Shallow Fossa Research Articles

Persistent neonatal hypoglycaemia as a result of hypoplastic pituitary gland

An Indonesian female infant developed hypoglycaemia shortly after delivery by lower segment caesarean section. Following admission to the neonatal intensive care unit, she continued to have episodes of hypoglycaemia despite adequate glucose intake of up to a maximum of 12 mg/kg/minute. During the episodes of hypoglycaemia, repeated measurement of her blood samples revealed persistently low levels of serum insulin of <2 IU/ml, serum free thyroxine of 4.78 pmol/litre, thyroid stimulating hormone of 0.31 uIU/ml and growth hormone of 0.27 mIU/litre, all suggesting a diagnosis of hypopituitarism. Empirical replacement therapy with hydrocortisone (10 mg four times daily) was started at 26 days. However, her hypoglycaemic attacks ceased only with commencement of additional hormone replacement therapy of growth hormone (0.1 mg once daily for 6 days per week) and thyroxine (50 μg once daily). The hydrocortisone dose was gradually tailed to a maintenance dose of 2.5 mg twice daily. Stimulatory tests such as adrenocorticotropic hormone and luteinizing hormone-releasing hormone tests and posterior pituitary function were not performed at that time as the infant developed Klebsiella pneumoniae and coagulase negative staphylococcus sepsis which may have affected the test results. A magnetic resonance imaging (MRI) scan of her brain at 1 month of age showed a hypoplastic pituitary gland with a shallow pituitary fossa (Figure 1). The posterior lobe of the gland was undescended, lying ectopic at the base of the third ventricle with an absent pituitary stalk (Figure 2). The rest of the MRI was normal with no associated anomalies of the midline forebrain structures. No abnormalities were detected in detailed opthalmological examination of her eyes excluding the possibility of septo-optic dysplasia. When followed up at 8 months of age, she remained well with improved hormonal profiles and normal levels of serum urea and electrolytes. Her weight, height and occipito-frontal circumference were all below the third percentile.

Mandibular fossa of fossil Australians

Many questions about the skeletal adaptations and morphology of hunter-gatherers on the Australian continent remain unanswered. One anatomical region receiving little research in Australian fossils to date is the mandibular fossa. Here we report a study of three size dimensions, three shape indices and three morphological (non-metric) features of the mandibular fossa in 11 fossil Australians comparing them with modern Australo-Melanesian samples. We find broad similarities in past and modern populations in this region. Early and modern Australians and modern Papua New Guineans have elongate, broad and shallow fossae. All three populations show similarity in articular tubercle size, but postglenoid tubercle and entoglenoid process sizes show unexpected affinities. We also test for the possible presence of temporal trends in mandibular fossa size among fossil Australians. Our analyses indicate that none are present.

Spermatogenesis in the archaic hydrothermal vent bivalve, Bathypecten vulcani, and comparison of spermatozoon ultrastructure with littoral pectinids

Summary Bathypecten vulcani is considered a relict species from the Paleozoic, based on shell characteristics such as the presence of calcite prisms. To date, it is the only pectinid species reported from hydrothermal ecosystems. Histological and ultrastructural studies show that spermatogenesis is identical to that of littoral pectinids. The spermatozoon has a 2.7 μm long pyriform head and a 40 μm flagellum. The four mitochondria of the mid-piece are about 1.2 μm in diameter. The nucleus contains dense chromatin fibres and possesses a wide, shallow (0.1 μm) anterior fossa and a narrow, deeper (0.2 μm) posterior nuclear fossa. Comparison of the ultrastructural characteristics of the spermatozoon of B. vulcani with those of littoral pectinids shows that they can be used as a diagnostic feature of this species. In particular, its acrosome characters will be a useful complement to the shell characters in the study of the phylogenetic position of this species in relation to other pectinids.

Galianemys, a New Side-Necked Turtle (Pelomedusoides: Bothremydidae) from the Late Cretaceous of Morocco

The Cenomanian redbeds of southern Morocco have yielded skulls of a new genus and two new species of side-necked turtles, Galianemys whitei and Galianemys emringeri. The genus is based on a series of nine well-preserved skulls and three partial skulls. Galianemys is a pelomedusoid pleurodire belonging to the family Bothremydidae Baur, 1891, because it has: (1) precolumellar fossa absent, (2) foramen stapedio-temporale facing anteriorly, (3) eustachian tube separated from stapes by bone, and (4) exoccipital-quadrate contact. Within the Bothremydidae Galianemys is best resolved as the sister group to Cearachelys because both have the jugal retracted from the orbital margin and a small, slitlike fenestra postotica. Galianemys emringeri has a deep fossa pterygoidei, ventrally exposed prootic, foramen nervi facialis and foramen nervi vidiani, a thicker labial ridge, and the jugal not exposed on the triturating surface, while Galianemys whitei has a shallow fossa pterygoidei, covered prootic and foramen nervi facialis and vidiani, a thinner labial ridge, and a jugal exposed on the triturating surface.

