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Biomedical subjects

B F Martin

Publications and source records attributed to B F Martin.

At least 19 recordsLinked to original sources
PubMed1984

The formation of abdomino-perineal sacs by the fasciae of Scarpa and Colles, and their clinical significance.

It has been shown that the membranous layer of the subcutaneous tissue, known as Scarpa's fascia, is confined to an oval area on each side of the abdominal wall. By its attachment to the deep fascia it encloses an obliquely directed oval sac which extends into the perineum by three pocket-like diverticulae. The fascial extension which forms the pockets is known as the fascia of Colles. Medially, the sac blends with the fundiform ligament, so that the sacs do not communicate with each other or with the interfascial space deep to the penile dartos. Laterally, the inferior margin creates the crease-line of the groin by its attachment to the fascia lata. Between these attachments the pockets arise from the sac. The lateral pocket continues into the superficial perineal pouch. The medial pocket, together with the intermediate, occupies the scrotum or labium majus. The intermediate pocket is associated with the spermatic cord or the round ligament of the uterus and blends with their coverings posteriorly. In the male it terminates just above the testis. The significance of the fascial arrangements in relation to urinary extravasation is discussed, and also the relationship of the intermediate pocket to an indirect inguinal hernia.

Abdominal Muscles↗
PubMed1981

Development and maturation of the bladder epithelium of the guinea pig.

In the fetal guinea pig, transitional epithelium develops at a little beyond mid-term of gestation from a single layer of columnar cells. Some of the cells elongate and overlap their neighbors, but remain attached to the basement membrane by fine cytoplasmic stalks. The fetal epithelial cells do not markedly vary in size. Within the basal layer, which is the site of mitotic activity, many cells are large and binucleate, which suggests that basal cell fusions occur. It is believed that these cells eventually become surface cells. The luminal membrane develops its asymmetric structure (asymmetric unit membrane; AUM) following the appearance of AUM-bound vesicles in the apical cytoplasm, indicating that they are the source of the luminal AUM. The vesicles originate in the Golgi cisternae and are initially cup-shaped. The immature surface cells are characterized by microvilli of varying density on the luminal surface. The characteristic mature surface ridges appear to develop from rows of microvilli which fuse and link with other rows to form a reticular pattern. The process commences shortly after mid-gestation. By -15 to -10 days, the majority of cells have a well-developed surface pattern. Microvilli, however, remain prevalent in some small surface cells. These are believed to be the younger surface cells derived from pyriform intermediate cells, with the surface not fully differentiated. During the first 3 postnatal weeks, the basal cell population reaches the adult level and mitotic activity declines. The epithelium also acquires its adult morphology, whilst its functional maturity is indicated by the adult distribution and content of both glycogen, which is reduced, and alkaline phosphatase, which is increased. Rejection of cells occurs both antenatally and postnatally, and is probably a consequence of excess cell production.

Animals↗
PubMed1980

Basal sympatho-adrenal function in quadriplegic man.

Plasma catecholamines (CA) were measured at 15 min intervals over a 4 h time period in 5 supine, chronic, quadriplegic male humans subjects. CA levels fluctuated over time through a wide range, often exhibiting brief bursts of very high CA levels which differed from the slower duration fluctuations seen in normal subjects. Spikes of increased plasma CA often, but not always, correlated with muscle spasms, urination or pain and were often accompanied by appropriate changes in blood pressure and heart rate. When examined over a 4 h period, the subjects' median plasma norepinephrine (NE) levels (305.5 +/- 26.8 pg/ml) were within the normal, age-corrected range while plasma epinephrine (E) levels (210.4 +/- 48.9 pg/ml) were higher than those seen in normal control subjects (89.0 +/- 6.9 pg/ml) tested under similar conditions. Also, plasma NE and E levels in the quadriplegics correlated positively in 3 out of 5 subjects which was similar to the balance in normal subjects. Therefore, resting sympatho-adrenal tone, as indicated by plasma catecholamine levels, in quadriplegics is not decreased, but is either normal or increased. Activation of these systems is probably under the control of local spinal reflexes which appear to be capable of maintaining many of the resting automatic functions of the individual.

Adrenal Glands↗
PubMed1980

Baclofen in the treatment of detrusor-sphincter dyssynergia in spinal cord injury patients.

The pharmacodynamics of baclofen on the bladder and urethral sphincters in acute and chronic spinal cord injury male patients were evaluated. A total of 100 supine and sitting urodynamic profiles was done in 25 patients. Baclofen decreased external urethral sphincter resistance by depressing pudendal-to-pudendal nerve reflex through spinal cord presynaptic hyperpolarization. This new centrally acting antispastic drug produced a significant reduction of residual urine in 73 per cent of the cases within an average of 4.98 weeks. Baclofen is a new alternative in the medical treatment of postural non-electrically induced detrusor striated sphincter dyssynergia in spinal cord injury patients. Indications for external sphincterotomy are discussed.

Adult↗
PubMed1980

The umbilical and paraumbilical veins of man.

