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Horseradish peroxidase (HRP) was injected into the thalamic ventral tier of squirrel monkey and the brainstem was examined for the presence of HRP-reactive cells in the external cuneate nucleus (ECN), nuclei Z and X, and the mesencephalic nucleus of the trigeminal nerve (MNV). Results indicate that the ECN, Z and X have a direct projection to contralateral ventral tier. Thalamic projecting cells in the ECN are located predominantly in the medial part of this nucleus. The MNV projects bilaterally to the ventral tier but predominantly to the ipsilateral side. Consequently, the present report establishes evidence that the above nuclei, which are known to be extensively interconnected with cerebellum, spinal cord and/or other brainstem nuclei, also have a thalamic projection in a New World primate, (Saimiri sciureus).

From newly incident cases in Western Canada, 415 patients with superficial spreading melanoma (SSM), 128 with nodular melanoma (NM), and 56 with lentigo maligna melanoma (LMM) were interviewed, with age- and sex-matched controls chosen from the general population. The associations of these 3 subtypes with pigmentation, skin reaction to sun, different types of sun exposure, sunburn, and suntan were assessed. Compared to the other types, LMM occurred in older patients, and 75% of lesions occurred on the head and neck: It was less strongly related to pigmentation factors, intermittent sun exposure, and skin reaction to sun. The associations of SSM and NM with pigmentation, chronic sun exposure, skin reaction, and suntan were very similar: Both were associated with intermittent sun exposure, but SSM was more strongly related to vacation exposures than was NM. These results were compared with those from a similar Australian study. While LMM appears different in its etiology from SSM and NM, there is no strong evidence of major etiological differences between SSM and NM.

According to the type of L. howensis the species belongs to the subgenus Levinseniella instead of the subgenus Monarrhenos as believed before. The genital atrium has two male pockets and one female pouch.

To decrease cellular degeneration and promote standardization of methods, the optimal conditions for urinary cytology need to be established. In separate experiments under controlled conditions, dissociated malignant human and benign rat bladder cells were collected and suspended in urine supernate at pH 4.5, 6.0 and 8.0. One-half of each suspension was added to an equal volume of 50% methanol, and aliquots were than examined at 1/2, 2, 24 and 72 hours for preservation of nuclear and cytoplasmic morphology and staining reactions. Cytologic detail was better preserved at pH 4.5, with little difference between fixed and unfixed specimens. Cellular morphology progressively deteriorated with increasing pH and prolonged storage. Fixation after collection improve preservation in urine of pH greater than 4.5. The pH of the first voided morning urine can be lowered by the ingestion of 1 gm of vitamin C at bedtime, improving cellular preservation both before and after voiding. These methods, if widely adopted, will improve the preservation of urine samples and reduce the variations in collection and preservation of specimens at different institutions.

The topographic arrangement and cytoarchitecture of cells in the ventral posterolateral nucleus (VPL) of a prosimian primate (Galago senegalensis) were studied using horseradish peroxidase (HRP) and Golgi impregnation techniques. Following cortical implants of HRP, reactive neurons in VPL are organized into medially concave lamellae which extend through the dorsoventral and rostrocaudal dimensions of the nucleus. After implant in forelimb and hindlimb areas of motor-sensory cortex, labeled cells are confined to the medial (VPLm) and lateral (VPLl) portions of VPL, respectively. HRP-positive cells in the ventral part of each lamella are organized into clusters which correspond to the clusters of cells and "parcellated-bursts" of preterminal debris previously described in bushbaby VPL (Pearson and Haines, this volume). HRP-reactive cells in the ventral intermediate nucleus (Vim) are evenly distributed as contrasted to the tightly clustered groups of somata in the adjacent VPL. This evidence argues in favor of the presence of Vim in dorsal thalamus of this prosimian. Golgi impregnations reveal two main types of relay cells in Galago VPL. Type I cells have multiangular somata, straight distal dendrites, and primary dendritic branch points which are free of appendages. Tye II cells have rounded somata, sinuous distal dendrites, and clusters of appendages located at primary branch points. Intermediate cells (i.e., cells with morphological features in between types I and II) are also present in VPL. Comparison of tufted Golgi impregnated cells with neurons labeled with HRP shows definite similarities in somata size and shape, and in the orientation of proximal dendrites. This evidence corroborates the relay nature of the tufted neurons in VPL. Relay cells in Galago VPL have morphological features which are similar to those of relay cells in lateral and medial geniculate nuclei of cat and primate. Type III cells have small round somata, radiate dendrites with elaborate appendages, and axons which appear to be intrinsic to VPL. Consequently, these cells are considered to be interneurons in the VPL of Galago. Glial-like neurons (type IV cells) were also observed. These have beaded dendritic processes similar to those which presumably represent presynaptic boutons in other species. Consequently, these cells are also assumed to function intrinsically within VPL.

