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Biomedical subjects

T D Allen

Publications and source records attributed to T D Allen.

At least 181 records · Page 10Linked to original sources
PubMed1978

Microphallus: clinical and endocrinological characteristics.

The clinical and endocrinological features of 15 male subjects with small but normally formed external genitalia are reviewed. Nine of these patients had a simple microphallus alone, while the other 6 patients exhibited associated central nervous system defects. The endocrine data obtained from both groups were the same and were consistent with defective hypothalamic function. Parenteral testosterone seems to be the present treatment of choice but we believe it should be started early in life to take advantage of the greater hyperplastic response of the young.

Adolescent↗
PubMed1977

Conditions controlling the proliferation of haemopoietic stem cells in vitro.

A liquid culture system is described whereby proliferation of haemopoietic stem cells (CFU-S), production of granulocyte precursor cells (CFU-C), and extensive granulopoiesis can be maintained in vetro for several months. Such cultures consist of adherent and non-adherent populations of cells. The adherent population contains phagocytic mononuclear cells, "epithelial" cells, and "giant fat" cells. The latter appear to be particularly important for stem cell maintenance and furthermore there is a strong tendency for maturing granulocytes to selectively cluster in and around areas of "giant fat" cell aggregations. By "feeding" the cultures at weekly intervals, between 10 to 15 "population doublings" of functionally normal CFU-S regularly occurs. Increased "population doublings" may be obtained by feeding twice weekly. The cultures show initially extensive granulopoiesis followed, in a majority of cases, by an accumulation of blast cells. Eventually both blast cells and granulocytes decline and the cultures contain predominantly phagocytic mononuclear cells. Culturing at 33 degrees C leads to the development of a more profuse growth of adherent cells and these cultures show better maintenance of stem cells and increased cell density. When tested for colony stimulating activity (CSA) the cultures were uniformly negative. Addition of exogenous CSA caused a rapid decline in stem cells, reduced granulopoiesis and an accumulation of phagocytic mononuclear cells.

Animals↗
PubMed1977

The non-neurogenic neurogenic bladder.

The records of 21 children with neuropathic bladder disease are reviewed. The natural history in these cases has been consistent with that of an acquired disorder and the results of urodynamic testing have supported Hinman's contention that the disease is basically a functional one, caused by a discoordination between detrusor contraction and sphincter relaxation. Bladder retraining and specific medication have yielded far better results than were obtained previously by surgical measures alone.

Behavior Therapy↗
PubMed1977

Urodynamic patterns in children with dysfunctional voiding problems.

Simultaneous measurements of the intravesical pressure, electromyographic activity of the anal sphincter and the urinary flow rate in 17 children with dysfunctional voiding problems have shown a variety of unusual patterns, each distinct for the particular child but all with the common denominator of failure to coordinate detrusor and sphincter activity. We postulate that these patterns represent persistence of the transitional phase in the development of micturitional control whereby the child learns to prevent involuntary wetting by forceful contraction of the external urethral sphincter.

Adolescent↗
PubMed1977

The transpubic approach for strictures of the posterior urethra superior to the urogenital diaphragm.

For strictures of the posterior urethra lying superior to the urogenital diaphragm, a transpubic approach with resection of the pubic symphysis has been employed. This has permitted primary excision of the scar with reanastomosis of the urethra, thus correcting the defect in a single operation without the introduction of hair-bearing skin and with preservation of the external urethral sphincter. The results in five cases have been most gratifying.

Humans↗
PubMed1976

Cellular interrelationships during in vitro granulopoiesis.

Long-term production of fully differentiated granulocytes can be maintained in vitro in a liquid system of cultured bone marrow. Marrow is cultured in medical flasks and allowed to form an adherent layer over a three-week period, and then recharged with fresh marrow resulting in continued mature granulocyte production for several months. During the initial establishment of the adherent layer, three attached populations become apparent: phagocytic monocytes, an attached epithelial cell type, and aggregations of epithelial cells swollen to enormous proportions by the presence of numerous lipid-containing vacuoles. Without the formation of these aggregations, granulocyte production is not maintained beyond an initial period and the culture converts to phagocytic mononuclear cell production alone. Thus not only is the presence of the fat-containing aggregations necessary to continued granulopoiesis, but cultures in full granulocyte production show a characteristic clumping of granulocytes around these aggregates. Electron microscopy has shown that the epithelial cells from the adherent layer form a layer covering some of the attached cells in these areas and thus may provide the necessary in vitro microenvironment for granulopoiesis to occur. Pinocytotic vesicles and gap junctions have been observed between the adjacent membranes of the undifferentiated granulocytes (possibly stem cells) and the epithelial cells themselves.

Animals↗
PubMed1976

Ultrastructural site variations in mouse epidermal organization.

Mouse dorsal, ear, tail and foot epidermis are compared according to their tissue architecture and cell kinetics. Cell proliferation is expected in terms of the daily volume of keratin replaced. The stratum corneum may be organized into vertical columns of squames, which may have minimal overlap as in dorsum and ear, or maximal overlap as in tail. Individual areas are adapted to their function both in squame fine structure and rate of cell replacement. The surface keratin loss/replacement rate is at its highest in foot and tail, and lowest in ear and dorsum. Observations on hairless mouse dorsum are also included.

Animals↗
PubMed1975

Neurogenic bladder of paraplegic patients: Management with radical Y-V-plasty.

In an effort to relieve subvesical resistance in the established paraplegic with unacceptable neurogenic vesical dysfunction while simultaneously preserving potency, a radical Y-V-plasty was carried out in 5 patients. The operation was successful in achieving low residual urines and freedom from clinically evident urinary tract infection without unfavorably affecting potency, but it committed the patients to a dependency on a condom appliance which some were unable to tolerate satisfactorily. The procedure is thought to have merit in selected cases; but whenever it is comtemplated, a trial with a condom catheter preoperatively is recommended.

Adult↗