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In this article, we describe a very rare case of pituitary acidophilic stem cell adenoma, accompanied by a literature review. We present the case of 33-year-old woman with a history of amenorrhea, galactorrhea, elevated prolactin levels, and pituitary tumor. Despite suppression of prolactin levels with cabergoline, the pituitary tumor continued to increase in size and the patient developed clinical symptoms and biochemistry consistent with the diagnosis of acromegaly due to acidophilic stem cell adenoma, an extremely rare subtype of mixed growth hormone/prolactin adenoma, which behaves more aggressively and has a lower surgical cure rate compared to the pure GH-secreting adenoma. The patient had in vitro fertilization 2 years after the successful pituitary surgery and delivered healthy twins. To our knowledge, this is the only case report which describes acromegaly developing during cabergoline treatment. This case also highlights the importance of having a correct histopathological diagnosis to determine the behavior of the tumor and decide on further management.

The peripheral blood cells of a sisorid catfish Glyptosternum maculatum were studied using light microscope and transmission electron microscope. The size of cells and nucleus, and the percentage of different leucocytes were also described. Erythrocytes and four types of leucocytes: lymphocytes, heterophils, monocytes, and thrombocytes were characterized in G. maculatum blood. The dividing erythrocytes could be found sporadically. A plasma cell was observed under a transmission electron microscope. The morphology and structure of blood cells of G. maculatum were basically similar to those of other fish species, although there were also main differences, such as larger erythrocytes than other catfishes, absence of basophils and acidophils, and various types of thrombocytes (five types: lone nucleus, fusiform, tadpole-like, oval, and in a cluster).

We report a rare case of hepatic carcinosarcoma consisting of two carcinomatous components and four sarcomatous components. A 54-year-old Japanese man presented with sudden right upper abdominal pain. Computed tomography showed a hepatic tumor measuring 17 cm in the greatest dimension and intractable ascites, suggesting rupture of hepatocellular carcinoma (HCC). Transcatheter arterial embolization was repeated at our hospital, resulting in stabilization of the patient's general condition. Right anterior and left median sectionectomies were performed. Histologically, the tumor consisted of carcinomatous and sarcomatous elements. The carcinomatous elements consisted of moderately differentiated HCC (positive for hepatocyte antibody, murine monoclonal anti-cytokeratin antibody, and alpha-fetoprotein and negative for S-100 and desmin) and adenocarcinoma (negative for cytokeratin 7 and positive for carcinoembryonic antigen). Sarcomatous elements consisted of undifferentiated spindle cell sarcoma, rhabdomyosarcoma with acidophil striated cells including striped cells (desmin-positive), chondrosarcoma with cartilage matrix (S-100-positive), and osteosarcoma with osteoid. The sarcomatous elements were negative for epithelial markers. The patient is alive at 34 months after the operation with peritoneal dissemination. A total of 23 cases, including the present case, of hepatic carcinosarcoma have been reported in the English language literature. This is the third reported case of hepatic carcinosarcoma with heterogeneous carcinomatous and sarcomatous elements.

A 44-year-old Japanese man with elevated growth hormone levels and gradual deterioration of mental and renal function was admitted to the hospital. With his deteriorated general condition and renal failure, the patient developed pulmonary thromboembolism and died of respiratory failure. Autopsy examination was conducted, which revealed abnormal accumulation or intracytoplasmic storage of lipid-rich material in the small blood vessels, kidney, heart, and nervous system. After postmortem pathologic studies, including light-microscopic histochemistry, electron microscopy, and biochemical analysis of the stored lipid contents, a final diagnosis of Fabry disease was made. Histopathologic examination revealed a unique vasculopathy characterized by the presence of abnormal intracytoplasmic lipid inclusions and vascular remodeling. With regard to the clinical presentation of acromegaly, hyperplasia but not adenomatous transformation of the acidophils of the anterior pituitary gland with immunohistochemical detection of growth hormone within the cells was noted. In this case, the complication of acromegaly with hyperplasia of the acidophilic cells of the anterior pituitary gland and the unique vasculopathy causing significant organ failure, mainly of the kidney, heart, and central nervous systems, possibly as a result of microcirculatory failure, are considered to be not incidental findings but to be intimately involved in the pathogenesis of Farby disease.