The configuration of somatosensory relay nuclei and termination of spinothalamic fibers were studied in the dorsal thalamus of a prosimian primate(Galago senegalensis) using Nissl, Klüver and Barrera ('53), Weil ('45), and Fink and Heimer ('67) methods. The ventral posterolateral nucleus (VPL) is divided into medial and lateral parts (VPLm and VPLl, respectively) by a sheet-like lamina of fibers. Spinothalamic input to Galago VPL is somatopically arranged; input from the forelimb terminates in VPLm and that from hindlimb in VPLl. In addition, preterminal debris in caudal VPL is dense and organized into "parcellated bursts" (terminology of Mehler, '69). Consequently, the nature of the spinothalamic debris in VPL of Galago is similar to that reported for higher primates (Mehler et al., '60). Located dorsomedial to the rostral extension of VPL is a zone of large, deeply staining cells designated as the ventral intermediate nucleus (Vim). Following hemisection at either cervical or lumbar spinal cord levels, preterminal debris, independent of that coursing into VPL, enters the Vim. This substantiates the presence of an intermediate nucleus (i.e., Vim) between VPL and the more rostral ventral lateral nucleus. In the medial thalamic region, axonal degeneration is located in the central lateral nucleus (CL) and in the densocellular and the multiform portions of the dorsomedial nucleus. Only fibers of passage are identified in the centre median, the paracentral and the subparacentral nuclei. The posterior nuclear group (PO) in Galago is divided into medial and lateral parts designated as POm and POl, respectively. In addition, PO contains three distinct nuclei: 1) the magnocellular (MC) portion of the medial geniculate nucleus; 2) the nucleus limitans (Lim); and 3) the suprageniculate nucleus (SG). Following spinal cord hemisection, preterminal debris is located throughout the POm and around cells of the MC. Lim and SG contain no discernible degeneration. Preterminals are also found in a group of cells designated as the caudal part of the central lateral nucleus (CLC).

The morphology of neurons in the subthalamic nucleus (STN) of the lesser bushbaby (Galago senegalensis) is described in coronal brain sections processed by Golgi- and Nissl-staining techniques. Quantitative and statistical methods are used to evaluate (1) soma size and shape, (2) dendritic field size, shape, and branch frequency, (3) the number of dendritic and somatic spines per neuron, and (4) neuron location within the STN. Principal components analysis of these variables suggests that three classes of neurons are present. Two of these classes are considered to be projection cells, referred to as elongate-fusiform and radiate neurons, respectively. Elongatefusiform neurons have somata and dendritic fields which are large in diameter, extremely fusiform in shape, and give rise to few appendages. Somata and dendritic fields of radiate neurons are smaller in diameter, more rounded in shape, and support more spines than the elongate-fusiform neurons. The third class of cells in Galago STN is tentatively identified as consisting of interneurons on the basis of small soma and dendritic field size, thin and varicose dendritic morphology, and the presence of multilobulated dendritic appendages.