Spermatozoon structure and spermiogenesis in four species of Melanopsis (Gastropoda, Prosobranchia, Cerithioidea) from Israel

Summary The structure of the spermatozoa of four species of Melanopsis (Melanopsidae) is described by light and transmission electron microscopy. All species produce two types of spermatozoa, euspermatozoa (fertilizing) and paraspermatozoa (non-fertilizing). The eusperm of all species are about 42–44 μm long and have a morphology similar to that of other cerithioideans. The head is composed of a laterally flattened nucleus and conical acrosome of approximately equal size. The nucleus has a shallow posterior fossa which houses a centriolar derivative from which the axoneme emerges. The four equal-sized mitochondria of the midpiece are non-helically arranged around the axoneme. Each mitochondrion has an anterior flange and the cristae are plate-like. This midpiece arrangement suggests that the Melanopsidae are more closely related to the Modulidae, Potamididae and possibly Pachychilidae than to other cerithiacean taxa. Posterior to the midpiece is a 10–12 μm-long glycogen piece in which the glycogen granules encircle the axoneme as inner and outer rings. Although the structure of the euspermatozoa is very similar in all four species, there are significant differences in the lengths of the nucleus, acrosome and midpiece between species. These dimensional differences suggest that sperm morphology could be of value in the separation and identification of species within the genus Melanopsis. The oligopyrenic parasperm are about 65 μm long and consist of a head and tail region of multiple flagella. The axonemes of the flagella are positioned centrally within the head and run for its length. Spermiogenesis (both eu- and paraspermiogenesis) is as described for other caenogastropods. During sperm development, spermatids are closely associated with Sertoli cells. Unlike previous reports for some caenogastropods, the Sertoli cells do not completely surround the early spermatids. Instead, long tubular cytoplasmic processes from the Sertoli cells encircle the developing spermatozoa. These processes contain microfilaments which are thought to be composed of actin.

EUSPERMATOZOAN ULTRASTRUCTURE IN BEMBICIUM AURATUM (GASTROPODA): COMPARISON WITH OTHER CAENOGASTROPODS ESPECIALLY OTHER LITTORINIDAE

Euspermatozoa of Bembicium auratum Quoy & Gaimard are examined ultrastructurally and compared with euspermatozoa of other caenogastropods, especially other species of Littorinidae. The acrosomal vesicle is conical, deeply invaginated (accommodating an axial rod) and exhibits radial plates and a weakly developed apical bleb. Unlike euspermatozoa of the Littorininae which have a long tubular nucleus (sheathing a significant portion of the axoneme), the eusperm nucleus of B. auratum is short, rod-shaped and solid with the exception of a shallow centriolar fossa posteriorly. Available evidence suggests this is also the case for other species of Lacuninae and for the Laevilitorininae. The eusperm midpiece of B. auratum consists of the axoneme and 7-9 helically arranged mitochondria (containing short, randomly arranged cristae). Immediately posterior to the annulus, the axoneme is surrounded by nine tracts of glycogen granules to form the glycogen piece. The euspermatozoon terminates in a short end piece, in which the 9+2 axoneme degenerates into isolated microtubules, only two of which survive to the posterior extremity of the cell. Paraspermatozoa have not been observed in any species of Bembicium or in fact any other species of the Lacuninae, suggesting that absence of paraspermatozoa is characteristic of the subfamily (contrasting with well developed round paraspermatozoa of the Littorininae).

Is Exencephaly the Forerunner of Anencephaly?

Exencephaly is said to precede anencephaly resulting from failure of the rostral neuropore closure. In order to verify if the exencephaly induced after neural tube closure would also lead to anencephaly, exencephaly was induced in rat fetuses by maternal administration of a single dose (15 mg/kg) of cyclophosphamide on day 12 of gestation and pregnancy was prolonged by uterine ligation until postconception (PC) day 24. Fetal death was found to increase with prolongation of gestation and no sign of recovery from growth retardation was observed. Alizarin red-S-stained skeletal preparations substantiated the persistence of skull malformations in the exencephalic fetuses. Histological observations of the mesenchyme and the brain indicated degenerative changes that were intensifying with time. The ventricular system expanded progressively; the ependyma was denuded and neural mass lay free in the ventricle. The choroid plexus appeared to be elaborate and extensive. The haemorrhagic capillary network around the brain tissue was highly proliferative and appeared to penetrate the former from the exterior. Tissue necrosis seemed to progress unabated. Cystic spaces appeared beneath the base of the brain and became progressively large and it appeared as if the brain was being pushed out of the shallow cranial fossae. By PC day 24, most of the brain tissue had degenerated, thus giving clearly the appearance of the anencephalic condition.