The inhibitory effects of dopamine on adenohypophysial cells are mediated via dopamine subtype 2 receptor (D2R). Dopamine agonists inhibit hormone release and induce tumor shrinkage in most prolactin-secreting adenomas, whereas in other adenoma types such effects are sporadic. We investigated D2R gene expression by in situ hybridization (ISH) and immunocytochemistry in different types of pituitary adenomas. By ISH, a variable D2R signal was detected in 79 of 89 cases: 4 of 6 densely granulated and 8 of 8 sparsely granulated somatotroph, 4 of 4 mammosomatotroph, 7 of 7 mixed somatotroph-lactotroph, 4 of 4 acidophil stem cell, 16 of 16 sparsely granulated lactotroph, 11 of 16 corticotroph (functioning and silent), 3 of 4 silent subtype 3, 5 of 5 thyrotroph, 5 of 6 gonadotroph, 5 of 6 null cell, and 7 of 7 oncocytic adenomas. By immunocytochemistry, D2R protein was localized in cytoplasm and nuclei of 60 of 62 adenomas. In lactotroph adenomas, long-acting bromocriptine (BEC-LAR) induced a major increase in D2R mRNA, which was not accompanied by increased D2R immunoreactivity, suggesting mRNA stabilization. In conclusion, D2R gene is expressed in the majority of pituitary adenomas representing all tumor types. The significance of nuclear localization of D2R protein remains to be clarified.

Objective: To explore the effect of combined acupoint desensitizing therapy.Methods: A total of 419 cases of allergic rhinitis accompanied with asthma were treated by combined acupoint desensitizing therapy with positive allergen extract on acupoints of head and upper back region.Results: After 3 courses of treatment, skin test repeated with responding allergen extract showed that the scope of redness and swelling of skin were smaller than those before treatment,P < 0.01. The3H-TdR incorporation lymphocyte transformation rate, acidophil count, IgA, IgG level and E-rosette formation rate of acupoint desensitizing group were different significantly from those of the two control groups (the acupoint 0.85% normal saline injection group and the subcutaneous desensitizing group),P < 0.01 orP < 0.05. Follow-up study for over 3 years showed that the markedly effective rate of the acupoint desensitizing group was 68.73%, the effective rate 29.12% and total effective rate, 97.85%. The effect was higher than that of the two control groups, P