Studies carried out in 1978 and 1981 found postneonatal mortality to be associated with poor environmental conditions. Since then, many changes have occurred to the environment. This study was designed to discover which factors are now associated with a higher risk of postneonatal death. A retrospective case-control study was carried out using 107 cases and 422 controls matched only for date of birth, to look at the effect of area of residence, social class, mother's age, and sex, birthweight, legitimacy and number of siblings. Fifty-eight per cent of the deaths were due to the sudden infant death syndrome, making this the leading cause of death. Causes previously absent from the death certificates are now appearing, particularly prematurity related deaths which now account for almost 6 per cent. The deaths were found to occur more frequently at home, in the winter, and at a peak age of 2 to 4 months. As shown previously in Nottingham, the deaths were more likely to have been male (relative risk 2.03), illegitimate (2.91), and of low birthweight (28.8). Total mortality was significantly higher in babies of mothers aged 19 or less and in babies of manual workers. Surprisingly, babies born to unemployed parents were found to have a very low relative risk of death (0.26). Mortality is still higher in the city than the suburbs and in areas of deprivation. Although still a risk factor for SIDS, high parity of the mother was found to be non-significant for postneonatal mortality in total.(ABSTRACT TRUNCATED AT 250 WORDS)

A method of improving information about injuries sustained in road traffic accidents is described. It was achieved by combining data from the police with that from the accident and emergency department in such a way that patient confidentiality was preserved. This improved data base shows that present estimates of the number of injuries sustained on the road are too low and that assessments of their severity are probably inaccurate.

The primary visual cortex is known to process stimuli in a given part of the visual field such that divisions of the cortical column into orientation and ocular dominance minicolumns are present. Applying a model incorporating both the Hebb learning hypothesis and a Mountcastle-like organizational structure to the visual cortex, we predicted that the processing capabilities of the column involve dynamic interactions among minicolumns and are much greater than presently documented. In particular, processing of rotational stimuli in area 17 was suggested by the model. Motivated by this, a psychophysics experiment was conducted that demonstrated a spatial-temporal filling-in process in apparent motion. We have now presented this "human illusion" to cats and recorded from units in area 17 with results which clearly demonstrate striking phenomena not simply understood. The purpose of this note is to present our experimental paradigm with the preliminary results.

A simple methoxylated derivative of the triazine dye, Procion blue H-B, selectively precipitates rabbit muscle lactate dehydrogenase from solution. Optimum protein precipitation occurred at an enzyme subunit:dye ratio of approximately 2:1 and was fully reversible upon addition of competitive ligands such as NADH. With a crude extract of rabbit muscle, affinity precipitation with the dye followed by dissolution with NADH yielded homogeneous lactate dehydrogenase in 97% overall yield.

A double immunofluorescence labeling method was used to study the localization of serotonin (5-HT)- and substance P (SP)-like immunoreactivities within neuronal fibers in the caudal spinal trigeminal nucleus of the rat. The 5-HT- and SP-immunoreactive fibers share extensive topographical overlap within the superficial laminae of the caudal trigeminal nucleus; however, the majority of stained fibers are immunoreactive for either 5-HT or SP, but not both simultaneously. A small population of fibers in which 5-HT and SP are co-localized is present and restricted to the marginal zone as well as the inner and outer layers of the substantia gelatinosa. The results of the present study suggest that fibers containing coexistent 5-HT and SP may be involved in the processing of nociceptive somatic sensation in the medullary dorsal horn of rat.

Photoleter anterouterus Fischthal & Nasir, 1974, from Pelecanus occidentalis Linnaeus and Pelecanus erythrorhynchos Gmelin from Florida, USA and the ventro-genital complexes of Photeleter gastrophilus (Kossack, 1910) from Delphinus delphis Linnaeus from Queensland, Australia and of Phocitrema fusiforme Goto & Ozaki, 1930 from Alopex lagopus (Linnaeus) and Phoca vitulina Linnaeus from Alaska are redescribed. The genus Photoleter Odhner, 1914 is emended and compared with Phocitrema Goto & Ozaki, 1930 and both genera are compared with members of, and as a result transferred from the family Opisthorchiidae Looss, 1899 to, the subfamily Centrocestinae Looss, 1899, family Heterophyidae Odhner, 1914.