An Ultrastructural Investigation of Spermatogenesis in the Holopelagic PolychaetesVanadis formosaandKrohnia lepidota(Polychaeta: Alciopidae)

The earliest stages encountered were clusters of spermatogonial cells floating free in the coelom. Neither germinal epithelium nor definitive gonad was observed. Mitotic divisions of spermatogonial cells resulted in large coelomic clusters containing up to 800 cells each. Cells within these clusters were connected to neighboring cells via cytoplasmic bridges that were characterized by a dense collar around the cell membrane and by microtubules traversing the common cytoplasm between cells. Peripheral cells detached from large cell clusters and entered meiotic divisions in the coelom. Spermatid nuclei initially contained granular chromatin that became fibrillar and eventually electron opaque as nuclear elongation and condensation proceeded. The acrosome first appeared in the posterior cytoplasm as a proacrosomal vesicle with an associated Golgi complex. The plate-like proacrosome migrated toward the anterior end of the sperm and reached the apex prior to completion of nuclear condensation. The middlepiece contained 5-7 mitochondria in Vanadis formosa and 8-10 mitochondria in Krohnia lepidota. Two centrioles, perpendicular to each other, were located in the middlepiece with the proximal centriole residing in a shallow fossa at the base of the nucleus. The distal centriole was associated with a nine-spoke, branched anchoring apparatus at the posterior edge of the middlepiece. Sperm development and mature sperm ultrastructure were very similar in V. formosa and K. lepidota. The mature coelomic sperm of K. lepidota were longer than those of V. formosa (8.7 µm vs. 11.0 µm, nucleus + middlepiece). The posterior nuclear region of V. formosa sperm was irregular in shape while that of K. lepidota was symmetrical. A series of dense accessory "membranes" was observed between the nucleus and the plasmalemma of K. lepidota sperm but not in V. formosa. Stored sperm in female worms were observed in V. formosa but no female K. lepidota were available in this study. Sperm storage and elongated sperm structure in alciopid polychaetes may be related to the pelagic environment in which they live and the suspected infrequent encounters between individuals.

Necropsy study of right atrial appendage: morphology and quantitative measurements.

The right atrial appendage (RAA) of 23 randomly selected autopsied patients was examined at necropsy, and data related to orifice size and appendicular depth measurements and features of the endocardial surface were recorded. The study included 21 men and 2 women aged 71 +/- 15 years (range, 32-91); underlying coronary artery disease was present in 16 patients. The orifice size of the RAA measured 2.0 +/- 1.0 cm (range, 0-5 cm). The orifice size was slightly, but not significantly, smaller in patients over age 70 years compared with those younger than 70. In hearts weighing more than 450 g, the orifice was significantly larger (2.6 cm) than in hearts weighing less (1.4 cm). The appendicular depth averaged 1.2 +/- 0.7 cm (range, 0-2.5 cm), and a significant difference was noted in patients older and younger than 70 years (depth of 0.9 cm vs. 1.5 cm; p less than 0.05). The RAA depth was 0.5 cm or less in 8 patients (35%), 6 of whom represented patients older than 70 years. Antemortem mural thrombi within the RAA were found in three hearts and completely filled the lumen in one. The suitability of the RAA as a site for atrial pacing and secure electrode implantation, particularly when anatomical deficiencies are identified, was also considered. Atrial lead displacement, a relatively common postoperative complication, may be related more to implantation within a shallow appendicular fossa and/or one with larger orifice than to faulty technique.(ABSTRACT TRUNCATED AT 250 WORDS)

Cranial base morphology in untreated hydrocephalics

Cephalostat radiographs of five untreated adult hydrocephalic patients were studied in order to explain events related to increased intracranial pressure and to differentiate them from those following shunt treatment. The hypophyseal fossa appeared to be well formed in every patient and no shallow fossa was found. The tip of the dorsum sella was rounded. The distances from the nasion to the sella region were increased, but those from the basion were decreased. The hypophyseal fossa was depressed inferiorly. The cranial base angle was more obtuse than in normal subjects or shunt-treated patients. The findings seem to indicate that a shallow. J-shaped sella results from the combined effect of the hydrocephalic condition and the shunt treatment, which cause a shortening of the anterior cranial base and move the fossa upwards and posteriorly away from the sphenoid bone.

Anatomical Identification and Anthropological Consideration of a Humerus of the Dugong (<i>Dugong dugon</i>) from Urasoe Shellmound in Okinawa Island

The author made a comparative anatomical identification of a humerus of the dugong excavated from Urasoe shellmound with Ichiki type potteries (late Jomon period) in Okinawa island. The specimen, weighing 460 g, is 195 mm long and is calcified to a little extent. In close to a big head are a short neck and two tubercles-a greater and a lesser. There is a long, narrow and shallow intertubercular groove. It has a long deltoid crest and a spiral groove of the radial nerve. In the posterior aspect there is a shallow olecranon fossa. In South Sea Islands, for instance, the Palau islands, atlases of the sea mammals have been generally used for personal ornaments. But it still remains undetermined whether this specimen was used for personal ornaments or not.