As part of the World Health Organization (WHO) ‘‘blue book’’ series, the recently updated endocrine volume includes a 38-page chapter on pituitary tumors [3], divided into concise multi-authored sections. New developments, remaining shortcomings, and future directions of research have been summarized by Al-Shraim and Asa in the current issue [1]. Overall, this newest ‘‘blue book’’ is superbly written, provides a wealth of useful information, and is sold at a readily affordable price, making it a bargain to anyone even remotely interested in pituitary pathology. As with other issues of the WHO series, current molecular data are well integrated with classic pathology and the entities are beautifully illustrated. The pituitary falls under the purview of both endocrine and neuropathology. However, given its intracranial location, the gland is biopsied by neurosurgeons. Therefore, despite crossing subspecialty boundaries, neuropathologists must be well acquainted with this area of endocrine pathology. In the current summary, we attempt to represent the working neuropathologist’s perspective. Pituitary adenomas can be classified on the basis of their gross/radiographic features (macrovs microadenoma, invasive vs noninvasive), hormone status (functional vs nonfunctional), cytology (acidophil, basophil, chromophobe), grade (typical, atypical, carcinoma), immunohistochemical/ultrastructural cell type (lactotroph, somatotroph, corticotroph, gonadotroph, thyrotroph), and molecular attributes (transcription factor, growth factor, and or tumor suppressor gene expression). Practicing neuropathologists are also aware of the wide morphological spectrum encountered routinely. Depending upon the histological pattern, particularly in nonfunctioning adenomas, one can consider diagnoses such as ependymoma, oligodendroglioma, meningioma, or even carcinoma, particularly if one is unaware of the sellar origin of the tissue sample. Despite the limitations of classifying adenomas by their tinctorial characteristics, as discussed in the introductory chapter of the WHO book [3], a more complete discussion of helpful morphological features is worthy of re-emphasis. For example, calcospherites (prolactinomas), eosinophilia or fibrous bodies (growth hormone adenomas), paranuclear vacuolation (acidophil stem cell adenoma), cytoplasmic basophilia or Crooke’s hyaline (corticotroph adenomas), pseudorosette formation (gonadotroph adenomas), and oncocytic change (gonadotroph or null cell adenomas) serve as clues to tumor subtype. Synaptophysin immunoreactivity was also emphasized as a more consistent broad spectrum neuroendocrine marker for pituitary adenoma than chromogranin [3]. This distinctive immunophenotypic feature is generally under appreciated. As common as pituitary adenomas are, it is surprising to see the current inter-institutional variation in diagnostic approach. This ranges from a single hematoxylin and eosin section and a final diagnosis of ‘‘pituitary adenoma’’ in virtually every case, to the ‘‘Cadillac approach’’ of a full pituitary hormone immunostain panel in nearly all instances and electron microscopy in selected cases. An interesting point highlighted in the review of Al-Shraim and Asa [1] is the histogenetic link between transcription factor expression in normal development and pituitary adenomas. Work in this area [4] has advanced our understanding of plurihormonal adenomas, such as the coexpression of growth hormone, prolactin and thyrotropin in the majority of acromegalyassociated adenomas, as well as the gonadotroph-like properties of so-called ‘‘null cell’’ adenomas. NonetheA. Perry (&) Division of Neuropathology, Washington University School of Medicine, Campus Box 8118, 660 S. Euclid Ave, 63110-1093 St. Louis, MO E-mail: aperry@wustl.edu Tel.: +1-314-3627426 Fax: +1-314-3624096

Growth hormone(GH)-producing pituitary adenomas are morphologically heterogeneous and frequently contain not only GH immunoreactivity but also variable numbers of prolactin (PRL) immunopositive cells. Paraffin sections of 59 surgically removed GH- and/or PRL-producing adenomas classified by histology, immunocytochemistry (ICC) and electron microscopy were studied using in situ hybridization (ISH) for GH and PRL mRNA and combined with ICC for the coded hormones. Somatotroph adenomas (10 densely and 10 sparsely granulated tumours) and mammosomatotroph adenomas (10 cases) contained both GH mRNA and GH immunoreactivity. In 4 densely and 4 sparsely granulated somatotroph adenomas and 4 mammosomatotroph adenomas, only GH mRNA and its product were found. In 28 cases (6 densely and 6 sparsely granulated somatotroph adenomas, 10 mixed somatotroph-lactotroph adenomas and 6 mammosomatotroph adenomas) both GH and PRL mRNA were present, although no PRL immunoreactivity was not in 2 densely granulated somatotroph adenomas. In these cases, ISH for PRL mRNA combined with GH immunostaining revealed the presence of variable numbers of mammosomatotrophs. In 9 acidophil stem cell adenomas only PRL mRNA and its product were found; one tumour expressed both GH and PRL mRNA and their products. Nine lactotroph adenomas contained only PRL mRNA and PRL immunoreactivity. The results show that GH and/or PRL mRNA content could not be correlated with ICC for coded proteins and ultrastructural features. The mammosomatotrophs were more numerous using ISH when compared with ICC. Somatotroph, mammosomatotroph and mixed adenomas are closely related and they can be considered to represent one basic tumour type originating in a cell committed to GH production. This may undergo clonal differentiation towards a mammosomatotroph and further to the lactotroph line. The results also indicate that lactotroph adenomas arise in a cell committed to PRL production. Acidophil stem cell adenomas seem to be more closely related to lactotroph cells than somatotroph.

Fluorosis was induced in rabbits by daily subcutaneous injections of sodium fluoride in a dose of 12 mg/kg for 12 weeks. Stimulation of adenohypophyseal function was observed during the first days and weeks of poisoning. In chronic experiments depression of the function of the basophils and acidophils was observed. During the 8 weeks of the recovery period the adenohypophysis of the experimental rats was practically indistinguishable from that of the controls.

