

Behavioral and endocrine effects of a synthetic androgen, 7 alpha-methyl-19-nortestosterone (MENT), which is not 5 alpha-reduced to dihydrotestosterone, were compared to those of testosterone in two inbred strains of male mice, C57BL/6J and DBA/2J, in two experiments. In the first experiment, seminal vesicle (SV) weights, kidney weights, and circulating steroid levels were examined in castrated mice treated with three doses of testosterone (3.125, 12.5, or 50 micrograms/day) or four doses of MENT (1, 4, 16, or 64 micrograms/day) for 2 weeks to determine the optimal replacement levels of the two androgens for behavioral studies. Both testosterone and MENT dose-dependently increased the SV weights that were greatly reduced, in both strains, by castration. MENT was more effective than testosterone in increasing SV weights, fully restoring them to intact levels in both strains, at the dose of 4 micrograms/day. At the dose of 12.5 micrograms/day, testosterone restored the SV weights completely in C57BL/6J and up to 80% in DBA/2J mice. DBA/2J mice were more sensitive than C57BL/6J mice to both androgens, as measured by kidney weights, although circulating levels of either steroid were very similar between the two strains of mice. In the second experiment, we investigated the effects of testosterone (12.5 micrograms/day) and MENT (4 micrograms/day) on sexual and aggressive behaviors. In each strain, MENT-treated and testosterone-treated mice showed similar numbers of mounts or intromissions. MENT was equally effective as testosterone to fully (C57BL/6J) or partially (DBA/2J) restore sexual behaviors as well as the SV weights to the intact levels. In contrast, MENT-treated mice of both strains were much less aggressive than testosterone-treated mice. In both C57BL/6J and DBA/2J mice, testosterone fully restored aggression to the intact levels as measured by aggression latency, number of aggressive bouts, and duration of aggression, whereas aggressive behaviors of the MENT-treated groups were not different from those of the castrated control groups. These results suggest that MENT can restore both male sexual behaviors and reproductive organ weights as effectively as testosterone, at one-third of the testosterone dose, without stimulating male aggressive behaviors.