Two patients with filling defects on films of the upper urinary tract caused by venous impressions are reported. To date, the literature includes 22 other cases. These cases are frequently associated with hematuria, flank or abdominal pain; the filling defect might be found incidentally during the evaluation of another problem. The two most frequent causes are varices--of renal vein, renal pelvic vein, ureteral veins, and normal renal vessels. Generally, the lesions were not diagnosed without surgical intervention. The filling defects of our cases were caused by other types of lesions. Their diagnosis was made nonoperatively through the use of intravenous pyelography, renal arteriography, and retrograde phlebography. Filling defects caused by venous impressions on the upper urinary tract should be diagnosed by the use of these three studies rather than surgically.

This investigation determined choice of compliance-resisting behaviors on the basis of compliance-gaining strategy, gender of parent, and gender of adolescent. One hundred and eighteen 9th- through 12th-grade students identified resistance strategies they would use when confronted with five compliance-gaining attempts: manipulation, nonnegotiation, emotional appeal, personal rejection, and empathic understanding. Each compliance-gaining attempt was associated with a specific parent and a specific compliance-gaining strategy. The results demonstrate significant differences in resistance strategy selected on the basis of parent's gender, adolescent's gender, and compliance-gaining strategy. When mothers employed personal rejection or empathic understanding, the adolescent was most likely to use nonnegotiation. When the mother used an emotional appeal, adolescents used identity management. Fathers who employed manipulation by using an emotional appeal were resisted with justification. When fathers used nonnegotiation or personal rejection, adolescents used nonnegotiation. The father's use of empathic understanding was countered with identity management. Adolescents are more likely to use identity management with their mothers and justification with their fathers. Female adolescents are more likely to use identity management than are male adolescents, while males are more likely to use nonnegotiation and negotiation than are females. Nonnegotiation occurs most often from son to mother, followed by son to father, daughter to father, and daughter to mother.

Neurons in the cuneate nucleus of the rat were examined for gamma-aminobutyric acid-like immunoreactivity (GABA-LI) using antiserum raised against GABA-glutaraldehyde-keyhole limpet hemocyanin. GABA-LI neurons were analyzed for size, shape, and distribution and compared to Nissl-stained neurons. GABA-LI cell bodies were located at all rostral-caudal levels and were distributed randomly throughout the nucleus except at the level of the obex, where they were limited to the peripheral region of the cuneate nucleus. GABA-LI cell bodies had a significantly smaller mean cross-sectional area than the total cuneate neuronal population and comprised 21.5% of the total neuronal population as assessed with Nissl-staining. These results are consistent with the hypothesis that GABA is involved in processing somatosensory information in the rat dorsal column nuclei.

The last decade or so has been the introduction of multi-coloured reactive dyes as substitutes for natural biological ligands in the purification of proteins by affinity chromatography. This paper reviews the evidence for the remarkable selectivity of the interaction of reactive dyes with proteins and describes our recent work with dye analogues. Terminal ring, bridging ring and anthraquinone ring analogues of Cibacron Blue F3G-A were synthesised de novo and shown to interact selectively with the NAD+-binding site of horse liver alcohol dehydrogenase but with affinities differing by several orders of magnitude. It is anticipated that these novel dye ligands will lead to affinity adsorbents with improved affinity, capacity and specificity.