Mitotic rates of the six types of immunohistochemically identifiable adenohypophysial cells were histometrically calculated in colchicine-pretrated male rats 5, 17, 30 and 70 days old. Sections were stained with the antisera against rLH, rFSH, rTSH, oGH, rPRL and pACTH1–39. The mitotic growth rate of the anterior pituitary gland at 30 days of age was much higher than at other times. Mitotic growth rates of GH and PRL cells increased with advancing age, while those of ACTH-, TSH- and immunonegative cells decreased with advancing age. LH/FSH cells showed no variation in mitotic growth rate with age. Mitotic cells can be classified into six cell types based on their fine structural properties: (1) agranular cells associated with the folliculo-stellate cells; (2) ambiguous cells with scanty minute secretory granules (50–150 nm in diameter); (3) basophils with a number of small secretory granules (130–200 nm); (4) immature acidophils whose large secretory granules (130–300 nm) are sporadically scattered; (5) acidophils with numerous spherical larger secretory granules (200–300 nm); and (6) prolactin cells with large polymorphic granules. At day 5 there was a high mitotic rate of the agranular and ambiguous cells [types (1) and (2)]; at day 70 a high mitotic rate was found in immature and mature acidophils [types (4) and (5)]. The mitotic rate of basophils (type 3) was high only at day 17 and low at all other times. The mitotic rate of prolactin cells (type 6) showed a slight increment with advancing age. It is concluded that the mitotic rates of the six cell types are age-dependent.

The pituitary glands ofTaphozous melanopogon were examined histologically and cytochemically by employing several cytochemical staining techniques. The neural lobe is composed mostly of nerve fibres amidst which occur numerous small glial cells and a few Herring’s bodies. Two cell types have been identified in the pars intermedia. In addition to chromophobes, 5 different cell types, namely, 3 types of basophils (thyroid stimulating hormone, follicle stimulating hormone and luteinising hormone producing cells) and two types of acidophils (lactotrophic hormone and somatotrophic hormone producing cells), were identified in the pars distalis. The gonadotrophs and the lactotrophs aggregate in patches in certain regions of the pars distalis and exhibit cyclical changes in structure and number. The physiological significance of the cyclical changes of these cells is discussed in relation to the reproductive cycle of the animal.

The pituitary gland of Latimeria chalumnae is situated rostroventral to the telencephalon. The hollow pituitary stalk is bent forward and is ventrally connected to a saccus-vasculosus-like organ, rostrally to a neurointermediate lobe. The infundibular lumen protrudes far into the neurohypophysial lobules. The elongated principal part (pars cerebralis) of the pars distalis is partly embedded in a dorsal depression of the pars intermedia and caudally invaded by the neurohypophysis. It may be divided into rostral and proximal pars distalis and includes a ramified hypophysial cleft, which continues rostrally as a duct with adjacent islets of pars distalis tissue (parts of a pars buccalis). The adenohypophysis consists of cell cords and follicles. Eight tinctorial cell types can be distinguished: in the rostral islets: large basophils with acidophil globules, in the rostral pars distalis: small basophils, large basophils with amphiphil characters and erythrosin-, orange G-positive acidophils; in the proximal pars distalis: orange G-positive acidophils and small and large basophils, having similar staining properties; in the pars intermedia: one amphiphil cell type.

In 100 patients who had taken an acute overdose of paracetamol the liver was biopsied percutaneously on the 4th day or as soon thereafter as recovery of the clotting mechanism allowed. A system for grading the histological changes in the liver is described. The hallmark of severe (grade III) damage is centrizonal necrosis, for which there is probably a dosage threshold. Consequent changes include phagocytosis of cell debris, reticulin collapse, and an inflammatory infiltration; acidophil degeneration of hepatocytes is sometimes prominent; regenerative growth is already evident after 4 days. Mild (grade I) damage is characterized by excess of lipofuscin pigment in centrizonal hepatocytes, sparse focal necrosis of liver cells, and some phagocytosis of lipofuscin. The findings in moderate (grade II) damage are similar but more pronounced. Five patients died in acute hepatic failure, and 22/100 showed severe (grade III) changes but survived. Forty-nine patients representing all three grades of liver damage were rebiopsied after 3 months. Central necrotic zones were found to have been completely reconstituted leaving only minor abnormalities except for one patient who showed mild centrilobular fibrosis and scarring of a nonprogressive nature.

