Is tibial tuberosity-trochlear groove distance an appropriate measure for the identification of knees with patellar instability?

PURPOSE

Tibial tuberosity-trochlear groove distance (TT-TG) has been regarded as a useful tool for establishing therapeutic choices for patellar instability. Recently, it has been shown that TT-TG negatively correlated with the quadriceps angle, suggesting that if used individually, neither provide a valid measure of instability. This study aimed to compare TT-TG distance between both knees in patients with unilateral instability to assess whether this measurement is a decisive element in the management decisions for patellar instability.

METHODS

Sixty-two patients (18 male and 44 female), reporting to a specialist patella clinic for recurrent unilateral patellar instability, were included in the study. Patients underwent bilateral long leg computed tomography scan to determine TT-TG distance in both knees. Tibial TT-TG in symptomatic and asymptomatic knees in the same individual was compared statistically.

RESULTS

Mean TT-TG distance in the symptomatic knee was 16.9 (±4.9) mm, compared to 15.6 (±5.6) mm in the asymptomatic knee. Tibial TT-TG was not significantly different between stable and unstable knees (n.s.).

CONCLUSIONS

The lack of difference in TT-TG distance between stable and unstable knees suggests that TT-TG distance alone may not be a decisive element in establishing therapeutic choices for patellar instability. It should, therefore, be interpreted with caution during clinical evaluations.

LEVEL OF EVIDENCE

II.

Transition to adulthood of female garment-factory workers in Bangladesh

This article examines data from a study on garment-factory workers in Bangladesh to explore the implications of work for the early socialization of young women. For the first time, large numbers of young Bangladeshi women are being given an alternative to lives in which they move directly from childhood to adulthood through early marriage and childbearing. Employment creates a period of transition in contrast to the abrupt assumption of adult roles at very young ages that marriage and childbearing mandate. This longer transition creates a period of adolescence for young women working in the garment sector that is shown to have strong implications for the women's long-term reproductive health.

A cost comparison of allogeneic and preoperatively or intraoperatively donated autologous blood

We determined the cost of allogeneic packed red blood cells and autologous whole blood donated either preoperatively or in the operating room during hemodilution. Direct and indirect cost estimates were based on patients requiring simple transfusion and included procurement and preparation of the blood including testing performed, materials and time used, waste, and materials for administration. Data were derived from prospective blood bank time studies, material invoice records, and retrospective review of anesthesia times. Viral infection and transfusion reaction costs were accepted from previously published sources. Direct cost of purchasing and indirect costs of preparation resulted in an overall cost of $107.26 for the first unit of allogeneic packed red blood cells transfused. A second unit was slightly less costly ($100.89), as no type and screen was required and the same delivery set and filter can be used. The total cost of acquisition, processing, and transfusion of 1 U of preoperatively donated autologous blood was $97.83. The total cost of a 2-U transfusion of autologous whole blood donated in the operating room during acute normovolemic hemodilution was $83.10. These data suggest that autologous predonation of whole blood is somewhat less expensive than allogeneic packed red blood cells, and that hemodilution may be a cost effective alternative to autologous predonation in selected patients.

A cost comparison of allogeneic and preoperatively or intraoperatively donated autologous blood

We determined the cost of allogeneic packed red blood cells and autologous whole blood donated either preoperatively or in the operating room during hemodilution. Direct and indirect cost estimates were based on patients requiring simple transfusion and included procurement and preparation of the blood including testing performed, materials and time used, waste, and materials for administration. Data were derived from prospective blood bank time studies, material invoice records, and retrospective review of anesthesia times. Viral infection and transfusion reaction costs were accepted from previously published sources. Direct cost of purchasing and indirect costs of preparation resulted in an overall cost of $107.26 for the first unit of allogeneic packed red blood cells transfused. A second unit was slightly less costly ($100.89), as no type and screen was required and the same delivery set and filter can be used. The total cost of acquisition, processing, and transfusion of 1 U of preoperatively donated autologous blood was $97.83. The total cost of a 2-U transfusion of autologous whole blood donated in the operating room during acute normovolemic hemodilution was $83.10. These data suggest that autologous predonation of whole blood is somewhat less expensive than allogeneic packed red blood cells, and that hemodilution may be a cost effective alternative to autologous predonation in selected patients.

