Geriatric medicine in Hull: a comprehensive service.

A partially age-related admission policy coupled with a "single-ward" scheme for treatment and rehabilitation was introduced by the Hull geriatric department in 1970. With rare exceptions, elderly patients needing hospital care have been admitted directly to the geriatric unit, and the proportion of the retired population admitted by the general physicians has been greatly reduced. The proportion of inpatients needing continuing care has been reduced to less than 20%, the mean length of inpatient stay has fallen to under 30 days, and separate long-stay wards are no longer needed. More than 91% of patients are admitted without preceding domiciliary assessment, and only 5-6% of admissions are transferred from other units within the area.     

RU486 blocks the secondary surge of follicle-stimulating hormone in the rat without blocking the drop in serum inhibin.

The stimulatory effect of progesterone on the release of the primary surges of serum LH and FSH is well characterized. Less is known about the relationship of progesterone to the secondary FSH surge. We used the antiprogesterone, RU486, to block the action of progesterone and studied the effects on the primary surges of LH and FSH, and especially on the secondary surge of FSH. Proestrous rats were treated with RU486 at 1,200 h. Rats were killed on proestrus and estrus, and serum levels of LH, FSH, and inhibin were measured. In all RU486-treated rats, the primary surges of LH and FSH were significantly attenuated, and the secondary FSH surge was completely abolished, despite a drop in inhibin levels following the primary surges. A high replacement dose of progesterone, delivered immediately after RU486 treatment, did not restore the primary surges of LH and FSH, or the secondary surge of FSH. These data suggest that other factors in addition to a drop in inhibin are responsible for producing the secondary FSH surge.     

Sperm cells of the pollen tubes of Brassica: Ultrastructure and isolation

Summary Sperm cells of pollen tubes grown both in vivo and in vitro form a male germ unit. Extensions from both sperm cells of each pollen tube are closely associated with the tube nucleus. A high yield (2.7 × 10⁴. 20 mg^–1 pollen grains germinated) of intact sperm cells was obtained following release by osmotic shock from pollen tubes grown in vitro. Structural integrity of isolated sperm was maintained by isolation at low temperature in an osmotically balanced medium. At 4° C many isolated sperm pairs were still enclosed within the pollentube inner plasma membrane. Sperm cells not enclosed within this membrane no longer remained connected as a pair. During isolation vesicles formed on the sperm cell surface from disruption of the fibrillar components bridging the periplasmic space. Both in the pollen tube and after isolation the sperm nucleus is in close association with at least one region of the sperm plasma membrane. Sperm isolated at room temperature showed the presence of nucleopores, and nuclei were euchromatic, instead of heterochromatic as in intact sperm in the pollen tube.     

A scanning electron microscope study of healthy pecan tissues showing the presence or absence of internal fungal contamination

Summary Healthy pecan, Caryaillinoensis (Wang) Koch, tissue was obtained from an 8-year-old grafted Cherokee tree. Dormant buds were gathered and stored until spring growth. After rigorous surface sterilization, halves of both stored and freshly harvested dormant buds and of actively growing shoots were plated onto sterile PDA. Corresponding halves wre fixed in FAA and processed for scanning electron microscopy (SEM). All plated dormant buds (both stored and freshly harvested) showed presence internally of a fungus, and SEM studies revealed hyphalike strands similar to those of the isolated fungi within cells of those buds. The spring flush was sterile in culture, and strands were absent in SEM studies.     

Plasmodium falciparum: Synthesis of glycoprotein by cultured erythrocytic stages

The human malarial parasite, Plasmodium falciparum, incorporated significant radioactivity into glycoconjugates when cultured in the presence of [¹⁴C]- or [³H]glucosamine for 48 to 50 hr. Digestion of the labeled proteins with pronase and subsequent precipitation with absolute ethanol showed that 90 to 95% of the radioactive glucosamine was incorporated into the precipitated material. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the labeled macromolecules revealed eight bands with approximate molecular weights from 19,000 to 90,000 daltons.     

Tissue pressures and fluid dynamics in the kidney.

The kidney has several characteristics which make renal pressures and fluid dynamics unique when compared to other organs. Renal blood flow is roughly 100 times that of skeletal muscle. The renal circulation consists of two distinct capillary beds in series: a high pressure system in the glomerulus that favors filtration and a low pressure system in the peritubule network that favors reabsorption. The hydrostatic pressure in the glomerular capillary is 4-6 times higher than the hydrostatic pressure in the peritubule capillary so that approximately 25% of the plasma is filtered. The bulk of the filtrate is subsequently reabsorbed by the peritubule capillary network. Micropuncture techniques have been used to obtain quantitative measurements of the pressures and fluid dynamics of the peritubule microcirculation. The net force for uptake of all the fluid reabsorbed by a single proximal tubule up to the point of micropuncture is 21 mm Hg acting over a capillary bed with a permeability surface area product of 2 nl/min per mm Hg. In contrast to subcutaneous tissue and muscle, the renal interstitial fluid pressure is positive. The consequence of a positive interstitial fluid pressure is that normal lymph flow is relatively high and changes in interstitial fluid pressure have relatively little effects on lymph flow.