When cryostat sections of endocrine tissue were examined in a dark-field microscope, a brillant granular luminescence was revealed in the endocrine cells thought to be concerned with protein or polypeptide horome production. The sections were prepared from fresh materials either frozen in a cryostat chamber at --25 degrees C, in dry ice-acetone, or fixed in formalin-calcium for 24 hr. The neurosecretory substance in the hypothalamus and the posterior lobe of the pituitary showed a blue luminescence; the acidophil cells of the anterior lobe of the pituitary, orange; basophile cell, green or blue; intermediate lobe cells, no luminescence; thyroid C cells, white-blue; pancreatic A cells, blue; B cells, orange; adrenomedullary cells, greenish blue; enterochromatin cells, green; and other endocrine cells in the gastrointestinal tract, blue or orange. After tearing and spreading the pituitary and hypothalamus with a pair of needles on a glass slide, and examining the teased specimen by dark-field microscopy, various cells of different lumunescent colours became apparent in the anterior lobe of the pituitary, a blue fluorescent substance in the posterior lobe, and neurosecretory cells bodies in the hypothalamus. The different colours appear to be inherent in the granules of living tissues.

The structure and ultrastructure of the meso-adenohypophysis of the viviparous teleost, Cymatogaster aggregata Gibbons are described. One acidophil, one chromophobe and two basophil cell types were identified. Following treatment of the fish with “methallibure”, the gonadotroph basophils were completely, and the somatotroph acidophils partially, depleted of electron-dense granules, whereas the thyrotroph basophils were slightly hypertrophied. The usefulness of “methallibure” as an agent for chemical hypophysectomy in studies of gametogenesis is discussed.

Adult male common frogs (Rana temporaria) were exposed to increased temperatures (10 and 26°C) and various tissues and organs were examined histologically two and seven weeks later. Appropriate control tissue was obtained from hibernating animals. The following tissues and organs were examined: pars distalis of the adenohypophysis (acidophils type 1, basophils types 2 and 3); interrenal gland; interstitial tissue (Leydig cells) and germinal epithelium of the testis.

Administration of the anti-adrenal drug metopirone (SU 4885) allows for the identification of the ACTH cells in the adenohypophysis of the teleost Anoptichthys jordani. The drug causes a correlated stimulation of the interrenal cells and one cell type in the pituitary gland, i.e. the amphiphilic pro-2 cells, situated in a palisade like layer between the acidophils of the pro-adenohypophysis and the neurohypophysis.

Cytochemical techniques, performed sequentially on single sections, have confirmed the identity of human and murine pituitary corticotrophs as APUD cells. These same methods indicate that in both species the acidophil somatotroph, identified as such by immunofluorescence using anti-human GH, possesses APUD qualities not only with respect to amine-handling, but also in terms of enzyme content. Inclusion of the somatotroph in the APUD series of cells which produce polypeptide hormones has far-reaching implications.

Nuclear and cytoplasmic size (μ2) of acidophils in the pars distalis of adult male deer were measured and the data analyzed statistically with reference to the four classical seasons of the photoperiodic cycle and five periods and two events of the antler cycle. The seasons, and the respective mean cross-sectional areas of cell nuclei and cytoplasm, are: Spring (21 March–20 June; increasing photoperiod greater than 12 hours), 28.45 and 48.68 μ2; Summer (21 June–20 September; decreasing photoperiod greater than 12 hours), 27.81 and 44.25 μ2; Fall (21 September–20 December; decreasing photoperiod less than 12 hours), 30.40 and 45.07 μ2; Winter (21 December–20 March; increasing photoperiod less than 12 hours) 27.28 and 40.30 μ2. Beginning in late winter and early spring the components of the antler cycle, and the respective cross-sectional areas of cell nuclei and cytoplasm, are: Initial Antler Growth, 28.08 and 38.58 μ2; Growth of Velvet Antler Form, 28.93 and 50.61 μ2, Antlers Hardening, 27.53 and 40.83 μ2; Velvet Shedding, 29.03 and 53.20 μ2; Rutting Season, 29.95 and 44.97 μ2; Preparation for Shedding, 26.50 and 40.38 μ2; Antlers Recently Shed, 27.53 and 47.85 μ2. Shedding of boney antlers, growth of velvet antlers and increases in nuclear and cytoplasmic areas of acidophil cells in the pars distalis occur when the photoperiod is increasing. Construction and retention of hard antlers occur when photoperiod is decreasing. This lessening of day length appears to influence the gonadotrophs that regulate secretion of testosterone.