The hypothalamic-pituitary-testicular axis finely regulates levels of circulating sex steroids--especially testosterone and estradiol--and spermatogenesis. Testosterone, directly as an androgen and as a prehormone for estradiol, regulates LH secretion at both hypothalamic and pituitary levels. Leydig cells, principally under the control of LH, produce testosterone. Sertoli cells, under the control of FSH, and sensitive to intratesticular levels of testosterone, produce estradiol. This locally produced estrogen seems to be necessary for maturation of the germ cells. An abnormality in this sensitive control system, leading to elevations in gonadotrophins or steroid levels, may be etiologically important in both germ cell and nongerm cell neoplasia. Testicular cancers are associated frequently with endocrinologic manifestations, which may be more disabling to the patient than the malignant potential of the tumor, especially with childhood Leydig cell tumors. Estrogen dominance with an elevated estrogen/testosterone ratio can be seen in any testicular neoplasm and may result in gynecomastia. It may be due to a decrease in circulating testosterone or to an increase in estrogens. Virilization is seen frequently in Leydig cell tumors of adolescents. Further elucidation of hormonal interrelationships should lead to better understanding of the genesis of testicular neoplasia and to more effective therapy.

We report 3 cases of bilateral renal cell carcinoma associated with von Hippel-Lindau disease. Treatment consisted of local excision or simply shelling out of the lesion from the surrounding tissue. The 3 patients are free of disease (followup 6 to 36 months). Although multifocal the lesions are removed easily; thus, normal renal function is preserved and patients are spared the morbidity and mortality associated with hemodialysis or transplantation.

Colocalization of gamma-aminobutyric acid (GABA) immunoreactivity with somatostatin (SOM), neuropeptide Y (NPY), cholecystokinin (CCK), and vasoactive intestinal polypeptide (VIP) immunoreactivity was demonstrated in non-pyramidal neurons of the basolateral amygdala using a two-color immunoperoxidase procedure. Approximately 80-90% of SOM- and NPY-positive neurons in the basolateral amygdala were also immunoreactive for GABA. Virtually all large CCK-positive neurons also exhibited GABA-like immunoreactivity. About one-half of VIP-positive neurons and small CCK-positive cells were also immunoreactive for GABA.

Between 1 April 1979 and 31 March 1981, 904 residents of the four western provinces of Canada (population 6.5 million), were diagnosed as suffering from primary cutaneous malignant melanoma. Of 801 patients aged 20-79 years, 665 (83%) were interviewed along with control subjects chosen at random from the general population and matched for age, sex, and province. After exclusion of 70 subjects with lentigo maligna or acral lentiginous melanoma, comparisons of the 595 case-control pairs showed that light hair, skin, and eye colour, a history of heavy freckling in adolescence, and a tendency to burn readily and tan poorly in the sun were significant risk factors for melanoma. The strongest primary associations were with blond hair (relative risk 7.1 compared with black hair), light colour of unexposed skin (relative risk 2.4), and severe freckling (relative risk 2.1). These associations were independent of ethnic origin and of recorded amount of exposure to the sun and were somewhat stronger for superficial spreading than for nodular melanoma. This study is the largest and most detailed of an incident series of melanomas to be published to date. The results were consistent with other studies reporting associations between melanoma and poor tanning ability, a tendency to burn easily, and a history of sunburn and showed that light hair colour was the strongest risk factor for the disease.