During its transit through the umbilicus structural changes occur in the thick wall of the extra-abdominal segment of the umbilical vein whereby the components of the intra-abdominal segment acquire an essentially longitudinal direction and become arranged in fibro-elastic and fibro-muscular zones. The vein lumen becomes largely obliterated by asymmetrical proliferation of loose subendothelial conective tissue. The latter forms a new inner zone within which a small segment of the lumen persists in an eccentric position. This residual lumen transmits blood to the portal system from paraumbilical and systemic sources, and is retained in the upper part of the vein, even in old age. A similar process of lumen closure is observed in the ductus venosus. In early childhood the lower third of the vein undergoes breakdown, with fatty infiltration, resulting in its complete division into vascular fibro-elastic strands, and in old age some breakdown occurs in the outermost part of the wall of the upper two thirds. The paraumbilical veins are thick-walled and of similar structure to the umbilical vein. Together they constitute an accessory portal system which is confined between the layers of the falciform ligament and is in communication with the veins of the ventral abdominal wall. The constituents form an ascending series, namely, Burow's veins, the umbilical vein, and Sappey's inferior and superior veins. The main channel of Sappey's inferior veins may be the remnant of the right umbilical vein since it communicates with the right rectus sheath and often communicates directly with the portal system within the right lobe of the liver. The results are of significance in relation to clinical usage of the umbilical vein.

Adolescent↗
PubMed1979

Effects of transcutaneous nerve stimulation on the vesicourethral function in spinal cord injury patients.

There were 17 spinal cord injury men with drug-resistant pain who were treated with transcutaneous nerve stimulation. Bladder and sphincter dysfunctions were evaluated by gas cystosphincterometry and rectal sphinctero-electromyography with the patient in 2 different positions. With the use of transcutaneous nerve stimulation for pain we noted no demonstrable urodynamic changes in acute and chronic paraplegics and chronic quadriplegics. However, there was an increase in the urethral pressures and in the rectal electromyogram spike potentials in acute and recent (less than 2 years post-injury) quadriplegics with postural detrusor-striated sphincter dyssynergia. Therefore, caution is necessary when transcutaneous nerve stimulation is used in this particular group of patients since it might be detrimental to the genitourinary tract.

Adult↗
PubMed1978

Effects of bethanechol chloride on the external urethral sphincter in spinal cord injury patients.

The neuropharmacodynamics of bethanechol chloride on the external urethral sphincter in male spinal cord injury patients with chronic lesions have been investigated. There were 90 cystosphincterometric and sphincteroperineal electromyographic studies conducted on 45 subjects in 4 different positions, showing varying urodynamic patterns. A gross postural cystophincteric discordant reflex was noted in the majority of patients with recent complete upper motor neuron bladders (less than 2 years in duration). The external sphincter tends to be coordinated in late cases of quadriplegics and in all paraplegics. With the administration of bethanechol chloride there was an increase in the striated sphincter pressure profile when the patient was in the sitting position, resulting in detrusor sphincter dyssnergia. This phenomenon seems to be dose-related. When the dose of bethanechol chloride is adjusted according to the types of vesicourethral dysfunctions or in combination with dantrolene sodium the most beneficial non-surgical rehabilitation of the urinary tract can be obtained in this particular group of patients.

Adolescent↗
PubMed1977

A study of light and scanning electron microscopy of the lining epithelium of the guinea pig bladder following artificial ulceration.

Following artificial ulceration of the guinea pig bladder epithelium, study by light microscopy showed that mitotic activity occurs within 24 hours in the basal layer of the remaining epithelium; which leads to thickening, disorganization and cell shedding. At the ulcer margin, the epithelium forms a rolled edge, from the extremity of which a two-layered sheet of flat cells grows over the edematous ulcer bed, and the ulcer site is protected during dilation of the bladder by localized muscle spasm. Healing is effected within about one week, as the mitotic activity declines. Organization of the new epithelium commences at the periphery and the cells acquire glycogen and alkaline phosphatase. Study by SEM, which included normal bladders, confirmed that new epithelium spreads from a rolled epithelial edge, and also showed that cells undergoing rejection have globular profiles with surface microvilli. The immature epithelial cells are markedly distorted from mutual pressure during migration and their surfaces show only short microvilli. Ulcers heal after four to seven days, depending on size, and the new cells rapidly assume the pentagonal and hexagonal outlines and the reticular pattern of surface ridges, characteristic of mature surface cells. The ridges apparently develop by fusion of rows of microvilli. By the tenth day it is difficult to identify the original ulcer site.

Animals↗
PubMed1977

A study by scanning electron microscopy of the bladder epithelium of the guinea pig.

Under scanning electron microscopy (SEM) the surface cells of the guinea pig bladder have pentagonal or hexagonal outlines. Their borders are clearly defined since they are elevated. They possess a large reserve of surface membrane which is markedly folded and wrinkled when the bladder is empty. The folds disappear and the cells become flat during distension. The luminal surface is characterized by numerous reticular ridges which are a remarkably constant feature and persist even under acute artificial distension. A small proportion of the surface cells are small and have less than five sides. Since they show only sparse microvilli as a surface feature, they have a smooth appearance. These are believed to be young surface cells which have just emerged from the intermediate layer, and have not yet acquired the ridged pattern of mature cells.

Animals↗
PubMed1977

Postnatal growth of Brunner's glands in the mouse.

In the newborn mouse the glands of Brunner consist of a few tubular downgrowths from the proximal duodenal crypts. Within three weeks the characteristic 'comma' shape of the gland is established by later downgrowths from more distal growths. The gland cells, although specialized from birth, show a high mitotic index, and a high labelling index with 3H-T, during the first three weeks, and particularly during the first two weeks. Nevertheless, the daily mitotic rate during this period is insufficient to account for the daily addition of glandular cells, suggesting that there is a continuing contribution of cells from the crypts. After this time, however, the mitotic activity of the mature gland cells is sufficient to account for the continuing increase in cell population. After the fourth postnatal week the mitotic and labelling indices decline markedly, and although mitoses are rarely seen in individual sections from older animals, cellular addition at a very slow rate is sufficient to account for the gradual expansion in size of the gland, and the process continues long after the adult body weight has been established.

Animals↗