A CONSIDERATION of the development of endocrine histology throws considerable light both upon the problems which have confronted the investigator and the way in which attempts have been made to solve them. When the physiological significance of the endocrines was less understood than it is now, their histological descriptions were relatively simple. For example, in the anterior lobe of the pituitary two chromophilic and one chromo-phobic type of cell were described. As the gland came to be investigated in the light of an increasing knowledge of its physiological activities and with improved techniques, the complexity of the histological picture increased. Transition cells between chromophobe and chromophil have been recognized in many animals investigated1*2'3, and in the dog4 dark and light varieties of the basophil cells have been described, as have special carmine acidophils in the cat5. In a like manner, the original principal and oxyphil cells of the human parathyroid6*7 have each been divided into two types-dark and light; osmiophilic and non-osmiophilic cells have been described in what was originally considered as the uniform parenchyma of the rat parathyroid8*9, and I10 have observed a somewhat similar differentiation with intermediate cell types in the mouse. Again, in the human pancreatic islets Gomori11 has recorded cells intermediate between A -cells and the D-cells of Bloom, and Hoerr12 and others have described dark and light cells in the zona reticularis of the adrenal cortex.

The percentages in female rats of acidophil, basophil, and chromophobe cells in the central and peripheral portions of the anterior pituitary lobe, as well as in the portion adjacent to the posterior lobe were determined. It was shown that the number of chromophobe cells in the various portions ranged from 56.3 to 59.3%. The number of acidophils varied between 30.7 and 35.9%, and basophils from 6.6 to 9.9%. The basophil count was higher in the peripheral portion than in the portion adjacent to the posterior lobe; there were fewer acidophil cells in the peripheral than in the central portion or in the portion adjacent to the posterior lobe.

The indirect immunofluorescence procedure was used to identify prolactin (LTH)-and somatotropin (STH)-producing cells in the pituitary of the Mexican axolotl. Histological staining techniques were employed to corroborate immunocytological results. The LTH cells are large, orange-staining cells (acidophils 1) distributed in the posterior two-thirds of the pars distalis. The STH cells are small, erythrosinophilic elements (acidophils 2) principally concentrated in the dorsal part of the pars distalis.

Pituitary somatotrops were localized in four species from the genus Oncorhynchus using an antiserum to chum salmon (Oncorhynchus keta) growth hormone. The antiserum cross-reacted specifically with the acidophils in the caudal pars distalis of all species tested. Corroborative immunodiffusion studies were also conducted with pituitary homogenates from the same species. Immunological identity of the GH molecule was observed for all species tested.

In the course of light and electron microscopic studies of 142 surgically-removed human pituitary adenomas, 28 tumors were found containing fibrous bodies composed of type II microfilaments with an average width of 115A. These spherical structures, measuring up to 4-5 micrometer occur exclusively in sparsely granulated growth hormone cells and acidophil stem cells, but as revealed by the immunoperoxidase technique, contain no growth hormone. Fibrous bodies are located in the Golgi region and are consistently associated with Golgi membranes and smooth-surfaced endoplasmic reticulum. Their association with centrioles is thought to be anatomical rather than functional. Several adenoma cells possess spherical formations composed entirely of smooth-walled membranes or transitional forms between smooth tubules and type II microfilaments, suggesting that smooth membranes may play a key role in the production of fibrillar substance. Fibrous bodies appear to be reliable morphologic markers and are valuable in the differential diagnosis of pituitary adenomas.