Hematopoiesis and suppressor bone marrow cells in mice bearing large metastatic Lewis lung carcinoma tumors

Mice bearing a metastatic variant of Lewis lung carcinoma (LLC-C3) were studied to determine if there might be a relationship between tumor induced hematopoiesis and immune suppression. Growth of LLC-C3 in C57BL/6 mice corresponded with increased hematopoiesis and an increase in the proportion of monocytes in the peripheral blood, spleen, and bone marrow. The LLC-C3 cells secreted colony stimulating factor activity and, thus, could have directly stimulated the hematopoiesis in the hosts. As tumor growth progressed, the bone marrow of the tumor bearing mice became suppressive to T-cell blastogenesis. The bone marrow suppressor cells obtained from mice bearing large (greater than 3 g) LLC-C3 tumors were nonadherent to nylon wool, sensitive to treatment with L-leucine methyl ester, insensitive to treatment with anti-Thy-1.2 and complement, and mediated their suppression through an indomethacin sensitive mechanism. Secretion of colony stimulating factor activity by the LLC-C3 cells could have induced the appearance of the bone marrow suppressor cells since normal bone marrow cells which were cultured in the presence of LLC-C3 culture supernatants had an increased proportion of monocytes and were suppressive to T-lymphocyte blastogenesis. Our results suggest that the colony stimulating factor activity produced by LLC-C3 cells stimulates hematopoiesis which, in turn, could result in the appearance of bone marrow suppressor cells.

Differential induction of suppressor macrophages by cloned Lewis lung carcinoma variants in mice

The splenic T-lymphocyte blastogenic and natural killer cell (NK) activities of C57BL/6 mice bearing cloned metastatic C3 or nonmetastatic C8 variants of the Lewis lung carcinoma were suppressed. The suppression was greater in mice bearing the metastatic C3 tumors than the nonmetastatic C8 tumors, although primary tumor sizes were similar. Macrophages were shown to cause this differential in immune responsiveness, while depletion of splenic macrophages by adherence restored the T-cell and NK responses. Also, splenic macrophages from C3 tumor bearers were more suppressive to normal spleen cell activities than were splenic macrophages from C8 tumor bearers. The suppression by the macrophages of C3 bearers was indomethacin sensitive and was associated with an increased secretion of prostaglandin E2 (PGE2). Normal macrophages incubated with C3 culture supernatants were more suppressive to NK and T-cell activities and secreted more PGE2 than did macrophages incubated with the C8 supernatants or with medium. This finding suggested that the immune suppression in mice bearing C3 tumors was initiated by a soluble tumor factor(s) that stimulated the development of prostaglandin-dependent suppressor macrophages. An in vivo study examined if treating C3-bearing mice with indomethacin to prevent the prostaglandin-dependent macrophage suppressor activity would influence host survival. The survival time of C3-bearing mice treated with indomethacin was prolonged. These results suggest that the macrophage-mediated immune suppression induced by tumor cells may facilitate tumor growth and metastasis.

Stimulation of prostaglandin-dependent macrophage suppressor cells by the subcutaneous injection of polyunsaturated fatty acids

Polyunsaturated fatty acids (PUFAs), in the form of pure linoleic, linolenic, or arachidonic acid, were injected subcutaneously into male C57Bl/6 mice daily for 10 days. Injection of 3.6 mg/day of PUFA resulted in up to a two- to threefold increase in spleen weight. Spleen cell response to mitogens was reduced by about 70%; mixed lymphocyte responses were reduced by about 90% when compared to normal values. In admixture experiments, spleen cells from PUFA treated mice suppressed the mitogen induced blastogenic response of control spleen cells by up to 90%. Fractionation of spleen cells from PUFA treated mice by G-10 adherence resulted in an enrichment of suppressive activity in the adherent cells. The suppressive effect of G-10 adherent cells was abolished by the addition of indomethacin as well as by depletion of macrophages by treatments with agents such as carbonyl iron and leucine methyl ester. These studies indicate that the administration of PUFA has marked immunosuppressive effects in mice. These effects may be related to increased prostaglandin production and appear to be mediated by a macrophage type cell.

