Hemiagenesia tiroidea: caso clínico y revisión de la literatura / Thyroid hemiagenesis: clinical case and review of the literature

La hemiagenesia tiroidea representa un trastorno congénito caracterizado por la ausencia de desarrollo de uno de los lóbulos tiroideos, asociado o no a ausencia del istmo. Es más frecuente en las mujeres y por lo general se presenta como falta del lóbulo izquierdo, con hipertrofia compensatoria del lóbulo contralateral. Su diagnóstico es generalmente incidental o por manifestaciones del lóbulo tiroideo presente. Se hizo una revisión bibliografía, en donde no se encontraron casos reportados en Venezuela de hemiagenesia o agenesia tiroidea, describiéndose el siguiente. Presentamos a una paciente de 50 años de edad, conocida con hipotiroidismo desde los 31 años, negando cualquier cirugía en el área de cabeza y cuello. Desde febrero 2019 presentó aumento progresivo de volumen en región anterior de cuello. Al examen físico se observó aumento de volumen en región anterior derecha del cuello, palpándose lóbulo tiroideo derecho aumentado de tamaño, de aspecto nodular, no doloroso. En ecosonograma tiroideo se concluyó como bocio tiroideo derecho de aspecto multinodular, con ausencia del lóbulo izquierdo. Perfil tiroideo dentro de límites normales. Se lleva a mesa operatoria corroborándose ausencia del lóbulo izquierdo y presentado en la biopsia definitiva hiperplasia nodular en el lóbulo derecho. Se discute su frecuencia, la forma de presentación y se hace revisión de la literatura(AU)

Thyroid hemiagenesis represents a congenital disorder characterized by the absence of development of one of thyroid lobes, associated or not with absence of isthmus. It is more frequent in women and generally presents as absence of the left lobe, with compensatory hypertrophy of the contralateral lobe. Its diagnosis is generally incidental or by manifestations of the present thyroid lobe. A bibliography review was made, where no cases reported in Venezuela of hemiagenesis or thyroid agenesis were found, describing the following. We present a 50-year-old patient, known with hypothyroidism since she was 31, denying any surgery in the head and neck area. Since February 2019, presented a progressive increase in volume in the anterior neck region. On physical examination, an increase in volume was observed in right anterior region of the neck, palpating an enlarged right thyroid lobe, with a nodular appearance and not painful. In a thyroid echo-sonogram, it was concluded as a right thyroid goiter with a multinodular appearance, with the absence of the left lobe. Thyroid profile within normal limits. It is taken to the operating table, confirming the absence of the left lobe and presented in the definitive biopsy nodular hyperplasia in the right lobe. Its frequency, form of presentation, and literature review are discussed(AU)

Systematic review of the synergist muscle ablation model for compensatory hypertrophy / Revisão sistemática do modelo de ablação dos músculos sinérgicos na hipertrofia compensatória

Summary Objective: The aim was to evaluate the effectiveness of the experimental synergists muscle ablation model to promote muscle hypertrophy, determine the period of greatest hypertrophy and its influence on muscle fiber types and determine differences in bilateral and unilateral removal to reduce the number of animals used in this model. Method: Following the application of the eligibility criteria for the mechanical overload of the plantar muscle in rats, nineteen papers were included in the review. Results: The results reveal a greatest hypertrophy occurring between days 12 and 15, and based on the findings, synergist muscle ablation is an efficient model for achieving rapid hypertrophy and the contralateral limb can be used as there was no difference between unilateral and bilateral surgery, which reduces the number of animals used in this model. Conclusion: This model differs from other overload models (exercise and training) regarding the characteristics involved in the hypertrophy process (acute) and result in a chronic muscle adaptation with selective regulation and modification of fast-twitch fibers in skeletal muscle. This is an efficient and rapid model for compensatory hypertrophy.

Resumo Objetivo: Avaliar a eficácia do modelo experimental de ablação dos sinergistas para promover a hipertrofia muscular, determinar o período de maior hipertrofia, sua influência sobre os tipos de fibras musculares e determinar diferenças na remoção unilateral ou bilateral para reduzir o número de animais utilizados nesse modelo. Método: Após a aplicação dos critérios de elegibilidade para sobrecarga mecânica do músculo plantar em ratos, 19 artigos foram incluídos na revisão. Resultados: Ocorre maior hipertrofia entre os dias 12 e 15, o que torna o modelo eficiente para alcançar a hipertrofia rapidamente. O membro contralateral também pode ser usado, pois não houve diferença entre a cirurgia unilateral e bilateral, o que reduz o número de animais usados no experimento. Conclusão: O modelo difere de outros modelos de sobrecarga (exercício e treinamento) em razão das características envolvidas no processo de sobrecarga imposta (aguda), resultando em uma adaptação crônica muscular com modificação de fibras de contração rápida do músculo esquelético. É um modelo rápido e eficiente para se estudar hipertrofia compensatória.

Role of follicle stimulating hormone in the induction of hyperplasia during compensatory ovarian hypertrophy.