The fine structure of some oval anterior pituitary cells of the adult male rats immunostained with an antiserum to rat prolactin was investigated electron microscopically on the adjacent thin sections. Their fine structural appearance is identical with that of acidophils of the small granule type (Yoshimura et al. 1974) resembling the Kurosumi-Oota LH gonadotrophs. The secretory granules of the oval cells are spherical in shape, ranging from 130 to 200 nm in diameter. Large polymorphic granules, which are generally believed to be characteristic of prolactin cells, are absent from their cytoplasm. It is concluded that the acidophil of the small granule type with a similar fine structure to the Kurosumi-Oota LH gonadotroph is a prolactin secreting cell.

The pituitary gland of the flounder, Pleuronectes flesus, showed several unusual cytological features. Between the RPD and the PPD was a zone of cells that stained purple with Alcian blue--PAS--orange G. Many of these cells were apparently degenerating. In the PPD the strands and coils of presumptive STH cells showed a tremendous variation in both size and staining properties. In the PI there were two cell types, the PAS-positive one bordering the neurohypophysis. Around the periphery of the PI was a zone of chromophobic cells, and throughout the PI were numerous intracellular and extracellular acidophil spheres. No well defined ACTH cells were found in the RPD of the minnow (Phoxinus phoxinus). The Alcian blue--PAS--orange G technique distinguishes between blue TSH cells and purple GTH cells in the RPD and PPD. GTH cells from animals collected in the winter were vacuolated. The PI contained two cell types whose staining reactions and ultrastructure were extremely variable. Intra- and extra-cellular acidophil spheres were present.

IN previous investigations on the anterior pituitary of rats intoxicated with benzene we found histochemical changes suggesting an increased hormone secretion from both the acidophil cells and the beta cells1. Since the beta cells are believed to be concerned in the rat with the secretion of thyrotrophic hormone and are therefore also called thyrotrophs2,3, it seemed of interest to determine whether the hyperfunction of the pituitary beta cells is paralleled by cytological signs of augmented activity in their target gland, the thyroid.

PINEALECTOMY in rats has been variously reported as resulting in no change1 or as causing a hypertrophy of the pituitary, with an increase in the proportion of acidophils of the anterior lobe, and some degeneration of the basophils2.

THE discovery of large acidophil intranuclear bodies in the convoluted tubule cells of the kidneys of London sewer rats1 has led to the examination of rats from other localities in order to determine the prevalence of these structures. The results of this examination have shown that intranuclear bodies are almost invariably present in London sewer rats, including both Rattus norvegicus and Rattus rattus, but in rats from other localities have been found only in those which presumably might have lived in sewers or fed on town refuse, and have been absent from rats caught in the country under hay-stacks, or in similar localities. Moreover, with two exceptions, they have never been found in white rats, including both normal individuals and others infected with various diseases, or exposed to the action of kidney irritants, such as uranium nitrate. The two exceptions were rats which had been kept with infected sewer rats and may have acquired the infection from them.

A CHLORIDE secretory function for the adidophil cells in the pseudobranch of fishes has been disclaimed1,2. If these cells in the gills of fish are regarded as ion-regulatory it becomes important to establish whether the cells of gills and pseudobranch are the same. The morphological and staining properties, as seen under the light microscope, suggested that they were very similar. Recently, a number of papers have been published describing the electron-microscopic struction of the acidophil cells in the gills3–5 and the pseudobranch6. Comparisons of the photographs and their descriptions in these publications is again suggestive that the cells in both areas may be identical.

IN recent papers Buchner1 and his disciples Pichotka2, Muller and Rotter3, as well as Hesse4, have described peculiar histological findings in livers of airmen who died under the effect of atmospheric conditions at a high altitude. The pictures under consideration consist in the formation of big, round or polyhedric vacuoles in liver cells nearest the acinus centres; these vacuoles do not contain either fat or glycogen; they appear as optically empty spaces, including here and there a crescent-like hem of slightly acidophil, homogeneous material, probably serous liquid.