The morphology of neurons in the centromedian (CM) and parafascicular (PF) nuclei in the lesser bushbaby (Galago senegalensis) is described in coronal and horizontal brain sections using Golgi-, horseradish peroxidase (HRP)-, and Nissl-staining procedures. The CM contains two types of cells referred to as principal neurons and Golgi type II (like) neurons. Cell bodies of principal neurons are relatively large in cross-sectional area (mean = 130.42 micron2), round to spindle in shape, support short somatic spines, and give rise to three to five primary dendrites. The dendrites branch in a "radiate" pattern and possess numerous appendages consisting of narrow, stalk-supported swellings. The presumed axons of these cells are impregnated only in their initial segments. On the basis of the similarity of principal neuron soma shapes and cross-sectional areas with those of HRP-reactive somata following cortical HRP implantation, it is concluded that at least some of the principal neurons in Galago CM project to somatic sensory-motor cortex. Golgi type II (like) neurons have small (mean = 79.43 micron2), round somata which support several spines and give rise to three to four small-diameter dendrites. The dendrites are infrequently branched, sinuous in their courses, and give rise to complex appendages and beaded processes. However, the axons of these cells could not be seen to ramify in the immediate vicinity of the dendritic field or soma, and there is considerable overlap in the cross-sectional areas of Golgi type II (like) neurons seen in Golgi preparations and HRP-stained cells following cortical implant of HRP pellets. Consequently, although Golgi type II (like) cells have traits characteristic of classically described intrinsic neurons, a cortical projection of these cells cannot be ruled out by the present study. The parafascicular nucleus contains two groups of large, radiate cells characterized by the presence or absence of somatic spines. Cells with somatic spines also contain numerous appendages on the dendrites. Cells without somatic spines support only a few, isolated, short dendritic appendages. Numerous small cell-bodied neurons are present in Nissl-stained sections of PF; however, cells which resemble Golgi type II neurons were not observed in the PF in the present Golgi-impregnated material. In contrast to the CM, the large cell-bodied neurons in PF were not found to project to somatic sensory-motor cortex in Galago.

The effect of prostatic massage on the concentration of prostatic acid phosphatase (PAP) in blood serum as determined by radioimmunoassay (RIA) was compared with that determined by a standard enzymatic assay (EA). Serum was drawn from 24 men before prostatic massage and after--at specified intervals, up to twenty-four hours. Three of these men were young, normal controls; 10 had biopsy-proved prostate cancer (CA); 11 had histologically confirmed benign prostatic hyperplasia (BPH). After prostatic massage, 3 of the 10 CA patients (30%) had elevation of PAP as determined by EA and 4 of the 11 BPH patients (36%) as determined by RIA. None of the controls showed elevated levels of PAP by either assay. In all patients elevated levels of PAP by both assays had returned to normal twenty-four hours after massage. It was concluded that serum for PAP testing by either assay method should be drawn before or twenty-four hours after rectal examination to prevent false positive results and the need for retesting.

Cytoarchitectural and hodological evidence is given which supports the contention that the large-celled, intermediate zone between ventral posterior lateral (VPL) and ventral lateral (VL) nuclei is an independent thalamic nucleus, designated as the ventral intermediate nucleus (Vim), in the thalamic ventral tier of Galago senegalensis. Observation of Nissl-stained sections indicates that Vim contains cells which are larger than those in VL and more scattered in appearance than those in VPL. Fink and Heimer stained brains show that after cord hemisection the spinothalamic degeneration in Vim is sparse in amount and scattered in organization as opposed to the 'bursts' of dense degeneration in VPL. Following cortical injection of horseradish peroxidase, thalamocortical relay cells in Vim are distinct form those in VPL in both size and organization. Consequently, this study corroborates previous results on another primate and suggests that a distinct VPL-VL transitional nucleus, Vim, is present in the ventral tier of the prosimian primate galago senegalensis. The functional significance of Vim and its possible role in the evolution of primate locomotor behavior are discussed.

Fibers showing serotonin-like immunoreactivity (5-HT-LI) are demonstrated in the gracile, cuneate and external cuneate nuclei of the cat using avidin-biotinylated horseradish peroxidase and indirect fluorescence immunohistochemical methods. 5-HT-LI fibers are located in all cytoarchitectural subdivisions of the gracile and cuneate nuclei but are restricted to the medial half of the external cuneate nucleus. In all nuclei, 5-HT-LI fibers consist of long, varicose strands showing a wide range in the diameters of both varicosities and intervaricose segments. Results support the concept that serotonergic systems may be involved in the processing of non-noxious somatosensory submodalities.