Macrophage-mediated suppression of natural killer cell activity in mice bearing Lewis lung carcinoma

The natural killer (NK) cell cytotoxic capacity of C57BL/6 mice with implantation of Lewis lung carcinoma (LLC) was quantitated during tumor growth. The NK activity became suppressed at 1 week of tumor growth and remained suppressed. The mechanisms for the suppression during the first 3 weeks of tumor growth included secretion of prostaglandin E2 (PGE2) by both the LLC tumor and host macrophages. With tumor growth, plasma PGE2 concentrations progressively increased. Oral administration of indomethacin to tumor-bearing mice prevented the rise in serum PGE2 concentrations and the suppression of NK activity. Cultured LLC cells and splenic macrophages isolated from mice during the first 3 weeks of tumor growth secreted increased amounts of PGE2. Macrophages from tumor-bearer spleen cells were shown to suppress NK activity. Depletion of these macrophages restored the NK activity, and addition of these macrophages to normal spleen cells resulted in an indomethacin-sensitive suppression of the NK response. The mechanisms of suppression in mice bearing large tumors were different than those observed with smaller tumors. With a large tumor burden, the plasma PGE2 concentrations declined. Indomethacin treatment did not prevent the suppression of NK activity, and depletion of splenic macrophages did not restore NK cytotoxicity.

Enhancement of Lewis lung carcinoma cell migration by prostaglandin E2 produced by macrophages

The role of macrophages in tumor metastasis was examined by using migration of a cloned metastatic Lewis lung carcinoma (LLC) variant, LLC-C4, out of glass capillary tubes as an in vitro model for dissemination of tumor cells from a primary tumor mass. Macrophages, derived from LLC tumors of C57BL/6 mice or from peritoneal exudates of mice given injections of complete Freund's adjuvant, enhanced tumor cell migration through an indomethacin-sensitive mechanism. Resident peritoneal macrophages did not produce a tumor migration-enhancing activity but could be induced to do so by preincubation with LLC-C4 cells or their culture supernatants. The capacity of macrophages to enhance LLC-C4 migration corresponded to their secretion of prostaglandin E2. Addition of similar concentrations of prostaglandin E2 to the migration medium of LLC-C4 cells enhanced their migration out of the capillary tubes. These results suggest that macrophages, following exposure to tumor cells or their products or following stimulation with complete Freund's adjuvant, secrete elevated amounts of prostaglandin E2 which in turn may enhance tumor dissemination.

Stimulation of hematopoiesis in untreated and cyclophosphamide treated mice by the inhibition of prostaglandin synthesis

Indomethacin (IN) was administered to untreated or to cyclophosphamide (CY) treated C57B1/6 mice to study the roles of prostaglandins in regulating hematopoiesis. The following hematopoietic parameters were quantitated: peripheral blood leukocyte (PBL) count; total nucleated cells per spleen; total nucleated cells per femur; and spleen weight. Assays were performed in vitro to measure the number of colony forming units (CFU) present in the bone marrow and spleen. Untreated mice administered IN had a transient rise in their PBL count. These animals also developed splenomegaly and had an increased number of nucleated cells in their spleen. All CY treated mice had a marked decrease in PBL count, spleen cellularity, bone marrow cellularity, and spleen size during the first 5 days after CY treatment. These observations were followed by hematopoietic recovery over the next 10 days. Cyclophosphamide treated mice exhibited a more rapid hematopoietic recovery when treated with IN than without IN treatment. Analysis of the CFU capacity of bone marrow and spleen cells in soft agar showed a larger number of CFU in the bone marrow and spleen of IN treated mice or of CY/IN treated mice than in animals not receiving IN. These results indicate that prostaglandins are involved in the regulation of hematopoiesis in untreated mice and that prostaglandins may limit the hematopoietic recovery of CY treated mice.