Spermatogenesis in anthozoa: Differentiation of the spermatid

The fine structure of spermatids has been examined in Calliactis, Protanthea, Gonactinia and Parazoanthus (Cnidaria, Anthozoa). The sperm cells are relatively simple and lack distinct acrosomes. Their nuclei, spherical in the zoanthid, in the actinians are slendertipped cones. Condensation of the chromatin is interpreted in terms of progressive coiling of densely-stained filaments and the elimination of nucleoplasm. Nuclear elongation occurs in the absence of microtubules. A well-developed centriolar complex is attached to the nuclear envelope by fibres and in this area (that of a shallow fossa in actinian spern) the nuclear membranes seem to be thickened. The centrioles are surrounded by a mitochondrial collar, especially pronounced in Calliactis. In contact with the mitochondria and nucleus is a ring of lipid-containing vesicles 300-700 nm in diameter. A system of densely-staining vesicles 150-300 nm in size corresponds to the "pro-acrosomal vesicles" described for other coelenterates. They are scattered in the peripheral cytoplasm and are regarded as derivatives of the endoplasmic reticulum. Problems of organelle function and of differentiation during spermiogenesis are discussed.

Roentgen appearance of lacrimal-gland tumors.

tumors of the lacrimal glands frequently cause changes in the adjacent bone structures that are recognizable roentgenographically. Some authors (1, 3, 6) have stated that roentgenograms rarely show appreciable changes in the presence of these tumors. Jones and Pfeiffer (4), on the other hand, have published a report—the only one of its kind—emphasizing the importance of such changes in the diagnosis and prognosis of lacrimal-gland tumors. The purpose of this paper is to re-emphasize the important role of roentgen evaluation of these lesions. Pathology The lacrimal gland lies in a shallow fossa in the superolateral portion of the orbit behind the superior orbital rim (Fig. 1). This fossa represents an indentation in the roof of the orbit that can better be appreciated by palpation than by inspection of the dried skull. Epithelial tumors of the lacrimal gland appear similar to salivary-gland tumors and are classified as (a) mixed tumors, (b) carcinomas—adenoid-cystic type, and (c) carcinomas—miscellaneous types (8). Mixed tumors are slowly expanding benign neoplasms that exert local pressure against the adjacent bone. Frequently tumor nodules are found in the capsule and, unless these are completely removed, recurrences are common. Carcinomas, either of the adenoid-cystic or of the miscellaneous types, however, tend to invade adjacent bony structures early. This invasion is not limited to the lacrimal fossa but may extend superiorly through the orbital roof intracranially, laterally into the sphenoid, malar or temporal bones, or medially toward the apex of the orbit. Metastasis to the skull and lungs is a frequent occurrence in the later stages. The prognosis of lacrimal-gland tumors depends on the histologic changes and the extent of the growth (2). Benign mixed tumors, if completely removed with the capsule intact, have a favorable prognosis. In contrast, carcinomas, either of the adenoid-cystic or miscellaneous type, have been almost universally fatal. The prognosis of lacrimal-gland tumors is much more serious than of the histologically similar salivary-gland tumors (5, 7). This difference is due to the immediate proximity of the lacrimal gland to bone and a tendency to early bone invasion. In addition, the difficult surgical approach and hesitancy in performing an early radical operation contribute to the poor prognosis. Methods and Results The present study is based on 12 patients with lacrimal-gland tumors whose ages ranged from fourteen to seventy-nine years. Their clinical histories are summarized in Table I. The most frequent presenting symptoms were proptosis, diplopia, and blurred vision, which were related to an expanding mass in the lacrimal fossa. Four patients had benign mixed tumors. Three of these are well five, fourteen, and twenty-three years after the initial excision; the fourth patient died of unrelated disease without local recurrence six years after operation.

CHRONIC NONINFLAMMATORY LESIONS OF THE KNEE JOINT

The knee joint is the largest joint in the body, and one looks at its structure in the skeleton, only to marvel at its stability during life. The two broad surfaces of the femur and tibia are fitted together only lightly, the round condyles of the femur resting in the slightly concave surfaces of the tuberosities of the tibia. The semilunar cartilages deepen somewhat the shallow fossae for the reception of the condyles, and to a certain extent increase stability, although they do not act as ligaments. They are fibrocartilaginous and, therefore, are more prone to rip or to tear than they are to fracture. The patella is a sesamoid bone, and is of importance in maintaining stability of the joint only so far as its association with the quadriceps muscle is concerned. It is, therefore, evident that the strength of the knee joint must be furnished by a satisfactory