A retrospective study of 1,100 consecutive renal transplantations done on 959 patients revealed postoperative pyelonephritis in 15 patients, 14 of whom were women. Sixteen of the 20 episodes of pyelonephritis were caused by Escherichia coli and only 4 episodes occurred within the first year after transplantation, thus revealing the crucial differentiation from a rejection episode. When the etiology of the original renal failure was pyelonephritis the incidence of pyelonephritis in the transplanted kidneys was high. This high incidence also was true for cases associated with post-transplantation urological complications. When the etiology of renal failure was diabetes or polycystic renal disease, or when urologic abnormalities pre-existed the incidence of pyelonephritis was low. No transplant or patient loss was caused by post-transplantation pyelonephritis, probably because of prompt, correct diagnosis and a low urological complication rate.

Medical students in Nottingham all complete an honours Bachelor of Medical Sciences course in one department including a research project. The honours programme in community health is described, with results from a survey of the 122 graduates since the medical school started. The 98 (80%) responses showed high levels of satisfaction and gain from the programme, the great majority regarding the course as valuable, enjoyable, and giving both research skills and skills in interpersonal relationships.

A case-control study of 374 patients with primary epithelial cancers of the oral cavity, oro- and hypopharynx, and larynx is reported, the controls being patients with selected other cancers, matched for age and sex. Of all eligible patients, 93% were interviewed. Increased risks were seen with alcohol consumption and, less strongly, with smoking, which for all sites could be adequately fitted by either a multiplicative or an additive model. However, the site-specific relationships were different, alcohol consumption being significantly associated only with oral cavity, pharyngeal and extrinsic laryngeal tumours, and smoking only with intrinsic laryngeal tumours. Increased risks were associated with low socio-economic status, the unmarried state, and poor dental care. No significant associations were seen with specific occupational exposures.

The morphology of neurons in the ventral basal complex (VBC) of the adult opossum (Didelphis virginiana) is described from thick coronal brain sections, using Golgi-, horseradish peroxidase (HRP)-, and Nissl-staining methods. Soma cross-sectional area, dendritic field shape, and the number of appendages (spines) in a defined major branch zone (MBZ) are quantified and statistically analyzed. Results indicate that neurons in opossum VBC have relatively large cell bodies, dendrites which branch in a tufted pattern, and numerous dendritic appendages. These neurons are designated as relay cells because of (1) their tufted dendritic branch patterns, considered characteristic of thalamic relay cells (Ramon-Moliner, '62), and (2) the similarity of their soma sizes with HRP-labeled somata after somatosensory cortical injections. Neurons with traditionally described interneuron morphology do not appear to be present in the VBC of this animal, and, in this respect, the neuronal morphology of opossum VBC is similar to that in rat (McAllister and Wells, '81). Based on statistical analysis of the structural features observed, the presumed relay cells in opossum VBC do not show significant differences in morphology, and consequently are not subdivided into classes. Opossum VBC neurons are recognized as forming a single category in which broad and continuous variations in morphology are indicated. Recognition of a singular class of relay cell is consistent with descriptions for rat and cat VBC (Scheibel and Scheibel, '66), but at variance with a previous report for the primate Galago VBC (Pearson and Haines, '80) subdividing thalamic relay cells into Types I, II, and intermediate categories.

In a survey of the farming population of Orkney, Ayrshire, and East Lothian the prevalence of farmer's lung was estimated at 86 per 1,000 in both Orkney and Ayrshire and 23 per 1,000 in East Lothian. If cases with a negative farmer's lung hay (F.L.H.) precipitin test are excluded these figures are reduced to 43, 36, and nil respectively, but those for Orkney and Ayrshire are still about 20 times higher than any figure previously reported for the prevalence of farmer's lung in Britain.Regional variations in prevalence are probably related both to climatic conditions and to differences in agricultural methods, the latter often being dictated by economic circumstances. Nevertheless the prevalence of farmer's lung could be reduced considerably by the energetic application of preventive measures, backed by financial incentives. The most important of these are efficient drying of hay and cereals before storage, more extensive use of silage, better ventilation of farm buildings, and the introduction of mechanical feeding systems. Individual farmworkers could be taught how to recognize the early symptoms of the disease and encouraged to wear respirators when handling mouldy fodder.