Relationships between morphology, dissemination, migration, and prostaglandin E2 secretion by cloned variants of Lewis lung carcinoma

Lewis lung carcinoma cells (LLC) were isolated and cloned from metastatic lung nodules of C57BL/6 mice or from a cultured parental LLC line. Their dissemination abilities were defined in vivo by their capacities to disseminate to the lungs following s.c. or i.v. injection into mice and in an in vitro model for tumor dissemination by their ability to migrate out of glass capillary tubes. Cloned LLC cells with an enhanced dissemination capacity exhibited a rounded morphology, were nonadherent during in vitro culture, and readily migrated out of capillary tubes. In contrast, clones not capable of dissemination were adherent and spread during in vitro culture and did not migrate out of capillary tubes. Production of prostaglandin E2 by these clones was measured by a radioimmunoassay. An inverse relationship was observed between the extent of migration and dissemination of clones and their ability to secrete prostaglandin E2 in vitro and in vivo. However, the prostaglandin E2 did not regulate the migration-dissemination capacities of LLC clones as inhibiting prostaglandin synthesis did not alter their capacity to migrate in vitro or to lodge in the lungs following i.v. inoculation into mice.

Prostaglandin E2 production by EL 4 leukemia cells from C57BL/6 mice: mechanism for tumor dissemination

Murine EL 4 leukemia cells contained and secreted prostaglandin E2 (PGE2). PGE2 was secreted into the culture media during in vitro growth, as well as into plasma during growth in the peritoneum of inbred C57BL/6 mice. For the study of the role of PGE2 in tumor dissemination, migration of EL 4 cells out of glass capillary tubes was used as an in vitro model for tumor spread in a host. PGE2 enhanced the in vitro migration of EL 4 cells while indomethacin, a prostaglandin synthesis inhibitor, reduced the extent of migration. When EL 4 cells were allowed to migrate into medium containing both indomethacin and PGE2, the cells exhibited an enhanced migration ability suggesting an extrinsic effect on cells by PGE2. The participation of tumor-derived PGE2 in promoting tumor spread in a host was supported by demonstration that EL 4 cells grown in indomethacin-treated mice secreted less PGE2 and had reduced in vivo dissemination ability. These results indicated that tumor spread was promoted by tumor-derived PGE2. The extent of migration and dissemination can be reduced by prostaglandin synthesis inhibitors such as indomethacin.

Effect of leucogenenol, a thymothyroid hormone, on the growth of immature and neonatally thymectomized rats

The reports of early investigators that growth is delayed by thymectomy of immature animals have been confirmed. Although growth is delayed by thymectomy, thymectomized animals approach asymptotically with age the same final weight as corresponding intact animals. Treatment with leucogenenol, a thymothyroid hormone, accelerates the rate of growth of immature neonatally thymectomized rats to that of normal rats. However, treatment with leucogenenol does not increase the rate of growth of normal rats. Treatment with leucogenenol does not change levels of growth hormone (GH) or thyroxine (T4) in the serum of either thymectomized or intact immature and adult rats. Neither is the depression in levels of serum leucogenenol that follows thymectomy associated with a change in serum levels of GH or T4. Thus it is apparent that levels of serum leucogenenol do not affect the rate of growth of immature animals by increasing serum levels of GH or T4. By analogy with the finding that treatment with leucogenenol increases the rate at which committed cells of the bone marrow and cells involved in the immune response develop into functional cells, it is suggested that the levels of serum leucogenenol are one of the factors that determine the rate at which types of body cells that make up bone and other body tissues develop from committed precursors.