In adult rats, removal of one ovary leads to an acute albeit transient rise in serum follicle stimulating hormone and an increase in the weight of the remaining ovary. In an attempt to correlate the high titre of endogenous follicle stimulating hormone with the changes taking place at the macromolecular level, the phenomenon of compensatory ovarian hypertrophy was studied for one cycle after hemiovariectomy at metoestrus in the adult, cycling female rats derived from the Holtzman strain. The significant finding with respect to hormonal changes was an acute follicle stimulating hormone surge commencing 6h post-unilateral ovariectomy, reaching a maximum at 12 h and declining thereafter, hitherto not reported in the Holtzman strain. Serum luteinizing hormone, prolactin, oestradiol-17ß and testosterone remained unaltered while progesterone showed a decline at 6 h after surgery. There was an increase in the number of healthy class III (> 350 μm) follicles with a concomitant drop in atretic class III follicles 24 h post-unilateral ovariectomy. Analysis for DNA, RNA and protein content showed that all three constituents registered a continuous rise in the hypertrophying ovary up to 120h after surgery. When expressed as μg/mg ovarian weight, the increase in DNA reached a maximum at 24 h and declined thereafter. The kinetics of DNA synthesis was followed by pulse labelling with [3H] thymidine at 18, 24, 36 and 48 h after unilateral ovariectomy. Maximum incorporation occurred at 36 h. Autoradiographic studies showed that the granulosa cells of healthy follicles preferentially incorporated the label. In an extension of this study, it was found that labelling index registered a significant increase following ovariectomy, the maximum being reached at 24 h especially in class III follicles. The results clearly point out the crucial role of hyperplasia in the response of the contralateral ovary to the surgery and implicate the rise in follicle stimulating hormone as the primary signal for initiation of such a response. This raises the question whether in compensatory ovarian hypertrophy follicle stimulating hormone has a mitogenic role.

Muscle Fiber Hypertrophy Following Monocular Medial Rectus Recession and Lateral Rectus Resection in Rats

Compensatory hypertrophy of muscle fibers has been known to occur when burden on a skeletal muscle is increased. However, there have not been reports concerning the response of extraocular muscles following a monocular resection and recession of horizontal muscles, which procedure is a common form of strabismus surgery. A large lateral rectus resection and medial rectus recession was performed in each right eye of 28 rats. After the horizontal muscle surgery, both medial and lateral rectus muscles were obtained from both eyes of each rat with an interval of 2 weeks from the initial operation until 8th week after operation. A mid-portion of an extirpated muscles were frozen and prepared for ATPase staining. With a differential preincubation in two buffered solutions, pH 4.6 and pH 10.3 and ATPase staining, muscle fibers were classified into 3 kinds-global singly innervated fiber(GSIF, alkali-stable), global multi-innervated fiber(GMIF, alkali-labile), and orbital surface layer fiber(OSLF). These muscle fibers were measured using micrometer to find out their diameters and compared with the diameter of extraocular muscle fibers of unoperated rats. All kinds of muscle fibers of a resected lateral rectus showed an increase in their diameteris(p<0.05, Wilcoxon rank sum test) but there was no hypertrophy in the recessed medial rectus the yolk muscle of the resected lateral rectus, medial rectus of the fellow eye also showed hypertrophy of GMIF and OSLF. The lateral rectus of the unoperated fellow eye did not reveal muscle fiber hypertrophy. The postoperative hypertrophy of muscle fibers were observed only at the 2nd and 4th postoperative week specimens. the hypertrophied muscles subsequently returned to the baseline fiber diameter.

Studies on Compensatory Hypertrophy of Testis / 대한비뇨기과학회지

The effects on the remaining gland of unilateral and partial orchiectomy were studied in the adult male rats. The enlargement of the remaining testis following unilateral orchiectomy was observed and it seems to be the result of cellular hypertrophy rather than hyperplasia. Following one and a half orchiectomy the remaining testicular tissue was mainly replaced by scar tissue. It is probably due to difficult technique in partial excision of testis.

EXPERIMENTAL STUDIES ON THE RENAL VESSELS LIGATION IN RABBITS / 解剖学报

36 rabbits were divided into control and experimental groups.In the experimen-tal group,the left renal artery was ligated or the left renal artery and vein wereligated simultaneously.All the animals were alive.After 3—8 months of the opera-tion,the rabbits were killed.The establishment of collateral circulation and theanatomical,histological and histochemical changes of the kidny were observed.The resultsobtained were as follows:1.Ligation of the left renal vessels causes atrophy of theleft kidney on account of the failure of collateral circulation establishment.Theright kidney of the experimental group showed obviously compensatory hypertrophy.The weight of the compensatory hypertrophied kidneys obviously increased.2.Thecompensatory hypertrophic growth of kidneys is due to the hypertrophy of existingn(?)phrons and the hyperplasia connective tissue.3.comparison of the controls,inthe JGI,PAS and AlP reactions with the compensatory hypertrophied kidneys,there were no striking differences.The results suggest that the compensatory hyper-trophied kidneys were normal at least on the renin secretion and reabsorption func-tion.